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_posix.inline.hpp"
  42 #include "os_share_bsd.hpp"
  43 #include "prims/jniFastGetField.hpp"
  44 #include "prims/jvm_misc.hpp"
  45 #include "runtime/arguments.hpp"
  46 #include "runtime/atomic.hpp"
  47 #include "runtime/extendedPC.hpp"
  48 #include "runtime/globals.hpp"
  49 #include "runtime/interfaceSupport.inline.hpp"
  50 #include "runtime/java.hpp"
  51 #include "runtime/javaCalls.hpp"
  52 #include "runtime/mutexLocker.hpp"
  53 #include "runtime/objectMonitor.hpp"
  54 #include "runtime/orderAccess.hpp"
  55 #include "runtime/osThread.hpp"
  56 #include "runtime/perfMemory.hpp"
  57 #include "runtime/semaphore.hpp"
  58 #include "runtime/sharedRuntime.hpp"
  59 #include "runtime/statSampler.hpp"
  60 #include "runtime/stubRoutines.hpp"
  61 #include "runtime/thread.inline.hpp"
  62 #include "runtime/threadCritical.hpp"
  63 #include "runtime/timer.hpp"
  64 #include "services/attachListener.hpp"
  65 #include "services/memTracker.hpp"
  66 #include "services/runtimeService.hpp"
  67 #include "utilities/align.hpp"
  68 #include "utilities/decoder.hpp"
  69 #include "utilities/defaultStream.hpp"
  70 #include "utilities/events.hpp"
  71 #include "utilities/growableArray.hpp"
  72 #include "utilities/vmError.hpp"
  73 
  74 // put OS-includes here
  75 # include <dlfcn.h>
  76 # include <errno.h>
  77 # include <fcntl.h>
  78 # include <inttypes.h>
  79 # include <poll.h>
  80 # include <pthread.h>
  81 # include <pwd.h>
  82 # include <signal.h>
  83 # include <stdint.h>
  84 # include <stdio.h>
  85 # include <string.h>
  86 # include <sys/ioctl.h>
  87 # include <sys/mman.h>
  88 # include <sys/param.h>
  89 # include <sys/resource.h>
  90 # include <sys/socket.h>
  91 # include <sys/stat.h>
  92 # include <sys/syscall.h>
  93 # include <sys/sysctl.h>
  94 # include <sys/time.h>
  95 # include <sys/times.h>
  96 # include <sys/types.h>
  97 # include <sys/wait.h>
  98 # include <time.h>
  99 # include <unistd.h>
 100 
 101 #if defined(__FreeBSD__) || defined(__NetBSD__)
 102   #include <elf.h>
 103 #endif
 104 
 105 #ifdef __APPLE__
 106   #include <mach-o/dyld.h>
 107 #endif
 108 
 109 #ifndef MAP_ANONYMOUS
 110   #define MAP_ANONYMOUS MAP_ANON
 111 #endif
 112 
 113 #define MAX_PATH    (2 * K)
 114 
 115 // for timer info max values which include all bits
 116 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 117 
 118 ////////////////////////////////////////////////////////////////////////////////
 119 // global variables
 120 julong os::Bsd::_physical_memory = 0;
 121 
 122 #ifdef __APPLE__
 123 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
 124 volatile uint64_t         os::Bsd::_max_abstime   = 0;
 125 #else
 126 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 127 #endif
 128 pthread_t os::Bsd::_main_thread;
 129 int os::Bsd::_page_size = -1;
 130 
 131 static jlong initial_time_count=0;
 132 
 133 static int clock_tics_per_sec = 100;
 134 
 135 // For diagnostics to print a message once. see run_periodic_checks
 136 static sigset_t check_signal_done;
 137 static bool check_signals = true;
 138 
 139 static pid_t _initial_pid = 0;
 140 
 141 // Signal number used to suspend/resume a thread
 142 
 143 // do not use any signal number less than SIGSEGV, see 4355769
 144 static int SR_signum = SIGUSR2;
 145 sigset_t SR_sigset;
 146 
 147 
 148 ////////////////////////////////////////////////////////////////////////////////
 149 // utility functions
 150 
 151 static int SR_initialize();
 152 
 153 julong os::available_memory() {
 154   return Bsd::available_memory();
 155 }
 156 
 157 // available here means free
 158 julong os::Bsd::available_memory() {
 159   uint64_t available = physical_memory() >> 2;
 160 #ifdef __APPLE__
 161   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
 162   vm_statistics64_data_t vmstat;
 163   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
 164                                          (host_info64_t)&vmstat, &count);
 165   assert(kerr == KERN_SUCCESS,
 166          "host_statistics64 failed - check mach_host_self() and count");
 167   if (kerr == KERN_SUCCESS) {
 168     available = vmstat.free_count * os::vm_page_size();
 169   }
 170 #endif
 171   return available;
 172 }
 173 
 174 julong os::physical_memory() {
 175   return Bsd::physical_memory();
 176 }
 177 
 178 // Return true if user is running as root.
 179 
 180 bool os::have_special_privileges() {
 181   static bool init = false;
 182   static bool privileges = false;
 183   if (!init) {
 184     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 185     init = true;
 186   }
 187   return privileges;
 188 }
 189 
 190 
 191 
 192 // Cpu architecture string
 193 #if   defined(ZERO)
 194 static char cpu_arch[] = ZERO_LIBARCH;
 195 #elif defined(IA64)
 196 static char cpu_arch[] = "ia64";
 197 #elif defined(IA32)
 198 static char cpu_arch[] = "i386";
 199 #elif defined(AMD64)
 200 static char cpu_arch[] = "amd64";
 201 #elif defined(ARM)
 202 static char cpu_arch[] = "arm";
 203 #elif defined(PPC32)
 204 static char cpu_arch[] = "ppc";
 205 #elif defined(SPARC)
 206   #ifdef _LP64
 207 static char cpu_arch[] = "sparcv9";
 208   #else
 209 static char cpu_arch[] = "sparc";
 210   #endif
 211 #else
 212   #error Add appropriate cpu_arch setting
 213 #endif
 214 
 215 // Compiler variant
 216 #ifdef COMPILER2
 217   #define COMPILER_VARIANT "server"
 218 #else
 219   #define COMPILER_VARIANT "client"
 220 #endif
 221 
 222 
 223 void os::Bsd::initialize_system_info() {
 224   int mib[2];
 225   size_t len;
 226   int cpu_val;
 227   julong mem_val;
 228 
 229   // get processors count via hw.ncpus sysctl
 230   mib[0] = CTL_HW;
 231   mib[1] = HW_NCPU;
 232   len = sizeof(cpu_val);
 233   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 234     assert(len == sizeof(cpu_val), "unexpected data size");
 235     set_processor_count(cpu_val);
 236   } else {
 237     set_processor_count(1);   // fallback
 238   }
 239 
 240   // get physical memory via hw.memsize sysctl (hw.memsize is used
 241   // since it returns a 64 bit value)
 242   mib[0] = CTL_HW;
 243 
 244 #if defined (HW_MEMSIZE) // Apple
 245   mib[1] = HW_MEMSIZE;
 246 #elif defined(HW_PHYSMEM) // Most of BSD
 247   mib[1] = HW_PHYSMEM;
 248 #elif defined(HW_REALMEM) // Old FreeBSD
 249   mib[1] = HW_REALMEM;
 250 #else
 251   #error No ways to get physmem
 252 #endif
 253 
 254   len = sizeof(mem_val);
 255   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 256     assert(len == sizeof(mem_val), "unexpected data size");
 257     _physical_memory = mem_val;
 258   } else {
 259     _physical_memory = 256 * 1024 * 1024;       // fallback (XXXBSD?)
 260   }
 261 
 262 #ifdef __OpenBSD__
 263   {
 264     // limit _physical_memory memory view on OpenBSD since
 265     // datasize rlimit restricts us anyway.
 266     struct rlimit limits;
 267     getrlimit(RLIMIT_DATA, &limits);
 268     _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 269   }
 270 #endif
 271 }
 272 
 273 #ifdef __APPLE__
 274 static const char *get_home() {
 275   const char *home_dir = ::getenv("HOME");
 276   if ((home_dir == NULL) || (*home_dir == '\0')) {
 277     struct passwd *passwd_info = getpwuid(geteuid());
 278     if (passwd_info != NULL) {
 279       home_dir = passwd_info->pw_dir;
 280     }
 281   }
 282 
 283   return home_dir;
 284 }
 285 #endif
 286 
 287 void os::init_system_properties_values() {
 288   // The next steps are taken in the product version:
 289   //
 290   // Obtain the JAVA_HOME value from the location of libjvm.so.
 291   // This library should be located at:
 292   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 293   //
 294   // If "/jre/lib/" appears at the right place in the path, then we
 295   // assume libjvm.so is installed in a JDK and we use this path.
 296   //
 297   // Otherwise exit with message: "Could not create the Java virtual machine."
 298   //
 299   // The following extra steps are taken in the debugging version:
 300   //
 301   // If "/jre/lib/" does NOT appear at the right place in the path
 302   // instead of exit check for $JAVA_HOME environment variable.
 303   //
 304   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 305   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 306   // it looks like libjvm.so is installed there
 307   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 308   //
 309   // Otherwise exit.
 310   //
 311   // Important note: if the location of libjvm.so changes this
 312   // code needs to be changed accordingly.
 313 
 314   // See ld(1):
 315   //      The linker uses the following search paths to locate required
 316   //      shared libraries:
 317   //        1: ...
 318   //        ...
 319   //        7: The default directories, normally /lib and /usr/lib.
 320 #ifndef DEFAULT_LIBPATH
 321   #ifndef OVERRIDE_LIBPATH
 322     #define DEFAULT_LIBPATH "/lib:/usr/lib"
 323   #else
 324     #define DEFAULT_LIBPATH OVERRIDE_LIBPATH
 325   #endif
 326 #endif
 327 
 328 // Base path of extensions installed on the system.
 329 #define SYS_EXT_DIR     "/usr/java/packages"
 330 #define EXTENSIONS_DIR  "/lib/ext"
 331 
 332 #ifndef __APPLE__
 333 
 334   // Buffer that fits several sprintfs.
 335   // Note that the space for the colon and the trailing null are provided
 336   // by the nulls included by the sizeof operator.
 337   const size_t bufsize =
 338     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 339          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
 340   char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 341 
 342   // sysclasspath, java_home, dll_dir
 343   {
 344     char *pslash;
 345     os::jvm_path(buf, bufsize);
 346 
 347     // Found the full path to libjvm.so.
 348     // Now cut the path to <java_home>/jre if we can.
 349     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 350     pslash = strrchr(buf, '/');
 351     if (pslash != NULL) {
 352       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 353     }
 354     Arguments::set_dll_dir(buf);
 355 
 356     if (pslash != NULL) {
 357       pslash = strrchr(buf, '/');
 358       if (pslash != NULL) {
 359         *pslash = '\0';          // Get rid of /<arch>.
 360         pslash = strrchr(buf, '/');
 361         if (pslash != NULL) {
 362           *pslash = '\0';        // Get rid of /lib.
 363         }
 364       }
 365     }
 366     Arguments::set_java_home(buf);
 367     if (!set_boot_path('/', ':')) {
 368       vm_exit_during_initialization("Failed setting boot class path.", NULL);
 369     }
 370   }
 371 
 372   // Where to look for native libraries.
 373   //
 374   // Note: Due to a legacy implementation, most of the library path
 375   // is set in the launcher. This was to accomodate linking restrictions
 376   // on legacy Bsd implementations (which are no longer supported).
 377   // Eventually, all the library path setting will be done here.
 378   //
 379   // However, to prevent the proliferation of improperly built native
 380   // libraries, the new path component /usr/java/packages is added here.
 381   // Eventually, all the library path setting will be done here.
 382   {
 383     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 384     // should always exist (until the legacy problem cited above is
 385     // addressed).
 386     const char *v = ::getenv("LD_LIBRARY_PATH");
 387     const char *v_colon = ":";
 388     if (v == NULL) { v = ""; v_colon = ""; }
 389     // That's +1 for the colon and +1 for the trailing '\0'.
 390     char *ld_library_path = NEW_C_HEAP_ARRAY(char,
 391                                              strlen(v) + 1 +
 392                                              sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
 393                                              mtInternal);
 394     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
 395     Arguments::set_library_path(ld_library_path);
 396     FREE_C_HEAP_ARRAY(char, ld_library_path);
 397   }
 398 
 399   // Extensions directories.
 400   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
 401   Arguments::set_ext_dirs(buf);
 402 
 403   FREE_C_HEAP_ARRAY(char, buf);
 404 
 405 #else // __APPLE__
 406 
 407   #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 408   #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 409 
 410   const char *user_home_dir = get_home();
 411   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
 412   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 413     sizeof(SYS_EXTENSIONS_DIRS);
 414 
 415   // Buffer that fits several sprintfs.
 416   // Note that the space for the colon and the trailing null are provided
 417   // by the nulls included by the sizeof operator.
 418   const size_t bufsize =
 419     MAX2((size_t)MAXPATHLEN,  // for dll_dir & friends.
 420          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
 421   char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 422 
 423   // sysclasspath, java_home, dll_dir
 424   {
 425     char *pslash;
 426     os::jvm_path(buf, bufsize);
 427 
 428     // Found the full path to libjvm.so.
 429     // Now cut the path to <java_home>/jre if we can.
 430     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 431     pslash = strrchr(buf, '/');
 432     if (pslash != NULL) {
 433       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 434     }
 435 #ifdef STATIC_BUILD
 436     strcat(buf, "/lib");
 437 #endif
 438 
 439     Arguments::set_dll_dir(buf);
 440 
 441     if (pslash != NULL) {
 442       pslash = strrchr(buf, '/');
 443       if (pslash != NULL) {
 444         *pslash = '\0';          // Get rid of /lib.
 445       }
 446     }
 447     Arguments::set_java_home(buf);
 448     set_boot_path('/', ':');
 449   }
 450 
 451   // Where to look for native libraries.
 452   //
 453   // Note: Due to a legacy implementation, most of the library path
 454   // is set in the launcher. This was to accomodate linking restrictions
 455   // on legacy Bsd implementations (which are no longer supported).
 456   // Eventually, all the library path setting will be done here.
 457   //
 458   // However, to prevent the proliferation of improperly built native
 459   // libraries, the new path component /usr/java/packages is added here.
 460   // Eventually, all the library path setting will be done here.
 461   {
 462     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 463     // should always exist (until the legacy problem cited above is
 464     // addressed).
 465     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
 466     // can specify a directory inside an app wrapper
 467     const char *l = ::getenv("JAVA_LIBRARY_PATH");
 468     const char *l_colon = ":";
 469     if (l == NULL) { l = ""; l_colon = ""; }
 470 
 471     const char *v = ::getenv("DYLD_LIBRARY_PATH");
 472     const char *v_colon = ":";
 473     if (v == NULL) { v = ""; v_colon = ""; }
 474 
 475     // Apple's Java6 has "." at the beginning of java.library.path.
 476     // OpenJDK on Windows has "." at the end of java.library.path.
 477     // OpenJDK on Linux and Solaris don't have "." in java.library.path
 478     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 479     // "." is appended to the end of java.library.path. Yes, this
 480     // could cause a change in behavior, but Apple's Java6 behavior
 481     // can be achieved by putting "." at the beginning of the
 482     // JAVA_LIBRARY_PATH environment variable.
 483     char *ld_library_path = NEW_C_HEAP_ARRAY(char,
 484                                              strlen(v) + 1 + strlen(l) + 1 +
 485                                              system_ext_size + 3,
 486                                              mtInternal);
 487     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
 488             v, v_colon, l, l_colon, user_home_dir);
 489     Arguments::set_library_path(ld_library_path);
 490     FREE_C_HEAP_ARRAY(char, ld_library_path);
 491   }
 492 
 493   // Extensions directories.
 494   //
 495   // Note that the space for the colon and the trailing null are provided
 496   // by the nulls included by the sizeof operator (so actually one byte more
 497   // than necessary is allocated).
 498   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
 499           user_home_dir, Arguments::get_java_home());
 500   Arguments::set_ext_dirs(buf);
 501 
 502   FREE_C_HEAP_ARRAY(char, buf);
 503 
 504 #undef SYS_EXTENSIONS_DIR
 505 #undef SYS_EXTENSIONS_DIRS
 506 
 507 #endif // __APPLE__
 508 
 509 #undef SYS_EXT_DIR
 510 #undef EXTENSIONS_DIR
 511 }
 512 
 513 ////////////////////////////////////////////////////////////////////////////////
 514 // breakpoint support
 515 
 516 void os::breakpoint() {
 517   BREAKPOINT;
 518 }
 519 
 520 extern "C" void breakpoint() {
 521   // use debugger to set breakpoint here
 522 }
 523 
 524 ////////////////////////////////////////////////////////////////////////////////
 525 // signal support
 526 
 527 debug_only(static bool signal_sets_initialized = false);
 528 static sigset_t unblocked_sigs, vm_sigs;
 529 
 530 void os::Bsd::signal_sets_init() {
 531   // Should also have an assertion stating we are still single-threaded.
 532   assert(!signal_sets_initialized, "Already initialized");
 533   // Fill in signals that are necessarily unblocked for all threads in
 534   // the VM. Currently, we unblock the following signals:
 535   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 536   //                         by -Xrs (=ReduceSignalUsage));
 537   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 538   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 539   // the dispositions or masks wrt these signals.
 540   // Programs embedding the VM that want to use the above signals for their
 541   // own purposes must, at this time, use the "-Xrs" option to prevent
 542   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 543   // (See bug 4345157, and other related bugs).
 544   // In reality, though, unblocking these signals is really a nop, since
 545   // these signals are not blocked by default.
 546   sigemptyset(&unblocked_sigs);
 547   sigaddset(&unblocked_sigs, SIGILL);
 548   sigaddset(&unblocked_sigs, SIGSEGV);
 549   sigaddset(&unblocked_sigs, SIGBUS);
 550   sigaddset(&unblocked_sigs, SIGFPE);
 551   sigaddset(&unblocked_sigs, SR_signum);
 552 
 553   if (!ReduceSignalUsage) {
 554     if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 555       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 556 
 557     }
 558     if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 559       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 560     }
 561     if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 562       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 563     }
 564   }
 565   // Fill in signals that are blocked by all but the VM thread.
 566   sigemptyset(&vm_sigs);
 567   if (!ReduceSignalUsage) {
 568     sigaddset(&vm_sigs, BREAK_SIGNAL);
 569   }
 570   debug_only(signal_sets_initialized = true);
 571 
 572 }
 573 
 574 // These are signals that are unblocked while a thread is running Java.
 575 // (For some reason, they get blocked by default.)
 576 sigset_t* os::Bsd::unblocked_signals() {
 577   assert(signal_sets_initialized, "Not initialized");
 578   return &unblocked_sigs;
 579 }
 580 
 581 // These are the signals that are blocked while a (non-VM) thread is
 582 // running Java. Only the VM thread handles these signals.
 583 sigset_t* os::Bsd::vm_signals() {
 584   assert(signal_sets_initialized, "Not initialized");
 585   return &vm_sigs;
 586 }
 587 
 588 void os::Bsd::hotspot_sigmask(Thread* thread) {
 589 
 590   //Save caller's signal mask before setting VM signal mask
 591   sigset_t caller_sigmask;
 592   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 593 
 594   OSThread* osthread = thread->osthread();
 595   osthread->set_caller_sigmask(caller_sigmask);
 596 
 597   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 598 
 599   if (!ReduceSignalUsage) {
 600     if (thread->is_VM_thread()) {
 601       // Only the VM thread handles BREAK_SIGNAL ...
 602       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 603     } else {
 604       // ... all other threads block BREAK_SIGNAL
 605       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 606     }
 607   }
 608 }
 609 
 610 
 611 //////////////////////////////////////////////////////////////////////////////
 612 // create new thread
 613 
 614 #ifdef __APPLE__
 615 // library handle for calling objc_registerThreadWithCollector()
 616 // without static linking to the libobjc library
 617   #define OBJC_LIB "/usr/lib/libobjc.dylib"
 618   #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 619 typedef void (*objc_registerThreadWithCollector_t)();
 620 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 621 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 622 #endif
 623 
 624 #ifdef __APPLE__
 625 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 626   // Additional thread_id used to correlate threads in SA
 627   thread_identifier_info_data_t     m_ident_info;
 628   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 629 
 630   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 631               (thread_info_t) &m_ident_info, &count);
 632 
 633   return m_ident_info.thread_id;
 634 }
 635 #endif
 636 
 637 // Thread start routine for all newly created threads
 638 static void *thread_native_entry(Thread *thread) {
 639 
 640   thread->record_stack_base_and_size();
 641 
 642   // Try to randomize the cache line index of hot stack frames.
 643   // This helps when threads of the same stack traces evict each other's
 644   // cache lines. The threads can be either from the same JVM instance, or
 645   // from different JVM instances. The benefit is especially true for
 646   // processors with hyperthreading technology.
 647   static int counter = 0;
 648   int pid = os::current_process_id();
 649   alloca(((pid ^ counter++) & 7) * 128);
 650 
 651   thread->initialize_thread_current();
 652 
 653   OSThread* osthread = thread->osthread();
 654   Monitor* sync = osthread->startThread_lock();
 655 
 656   osthread->set_thread_id(os::Bsd::gettid());
 657 
 658   log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 659     os::current_thread_id(), (uintx) pthread_self());
 660 
 661 #ifdef __APPLE__
 662   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 663   guarantee(unique_thread_id != 0, "unique thread id was not found");
 664   osthread->set_unique_thread_id(unique_thread_id);
 665 #endif
 666   // initialize signal mask for this thread
 667   os::Bsd::hotspot_sigmask(thread);
 668 
 669   // initialize floating point control register
 670   os::Bsd::init_thread_fpu_state();
 671 
 672 #ifdef __APPLE__
 673   // register thread with objc gc
 674   if (objc_registerThreadWithCollectorFunction != NULL) {
 675     objc_registerThreadWithCollectorFunction();
 676   }
 677 #endif
 678 
 679   // handshaking with parent thread
 680   {
 681     MutexLocker ml(sync, Mutex::_no_safepoint_check_flag);
 682 
 683     // notify parent thread
 684     osthread->set_state(INITIALIZED);
 685     sync->notify_all();
 686 
 687     // wait until os::start_thread()
 688     while (osthread->get_state() == INITIALIZED) {
 689       sync->wait_without_safepoint_check();
 690     }
 691   }
 692 
 693   // call one more level start routine
 694   thread->call_run();
 695 
 696   // Note: at this point the thread object may already have deleted itself.
 697   // Prevent dereferencing it from here on out.
 698   thread = NULL;
 699 
 700   log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 701     os::current_thread_id(), (uintx) pthread_self());
 702 
 703   return 0;
 704 }
 705 
 706 bool os::create_thread(Thread* thread, ThreadType thr_type,
 707                        size_t req_stack_size) {
 708   assert(thread->osthread() == NULL, "caller responsible");
 709 
 710   // Allocate the OSThread object
 711   OSThread* osthread = new OSThread(NULL, NULL);
 712   if (osthread == NULL) {
 713     return false;
 714   }
 715 
 716   // set the correct thread state
 717   osthread->set_thread_type(thr_type);
 718 
 719   // Initial state is ALLOCATED but not INITIALIZED
 720   osthread->set_state(ALLOCATED);
 721 
 722   thread->set_osthread(osthread);
 723 
 724   // init thread attributes
 725   pthread_attr_t attr;
 726   pthread_attr_init(&attr);
 727   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 728 
 729   // calculate stack size if it's not specified by caller
 730   size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
 731   int status = pthread_attr_setstacksize(&attr, stack_size);
 732   assert_status(status == 0, status, "pthread_attr_setstacksize");
 733 
 734   ThreadState state;
 735 
 736   {
 737     pthread_t tid;
 738     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
 739 
 740     char buf[64];
 741     if (ret == 0) {
 742       log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
 743         (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 744     } else {
 745       log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
 746         os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 747       // Log some OS information which might explain why creating the thread failed.
 748       log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
 749       LogStream st(Log(os, thread)::info());
 750       os::Posix::print_rlimit_info(&st);
 751       os::print_memory_info(&st);
 752     }
 753 
 754     pthread_attr_destroy(&attr);
 755 
 756     if (ret != 0) {
 757       // Need to clean up stuff we've allocated so far
 758       thread->set_osthread(NULL);
 759       delete osthread;
 760       return false;
 761     }
 762 
 763     // Store pthread info into the OSThread
 764     osthread->set_pthread_id(tid);
 765 
 766     // Wait until child thread is either initialized or aborted
 767     {
 768       Monitor* sync_with_child = osthread->startThread_lock();
 769       MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 770       while ((state = osthread->get_state()) == ALLOCATED) {
 771         sync_with_child->wait_without_safepoint_check();
 772       }
 773     }
 774 
 775   }
 776 
 777   // Aborted due to thread limit being reached
 778   if (state == ZOMBIE) {
 779     thread->set_osthread(NULL);
 780     delete osthread;
 781     return false;
 782   }
 783 
 784   // The thread is returned suspended (in state INITIALIZED),
 785   // and is started higher up in the call chain
 786   assert(state == INITIALIZED, "race condition");
 787   return true;
 788 }
 789 
 790 /////////////////////////////////////////////////////////////////////////////
 791 // attach existing thread
 792 
 793 // bootstrap the main thread
 794 bool os::create_main_thread(JavaThread* thread) {
 795   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 796   return create_attached_thread(thread);
 797 }
 798 
 799 bool os::create_attached_thread(JavaThread* thread) {
 800 #ifdef ASSERT
 801   thread->verify_not_published();
 802 #endif
 803 
 804   // Allocate the OSThread object
 805   OSThread* osthread = new OSThread(NULL, NULL);
 806 
 807   if (osthread == NULL) {
 808     return false;
 809   }
 810 
 811   osthread->set_thread_id(os::Bsd::gettid());
 812 
 813   // Store pthread info into the OSThread
 814 #ifdef __APPLE__
 815   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 816   guarantee(unique_thread_id != 0, "just checking");
 817   osthread->set_unique_thread_id(unique_thread_id);
 818 #endif
 819   osthread->set_pthread_id(::pthread_self());
 820 
 821   // initialize floating point control register
 822   os::Bsd::init_thread_fpu_state();
 823 
 824   // Initial thread state is RUNNABLE
 825   osthread->set_state(RUNNABLE);
 826 
 827   thread->set_osthread(osthread);
 828 
 829   // initialize signal mask for this thread
 830   // and save the caller's signal mask
 831   os::Bsd::hotspot_sigmask(thread);
 832 
 833   log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 834     os::current_thread_id(), (uintx) pthread_self());
 835 
 836   return true;
 837 }
 838 
 839 void os::pd_start_thread(Thread* thread) {
 840   OSThread * osthread = thread->osthread();
 841   assert(osthread->get_state() != INITIALIZED, "just checking");
 842   Monitor* sync_with_child = osthread->startThread_lock();
 843   MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 844   sync_with_child->notify();
 845 }
 846 
 847 // Free Bsd resources related to the OSThread
 848 void os::free_thread(OSThread* osthread) {
 849   assert(osthread != NULL, "osthread not set");
 850 
 851   // We are told to free resources of the argument thread,
 852   // but we can only really operate on the current thread.
 853   assert(Thread::current()->osthread() == osthread,
 854          "os::free_thread but not current thread");
 855 
 856   // Restore caller's signal mask
 857   sigset_t sigmask = osthread->caller_sigmask();
 858   pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 859 
 860   delete osthread;
 861 }
 862 
 863 ////////////////////////////////////////////////////////////////////////////////
 864 // time support
 865 
 866 // Time since start-up in seconds to a fine granularity.
 867 // Used by VMSelfDestructTimer and the MemProfiler.
 868 double os::elapsedTime() {
 869 
 870   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 871 }
 872 
 873 jlong os::elapsed_counter() {
 874   return javaTimeNanos() - initial_time_count;
 875 }
 876 
 877 jlong os::elapsed_frequency() {
 878   return NANOSECS_PER_SEC; // nanosecond resolution
 879 }
 880 
 881 bool os::supports_vtime() { return true; }
 882 bool os::enable_vtime()   { return false; }
 883 bool os::vtime_enabled()  { return false; }
 884 
 885 double os::elapsedVTime() {
 886   // better than nothing, but not much
 887   return elapsedTime();
 888 }
 889 
 890 jlong os::javaTimeMillis() {
 891   timeval time;
 892   int status = gettimeofday(&time, NULL);
 893   assert(status != -1, "bsd error");
 894   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 895 }
 896 
 897 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
 898   timeval time;
 899   int status = gettimeofday(&time, NULL);
 900   assert(status != -1, "bsd error");
 901   seconds = jlong(time.tv_sec);
 902   nanos = jlong(time.tv_usec) * 1000;
 903 }
 904 
 905 #ifndef __APPLE__
 906   #ifndef CLOCK_MONOTONIC
 907     #define CLOCK_MONOTONIC (1)
 908   #endif
 909 #endif
 910 
 911 #ifdef __APPLE__
 912 void os::Bsd::clock_init() {
 913   mach_timebase_info(&_timebase_info);
 914 }
 915 #else
 916 void os::Bsd::clock_init() {
 917   struct timespec res;
 918   struct timespec tp;
 919   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
 920       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
 921     // yes, monotonic clock is supported
 922     _clock_gettime = ::clock_gettime;
 923   }
 924 }
 925 #endif
 926 
 927 
 928 
 929 #ifdef __APPLE__
 930 
 931 jlong os::javaTimeNanos() {
 932   const uint64_t tm = mach_absolute_time();
 933   const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
 934   const uint64_t prev = Bsd::_max_abstime;
 935   if (now <= prev) {
 936     return prev;   // same or retrograde time;
 937   }
 938   const uint64_t obsv = Atomic::cmpxchg(now, &Bsd::_max_abstime, prev);
 939   assert(obsv >= prev, "invariant");   // Monotonicity
 940   // If the CAS succeeded then we're done and return "now".
 941   // If the CAS failed and the observed value "obsv" is >= now then
 942   // we should return "obsv".  If the CAS failed and now > obsv > prv then
 943   // some other thread raced this thread and installed a new value, in which case
 944   // we could either (a) retry the entire operation, (b) retry trying to install now
 945   // or (c) just return obsv.  We use (c).   No loop is required although in some cases
 946   // we might discard a higher "now" value in deference to a slightly lower but freshly
 947   // installed obsv value.   That's entirely benign -- it admits no new orderings compared
 948   // to (a) or (b) -- and greatly reduces coherence traffic.
 949   // We might also condition (c) on the magnitude of the delta between obsv and now.
 950   // Avoiding excessive CAS operations to hot RW locations is critical.
 951   // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
 952   return (prev == obsv) ? now : obsv;
 953 }
 954 
 955 #else // __APPLE__
 956 
 957 jlong os::javaTimeNanos() {
 958   if (os::supports_monotonic_clock()) {
 959     struct timespec tp;
 960     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
 961     assert(status == 0, "gettime error");
 962     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
 963     return result;
 964   } else {
 965     timeval time;
 966     int status = gettimeofday(&time, NULL);
 967     assert(status != -1, "bsd error");
 968     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
 969     return 1000 * usecs;
 970   }
 971 }
 972 
 973 #endif // __APPLE__
 974 
 975 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
 976   if (os::supports_monotonic_clock()) {
 977     info_ptr->max_value = ALL_64_BITS;
 978 
 979     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
 980     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
 981     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
 982   } else {
 983     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
 984     info_ptr->max_value = ALL_64_BITS;
 985 
 986     // gettimeofday is a real time clock so it skips
 987     info_ptr->may_skip_backward = true;
 988     info_ptr->may_skip_forward = true;
 989   }
 990 
 991   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
 992 }
 993 
 994 // Return the real, user, and system times in seconds from an
 995 // arbitrary fixed point in the past.
 996 bool os::getTimesSecs(double* process_real_time,
 997                       double* process_user_time,
 998                       double* process_system_time) {
 999   struct tms ticks;
1000   clock_t real_ticks = times(&ticks);
1001 
1002   if (real_ticks == (clock_t) (-1)) {
1003     return false;
1004   } else {
1005     double ticks_per_second = (double) clock_tics_per_sec;
1006     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1007     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1008     *process_real_time = ((double) real_ticks) / ticks_per_second;
1009 
1010     return true;
1011   }
1012 }
1013 
1014 
1015 char * os::local_time_string(char *buf, size_t buflen) {
1016   struct tm t;
1017   time_t long_time;
1018   time(&long_time);
1019   localtime_r(&long_time, &t);
1020   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1021                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1022                t.tm_hour, t.tm_min, t.tm_sec);
1023   return buf;
1024 }
1025 
1026 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1027   return localtime_r(clock, res);
1028 }
1029 
1030 ////////////////////////////////////////////////////////////////////////////////
1031 // runtime exit support
1032 
1033 // Note: os::shutdown() might be called very early during initialization, or
1034 // called from signal handler. Before adding something to os::shutdown(), make
1035 // sure it is async-safe and can handle partially initialized VM.
1036 void os::shutdown() {
1037 
1038   // allow PerfMemory to attempt cleanup of any persistent resources
1039   perfMemory_exit();
1040 
1041   // needs to remove object in file system
1042   AttachListener::abort();
1043 
1044   // flush buffered output, finish log files
1045   ostream_abort();
1046 
1047   // Check for abort hook
1048   abort_hook_t abort_hook = Arguments::abort_hook();
1049   if (abort_hook != NULL) {
1050     abort_hook();
1051   }
1052 
1053 }
1054 
1055 // Note: os::abort() might be called very early during initialization, or
1056 // called from signal handler. Before adding something to os::abort(), make
1057 // sure it is async-safe and can handle partially initialized VM.
1058 void os::abort(bool dump_core, void* siginfo, const void* context) {
1059   os::shutdown();
1060   if (dump_core) {
1061 #ifndef PRODUCT
1062     fdStream out(defaultStream::output_fd());
1063     out.print_raw("Current thread is ");
1064     char buf[16];
1065     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1066     out.print_raw_cr(buf);
1067     out.print_raw_cr("Dumping core ...");
1068 #endif
1069     ::abort(); // dump core
1070   }
1071 
1072   ::exit(1);
1073 }
1074 
1075 // Die immediately, no exit hook, no abort hook, no cleanup.
1076 // Dump a core file, if possible, for debugging.
1077 void os::die() {
1078   if (TestUnresponsiveErrorHandler && !CreateCoredumpOnCrash) {
1079     // For TimeoutInErrorHandlingTest.java, we just kill the VM
1080     // and don't take the time to generate a core file.
1081     os::signal_raise(SIGKILL);
1082   } else {
1083     // _exit() on BsdThreads only kills current thread
1084     ::abort();
1085   }
1086 }
1087 
1088 // Information of current thread in variety of formats
1089 pid_t os::Bsd::gettid() {
1090   int retval = -1;
1091 
1092 #ifdef __APPLE__ //XNU kernel
1093   // despite the fact mach port is actually not a thread id use it
1094   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1095   retval = ::pthread_mach_thread_np(::pthread_self());
1096   guarantee(retval != 0, "just checking");
1097   return retval;
1098 
1099 #else
1100   #ifdef __FreeBSD__
1101   retval = syscall(SYS_thr_self);
1102   #else
1103     #ifdef __OpenBSD__
1104   retval = syscall(SYS_getthrid);
1105     #else
1106       #ifdef __NetBSD__
1107   retval = (pid_t) syscall(SYS__lwp_self);
1108       #endif
1109     #endif
1110   #endif
1111 #endif
1112 
1113   if (retval == -1) {
1114     return getpid();
1115   }
1116 }
1117 
1118 intx os::current_thread_id() {
1119 #ifdef __APPLE__
1120   return (intx)::pthread_mach_thread_np(::pthread_self());
1121 #else
1122   return (intx)::pthread_self();
1123 #endif
1124 }
1125 
1126 int os::current_process_id() {
1127 
1128   // Under the old bsd thread library, bsd gives each thread
1129   // its own process id. Because of this each thread will return
1130   // a different pid if this method were to return the result
1131   // of getpid(2). Bsd provides no api that returns the pid
1132   // of the launcher thread for the vm. This implementation
1133   // returns a unique pid, the pid of the launcher thread
1134   // that starts the vm 'process'.
1135 
1136   // Under the NPTL, getpid() returns the same pid as the
1137   // launcher thread rather than a unique pid per thread.
1138   // Use gettid() if you want the old pre NPTL behaviour.
1139 
1140   // if you are looking for the result of a call to getpid() that
1141   // returns a unique pid for the calling thread, then look at the
1142   // OSThread::thread_id() method in osThread_bsd.hpp file
1143 
1144   return (int)(_initial_pid ? _initial_pid : getpid());
1145 }
1146 
1147 // DLL functions
1148 
1149 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1150 
1151 // This must be hard coded because it's the system's temporary
1152 // directory not the java application's temp directory, ala java.io.tmpdir.
1153 #ifdef __APPLE__
1154 // macosx has a secure per-user temporary directory
1155 char temp_path_storage[PATH_MAX];
1156 const char* os::get_temp_directory() {
1157   static char *temp_path = NULL;
1158   if (temp_path == NULL) {
1159     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1160     if (pathSize == 0 || pathSize > PATH_MAX) {
1161       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1162     }
1163     temp_path = temp_path_storage;
1164   }
1165   return temp_path;
1166 }
1167 #else // __APPLE__
1168 const char* os::get_temp_directory() { return "/tmp"; }
1169 #endif // __APPLE__
1170 
1171 // check if addr is inside libjvm.so
1172 bool os::address_is_in_vm(address addr) {
1173   static address libjvm_base_addr;
1174   Dl_info dlinfo;
1175 
1176   if (libjvm_base_addr == NULL) {
1177     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1178       libjvm_base_addr = (address)dlinfo.dli_fbase;
1179     }
1180     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1181   }
1182 
1183   if (dladdr((void *)addr, &dlinfo) != 0) {
1184     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1185   }
1186 
1187   return false;
1188 }
1189 
1190 
1191 #define MACH_MAXSYMLEN 256
1192 
1193 bool os::dll_address_to_function_name(address addr, char *buf,
1194                                       int buflen, int *offset,
1195                                       bool demangle) {
1196   // buf is not optional, but offset is optional
1197   assert(buf != NULL, "sanity check");
1198 
1199   Dl_info dlinfo;
1200   char localbuf[MACH_MAXSYMLEN];
1201 
1202   if (dladdr((void*)addr, &dlinfo) != 0) {
1203     // see if we have a matching symbol
1204     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1205       if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1206         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1207       }
1208       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1209       return true;
1210     }
1211     // no matching symbol so try for just file info
1212     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1213       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1214                           buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1215         return true;
1216       }
1217     }
1218 
1219     // Handle non-dynamic manually:
1220     if (dlinfo.dli_fbase != NULL &&
1221         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1222                         dlinfo.dli_fbase)) {
1223       if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) {
1224         jio_snprintf(buf, buflen, "%s", localbuf);
1225       }
1226       return true;
1227     }
1228   }
1229   buf[0] = '\0';
1230   if (offset != NULL) *offset = -1;
1231   return false;
1232 }
1233 
1234 // ported from solaris version
1235 bool os::dll_address_to_library_name(address addr, char* buf,
1236                                      int buflen, int* offset) {
1237   // buf is not optional, but offset is optional
1238   assert(buf != NULL, "sanity check");
1239 
1240   Dl_info dlinfo;
1241 
1242   if (dladdr((void*)addr, &dlinfo) != 0) {
1243     if (dlinfo.dli_fname != NULL) {
1244       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1245     }
1246     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1247       *offset = addr - (address)dlinfo.dli_fbase;
1248     }
1249     return true;
1250   }
1251 
1252   buf[0] = '\0';
1253   if (offset) *offset = -1;
1254   return false;
1255 }
1256 
1257 // Loads .dll/.so and
1258 // in case of error it checks if .dll/.so was built for the
1259 // same architecture as Hotspot is running on
1260 
1261 #ifdef __APPLE__
1262 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1263 #ifdef STATIC_BUILD
1264   return os::get_default_process_handle();
1265 #else
1266   log_info(os)("attempting shared library load of %s", filename);
1267 
1268   void * result= ::dlopen(filename, RTLD_LAZY);
1269   if (result != NULL) {
1270     Events::log(NULL, "Loaded shared library %s", filename);
1271     // Successful loading
1272     log_info(os)("shared library load of %s was successful", filename);
1273     return result;
1274   }
1275 
1276   const char* error_report = ::dlerror();
1277   if (error_report == NULL) {
1278     error_report = "dlerror returned no error description";
1279   }
1280   if (ebuf != NULL && ebuflen > 0) {
1281     // Read system error message into ebuf
1282     ::strncpy(ebuf, error_report, ebuflen-1);
1283     ebuf[ebuflen-1]='\0';
1284   }
1285   Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
1286   log_info(os)("shared library load of %s failed, %s", filename, error_report);
1287 
1288   return NULL;
1289 #endif // STATIC_BUILD
1290 }
1291 #else
1292 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1293 #ifdef STATIC_BUILD
1294   return os::get_default_process_handle();
1295 #else
1296   log_info(os)("attempting shared library load of %s", filename);
1297   void * result= ::dlopen(filename, RTLD_LAZY);
1298   if (result != NULL) {
1299     Events::log(NULL, "Loaded shared library %s", filename);
1300     // Successful loading
1301     log_info(os)("shared library load of %s was successful", filename);
1302     return result;
1303   }
1304 
1305   Elf32_Ehdr elf_head;
1306 
1307   const char* const error_report = ::dlerror();
1308   if (error_report == NULL) {
1309     error_report = "dlerror returned no error description";
1310   }
1311   if (ebuf != NULL && ebuflen > 0) {
1312     // Read system error message into ebuf
1313     ::strncpy(ebuf, error_report, ebuflen-1);
1314     ebuf[ebuflen-1]='\0';
1315   }
1316   Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
1317   log_info(os)("shared library load of %s failed, %s", filename, error_report);
1318 
1319   int diag_msg_max_length=ebuflen-strlen(ebuf);
1320   char* diag_msg_buf=ebuf+strlen(ebuf);
1321 
1322   if (diag_msg_max_length==0) {
1323     // No more space in ebuf for additional diagnostics message
1324     return NULL;
1325   }
1326 
1327 
1328   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1329 
1330   if (file_descriptor < 0) {
1331     // Can't open library, report dlerror() message
1332     return NULL;
1333   }
1334 
1335   bool failed_to_read_elf_head=
1336     (sizeof(elf_head)!=
1337      (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1338 
1339   ::close(file_descriptor);
1340   if (failed_to_read_elf_head) {
1341     // file i/o error - report dlerror() msg
1342     return NULL;
1343   }
1344 
1345   typedef struct {
1346     Elf32_Half  code;         // Actual value as defined in elf.h
1347     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1348     char        elf_class;    // 32 or 64 bit
1349     char        endianess;    // MSB or LSB
1350     char*       name;         // String representation
1351   } arch_t;
1352 
1353   #ifndef EM_486
1354     #define EM_486          6               /* Intel 80486 */
1355   #endif
1356 
1357   #ifndef EM_MIPS_RS3_LE
1358     #define EM_MIPS_RS3_LE  10              /* MIPS */
1359   #endif
1360 
1361   #ifndef EM_PPC64
1362     #define EM_PPC64        21              /* PowerPC64 */
1363   #endif
1364 
1365   #ifndef EM_S390
1366     #define EM_S390         22              /* IBM System/390 */
1367   #endif
1368 
1369   #ifndef EM_IA_64
1370     #define EM_IA_64        50              /* HP/Intel IA-64 */
1371   #endif
1372 
1373   #ifndef EM_X86_64
1374     #define EM_X86_64       62              /* AMD x86-64 */
1375   #endif
1376 
1377   static const arch_t arch_array[]={
1378     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1379     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1380     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1381     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1382     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1383     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1384     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1385     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1386     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1387     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1388     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1389     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1390     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1391     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1392     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1393     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1394   };
1395 
1396   #if  (defined IA32)
1397   static  Elf32_Half running_arch_code=EM_386;
1398   #elif   (defined AMD64)
1399   static  Elf32_Half running_arch_code=EM_X86_64;
1400   #elif  (defined IA64)
1401   static  Elf32_Half running_arch_code=EM_IA_64;
1402   #elif  (defined __sparc) && (defined _LP64)
1403   static  Elf32_Half running_arch_code=EM_SPARCV9;
1404   #elif  (defined __sparc) && (!defined _LP64)
1405   static  Elf32_Half running_arch_code=EM_SPARC;
1406   #elif  (defined __powerpc64__)
1407   static  Elf32_Half running_arch_code=EM_PPC64;
1408   #elif  (defined __powerpc__)
1409   static  Elf32_Half running_arch_code=EM_PPC;
1410   #elif  (defined ARM)
1411   static  Elf32_Half running_arch_code=EM_ARM;
1412   #elif  (defined S390)
1413   static  Elf32_Half running_arch_code=EM_S390;
1414   #elif  (defined ALPHA)
1415   static  Elf32_Half running_arch_code=EM_ALPHA;
1416   #elif  (defined MIPSEL)
1417   static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1418   #elif  (defined PARISC)
1419   static  Elf32_Half running_arch_code=EM_PARISC;
1420   #elif  (defined MIPS)
1421   static  Elf32_Half running_arch_code=EM_MIPS;
1422   #elif  (defined M68K)
1423   static  Elf32_Half running_arch_code=EM_68K;
1424   #else
1425     #error Method os::dll_load requires that one of following is defined:\
1426          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1427   #endif
1428 
1429   // Identify compatability class for VM's architecture and library's architecture
1430   // Obtain string descriptions for architectures
1431 
1432   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1433   int running_arch_index=-1;
1434 
1435   for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1436     if (running_arch_code == arch_array[i].code) {
1437       running_arch_index    = i;
1438     }
1439     if (lib_arch.code == arch_array[i].code) {
1440       lib_arch.compat_class = arch_array[i].compat_class;
1441       lib_arch.name         = arch_array[i].name;
1442     }
1443   }
1444 
1445   assert(running_arch_index != -1,
1446          "Didn't find running architecture code (running_arch_code) in arch_array");
1447   if (running_arch_index == -1) {
1448     // Even though running architecture detection failed
1449     // we may still continue with reporting dlerror() message
1450     return NULL;
1451   }
1452 
1453   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1454     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1455     return NULL;
1456   }
1457 
1458 #ifndef S390
1459   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1460     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1461     return NULL;
1462   }
1463 #endif // !S390
1464 
1465   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1466     if (lib_arch.name!=NULL) {
1467       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1468                  " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1469                  lib_arch.name, arch_array[running_arch_index].name);
1470     } else {
1471       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1472                  " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1473                  lib_arch.code,
1474                  arch_array[running_arch_index].name);
1475     }
1476   }
1477 
1478   return NULL;
1479 #endif // STATIC_BUILD
1480 }
1481 #endif // !__APPLE__
1482 
1483 void* os::get_default_process_handle() {
1484 #ifdef __APPLE__
1485   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1486   // to avoid finding unexpected symbols on second (or later)
1487   // loads of a library.
1488   return (void*)::dlopen(NULL, RTLD_FIRST);
1489 #else
1490   return (void*)::dlopen(NULL, RTLD_LAZY);
1491 #endif
1492 }
1493 
1494 // XXX: Do we need a lock around this as per Linux?
1495 void* os::dll_lookup(void* handle, const char* name) {
1496   return dlsym(handle, name);
1497 }
1498 
1499 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1500   outputStream * out = (outputStream *) param;
1501   out->print_cr(INTPTR_FORMAT " \t%s", (intptr_t)base_address, name);
1502   return 0;
1503 }
1504 
1505 void os::print_dll_info(outputStream *st) {
1506   st->print_cr("Dynamic libraries:");
1507   if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1508     st->print_cr("Error: Cannot print dynamic libraries.");
1509   }
1510 }
1511 
1512 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1513 #ifdef RTLD_DI_LINKMAP
1514   Dl_info dli;
1515   void *handle;
1516   Link_map *map;
1517   Link_map *p;
1518 
1519   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1520       dli.dli_fname == NULL) {
1521     return 1;
1522   }
1523   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1524   if (handle == NULL) {
1525     return 1;
1526   }
1527   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1528   if (map == NULL) {
1529     dlclose(handle);
1530     return 1;
1531   }
1532 
1533   while (map->l_prev != NULL)
1534     map = map->l_prev;
1535 
1536   while (map != NULL) {
1537     // Value for top_address is returned as 0 since we don't have any information about module size
1538     if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1539       dlclose(handle);
1540       return 1;
1541     }
1542     map = map->l_next;
1543   }
1544 
1545   dlclose(handle);
1546 #elif defined(__APPLE__)
1547   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1548     // Value for top_address is returned as 0 since we don't have any information about module size
1549     if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1550       return 1;
1551     }
1552   }
1553   return 0;
1554 #else
1555   return 1;
1556 #endif
1557 }
1558 
1559 void os::get_summary_os_info(char* buf, size_t buflen) {
1560   // These buffers are small because we want this to be brief
1561   // and not use a lot of stack while generating the hs_err file.
1562   char os[100];
1563   size_t size = sizeof(os);
1564   int mib_kern[] = { CTL_KERN, KERN_OSTYPE };
1565   if (sysctl(mib_kern, 2, os, &size, NULL, 0) < 0) {
1566 #ifdef __APPLE__
1567       strncpy(os, "Darwin", sizeof(os));
1568 #elif __OpenBSD__
1569       strncpy(os, "OpenBSD", sizeof(os));
1570 #else
1571       strncpy(os, "BSD", sizeof(os));
1572 #endif
1573   }
1574 
1575   char release[100];
1576   size = sizeof(release);
1577   int mib_release[] = { CTL_KERN, KERN_OSRELEASE };
1578   if (sysctl(mib_release, 2, release, &size, NULL, 0) < 0) {
1579       // if error, leave blank
1580       strncpy(release, "", sizeof(release));
1581   }
1582   snprintf(buf, buflen, "%s %s", os, release);
1583 }
1584 
1585 void os::print_os_info_brief(outputStream* st) {
1586   os::Posix::print_uname_info(st);
1587 }
1588 
1589 void os::print_os_info(outputStream* st) {
1590   st->print("OS:");
1591 
1592   os::Posix::print_uname_info(st);
1593 
1594   os::Posix::print_rlimit_info(st);
1595 
1596   os::Posix::print_load_average(st);
1597 }
1598 
1599 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1600   // Nothing to do for now.
1601 }
1602 
1603 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1604   unsigned int mhz;
1605   size_t size = sizeof(mhz);
1606   int mib[] = { CTL_HW, HW_CPU_FREQ };
1607   if (sysctl(mib, 2, &mhz, &size, NULL, 0) < 0) {
1608     mhz = 1;  // looks like an error but can be divided by
1609   } else {
1610     mhz /= 1000000;  // reported in millions
1611   }
1612 
1613   char model[100];
1614   size = sizeof(model);
1615   int mib_model[] = { CTL_HW, HW_MODEL };
1616   if (sysctl(mib_model, 2, model, &size, NULL, 0) < 0) {
1617     strncpy(model, cpu_arch, sizeof(model));
1618   }
1619 
1620   char machine[100];
1621   size = sizeof(machine);
1622   int mib_machine[] = { CTL_HW, HW_MACHINE };
1623   if (sysctl(mib_machine, 2, machine, &size, NULL, 0) < 0) {
1624       strncpy(machine, "", sizeof(machine));
1625   }
1626 
1627   snprintf(buf, buflen, "%s %s %d MHz", model, machine, mhz);
1628 }
1629 
1630 void os::print_memory_info(outputStream* st) {
1631   xsw_usage swap_usage;
1632   size_t size = sizeof(swap_usage);
1633 
1634   st->print("Memory:");
1635   st->print(" %dk page", os::vm_page_size()>>10);
1636 
1637   st->print(", physical " UINT64_FORMAT "k",
1638             os::physical_memory() >> 10);
1639   st->print("(" UINT64_FORMAT "k free)",
1640             os::available_memory() >> 10);
1641 
1642   if((sysctlbyname("vm.swapusage", &swap_usage, &size, NULL, 0) == 0) || (errno == ENOMEM)) {
1643     if (size >= offset_of(xsw_usage, xsu_used)) {
1644       st->print(", swap " UINT64_FORMAT "k",
1645                 ((julong) swap_usage.xsu_total) >> 10);
1646       st->print("(" UINT64_FORMAT "k free)",
1647                 ((julong) swap_usage.xsu_avail) >> 10);
1648     }
1649   }
1650 
1651   st->cr();
1652 }
1653 
1654 static void print_signal_handler(outputStream* st, int sig,
1655                                  char* buf, size_t buflen);
1656 
1657 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1658   st->print_cr("Signal Handlers:");
1659   print_signal_handler(st, SIGSEGV, buf, buflen);
1660   print_signal_handler(st, SIGBUS , buf, buflen);
1661   print_signal_handler(st, SIGFPE , buf, buflen);
1662   print_signal_handler(st, SIGPIPE, buf, buflen);
1663   print_signal_handler(st, SIGXFSZ, buf, buflen);
1664   print_signal_handler(st, SIGILL , buf, buflen);
1665   print_signal_handler(st, SR_signum, buf, buflen);
1666   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1667   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1668   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1669   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1670 }
1671 
1672 static char saved_jvm_path[MAXPATHLEN] = {0};
1673 
1674 // Find the full path to the current module, libjvm
1675 void os::jvm_path(char *buf, jint buflen) {
1676   // Error checking.
1677   if (buflen < MAXPATHLEN) {
1678     assert(false, "must use a large-enough buffer");
1679     buf[0] = '\0';
1680     return;
1681   }
1682   // Lazy resolve the path to current module.
1683   if (saved_jvm_path[0] != 0) {
1684     strcpy(buf, saved_jvm_path);
1685     return;
1686   }
1687 
1688   char dli_fname[MAXPATHLEN];
1689   bool ret = dll_address_to_library_name(
1690                                          CAST_FROM_FN_PTR(address, os::jvm_path),
1691                                          dli_fname, sizeof(dli_fname), NULL);
1692   assert(ret, "cannot locate libjvm");
1693   char *rp = NULL;
1694   if (ret && dli_fname[0] != '\0') {
1695     rp = os::Posix::realpath(dli_fname, buf, buflen);
1696   }
1697   if (rp == NULL) {
1698     return;
1699   }
1700 
1701   if (Arguments::sun_java_launcher_is_altjvm()) {
1702     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1703     // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1704     // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1705     // appears at the right place in the string, then assume we are
1706     // installed in a JDK and we're done. Otherwise, check for a
1707     // JAVA_HOME environment variable and construct a path to the JVM
1708     // being overridden.
1709 
1710     const char *p = buf + strlen(buf) - 1;
1711     for (int count = 0; p > buf && count < 5; ++count) {
1712       for (--p; p > buf && *p != '/'; --p)
1713         /* empty */ ;
1714     }
1715 
1716     if (strncmp(p, "/jre/lib/", 9) != 0) {
1717       // Look for JAVA_HOME in the environment.
1718       char* java_home_var = ::getenv("JAVA_HOME");
1719       if (java_home_var != NULL && java_home_var[0] != 0) {
1720         char* jrelib_p;
1721         int len;
1722 
1723         // Check the current module name "libjvm"
1724         p = strrchr(buf, '/');
1725         assert(strstr(p, "/libjvm") == p, "invalid library name");
1726 
1727         rp = os::Posix::realpath(java_home_var, buf, buflen);
1728         if (rp == NULL) {
1729           return;
1730         }
1731 
1732         // determine if this is a legacy image or modules image
1733         // modules image doesn't have "jre" subdirectory
1734         len = strlen(buf);
1735         assert(len < buflen, "Ran out of buffer space");
1736         jrelib_p = buf + len;
1737 
1738         // Add the appropriate library subdir
1739         snprintf(jrelib_p, buflen-len, "/jre/lib");
1740         if (0 != access(buf, F_OK)) {
1741           snprintf(jrelib_p, buflen-len, "/lib");
1742         }
1743 
1744         // Add the appropriate client or server subdir
1745         len = strlen(buf);
1746         jrelib_p = buf + len;
1747         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1748         if (0 != access(buf, F_OK)) {
1749           snprintf(jrelib_p, buflen-len, "%s", "");
1750         }
1751 
1752         // If the path exists within JAVA_HOME, add the JVM library name
1753         // to complete the path to JVM being overridden.  Otherwise fallback
1754         // to the path to the current library.
1755         if (0 == access(buf, F_OK)) {
1756           // Use current module name "libjvm"
1757           len = strlen(buf);
1758           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1759         } else {
1760           // Fall back to path of current library
1761           rp = os::Posix::realpath(dli_fname, buf, buflen);
1762           if (rp == NULL) {
1763             return;
1764           }
1765         }
1766       }
1767     }
1768   }
1769 
1770   strncpy(saved_jvm_path, buf, MAXPATHLEN);
1771   saved_jvm_path[MAXPATHLEN - 1] = '\0';
1772 }
1773 
1774 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1775   // no prefix required, not even "_"
1776 }
1777 
1778 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1779   // no suffix required
1780 }
1781 
1782 ////////////////////////////////////////////////////////////////////////////////
1783 // sun.misc.Signal support
1784 
1785 static void UserHandler(int sig, void *siginfo, void *context) {
1786   // Ctrl-C is pressed during error reporting, likely because the error
1787   // handler fails to abort. Let VM die immediately.
1788   if (sig == SIGINT && VMError::is_error_reported()) {
1789     os::die();
1790   }
1791 
1792   os::signal_notify(sig);
1793 }
1794 
1795 void* os::user_handler() {
1796   return CAST_FROM_FN_PTR(void*, UserHandler);
1797 }
1798 
1799 extern "C" {
1800   typedef void (*sa_handler_t)(int);
1801   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1802 }
1803 
1804 void* os::signal(int signal_number, void* handler) {
1805   struct sigaction sigAct, oldSigAct;
1806 
1807   sigfillset(&(sigAct.sa_mask));
1808   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1809   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1810 
1811   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1812     // -1 means registration failed
1813     return (void *)-1;
1814   }
1815 
1816   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1817 }
1818 
1819 void os::signal_raise(int signal_number) {
1820   ::raise(signal_number);
1821 }
1822 
1823 // The following code is moved from os.cpp for making this
1824 // code platform specific, which it is by its very nature.
1825 
1826 // Will be modified when max signal is changed to be dynamic
1827 int os::sigexitnum_pd() {
1828   return NSIG;
1829 }
1830 
1831 // a counter for each possible signal value
1832 static volatile jint pending_signals[NSIG+1] = { 0 };
1833 static Semaphore* sig_sem = NULL;
1834 
1835 static void jdk_misc_signal_init() {
1836   // Initialize signal structures
1837   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1838 
1839   // Initialize signal semaphore
1840   sig_sem = new Semaphore();
1841 }
1842 
1843 void os::signal_notify(int sig) {
1844   if (sig_sem != NULL) {
1845     Atomic::inc(&pending_signals[sig]);
1846     sig_sem->signal();
1847   } else {
1848     // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
1849     // initialization isn't called.
1850     assert(ReduceSignalUsage, "signal semaphore should be created");
1851   }
1852 }
1853 
1854 static int check_pending_signals() {
1855   for (;;) {
1856     for (int i = 0; i < NSIG + 1; i++) {
1857       jint n = pending_signals[i];
1858       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1859         return i;
1860       }
1861     }
1862     JavaThread *thread = JavaThread::current();
1863     ThreadBlockInVM tbivm(thread);
1864 
1865     bool threadIsSuspended;
1866     do {
1867       thread->set_suspend_equivalent();
1868       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1869       sig_sem->wait();
1870 
1871       // were we externally suspended while we were waiting?
1872       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1873       if (threadIsSuspended) {
1874         // The semaphore has been incremented, but while we were waiting
1875         // another thread suspended us. We don't want to continue running
1876         // while suspended because that would surprise the thread that
1877         // suspended us.
1878         sig_sem->signal();
1879 
1880         thread->java_suspend_self();
1881       }
1882     } while (threadIsSuspended);
1883   }
1884 }
1885 
1886 int os::signal_wait() {
1887   return check_pending_signals();
1888 }
1889 
1890 ////////////////////////////////////////////////////////////////////////////////
1891 // Virtual Memory
1892 
1893 int os::vm_page_size() {
1894   // Seems redundant as all get out
1895   assert(os::Bsd::page_size() != -1, "must call os::init");
1896   return os::Bsd::page_size();
1897 }
1898 
1899 // Solaris allocates memory by pages.
1900 int os::vm_allocation_granularity() {
1901   assert(os::Bsd::page_size() != -1, "must call os::init");
1902   return os::Bsd::page_size();
1903 }
1904 
1905 // Rationale behind this function:
1906 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
1907 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
1908 //  samples for JITted code. Here we create private executable mapping over the code cache
1909 //  and then we can use standard (well, almost, as mapping can change) way to provide
1910 //  info for the reporting script by storing timestamp and location of symbol
1911 void bsd_wrap_code(char* base, size_t size) {
1912   static volatile jint cnt = 0;
1913 
1914   if (!UseOprofile) {
1915     return;
1916   }
1917 
1918   char buf[PATH_MAX + 1];
1919   int num = Atomic::add(1, &cnt);
1920 
1921   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
1922            os::get_temp_directory(), os::current_process_id(), num);
1923   unlink(buf);
1924 
1925   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
1926 
1927   if (fd != -1) {
1928     off_t rv = ::lseek(fd, size-2, SEEK_SET);
1929     if (rv != (off_t)-1) {
1930       if (::write(fd, "", 1) == 1) {
1931         mmap(base, size,
1932              PROT_READ|PROT_WRITE|PROT_EXEC,
1933              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
1934       }
1935     }
1936     ::close(fd);
1937     unlink(buf);
1938   }
1939 }
1940 
1941 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
1942                                     int err) {
1943   warning("INFO: os::commit_memory(" INTPTR_FORMAT ", " SIZE_FORMAT
1944           ", %d) failed; error='%s' (errno=%d)", (intptr_t)addr, size, exec,
1945            os::errno_name(err), err);
1946 }
1947 
1948 // NOTE: Bsd kernel does not really reserve the pages for us.
1949 //       All it does is to check if there are enough free pages
1950 //       left at the time of mmap(). This could be a potential
1951 //       problem.
1952 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
1953   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
1954 #ifdef __OpenBSD__
1955   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
1956   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
1957   if (::mprotect(addr, size, prot) == 0) {
1958     return true;
1959   }
1960 #else
1961   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
1962                                      MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
1963   if (res != (uintptr_t) MAP_FAILED) {
1964     return true;
1965   }
1966 #endif
1967 
1968   // Warn about any commit errors we see in non-product builds just
1969   // in case mmap() doesn't work as described on the man page.
1970   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
1971 
1972   return false;
1973 }
1974 
1975 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
1976                           bool exec) {
1977   // alignment_hint is ignored on this OS
1978   return pd_commit_memory(addr, size, exec);
1979 }
1980 
1981 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
1982                                   const char* mesg) {
1983   assert(mesg != NULL, "mesg must be specified");
1984   if (!pd_commit_memory(addr, size, exec)) {
1985     // add extra info in product mode for vm_exit_out_of_memory():
1986     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
1987     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
1988   }
1989 }
1990 
1991 void os::pd_commit_memory_or_exit(char* addr, size_t size,
1992                                   size_t alignment_hint, bool exec,
1993                                   const char* mesg) {
1994   // alignment_hint is ignored on this OS
1995   pd_commit_memory_or_exit(addr, size, exec, mesg);
1996 }
1997 
1998 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1999 }
2000 
2001 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2002   ::madvise(addr, bytes, MADV_DONTNEED);
2003 }
2004 
2005 void os::numa_make_global(char *addr, size_t bytes) {
2006 }
2007 
2008 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2009 }
2010 
2011 bool os::numa_topology_changed()   { return false; }
2012 
2013 size_t os::numa_get_groups_num() {
2014   return 1;
2015 }
2016 
2017 int os::numa_get_group_id() {
2018   return 0;
2019 }
2020 
2021 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2022   if (size > 0) {
2023     ids[0] = 0;
2024     return 1;
2025   }
2026   return 0;
2027 }
2028 
2029 bool os::get_page_info(char *start, page_info* info) {
2030   return false;
2031 }
2032 
2033 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2034   return end;
2035 }
2036 
2037 
2038 bool os::pd_uncommit_memory(char* addr, size_t size) {
2039 #ifdef __OpenBSD__
2040   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2041   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with PROT_NONE", p2i(addr), p2i(addr+size));
2042   return ::mprotect(addr, size, PROT_NONE) == 0;
2043 #else
2044   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2045                                      MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2046   return res  != (uintptr_t) MAP_FAILED;
2047 #endif
2048 }
2049 
2050 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2051   return os::commit_memory(addr, size, !ExecMem);
2052 }
2053 
2054 // If this is a growable mapping, remove the guard pages entirely by
2055 // munmap()ping them.  If not, just call uncommit_memory().
2056 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2057   return os::uncommit_memory(addr, size);
2058 }
2059 
2060 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2061 // at 'requested_addr'. If there are existing memory mappings at the same
2062 // location, however, they will be overwritten. If 'fixed' is false,
2063 // 'requested_addr' is only treated as a hint, the return value may or
2064 // may not start from the requested address. Unlike Bsd mmap(), this
2065 // function returns NULL to indicate failure.
2066 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2067   char * addr;
2068   int flags;
2069 
2070   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2071   if (fixed) {
2072     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2073     flags |= MAP_FIXED;
2074   }
2075 
2076   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2077   // touch an uncommitted page. Otherwise, the read/write might
2078   // succeed if we have enough swap space to back the physical page.
2079   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2080                        flags, -1, 0);
2081 
2082   return addr == MAP_FAILED ? NULL : addr;
2083 }
2084 
2085 static int anon_munmap(char * addr, size_t size) {
2086   return ::munmap(addr, size) == 0;
2087 }
2088 
2089 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2090                             size_t alignment_hint) {
2091   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2092 }
2093 
2094 bool os::pd_release_memory(char* addr, size_t size) {
2095   return anon_munmap(addr, size);
2096 }
2097 
2098 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2099   // Bsd wants the mprotect address argument to be page aligned.
2100   char* bottom = (char*)align_down((intptr_t)addr, os::Bsd::page_size());
2101 
2102   // According to SUSv3, mprotect() should only be used with mappings
2103   // established by mmap(), and mmap() always maps whole pages. Unaligned
2104   // 'addr' likely indicates problem in the VM (e.g. trying to change
2105   // protection of malloc'ed or statically allocated memory). Check the
2106   // caller if you hit this assert.
2107   assert(addr == bottom, "sanity check");
2108 
2109   size = align_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2110   Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(bottom), p2i(bottom+size), prot);
2111   return ::mprotect(bottom, size, prot) == 0;
2112 }
2113 
2114 // Set protections specified
2115 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2116                         bool is_committed) {
2117   unsigned int p = 0;
2118   switch (prot) {
2119   case MEM_PROT_NONE: p = PROT_NONE; break;
2120   case MEM_PROT_READ: p = PROT_READ; break;
2121   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2122   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2123   default:
2124     ShouldNotReachHere();
2125   }
2126   // is_committed is unused.
2127   return bsd_mprotect(addr, bytes, p);
2128 }
2129 
2130 bool os::guard_memory(char* addr, size_t size) {
2131   return bsd_mprotect(addr, size, PROT_NONE);
2132 }
2133 
2134 bool os::unguard_memory(char* addr, size_t size) {
2135   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2136 }
2137 
2138 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2139   return false;
2140 }
2141 
2142 // Large page support
2143 
2144 static size_t _large_page_size = 0;
2145 
2146 void os::large_page_init() {
2147 }
2148 
2149 
2150 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2151   fatal("os::reserve_memory_special should not be called on BSD.");
2152   return NULL;
2153 }
2154 
2155 bool os::release_memory_special(char* base, size_t bytes) {
2156   fatal("os::release_memory_special should not be called on BSD.");
2157   return false;
2158 }
2159 
2160 size_t os::large_page_size() {
2161   return _large_page_size;
2162 }
2163 
2164 bool os::can_commit_large_page_memory() {
2165   // Does not matter, we do not support huge pages.
2166   return false;
2167 }
2168 
2169 bool os::can_execute_large_page_memory() {
2170   // Does not matter, we do not support huge pages.
2171   return false;
2172 }
2173 
2174 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2175   assert(file_desc >= 0, "file_desc is not valid");
2176   char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
2177   if (result != NULL) {
2178     if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2179       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2180     }
2181   }
2182   return result;
2183 }
2184 
2185 // Reserve memory at an arbitrary address, only if that area is
2186 // available (and not reserved for something else).
2187 
2188 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2189   // Assert only that the size is a multiple of the page size, since
2190   // that's all that mmap requires, and since that's all we really know
2191   // about at this low abstraction level.  If we need higher alignment,
2192   // we can either pass an alignment to this method or verify alignment
2193   // in one of the methods further up the call chain.  See bug 5044738.
2194   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2195 
2196   // Repeatedly allocate blocks until the block is allocated at the
2197   // right spot.
2198 
2199   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2200   // if kernel honors the hint then we can return immediately.
2201   char * addr = anon_mmap(requested_addr, bytes, false);
2202   if (addr == requested_addr) {
2203     return requested_addr;
2204   }
2205 
2206   if (addr != NULL) {
2207     // mmap() is successful but it fails to reserve at the requested address
2208     anon_munmap(addr, bytes);
2209   }
2210 
2211   return NULL;
2212 }
2213 
2214 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2215 void os::infinite_sleep() {
2216   while (true) {    // sleep forever ...
2217     ::sleep(100);   // ... 100 seconds at a time
2218   }
2219 }
2220 
2221 // Used to convert frequent JVM_Yield() to nops
2222 bool os::dont_yield() {
2223   return DontYieldALot;
2224 }
2225 
2226 void os::naked_yield() {
2227   sched_yield();
2228 }
2229 
2230 ////////////////////////////////////////////////////////////////////////////////
2231 // thread priority support
2232 
2233 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2234 // only supports dynamic priority, static priority must be zero. For real-time
2235 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2236 // However, for large multi-threaded applications, SCHED_RR is not only slower
2237 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2238 // of 5 runs - Sep 2005).
2239 //
2240 // The following code actually changes the niceness of kernel-thread/LWP. It
2241 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2242 // not the entire user process, and user level threads are 1:1 mapped to kernel
2243 // threads. It has always been the case, but could change in the future. For
2244 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2245 // It is only used when ThreadPriorityPolicy=1 and may require system level permission
2246 // (e.g., root privilege or CAP_SYS_NICE capability).
2247 
2248 #if !defined(__APPLE__)
2249 int os::java_to_os_priority[CriticalPriority + 1] = {
2250   19,              // 0 Entry should never be used
2251 
2252    0,              // 1 MinPriority
2253    3,              // 2
2254    6,              // 3
2255 
2256   10,              // 4
2257   15,              // 5 NormPriority
2258   18,              // 6
2259 
2260   21,              // 7
2261   25,              // 8
2262   28,              // 9 NearMaxPriority
2263 
2264   31,              // 10 MaxPriority
2265 
2266   31               // 11 CriticalPriority
2267 };
2268 #else
2269 // Using Mach high-level priority assignments
2270 int os::java_to_os_priority[CriticalPriority + 1] = {
2271    0,              // 0 Entry should never be used (MINPRI_USER)
2272 
2273   27,              // 1 MinPriority
2274   28,              // 2
2275   29,              // 3
2276 
2277   30,              // 4
2278   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2279   32,              // 6
2280 
2281   33,              // 7
2282   34,              // 8
2283   35,              // 9 NearMaxPriority
2284 
2285   36,              // 10 MaxPriority
2286 
2287   36               // 11 CriticalPriority
2288 };
2289 #endif
2290 
2291 static int prio_init() {
2292   if (ThreadPriorityPolicy == 1) {
2293     if (geteuid() != 0) {
2294       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2295         warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
2296                 "e.g., being the root user. If the necessary permission is not " \
2297                 "possessed, changes to priority will be silently ignored.");
2298       }
2299     }
2300   }
2301   if (UseCriticalJavaThreadPriority) {
2302     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2303   }
2304   return 0;
2305 }
2306 
2307 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2308   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2309 
2310 #ifdef __OpenBSD__
2311   // OpenBSD pthread_setprio starves low priority threads
2312   return OS_OK;
2313 #elif defined(__FreeBSD__)
2314   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2315   return (ret == 0) ? OS_OK : OS_ERR;
2316 #elif defined(__APPLE__) || defined(__NetBSD__)
2317   struct sched_param sp;
2318   int policy;
2319 
2320   if (pthread_getschedparam(thread->osthread()->pthread_id(), &policy, &sp) != 0) {
2321     return OS_ERR;
2322   }
2323 
2324   sp.sched_priority = newpri;
2325   if (pthread_setschedparam(thread->osthread()->pthread_id(), policy, &sp) != 0) {
2326     return OS_ERR;
2327   }
2328 
2329   return OS_OK;
2330 #else
2331   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2332   return (ret == 0) ? OS_OK : OS_ERR;
2333 #endif
2334 }
2335 
2336 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2337   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2338     *priority_ptr = java_to_os_priority[NormPriority];
2339     return OS_OK;
2340   }
2341 
2342   errno = 0;
2343 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2344   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2345 #elif defined(__APPLE__) || defined(__NetBSD__)
2346   int policy;
2347   struct sched_param sp;
2348 
2349   int res = pthread_getschedparam(thread->osthread()->pthread_id(), &policy, &sp);
2350   if (res != 0) {
2351     *priority_ptr = -1;
2352     return OS_ERR;
2353   } else {
2354     *priority_ptr = sp.sched_priority;
2355     return OS_OK;
2356   }
2357 #else
2358   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2359 #endif
2360   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2361 }
2362 
2363 ////////////////////////////////////////////////////////////////////////////////
2364 // suspend/resume support
2365 
2366 //  The low-level signal-based suspend/resume support is a remnant from the
2367 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2368 //  within hotspot. Currently used by JFR's OSThreadSampler
2369 //
2370 //  The remaining code is greatly simplified from the more general suspension
2371 //  code that used to be used.
2372 //
2373 //  The protocol is quite simple:
2374 //  - suspend:
2375 //      - sends a signal to the target thread
2376 //      - polls the suspend state of the osthread using a yield loop
2377 //      - target thread signal handler (SR_handler) sets suspend state
2378 //        and blocks in sigsuspend until continued
2379 //  - resume:
2380 //      - sets target osthread state to continue
2381 //      - sends signal to end the sigsuspend loop in the SR_handler
2382 //
2383 //  Note that the SR_lock plays no role in this suspend/resume protocol,
2384 //  but is checked for NULL in SR_handler as a thread termination indicator.
2385 //  The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
2386 //
2387 //  Note that resume_clear_context() and suspend_save_context() are needed
2388 //  by SR_handler(), so that fetch_frame_from_ucontext() works,
2389 //  which in part is used by:
2390 //    - Forte Analyzer: AsyncGetCallTrace()
2391 //    - StackBanging: get_frame_at_stack_banging_point()
2392 
2393 static void resume_clear_context(OSThread *osthread) {
2394   osthread->set_ucontext(NULL);
2395   osthread->set_siginfo(NULL);
2396 }
2397 
2398 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2399   osthread->set_ucontext(context);
2400   osthread->set_siginfo(siginfo);
2401 }
2402 
2403 // Handler function invoked when a thread's execution is suspended or
2404 // resumed. We have to be careful that only async-safe functions are
2405 // called here (Note: most pthread functions are not async safe and
2406 // should be avoided.)
2407 //
2408 // Note: sigwait() is a more natural fit than sigsuspend() from an
2409 // interface point of view, but sigwait() prevents the signal hander
2410 // from being run. libpthread would get very confused by not having
2411 // its signal handlers run and prevents sigwait()'s use with the
2412 // mutex granting granting signal.
2413 //
2414 // Currently only ever called on the VMThread or JavaThread
2415 //
2416 #ifdef __APPLE__
2417 static OSXSemaphore sr_semaphore;
2418 #else
2419 static PosixSemaphore sr_semaphore;
2420 #endif
2421 
2422 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2423   // Save and restore errno to avoid confusing native code with EINTR
2424   // after sigsuspend.
2425   int old_errno = errno;
2426 
2427   Thread* thread = Thread::current_or_null_safe();
2428   assert(thread != NULL, "Missing current thread in SR_handler");
2429 
2430   // On some systems we have seen signal delivery get "stuck" until the signal
2431   // mask is changed as part of thread termination. Check that the current thread
2432   // has not already terminated (via SR_lock()) - else the following assertion
2433   // will fail because the thread is no longer a JavaThread as the ~JavaThread
2434   // destructor has completed.
2435 
2436   if (thread->SR_lock() == NULL) {
2437     return;
2438   }
2439 
2440   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2441 
2442   OSThread* osthread = thread->osthread();
2443 
2444   os::SuspendResume::State current = osthread->sr.state();
2445   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2446     suspend_save_context(osthread, siginfo, context);
2447 
2448     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2449     os::SuspendResume::State state = osthread->sr.suspended();
2450     if (state == os::SuspendResume::SR_SUSPENDED) {
2451       sigset_t suspend_set;  // signals for sigsuspend()
2452 
2453       // get current set of blocked signals and unblock resume signal
2454       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2455       sigdelset(&suspend_set, SR_signum);
2456 
2457       sr_semaphore.signal();
2458       // wait here until we are resumed
2459       while (1) {
2460         sigsuspend(&suspend_set);
2461 
2462         os::SuspendResume::State result = osthread->sr.running();
2463         if (result == os::SuspendResume::SR_RUNNING) {
2464           sr_semaphore.signal();
2465           break;
2466         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2467           ShouldNotReachHere();
2468         }
2469       }
2470 
2471     } else if (state == os::SuspendResume::SR_RUNNING) {
2472       // request was cancelled, continue
2473     } else {
2474       ShouldNotReachHere();
2475     }
2476 
2477     resume_clear_context(osthread);
2478   } else if (current == os::SuspendResume::SR_RUNNING) {
2479     // request was cancelled, continue
2480   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2481     // ignore
2482   } else {
2483     // ignore
2484   }
2485 
2486   errno = old_errno;
2487 }
2488 
2489 
2490 static int SR_initialize() {
2491   struct sigaction act;
2492   char *s;
2493   // Get signal number to use for suspend/resume
2494   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2495     int sig = ::strtol(s, 0, 10);
2496     if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
2497         sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
2498       SR_signum = sig;
2499     } else {
2500       warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2501               sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2502     }
2503   }
2504 
2505   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2506          "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2507 
2508   sigemptyset(&SR_sigset);
2509   sigaddset(&SR_sigset, SR_signum);
2510 
2511   // Set up signal handler for suspend/resume
2512   act.sa_flags = SA_RESTART|SA_SIGINFO;
2513   act.sa_handler = (void (*)(int)) SR_handler;
2514 
2515   // SR_signum is blocked by default.
2516   // 4528190 - We also need to block pthread restart signal (32 on all
2517   // supported Bsd platforms). Note that BsdThreads need to block
2518   // this signal for all threads to work properly. So we don't have
2519   // to use hard-coded signal number when setting up the mask.
2520   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2521 
2522   if (sigaction(SR_signum, &act, 0) == -1) {
2523     return -1;
2524   }
2525 
2526   // Save signal flag
2527   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2528   return 0;
2529 }
2530 
2531 static int sr_notify(OSThread* osthread) {
2532   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2533   assert_status(status == 0, status, "pthread_kill");
2534   return status;
2535 }
2536 
2537 // "Randomly" selected value for how long we want to spin
2538 // before bailing out on suspending a thread, also how often
2539 // we send a signal to a thread we want to resume
2540 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2541 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2542 
2543 // returns true on success and false on error - really an error is fatal
2544 // but this seems the normal response to library errors
2545 static bool do_suspend(OSThread* osthread) {
2546   assert(osthread->sr.is_running(), "thread should be running");
2547   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2548 
2549   // mark as suspended and send signal
2550   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2551     // failed to switch, state wasn't running?
2552     ShouldNotReachHere();
2553     return false;
2554   }
2555 
2556   if (sr_notify(osthread) != 0) {
2557     ShouldNotReachHere();
2558   }
2559 
2560   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2561   while (true) {
2562     if (sr_semaphore.timedwait(2)) {
2563       break;
2564     } else {
2565       // timeout
2566       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2567       if (cancelled == os::SuspendResume::SR_RUNNING) {
2568         return false;
2569       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2570         // make sure that we consume the signal on the semaphore as well
2571         sr_semaphore.wait();
2572         break;
2573       } else {
2574         ShouldNotReachHere();
2575         return false;
2576       }
2577     }
2578   }
2579 
2580   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2581   return true;
2582 }
2583 
2584 static void do_resume(OSThread* osthread) {
2585   assert(osthread->sr.is_suspended(), "thread should be suspended");
2586   assert(!sr_semaphore.trywait(), "invalid semaphore state");
2587 
2588   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2589     // failed to switch to WAKEUP_REQUEST
2590     ShouldNotReachHere();
2591     return;
2592   }
2593 
2594   while (true) {
2595     if (sr_notify(osthread) == 0) {
2596       if (sr_semaphore.timedwait(2)) {
2597         if (osthread->sr.is_running()) {
2598           return;
2599         }
2600       }
2601     } else {
2602       ShouldNotReachHere();
2603     }
2604   }
2605 
2606   guarantee(osthread->sr.is_running(), "Must be running!");
2607 }
2608 
2609 ///////////////////////////////////////////////////////////////////////////////////
2610 // signal handling (except suspend/resume)
2611 
2612 // This routine may be used by user applications as a "hook" to catch signals.
2613 // The user-defined signal handler must pass unrecognized signals to this
2614 // routine, and if it returns true (non-zero), then the signal handler must
2615 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
2616 // routine will never retun false (zero), but instead will execute a VM panic
2617 // routine kill the process.
2618 //
2619 // If this routine returns false, it is OK to call it again.  This allows
2620 // the user-defined signal handler to perform checks either before or after
2621 // the VM performs its own checks.  Naturally, the user code would be making
2622 // a serious error if it tried to handle an exception (such as a null check
2623 // or breakpoint) that the VM was generating for its own correct operation.
2624 //
2625 // This routine may recognize any of the following kinds of signals:
2626 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2627 // It should be consulted by handlers for any of those signals.
2628 //
2629 // The caller of this routine must pass in the three arguments supplied
2630 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2631 // field of the structure passed to sigaction().  This routine assumes that
2632 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2633 //
2634 // Note that the VM will print warnings if it detects conflicting signal
2635 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2636 //
2637 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2638                                                void* ucontext,
2639                                                int abort_if_unrecognized);
2640 
2641 static void signalHandler(int sig, siginfo_t* info, void* uc) {
2642   assert(info != NULL && uc != NULL, "it must be old kernel");
2643   int orig_errno = errno;  // Preserve errno value over signal handler.
2644   JVM_handle_bsd_signal(sig, info, uc, true);
2645   errno = orig_errno;
2646 }
2647 
2648 
2649 // This boolean allows users to forward their own non-matching signals
2650 // to JVM_handle_bsd_signal, harmlessly.
2651 bool os::Bsd::signal_handlers_are_installed = false;
2652 
2653 // For signal-chaining
2654 bool os::Bsd::libjsig_is_loaded = false;
2655 typedef struct sigaction *(*get_signal_t)(int);
2656 get_signal_t os::Bsd::get_signal_action = NULL;
2657 
2658 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2659   struct sigaction *actp = NULL;
2660 
2661   if (libjsig_is_loaded) {
2662     // Retrieve the old signal handler from libjsig
2663     actp = (*get_signal_action)(sig);
2664   }
2665   if (actp == NULL) {
2666     // Retrieve the preinstalled signal handler from jvm
2667     actp = os::Posix::get_preinstalled_handler(sig);
2668   }
2669 
2670   return actp;
2671 }
2672 
2673 static bool call_chained_handler(struct sigaction *actp, int sig,
2674                                  siginfo_t *siginfo, void *context) {
2675   // Call the old signal handler
2676   if (actp->sa_handler == SIG_DFL) {
2677     // It's more reasonable to let jvm treat it as an unexpected exception
2678     // instead of taking the default action.
2679     return false;
2680   } else if (actp->sa_handler != SIG_IGN) {
2681     if ((actp->sa_flags & SA_NODEFER) == 0) {
2682       // automaticlly block the signal
2683       sigaddset(&(actp->sa_mask), sig);
2684     }
2685 
2686     sa_handler_t hand;
2687     sa_sigaction_t sa;
2688     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
2689     // retrieve the chained handler
2690     if (siginfo_flag_set) {
2691       sa = actp->sa_sigaction;
2692     } else {
2693       hand = actp->sa_handler;
2694     }
2695 
2696     if ((actp->sa_flags & SA_RESETHAND) != 0) {
2697       actp->sa_handler = SIG_DFL;
2698     }
2699 
2700     // try to honor the signal mask
2701     sigset_t oset;
2702     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
2703 
2704     // call into the chained handler
2705     if (siginfo_flag_set) {
2706       (*sa)(sig, siginfo, context);
2707     } else {
2708       (*hand)(sig);
2709     }
2710 
2711     // restore the signal mask
2712     pthread_sigmask(SIG_SETMASK, &oset, 0);
2713   }
2714   // Tell jvm's signal handler the signal is taken care of.
2715   return true;
2716 }
2717 
2718 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
2719   bool chained = false;
2720   // signal-chaining
2721   if (UseSignalChaining) {
2722     struct sigaction *actp = get_chained_signal_action(sig);
2723     if (actp != NULL) {
2724       chained = call_chained_handler(actp, sig, siginfo, context);
2725     }
2726   }
2727   return chained;
2728 }
2729 
2730 // for diagnostic
2731 int sigflags[NSIG];
2732 
2733 int os::Bsd::get_our_sigflags(int sig) {
2734   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2735   return sigflags[sig];
2736 }
2737 
2738 void os::Bsd::set_our_sigflags(int sig, int flags) {
2739   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2740   if (sig > 0 && sig < NSIG) {
2741     sigflags[sig] = flags;
2742   }
2743 }
2744 
2745 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
2746   // Check for overwrite.
2747   struct sigaction oldAct;
2748   sigaction(sig, (struct sigaction*)NULL, &oldAct);
2749 
2750   void* oldhand = oldAct.sa_sigaction
2751                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
2752                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
2753   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
2754       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
2755       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
2756     if (AllowUserSignalHandlers || !set_installed) {
2757       // Do not overwrite; user takes responsibility to forward to us.
2758       return;
2759     } else if (UseSignalChaining) {
2760       // save the old handler in jvm
2761       os::Posix::save_preinstalled_handler(sig, oldAct);
2762       // libjsig also interposes the sigaction() call below and saves the
2763       // old sigaction on it own.
2764     } else {
2765       fatal("Encountered unexpected pre-existing sigaction handler "
2766             "%#lx for signal %d.", (long)oldhand, sig);
2767     }
2768   }
2769 
2770   struct sigaction sigAct;
2771   sigfillset(&(sigAct.sa_mask));
2772   sigAct.sa_handler = SIG_DFL;
2773   if (!set_installed) {
2774     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
2775   } else {
2776     sigAct.sa_sigaction = signalHandler;
2777     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
2778   }
2779 #ifdef __APPLE__
2780   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
2781   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
2782   // if the signal handler declares it will handle it on alternate stack.
2783   // Notice we only declare we will handle it on alt stack, but we are not
2784   // actually going to use real alt stack - this is just a workaround.
2785   // Please see ux_exception.c, method catch_mach_exception_raise for details
2786   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
2787   if (sig == SIGSEGV) {
2788     sigAct.sa_flags |= SA_ONSTACK;
2789   }
2790 #endif
2791 
2792   // Save flags, which are set by ours
2793   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2794   sigflags[sig] = sigAct.sa_flags;
2795 
2796   int ret = sigaction(sig, &sigAct, &oldAct);
2797   assert(ret == 0, "check");
2798 
2799   void* oldhand2  = oldAct.sa_sigaction
2800                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
2801                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
2802   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
2803 }
2804 
2805 // install signal handlers for signals that HotSpot needs to
2806 // handle in order to support Java-level exception handling.
2807 
2808 void os::Bsd::install_signal_handlers() {
2809   if (!signal_handlers_are_installed) {
2810     signal_handlers_are_installed = true;
2811 
2812     // signal-chaining
2813     typedef void (*signal_setting_t)();
2814     signal_setting_t begin_signal_setting = NULL;
2815     signal_setting_t end_signal_setting = NULL;
2816     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
2817                                           dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
2818     if (begin_signal_setting != NULL) {
2819       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
2820                                           dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
2821       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
2822                                          dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
2823       libjsig_is_loaded = true;
2824       assert(UseSignalChaining, "should enable signal-chaining");
2825     }
2826     if (libjsig_is_loaded) {
2827       // Tell libjsig jvm is setting signal handlers
2828       (*begin_signal_setting)();
2829     }
2830 
2831     set_signal_handler(SIGSEGV, true);
2832     set_signal_handler(SIGPIPE, true);
2833     set_signal_handler(SIGBUS, true);
2834     set_signal_handler(SIGILL, true);
2835     set_signal_handler(SIGFPE, true);
2836     set_signal_handler(SIGXFSZ, true);
2837 
2838 #if defined(__APPLE__)
2839     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
2840     // signals caught and handled by the JVM. To work around this, we reset the mach task
2841     // signal handler that's placed on our process by CrashReporter. This disables
2842     // CrashReporter-based reporting.
2843     //
2844     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
2845     // on caught fatal signals.
2846     //
2847     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
2848     // handlers. By replacing the existing task exception handler, we disable gdb's mach
2849     // exception handling, while leaving the standard BSD signal handlers functional.
2850     kern_return_t kr;
2851     kr = task_set_exception_ports(mach_task_self(),
2852                                   EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
2853                                   MACH_PORT_NULL,
2854                                   EXCEPTION_STATE_IDENTITY,
2855                                   MACHINE_THREAD_STATE);
2856 
2857     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
2858 #endif
2859 
2860     if (libjsig_is_loaded) {
2861       // Tell libjsig jvm finishes setting signal handlers
2862       (*end_signal_setting)();
2863     }
2864 
2865     // We don't activate signal checker if libjsig is in place, we trust ourselves
2866     // and if UserSignalHandler is installed all bets are off
2867     if (CheckJNICalls) {
2868       if (libjsig_is_loaded) {
2869         if (PrintJNIResolving) {
2870           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
2871         }
2872         check_signals = false;
2873       }
2874       if (AllowUserSignalHandlers) {
2875         if (PrintJNIResolving) {
2876           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
2877         }
2878         check_signals = false;
2879       }
2880     }
2881   }
2882 }
2883 
2884 
2885 /////
2886 // glibc on Bsd platform uses non-documented flag
2887 // to indicate, that some special sort of signal
2888 // trampoline is used.
2889 // We will never set this flag, and we should
2890 // ignore this flag in our diagnostic
2891 #ifdef SIGNIFICANT_SIGNAL_MASK
2892   #undef SIGNIFICANT_SIGNAL_MASK
2893 #endif
2894 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
2895 
2896 static const char* get_signal_handler_name(address handler,
2897                                            char* buf, int buflen) {
2898   int offset;
2899   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
2900   if (found) {
2901     // skip directory names
2902     const char *p1, *p2;
2903     p1 = buf;
2904     size_t len = strlen(os::file_separator());
2905     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
2906     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
2907   } else {
2908     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
2909   }
2910   return buf;
2911 }
2912 
2913 static void print_signal_handler(outputStream* st, int sig,
2914                                  char* buf, size_t buflen) {
2915   struct sigaction sa;
2916 
2917   sigaction(sig, NULL, &sa);
2918 
2919   // See comment for SIGNIFICANT_SIGNAL_MASK define
2920   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
2921 
2922   st->print("%s: ", os::exception_name(sig, buf, buflen));
2923 
2924   address handler = (sa.sa_flags & SA_SIGINFO)
2925     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
2926     : CAST_FROM_FN_PTR(address, sa.sa_handler);
2927 
2928   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
2929     st->print("SIG_DFL");
2930   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
2931     st->print("SIG_IGN");
2932   } else {
2933     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
2934   }
2935 
2936   st->print(", sa_mask[0]=");
2937   os::Posix::print_signal_set_short(st, &sa.sa_mask);
2938 
2939   address rh = VMError::get_resetted_sighandler(sig);
2940   // May be, handler was resetted by VMError?
2941   if (rh != NULL) {
2942     handler = rh;
2943     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
2944   }
2945 
2946   st->print(", sa_flags=");
2947   os::Posix::print_sa_flags(st, sa.sa_flags);
2948 
2949   // Check: is it our handler?
2950   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
2951       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
2952     // It is our signal handler
2953     // check for flags, reset system-used one!
2954     if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
2955       st->print(
2956                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
2957                 os::Bsd::get_our_sigflags(sig));
2958     }
2959   }
2960   st->cr();
2961 }
2962 
2963 
2964 #define DO_SIGNAL_CHECK(sig)                      \
2965   do {                                            \
2966     if (!sigismember(&check_signal_done, sig)) {  \
2967       os::Bsd::check_signal_handler(sig);         \
2968     }                                             \
2969   } while (0)
2970 
2971 // This method is a periodic task to check for misbehaving JNI applications
2972 // under CheckJNI, we can add any periodic checks here
2973 
2974 void os::run_periodic_checks() {
2975 
2976   if (check_signals == false) return;
2977 
2978   // SEGV and BUS if overridden could potentially prevent
2979   // generation of hs*.log in the event of a crash, debugging
2980   // such a case can be very challenging, so we absolutely
2981   // check the following for a good measure:
2982   DO_SIGNAL_CHECK(SIGSEGV);
2983   DO_SIGNAL_CHECK(SIGILL);
2984   DO_SIGNAL_CHECK(SIGFPE);
2985   DO_SIGNAL_CHECK(SIGBUS);
2986   DO_SIGNAL_CHECK(SIGPIPE);
2987   DO_SIGNAL_CHECK(SIGXFSZ);
2988 
2989 
2990   // ReduceSignalUsage allows the user to override these handlers
2991   // see comments at the very top and jvm_md.h
2992   if (!ReduceSignalUsage) {
2993     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
2994     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
2995     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
2996     DO_SIGNAL_CHECK(BREAK_SIGNAL);
2997   }
2998 
2999   DO_SIGNAL_CHECK(SR_signum);
3000 }
3001 
3002 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3003 
3004 static os_sigaction_t os_sigaction = NULL;
3005 
3006 void os::Bsd::check_signal_handler(int sig) {
3007   char buf[O_BUFLEN];
3008   address jvmHandler = NULL;
3009 
3010 
3011   struct sigaction act;
3012   if (os_sigaction == NULL) {
3013     // only trust the default sigaction, in case it has been interposed
3014     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3015     if (os_sigaction == NULL) return;
3016   }
3017 
3018   os_sigaction(sig, (struct sigaction*)NULL, &act);
3019 
3020 
3021   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3022 
3023   address thisHandler = (act.sa_flags & SA_SIGINFO)
3024     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3025     : CAST_FROM_FN_PTR(address, act.sa_handler);
3026 
3027 
3028   switch (sig) {
3029   case SIGSEGV:
3030   case SIGBUS:
3031   case SIGFPE:
3032   case SIGPIPE:
3033   case SIGILL:
3034   case SIGXFSZ:
3035     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3036     break;
3037 
3038   case SHUTDOWN1_SIGNAL:
3039   case SHUTDOWN2_SIGNAL:
3040   case SHUTDOWN3_SIGNAL:
3041   case BREAK_SIGNAL:
3042     jvmHandler = (address)user_handler();
3043     break;
3044 
3045   default:
3046     if (sig == SR_signum) {
3047       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3048     } else {
3049       return;
3050     }
3051     break;
3052   }
3053 
3054   if (thisHandler != jvmHandler) {
3055     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3056     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3057     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3058     // No need to check this sig any longer
3059     sigaddset(&check_signal_done, sig);
3060     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3061     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3062       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3063                     exception_name(sig, buf, O_BUFLEN));
3064     }
3065   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3066     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3067     tty->print("expected:");
3068     os::Posix::print_sa_flags(tty, os::Bsd::get_our_sigflags(sig));
3069     tty->cr();
3070     tty->print("  found:");
3071     os::Posix::print_sa_flags(tty, act.sa_flags);
3072     tty->cr();
3073     // No need to check this sig any longer
3074     sigaddset(&check_signal_done, sig);
3075   }
3076 
3077   // Dump all the signal
3078   if (sigismember(&check_signal_done, sig)) {
3079     print_signal_handlers(tty, buf, O_BUFLEN);
3080   }
3081 }
3082 
3083 extern void report_error(char* file_name, int line_no, char* title,
3084                          char* format, ...);
3085 
3086 // this is called _before_ the most of global arguments have been parsed
3087 void os::init(void) {
3088   char dummy;   // used to get a guess on initial stack address
3089 
3090   // With BsdThreads the JavaMain thread pid (primordial thread)
3091   // is different than the pid of the java launcher thread.
3092   // So, on Bsd, the launcher thread pid is passed to the VM
3093   // via the sun.java.launcher.pid property.
3094   // Use this property instead of getpid() if it was correctly passed.
3095   // See bug 6351349.
3096   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3097 
3098   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3099 
3100   clock_tics_per_sec = CLK_TCK;
3101 
3102   init_random(1234567);
3103 
3104   Bsd::set_page_size(getpagesize());
3105   if (Bsd::page_size() == -1) {
3106     fatal("os_bsd.cpp: os::init: sysconf failed (%s)", os::strerror(errno));
3107   }
3108   init_page_sizes((size_t) Bsd::page_size());
3109 
3110   Bsd::initialize_system_info();
3111 
3112   // _main_thread points to the thread that created/loaded the JVM.
3113   Bsd::_main_thread = pthread_self();
3114 
3115   Bsd::clock_init();
3116   initial_time_count = javaTimeNanos();
3117 
3118   os::Posix::init();
3119 }
3120 
3121 // To install functions for atexit system call
3122 extern "C" {
3123   static void perfMemory_exit_helper() {
3124     perfMemory_exit();
3125   }
3126 }
3127 
3128 // this is called _after_ the global arguments have been parsed
3129 jint os::init_2(void) {
3130 
3131   // This could be set after os::Posix::init() but all platforms
3132   // have to set it the same so we have to mirror Solaris.
3133   DEBUG_ONLY(os::set_mutex_init_done();)
3134 
3135   os::Posix::init_2();
3136 
3137   // initialize suspend/resume support - must do this before signal_sets_init()
3138   if (SR_initialize() != 0) {
3139     perror("SR_initialize failed");
3140     return JNI_ERR;
3141   }
3142 
3143   Bsd::signal_sets_init();
3144   Bsd::install_signal_handlers();
3145   // Initialize data for jdk.internal.misc.Signal
3146   if (!ReduceSignalUsage) {
3147     jdk_misc_signal_init();
3148   }
3149 
3150   // Check and sets minimum stack sizes against command line options
3151   if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
3152     return JNI_ERR;
3153   }
3154 
3155   if (MaxFDLimit) {
3156     // set the number of file descriptors to max. print out error
3157     // if getrlimit/setrlimit fails but continue regardless.
3158     struct rlimit nbr_files;
3159     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3160     if (status != 0) {
3161       log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3162     } else {
3163       nbr_files.rlim_cur = nbr_files.rlim_max;
3164 
3165 #ifdef __APPLE__
3166       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3167       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3168       // be used instead
3169       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3170 #endif
3171 
3172       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3173       if (status != 0) {
3174         log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3175       }
3176     }
3177   }
3178 
3179   // at-exit methods are called in the reverse order of their registration.
3180   // atexit functions are called on return from main or as a result of a
3181   // call to exit(3C). There can be only 32 of these functions registered
3182   // and atexit() does not set errno.
3183 
3184   if (PerfAllowAtExitRegistration) {
3185     // only register atexit functions if PerfAllowAtExitRegistration is set.
3186     // atexit functions can be delayed until process exit time, which
3187     // can be problematic for embedded VM situations. Embedded VMs should
3188     // call DestroyJavaVM() to assure that VM resources are released.
3189 
3190     // note: perfMemory_exit_helper atexit function may be removed in
3191     // the future if the appropriate cleanup code can be added to the
3192     // VM_Exit VMOperation's doit method.
3193     if (atexit(perfMemory_exit_helper) != 0) {
3194       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
3195     }
3196   }
3197 
3198   // initialize thread priority policy
3199   prio_init();
3200 
3201 #ifdef __APPLE__
3202   // dynamically link to objective c gc registration
3203   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3204   if (handleLibObjc != NULL) {
3205     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3206   }
3207 #endif
3208 
3209   return JNI_OK;
3210 }
3211 
3212 // Mark the polling page as unreadable
3213 void os::make_polling_page_unreadable(void) {
3214   if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3215     fatal("Could not disable polling page");
3216   }
3217 }
3218 
3219 // Mark the polling page as readable
3220 void os::make_polling_page_readable(void) {
3221   if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3222     fatal("Could not enable polling page");
3223   }
3224 }
3225 
3226 int os::active_processor_count() {
3227   // User has overridden the number of active processors
3228   if (ActiveProcessorCount > 0) {
3229     log_trace(os)("active_processor_count: "
3230                   "active processor count set by user : %d",
3231                   ActiveProcessorCount);
3232     return ActiveProcessorCount;
3233   }
3234 
3235   return _processor_count;
3236 }
3237 
3238 #ifdef __APPLE__
3239 uint os::processor_id() {
3240   static volatile int* volatile apic_to_cpu_mapping = NULL;
3241   static volatile int next_cpu_id = 0;
3242 
3243   volatile int* mapping = OrderAccess::load_acquire(&apic_to_cpu_mapping);
3244   if (mapping == NULL) {
3245     // Calculate possible number space for APIC ids. This space is not necessarily
3246     // in the range [0, number_of_cpus).
3247     uint total_bits = 0;
3248     for (uint i = 0;; ++i) {
3249       uint eax = 0xb; // Query topology leaf
3250       uint ebx;
3251       uint ecx = i;
3252       uint edx;
3253 
3254       __asm__ ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
3255 
3256       uint level_type = (ecx >> 8) & 0xFF;
3257       if (level_type == 0) {
3258         // Invalid level; end of topology
3259         break;
3260       }
3261       uint level_apic_id_shift = eax & ((1u << 5) - 1);
3262       total_bits += level_apic_id_shift;
3263     }
3264 
3265     uint max_apic_ids = 1u << total_bits;
3266     mapping = NEW_C_HEAP_ARRAY(int, max_apic_ids, mtInternal);
3267 
3268     for (uint i = 0; i < max_apic_ids; ++i) {
3269       mapping[i] = -1;
3270     }
3271 
3272     if (!Atomic::replace_if_null(mapping, &apic_to_cpu_mapping)) {
3273       FREE_C_HEAP_ARRAY(int, mapping);
3274       mapping = OrderAccess::load_acquire(&apic_to_cpu_mapping);
3275     }
3276   }
3277 
3278   uint eax = 0xb;
3279   uint ebx;
3280   uint ecx = 0;
3281   uint edx;
3282 
3283   asm ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
3284 
3285   // Map from APIC id to a unique logical processor ID in the expected
3286   // [0, num_processors) range.
3287 
3288   uint apic_id = edx;
3289   int cpu_id = Atomic::load(&mapping[apic_id]);
3290 
3291   while (cpu_id < 0) {
3292     if (Atomic::cmpxchg(-2, &mapping[apic_id], -1)) {
3293       Atomic::store(Atomic::add(1, &next_cpu_id) - 1, &mapping[apic_id]);
3294     }
3295     cpu_id = Atomic::load(&mapping[apic_id]);
3296   }
3297 
3298   return (uint)cpu_id;
3299 }
3300 #endif
3301 
3302 void os::set_native_thread_name(const char *name) {
3303 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3304   // This is only supported in Snow Leopard and beyond
3305   if (name != NULL) {
3306     // Add a "Java: " prefix to the name
3307     char buf[MAXTHREADNAMESIZE];
3308     snprintf(buf, sizeof(buf), "Java: %s", name);
3309     pthread_setname_np(buf);
3310   }
3311 #endif
3312 }
3313 
3314 bool os::distribute_processes(uint length, uint* distribution) {
3315   // Not yet implemented.
3316   return false;
3317 }
3318 
3319 bool os::bind_to_processor(uint processor_id) {
3320   // Not yet implemented.
3321   return false;
3322 }
3323 
3324 void os::SuspendedThreadTask::internal_do_task() {
3325   if (do_suspend(_thread->osthread())) {
3326     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3327     do_task(context);
3328     do_resume(_thread->osthread());
3329   }
3330 }
3331 
3332 ////////////////////////////////////////////////////////////////////////////////
3333 // debug support
3334 
3335 bool os::find(address addr, outputStream* st) {
3336   Dl_info dlinfo;
3337   memset(&dlinfo, 0, sizeof(dlinfo));
3338   if (dladdr(addr, &dlinfo) != 0) {
3339     st->print(INTPTR_FORMAT ": ", (intptr_t)addr);
3340     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3341       st->print("%s+%#x", dlinfo.dli_sname,
3342                 (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_saddr));
3343     } else if (dlinfo.dli_fbase != NULL) {
3344       st->print("<offset %#x>", (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_fbase));
3345     } else {
3346       st->print("<absolute address>");
3347     }
3348     if (dlinfo.dli_fname != NULL) {
3349       st->print(" in %s", dlinfo.dli_fname);
3350     }
3351     if (dlinfo.dli_fbase != NULL) {
3352       st->print(" at " INTPTR_FORMAT, (intptr_t)dlinfo.dli_fbase);
3353     }
3354     st->cr();
3355 
3356     if (Verbose) {
3357       // decode some bytes around the PC
3358       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3359       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3360       address       lowest = (address) dlinfo.dli_sname;
3361       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3362       if (begin < lowest)  begin = lowest;
3363       Dl_info dlinfo2;
3364       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3365           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3366         end = (address) dlinfo2.dli_saddr;
3367       }
3368       Disassembler::decode(begin, end, st);
3369     }
3370     return true;
3371   }
3372   return false;
3373 }
3374 
3375 ////////////////////////////////////////////////////////////////////////////////
3376 // misc
3377 
3378 // This does not do anything on Bsd. This is basically a hook for being
3379 // able to use structured exception handling (thread-local exception filters)
3380 // on, e.g., Win32.
3381 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3382                               const methodHandle& method, JavaCallArguments* args,
3383                               Thread* thread) {
3384   f(value, method, args, thread);
3385 }
3386 
3387 void os::print_statistics() {
3388 }
3389 
3390 bool os::message_box(const char* title, const char* message) {
3391   int i;
3392   fdStream err(defaultStream::error_fd());
3393   for (i = 0; i < 78; i++) err.print_raw("=");
3394   err.cr();
3395   err.print_raw_cr(title);
3396   for (i = 0; i < 78; i++) err.print_raw("-");
3397   err.cr();
3398   err.print_raw_cr(message);
3399   for (i = 0; i < 78; i++) err.print_raw("=");
3400   err.cr();
3401 
3402   char buf[16];
3403   // Prevent process from exiting upon "read error" without consuming all CPU
3404   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3405 
3406   return buf[0] == 'y' || buf[0] == 'Y';
3407 }
3408 
3409 static inline struct timespec get_mtime(const char* filename) {
3410   struct stat st;
3411   int ret = os::stat(filename, &st);
3412   assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
3413 #ifdef __APPLE__
3414   return st.st_mtimespec;
3415 #else
3416   return st.st_mtim;
3417 #endif
3418 }
3419 
3420 int os::compare_file_modified_times(const char* file1, const char* file2) {
3421   struct timespec filetime1 = get_mtime(file1);
3422   struct timespec filetime2 = get_mtime(file2);
3423   int diff = filetime1.tv_sec - filetime2.tv_sec;
3424   if (diff == 0) {
3425     return filetime1.tv_nsec - filetime2.tv_nsec;
3426   }
3427   return diff;
3428 }
3429 
3430 // Is a (classpath) directory empty?
3431 bool os::dir_is_empty(const char* path) {
3432   DIR *dir = NULL;
3433   struct dirent *ptr;
3434 
3435   dir = opendir(path);
3436   if (dir == NULL) return true;
3437 
3438   // Scan the directory
3439   bool result = true;
3440   while (result && (ptr = readdir(dir)) != NULL) {
3441     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3442       result = false;
3443     }
3444   }
3445   closedir(dir);
3446   return result;
3447 }
3448 
3449 // This code originates from JDK's sysOpen and open64_w
3450 // from src/solaris/hpi/src/system_md.c
3451 
3452 int os::open(const char *path, int oflag, int mode) {
3453   if (strlen(path) > MAX_PATH - 1) {
3454     errno = ENAMETOOLONG;
3455     return -1;
3456   }
3457   int fd;
3458 
3459   fd = ::open(path, oflag, mode);
3460   if (fd == -1) return -1;
3461 
3462   // If the open succeeded, the file might still be a directory
3463   {
3464     struct stat buf;
3465     int ret = ::fstat(fd, &buf);
3466     int st_mode = buf.st_mode;
3467 
3468     if (ret != -1) {
3469       if ((st_mode & S_IFMT) == S_IFDIR) {
3470         errno = EISDIR;
3471         ::close(fd);
3472         return -1;
3473       }
3474     } else {
3475       ::close(fd);
3476       return -1;
3477     }
3478   }
3479 
3480   // All file descriptors that are opened in the JVM and not
3481   // specifically destined for a subprocess should have the
3482   // close-on-exec flag set.  If we don't set it, then careless 3rd
3483   // party native code might fork and exec without closing all
3484   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3485   // UNIXProcess.c), and this in turn might:
3486   //
3487   // - cause end-of-file to fail to be detected on some file
3488   //   descriptors, resulting in mysterious hangs, or
3489   //
3490   // - might cause an fopen in the subprocess to fail on a system
3491   //   suffering from bug 1085341.
3492   //
3493   // (Yes, the default setting of the close-on-exec flag is a Unix
3494   // design flaw)
3495   //
3496   // See:
3497   // 1085341: 32-bit stdio routines should support file descriptors >255
3498   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3499   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3500   //
3501 #ifdef FD_CLOEXEC
3502   {
3503     int flags = ::fcntl(fd, F_GETFD);
3504     if (flags != -1) {
3505       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3506     }
3507   }
3508 #endif
3509 
3510   return fd;
3511 }
3512 
3513 
3514 // create binary file, rewriting existing file if required
3515 int os::create_binary_file(const char* path, bool rewrite_existing) {
3516   int oflags = O_WRONLY | O_CREAT;
3517   if (!rewrite_existing) {
3518     oflags |= O_EXCL;
3519   }
3520   return ::open(path, oflags, S_IREAD | S_IWRITE);
3521 }
3522 
3523 // return current position of file pointer
3524 jlong os::current_file_offset(int fd) {
3525   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3526 }
3527 
3528 // move file pointer to the specified offset
3529 jlong os::seek_to_file_offset(int fd, jlong offset) {
3530   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3531 }
3532 
3533 // This code originates from JDK's sysAvailable
3534 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3535 
3536 int os::available(int fd, jlong *bytes) {
3537   jlong cur, end;
3538   int mode;
3539   struct stat buf;
3540 
3541   if (::fstat(fd, &buf) >= 0) {
3542     mode = buf.st_mode;
3543     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3544       int n;
3545       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3546         *bytes = n;
3547         return 1;
3548       }
3549     }
3550   }
3551   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3552     return 0;
3553   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3554     return 0;
3555   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3556     return 0;
3557   }
3558   *bytes = end - cur;
3559   return 1;
3560 }
3561 
3562 // Map a block of memory.
3563 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3564                         char *addr, size_t bytes, bool read_only,
3565                         bool allow_exec) {
3566   int prot;
3567   int flags;
3568 
3569   if (read_only) {
3570     prot = PROT_READ;
3571     flags = MAP_SHARED;
3572   } else {
3573     prot = PROT_READ | PROT_WRITE;
3574     flags = MAP_PRIVATE;
3575   }
3576 
3577   if (allow_exec) {
3578     prot |= PROT_EXEC;
3579   }
3580 
3581   if (addr != NULL) {
3582     flags |= MAP_FIXED;
3583   }
3584 
3585   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3586                                      fd, file_offset);
3587   if (mapped_address == MAP_FAILED) {
3588     return NULL;
3589   }
3590   return mapped_address;
3591 }
3592 
3593 
3594 // Remap a block of memory.
3595 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3596                           char *addr, size_t bytes, bool read_only,
3597                           bool allow_exec) {
3598   // same as map_memory() on this OS
3599   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3600                         allow_exec);
3601 }
3602 
3603 
3604 // Unmap a block of memory.
3605 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3606   return munmap(addr, bytes) == 0;
3607 }
3608 
3609 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3610 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3611 // of a thread.
3612 //
3613 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3614 // the fast estimate available on the platform.
3615 
3616 jlong os::current_thread_cpu_time() {
3617 #ifdef __APPLE__
3618   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3619 #else
3620   Unimplemented();
3621   return 0;
3622 #endif
3623 }
3624 
3625 jlong os::thread_cpu_time(Thread* thread) {
3626 #ifdef __APPLE__
3627   return os::thread_cpu_time(thread, true /* user + sys */);
3628 #else
3629   Unimplemented();
3630   return 0;
3631 #endif
3632 }
3633 
3634 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3635 #ifdef __APPLE__
3636   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3637 #else
3638   Unimplemented();
3639   return 0;
3640 #endif
3641 }
3642 
3643 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3644 #ifdef __APPLE__
3645   struct thread_basic_info tinfo;
3646   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
3647   kern_return_t kr;
3648   thread_t mach_thread;
3649 
3650   mach_thread = thread->osthread()->thread_id();
3651   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
3652   if (kr != KERN_SUCCESS) {
3653     return -1;
3654   }
3655 
3656   if (user_sys_cpu_time) {
3657     jlong nanos;
3658     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
3659     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
3660     return nanos;
3661   } else {
3662     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
3663   }
3664 #else
3665   Unimplemented();
3666   return 0;
3667 #endif
3668 }
3669 
3670 
3671 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3672   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3673   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3674   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3675   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3676 }
3677 
3678 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3679   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3680   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3681   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3682   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3683 }
3684 
3685 bool os::is_thread_cpu_time_supported() {
3686 #ifdef __APPLE__
3687   return true;
3688 #else
3689   return false;
3690 #endif
3691 }
3692 
3693 // System loadavg support.  Returns -1 if load average cannot be obtained.
3694 // Bsd doesn't yet have a (official) notion of processor sets,
3695 // so just return the system wide load average.
3696 int os::loadavg(double loadavg[], int nelem) {
3697   return ::getloadavg(loadavg, nelem);
3698 }
3699 
3700 void os::pause() {
3701   char filename[MAX_PATH];
3702   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
3703     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
3704   } else {
3705     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
3706   }
3707 
3708   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
3709   if (fd != -1) {
3710     struct stat buf;
3711     ::close(fd);
3712     while (::stat(filename, &buf) == 0) {
3713       (void)::poll(NULL, 0, 100);
3714     }
3715   } else {
3716     jio_fprintf(stderr,
3717                 "Could not open pause file '%s', continuing immediately.\n", filename);
3718   }
3719 }
3720 
3721 // Darwin has no "environ" in a dynamic library.
3722 #ifdef __APPLE__
3723   #include <crt_externs.h>
3724   #define environ (*_NSGetEnviron())
3725 #else
3726 extern char** environ;
3727 #endif
3728 
3729 // Run the specified command in a separate process. Return its exit value,
3730 // or -1 on failure (e.g. can't fork a new process).
3731 // Unlike system(), this function can be called from signal handler. It
3732 // doesn't block SIGINT et al.
3733 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
3734   const char * argv[4] = {"sh", "-c", cmd, NULL};
3735 
3736   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
3737   // pthread_atfork handlers and reset pthread library. All we need is a
3738   // separate process to execve. Make a direct syscall to fork process.
3739   // On IA64 there's no fork syscall, we have to use fork() and hope for
3740   // the best...
3741   pid_t pid = fork();
3742 
3743   if (pid < 0) {
3744     // fork failed
3745     return -1;
3746 
3747   } else if (pid == 0) {
3748     // child process
3749 
3750     // execve() in BsdThreads will call pthread_kill_other_threads_np()
3751     // first to kill every thread on the thread list. Because this list is
3752     // not reset by fork() (see notes above), execve() will instead kill
3753     // every thread in the parent process. We know this is the only thread
3754     // in the new process, so make a system call directly.
3755     // IA64 should use normal execve() from glibc to match the glibc fork()
3756     // above.
3757     execve("/bin/sh", (char* const*)argv, environ);
3758 
3759     // execve failed
3760     _exit(-1);
3761 
3762   } else  {
3763     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
3764     // care about the actual exit code, for now.
3765 
3766     int status;
3767 
3768     // Wait for the child process to exit.  This returns immediately if
3769     // the child has already exited. */
3770     while (waitpid(pid, &status, 0) < 0) {
3771       switch (errno) {
3772       case ECHILD: return 0;
3773       case EINTR: break;
3774       default: return -1;
3775       }
3776     }
3777 
3778     if (WIFEXITED(status)) {
3779       // The child exited normally; get its exit code.
3780       return WEXITSTATUS(status);
3781     } else if (WIFSIGNALED(status)) {
3782       // The child exited because of a signal
3783       // The best value to return is 0x80 + signal number,
3784       // because that is what all Unix shells do, and because
3785       // it allows callers to distinguish between process exit and
3786       // process death by signal.
3787       return 0x80 + WTERMSIG(status);
3788     } else {
3789       // Unknown exit code; pass it through
3790       return status;
3791     }
3792   }
3793 }
3794 
3795 // Get the default path to the core file
3796 // Returns the length of the string
3797 int os::get_core_path(char* buffer, size_t bufferSize) {
3798   int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
3799 
3800   // Truncate if theoretical string was longer than bufferSize
3801   n = MIN2(n, (int)bufferSize);
3802 
3803   return n;
3804 }
3805 
3806 bool os::supports_map_sync() {
3807   return false;
3808 }
3809 
3810 #ifndef PRODUCT
3811 void TestReserveMemorySpecial_test() {
3812   // No tests available for this platform
3813 }
3814 #endif
3815 
3816 bool os::start_debugging(char *buf, int buflen) {
3817   int len = (int)strlen(buf);
3818   char *p = &buf[len];
3819 
3820   jio_snprintf(p, buflen-len,
3821              "\n\n"
3822              "Do you want to debug the problem?\n\n"
3823              "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT " (" INTPTR_FORMAT ")\n"
3824              "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
3825              "Otherwise, press RETURN to abort...",
3826              os::current_process_id(), os::current_process_id(),
3827              os::current_thread_id(), os::current_thread_id());
3828 
3829   bool yes = os::message_box("Unexpected Error", buf);
3830 
3831   if (yes) {
3832     // yes, user asked VM to launch debugger
3833     jio_snprintf(buf, sizeof(buf), "gdb /proc/%d/exe %d",
3834                      os::current_process_id(), os::current_process_id());
3835 
3836     os::fork_and_exec(buf);
3837     yes = false;
3838   }
3839   return yes;
3840 }