1 /*
   2  * Copyright (c) 1999, 2019, 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 "jvm.h"
  27 #include "classfile/classLoader.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "classfile/vmSymbols.hpp"
  30 #include "code/icBuffer.hpp"
  31 #include "code/vtableStubs.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "compiler/disassembler.hpp"
  34 #include "interpreter/interpreter.hpp"
  35 #include "logging/log.hpp"
  36 #include "logging/logStream.hpp"
  37 #include "memory/allocation.inline.hpp"
  38 #include "memory/filemap.hpp"
  39 #include "oops/oop.inline.hpp"
  40 #include "os_bsd.inline.hpp"
  41 #include "os_share_bsd.hpp"
  42 #include "prims/jniFastGetField.hpp"
  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.inline.hpp"
  49 #include "runtime/java.hpp"
  50 #include "runtime/javaCalls.hpp"
  51 #include "runtime/mutexLocker.hpp"
  52 #include "runtime/objectMonitor.hpp"
  53 #include "runtime/orderAccess.hpp"
  54 #include "runtime/osThread.hpp"
  55 #include "runtime/perfMemory.hpp"
  56 #include "runtime/semaphore.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 "services/attachListener.hpp"
  64 #include "services/memTracker.hpp"
  65 #include "services/runtimeService.hpp"
  66 #include "utilities/align.hpp"
  67 #include "utilities/decoder.hpp"
  68 #include "utilities/defaultStream.hpp"
  69 #include "utilities/events.hpp"
  70 #include "utilities/growableArray.hpp"
  71 #include "utilities/vmError.hpp"
  72 
  73 // put OS-includes here
  74 # include <sys/types.h>
  75 # include <sys/mman.h>
  76 # include <sys/stat.h>
  77 # include <sys/select.h>
  78 # include <pthread.h>
  79 # include <signal.h>
  80 # include <errno.h>
  81 # include <dlfcn.h>
  82 # include <stdio.h>
  83 # include <unistd.h>
  84 # include <sys/resource.h>
  85 # include <pthread.h>
  86 # include <sys/stat.h>
  87 # include <sys/time.h>
  88 # include <sys/times.h>
  89 # include <sys/utsname.h>
  90 # include <sys/socket.h>
  91 # include <sys/wait.h>
  92 # include <time.h>
  93 # include <pwd.h>
  94 # include <poll.h>
  95 # include <fcntl.h>
  96 # include <string.h>
  97 # include <sys/param.h>
  98 # include <sys/sysctl.h>
  99 # include <sys/ipc.h>
 100 # include <sys/shm.h>
 101 #ifndef __APPLE__
 102 # include <link.h>
 103 #endif
 104 # include <stdint.h>
 105 # include <inttypes.h>
 106 # include <sys/ioctl.h>
 107 # include <sys/syscall.h>
 108 
 109 #if defined(__FreeBSD__) || defined(__NetBSD__)
 110   #include <elf.h>
 111 #endif
 112 
 113 #ifdef __APPLE__
 114   #include <mach/mach.h> // semaphore_* API
 115   #include <mach-o/dyld.h>
 116   #include <sys/proc_info.h>
 117   #include <objc/objc-auto.h>
 118 #endif
 119 
 120 #ifndef MAP_ANONYMOUS
 121   #define MAP_ANONYMOUS MAP_ANON
 122 #endif
 123 
 124 #define MAX_PATH    (2 * K)
 125 
 126 // for timer info max values which include all bits
 127 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 128 
 129 #define LARGEPAGES_BIT (1 << 6)
 130 
 131 ////////////////////////////////////////////////////////////////////////////////
 132 // global variables
 133 julong os::Bsd::_physical_memory = 0;
 134 
 135 #ifdef __APPLE__
 136 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
 137 volatile uint64_t         os::Bsd::_max_abstime   = 0;
 138 #else
 139 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 140 #endif
 141 pthread_t os::Bsd::_main_thread;
 142 int os::Bsd::_page_size = -1;
 143 
 144 static jlong initial_time_count=0;
 145 
 146 static int clock_tics_per_sec = 100;
 147 
 148 // For diagnostics to print a message once. see run_periodic_checks
 149 static sigset_t check_signal_done;
 150 static bool check_signals = true;
 151 
 152 static pid_t _initial_pid = 0;
 153 
 154 // Signal number used to suspend/resume a thread
 155 
 156 // do not use any signal number less than SIGSEGV, see 4355769
 157 static int SR_signum = SIGUSR2;
 158 sigset_t SR_sigset;
 159 
 160 
 161 ////////////////////////////////////////////////////////////////////////////////
 162 // utility functions
 163 
 164 static int SR_initialize();
 165 
 166 julong os::available_memory() {
 167   return Bsd::available_memory();
 168 }
 169 
 170 // available here means free
 171 julong os::Bsd::available_memory() {
 172   uint64_t available = physical_memory() >> 2;
 173 #ifdef __APPLE__
 174   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
 175   vm_statistics64_data_t vmstat;
 176   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
 177                                          (host_info64_t)&vmstat, &count);
 178   assert(kerr == KERN_SUCCESS,
 179          "host_statistics64 failed - check mach_host_self() and count");
 180   if (kerr == KERN_SUCCESS) {
 181     available = vmstat.free_count * os::vm_page_size();
 182   }
 183 #endif
 184   return available;
 185 }
 186 
 187 julong os::physical_memory() {
 188   return Bsd::physical_memory();
 189 }
 190 
 191 // Return true if user is running as root.
 192 
 193 bool os::have_special_privileges() {
 194   static bool init = false;
 195   static bool privileges = false;
 196   if (!init) {
 197     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 198     init = true;
 199   }
 200   return privileges;
 201 }
 202 
 203 
 204 
 205 // Cpu architecture string
 206 #if   defined(ZERO)
 207 static char cpu_arch[] = ZERO_LIBARCH;
 208 #elif defined(IA64)
 209 static char cpu_arch[] = "ia64";
 210 #elif defined(IA32)
 211 static char cpu_arch[] = "i386";
 212 #elif defined(AMD64)
 213 static char cpu_arch[] = "amd64";
 214 #elif defined(ARM)
 215 static char cpu_arch[] = "arm";
 216 #elif defined(PPC32)
 217 static char cpu_arch[] = "ppc";
 218 #elif defined(SPARC)
 219   #ifdef _LP64
 220 static char cpu_arch[] = "sparcv9";
 221   #else
 222 static char cpu_arch[] = "sparc";
 223   #endif
 224 #else
 225   #error Add appropriate cpu_arch setting
 226 #endif
 227 
 228 // Compiler variant
 229 #ifdef COMPILER2
 230   #define COMPILER_VARIANT "server"
 231 #else
 232   #define COMPILER_VARIANT "client"
 233 #endif
 234 
 235 
 236 void os::Bsd::initialize_system_info() {
 237   int mib[2];
 238   size_t len;
 239   int cpu_val;
 240   julong mem_val;
 241 
 242   // get processors count via hw.ncpus sysctl
 243   mib[0] = CTL_HW;
 244   mib[1] = HW_NCPU;
 245   len = sizeof(cpu_val);
 246   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 247     assert(len == sizeof(cpu_val), "unexpected data size");
 248     set_processor_count(cpu_val);
 249   } else {
 250     set_processor_count(1);   // fallback
 251   }
 252 
 253   // get physical memory via hw.memsize sysctl (hw.memsize is used
 254   // since it returns a 64 bit value)
 255   mib[0] = CTL_HW;
 256 
 257 #if defined (HW_MEMSIZE) // Apple
 258   mib[1] = HW_MEMSIZE;
 259 #elif defined(HW_PHYSMEM) // Most of BSD
 260   mib[1] = HW_PHYSMEM;
 261 #elif defined(HW_REALMEM) // Old FreeBSD
 262   mib[1] = HW_REALMEM;
 263 #else
 264   #error No ways to get physmem
 265 #endif
 266 
 267   len = sizeof(mem_val);
 268   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 269     assert(len == sizeof(mem_val), "unexpected data size");
 270     _physical_memory = mem_val;
 271   } else {
 272     _physical_memory = 256 * 1024 * 1024;       // fallback (XXXBSD?)
 273   }
 274 
 275 #ifdef __OpenBSD__
 276   {
 277     // limit _physical_memory memory view on OpenBSD since
 278     // datasize rlimit restricts us anyway.
 279     struct rlimit limits;
 280     getrlimit(RLIMIT_DATA, &limits);
 281     _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 282   }
 283 #endif
 284 }
 285 
 286 #ifdef __APPLE__
 287 static const char *get_home() {
 288   const char *home_dir = ::getenv("HOME");
 289   if ((home_dir == NULL) || (*home_dir == '\0')) {
 290     struct passwd *passwd_info = getpwuid(geteuid());
 291     if (passwd_info != NULL) {
 292       home_dir = passwd_info->pw_dir;
 293     }
 294   }
 295 
 296   return home_dir;
 297 }
 298 #endif
 299 
 300 void os::init_system_properties_values() {
 301   // The next steps are taken in the product version:
 302   //
 303   // Obtain the JAVA_HOME value from the location of libjvm.so.
 304   // This library should be located at:
 305   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 306   //
 307   // If "/jre/lib/" appears at the right place in the path, then we
 308   // assume libjvm.so is installed in a JDK and we use this path.
 309   //
 310   // Otherwise exit with message: "Could not create the Java virtual machine."
 311   //
 312   // The following extra steps are taken in the debugging version:
 313   //
 314   // If "/jre/lib/" does NOT appear at the right place in the path
 315   // instead of exit check for $JAVA_HOME environment variable.
 316   //
 317   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 318   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 319   // it looks like libjvm.so is installed there
 320   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 321   //
 322   // Otherwise exit.
 323   //
 324   // Important note: if the location of libjvm.so changes this
 325   // code needs to be changed accordingly.
 326 
 327   // See ld(1):
 328   //      The linker uses the following search paths to locate required
 329   //      shared libraries:
 330   //        1: ...
 331   //        ...
 332   //        7: The default directories, normally /lib and /usr/lib.
 333 #ifndef DEFAULT_LIBPATH
 334   #define DEFAULT_LIBPATH "/lib:/usr/lib"
 335 #endif
 336 
 337 // Base path of extensions installed on the system.
 338 #define SYS_EXT_DIR     "/usr/java/packages"
 339 #define EXTENSIONS_DIR  "/lib/ext"
 340 
 341 #ifndef __APPLE__
 342 
 343   // Buffer that fits several sprintfs.
 344   // Note that the space for the colon and the trailing null are provided
 345   // by the nulls included by the sizeof operator.
 346   const size_t bufsize =
 347     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 348          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
 349   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 350 
 351   // sysclasspath, java_home, dll_dir
 352   {
 353     char *pslash;
 354     os::jvm_path(buf, bufsize);
 355 
 356     // Found the full path to libjvm.so.
 357     // Now cut the path to <java_home>/jre if we can.
 358     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 359     pslash = strrchr(buf, '/');
 360     if (pslash != NULL) {
 361       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 362     }
 363     Arguments::set_dll_dir(buf);
 364 
 365     if (pslash != NULL) {
 366       pslash = strrchr(buf, '/');
 367       if (pslash != NULL) {
 368         *pslash = '\0';          // Get rid of /<arch>.
 369         pslash = strrchr(buf, '/');
 370         if (pslash != NULL) {
 371           *pslash = '\0';        // Get rid of /lib.
 372         }
 373       }
 374     }
 375     Arguments::set_java_home(buf);
 376     set_boot_path('/', ':');
 377   }
 378 
 379   // Where to look for native libraries.
 380   //
 381   // Note: Due to a legacy implementation, most of the library path
 382   // is set in the launcher. This was to accomodate linking restrictions
 383   // on legacy Bsd implementations (which are no longer supported).
 384   // Eventually, all the library path setting will be done here.
 385   //
 386   // However, to prevent the proliferation of improperly built native
 387   // libraries, the new path component /usr/java/packages is added here.
 388   // Eventually, all the library path setting will be done here.
 389   {
 390     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 391     // should always exist (until the legacy problem cited above is
 392     // addressed).
 393     const char *v = ::getenv("LD_LIBRARY_PATH");
 394     const char *v_colon = ":";
 395     if (v == NULL) { v = ""; v_colon = ""; }
 396     // That's +1 for the colon and +1 for the trailing '\0'.
 397     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 398                                                      strlen(v) + 1 +
 399                                                      sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
 400                                                      mtInternal);
 401     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
 402     Arguments::set_library_path(ld_library_path);
 403     FREE_C_HEAP_ARRAY(char, ld_library_path);
 404   }
 405 
 406   // Extensions directories.
 407   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
 408   Arguments::set_ext_dirs(buf);
 409 
 410   FREE_C_HEAP_ARRAY(char, buf);
 411 
 412 #else // __APPLE__
 413 
 414   #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 415   #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 416 
 417   const char *user_home_dir = get_home();
 418   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
 419   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 420     sizeof(SYS_EXTENSIONS_DIRS);
 421 
 422   // Buffer that fits several sprintfs.
 423   // Note that the space for the colon and the trailing null are provided
 424   // by the nulls included by the sizeof operator.
 425   const size_t bufsize =
 426     MAX2((size_t)MAXPATHLEN,  // for dll_dir & friends.
 427          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
 428   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 429 
 430   // sysclasspath, java_home, dll_dir
 431   {
 432     char *pslash;
 433     os::jvm_path(buf, bufsize);
 434 
 435     // Found the full path to libjvm.so.
 436     // Now cut the path to <java_home>/jre if we can.
 437     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 438     pslash = strrchr(buf, '/');
 439     if (pslash != NULL) {
 440       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 441     }
 442 #ifdef STATIC_BUILD
 443     strcat(buf, "/lib");
 444 #endif
 445 
 446     Arguments::set_dll_dir(buf);
 447 
 448     if (pslash != NULL) {
 449       pslash = strrchr(buf, '/');
 450       if (pslash != NULL) {
 451         *pslash = '\0';          // Get rid of /lib.
 452       }
 453     }
 454     Arguments::set_java_home(buf);
 455     set_boot_path('/', ':');
 456   }
 457 
 458   // Where to look for native libraries.
 459   //
 460   // Note: Due to a legacy implementation, most of the library path
 461   // is set in the launcher. This was to accomodate linking restrictions
 462   // on legacy Bsd implementations (which are no longer supported).
 463   // Eventually, all the library path setting will be done here.
 464   //
 465   // However, to prevent the proliferation of improperly built native
 466   // libraries, the new path component /usr/java/packages is added here.
 467   // Eventually, all the library path setting will be done here.
 468   {
 469     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 470     // should always exist (until the legacy problem cited above is
 471     // addressed).
 472     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
 473     // can specify a directory inside an app wrapper
 474     const char *l = ::getenv("JAVA_LIBRARY_PATH");
 475     const char *l_colon = ":";
 476     if (l == NULL) { l = ""; l_colon = ""; }
 477 
 478     const char *v = ::getenv("DYLD_LIBRARY_PATH");
 479     const char *v_colon = ":";
 480     if (v == NULL) { v = ""; v_colon = ""; }
 481 
 482     // Apple's Java6 has "." at the beginning of java.library.path.
 483     // OpenJDK on Windows has "." at the end of java.library.path.
 484     // OpenJDK on Linux and Solaris don't have "." in java.library.path
 485     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 486     // "." is appended to the end of java.library.path. Yes, this
 487     // could cause a change in behavior, but Apple's Java6 behavior
 488     // can be achieved by putting "." at the beginning of the
 489     // JAVA_LIBRARY_PATH environment variable.
 490     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 491                                                      strlen(v) + 1 + strlen(l) + 1 +
 492                                                      system_ext_size + 3,
 493                                                      mtInternal);
 494     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
 495             v, v_colon, l, l_colon, user_home_dir);
 496     Arguments::set_library_path(ld_library_path);
 497     FREE_C_HEAP_ARRAY(char, ld_library_path);
 498   }
 499 
 500   // Extensions directories.
 501   //
 502   // Note that the space for the colon and the trailing null are provided
 503   // by the nulls included by the sizeof operator (so actually one byte more
 504   // than necessary is allocated).
 505   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
 506           user_home_dir, Arguments::get_java_home());
 507   Arguments::set_ext_dirs(buf);
 508 
 509   FREE_C_HEAP_ARRAY(char, buf);
 510 
 511 #undef SYS_EXTENSIONS_DIR
 512 #undef SYS_EXTENSIONS_DIRS
 513 
 514 #endif // __APPLE__
 515 
 516 #undef SYS_EXT_DIR
 517 #undef EXTENSIONS_DIR
 518 }
 519 
 520 ////////////////////////////////////////////////////////////////////////////////
 521 // breakpoint support
 522 
 523 void os::breakpoint() {
 524   BREAKPOINT;
 525 }
 526 
 527 extern "C" void breakpoint() {
 528   // use debugger to set breakpoint here
 529 }
 530 
 531 ////////////////////////////////////////////////////////////////////////////////
 532 // signal support
 533 
 534 debug_only(static bool signal_sets_initialized = false);
 535 static sigset_t unblocked_sigs, vm_sigs;
 536 
 537 void os::Bsd::signal_sets_init() {
 538   // Should also have an assertion stating we are still single-threaded.
 539   assert(!signal_sets_initialized, "Already initialized");
 540   // Fill in signals that are necessarily unblocked for all threads in
 541   // the VM. Currently, we unblock the following signals:
 542   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 543   //                         by -Xrs (=ReduceSignalUsage));
 544   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 545   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 546   // the dispositions or masks wrt these signals.
 547   // Programs embedding the VM that want to use the above signals for their
 548   // own purposes must, at this time, use the "-Xrs" option to prevent
 549   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 550   // (See bug 4345157, and other related bugs).
 551   // In reality, though, unblocking these signals is really a nop, since
 552   // these signals are not blocked by default.
 553   sigemptyset(&unblocked_sigs);
 554   sigaddset(&unblocked_sigs, SIGILL);
 555   sigaddset(&unblocked_sigs, SIGSEGV);
 556   sigaddset(&unblocked_sigs, SIGBUS);
 557   sigaddset(&unblocked_sigs, SIGFPE);
 558   sigaddset(&unblocked_sigs, SR_signum);
 559 
 560   if (!ReduceSignalUsage) {
 561     if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 562       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 563 
 564     }
 565     if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 566       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 567     }
 568     if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 569       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 570     }
 571   }
 572   // Fill in signals that are blocked by all but the VM thread.
 573   sigemptyset(&vm_sigs);
 574   if (!ReduceSignalUsage) {
 575     sigaddset(&vm_sigs, BREAK_SIGNAL);
 576   }
 577   debug_only(signal_sets_initialized = true);
 578 
 579 }
 580 
 581 // These are signals that are unblocked while a thread is running Java.
 582 // (For some reason, they get blocked by default.)
 583 sigset_t* os::Bsd::unblocked_signals() {
 584   assert(signal_sets_initialized, "Not initialized");
 585   return &unblocked_sigs;
 586 }
 587 
 588 // These are the signals that are blocked while a (non-VM) thread is
 589 // running Java. Only the VM thread handles these signals.
 590 sigset_t* os::Bsd::vm_signals() {
 591   assert(signal_sets_initialized, "Not initialized");
 592   return &vm_sigs;
 593 }
 594 
 595 void os::Bsd::hotspot_sigmask(Thread* thread) {
 596 
 597   //Save caller's signal mask before setting VM signal mask
 598   sigset_t caller_sigmask;
 599   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 600 
 601   OSThread* osthread = thread->osthread();
 602   osthread->set_caller_sigmask(caller_sigmask);
 603 
 604   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 605 
 606   if (!ReduceSignalUsage) {
 607     if (thread->is_VM_thread()) {
 608       // Only the VM thread handles BREAK_SIGNAL ...
 609       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 610     } else {
 611       // ... all other threads block BREAK_SIGNAL
 612       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 613     }
 614   }
 615 }
 616 
 617 
 618 //////////////////////////////////////////////////////////////////////////////
 619 // create new thread
 620 
 621 #ifdef __APPLE__
 622 // library handle for calling objc_registerThreadWithCollector()
 623 // without static linking to the libobjc library
 624   #define OBJC_LIB "/usr/lib/libobjc.dylib"
 625   #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 626 typedef void (*objc_registerThreadWithCollector_t)();
 627 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 628 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 629 #endif
 630 
 631 #ifdef __APPLE__
 632 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 633   // Additional thread_id used to correlate threads in SA
 634   thread_identifier_info_data_t     m_ident_info;
 635   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 636 
 637   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 638               (thread_info_t) &m_ident_info, &count);
 639 
 640   return m_ident_info.thread_id;
 641 }
 642 #endif
 643 
 644 // Thread start routine for all newly created threads
 645 static void *thread_native_entry(Thread *thread) {
 646 
 647   thread->record_stack_base_and_size();
 648 
 649   // Try to randomize the cache line index of hot stack frames.
 650   // This helps when threads of the same stack traces evict each other's
 651   // cache lines. The threads can be either from the same JVM instance, or
 652   // from different JVM instances. The benefit is especially true for
 653   // processors with hyperthreading technology.
 654   static int counter = 0;
 655   int pid = os::current_process_id();
 656   alloca(((pid ^ counter++) & 7) * 128);
 657 
 658   thread->initialize_thread_current();
 659 
 660   OSThread* osthread = thread->osthread();
 661   Monitor* sync = osthread->startThread_lock();
 662 
 663   osthread->set_thread_id(os::Bsd::gettid());
 664 
 665   log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 666     os::current_thread_id(), (uintx) pthread_self());
 667 
 668 #ifdef __APPLE__
 669   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 670   guarantee(unique_thread_id != 0, "unique thread id was not found");
 671   osthread->set_unique_thread_id(unique_thread_id);
 672 #endif
 673   // initialize signal mask for this thread
 674   os::Bsd::hotspot_sigmask(thread);
 675 
 676   // initialize floating point control register
 677   os::Bsd::init_thread_fpu_state();
 678 
 679 #ifdef __APPLE__
 680   // register thread with objc gc
 681   if (objc_registerThreadWithCollectorFunction != NULL) {
 682     objc_registerThreadWithCollectorFunction();
 683   }
 684 #endif
 685 
 686   // handshaking with parent thread
 687   {
 688     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 689 
 690     // notify parent thread
 691     osthread->set_state(INITIALIZED);
 692     sync->notify_all();
 693 
 694     // wait until os::start_thread()
 695     while (osthread->get_state() == INITIALIZED) {
 696       sync->wait(Mutex::_no_safepoint_check_flag);
 697     }
 698   }
 699 
 700   // call one more level start routine
 701   thread->call_run();
 702 
 703   // Note: at this point the thread object may already have deleted itself.
 704   // Prevent dereferencing it from here on out.
 705   thread = NULL;
 706 
 707   log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 708     os::current_thread_id(), (uintx) pthread_self());
 709 
 710   return 0;
 711 }
 712 
 713 bool os::create_thread(Thread* thread, ThreadType thr_type,
 714                        size_t req_stack_size) {
 715   assert(thread->osthread() == NULL, "caller responsible");
 716 
 717   // Allocate the OSThread object
 718   OSThread* osthread = new OSThread(NULL, NULL);
 719   if (osthread == NULL) {
 720     return false;
 721   }
 722 
 723   // set the correct thread state
 724   osthread->set_thread_type(thr_type);
 725 
 726   // Initial state is ALLOCATED but not INITIALIZED
 727   osthread->set_state(ALLOCATED);
 728 
 729   thread->set_osthread(osthread);
 730 
 731   // init thread attributes
 732   pthread_attr_t attr;
 733   pthread_attr_init(&attr);
 734   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 735 
 736   // calculate stack size if it's not specified by caller
 737   size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
 738   int status = pthread_attr_setstacksize(&attr, stack_size);
 739   assert_status(status == 0, status, "pthread_attr_setstacksize");
 740 
 741   ThreadState state;
 742 
 743   {
 744     pthread_t tid;
 745     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
 746 
 747     char buf[64];
 748     if (ret == 0) {
 749       log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
 750         (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 751     } else {
 752       log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
 753         os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 754       // Log some OS information which might explain why creating the thread failed.
 755       log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
 756       LogStream st(Log(os, thread)::info());
 757       os::Posix::print_rlimit_info(&st);
 758       os::print_memory_info(&st);
 759     }
 760 
 761     pthread_attr_destroy(&attr);
 762 
 763     if (ret != 0) {
 764       // Need to clean up stuff we've allocated so far
 765       thread->set_osthread(NULL);
 766       delete osthread;
 767       return false;
 768     }
 769 
 770     // Store pthread info into the OSThread
 771     osthread->set_pthread_id(tid);
 772 
 773     // Wait until child thread is either initialized or aborted
 774     {
 775       Monitor* sync_with_child = osthread->startThread_lock();
 776       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 777       while ((state = osthread->get_state()) == ALLOCATED) {
 778         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 779       }
 780     }
 781 
 782   }
 783 
 784   // Aborted due to thread limit being reached
 785   if (state == ZOMBIE) {
 786     thread->set_osthread(NULL);
 787     delete osthread;
 788     return false;
 789   }
 790 
 791   // The thread is returned suspended (in state INITIALIZED),
 792   // and is started higher up in the call chain
 793   assert(state == INITIALIZED, "race condition");
 794   return true;
 795 }
 796 
 797 /////////////////////////////////////////////////////////////////////////////
 798 // attach existing thread
 799 
 800 // bootstrap the main thread
 801 bool os::create_main_thread(JavaThread* thread) {
 802   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 803   return create_attached_thread(thread);
 804 }
 805 
 806 bool os::create_attached_thread(JavaThread* thread) {
 807 #ifdef ASSERT
 808   thread->verify_not_published();
 809 #endif
 810 
 811   // Allocate the OSThread object
 812   OSThread* osthread = new OSThread(NULL, NULL);
 813 
 814   if (osthread == NULL) {
 815     return false;
 816   }
 817 
 818   osthread->set_thread_id(os::Bsd::gettid());
 819 
 820   // Store pthread info into the OSThread
 821 #ifdef __APPLE__
 822   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 823   guarantee(unique_thread_id != 0, "just checking");
 824   osthread->set_unique_thread_id(unique_thread_id);
 825 #endif
 826   osthread->set_pthread_id(::pthread_self());
 827 
 828   // initialize floating point control register
 829   os::Bsd::init_thread_fpu_state();
 830 
 831   // Initial thread state is RUNNABLE
 832   osthread->set_state(RUNNABLE);
 833 
 834   thread->set_osthread(osthread);
 835 
 836   // initialize signal mask for this thread
 837   // and save the caller's signal mask
 838   os::Bsd::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 Bsd 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   // Restore caller's signal mask
 864   sigset_t sigmask = osthread->caller_sigmask();
 865   pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 866 
 867   delete osthread;
 868 }
 869 
 870 ////////////////////////////////////////////////////////////////////////////////
 871 // time support
 872 
 873 // Time since start-up in seconds to a fine granularity.
 874 // Used by VMSelfDestructTimer and the MemProfiler.
 875 double os::elapsedTime() {
 876 
 877   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 878 }
 879 
 880 jlong os::elapsed_counter() {
 881   return javaTimeNanos() - initial_time_count;
 882 }
 883 
 884 jlong os::elapsed_frequency() {
 885   return NANOSECS_PER_SEC; // nanosecond resolution
 886 }
 887 
 888 bool os::supports_vtime() { return true; }
 889 bool os::enable_vtime()   { return false; }
 890 bool os::vtime_enabled()  { return false; }
 891 
 892 double os::elapsedVTime() {
 893   // better than nothing, but not much
 894   return elapsedTime();
 895 }
 896 
 897 jlong os::javaTimeMillis() {
 898   timeval time;
 899   int status = gettimeofday(&time, NULL);
 900   assert(status != -1, "bsd error");
 901   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 902 }
 903 
 904 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
 905   timeval time;
 906   int status = gettimeofday(&time, NULL);
 907   assert(status != -1, "bsd error");
 908   seconds = jlong(time.tv_sec);
 909   nanos = jlong(time.tv_usec) * 1000;
 910 }
 911 
 912 #ifndef __APPLE__
 913   #ifndef CLOCK_MONOTONIC
 914     #define CLOCK_MONOTONIC (1)
 915   #endif
 916 #endif
 917 
 918 #ifdef __APPLE__
 919 void os::Bsd::clock_init() {
 920   mach_timebase_info(&_timebase_info);
 921 }
 922 #else
 923 void os::Bsd::clock_init() {
 924   struct timespec res;
 925   struct timespec tp;
 926   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
 927       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
 928     // yes, monotonic clock is supported
 929     _clock_gettime = ::clock_gettime;
 930   }
 931 }
 932 #endif
 933 
 934 
 935 
 936 #ifdef __APPLE__
 937 
 938 jlong os::javaTimeNanos() {
 939   const uint64_t tm = mach_absolute_time();
 940   const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
 941   const uint64_t prev = Bsd::_max_abstime;
 942   if (now <= prev) {
 943     return prev;   // same or retrograde time;
 944   }
 945   const uint64_t obsv = Atomic::cmpxchg(now, &Bsd::_max_abstime, prev);
 946   assert(obsv >= prev, "invariant");   // Monotonicity
 947   // If the CAS succeeded then we're done and return "now".
 948   // If the CAS failed and the observed value "obsv" is >= now then
 949   // we should return "obsv".  If the CAS failed and now > obsv > prv then
 950   // some other thread raced this thread and installed a new value, in which case
 951   // we could either (a) retry the entire operation, (b) retry trying to install now
 952   // or (c) just return obsv.  We use (c).   No loop is required although in some cases
 953   // we might discard a higher "now" value in deference to a slightly lower but freshly
 954   // installed obsv value.   That's entirely benign -- it admits no new orderings compared
 955   // to (a) or (b) -- and greatly reduces coherence traffic.
 956   // We might also condition (c) on the magnitude of the delta between obsv and now.
 957   // Avoiding excessive CAS operations to hot RW locations is critical.
 958   // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
 959   return (prev == obsv) ? now : obsv;
 960 }
 961 
 962 #else // __APPLE__
 963 
 964 jlong os::javaTimeNanos() {
 965   if (os::supports_monotonic_clock()) {
 966     struct timespec tp;
 967     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
 968     assert(status == 0, "gettime error");
 969     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
 970     return result;
 971   } else {
 972     timeval time;
 973     int status = gettimeofday(&time, NULL);
 974     assert(status != -1, "bsd error");
 975     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
 976     return 1000 * usecs;
 977   }
 978 }
 979 
 980 #endif // __APPLE__
 981 
 982 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
 983   if (os::supports_monotonic_clock()) {
 984     info_ptr->max_value = ALL_64_BITS;
 985 
 986     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
 987     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
 988     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
 989   } else {
 990     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
 991     info_ptr->max_value = ALL_64_BITS;
 992 
 993     // gettimeofday is a real time clock so it skips
 994     info_ptr->may_skip_backward = true;
 995     info_ptr->may_skip_forward = true;
 996   }
 997 
 998   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
 999 }
1000 
1001 // Return the real, user, and system times in seconds from an
1002 // arbitrary fixed point in the past.
1003 bool os::getTimesSecs(double* process_real_time,
1004                       double* process_user_time,
1005                       double* process_system_time) {
1006   struct tms ticks;
1007   clock_t real_ticks = times(&ticks);
1008 
1009   if (real_ticks == (clock_t) (-1)) {
1010     return false;
1011   } else {
1012     double ticks_per_second = (double) clock_tics_per_sec;
1013     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1014     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1015     *process_real_time = ((double) real_ticks) / ticks_per_second;
1016 
1017     return true;
1018   }
1019 }
1020 
1021 
1022 char * os::local_time_string(char *buf, size_t buflen) {
1023   struct tm t;
1024   time_t long_time;
1025   time(&long_time);
1026   localtime_r(&long_time, &t);
1027   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1028                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1029                t.tm_hour, t.tm_min, t.tm_sec);
1030   return buf;
1031 }
1032 
1033 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1034   return localtime_r(clock, res);
1035 }
1036 
1037 ////////////////////////////////////////////////////////////////////////////////
1038 // runtime exit support
1039 
1040 // Note: os::shutdown() might be called very early during initialization, or
1041 // called from signal handler. Before adding something to os::shutdown(), make
1042 // sure it is async-safe and can handle partially initialized VM.
1043 void os::shutdown() {
1044 
1045   // allow PerfMemory to attempt cleanup of any persistent resources
1046   perfMemory_exit();
1047 
1048   // needs to remove object in file system
1049   AttachListener::abort();
1050 
1051   // flush buffered output, finish log files
1052   ostream_abort();
1053 
1054   // Check for abort hook
1055   abort_hook_t abort_hook = Arguments::abort_hook();
1056   if (abort_hook != NULL) {
1057     abort_hook();
1058   }
1059 
1060 }
1061 
1062 // Note: os::abort() might be called very early during initialization, or
1063 // called from signal handler. Before adding something to os::abort(), make
1064 // sure it is async-safe and can handle partially initialized VM.
1065 void os::abort(bool dump_core, void* siginfo, const void* context) {
1066   os::shutdown();
1067   if (dump_core) {
1068 #ifndef PRODUCT
1069     fdStream out(defaultStream::output_fd());
1070     out.print_raw("Current thread is ");
1071     char buf[16];
1072     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1073     out.print_raw_cr(buf);
1074     out.print_raw_cr("Dumping core ...");
1075 #endif
1076     ::abort(); // dump core
1077   }
1078 
1079   ::exit(1);
1080 }
1081 
1082 // Die immediately, no exit hook, no abort hook, no cleanup.
1083 void os::die() {
1084   // _exit() on BsdThreads only kills current thread
1085   ::abort();
1086 }
1087 
1088 // This method is a copy of JDK's sysGetLastErrorString
1089 // from src/solaris/hpi/src/system_md.c
1090 
1091 size_t os::lasterror(char *buf, size_t len) {
1092   if (errno == 0)  return 0;
1093 
1094   const char *s = os::strerror(errno);
1095   size_t n = ::strlen(s);
1096   if (n >= len) {
1097     n = len - 1;
1098   }
1099   ::strncpy(buf, s, n);
1100   buf[n] = '\0';
1101   return n;
1102 }
1103 
1104 // Information of current thread in variety of formats
1105 pid_t os::Bsd::gettid() {
1106   int retval = -1;
1107 
1108 #ifdef __APPLE__ //XNU kernel
1109   // despite the fact mach port is actually not a thread id use it
1110   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1111   retval = ::pthread_mach_thread_np(::pthread_self());
1112   guarantee(retval != 0, "just checking");
1113   return retval;
1114 
1115 #else
1116   #ifdef __FreeBSD__
1117   retval = syscall(SYS_thr_self);
1118   #else
1119     #ifdef __OpenBSD__
1120   retval = syscall(SYS_getthrid);
1121     #else
1122       #ifdef __NetBSD__
1123   retval = (pid_t) syscall(SYS__lwp_self);
1124       #endif
1125     #endif
1126   #endif
1127 #endif
1128 
1129   if (retval == -1) {
1130     return getpid();
1131   }
1132 }
1133 
1134 intx os::current_thread_id() {
1135 #ifdef __APPLE__
1136   return (intx)::pthread_mach_thread_np(::pthread_self());
1137 #else
1138   return (intx)::pthread_self();
1139 #endif
1140 }
1141 
1142 int os::current_process_id() {
1143 
1144   // Under the old bsd thread library, bsd gives each thread
1145   // its own process id. Because of this each thread will return
1146   // a different pid if this method were to return the result
1147   // of getpid(2). Bsd provides no api that returns the pid
1148   // of the launcher thread for the vm. This implementation
1149   // returns a unique pid, the pid of the launcher thread
1150   // that starts the vm 'process'.
1151 
1152   // Under the NPTL, getpid() returns the same pid as the
1153   // launcher thread rather than a unique pid per thread.
1154   // Use gettid() if you want the old pre NPTL behaviour.
1155 
1156   // if you are looking for the result of a call to getpid() that
1157   // returns a unique pid for the calling thread, then look at the
1158   // OSThread::thread_id() method in osThread_bsd.hpp file
1159 
1160   return (int)(_initial_pid ? _initial_pid : getpid());
1161 }
1162 
1163 // DLL functions
1164 
1165 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1166 
1167 // This must be hard coded because it's the system's temporary
1168 // directory not the java application's temp directory, ala java.io.tmpdir.
1169 #ifdef __APPLE__
1170 // macosx has a secure per-user temporary directory
1171 char temp_path_storage[PATH_MAX];
1172 const char* os::get_temp_directory() {
1173   static char *temp_path = NULL;
1174   if (temp_path == NULL) {
1175     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1176     if (pathSize == 0 || pathSize > PATH_MAX) {
1177       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1178     }
1179     temp_path = temp_path_storage;
1180   }
1181   return temp_path;
1182 }
1183 #else // __APPLE__
1184 const char* os::get_temp_directory() { return "/tmp"; }
1185 #endif // __APPLE__
1186 
1187 // check if addr is inside libjvm.so
1188 bool os::address_is_in_vm(address addr) {
1189   static address libjvm_base_addr;
1190   Dl_info dlinfo;
1191 
1192   if (libjvm_base_addr == NULL) {
1193     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1194       libjvm_base_addr = (address)dlinfo.dli_fbase;
1195     }
1196     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1197   }
1198 
1199   if (dladdr((void *)addr, &dlinfo) != 0) {
1200     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1201   }
1202 
1203   return false;
1204 }
1205 
1206 
1207 #define MACH_MAXSYMLEN 256
1208 
1209 bool os::dll_address_to_function_name(address addr, char *buf,
1210                                       int buflen, int *offset,
1211                                       bool demangle) {
1212   // buf is not optional, but offset is optional
1213   assert(buf != NULL, "sanity check");
1214 
1215   Dl_info dlinfo;
1216   char localbuf[MACH_MAXSYMLEN];
1217 
1218   if (dladdr((void*)addr, &dlinfo) != 0) {
1219     // see if we have a matching symbol
1220     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1221       if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1222         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1223       }
1224       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1225       return true;
1226     }
1227     // no matching symbol so try for just file info
1228     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1229       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1230                           buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1231         return true;
1232       }
1233     }
1234 
1235     // Handle non-dynamic manually:
1236     if (dlinfo.dli_fbase != NULL &&
1237         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1238                         dlinfo.dli_fbase)) {
1239       if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) {
1240         jio_snprintf(buf, buflen, "%s", localbuf);
1241       }
1242       return true;
1243     }
1244   }
1245   buf[0] = '\0';
1246   if (offset != NULL) *offset = -1;
1247   return false;
1248 }
1249 
1250 // ported from solaris version
1251 bool os::dll_address_to_library_name(address addr, char* buf,
1252                                      int buflen, int* offset) {
1253   // buf is not optional, but offset is optional
1254   assert(buf != NULL, "sanity check");
1255 
1256   Dl_info dlinfo;
1257 
1258   if (dladdr((void*)addr, &dlinfo) != 0) {
1259     if (dlinfo.dli_fname != NULL) {
1260       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1261     }
1262     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1263       *offset = addr - (address)dlinfo.dli_fbase;
1264     }
1265     return true;
1266   }
1267 
1268   buf[0] = '\0';
1269   if (offset) *offset = -1;
1270   return false;
1271 }
1272 
1273 // Loads .dll/.so and
1274 // in case of error it checks if .dll/.so was built for the
1275 // same architecture as Hotspot is running on
1276 
1277 #ifdef __APPLE__
1278 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1279 #ifdef STATIC_BUILD
1280   return os::get_default_process_handle();
1281 #else
1282   void * result= ::dlopen(filename, RTLD_LAZY);
1283   if (result != NULL) {
1284     // Successful loading
1285     return result;
1286   }
1287 
1288   // Read system error message into ebuf
1289   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1290   ebuf[ebuflen-1]='\0';
1291 
1292   return NULL;
1293 #endif // STATIC_BUILD
1294 }
1295 #else
1296 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1297 #ifdef STATIC_BUILD
1298   return os::get_default_process_handle();
1299 #else
1300   void * result= ::dlopen(filename, RTLD_LAZY);
1301   if (result != NULL) {
1302     // Successful loading
1303     return result;
1304   }
1305 
1306   Elf32_Ehdr elf_head;
1307 
1308   // Read system error message into ebuf
1309   // It may or may not be overwritten below
1310   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1311   ebuf[ebuflen-1]='\0';
1312   int diag_msg_max_length=ebuflen-strlen(ebuf);
1313   char* diag_msg_buf=ebuf+strlen(ebuf);
1314 
1315   if (diag_msg_max_length==0) {
1316     // No more space in ebuf for additional diagnostics message
1317     return NULL;
1318   }
1319 
1320 
1321   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1322 
1323   if (file_descriptor < 0) {
1324     // Can't open library, report dlerror() message
1325     return NULL;
1326   }
1327 
1328   bool failed_to_read_elf_head=
1329     (sizeof(elf_head)!=
1330      (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1331 
1332   ::close(file_descriptor);
1333   if (failed_to_read_elf_head) {
1334     // file i/o error - report dlerror() msg
1335     return NULL;
1336   }
1337 
1338   typedef struct {
1339     Elf32_Half  code;         // Actual value as defined in elf.h
1340     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1341     char        elf_class;    // 32 or 64 bit
1342     char        endianess;    // MSB or LSB
1343     char*       name;         // String representation
1344   } arch_t;
1345 
1346   #ifndef EM_486
1347     #define EM_486          6               /* Intel 80486 */
1348   #endif
1349 
1350   #ifndef EM_MIPS_RS3_LE
1351     #define EM_MIPS_RS3_LE  10              /* MIPS */
1352   #endif
1353 
1354   #ifndef EM_PPC64
1355     #define EM_PPC64        21              /* PowerPC64 */
1356   #endif
1357 
1358   #ifndef EM_S390
1359     #define EM_S390         22              /* IBM System/390 */
1360   #endif
1361 
1362   #ifndef EM_IA_64
1363     #define EM_IA_64        50              /* HP/Intel IA-64 */
1364   #endif
1365 
1366   #ifndef EM_X86_64
1367     #define EM_X86_64       62              /* AMD x86-64 */
1368   #endif
1369 
1370   static const arch_t arch_array[]={
1371     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1372     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1373     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1374     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1375     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1376     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1377     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1378     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1379     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1380     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1381     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1382     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1383     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1384     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1385     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1386     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1387   };
1388 
1389   #if  (defined IA32)
1390   static  Elf32_Half running_arch_code=EM_386;
1391   #elif   (defined AMD64)
1392   static  Elf32_Half running_arch_code=EM_X86_64;
1393   #elif  (defined IA64)
1394   static  Elf32_Half running_arch_code=EM_IA_64;
1395   #elif  (defined __sparc) && (defined _LP64)
1396   static  Elf32_Half running_arch_code=EM_SPARCV9;
1397   #elif  (defined __sparc) && (!defined _LP64)
1398   static  Elf32_Half running_arch_code=EM_SPARC;
1399   #elif  (defined __powerpc64__)
1400   static  Elf32_Half running_arch_code=EM_PPC64;
1401   #elif  (defined __powerpc__)
1402   static  Elf32_Half running_arch_code=EM_PPC;
1403   #elif  (defined ARM)
1404   static  Elf32_Half running_arch_code=EM_ARM;
1405   #elif  (defined S390)
1406   static  Elf32_Half running_arch_code=EM_S390;
1407   #elif  (defined ALPHA)
1408   static  Elf32_Half running_arch_code=EM_ALPHA;
1409   #elif  (defined MIPSEL)
1410   static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1411   #elif  (defined PARISC)
1412   static  Elf32_Half running_arch_code=EM_PARISC;
1413   #elif  (defined MIPS)
1414   static  Elf32_Half running_arch_code=EM_MIPS;
1415   #elif  (defined M68K)
1416   static  Elf32_Half running_arch_code=EM_68K;
1417   #else
1418     #error Method os::dll_load requires that one of following is defined:\
1419          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1420   #endif
1421 
1422   // Identify compatability class for VM's architecture and library's architecture
1423   // Obtain string descriptions for architectures
1424 
1425   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1426   int running_arch_index=-1;
1427 
1428   for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1429     if (running_arch_code == arch_array[i].code) {
1430       running_arch_index    = i;
1431     }
1432     if (lib_arch.code == arch_array[i].code) {
1433       lib_arch.compat_class = arch_array[i].compat_class;
1434       lib_arch.name         = arch_array[i].name;
1435     }
1436   }
1437 
1438   assert(running_arch_index != -1,
1439          "Didn't find running architecture code (running_arch_code) in arch_array");
1440   if (running_arch_index == -1) {
1441     // Even though running architecture detection failed
1442     // we may still continue with reporting dlerror() message
1443     return NULL;
1444   }
1445 
1446   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1447     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1448     return NULL;
1449   }
1450 
1451 #ifndef S390
1452   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1453     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1454     return NULL;
1455   }
1456 #endif // !S390
1457 
1458   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1459     if (lib_arch.name!=NULL) {
1460       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1461                  " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1462                  lib_arch.name, arch_array[running_arch_index].name);
1463     } else {
1464       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1465                  " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1466                  lib_arch.code,
1467                  arch_array[running_arch_index].name);
1468     }
1469   }
1470 
1471   return NULL;
1472 #endif // STATIC_BUILD
1473 }
1474 #endif // !__APPLE__
1475 
1476 void* os::get_default_process_handle() {
1477 #ifdef __APPLE__
1478   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1479   // to avoid finding unexpected symbols on second (or later)
1480   // loads of a library.
1481   return (void*)::dlopen(NULL, RTLD_FIRST);
1482 #else
1483   return (void*)::dlopen(NULL, RTLD_LAZY);
1484 #endif
1485 }
1486 
1487 // XXX: Do we need a lock around this as per Linux?
1488 void* os::dll_lookup(void* handle, const char* name) {
1489   return dlsym(handle, name);
1490 }
1491 
1492 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1493   outputStream * out = (outputStream *) param;
1494   out->print_cr(INTPTR_FORMAT " \t%s", (intptr_t)base_address, name);
1495   return 0;
1496 }
1497 
1498 void os::print_dll_info(outputStream *st) {
1499   st->print_cr("Dynamic libraries:");
1500   if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1501     st->print_cr("Error: Cannot print dynamic libraries.");
1502   }
1503 }
1504 
1505 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1506 #ifdef RTLD_DI_LINKMAP
1507   Dl_info dli;
1508   void *handle;
1509   Link_map *map;
1510   Link_map *p;
1511 
1512   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1513       dli.dli_fname == NULL) {
1514     return 1;
1515   }
1516   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1517   if (handle == NULL) {
1518     return 1;
1519   }
1520   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1521   if (map == NULL) {
1522     dlclose(handle);
1523     return 1;
1524   }
1525 
1526   while (map->l_prev != NULL)
1527     map = map->l_prev;
1528 
1529   while (map != NULL) {
1530     // Value for top_address is returned as 0 since we don't have any information about module size
1531     if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1532       dlclose(handle);
1533       return 1;
1534     }
1535     map = map->l_next;
1536   }
1537 
1538   dlclose(handle);
1539 #elif defined(__APPLE__)
1540   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1541     // Value for top_address is returned as 0 since we don't have any information about module size
1542     if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1543       return 1;
1544     }
1545   }
1546   return 0;
1547 #else
1548   return 1;
1549 #endif
1550 }
1551 
1552 void os::get_summary_os_info(char* buf, size_t buflen) {
1553   // These buffers are small because we want this to be brief
1554   // and not use a lot of stack while generating the hs_err file.
1555   char os[100];
1556   size_t size = sizeof(os);
1557   int mib_kern[] = { CTL_KERN, KERN_OSTYPE };
1558   if (sysctl(mib_kern, 2, os, &size, NULL, 0) < 0) {
1559 #ifdef __APPLE__
1560       strncpy(os, "Darwin", sizeof(os));
1561 #elif __OpenBSD__
1562       strncpy(os, "OpenBSD", sizeof(os));
1563 #else
1564       strncpy(os, "BSD", sizeof(os));
1565 #endif
1566   }
1567 
1568   char release[100];
1569   size = sizeof(release);
1570   int mib_release[] = { CTL_KERN, KERN_OSRELEASE };
1571   if (sysctl(mib_release, 2, release, &size, NULL, 0) < 0) {
1572       // if error, leave blank
1573       strncpy(release, "", sizeof(release));
1574   }
1575   snprintf(buf, buflen, "%s %s", os, release);
1576 }
1577 
1578 void os::print_os_info_brief(outputStream* st) {
1579   os::Posix::print_uname_info(st);
1580 }
1581 
1582 void os::print_os_info(outputStream* st) {
1583   st->print("OS:");
1584 
1585   os::Posix::print_uname_info(st);
1586 
1587   os::Posix::print_rlimit_info(st);
1588 
1589   os::Posix::print_load_average(st);
1590 }
1591 
1592 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1593   // Nothing to do for now.
1594 }
1595 
1596 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1597   unsigned int mhz;
1598   size_t size = sizeof(mhz);
1599   int mib[] = { CTL_HW, HW_CPU_FREQ };
1600   if (sysctl(mib, 2, &mhz, &size, NULL, 0) < 0) {
1601     mhz = 1;  // looks like an error but can be divided by
1602   } else {
1603     mhz /= 1000000;  // reported in millions
1604   }
1605 
1606   char model[100];
1607   size = sizeof(model);
1608   int mib_model[] = { CTL_HW, HW_MODEL };
1609   if (sysctl(mib_model, 2, model, &size, NULL, 0) < 0) {
1610     strncpy(model, cpu_arch, sizeof(model));
1611   }
1612 
1613   char machine[100];
1614   size = sizeof(machine);
1615   int mib_machine[] = { CTL_HW, HW_MACHINE };
1616   if (sysctl(mib_machine, 2, machine, &size, NULL, 0) < 0) {
1617       strncpy(machine, "", sizeof(machine));
1618   }
1619 
1620   snprintf(buf, buflen, "%s %s %d MHz", model, machine, mhz);
1621 }
1622 
1623 void os::print_memory_info(outputStream* st) {
1624   xsw_usage swap_usage;
1625   size_t size = sizeof(swap_usage);
1626 
1627   st->print("Memory:");
1628   st->print(" %dk page", os::vm_page_size()>>10);
1629 
1630   st->print(", physical " UINT64_FORMAT "k",
1631             os::physical_memory() >> 10);
1632   st->print("(" UINT64_FORMAT "k free)",
1633             os::available_memory() >> 10);
1634 
1635   if((sysctlbyname("vm.swapusage", &swap_usage, &size, NULL, 0) == 0) || (errno == ENOMEM)) {
1636     if (size >= offset_of(xsw_usage, xsu_used)) {
1637       st->print(", swap " UINT64_FORMAT "k",
1638                 ((julong) swap_usage.xsu_total) >> 10);
1639       st->print("(" UINT64_FORMAT "k free)",
1640                 ((julong) swap_usage.xsu_avail) >> 10);
1641     }
1642   }
1643 
1644   st->cr();
1645 }
1646 
1647 static void print_signal_handler(outputStream* st, int sig,
1648                                  char* buf, size_t buflen);
1649 
1650 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1651   st->print_cr("Signal Handlers:");
1652   print_signal_handler(st, SIGSEGV, buf, buflen);
1653   print_signal_handler(st, SIGBUS , buf, buflen);
1654   print_signal_handler(st, SIGFPE , buf, buflen);
1655   print_signal_handler(st, SIGPIPE, buf, buflen);
1656   print_signal_handler(st, SIGXFSZ, buf, buflen);
1657   print_signal_handler(st, SIGILL , buf, buflen);
1658   print_signal_handler(st, SR_signum, buf, buflen);
1659   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1660   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1661   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1662   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1663 }
1664 
1665 static char saved_jvm_path[MAXPATHLEN] = {0};
1666 
1667 // Find the full path to the current module, libjvm
1668 void os::jvm_path(char *buf, jint buflen) {
1669   // Error checking.
1670   if (buflen < MAXPATHLEN) {
1671     assert(false, "must use a large-enough buffer");
1672     buf[0] = '\0';
1673     return;
1674   }
1675   // Lazy resolve the path to current module.
1676   if (saved_jvm_path[0] != 0) {
1677     strcpy(buf, saved_jvm_path);
1678     return;
1679   }
1680 
1681   char dli_fname[MAXPATHLEN];
1682   bool ret = dll_address_to_library_name(
1683                                          CAST_FROM_FN_PTR(address, os::jvm_path),
1684                                          dli_fname, sizeof(dli_fname), NULL);
1685   assert(ret, "cannot locate libjvm");
1686   char *rp = NULL;
1687   if (ret && dli_fname[0] != '\0') {
1688     rp = os::Posix::realpath(dli_fname, buf, buflen);
1689   }
1690   if (rp == NULL) {
1691     return;
1692   }
1693 
1694   if (Arguments::sun_java_launcher_is_altjvm()) {
1695     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1696     // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1697     // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1698     // appears at the right place in the string, then assume we are
1699     // installed in a JDK and we're done. Otherwise, check for a
1700     // JAVA_HOME environment variable and construct a path to the JVM
1701     // being overridden.
1702 
1703     const char *p = buf + strlen(buf) - 1;
1704     for (int count = 0; p > buf && count < 5; ++count) {
1705       for (--p; p > buf && *p != '/'; --p)
1706         /* empty */ ;
1707     }
1708 
1709     if (strncmp(p, "/jre/lib/", 9) != 0) {
1710       // Look for JAVA_HOME in the environment.
1711       char* java_home_var = ::getenv("JAVA_HOME");
1712       if (java_home_var != NULL && java_home_var[0] != 0) {
1713         char* jrelib_p;
1714         int len;
1715 
1716         // Check the current module name "libjvm"
1717         p = strrchr(buf, '/');
1718         assert(strstr(p, "/libjvm") == p, "invalid library name");
1719 
1720         rp = os::Posix::realpath(java_home_var, buf, buflen);
1721         if (rp == NULL) {
1722           return;
1723         }
1724 
1725         // determine if this is a legacy image or modules image
1726         // modules image doesn't have "jre" subdirectory
1727         len = strlen(buf);
1728         assert(len < buflen, "Ran out of buffer space");
1729         jrelib_p = buf + len;
1730 
1731         // Add the appropriate library subdir
1732         snprintf(jrelib_p, buflen-len, "/jre/lib");
1733         if (0 != access(buf, F_OK)) {
1734           snprintf(jrelib_p, buflen-len, "/lib");
1735         }
1736 
1737         // Add the appropriate client or server subdir
1738         len = strlen(buf);
1739         jrelib_p = buf + len;
1740         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1741         if (0 != access(buf, F_OK)) {
1742           snprintf(jrelib_p, buflen-len, "%s", "");
1743         }
1744 
1745         // If the path exists within JAVA_HOME, add the JVM library name
1746         // to complete the path to JVM being overridden.  Otherwise fallback
1747         // to the path to the current library.
1748         if (0 == access(buf, F_OK)) {
1749           // Use current module name "libjvm"
1750           len = strlen(buf);
1751           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1752         } else {
1753           // Fall back to path of current library
1754           rp = os::Posix::realpath(dli_fname, buf, buflen);
1755           if (rp == NULL) {
1756             return;
1757           }
1758         }
1759       }
1760     }
1761   }
1762 
1763   strncpy(saved_jvm_path, buf, MAXPATHLEN);
1764   saved_jvm_path[MAXPATHLEN - 1] = '\0';
1765 }
1766 
1767 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1768   // no prefix required, not even "_"
1769 }
1770 
1771 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1772   // no suffix required
1773 }
1774 
1775 ////////////////////////////////////////////////////////////////////////////////
1776 // sun.misc.Signal support
1777 
1778 static volatile jint sigint_count = 0;
1779 
1780 static void UserHandler(int sig, void *siginfo, void *context) {
1781   // 4511530 - sem_post is serialized and handled by the manager thread. When
1782   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1783   // don't want to flood the manager thread with sem_post requests.
1784   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
1785     return;
1786   }
1787 
1788   // Ctrl-C is pressed during error reporting, likely because the error
1789   // handler fails to abort. Let VM die immediately.
1790   if (sig == SIGINT && VMError::is_error_reported()) {
1791     os::die();
1792   }
1793 
1794   os::signal_notify(sig);
1795 }
1796 
1797 void* os::user_handler() {
1798   return CAST_FROM_FN_PTR(void*, UserHandler);
1799 }
1800 
1801 extern "C" {
1802   typedef void (*sa_handler_t)(int);
1803   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1804 }
1805 
1806 void* os::signal(int signal_number, void* handler) {
1807   struct sigaction sigAct, oldSigAct;
1808 
1809   sigfillset(&(sigAct.sa_mask));
1810   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1811   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1812 
1813   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1814     // -1 means registration failed
1815     return (void *)-1;
1816   }
1817 
1818   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1819 }
1820 
1821 void os::signal_raise(int signal_number) {
1822   ::raise(signal_number);
1823 }
1824 
1825 // The following code is moved from os.cpp for making this
1826 // code platform specific, which it is by its very nature.
1827 
1828 // Will be modified when max signal is changed to be dynamic
1829 int os::sigexitnum_pd() {
1830   return NSIG;
1831 }
1832 
1833 // a counter for each possible signal value
1834 static volatile jint pending_signals[NSIG+1] = { 0 };
1835 static Semaphore* sig_sem = NULL;
1836 
1837 static void jdk_misc_signal_init() {
1838   // Initialize signal structures
1839   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1840 
1841   // Initialize signal semaphore
1842   sig_sem = new Semaphore();
1843 }
1844 
1845 void os::signal_notify(int sig) {
1846   if (sig_sem != NULL) {
1847     Atomic::inc(&pending_signals[sig]);
1848     sig_sem->signal();
1849   } else {
1850     // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
1851     // initialization isn't called.
1852     assert(ReduceSignalUsage, "signal semaphore should be created");
1853   }
1854 }
1855 
1856 static int check_pending_signals() {
1857   Atomic::store(0, &sigint_count);
1858   for (;;) {
1859     for (int i = 0; i < NSIG + 1; i++) {
1860       jint n = pending_signals[i];
1861       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1862         return i;
1863       }
1864     }
1865     JavaThread *thread = JavaThread::current();
1866     ThreadBlockInVM tbivm(thread);
1867 
1868     bool threadIsSuspended;
1869     do {
1870       thread->set_suspend_equivalent();
1871       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1872       sig_sem->wait();
1873 
1874       // were we externally suspended while we were waiting?
1875       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1876       if (threadIsSuspended) {
1877         // The semaphore has been incremented, but while we were waiting
1878         // another thread suspended us. We don't want to continue running
1879         // while suspended because that would surprise the thread that
1880         // suspended us.
1881         sig_sem->signal();
1882 
1883         thread->java_suspend_self();
1884       }
1885     } while (threadIsSuspended);
1886   }
1887 }
1888 
1889 int os::signal_wait() {
1890   return check_pending_signals();
1891 }
1892 
1893 ////////////////////////////////////////////////////////////////////////////////
1894 // Virtual Memory
1895 
1896 int os::vm_page_size() {
1897   // Seems redundant as all get out
1898   assert(os::Bsd::page_size() != -1, "must call os::init");
1899   return os::Bsd::page_size();
1900 }
1901 
1902 // Solaris allocates memory by pages.
1903 int os::vm_allocation_granularity() {
1904   assert(os::Bsd::page_size() != -1, "must call os::init");
1905   return os::Bsd::page_size();
1906 }
1907 
1908 // Rationale behind this function:
1909 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
1910 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
1911 //  samples for JITted code. Here we create private executable mapping over the code cache
1912 //  and then we can use standard (well, almost, as mapping can change) way to provide
1913 //  info for the reporting script by storing timestamp and location of symbol
1914 void bsd_wrap_code(char* base, size_t size) {
1915   static volatile jint cnt = 0;
1916 
1917   if (!UseOprofile) {
1918     return;
1919   }
1920 
1921   char buf[PATH_MAX + 1];
1922   int num = Atomic::add(1, &cnt);
1923 
1924   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
1925            os::get_temp_directory(), os::current_process_id(), num);
1926   unlink(buf);
1927 
1928   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
1929 
1930   if (fd != -1) {
1931     off_t rv = ::lseek(fd, size-2, SEEK_SET);
1932     if (rv != (off_t)-1) {
1933       if (::write(fd, "", 1) == 1) {
1934         mmap(base, size,
1935              PROT_READ|PROT_WRITE|PROT_EXEC,
1936              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
1937       }
1938     }
1939     ::close(fd);
1940     unlink(buf);
1941   }
1942 }
1943 
1944 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
1945                                     int err) {
1946   warning("INFO: os::commit_memory(" INTPTR_FORMAT ", " SIZE_FORMAT
1947           ", %d) failed; error='%s' (errno=%d)", (intptr_t)addr, size, exec,
1948            os::errno_name(err), err);
1949 }
1950 
1951 // NOTE: Bsd kernel does not really reserve the pages for us.
1952 //       All it does is to check if there are enough free pages
1953 //       left at the time of mmap(). This could be a potential
1954 //       problem.
1955 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
1956   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
1957 #ifdef __OpenBSD__
1958   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
1959   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
1960   if (::mprotect(addr, size, prot) == 0) {
1961     return true;
1962   }
1963 #else
1964   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
1965                                      MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
1966   if (res != (uintptr_t) MAP_FAILED) {
1967     return true;
1968   }
1969 #endif
1970 
1971   // Warn about any commit errors we see in non-product builds just
1972   // in case mmap() doesn't work as described on the man page.
1973   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
1974 
1975   return false;
1976 }
1977 
1978 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
1979                           bool exec) {
1980   // alignment_hint is ignored on this OS
1981   return pd_commit_memory(addr, size, exec);
1982 }
1983 
1984 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
1985                                   const char* mesg) {
1986   assert(mesg != NULL, "mesg must be specified");
1987   if (!pd_commit_memory(addr, size, exec)) {
1988     // add extra info in product mode for vm_exit_out_of_memory():
1989     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
1990     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
1991   }
1992 }
1993 
1994 void os::pd_commit_memory_or_exit(char* addr, size_t size,
1995                                   size_t alignment_hint, bool exec,
1996                                   const char* mesg) {
1997   // alignment_hint is ignored on this OS
1998   pd_commit_memory_or_exit(addr, size, exec, mesg);
1999 }
2000 
2001 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2002 }
2003 
2004 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2005   ::madvise(addr, bytes, MADV_DONTNEED);
2006 }
2007 
2008 void os::numa_make_global(char *addr, size_t bytes) {
2009 }
2010 
2011 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2012 }
2013 
2014 bool os::numa_topology_changed()   { return false; }
2015 
2016 size_t os::numa_get_groups_num() {
2017   return 1;
2018 }
2019 
2020 int os::numa_get_group_id() {
2021   return 0;
2022 }
2023 
2024 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2025   if (size > 0) {
2026     ids[0] = 0;
2027     return 1;
2028   }
2029   return 0;
2030 }
2031 
2032 bool os::get_page_info(char *start, page_info* info) {
2033   return false;
2034 }
2035 
2036 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2037   return end;
2038 }
2039 
2040 
2041 bool os::pd_uncommit_memory(char* addr, size_t size) {
2042 #ifdef __OpenBSD__
2043   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2044   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with PROT_NONE", p2i(addr), p2i(addr+size));
2045   return ::mprotect(addr, size, PROT_NONE) == 0;
2046 #else
2047   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2048                                      MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2049   return res  != (uintptr_t) MAP_FAILED;
2050 #endif
2051 }
2052 
2053 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2054   return os::commit_memory(addr, size, !ExecMem);
2055 }
2056 
2057 // If this is a growable mapping, remove the guard pages entirely by
2058 // munmap()ping them.  If not, just call uncommit_memory().
2059 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2060   return os::uncommit_memory(addr, size);
2061 }
2062 
2063 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2064 // at 'requested_addr'. If there are existing memory mappings at the same
2065 // location, however, they will be overwritten. If 'fixed' is false,
2066 // 'requested_addr' is only treated as a hint, the return value may or
2067 // may not start from the requested address. Unlike Bsd mmap(), this
2068 // function returns NULL to indicate failure.
2069 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2070   char * addr;
2071   int flags;
2072 
2073   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2074   if (fixed) {
2075     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2076     flags |= MAP_FIXED;
2077   }
2078 
2079   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2080   // touch an uncommitted page. Otherwise, the read/write might
2081   // succeed if we have enough swap space to back the physical page.
2082   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2083                        flags, -1, 0);
2084 
2085   return addr == MAP_FAILED ? NULL : addr;
2086 }
2087 
2088 static int anon_munmap(char * addr, size_t size) {
2089   return ::munmap(addr, size) == 0;
2090 }
2091 
2092 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2093                             size_t alignment_hint) {
2094   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2095 }
2096 
2097 bool os::pd_release_memory(char* addr, size_t size) {
2098   return anon_munmap(addr, size);
2099 }
2100 
2101 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2102   // Bsd wants the mprotect address argument to be page aligned.
2103   char* bottom = (char*)align_down((intptr_t)addr, os::Bsd::page_size());
2104 
2105   // According to SUSv3, mprotect() should only be used with mappings
2106   // established by mmap(), and mmap() always maps whole pages. Unaligned
2107   // 'addr' likely indicates problem in the VM (e.g. trying to change
2108   // protection of malloc'ed or statically allocated memory). Check the
2109   // caller if you hit this assert.
2110   assert(addr == bottom, "sanity check");
2111 
2112   size = align_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2113   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(bottom), p2i(bottom+size), prot);
2114   return ::mprotect(bottom, size, prot) == 0;
2115 }
2116 
2117 // Set protections specified
2118 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2119                         bool is_committed) {
2120   unsigned int p = 0;
2121   switch (prot) {
2122   case MEM_PROT_NONE: p = PROT_NONE; break;
2123   case MEM_PROT_READ: p = PROT_READ; break;
2124   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2125   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2126   default:
2127     ShouldNotReachHere();
2128   }
2129   // is_committed is unused.
2130   return bsd_mprotect(addr, bytes, p);
2131 }
2132 
2133 bool os::guard_memory(char* addr, size_t size) {
2134   return bsd_mprotect(addr, size, PROT_NONE);
2135 }
2136 
2137 bool os::unguard_memory(char* addr, size_t size) {
2138   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2139 }
2140 
2141 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2142   return false;
2143 }
2144 
2145 // Large page support
2146 
2147 static size_t _large_page_size = 0;
2148 
2149 void os::large_page_init() {
2150 }
2151 
2152 
2153 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2154   fatal("This code is not used or maintained.");
2155 
2156   // "exec" is passed in but not used.  Creating the shared image for
2157   // the code cache doesn't have an SHM_X executable permission to check.
2158   assert(UseLargePages && UseSHM, "only for SHM large pages");
2159 
2160   key_t key = IPC_PRIVATE;
2161   char *addr;
2162 
2163   bool warn_on_failure = UseLargePages &&
2164                          (!FLAG_IS_DEFAULT(UseLargePages) ||
2165                           !FLAG_IS_DEFAULT(LargePageSizeInBytes));
2166 
2167   // Create a large shared memory region to attach to based on size.
2168   // Currently, size is the total size of the heap
2169   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2170   if (shmid == -1) {
2171     // Possible reasons for shmget failure:
2172     // 1. shmmax is too small for Java heap.
2173     //    > check shmmax value: cat /proc/sys/kernel/shmmax
2174     //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2175     // 2. not enough large page memory.
2176     //    > check available large pages: cat /proc/meminfo
2177     //    > increase amount of large pages:
2178     //          echo new_value > /proc/sys/vm/nr_hugepages
2179     //      Note 1: different Bsd may use different name for this property,
2180     //            e.g. on Redhat AS-3 it is "hugetlb_pool".
2181     //      Note 2: it's possible there's enough physical memory available but
2182     //            they are so fragmented after a long run that they can't
2183     //            coalesce into large pages. Try to reserve large pages when
2184     //            the system is still "fresh".
2185     if (warn_on_failure) {
2186       warning("Failed to reserve shared memory (errno = %d).", errno);
2187     }
2188     return NULL;
2189   }
2190 
2191   // attach to the region
2192   addr = (char*)shmat(shmid, req_addr, 0);
2193   int err = errno;
2194 
2195   // Remove shmid. If shmat() is successful, the actual shared memory segment
2196   // will be deleted when it's detached by shmdt() or when the process
2197   // terminates. If shmat() is not successful this will remove the shared
2198   // segment immediately.
2199   shmctl(shmid, IPC_RMID, NULL);
2200 
2201   if ((intptr_t)addr == -1) {
2202     if (warn_on_failure) {
2203       warning("Failed to attach shared memory (errno = %d).", err);
2204     }
2205     return NULL;
2206   }
2207 
2208   // The memory is committed
2209   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
2210 
2211   return addr;
2212 }
2213 
2214 bool os::release_memory_special(char* base, size_t bytes) {
2215   if (MemTracker::tracking_level() > NMT_minimal) {
2216     Tracker tkr(Tracker::release);
2217     // detaching the SHM segment will also delete it, see reserve_memory_special()
2218     int rslt = shmdt(base);
2219     if (rslt == 0) {
2220       tkr.record((address)base, bytes);
2221       return true;
2222     } else {
2223       return false;
2224     }
2225   } else {
2226     return shmdt(base) == 0;
2227   }
2228 }
2229 
2230 size_t os::large_page_size() {
2231   return _large_page_size;
2232 }
2233 
2234 // HugeTLBFS allows application to commit large page memory on demand;
2235 // with SysV SHM the entire memory region must be allocated as shared
2236 // memory.
2237 bool os::can_commit_large_page_memory() {
2238   return UseHugeTLBFS;
2239 }
2240 
2241 bool os::can_execute_large_page_memory() {
2242   return UseHugeTLBFS;
2243 }
2244 
2245 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2246   assert(file_desc >= 0, "file_desc is not valid");
2247   char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
2248   if (result != NULL) {
2249     if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2250       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2251     }
2252   }
2253   return result;
2254 }
2255 
2256 // Reserve memory at an arbitrary address, only if that area is
2257 // available (and not reserved for something else).
2258 
2259 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2260   const int max_tries = 10;
2261   char* base[max_tries];
2262   size_t size[max_tries];
2263   const size_t gap = 0x000000;
2264 
2265   // Assert only that the size is a multiple of the page size, since
2266   // that's all that mmap requires, and since that's all we really know
2267   // about at this low abstraction level.  If we need higher alignment,
2268   // we can either pass an alignment to this method or verify alignment
2269   // in one of the methods further up the call chain.  See bug 5044738.
2270   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2271 
2272   // Repeatedly allocate blocks until the block is allocated at the
2273   // right spot.
2274 
2275   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2276   // if kernel honors the hint then we can return immediately.
2277   char * addr = anon_mmap(requested_addr, bytes, false);
2278   if (addr == requested_addr) {
2279     return requested_addr;
2280   }
2281 
2282   if (addr != NULL) {
2283     // mmap() is successful but it fails to reserve at the requested address
2284     anon_munmap(addr, bytes);
2285   }
2286 
2287   int i;
2288   for (i = 0; i < max_tries; ++i) {
2289     base[i] = reserve_memory(bytes);
2290 
2291     if (base[i] != NULL) {
2292       // Is this the block we wanted?
2293       if (base[i] == requested_addr) {
2294         size[i] = bytes;
2295         break;
2296       }
2297 
2298       // Does this overlap the block we wanted? Give back the overlapped
2299       // parts and try again.
2300 
2301       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2302       if (top_overlap >= 0 && top_overlap < bytes) {
2303         unmap_memory(base[i], top_overlap);
2304         base[i] += top_overlap;
2305         size[i] = bytes - top_overlap;
2306       } else {
2307         size_t bottom_overlap = base[i] + bytes - requested_addr;
2308         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2309           unmap_memory(requested_addr, bottom_overlap);
2310           size[i] = bytes - bottom_overlap;
2311         } else {
2312           size[i] = bytes;
2313         }
2314       }
2315     }
2316   }
2317 
2318   // Give back the unused reserved pieces.
2319 
2320   for (int j = 0; j < i; ++j) {
2321     if (base[j] != NULL) {
2322       unmap_memory(base[j], size[j]);
2323     }
2324   }
2325 
2326   if (i < max_tries) {
2327     return requested_addr;
2328   } else {
2329     return NULL;
2330   }
2331 }
2332 
2333 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2334   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2335 }
2336 
2337 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
2338   RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset));
2339 }
2340 
2341 void os::naked_short_sleep(jlong ms) {
2342   struct timespec req;
2343 
2344   assert(ms < 1000, "Un-interruptable sleep, short time use only");
2345   req.tv_sec = 0;
2346   if (ms > 0) {
2347     req.tv_nsec = (ms % 1000) * 1000000;
2348   } else {
2349     req.tv_nsec = 1;
2350   }
2351 
2352   nanosleep(&req, NULL);
2353 
2354   return;
2355 }
2356 
2357 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2358 void os::infinite_sleep() {
2359   while (true) {    // sleep forever ...
2360     ::sleep(100);   // ... 100 seconds at a time
2361   }
2362 }
2363 
2364 // Used to convert frequent JVM_Yield() to nops
2365 bool os::dont_yield() {
2366   return DontYieldALot;
2367 }
2368 
2369 void os::naked_yield() {
2370   sched_yield();
2371 }
2372 
2373 ////////////////////////////////////////////////////////////////////////////////
2374 // thread priority support
2375 
2376 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2377 // only supports dynamic priority, static priority must be zero. For real-time
2378 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2379 // However, for large multi-threaded applications, SCHED_RR is not only slower
2380 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2381 // of 5 runs - Sep 2005).
2382 //
2383 // The following code actually changes the niceness of kernel-thread/LWP. It
2384 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2385 // not the entire user process, and user level threads are 1:1 mapped to kernel
2386 // threads. It has always been the case, but could change in the future. For
2387 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2388 // It is only used when ThreadPriorityPolicy=1 and may require system level permission
2389 // (e.g., root privilege or CAP_SYS_NICE capability).
2390 
2391 #if !defined(__APPLE__)
2392 int os::java_to_os_priority[CriticalPriority + 1] = {
2393   19,              // 0 Entry should never be used
2394 
2395    0,              // 1 MinPriority
2396    3,              // 2
2397    6,              // 3
2398 
2399   10,              // 4
2400   15,              // 5 NormPriority
2401   18,              // 6
2402 
2403   21,              // 7
2404   25,              // 8
2405   28,              // 9 NearMaxPriority
2406 
2407   31,              // 10 MaxPriority
2408 
2409   31               // 11 CriticalPriority
2410 };
2411 #else
2412 // Using Mach high-level priority assignments
2413 int os::java_to_os_priority[CriticalPriority + 1] = {
2414    0,              // 0 Entry should never be used (MINPRI_USER)
2415 
2416   27,              // 1 MinPriority
2417   28,              // 2
2418   29,              // 3
2419 
2420   30,              // 4
2421   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2422   32,              // 6
2423 
2424   33,              // 7
2425   34,              // 8
2426   35,              // 9 NearMaxPriority
2427 
2428   36,              // 10 MaxPriority
2429 
2430   36               // 11 CriticalPriority
2431 };
2432 #endif
2433 
2434 static int prio_init() {
2435   if (ThreadPriorityPolicy == 1) {
2436     if (geteuid() != 0) {
2437       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2438         warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
2439                 "e.g., being the root user. If the necessary permission is not " \
2440                 "possessed, changes to priority will be silently ignored.");
2441       }
2442     }
2443   }
2444   if (UseCriticalJavaThreadPriority) {
2445     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2446   }
2447   return 0;
2448 }
2449 
2450 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2451   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2452 
2453 #ifdef __OpenBSD__
2454   // OpenBSD pthread_setprio starves low priority threads
2455   return OS_OK;
2456 #elif defined(__FreeBSD__)
2457   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2458   return (ret == 0) ? OS_OK : OS_ERR;
2459 #elif defined(__APPLE__) || defined(__NetBSD__)
2460   struct sched_param sp;
2461   int policy;
2462 
2463   if (pthread_getschedparam(thread->osthread()->pthread_id(), &policy, &sp) != 0) {
2464     return OS_ERR;
2465   }
2466 
2467   sp.sched_priority = newpri;
2468   if (pthread_setschedparam(thread->osthread()->pthread_id(), policy, &sp) != 0) {
2469     return OS_ERR;
2470   }
2471 
2472   return OS_OK;
2473 #else
2474   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2475   return (ret == 0) ? OS_OK : OS_ERR;
2476 #endif
2477 }
2478 
2479 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2480   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2481     *priority_ptr = java_to_os_priority[NormPriority];
2482     return OS_OK;
2483   }
2484 
2485   errno = 0;
2486 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2487   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2488 #elif defined(__APPLE__) || defined(__NetBSD__)
2489   int policy;
2490   struct sched_param sp;
2491 
2492   int res = pthread_getschedparam(thread->osthread()->pthread_id(), &policy, &sp);
2493   if (res != 0) {
2494     *priority_ptr = -1;
2495     return OS_ERR;
2496   } else {
2497     *priority_ptr = sp.sched_priority;
2498     return OS_OK;
2499   }
2500 #else
2501   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2502 #endif
2503   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2504 }
2505 
2506 // Hint to the underlying OS that a task switch would not be good.
2507 // Void return because it's a hint and can fail.
2508 void os::hint_no_preempt() {}
2509 
2510 ////////////////////////////////////////////////////////////////////////////////
2511 // suspend/resume support
2512 
2513 //  The low-level signal-based suspend/resume support is a remnant from the
2514 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2515 //  within hotspot. Currently used by JFR's OSThreadSampler
2516 //
2517 //  The remaining code is greatly simplified from the more general suspension
2518 //  code that used to be used.
2519 //
2520 //  The protocol is quite simple:
2521 //  - suspend:
2522 //      - sends a signal to the target thread
2523 //      - polls the suspend state of the osthread using a yield loop
2524 //      - target thread signal handler (SR_handler) sets suspend state
2525 //        and blocks in sigsuspend until continued
2526 //  - resume:
2527 //      - sets target osthread state to continue
2528 //      - sends signal to end the sigsuspend loop in the SR_handler
2529 //
2530 //  Note that the SR_lock plays no role in this suspend/resume protocol,
2531 //  but is checked for NULL in SR_handler as a thread termination indicator.
2532 //  The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
2533 //
2534 //  Note that resume_clear_context() and suspend_save_context() are needed
2535 //  by SR_handler(), so that fetch_frame_from_ucontext() works,
2536 //  which in part is used by:
2537 //    - Forte Analyzer: AsyncGetCallTrace()
2538 //    - StackBanging: get_frame_at_stack_banging_point()
2539 
2540 static void resume_clear_context(OSThread *osthread) {
2541   osthread->set_ucontext(NULL);
2542   osthread->set_siginfo(NULL);
2543 }
2544 
2545 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2546   osthread->set_ucontext(context);
2547   osthread->set_siginfo(siginfo);
2548 }
2549 
2550 // Handler function invoked when a thread's execution is suspended or
2551 // resumed. We have to be careful that only async-safe functions are
2552 // called here (Note: most pthread functions are not async safe and
2553 // should be avoided.)
2554 //
2555 // Note: sigwait() is a more natural fit than sigsuspend() from an
2556 // interface point of view, but sigwait() prevents the signal hander
2557 // from being run. libpthread would get very confused by not having
2558 // its signal handlers run and prevents sigwait()'s use with the
2559 // mutex granting granting signal.
2560 //
2561 // Currently only ever called on the VMThread or JavaThread
2562 //
2563 #ifdef __APPLE__
2564 static OSXSemaphore sr_semaphore;
2565 #else
2566 static PosixSemaphore sr_semaphore;
2567 #endif
2568 
2569 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2570   // Save and restore errno to avoid confusing native code with EINTR
2571   // after sigsuspend.
2572   int old_errno = errno;
2573 
2574   Thread* thread = Thread::current_or_null_safe();
2575   assert(thread != NULL, "Missing current thread in SR_handler");
2576 
2577   // On some systems we have seen signal delivery get "stuck" until the signal
2578   // mask is changed as part of thread termination. Check that the current thread
2579   // has not already terminated (via SR_lock()) - else the following assertion
2580   // will fail because the thread is no longer a JavaThread as the ~JavaThread
2581   // destructor has completed.
2582 
2583   if (thread->SR_lock() == NULL) {
2584     return;
2585   }
2586 
2587   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2588 
2589   OSThread* osthread = thread->osthread();
2590 
2591   os::SuspendResume::State current = osthread->sr.state();
2592   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2593     suspend_save_context(osthread, siginfo, context);
2594 
2595     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2596     os::SuspendResume::State state = osthread->sr.suspended();
2597     if (state == os::SuspendResume::SR_SUSPENDED) {
2598       sigset_t suspend_set;  // signals for sigsuspend()
2599 
2600       // get current set of blocked signals and unblock resume signal
2601       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2602       sigdelset(&suspend_set, SR_signum);
2603 
2604       sr_semaphore.signal();
2605       // wait here until we are resumed
2606       while (1) {
2607         sigsuspend(&suspend_set);
2608 
2609         os::SuspendResume::State result = osthread->sr.running();
2610         if (result == os::SuspendResume::SR_RUNNING) {
2611           sr_semaphore.signal();
2612           break;
2613         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2614           ShouldNotReachHere();
2615         }
2616       }
2617 
2618     } else if (state == os::SuspendResume::SR_RUNNING) {
2619       // request was cancelled, continue
2620     } else {
2621       ShouldNotReachHere();
2622     }
2623 
2624     resume_clear_context(osthread);
2625   } else if (current == os::SuspendResume::SR_RUNNING) {
2626     // request was cancelled, continue
2627   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2628     // ignore
2629   } else {
2630     // ignore
2631   }
2632 
2633   errno = old_errno;
2634 }
2635 
2636 
2637 static int SR_initialize() {
2638   struct sigaction act;
2639   char *s;
2640   // Get signal number to use for suspend/resume
2641   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2642     int sig = ::strtol(s, 0, 10);
2643     if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
2644         sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
2645       SR_signum = sig;
2646     } else {
2647       warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2648               sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2649     }
2650   }
2651 
2652   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2653          "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2654 
2655   sigemptyset(&SR_sigset);
2656   sigaddset(&SR_sigset, SR_signum);
2657 
2658   // Set up signal handler for suspend/resume
2659   act.sa_flags = SA_RESTART|SA_SIGINFO;
2660   act.sa_handler = (void (*)(int)) SR_handler;
2661 
2662   // SR_signum is blocked by default.
2663   // 4528190 - We also need to block pthread restart signal (32 on all
2664   // supported Bsd platforms). Note that BsdThreads need to block
2665   // this signal for all threads to work properly. So we don't have
2666   // to use hard-coded signal number when setting up the mask.
2667   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2668 
2669   if (sigaction(SR_signum, &act, 0) == -1) {
2670     return -1;
2671   }
2672 
2673   // Save signal flag
2674   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2675   return 0;
2676 }
2677 
2678 static int sr_notify(OSThread* osthread) {
2679   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2680   assert_status(status == 0, status, "pthread_kill");
2681   return status;
2682 }
2683 
2684 // "Randomly" selected value for how long we want to spin
2685 // before bailing out on suspending a thread, also how often
2686 // we send a signal to a thread we want to resume
2687 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2688 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2689 
2690 // returns true on success and false on error - really an error is fatal
2691 // but this seems the normal response to library errors
2692 static bool do_suspend(OSThread* osthread) {
2693   assert(osthread->sr.is_running(), "thread should be running");
2694   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2695 
2696   // mark as suspended and send signal
2697   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2698     // failed to switch, state wasn't running?
2699     ShouldNotReachHere();
2700     return false;
2701   }
2702 
2703   if (sr_notify(osthread) != 0) {
2704     ShouldNotReachHere();
2705   }
2706 
2707   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2708   while (true) {
2709     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2710       break;
2711     } else {
2712       // timeout
2713       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2714       if (cancelled == os::SuspendResume::SR_RUNNING) {
2715         return false;
2716       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2717         // make sure that we consume the signal on the semaphore as well
2718         sr_semaphore.wait();
2719         break;
2720       } else {
2721         ShouldNotReachHere();
2722         return false;
2723       }
2724     }
2725   }
2726 
2727   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2728   return true;
2729 }
2730 
2731 static void do_resume(OSThread* osthread) {
2732   assert(osthread->sr.is_suspended(), "thread should be suspended");
2733   assert(!sr_semaphore.trywait(), "invalid semaphore state");
2734 
2735   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2736     // failed to switch to WAKEUP_REQUEST
2737     ShouldNotReachHere();
2738     return;
2739   }
2740 
2741   while (true) {
2742     if (sr_notify(osthread) == 0) {
2743       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2744         if (osthread->sr.is_running()) {
2745           return;
2746         }
2747       }
2748     } else {
2749       ShouldNotReachHere();
2750     }
2751   }
2752 
2753   guarantee(osthread->sr.is_running(), "Must be running!");
2754 }
2755 
2756 ///////////////////////////////////////////////////////////////////////////////////
2757 // signal handling (except suspend/resume)
2758 
2759 // This routine may be used by user applications as a "hook" to catch signals.
2760 // The user-defined signal handler must pass unrecognized signals to this
2761 // routine, and if it returns true (non-zero), then the signal handler must
2762 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
2763 // routine will never retun false (zero), but instead will execute a VM panic
2764 // routine kill the process.
2765 //
2766 // If this routine returns false, it is OK to call it again.  This allows
2767 // the user-defined signal handler to perform checks either before or after
2768 // the VM performs its own checks.  Naturally, the user code would be making
2769 // a serious error if it tried to handle an exception (such as a null check
2770 // or breakpoint) that the VM was generating for its own correct operation.
2771 //
2772 // This routine may recognize any of the following kinds of signals:
2773 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2774 // It should be consulted by handlers for any of those signals.
2775 //
2776 // The caller of this routine must pass in the three arguments supplied
2777 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2778 // field of the structure passed to sigaction().  This routine assumes that
2779 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2780 //
2781 // Note that the VM will print warnings if it detects conflicting signal
2782 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2783 //
2784 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2785                                                void* ucontext,
2786                                                int abort_if_unrecognized);
2787 
2788 static void signalHandler(int sig, siginfo_t* info, void* uc) {
2789   assert(info != NULL && uc != NULL, "it must be old kernel");
2790   int orig_errno = errno;  // Preserve errno value over signal handler.
2791   JVM_handle_bsd_signal(sig, info, uc, true);
2792   errno = orig_errno;
2793 }
2794 
2795 
2796 // This boolean allows users to forward their own non-matching signals
2797 // to JVM_handle_bsd_signal, harmlessly.
2798 bool os::Bsd::signal_handlers_are_installed = false;
2799 
2800 // For signal-chaining
2801 bool os::Bsd::libjsig_is_loaded = false;
2802 typedef struct sigaction *(*get_signal_t)(int);
2803 get_signal_t os::Bsd::get_signal_action = NULL;
2804 
2805 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2806   struct sigaction *actp = NULL;
2807 
2808   if (libjsig_is_loaded) {
2809     // Retrieve the old signal handler from libjsig
2810     actp = (*get_signal_action)(sig);
2811   }
2812   if (actp == NULL) {
2813     // Retrieve the preinstalled signal handler from jvm
2814     actp = os::Posix::get_preinstalled_handler(sig);
2815   }
2816 
2817   return actp;
2818 }
2819 
2820 static bool call_chained_handler(struct sigaction *actp, int sig,
2821                                  siginfo_t *siginfo, void *context) {
2822   // Call the old signal handler
2823   if (actp->sa_handler == SIG_DFL) {
2824     // It's more reasonable to let jvm treat it as an unexpected exception
2825     // instead of taking the default action.
2826     return false;
2827   } else if (actp->sa_handler != SIG_IGN) {
2828     if ((actp->sa_flags & SA_NODEFER) == 0) {
2829       // automaticlly block the signal
2830       sigaddset(&(actp->sa_mask), sig);
2831     }
2832 
2833     sa_handler_t hand;
2834     sa_sigaction_t sa;
2835     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
2836     // retrieve the chained handler
2837     if (siginfo_flag_set) {
2838       sa = actp->sa_sigaction;
2839     } else {
2840       hand = actp->sa_handler;
2841     }
2842 
2843     if ((actp->sa_flags & SA_RESETHAND) != 0) {
2844       actp->sa_handler = SIG_DFL;
2845     }
2846 
2847     // try to honor the signal mask
2848     sigset_t oset;
2849     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
2850 
2851     // call into the chained handler
2852     if (siginfo_flag_set) {
2853       (*sa)(sig, siginfo, context);
2854     } else {
2855       (*hand)(sig);
2856     }
2857 
2858     // restore the signal mask
2859     pthread_sigmask(SIG_SETMASK, &oset, 0);
2860   }
2861   // Tell jvm's signal handler the signal is taken care of.
2862   return true;
2863 }
2864 
2865 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
2866   bool chained = false;
2867   // signal-chaining
2868   if (UseSignalChaining) {
2869     struct sigaction *actp = get_chained_signal_action(sig);
2870     if (actp != NULL) {
2871       chained = call_chained_handler(actp, sig, siginfo, context);
2872     }
2873   }
2874   return chained;
2875 }
2876 
2877 // for diagnostic
2878 int sigflags[NSIG];
2879 
2880 int os::Bsd::get_our_sigflags(int sig) {
2881   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2882   return sigflags[sig];
2883 }
2884 
2885 void os::Bsd::set_our_sigflags(int sig, int flags) {
2886   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2887   if (sig > 0 && sig < NSIG) {
2888     sigflags[sig] = flags;
2889   }
2890 }
2891 
2892 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
2893   // Check for overwrite.
2894   struct sigaction oldAct;
2895   sigaction(sig, (struct sigaction*)NULL, &oldAct);
2896 
2897   void* oldhand = oldAct.sa_sigaction
2898                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
2899                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
2900   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
2901       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
2902       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
2903     if (AllowUserSignalHandlers || !set_installed) {
2904       // Do not overwrite; user takes responsibility to forward to us.
2905       return;
2906     } else if (UseSignalChaining) {
2907       // save the old handler in jvm
2908       os::Posix::save_preinstalled_handler(sig, oldAct);
2909       // libjsig also interposes the sigaction() call below and saves the
2910       // old sigaction on it own.
2911     } else {
2912       fatal("Encountered unexpected pre-existing sigaction handler "
2913             "%#lx for signal %d.", (long)oldhand, sig);
2914     }
2915   }
2916 
2917   struct sigaction sigAct;
2918   sigfillset(&(sigAct.sa_mask));
2919   sigAct.sa_handler = SIG_DFL;
2920   if (!set_installed) {
2921     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
2922   } else {
2923     sigAct.sa_sigaction = signalHandler;
2924     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
2925   }
2926 #ifdef __APPLE__
2927   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
2928   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
2929   // if the signal handler declares it will handle it on alternate stack.
2930   // Notice we only declare we will handle it on alt stack, but we are not
2931   // actually going to use real alt stack - this is just a workaround.
2932   // Please see ux_exception.c, method catch_mach_exception_raise for details
2933   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
2934   if (sig == SIGSEGV) {
2935     sigAct.sa_flags |= SA_ONSTACK;
2936   }
2937 #endif
2938 
2939   // Save flags, which are set by ours
2940   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2941   sigflags[sig] = sigAct.sa_flags;
2942 
2943   int ret = sigaction(sig, &sigAct, &oldAct);
2944   assert(ret == 0, "check");
2945 
2946   void* oldhand2  = oldAct.sa_sigaction
2947                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
2948                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
2949   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
2950 }
2951 
2952 // install signal handlers for signals that HotSpot needs to
2953 // handle in order to support Java-level exception handling.
2954 
2955 void os::Bsd::install_signal_handlers() {
2956   if (!signal_handlers_are_installed) {
2957     signal_handlers_are_installed = true;
2958 
2959     // signal-chaining
2960     typedef void (*signal_setting_t)();
2961     signal_setting_t begin_signal_setting = NULL;
2962     signal_setting_t end_signal_setting = NULL;
2963     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
2964                                           dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
2965     if (begin_signal_setting != NULL) {
2966       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
2967                                           dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
2968       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
2969                                          dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
2970       libjsig_is_loaded = true;
2971       assert(UseSignalChaining, "should enable signal-chaining");
2972     }
2973     if (libjsig_is_loaded) {
2974       // Tell libjsig jvm is setting signal handlers
2975       (*begin_signal_setting)();
2976     }
2977 
2978     set_signal_handler(SIGSEGV, true);
2979     set_signal_handler(SIGPIPE, true);
2980     set_signal_handler(SIGBUS, true);
2981     set_signal_handler(SIGILL, true);
2982     set_signal_handler(SIGFPE, true);
2983     set_signal_handler(SIGXFSZ, true);
2984 
2985 #if defined(__APPLE__)
2986     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
2987     // signals caught and handled by the JVM. To work around this, we reset the mach task
2988     // signal handler that's placed on our process by CrashReporter. This disables
2989     // CrashReporter-based reporting.
2990     //
2991     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
2992     // on caught fatal signals.
2993     //
2994     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
2995     // handlers. By replacing the existing task exception handler, we disable gdb's mach
2996     // exception handling, while leaving the standard BSD signal handlers functional.
2997     kern_return_t kr;
2998     kr = task_set_exception_ports(mach_task_self(),
2999                                   EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3000                                   MACH_PORT_NULL,
3001                                   EXCEPTION_STATE_IDENTITY,
3002                                   MACHINE_THREAD_STATE);
3003 
3004     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3005 #endif
3006 
3007     if (libjsig_is_loaded) {
3008       // Tell libjsig jvm finishes setting signal handlers
3009       (*end_signal_setting)();
3010     }
3011 
3012     // We don't activate signal checker if libjsig is in place, we trust ourselves
3013     // and if UserSignalHandler is installed all bets are off
3014     if (CheckJNICalls) {
3015       if (libjsig_is_loaded) {
3016         if (PrintJNIResolving) {
3017           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3018         }
3019         check_signals = false;
3020       }
3021       if (AllowUserSignalHandlers) {
3022         if (PrintJNIResolving) {
3023           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3024         }
3025         check_signals = false;
3026       }
3027     }
3028   }
3029 }
3030 
3031 
3032 /////
3033 // glibc on Bsd platform uses non-documented flag
3034 // to indicate, that some special sort of signal
3035 // trampoline is used.
3036 // We will never set this flag, and we should
3037 // ignore this flag in our diagnostic
3038 #ifdef SIGNIFICANT_SIGNAL_MASK
3039   #undef SIGNIFICANT_SIGNAL_MASK
3040 #endif
3041 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3042 
3043 static const char* get_signal_handler_name(address handler,
3044                                            char* buf, int buflen) {
3045   int offset;
3046   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3047   if (found) {
3048     // skip directory names
3049     const char *p1, *p2;
3050     p1 = buf;
3051     size_t len = strlen(os::file_separator());
3052     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3053     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3054   } else {
3055     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3056   }
3057   return buf;
3058 }
3059 
3060 static void print_signal_handler(outputStream* st, int sig,
3061                                  char* buf, size_t buflen) {
3062   struct sigaction sa;
3063 
3064   sigaction(sig, NULL, &sa);
3065 
3066   // See comment for SIGNIFICANT_SIGNAL_MASK define
3067   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3068 
3069   st->print("%s: ", os::exception_name(sig, buf, buflen));
3070 
3071   address handler = (sa.sa_flags & SA_SIGINFO)
3072     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3073     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3074 
3075   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3076     st->print("SIG_DFL");
3077   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3078     st->print("SIG_IGN");
3079   } else {
3080     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3081   }
3082 
3083   st->print(", sa_mask[0]=");
3084   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3085 
3086   address rh = VMError::get_resetted_sighandler(sig);
3087   // May be, handler was resetted by VMError?
3088   if (rh != NULL) {
3089     handler = rh;
3090     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3091   }
3092 
3093   st->print(", sa_flags=");
3094   os::Posix::print_sa_flags(st, sa.sa_flags);
3095 
3096   // Check: is it our handler?
3097   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3098       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3099     // It is our signal handler
3100     // check for flags, reset system-used one!
3101     if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3102       st->print(
3103                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3104                 os::Bsd::get_our_sigflags(sig));
3105     }
3106   }
3107   st->cr();
3108 }
3109 
3110 
3111 #define DO_SIGNAL_CHECK(sig)                      \
3112   do {                                            \
3113     if (!sigismember(&check_signal_done, sig)) {  \
3114       os::Bsd::check_signal_handler(sig);         \
3115     }                                             \
3116   } while (0)
3117 
3118 // This method is a periodic task to check for misbehaving JNI applications
3119 // under CheckJNI, we can add any periodic checks here
3120 
3121 void os::run_periodic_checks() {
3122 
3123   if (check_signals == false) return;
3124 
3125   // SEGV and BUS if overridden could potentially prevent
3126   // generation of hs*.log in the event of a crash, debugging
3127   // such a case can be very challenging, so we absolutely
3128   // check the following for a good measure:
3129   DO_SIGNAL_CHECK(SIGSEGV);
3130   DO_SIGNAL_CHECK(SIGILL);
3131   DO_SIGNAL_CHECK(SIGFPE);
3132   DO_SIGNAL_CHECK(SIGBUS);
3133   DO_SIGNAL_CHECK(SIGPIPE);
3134   DO_SIGNAL_CHECK(SIGXFSZ);
3135 
3136 
3137   // ReduceSignalUsage allows the user to override these handlers
3138   // see comments at the very top and jvm_md.h
3139   if (!ReduceSignalUsage) {
3140     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3141     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3142     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3143     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3144   }
3145 
3146   DO_SIGNAL_CHECK(SR_signum);
3147 }
3148 
3149 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3150 
3151 static os_sigaction_t os_sigaction = NULL;
3152 
3153 void os::Bsd::check_signal_handler(int sig) {
3154   char buf[O_BUFLEN];
3155   address jvmHandler = NULL;
3156 
3157 
3158   struct sigaction act;
3159   if (os_sigaction == NULL) {
3160     // only trust the default sigaction, in case it has been interposed
3161     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3162     if (os_sigaction == NULL) return;
3163   }
3164 
3165   os_sigaction(sig, (struct sigaction*)NULL, &act);
3166 
3167 
3168   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3169 
3170   address thisHandler = (act.sa_flags & SA_SIGINFO)
3171     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3172     : CAST_FROM_FN_PTR(address, act.sa_handler);
3173 
3174 
3175   switch (sig) {
3176   case SIGSEGV:
3177   case SIGBUS:
3178   case SIGFPE:
3179   case SIGPIPE:
3180   case SIGILL:
3181   case SIGXFSZ:
3182     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3183     break;
3184 
3185   case SHUTDOWN1_SIGNAL:
3186   case SHUTDOWN2_SIGNAL:
3187   case SHUTDOWN3_SIGNAL:
3188   case BREAK_SIGNAL:
3189     jvmHandler = (address)user_handler();
3190     break;
3191 
3192   default:
3193     if (sig == SR_signum) {
3194       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3195     } else {
3196       return;
3197     }
3198     break;
3199   }
3200 
3201   if (thisHandler != jvmHandler) {
3202     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3203     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3204     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3205     // No need to check this sig any longer
3206     sigaddset(&check_signal_done, sig);
3207     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3208     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3209       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3210                     exception_name(sig, buf, O_BUFLEN));
3211     }
3212   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3213     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3214     tty->print("expected:");
3215     os::Posix::print_sa_flags(tty, os::Bsd::get_our_sigflags(sig));
3216     tty->cr();
3217     tty->print("  found:");
3218     os::Posix::print_sa_flags(tty, act.sa_flags);
3219     tty->cr();
3220     // No need to check this sig any longer
3221     sigaddset(&check_signal_done, sig);
3222   }
3223 
3224   // Dump all the signal
3225   if (sigismember(&check_signal_done, sig)) {
3226     print_signal_handlers(tty, buf, O_BUFLEN);
3227   }
3228 }
3229 
3230 extern void report_error(char* file_name, int line_no, char* title,
3231                          char* format, ...);
3232 
3233 // this is called _before_ the most of global arguments have been parsed
3234 void os::init(void) {
3235   char dummy;   // used to get a guess on initial stack address
3236 
3237   // With BsdThreads the JavaMain thread pid (primordial thread)
3238   // is different than the pid of the java launcher thread.
3239   // So, on Bsd, the launcher thread pid is passed to the VM
3240   // via the sun.java.launcher.pid property.
3241   // Use this property instead of getpid() if it was correctly passed.
3242   // See bug 6351349.
3243   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3244 
3245   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3246 
3247   clock_tics_per_sec = CLK_TCK;
3248 
3249   init_random(1234567);
3250 
3251   Bsd::set_page_size(getpagesize());
3252   if (Bsd::page_size() == -1) {
3253     fatal("os_bsd.cpp: os::init: sysconf failed (%s)", os::strerror(errno));
3254   }
3255   init_page_sizes((size_t) Bsd::page_size());
3256 
3257   Bsd::initialize_system_info();
3258 
3259   // _main_thread points to the thread that created/loaded the JVM.
3260   Bsd::_main_thread = pthread_self();
3261 
3262   Bsd::clock_init();
3263   initial_time_count = javaTimeNanos();
3264 
3265 #ifdef __APPLE__
3266   // XXXDARWIN
3267   // Work around the unaligned VM callbacks in hotspot's
3268   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3269   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3270   // alignment when doing symbol lookup. To work around this, we force early
3271   // binding of all symbols now, thus binding when alignment is known-good.
3272   _dyld_bind_fully_image_containing_address((const void *) &os::init);
3273 #endif
3274 
3275   os::Posix::init();
3276 }
3277 
3278 // To install functions for atexit system call
3279 extern "C" {
3280   static void perfMemory_exit_helper() {
3281     perfMemory_exit();
3282   }
3283 }
3284 
3285 // this is called _after_ the global arguments have been parsed
3286 jint os::init_2(void) {
3287 
3288   os::Posix::init_2();
3289 
3290   // initialize suspend/resume support - must do this before signal_sets_init()
3291   if (SR_initialize() != 0) {
3292     perror("SR_initialize failed");
3293     return JNI_ERR;
3294   }
3295 
3296   Bsd::signal_sets_init();
3297   Bsd::install_signal_handlers();
3298   // Initialize data for jdk.internal.misc.Signal
3299   if (!ReduceSignalUsage) {
3300     jdk_misc_signal_init();
3301   }
3302 
3303   // Check and sets minimum stack sizes against command line options
3304   if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
3305     return JNI_ERR;
3306   }
3307 
3308   if (MaxFDLimit) {
3309     // set the number of file descriptors to max. print out error
3310     // if getrlimit/setrlimit fails but continue regardless.
3311     struct rlimit nbr_files;
3312     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3313     if (status != 0) {
3314       log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3315     } else {
3316       nbr_files.rlim_cur = nbr_files.rlim_max;
3317 
3318 #ifdef __APPLE__
3319       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3320       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3321       // be used instead
3322       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3323 #endif
3324 
3325       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3326       if (status != 0) {
3327         log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3328       }
3329     }
3330   }
3331 
3332   // at-exit methods are called in the reverse order of their registration.
3333   // atexit functions are called on return from main or as a result of a
3334   // call to exit(3C). There can be only 32 of these functions registered
3335   // and atexit() does not set errno.
3336 
3337   if (PerfAllowAtExitRegistration) {
3338     // only register atexit functions if PerfAllowAtExitRegistration is set.
3339     // atexit functions can be delayed until process exit time, which
3340     // can be problematic for embedded VM situations. Embedded VMs should
3341     // call DestroyJavaVM() to assure that VM resources are released.
3342 
3343     // note: perfMemory_exit_helper atexit function may be removed in
3344     // the future if the appropriate cleanup code can be added to the
3345     // VM_Exit VMOperation's doit method.
3346     if (atexit(perfMemory_exit_helper) != 0) {
3347       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
3348     }
3349   }
3350 
3351   // initialize thread priority policy
3352   prio_init();
3353 
3354 #ifdef __APPLE__
3355   // dynamically link to objective c gc registration
3356   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3357   if (handleLibObjc != NULL) {
3358     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3359   }
3360 #endif
3361 
3362   return JNI_OK;
3363 }
3364 
3365 // Mark the polling page as unreadable
3366 void os::make_polling_page_unreadable(void) {
3367   if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3368     fatal("Could not disable polling page");
3369   }
3370 }
3371 
3372 // Mark the polling page as readable
3373 void os::make_polling_page_readable(void) {
3374   if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3375     fatal("Could not enable polling page");
3376   }
3377 }
3378 
3379 int os::active_processor_count() {
3380   // User has overridden the number of active processors
3381   if (ActiveProcessorCount > 0) {
3382     log_trace(os)("active_processor_count: "
3383                   "active processor count set by user : %d",
3384                   ActiveProcessorCount);
3385     return ActiveProcessorCount;
3386   }
3387 
3388   return _processor_count;
3389 }
3390 
3391 void os::set_native_thread_name(const char *name) {
3392 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3393   // This is only supported in Snow Leopard and beyond
3394   if (name != NULL) {
3395     // Add a "Java: " prefix to the name
3396     char buf[MAXTHREADNAMESIZE];
3397     snprintf(buf, sizeof(buf), "Java: %s", name);
3398     pthread_setname_np(buf);
3399   }
3400 #endif
3401 }
3402 
3403 bool os::distribute_processes(uint length, uint* distribution) {
3404   // Not yet implemented.
3405   return false;
3406 }
3407 
3408 bool os::bind_to_processor(uint processor_id) {
3409   // Not yet implemented.
3410   return false;
3411 }
3412 
3413 void os::SuspendedThreadTask::internal_do_task() {
3414   if (do_suspend(_thread->osthread())) {
3415     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3416     do_task(context);
3417     do_resume(_thread->osthread());
3418   }
3419 }
3420 
3421 ////////////////////////////////////////////////////////////////////////////////
3422 // debug support
3423 
3424 bool os::find(address addr, outputStream* st) {
3425   Dl_info dlinfo;
3426   memset(&dlinfo, 0, sizeof(dlinfo));
3427   if (dladdr(addr, &dlinfo) != 0) {
3428     st->print(INTPTR_FORMAT ": ", (intptr_t)addr);
3429     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3430       st->print("%s+%#x", dlinfo.dli_sname,
3431                 (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_saddr));
3432     } else if (dlinfo.dli_fbase != NULL) {
3433       st->print("<offset %#x>", (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_fbase));
3434     } else {
3435       st->print("<absolute address>");
3436     }
3437     if (dlinfo.dli_fname != NULL) {
3438       st->print(" in %s", dlinfo.dli_fname);
3439     }
3440     if (dlinfo.dli_fbase != NULL) {
3441       st->print(" at " INTPTR_FORMAT, (intptr_t)dlinfo.dli_fbase);
3442     }
3443     st->cr();
3444 
3445     if (Verbose) {
3446       // decode some bytes around the PC
3447       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3448       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3449       address       lowest = (address) dlinfo.dli_sname;
3450       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3451       if (begin < lowest)  begin = lowest;
3452       Dl_info dlinfo2;
3453       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3454           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3455         end = (address) dlinfo2.dli_saddr;
3456       }
3457       Disassembler::decode(begin, end, st);
3458     }
3459     return true;
3460   }
3461   return false;
3462 }
3463 
3464 ////////////////////////////////////////////////////////////////////////////////
3465 // misc
3466 
3467 // This does not do anything on Bsd. This is basically a hook for being
3468 // able to use structured exception handling (thread-local exception filters)
3469 // on, e.g., Win32.
3470 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3471                               const methodHandle& method, JavaCallArguments* args,
3472                               Thread* thread) {
3473   f(value, method, args, thread);
3474 }
3475 
3476 void os::print_statistics() {
3477 }
3478 
3479 bool os::message_box(const char* title, const char* message) {
3480   int i;
3481   fdStream err(defaultStream::error_fd());
3482   for (i = 0; i < 78; i++) err.print_raw("=");
3483   err.cr();
3484   err.print_raw_cr(title);
3485   for (i = 0; i < 78; i++) err.print_raw("-");
3486   err.cr();
3487   err.print_raw_cr(message);
3488   for (i = 0; i < 78; i++) err.print_raw("=");
3489   err.cr();
3490 
3491   char buf[16];
3492   // Prevent process from exiting upon "read error" without consuming all CPU
3493   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3494 
3495   return buf[0] == 'y' || buf[0] == 'Y';
3496 }
3497 
3498 static inline struct timespec get_mtime(const char* filename) {
3499   struct stat st;
3500   int ret = os::stat(filename, &st);
3501   assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
3502 #ifdef __APPLE__
3503   return st.st_mtimespec;
3504 #else
3505   return st.st_mtim;
3506 #endif
3507 }
3508 
3509 int os::compare_file_modified_times(const char* file1, const char* file2) {
3510   struct timespec filetime1 = get_mtime(file1);
3511   struct timespec filetime2 = get_mtime(file2);
3512   int diff = filetime1.tv_sec - filetime2.tv_sec;
3513   if (diff == 0) {
3514     return filetime1.tv_nsec - filetime2.tv_nsec;
3515   }
3516   return diff;
3517 }
3518 
3519 // Is a (classpath) directory empty?
3520 bool os::dir_is_empty(const char* path) {
3521   DIR *dir = NULL;
3522   struct dirent *ptr;
3523 
3524   dir = opendir(path);
3525   if (dir == NULL) return true;
3526 
3527   // Scan the directory
3528   bool result = true;
3529   while (result && (ptr = readdir(dir)) != NULL) {
3530     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3531       result = false;
3532     }
3533   }
3534   closedir(dir);
3535   return result;
3536 }
3537 
3538 // This code originates from JDK's sysOpen and open64_w
3539 // from src/solaris/hpi/src/system_md.c
3540 
3541 int os::open(const char *path, int oflag, int mode) {
3542   if (strlen(path) > MAX_PATH - 1) {
3543     errno = ENAMETOOLONG;
3544     return -1;
3545   }
3546   int fd;
3547 
3548   fd = ::open(path, oflag, mode);
3549   if (fd == -1) return -1;
3550 
3551   // If the open succeeded, the file might still be a directory
3552   {
3553     struct stat buf;
3554     int ret = ::fstat(fd, &buf);
3555     int st_mode = buf.st_mode;
3556 
3557     if (ret != -1) {
3558       if ((st_mode & S_IFMT) == S_IFDIR) {
3559         errno = EISDIR;
3560         ::close(fd);
3561         return -1;
3562       }
3563     } else {
3564       ::close(fd);
3565       return -1;
3566     }
3567   }
3568 
3569   // All file descriptors that are opened in the JVM and not
3570   // specifically destined for a subprocess should have the
3571   // close-on-exec flag set.  If we don't set it, then careless 3rd
3572   // party native code might fork and exec without closing all
3573   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3574   // UNIXProcess.c), and this in turn might:
3575   //
3576   // - cause end-of-file to fail to be detected on some file
3577   //   descriptors, resulting in mysterious hangs, or
3578   //
3579   // - might cause an fopen in the subprocess to fail on a system
3580   //   suffering from bug 1085341.
3581   //
3582   // (Yes, the default setting of the close-on-exec flag is a Unix
3583   // design flaw)
3584   //
3585   // See:
3586   // 1085341: 32-bit stdio routines should support file descriptors >255
3587   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3588   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3589   //
3590 #ifdef FD_CLOEXEC
3591   {
3592     int flags = ::fcntl(fd, F_GETFD);
3593     if (flags != -1) {
3594       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3595     }
3596   }
3597 #endif
3598 
3599   return fd;
3600 }
3601 
3602 
3603 // create binary file, rewriting existing file if required
3604 int os::create_binary_file(const char* path, bool rewrite_existing) {
3605   int oflags = O_WRONLY | O_CREAT;
3606   if (!rewrite_existing) {
3607     oflags |= O_EXCL;
3608   }
3609   return ::open(path, oflags, S_IREAD | S_IWRITE);
3610 }
3611 
3612 // return current position of file pointer
3613 jlong os::current_file_offset(int fd) {
3614   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3615 }
3616 
3617 // move file pointer to the specified offset
3618 jlong os::seek_to_file_offset(int fd, jlong offset) {
3619   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3620 }
3621 
3622 // This code originates from JDK's sysAvailable
3623 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3624 
3625 int os::available(int fd, jlong *bytes) {
3626   jlong cur, end;
3627   int mode;
3628   struct stat buf;
3629 
3630   if (::fstat(fd, &buf) >= 0) {
3631     mode = buf.st_mode;
3632     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3633       int n;
3634       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3635         *bytes = n;
3636         return 1;
3637       }
3638     }
3639   }
3640   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3641     return 0;
3642   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3643     return 0;
3644   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3645     return 0;
3646   }
3647   *bytes = end - cur;
3648   return 1;
3649 }
3650 
3651 // Map a block of memory.
3652 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3653                         char *addr, size_t bytes, bool read_only,
3654                         bool allow_exec) {
3655   int prot;
3656   int flags;
3657 
3658   if (read_only) {
3659     prot = PROT_READ;
3660     flags = MAP_SHARED;
3661   } else {
3662     prot = PROT_READ | PROT_WRITE;
3663     flags = MAP_PRIVATE;
3664   }
3665 
3666   if (allow_exec) {
3667     prot |= PROT_EXEC;
3668   }
3669 
3670   if (addr != NULL) {
3671     flags |= MAP_FIXED;
3672   }
3673 
3674   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3675                                      fd, file_offset);
3676   if (mapped_address == MAP_FAILED) {
3677     return NULL;
3678   }
3679   return mapped_address;
3680 }
3681 
3682 
3683 // Remap a block of memory.
3684 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3685                           char *addr, size_t bytes, bool read_only,
3686                           bool allow_exec) {
3687   // same as map_memory() on this OS
3688   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3689                         allow_exec);
3690 }
3691 
3692 
3693 // Unmap a block of memory.
3694 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3695   return munmap(addr, bytes) == 0;
3696 }
3697 
3698 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3699 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3700 // of a thread.
3701 //
3702 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3703 // the fast estimate available on the platform.
3704 
3705 jlong os::current_thread_cpu_time() {
3706 #ifdef __APPLE__
3707   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3708 #else
3709   Unimplemented();
3710   return 0;
3711 #endif
3712 }
3713 
3714 jlong os::thread_cpu_time(Thread* thread) {
3715 #ifdef __APPLE__
3716   return os::thread_cpu_time(thread, true /* user + sys */);
3717 #else
3718   Unimplemented();
3719   return 0;
3720 #endif
3721 }
3722 
3723 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3724 #ifdef __APPLE__
3725   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3726 #else
3727   Unimplemented();
3728   return 0;
3729 #endif
3730 }
3731 
3732 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3733 #ifdef __APPLE__
3734   struct thread_basic_info tinfo;
3735   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
3736   kern_return_t kr;
3737   thread_t mach_thread;
3738 
3739   mach_thread = thread->osthread()->thread_id();
3740   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
3741   if (kr != KERN_SUCCESS) {
3742     return -1;
3743   }
3744 
3745   if (user_sys_cpu_time) {
3746     jlong nanos;
3747     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
3748     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
3749     return nanos;
3750   } else {
3751     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
3752   }
3753 #else
3754   Unimplemented();
3755   return 0;
3756 #endif
3757 }
3758 
3759 
3760 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3761   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3762   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3763   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3764   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3765 }
3766 
3767 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3768   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3769   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3770   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3771   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3772 }
3773 
3774 bool os::is_thread_cpu_time_supported() {
3775 #ifdef __APPLE__
3776   return true;
3777 #else
3778   return false;
3779 #endif
3780 }
3781 
3782 // System loadavg support.  Returns -1 if load average cannot be obtained.
3783 // Bsd doesn't yet have a (official) notion of processor sets,
3784 // so just return the system wide load average.
3785 int os::loadavg(double loadavg[], int nelem) {
3786   return ::getloadavg(loadavg, nelem);
3787 }
3788 
3789 void os::pause() {
3790   char filename[MAX_PATH];
3791   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
3792     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
3793   } else {
3794     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
3795   }
3796 
3797   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
3798   if (fd != -1) {
3799     struct stat buf;
3800     ::close(fd);
3801     while (::stat(filename, &buf) == 0) {
3802       (void)::poll(NULL, 0, 100);
3803     }
3804   } else {
3805     jio_fprintf(stderr,
3806                 "Could not open pause file '%s', continuing immediately.\n", filename);
3807   }
3808 }
3809 
3810 // Darwin has no "environ" in a dynamic library.
3811 #ifdef __APPLE__
3812   #include <crt_externs.h>
3813   #define environ (*_NSGetEnviron())
3814 #else
3815 extern char** environ;
3816 #endif
3817 
3818 // Run the specified command in a separate process. Return its exit value,
3819 // or -1 on failure (e.g. can't fork a new process).
3820 // Unlike system(), this function can be called from signal handler. It
3821 // doesn't block SIGINT et al.
3822 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
3823   const char * argv[4] = {"sh", "-c", cmd, NULL};
3824 
3825   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
3826   // pthread_atfork handlers and reset pthread library. All we need is a
3827   // separate process to execve. Make a direct syscall to fork process.
3828   // On IA64 there's no fork syscall, we have to use fork() and hope for
3829   // the best...
3830   pid_t pid = fork();
3831 
3832   if (pid < 0) {
3833     // fork failed
3834     return -1;
3835 
3836   } else if (pid == 0) {
3837     // child process
3838 
3839     // execve() in BsdThreads will call pthread_kill_other_threads_np()
3840     // first to kill every thread on the thread list. Because this list is
3841     // not reset by fork() (see notes above), execve() will instead kill
3842     // every thread in the parent process. We know this is the only thread
3843     // in the new process, so make a system call directly.
3844     // IA64 should use normal execve() from glibc to match the glibc fork()
3845     // above.
3846     execve("/bin/sh", (char* const*)argv, environ);
3847 
3848     // execve failed
3849     _exit(-1);
3850 
3851   } else  {
3852     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
3853     // care about the actual exit code, for now.
3854 
3855     int status;
3856 
3857     // Wait for the child process to exit.  This returns immediately if
3858     // the child has already exited. */
3859     while (waitpid(pid, &status, 0) < 0) {
3860       switch (errno) {
3861       case ECHILD: return 0;
3862       case EINTR: break;
3863       default: return -1;
3864       }
3865     }
3866 
3867     if (WIFEXITED(status)) {
3868       // The child exited normally; get its exit code.
3869       return WEXITSTATUS(status);
3870     } else if (WIFSIGNALED(status)) {
3871       // The child exited because of a signal
3872       // The best value to return is 0x80 + signal number,
3873       // because that is what all Unix shells do, and because
3874       // it allows callers to distinguish between process exit and
3875       // process death by signal.
3876       return 0x80 + WTERMSIG(status);
3877     } else {
3878       // Unknown exit code; pass it through
3879       return status;
3880     }
3881   }
3882 }
3883 
3884 // Get the default path to the core file
3885 // Returns the length of the string
3886 int os::get_core_path(char* buffer, size_t bufferSize) {
3887   int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
3888 
3889   // Truncate if theoretical string was longer than bufferSize
3890   n = MIN2(n, (int)bufferSize);
3891 
3892   return n;
3893 }
3894 
3895 #ifndef PRODUCT
3896 void TestReserveMemorySpecial_test() {
3897   // No tests available for this platform
3898 }
3899 #endif
3900 
3901 bool os::start_debugging(char *buf, int buflen) {
3902   int len = (int)strlen(buf);
3903   char *p = &buf[len];
3904 
3905   jio_snprintf(p, buflen-len,
3906              "\n\n"
3907              "Do you want to debug the problem?\n\n"
3908              "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT " (" INTPTR_FORMAT ")\n"
3909              "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
3910              "Otherwise, press RETURN to abort...",
3911              os::current_process_id(), os::current_process_id(),
3912              os::current_thread_id(), os::current_thread_id());
3913 
3914   bool yes = os::message_box("Unexpected Error", buf);
3915 
3916   if (yes) {
3917     // yes, user asked VM to launch debugger
3918     jio_snprintf(buf, sizeof(buf), "gdb /proc/%d/exe %d",
3919                      os::current_process_id(), os::current_process_id());
3920 
3921     os::fork_and_exec(buf);
3922     yes = false;
3923   }
3924   return yes;
3925 }