1 /* 2 * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 // no precompiled headers 26 #include "classfile/classLoader.hpp" 27 #include "classfile/systemDictionary.hpp" 28 #include "classfile/vmSymbols.hpp" 29 #include "code/icBuffer.hpp" 30 #include "code/vtableStubs.hpp" 31 #include "compiler/compileBroker.hpp" 32 #include "compiler/disassembler.hpp" 33 #include "interpreter/interpreter.hpp" 34 #include "jvm_linux.h" 35 #include "logging/log.hpp" 36 #include "memory/allocation.inline.hpp" 37 #include "memory/filemap.hpp" 38 #include "oops/oop.inline.hpp" 39 #include "os_linux.inline.hpp" 40 #include "os_share_linux.hpp" 41 #include "prims/jniFastGetField.hpp" 42 #include "prims/jvm.h" 43 #include "prims/jvm_misc.hpp" 44 #include "runtime/arguments.hpp" 45 #include "runtime/atomic.hpp" 46 #include "runtime/extendedPC.hpp" 47 #include "runtime/globals.hpp" 48 #include "runtime/interfaceSupport.hpp" 49 #include "runtime/init.hpp" 50 #include "runtime/java.hpp" 51 #include "runtime/javaCalls.hpp" 52 #include "runtime/mutexLocker.hpp" 53 #include "runtime/objectMonitor.hpp" 54 #include "runtime/orderAccess.inline.hpp" 55 #include "runtime/osThread.hpp" 56 #include "runtime/perfMemory.hpp" 57 #include "runtime/sharedRuntime.hpp" 58 #include "runtime/statSampler.hpp" 59 #include "runtime/stubRoutines.hpp" 60 #include "runtime/thread.inline.hpp" 61 #include "runtime/threadCritical.hpp" 62 #include "runtime/timer.hpp" 63 #include "semaphore_posix.hpp" 64 #include "services/attachListener.hpp" 65 #include "services/memTracker.hpp" 66 #include "services/runtimeService.hpp" 67 #include "utilities/align.hpp" 68 #include "utilities/decoder.hpp" 69 #include "utilities/defaultStream.hpp" 70 #include "utilities/events.hpp" 71 #include "utilities/elfFile.hpp" 72 #include "utilities/growableArray.hpp" 73 #include "utilities/macros.hpp" 74 #include "utilities/vmError.hpp" 75 76 // put OS-includes here 77 # include <sys/types.h> 78 # include <sys/mman.h> 79 # include <sys/stat.h> 80 # include <sys/select.h> 81 # include <pthread.h> 82 # include <signal.h> 83 # include <errno.h> 84 # include <dlfcn.h> 85 # include <stdio.h> 86 # include <unistd.h> 87 # include <sys/resource.h> 88 # include <pthread.h> 89 # include <sys/stat.h> 90 # include <sys/time.h> 91 # include <sys/times.h> 92 # include <sys/utsname.h> 93 # include <sys/socket.h> 94 # include <sys/wait.h> 95 # include <pwd.h> 96 # include <poll.h> 97 # include <semaphore.h> 98 # include <fcntl.h> 99 # include <string.h> 100 # include <syscall.h> 101 # include <sys/sysinfo.h> 102 # include <gnu/libc-version.h> 103 # include <sys/ipc.h> 104 # include <sys/shm.h> 105 # include <link.h> 106 # include <stdint.h> 107 # include <inttypes.h> 108 # include <sys/ioctl.h> 109 110 #ifndef _GNU_SOURCE 111 #define _GNU_SOURCE 112 #include <sched.h> 113 #undef _GNU_SOURCE 114 #else 115 #include <sched.h> 116 #endif 117 118 // if RUSAGE_THREAD for getrusage() has not been defined, do it here. The code calling 119 // getrusage() is prepared to handle the associated failure. 120 #ifndef RUSAGE_THREAD 121 #define RUSAGE_THREAD (1) /* only the calling thread */ 122 #endif 123 124 #define MAX_PATH (2 * K) 125 126 #define MAX_SECS 100000000 127 128 // for timer info max values which include all bits 129 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF) 130 131 #define LARGEPAGES_BIT (1 << 6) 132 //////////////////////////////////////////////////////////////////////////////// 133 // global variables 134 julong os::Linux::_physical_memory = 0; 135 136 address os::Linux::_initial_thread_stack_bottom = NULL; 137 uintptr_t os::Linux::_initial_thread_stack_size = 0; 138 139 int (*os::Linux::_clock_gettime)(clockid_t, struct timespec *) = NULL; 140 int (*os::Linux::_pthread_getcpuclockid)(pthread_t, clockid_t *) = NULL; 141 int (*os::Linux::_pthread_setname_np)(pthread_t, const char*) = NULL; 142 Mutex* os::Linux::_createThread_lock = NULL; 143 pthread_t os::Linux::_main_thread; 144 int os::Linux::_page_size = -1; 145 bool os::Linux::_supports_fast_thread_cpu_time = false; 146 uint32_t os::Linux::_os_version = 0; 147 const char * os::Linux::_glibc_version = NULL; 148 const char * os::Linux::_libpthread_version = NULL; 149 150 static jlong initial_time_count=0; 151 152 static int clock_tics_per_sec = 100; 153 154 // For diagnostics to print a message once. see run_periodic_checks 155 static sigset_t check_signal_done; 156 static bool check_signals = true; 157 158 // Signal number used to suspend/resume a thread 159 160 // do not use any signal number less than SIGSEGV, see 4355769 161 static int SR_signum = SIGUSR2; 162 sigset_t SR_sigset; 163 164 // utility functions 165 166 static int SR_initialize(); 167 168 julong os::available_memory() { 169 return Linux::available_memory(); 170 } 171 172 julong os::Linux::available_memory() { 173 // values in struct sysinfo are "unsigned long" 174 struct sysinfo si; 175 sysinfo(&si); 176 177 return (julong)si.freeram * si.mem_unit; 178 } 179 180 julong os::physical_memory() { 181 return Linux::physical_memory(); 182 } 183 184 // Return true if user is running as root. 185 186 bool os::have_special_privileges() { 187 static bool init = false; 188 static bool privileges = false; 189 if (!init) { 190 privileges = (getuid() != geteuid()) || (getgid() != getegid()); 191 init = true; 192 } 193 return privileges; 194 } 195 196 197 #ifndef SYS_gettid 198 // i386: 224, ia64: 1105, amd64: 186, sparc 143 199 #ifdef __ia64__ 200 #define SYS_gettid 1105 201 #else 202 #ifdef __i386__ 203 #define SYS_gettid 224 204 #else 205 #ifdef __amd64__ 206 #define SYS_gettid 186 207 #else 208 #ifdef __sparc__ 209 #define SYS_gettid 143 210 #else 211 #error define gettid for the arch 212 #endif 213 #endif 214 #endif 215 #endif 216 #endif 217 218 219 // pid_t gettid() 220 // 221 // Returns the kernel thread id of the currently running thread. Kernel 222 // thread id is used to access /proc. 223 pid_t os::Linux::gettid() { 224 int rslt = syscall(SYS_gettid); 225 assert(rslt != -1, "must be."); // old linuxthreads implementation? 226 return (pid_t)rslt; 227 } 228 229 // Most versions of linux have a bug where the number of processors are 230 // determined by looking at the /proc file system. In a chroot environment, 231 // the system call returns 1. This causes the VM to act as if it is 232 // a single processor and elide locking (see is_MP() call). 233 static bool unsafe_chroot_detected = false; 234 static const char *unstable_chroot_error = "/proc file system not found.\n" 235 "Java may be unstable running multithreaded in a chroot " 236 "environment on Linux when /proc filesystem is not mounted."; 237 238 void os::Linux::initialize_system_info() { 239 set_processor_count(sysconf(_SC_NPROCESSORS_CONF)); 240 if (processor_count() == 1) { 241 pid_t pid = os::Linux::gettid(); 242 char fname[32]; 243 jio_snprintf(fname, sizeof(fname), "/proc/%d", pid); 244 FILE *fp = fopen(fname, "r"); 245 if (fp == NULL) { 246 unsafe_chroot_detected = true; 247 } else { 248 fclose(fp); 249 } 250 } 251 _physical_memory = (julong)sysconf(_SC_PHYS_PAGES) * (julong)sysconf(_SC_PAGESIZE); 252 assert(processor_count() > 0, "linux error"); 253 } 254 255 void os::init_system_properties_values() { 256 // The next steps are taken in the product version: 257 // 258 // Obtain the JAVA_HOME value from the location of libjvm.so. 259 // This library should be located at: 260 // <JAVA_HOME>/lib/{client|server}/libjvm.so. 261 // 262 // If "/jre/lib/" appears at the right place in the path, then we 263 // assume libjvm.so is installed in a JDK and we use this path. 264 // 265 // Otherwise exit with message: "Could not create the Java virtual machine." 266 // 267 // The following extra steps are taken in the debugging version: 268 // 269 // If "/jre/lib/" does NOT appear at the right place in the path 270 // instead of exit check for $JAVA_HOME environment variable. 271 // 272 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>, 273 // then we append a fake suffix "hotspot/libjvm.so" to this path so 274 // it looks like libjvm.so is installed there 275 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so. 276 // 277 // Otherwise exit. 278 // 279 // Important note: if the location of libjvm.so changes this 280 // code needs to be changed accordingly. 281 282 // See ld(1): 283 // The linker uses the following search paths to locate required 284 // shared libraries: 285 // 1: ... 286 // ... 287 // 7: The default directories, normally /lib and /usr/lib. 288 #if defined(AMD64) || (defined(_LP64) && defined(SPARC)) || defined(PPC64) || defined(S390) 289 #define DEFAULT_LIBPATH "/usr/lib64:/lib64:/lib:/usr/lib" 290 #else 291 #define DEFAULT_LIBPATH "/lib:/usr/lib" 292 #endif 293 294 // Base path of extensions installed on the system. 295 #define SYS_EXT_DIR "/usr/java/packages" 296 #define EXTENSIONS_DIR "/lib/ext" 297 298 // Buffer that fits several sprintfs. 299 // Note that the space for the colon and the trailing null are provided 300 // by the nulls included by the sizeof operator. 301 const size_t bufsize = 302 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends. 303 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir 304 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal); 305 306 // sysclasspath, java_home, dll_dir 307 { 308 char *pslash; 309 os::jvm_path(buf, bufsize); 310 311 // Found the full path to libjvm.so. 312 // Now cut the path to <java_home>/jre if we can. 313 pslash = strrchr(buf, '/'); 314 if (pslash != NULL) { 315 *pslash = '\0'; // Get rid of /libjvm.so. 316 } 317 pslash = strrchr(buf, '/'); 318 if (pslash != NULL) { 319 *pslash = '\0'; // Get rid of /{client|server|hotspot}. 320 } 321 Arguments::set_dll_dir(buf); 322 323 if (pslash != NULL) { 324 pslash = strrchr(buf, '/'); 325 if (pslash != NULL) { 326 *pslash = '\0'; // Get rid of /lib. 327 } 328 } 329 Arguments::set_java_home(buf); 330 set_boot_path('/', ':'); 331 } 332 333 // Where to look for native libraries. 334 // 335 // Note: Due to a legacy implementation, most of the library path 336 // is set in the launcher. This was to accomodate linking restrictions 337 // on legacy Linux implementations (which are no longer supported). 338 // Eventually, all the library path setting will be done here. 339 // 340 // However, to prevent the proliferation of improperly built native 341 // libraries, the new path component /usr/java/packages is added here. 342 // Eventually, all the library path setting will be done here. 343 { 344 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It 345 // should always exist (until the legacy problem cited above is 346 // addressed). 347 const char *v = ::getenv("LD_LIBRARY_PATH"); 348 const char *v_colon = ":"; 349 if (v == NULL) { v = ""; v_colon = ""; } 350 // That's +1 for the colon and +1 for the trailing '\0'. 351 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char, 352 strlen(v) + 1 + 353 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + sizeof(DEFAULT_LIBPATH) + 1, 354 mtInternal); 355 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib:" DEFAULT_LIBPATH, v, v_colon); 356 Arguments::set_library_path(ld_library_path); 357 FREE_C_HEAP_ARRAY(char, ld_library_path); 358 } 359 360 // Extensions directories. 361 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home()); 362 Arguments::set_ext_dirs(buf); 363 364 FREE_C_HEAP_ARRAY(char, buf); 365 366 #undef DEFAULT_LIBPATH 367 #undef SYS_EXT_DIR 368 #undef EXTENSIONS_DIR 369 } 370 371 //////////////////////////////////////////////////////////////////////////////// 372 // breakpoint support 373 374 void os::breakpoint() { 375 BREAKPOINT; 376 } 377 378 extern "C" void breakpoint() { 379 // use debugger to set breakpoint here 380 } 381 382 //////////////////////////////////////////////////////////////////////////////// 383 // signal support 384 385 debug_only(static bool signal_sets_initialized = false); 386 static sigset_t unblocked_sigs, vm_sigs; 387 388 bool os::Linux::is_sig_ignored(int sig) { 389 struct sigaction oact; 390 sigaction(sig, (struct sigaction*)NULL, &oact); 391 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction) 392 : CAST_FROM_FN_PTR(void*, oact.sa_handler); 393 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) { 394 return true; 395 } else { 396 return false; 397 } 398 } 399 400 void os::Linux::signal_sets_init() { 401 // Should also have an assertion stating we are still single-threaded. 402 assert(!signal_sets_initialized, "Already initialized"); 403 // Fill in signals that are necessarily unblocked for all threads in 404 // the VM. Currently, we unblock the following signals: 405 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden 406 // by -Xrs (=ReduceSignalUsage)); 407 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all 408 // other threads. The "ReduceSignalUsage" boolean tells us not to alter 409 // the dispositions or masks wrt these signals. 410 // Programs embedding the VM that want to use the above signals for their 411 // own purposes must, at this time, use the "-Xrs" option to prevent 412 // interference with shutdown hooks and BREAK_SIGNAL thread dumping. 413 // (See bug 4345157, and other related bugs). 414 // In reality, though, unblocking these signals is really a nop, since 415 // these signals are not blocked by default. 416 sigemptyset(&unblocked_sigs); 417 sigaddset(&unblocked_sigs, SIGILL); 418 sigaddset(&unblocked_sigs, SIGSEGV); 419 sigaddset(&unblocked_sigs, SIGBUS); 420 sigaddset(&unblocked_sigs, SIGFPE); 421 #if defined(PPC64) 422 sigaddset(&unblocked_sigs, SIGTRAP); 423 #endif 424 sigaddset(&unblocked_sigs, SR_signum); 425 426 if (!ReduceSignalUsage) { 427 if (!os::Linux::is_sig_ignored(SHUTDOWN1_SIGNAL)) { 428 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL); 429 } 430 if (!os::Linux::is_sig_ignored(SHUTDOWN2_SIGNAL)) { 431 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL); 432 } 433 if (!os::Linux::is_sig_ignored(SHUTDOWN3_SIGNAL)) { 434 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL); 435 } 436 } 437 // Fill in signals that are blocked by all but the VM thread. 438 sigemptyset(&vm_sigs); 439 if (!ReduceSignalUsage) { 440 sigaddset(&vm_sigs, BREAK_SIGNAL); 441 } 442 debug_only(signal_sets_initialized = true); 443 444 } 445 446 // These are signals that are unblocked while a thread is running Java. 447 // (For some reason, they get blocked by default.) 448 sigset_t* os::Linux::unblocked_signals() { 449 assert(signal_sets_initialized, "Not initialized"); 450 return &unblocked_sigs; 451 } 452 453 // These are the signals that are blocked while a (non-VM) thread is 454 // running Java. Only the VM thread handles these signals. 455 sigset_t* os::Linux::vm_signals() { 456 assert(signal_sets_initialized, "Not initialized"); 457 return &vm_sigs; 458 } 459 460 void os::Linux::hotspot_sigmask(Thread* thread) { 461 462 //Save caller's signal mask before setting VM signal mask 463 sigset_t caller_sigmask; 464 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask); 465 466 OSThread* osthread = thread->osthread(); 467 osthread->set_caller_sigmask(caller_sigmask); 468 469 pthread_sigmask(SIG_UNBLOCK, os::Linux::unblocked_signals(), NULL); 470 471 if (!ReduceSignalUsage) { 472 if (thread->is_VM_thread()) { 473 // Only the VM thread handles BREAK_SIGNAL ... 474 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL); 475 } else { 476 // ... all other threads block BREAK_SIGNAL 477 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL); 478 } 479 } 480 } 481 482 ////////////////////////////////////////////////////////////////////////////// 483 // detecting pthread library 484 485 void os::Linux::libpthread_init() { 486 // Save glibc and pthread version strings. 487 #if !defined(_CS_GNU_LIBC_VERSION) || \ 488 !defined(_CS_GNU_LIBPTHREAD_VERSION) 489 #error "glibc too old (< 2.3.2)" 490 #endif 491 492 size_t n = confstr(_CS_GNU_LIBC_VERSION, NULL, 0); 493 assert(n > 0, "cannot retrieve glibc version"); 494 char *str = (char *)malloc(n, mtInternal); 495 confstr(_CS_GNU_LIBC_VERSION, str, n); 496 os::Linux::set_glibc_version(str); 497 498 n = confstr(_CS_GNU_LIBPTHREAD_VERSION, NULL, 0); 499 assert(n > 0, "cannot retrieve pthread version"); 500 str = (char *)malloc(n, mtInternal); 501 confstr(_CS_GNU_LIBPTHREAD_VERSION, str, n); 502 os::Linux::set_libpthread_version(str); 503 } 504 505 ///////////////////////////////////////////////////////////////////////////// 506 // thread stack expansion 507 508 // os::Linux::manually_expand_stack() takes care of expanding the thread 509 // stack. Note that this is normally not needed: pthread stacks allocate 510 // thread stack using mmap() without MAP_NORESERVE, so the stack is already 511 // committed. Therefore it is not necessary to expand the stack manually. 512 // 513 // Manually expanding the stack was historically needed on LinuxThreads 514 // thread stacks, which were allocated with mmap(MAP_GROWSDOWN). Nowadays 515 // it is kept to deal with very rare corner cases: 516 // 517 // For one, user may run the VM on an own implementation of threads 518 // whose stacks are - like the old LinuxThreads - implemented using 519 // mmap(MAP_GROWSDOWN). 520 // 521 // Also, this coding may be needed if the VM is running on the primordial 522 // thread. Normally we avoid running on the primordial thread; however, 523 // user may still invoke the VM on the primordial thread. 524 // 525 // The following historical comment describes the details about running 526 // on a thread stack allocated with mmap(MAP_GROWSDOWN): 527 528 529 // Force Linux kernel to expand current thread stack. If "bottom" is close 530 // to the stack guard, caller should block all signals. 531 // 532 // MAP_GROWSDOWN: 533 // A special mmap() flag that is used to implement thread stacks. It tells 534 // kernel that the memory region should extend downwards when needed. This 535 // allows early versions of LinuxThreads to only mmap the first few pages 536 // when creating a new thread. Linux kernel will automatically expand thread 537 // stack as needed (on page faults). 538 // 539 // However, because the memory region of a MAP_GROWSDOWN stack can grow on 540 // demand, if a page fault happens outside an already mapped MAP_GROWSDOWN 541 // region, it's hard to tell if the fault is due to a legitimate stack 542 // access or because of reading/writing non-exist memory (e.g. buffer 543 // overrun). As a rule, if the fault happens below current stack pointer, 544 // Linux kernel does not expand stack, instead a SIGSEGV is sent to the 545 // application (see Linux kernel fault.c). 546 // 547 // This Linux feature can cause SIGSEGV when VM bangs thread stack for 548 // stack overflow detection. 549 // 550 // Newer version of LinuxThreads (since glibc-2.2, or, RH-7.x) and NPTL do 551 // not use MAP_GROWSDOWN. 552 // 553 // To get around the problem and allow stack banging on Linux, we need to 554 // manually expand thread stack after receiving the SIGSEGV. 555 // 556 // There are two ways to expand thread stack to address "bottom", we used 557 // both of them in JVM before 1.5: 558 // 1. adjust stack pointer first so that it is below "bottom", and then 559 // touch "bottom" 560 // 2. mmap() the page in question 561 // 562 // Now alternate signal stack is gone, it's harder to use 2. For instance, 563 // if current sp is already near the lower end of page 101, and we need to 564 // call mmap() to map page 100, it is possible that part of the mmap() frame 565 // will be placed in page 100. When page 100 is mapped, it is zero-filled. 566 // That will destroy the mmap() frame and cause VM to crash. 567 // 568 // The following code works by adjusting sp first, then accessing the "bottom" 569 // page to force a page fault. Linux kernel will then automatically expand the 570 // stack mapping. 571 // 572 // _expand_stack_to() assumes its frame size is less than page size, which 573 // should always be true if the function is not inlined. 574 575 static void NOINLINE _expand_stack_to(address bottom) { 576 address sp; 577 size_t size; 578 volatile char *p; 579 580 // Adjust bottom to point to the largest address within the same page, it 581 // gives us a one-page buffer if alloca() allocates slightly more memory. 582 bottom = (address)align_down((uintptr_t)bottom, os::Linux::page_size()); 583 bottom += os::Linux::page_size() - 1; 584 585 // sp might be slightly above current stack pointer; if that's the case, we 586 // will alloca() a little more space than necessary, which is OK. Don't use 587 // os::current_stack_pointer(), as its result can be slightly below current 588 // stack pointer, causing us to not alloca enough to reach "bottom". 589 sp = (address)&sp; 590 591 if (sp > bottom) { 592 size = sp - bottom; 593 p = (volatile char *)alloca(size); 594 assert(p != NULL && p <= (volatile char *)bottom, "alloca problem?"); 595 p[0] = '\0'; 596 } 597 } 598 599 bool os::Linux::manually_expand_stack(JavaThread * t, address addr) { 600 assert(t!=NULL, "just checking"); 601 assert(t->osthread()->expanding_stack(), "expand should be set"); 602 assert(t->stack_base() != NULL, "stack_base was not initialized"); 603 604 if (addr < t->stack_base() && addr >= t->stack_reserved_zone_base()) { 605 sigset_t mask_all, old_sigset; 606 sigfillset(&mask_all); 607 pthread_sigmask(SIG_SETMASK, &mask_all, &old_sigset); 608 _expand_stack_to(addr); 609 pthread_sigmask(SIG_SETMASK, &old_sigset, NULL); 610 return true; 611 } 612 return false; 613 } 614 615 ////////////////////////////////////////////////////////////////////////////// 616 // create new thread 617 618 // Thread start routine for all newly created threads 619 static void *thread_native_entry(Thread *thread) { 620 // Try to randomize the cache line index of hot stack frames. 621 // This helps when threads of the same stack traces evict each other's 622 // cache lines. The threads can be either from the same JVM instance, or 623 // from different JVM instances. The benefit is especially true for 624 // processors with hyperthreading technology. 625 static int counter = 0; 626 int pid = os::current_process_id(); 627 alloca(((pid ^ counter++) & 7) * 128); 628 629 thread->initialize_thread_current(); 630 631 OSThread* osthread = thread->osthread(); 632 Monitor* sync = osthread->startThread_lock(); 633 634 osthread->set_thread_id(os::current_thread_id()); 635 636 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 637 os::current_thread_id(), (uintx) pthread_self()); 638 639 if (UseNUMA) { 640 int lgrp_id = os::numa_get_group_id(); 641 if (lgrp_id != -1) { 642 thread->set_lgrp_id(lgrp_id); 643 } 644 } 645 // initialize signal mask for this thread 646 os::Linux::hotspot_sigmask(thread); 647 648 // initialize floating point control register 649 os::Linux::init_thread_fpu_state(); 650 651 // handshaking with parent thread 652 { 653 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag); 654 655 // notify parent thread 656 osthread->set_state(INITIALIZED); 657 sync->notify_all(); 658 659 // wait until os::start_thread() 660 while (osthread->get_state() == INITIALIZED) { 661 sync->wait(Mutex::_no_safepoint_check_flag); 662 } 663 } 664 665 // call one more level start routine 666 thread->run(); 667 668 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 669 os::current_thread_id(), (uintx) pthread_self()); 670 671 // If a thread has not deleted itself ("delete this") as part of its 672 // termination sequence, we have to ensure thread-local-storage is 673 // cleared before we actually terminate. No threads should ever be 674 // deleted asynchronously with respect to their termination. 675 if (Thread::current_or_null_safe() != NULL) { 676 assert(Thread::current_or_null_safe() == thread, "current thread is wrong"); 677 thread->clear_thread_current(); 678 } 679 680 return 0; 681 } 682 683 bool os::create_thread(Thread* thread, ThreadType thr_type, 684 size_t req_stack_size) { 685 assert(thread->osthread() == NULL, "caller responsible"); 686 687 // Allocate the OSThread object 688 OSThread* osthread = new OSThread(NULL, NULL); 689 if (osthread == NULL) { 690 return false; 691 } 692 693 // set the correct thread state 694 osthread->set_thread_type(thr_type); 695 696 // Initial state is ALLOCATED but not INITIALIZED 697 osthread->set_state(ALLOCATED); 698 699 thread->set_osthread(osthread); 700 701 // init thread attributes 702 pthread_attr_t attr; 703 pthread_attr_init(&attr); 704 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); 705 706 // Calculate stack size if it's not specified by caller. 707 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size); 708 // In the Linux NPTL pthread implementation the guard size mechanism 709 // is not implemented properly. The posix standard requires adding 710 // the size of the guard pages to the stack size, instead Linux 711 // takes the space out of 'stacksize'. Thus we adapt the requested 712 // stack_size by the size of the guard pages to mimick proper 713 // behaviour. However, be careful not to end up with a size 714 // of zero due to overflow. Don't add the guard page in that case. 715 size_t guard_size = os::Linux::default_guard_size(thr_type); 716 if (stack_size <= SIZE_MAX - guard_size) { 717 stack_size += guard_size; 718 } 719 assert(is_aligned(stack_size, os::vm_page_size()), "stack_size not aligned"); 720 721 int status = pthread_attr_setstacksize(&attr, stack_size); 722 assert_status(status == 0, status, "pthread_attr_setstacksize"); 723 724 // Configure glibc guard page. 725 pthread_attr_setguardsize(&attr, os::Linux::default_guard_size(thr_type)); 726 727 ThreadState state; 728 729 { 730 pthread_t tid; 731 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread); 732 733 char buf[64]; 734 if (ret == 0) { 735 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ", 736 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); 737 } else { 738 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.", 739 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr)); 740 } 741 742 pthread_attr_destroy(&attr); 743 744 if (ret != 0) { 745 // Need to clean up stuff we've allocated so far 746 thread->set_osthread(NULL); 747 delete osthread; 748 return false; 749 } 750 751 // Store pthread info into the OSThread 752 osthread->set_pthread_id(tid); 753 754 // Wait until child thread is either initialized or aborted 755 { 756 Monitor* sync_with_child = osthread->startThread_lock(); 757 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 758 while ((state = osthread->get_state()) == ALLOCATED) { 759 sync_with_child->wait(Mutex::_no_safepoint_check_flag); 760 } 761 } 762 } 763 764 // Aborted due to thread limit being reached 765 if (state == ZOMBIE) { 766 thread->set_osthread(NULL); 767 delete osthread; 768 return false; 769 } 770 771 // The thread is returned suspended (in state INITIALIZED), 772 // and is started higher up in the call chain 773 assert(state == INITIALIZED, "race condition"); 774 return true; 775 } 776 777 ///////////////////////////////////////////////////////////////////////////// 778 // attach existing thread 779 780 // bootstrap the main thread 781 bool os::create_main_thread(JavaThread* thread) { 782 assert(os::Linux::_main_thread == pthread_self(), "should be called inside main thread"); 783 return create_attached_thread(thread); 784 } 785 786 bool os::create_attached_thread(JavaThread* thread) { 787 #ifdef ASSERT 788 thread->verify_not_published(); 789 #endif 790 791 // Allocate the OSThread object 792 OSThread* osthread = new OSThread(NULL, NULL); 793 794 if (osthread == NULL) { 795 return false; 796 } 797 798 // Store pthread info into the OSThread 799 osthread->set_thread_id(os::Linux::gettid()); 800 osthread->set_pthread_id(::pthread_self()); 801 802 // initialize floating point control register 803 os::Linux::init_thread_fpu_state(); 804 805 // Initial thread state is RUNNABLE 806 osthread->set_state(RUNNABLE); 807 808 thread->set_osthread(osthread); 809 810 if (UseNUMA) { 811 int lgrp_id = os::numa_get_group_id(); 812 if (lgrp_id != -1) { 813 thread->set_lgrp_id(lgrp_id); 814 } 815 } 816 817 if (os::Linux::is_initial_thread()) { 818 // If current thread is initial thread, its stack is mapped on demand, 819 // see notes about MAP_GROWSDOWN. Here we try to force kernel to map 820 // the entire stack region to avoid SEGV in stack banging. 821 // It is also useful to get around the heap-stack-gap problem on SuSE 822 // kernel (see 4821821 for details). We first expand stack to the top 823 // of yellow zone, then enable stack yellow zone (order is significant, 824 // enabling yellow zone first will crash JVM on SuSE Linux), so there 825 // is no gap between the last two virtual memory regions. 826 827 JavaThread *jt = (JavaThread *)thread; 828 address addr = jt->stack_reserved_zone_base(); 829 assert(addr != NULL, "initialization problem?"); 830 assert(jt->stack_available(addr) > 0, "stack guard should not be enabled"); 831 832 osthread->set_expanding_stack(); 833 os::Linux::manually_expand_stack(jt, addr); 834 osthread->clear_expanding_stack(); 835 } 836 837 // initialize signal mask for this thread 838 // and save the caller's signal mask 839 os::Linux::hotspot_sigmask(thread); 840 841 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").", 842 os::current_thread_id(), (uintx) pthread_self()); 843 844 return true; 845 } 846 847 void os::pd_start_thread(Thread* thread) { 848 OSThread * osthread = thread->osthread(); 849 assert(osthread->get_state() != INITIALIZED, "just checking"); 850 Monitor* sync_with_child = osthread->startThread_lock(); 851 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag); 852 sync_with_child->notify(); 853 } 854 855 // Free Linux resources related to the OSThread 856 void os::free_thread(OSThread* osthread) { 857 assert(osthread != NULL, "osthread not set"); 858 859 // We are told to free resources of the argument thread, 860 // but we can only really operate on the current thread. 861 assert(Thread::current()->osthread() == osthread, 862 "os::free_thread but not current thread"); 863 864 #ifdef ASSERT 865 sigset_t current; 866 sigemptyset(¤t); 867 pthread_sigmask(SIG_SETMASK, NULL, ¤t); 868 assert(!sigismember(¤t, SR_signum), "SR signal should not be blocked!"); 869 #endif 870 871 // Restore caller's signal mask 872 sigset_t sigmask = osthread->caller_sigmask(); 873 pthread_sigmask(SIG_SETMASK, &sigmask, NULL); 874 875 delete osthread; 876 } 877 878 ////////////////////////////////////////////////////////////////////////////// 879 // initial thread 880 881 // Check if current thread is the initial thread, similar to Solaris thr_main. 882 bool os::Linux::is_initial_thread(void) { 883 char dummy; 884 // If called before init complete, thread stack bottom will be null. 885 // Can be called if fatal error occurs before initialization. 886 if (initial_thread_stack_bottom() == NULL) return false; 887 assert(initial_thread_stack_bottom() != NULL && 888 initial_thread_stack_size() != 0, 889 "os::init did not locate initial thread's stack region"); 890 if ((address)&dummy >= initial_thread_stack_bottom() && 891 (address)&dummy < initial_thread_stack_bottom() + initial_thread_stack_size()) { 892 return true; 893 } else { 894 return false; 895 } 896 } 897 898 // Find the virtual memory area that contains addr 899 static bool find_vma(address addr, address* vma_low, address* vma_high) { 900 FILE *fp = fopen("/proc/self/maps", "r"); 901 if (fp) { 902 address low, high; 903 while (!feof(fp)) { 904 if (fscanf(fp, "%p-%p", &low, &high) == 2) { 905 if (low <= addr && addr < high) { 906 if (vma_low) *vma_low = low; 907 if (vma_high) *vma_high = high; 908 fclose(fp); 909 return true; 910 } 911 } 912 for (;;) { 913 int ch = fgetc(fp); 914 if (ch == EOF || ch == (int)'\n') break; 915 } 916 } 917 fclose(fp); 918 } 919 return false; 920 } 921 922 // Locate initial thread stack. This special handling of initial thread stack 923 // is needed because pthread_getattr_np() on most (all?) Linux distros returns 924 // bogus value for the primordial process thread. While the launcher has created 925 // the VM in a new thread since JDK 6, we still have to allow for the use of the 926 // JNI invocation API from a primordial thread. 927 void os::Linux::capture_initial_stack(size_t max_size) { 928 929 // max_size is either 0 (which means accept OS default for thread stacks) or 930 // a user-specified value known to be at least the minimum needed. If we 931 // are actually on the primordial thread we can make it appear that we have a 932 // smaller max_size stack by inserting the guard pages at that location. But we 933 // cannot do anything to emulate a larger stack than what has been provided by 934 // the OS or threading library. In fact if we try to use a stack greater than 935 // what is set by rlimit then we will crash the hosting process. 936 937 // Maximum stack size is the easy part, get it from RLIMIT_STACK. 938 // If this is "unlimited" then it will be a huge value. 939 struct rlimit rlim; 940 getrlimit(RLIMIT_STACK, &rlim); 941 size_t stack_size = rlim.rlim_cur; 942 943 // 6308388: a bug in ld.so will relocate its own .data section to the 944 // lower end of primordial stack; reduce ulimit -s value a little bit 945 // so we won't install guard page on ld.so's data section. 946 stack_size -= 2 * page_size(); 947 948 // Try to figure out where the stack base (top) is. This is harder. 949 // 950 // When an application is started, glibc saves the initial stack pointer in 951 // a global variable "__libc_stack_end", which is then used by system 952 // libraries. __libc_stack_end should be pretty close to stack top. The 953 // variable is available since the very early days. However, because it is 954 // a private interface, it could disappear in the future. 955 // 956 // Linux kernel saves start_stack information in /proc/<pid>/stat. Similar 957 // to __libc_stack_end, it is very close to stack top, but isn't the real 958 // stack top. Note that /proc may not exist if VM is running as a chroot 959 // program, so reading /proc/<pid>/stat could fail. Also the contents of 960 // /proc/<pid>/stat could change in the future (though unlikely). 961 // 962 // We try __libc_stack_end first. If that doesn't work, look for 963 // /proc/<pid>/stat. If neither of them works, we use current stack pointer 964 // as a hint, which should work well in most cases. 965 966 uintptr_t stack_start; 967 968 // try __libc_stack_end first 969 uintptr_t *p = (uintptr_t *)dlsym(RTLD_DEFAULT, "__libc_stack_end"); 970 if (p && *p) { 971 stack_start = *p; 972 } else { 973 // see if we can get the start_stack field from /proc/self/stat 974 FILE *fp; 975 int pid; 976 char state; 977 int ppid; 978 int pgrp; 979 int session; 980 int nr; 981 int tpgrp; 982 unsigned long flags; 983 unsigned long minflt; 984 unsigned long cminflt; 985 unsigned long majflt; 986 unsigned long cmajflt; 987 unsigned long utime; 988 unsigned long stime; 989 long cutime; 990 long cstime; 991 long prio; 992 long nice; 993 long junk; 994 long it_real; 995 uintptr_t start; 996 uintptr_t vsize; 997 intptr_t rss; 998 uintptr_t rsslim; 999 uintptr_t scodes; 1000 uintptr_t ecode; 1001 int i; 1002 1003 // Figure what the primordial thread stack base is. Code is inspired 1004 // by email from Hans Boehm. /proc/self/stat begins with current pid, 1005 // followed by command name surrounded by parentheses, state, etc. 1006 char stat[2048]; 1007 int statlen; 1008 1009 fp = fopen("/proc/self/stat", "r"); 1010 if (fp) { 1011 statlen = fread(stat, 1, 2047, fp); 1012 stat[statlen] = '\0'; 1013 fclose(fp); 1014 1015 // Skip pid and the command string. Note that we could be dealing with 1016 // weird command names, e.g. user could decide to rename java launcher 1017 // to "java 1.4.2 :)", then the stat file would look like 1018 // 1234 (java 1.4.2 :)) R ... ... 1019 // We don't really need to know the command string, just find the last 1020 // occurrence of ")" and then start parsing from there. See bug 4726580. 1021 char * s = strrchr(stat, ')'); 1022 1023 i = 0; 1024 if (s) { 1025 // Skip blank chars 1026 do { s++; } while (s && isspace(*s)); 1027 1028 #define _UFM UINTX_FORMAT 1029 #define _DFM INTX_FORMAT 1030 1031 // 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 1032 // 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 1033 i = sscanf(s, "%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld " _UFM _UFM _DFM _UFM _UFM _UFM _UFM, 1034 &state, // 3 %c 1035 &ppid, // 4 %d 1036 &pgrp, // 5 %d 1037 &session, // 6 %d 1038 &nr, // 7 %d 1039 &tpgrp, // 8 %d 1040 &flags, // 9 %lu 1041 &minflt, // 10 %lu 1042 &cminflt, // 11 %lu 1043 &majflt, // 12 %lu 1044 &cmajflt, // 13 %lu 1045 &utime, // 14 %lu 1046 &stime, // 15 %lu 1047 &cutime, // 16 %ld 1048 &cstime, // 17 %ld 1049 &prio, // 18 %ld 1050 &nice, // 19 %ld 1051 &junk, // 20 %ld 1052 &it_real, // 21 %ld 1053 &start, // 22 UINTX_FORMAT 1054 &vsize, // 23 UINTX_FORMAT 1055 &rss, // 24 INTX_FORMAT 1056 &rsslim, // 25 UINTX_FORMAT 1057 &scodes, // 26 UINTX_FORMAT 1058 &ecode, // 27 UINTX_FORMAT 1059 &stack_start); // 28 UINTX_FORMAT 1060 } 1061 1062 #undef _UFM 1063 #undef _DFM 1064 1065 if (i != 28 - 2) { 1066 assert(false, "Bad conversion from /proc/self/stat"); 1067 // product mode - assume we are the initial thread, good luck in the 1068 // embedded case. 1069 warning("Can't detect initial thread stack location - bad conversion"); 1070 stack_start = (uintptr_t) &rlim; 1071 } 1072 } else { 1073 // For some reason we can't open /proc/self/stat (for example, running on 1074 // FreeBSD with a Linux emulator, or inside chroot), this should work for 1075 // most cases, so don't abort: 1076 warning("Can't detect initial thread stack location - no /proc/self/stat"); 1077 stack_start = (uintptr_t) &rlim; 1078 } 1079 } 1080 1081 // Now we have a pointer (stack_start) very close to the stack top, the 1082 // next thing to do is to figure out the exact location of stack top. We 1083 // can find out the virtual memory area that contains stack_start by 1084 // reading /proc/self/maps, it should be the last vma in /proc/self/maps, 1085 // and its upper limit is the real stack top. (again, this would fail if 1086 // running inside chroot, because /proc may not exist.) 1087 1088 uintptr_t stack_top; 1089 address low, high; 1090 if (find_vma((address)stack_start, &low, &high)) { 1091 // success, "high" is the true stack top. (ignore "low", because initial 1092 // thread stack grows on demand, its real bottom is high - RLIMIT_STACK.) 1093 stack_top = (uintptr_t)high; 1094 } else { 1095 // failed, likely because /proc/self/maps does not exist 1096 warning("Can't detect initial thread stack location - find_vma failed"); 1097 // best effort: stack_start is normally within a few pages below the real 1098 // stack top, use it as stack top, and reduce stack size so we won't put 1099 // guard page outside stack. 1100 stack_top = stack_start; 1101 stack_size -= 16 * page_size(); 1102 } 1103 1104 // stack_top could be partially down the page so align it 1105 stack_top = align_up(stack_top, page_size()); 1106 1107 // Allowed stack value is minimum of max_size and what we derived from rlimit 1108 if (max_size > 0) { 1109 _initial_thread_stack_size = MIN2(max_size, stack_size); 1110 } else { 1111 // Accept the rlimit max, but if stack is unlimited then it will be huge, so 1112 // clamp it at 8MB as we do on Solaris 1113 _initial_thread_stack_size = MIN2(stack_size, 8*M); 1114 } 1115 _initial_thread_stack_size = align_down(_initial_thread_stack_size, page_size()); 1116 _initial_thread_stack_bottom = (address)stack_top - _initial_thread_stack_size; 1117 1118 assert(_initial_thread_stack_bottom < (address)stack_top, "overflow!"); 1119 1120 if (log_is_enabled(Info, os, thread)) { 1121 // See if we seem to be on primordial process thread 1122 bool primordial = uintptr_t(&rlim) > uintptr_t(_initial_thread_stack_bottom) && 1123 uintptr_t(&rlim) < stack_top; 1124 1125 log_info(os, thread)("Capturing initial stack in %s thread: req. size: " SIZE_FORMAT "K, actual size: " 1126 SIZE_FORMAT "K, top=" INTPTR_FORMAT ", bottom=" INTPTR_FORMAT, 1127 primordial ? "primordial" : "user", max_size / K, _initial_thread_stack_size / K, 1128 stack_top, intptr_t(_initial_thread_stack_bottom)); 1129 } 1130 } 1131 1132 //////////////////////////////////////////////////////////////////////////////// 1133 // time support 1134 1135 // Time since start-up in seconds to a fine granularity. 1136 // Used by VMSelfDestructTimer and the MemProfiler. 1137 double os::elapsedTime() { 1138 1139 return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution 1140 } 1141 1142 jlong os::elapsed_counter() { 1143 return javaTimeNanos() - initial_time_count; 1144 } 1145 1146 jlong os::elapsed_frequency() { 1147 return NANOSECS_PER_SEC; // nanosecond resolution 1148 } 1149 1150 bool os::supports_vtime() { return true; } 1151 bool os::enable_vtime() { return false; } 1152 bool os::vtime_enabled() { return false; } 1153 1154 double os::elapsedVTime() { 1155 struct rusage usage; 1156 int retval = getrusage(RUSAGE_THREAD, &usage); 1157 if (retval == 0) { 1158 return (double) (usage.ru_utime.tv_sec + usage.ru_stime.tv_sec) + (double) (usage.ru_utime.tv_usec + usage.ru_stime.tv_usec) / (1000 * 1000); 1159 } else { 1160 // better than nothing, but not much 1161 return elapsedTime(); 1162 } 1163 } 1164 1165 jlong os::javaTimeMillis() { 1166 timeval time; 1167 int status = gettimeofday(&time, NULL); 1168 assert(status != -1, "linux error"); 1169 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000); 1170 } 1171 1172 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) { 1173 timeval time; 1174 int status = gettimeofday(&time, NULL); 1175 assert(status != -1, "linux error"); 1176 seconds = jlong(time.tv_sec); 1177 nanos = jlong(time.tv_usec) * 1000; 1178 } 1179 1180 1181 #ifndef CLOCK_MONOTONIC 1182 #define CLOCK_MONOTONIC (1) 1183 #endif 1184 1185 void os::Linux::clock_init() { 1186 // we do dlopen's in this particular order due to bug in linux 1187 // dynamical loader (see 6348968) leading to crash on exit 1188 void* handle = dlopen("librt.so.1", RTLD_LAZY); 1189 if (handle == NULL) { 1190 handle = dlopen("librt.so", RTLD_LAZY); 1191 } 1192 1193 if (handle) { 1194 int (*clock_getres_func)(clockid_t, struct timespec*) = 1195 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_getres"); 1196 int (*clock_gettime_func)(clockid_t, struct timespec*) = 1197 (int(*)(clockid_t, struct timespec*))dlsym(handle, "clock_gettime"); 1198 if (clock_getres_func && clock_gettime_func) { 1199 // See if monotonic clock is supported by the kernel. Note that some 1200 // early implementations simply return kernel jiffies (updated every 1201 // 1/100 or 1/1000 second). It would be bad to use such a low res clock 1202 // for nano time (though the monotonic property is still nice to have). 1203 // It's fixed in newer kernels, however clock_getres() still returns 1204 // 1/HZ. We check if clock_getres() works, but will ignore its reported 1205 // resolution for now. Hopefully as people move to new kernels, this 1206 // won't be a problem. 1207 struct timespec res; 1208 struct timespec tp; 1209 if (clock_getres_func (CLOCK_MONOTONIC, &res) == 0 && 1210 clock_gettime_func(CLOCK_MONOTONIC, &tp) == 0) { 1211 // yes, monotonic clock is supported 1212 _clock_gettime = clock_gettime_func; 1213 return; 1214 } else { 1215 // close librt if there is no monotonic clock 1216 dlclose(handle); 1217 } 1218 } 1219 } 1220 warning("No monotonic clock was available - timed services may " \ 1221 "be adversely affected if the time-of-day clock changes"); 1222 } 1223 1224 #ifndef SYS_clock_getres 1225 #if defined(X86) || defined(PPC64) || defined(S390) 1226 #define SYS_clock_getres AMD64_ONLY(229) IA32_ONLY(266) PPC64_ONLY(247) S390_ONLY(261) 1227 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) 1228 #else 1229 #warning "SYS_clock_getres not defined for this platform, disabling fast_thread_cpu_time" 1230 #define sys_clock_getres(x,y) -1 1231 #endif 1232 #else 1233 #define sys_clock_getres(x,y) ::syscall(SYS_clock_getres, x, y) 1234 #endif 1235 1236 void os::Linux::fast_thread_clock_init() { 1237 if (!UseLinuxPosixThreadCPUClocks) { 1238 return; 1239 } 1240 clockid_t clockid; 1241 struct timespec tp; 1242 int (*pthread_getcpuclockid_func)(pthread_t, clockid_t *) = 1243 (int(*)(pthread_t, clockid_t *)) dlsym(RTLD_DEFAULT, "pthread_getcpuclockid"); 1244 1245 // Switch to using fast clocks for thread cpu time if 1246 // the sys_clock_getres() returns 0 error code. 1247 // Note, that some kernels may support the current thread 1248 // clock (CLOCK_THREAD_CPUTIME_ID) but not the clocks 1249 // returned by the pthread_getcpuclockid(). 1250 // If the fast Posix clocks are supported then the sys_clock_getres() 1251 // must return at least tp.tv_sec == 0 which means a resolution 1252 // better than 1 sec. This is extra check for reliability. 1253 1254 if (pthread_getcpuclockid_func && 1255 pthread_getcpuclockid_func(_main_thread, &clockid) == 0 && 1256 sys_clock_getres(clockid, &tp) == 0 && tp.tv_sec == 0) { 1257 _supports_fast_thread_cpu_time = true; 1258 _pthread_getcpuclockid = pthread_getcpuclockid_func; 1259 } 1260 } 1261 1262 jlong os::javaTimeNanos() { 1263 if (os::supports_monotonic_clock()) { 1264 struct timespec tp; 1265 int status = Linux::clock_gettime(CLOCK_MONOTONIC, &tp); 1266 assert(status == 0, "gettime error"); 1267 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec); 1268 return result; 1269 } else { 1270 timeval time; 1271 int status = gettimeofday(&time, NULL); 1272 assert(status != -1, "linux error"); 1273 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec); 1274 return 1000 * usecs; 1275 } 1276 } 1277 1278 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) { 1279 if (os::supports_monotonic_clock()) { 1280 info_ptr->max_value = ALL_64_BITS; 1281 1282 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past 1283 info_ptr->may_skip_backward = false; // not subject to resetting or drifting 1284 info_ptr->may_skip_forward = false; // not subject to resetting or drifting 1285 } else { 1286 // gettimeofday - based on time in seconds since the Epoch thus does not wrap 1287 info_ptr->max_value = ALL_64_BITS; 1288 1289 // gettimeofday is a real time clock so it skips 1290 info_ptr->may_skip_backward = true; 1291 info_ptr->may_skip_forward = true; 1292 } 1293 1294 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time 1295 } 1296 1297 // Return the real, user, and system times in seconds from an 1298 // arbitrary fixed point in the past. 1299 bool os::getTimesSecs(double* process_real_time, 1300 double* process_user_time, 1301 double* process_system_time) { 1302 struct tms ticks; 1303 clock_t real_ticks = times(&ticks); 1304 1305 if (real_ticks == (clock_t) (-1)) { 1306 return false; 1307 } else { 1308 double ticks_per_second = (double) clock_tics_per_sec; 1309 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second; 1310 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second; 1311 *process_real_time = ((double) real_ticks) / ticks_per_second; 1312 1313 return true; 1314 } 1315 } 1316 1317 1318 char * os::local_time_string(char *buf, size_t buflen) { 1319 struct tm t; 1320 time_t long_time; 1321 time(&long_time); 1322 localtime_r(&long_time, &t); 1323 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d", 1324 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday, 1325 t.tm_hour, t.tm_min, t.tm_sec); 1326 return buf; 1327 } 1328 1329 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) { 1330 return localtime_r(clock, res); 1331 } 1332 1333 //////////////////////////////////////////////////////////////////////////////// 1334 // runtime exit support 1335 1336 // Note: os::shutdown() might be called very early during initialization, or 1337 // called from signal handler. Before adding something to os::shutdown(), make 1338 // sure it is async-safe and can handle partially initialized VM. 1339 void os::shutdown() { 1340 1341 // allow PerfMemory to attempt cleanup of any persistent resources 1342 perfMemory_exit(); 1343 1344 // needs to remove object in file system 1345 AttachListener::abort(); 1346 1347 // flush buffered output, finish log files 1348 ostream_abort(); 1349 1350 // Check for abort hook 1351 abort_hook_t abort_hook = Arguments::abort_hook(); 1352 if (abort_hook != NULL) { 1353 abort_hook(); 1354 } 1355 1356 } 1357 1358 // Note: os::abort() might be called very early during initialization, or 1359 // called from signal handler. Before adding something to os::abort(), make 1360 // sure it is async-safe and can handle partially initialized VM. 1361 void os::abort(bool dump_core, void* siginfo, const void* context) { 1362 os::shutdown(); 1363 if (dump_core) { 1364 #ifndef PRODUCT 1365 fdStream out(defaultStream::output_fd()); 1366 out.print_raw("Current thread is "); 1367 char buf[16]; 1368 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id()); 1369 out.print_raw_cr(buf); 1370 out.print_raw_cr("Dumping core ..."); 1371 #endif 1372 ::abort(); // dump core 1373 } 1374 1375 ::exit(1); 1376 } 1377 1378 // Die immediately, no exit hook, no abort hook, no cleanup. 1379 void os::die() { 1380 ::abort(); 1381 } 1382 1383 1384 // This method is a copy of JDK's sysGetLastErrorString 1385 // from src/solaris/hpi/src/system_md.c 1386 1387 size_t os::lasterror(char *buf, size_t len) { 1388 if (errno == 0) return 0; 1389 1390 const char *s = os::strerror(errno); 1391 size_t n = ::strlen(s); 1392 if (n >= len) { 1393 n = len - 1; 1394 } 1395 ::strncpy(buf, s, n); 1396 buf[n] = '\0'; 1397 return n; 1398 } 1399 1400 // thread_id is kernel thread id (similar to Solaris LWP id) 1401 intx os::current_thread_id() { return os::Linux::gettid(); } 1402 int os::current_process_id() { 1403 return ::getpid(); 1404 } 1405 1406 // DLL functions 1407 1408 const char* os::dll_file_extension() { return ".so"; } 1409 1410 // This must be hard coded because it's the system's temporary 1411 // directory not the java application's temp directory, ala java.io.tmpdir. 1412 const char* os::get_temp_directory() { return "/tmp"; } 1413 1414 static bool file_exists(const char* filename) { 1415 struct stat statbuf; 1416 if (filename == NULL || strlen(filename) == 0) { 1417 return false; 1418 } 1419 return os::stat(filename, &statbuf) == 0; 1420 } 1421 1422 bool os::dll_build_name(char* buffer, size_t buflen, 1423 const char* pname, const char* fname) { 1424 bool retval = false; 1425 // Copied from libhpi 1426 const size_t pnamelen = pname ? strlen(pname) : 0; 1427 1428 // Return error on buffer overflow. 1429 if (pnamelen + strlen(fname) + 10 > (size_t) buflen) { 1430 return retval; 1431 } 1432 1433 if (pnamelen == 0) { 1434 snprintf(buffer, buflen, "lib%s.so", fname); 1435 retval = true; 1436 } else if (strchr(pname, *os::path_separator()) != NULL) { 1437 int n; 1438 char** pelements = split_path(pname, &n); 1439 if (pelements == NULL) { 1440 return false; 1441 } 1442 for (int i = 0; i < n; i++) { 1443 // Really shouldn't be NULL, but check can't hurt 1444 if (pelements[i] == NULL || strlen(pelements[i]) == 0) { 1445 continue; // skip the empty path values 1446 } 1447 snprintf(buffer, buflen, "%s/lib%s.so", pelements[i], fname); 1448 if (file_exists(buffer)) { 1449 retval = true; 1450 break; 1451 } 1452 } 1453 // release the storage 1454 for (int i = 0; i < n; i++) { 1455 if (pelements[i] != NULL) { 1456 FREE_C_HEAP_ARRAY(char, pelements[i]); 1457 } 1458 } 1459 if (pelements != NULL) { 1460 FREE_C_HEAP_ARRAY(char*, pelements); 1461 } 1462 } else { 1463 snprintf(buffer, buflen, "%s/lib%s.so", pname, fname); 1464 retval = true; 1465 } 1466 return retval; 1467 } 1468 1469 // check if addr is inside libjvm.so 1470 bool os::address_is_in_vm(address addr) { 1471 static address libjvm_base_addr; 1472 Dl_info dlinfo; 1473 1474 if (libjvm_base_addr == NULL) { 1475 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) { 1476 libjvm_base_addr = (address)dlinfo.dli_fbase; 1477 } 1478 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm"); 1479 } 1480 1481 if (dladdr((void *)addr, &dlinfo) != 0) { 1482 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true; 1483 } 1484 1485 return false; 1486 } 1487 1488 bool os::dll_address_to_function_name(address addr, char *buf, 1489 int buflen, int *offset, 1490 bool demangle) { 1491 // buf is not optional, but offset is optional 1492 assert(buf != NULL, "sanity check"); 1493 1494 Dl_info dlinfo; 1495 1496 if (dladdr((void*)addr, &dlinfo) != 0) { 1497 // see if we have a matching symbol 1498 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) { 1499 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) { 1500 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname); 1501 } 1502 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr; 1503 return true; 1504 } 1505 // no matching symbol so try for just file info 1506 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) { 1507 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase), 1508 buf, buflen, offset, dlinfo.dli_fname, demangle)) { 1509 return true; 1510 } 1511 } 1512 } 1513 1514 buf[0] = '\0'; 1515 if (offset != NULL) *offset = -1; 1516 return false; 1517 } 1518 1519 struct _address_to_library_name { 1520 address addr; // input : memory address 1521 size_t buflen; // size of fname 1522 char* fname; // output: library name 1523 address base; // library base addr 1524 }; 1525 1526 static int address_to_library_name_callback(struct dl_phdr_info *info, 1527 size_t size, void *data) { 1528 int i; 1529 bool found = false; 1530 address libbase = NULL; 1531 struct _address_to_library_name * d = (struct _address_to_library_name *)data; 1532 1533 // iterate through all loadable segments 1534 for (i = 0; i < info->dlpi_phnum; i++) { 1535 address segbase = (address)(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); 1536 if (info->dlpi_phdr[i].p_type == PT_LOAD) { 1537 // base address of a library is the lowest address of its loaded 1538 // segments. 1539 if (libbase == NULL || libbase > segbase) { 1540 libbase = segbase; 1541 } 1542 // see if 'addr' is within current segment 1543 if (segbase <= d->addr && 1544 d->addr < segbase + info->dlpi_phdr[i].p_memsz) { 1545 found = true; 1546 } 1547 } 1548 } 1549 1550 // dlpi_name is NULL or empty if the ELF file is executable, return 0 1551 // so dll_address_to_library_name() can fall through to use dladdr() which 1552 // can figure out executable name from argv[0]. 1553 if (found && info->dlpi_name && info->dlpi_name[0]) { 1554 d->base = libbase; 1555 if (d->fname) { 1556 jio_snprintf(d->fname, d->buflen, "%s", info->dlpi_name); 1557 } 1558 return 1; 1559 } 1560 return 0; 1561 } 1562 1563 bool os::dll_address_to_library_name(address addr, char* buf, 1564 int buflen, int* offset) { 1565 // buf is not optional, but offset is optional 1566 assert(buf != NULL, "sanity check"); 1567 1568 Dl_info dlinfo; 1569 struct _address_to_library_name data; 1570 1571 // There is a bug in old glibc dladdr() implementation that it could resolve 1572 // to wrong library name if the .so file has a base address != NULL. Here 1573 // we iterate through the program headers of all loaded libraries to find 1574 // out which library 'addr' really belongs to. This workaround can be 1575 // removed once the minimum requirement for glibc is moved to 2.3.x. 1576 data.addr = addr; 1577 data.fname = buf; 1578 data.buflen = buflen; 1579 data.base = NULL; 1580 int rslt = dl_iterate_phdr(address_to_library_name_callback, (void *)&data); 1581 1582 if (rslt) { 1583 // buf already contains library name 1584 if (offset) *offset = addr - data.base; 1585 return true; 1586 } 1587 if (dladdr((void*)addr, &dlinfo) != 0) { 1588 if (dlinfo.dli_fname != NULL) { 1589 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname); 1590 } 1591 if (dlinfo.dli_fbase != NULL && offset != NULL) { 1592 *offset = addr - (address)dlinfo.dli_fbase; 1593 } 1594 return true; 1595 } 1596 1597 buf[0] = '\0'; 1598 if (offset) *offset = -1; 1599 return false; 1600 } 1601 1602 // Loads .dll/.so and 1603 // in case of error it checks if .dll/.so was built for the 1604 // same architecture as Hotspot is running on 1605 1606 1607 // Remember the stack's state. The Linux dynamic linker will change 1608 // the stack to 'executable' at most once, so we must safepoint only once. 1609 bool os::Linux::_stack_is_executable = false; 1610 1611 // VM operation that loads a library. This is necessary if stack protection 1612 // of the Java stacks can be lost during loading the library. If we 1613 // do not stop the Java threads, they can stack overflow before the stacks 1614 // are protected again. 1615 class VM_LinuxDllLoad: public VM_Operation { 1616 private: 1617 const char *_filename; 1618 char *_ebuf; 1619 int _ebuflen; 1620 void *_lib; 1621 public: 1622 VM_LinuxDllLoad(const char *fn, char *ebuf, int ebuflen) : 1623 _filename(fn), _ebuf(ebuf), _ebuflen(ebuflen), _lib(NULL) {} 1624 VMOp_Type type() const { return VMOp_LinuxDllLoad; } 1625 void doit() { 1626 _lib = os::Linux::dll_load_in_vmthread(_filename, _ebuf, _ebuflen); 1627 os::Linux::_stack_is_executable = true; 1628 } 1629 void* loaded_library() { return _lib; } 1630 }; 1631 1632 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) { 1633 void * result = NULL; 1634 bool load_attempted = false; 1635 1636 // Check whether the library to load might change execution rights 1637 // of the stack. If they are changed, the protection of the stack 1638 // guard pages will be lost. We need a safepoint to fix this. 1639 // 1640 // See Linux man page execstack(8) for more info. 1641 if (os::uses_stack_guard_pages() && !os::Linux::_stack_is_executable) { 1642 if (!ElfFile::specifies_noexecstack(filename)) { 1643 if (!is_init_completed()) { 1644 os::Linux::_stack_is_executable = true; 1645 // This is OK - No Java threads have been created yet, and hence no 1646 // stack guard pages to fix. 1647 // 1648 // This should happen only when you are building JDK7 using a very 1649 // old version of JDK6 (e.g., with JPRT) and running test_gamma. 1650 // 1651 // Dynamic loader will make all stacks executable after 1652 // this function returns, and will not do that again. 1653 assert(Threads::first() == NULL, "no Java threads should exist yet."); 1654 } else { 1655 warning("You have loaded library %s which might have disabled stack guard. " 1656 "The VM will try to fix the stack guard now.\n" 1657 "It's highly recommended that you fix the library with " 1658 "'execstack -c <libfile>', or link it with '-z noexecstack'.", 1659 filename); 1660 1661 assert(Thread::current()->is_Java_thread(), "must be Java thread"); 1662 JavaThread *jt = JavaThread::current(); 1663 if (jt->thread_state() != _thread_in_native) { 1664 // This happens when a compiler thread tries to load a hsdis-<arch>.so file 1665 // that requires ExecStack. Cannot enter safe point. Let's give up. 1666 warning("Unable to fix stack guard. Giving up."); 1667 } else { 1668 if (!LoadExecStackDllInVMThread) { 1669 // This is for the case where the DLL has an static 1670 // constructor function that executes JNI code. We cannot 1671 // load such DLLs in the VMThread. 1672 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1673 } 1674 1675 ThreadInVMfromNative tiv(jt); 1676 debug_only(VMNativeEntryWrapper vew;) 1677 1678 VM_LinuxDllLoad op(filename, ebuf, ebuflen); 1679 VMThread::execute(&op); 1680 if (LoadExecStackDllInVMThread) { 1681 result = op.loaded_library(); 1682 } 1683 load_attempted = true; 1684 } 1685 } 1686 } 1687 } 1688 1689 if (!load_attempted) { 1690 result = os::Linux::dlopen_helper(filename, ebuf, ebuflen); 1691 } 1692 1693 if (result != NULL) { 1694 // Successful loading 1695 return result; 1696 } 1697 1698 Elf32_Ehdr elf_head; 1699 int diag_msg_max_length=ebuflen-strlen(ebuf); 1700 char* diag_msg_buf=ebuf+strlen(ebuf); 1701 1702 if (diag_msg_max_length==0) { 1703 // No more space in ebuf for additional diagnostics message 1704 return NULL; 1705 } 1706 1707 1708 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK); 1709 1710 if (file_descriptor < 0) { 1711 // Can't open library, report dlerror() message 1712 return NULL; 1713 } 1714 1715 bool failed_to_read_elf_head= 1716 (sizeof(elf_head)!= 1717 (::read(file_descriptor, &elf_head,sizeof(elf_head)))); 1718 1719 ::close(file_descriptor); 1720 if (failed_to_read_elf_head) { 1721 // file i/o error - report dlerror() msg 1722 return NULL; 1723 } 1724 1725 typedef struct { 1726 Elf32_Half code; // Actual value as defined in elf.h 1727 Elf32_Half compat_class; // Compatibility of archs at VM's sense 1728 unsigned char elf_class; // 32 or 64 bit 1729 unsigned char endianess; // MSB or LSB 1730 char* name; // String representation 1731 } arch_t; 1732 1733 #ifndef EM_486 1734 #define EM_486 6 /* Intel 80486 */ 1735 #endif 1736 #ifndef EM_AARCH64 1737 #define EM_AARCH64 183 /* ARM AARCH64 */ 1738 #endif 1739 1740 static const arch_t arch_array[]={ 1741 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1742 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"}, 1743 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"}, 1744 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"}, 1745 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1746 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"}, 1747 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"}, 1748 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"}, 1749 #if defined(VM_LITTLE_ENDIAN) 1750 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2LSB, (char*)"Power PC 64"}, 1751 #else 1752 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64 LE"}, 1753 #endif 1754 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"}, 1755 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"}, 1756 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"}, 1757 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"}, 1758 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"}, 1759 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"}, 1760 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}, 1761 {EM_AARCH64, EM_AARCH64, ELFCLASS64, ELFDATA2LSB, (char*)"AARCH64"}, 1762 }; 1763 1764 #if (defined IA32) 1765 static Elf32_Half running_arch_code=EM_386; 1766 #elif (defined AMD64) 1767 static Elf32_Half running_arch_code=EM_X86_64; 1768 #elif (defined IA64) 1769 static Elf32_Half running_arch_code=EM_IA_64; 1770 #elif (defined __sparc) && (defined _LP64) 1771 static Elf32_Half running_arch_code=EM_SPARCV9; 1772 #elif (defined __sparc) && (!defined _LP64) 1773 static Elf32_Half running_arch_code=EM_SPARC; 1774 #elif (defined __powerpc64__) 1775 static Elf32_Half running_arch_code=EM_PPC64; 1776 #elif (defined __powerpc__) 1777 static Elf32_Half running_arch_code=EM_PPC; 1778 #elif (defined AARCH64) 1779 static Elf32_Half running_arch_code=EM_AARCH64; 1780 #elif (defined ARM) 1781 static Elf32_Half running_arch_code=EM_ARM; 1782 #elif (defined S390) 1783 static Elf32_Half running_arch_code=EM_S390; 1784 #elif (defined ALPHA) 1785 static Elf32_Half running_arch_code=EM_ALPHA; 1786 #elif (defined MIPSEL) 1787 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE; 1788 #elif (defined PARISC) 1789 static Elf32_Half running_arch_code=EM_PARISC; 1790 #elif (defined MIPS) 1791 static Elf32_Half running_arch_code=EM_MIPS; 1792 #elif (defined M68K) 1793 static Elf32_Half running_arch_code=EM_68K; 1794 #else 1795 #error Method os::dll_load requires that one of following is defined:\ 1796 AARCH64, ALPHA, ARM, AMD64, IA32, IA64, M68K, MIPS, MIPSEL, PARISC, __powerpc__, __powerpc64__, S390, __sparc 1797 #endif 1798 1799 // Identify compatability class for VM's architecture and library's architecture 1800 // Obtain string descriptions for architectures 1801 1802 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL}; 1803 int running_arch_index=-1; 1804 1805 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) { 1806 if (running_arch_code == arch_array[i].code) { 1807 running_arch_index = i; 1808 } 1809 if (lib_arch.code == arch_array[i].code) { 1810 lib_arch.compat_class = arch_array[i].compat_class; 1811 lib_arch.name = arch_array[i].name; 1812 } 1813 } 1814 1815 assert(running_arch_index != -1, 1816 "Didn't find running architecture code (running_arch_code) in arch_array"); 1817 if (running_arch_index == -1) { 1818 // Even though running architecture detection failed 1819 // we may still continue with reporting dlerror() message 1820 return NULL; 1821 } 1822 1823 if (lib_arch.endianess != arch_array[running_arch_index].endianess) { 1824 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)"); 1825 return NULL; 1826 } 1827 1828 #ifndef S390 1829 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) { 1830 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)"); 1831 return NULL; 1832 } 1833 #endif // !S390 1834 1835 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) { 1836 if (lib_arch.name!=NULL) { 1837 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1838 " (Possible cause: can't load %s-bit .so on a %s-bit platform)", 1839 lib_arch.name, arch_array[running_arch_index].name); 1840 } else { 1841 ::snprintf(diag_msg_buf, diag_msg_max_length-1, 1842 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)", 1843 lib_arch.code, 1844 arch_array[running_arch_index].name); 1845 } 1846 } 1847 1848 return NULL; 1849 } 1850 1851 void * os::Linux::dlopen_helper(const char *filename, char *ebuf, 1852 int ebuflen) { 1853 void * result = ::dlopen(filename, RTLD_LAZY); 1854 if (result == NULL) { 1855 ::strncpy(ebuf, ::dlerror(), ebuflen - 1); 1856 ebuf[ebuflen-1] = '\0'; 1857 } 1858 return result; 1859 } 1860 1861 void * os::Linux::dll_load_in_vmthread(const char *filename, char *ebuf, 1862 int ebuflen) { 1863 void * result = NULL; 1864 if (LoadExecStackDllInVMThread) { 1865 result = dlopen_helper(filename, ebuf, ebuflen); 1866 } 1867 1868 // Since 7019808, libjvm.so is linked with -noexecstack. If the VM loads a 1869 // library that requires an executable stack, or which does not have this 1870 // stack attribute set, dlopen changes the stack attribute to executable. The 1871 // read protection of the guard pages gets lost. 1872 // 1873 // Need to check _stack_is_executable again as multiple VM_LinuxDllLoad 1874 // may have been queued at the same time. 1875 1876 if (!_stack_is_executable) { 1877 JavaThread *jt = Threads::first(); 1878 1879 while (jt) { 1880 if (!jt->stack_guard_zone_unused() && // Stack not yet fully initialized 1881 jt->stack_guards_enabled()) { // No pending stack overflow exceptions 1882 if (!os::guard_memory((char *)jt->stack_end(), jt->stack_guard_zone_size())) { 1883 warning("Attempt to reguard stack yellow zone failed."); 1884 } 1885 } 1886 jt = jt->next(); 1887 } 1888 } 1889 1890 return result; 1891 } 1892 1893 void* os::dll_lookup(void* handle, const char* name) { 1894 void* res = dlsym(handle, name); 1895 return res; 1896 } 1897 1898 void* os::get_default_process_handle() { 1899 return (void*)::dlopen(NULL, RTLD_LAZY); 1900 } 1901 1902 static bool _print_ascii_file(const char* filename, outputStream* st) { 1903 int fd = ::open(filename, O_RDONLY); 1904 if (fd == -1) { 1905 return false; 1906 } 1907 1908 char buf[33]; 1909 int bytes; 1910 buf[32] = '\0'; 1911 while ((bytes = ::read(fd, buf, sizeof(buf)-1)) > 0) { 1912 st->print_raw(buf, bytes); 1913 } 1914 1915 ::close(fd); 1916 1917 return true; 1918 } 1919 1920 void os::print_dll_info(outputStream *st) { 1921 st->print_cr("Dynamic libraries:"); 1922 1923 char fname[32]; 1924 pid_t pid = os::Linux::gettid(); 1925 1926 jio_snprintf(fname, sizeof(fname), "/proc/%d/maps", pid); 1927 1928 if (!_print_ascii_file(fname, st)) { 1929 st->print("Can not get library information for pid = %d\n", pid); 1930 } 1931 } 1932 1933 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) { 1934 FILE *procmapsFile = NULL; 1935 1936 // Open the procfs maps file for the current process 1937 if ((procmapsFile = fopen("/proc/self/maps", "r")) != NULL) { 1938 // Allocate PATH_MAX for file name plus a reasonable size for other fields. 1939 char line[PATH_MAX + 100]; 1940 1941 // Read line by line from 'file' 1942 while (fgets(line, sizeof(line), procmapsFile) != NULL) { 1943 u8 base, top, offset, inode; 1944 char permissions[5]; 1945 char device[6]; 1946 char name[PATH_MAX + 1]; 1947 1948 // Parse fields from line 1949 sscanf(line, UINT64_FORMAT_X "-" UINT64_FORMAT_X " %4s " UINT64_FORMAT_X " %5s " INT64_FORMAT " %s", 1950 &base, &top, permissions, &offset, device, &inode, name); 1951 1952 // Filter by device id '00:00' so that we only get file system mapped files. 1953 if (strcmp(device, "00:00") != 0) { 1954 1955 // Call callback with the fields of interest 1956 if(callback(name, (address)base, (address)top, param)) { 1957 // Oops abort, callback aborted 1958 fclose(procmapsFile); 1959 return 1; 1960 } 1961 } 1962 } 1963 fclose(procmapsFile); 1964 } 1965 return 0; 1966 } 1967 1968 void os::print_os_info_brief(outputStream* st) { 1969 os::Linux::print_distro_info(st); 1970 1971 os::Posix::print_uname_info(st); 1972 1973 os::Linux::print_libversion_info(st); 1974 1975 } 1976 1977 void os::print_os_info(outputStream* st) { 1978 st->print("OS:"); 1979 1980 os::Linux::print_distro_info(st); 1981 1982 os::Posix::print_uname_info(st); 1983 1984 // Print warning if unsafe chroot environment detected 1985 if (unsafe_chroot_detected) { 1986 st->print("WARNING!! "); 1987 st->print_cr("%s", unstable_chroot_error); 1988 } 1989 1990 os::Linux::print_libversion_info(st); 1991 1992 os::Posix::print_rlimit_info(st); 1993 1994 os::Posix::print_load_average(st); 1995 1996 os::Linux::print_full_memory_info(st); 1997 } 1998 1999 // Try to identify popular distros. 2000 // Most Linux distributions have a /etc/XXX-release file, which contains 2001 // the OS version string. Newer Linux distributions have a /etc/lsb-release 2002 // file that also contains the OS version string. Some have more than one 2003 // /etc/XXX-release file (e.g. Mandrake has both /etc/mandrake-release and 2004 // /etc/redhat-release.), so the order is important. 2005 // Any Linux that is based on Redhat (i.e. Oracle, Mandrake, Sun JDS...) have 2006 // their own specific XXX-release file as well as a redhat-release file. 2007 // Because of this the XXX-release file needs to be searched for before the 2008 // redhat-release file. 2009 // Since Red Hat and SuSE have an lsb-release file that is not very descriptive the 2010 // search for redhat-release / SuSE-release needs to be before lsb-release. 2011 // Since the lsb-release file is the new standard it needs to be searched 2012 // before the older style release files. 2013 // Searching system-release (Red Hat) and os-release (other Linuxes) are a 2014 // next to last resort. The os-release file is a new standard that contains 2015 // distribution information and the system-release file seems to be an old 2016 // standard that has been replaced by the lsb-release and os-release files. 2017 // Searching for the debian_version file is the last resort. It contains 2018 // an informative string like "6.0.6" or "wheezy/sid". Because of this 2019 // "Debian " is printed before the contents of the debian_version file. 2020 2021 const char* distro_files[] = { 2022 "/etc/oracle-release", 2023 "/etc/mandriva-release", 2024 "/etc/mandrake-release", 2025 "/etc/sun-release", 2026 "/etc/redhat-release", 2027 "/etc/SuSE-release", 2028 "/etc/lsb-release", 2029 "/etc/turbolinux-release", 2030 "/etc/gentoo-release", 2031 "/etc/ltib-release", 2032 "/etc/angstrom-version", 2033 "/etc/system-release", 2034 "/etc/os-release", 2035 NULL }; 2036 2037 void os::Linux::print_distro_info(outputStream* st) { 2038 for (int i = 0;; i++) { 2039 const char* file = distro_files[i]; 2040 if (file == NULL) { 2041 break; // done 2042 } 2043 // If file prints, we found it. 2044 if (_print_ascii_file(file, st)) { 2045 return; 2046 } 2047 } 2048 2049 if (file_exists("/etc/debian_version")) { 2050 st->print("Debian "); 2051 _print_ascii_file("/etc/debian_version", st); 2052 } else { 2053 st->print("Linux"); 2054 } 2055 st->cr(); 2056 } 2057 2058 static void parse_os_info_helper(FILE* fp, char* distro, size_t length, bool get_first_line) { 2059 char buf[256]; 2060 while (fgets(buf, sizeof(buf), fp)) { 2061 // Edit out extra stuff in expected format 2062 if (strstr(buf, "DISTRIB_DESCRIPTION=") != NULL || strstr(buf, "PRETTY_NAME=") != NULL) { 2063 char* ptr = strstr(buf, "\""); // the name is in quotes 2064 if (ptr != NULL) { 2065 ptr++; // go beyond first quote 2066 char* nl = strchr(ptr, '\"'); 2067 if (nl != NULL) *nl = '\0'; 2068 strncpy(distro, ptr, length); 2069 } else { 2070 ptr = strstr(buf, "="); 2071 ptr++; // go beyond equals then 2072 char* nl = strchr(ptr, '\n'); 2073 if (nl != NULL) *nl = '\0'; 2074 strncpy(distro, ptr, length); 2075 } 2076 return; 2077 } else if (get_first_line) { 2078 char* nl = strchr(buf, '\n'); 2079 if (nl != NULL) *nl = '\0'; 2080 strncpy(distro, buf, length); 2081 return; 2082 } 2083 } 2084 // print last line and close 2085 char* nl = strchr(buf, '\n'); 2086 if (nl != NULL) *nl = '\0'; 2087 strncpy(distro, buf, length); 2088 } 2089 2090 static void parse_os_info(char* distro, size_t length, const char* file) { 2091 FILE* fp = fopen(file, "r"); 2092 if (fp != NULL) { 2093 // if suse format, print out first line 2094 bool get_first_line = (strcmp(file, "/etc/SuSE-release") == 0); 2095 parse_os_info_helper(fp, distro, length, get_first_line); 2096 fclose(fp); 2097 } 2098 } 2099 2100 void os::get_summary_os_info(char* buf, size_t buflen) { 2101 for (int i = 0;; i++) { 2102 const char* file = distro_files[i]; 2103 if (file == NULL) { 2104 break; // ran out of distro_files 2105 } 2106 if (file_exists(file)) { 2107 parse_os_info(buf, buflen, file); 2108 return; 2109 } 2110 } 2111 // special case for debian 2112 if (file_exists("/etc/debian_version")) { 2113 strncpy(buf, "Debian ", buflen); 2114 parse_os_info(&buf[7], buflen-7, "/etc/debian_version"); 2115 } else { 2116 strncpy(buf, "Linux", buflen); 2117 } 2118 } 2119 2120 void os::Linux::print_libversion_info(outputStream* st) { 2121 // libc, pthread 2122 st->print("libc:"); 2123 st->print("%s ", os::Linux::glibc_version()); 2124 st->print("%s ", os::Linux::libpthread_version()); 2125 st->cr(); 2126 } 2127 2128 void os::Linux::print_full_memory_info(outputStream* st) { 2129 st->print("\n/proc/meminfo:\n"); 2130 _print_ascii_file("/proc/meminfo", st); 2131 st->cr(); 2132 } 2133 2134 void os::print_memory_info(outputStream* st) { 2135 2136 st->print("Memory:"); 2137 st->print(" %dk page", os::vm_page_size()>>10); 2138 2139 // values in struct sysinfo are "unsigned long" 2140 struct sysinfo si; 2141 sysinfo(&si); 2142 2143 st->print(", physical " UINT64_FORMAT "k", 2144 os::physical_memory() >> 10); 2145 st->print("(" UINT64_FORMAT "k free)", 2146 os::available_memory() >> 10); 2147 st->print(", swap " UINT64_FORMAT "k", 2148 ((jlong)si.totalswap * si.mem_unit) >> 10); 2149 st->print("(" UINT64_FORMAT "k free)", 2150 ((jlong)si.freeswap * si.mem_unit) >> 10); 2151 st->cr(); 2152 } 2153 2154 // Print the first "model name" line and the first "flags" line 2155 // that we find and nothing more. We assume "model name" comes 2156 // before "flags" so if we find a second "model name", then the 2157 // "flags" field is considered missing. 2158 static bool print_model_name_and_flags(outputStream* st, char* buf, size_t buflen) { 2159 #if defined(IA32) || defined(AMD64) 2160 // Other platforms have less repetitive cpuinfo files 2161 FILE *fp = fopen("/proc/cpuinfo", "r"); 2162 if (fp) { 2163 while (!feof(fp)) { 2164 if (fgets(buf, buflen, fp)) { 2165 // Assume model name comes before flags 2166 bool model_name_printed = false; 2167 if (strstr(buf, "model name") != NULL) { 2168 if (!model_name_printed) { 2169 st->print_raw("CPU Model and flags from /proc/cpuinfo:\n"); 2170 st->print_raw(buf); 2171 model_name_printed = true; 2172 } else { 2173 // model name printed but not flags? Odd, just return 2174 fclose(fp); 2175 return true; 2176 } 2177 } 2178 // print the flags line too 2179 if (strstr(buf, "flags") != NULL) { 2180 st->print_raw(buf); 2181 fclose(fp); 2182 return true; 2183 } 2184 } 2185 } 2186 fclose(fp); 2187 } 2188 #endif // x86 platforms 2189 return false; 2190 } 2191 2192 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) { 2193 // Only print the model name if the platform provides this as a summary 2194 if (!print_model_name_and_flags(st, buf, buflen)) { 2195 st->print("\n/proc/cpuinfo:\n"); 2196 if (!_print_ascii_file("/proc/cpuinfo", st)) { 2197 st->print_cr(" <Not Available>"); 2198 } 2199 } 2200 } 2201 2202 #if defined(AMD64) || defined(IA32) || defined(X32) 2203 const char* search_string = "model name"; 2204 #elif defined(PPC64) 2205 const char* search_string = "cpu"; 2206 #elif defined(S390) 2207 const char* search_string = "processor"; 2208 #elif defined(SPARC) 2209 const char* search_string = "cpu"; 2210 #else 2211 const char* search_string = "Processor"; 2212 #endif 2213 2214 // Parses the cpuinfo file for string representing the model name. 2215 void os::get_summary_cpu_info(char* cpuinfo, size_t length) { 2216 FILE* fp = fopen("/proc/cpuinfo", "r"); 2217 if (fp != NULL) { 2218 while (!feof(fp)) { 2219 char buf[256]; 2220 if (fgets(buf, sizeof(buf), fp)) { 2221 char* start = strstr(buf, search_string); 2222 if (start != NULL) { 2223 char *ptr = start + strlen(search_string); 2224 char *end = buf + strlen(buf); 2225 while (ptr != end) { 2226 // skip whitespace and colon for the rest of the name. 2227 if (*ptr != ' ' && *ptr != '\t' && *ptr != ':') { 2228 break; 2229 } 2230 ptr++; 2231 } 2232 if (ptr != end) { 2233 // reasonable string, get rid of newline and keep the rest 2234 char* nl = strchr(buf, '\n'); 2235 if (nl != NULL) *nl = '\0'; 2236 strncpy(cpuinfo, ptr, length); 2237 fclose(fp); 2238 return; 2239 } 2240 } 2241 } 2242 } 2243 fclose(fp); 2244 } 2245 // cpuinfo not found or parsing failed, just print generic string. The entire 2246 // /proc/cpuinfo file will be printed later in the file (or enough of it for x86) 2247 #if defined(AARCH64) 2248 strncpy(cpuinfo, "AArch64", length); 2249 #elif defined(AMD64) 2250 strncpy(cpuinfo, "x86_64", length); 2251 #elif defined(ARM) // Order wrt. AARCH64 is relevant! 2252 strncpy(cpuinfo, "ARM", length); 2253 #elif defined(IA32) 2254 strncpy(cpuinfo, "x86_32", length); 2255 #elif defined(IA64) 2256 strncpy(cpuinfo, "IA64", length); 2257 #elif defined(PPC) 2258 strncpy(cpuinfo, "PPC64", length); 2259 #elif defined(S390) 2260 strncpy(cpuinfo, "S390", length); 2261 #elif defined(SPARC) 2262 strncpy(cpuinfo, "sparcv9", length); 2263 #elif defined(ZERO_LIBARCH) 2264 strncpy(cpuinfo, ZERO_LIBARCH, length); 2265 #else 2266 strncpy(cpuinfo, "unknown", length); 2267 #endif 2268 } 2269 2270 static void print_signal_handler(outputStream* st, int sig, 2271 char* buf, size_t buflen); 2272 2273 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) { 2274 st->print_cr("Signal Handlers:"); 2275 print_signal_handler(st, SIGSEGV, buf, buflen); 2276 print_signal_handler(st, SIGBUS , buf, buflen); 2277 print_signal_handler(st, SIGFPE , buf, buflen); 2278 print_signal_handler(st, SIGPIPE, buf, buflen); 2279 print_signal_handler(st, SIGXFSZ, buf, buflen); 2280 print_signal_handler(st, SIGILL , buf, buflen); 2281 print_signal_handler(st, SR_signum, buf, buflen); 2282 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen); 2283 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen); 2284 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen); 2285 print_signal_handler(st, BREAK_SIGNAL, buf, buflen); 2286 #if defined(PPC64) 2287 print_signal_handler(st, SIGTRAP, buf, buflen); 2288 #endif 2289 } 2290 2291 static char saved_jvm_path[MAXPATHLEN] = {0}; 2292 2293 // Find the full path to the current module, libjvm.so 2294 void os::jvm_path(char *buf, jint buflen) { 2295 // Error checking. 2296 if (buflen < MAXPATHLEN) { 2297 assert(false, "must use a large-enough buffer"); 2298 buf[0] = '\0'; 2299 return; 2300 } 2301 // Lazy resolve the path to current module. 2302 if (saved_jvm_path[0] != 0) { 2303 strcpy(buf, saved_jvm_path); 2304 return; 2305 } 2306 2307 char dli_fname[MAXPATHLEN]; 2308 bool ret = dll_address_to_library_name( 2309 CAST_FROM_FN_PTR(address, os::jvm_path), 2310 dli_fname, sizeof(dli_fname), NULL); 2311 assert(ret, "cannot locate libjvm"); 2312 char *rp = NULL; 2313 if (ret && dli_fname[0] != '\0') { 2314 rp = os::Posix::realpath(dli_fname, buf, buflen); 2315 } 2316 if (rp == NULL) { 2317 return; 2318 } 2319 2320 if (Arguments::sun_java_launcher_is_altjvm()) { 2321 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical 2322 // value for buf is "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.so". 2323 // If "/jre/lib/" appears at the right place in the string, then 2324 // assume we are installed in a JDK and we're done. Otherwise, check 2325 // for a JAVA_HOME environment variable and fix up the path so it 2326 // looks like libjvm.so is installed there (append a fake suffix 2327 // hotspot/libjvm.so). 2328 const char *p = buf + strlen(buf) - 1; 2329 for (int count = 0; p > buf && count < 5; ++count) { 2330 for (--p; p > buf && *p != '/'; --p) 2331 /* empty */ ; 2332 } 2333 2334 if (strncmp(p, "/jre/lib/", 9) != 0) { 2335 // Look for JAVA_HOME in the environment. 2336 char* java_home_var = ::getenv("JAVA_HOME"); 2337 if (java_home_var != NULL && java_home_var[0] != 0) { 2338 char* jrelib_p; 2339 int len; 2340 2341 // Check the current module name "libjvm.so". 2342 p = strrchr(buf, '/'); 2343 if (p == NULL) { 2344 return; 2345 } 2346 assert(strstr(p, "/libjvm") == p, "invalid library name"); 2347 2348 rp = os::Posix::realpath(java_home_var, buf, buflen); 2349 if (rp == NULL) { 2350 return; 2351 } 2352 2353 // determine if this is a legacy image or modules image 2354 // modules image doesn't have "jre" subdirectory 2355 len = strlen(buf); 2356 assert(len < buflen, "Ran out of buffer room"); 2357 jrelib_p = buf + len; 2358 snprintf(jrelib_p, buflen-len, "/jre/lib"); 2359 if (0 != access(buf, F_OK)) { 2360 snprintf(jrelib_p, buflen-len, "/lib"); 2361 } 2362 2363 if (0 == access(buf, F_OK)) { 2364 // Use current module name "libjvm.so" 2365 len = strlen(buf); 2366 snprintf(buf + len, buflen-len, "/hotspot/libjvm.so"); 2367 } else { 2368 // Go back to path of .so 2369 rp = os::Posix::realpath(dli_fname, buf, buflen); 2370 if (rp == NULL) { 2371 return; 2372 } 2373 } 2374 } 2375 } 2376 } 2377 2378 strncpy(saved_jvm_path, buf, MAXPATHLEN); 2379 saved_jvm_path[MAXPATHLEN - 1] = '\0'; 2380 } 2381 2382 void os::print_jni_name_prefix_on(outputStream* st, int args_size) { 2383 // no prefix required, not even "_" 2384 } 2385 2386 void os::print_jni_name_suffix_on(outputStream* st, int args_size) { 2387 // no suffix required 2388 } 2389 2390 //////////////////////////////////////////////////////////////////////////////// 2391 // sun.misc.Signal support 2392 2393 static volatile jint sigint_count = 0; 2394 2395 static void UserHandler(int sig, void *siginfo, void *context) { 2396 // 4511530 - sem_post is serialized and handled by the manager thread. When 2397 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We 2398 // don't want to flood the manager thread with sem_post requests. 2399 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) { 2400 return; 2401 } 2402 2403 // Ctrl-C is pressed during error reporting, likely because the error 2404 // handler fails to abort. Let VM die immediately. 2405 if (sig == SIGINT && VMError::is_error_reported()) { 2406 os::die(); 2407 } 2408 2409 os::signal_notify(sig); 2410 } 2411 2412 void* os::user_handler() { 2413 return CAST_FROM_FN_PTR(void*, UserHandler); 2414 } 2415 2416 struct timespec PosixSemaphore::create_timespec(unsigned int sec, int nsec) { 2417 struct timespec ts; 2418 // Semaphore's are always associated with CLOCK_REALTIME 2419 os::Linux::clock_gettime(CLOCK_REALTIME, &ts); 2420 // see unpackTime for discussion on overflow checking 2421 if (sec >= MAX_SECS) { 2422 ts.tv_sec += MAX_SECS; 2423 ts.tv_nsec = 0; 2424 } else { 2425 ts.tv_sec += sec; 2426 ts.tv_nsec += nsec; 2427 if (ts.tv_nsec >= NANOSECS_PER_SEC) { 2428 ts.tv_nsec -= NANOSECS_PER_SEC; 2429 ++ts.tv_sec; // note: this must be <= max_secs 2430 } 2431 } 2432 2433 return ts; 2434 } 2435 2436 extern "C" { 2437 typedef void (*sa_handler_t)(int); 2438 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 2439 } 2440 2441 void* os::signal(int signal_number, void* handler) { 2442 struct sigaction sigAct, oldSigAct; 2443 2444 sigfillset(&(sigAct.sa_mask)); 2445 sigAct.sa_flags = SA_RESTART|SA_SIGINFO; 2446 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler); 2447 2448 if (sigaction(signal_number, &sigAct, &oldSigAct)) { 2449 // -1 means registration failed 2450 return (void *)-1; 2451 } 2452 2453 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler); 2454 } 2455 2456 void os::signal_raise(int signal_number) { 2457 ::raise(signal_number); 2458 } 2459 2460 // The following code is moved from os.cpp for making this 2461 // code platform specific, which it is by its very nature. 2462 2463 // Will be modified when max signal is changed to be dynamic 2464 int os::sigexitnum_pd() { 2465 return NSIG; 2466 } 2467 2468 // a counter for each possible signal value 2469 static volatile jint pending_signals[NSIG+1] = { 0 }; 2470 2471 // Linux(POSIX) specific hand shaking semaphore. 2472 static sem_t sig_sem; 2473 static PosixSemaphore sr_semaphore; 2474 2475 void os::signal_init_pd() { 2476 // Initialize signal structures 2477 ::memset((void*)pending_signals, 0, sizeof(pending_signals)); 2478 2479 // Initialize signal semaphore 2480 ::sem_init(&sig_sem, 0, 0); 2481 } 2482 2483 void os::signal_notify(int sig) { 2484 Atomic::inc(&pending_signals[sig]); 2485 ::sem_post(&sig_sem); 2486 } 2487 2488 static int check_pending_signals(bool wait) { 2489 Atomic::store(0, &sigint_count); 2490 for (;;) { 2491 for (int i = 0; i < NSIG + 1; i++) { 2492 jint n = pending_signals[i]; 2493 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) { 2494 return i; 2495 } 2496 } 2497 if (!wait) { 2498 return -1; 2499 } 2500 JavaThread *thread = JavaThread::current(); 2501 ThreadBlockInVM tbivm(thread); 2502 2503 bool threadIsSuspended; 2504 do { 2505 thread->set_suspend_equivalent(); 2506 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self() 2507 ::sem_wait(&sig_sem); 2508 2509 // were we externally suspended while we were waiting? 2510 threadIsSuspended = thread->handle_special_suspend_equivalent_condition(); 2511 if (threadIsSuspended) { 2512 // The semaphore has been incremented, but while we were waiting 2513 // another thread suspended us. We don't want to continue running 2514 // while suspended because that would surprise the thread that 2515 // suspended us. 2516 ::sem_post(&sig_sem); 2517 2518 thread->java_suspend_self(); 2519 } 2520 } while (threadIsSuspended); 2521 } 2522 } 2523 2524 int os::signal_lookup() { 2525 return check_pending_signals(false); 2526 } 2527 2528 int os::signal_wait() { 2529 return check_pending_signals(true); 2530 } 2531 2532 //////////////////////////////////////////////////////////////////////////////// 2533 // Virtual Memory 2534 2535 int os::vm_page_size() { 2536 // Seems redundant as all get out 2537 assert(os::Linux::page_size() != -1, "must call os::init"); 2538 return os::Linux::page_size(); 2539 } 2540 2541 // Solaris allocates memory by pages. 2542 int os::vm_allocation_granularity() { 2543 assert(os::Linux::page_size() != -1, "must call os::init"); 2544 return os::Linux::page_size(); 2545 } 2546 2547 // Rationale behind this function: 2548 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable 2549 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get 2550 // samples for JITted code. Here we create private executable mapping over the code cache 2551 // and then we can use standard (well, almost, as mapping can change) way to provide 2552 // info for the reporting script by storing timestamp and location of symbol 2553 void linux_wrap_code(char* base, size_t size) { 2554 static volatile jint cnt = 0; 2555 2556 if (!UseOprofile) { 2557 return; 2558 } 2559 2560 char buf[PATH_MAX+1]; 2561 int num = Atomic::add(1, &cnt); 2562 2563 snprintf(buf, sizeof(buf), "%s/hs-vm-%d-%d", 2564 os::get_temp_directory(), os::current_process_id(), num); 2565 unlink(buf); 2566 2567 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU); 2568 2569 if (fd != -1) { 2570 off_t rv = ::lseek(fd, size-2, SEEK_SET); 2571 if (rv != (off_t)-1) { 2572 if (::write(fd, "", 1) == 1) { 2573 mmap(base, size, 2574 PROT_READ|PROT_WRITE|PROT_EXEC, 2575 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0); 2576 } 2577 } 2578 ::close(fd); 2579 unlink(buf); 2580 } 2581 } 2582 2583 static bool recoverable_mmap_error(int err) { 2584 // See if the error is one we can let the caller handle. This 2585 // list of errno values comes from JBS-6843484. I can't find a 2586 // Linux man page that documents this specific set of errno 2587 // values so while this list currently matches Solaris, it may 2588 // change as we gain experience with this failure mode. 2589 switch (err) { 2590 case EBADF: 2591 case EINVAL: 2592 case ENOTSUP: 2593 // let the caller deal with these errors 2594 return true; 2595 2596 default: 2597 // Any remaining errors on this OS can cause our reserved mapping 2598 // to be lost. That can cause confusion where different data 2599 // structures think they have the same memory mapped. The worst 2600 // scenario is if both the VM and a library think they have the 2601 // same memory mapped. 2602 return false; 2603 } 2604 } 2605 2606 static void warn_fail_commit_memory(char* addr, size_t size, bool exec, 2607 int err) { 2608 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2609 ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, exec, 2610 os::strerror(err), err); 2611 } 2612 2613 static void warn_fail_commit_memory(char* addr, size_t size, 2614 size_t alignment_hint, bool exec, 2615 int err) { 2616 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT 2617 ", " SIZE_FORMAT ", %d) failed; error='%s' (errno=%d)", p2i(addr), size, 2618 alignment_hint, exec, os::strerror(err), err); 2619 } 2620 2621 // NOTE: Linux kernel does not really reserve the pages for us. 2622 // All it does is to check if there are enough free pages 2623 // left at the time of mmap(). This could be a potential 2624 // problem. 2625 int os::Linux::commit_memory_impl(char* addr, size_t size, bool exec) { 2626 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 2627 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot, 2628 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0); 2629 if (res != (uintptr_t) MAP_FAILED) { 2630 if (UseNUMAInterleaving) { 2631 numa_make_global(addr, size); 2632 } 2633 return 0; 2634 } 2635 2636 int err = errno; // save errno from mmap() call above 2637 2638 if (!recoverable_mmap_error(err)) { 2639 warn_fail_commit_memory(addr, size, exec, err); 2640 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "committing reserved memory."); 2641 } 2642 2643 return err; 2644 } 2645 2646 bool os::pd_commit_memory(char* addr, size_t size, bool exec) { 2647 return os::Linux::commit_memory_impl(addr, size, exec) == 0; 2648 } 2649 2650 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec, 2651 const char* mesg) { 2652 assert(mesg != NULL, "mesg must be specified"); 2653 int err = os::Linux::commit_memory_impl(addr, size, exec); 2654 if (err != 0) { 2655 // the caller wants all commit errors to exit with the specified mesg: 2656 warn_fail_commit_memory(addr, size, exec, err); 2657 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2658 } 2659 } 2660 2661 // Define MAP_HUGETLB here so we can build HotSpot on old systems. 2662 #ifndef MAP_HUGETLB 2663 #define MAP_HUGETLB 0x40000 2664 #endif 2665 2666 // Define MADV_HUGEPAGE here so we can build HotSpot on old systems. 2667 #ifndef MADV_HUGEPAGE 2668 #define MADV_HUGEPAGE 14 2669 #endif 2670 2671 int os::Linux::commit_memory_impl(char* addr, size_t size, 2672 size_t alignment_hint, bool exec) { 2673 int err = os::Linux::commit_memory_impl(addr, size, exec); 2674 if (err == 0) { 2675 realign_memory(addr, size, alignment_hint); 2676 } 2677 return err; 2678 } 2679 2680 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint, 2681 bool exec) { 2682 return os::Linux::commit_memory_impl(addr, size, alignment_hint, exec) == 0; 2683 } 2684 2685 void os::pd_commit_memory_or_exit(char* addr, size_t size, 2686 size_t alignment_hint, bool exec, 2687 const char* mesg) { 2688 assert(mesg != NULL, "mesg must be specified"); 2689 int err = os::Linux::commit_memory_impl(addr, size, alignment_hint, exec); 2690 if (err != 0) { 2691 // the caller wants all commit errors to exit with the specified mesg: 2692 warn_fail_commit_memory(addr, size, alignment_hint, exec, err); 2693 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg); 2694 } 2695 } 2696 2697 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) { 2698 if (UseTransparentHugePages && alignment_hint > (size_t)vm_page_size()) { 2699 // We don't check the return value: madvise(MADV_HUGEPAGE) may not 2700 // be supported or the memory may already be backed by huge pages. 2701 ::madvise(addr, bytes, MADV_HUGEPAGE); 2702 } 2703 } 2704 2705 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) { 2706 // This method works by doing an mmap over an existing mmaping and effectively discarding 2707 // the existing pages. However it won't work for SHM-based large pages that cannot be 2708 // uncommitted at all. We don't do anything in this case to avoid creating a segment with 2709 // small pages on top of the SHM segment. This method always works for small pages, so we 2710 // allow that in any case. 2711 if (alignment_hint <= (size_t)os::vm_page_size() || can_commit_large_page_memory()) { 2712 commit_memory(addr, bytes, alignment_hint, !ExecMem); 2713 } 2714 } 2715 2716 void os::numa_make_global(char *addr, size_t bytes) { 2717 Linux::numa_interleave_memory(addr, bytes); 2718 } 2719 2720 // Define for numa_set_bind_policy(int). Setting the argument to 0 will set the 2721 // bind policy to MPOL_PREFERRED for the current thread. 2722 #define USE_MPOL_PREFERRED 0 2723 2724 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) { 2725 // To make NUMA and large pages more robust when both enabled, we need to ease 2726 // the requirements on where the memory should be allocated. MPOL_BIND is the 2727 // default policy and it will force memory to be allocated on the specified 2728 // node. Changing this to MPOL_PREFERRED will prefer to allocate the memory on 2729 // the specified node, but will not force it. Using this policy will prevent 2730 // getting SIGBUS when trying to allocate large pages on NUMA nodes with no 2731 // free large pages. 2732 Linux::numa_set_bind_policy(USE_MPOL_PREFERRED); 2733 Linux::numa_tonode_memory(addr, bytes, lgrp_hint); 2734 } 2735 2736 bool os::numa_topology_changed() { return false; } 2737 2738 size_t os::numa_get_groups_num() { 2739 // Return just the number of nodes in which it's possible to allocate memory 2740 // (in numa terminology, configured nodes). 2741 return Linux::numa_num_configured_nodes(); 2742 } 2743 2744 int os::numa_get_group_id() { 2745 int cpu_id = Linux::sched_getcpu(); 2746 if (cpu_id != -1) { 2747 int lgrp_id = Linux::get_node_by_cpu(cpu_id); 2748 if (lgrp_id != -1) { 2749 return lgrp_id; 2750 } 2751 } 2752 return 0; 2753 } 2754 2755 int os::Linux::get_existing_num_nodes() { 2756 size_t node; 2757 size_t highest_node_number = Linux::numa_max_node(); 2758 int num_nodes = 0; 2759 2760 // Get the total number of nodes in the system including nodes without memory. 2761 for (node = 0; node <= highest_node_number; node++) { 2762 if (isnode_in_existing_nodes(node)) { 2763 num_nodes++; 2764 } 2765 } 2766 return num_nodes; 2767 } 2768 2769 size_t os::numa_get_leaf_groups(int *ids, size_t size) { 2770 size_t highest_node_number = Linux::numa_max_node(); 2771 size_t i = 0; 2772 2773 // Map all node ids in which is possible to allocate memory. Also nodes are 2774 // not always consecutively available, i.e. available from 0 to the highest 2775 // node number. 2776 for (size_t node = 0; node <= highest_node_number; node++) { 2777 if (Linux::isnode_in_configured_nodes(node)) { 2778 ids[i++] = node; 2779 } 2780 } 2781 return i; 2782 } 2783 2784 bool os::get_page_info(char *start, page_info* info) { 2785 return false; 2786 } 2787 2788 char *os::scan_pages(char *start, char* end, page_info* page_expected, 2789 page_info* page_found) { 2790 return end; 2791 } 2792 2793 2794 int os::Linux::sched_getcpu_syscall(void) { 2795 unsigned int cpu = 0; 2796 int retval = -1; 2797 2798 #if defined(IA32) 2799 #ifndef SYS_getcpu 2800 #define SYS_getcpu 318 2801 #endif 2802 retval = syscall(SYS_getcpu, &cpu, NULL, NULL); 2803 #elif defined(AMD64) 2804 // Unfortunately we have to bring all these macros here from vsyscall.h 2805 // to be able to compile on old linuxes. 2806 #define __NR_vgetcpu 2 2807 #define VSYSCALL_START (-10UL << 20) 2808 #define VSYSCALL_SIZE 1024 2809 #define VSYSCALL_ADDR(vsyscall_nr) (VSYSCALL_START+VSYSCALL_SIZE*(vsyscall_nr)) 2810 typedef long (*vgetcpu_t)(unsigned int *cpu, unsigned int *node, unsigned long *tcache); 2811 vgetcpu_t vgetcpu = (vgetcpu_t)VSYSCALL_ADDR(__NR_vgetcpu); 2812 retval = vgetcpu(&cpu, NULL, NULL); 2813 #endif 2814 2815 return (retval == -1) ? retval : cpu; 2816 } 2817 2818 void os::Linux::sched_getcpu_init() { 2819 // sched_getcpu() should be in libc. 2820 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2821 dlsym(RTLD_DEFAULT, "sched_getcpu"))); 2822 2823 // If it's not, try a direct syscall. 2824 if (sched_getcpu() == -1) { 2825 set_sched_getcpu(CAST_TO_FN_PTR(sched_getcpu_func_t, 2826 (void*)&sched_getcpu_syscall)); 2827 } 2828 } 2829 2830 // Something to do with the numa-aware allocator needs these symbols 2831 extern "C" JNIEXPORT void numa_warn(int number, char *where, ...) { } 2832 extern "C" JNIEXPORT void numa_error(char *where) { } 2833 2834 // Handle request to load libnuma symbol version 1.1 (API v1). If it fails 2835 // load symbol from base version instead. 2836 void* os::Linux::libnuma_dlsym(void* handle, const char *name) { 2837 void *f = dlvsym(handle, name, "libnuma_1.1"); 2838 if (f == NULL) { 2839 f = dlsym(handle, name); 2840 } 2841 return f; 2842 } 2843 2844 // Handle request to load libnuma symbol version 1.2 (API v2) only. 2845 // Return NULL if the symbol is not defined in this particular version. 2846 void* os::Linux::libnuma_v2_dlsym(void* handle, const char* name) { 2847 return dlvsym(handle, name, "libnuma_1.2"); 2848 } 2849 2850 bool os::Linux::libnuma_init() { 2851 if (sched_getcpu() != -1) { // Requires sched_getcpu() support 2852 void *handle = dlopen("libnuma.so.1", RTLD_LAZY); 2853 if (handle != NULL) { 2854 set_numa_node_to_cpus(CAST_TO_FN_PTR(numa_node_to_cpus_func_t, 2855 libnuma_dlsym(handle, "numa_node_to_cpus"))); 2856 set_numa_max_node(CAST_TO_FN_PTR(numa_max_node_func_t, 2857 libnuma_dlsym(handle, "numa_max_node"))); 2858 set_numa_num_configured_nodes(CAST_TO_FN_PTR(numa_num_configured_nodes_func_t, 2859 libnuma_dlsym(handle, "numa_num_configured_nodes"))); 2860 set_numa_available(CAST_TO_FN_PTR(numa_available_func_t, 2861 libnuma_dlsym(handle, "numa_available"))); 2862 set_numa_tonode_memory(CAST_TO_FN_PTR(numa_tonode_memory_func_t, 2863 libnuma_dlsym(handle, "numa_tonode_memory"))); 2864 set_numa_interleave_memory(CAST_TO_FN_PTR(numa_interleave_memory_func_t, 2865 libnuma_dlsym(handle, "numa_interleave_memory"))); 2866 set_numa_interleave_memory_v2(CAST_TO_FN_PTR(numa_interleave_memory_v2_func_t, 2867 libnuma_v2_dlsym(handle, "numa_interleave_memory"))); 2868 set_numa_set_bind_policy(CAST_TO_FN_PTR(numa_set_bind_policy_func_t, 2869 libnuma_dlsym(handle, "numa_set_bind_policy"))); 2870 set_numa_bitmask_isbitset(CAST_TO_FN_PTR(numa_bitmask_isbitset_func_t, 2871 libnuma_dlsym(handle, "numa_bitmask_isbitset"))); 2872 set_numa_distance(CAST_TO_FN_PTR(numa_distance_func_t, 2873 libnuma_dlsym(handle, "numa_distance"))); 2874 2875 if (numa_available() != -1) { 2876 set_numa_all_nodes((unsigned long*)libnuma_dlsym(handle, "numa_all_nodes")); 2877 set_numa_all_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_all_nodes_ptr")); 2878 set_numa_nodes_ptr((struct bitmask **)libnuma_dlsym(handle, "numa_nodes_ptr")); 2879 // Create an index -> node mapping, since nodes are not always consecutive 2880 _nindex_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2881 rebuild_nindex_to_node_map(); 2882 // Create a cpu -> node mapping 2883 _cpu_to_node = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<int>(0, true); 2884 rebuild_cpu_to_node_map(); 2885 return true; 2886 } 2887 } 2888 } 2889 return false; 2890 } 2891 2892 size_t os::Linux::default_guard_size(os::ThreadType thr_type) { 2893 // Creating guard page is very expensive. Java thread has HotSpot 2894 // guard pages, only enable glibc guard page for non-Java threads. 2895 // (Remember: compiler thread is a Java thread, too!) 2896 return ((thr_type == java_thread || thr_type == compiler_thread) ? 0 : page_size()); 2897 } 2898 2899 void os::Linux::rebuild_nindex_to_node_map() { 2900 int highest_node_number = Linux::numa_max_node(); 2901 2902 nindex_to_node()->clear(); 2903 for (int node = 0; node <= highest_node_number; node++) { 2904 if (Linux::isnode_in_existing_nodes(node)) { 2905 nindex_to_node()->append(node); 2906 } 2907 } 2908 } 2909 2910 // rebuild_cpu_to_node_map() constructs a table mapping cpud id to node id. 2911 // The table is later used in get_node_by_cpu(). 2912 void os::Linux::rebuild_cpu_to_node_map() { 2913 const size_t NCPUS = 32768; // Since the buffer size computation is very obscure 2914 // in libnuma (possible values are starting from 16, 2915 // and continuing up with every other power of 2, but less 2916 // than the maximum number of CPUs supported by kernel), and 2917 // is a subject to change (in libnuma version 2 the requirements 2918 // are more reasonable) we'll just hardcode the number they use 2919 // in the library. 2920 const size_t BitsPerCLong = sizeof(long) * CHAR_BIT; 2921 2922 size_t cpu_num = processor_count(); 2923 size_t cpu_map_size = NCPUS / BitsPerCLong; 2924 size_t cpu_map_valid_size = 2925 MIN2((cpu_num + BitsPerCLong - 1) / BitsPerCLong, cpu_map_size); 2926 2927 cpu_to_node()->clear(); 2928 cpu_to_node()->at_grow(cpu_num - 1); 2929 2930 size_t node_num = get_existing_num_nodes(); 2931 2932 int distance = 0; 2933 int closest_distance = INT_MAX; 2934 int closest_node = 0; 2935 unsigned long *cpu_map = NEW_C_HEAP_ARRAY(unsigned long, cpu_map_size, mtInternal); 2936 for (size_t i = 0; i < node_num; i++) { 2937 // Check if node is configured (not a memory-less node). If it is not, find 2938 // the closest configured node. 2939 if (!isnode_in_configured_nodes(nindex_to_node()->at(i))) { 2940 closest_distance = INT_MAX; 2941 // Check distance from all remaining nodes in the system. Ignore distance 2942 // from itself and from another non-configured node. 2943 for (size_t m = 0; m < node_num; m++) { 2944 if (m != i && isnode_in_configured_nodes(nindex_to_node()->at(m))) { 2945 distance = numa_distance(nindex_to_node()->at(i), nindex_to_node()->at(m)); 2946 // If a closest node is found, update. There is always at least one 2947 // configured node in the system so there is always at least one node 2948 // close. 2949 if (distance != 0 && distance < closest_distance) { 2950 closest_distance = distance; 2951 closest_node = nindex_to_node()->at(m); 2952 } 2953 } 2954 } 2955 } else { 2956 // Current node is already a configured node. 2957 closest_node = nindex_to_node()->at(i); 2958 } 2959 2960 // Get cpus from the original node and map them to the closest node. If node 2961 // is a configured node (not a memory-less node), then original node and 2962 // closest node are the same. 2963 if (numa_node_to_cpus(nindex_to_node()->at(i), cpu_map, cpu_map_size * sizeof(unsigned long)) != -1) { 2964 for (size_t j = 0; j < cpu_map_valid_size; j++) { 2965 if (cpu_map[j] != 0) { 2966 for (size_t k = 0; k < BitsPerCLong; k++) { 2967 if (cpu_map[j] & (1UL << k)) { 2968 cpu_to_node()->at_put(j * BitsPerCLong + k, closest_node); 2969 } 2970 } 2971 } 2972 } 2973 } 2974 } 2975 FREE_C_HEAP_ARRAY(unsigned long, cpu_map); 2976 } 2977 2978 int os::Linux::get_node_by_cpu(int cpu_id) { 2979 if (cpu_to_node() != NULL && cpu_id >= 0 && cpu_id < cpu_to_node()->length()) { 2980 return cpu_to_node()->at(cpu_id); 2981 } 2982 return -1; 2983 } 2984 2985 GrowableArray<int>* os::Linux::_cpu_to_node; 2986 GrowableArray<int>* os::Linux::_nindex_to_node; 2987 os::Linux::sched_getcpu_func_t os::Linux::_sched_getcpu; 2988 os::Linux::numa_node_to_cpus_func_t os::Linux::_numa_node_to_cpus; 2989 os::Linux::numa_max_node_func_t os::Linux::_numa_max_node; 2990 os::Linux::numa_num_configured_nodes_func_t os::Linux::_numa_num_configured_nodes; 2991 os::Linux::numa_available_func_t os::Linux::_numa_available; 2992 os::Linux::numa_tonode_memory_func_t os::Linux::_numa_tonode_memory; 2993 os::Linux::numa_interleave_memory_func_t os::Linux::_numa_interleave_memory; 2994 os::Linux::numa_interleave_memory_v2_func_t os::Linux::_numa_interleave_memory_v2; 2995 os::Linux::numa_set_bind_policy_func_t os::Linux::_numa_set_bind_policy; 2996 os::Linux::numa_bitmask_isbitset_func_t os::Linux::_numa_bitmask_isbitset; 2997 os::Linux::numa_distance_func_t os::Linux::_numa_distance; 2998 unsigned long* os::Linux::_numa_all_nodes; 2999 struct bitmask* os::Linux::_numa_all_nodes_ptr; 3000 struct bitmask* os::Linux::_numa_nodes_ptr; 3001 3002 bool os::pd_uncommit_memory(char* addr, size_t size) { 3003 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE, 3004 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0); 3005 return res != (uintptr_t) MAP_FAILED; 3006 } 3007 3008 static address get_stack_commited_bottom(address bottom, size_t size) { 3009 address nbot = bottom; 3010 address ntop = bottom + size; 3011 3012 size_t page_sz = os::vm_page_size(); 3013 unsigned pages = size / page_sz; 3014 3015 unsigned char vec[1]; 3016 unsigned imin = 1, imax = pages + 1, imid; 3017 int mincore_return_value = 0; 3018 3019 assert(imin <= imax, "Unexpected page size"); 3020 3021 while (imin < imax) { 3022 imid = (imax + imin) / 2; 3023 nbot = ntop - (imid * page_sz); 3024 3025 // Use a trick with mincore to check whether the page is mapped or not. 3026 // mincore sets vec to 1 if page resides in memory and to 0 if page 3027 // is swapped output but if page we are asking for is unmapped 3028 // it returns -1,ENOMEM 3029 mincore_return_value = mincore(nbot, page_sz, vec); 3030 3031 if (mincore_return_value == -1) { 3032 // Page is not mapped go up 3033 // to find first mapped page 3034 if (errno != EAGAIN) { 3035 assert(errno == ENOMEM, "Unexpected mincore errno"); 3036 imax = imid; 3037 } 3038 } else { 3039 // Page is mapped go down 3040 // to find first not mapped page 3041 imin = imid + 1; 3042 } 3043 } 3044 3045 nbot = nbot + page_sz; 3046 3047 // Adjust stack bottom one page up if last checked page is not mapped 3048 if (mincore_return_value == -1) { 3049 nbot = nbot + page_sz; 3050 } 3051 3052 return nbot; 3053 } 3054 3055 3056 // Linux uses a growable mapping for the stack, and if the mapping for 3057 // the stack guard pages is not removed when we detach a thread the 3058 // stack cannot grow beyond the pages where the stack guard was 3059 // mapped. If at some point later in the process the stack expands to 3060 // that point, the Linux kernel cannot expand the stack any further 3061 // because the guard pages are in the way, and a segfault occurs. 3062 // 3063 // However, it's essential not to split the stack region by unmapping 3064 // a region (leaving a hole) that's already part of the stack mapping, 3065 // so if the stack mapping has already grown beyond the guard pages at 3066 // the time we create them, we have to truncate the stack mapping. 3067 // So, we need to know the extent of the stack mapping when 3068 // create_stack_guard_pages() is called. 3069 3070 // We only need this for stacks that are growable: at the time of 3071 // writing thread stacks don't use growable mappings (i.e. those 3072 // creeated with MAP_GROWSDOWN), and aren't marked "[stack]", so this 3073 // only applies to the main thread. 3074 3075 // If the (growable) stack mapping already extends beyond the point 3076 // where we're going to put our guard pages, truncate the mapping at 3077 // that point by munmap()ping it. This ensures that when we later 3078 // munmap() the guard pages we don't leave a hole in the stack 3079 // mapping. This only affects the main/initial thread 3080 3081 bool os::pd_create_stack_guard_pages(char* addr, size_t size) { 3082 if (os::Linux::is_initial_thread()) { 3083 // As we manually grow stack up to bottom inside create_attached_thread(), 3084 // it's likely that os::Linux::initial_thread_stack_bottom is mapped and 3085 // we don't need to do anything special. 3086 // Check it first, before calling heavy function. 3087 uintptr_t stack_extent = (uintptr_t) os::Linux::initial_thread_stack_bottom(); 3088 unsigned char vec[1]; 3089 3090 if (mincore((address)stack_extent, os::vm_page_size(), vec) == -1) { 3091 // Fallback to slow path on all errors, including EAGAIN 3092 stack_extent = (uintptr_t) get_stack_commited_bottom( 3093 os::Linux::initial_thread_stack_bottom(), 3094 (size_t)addr - stack_extent); 3095 } 3096 3097 if (stack_extent < (uintptr_t)addr) { 3098 ::munmap((void*)stack_extent, (uintptr_t)(addr - stack_extent)); 3099 } 3100 } 3101 3102 return os::commit_memory(addr, size, !ExecMem); 3103 } 3104 3105 // If this is a growable mapping, remove the guard pages entirely by 3106 // munmap()ping them. If not, just call uncommit_memory(). This only 3107 // affects the main/initial thread, but guard against future OS changes 3108 // It's safe to always unmap guard pages for initial thread because we 3109 // always place it right after end of the mapped region 3110 3111 bool os::remove_stack_guard_pages(char* addr, size_t size) { 3112 uintptr_t stack_extent, stack_base; 3113 3114 if (os::Linux::is_initial_thread()) { 3115 return ::munmap(addr, size) == 0; 3116 } 3117 3118 return os::uncommit_memory(addr, size); 3119 } 3120 3121 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory 3122 // at 'requested_addr'. If there are existing memory mappings at the same 3123 // location, however, they will be overwritten. If 'fixed' is false, 3124 // 'requested_addr' is only treated as a hint, the return value may or 3125 // may not start from the requested address. Unlike Linux mmap(), this 3126 // function returns NULL to indicate failure. 3127 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) { 3128 char * addr; 3129 int flags; 3130 3131 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS; 3132 if (fixed) { 3133 assert((uintptr_t)requested_addr % os::Linux::page_size() == 0, "unaligned address"); 3134 flags |= MAP_FIXED; 3135 } 3136 3137 // Map reserved/uncommitted pages PROT_NONE so we fail early if we 3138 // touch an uncommitted page. Otherwise, the read/write might 3139 // succeed if we have enough swap space to back the physical page. 3140 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE, 3141 flags, -1, 0); 3142 3143 return addr == MAP_FAILED ? NULL : addr; 3144 } 3145 3146 // Allocate (using mmap, NO_RESERVE, with small pages) at either a given request address 3147 // (req_addr != NULL) or with a given alignment. 3148 // - bytes shall be a multiple of alignment. 3149 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3150 // - alignment sets the alignment at which memory shall be allocated. 3151 // It must be a multiple of allocation granularity. 3152 // Returns address of memory or NULL. If req_addr was not NULL, will only return 3153 // req_addr or NULL. 3154 static char* anon_mmap_aligned(size_t bytes, size_t alignment, char* req_addr) { 3155 3156 size_t extra_size = bytes; 3157 if (req_addr == NULL && alignment > 0) { 3158 extra_size += alignment; 3159 } 3160 3161 char* start = (char*) ::mmap(req_addr, extra_size, PROT_NONE, 3162 MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 3163 -1, 0); 3164 if (start == MAP_FAILED) { 3165 start = NULL; 3166 } else { 3167 if (req_addr != NULL) { 3168 if (start != req_addr) { 3169 ::munmap(start, extra_size); 3170 start = NULL; 3171 } 3172 } else { 3173 char* const start_aligned = align_up(start, alignment); 3174 char* const end_aligned = start_aligned + bytes; 3175 char* const end = start + extra_size; 3176 if (start_aligned > start) { 3177 ::munmap(start, start_aligned - start); 3178 } 3179 if (end_aligned < end) { 3180 ::munmap(end_aligned, end - end_aligned); 3181 } 3182 start = start_aligned; 3183 } 3184 } 3185 return start; 3186 } 3187 3188 static int anon_munmap(char * addr, size_t size) { 3189 return ::munmap(addr, size) == 0; 3190 } 3191 3192 char* os::pd_reserve_memory(size_t bytes, char* requested_addr, 3193 size_t alignment_hint) { 3194 return anon_mmap(requested_addr, bytes, (requested_addr != NULL)); 3195 } 3196 3197 bool os::pd_release_memory(char* addr, size_t size) { 3198 return anon_munmap(addr, size); 3199 } 3200 3201 static bool linux_mprotect(char* addr, size_t size, int prot) { 3202 // Linux wants the mprotect address argument to be page aligned. 3203 char* bottom = (char*)align_down((intptr_t)addr, os::Linux::page_size()); 3204 3205 // According to SUSv3, mprotect() should only be used with mappings 3206 // established by mmap(), and mmap() always maps whole pages. Unaligned 3207 // 'addr' likely indicates problem in the VM (e.g. trying to change 3208 // protection of malloc'ed or statically allocated memory). Check the 3209 // caller if you hit this assert. 3210 assert(addr == bottom, "sanity check"); 3211 3212 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Linux::page_size()); 3213 return ::mprotect(bottom, size, prot) == 0; 3214 } 3215 3216 // Set protections specified 3217 bool os::protect_memory(char* addr, size_t bytes, ProtType prot, 3218 bool is_committed) { 3219 unsigned int p = 0; 3220 switch (prot) { 3221 case MEM_PROT_NONE: p = PROT_NONE; break; 3222 case MEM_PROT_READ: p = PROT_READ; break; 3223 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break; 3224 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break; 3225 default: 3226 ShouldNotReachHere(); 3227 } 3228 // is_committed is unused. 3229 return linux_mprotect(addr, bytes, p); 3230 } 3231 3232 bool os::guard_memory(char* addr, size_t size) { 3233 return linux_mprotect(addr, size, PROT_NONE); 3234 } 3235 3236 bool os::unguard_memory(char* addr, size_t size) { 3237 return linux_mprotect(addr, size, PROT_READ|PROT_WRITE); 3238 } 3239 3240 bool os::Linux::transparent_huge_pages_sanity_check(bool warn, 3241 size_t page_size) { 3242 bool result = false; 3243 void *p = mmap(NULL, page_size * 2, PROT_READ|PROT_WRITE, 3244 MAP_ANONYMOUS|MAP_PRIVATE, 3245 -1, 0); 3246 if (p != MAP_FAILED) { 3247 void *aligned_p = align_up(p, page_size); 3248 3249 result = madvise(aligned_p, page_size, MADV_HUGEPAGE) == 0; 3250 3251 munmap(p, page_size * 2); 3252 } 3253 3254 if (warn && !result) { 3255 warning("TransparentHugePages is not supported by the operating system."); 3256 } 3257 3258 return result; 3259 } 3260 3261 bool os::Linux::hugetlbfs_sanity_check(bool warn, size_t page_size) { 3262 bool result = false; 3263 void *p = mmap(NULL, page_size, PROT_READ|PROT_WRITE, 3264 MAP_ANONYMOUS|MAP_PRIVATE|MAP_HUGETLB, 3265 -1, 0); 3266 3267 if (p != MAP_FAILED) { 3268 // We don't know if this really is a huge page or not. 3269 FILE *fp = fopen("/proc/self/maps", "r"); 3270 if (fp) { 3271 while (!feof(fp)) { 3272 char chars[257]; 3273 long x = 0; 3274 if (fgets(chars, sizeof(chars), fp)) { 3275 if (sscanf(chars, "%lx-%*x", &x) == 1 3276 && x == (long)p) { 3277 if (strstr (chars, "hugepage")) { 3278 result = true; 3279 break; 3280 } 3281 } 3282 } 3283 } 3284 fclose(fp); 3285 } 3286 munmap(p, page_size); 3287 } 3288 3289 if (warn && !result) { 3290 warning("HugeTLBFS is not supported by the operating system."); 3291 } 3292 3293 return result; 3294 } 3295 3296 // Set the coredump_filter bits to include largepages in core dump (bit 6) 3297 // 3298 // From the coredump_filter documentation: 3299 // 3300 // - (bit 0) anonymous private memory 3301 // - (bit 1) anonymous shared memory 3302 // - (bit 2) file-backed private memory 3303 // - (bit 3) file-backed shared memory 3304 // - (bit 4) ELF header pages in file-backed private memory areas (it is 3305 // effective only if the bit 2 is cleared) 3306 // - (bit 5) hugetlb private memory 3307 // - (bit 6) hugetlb shared memory 3308 // 3309 static void set_coredump_filter(void) { 3310 FILE *f; 3311 long cdm; 3312 3313 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) { 3314 return; 3315 } 3316 3317 if (fscanf(f, "%lx", &cdm) != 1) { 3318 fclose(f); 3319 return; 3320 } 3321 3322 rewind(f); 3323 3324 if ((cdm & LARGEPAGES_BIT) == 0) { 3325 cdm |= LARGEPAGES_BIT; 3326 fprintf(f, "%#lx", cdm); 3327 } 3328 3329 fclose(f); 3330 } 3331 3332 // Large page support 3333 3334 static size_t _large_page_size = 0; 3335 3336 size_t os::Linux::find_large_page_size() { 3337 size_t large_page_size = 0; 3338 3339 // large_page_size on Linux is used to round up heap size. x86 uses either 3340 // 2M or 4M page, depending on whether PAE (Physical Address Extensions) 3341 // mode is enabled. AMD64/EM64T uses 2M page in 64bit mode. IA64 can use 3342 // page as large as 256M. 3343 // 3344 // Here we try to figure out page size by parsing /proc/meminfo and looking 3345 // for a line with the following format: 3346 // Hugepagesize: 2048 kB 3347 // 3348 // If we can't determine the value (e.g. /proc is not mounted, or the text 3349 // format has been changed), we'll use the largest page size supported by 3350 // the processor. 3351 3352 #ifndef ZERO 3353 large_page_size = 3354 AARCH64_ONLY(2 * M) 3355 AMD64_ONLY(2 * M) 3356 ARM32_ONLY(2 * M) 3357 IA32_ONLY(4 * M) 3358 IA64_ONLY(256 * M) 3359 PPC_ONLY(4 * M) 3360 S390_ONLY(1 * M) 3361 SPARC_ONLY(4 * M); 3362 #endif // ZERO 3363 3364 FILE *fp = fopen("/proc/meminfo", "r"); 3365 if (fp) { 3366 while (!feof(fp)) { 3367 int x = 0; 3368 char buf[16]; 3369 if (fscanf(fp, "Hugepagesize: %d", &x) == 1) { 3370 if (x && fgets(buf, sizeof(buf), fp) && strcmp(buf, " kB\n") == 0) { 3371 large_page_size = x * K; 3372 break; 3373 } 3374 } else { 3375 // skip to next line 3376 for (;;) { 3377 int ch = fgetc(fp); 3378 if (ch == EOF || ch == (int)'\n') break; 3379 } 3380 } 3381 } 3382 fclose(fp); 3383 } 3384 3385 if (!FLAG_IS_DEFAULT(LargePageSizeInBytes) && LargePageSizeInBytes != large_page_size) { 3386 warning("Setting LargePageSizeInBytes has no effect on this OS. Large page size is " 3387 SIZE_FORMAT "%s.", byte_size_in_proper_unit(large_page_size), 3388 proper_unit_for_byte_size(large_page_size)); 3389 } 3390 3391 return large_page_size; 3392 } 3393 3394 size_t os::Linux::setup_large_page_size() { 3395 _large_page_size = Linux::find_large_page_size(); 3396 const size_t default_page_size = (size_t)Linux::page_size(); 3397 if (_large_page_size > default_page_size) { 3398 _page_sizes[0] = _large_page_size; 3399 _page_sizes[1] = default_page_size; 3400 _page_sizes[2] = 0; 3401 } 3402 3403 return _large_page_size; 3404 } 3405 3406 bool os::Linux::setup_large_page_type(size_t page_size) { 3407 if (FLAG_IS_DEFAULT(UseHugeTLBFS) && 3408 FLAG_IS_DEFAULT(UseSHM) && 3409 FLAG_IS_DEFAULT(UseTransparentHugePages)) { 3410 3411 // The type of large pages has not been specified by the user. 3412 3413 // Try UseHugeTLBFS and then UseSHM. 3414 UseHugeTLBFS = UseSHM = true; 3415 3416 // Don't try UseTransparentHugePages since there are known 3417 // performance issues with it turned on. This might change in the future. 3418 UseTransparentHugePages = false; 3419 } 3420 3421 if (UseTransparentHugePages) { 3422 bool warn_on_failure = !FLAG_IS_DEFAULT(UseTransparentHugePages); 3423 if (transparent_huge_pages_sanity_check(warn_on_failure, page_size)) { 3424 UseHugeTLBFS = false; 3425 UseSHM = false; 3426 return true; 3427 } 3428 UseTransparentHugePages = false; 3429 } 3430 3431 if (UseHugeTLBFS) { 3432 bool warn_on_failure = !FLAG_IS_DEFAULT(UseHugeTLBFS); 3433 if (hugetlbfs_sanity_check(warn_on_failure, page_size)) { 3434 UseSHM = false; 3435 return true; 3436 } 3437 UseHugeTLBFS = false; 3438 } 3439 3440 return UseSHM; 3441 } 3442 3443 void os::large_page_init() { 3444 if (!UseLargePages && 3445 !UseTransparentHugePages && 3446 !UseHugeTLBFS && 3447 !UseSHM) { 3448 // Not using large pages. 3449 return; 3450 } 3451 3452 if (!FLAG_IS_DEFAULT(UseLargePages) && !UseLargePages) { 3453 // The user explicitly turned off large pages. 3454 // Ignore the rest of the large pages flags. 3455 UseTransparentHugePages = false; 3456 UseHugeTLBFS = false; 3457 UseSHM = false; 3458 return; 3459 } 3460 3461 size_t large_page_size = Linux::setup_large_page_size(); 3462 UseLargePages = Linux::setup_large_page_type(large_page_size); 3463 3464 set_coredump_filter(); 3465 } 3466 3467 #ifndef SHM_HUGETLB 3468 #define SHM_HUGETLB 04000 3469 #endif 3470 3471 #define shm_warning_format(format, ...) \ 3472 do { \ 3473 if (UseLargePages && \ 3474 (!FLAG_IS_DEFAULT(UseLargePages) || \ 3475 !FLAG_IS_DEFAULT(UseSHM) || \ 3476 !FLAG_IS_DEFAULT(LargePageSizeInBytes))) { \ 3477 warning(format, __VA_ARGS__); \ 3478 } \ 3479 } while (0) 3480 3481 #define shm_warning(str) shm_warning_format("%s", str) 3482 3483 #define shm_warning_with_errno(str) \ 3484 do { \ 3485 int err = errno; \ 3486 shm_warning_format(str " (error = %d)", err); \ 3487 } while (0) 3488 3489 static char* shmat_with_alignment(int shmid, size_t bytes, size_t alignment) { 3490 assert(is_aligned(bytes, alignment), "Must be divisible by the alignment"); 3491 3492 if (!is_aligned(alignment, SHMLBA)) { 3493 assert(false, "Code below assumes that alignment is at least SHMLBA aligned"); 3494 return NULL; 3495 } 3496 3497 // To ensure that we get 'alignment' aligned memory from shmat, 3498 // we pre-reserve aligned virtual memory and then attach to that. 3499 3500 char* pre_reserved_addr = anon_mmap_aligned(bytes, alignment, NULL); 3501 if (pre_reserved_addr == NULL) { 3502 // Couldn't pre-reserve aligned memory. 3503 shm_warning("Failed to pre-reserve aligned memory for shmat."); 3504 return NULL; 3505 } 3506 3507 // SHM_REMAP is needed to allow shmat to map over an existing mapping. 3508 char* addr = (char*)shmat(shmid, pre_reserved_addr, SHM_REMAP); 3509 3510 if ((intptr_t)addr == -1) { 3511 int err = errno; 3512 shm_warning_with_errno("Failed to attach shared memory."); 3513 3514 assert(err != EACCES, "Unexpected error"); 3515 assert(err != EIDRM, "Unexpected error"); 3516 assert(err != EINVAL, "Unexpected error"); 3517 3518 // Since we don't know if the kernel unmapped the pre-reserved memory area 3519 // we can't unmap it, since that would potentially unmap memory that was 3520 // mapped from other threads. 3521 return NULL; 3522 } 3523 3524 return addr; 3525 } 3526 3527 static char* shmat_at_address(int shmid, char* req_addr) { 3528 if (!is_aligned(req_addr, SHMLBA)) { 3529 assert(false, "Requested address needs to be SHMLBA aligned"); 3530 return NULL; 3531 } 3532 3533 char* addr = (char*)shmat(shmid, req_addr, 0); 3534 3535 if ((intptr_t)addr == -1) { 3536 shm_warning_with_errno("Failed to attach shared memory."); 3537 return NULL; 3538 } 3539 3540 return addr; 3541 } 3542 3543 static char* shmat_large_pages(int shmid, size_t bytes, size_t alignment, char* req_addr) { 3544 // If a req_addr has been provided, we assume that the caller has already aligned the address. 3545 if (req_addr != NULL) { 3546 assert(is_aligned(req_addr, os::large_page_size()), "Must be divisible by the large page size"); 3547 assert(is_aligned(req_addr, alignment), "Must be divisible by given alignment"); 3548 return shmat_at_address(shmid, req_addr); 3549 } 3550 3551 // Since shmid has been setup with SHM_HUGETLB, shmat will automatically 3552 // return large page size aligned memory addresses when req_addr == NULL. 3553 // However, if the alignment is larger than the large page size, we have 3554 // to manually ensure that the memory returned is 'alignment' aligned. 3555 if (alignment > os::large_page_size()) { 3556 assert(is_aligned(alignment, os::large_page_size()), "Must be divisible by the large page size"); 3557 return shmat_with_alignment(shmid, bytes, alignment); 3558 } else { 3559 return shmat_at_address(shmid, NULL); 3560 } 3561 } 3562 3563 char* os::Linux::reserve_memory_special_shm(size_t bytes, size_t alignment, 3564 char* req_addr, bool exec) { 3565 // "exec" is passed in but not used. Creating the shared image for 3566 // the code cache doesn't have an SHM_X executable permission to check. 3567 assert(UseLargePages && UseSHM, "only for SHM large pages"); 3568 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3569 assert(is_aligned(req_addr, alignment), "Unaligned address"); 3570 3571 if (!is_aligned(bytes, os::large_page_size())) { 3572 return NULL; // Fallback to small pages. 3573 } 3574 3575 // Create a large shared memory region to attach to based on size. 3576 // Currently, size is the total size of the heap. 3577 int shmid = shmget(IPC_PRIVATE, bytes, SHM_HUGETLB|IPC_CREAT|SHM_R|SHM_W); 3578 if (shmid == -1) { 3579 // Possible reasons for shmget failure: 3580 // 1. shmmax is too small for Java heap. 3581 // > check shmmax value: cat /proc/sys/kernel/shmmax 3582 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax 3583 // 2. not enough large page memory. 3584 // > check available large pages: cat /proc/meminfo 3585 // > increase amount of large pages: 3586 // echo new_value > /proc/sys/vm/nr_hugepages 3587 // Note 1: different Linux may use different name for this property, 3588 // e.g. on Redhat AS-3 it is "hugetlb_pool". 3589 // Note 2: it's possible there's enough physical memory available but 3590 // they are so fragmented after a long run that they can't 3591 // coalesce into large pages. Try to reserve large pages when 3592 // the system is still "fresh". 3593 shm_warning_with_errno("Failed to reserve shared memory."); 3594 return NULL; 3595 } 3596 3597 // Attach to the region. 3598 char* addr = shmat_large_pages(shmid, bytes, alignment, req_addr); 3599 3600 // Remove shmid. If shmat() is successful, the actual shared memory segment 3601 // will be deleted when it's detached by shmdt() or when the process 3602 // terminates. If shmat() is not successful this will remove the shared 3603 // segment immediately. 3604 shmctl(shmid, IPC_RMID, NULL); 3605 3606 return addr; 3607 } 3608 3609 static void warn_on_large_pages_failure(char* req_addr, size_t bytes, 3610 int error) { 3611 assert(error == ENOMEM, "Only expect to fail if no memory is available"); 3612 3613 bool warn_on_failure = UseLargePages && 3614 (!FLAG_IS_DEFAULT(UseLargePages) || 3615 !FLAG_IS_DEFAULT(UseHugeTLBFS) || 3616 !FLAG_IS_DEFAULT(LargePageSizeInBytes)); 3617 3618 if (warn_on_failure) { 3619 char msg[128]; 3620 jio_snprintf(msg, sizeof(msg), "Failed to reserve large pages memory req_addr: " 3621 PTR_FORMAT " bytes: " SIZE_FORMAT " (errno = %d).", req_addr, bytes, error); 3622 warning("%s", msg); 3623 } 3624 } 3625 3626 char* os::Linux::reserve_memory_special_huge_tlbfs_only(size_t bytes, 3627 char* req_addr, 3628 bool exec) { 3629 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3630 assert(is_aligned(bytes, os::large_page_size()), "Unaligned size"); 3631 assert(is_aligned(req_addr, os::large_page_size()), "Unaligned address"); 3632 3633 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3634 char* addr = (char*)::mmap(req_addr, bytes, prot, 3635 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, 3636 -1, 0); 3637 3638 if (addr == MAP_FAILED) { 3639 warn_on_large_pages_failure(req_addr, bytes, errno); 3640 return NULL; 3641 } 3642 3643 assert(is_aligned(addr, os::large_page_size()), "Must be"); 3644 3645 return addr; 3646 } 3647 3648 // Reserve memory using mmap(MAP_HUGETLB). 3649 // - bytes shall be a multiple of alignment. 3650 // - req_addr can be NULL. If not NULL, it must be a multiple of alignment. 3651 // - alignment sets the alignment at which memory shall be allocated. 3652 // It must be a multiple of allocation granularity. 3653 // Returns address of memory or NULL. If req_addr was not NULL, will only return 3654 // req_addr or NULL. 3655 char* os::Linux::reserve_memory_special_huge_tlbfs_mixed(size_t bytes, 3656 size_t alignment, 3657 char* req_addr, 3658 bool exec) { 3659 size_t large_page_size = os::large_page_size(); 3660 assert(bytes >= large_page_size, "Shouldn't allocate large pages for small sizes"); 3661 3662 assert(is_aligned(req_addr, alignment), "Must be"); 3663 assert(is_aligned(bytes, alignment), "Must be"); 3664 3665 // First reserve - but not commit - the address range in small pages. 3666 char* const start = anon_mmap_aligned(bytes, alignment, req_addr); 3667 3668 if (start == NULL) { 3669 return NULL; 3670 } 3671 3672 assert(is_aligned(start, alignment), "Must be"); 3673 3674 char* end = start + bytes; 3675 3676 // Find the regions of the allocated chunk that can be promoted to large pages. 3677 char* lp_start = align_up(start, large_page_size); 3678 char* lp_end = align_down(end, large_page_size); 3679 3680 size_t lp_bytes = lp_end - lp_start; 3681 3682 assert(is_aligned(lp_bytes, large_page_size), "Must be"); 3683 3684 if (lp_bytes == 0) { 3685 // The mapped region doesn't even span the start and the end of a large page. 3686 // Fall back to allocate a non-special area. 3687 ::munmap(start, end - start); 3688 return NULL; 3689 } 3690 3691 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE; 3692 3693 void* result; 3694 3695 // Commit small-paged leading area. 3696 if (start != lp_start) { 3697 result = ::mmap(start, lp_start - start, prot, 3698 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3699 -1, 0); 3700 if (result == MAP_FAILED) { 3701 ::munmap(lp_start, end - lp_start); 3702 return NULL; 3703 } 3704 } 3705 3706 // Commit large-paged area. 3707 result = ::mmap(lp_start, lp_bytes, prot, 3708 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED|MAP_HUGETLB, 3709 -1, 0); 3710 if (result == MAP_FAILED) { 3711 warn_on_large_pages_failure(lp_start, lp_bytes, errno); 3712 // If the mmap above fails, the large pages region will be unmapped and we 3713 // have regions before and after with small pages. Release these regions. 3714 // 3715 // | mapped | unmapped | mapped | 3716 // ^ ^ ^ ^ 3717 // start lp_start lp_end end 3718 // 3719 ::munmap(start, lp_start - start); 3720 ::munmap(lp_end, end - lp_end); 3721 return NULL; 3722 } 3723 3724 // Commit small-paged trailing area. 3725 if (lp_end != end) { 3726 result = ::mmap(lp_end, end - lp_end, prot, 3727 MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, 3728 -1, 0); 3729 if (result == MAP_FAILED) { 3730 ::munmap(start, lp_end - start); 3731 return NULL; 3732 } 3733 } 3734 3735 return start; 3736 } 3737 3738 char* os::Linux::reserve_memory_special_huge_tlbfs(size_t bytes, 3739 size_t alignment, 3740 char* req_addr, 3741 bool exec) { 3742 assert(UseLargePages && UseHugeTLBFS, "only for Huge TLBFS large pages"); 3743 assert(is_aligned(req_addr, alignment), "Must be"); 3744 assert(is_aligned(alignment, os::vm_allocation_granularity()), "Must be"); 3745 assert(is_power_of_2(os::large_page_size()), "Must be"); 3746 assert(bytes >= os::large_page_size(), "Shouldn't allocate large pages for small sizes"); 3747 3748 if (is_aligned(bytes, os::large_page_size()) && alignment <= os::large_page_size()) { 3749 return reserve_memory_special_huge_tlbfs_only(bytes, req_addr, exec); 3750 } else { 3751 return reserve_memory_special_huge_tlbfs_mixed(bytes, alignment, req_addr, exec); 3752 } 3753 } 3754 3755 char* os::reserve_memory_special(size_t bytes, size_t alignment, 3756 char* req_addr, bool exec) { 3757 assert(UseLargePages, "only for large pages"); 3758 3759 char* addr; 3760 if (UseSHM) { 3761 addr = os::Linux::reserve_memory_special_shm(bytes, alignment, req_addr, exec); 3762 } else { 3763 assert(UseHugeTLBFS, "must be"); 3764 addr = os::Linux::reserve_memory_special_huge_tlbfs(bytes, alignment, req_addr, exec); 3765 } 3766 3767 if (addr != NULL) { 3768 if (UseNUMAInterleaving) { 3769 numa_make_global(addr, bytes); 3770 } 3771 3772 // The memory is committed 3773 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC); 3774 } 3775 3776 return addr; 3777 } 3778 3779 bool os::Linux::release_memory_special_shm(char* base, size_t bytes) { 3780 // detaching the SHM segment will also delete it, see reserve_memory_special_shm() 3781 return shmdt(base) == 0; 3782 } 3783 3784 bool os::Linux::release_memory_special_huge_tlbfs(char* base, size_t bytes) { 3785 return pd_release_memory(base, bytes); 3786 } 3787 3788 bool os::release_memory_special(char* base, size_t bytes) { 3789 bool res; 3790 if (MemTracker::tracking_level() > NMT_minimal) { 3791 Tracker tkr = MemTracker::get_virtual_memory_release_tracker(); 3792 res = os::Linux::release_memory_special_impl(base, bytes); 3793 if (res) { 3794 tkr.record((address)base, bytes); 3795 } 3796 3797 } else { 3798 res = os::Linux::release_memory_special_impl(base, bytes); 3799 } 3800 return res; 3801 } 3802 3803 bool os::Linux::release_memory_special_impl(char* base, size_t bytes) { 3804 assert(UseLargePages, "only for large pages"); 3805 bool res; 3806 3807 if (UseSHM) { 3808 res = os::Linux::release_memory_special_shm(base, bytes); 3809 } else { 3810 assert(UseHugeTLBFS, "must be"); 3811 res = os::Linux::release_memory_special_huge_tlbfs(base, bytes); 3812 } 3813 return res; 3814 } 3815 3816 size_t os::large_page_size() { 3817 return _large_page_size; 3818 } 3819 3820 // With SysV SHM the entire memory region must be allocated as shared 3821 // memory. 3822 // HugeTLBFS allows application to commit large page memory on demand. 3823 // However, when committing memory with HugeTLBFS fails, the region 3824 // that was supposed to be committed will lose the old reservation 3825 // and allow other threads to steal that memory region. Because of this 3826 // behavior we can't commit HugeTLBFS memory. 3827 bool os::can_commit_large_page_memory() { 3828 return UseTransparentHugePages; 3829 } 3830 3831 bool os::can_execute_large_page_memory() { 3832 return UseTransparentHugePages || UseHugeTLBFS; 3833 } 3834 3835 // Reserve memory at an arbitrary address, only if that area is 3836 // available (and not reserved for something else). 3837 3838 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) { 3839 const int max_tries = 10; 3840 char* base[max_tries]; 3841 size_t size[max_tries]; 3842 const size_t gap = 0x000000; 3843 3844 // Assert only that the size is a multiple of the page size, since 3845 // that's all that mmap requires, and since that's all we really know 3846 // about at this low abstraction level. If we need higher alignment, 3847 // we can either pass an alignment to this method or verify alignment 3848 // in one of the methods further up the call chain. See bug 5044738. 3849 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block"); 3850 3851 // Repeatedly allocate blocks until the block is allocated at the 3852 // right spot. 3853 3854 // Linux mmap allows caller to pass an address as hint; give it a try first, 3855 // if kernel honors the hint then we can return immediately. 3856 char * addr = anon_mmap(requested_addr, bytes, false); 3857 if (addr == requested_addr) { 3858 return requested_addr; 3859 } 3860 3861 if (addr != NULL) { 3862 // mmap() is successful but it fails to reserve at the requested address 3863 anon_munmap(addr, bytes); 3864 } 3865 3866 int i; 3867 for (i = 0; i < max_tries; ++i) { 3868 base[i] = reserve_memory(bytes); 3869 3870 if (base[i] != NULL) { 3871 // Is this the block we wanted? 3872 if (base[i] == requested_addr) { 3873 size[i] = bytes; 3874 break; 3875 } 3876 3877 // Does this overlap the block we wanted? Give back the overlapped 3878 // parts and try again. 3879 3880 ptrdiff_t top_overlap = requested_addr + (bytes + gap) - base[i]; 3881 if (top_overlap >= 0 && (size_t)top_overlap < bytes) { 3882 unmap_memory(base[i], top_overlap); 3883 base[i] += top_overlap; 3884 size[i] = bytes - top_overlap; 3885 } else { 3886 ptrdiff_t bottom_overlap = base[i] + bytes - requested_addr; 3887 if (bottom_overlap >= 0 && (size_t)bottom_overlap < bytes) { 3888 unmap_memory(requested_addr, bottom_overlap); 3889 size[i] = bytes - bottom_overlap; 3890 } else { 3891 size[i] = bytes; 3892 } 3893 } 3894 } 3895 } 3896 3897 // Give back the unused reserved pieces. 3898 3899 for (int j = 0; j < i; ++j) { 3900 if (base[j] != NULL) { 3901 unmap_memory(base[j], size[j]); 3902 } 3903 } 3904 3905 if (i < max_tries) { 3906 return requested_addr; 3907 } else { 3908 return NULL; 3909 } 3910 } 3911 3912 size_t os::read(int fd, void *buf, unsigned int nBytes) { 3913 return ::read(fd, buf, nBytes); 3914 } 3915 3916 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) { 3917 return ::pread(fd, buf, nBytes, offset); 3918 } 3919 3920 // Short sleep, direct OS call. 3921 // 3922 // Note: certain versions of Linux CFS scheduler (since 2.6.23) do not guarantee 3923 // sched_yield(2) will actually give up the CPU: 3924 // 3925 // * Alone on this pariticular CPU, keeps running. 3926 // * Before the introduction of "skip_buddy" with "compat_yield" disabled 3927 // (pre 2.6.39). 3928 // 3929 // So calling this with 0 is an alternative. 3930 // 3931 void os::naked_short_sleep(jlong ms) { 3932 struct timespec req; 3933 3934 assert(ms < 1000, "Un-interruptable sleep, short time use only"); 3935 req.tv_sec = 0; 3936 if (ms > 0) { 3937 req.tv_nsec = (ms % 1000) * 1000000; 3938 } else { 3939 req.tv_nsec = 1; 3940 } 3941 3942 nanosleep(&req, NULL); 3943 3944 return; 3945 } 3946 3947 // Sleep forever; naked call to OS-specific sleep; use with CAUTION 3948 void os::infinite_sleep() { 3949 while (true) { // sleep forever ... 3950 ::sleep(100); // ... 100 seconds at a time 3951 } 3952 } 3953 3954 // Used to convert frequent JVM_Yield() to nops 3955 bool os::dont_yield() { 3956 return DontYieldALot; 3957 } 3958 3959 void os::naked_yield() { 3960 sched_yield(); 3961 } 3962 3963 //////////////////////////////////////////////////////////////////////////////// 3964 // thread priority support 3965 3966 // Note: Normal Linux applications are run with SCHED_OTHER policy. SCHED_OTHER 3967 // only supports dynamic priority, static priority must be zero. For real-time 3968 // applications, Linux supports SCHED_RR which allows static priority (1-99). 3969 // However, for large multi-threaded applications, SCHED_RR is not only slower 3970 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out 3971 // of 5 runs - Sep 2005). 3972 // 3973 // The following code actually changes the niceness of kernel-thread/LWP. It 3974 // has an assumption that setpriority() only modifies one kernel-thread/LWP, 3975 // not the entire user process, and user level threads are 1:1 mapped to kernel 3976 // threads. It has always been the case, but could change in the future. For 3977 // this reason, the code should not be used as default (ThreadPriorityPolicy=0). 3978 // It is only used when ThreadPriorityPolicy=1 and requires root privilege. 3979 3980 int os::java_to_os_priority[CriticalPriority + 1] = { 3981 19, // 0 Entry should never be used 3982 3983 4, // 1 MinPriority 3984 3, // 2 3985 2, // 3 3986 3987 1, // 4 3988 0, // 5 NormPriority 3989 -1, // 6 3990 3991 -2, // 7 3992 -3, // 8 3993 -4, // 9 NearMaxPriority 3994 3995 -5, // 10 MaxPriority 3996 3997 -5 // 11 CriticalPriority 3998 }; 3999 4000 static int prio_init() { 4001 if (ThreadPriorityPolicy == 1) { 4002 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1 4003 // if effective uid is not root. Perhaps, a more elegant way of doing 4004 // this is to test CAP_SYS_NICE capability, but that will require libcap.so 4005 if (geteuid() != 0) { 4006 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) { 4007 warning("-XX:ThreadPriorityPolicy requires root privilege on Linux"); 4008 } 4009 ThreadPriorityPolicy = 0; 4010 } 4011 } 4012 if (UseCriticalJavaThreadPriority) { 4013 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority]; 4014 } 4015 return 0; 4016 } 4017 4018 OSReturn os::set_native_priority(Thread* thread, int newpri) { 4019 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK; 4020 4021 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri); 4022 return (ret == 0) ? OS_OK : OS_ERR; 4023 } 4024 4025 OSReturn os::get_native_priority(const Thread* const thread, 4026 int *priority_ptr) { 4027 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) { 4028 *priority_ptr = java_to_os_priority[NormPriority]; 4029 return OS_OK; 4030 } 4031 4032 errno = 0; 4033 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id()); 4034 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR); 4035 } 4036 4037 // Hint to the underlying OS that a task switch would not be good. 4038 // Void return because it's a hint and can fail. 4039 void os::hint_no_preempt() {} 4040 4041 //////////////////////////////////////////////////////////////////////////////// 4042 // suspend/resume support 4043 4044 // the low-level signal-based suspend/resume support is a remnant from the 4045 // old VM-suspension that used to be for java-suspension, safepoints etc, 4046 // within hotspot. Now there is a single use-case for this: 4047 // - calling get_thread_pc() on the VMThread by the flat-profiler task 4048 // that runs in the watcher thread. 4049 // The remaining code is greatly simplified from the more general suspension 4050 // code that used to be used. 4051 // 4052 // The protocol is quite simple: 4053 // - suspend: 4054 // - sends a signal to the target thread 4055 // - polls the suspend state of the osthread using a yield loop 4056 // - target thread signal handler (SR_handler) sets suspend state 4057 // and blocks in sigsuspend until continued 4058 // - resume: 4059 // - sets target osthread state to continue 4060 // - sends signal to end the sigsuspend loop in the SR_handler 4061 // 4062 // Note that the SR_lock plays no role in this suspend/resume protocol, 4063 // but is checked for NULL in SR_handler as a thread termination indicator. 4064 4065 static void resume_clear_context(OSThread *osthread) { 4066 osthread->set_ucontext(NULL); 4067 osthread->set_siginfo(NULL); 4068 } 4069 4070 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, 4071 ucontext_t* context) { 4072 osthread->set_ucontext(context); 4073 osthread->set_siginfo(siginfo); 4074 } 4075 4076 // Handler function invoked when a thread's execution is suspended or 4077 // resumed. We have to be careful that only async-safe functions are 4078 // called here (Note: most pthread functions are not async safe and 4079 // should be avoided.) 4080 // 4081 // Note: sigwait() is a more natural fit than sigsuspend() from an 4082 // interface point of view, but sigwait() prevents the signal hander 4083 // from being run. libpthread would get very confused by not having 4084 // its signal handlers run and prevents sigwait()'s use with the 4085 // mutex granting granting signal. 4086 // 4087 // Currently only ever called on the VMThread and JavaThreads (PC sampling) 4088 // 4089 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) { 4090 // Save and restore errno to avoid confusing native code with EINTR 4091 // after sigsuspend. 4092 int old_errno = errno; 4093 4094 Thread* thread = Thread::current_or_null_safe(); 4095 assert(thread != NULL, "Missing current thread in SR_handler"); 4096 4097 // On some systems we have seen signal delivery get "stuck" until the signal 4098 // mask is changed as part of thread termination. Check that the current thread 4099 // has not already terminated (via SR_lock()) - else the following assertion 4100 // will fail because the thread is no longer a JavaThread as the ~JavaThread 4101 // destructor has completed. 4102 4103 if (thread->SR_lock() == NULL) { 4104 return; 4105 } 4106 4107 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread"); 4108 4109 OSThread* osthread = thread->osthread(); 4110 4111 os::SuspendResume::State current = osthread->sr.state(); 4112 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) { 4113 suspend_save_context(osthread, siginfo, context); 4114 4115 // attempt to switch the state, we assume we had a SUSPEND_REQUEST 4116 os::SuspendResume::State state = osthread->sr.suspended(); 4117 if (state == os::SuspendResume::SR_SUSPENDED) { 4118 sigset_t suspend_set; // signals for sigsuspend() 4119 sigemptyset(&suspend_set); 4120 // get current set of blocked signals and unblock resume signal 4121 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set); 4122 sigdelset(&suspend_set, SR_signum); 4123 4124 sr_semaphore.signal(); 4125 // wait here until we are resumed 4126 while (1) { 4127 sigsuspend(&suspend_set); 4128 4129 os::SuspendResume::State result = osthread->sr.running(); 4130 if (result == os::SuspendResume::SR_RUNNING) { 4131 sr_semaphore.signal(); 4132 break; 4133 } 4134 } 4135 4136 } else if (state == os::SuspendResume::SR_RUNNING) { 4137 // request was cancelled, continue 4138 } else { 4139 ShouldNotReachHere(); 4140 } 4141 4142 resume_clear_context(osthread); 4143 } else if (current == os::SuspendResume::SR_RUNNING) { 4144 // request was cancelled, continue 4145 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) { 4146 // ignore 4147 } else { 4148 // ignore 4149 } 4150 4151 errno = old_errno; 4152 } 4153 4154 static int SR_initialize() { 4155 struct sigaction act; 4156 char *s; 4157 4158 // Get signal number to use for suspend/resume 4159 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) { 4160 int sig = ::strtol(s, 0, 10); 4161 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769. 4162 sig < NSIG) { // Must be legal signal and fit into sigflags[]. 4163 SR_signum = sig; 4164 } else { 4165 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.", 4166 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum); 4167 } 4168 } 4169 4170 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS, 4171 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769"); 4172 4173 sigemptyset(&SR_sigset); 4174 sigaddset(&SR_sigset, SR_signum); 4175 4176 // Set up signal handler for suspend/resume 4177 act.sa_flags = SA_RESTART|SA_SIGINFO; 4178 act.sa_handler = (void (*)(int)) SR_handler; 4179 4180 // SR_signum is blocked by default. 4181 // 4528190 - We also need to block pthread restart signal (32 on all 4182 // supported Linux platforms). Note that LinuxThreads need to block 4183 // this signal for all threads to work properly. So we don't have 4184 // to use hard-coded signal number when setting up the mask. 4185 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask); 4186 4187 if (sigaction(SR_signum, &act, 0) == -1) { 4188 return -1; 4189 } 4190 4191 // Save signal flag 4192 os::Linux::set_our_sigflags(SR_signum, act.sa_flags); 4193 return 0; 4194 } 4195 4196 static int sr_notify(OSThread* osthread) { 4197 int status = pthread_kill(osthread->pthread_id(), SR_signum); 4198 assert_status(status == 0, status, "pthread_kill"); 4199 return status; 4200 } 4201 4202 // "Randomly" selected value for how long we want to spin 4203 // before bailing out on suspending a thread, also how often 4204 // we send a signal to a thread we want to resume 4205 static const int RANDOMLY_LARGE_INTEGER = 1000000; 4206 static const int RANDOMLY_LARGE_INTEGER2 = 100; 4207 4208 // returns true on success and false on error - really an error is fatal 4209 // but this seems the normal response to library errors 4210 static bool do_suspend(OSThread* osthread) { 4211 assert(osthread->sr.is_running(), "thread should be running"); 4212 assert(!sr_semaphore.trywait(), "semaphore has invalid state"); 4213 4214 // mark as suspended and send signal 4215 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) { 4216 // failed to switch, state wasn't running? 4217 ShouldNotReachHere(); 4218 return false; 4219 } 4220 4221 if (sr_notify(osthread) != 0) { 4222 ShouldNotReachHere(); 4223 } 4224 4225 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED 4226 while (true) { 4227 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 4228 break; 4229 } else { 4230 // timeout 4231 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend(); 4232 if (cancelled == os::SuspendResume::SR_RUNNING) { 4233 return false; 4234 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) { 4235 // make sure that we consume the signal on the semaphore as well 4236 sr_semaphore.wait(); 4237 break; 4238 } else { 4239 ShouldNotReachHere(); 4240 return false; 4241 } 4242 } 4243 } 4244 4245 guarantee(osthread->sr.is_suspended(), "Must be suspended"); 4246 return true; 4247 } 4248 4249 static void do_resume(OSThread* osthread) { 4250 assert(osthread->sr.is_suspended(), "thread should be suspended"); 4251 assert(!sr_semaphore.trywait(), "invalid semaphore state"); 4252 4253 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) { 4254 // failed to switch to WAKEUP_REQUEST 4255 ShouldNotReachHere(); 4256 return; 4257 } 4258 4259 while (true) { 4260 if (sr_notify(osthread) == 0) { 4261 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) { 4262 if (osthread->sr.is_running()) { 4263 return; 4264 } 4265 } 4266 } else { 4267 ShouldNotReachHere(); 4268 } 4269 } 4270 4271 guarantee(osthread->sr.is_running(), "Must be running!"); 4272 } 4273 4274 /////////////////////////////////////////////////////////////////////////////////// 4275 // signal handling (except suspend/resume) 4276 4277 // This routine may be used by user applications as a "hook" to catch signals. 4278 // The user-defined signal handler must pass unrecognized signals to this 4279 // routine, and if it returns true (non-zero), then the signal handler must 4280 // return immediately. If the flag "abort_if_unrecognized" is true, then this 4281 // routine will never retun false (zero), but instead will execute a VM panic 4282 // routine kill the process. 4283 // 4284 // If this routine returns false, it is OK to call it again. This allows 4285 // the user-defined signal handler to perform checks either before or after 4286 // the VM performs its own checks. Naturally, the user code would be making 4287 // a serious error if it tried to handle an exception (such as a null check 4288 // or breakpoint) that the VM was generating for its own correct operation. 4289 // 4290 // This routine may recognize any of the following kinds of signals: 4291 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1. 4292 // It should be consulted by handlers for any of those signals. 4293 // 4294 // The caller of this routine must pass in the three arguments supplied 4295 // to the function referred to in the "sa_sigaction" (not the "sa_handler") 4296 // field of the structure passed to sigaction(). This routine assumes that 4297 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART. 4298 // 4299 // Note that the VM will print warnings if it detects conflicting signal 4300 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers". 4301 // 4302 extern "C" JNIEXPORT int JVM_handle_linux_signal(int signo, 4303 siginfo_t* siginfo, 4304 void* ucontext, 4305 int abort_if_unrecognized); 4306 4307 void signalHandler(int sig, siginfo_t* info, void* uc) { 4308 assert(info != NULL && uc != NULL, "it must be old kernel"); 4309 int orig_errno = errno; // Preserve errno value over signal handler. 4310 JVM_handle_linux_signal(sig, info, uc, true); 4311 errno = orig_errno; 4312 } 4313 4314 4315 // This boolean allows users to forward their own non-matching signals 4316 // to JVM_handle_linux_signal, harmlessly. 4317 bool os::Linux::signal_handlers_are_installed = false; 4318 4319 // For signal-chaining 4320 struct sigaction sigact[NSIG]; 4321 uint64_t sigs = 0; 4322 #if (64 < NSIG-1) 4323 #error "Not all signals can be encoded in sigs. Adapt its type!" 4324 #endif 4325 bool os::Linux::libjsig_is_loaded = false; 4326 typedef struct sigaction *(*get_signal_t)(int); 4327 get_signal_t os::Linux::get_signal_action = NULL; 4328 4329 struct sigaction* os::Linux::get_chained_signal_action(int sig) { 4330 struct sigaction *actp = NULL; 4331 4332 if (libjsig_is_loaded) { 4333 // Retrieve the old signal handler from libjsig 4334 actp = (*get_signal_action)(sig); 4335 } 4336 if (actp == NULL) { 4337 // Retrieve the preinstalled signal handler from jvm 4338 actp = get_preinstalled_handler(sig); 4339 } 4340 4341 return actp; 4342 } 4343 4344 static bool call_chained_handler(struct sigaction *actp, int sig, 4345 siginfo_t *siginfo, void *context) { 4346 // Call the old signal handler 4347 if (actp->sa_handler == SIG_DFL) { 4348 // It's more reasonable to let jvm treat it as an unexpected exception 4349 // instead of taking the default action. 4350 return false; 4351 } else if (actp->sa_handler != SIG_IGN) { 4352 if ((actp->sa_flags & SA_NODEFER) == 0) { 4353 // automaticlly block the signal 4354 sigaddset(&(actp->sa_mask), sig); 4355 } 4356 4357 sa_handler_t hand = NULL; 4358 sa_sigaction_t sa = NULL; 4359 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0; 4360 // retrieve the chained handler 4361 if (siginfo_flag_set) { 4362 sa = actp->sa_sigaction; 4363 } else { 4364 hand = actp->sa_handler; 4365 } 4366 4367 if ((actp->sa_flags & SA_RESETHAND) != 0) { 4368 actp->sa_handler = SIG_DFL; 4369 } 4370 4371 // try to honor the signal mask 4372 sigset_t oset; 4373 sigemptyset(&oset); 4374 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset); 4375 4376 // call into the chained handler 4377 if (siginfo_flag_set) { 4378 (*sa)(sig, siginfo, context); 4379 } else { 4380 (*hand)(sig); 4381 } 4382 4383 // restore the signal mask 4384 pthread_sigmask(SIG_SETMASK, &oset, NULL); 4385 } 4386 // Tell jvm's signal handler the signal is taken care of. 4387 return true; 4388 } 4389 4390 bool os::Linux::chained_handler(int sig, siginfo_t* siginfo, void* context) { 4391 bool chained = false; 4392 // signal-chaining 4393 if (UseSignalChaining) { 4394 struct sigaction *actp = get_chained_signal_action(sig); 4395 if (actp != NULL) { 4396 chained = call_chained_handler(actp, sig, siginfo, context); 4397 } 4398 } 4399 return chained; 4400 } 4401 4402 struct sigaction* os::Linux::get_preinstalled_handler(int sig) { 4403 if ((((uint64_t)1 << (sig-1)) & sigs) != 0) { 4404 return &sigact[sig]; 4405 } 4406 return NULL; 4407 } 4408 4409 void os::Linux::save_preinstalled_handler(int sig, struct sigaction& oldAct) { 4410 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4411 sigact[sig] = oldAct; 4412 sigs |= (uint64_t)1 << (sig-1); 4413 } 4414 4415 // for diagnostic 4416 int sigflags[NSIG]; 4417 4418 int os::Linux::get_our_sigflags(int sig) { 4419 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4420 return sigflags[sig]; 4421 } 4422 4423 void os::Linux::set_our_sigflags(int sig, int flags) { 4424 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4425 if (sig > 0 && sig < NSIG) { 4426 sigflags[sig] = flags; 4427 } 4428 } 4429 4430 void os::Linux::set_signal_handler(int sig, bool set_installed) { 4431 // Check for overwrite. 4432 struct sigaction oldAct; 4433 sigaction(sig, (struct sigaction*)NULL, &oldAct); 4434 4435 void* oldhand = oldAct.sa_sigaction 4436 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4437 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4438 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) && 4439 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) && 4440 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) { 4441 if (AllowUserSignalHandlers || !set_installed) { 4442 // Do not overwrite; user takes responsibility to forward to us. 4443 return; 4444 } else if (UseSignalChaining) { 4445 // save the old handler in jvm 4446 save_preinstalled_handler(sig, oldAct); 4447 // libjsig also interposes the sigaction() call below and saves the 4448 // old sigaction on it own. 4449 } else { 4450 fatal("Encountered unexpected pre-existing sigaction handler " 4451 "%#lx for signal %d.", (long)oldhand, sig); 4452 } 4453 } 4454 4455 struct sigaction sigAct; 4456 sigfillset(&(sigAct.sa_mask)); 4457 sigAct.sa_handler = SIG_DFL; 4458 if (!set_installed) { 4459 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4460 } else { 4461 sigAct.sa_sigaction = signalHandler; 4462 sigAct.sa_flags = SA_SIGINFO|SA_RESTART; 4463 } 4464 // Save flags, which are set by ours 4465 assert(sig > 0 && sig < NSIG, "vm signal out of expected range"); 4466 sigflags[sig] = sigAct.sa_flags; 4467 4468 int ret = sigaction(sig, &sigAct, &oldAct); 4469 assert(ret == 0, "check"); 4470 4471 void* oldhand2 = oldAct.sa_sigaction 4472 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction) 4473 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler); 4474 assert(oldhand2 == oldhand, "no concurrent signal handler installation"); 4475 } 4476 4477 // install signal handlers for signals that HotSpot needs to 4478 // handle in order to support Java-level exception handling. 4479 4480 void os::Linux::install_signal_handlers() { 4481 if (!signal_handlers_are_installed) { 4482 signal_handlers_are_installed = true; 4483 4484 // signal-chaining 4485 typedef void (*signal_setting_t)(); 4486 signal_setting_t begin_signal_setting = NULL; 4487 signal_setting_t end_signal_setting = NULL; 4488 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4489 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting")); 4490 if (begin_signal_setting != NULL) { 4491 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t, 4492 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting")); 4493 get_signal_action = CAST_TO_FN_PTR(get_signal_t, 4494 dlsym(RTLD_DEFAULT, "JVM_get_signal_action")); 4495 libjsig_is_loaded = true; 4496 assert(UseSignalChaining, "should enable signal-chaining"); 4497 } 4498 if (libjsig_is_loaded) { 4499 // Tell libjsig jvm is setting signal handlers 4500 (*begin_signal_setting)(); 4501 } 4502 4503 set_signal_handler(SIGSEGV, true); 4504 set_signal_handler(SIGPIPE, true); 4505 set_signal_handler(SIGBUS, true); 4506 set_signal_handler(SIGILL, true); 4507 set_signal_handler(SIGFPE, true); 4508 #if defined(PPC64) 4509 set_signal_handler(SIGTRAP, true); 4510 #endif 4511 set_signal_handler(SIGXFSZ, true); 4512 4513 if (libjsig_is_loaded) { 4514 // Tell libjsig jvm finishes setting signal handlers 4515 (*end_signal_setting)(); 4516 } 4517 4518 // We don't activate signal checker if libjsig is in place, we trust ourselves 4519 // and if UserSignalHandler is installed all bets are off. 4520 // Log that signal checking is off only if -verbose:jni is specified. 4521 if (CheckJNICalls) { 4522 if (libjsig_is_loaded) { 4523 if (PrintJNIResolving) { 4524 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled"); 4525 } 4526 check_signals = false; 4527 } 4528 if (AllowUserSignalHandlers) { 4529 if (PrintJNIResolving) { 4530 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled"); 4531 } 4532 check_signals = false; 4533 } 4534 } 4535 } 4536 } 4537 4538 // This is the fastest way to get thread cpu time on Linux. 4539 // Returns cpu time (user+sys) for any thread, not only for current. 4540 // POSIX compliant clocks are implemented in the kernels 2.6.16+. 4541 // It might work on 2.6.10+ with a special kernel/glibc patch. 4542 // For reference, please, see IEEE Std 1003.1-2004: 4543 // http://www.unix.org/single_unix_specification 4544 4545 jlong os::Linux::fast_thread_cpu_time(clockid_t clockid) { 4546 struct timespec tp; 4547 int rc = os::Linux::clock_gettime(clockid, &tp); 4548 assert(rc == 0, "clock_gettime is expected to return 0 code"); 4549 4550 return (tp.tv_sec * NANOSECS_PER_SEC) + tp.tv_nsec; 4551 } 4552 4553 void os::Linux::initialize_os_info() { 4554 assert(_os_version == 0, "OS info already initialized"); 4555 4556 struct utsname _uname; 4557 4558 uint32_t major; 4559 uint32_t minor; 4560 uint32_t fix; 4561 4562 int rc; 4563 4564 // Kernel version is unknown if 4565 // verification below fails. 4566 _os_version = 0x01000000; 4567 4568 rc = uname(&_uname); 4569 if (rc != -1) { 4570 4571 rc = sscanf(_uname.release,"%d.%d.%d", &major, &minor, &fix); 4572 if (rc == 3) { 4573 4574 if (major < 256 && minor < 256 && fix < 256) { 4575 // Kernel version format is as expected, 4576 // set it overriding unknown state. 4577 _os_version = (major << 16) | 4578 (minor << 8 ) | 4579 (fix << 0 ) ; 4580 } 4581 } 4582 } 4583 } 4584 4585 uint32_t os::Linux::os_version() { 4586 assert(_os_version != 0, "not initialized"); 4587 return _os_version & 0x00FFFFFF; 4588 } 4589 4590 bool os::Linux::os_version_is_known() { 4591 assert(_os_version != 0, "not initialized"); 4592 return _os_version & 0x01000000 ? false : true; 4593 } 4594 4595 ///// 4596 // glibc on Linux platform uses non-documented flag 4597 // to indicate, that some special sort of signal 4598 // trampoline is used. 4599 // We will never set this flag, and we should 4600 // ignore this flag in our diagnostic 4601 #ifdef SIGNIFICANT_SIGNAL_MASK 4602 #undef SIGNIFICANT_SIGNAL_MASK 4603 #endif 4604 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000) 4605 4606 static const char* get_signal_handler_name(address handler, 4607 char* buf, int buflen) { 4608 int offset = 0; 4609 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset); 4610 if (found) { 4611 // skip directory names 4612 const char *p1, *p2; 4613 p1 = buf; 4614 size_t len = strlen(os::file_separator()); 4615 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len; 4616 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset); 4617 } else { 4618 jio_snprintf(buf, buflen, PTR_FORMAT, handler); 4619 } 4620 return buf; 4621 } 4622 4623 static void print_signal_handler(outputStream* st, int sig, 4624 char* buf, size_t buflen) { 4625 struct sigaction sa; 4626 4627 sigaction(sig, NULL, &sa); 4628 4629 // See comment for SIGNIFICANT_SIGNAL_MASK define 4630 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4631 4632 st->print("%s: ", os::exception_name(sig, buf, buflen)); 4633 4634 address handler = (sa.sa_flags & SA_SIGINFO) 4635 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction) 4636 : CAST_FROM_FN_PTR(address, sa.sa_handler); 4637 4638 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) { 4639 st->print("SIG_DFL"); 4640 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) { 4641 st->print("SIG_IGN"); 4642 } else { 4643 st->print("[%s]", get_signal_handler_name(handler, buf, buflen)); 4644 } 4645 4646 st->print(", sa_mask[0]="); 4647 os::Posix::print_signal_set_short(st, &sa.sa_mask); 4648 4649 address rh = VMError::get_resetted_sighandler(sig); 4650 // May be, handler was resetted by VMError? 4651 if (rh != NULL) { 4652 handler = rh; 4653 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK; 4654 } 4655 4656 st->print(", sa_flags="); 4657 os::Posix::print_sa_flags(st, sa.sa_flags); 4658 4659 // Check: is it our handler? 4660 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) || 4661 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) { 4662 // It is our signal handler 4663 // check for flags, reset system-used one! 4664 if ((int)sa.sa_flags != os::Linux::get_our_sigflags(sig)) { 4665 st->print( 4666 ", flags was changed from " PTR32_FORMAT ", consider using jsig library", 4667 os::Linux::get_our_sigflags(sig)); 4668 } 4669 } 4670 st->cr(); 4671 } 4672 4673 4674 #define DO_SIGNAL_CHECK(sig) \ 4675 do { \ 4676 if (!sigismember(&check_signal_done, sig)) { \ 4677 os::Linux::check_signal_handler(sig); \ 4678 } \ 4679 } while (0) 4680 4681 // This method is a periodic task to check for misbehaving JNI applications 4682 // under CheckJNI, we can add any periodic checks here 4683 4684 void os::run_periodic_checks() { 4685 if (check_signals == false) return; 4686 4687 // SEGV and BUS if overridden could potentially prevent 4688 // generation of hs*.log in the event of a crash, debugging 4689 // such a case can be very challenging, so we absolutely 4690 // check the following for a good measure: 4691 DO_SIGNAL_CHECK(SIGSEGV); 4692 DO_SIGNAL_CHECK(SIGILL); 4693 DO_SIGNAL_CHECK(SIGFPE); 4694 DO_SIGNAL_CHECK(SIGBUS); 4695 DO_SIGNAL_CHECK(SIGPIPE); 4696 DO_SIGNAL_CHECK(SIGXFSZ); 4697 #if defined(PPC64) 4698 DO_SIGNAL_CHECK(SIGTRAP); 4699 #endif 4700 4701 // ReduceSignalUsage allows the user to override these handlers 4702 // see comments at the very top and jvm_solaris.h 4703 if (!ReduceSignalUsage) { 4704 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL); 4705 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL); 4706 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL); 4707 DO_SIGNAL_CHECK(BREAK_SIGNAL); 4708 } 4709 4710 DO_SIGNAL_CHECK(SR_signum); 4711 } 4712 4713 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *); 4714 4715 static os_sigaction_t os_sigaction = NULL; 4716 4717 void os::Linux::check_signal_handler(int sig) { 4718 char buf[O_BUFLEN]; 4719 address jvmHandler = NULL; 4720 4721 4722 struct sigaction act; 4723 if (os_sigaction == NULL) { 4724 // only trust the default sigaction, in case it has been interposed 4725 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction"); 4726 if (os_sigaction == NULL) return; 4727 } 4728 4729 os_sigaction(sig, (struct sigaction*)NULL, &act); 4730 4731 4732 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK; 4733 4734 address thisHandler = (act.sa_flags & SA_SIGINFO) 4735 ? CAST_FROM_FN_PTR(address, act.sa_sigaction) 4736 : CAST_FROM_FN_PTR(address, act.sa_handler); 4737 4738 4739 switch (sig) { 4740 case SIGSEGV: 4741 case SIGBUS: 4742 case SIGFPE: 4743 case SIGPIPE: 4744 case SIGILL: 4745 case SIGXFSZ: 4746 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler); 4747 break; 4748 4749 case SHUTDOWN1_SIGNAL: 4750 case SHUTDOWN2_SIGNAL: 4751 case SHUTDOWN3_SIGNAL: 4752 case BREAK_SIGNAL: 4753 jvmHandler = (address)user_handler(); 4754 break; 4755 4756 default: 4757 if (sig == SR_signum) { 4758 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler); 4759 } else { 4760 return; 4761 } 4762 break; 4763 } 4764 4765 if (thisHandler != jvmHandler) { 4766 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN)); 4767 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN)); 4768 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN)); 4769 // No need to check this sig any longer 4770 sigaddset(&check_signal_done, sig); 4771 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN 4772 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) { 4773 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell", 4774 exception_name(sig, buf, O_BUFLEN)); 4775 } 4776 } else if(os::Linux::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Linux::get_our_sigflags(sig)) { 4777 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN)); 4778 tty->print("expected:"); 4779 os::Posix::print_sa_flags(tty, os::Linux::get_our_sigflags(sig)); 4780 tty->cr(); 4781 tty->print(" found:"); 4782 os::Posix::print_sa_flags(tty, act.sa_flags); 4783 tty->cr(); 4784 // No need to check this sig any longer 4785 sigaddset(&check_signal_done, sig); 4786 } 4787 4788 // Dump all the signal 4789 if (sigismember(&check_signal_done, sig)) { 4790 print_signal_handlers(tty, buf, O_BUFLEN); 4791 } 4792 } 4793 4794 extern void report_error(char* file_name, int line_no, char* title, 4795 char* format, ...); 4796 4797 // this is called _before_ the most of global arguments have been parsed 4798 void os::init(void) { 4799 char dummy; // used to get a guess on initial stack address 4800 // first_hrtime = gethrtime(); 4801 4802 clock_tics_per_sec = sysconf(_SC_CLK_TCK); 4803 4804 init_random(1234567); 4805 4806 ThreadCritical::initialize(); 4807 4808 Linux::set_page_size(sysconf(_SC_PAGESIZE)); 4809 if (Linux::page_size() == -1) { 4810 fatal("os_linux.cpp: os::init: sysconf failed (%s)", 4811 os::strerror(errno)); 4812 } 4813 init_page_sizes((size_t) Linux::page_size()); 4814 4815 Linux::initialize_system_info(); 4816 4817 Linux::initialize_os_info(); 4818 4819 // main_thread points to the aboriginal thread 4820 Linux::_main_thread = pthread_self(); 4821 4822 Linux::clock_init(); 4823 initial_time_count = javaTimeNanos(); 4824 4825 // retrieve entry point for pthread_setname_np 4826 Linux::_pthread_setname_np = 4827 (int(*)(pthread_t, const char*))dlsym(RTLD_DEFAULT, "pthread_setname_np"); 4828 4829 os::Posix::init(); 4830 } 4831 4832 // To install functions for atexit system call 4833 extern "C" { 4834 static void perfMemory_exit_helper() { 4835 perfMemory_exit(); 4836 } 4837 } 4838 4839 // this is called _after_ the global arguments have been parsed 4840 jint os::init_2(void) { 4841 4842 os::Posix::init_2(); 4843 4844 Linux::fast_thread_clock_init(); 4845 4846 // Allocate a single page and mark it as readable for safepoint polling 4847 address polling_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 4848 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page"); 4849 4850 os::set_polling_page(polling_page); 4851 log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page)); 4852 4853 if (!UseMembar) { 4854 address mem_serialize_page = (address) ::mmap(NULL, Linux::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); 4855 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page"); 4856 os::set_memory_serialize_page(mem_serialize_page); 4857 log_info(os)("Memory Serialize Page address: " INTPTR_FORMAT, p2i(mem_serialize_page)); 4858 } 4859 4860 // initialize suspend/resume support - must do this before signal_sets_init() 4861 if (SR_initialize() != 0) { 4862 perror("SR_initialize failed"); 4863 return JNI_ERR; 4864 } 4865 4866 Linux::signal_sets_init(); 4867 Linux::install_signal_handlers(); 4868 4869 // Check and sets minimum stack sizes against command line options 4870 if (Posix::set_minimum_stack_sizes() == JNI_ERR) { 4871 return JNI_ERR; 4872 } 4873 Linux::capture_initial_stack(JavaThread::stack_size_at_create()); 4874 4875 #if defined(IA32) 4876 workaround_expand_exec_shield_cs_limit(); 4877 #endif 4878 4879 Linux::libpthread_init(); 4880 Linux::sched_getcpu_init(); 4881 log_info(os)("HotSpot is running with %s, %s", 4882 Linux::glibc_version(), Linux::libpthread_version()); 4883 4884 if (UseNUMA) { 4885 if (!Linux::libnuma_init()) { 4886 UseNUMA = false; 4887 } else { 4888 if ((Linux::numa_max_node() < 1)) { 4889 // There's only one node(they start from 0), disable NUMA. 4890 UseNUMA = false; 4891 } 4892 } 4893 // With SHM and HugeTLBFS large pages we cannot uncommit a page, so there's no way 4894 // we can make the adaptive lgrp chunk resizing work. If the user specified 4895 // both UseNUMA and UseLargePages (or UseSHM/UseHugeTLBFS) on the command line - warn and 4896 // disable adaptive resizing. 4897 if (UseNUMA && UseLargePages && !can_commit_large_page_memory()) { 4898 if (FLAG_IS_DEFAULT(UseNUMA)) { 4899 UseNUMA = false; 4900 } else { 4901 if (FLAG_IS_DEFAULT(UseLargePages) && 4902 FLAG_IS_DEFAULT(UseSHM) && 4903 FLAG_IS_DEFAULT(UseHugeTLBFS)) { 4904 UseLargePages = false; 4905 } else if (UseAdaptiveSizePolicy || UseAdaptiveNUMAChunkSizing) { 4906 warning("UseNUMA is not fully compatible with SHM/HugeTLBFS large pages, disabling adaptive resizing (-XX:-UseAdaptiveSizePolicy -XX:-UseAdaptiveNUMAChunkSizing)"); 4907 UseAdaptiveSizePolicy = false; 4908 UseAdaptiveNUMAChunkSizing = false; 4909 } 4910 } 4911 } 4912 if (!UseNUMA && ForceNUMA) { 4913 UseNUMA = true; 4914 } 4915 } 4916 4917 if (MaxFDLimit) { 4918 // set the number of file descriptors to max. print out error 4919 // if getrlimit/setrlimit fails but continue regardless. 4920 struct rlimit nbr_files; 4921 int status = getrlimit(RLIMIT_NOFILE, &nbr_files); 4922 if (status != 0) { 4923 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno)); 4924 } else { 4925 nbr_files.rlim_cur = nbr_files.rlim_max; 4926 status = setrlimit(RLIMIT_NOFILE, &nbr_files); 4927 if (status != 0) { 4928 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno)); 4929 } 4930 } 4931 } 4932 4933 // Initialize lock used to serialize thread creation (see os::create_thread) 4934 Linux::set_createThread_lock(new Mutex(Mutex::leaf, "createThread_lock", false)); 4935 4936 // at-exit methods are called in the reverse order of their registration. 4937 // atexit functions are called on return from main or as a result of a 4938 // call to exit(3C). There can be only 32 of these functions registered 4939 // and atexit() does not set errno. 4940 4941 if (PerfAllowAtExitRegistration) { 4942 // only register atexit functions if PerfAllowAtExitRegistration is set. 4943 // atexit functions can be delayed until process exit time, which 4944 // can be problematic for embedded VM situations. Embedded VMs should 4945 // call DestroyJavaVM() to assure that VM resources are released. 4946 4947 // note: perfMemory_exit_helper atexit function may be removed in 4948 // the future if the appropriate cleanup code can be added to the 4949 // VM_Exit VMOperation's doit method. 4950 if (atexit(perfMemory_exit_helper) != 0) { 4951 warning("os::init_2 atexit(perfMemory_exit_helper) failed"); 4952 } 4953 } 4954 4955 // initialize thread priority policy 4956 prio_init(); 4957 4958 return JNI_OK; 4959 } 4960 4961 // Mark the polling page as unreadable 4962 void os::make_polling_page_unreadable(void) { 4963 if (!guard_memory((char*)_polling_page, Linux::page_size())) { 4964 fatal("Could not disable polling page"); 4965 } 4966 } 4967 4968 // Mark the polling page as readable 4969 void os::make_polling_page_readable(void) { 4970 if (!linux_mprotect((char *)_polling_page, Linux::page_size(), PROT_READ)) { 4971 fatal("Could not enable polling page"); 4972 } 4973 } 4974 4975 // older glibc versions don't have this macro (which expands to 4976 // an optimized bit-counting function) so we have to roll our own 4977 #ifndef CPU_COUNT 4978 4979 static int _cpu_count(const cpu_set_t* cpus) { 4980 int count = 0; 4981 // only look up to the number of configured processors 4982 for (int i = 0; i < os::processor_count(); i++) { 4983 if (CPU_ISSET(i, cpus)) { 4984 count++; 4985 } 4986 } 4987 return count; 4988 } 4989 4990 #define CPU_COUNT(cpus) _cpu_count(cpus) 4991 4992 #endif // CPU_COUNT 4993 4994 // Get the current number of available processors for this process. 4995 // This value can change at any time during a process's lifetime. 4996 // sched_getaffinity gives an accurate answer as it accounts for cpusets. 4997 // If it appears there may be more than 1024 processors then we do a 4998 // dynamic check - see 6515172 for details. 4999 // If anything goes wrong we fallback to returning the number of online 5000 // processors - which can be greater than the number available to the process. 5001 int os::active_processor_count() { 5002 cpu_set_t cpus; // can represent at most 1024 (CPU_SETSIZE) processors 5003 cpu_set_t* cpus_p = &cpus; 5004 int cpus_size = sizeof(cpu_set_t); 5005 5006 int configured_cpus = processor_count(); // upper bound on available cpus 5007 int cpu_count = 0; 5008 5009 // old build platforms may not support dynamic cpu sets 5010 #ifdef CPU_ALLOC 5011 5012 // To enable easy testing of the dynamic path on different platforms we 5013 // introduce a diagnostic flag: UseCpuAllocPath 5014 if (configured_cpus >= CPU_SETSIZE || UseCpuAllocPath) { 5015 // kernel may use a mask bigger than cpu_set_t 5016 log_trace(os)("active_processor_count: using dynamic path %s" 5017 "- configured processors: %d", 5018 UseCpuAllocPath ? "(forced) " : "", 5019 configured_cpus); 5020 cpus_p = CPU_ALLOC(configured_cpus); 5021 if (cpus_p != NULL) { 5022 cpus_size = CPU_ALLOC_SIZE(configured_cpus); 5023 // zero it just to be safe 5024 CPU_ZERO_S(cpus_size, cpus_p); 5025 } 5026 else { 5027 // failed to allocate so fallback to online cpus 5028 int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN); 5029 log_trace(os)("active_processor_count: " 5030 "CPU_ALLOC failed (%s) - using " 5031 "online processor count: %d", 5032 os::strerror(errno), online_cpus); 5033 return online_cpus; 5034 } 5035 } 5036 else { 5037 log_trace(os)("active_processor_count: using static path - configured processors: %d", 5038 configured_cpus); 5039 } 5040 #else // CPU_ALLOC 5041 // these stubs won't be executed 5042 #define CPU_COUNT_S(size, cpus) -1 5043 #define CPU_FREE(cpus) 5044 5045 log_trace(os)("active_processor_count: only static path available - configured processors: %d", 5046 configured_cpus); 5047 #endif // CPU_ALLOC 5048 5049 // pid 0 means the current thread - which we have to assume represents the process 5050 if (sched_getaffinity(0, cpus_size, cpus_p) == 0) { 5051 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used 5052 cpu_count = CPU_COUNT_S(cpus_size, cpus_p); 5053 } 5054 else { 5055 cpu_count = CPU_COUNT(cpus_p); 5056 } 5057 log_trace(os)("active_processor_count: sched_getaffinity processor count: %d", cpu_count); 5058 } 5059 else { 5060 cpu_count = ::sysconf(_SC_NPROCESSORS_ONLN); 5061 warning("sched_getaffinity failed (%s)- using online processor count (%d) " 5062 "which may exceed available processors", os::strerror(errno), cpu_count); 5063 } 5064 5065 if (cpus_p != &cpus) { // can only be true when CPU_ALLOC used 5066 CPU_FREE(cpus_p); 5067 } 5068 5069 assert(cpu_count > 0 && cpu_count <= processor_count(), "sanity check"); 5070 return cpu_count; 5071 } 5072 5073 void os::set_native_thread_name(const char *name) { 5074 if (Linux::_pthread_setname_np) { 5075 char buf [16]; // according to glibc manpage, 16 chars incl. '/0' 5076 snprintf(buf, sizeof(buf), "%s", name); 5077 buf[sizeof(buf) - 1] = '\0'; 5078 const int rc = Linux::_pthread_setname_np(pthread_self(), buf); 5079 // ERANGE should not happen; all other errors should just be ignored. 5080 assert(rc != ERANGE, "pthread_setname_np failed"); 5081 } 5082 } 5083 5084 bool os::distribute_processes(uint length, uint* distribution) { 5085 // Not yet implemented. 5086 return false; 5087 } 5088 5089 bool os::bind_to_processor(uint processor_id) { 5090 // Not yet implemented. 5091 return false; 5092 } 5093 5094 /// 5095 5096 void os::SuspendedThreadTask::internal_do_task() { 5097 if (do_suspend(_thread->osthread())) { 5098 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext()); 5099 do_task(context); 5100 do_resume(_thread->osthread()); 5101 } 5102 } 5103 5104 class PcFetcher : public os::SuspendedThreadTask { 5105 public: 5106 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {} 5107 ExtendedPC result(); 5108 protected: 5109 void do_task(const os::SuspendedThreadTaskContext& context); 5110 private: 5111 ExtendedPC _epc; 5112 }; 5113 5114 ExtendedPC PcFetcher::result() { 5115 guarantee(is_done(), "task is not done yet."); 5116 return _epc; 5117 } 5118 5119 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) { 5120 Thread* thread = context.thread(); 5121 OSThread* osthread = thread->osthread(); 5122 if (osthread->ucontext() != NULL) { 5123 _epc = os::Linux::ucontext_get_pc((const ucontext_t *) context.ucontext()); 5124 } else { 5125 // NULL context is unexpected, double-check this is the VMThread 5126 guarantee(thread->is_VM_thread(), "can only be called for VMThread"); 5127 } 5128 } 5129 5130 // Suspends the target using the signal mechanism and then grabs the PC before 5131 // resuming the target. Used by the flat-profiler only 5132 ExtendedPC os::get_thread_pc(Thread* thread) { 5133 // Make sure that it is called by the watcher for the VMThread 5134 assert(Thread::current()->is_Watcher_thread(), "Must be watcher"); 5135 assert(thread->is_VM_thread(), "Can only be called for VMThread"); 5136 5137 PcFetcher fetcher(thread); 5138 fetcher.run(); 5139 return fetcher.result(); 5140 } 5141 5142 //////////////////////////////////////////////////////////////////////////////// 5143 // debug support 5144 5145 bool os::find(address addr, outputStream* st) { 5146 Dl_info dlinfo; 5147 memset(&dlinfo, 0, sizeof(dlinfo)); 5148 if (dladdr(addr, &dlinfo) != 0) { 5149 st->print(PTR_FORMAT ": ", p2i(addr)); 5150 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) { 5151 st->print("%s+" PTR_FORMAT, dlinfo.dli_sname, 5152 p2i(addr) - p2i(dlinfo.dli_saddr)); 5153 } else if (dlinfo.dli_fbase != NULL) { 5154 st->print("<offset " PTR_FORMAT ">", p2i(addr) - p2i(dlinfo.dli_fbase)); 5155 } else { 5156 st->print("<absolute address>"); 5157 } 5158 if (dlinfo.dli_fname != NULL) { 5159 st->print(" in %s", dlinfo.dli_fname); 5160 } 5161 if (dlinfo.dli_fbase != NULL) { 5162 st->print(" at " PTR_FORMAT, p2i(dlinfo.dli_fbase)); 5163 } 5164 st->cr(); 5165 5166 if (Verbose) { 5167 // decode some bytes around the PC 5168 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size()); 5169 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size()); 5170 address lowest = (address) dlinfo.dli_sname; 5171 if (!lowest) lowest = (address) dlinfo.dli_fbase; 5172 if (begin < lowest) begin = lowest; 5173 Dl_info dlinfo2; 5174 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr 5175 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) { 5176 end = (address) dlinfo2.dli_saddr; 5177 } 5178 Disassembler::decode(begin, end, st); 5179 } 5180 return true; 5181 } 5182 return false; 5183 } 5184 5185 //////////////////////////////////////////////////////////////////////////////// 5186 // misc 5187 5188 // This does not do anything on Linux. This is basically a hook for being 5189 // able to use structured exception handling (thread-local exception filters) 5190 // on, e.g., Win32. 5191 void 5192 os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, 5193 JavaCallArguments* args, Thread* thread) { 5194 f(value, method, args, thread); 5195 } 5196 5197 void os::print_statistics() { 5198 } 5199 5200 bool os::message_box(const char* title, const char* message) { 5201 int i; 5202 fdStream err(defaultStream::error_fd()); 5203 for (i = 0; i < 78; i++) err.print_raw("="); 5204 err.cr(); 5205 err.print_raw_cr(title); 5206 for (i = 0; i < 78; i++) err.print_raw("-"); 5207 err.cr(); 5208 err.print_raw_cr(message); 5209 for (i = 0; i < 78; i++) err.print_raw("="); 5210 err.cr(); 5211 5212 char buf[16]; 5213 // Prevent process from exiting upon "read error" without consuming all CPU 5214 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); } 5215 5216 return buf[0] == 'y' || buf[0] == 'Y'; 5217 } 5218 5219 int os::stat(const char *path, struct stat *sbuf) { 5220 char pathbuf[MAX_PATH]; 5221 if (strlen(path) > MAX_PATH - 1) { 5222 errno = ENAMETOOLONG; 5223 return -1; 5224 } 5225 os::native_path(strcpy(pathbuf, path)); 5226 return ::stat(pathbuf, sbuf); 5227 } 5228 5229 // Is a (classpath) directory empty? 5230 bool os::dir_is_empty(const char* path) { 5231 DIR *dir = NULL; 5232 struct dirent *ptr; 5233 5234 dir = opendir(path); 5235 if (dir == NULL) return true; 5236 5237 // Scan the directory 5238 bool result = true; 5239 char buf[sizeof(struct dirent) + MAX_PATH]; 5240 while (result && (ptr = ::readdir(dir)) != NULL) { 5241 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) { 5242 result = false; 5243 } 5244 } 5245 closedir(dir); 5246 return result; 5247 } 5248 5249 // This code originates from JDK's sysOpen and open64_w 5250 // from src/solaris/hpi/src/system_md.c 5251 5252 int os::open(const char *path, int oflag, int mode) { 5253 if (strlen(path) > MAX_PATH - 1) { 5254 errno = ENAMETOOLONG; 5255 return -1; 5256 } 5257 5258 // All file descriptors that are opened in the Java process and not 5259 // specifically destined for a subprocess should have the close-on-exec 5260 // flag set. If we don't set it, then careless 3rd party native code 5261 // might fork and exec without closing all appropriate file descriptors 5262 // (e.g. as we do in closeDescriptors in UNIXProcess.c), and this in 5263 // turn might: 5264 // 5265 // - cause end-of-file to fail to be detected on some file 5266 // descriptors, resulting in mysterious hangs, or 5267 // 5268 // - might cause an fopen in the subprocess to fail on a system 5269 // suffering from bug 1085341. 5270 // 5271 // (Yes, the default setting of the close-on-exec flag is a Unix 5272 // design flaw) 5273 // 5274 // See: 5275 // 1085341: 32-bit stdio routines should support file descriptors >255 5276 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed 5277 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9 5278 // 5279 // Modern Linux kernels (after 2.6.23 2007) support O_CLOEXEC with open(). 5280 // O_CLOEXEC is preferable to using FD_CLOEXEC on an open file descriptor 5281 // because it saves a system call and removes a small window where the flag 5282 // is unset. On ancient Linux kernels the O_CLOEXEC flag will be ignored 5283 // and we fall back to using FD_CLOEXEC (see below). 5284 #ifdef O_CLOEXEC 5285 oflag |= O_CLOEXEC; 5286 #endif 5287 5288 int fd = ::open64(path, oflag, mode); 5289 if (fd == -1) return -1; 5290 5291 //If the open succeeded, the file might still be a directory 5292 { 5293 struct stat64 buf64; 5294 int ret = ::fstat64(fd, &buf64); 5295 int st_mode = buf64.st_mode; 5296 5297 if (ret != -1) { 5298 if ((st_mode & S_IFMT) == S_IFDIR) { 5299 errno = EISDIR; 5300 ::close(fd); 5301 return -1; 5302 } 5303 } else { 5304 ::close(fd); 5305 return -1; 5306 } 5307 } 5308 5309 #ifdef FD_CLOEXEC 5310 // Validate that the use of the O_CLOEXEC flag on open above worked. 5311 // With recent kernels, we will perform this check exactly once. 5312 static sig_atomic_t O_CLOEXEC_is_known_to_work = 0; 5313 if (!O_CLOEXEC_is_known_to_work) { 5314 int flags = ::fcntl(fd, F_GETFD); 5315 if (flags != -1) { 5316 if ((flags & FD_CLOEXEC) != 0) 5317 O_CLOEXEC_is_known_to_work = 1; 5318 else 5319 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC); 5320 } 5321 } 5322 #endif 5323 5324 return fd; 5325 } 5326 5327 5328 // create binary file, rewriting existing file if required 5329 int os::create_binary_file(const char* path, bool rewrite_existing) { 5330 int oflags = O_WRONLY | O_CREAT; 5331 if (!rewrite_existing) { 5332 oflags |= O_EXCL; 5333 } 5334 return ::open64(path, oflags, S_IREAD | S_IWRITE); 5335 } 5336 5337 // return current position of file pointer 5338 jlong os::current_file_offset(int fd) { 5339 return (jlong)::lseek64(fd, (off64_t)0, SEEK_CUR); 5340 } 5341 5342 // move file pointer to the specified offset 5343 jlong os::seek_to_file_offset(int fd, jlong offset) { 5344 return (jlong)::lseek64(fd, (off64_t)offset, SEEK_SET); 5345 } 5346 5347 // This code originates from JDK's sysAvailable 5348 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c 5349 5350 int os::available(int fd, jlong *bytes) { 5351 jlong cur, end; 5352 int mode; 5353 struct stat64 buf64; 5354 5355 if (::fstat64(fd, &buf64) >= 0) { 5356 mode = buf64.st_mode; 5357 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) { 5358 int n; 5359 if (::ioctl(fd, FIONREAD, &n) >= 0) { 5360 *bytes = n; 5361 return 1; 5362 } 5363 } 5364 } 5365 if ((cur = ::lseek64(fd, 0L, SEEK_CUR)) == -1) { 5366 return 0; 5367 } else if ((end = ::lseek64(fd, 0L, SEEK_END)) == -1) { 5368 return 0; 5369 } else if (::lseek64(fd, cur, SEEK_SET) == -1) { 5370 return 0; 5371 } 5372 *bytes = end - cur; 5373 return 1; 5374 } 5375 5376 // Map a block of memory. 5377 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset, 5378 char *addr, size_t bytes, bool read_only, 5379 bool allow_exec) { 5380 int prot; 5381 int flags = MAP_PRIVATE; 5382 5383 if (read_only) { 5384 prot = PROT_READ; 5385 } else { 5386 prot = PROT_READ | PROT_WRITE; 5387 } 5388 5389 if (allow_exec) { 5390 prot |= PROT_EXEC; 5391 } 5392 5393 if (addr != NULL) { 5394 flags |= MAP_FIXED; 5395 } 5396 5397 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags, 5398 fd, file_offset); 5399 if (mapped_address == MAP_FAILED) { 5400 return NULL; 5401 } 5402 return mapped_address; 5403 } 5404 5405 5406 // Remap a block of memory. 5407 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset, 5408 char *addr, size_t bytes, bool read_only, 5409 bool allow_exec) { 5410 // same as map_memory() on this OS 5411 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only, 5412 allow_exec); 5413 } 5414 5415 5416 // Unmap a block of memory. 5417 bool os::pd_unmap_memory(char* addr, size_t bytes) { 5418 return munmap(addr, bytes) == 0; 5419 } 5420 5421 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time); 5422 5423 static clockid_t thread_cpu_clockid(Thread* thread) { 5424 pthread_t tid = thread->osthread()->pthread_id(); 5425 clockid_t clockid; 5426 5427 // Get thread clockid 5428 int rc = os::Linux::pthread_getcpuclockid(tid, &clockid); 5429 assert(rc == 0, "pthread_getcpuclockid is expected to return 0 code"); 5430 return clockid; 5431 } 5432 5433 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool) 5434 // are used by JVM M&M and JVMTI to get user+sys or user CPU time 5435 // of a thread. 5436 // 5437 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns 5438 // the fast estimate available on the platform. 5439 5440 jlong os::current_thread_cpu_time() { 5441 if (os::Linux::supports_fast_thread_cpu_time()) { 5442 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5443 } else { 5444 // return user + sys since the cost is the same 5445 return slow_thread_cpu_time(Thread::current(), true /* user + sys */); 5446 } 5447 } 5448 5449 jlong os::thread_cpu_time(Thread* thread) { 5450 // consistent with what current_thread_cpu_time() returns 5451 if (os::Linux::supports_fast_thread_cpu_time()) { 5452 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); 5453 } else { 5454 return slow_thread_cpu_time(thread, true /* user + sys */); 5455 } 5456 } 5457 5458 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) { 5459 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5460 return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID); 5461 } else { 5462 return slow_thread_cpu_time(Thread::current(), user_sys_cpu_time); 5463 } 5464 } 5465 5466 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5467 if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) { 5468 return os::Linux::fast_thread_cpu_time(thread_cpu_clockid(thread)); 5469 } else { 5470 return slow_thread_cpu_time(thread, user_sys_cpu_time); 5471 } 5472 } 5473 5474 // -1 on error. 5475 static jlong slow_thread_cpu_time(Thread *thread, bool user_sys_cpu_time) { 5476 pid_t tid = thread->osthread()->thread_id(); 5477 char *s; 5478 char stat[2048]; 5479 int statlen; 5480 char proc_name[64]; 5481 int count; 5482 long sys_time, user_time; 5483 char cdummy; 5484 int idummy; 5485 long ldummy; 5486 FILE *fp; 5487 5488 snprintf(proc_name, 64, "/proc/self/task/%d/stat", tid); 5489 fp = fopen(proc_name, "r"); 5490 if (fp == NULL) return -1; 5491 statlen = fread(stat, 1, 2047, fp); 5492 stat[statlen] = '\0'; 5493 fclose(fp); 5494 5495 // Skip pid and the command string. Note that we could be dealing with 5496 // weird command names, e.g. user could decide to rename java launcher 5497 // to "java 1.4.2 :)", then the stat file would look like 5498 // 1234 (java 1.4.2 :)) R ... ... 5499 // We don't really need to know the command string, just find the last 5500 // occurrence of ")" and then start parsing from there. See bug 4726580. 5501 s = strrchr(stat, ')'); 5502 if (s == NULL) return -1; 5503 5504 // Skip blank chars 5505 do { s++; } while (s && isspace(*s)); 5506 5507 count = sscanf(s,"%c %d %d %d %d %d %lu %lu %lu %lu %lu %lu %lu", 5508 &cdummy, &idummy, &idummy, &idummy, &idummy, &idummy, 5509 &ldummy, &ldummy, &ldummy, &ldummy, &ldummy, 5510 &user_time, &sys_time); 5511 if (count != 13) return -1; 5512 if (user_sys_cpu_time) { 5513 return ((jlong)sys_time + (jlong)user_time) * (1000000000 / clock_tics_per_sec); 5514 } else { 5515 return (jlong)user_time * (1000000000 / clock_tics_per_sec); 5516 } 5517 } 5518 5519 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5520 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5521 info_ptr->may_skip_backward = false; // elapsed time not wall time 5522 info_ptr->may_skip_forward = false; // elapsed time not wall time 5523 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5524 } 5525 5526 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) { 5527 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits 5528 info_ptr->may_skip_backward = false; // elapsed time not wall time 5529 info_ptr->may_skip_forward = false; // elapsed time not wall time 5530 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned 5531 } 5532 5533 bool os::is_thread_cpu_time_supported() { 5534 return true; 5535 } 5536 5537 // System loadavg support. Returns -1 if load average cannot be obtained. 5538 // Linux doesn't yet have a (official) notion of processor sets, 5539 // so just return the system wide load average. 5540 int os::loadavg(double loadavg[], int nelem) { 5541 return ::getloadavg(loadavg, nelem); 5542 } 5543 5544 void os::pause() { 5545 char filename[MAX_PATH]; 5546 if (PauseAtStartupFile && PauseAtStartupFile[0]) { 5547 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile); 5548 } else { 5549 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id()); 5550 } 5551 5552 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); 5553 if (fd != -1) { 5554 struct stat buf; 5555 ::close(fd); 5556 while (::stat(filename, &buf) == 0) { 5557 (void)::poll(NULL, 0, 100); 5558 } 5559 } else { 5560 jio_fprintf(stderr, 5561 "Could not open pause file '%s', continuing immediately.\n", filename); 5562 } 5563 } 5564 5565 extern char** environ; 5566 5567 // Run the specified command in a separate process. Return its exit value, 5568 // or -1 on failure (e.g. can't fork a new process). 5569 // Unlike system(), this function can be called from signal handler. It 5570 // doesn't block SIGINT et al. 5571 int os::fork_and_exec(char* cmd) { 5572 const char * argv[4] = {"sh", "-c", cmd, NULL}; 5573 5574 pid_t pid = fork(); 5575 5576 if (pid < 0) { 5577 // fork failed 5578 return -1; 5579 5580 } else if (pid == 0) { 5581 // child process 5582 5583 execve("/bin/sh", (char* const*)argv, environ); 5584 5585 // execve failed 5586 _exit(-1); 5587 5588 } else { 5589 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't 5590 // care about the actual exit code, for now. 5591 5592 int status; 5593 5594 // Wait for the child process to exit. This returns immediately if 5595 // the child has already exited. */ 5596 while (waitpid(pid, &status, 0) < 0) { 5597 switch (errno) { 5598 case ECHILD: return 0; 5599 case EINTR: break; 5600 default: return -1; 5601 } 5602 } 5603 5604 if (WIFEXITED(status)) { 5605 // The child exited normally; get its exit code. 5606 return WEXITSTATUS(status); 5607 } else if (WIFSIGNALED(status)) { 5608 // The child exited because of a signal 5609 // The best value to return is 0x80 + signal number, 5610 // because that is what all Unix shells do, and because 5611 // it allows callers to distinguish between process exit and 5612 // process death by signal. 5613 return 0x80 + WTERMSIG(status); 5614 } else { 5615 // Unknown exit code; pass it through 5616 return status; 5617 } 5618 } 5619 } 5620 5621 // is_headless_jre() 5622 // 5623 // Test for the existence of xawt/libmawt.so or libawt_xawt.so 5624 // in order to report if we are running in a headless jre 5625 // 5626 // Since JDK8 xawt/libmawt.so was moved into the same directory 5627 // as libawt.so, and renamed libawt_xawt.so 5628 // 5629 bool os::is_headless_jre() { 5630 struct stat statbuf; 5631 char buf[MAXPATHLEN]; 5632 char libmawtpath[MAXPATHLEN]; 5633 const char *xawtstr = "/xawt/libmawt.so"; 5634 const char *new_xawtstr = "/libawt_xawt.so"; 5635 char *p; 5636 5637 // Get path to libjvm.so 5638 os::jvm_path(buf, sizeof(buf)); 5639 5640 // Get rid of libjvm.so 5641 p = strrchr(buf, '/'); 5642 if (p == NULL) { 5643 return false; 5644 } else { 5645 *p = '\0'; 5646 } 5647 5648 // Get rid of client or server 5649 p = strrchr(buf, '/'); 5650 if (p == NULL) { 5651 return false; 5652 } else { 5653 *p = '\0'; 5654 } 5655 5656 // check xawt/libmawt.so 5657 strcpy(libmawtpath, buf); 5658 strcat(libmawtpath, xawtstr); 5659 if (::stat(libmawtpath, &statbuf) == 0) return false; 5660 5661 // check libawt_xawt.so 5662 strcpy(libmawtpath, buf); 5663 strcat(libmawtpath, new_xawtstr); 5664 if (::stat(libmawtpath, &statbuf) == 0) return false; 5665 5666 return true; 5667 } 5668 5669 // Get the default path to the core file 5670 // Returns the length of the string 5671 int os::get_core_path(char* buffer, size_t bufferSize) { 5672 /* 5673 * Max length of /proc/sys/kernel/core_pattern is 128 characters. 5674 * See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt 5675 */ 5676 const int core_pattern_len = 129; 5677 char core_pattern[core_pattern_len] = {0}; 5678 5679 int core_pattern_file = ::open("/proc/sys/kernel/core_pattern", O_RDONLY); 5680 if (core_pattern_file == -1) { 5681 return -1; 5682 } 5683 5684 ssize_t ret = ::read(core_pattern_file, core_pattern, core_pattern_len); 5685 ::close(core_pattern_file); 5686 if (ret <= 0 || ret >= core_pattern_len || core_pattern[0] == '\n') { 5687 return -1; 5688 } 5689 if (core_pattern[ret-1] == '\n') { 5690 core_pattern[ret-1] = '\0'; 5691 } else { 5692 core_pattern[ret] = '\0'; 5693 } 5694 5695 char *pid_pos = strstr(core_pattern, "%p"); 5696 int written; 5697 5698 if (core_pattern[0] == '/') { 5699 written = jio_snprintf(buffer, bufferSize, "%s", core_pattern); 5700 } else { 5701 char cwd[PATH_MAX]; 5702 5703 const char* p = get_current_directory(cwd, PATH_MAX); 5704 if (p == NULL) { 5705 return -1; 5706 } 5707 5708 if (core_pattern[0] == '|') { 5709 written = jio_snprintf(buffer, bufferSize, 5710 "\"%s\" (or dumping to %s/core.%d)", 5711 &core_pattern[1], p, current_process_id()); 5712 } else { 5713 written = jio_snprintf(buffer, bufferSize, "%s/%s", p, core_pattern); 5714 } 5715 } 5716 5717 if (written < 0) { 5718 return -1; 5719 } 5720 5721 if (((size_t)written < bufferSize) && (pid_pos == NULL) && (core_pattern[0] != '|')) { 5722 int core_uses_pid_file = ::open("/proc/sys/kernel/core_uses_pid", O_RDONLY); 5723 5724 if (core_uses_pid_file != -1) { 5725 char core_uses_pid = 0; 5726 ssize_t ret = ::read(core_uses_pid_file, &core_uses_pid, 1); 5727 ::close(core_uses_pid_file); 5728 5729 if (core_uses_pid == '1') { 5730 jio_snprintf(buffer + written, bufferSize - written, 5731 ".%d", current_process_id()); 5732 } 5733 } 5734 } 5735 5736 return strlen(buffer); 5737 } 5738 5739 bool os::start_debugging(char *buf, int buflen) { 5740 int len = (int)strlen(buf); 5741 char *p = &buf[len]; 5742 5743 jio_snprintf(p, buflen-len, 5744 "\n\n" 5745 "Do you want to debug the problem?\n\n" 5746 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " UINTX_FORMAT " (" INTPTR_FORMAT ")\n" 5747 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n" 5748 "Otherwise, press RETURN to abort...", 5749 os::current_process_id(), os::current_process_id(), 5750 os::current_thread_id(), os::current_thread_id()); 5751 5752 bool yes = os::message_box("Unexpected Error", buf); 5753 5754 if (yes) { 5755 // yes, user asked VM to launch debugger 5756 jio_snprintf(buf, sizeof(char)*buflen, "gdb /proc/%d/exe %d", 5757 os::current_process_id(), os::current_process_id()); 5758 5759 os::fork_and_exec(buf); 5760 yes = false; 5761 } 5762 return yes; 5763 } 5764 5765 5766 // Java/Compiler thread: 5767 // 5768 // Low memory addresses 5769 // P0 +------------------------+ 5770 // | |\ Java thread created by VM does not have glibc 5771 // | glibc guard page | - guard page, attached Java thread usually has 5772 // | |/ 1 glibc guard page. 5773 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 5774 // | |\ 5775 // | HotSpot Guard Pages | - red, yellow and reserved pages 5776 // | |/ 5777 // +------------------------+ JavaThread::stack_reserved_zone_base() 5778 // | |\ 5779 // | Normal Stack | - 5780 // | |/ 5781 // P2 +------------------------+ Thread::stack_base() 5782 // 5783 // Non-Java thread: 5784 // 5785 // Low memory addresses 5786 // P0 +------------------------+ 5787 // | |\ 5788 // | glibc guard page | - usually 1 page 5789 // | |/ 5790 // P1 +------------------------+ Thread::stack_base() - Thread::stack_size() 5791 // | |\ 5792 // | Normal Stack | - 5793 // | |/ 5794 // P2 +------------------------+ Thread::stack_base() 5795 // 5796 // ** P1 (aka bottom) and size (P2 = P1 - size) are the address and stack size 5797 // returned from pthread_attr_getstack(). 5798 // ** Due to NPTL implementation error, linux takes the glibc guard page out 5799 // of the stack size given in pthread_attr. We work around this for 5800 // threads created by the VM. (We adapt bottom to be P1 and size accordingly.) 5801 // 5802 #ifndef ZERO 5803 static void current_stack_region(address * bottom, size_t * size) { 5804 if (os::Linux::is_initial_thread()) { 5805 // initial thread needs special handling because pthread_getattr_np() 5806 // may return bogus value. 5807 *bottom = os::Linux::initial_thread_stack_bottom(); 5808 *size = os::Linux::initial_thread_stack_size(); 5809 } else { 5810 pthread_attr_t attr; 5811 5812 int rslt = pthread_getattr_np(pthread_self(), &attr); 5813 5814 // JVM needs to know exact stack location, abort if it fails 5815 if (rslt != 0) { 5816 if (rslt == ENOMEM) { 5817 vm_exit_out_of_memory(0, OOM_MMAP_ERROR, "pthread_getattr_np"); 5818 } else { 5819 fatal("pthread_getattr_np failed with error = %d", rslt); 5820 } 5821 } 5822 5823 if (pthread_attr_getstack(&attr, (void **)bottom, size) != 0) { 5824 fatal("Cannot locate current stack attributes!"); 5825 } 5826 5827 // Work around NPTL stack guard error. 5828 size_t guard_size = 0; 5829 rslt = pthread_attr_getguardsize(&attr, &guard_size); 5830 if (rslt != 0) { 5831 fatal("pthread_attr_getguardsize failed with error = %d", rslt); 5832 } 5833 *bottom += guard_size; 5834 *size -= guard_size; 5835 5836 pthread_attr_destroy(&attr); 5837 5838 } 5839 assert(os::current_stack_pointer() >= *bottom && 5840 os::current_stack_pointer() < *bottom + *size, "just checking"); 5841 } 5842 5843 address os::current_stack_base() { 5844 address bottom; 5845 size_t size; 5846 current_stack_region(&bottom, &size); 5847 return (bottom + size); 5848 } 5849 5850 size_t os::current_stack_size() { 5851 // This stack size includes the usable stack and HotSpot guard pages 5852 // (for the threads that have Hotspot guard pages). 5853 address bottom; 5854 size_t size; 5855 current_stack_region(&bottom, &size); 5856 return size; 5857 } 5858 #endif 5859 5860 static inline struct timespec get_mtime(const char* filename) { 5861 struct stat st; 5862 int ret = os::stat(filename, &st); 5863 assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno)); 5864 return st.st_mtim; 5865 } 5866 5867 int os::compare_file_modified_times(const char* file1, const char* file2) { 5868 struct timespec filetime1 = get_mtime(file1); 5869 struct timespec filetime2 = get_mtime(file2); 5870 int diff = filetime1.tv_sec - filetime2.tv_sec; 5871 if (diff == 0) { 5872 return filetime1.tv_nsec - filetime2.tv_nsec; 5873 } 5874 return diff; 5875 } 5876 5877 /////////////// Unit tests /////////////// 5878 5879 #ifndef PRODUCT 5880 5881 #define test_log(...) \ 5882 do { \ 5883 if (VerboseInternalVMTests) { \ 5884 tty->print_cr(__VA_ARGS__); \ 5885 tty->flush(); \ 5886 } \ 5887 } while (false) 5888 5889 class TestReserveMemorySpecial : AllStatic { 5890 public: 5891 static void small_page_write(void* addr, size_t size) { 5892 size_t page_size = os::vm_page_size(); 5893 5894 char* end = (char*)addr + size; 5895 for (char* p = (char*)addr; p < end; p += page_size) { 5896 *p = 1; 5897 } 5898 } 5899 5900 static void test_reserve_memory_special_huge_tlbfs_only(size_t size) { 5901 if (!UseHugeTLBFS) { 5902 return; 5903 } 5904 5905 test_log("test_reserve_memory_special_huge_tlbfs_only(" SIZE_FORMAT ")", size); 5906 5907 char* addr = os::Linux::reserve_memory_special_huge_tlbfs_only(size, NULL, false); 5908 5909 if (addr != NULL) { 5910 small_page_write(addr, size); 5911 5912 os::Linux::release_memory_special_huge_tlbfs(addr, size); 5913 } 5914 } 5915 5916 static void test_reserve_memory_special_huge_tlbfs_only() { 5917 if (!UseHugeTLBFS) { 5918 return; 5919 } 5920 5921 size_t lp = os::large_page_size(); 5922 5923 for (size_t size = lp; size <= lp * 10; size += lp) { 5924 test_reserve_memory_special_huge_tlbfs_only(size); 5925 } 5926 } 5927 5928 static void test_reserve_memory_special_huge_tlbfs_mixed() { 5929 size_t lp = os::large_page_size(); 5930 size_t ag = os::vm_allocation_granularity(); 5931 5932 // sizes to test 5933 const size_t sizes[] = { 5934 lp, lp + ag, lp + lp / 2, lp * 2, 5935 lp * 2 + ag, lp * 2 - ag, lp * 2 + lp / 2, 5936 lp * 10, lp * 10 + lp / 2 5937 }; 5938 const int num_sizes = sizeof(sizes) / sizeof(size_t); 5939 5940 // For each size/alignment combination, we test three scenarios: 5941 // 1) with req_addr == NULL 5942 // 2) with a non-null req_addr at which we expect to successfully allocate 5943 // 3) with a non-null req_addr which contains a pre-existing mapping, at which we 5944 // expect the allocation to either fail or to ignore req_addr 5945 5946 // Pre-allocate two areas; they shall be as large as the largest allocation 5947 // and aligned to the largest alignment we will be testing. 5948 const size_t mapping_size = sizes[num_sizes - 1] * 2; 5949 char* const mapping1 = (char*) ::mmap(NULL, mapping_size, 5950 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 5951 -1, 0); 5952 assert(mapping1 != MAP_FAILED, "should work"); 5953 5954 char* const mapping2 = (char*) ::mmap(NULL, mapping_size, 5955 PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, 5956 -1, 0); 5957 assert(mapping2 != MAP_FAILED, "should work"); 5958 5959 // Unmap the first mapping, but leave the second mapping intact: the first 5960 // mapping will serve as a value for a "good" req_addr (case 2). The second 5961 // mapping, still intact, as "bad" req_addr (case 3). 5962 ::munmap(mapping1, mapping_size); 5963 5964 // Case 1 5965 test_log("%s, req_addr NULL:", __FUNCTION__); 5966 test_log("size align result"); 5967 5968 for (int i = 0; i < num_sizes; i++) { 5969 const size_t size = sizes[i]; 5970 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 5971 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, NULL, false); 5972 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " -> " PTR_FORMAT " %s", 5973 size, alignment, p2i(p), (p != NULL ? "" : "(failed)")); 5974 if (p != NULL) { 5975 assert(is_aligned(p, alignment), "must be"); 5976 small_page_write(p, size); 5977 os::Linux::release_memory_special_huge_tlbfs(p, size); 5978 } 5979 } 5980 } 5981 5982 // Case 2 5983 test_log("%s, req_addr non-NULL:", __FUNCTION__); 5984 test_log("size align req_addr result"); 5985 5986 for (int i = 0; i < num_sizes; i++) { 5987 const size_t size = sizes[i]; 5988 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 5989 char* const req_addr = align_up(mapping1, alignment); 5990 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); 5991 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", 5992 size, alignment, p2i(req_addr), p2i(p), 5993 ((p != NULL ? (p == req_addr ? "(exact match)" : "") : "(failed)"))); 5994 if (p != NULL) { 5995 assert(p == req_addr, "must be"); 5996 small_page_write(p, size); 5997 os::Linux::release_memory_special_huge_tlbfs(p, size); 5998 } 5999 } 6000 } 6001 6002 // Case 3 6003 test_log("%s, req_addr non-NULL with preexisting mapping:", __FUNCTION__); 6004 test_log("size align req_addr result"); 6005 6006 for (int i = 0; i < num_sizes; i++) { 6007 const size_t size = sizes[i]; 6008 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6009 char* const req_addr = align_up(mapping2, alignment); 6010 char* p = os::Linux::reserve_memory_special_huge_tlbfs_mixed(size, alignment, req_addr, false); 6011 test_log(SIZE_FORMAT_HEX " " SIZE_FORMAT_HEX " " PTR_FORMAT " -> " PTR_FORMAT " %s", 6012 size, alignment, p2i(req_addr), p2i(p), ((p != NULL ? "" : "(failed)"))); 6013 // as the area around req_addr contains already existing mappings, the API should always 6014 // return NULL (as per contract, it cannot return another address) 6015 assert(p == NULL, "must be"); 6016 } 6017 } 6018 6019 ::munmap(mapping2, mapping_size); 6020 6021 } 6022 6023 static void test_reserve_memory_special_huge_tlbfs() { 6024 if (!UseHugeTLBFS) { 6025 return; 6026 } 6027 6028 test_reserve_memory_special_huge_tlbfs_only(); 6029 test_reserve_memory_special_huge_tlbfs_mixed(); 6030 } 6031 6032 static void test_reserve_memory_special_shm(size_t size, size_t alignment) { 6033 if (!UseSHM) { 6034 return; 6035 } 6036 6037 test_log("test_reserve_memory_special_shm(" SIZE_FORMAT ", " SIZE_FORMAT ")", size, alignment); 6038 6039 char* addr = os::Linux::reserve_memory_special_shm(size, alignment, NULL, false); 6040 6041 if (addr != NULL) { 6042 assert(is_aligned(addr, alignment), "Check"); 6043 assert(is_aligned(addr, os::large_page_size()), "Check"); 6044 6045 small_page_write(addr, size); 6046 6047 os::Linux::release_memory_special_shm(addr, size); 6048 } 6049 } 6050 6051 static void test_reserve_memory_special_shm() { 6052 size_t lp = os::large_page_size(); 6053 size_t ag = os::vm_allocation_granularity(); 6054 6055 for (size_t size = ag; size < lp * 3; size += ag) { 6056 for (size_t alignment = ag; is_aligned(size, alignment); alignment *= 2) { 6057 test_reserve_memory_special_shm(size, alignment); 6058 } 6059 } 6060 } 6061 6062 static void test() { 6063 test_reserve_memory_special_huge_tlbfs(); 6064 test_reserve_memory_special_shm(); 6065 } 6066 }; 6067 6068 void TestReserveMemorySpecial_test() { 6069 TestReserveMemorySpecial::test(); 6070 } 6071 6072 #endif