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