1 /*
   2  * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // no precompiled headers
  26 #include "classfile/classLoader.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/icBuffer.hpp"
  30 #include "code/vtableStubs.hpp"
  31 #include "compiler/compileBroker.hpp"
  32 #include "compiler/disassembler.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "jvm_bsd.h"
  35 #include "memory/allocation.inline.hpp"
  36 #include "memory/filemap.hpp"
  37 #include "mutex_bsd.inline.hpp"
  38 #include "oops/oop.inline.hpp"
  39 #include "os_bsd.inline.hpp"
  40 #include "os_share_bsd.hpp"
  41 #include "prims/jniFastGetField.hpp"
  42 #include "prims/jvm.h"
  43 #include "prims/jvm_misc.hpp"
  44 #include "runtime/arguments.hpp"
  45 #include "runtime/atomic.inline.hpp"
  46 #include "runtime/extendedPC.hpp"
  47 #include "runtime/globals.hpp"
  48 #include "runtime/interfaceSupport.hpp"
  49 #include "runtime/java.hpp"
  50 #include "runtime/javaCalls.hpp"
  51 #include "runtime/mutexLocker.hpp"
  52 #include "runtime/objectMonitor.hpp"
  53 #include "runtime/orderAccess.inline.hpp"
  54 #include "runtime/osThread.hpp"
  55 #include "runtime/perfMemory.hpp"
  56 #include "runtime/sharedRuntime.hpp"
  57 #include "runtime/statSampler.hpp"
  58 #include "runtime/stubRoutines.hpp"
  59 #include "runtime/thread.inline.hpp"
  60 #include "runtime/threadCritical.hpp"
  61 #include "runtime/timer.hpp"
  62 #include "services/attachListener.hpp"
  63 #include "services/memTracker.hpp"
  64 #include "services/runtimeService.hpp"
  65 #include "utilities/decoder.hpp"
  66 #include "utilities/defaultStream.hpp"
  67 #include "utilities/events.hpp"
  68 #include "utilities/growableArray.hpp"
  69 #include "utilities/vmError.hpp"
  70 
  71 // put OS-includes here
  72 # include <sys/types.h>
  73 # include <sys/mman.h>
  74 # include <sys/stat.h>
  75 # include <sys/select.h>
  76 # include <pthread.h>
  77 # include <signal.h>
  78 # include <errno.h>
  79 # include <dlfcn.h>
  80 # include <stdio.h>
  81 # include <unistd.h>
  82 # include <sys/resource.h>
  83 # include <pthread.h>
  84 # include <sys/stat.h>
  85 # include <sys/time.h>
  86 # include <sys/times.h>
  87 # include <sys/utsname.h>
  88 # include <sys/socket.h>
  89 # include <sys/wait.h>
  90 # include <time.h>
  91 # include <pwd.h>
  92 # include <poll.h>
  93 # include <semaphore.h>
  94 # include <fcntl.h>
  95 # include <string.h>
  96 # include <sys/param.h>
  97 # include <sys/sysctl.h>
  98 # include <sys/ipc.h>
  99 # include <sys/shm.h>
 100 #ifndef __APPLE__
 101 # include <link.h>
 102 #endif
 103 # include <stdint.h>
 104 # include <inttypes.h>
 105 # include <sys/ioctl.h>
 106 # include <sys/syscall.h>
 107 
 108 #if defined(__FreeBSD__) || defined(__NetBSD__)
 109   #include <elf.h>
 110 #endif
 111 
 112 #ifdef __APPLE__
 113   #include <mach/mach.h> // semaphore_* API
 114   #include <mach-o/dyld.h>
 115   #include <sys/proc_info.h>
 116   #include <objc/objc-auto.h>
 117 #endif
 118 
 119 #ifndef MAP_ANONYMOUS
 120   #define MAP_ANONYMOUS MAP_ANON
 121 #endif
 122 
 123 #define MAX_PATH    (2 * K)
 124 
 125 // for timer info max values which include all bits
 126 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 127 
 128 #define LARGEPAGES_BIT (1 << 6)
 129 
 130 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 131 
 132 ////////////////////////////////////////////////////////////////////////////////
 133 // global variables
 134 julong os::Bsd::_physical_memory = 0;
 135 
 136 #ifdef __APPLE__
 137 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
 138 volatile uint64_t         os::Bsd::_max_abstime   = 0;
 139 #else
 140 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 141 #endif
 142 pthread_t os::Bsd::_main_thread;
 143 int os::Bsd::_page_size = -1;
 144 
 145 static jlong initial_time_count=0;
 146 
 147 static int clock_tics_per_sec = 100;
 148 
 149 // For diagnostics to print a message once. see run_periodic_checks
 150 static sigset_t check_signal_done;
 151 static bool check_signals = true;
 152 
 153 static pid_t _initial_pid = 0;
 154 
 155 // Signal number used to suspend/resume a thread
 156 
 157 // do not use any signal number less than SIGSEGV, see 4355769
 158 static int SR_signum = SIGUSR2;
 159 sigset_t SR_sigset;
 160 
 161 
 162 ////////////////////////////////////////////////////////////////////////////////
 163 // utility functions
 164 
 165 static int SR_initialize();
 166 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
 167 
 168 julong os::available_memory() {
 169   return Bsd::available_memory();
 170 }
 171 
 172 // available here means free
 173 julong os::Bsd::available_memory() {
 174   uint64_t available = physical_memory() >> 2;
 175 #ifdef __APPLE__
 176   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
 177   vm_statistics64_data_t vmstat;
 178   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
 179                                          (host_info64_t)&vmstat, &count);
 180   assert(kerr == KERN_SUCCESS,
 181          "host_statistics64 failed - check mach_host_self() and count");
 182   if (kerr == KERN_SUCCESS) {
 183     available = vmstat.free_count * os::vm_page_size();
 184   }
 185 #endif
 186   return available;
 187 }
 188 
 189 julong os::physical_memory() {
 190   return Bsd::physical_memory();
 191 }
 192 
 193 // Return true if user is running as root.
 194 
 195 bool os::have_special_privileges() {
 196   static bool init = false;
 197   static bool privileges = false;
 198   if (!init) {
 199     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 200     init = true;
 201   }
 202   return privileges;
 203 }
 204 
 205 
 206 
 207 // Cpu architecture string
 208 #if   defined(ZERO)
 209 static char cpu_arch[] = ZERO_LIBARCH;
 210 #elif defined(IA64)
 211 static char cpu_arch[] = "ia64";
 212 #elif defined(IA32)
 213 static char cpu_arch[] = "i386";
 214 #elif defined(AMD64)
 215 static char cpu_arch[] = "amd64";
 216 #elif defined(ARM)
 217 static char cpu_arch[] = "arm";
 218 #elif defined(PPC32)
 219 static char cpu_arch[] = "ppc";
 220 #elif defined(SPARC)
 221   #ifdef _LP64
 222 static char cpu_arch[] = "sparcv9";
 223   #else
 224 static char cpu_arch[] = "sparc";
 225   #endif
 226 #else
 227   #error Add appropriate cpu_arch setting
 228 #endif
 229 
 230 // Compiler variant
 231 #ifdef COMPILER2
 232   #define COMPILER_VARIANT "server"
 233 #else
 234   #define COMPILER_VARIANT "client"
 235 #endif
 236 
 237 
 238 void os::Bsd::initialize_system_info() {
 239   int mib[2];
 240   size_t len;
 241   int cpu_val;
 242   julong mem_val;
 243 
 244   // get processors count via hw.ncpus sysctl
 245   mib[0] = CTL_HW;
 246   mib[1] = HW_NCPU;
 247   len = sizeof(cpu_val);
 248   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 249     assert(len == sizeof(cpu_val), "unexpected data size");
 250     set_processor_count(cpu_val);
 251   } else {
 252     set_processor_count(1);   // fallback
 253   }
 254 
 255   // get physical memory via hw.memsize sysctl (hw.memsize is used
 256   // since it returns a 64 bit value)
 257   mib[0] = CTL_HW;
 258 
 259 #if defined (HW_MEMSIZE) // Apple
 260   mib[1] = HW_MEMSIZE;
 261 #elif defined(HW_PHYSMEM) // Most of BSD
 262   mib[1] = HW_PHYSMEM;
 263 #elif defined(HW_REALMEM) // Old FreeBSD
 264   mib[1] = HW_REALMEM;
 265 #else
 266   #error No ways to get physmem
 267 #endif
 268 
 269   len = sizeof(mem_val);
 270   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 271     assert(len == sizeof(mem_val), "unexpected data size");
 272     _physical_memory = mem_val;
 273   } else {
 274     _physical_memory = 256 * 1024 * 1024;       // fallback (XXXBSD?)
 275   }
 276 
 277 #ifdef __OpenBSD__
 278   {
 279     // limit _physical_memory memory view on OpenBSD since
 280     // datasize rlimit restricts us anyway.
 281     struct rlimit limits;
 282     getrlimit(RLIMIT_DATA, &limits);
 283     _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 284   }
 285 #endif
 286 }
 287 
 288 #ifdef __APPLE__
 289 static const char *get_home() {
 290   const char *home_dir = ::getenv("HOME");
 291   if ((home_dir == NULL) || (*home_dir == '\0')) {
 292     struct passwd *passwd_info = getpwuid(geteuid());
 293     if (passwd_info != NULL) {
 294       home_dir = passwd_info->pw_dir;
 295     }
 296   }
 297 
 298   return home_dir;
 299 }
 300 #endif
 301 
 302 void os::init_system_properties_values() {
 303   // The next steps are taken in the product version:
 304   //
 305   // Obtain the JAVA_HOME value from the location of libjvm.so.
 306   // This library should be located at:
 307   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 308   //
 309   // If "/jre/lib/" appears at the right place in the path, then we
 310   // assume libjvm.so is installed in a JDK and we use this path.
 311   //
 312   // Otherwise exit with message: "Could not create the Java virtual machine."
 313   //
 314   // The following extra steps are taken in the debugging version:
 315   //
 316   // If "/jre/lib/" does NOT appear at the right place in the path
 317   // instead of exit check for $JAVA_HOME environment variable.
 318   //
 319   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 320   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 321   // it looks like libjvm.so is installed there
 322   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 323   //
 324   // Otherwise exit.
 325   //
 326   // Important note: if the location of libjvm.so changes this
 327   // code needs to be changed accordingly.
 328 
 329   // See ld(1):
 330   //      The linker uses the following search paths to locate required
 331   //      shared libraries:
 332   //        1: ...
 333   //        ...
 334   //        7: The default directories, normally /lib and /usr/lib.
 335 #ifndef DEFAULT_LIBPATH
 336   #define DEFAULT_LIBPATH "/lib:/usr/lib"
 337 #endif
 338 
 339 // Base path of extensions installed on the system.
 340 #define SYS_EXT_DIR     "/usr/java/packages"
 341 #define EXTENSIONS_DIR  "/lib/ext"
 342 
 343 #ifndef __APPLE__
 344 
 345   // Buffer that fits several sprintfs.
 346   // Note that the space for the colon and the trailing null are provided
 347   // by the nulls included by the sizeof operator.
 348   const size_t bufsize =
 349     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 350          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
 351   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 352 
 353   // sysclasspath, java_home, dll_dir
 354   {
 355     char *pslash;
 356     os::jvm_path(buf, bufsize);
 357 
 358     // Found the full path to libjvm.so.
 359     // Now cut the path to <java_home>/jre if we can.
 360     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 361     pslash = strrchr(buf, '/');
 362     if (pslash != NULL) {
 363       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 364     }
 365     Arguments::set_dll_dir(buf);
 366 
 367     if (pslash != NULL) {
 368       pslash = strrchr(buf, '/');
 369       if (pslash != NULL) {
 370         *pslash = '\0';          // Get rid of /<arch>.
 371         pslash = strrchr(buf, '/');
 372         if (pslash != NULL) {
 373           *pslash = '\0';        // Get rid of /lib.
 374         }
 375       }
 376     }
 377     Arguments::set_java_home(buf);
 378     set_boot_path('/', ':');
 379   }
 380 
 381   // Where to look for native libraries.
 382   //
 383   // Note: Due to a legacy implementation, most of the library path
 384   // is set in the launcher. This was to accomodate linking restrictions
 385   // on legacy Bsd implementations (which are no longer supported).
 386   // Eventually, all the library path setting will be done here.
 387   //
 388   // However, to prevent the proliferation of improperly built native
 389   // libraries, the new path component /usr/java/packages is added here.
 390   // Eventually, all the library path setting will be done here.
 391   {
 392     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 393     // should always exist (until the legacy problem cited above is
 394     // addressed).
 395     const char *v = ::getenv("LD_LIBRARY_PATH");
 396     const char *v_colon = ":";
 397     if (v == NULL) { v = ""; v_colon = ""; }
 398     // That's +1 for the colon and +1 for the trailing '\0'.
 399     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 400                                                      strlen(v) + 1 +
 401                                                      sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
 402                                                      mtInternal);
 403     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
 404     Arguments::set_library_path(ld_library_path);
 405     FREE_C_HEAP_ARRAY(char, ld_library_path);
 406   }
 407 
 408   // Extensions directories.
 409   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
 410   Arguments::set_ext_dirs(buf);
 411 
 412   FREE_C_HEAP_ARRAY(char, buf);
 413 
 414 #else // __APPLE__
 415 
 416   #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 417   #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 418 
 419   const char *user_home_dir = get_home();
 420   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
 421   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 422     sizeof(SYS_EXTENSIONS_DIRS);
 423 
 424   // Buffer that fits several sprintfs.
 425   // Note that the space for the colon and the trailing null are provided
 426   // by the nulls included by the sizeof operator.
 427   const size_t bufsize =
 428     MAX2((size_t)MAXPATHLEN,  // for dll_dir & friends.
 429          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
 430   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 431 
 432   // sysclasspath, java_home, dll_dir
 433   {
 434     char *pslash;
 435     os::jvm_path(buf, bufsize);
 436 
 437     // Found the full path to libjvm.so.
 438     // Now cut the path to <java_home>/jre if we can.
 439     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 440     pslash = strrchr(buf, '/');
 441     if (pslash != NULL) {
 442       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 443     }
 444     Arguments::set_dll_dir(buf);
 445 
 446     if (pslash != NULL) {
 447       pslash = strrchr(buf, '/');
 448       if (pslash != NULL) {
 449         *pslash = '\0';          // Get rid of /lib.
 450       }
 451     }
 452     Arguments::set_java_home(buf);
 453     set_boot_path('/', ':');
 454   }
 455 
 456   // Where to look for native libraries.
 457   //
 458   // Note: Due to a legacy implementation, most of the library path
 459   // is set in the launcher. This was to accomodate linking restrictions
 460   // on legacy Bsd implementations (which are no longer supported).
 461   // Eventually, all the library path setting will be done here.
 462   //
 463   // However, to prevent the proliferation of improperly built native
 464   // libraries, the new path component /usr/java/packages is added here.
 465   // Eventually, all the library path setting will be done here.
 466   {
 467     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 468     // should always exist (until the legacy problem cited above is
 469     // addressed).
 470     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
 471     // can specify a directory inside an app wrapper
 472     const char *l = ::getenv("JAVA_LIBRARY_PATH");
 473     const char *l_colon = ":";
 474     if (l == NULL) { l = ""; l_colon = ""; }
 475 
 476     const char *v = ::getenv("DYLD_LIBRARY_PATH");
 477     const char *v_colon = ":";
 478     if (v == NULL) { v = ""; v_colon = ""; }
 479 
 480     // Apple's Java6 has "." at the beginning of java.library.path.
 481     // OpenJDK on Windows has "." at the end of java.library.path.
 482     // OpenJDK on Linux and Solaris don't have "." in java.library.path
 483     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 484     // "." is appended to the end of java.library.path. Yes, this
 485     // could cause a change in behavior, but Apple's Java6 behavior
 486     // can be achieved by putting "." at the beginning of the
 487     // JAVA_LIBRARY_PATH environment variable.
 488     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 489                                                      strlen(v) + 1 + strlen(l) + 1 +
 490                                                      system_ext_size + 3,
 491                                                      mtInternal);
 492     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
 493             v, v_colon, l, l_colon, user_home_dir);
 494     Arguments::set_library_path(ld_library_path);
 495     FREE_C_HEAP_ARRAY(char, ld_library_path);
 496   }
 497 
 498   // Extensions directories.
 499   //
 500   // Note that the space for the colon and the trailing null are provided
 501   // by the nulls included by the sizeof operator (so actually one byte more
 502   // than necessary is allocated).
 503   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
 504           user_home_dir, Arguments::get_java_home());
 505   Arguments::set_ext_dirs(buf);
 506 
 507   FREE_C_HEAP_ARRAY(char, buf);
 508 
 509 #undef SYS_EXTENSIONS_DIR
 510 #undef SYS_EXTENSIONS_DIRS
 511 
 512 #endif // __APPLE__
 513 
 514 #undef SYS_EXT_DIR
 515 #undef EXTENSIONS_DIR
 516 }
 517 
 518 ////////////////////////////////////////////////////////////////////////////////
 519 // breakpoint support
 520 
 521 void os::breakpoint() {
 522   BREAKPOINT;
 523 }
 524 
 525 extern "C" void breakpoint() {
 526   // use debugger to set breakpoint here
 527 }
 528 
 529 ////////////////////////////////////////////////////////////////////////////////
 530 // signal support
 531 
 532 debug_only(static bool signal_sets_initialized = false);
 533 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
 534 
 535 bool os::Bsd::is_sig_ignored(int sig) {
 536   struct sigaction oact;
 537   sigaction(sig, (struct sigaction*)NULL, &oact);
 538   void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
 539                                  : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
 540   if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
 541     return true;
 542   } else {
 543     return false;
 544   }
 545 }
 546 
 547 void os::Bsd::signal_sets_init() {
 548   // Should also have an assertion stating we are still single-threaded.
 549   assert(!signal_sets_initialized, "Already initialized");
 550   // Fill in signals that are necessarily unblocked for all threads in
 551   // the VM. Currently, we unblock the following signals:
 552   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 553   //                         by -Xrs (=ReduceSignalUsage));
 554   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 555   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 556   // the dispositions or masks wrt these signals.
 557   // Programs embedding the VM that want to use the above signals for their
 558   // own purposes must, at this time, use the "-Xrs" option to prevent
 559   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 560   // (See bug 4345157, and other related bugs).
 561   // In reality, though, unblocking these signals is really a nop, since
 562   // these signals are not blocked by default.
 563   sigemptyset(&unblocked_sigs);
 564   sigemptyset(&allowdebug_blocked_sigs);
 565   sigaddset(&unblocked_sigs, SIGILL);
 566   sigaddset(&unblocked_sigs, SIGSEGV);
 567   sigaddset(&unblocked_sigs, SIGBUS);
 568   sigaddset(&unblocked_sigs, SIGFPE);
 569   sigaddset(&unblocked_sigs, SR_signum);
 570 
 571   if (!ReduceSignalUsage) {
 572     if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 573       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 574       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
 575     }
 576     if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 577       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 578       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
 579     }
 580     if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 581       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 582       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
 583     }
 584   }
 585   // Fill in signals that are blocked by all but the VM thread.
 586   sigemptyset(&vm_sigs);
 587   if (!ReduceSignalUsage) {
 588     sigaddset(&vm_sigs, BREAK_SIGNAL);
 589   }
 590   debug_only(signal_sets_initialized = true);
 591 
 592 }
 593 
 594 // These are signals that are unblocked while a thread is running Java.
 595 // (For some reason, they get blocked by default.)
 596 sigset_t* os::Bsd::unblocked_signals() {
 597   assert(signal_sets_initialized, "Not initialized");
 598   return &unblocked_sigs;
 599 }
 600 
 601 // These are the signals that are blocked while a (non-VM) thread is
 602 // running Java. Only the VM thread handles these signals.
 603 sigset_t* os::Bsd::vm_signals() {
 604   assert(signal_sets_initialized, "Not initialized");
 605   return &vm_sigs;
 606 }
 607 
 608 // These are signals that are blocked during cond_wait to allow debugger in
 609 sigset_t* os::Bsd::allowdebug_blocked_signals() {
 610   assert(signal_sets_initialized, "Not initialized");
 611   return &allowdebug_blocked_sigs;
 612 }
 613 
 614 void os::Bsd::hotspot_sigmask(Thread* thread) {
 615 
 616   //Save caller's signal mask before setting VM signal mask
 617   sigset_t caller_sigmask;
 618   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 619 
 620   OSThread* osthread = thread->osthread();
 621   osthread->set_caller_sigmask(caller_sigmask);
 622 
 623   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 624 
 625   if (!ReduceSignalUsage) {
 626     if (thread->is_VM_thread()) {
 627       // Only the VM thread handles BREAK_SIGNAL ...
 628       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 629     } else {
 630       // ... all other threads block BREAK_SIGNAL
 631       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 632     }
 633   }
 634 }
 635 
 636 
 637 //////////////////////////////////////////////////////////////////////////////
 638 // create new thread
 639 
 640 // check if it's safe to start a new thread
 641 static bool _thread_safety_check(Thread* thread) {
 642   return true;
 643 }
 644 
 645 #ifdef __APPLE__
 646 // library handle for calling objc_registerThreadWithCollector()
 647 // without static linking to the libobjc library
 648   #define OBJC_LIB "/usr/lib/libobjc.dylib"
 649   #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 650 typedef void (*objc_registerThreadWithCollector_t)();
 651 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 652 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 653 #endif
 654 
 655 #ifdef __APPLE__
 656 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 657   // Additional thread_id used to correlate threads in SA
 658   thread_identifier_info_data_t     m_ident_info;
 659   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 660 
 661   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 662               (thread_info_t) &m_ident_info, &count);
 663 
 664   return m_ident_info.thread_id;
 665 }
 666 #endif
 667 
 668 // Thread start routine for all newly created threads
 669 static void *java_start(Thread *thread) {
 670   // Try to randomize the cache line index of hot stack frames.
 671   // This helps when threads of the same stack traces evict each other's
 672   // cache lines. The threads can be either from the same JVM instance, or
 673   // from different JVM instances. The benefit is especially true for
 674   // processors with hyperthreading technology.
 675   static int counter = 0;
 676   int pid = os::current_process_id();
 677   alloca(((pid ^ counter++) & 7) * 128);
 678 
 679   ThreadLocalStorage::set_thread(thread);
 680 
 681   OSThread* osthread = thread->osthread();
 682   Monitor* sync = osthread->startThread_lock();
 683 
 684   // non floating stack BsdThreads needs extra check, see above
 685   if (!_thread_safety_check(thread)) {
 686     // notify parent thread
 687     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 688     osthread->set_state(ZOMBIE);
 689     sync->notify_all();
 690     return NULL;
 691   }
 692 
 693   osthread->set_thread_id(os::Bsd::gettid());
 694 
 695 #ifdef __APPLE__
 696   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 697   guarantee(unique_thread_id != 0, "unique thread id was not found");
 698   osthread->set_unique_thread_id(unique_thread_id);
 699 #endif
 700   // initialize signal mask for this thread
 701   os::Bsd::hotspot_sigmask(thread);
 702 
 703   // initialize floating point control register
 704   os::Bsd::init_thread_fpu_state();
 705 
 706 #ifdef __APPLE__
 707   // register thread with objc gc
 708   if (objc_registerThreadWithCollectorFunction != NULL) {
 709     objc_registerThreadWithCollectorFunction();
 710   }
 711 #endif
 712 
 713   // handshaking with parent thread
 714   {
 715     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 716 
 717     // notify parent thread
 718     osthread->set_state(INITIALIZED);
 719     sync->notify_all();
 720 
 721     // wait until os::start_thread()
 722     while (osthread->get_state() == INITIALIZED) {
 723       sync->wait(Mutex::_no_safepoint_check_flag);
 724     }
 725   }
 726 
 727   // call one more level start routine
 728   thread->run();
 729 
 730   return 0;
 731 }
 732 
 733 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
 734   assert(thread->osthread() == NULL, "caller responsible");
 735 
 736   // Allocate the OSThread object
 737   OSThread* osthread = new OSThread(NULL, NULL);
 738   if (osthread == NULL) {
 739     return false;
 740   }
 741 
 742   // set the correct thread state
 743   osthread->set_thread_type(thr_type);
 744 
 745   // Initial state is ALLOCATED but not INITIALIZED
 746   osthread->set_state(ALLOCATED);
 747 
 748   thread->set_osthread(osthread);
 749 
 750   // init thread attributes
 751   pthread_attr_t attr;
 752   pthread_attr_init(&attr);
 753   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 754 
 755   // stack size
 756   if (os::Bsd::supports_variable_stack_size()) {
 757     // calculate stack size if it's not specified by caller
 758     if (stack_size == 0) {
 759       stack_size = os::Bsd::default_stack_size(thr_type);
 760 
 761       switch (thr_type) {
 762       case os::java_thread:
 763         // Java threads use ThreadStackSize which default value can be
 764         // changed with the flag -Xss
 765         assert(JavaThread::stack_size_at_create() > 0, "this should be set");
 766         stack_size = JavaThread::stack_size_at_create();
 767         break;
 768       case os::compiler_thread:
 769         if (CompilerThreadStackSize > 0) {
 770           stack_size = (size_t)(CompilerThreadStackSize * K);
 771           break;
 772         } // else fall through:
 773           // use VMThreadStackSize if CompilerThreadStackSize is not defined
 774       case os::vm_thread:
 775       case os::pgc_thread:
 776       case os::cgc_thread:
 777       case os::watcher_thread:
 778         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 779         break;
 780       }
 781     }
 782 
 783     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
 784     pthread_attr_setstacksize(&attr, stack_size);
 785   } else {
 786     // let pthread_create() pick the default value.
 787   }
 788 
 789   ThreadState state;
 790 
 791   {
 792     pthread_t tid;
 793     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
 794 
 795     pthread_attr_destroy(&attr);
 796 
 797     if (ret != 0) {
 798       if (PrintMiscellaneous && (Verbose || WizardMode)) {
 799         perror("pthread_create()");
 800       }
 801       // Need to clean up stuff we've allocated so far
 802       thread->set_osthread(NULL);
 803       delete osthread;
 804       return false;
 805     }
 806 
 807     // Store pthread info into the OSThread
 808     osthread->set_pthread_id(tid);
 809 
 810     // Wait until child thread is either initialized or aborted
 811     {
 812       Monitor* sync_with_child = osthread->startThread_lock();
 813       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 814       while ((state = osthread->get_state()) == ALLOCATED) {
 815         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 816       }
 817     }
 818 
 819   }
 820 
 821   // Aborted due to thread limit being reached
 822   if (state == ZOMBIE) {
 823     thread->set_osthread(NULL);
 824     delete osthread;
 825     return false;
 826   }
 827 
 828   // The thread is returned suspended (in state INITIALIZED),
 829   // and is started higher up in the call chain
 830   assert(state == INITIALIZED, "race condition");
 831   return true;
 832 }
 833 
 834 /////////////////////////////////////////////////////////////////////////////
 835 // attach existing thread
 836 
 837 // bootstrap the main thread
 838 bool os::create_main_thread(JavaThread* thread) {
 839   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 840   return create_attached_thread(thread);
 841 }
 842 
 843 bool os::create_attached_thread(JavaThread* thread) {
 844 #ifdef ASSERT
 845   thread->verify_not_published();
 846 #endif
 847 
 848   // Allocate the OSThread object
 849   OSThread* osthread = new OSThread(NULL, NULL);
 850 
 851   if (osthread == NULL) {
 852     return false;
 853   }
 854 
 855   osthread->set_thread_id(os::Bsd::gettid());
 856 
 857   // Store pthread info into the OSThread
 858 #ifdef __APPLE__
 859   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 860   guarantee(unique_thread_id != 0, "just checking");
 861   osthread->set_unique_thread_id(unique_thread_id);
 862 #endif
 863   osthread->set_pthread_id(::pthread_self());
 864 
 865   // initialize floating point control register
 866   os::Bsd::init_thread_fpu_state();
 867 
 868   // Initial thread state is RUNNABLE
 869   osthread->set_state(RUNNABLE);
 870 
 871   thread->set_osthread(osthread);
 872 
 873   // initialize signal mask for this thread
 874   // and save the caller's signal mask
 875   os::Bsd::hotspot_sigmask(thread);
 876 
 877   return true;
 878 }
 879 
 880 void os::pd_start_thread(Thread* thread) {
 881   OSThread * osthread = thread->osthread();
 882   assert(osthread->get_state() != INITIALIZED, "just checking");
 883   Monitor* sync_with_child = osthread->startThread_lock();
 884   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 885   sync_with_child->notify();
 886 }
 887 
 888 // Free Bsd resources related to the OSThread
 889 void os::free_thread(OSThread* osthread) {
 890   assert(osthread != NULL, "osthread not set");
 891 
 892   if (Thread::current()->osthread() == osthread) {
 893     // Restore caller's signal mask
 894     sigset_t sigmask = osthread->caller_sigmask();
 895     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 896   }
 897 
 898   delete osthread;
 899 }
 900 
 901 //////////////////////////////////////////////////////////////////////////////
 902 // thread local storage
 903 
 904 // Restore the thread pointer if the destructor is called. This is in case
 905 // someone from JNI code sets up a destructor with pthread_key_create to run
 906 // detachCurrentThread on thread death. Unless we restore the thread pointer we
 907 // will hang or crash. When detachCurrentThread is called the key will be set
 908 // to null and we will not be called again. If detachCurrentThread is never
 909 // called we could loop forever depending on the pthread implementation.
 910 static void restore_thread_pointer(void* p) {
 911   Thread* thread = (Thread*) p;
 912   os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
 913 }
 914 
 915 int os::allocate_thread_local_storage() {
 916   pthread_key_t key;
 917   int rslt = pthread_key_create(&key, restore_thread_pointer);
 918   assert(rslt == 0, "cannot allocate thread local storage");
 919   return (int)key;
 920 }
 921 
 922 // Note: This is currently not used by VM, as we don't destroy TLS key
 923 // on VM exit.
 924 void os::free_thread_local_storage(int index) {
 925   int rslt = pthread_key_delete((pthread_key_t)index);
 926   assert(rslt == 0, "invalid index");
 927 }
 928 
 929 void os::thread_local_storage_at_put(int index, void* value) {
 930   int rslt = pthread_setspecific((pthread_key_t)index, value);
 931   assert(rslt == 0, "pthread_setspecific failed");
 932 }
 933 
 934 extern "C" Thread* get_thread() {
 935   return ThreadLocalStorage::thread();
 936 }
 937 
 938 
 939 ////////////////////////////////////////////////////////////////////////////////
 940 // time support
 941 
 942 // Time since start-up in seconds to a fine granularity.
 943 // Used by VMSelfDestructTimer and the MemProfiler.
 944 double os::elapsedTime() {
 945 
 946   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 947 }
 948 
 949 jlong os::elapsed_counter() {
 950   return javaTimeNanos() - initial_time_count;
 951 }
 952 
 953 jlong os::elapsed_frequency() {
 954   return NANOSECS_PER_SEC; // nanosecond resolution
 955 }
 956 
 957 bool os::supports_vtime() { return true; }
 958 bool os::enable_vtime()   { return false; }
 959 bool os::vtime_enabled()  { return false; }
 960 
 961 double os::elapsedVTime() {
 962   // better than nothing, but not much
 963   return elapsedTime();
 964 }
 965 
 966 jlong os::javaTimeMillis() {
 967   timeval time;
 968   int status = gettimeofday(&time, NULL);
 969   assert(status != -1, "bsd error");
 970   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 971 }
 972 
 973 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
 974   timeval time;
 975   int status = gettimeofday(&time, NULL);
 976   assert(status != -1, "bsd error");
 977   seconds = jlong(time.tv_sec);
 978   nanos = jlong(time.tv_usec) * 1000;
 979 }
 980 
 981 #ifndef __APPLE__
 982   #ifndef CLOCK_MONOTONIC
 983     #define CLOCK_MONOTONIC (1)
 984   #endif
 985 #endif
 986 
 987 #ifdef __APPLE__
 988 void os::Bsd::clock_init() {
 989   mach_timebase_info(&_timebase_info);
 990 }
 991 #else
 992 void os::Bsd::clock_init() {
 993   struct timespec res;
 994   struct timespec tp;
 995   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
 996       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
 997     // yes, monotonic clock is supported
 998     _clock_gettime = ::clock_gettime;
 999   }
1000 }
1001 #endif
1002 
1003 
1004 
1005 #ifdef __APPLE__
1006 
1007 jlong os::javaTimeNanos() {
1008   const uint64_t tm = mach_absolute_time();
1009   const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
1010   const uint64_t prev = Bsd::_max_abstime;
1011   if (now <= prev) {
1012     return prev;   // same or retrograde time;
1013   }
1014   const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
1015   assert(obsv >= prev, "invariant");   // Monotonicity
1016   // If the CAS succeeded then we're done and return "now".
1017   // If the CAS failed and the observed value "obsv" is >= now then
1018   // we should return "obsv".  If the CAS failed and now > obsv > prv then
1019   // some other thread raced this thread and installed a new value, in which case
1020   // we could either (a) retry the entire operation, (b) retry trying to install now
1021   // or (c) just return obsv.  We use (c).   No loop is required although in some cases
1022   // we might discard a higher "now" value in deference to a slightly lower but freshly
1023   // installed obsv value.   That's entirely benign -- it admits no new orderings compared
1024   // to (a) or (b) -- and greatly reduces coherence traffic.
1025   // We might also condition (c) on the magnitude of the delta between obsv and now.
1026   // Avoiding excessive CAS operations to hot RW locations is critical.
1027   // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1028   return (prev == obsv) ? now : obsv;
1029 }
1030 
1031 #else // __APPLE__
1032 
1033 jlong os::javaTimeNanos() {
1034   if (os::supports_monotonic_clock()) {
1035     struct timespec tp;
1036     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
1037     assert(status == 0, "gettime error");
1038     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1039     return result;
1040   } else {
1041     timeval time;
1042     int status = gettimeofday(&time, NULL);
1043     assert(status != -1, "bsd error");
1044     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1045     return 1000 * usecs;
1046   }
1047 }
1048 
1049 #endif // __APPLE__
1050 
1051 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1052   if (os::supports_monotonic_clock()) {
1053     info_ptr->max_value = ALL_64_BITS;
1054 
1055     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1056     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
1057     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
1058   } else {
1059     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1060     info_ptr->max_value = ALL_64_BITS;
1061 
1062     // gettimeofday is a real time clock so it skips
1063     info_ptr->may_skip_backward = true;
1064     info_ptr->may_skip_forward = true;
1065   }
1066 
1067   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
1068 }
1069 
1070 // Return the real, user, and system times in seconds from an
1071 // arbitrary fixed point in the past.
1072 bool os::getTimesSecs(double* process_real_time,
1073                       double* process_user_time,
1074                       double* process_system_time) {
1075   struct tms ticks;
1076   clock_t real_ticks = times(&ticks);
1077 
1078   if (real_ticks == (clock_t) (-1)) {
1079     return false;
1080   } else {
1081     double ticks_per_second = (double) clock_tics_per_sec;
1082     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1083     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1084     *process_real_time = ((double) real_ticks) / ticks_per_second;
1085 
1086     return true;
1087   }
1088 }
1089 
1090 
1091 char * os::local_time_string(char *buf, size_t buflen) {
1092   struct tm t;
1093   time_t long_time;
1094   time(&long_time);
1095   localtime_r(&long_time, &t);
1096   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1097                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1098                t.tm_hour, t.tm_min, t.tm_sec);
1099   return buf;
1100 }
1101 
1102 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1103   return localtime_r(clock, res);
1104 }
1105 
1106 ////////////////////////////////////////////////////////////////////////////////
1107 // runtime exit support
1108 
1109 // Note: os::shutdown() might be called very early during initialization, or
1110 // called from signal handler. Before adding something to os::shutdown(), make
1111 // sure it is async-safe and can handle partially initialized VM.
1112 void os::shutdown() {
1113 
1114   // allow PerfMemory to attempt cleanup of any persistent resources
1115   perfMemory_exit();
1116 
1117   // needs to remove object in file system
1118   AttachListener::abort();
1119 
1120   // flush buffered output, finish log files
1121   ostream_abort();
1122 
1123   // Check for abort hook
1124   abort_hook_t abort_hook = Arguments::abort_hook();
1125   if (abort_hook != NULL) {
1126     abort_hook();
1127   }
1128 
1129 }
1130 
1131 // Note: os::abort() might be called very early during initialization, or
1132 // called from signal handler. Before adding something to os::abort(), make
1133 // sure it is async-safe and can handle partially initialized VM.
1134 void os::abort(bool dump_core) {
1135   os::shutdown();
1136   if (dump_core) {
1137 #ifndef PRODUCT
1138     fdStream out(defaultStream::output_fd());
1139     out.print_raw("Current thread is ");
1140     char buf[16];
1141     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1142     out.print_raw_cr(buf);
1143     out.print_raw_cr("Dumping core ...");
1144 #endif
1145     ::abort(); // dump core
1146   }
1147 
1148   ::exit(1);
1149 }
1150 
1151 // Die immediately, no exit hook, no abort hook, no cleanup.
1152 void os::die() {
1153   // _exit() on BsdThreads only kills current thread
1154   ::abort();
1155 }
1156 
1157 // This method is a copy of JDK's sysGetLastErrorString
1158 // from src/solaris/hpi/src/system_md.c
1159 
1160 size_t os::lasterror(char *buf, size_t len) {
1161   if (errno == 0)  return 0;
1162 
1163   const char *s = ::strerror(errno);
1164   size_t n = ::strlen(s);
1165   if (n >= len) {
1166     n = len - 1;
1167   }
1168   ::strncpy(buf, s, n);
1169   buf[n] = '\0';
1170   return n;
1171 }
1172 
1173 // Information of current thread in variety of formats
1174 pid_t os::Bsd::gettid() {
1175   int retval = -1;
1176 
1177 #ifdef __APPLE__ //XNU kernel
1178   // despite the fact mach port is actually not a thread id use it
1179   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1180   retval = ::pthread_mach_thread_np(::pthread_self());
1181   guarantee(retval != 0, "just checking");
1182   return retval;
1183 
1184 #elif __FreeBSD__
1185   retval = syscall(SYS_thr_self);
1186 #elif __OpenBSD__
1187   retval = syscall(SYS_getthrid);
1188 #elif __NetBSD__
1189   retval = (pid_t) syscall(SYS__lwp_self);
1190 #endif
1191 
1192   if (retval == -1) {
1193     return getpid();
1194   }
1195 }
1196 
1197 intx os::current_thread_id() {
1198 #ifdef __APPLE__
1199   return (intx)::pthread_mach_thread_np(::pthread_self());
1200 #else
1201   return (intx)::pthread_self();
1202 #endif
1203 }
1204 
1205 int os::current_process_id() {
1206 
1207   // Under the old bsd thread library, bsd gives each thread
1208   // its own process id. Because of this each thread will return
1209   // a different pid if this method were to return the result
1210   // of getpid(2). Bsd provides no api that returns the pid
1211   // of the launcher thread for the vm. This implementation
1212   // returns a unique pid, the pid of the launcher thread
1213   // that starts the vm 'process'.
1214 
1215   // Under the NPTL, getpid() returns the same pid as the
1216   // launcher thread rather than a unique pid per thread.
1217   // Use gettid() if you want the old pre NPTL behaviour.
1218 
1219   // if you are looking for the result of a call to getpid() that
1220   // returns a unique pid for the calling thread, then look at the
1221   // OSThread::thread_id() method in osThread_bsd.hpp file
1222 
1223   return (int)(_initial_pid ? _initial_pid : getpid());
1224 }
1225 
1226 // DLL functions
1227 
1228 #define JNI_LIB_PREFIX "lib"
1229 #ifdef __APPLE__
1230   #define JNI_LIB_SUFFIX ".dylib"
1231 #else
1232   #define JNI_LIB_SUFFIX ".so"
1233 #endif
1234 
1235 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1236 
1237 // This must be hard coded because it's the system's temporary
1238 // directory not the java application's temp directory, ala java.io.tmpdir.
1239 #ifdef __APPLE__
1240 // macosx has a secure per-user temporary directory
1241 char temp_path_storage[PATH_MAX];
1242 const char* os::get_temp_directory() {
1243   static char *temp_path = NULL;
1244   if (temp_path == NULL) {
1245     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1246     if (pathSize == 0 || pathSize > PATH_MAX) {
1247       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1248     }
1249     temp_path = temp_path_storage;
1250   }
1251   return temp_path;
1252 }
1253 #else // __APPLE__
1254 const char* os::get_temp_directory() { return "/tmp"; }
1255 #endif // __APPLE__
1256 
1257 static bool file_exists(const char* filename) {
1258   struct stat statbuf;
1259   if (filename == NULL || strlen(filename) == 0) {
1260     return false;
1261   }
1262   return os::stat(filename, &statbuf) == 0;
1263 }
1264 
1265 bool os::dll_build_name(char* buffer, size_t buflen,
1266                         const char* pname, const char* fname) {
1267   bool retval = false;
1268   // Copied from libhpi
1269   const size_t pnamelen = pname ? strlen(pname) : 0;
1270 
1271   // Return error on buffer overflow.
1272   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1273     return retval;
1274   }
1275 
1276   if (pnamelen == 0) {
1277     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1278     retval = true;
1279   } else if (strchr(pname, *os::path_separator()) != NULL) {
1280     int n;
1281     char** pelements = split_path(pname, &n);
1282     if (pelements == NULL) {
1283       return false;
1284     }
1285     for (int i = 0; i < n; i++) {
1286       // Really shouldn't be NULL, but check can't hurt
1287       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1288         continue; // skip the empty path values
1289       }
1290       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1291                pelements[i], fname);
1292       if (file_exists(buffer)) {
1293         retval = true;
1294         break;
1295       }
1296     }
1297     // release the storage
1298     for (int i = 0; i < n; i++) {
1299       if (pelements[i] != NULL) {
1300         FREE_C_HEAP_ARRAY(char, pelements[i]);
1301       }
1302     }
1303     if (pelements != NULL) {
1304       FREE_C_HEAP_ARRAY(char*, pelements);
1305     }
1306   } else {
1307     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1308     retval = true;
1309   }
1310   return retval;
1311 }
1312 
1313 // check if addr is inside libjvm.so
1314 bool os::address_is_in_vm(address addr) {
1315   static address libjvm_base_addr;
1316   Dl_info dlinfo;
1317 
1318   if (libjvm_base_addr == NULL) {
1319     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1320       libjvm_base_addr = (address)dlinfo.dli_fbase;
1321     }
1322     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1323   }
1324 
1325   if (dladdr((void *)addr, &dlinfo) != 0) {
1326     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1327   }
1328 
1329   return false;
1330 }
1331 
1332 
1333 #define MACH_MAXSYMLEN 256
1334 
1335 bool os::dll_address_to_function_name(address addr, char *buf,
1336                                       int buflen, int *offset) {
1337   // buf is not optional, but offset is optional
1338   assert(buf != NULL, "sanity check");
1339 
1340   Dl_info dlinfo;
1341   char localbuf[MACH_MAXSYMLEN];
1342 
1343   if (dladdr((void*)addr, &dlinfo) != 0) {
1344     // see if we have a matching symbol
1345     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1346       if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1347         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1348       }
1349       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1350       return true;
1351     }
1352     // no matching symbol so try for just file info
1353     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1354       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1355                           buf, buflen, offset, dlinfo.dli_fname)) {
1356         return true;
1357       }
1358     }
1359 
1360     // Handle non-dynamic manually:
1361     if (dlinfo.dli_fbase != NULL &&
1362         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
1363       if (!Decoder::demangle(localbuf, buf, buflen)) {
1364         jio_snprintf(buf, buflen, "%s", localbuf);
1365       }
1366       return true;
1367     }
1368   }
1369   buf[0] = '\0';
1370   if (offset != NULL) *offset = -1;
1371   return false;
1372 }
1373 
1374 // ported from solaris version
1375 bool os::dll_address_to_library_name(address addr, char* buf,
1376                                      int buflen, int* offset) {
1377   // buf is not optional, but offset is optional
1378   assert(buf != NULL, "sanity check");
1379 
1380   Dl_info dlinfo;
1381 
1382   if (dladdr((void*)addr, &dlinfo) != 0) {
1383     if (dlinfo.dli_fname != NULL) {
1384       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1385     }
1386     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1387       *offset = addr - (address)dlinfo.dli_fbase;
1388     }
1389     return true;
1390   }
1391 
1392   buf[0] = '\0';
1393   if (offset) *offset = -1;
1394   return false;
1395 }
1396 
1397 // Loads .dll/.so and
1398 // in case of error it checks if .dll/.so was built for the
1399 // same architecture as Hotspot is running on
1400 
1401 #ifdef __APPLE__
1402 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1403   void * result= ::dlopen(filename, RTLD_LAZY);
1404   if (result != NULL) {
1405     // Successful loading
1406     return result;
1407   }
1408 
1409   // Read system error message into ebuf
1410   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1411   ebuf[ebuflen-1]='\0';
1412 
1413   return NULL;
1414 }
1415 #else
1416 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1417   void * result= ::dlopen(filename, RTLD_LAZY);
1418   if (result != NULL) {
1419     // Successful loading
1420     return result;
1421   }
1422 
1423   Elf32_Ehdr elf_head;
1424 
1425   // Read system error message into ebuf
1426   // It may or may not be overwritten below
1427   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1428   ebuf[ebuflen-1]='\0';
1429   int diag_msg_max_length=ebuflen-strlen(ebuf);
1430   char* diag_msg_buf=ebuf+strlen(ebuf);
1431 
1432   if (diag_msg_max_length==0) {
1433     // No more space in ebuf for additional diagnostics message
1434     return NULL;
1435   }
1436 
1437 
1438   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1439 
1440   if (file_descriptor < 0) {
1441     // Can't open library, report dlerror() message
1442     return NULL;
1443   }
1444 
1445   bool failed_to_read_elf_head=
1446     (sizeof(elf_head)!=
1447      (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1448 
1449   ::close(file_descriptor);
1450   if (failed_to_read_elf_head) {
1451     // file i/o error - report dlerror() msg
1452     return NULL;
1453   }
1454 
1455   typedef struct {
1456     Elf32_Half  code;         // Actual value as defined in elf.h
1457     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1458     char        elf_class;    // 32 or 64 bit
1459     char        endianess;    // MSB or LSB
1460     char*       name;         // String representation
1461   } arch_t;
1462 
1463   #ifndef EM_486
1464     #define EM_486          6               /* Intel 80486 */
1465   #endif
1466 
1467   #ifndef EM_MIPS_RS3_LE
1468     #define EM_MIPS_RS3_LE  10              /* MIPS */
1469   #endif
1470 
1471   #ifndef EM_PPC64
1472     #define EM_PPC64        21              /* PowerPC64 */
1473   #endif
1474 
1475   #ifndef EM_S390
1476     #define EM_S390         22              /* IBM System/390 */
1477   #endif
1478 
1479   #ifndef EM_IA_64
1480     #define EM_IA_64        50              /* HP/Intel IA-64 */
1481   #endif
1482 
1483   #ifndef EM_X86_64
1484     #define EM_X86_64       62              /* AMD x86-64 */
1485   #endif
1486 
1487   static const arch_t arch_array[]={
1488     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1489     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1490     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1491     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1492     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1493     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1494     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1495     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1496     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1497     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1498     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1499     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1500     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1501     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1502     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1503     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1504   };
1505 
1506   #if  (defined IA32)
1507   static  Elf32_Half running_arch_code=EM_386;
1508   #elif   (defined AMD64)
1509   static  Elf32_Half running_arch_code=EM_X86_64;
1510   #elif  (defined IA64)
1511   static  Elf32_Half running_arch_code=EM_IA_64;
1512   #elif  (defined __sparc) && (defined _LP64)
1513   static  Elf32_Half running_arch_code=EM_SPARCV9;
1514   #elif  (defined __sparc) && (!defined _LP64)
1515   static  Elf32_Half running_arch_code=EM_SPARC;
1516   #elif  (defined __powerpc64__)
1517   static  Elf32_Half running_arch_code=EM_PPC64;
1518   #elif  (defined __powerpc__)
1519   static  Elf32_Half running_arch_code=EM_PPC;
1520   #elif  (defined ARM)
1521   static  Elf32_Half running_arch_code=EM_ARM;
1522   #elif  (defined S390)
1523   static  Elf32_Half running_arch_code=EM_S390;
1524   #elif  (defined ALPHA)
1525   static  Elf32_Half running_arch_code=EM_ALPHA;
1526   #elif  (defined MIPSEL)
1527   static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1528   #elif  (defined PARISC)
1529   static  Elf32_Half running_arch_code=EM_PARISC;
1530   #elif  (defined MIPS)
1531   static  Elf32_Half running_arch_code=EM_MIPS;
1532   #elif  (defined M68K)
1533   static  Elf32_Half running_arch_code=EM_68K;
1534   #else
1535     #error Method os::dll_load requires that one of following is defined:\
1536          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1537   #endif
1538 
1539   // Identify compatability class for VM's architecture and library's architecture
1540   // Obtain string descriptions for architectures
1541 
1542   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1543   int running_arch_index=-1;
1544 
1545   for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1546     if (running_arch_code == arch_array[i].code) {
1547       running_arch_index    = i;
1548     }
1549     if (lib_arch.code == arch_array[i].code) {
1550       lib_arch.compat_class = arch_array[i].compat_class;
1551       lib_arch.name         = arch_array[i].name;
1552     }
1553   }
1554 
1555   assert(running_arch_index != -1,
1556          "Didn't find running architecture code (running_arch_code) in arch_array");
1557   if (running_arch_index == -1) {
1558     // Even though running architecture detection failed
1559     // we may still continue with reporting dlerror() message
1560     return NULL;
1561   }
1562 
1563   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1564     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1565     return NULL;
1566   }
1567 
1568 #ifndef S390
1569   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1570     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1571     return NULL;
1572   }
1573 #endif // !S390
1574 
1575   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1576     if (lib_arch.name!=NULL) {
1577       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1578                  " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1579                  lib_arch.name, arch_array[running_arch_index].name);
1580     } else {
1581       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1582                  " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1583                  lib_arch.code,
1584                  arch_array[running_arch_index].name);
1585     }
1586   }
1587 
1588   return NULL;
1589 }
1590 #endif // !__APPLE__
1591 
1592 void* os::get_default_process_handle() {
1593 #ifdef __APPLE__
1594   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1595   // to avoid finding unexpected symbols on second (or later)
1596   // loads of a library.
1597   return (void*)::dlopen(NULL, RTLD_FIRST);
1598 #else
1599   return (void*)::dlopen(NULL, RTLD_LAZY);
1600 #endif
1601 }
1602 
1603 // XXX: Do we need a lock around this as per Linux?
1604 void* os::dll_lookup(void* handle, const char* name) {
1605   return dlsym(handle, name);
1606 }
1607 
1608 
1609 static bool _print_ascii_file(const char* filename, outputStream* st) {
1610   int fd = ::open(filename, O_RDONLY);
1611   if (fd == -1) {
1612     return false;
1613   }
1614 
1615   char buf[32];
1616   int bytes;
1617   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1618     st->print_raw(buf, bytes);
1619   }
1620 
1621   ::close(fd);
1622 
1623   return true;
1624 }
1625 
1626 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1627   outputStream * out = (outputStream *) param;
1628   out->print_cr(PTR_FORMAT " \t%s", base_address, name);
1629   return 0;
1630 }
1631 
1632 void os::print_dll_info(outputStream *st) {
1633   st->print_cr("Dynamic libraries:");
1634   if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1635     st->print_cr("Error: Cannot print dynamic libraries.");
1636   }
1637 }
1638 
1639 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1640 #ifdef RTLD_DI_LINKMAP
1641   Dl_info dli;
1642   void *handle;
1643   Link_map *map;
1644   Link_map *p;
1645 
1646   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1647       dli.dli_fname == NULL) {
1648     return 1;
1649   }
1650   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1651   if (handle == NULL) {
1652     return 1;
1653   }
1654   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1655   if (map == NULL) {
1656     dlclose(handle);
1657     return 1;
1658   }
1659 
1660   while (map->l_prev != NULL)
1661     map = map->l_prev;
1662 
1663   while (map != NULL) {
1664     // Value for top_address is returned as 0 since we don't have any information about module size
1665     if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1666       dlclose(handle);
1667       return 1;
1668     }
1669     map = map->l_next;
1670   }
1671 
1672   dlclose(handle);
1673 #elif defined(__APPLE__)
1674   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1675     // Value for top_address is returned as 0 since we don't have any information about module size
1676     if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1677       return 1;
1678     }
1679   }
1680   return 0;
1681 #else
1682   return 1;
1683 #endif
1684 }
1685 
1686 void os::print_os_info_brief(outputStream* st) {
1687   st->print("Bsd");
1688 
1689   os::Posix::print_uname_info(st);
1690 }
1691 
1692 void os::print_os_info(outputStream* st) {
1693   st->print("OS:");
1694   st->print("Bsd");
1695 
1696   os::Posix::print_uname_info(st);
1697 
1698   os::Posix::print_rlimit_info(st);
1699 
1700   os::Posix::print_load_average(st);
1701 }
1702 
1703 void os::pd_print_cpu_info(outputStream* st) {
1704   // Nothing to do for now.
1705 }
1706 
1707 void os::print_memory_info(outputStream* st) {
1708 
1709   st->print("Memory:");
1710   st->print(" %dk page", os::vm_page_size()>>10);
1711 
1712   st->print(", physical " UINT64_FORMAT "k",
1713             os::physical_memory() >> 10);
1714   st->print("(" UINT64_FORMAT "k free)",
1715             os::available_memory() >> 10);
1716   st->cr();
1717 
1718   // meminfo
1719   st->print("\n/proc/meminfo:\n");
1720   _print_ascii_file("/proc/meminfo", st);
1721   st->cr();
1722 }
1723 
1724 void os::print_siginfo(outputStream* st, void* siginfo) {
1725   const siginfo_t* si = (const siginfo_t*)siginfo;
1726 
1727   os::Posix::print_siginfo_brief(st, si);
1728 
1729   if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1730       UseSharedSpaces) {
1731     FileMapInfo* mapinfo = FileMapInfo::current_info();
1732     if (mapinfo->is_in_shared_space(si->si_addr)) {
1733       st->print("\n\nError accessing class data sharing archive."   \
1734                 " Mapped file inaccessible during execution, "      \
1735                 " possible disk/network problem.");
1736     }
1737   }
1738   st->cr();
1739 }
1740 
1741 
1742 static void print_signal_handler(outputStream* st, int sig,
1743                                  char* buf, size_t buflen);
1744 
1745 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1746   st->print_cr("Signal Handlers:");
1747   print_signal_handler(st, SIGSEGV, buf, buflen);
1748   print_signal_handler(st, SIGBUS , buf, buflen);
1749   print_signal_handler(st, SIGFPE , buf, buflen);
1750   print_signal_handler(st, SIGPIPE, buf, buflen);
1751   print_signal_handler(st, SIGXFSZ, buf, buflen);
1752   print_signal_handler(st, SIGILL , buf, buflen);
1753   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1754   print_signal_handler(st, SR_signum, buf, buflen);
1755   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1756   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1757   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1758   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1759 }
1760 
1761 static char saved_jvm_path[MAXPATHLEN] = {0};
1762 
1763 // Find the full path to the current module, libjvm
1764 void os::jvm_path(char *buf, jint buflen) {
1765   // Error checking.
1766   if (buflen < MAXPATHLEN) {
1767     assert(false, "must use a large-enough buffer");
1768     buf[0] = '\0';
1769     return;
1770   }
1771   // Lazy resolve the path to current module.
1772   if (saved_jvm_path[0] != 0) {
1773     strcpy(buf, saved_jvm_path);
1774     return;
1775   }
1776 
1777   char dli_fname[MAXPATHLEN];
1778   bool ret = dll_address_to_library_name(
1779                                          CAST_FROM_FN_PTR(address, os::jvm_path),
1780                                          dli_fname, sizeof(dli_fname), NULL);
1781   assert(ret, "cannot locate libjvm");
1782   char *rp = NULL;
1783   if (ret && dli_fname[0] != '\0') {
1784     rp = realpath(dli_fname, buf);
1785   }
1786   if (rp == NULL) {
1787     return;
1788   }
1789 
1790   if (Arguments::sun_java_launcher_is_altjvm()) {
1791     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1792     // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1793     // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1794     // appears at the right place in the string, then assume we are
1795     // installed in a JDK and we're done. Otherwise, check for a
1796     // JAVA_HOME environment variable and construct a path to the JVM
1797     // being overridden.
1798 
1799     const char *p = buf + strlen(buf) - 1;
1800     for (int count = 0; p > buf && count < 5; ++count) {
1801       for (--p; p > buf && *p != '/'; --p)
1802         /* empty */ ;
1803     }
1804 
1805     if (strncmp(p, "/jre/lib/", 9) != 0) {
1806       // Look for JAVA_HOME in the environment.
1807       char* java_home_var = ::getenv("JAVA_HOME");
1808       if (java_home_var != NULL && java_home_var[0] != 0) {
1809         char* jrelib_p;
1810         int len;
1811 
1812         // Check the current module name "libjvm"
1813         p = strrchr(buf, '/');
1814         assert(strstr(p, "/libjvm") == p, "invalid library name");
1815 
1816         rp = realpath(java_home_var, buf);
1817         if (rp == NULL) {
1818           return;
1819         }
1820 
1821         // determine if this is a legacy image or modules image
1822         // modules image doesn't have "jre" subdirectory
1823         len = strlen(buf);
1824         assert(len < buflen, "Ran out of buffer space");
1825         jrelib_p = buf + len;
1826 
1827         // Add the appropriate library subdir
1828         snprintf(jrelib_p, buflen-len, "/jre/lib");
1829         if (0 != access(buf, F_OK)) {
1830           snprintf(jrelib_p, buflen-len, "/lib");
1831         }
1832 
1833         // Add the appropriate client or server subdir
1834         len = strlen(buf);
1835         jrelib_p = buf + len;
1836         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1837         if (0 != access(buf, F_OK)) {
1838           snprintf(jrelib_p, buflen-len, "%s", "");
1839         }
1840 
1841         // If the path exists within JAVA_HOME, add the JVM library name
1842         // to complete the path to JVM being overridden.  Otherwise fallback
1843         // to the path to the current library.
1844         if (0 == access(buf, F_OK)) {
1845           // Use current module name "libjvm"
1846           len = strlen(buf);
1847           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1848         } else {
1849           // Fall back to path of current library
1850           rp = realpath(dli_fname, buf);
1851           if (rp == NULL) {
1852             return;
1853           }
1854         }
1855       }
1856     }
1857   }
1858 
1859   strncpy(saved_jvm_path, buf, MAXPATHLEN);
1860   saved_jvm_path[MAXPATHLEN - 1] = '\0';
1861 }
1862 
1863 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1864   // no prefix required, not even "_"
1865 }
1866 
1867 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1868   // no suffix required
1869 }
1870 
1871 ////////////////////////////////////////////////////////////////////////////////
1872 // sun.misc.Signal support
1873 
1874 static volatile jint sigint_count = 0;
1875 
1876 static void UserHandler(int sig, void *siginfo, void *context) {
1877   // 4511530 - sem_post is serialized and handled by the manager thread. When
1878   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1879   // don't want to flood the manager thread with sem_post requests.
1880   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
1881     return;
1882   }
1883 
1884   // Ctrl-C is pressed during error reporting, likely because the error
1885   // handler fails to abort. Let VM die immediately.
1886   if (sig == SIGINT && is_error_reported()) {
1887     os::die();
1888   }
1889 
1890   os::signal_notify(sig);
1891 }
1892 
1893 void* os::user_handler() {
1894   return CAST_FROM_FN_PTR(void*, UserHandler);
1895 }
1896 
1897 extern "C" {
1898   typedef void (*sa_handler_t)(int);
1899   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1900 }
1901 
1902 void* os::signal(int signal_number, void* handler) {
1903   struct sigaction sigAct, oldSigAct;
1904 
1905   sigfillset(&(sigAct.sa_mask));
1906   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1907   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1908 
1909   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1910     // -1 means registration failed
1911     return (void *)-1;
1912   }
1913 
1914   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1915 }
1916 
1917 void os::signal_raise(int signal_number) {
1918   ::raise(signal_number);
1919 }
1920 
1921 // The following code is moved from os.cpp for making this
1922 // code platform specific, which it is by its very nature.
1923 
1924 // Will be modified when max signal is changed to be dynamic
1925 int os::sigexitnum_pd() {
1926   return NSIG;
1927 }
1928 
1929 // a counter for each possible signal value
1930 static volatile jint pending_signals[NSIG+1] = { 0 };
1931 
1932 // Bsd(POSIX) specific hand shaking semaphore.
1933 #ifdef __APPLE__
1934 typedef semaphore_t os_semaphore_t;
1935 
1936   #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1937   #define SEM_WAIT(sem)           semaphore_wait(sem)
1938   #define SEM_POST(sem)           semaphore_signal(sem)
1939   #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
1940 #else
1941 typedef sem_t os_semaphore_t;
1942 
1943   #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
1944   #define SEM_WAIT(sem)           sem_wait(&sem)
1945   #define SEM_POST(sem)           sem_post(&sem)
1946   #define SEM_DESTROY(sem)        sem_destroy(&sem)
1947 #endif
1948 
1949 class Semaphore : public StackObj {
1950  public:
1951   Semaphore();
1952   ~Semaphore();
1953   void signal();
1954   void wait();
1955   bool trywait();
1956   bool timedwait(unsigned int sec, int nsec);
1957  private:
1958   jlong currenttime() const;
1959   os_semaphore_t _semaphore;
1960 };
1961 
1962 Semaphore::Semaphore() : _semaphore(0) {
1963   SEM_INIT(_semaphore, 0);
1964 }
1965 
1966 Semaphore::~Semaphore() {
1967   SEM_DESTROY(_semaphore);
1968 }
1969 
1970 void Semaphore::signal() {
1971   SEM_POST(_semaphore);
1972 }
1973 
1974 void Semaphore::wait() {
1975   SEM_WAIT(_semaphore);
1976 }
1977 
1978 jlong Semaphore::currenttime() const {
1979   struct timeval tv;
1980   gettimeofday(&tv, NULL);
1981   return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
1982 }
1983 
1984 #ifdef __APPLE__
1985 bool Semaphore::trywait() {
1986   return timedwait(0, 0);
1987 }
1988 
1989 bool Semaphore::timedwait(unsigned int sec, int nsec) {
1990   kern_return_t kr = KERN_ABORTED;
1991   mach_timespec_t waitspec;
1992   waitspec.tv_sec = sec;
1993   waitspec.tv_nsec = nsec;
1994 
1995   jlong starttime = currenttime();
1996 
1997   kr = semaphore_timedwait(_semaphore, waitspec);
1998   while (kr == KERN_ABORTED) {
1999     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
2000 
2001     jlong current = currenttime();
2002     jlong passedtime = current - starttime;
2003 
2004     if (passedtime >= totalwait) {
2005       waitspec.tv_sec = 0;
2006       waitspec.tv_nsec = 0;
2007     } else {
2008       jlong waittime = totalwait - (current - starttime);
2009       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
2010       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
2011     }
2012 
2013     kr = semaphore_timedwait(_semaphore, waitspec);
2014   }
2015 
2016   return kr == KERN_SUCCESS;
2017 }
2018 
2019 #else
2020 
2021 bool Semaphore::trywait() {
2022   return sem_trywait(&_semaphore) == 0;
2023 }
2024 
2025 bool Semaphore::timedwait(unsigned int sec, int nsec) {
2026   struct timespec ts;
2027   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2028 
2029   while (1) {
2030     int result = sem_timedwait(&_semaphore, &ts);
2031     if (result == 0) {
2032       return true;
2033     } else if (errno == EINTR) {
2034       continue;
2035     } else if (errno == ETIMEDOUT) {
2036       return false;
2037     } else {
2038       return false;
2039     }
2040   }
2041 }
2042 
2043 #endif // __APPLE__
2044 
2045 static os_semaphore_t sig_sem;
2046 static Semaphore sr_semaphore;
2047 
2048 void os::signal_init_pd() {
2049   // Initialize signal structures
2050   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2051 
2052   // Initialize signal semaphore
2053   ::SEM_INIT(sig_sem, 0);
2054 }
2055 
2056 void os::signal_notify(int sig) {
2057   Atomic::inc(&pending_signals[sig]);
2058   ::SEM_POST(sig_sem);
2059 }
2060 
2061 static int check_pending_signals(bool wait) {
2062   Atomic::store(0, &sigint_count);
2063   for (;;) {
2064     for (int i = 0; i < NSIG + 1; i++) {
2065       jint n = pending_signals[i];
2066       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2067         return i;
2068       }
2069     }
2070     if (!wait) {
2071       return -1;
2072     }
2073     JavaThread *thread = JavaThread::current();
2074     ThreadBlockInVM tbivm(thread);
2075 
2076     bool threadIsSuspended;
2077     do {
2078       thread->set_suspend_equivalent();
2079       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2080       ::SEM_WAIT(sig_sem);
2081 
2082       // were we externally suspended while we were waiting?
2083       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2084       if (threadIsSuspended) {
2085         // The semaphore has been incremented, but while we were waiting
2086         // another thread suspended us. We don't want to continue running
2087         // while suspended because that would surprise the thread that
2088         // suspended us.
2089         ::SEM_POST(sig_sem);
2090 
2091         thread->java_suspend_self();
2092       }
2093     } while (threadIsSuspended);
2094   }
2095 }
2096 
2097 int os::signal_lookup() {
2098   return check_pending_signals(false);
2099 }
2100 
2101 int os::signal_wait() {
2102   return check_pending_signals(true);
2103 }
2104 
2105 ////////////////////////////////////////////////////////////////////////////////
2106 // Virtual Memory
2107 
2108 int os::vm_page_size() {
2109   // Seems redundant as all get out
2110   assert(os::Bsd::page_size() != -1, "must call os::init");
2111   return os::Bsd::page_size();
2112 }
2113 
2114 // Solaris allocates memory by pages.
2115 int os::vm_allocation_granularity() {
2116   assert(os::Bsd::page_size() != -1, "must call os::init");
2117   return os::Bsd::page_size();
2118 }
2119 
2120 // Rationale behind this function:
2121 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2122 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2123 //  samples for JITted code. Here we create private executable mapping over the code cache
2124 //  and then we can use standard (well, almost, as mapping can change) way to provide
2125 //  info for the reporting script by storing timestamp and location of symbol
2126 void bsd_wrap_code(char* base, size_t size) {
2127   static volatile jint cnt = 0;
2128 
2129   if (!UseOprofile) {
2130     return;
2131   }
2132 
2133   char buf[PATH_MAX + 1];
2134   int num = Atomic::add(1, &cnt);
2135 
2136   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2137            os::get_temp_directory(), os::current_process_id(), num);
2138   unlink(buf);
2139 
2140   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2141 
2142   if (fd != -1) {
2143     off_t rv = ::lseek(fd, size-2, SEEK_SET);
2144     if (rv != (off_t)-1) {
2145       if (::write(fd, "", 1) == 1) {
2146         mmap(base, size,
2147              PROT_READ|PROT_WRITE|PROT_EXEC,
2148              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2149       }
2150     }
2151     ::close(fd);
2152     unlink(buf);
2153   }
2154 }
2155 
2156 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2157                                     int err) {
2158   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2159           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2160           strerror(err), err);
2161 }
2162 
2163 // NOTE: Bsd kernel does not really reserve the pages for us.
2164 //       All it does is to check if there are enough free pages
2165 //       left at the time of mmap(). This could be a potential
2166 //       problem.
2167 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2168   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2169 #ifdef __OpenBSD__
2170   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2171   if (::mprotect(addr, size, prot) == 0) {
2172     return true;
2173   }
2174 #else
2175   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2176                                      MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2177   if (res != (uintptr_t) MAP_FAILED) {
2178     return true;
2179   }
2180 #endif
2181 
2182   // Warn about any commit errors we see in non-product builds just
2183   // in case mmap() doesn't work as described on the man page.
2184   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2185 
2186   return false;
2187 }
2188 
2189 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2190                           bool exec) {
2191   // alignment_hint is ignored on this OS
2192   return pd_commit_memory(addr, size, exec);
2193 }
2194 
2195 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2196                                   const char* mesg) {
2197   assert(mesg != NULL, "mesg must be specified");
2198   if (!pd_commit_memory(addr, size, exec)) {
2199     // add extra info in product mode for vm_exit_out_of_memory():
2200     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2201     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
2202   }
2203 }
2204 
2205 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2206                                   size_t alignment_hint, bool exec,
2207                                   const char* mesg) {
2208   // alignment_hint is ignored on this OS
2209   pd_commit_memory_or_exit(addr, size, exec, mesg);
2210 }
2211 
2212 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2213 }
2214 
2215 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2216   ::madvise(addr, bytes, MADV_DONTNEED);
2217 }
2218 
2219 void os::numa_make_global(char *addr, size_t bytes) {
2220 }
2221 
2222 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2223 }
2224 
2225 bool os::numa_topology_changed()   { return false; }
2226 
2227 size_t os::numa_get_groups_num() {
2228   return 1;
2229 }
2230 
2231 int os::numa_get_group_id() {
2232   return 0;
2233 }
2234 
2235 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2236   if (size > 0) {
2237     ids[0] = 0;
2238     return 1;
2239   }
2240   return 0;
2241 }
2242 
2243 bool os::get_page_info(char *start, page_info* info) {
2244   return false;
2245 }
2246 
2247 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2248   return end;
2249 }
2250 
2251 
2252 bool os::pd_uncommit_memory(char* addr, size_t size) {
2253 #ifdef __OpenBSD__
2254   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2255   return ::mprotect(addr, size, PROT_NONE) == 0;
2256 #else
2257   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2258                                      MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2259   return res  != (uintptr_t) MAP_FAILED;
2260 #endif
2261 }
2262 
2263 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2264   return os::commit_memory(addr, size, !ExecMem);
2265 }
2266 
2267 // If this is a growable mapping, remove the guard pages entirely by
2268 // munmap()ping them.  If not, just call uncommit_memory().
2269 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2270   return os::uncommit_memory(addr, size);
2271 }
2272 
2273 static address _highest_vm_reserved_address = NULL;
2274 
2275 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2276 // at 'requested_addr'. If there are existing memory mappings at the same
2277 // location, however, they will be overwritten. If 'fixed' is false,
2278 // 'requested_addr' is only treated as a hint, the return value may or
2279 // may not start from the requested address. Unlike Bsd mmap(), this
2280 // function returns NULL to indicate failure.
2281 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2282   char * addr;
2283   int flags;
2284 
2285   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2286   if (fixed) {
2287     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2288     flags |= MAP_FIXED;
2289   }
2290 
2291   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2292   // touch an uncommitted page. Otherwise, the read/write might
2293   // succeed if we have enough swap space to back the physical page.
2294   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2295                        flags, -1, 0);
2296 
2297   if (addr != MAP_FAILED) {
2298     // anon_mmap() should only get called during VM initialization,
2299     // don't need lock (actually we can skip locking even it can be called
2300     // from multiple threads, because _highest_vm_reserved_address is just a
2301     // hint about the upper limit of non-stack memory regions.)
2302     if ((address)addr + bytes > _highest_vm_reserved_address) {
2303       _highest_vm_reserved_address = (address)addr + bytes;
2304     }
2305   }
2306 
2307   return addr == MAP_FAILED ? NULL : addr;
2308 }
2309 
2310 // Don't update _highest_vm_reserved_address, because there might be memory
2311 // regions above addr + size. If so, releasing a memory region only creates
2312 // a hole in the address space, it doesn't help prevent heap-stack collision.
2313 //
2314 static int anon_munmap(char * addr, size_t size) {
2315   return ::munmap(addr, size) == 0;
2316 }
2317 
2318 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2319                             size_t alignment_hint) {
2320   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2321 }
2322 
2323 bool os::pd_release_memory(char* addr, size_t size) {
2324   return anon_munmap(addr, size);
2325 }
2326 
2327 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2328   // Bsd wants the mprotect address argument to be page aligned.
2329   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2330 
2331   // According to SUSv3, mprotect() should only be used with mappings
2332   // established by mmap(), and mmap() always maps whole pages. Unaligned
2333   // 'addr' likely indicates problem in the VM (e.g. trying to change
2334   // protection of malloc'ed or statically allocated memory). Check the
2335   // caller if you hit this assert.
2336   assert(addr == bottom, "sanity check");
2337 
2338   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2339   return ::mprotect(bottom, size, prot) == 0;
2340 }
2341 
2342 // Set protections specified
2343 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2344                         bool is_committed) {
2345   unsigned int p = 0;
2346   switch (prot) {
2347   case MEM_PROT_NONE: p = PROT_NONE; break;
2348   case MEM_PROT_READ: p = PROT_READ; break;
2349   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2350   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2351   default:
2352     ShouldNotReachHere();
2353   }
2354   // is_committed is unused.
2355   return bsd_mprotect(addr, bytes, p);
2356 }
2357 
2358 bool os::guard_memory(char* addr, size_t size) {
2359   return bsd_mprotect(addr, size, PROT_NONE);
2360 }
2361 
2362 bool os::unguard_memory(char* addr, size_t size) {
2363   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2364 }
2365 
2366 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2367   return false;
2368 }
2369 
2370 // Large page support
2371 
2372 static size_t _large_page_size = 0;
2373 
2374 void os::large_page_init() {
2375 }
2376 
2377 
2378 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2379   fatal("This code is not used or maintained.");
2380 
2381   // "exec" is passed in but not used.  Creating the shared image for
2382   // the code cache doesn't have an SHM_X executable permission to check.
2383   assert(UseLargePages && UseSHM, "only for SHM large pages");
2384 
2385   key_t key = IPC_PRIVATE;
2386   char *addr;
2387 
2388   bool warn_on_failure = UseLargePages &&
2389                          (!FLAG_IS_DEFAULT(UseLargePages) ||
2390                           !FLAG_IS_DEFAULT(LargePageSizeInBytes));
2391 
2392   // Create a large shared memory region to attach to based on size.
2393   // Currently, size is the total size of the heap
2394   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2395   if (shmid == -1) {
2396     // Possible reasons for shmget failure:
2397     // 1. shmmax is too small for Java heap.
2398     //    > check shmmax value: cat /proc/sys/kernel/shmmax
2399     //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2400     // 2. not enough large page memory.
2401     //    > check available large pages: cat /proc/meminfo
2402     //    > increase amount of large pages:
2403     //          echo new_value > /proc/sys/vm/nr_hugepages
2404     //      Note 1: different Bsd may use different name for this property,
2405     //            e.g. on Redhat AS-3 it is "hugetlb_pool".
2406     //      Note 2: it's possible there's enough physical memory available but
2407     //            they are so fragmented after a long run that they can't
2408     //            coalesce into large pages. Try to reserve large pages when
2409     //            the system is still "fresh".
2410     if (warn_on_failure) {
2411       warning("Failed to reserve shared memory (errno = %d).", errno);
2412     }
2413     return NULL;
2414   }
2415 
2416   // attach to the region
2417   addr = (char*)shmat(shmid, req_addr, 0);
2418   int err = errno;
2419 
2420   // Remove shmid. If shmat() is successful, the actual shared memory segment
2421   // will be deleted when it's detached by shmdt() or when the process
2422   // terminates. If shmat() is not successful this will remove the shared
2423   // segment immediately.
2424   shmctl(shmid, IPC_RMID, NULL);
2425 
2426   if ((intptr_t)addr == -1) {
2427     if (warn_on_failure) {
2428       warning("Failed to attach shared memory (errno = %d).", err);
2429     }
2430     return NULL;
2431   }
2432 
2433   // The memory is committed
2434   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
2435 
2436   return addr;
2437 }
2438 
2439 bool os::release_memory_special(char* base, size_t bytes) {
2440   if (MemTracker::tracking_level() > NMT_minimal) {
2441     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2442     // detaching the SHM segment will also delete it, see reserve_memory_special()
2443     int rslt = shmdt(base);
2444     if (rslt == 0) {
2445       tkr.record((address)base, bytes);
2446       return true;
2447     } else {
2448       return false;
2449     }
2450   } else {
2451     return shmdt(base) == 0;
2452   }
2453 }
2454 
2455 size_t os::large_page_size() {
2456   return _large_page_size;
2457 }
2458 
2459 // HugeTLBFS allows application to commit large page memory on demand;
2460 // with SysV SHM the entire memory region must be allocated as shared
2461 // memory.
2462 bool os::can_commit_large_page_memory() {
2463   return UseHugeTLBFS;
2464 }
2465 
2466 bool os::can_execute_large_page_memory() {
2467   return UseHugeTLBFS;
2468 }
2469 
2470 // Reserve memory at an arbitrary address, only if that area is
2471 // available (and not reserved for something else).
2472 
2473 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2474   const int max_tries = 10;
2475   char* base[max_tries];
2476   size_t size[max_tries];
2477   const size_t gap = 0x000000;
2478 
2479   // Assert only that the size is a multiple of the page size, since
2480   // that's all that mmap requires, and since that's all we really know
2481   // about at this low abstraction level.  If we need higher alignment,
2482   // we can either pass an alignment to this method or verify alignment
2483   // in one of the methods further up the call chain.  See bug 5044738.
2484   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2485 
2486   // Repeatedly allocate blocks until the block is allocated at the
2487   // right spot. Give up after max_tries. Note that reserve_memory() will
2488   // automatically update _highest_vm_reserved_address if the call is
2489   // successful. The variable tracks the highest memory address every reserved
2490   // by JVM. It is used to detect heap-stack collision if running with
2491   // fixed-stack BsdThreads. Because here we may attempt to reserve more
2492   // space than needed, it could confuse the collision detecting code. To
2493   // solve the problem, save current _highest_vm_reserved_address and
2494   // calculate the correct value before return.
2495   address old_highest = _highest_vm_reserved_address;
2496 
2497   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2498   // if kernel honors the hint then we can return immediately.
2499   char * addr = anon_mmap(requested_addr, bytes, false);
2500   if (addr == requested_addr) {
2501     return requested_addr;
2502   }
2503 
2504   if (addr != NULL) {
2505     // mmap() is successful but it fails to reserve at the requested address
2506     anon_munmap(addr, bytes);
2507   }
2508 
2509   int i;
2510   for (i = 0; i < max_tries; ++i) {
2511     base[i] = reserve_memory(bytes);
2512 
2513     if (base[i] != NULL) {
2514       // Is this the block we wanted?
2515       if (base[i] == requested_addr) {
2516         size[i] = bytes;
2517         break;
2518       }
2519 
2520       // Does this overlap the block we wanted? Give back the overlapped
2521       // parts and try again.
2522 
2523       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2524       if (top_overlap >= 0 && top_overlap < bytes) {
2525         unmap_memory(base[i], top_overlap);
2526         base[i] += top_overlap;
2527         size[i] = bytes - top_overlap;
2528       } else {
2529         size_t bottom_overlap = base[i] + bytes - requested_addr;
2530         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2531           unmap_memory(requested_addr, bottom_overlap);
2532           size[i] = bytes - bottom_overlap;
2533         } else {
2534           size[i] = bytes;
2535         }
2536       }
2537     }
2538   }
2539 
2540   // Give back the unused reserved pieces.
2541 
2542   for (int j = 0; j < i; ++j) {
2543     if (base[j] != NULL) {
2544       unmap_memory(base[j], size[j]);
2545     }
2546   }
2547 
2548   if (i < max_tries) {
2549     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2550     return requested_addr;
2551   } else {
2552     _highest_vm_reserved_address = old_highest;
2553     return NULL;
2554   }
2555 }
2556 
2557 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2558   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2559 }
2560 
2561 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
2562   RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset));
2563 }
2564 
2565 void os::naked_short_sleep(jlong ms) {
2566   struct timespec req;
2567 
2568   assert(ms < 1000, "Un-interruptable sleep, short time use only");
2569   req.tv_sec = 0;
2570   if (ms > 0) {
2571     req.tv_nsec = (ms % 1000) * 1000000;
2572   } else {
2573     req.tv_nsec = 1;
2574   }
2575 
2576   nanosleep(&req, NULL);
2577 
2578   return;
2579 }
2580 
2581 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2582 void os::infinite_sleep() {
2583   while (true) {    // sleep forever ...
2584     ::sleep(100);   // ... 100 seconds at a time
2585   }
2586 }
2587 
2588 // Used to convert frequent JVM_Yield() to nops
2589 bool os::dont_yield() {
2590   return DontYieldALot;
2591 }
2592 
2593 void os::naked_yield() {
2594   sched_yield();
2595 }
2596 
2597 ////////////////////////////////////////////////////////////////////////////////
2598 // thread priority support
2599 
2600 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2601 // only supports dynamic priority, static priority must be zero. For real-time
2602 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2603 // However, for large multi-threaded applications, SCHED_RR is not only slower
2604 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2605 // of 5 runs - Sep 2005).
2606 //
2607 // The following code actually changes the niceness of kernel-thread/LWP. It
2608 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2609 // not the entire user process, and user level threads are 1:1 mapped to kernel
2610 // threads. It has always been the case, but could change in the future. For
2611 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2612 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2613 
2614 #if !defined(__APPLE__)
2615 int os::java_to_os_priority[CriticalPriority + 1] = {
2616   19,              // 0 Entry should never be used
2617 
2618    0,              // 1 MinPriority
2619    3,              // 2
2620    6,              // 3
2621 
2622   10,              // 4
2623   15,              // 5 NormPriority
2624   18,              // 6
2625 
2626   21,              // 7
2627   25,              // 8
2628   28,              // 9 NearMaxPriority
2629 
2630   31,              // 10 MaxPriority
2631 
2632   31               // 11 CriticalPriority
2633 };
2634 #else
2635 // Using Mach high-level priority assignments
2636 int os::java_to_os_priority[CriticalPriority + 1] = {
2637    0,              // 0 Entry should never be used (MINPRI_USER)
2638 
2639   27,              // 1 MinPriority
2640   28,              // 2
2641   29,              // 3
2642 
2643   30,              // 4
2644   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2645   32,              // 6
2646 
2647   33,              // 7
2648   34,              // 8
2649   35,              // 9 NearMaxPriority
2650 
2651   36,              // 10 MaxPriority
2652 
2653   36               // 11 CriticalPriority
2654 };
2655 #endif
2656 
2657 static int prio_init() {
2658   if (ThreadPriorityPolicy == 1) {
2659     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2660     // if effective uid is not root. Perhaps, a more elegant way of doing
2661     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2662     if (geteuid() != 0) {
2663       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2664         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2665       }
2666       ThreadPriorityPolicy = 0;
2667     }
2668   }
2669   if (UseCriticalJavaThreadPriority) {
2670     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2671   }
2672   return 0;
2673 }
2674 
2675 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2676   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2677 
2678 #ifdef __OpenBSD__
2679   // OpenBSD pthread_setprio starves low priority threads
2680   return OS_OK;
2681 #elif defined(__FreeBSD__)
2682   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2683 #elif defined(__APPLE__) || defined(__NetBSD__)
2684   struct sched_param sp;
2685   int policy;
2686   pthread_t self = pthread_self();
2687 
2688   if (pthread_getschedparam(self, &policy, &sp) != 0) {
2689     return OS_ERR;
2690   }
2691 
2692   sp.sched_priority = newpri;
2693   if (pthread_setschedparam(self, policy, &sp) != 0) {
2694     return OS_ERR;
2695   }
2696 
2697   return OS_OK;
2698 #else
2699   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2700   return (ret == 0) ? OS_OK : OS_ERR;
2701 #endif
2702 }
2703 
2704 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2705   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2706     *priority_ptr = java_to_os_priority[NormPriority];
2707     return OS_OK;
2708   }
2709 
2710   errno = 0;
2711 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2712   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2713 #elif defined(__APPLE__) || defined(__NetBSD__)
2714   int policy;
2715   struct sched_param sp;
2716 
2717   pthread_getschedparam(pthread_self(), &policy, &sp);
2718   *priority_ptr = sp.sched_priority;
2719 #else
2720   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2721 #endif
2722   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2723 }
2724 
2725 // Hint to the underlying OS that a task switch would not be good.
2726 // Void return because it's a hint and can fail.
2727 void os::hint_no_preempt() {}
2728 
2729 ////////////////////////////////////////////////////////////////////////////////
2730 // suspend/resume support
2731 
2732 //  the low-level signal-based suspend/resume support is a remnant from the
2733 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2734 //  within hotspot. Now there is a single use-case for this:
2735 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
2736 //      that runs in the watcher thread.
2737 //  The remaining code is greatly simplified from the more general suspension
2738 //  code that used to be used.
2739 //
2740 //  The protocol is quite simple:
2741 //  - suspend:
2742 //      - sends a signal to the target thread
2743 //      - polls the suspend state of the osthread using a yield loop
2744 //      - target thread signal handler (SR_handler) sets suspend state
2745 //        and blocks in sigsuspend until continued
2746 //  - resume:
2747 //      - sets target osthread state to continue
2748 //      - sends signal to end the sigsuspend loop in the SR_handler
2749 //
2750 //  Note that the SR_lock plays no role in this suspend/resume protocol.
2751 
2752 static void resume_clear_context(OSThread *osthread) {
2753   osthread->set_ucontext(NULL);
2754   osthread->set_siginfo(NULL);
2755 }
2756 
2757 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2758   osthread->set_ucontext(context);
2759   osthread->set_siginfo(siginfo);
2760 }
2761 
2762 // Handler function invoked when a thread's execution is suspended or
2763 // resumed. We have to be careful that only async-safe functions are
2764 // called here (Note: most pthread functions are not async safe and
2765 // should be avoided.)
2766 //
2767 // Note: sigwait() is a more natural fit than sigsuspend() from an
2768 // interface point of view, but sigwait() prevents the signal hander
2769 // from being run. libpthread would get very confused by not having
2770 // its signal handlers run and prevents sigwait()'s use with the
2771 // mutex granting granting signal.
2772 //
2773 // Currently only ever called on the VMThread or JavaThread
2774 //
2775 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2776   // Save and restore errno to avoid confusing native code with EINTR
2777   // after sigsuspend.
2778   int old_errno = errno;
2779 
2780   Thread* thread = Thread::current();
2781   OSThread* osthread = thread->osthread();
2782   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2783 
2784   os::SuspendResume::State current = osthread->sr.state();
2785   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2786     suspend_save_context(osthread, siginfo, context);
2787 
2788     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2789     os::SuspendResume::State state = osthread->sr.suspended();
2790     if (state == os::SuspendResume::SR_SUSPENDED) {
2791       sigset_t suspend_set;  // signals for sigsuspend()
2792 
2793       // get current set of blocked signals and unblock resume signal
2794       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2795       sigdelset(&suspend_set, SR_signum);
2796 
2797       sr_semaphore.signal();
2798       // wait here until we are resumed
2799       while (1) {
2800         sigsuspend(&suspend_set);
2801 
2802         os::SuspendResume::State result = osthread->sr.running();
2803         if (result == os::SuspendResume::SR_RUNNING) {
2804           sr_semaphore.signal();
2805           break;
2806         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2807           ShouldNotReachHere();
2808         }
2809       }
2810 
2811     } else if (state == os::SuspendResume::SR_RUNNING) {
2812       // request was cancelled, continue
2813     } else {
2814       ShouldNotReachHere();
2815     }
2816 
2817     resume_clear_context(osthread);
2818   } else if (current == os::SuspendResume::SR_RUNNING) {
2819     // request was cancelled, continue
2820   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2821     // ignore
2822   } else {
2823     // ignore
2824   }
2825 
2826   errno = old_errno;
2827 }
2828 
2829 
2830 static int SR_initialize() {
2831   struct sigaction act;
2832   char *s;
2833   // Get signal number to use for suspend/resume
2834   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2835     int sig = ::strtol(s, 0, 10);
2836     if (sig > 0 || sig < NSIG) {
2837       SR_signum = sig;
2838     }
2839   }
2840 
2841   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2842          "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2843 
2844   sigemptyset(&SR_sigset);
2845   sigaddset(&SR_sigset, SR_signum);
2846 
2847   // Set up signal handler for suspend/resume
2848   act.sa_flags = SA_RESTART|SA_SIGINFO;
2849   act.sa_handler = (void (*)(int)) SR_handler;
2850 
2851   // SR_signum is blocked by default.
2852   // 4528190 - We also need to block pthread restart signal (32 on all
2853   // supported Bsd platforms). Note that BsdThreads need to block
2854   // this signal for all threads to work properly. So we don't have
2855   // to use hard-coded signal number when setting up the mask.
2856   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2857 
2858   if (sigaction(SR_signum, &act, 0) == -1) {
2859     return -1;
2860   }
2861 
2862   // Save signal flag
2863   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2864   return 0;
2865 }
2866 
2867 static int sr_notify(OSThread* osthread) {
2868   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2869   assert_status(status == 0, status, "pthread_kill");
2870   return status;
2871 }
2872 
2873 // "Randomly" selected value for how long we want to spin
2874 // before bailing out on suspending a thread, also how often
2875 // we send a signal to a thread we want to resume
2876 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2877 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2878 
2879 // returns true on success and false on error - really an error is fatal
2880 // but this seems the normal response to library errors
2881 static bool do_suspend(OSThread* osthread) {
2882   assert(osthread->sr.is_running(), "thread should be running");
2883   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2884 
2885   // mark as suspended and send signal
2886   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2887     // failed to switch, state wasn't running?
2888     ShouldNotReachHere();
2889     return false;
2890   }
2891 
2892   if (sr_notify(osthread) != 0) {
2893     ShouldNotReachHere();
2894   }
2895 
2896   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2897   while (true) {
2898     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2899       break;
2900     } else {
2901       // timeout
2902       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2903       if (cancelled == os::SuspendResume::SR_RUNNING) {
2904         return false;
2905       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2906         // make sure that we consume the signal on the semaphore as well
2907         sr_semaphore.wait();
2908         break;
2909       } else {
2910         ShouldNotReachHere();
2911         return false;
2912       }
2913     }
2914   }
2915 
2916   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2917   return true;
2918 }
2919 
2920 static void do_resume(OSThread* osthread) {
2921   assert(osthread->sr.is_suspended(), "thread should be suspended");
2922   assert(!sr_semaphore.trywait(), "invalid semaphore state");
2923 
2924   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2925     // failed to switch to WAKEUP_REQUEST
2926     ShouldNotReachHere();
2927     return;
2928   }
2929 
2930   while (true) {
2931     if (sr_notify(osthread) == 0) {
2932       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2933         if (osthread->sr.is_running()) {
2934           return;
2935         }
2936       }
2937     } else {
2938       ShouldNotReachHere();
2939     }
2940   }
2941 
2942   guarantee(osthread->sr.is_running(), "Must be running!");
2943 }
2944 
2945 ///////////////////////////////////////////////////////////////////////////////////
2946 // signal handling (except suspend/resume)
2947 
2948 // This routine may be used by user applications as a "hook" to catch signals.
2949 // The user-defined signal handler must pass unrecognized signals to this
2950 // routine, and if it returns true (non-zero), then the signal handler must
2951 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
2952 // routine will never retun false (zero), but instead will execute a VM panic
2953 // routine kill the process.
2954 //
2955 // If this routine returns false, it is OK to call it again.  This allows
2956 // the user-defined signal handler to perform checks either before or after
2957 // the VM performs its own checks.  Naturally, the user code would be making
2958 // a serious error if it tried to handle an exception (such as a null check
2959 // or breakpoint) that the VM was generating for its own correct operation.
2960 //
2961 // This routine may recognize any of the following kinds of signals:
2962 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2963 // It should be consulted by handlers for any of those signals.
2964 //
2965 // The caller of this routine must pass in the three arguments supplied
2966 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2967 // field of the structure passed to sigaction().  This routine assumes that
2968 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2969 //
2970 // Note that the VM will print warnings if it detects conflicting signal
2971 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2972 //
2973 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2974                                                void* ucontext,
2975                                                int abort_if_unrecognized);
2976 
2977 void signalHandler(int sig, siginfo_t* info, void* uc) {
2978   assert(info != NULL && uc != NULL, "it must be old kernel");
2979   int orig_errno = errno;  // Preserve errno value over signal handler.
2980   JVM_handle_bsd_signal(sig, info, uc, true);
2981   errno = orig_errno;
2982 }
2983 
2984 
2985 // This boolean allows users to forward their own non-matching signals
2986 // to JVM_handle_bsd_signal, harmlessly.
2987 bool os::Bsd::signal_handlers_are_installed = false;
2988 
2989 // For signal-chaining
2990 struct sigaction os::Bsd::sigact[MAXSIGNUM];
2991 unsigned int os::Bsd::sigs = 0;
2992 bool os::Bsd::libjsig_is_loaded = false;
2993 typedef struct sigaction *(*get_signal_t)(int);
2994 get_signal_t os::Bsd::get_signal_action = NULL;
2995 
2996 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2997   struct sigaction *actp = NULL;
2998 
2999   if (libjsig_is_loaded) {
3000     // Retrieve the old signal handler from libjsig
3001     actp = (*get_signal_action)(sig);
3002   }
3003   if (actp == NULL) {
3004     // Retrieve the preinstalled signal handler from jvm
3005     actp = get_preinstalled_handler(sig);
3006   }
3007 
3008   return actp;
3009 }
3010 
3011 static bool call_chained_handler(struct sigaction *actp, int sig,
3012                                  siginfo_t *siginfo, void *context) {
3013   // Call the old signal handler
3014   if (actp->sa_handler == SIG_DFL) {
3015     // It's more reasonable to let jvm treat it as an unexpected exception
3016     // instead of taking the default action.
3017     return false;
3018   } else if (actp->sa_handler != SIG_IGN) {
3019     if ((actp->sa_flags & SA_NODEFER) == 0) {
3020       // automaticlly block the signal
3021       sigaddset(&(actp->sa_mask), sig);
3022     }
3023 
3024     sa_handler_t hand;
3025     sa_sigaction_t sa;
3026     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3027     // retrieve the chained handler
3028     if (siginfo_flag_set) {
3029       sa = actp->sa_sigaction;
3030     } else {
3031       hand = actp->sa_handler;
3032     }
3033 
3034     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3035       actp->sa_handler = SIG_DFL;
3036     }
3037 
3038     // try to honor the signal mask
3039     sigset_t oset;
3040     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3041 
3042     // call into the chained handler
3043     if (siginfo_flag_set) {
3044       (*sa)(sig, siginfo, context);
3045     } else {
3046       (*hand)(sig);
3047     }
3048 
3049     // restore the signal mask
3050     pthread_sigmask(SIG_SETMASK, &oset, 0);
3051   }
3052   // Tell jvm's signal handler the signal is taken care of.
3053   return true;
3054 }
3055 
3056 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3057   bool chained = false;
3058   // signal-chaining
3059   if (UseSignalChaining) {
3060     struct sigaction *actp = get_chained_signal_action(sig);
3061     if (actp != NULL) {
3062       chained = call_chained_handler(actp, sig, siginfo, context);
3063     }
3064   }
3065   return chained;
3066 }
3067 
3068 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3069   if ((((unsigned int)1 << sig) & sigs) != 0) {
3070     return &sigact[sig];
3071   }
3072   return NULL;
3073 }
3074 
3075 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3076   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3077   sigact[sig] = oldAct;
3078   sigs |= (unsigned int)1 << sig;
3079 }
3080 
3081 // for diagnostic
3082 int os::Bsd::sigflags[MAXSIGNUM];
3083 
3084 int os::Bsd::get_our_sigflags(int sig) {
3085   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3086   return sigflags[sig];
3087 }
3088 
3089 void os::Bsd::set_our_sigflags(int sig, int flags) {
3090   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3091   sigflags[sig] = flags;
3092 }
3093 
3094 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3095   // Check for overwrite.
3096   struct sigaction oldAct;
3097   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3098 
3099   void* oldhand = oldAct.sa_sigaction
3100                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
3101                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
3102   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3103       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3104       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3105     if (AllowUserSignalHandlers || !set_installed) {
3106       // Do not overwrite; user takes responsibility to forward to us.
3107       return;
3108     } else if (UseSignalChaining) {
3109       // save the old handler in jvm
3110       save_preinstalled_handler(sig, oldAct);
3111       // libjsig also interposes the sigaction() call below and saves the
3112       // old sigaction on it own.
3113     } else {
3114       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3115                     "%#lx for signal %d.", (long)oldhand, sig));
3116     }
3117   }
3118 
3119   struct sigaction sigAct;
3120   sigfillset(&(sigAct.sa_mask));
3121   sigAct.sa_handler = SIG_DFL;
3122   if (!set_installed) {
3123     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3124   } else {
3125     sigAct.sa_sigaction = signalHandler;
3126     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3127   }
3128 #ifdef __APPLE__
3129   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3130   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3131   // if the signal handler declares it will handle it on alternate stack.
3132   // Notice we only declare we will handle it on alt stack, but we are not
3133   // actually going to use real alt stack - this is just a workaround.
3134   // Please see ux_exception.c, method catch_mach_exception_raise for details
3135   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3136   if (sig == SIGSEGV) {
3137     sigAct.sa_flags |= SA_ONSTACK;
3138   }
3139 #endif
3140 
3141   // Save flags, which are set by ours
3142   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3143   sigflags[sig] = sigAct.sa_flags;
3144 
3145   int ret = sigaction(sig, &sigAct, &oldAct);
3146   assert(ret == 0, "check");
3147 
3148   void* oldhand2  = oldAct.sa_sigaction
3149                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3150                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3151   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3152 }
3153 
3154 // install signal handlers for signals that HotSpot needs to
3155 // handle in order to support Java-level exception handling.
3156 
3157 void os::Bsd::install_signal_handlers() {
3158   if (!signal_handlers_are_installed) {
3159     signal_handlers_are_installed = true;
3160 
3161     // signal-chaining
3162     typedef void (*signal_setting_t)();
3163     signal_setting_t begin_signal_setting = NULL;
3164     signal_setting_t end_signal_setting = NULL;
3165     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3166                                           dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3167     if (begin_signal_setting != NULL) {
3168       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3169                                           dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3170       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3171                                          dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3172       libjsig_is_loaded = true;
3173       assert(UseSignalChaining, "should enable signal-chaining");
3174     }
3175     if (libjsig_is_loaded) {
3176       // Tell libjsig jvm is setting signal handlers
3177       (*begin_signal_setting)();
3178     }
3179 
3180     set_signal_handler(SIGSEGV, true);
3181     set_signal_handler(SIGPIPE, true);
3182     set_signal_handler(SIGBUS, true);
3183     set_signal_handler(SIGILL, true);
3184     set_signal_handler(SIGFPE, true);
3185     set_signal_handler(SIGXFSZ, true);
3186 
3187 #if defined(__APPLE__)
3188     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3189     // signals caught and handled by the JVM. To work around this, we reset the mach task
3190     // signal handler that's placed on our process by CrashReporter. This disables
3191     // CrashReporter-based reporting.
3192     //
3193     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3194     // on caught fatal signals.
3195     //
3196     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3197     // handlers. By replacing the existing task exception handler, we disable gdb's mach
3198     // exception handling, while leaving the standard BSD signal handlers functional.
3199     kern_return_t kr;
3200     kr = task_set_exception_ports(mach_task_self(),
3201                                   EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3202                                   MACH_PORT_NULL,
3203                                   EXCEPTION_STATE_IDENTITY,
3204                                   MACHINE_THREAD_STATE);
3205 
3206     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3207 #endif
3208 
3209     if (libjsig_is_loaded) {
3210       // Tell libjsig jvm finishes setting signal handlers
3211       (*end_signal_setting)();
3212     }
3213 
3214     // We don't activate signal checker if libjsig is in place, we trust ourselves
3215     // and if UserSignalHandler is installed all bets are off
3216     if (CheckJNICalls) {
3217       if (libjsig_is_loaded) {
3218         if (PrintJNIResolving) {
3219           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3220         }
3221         check_signals = false;
3222       }
3223       if (AllowUserSignalHandlers) {
3224         if (PrintJNIResolving) {
3225           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3226         }
3227         check_signals = false;
3228       }
3229     }
3230   }
3231 }
3232 
3233 
3234 /////
3235 // glibc on Bsd platform uses non-documented flag
3236 // to indicate, that some special sort of signal
3237 // trampoline is used.
3238 // We will never set this flag, and we should
3239 // ignore this flag in our diagnostic
3240 #ifdef SIGNIFICANT_SIGNAL_MASK
3241   #undef SIGNIFICANT_SIGNAL_MASK
3242 #endif
3243 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3244 
3245 static const char* get_signal_handler_name(address handler,
3246                                            char* buf, int buflen) {
3247   int offset;
3248   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3249   if (found) {
3250     // skip directory names
3251     const char *p1, *p2;
3252     p1 = buf;
3253     size_t len = strlen(os::file_separator());
3254     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3255     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3256   } else {
3257     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3258   }
3259   return buf;
3260 }
3261 
3262 static void print_signal_handler(outputStream* st, int sig,
3263                                  char* buf, size_t buflen) {
3264   struct sigaction sa;
3265 
3266   sigaction(sig, NULL, &sa);
3267 
3268   // See comment for SIGNIFICANT_SIGNAL_MASK define
3269   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3270 
3271   st->print("%s: ", os::exception_name(sig, buf, buflen));
3272 
3273   address handler = (sa.sa_flags & SA_SIGINFO)
3274     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3275     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3276 
3277   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3278     st->print("SIG_DFL");
3279   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3280     st->print("SIG_IGN");
3281   } else {
3282     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3283   }
3284 
3285   st->print(", sa_mask[0]=");
3286   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3287 
3288   address rh = VMError::get_resetted_sighandler(sig);
3289   // May be, handler was resetted by VMError?
3290   if (rh != NULL) {
3291     handler = rh;
3292     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3293   }
3294 
3295   st->print(", sa_flags=");
3296   os::Posix::print_sa_flags(st, sa.sa_flags);
3297 
3298   // Check: is it our handler?
3299   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3300       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3301     // It is our signal handler
3302     // check for flags, reset system-used one!
3303     if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3304       st->print(
3305                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3306                 os::Bsd::get_our_sigflags(sig));
3307     }
3308   }
3309   st->cr();
3310 }
3311 
3312 
3313 #define DO_SIGNAL_CHECK(sig)                      \
3314   do {                                            \
3315     if (!sigismember(&check_signal_done, sig)) {  \
3316       os::Bsd::check_signal_handler(sig);         \
3317     }                                             \
3318   } while (0)
3319 
3320 // This method is a periodic task to check for misbehaving JNI applications
3321 // under CheckJNI, we can add any periodic checks here
3322 
3323 void os::run_periodic_checks() {
3324 
3325   if (check_signals == false) return;
3326 
3327   // SEGV and BUS if overridden could potentially prevent
3328   // generation of hs*.log in the event of a crash, debugging
3329   // such a case can be very challenging, so we absolutely
3330   // check the following for a good measure:
3331   DO_SIGNAL_CHECK(SIGSEGV);
3332   DO_SIGNAL_CHECK(SIGILL);
3333   DO_SIGNAL_CHECK(SIGFPE);
3334   DO_SIGNAL_CHECK(SIGBUS);
3335   DO_SIGNAL_CHECK(SIGPIPE);
3336   DO_SIGNAL_CHECK(SIGXFSZ);
3337 
3338 
3339   // ReduceSignalUsage allows the user to override these handlers
3340   // see comments at the very top and jvm_solaris.h
3341   if (!ReduceSignalUsage) {
3342     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3343     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3344     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3345     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3346   }
3347 
3348   DO_SIGNAL_CHECK(SR_signum);
3349   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3350 }
3351 
3352 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3353 
3354 static os_sigaction_t os_sigaction = NULL;
3355 
3356 void os::Bsd::check_signal_handler(int sig) {
3357   char buf[O_BUFLEN];
3358   address jvmHandler = NULL;
3359 
3360 
3361   struct sigaction act;
3362   if (os_sigaction == NULL) {
3363     // only trust the default sigaction, in case it has been interposed
3364     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3365     if (os_sigaction == NULL) return;
3366   }
3367 
3368   os_sigaction(sig, (struct sigaction*)NULL, &act);
3369 
3370 
3371   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3372 
3373   address thisHandler = (act.sa_flags & SA_SIGINFO)
3374     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3375     : CAST_FROM_FN_PTR(address, act.sa_handler);
3376 
3377 
3378   switch (sig) {
3379   case SIGSEGV:
3380   case SIGBUS:
3381   case SIGFPE:
3382   case SIGPIPE:
3383   case SIGILL:
3384   case SIGXFSZ:
3385     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3386     break;
3387 
3388   case SHUTDOWN1_SIGNAL:
3389   case SHUTDOWN2_SIGNAL:
3390   case SHUTDOWN3_SIGNAL:
3391   case BREAK_SIGNAL:
3392     jvmHandler = (address)user_handler();
3393     break;
3394 
3395   case INTERRUPT_SIGNAL:
3396     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3397     break;
3398 
3399   default:
3400     if (sig == SR_signum) {
3401       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3402     } else {
3403       return;
3404     }
3405     break;
3406   }
3407 
3408   if (thisHandler != jvmHandler) {
3409     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3410     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3411     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3412     // No need to check this sig any longer
3413     sigaddset(&check_signal_done, sig);
3414     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3415     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3416       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3417                     exception_name(sig, buf, O_BUFLEN));
3418     }
3419   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3420     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3421     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3422     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
3423     // No need to check this sig any longer
3424     sigaddset(&check_signal_done, sig);
3425   }
3426 
3427   // Dump all the signal
3428   if (sigismember(&check_signal_done, sig)) {
3429     print_signal_handlers(tty, buf, O_BUFLEN);
3430   }
3431 }
3432 
3433 extern void report_error(char* file_name, int line_no, char* title,
3434                          char* format, ...);
3435 
3436 extern bool signal_name(int signo, char* buf, size_t len);
3437 
3438 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3439   if (0 < exception_code && exception_code <= SIGRTMAX) {
3440     // signal
3441     if (!signal_name(exception_code, buf, size)) {
3442       jio_snprintf(buf, size, "SIG%d", exception_code);
3443     }
3444     return buf;
3445   } else {
3446     return NULL;
3447   }
3448 }
3449 
3450 // this is called _before_ the most of global arguments have been parsed
3451 void os::init(void) {
3452   char dummy;   // used to get a guess on initial stack address
3453 //  first_hrtime = gethrtime();
3454 
3455   // With BsdThreads the JavaMain thread pid (primordial thread)
3456   // is different than the pid of the java launcher thread.
3457   // So, on Bsd, the launcher thread pid is passed to the VM
3458   // via the sun.java.launcher.pid property.
3459   // Use this property instead of getpid() if it was correctly passed.
3460   // See bug 6351349.
3461   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3462 
3463   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3464 
3465   clock_tics_per_sec = CLK_TCK;
3466 
3467   init_random(1234567);
3468 
3469   ThreadCritical::initialize();
3470 
3471   Bsd::set_page_size(getpagesize());
3472   if (Bsd::page_size() == -1) {
3473     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3474                   strerror(errno)));
3475   }
3476   init_page_sizes((size_t) Bsd::page_size());
3477 
3478   Bsd::initialize_system_info();
3479 
3480   // main_thread points to the aboriginal thread
3481   Bsd::_main_thread = pthread_self();
3482 
3483   Bsd::clock_init();
3484   initial_time_count = javaTimeNanos();
3485 
3486 #ifdef __APPLE__
3487   // XXXDARWIN
3488   // Work around the unaligned VM callbacks in hotspot's
3489   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3490   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3491   // alignment when doing symbol lookup. To work around this, we force early
3492   // binding of all symbols now, thus binding when alignment is known-good.
3493   _dyld_bind_fully_image_containing_address((const void *) &os::init);
3494 #endif
3495 }
3496 
3497 // To install functions for atexit system call
3498 extern "C" {
3499   static void perfMemory_exit_helper() {
3500     perfMemory_exit();
3501   }
3502 }
3503 
3504 // this is called _after_ the global arguments have been parsed
3505 jint os::init_2(void) {
3506   // Allocate a single page and mark it as readable for safepoint polling
3507   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3508   guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page");
3509 
3510   os::set_polling_page(polling_page);
3511 
3512 #ifndef PRODUCT
3513   if (Verbose && PrintMiscellaneous) {
3514     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n",
3515                (intptr_t)polling_page);
3516   }
3517 #endif
3518 
3519   if (!UseMembar) {
3520     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3521     guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3522     os::set_memory_serialize_page(mem_serialize_page);
3523 
3524 #ifndef PRODUCT
3525     if (Verbose && PrintMiscellaneous) {
3526       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n",
3527                  (intptr_t)mem_serialize_page);
3528     }
3529 #endif
3530   }
3531 
3532   // initialize suspend/resume support - must do this before signal_sets_init()
3533   if (SR_initialize() != 0) {
3534     perror("SR_initialize failed");
3535     return JNI_ERR;
3536   }
3537 
3538   Bsd::signal_sets_init();
3539   Bsd::install_signal_handlers();
3540 
3541   // Check minimum allowable stack size for thread creation and to initialize
3542   // the java system classes, including StackOverflowError - depends on page
3543   // size.  Add a page for compiler2 recursion in main thread.
3544   // Add in 2*BytesPerWord times page size to account for VM stack during
3545   // class initialization depending on 32 or 64 bit VM.
3546   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3547                                     (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3548                                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3549 
3550   size_t threadStackSizeInBytes = ThreadStackSize * K;
3551   if (threadStackSizeInBytes != 0 &&
3552       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3553     tty->print_cr("\nThe stack size specified is too small, "
3554                   "Specify at least %dk",
3555                   os::Bsd::min_stack_allowed/ K);
3556     return JNI_ERR;
3557   }
3558 
3559   // Make the stack size a multiple of the page size so that
3560   // the yellow/red zones can be guarded.
3561   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3562                                                 vm_page_size()));
3563 
3564   if (MaxFDLimit) {
3565     // set the number of file descriptors to max. print out error
3566     // if getrlimit/setrlimit fails but continue regardless.
3567     struct rlimit nbr_files;
3568     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3569     if (status != 0) {
3570       if (PrintMiscellaneous && (Verbose || WizardMode)) {
3571         perror("os::init_2 getrlimit failed");
3572       }
3573     } else {
3574       nbr_files.rlim_cur = nbr_files.rlim_max;
3575 
3576 #ifdef __APPLE__
3577       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3578       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3579       // be used instead
3580       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3581 #endif
3582 
3583       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3584       if (status != 0) {
3585         if (PrintMiscellaneous && (Verbose || WizardMode)) {
3586           perror("os::init_2 setrlimit failed");
3587         }
3588       }
3589     }
3590   }
3591 
3592   // at-exit methods are called in the reverse order of their registration.
3593   // atexit functions are called on return from main or as a result of a
3594   // call to exit(3C). There can be only 32 of these functions registered
3595   // and atexit() does not set errno.
3596 
3597   if (PerfAllowAtExitRegistration) {
3598     // only register atexit functions if PerfAllowAtExitRegistration is set.
3599     // atexit functions can be delayed until process exit time, which
3600     // can be problematic for embedded VM situations. Embedded VMs should
3601     // call DestroyJavaVM() to assure that VM resources are released.
3602 
3603     // note: perfMemory_exit_helper atexit function may be removed in
3604     // the future if the appropriate cleanup code can be added to the
3605     // VM_Exit VMOperation's doit method.
3606     if (atexit(perfMemory_exit_helper) != 0) {
3607       warning("os::init2 atexit(perfMemory_exit_helper) failed");
3608     }
3609   }
3610 
3611   // initialize thread priority policy
3612   prio_init();
3613 
3614 #ifdef __APPLE__
3615   // dynamically link to objective c gc registration
3616   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3617   if (handleLibObjc != NULL) {
3618     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3619   }
3620 #endif
3621 
3622   return JNI_OK;
3623 }
3624 
3625 // Mark the polling page as unreadable
3626 void os::make_polling_page_unreadable(void) {
3627   if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3628     fatal("Could not disable polling page");
3629   }
3630 }
3631 
3632 // Mark the polling page as readable
3633 void os::make_polling_page_readable(void) {
3634   if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3635     fatal("Could not enable polling page");
3636   }
3637 }
3638 
3639 int os::active_processor_count() {
3640   return _processor_count;
3641 }
3642 
3643 void os::set_native_thread_name(const char *name) {
3644 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3645   // This is only supported in Snow Leopard and beyond
3646   if (name != NULL) {
3647     // Add a "Java: " prefix to the name
3648     char buf[MAXTHREADNAMESIZE];
3649     snprintf(buf, sizeof(buf), "Java: %s", name);
3650     pthread_setname_np(buf);
3651   }
3652 #endif
3653 }
3654 
3655 bool os::distribute_processes(uint length, uint* distribution) {
3656   // Not yet implemented.
3657   return false;
3658 }
3659 
3660 bool os::bind_to_processor(uint processor_id) {
3661   // Not yet implemented.
3662   return false;
3663 }
3664 
3665 void os::SuspendedThreadTask::internal_do_task() {
3666   if (do_suspend(_thread->osthread())) {
3667     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3668     do_task(context);
3669     do_resume(_thread->osthread());
3670   }
3671 }
3672 
3673 ///
3674 class PcFetcher : public os::SuspendedThreadTask {
3675  public:
3676   PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3677   ExtendedPC result();
3678  protected:
3679   void do_task(const os::SuspendedThreadTaskContext& context);
3680  private:
3681   ExtendedPC _epc;
3682 };
3683 
3684 ExtendedPC PcFetcher::result() {
3685   guarantee(is_done(), "task is not done yet.");
3686   return _epc;
3687 }
3688 
3689 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3690   Thread* thread = context.thread();
3691   OSThread* osthread = thread->osthread();
3692   if (osthread->ucontext() != NULL) {
3693     _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
3694   } else {
3695     // NULL context is unexpected, double-check this is the VMThread
3696     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3697   }
3698 }
3699 
3700 // Suspends the target using the signal mechanism and then grabs the PC before
3701 // resuming the target. Used by the flat-profiler only
3702 ExtendedPC os::get_thread_pc(Thread* thread) {
3703   // Make sure that it is called by the watcher for the VMThread
3704   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3705   assert(thread->is_VM_thread(), "Can only be called for VMThread");
3706 
3707   PcFetcher fetcher(thread);
3708   fetcher.run();
3709   return fetcher.result();
3710 }
3711 
3712 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond,
3713                                  pthread_mutex_t *_mutex,
3714                                  const struct timespec *_abstime) {
3715   return pthread_cond_timedwait(_cond, _mutex, _abstime);
3716 }
3717 
3718 ////////////////////////////////////////////////////////////////////////////////
3719 // debug support
3720 
3721 bool os::find(address addr, outputStream* st) {
3722   Dl_info dlinfo;
3723   memset(&dlinfo, 0, sizeof(dlinfo));
3724   if (dladdr(addr, &dlinfo) != 0) {
3725     st->print(PTR_FORMAT ": ", addr);
3726     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3727       st->print("%s+%#x", dlinfo.dli_sname,
3728                 addr - (intptr_t)dlinfo.dli_saddr);
3729     } else if (dlinfo.dli_fbase != NULL) {
3730       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3731     } else {
3732       st->print("<absolute address>");
3733     }
3734     if (dlinfo.dli_fname != NULL) {
3735       st->print(" in %s", dlinfo.dli_fname);
3736     }
3737     if (dlinfo.dli_fbase != NULL) {
3738       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3739     }
3740     st->cr();
3741 
3742     if (Verbose) {
3743       // decode some bytes around the PC
3744       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3745       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3746       address       lowest = (address) dlinfo.dli_sname;
3747       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3748       if (begin < lowest)  begin = lowest;
3749       Dl_info dlinfo2;
3750       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3751           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3752         end = (address) dlinfo2.dli_saddr;
3753       }
3754       Disassembler::decode(begin, end, st);
3755     }
3756     return true;
3757   }
3758   return false;
3759 }
3760 
3761 ////////////////////////////////////////////////////////////////////////////////
3762 // misc
3763 
3764 // This does not do anything on Bsd. This is basically a hook for being
3765 // able to use structured exception handling (thread-local exception filters)
3766 // on, e.g., Win32.
3767 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3768                               methodHandle* method, JavaCallArguments* args,
3769                               Thread* thread) {
3770   f(value, method, args, thread);
3771 }
3772 
3773 void os::print_statistics() {
3774 }
3775 
3776 int os::message_box(const char* title, const char* message) {
3777   int i;
3778   fdStream err(defaultStream::error_fd());
3779   for (i = 0; i < 78; i++) err.print_raw("=");
3780   err.cr();
3781   err.print_raw_cr(title);
3782   for (i = 0; i < 78; i++) err.print_raw("-");
3783   err.cr();
3784   err.print_raw_cr(message);
3785   for (i = 0; i < 78; i++) err.print_raw("=");
3786   err.cr();
3787 
3788   char buf[16];
3789   // Prevent process from exiting upon "read error" without consuming all CPU
3790   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3791 
3792   return buf[0] == 'y' || buf[0] == 'Y';
3793 }
3794 
3795 int os::stat(const char *path, struct stat *sbuf) {
3796   char pathbuf[MAX_PATH];
3797   if (strlen(path) > MAX_PATH - 1) {
3798     errno = ENAMETOOLONG;
3799     return -1;
3800   }
3801   os::native_path(strcpy(pathbuf, path));
3802   return ::stat(pathbuf, sbuf);
3803 }
3804 
3805 bool os::check_heap(bool force) {
3806   return true;
3807 }
3808 
3809 // Is a (classpath) directory empty?
3810 bool os::dir_is_empty(const char* path) {
3811   DIR *dir = NULL;
3812   struct dirent *ptr;
3813 
3814   dir = opendir(path);
3815   if (dir == NULL) return true;
3816 
3817   // Scan the directory
3818   bool result = true;
3819   char buf[sizeof(struct dirent) + MAX_PATH];
3820   while (result && (ptr = ::readdir(dir)) != NULL) {
3821     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3822       result = false;
3823     }
3824   }
3825   closedir(dir);
3826   return result;
3827 }
3828 
3829 // This code originates from JDK's sysOpen and open64_w
3830 // from src/solaris/hpi/src/system_md.c
3831 
3832 int os::open(const char *path, int oflag, int mode) {
3833   if (strlen(path) > MAX_PATH - 1) {
3834     errno = ENAMETOOLONG;
3835     return -1;
3836   }
3837   int fd;
3838 
3839   fd = ::open(path, oflag, mode);
3840   if (fd == -1) return -1;
3841 
3842   // If the open succeeded, the file might still be a directory
3843   {
3844     struct stat buf;
3845     int ret = ::fstat(fd, &buf);
3846     int st_mode = buf.st_mode;
3847 
3848     if (ret != -1) {
3849       if ((st_mode & S_IFMT) == S_IFDIR) {
3850         errno = EISDIR;
3851         ::close(fd);
3852         return -1;
3853       }
3854     } else {
3855       ::close(fd);
3856       return -1;
3857     }
3858   }
3859 
3860   // All file descriptors that are opened in the JVM and not
3861   // specifically destined for a subprocess should have the
3862   // close-on-exec flag set.  If we don't set it, then careless 3rd
3863   // party native code might fork and exec without closing all
3864   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3865   // UNIXProcess.c), and this in turn might:
3866   //
3867   // - cause end-of-file to fail to be detected on some file
3868   //   descriptors, resulting in mysterious hangs, or
3869   //
3870   // - might cause an fopen in the subprocess to fail on a system
3871   //   suffering from bug 1085341.
3872   //
3873   // (Yes, the default setting of the close-on-exec flag is a Unix
3874   // design flaw)
3875   //
3876   // See:
3877   // 1085341: 32-bit stdio routines should support file descriptors >255
3878   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3879   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3880   //
3881 #ifdef FD_CLOEXEC
3882   {
3883     int flags = ::fcntl(fd, F_GETFD);
3884     if (flags != -1) {
3885       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3886     }
3887   }
3888 #endif
3889 
3890   return fd;
3891 }
3892 
3893 
3894 // create binary file, rewriting existing file if required
3895 int os::create_binary_file(const char* path, bool rewrite_existing) {
3896   int oflags = O_WRONLY | O_CREAT;
3897   if (!rewrite_existing) {
3898     oflags |= O_EXCL;
3899   }
3900   return ::open(path, oflags, S_IREAD | S_IWRITE);
3901 }
3902 
3903 // return current position of file pointer
3904 jlong os::current_file_offset(int fd) {
3905   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3906 }
3907 
3908 // move file pointer to the specified offset
3909 jlong os::seek_to_file_offset(int fd, jlong offset) {
3910   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3911 }
3912 
3913 // This code originates from JDK's sysAvailable
3914 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3915 
3916 int os::available(int fd, jlong *bytes) {
3917   jlong cur, end;
3918   int mode;
3919   struct stat buf;
3920 
3921   if (::fstat(fd, &buf) >= 0) {
3922     mode = buf.st_mode;
3923     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3924       // XXX: is the following call interruptible? If so, this might
3925       // need to go through the INTERRUPT_IO() wrapper as for other
3926       // blocking, interruptible calls in this file.
3927       int n;
3928       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3929         *bytes = n;
3930         return 1;
3931       }
3932     }
3933   }
3934   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3935     return 0;
3936   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3937     return 0;
3938   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3939     return 0;
3940   }
3941   *bytes = end - cur;
3942   return 1;
3943 }
3944 
3945 // Map a block of memory.
3946 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3947                         char *addr, size_t bytes, bool read_only,
3948                         bool allow_exec) {
3949   int prot;
3950   int flags;
3951 
3952   if (read_only) {
3953     prot = PROT_READ;
3954     flags = MAP_SHARED;
3955   } else {
3956     prot = PROT_READ | PROT_WRITE;
3957     flags = MAP_PRIVATE;
3958   }
3959 
3960   if (allow_exec) {
3961     prot |= PROT_EXEC;
3962   }
3963 
3964   if (addr != NULL) {
3965     flags |= MAP_FIXED;
3966   }
3967 
3968   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3969                                      fd, file_offset);
3970   if (mapped_address == MAP_FAILED) {
3971     return NULL;
3972   }
3973   return mapped_address;
3974 }
3975 
3976 
3977 // Remap a block of memory.
3978 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3979                           char *addr, size_t bytes, bool read_only,
3980                           bool allow_exec) {
3981   // same as map_memory() on this OS
3982   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3983                         allow_exec);
3984 }
3985 
3986 
3987 // Unmap a block of memory.
3988 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3989   return munmap(addr, bytes) == 0;
3990 }
3991 
3992 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3993 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3994 // of a thread.
3995 //
3996 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3997 // the fast estimate available on the platform.
3998 
3999 jlong os::current_thread_cpu_time() {
4000 #ifdef __APPLE__
4001   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
4002 #else
4003   Unimplemented();
4004   return 0;
4005 #endif
4006 }
4007 
4008 jlong os::thread_cpu_time(Thread* thread) {
4009 #ifdef __APPLE__
4010   return os::thread_cpu_time(thread, true /* user + sys */);
4011 #else
4012   Unimplemented();
4013   return 0;
4014 #endif
4015 }
4016 
4017 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4018 #ifdef __APPLE__
4019   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4020 #else
4021   Unimplemented();
4022   return 0;
4023 #endif
4024 }
4025 
4026 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4027 #ifdef __APPLE__
4028   struct thread_basic_info tinfo;
4029   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
4030   kern_return_t kr;
4031   thread_t mach_thread;
4032 
4033   mach_thread = thread->osthread()->thread_id();
4034   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
4035   if (kr != KERN_SUCCESS) {
4036     return -1;
4037   }
4038 
4039   if (user_sys_cpu_time) {
4040     jlong nanos;
4041     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4042     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4043     return nanos;
4044   } else {
4045     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4046   }
4047 #else
4048   Unimplemented();
4049   return 0;
4050 #endif
4051 }
4052 
4053 
4054 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4055   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4056   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4057   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4058   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4059 }
4060 
4061 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4062   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4063   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4064   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4065   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4066 }
4067 
4068 bool os::is_thread_cpu_time_supported() {
4069 #ifdef __APPLE__
4070   return true;
4071 #else
4072   return false;
4073 #endif
4074 }
4075 
4076 // System loadavg support.  Returns -1 if load average cannot be obtained.
4077 // Bsd doesn't yet have a (official) notion of processor sets,
4078 // so just return the system wide load average.
4079 int os::loadavg(double loadavg[], int nelem) {
4080   return ::getloadavg(loadavg, nelem);
4081 }
4082 
4083 void os::pause() {
4084   char filename[MAX_PATH];
4085   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4086     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4087   } else {
4088     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4089   }
4090 
4091   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4092   if (fd != -1) {
4093     struct stat buf;
4094     ::close(fd);
4095     while (::stat(filename, &buf) == 0) {
4096       (void)::poll(NULL, 0, 100);
4097     }
4098   } else {
4099     jio_fprintf(stderr,
4100                 "Could not open pause file '%s', continuing immediately.\n", filename);
4101   }
4102 }
4103 
4104 
4105 // Refer to the comments in os_solaris.cpp park-unpark. The next two
4106 // comment paragraphs are worth repeating here:
4107 //
4108 // Assumption:
4109 //    Only one parker can exist on an event, which is why we allocate
4110 //    them per-thread. Multiple unparkers can coexist.
4111 //
4112 // _Event serves as a restricted-range semaphore.
4113 //   -1 : thread is blocked, i.e. there is a waiter
4114 //    0 : neutral: thread is running or ready,
4115 //        could have been signaled after a wait started
4116 //    1 : signaled - thread is running or ready
4117 //
4118 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4119 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4120 // For specifics regarding the bug see GLIBC BUGID 261237 :
4121 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4122 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4123 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4124 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
4125 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4126 // and monitorenter when we're using 1-0 locking.  All those operations may result in
4127 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
4128 // of libpthread avoids the problem, but isn't practical.
4129 //
4130 // Possible remedies:
4131 //
4132 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
4133 //      This is palliative and probabilistic, however.  If the thread is preempted
4134 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
4135 //      than the minimum period may have passed, and the abstime may be stale (in the
4136 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
4137 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
4138 //
4139 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4140 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
4141 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4142 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
4143 //      thread.
4144 //
4145 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
4146 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
4147 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
4148 //      This also works well.  In fact it avoids kernel-level scalability impediments
4149 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
4150 //      timers in a graceful fashion.
4151 //
4152 // 4.   When the abstime value is in the past it appears that control returns
4153 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4154 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
4155 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
4156 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
4157 //      It may be possible to avoid reinitialization by checking the return
4158 //      value from pthread_cond_timedwait().  In addition to reinitializing the
4159 //      condvar we must establish the invariant that cond_signal() is only called
4160 //      within critical sections protected by the adjunct mutex.  This prevents
4161 //      cond_signal() from "seeing" a condvar that's in the midst of being
4162 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
4163 //      desirable signal-after-unlock optimization that avoids futile context switching.
4164 //
4165 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
4166 //      structure when a condvar is used or initialized.  cond_destroy()  would
4167 //      release the helper structure.  Our reinitialize-after-timedwait fix
4168 //      put excessive stress on malloc/free and locks protecting the c-heap.
4169 //
4170 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
4171 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4172 // and only enabling the work-around for vulnerable environments.
4173 
4174 // utility to compute the abstime argument to timedwait:
4175 // millis is the relative timeout time
4176 // abstime will be the absolute timeout time
4177 // TODO: replace compute_abstime() with unpackTime()
4178 
4179 static struct timespec* compute_abstime(struct timespec* abstime,
4180                                         jlong millis) {
4181   if (millis < 0)  millis = 0;
4182   struct timeval now;
4183   int status = gettimeofday(&now, NULL);
4184   assert(status == 0, "gettimeofday");
4185   jlong seconds = millis / 1000;
4186   millis %= 1000;
4187   if (seconds > 50000000) { // see man cond_timedwait(3T)
4188     seconds = 50000000;
4189   }
4190   abstime->tv_sec = now.tv_sec  + seconds;
4191   long       usec = now.tv_usec + millis * 1000;
4192   if (usec >= 1000000) {
4193     abstime->tv_sec += 1;
4194     usec -= 1000000;
4195   }
4196   abstime->tv_nsec = usec * 1000;
4197   return abstime;
4198 }
4199 
4200 void os::PlatformEvent::park() {       // AKA "down()"
4201   // Transitions for _Event:
4202   //   -1 => -1 : illegal
4203   //    1 =>  0 : pass - return immediately
4204   //    0 => -1 : block; then set _Event to 0 before returning
4205 
4206   // Invariant: Only the thread associated with the Event/PlatformEvent
4207   // may call park().
4208   // TODO: assert that _Assoc != NULL or _Assoc == Self
4209   assert(_nParked == 0, "invariant");
4210 
4211   int v;
4212   for (;;) {
4213     v = _Event;
4214     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4215   }
4216   guarantee(v >= 0, "invariant");
4217   if (v == 0) {
4218     // Do this the hard way by blocking ...
4219     int status = pthread_mutex_lock(_mutex);
4220     assert_status(status == 0, status, "mutex_lock");
4221     guarantee(_nParked == 0, "invariant");
4222     ++_nParked;
4223     while (_Event < 0) {
4224       status = pthread_cond_wait(_cond, _mutex);
4225       // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4226       // Treat this the same as if the wait was interrupted
4227       if (status == ETIMEDOUT) { status = EINTR; }
4228       assert_status(status == 0 || status == EINTR, status, "cond_wait");
4229     }
4230     --_nParked;
4231 
4232     _Event = 0;
4233     status = pthread_mutex_unlock(_mutex);
4234     assert_status(status == 0, status, "mutex_unlock");
4235     // Paranoia to ensure our locked and lock-free paths interact
4236     // correctly with each other.
4237     OrderAccess::fence();
4238   }
4239   guarantee(_Event >= 0, "invariant");
4240 }
4241 
4242 int os::PlatformEvent::park(jlong millis) {
4243   // Transitions for _Event:
4244   //   -1 => -1 : illegal
4245   //    1 =>  0 : pass - return immediately
4246   //    0 => -1 : block; then set _Event to 0 before returning
4247 
4248   guarantee(_nParked == 0, "invariant");
4249 
4250   int v;
4251   for (;;) {
4252     v = _Event;
4253     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4254   }
4255   guarantee(v >= 0, "invariant");
4256   if (v != 0) return OS_OK;
4257 
4258   // We do this the hard way, by blocking the thread.
4259   // Consider enforcing a minimum timeout value.
4260   struct timespec abst;
4261   compute_abstime(&abst, millis);
4262 
4263   int ret = OS_TIMEOUT;
4264   int status = pthread_mutex_lock(_mutex);
4265   assert_status(status == 0, status, "mutex_lock");
4266   guarantee(_nParked == 0, "invariant");
4267   ++_nParked;
4268 
4269   // Object.wait(timo) will return because of
4270   // (a) notification
4271   // (b) timeout
4272   // (c) thread.interrupt
4273   //
4274   // Thread.interrupt and object.notify{All} both call Event::set.
4275   // That is, we treat thread.interrupt as a special case of notification.
4276   // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false.
4277   // We assume all ETIME returns are valid.
4278   //
4279   // TODO: properly differentiate simultaneous notify+interrupt.
4280   // In that case, we should propagate the notify to another waiter.
4281 
4282   while (_Event < 0) {
4283     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4284     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4285       pthread_cond_destroy(_cond);
4286       pthread_cond_init(_cond, NULL);
4287     }
4288     assert_status(status == 0 || status == EINTR ||
4289                   status == ETIMEDOUT,
4290                   status, "cond_timedwait");
4291     if (!FilterSpuriousWakeups) break;                 // previous semantics
4292     if (status == ETIMEDOUT) break;
4293     // We consume and ignore EINTR and spurious wakeups.
4294   }
4295   --_nParked;
4296   if (_Event >= 0) {
4297     ret = OS_OK;
4298   }
4299   _Event = 0;
4300   status = pthread_mutex_unlock(_mutex);
4301   assert_status(status == 0, status, "mutex_unlock");
4302   assert(_nParked == 0, "invariant");
4303   // Paranoia to ensure our locked and lock-free paths interact
4304   // correctly with each other.
4305   OrderAccess::fence();
4306   return ret;
4307 }
4308 
4309 void os::PlatformEvent::unpark() {
4310   // Transitions for _Event:
4311   //    0 => 1 : just return
4312   //    1 => 1 : just return
4313   //   -1 => either 0 or 1; must signal target thread
4314   //         That is, we can safely transition _Event from -1 to either
4315   //         0 or 1.
4316   // See also: "Semaphores in Plan 9" by Mullender & Cox
4317   //
4318   // Note: Forcing a transition from "-1" to "1" on an unpark() means
4319   // that it will take two back-to-back park() calls for the owning
4320   // thread to block. This has the benefit of forcing a spurious return
4321   // from the first park() call after an unpark() call which will help
4322   // shake out uses of park() and unpark() without condition variables.
4323 
4324   if (Atomic::xchg(1, &_Event) >= 0) return;
4325 
4326   // Wait for the thread associated with the event to vacate
4327   int status = pthread_mutex_lock(_mutex);
4328   assert_status(status == 0, status, "mutex_lock");
4329   int AnyWaiters = _nParked;
4330   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4331   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4332     AnyWaiters = 0;
4333     pthread_cond_signal(_cond);
4334   }
4335   status = pthread_mutex_unlock(_mutex);
4336   assert_status(status == 0, status, "mutex_unlock");
4337   if (AnyWaiters != 0) {
4338     // Note that we signal() *after* dropping the lock for "immortal" Events.
4339     // This is safe and avoids a common class of  futile wakeups.  In rare
4340     // circumstances this can cause a thread to return prematurely from
4341     // cond_{timed}wait() but the spurious wakeup is benign and the victim
4342     // will simply re-test the condition and re-park itself.
4343     // This provides particular benefit if the underlying platform does not
4344     // provide wait morphing.
4345     status = pthread_cond_signal(_cond);
4346     assert_status(status == 0, status, "cond_signal");
4347   }
4348 }
4349 
4350 
4351 // JSR166
4352 // -------------------------------------------------------
4353 
4354 // The solaris and bsd implementations of park/unpark are fairly
4355 // conservative for now, but can be improved. They currently use a
4356 // mutex/condvar pair, plus a a count.
4357 // Park decrements count if > 0, else does a condvar wait.  Unpark
4358 // sets count to 1 and signals condvar.  Only one thread ever waits
4359 // on the condvar. Contention seen when trying to park implies that someone
4360 // is unparking you, so don't wait. And spurious returns are fine, so there
4361 // is no need to track notifications.
4362 
4363 #define MAX_SECS 100000000
4364 
4365 // This code is common to bsd and solaris and will be moved to a
4366 // common place in dolphin.
4367 //
4368 // The passed in time value is either a relative time in nanoseconds
4369 // or an absolute time in milliseconds. Either way it has to be unpacked
4370 // into suitable seconds and nanoseconds components and stored in the
4371 // given timespec structure.
4372 // Given time is a 64-bit value and the time_t used in the timespec is only
4373 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4374 // overflow if times way in the future are given. Further on Solaris versions
4375 // prior to 10 there is a restriction (see cond_timedwait) that the specified
4376 // number of seconds, in abstime, is less than current_time  + 100,000,000.
4377 // As it will be 28 years before "now + 100000000" will overflow we can
4378 // ignore overflow and just impose a hard-limit on seconds using the value
4379 // of "now + 100,000,000". This places a limit on the timeout of about 3.17
4380 // years from "now".
4381 
4382 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4383   assert(time > 0, "convertTime");
4384 
4385   struct timeval now;
4386   int status = gettimeofday(&now, NULL);
4387   assert(status == 0, "gettimeofday");
4388 
4389   time_t max_secs = now.tv_sec + MAX_SECS;
4390 
4391   if (isAbsolute) {
4392     jlong secs = time / 1000;
4393     if (secs > max_secs) {
4394       absTime->tv_sec = max_secs;
4395     } else {
4396       absTime->tv_sec = secs;
4397     }
4398     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4399   } else {
4400     jlong secs = time / NANOSECS_PER_SEC;
4401     if (secs >= MAX_SECS) {
4402       absTime->tv_sec = max_secs;
4403       absTime->tv_nsec = 0;
4404     } else {
4405       absTime->tv_sec = now.tv_sec + secs;
4406       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4407       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4408         absTime->tv_nsec -= NANOSECS_PER_SEC;
4409         ++absTime->tv_sec; // note: this must be <= max_secs
4410       }
4411     }
4412   }
4413   assert(absTime->tv_sec >= 0, "tv_sec < 0");
4414   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4415   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4416   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4417 }
4418 
4419 void Parker::park(bool isAbsolute, jlong time) {
4420   // Ideally we'd do something useful while spinning, such
4421   // as calling unpackTime().
4422 
4423   // Optional fast-path check:
4424   // Return immediately if a permit is available.
4425   // We depend on Atomic::xchg() having full barrier semantics
4426   // since we are doing a lock-free update to _counter.
4427   if (Atomic::xchg(0, &_counter) > 0) return;
4428 
4429   Thread* thread = Thread::current();
4430   assert(thread->is_Java_thread(), "Must be JavaThread");
4431   JavaThread *jt = (JavaThread *)thread;
4432 
4433   // Optional optimization -- avoid state transitions if there's an interrupt pending.
4434   // Check interrupt before trying to wait
4435   if (Thread::is_interrupted(thread, false)) {
4436     return;
4437   }
4438 
4439   // Next, demultiplex/decode time arguments
4440   struct timespec absTime;
4441   if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
4442     return;
4443   }
4444   if (time > 0) {
4445     unpackTime(&absTime, isAbsolute, time);
4446   }
4447 
4448 
4449   // Enter safepoint region
4450   // Beware of deadlocks such as 6317397.
4451   // The per-thread Parker:: mutex is a classic leaf-lock.
4452   // In particular a thread must never block on the Threads_lock while
4453   // holding the Parker:: mutex.  If safepoints are pending both the
4454   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4455   ThreadBlockInVM tbivm(jt);
4456 
4457   // Don't wait if cannot get lock since interference arises from
4458   // unblocking.  Also. check interrupt before trying wait
4459   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4460     return;
4461   }
4462 
4463   int status;
4464   if (_counter > 0)  { // no wait needed
4465     _counter = 0;
4466     status = pthread_mutex_unlock(_mutex);
4467     assert(status == 0, "invariant");
4468     // Paranoia to ensure our locked and lock-free paths interact
4469     // correctly with each other and Java-level accesses.
4470     OrderAccess::fence();
4471     return;
4472   }
4473 
4474 #ifdef ASSERT
4475   // Don't catch signals while blocked; let the running threads have the signals.
4476   // (This allows a debugger to break into the running thread.)
4477   sigset_t oldsigs;
4478   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4479   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4480 #endif
4481 
4482   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4483   jt->set_suspend_equivalent();
4484   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4485 
4486   if (time == 0) {
4487     status = pthread_cond_wait(_cond, _mutex);
4488   } else {
4489     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &absTime);
4490     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4491       pthread_cond_destroy(_cond);
4492       pthread_cond_init(_cond, NULL);
4493     }
4494   }
4495   assert_status(status == 0 || status == EINTR ||
4496                 status == ETIMEDOUT,
4497                 status, "cond_timedwait");
4498 
4499 #ifdef ASSERT
4500   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4501 #endif
4502 
4503   _counter = 0;
4504   status = pthread_mutex_unlock(_mutex);
4505   assert_status(status == 0, status, "invariant");
4506   // Paranoia to ensure our locked and lock-free paths interact
4507   // correctly with each other and Java-level accesses.
4508   OrderAccess::fence();
4509 
4510   // If externally suspended while waiting, re-suspend
4511   if (jt->handle_special_suspend_equivalent_condition()) {
4512     jt->java_suspend_self();
4513   }
4514 }
4515 
4516 void Parker::unpark() {
4517   int status = pthread_mutex_lock(_mutex);
4518   assert(status == 0, "invariant");
4519   const int s = _counter;
4520   _counter = 1;
4521   if (s < 1) {
4522     if (WorkAroundNPTLTimedWaitHang) {
4523       status = pthread_cond_signal(_cond);
4524       assert(status == 0, "invariant");
4525       status = pthread_mutex_unlock(_mutex);
4526       assert(status == 0, "invariant");
4527     } else {
4528       status = pthread_mutex_unlock(_mutex);
4529       assert(status == 0, "invariant");
4530       status = pthread_cond_signal(_cond);
4531       assert(status == 0, "invariant");
4532     }
4533   } else {
4534     pthread_mutex_unlock(_mutex);
4535     assert(status == 0, "invariant");
4536   }
4537 }
4538 
4539 
4540 // Darwin has no "environ" in a dynamic library.
4541 #ifdef __APPLE__
4542   #include <crt_externs.h>
4543   #define environ (*_NSGetEnviron())
4544 #else
4545 extern char** environ;
4546 #endif
4547 
4548 // Run the specified command in a separate process. Return its exit value,
4549 // or -1 on failure (e.g. can't fork a new process).
4550 // Unlike system(), this function can be called from signal handler. It
4551 // doesn't block SIGINT et al.
4552 int os::fork_and_exec(char* cmd) {
4553   const char * argv[4] = {"sh", "-c", cmd, NULL};
4554 
4555   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4556   // pthread_atfork handlers and reset pthread library. All we need is a
4557   // separate process to execve. Make a direct syscall to fork process.
4558   // On IA64 there's no fork syscall, we have to use fork() and hope for
4559   // the best...
4560   pid_t pid = fork();
4561 
4562   if (pid < 0) {
4563     // fork failed
4564     return -1;
4565 
4566   } else if (pid == 0) {
4567     // child process
4568 
4569     // execve() in BsdThreads will call pthread_kill_other_threads_np()
4570     // first to kill every thread on the thread list. Because this list is
4571     // not reset by fork() (see notes above), execve() will instead kill
4572     // every thread in the parent process. We know this is the only thread
4573     // in the new process, so make a system call directly.
4574     // IA64 should use normal execve() from glibc to match the glibc fork()
4575     // above.
4576     execve("/bin/sh", (char* const*)argv, environ);
4577 
4578     // execve failed
4579     _exit(-1);
4580 
4581   } else  {
4582     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4583     // care about the actual exit code, for now.
4584 
4585     int status;
4586 
4587     // Wait for the child process to exit.  This returns immediately if
4588     // the child has already exited. */
4589     while (waitpid(pid, &status, 0) < 0) {
4590       switch (errno) {
4591       case ECHILD: return 0;
4592       case EINTR: break;
4593       default: return -1;
4594       }
4595     }
4596 
4597     if (WIFEXITED(status)) {
4598       // The child exited normally; get its exit code.
4599       return WEXITSTATUS(status);
4600     } else if (WIFSIGNALED(status)) {
4601       // The child exited because of a signal
4602       // The best value to return is 0x80 + signal number,
4603       // because that is what all Unix shells do, and because
4604       // it allows callers to distinguish between process exit and
4605       // process death by signal.
4606       return 0x80 + WTERMSIG(status);
4607     } else {
4608       // Unknown exit code; pass it through
4609       return status;
4610     }
4611   }
4612 }
4613 
4614 // is_headless_jre()
4615 //
4616 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4617 // in order to report if we are running in a headless jre
4618 //
4619 // Since JDK8 xawt/libmawt.so was moved into the same directory
4620 // as libawt.so, and renamed libawt_xawt.so
4621 //
4622 bool os::is_headless_jre() {
4623 #ifdef __APPLE__
4624   // We no longer build headless-only on Mac OS X
4625   return false;
4626 #else
4627   struct stat statbuf;
4628   char buf[MAXPATHLEN];
4629   char libmawtpath[MAXPATHLEN];
4630   const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
4631   const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4632   char *p;
4633 
4634   // Get path to libjvm.so
4635   os::jvm_path(buf, sizeof(buf));
4636 
4637   // Get rid of libjvm.so
4638   p = strrchr(buf, '/');
4639   if (p == NULL) {
4640     return false;
4641   } else {
4642     *p = '\0';
4643   }
4644 
4645   // Get rid of client or server
4646   p = strrchr(buf, '/');
4647   if (p == NULL) {
4648     return false;
4649   } else {
4650     *p = '\0';
4651   }
4652 
4653   // check xawt/libmawt.so
4654   strcpy(libmawtpath, buf);
4655   strcat(libmawtpath, xawtstr);
4656   if (::stat(libmawtpath, &statbuf) == 0) return false;
4657 
4658   // check libawt_xawt.so
4659   strcpy(libmawtpath, buf);
4660   strcat(libmawtpath, new_xawtstr);
4661   if (::stat(libmawtpath, &statbuf) == 0) return false;
4662 
4663   return true;
4664 #endif
4665 }
4666 
4667 // Get the default path to the core file
4668 // Returns the length of the string
4669 int os::get_core_path(char* buffer, size_t bufferSize) {
4670   int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
4671 
4672   // Truncate if theoretical string was longer than bufferSize
4673   n = MIN2(n, (int)bufferSize);
4674 
4675   return n;
4676 }
4677 
4678 #ifndef PRODUCT
4679 void TestReserveMemorySpecial_test() {
4680   // No tests available for this platform
4681 }
4682 #endif