1 /*
   2  * Copyright (c) 1999, 2014, 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 ////////////////////////////////////////////////////////////////////////////////
 194 // environment support
 195 
 196 bool os::getenv(const char* name, char* buf, int len) {
 197   const char* val = ::getenv(name);
 198   if (val != NULL && strlen(val) < (size_t)len) {
 199     strcpy(buf, val);
 200     return true;
 201   }
 202   if (len > 0) buf[0] = 0;  // return a null string
 203   return false;
 204 }
 205 
 206 
 207 // Return true if user is running as root.
 208 
 209 bool os::have_special_privileges() {
 210   static bool init = false;
 211   static bool privileges = false;
 212   if (!init) {
 213     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 214     init = true;
 215   }
 216   return privileges;
 217 }
 218 
 219 
 220 
 221 // Cpu architecture string
 222 #if   defined(ZERO)
 223 static char cpu_arch[] = ZERO_LIBARCH;
 224 #elif defined(IA64)
 225 static char cpu_arch[] = "ia64";
 226 #elif defined(IA32)
 227 static char cpu_arch[] = "i386";
 228 #elif defined(AMD64)
 229 static char cpu_arch[] = "amd64";
 230 #elif defined(ARM)
 231 static char cpu_arch[] = "arm";
 232 #elif defined(PPC32)
 233 static char cpu_arch[] = "ppc";
 234 #elif defined(SPARC)
 235   #ifdef _LP64
 236 static char cpu_arch[] = "sparcv9";
 237   #else
 238 static char cpu_arch[] = "sparc";
 239   #endif
 240 #else
 241   #error Add appropriate cpu_arch setting
 242 #endif
 243 
 244 // Compiler variant
 245 #ifdef COMPILER2
 246   #define COMPILER_VARIANT "server"
 247 #else
 248   #define COMPILER_VARIANT "client"
 249 #endif
 250 
 251 
 252 void os::Bsd::initialize_system_info() {
 253   int mib[2];
 254   size_t len;
 255   int cpu_val;
 256   julong mem_val;
 257 
 258   // get processors count via hw.ncpus sysctl
 259   mib[0] = CTL_HW;
 260   mib[1] = HW_NCPU;
 261   len = sizeof(cpu_val);
 262   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 263     assert(len == sizeof(cpu_val), "unexpected data size");
 264     set_processor_count(cpu_val);
 265   } else {
 266     set_processor_count(1);   // fallback
 267   }
 268 
 269   // get physical memory via hw.memsize sysctl (hw.memsize is used
 270   // since it returns a 64 bit value)
 271   mib[0] = CTL_HW;
 272 
 273 #if defined (HW_MEMSIZE) // Apple
 274   mib[1] = HW_MEMSIZE;
 275 #elif defined(HW_PHYSMEM) // Most of BSD
 276   mib[1] = HW_PHYSMEM;
 277 #elif defined(HW_REALMEM) // Old FreeBSD
 278   mib[1] = HW_REALMEM;
 279 #else
 280   #error No ways to get physmem
 281 #endif
 282 
 283   len = sizeof(mem_val);
 284   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 285     assert(len == sizeof(mem_val), "unexpected data size");
 286     _physical_memory = mem_val;
 287   } else {
 288     _physical_memory = 256 * 1024 * 1024;       // fallback (XXXBSD?)
 289   }
 290 
 291 #ifdef __OpenBSD__
 292   {
 293     // limit _physical_memory memory view on OpenBSD since
 294     // datasize rlimit restricts us anyway.
 295     struct rlimit limits;
 296     getrlimit(RLIMIT_DATA, &limits);
 297     _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 298   }
 299 #endif
 300 }
 301 
 302 #ifdef __APPLE__
 303 static const char *get_home() {
 304   const char *home_dir = ::getenv("HOME");
 305   if ((home_dir == NULL) || (*home_dir == '\0')) {
 306     struct passwd *passwd_info = getpwuid(geteuid());
 307     if (passwd_info != NULL) {
 308       home_dir = passwd_info->pw_dir;
 309     }
 310   }
 311 
 312   return home_dir;
 313 }
 314 #endif
 315 
 316 void os::init_system_properties_values() {
 317   // The next steps are taken in the product version:
 318   //
 319   // Obtain the JAVA_HOME value from the location of libjvm.so.
 320   // This library should be located at:
 321   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 322   //
 323   // If "/jre/lib/" appears at the right place in the path, then we
 324   // assume libjvm.so is installed in a JDK and we use this path.
 325   //
 326   // Otherwise exit with message: "Could not create the Java virtual machine."
 327   //
 328   // The following extra steps are taken in the debugging version:
 329   //
 330   // If "/jre/lib/" does NOT appear at the right place in the path
 331   // instead of exit check for $JAVA_HOME environment variable.
 332   //
 333   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 334   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 335   // it looks like libjvm.so is installed there
 336   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 337   //
 338   // Otherwise exit.
 339   //
 340   // Important note: if the location of libjvm.so changes this
 341   // code needs to be changed accordingly.
 342 
 343   // See ld(1):
 344   //      The linker uses the following search paths to locate required
 345   //      shared libraries:
 346   //        1: ...
 347   //        ...
 348   //        7: The default directories, normally /lib and /usr/lib.
 349 #ifndef DEFAULT_LIBPATH
 350   #define DEFAULT_LIBPATH "/lib:/usr/lib"
 351 #endif
 352 
 353 // Base path of extensions installed on the system.
 354 #define SYS_EXT_DIR     "/usr/java/packages"
 355 #define EXTENSIONS_DIR  "/lib/ext"
 356 
 357 #ifndef __APPLE__
 358 
 359   // Buffer that fits several sprintfs.
 360   // Note that the space for the colon and the trailing null are provided
 361   // by the nulls included by the sizeof operator.
 362   const size_t bufsize =
 363     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 364          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
 365   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 366 
 367   // sysclasspath, java_home, dll_dir
 368   {
 369     char *pslash;
 370     os::jvm_path(buf, bufsize);
 371 
 372     // Found the full path to libjvm.so.
 373     // Now cut the path to <java_home>/jre if we can.
 374     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 375     pslash = strrchr(buf, '/');
 376     if (pslash != NULL) {
 377       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 378     }
 379     Arguments::set_dll_dir(buf);
 380 
 381     if (pslash != NULL) {
 382       pslash = strrchr(buf, '/');
 383       if (pslash != NULL) {
 384         *pslash = '\0';          // Get rid of /<arch>.
 385         pslash = strrchr(buf, '/');
 386         if (pslash != NULL) {
 387           *pslash = '\0';        // Get rid of /lib.
 388         }
 389       }
 390     }
 391     Arguments::set_java_home(buf);
 392     set_boot_path('/', ':');
 393   }
 394 
 395   // Where to look for native libraries.
 396   //
 397   // Note: Due to a legacy implementation, most of the library path
 398   // is set in the launcher. This was to accomodate linking restrictions
 399   // on legacy Bsd implementations (which are no longer supported).
 400   // Eventually, all the library path setting will be done here.
 401   //
 402   // However, to prevent the proliferation of improperly built native
 403   // libraries, the new path component /usr/java/packages is added here.
 404   // Eventually, all the library path setting will be done here.
 405   {
 406     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 407     // should always exist (until the legacy problem cited above is
 408     // addressed).
 409     const char *v = ::getenv("LD_LIBRARY_PATH");
 410     const char *v_colon = ":";
 411     if (v == NULL) { v = ""; v_colon = ""; }
 412     // That's +1 for the colon and +1 for the trailing '\0'.
 413     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 414                                                      strlen(v) + 1 +
 415                                                      sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
 416                                                      mtInternal);
 417     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
 418     Arguments::set_library_path(ld_library_path);
 419     FREE_C_HEAP_ARRAY(char, ld_library_path);
 420   }
 421 
 422   // Extensions directories.
 423   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
 424   Arguments::set_ext_dirs(buf);
 425 
 426   FREE_C_HEAP_ARRAY(char, buf);
 427 
 428 #else // __APPLE__
 429 
 430   #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 431   #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 432 
 433   const char *user_home_dir = get_home();
 434   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
 435   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 436     sizeof(SYS_EXTENSIONS_DIRS);
 437 
 438   // Buffer that fits several sprintfs.
 439   // Note that the space for the colon and the trailing null are provided
 440   // by the nulls included by the sizeof operator.
 441   const size_t bufsize =
 442     MAX2((size_t)MAXPATHLEN,  // for dll_dir & friends.
 443          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
 444   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 445 
 446   // sysclasspath, java_home, dll_dir
 447   {
 448     char *pslash;
 449     os::jvm_path(buf, bufsize);
 450 
 451     // Found the full path to libjvm.so.
 452     // Now cut the path to <java_home>/jre if we can.
 453     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 454     pslash = strrchr(buf, '/');
 455     if (pslash != NULL) {
 456       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 457     }
 458     Arguments::set_dll_dir(buf);
 459 
 460     if (pslash != NULL) {
 461       pslash = strrchr(buf, '/');
 462       if (pslash != NULL) {
 463         *pslash = '\0';          // Get rid of /lib.
 464       }
 465     }
 466     Arguments::set_java_home(buf);
 467     set_boot_path('/', ':');
 468   }
 469 
 470   // Where to look for native libraries.
 471   //
 472   // Note: Due to a legacy implementation, most of the library path
 473   // is set in the launcher. This was to accomodate linking restrictions
 474   // on legacy Bsd implementations (which are no longer supported).
 475   // Eventually, all the library path setting will be done here.
 476   //
 477   // However, to prevent the proliferation of improperly built native
 478   // libraries, the new path component /usr/java/packages is added here.
 479   // Eventually, all the library path setting will be done here.
 480   {
 481     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 482     // should always exist (until the legacy problem cited above is
 483     // addressed).
 484     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
 485     // can specify a directory inside an app wrapper
 486     const char *l = ::getenv("JAVA_LIBRARY_PATH");
 487     const char *l_colon = ":";
 488     if (l == NULL) { l = ""; l_colon = ""; }
 489 
 490     const char *v = ::getenv("DYLD_LIBRARY_PATH");
 491     const char *v_colon = ":";
 492     if (v == NULL) { v = ""; v_colon = ""; }
 493 
 494     // Apple's Java6 has "." at the beginning of java.library.path.
 495     // OpenJDK on Windows has "." at the end of java.library.path.
 496     // OpenJDK on Linux and Solaris don't have "." in java.library.path
 497     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 498     // "." is appended to the end of java.library.path. Yes, this
 499     // could cause a change in behavior, but Apple's Java6 behavior
 500     // can be achieved by putting "." at the beginning of the
 501     // JAVA_LIBRARY_PATH environment variable.
 502     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 503                                                      strlen(v) + 1 + strlen(l) + 1 +
 504                                                      system_ext_size + 3,
 505                                                      mtInternal);
 506     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
 507             v, v_colon, l, l_colon, user_home_dir);
 508     Arguments::set_library_path(ld_library_path);
 509     FREE_C_HEAP_ARRAY(char, ld_library_path);
 510   }
 511 
 512   // Extensions directories.
 513   //
 514   // Note that the space for the colon and the trailing null are provided
 515   // by the nulls included by the sizeof operator (so actually one byte more
 516   // than necessary is allocated).
 517   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
 518           user_home_dir, Arguments::get_java_home());
 519   Arguments::set_ext_dirs(buf);
 520 
 521   FREE_C_HEAP_ARRAY(char, buf);
 522 
 523 #undef SYS_EXTENSIONS_DIR
 524 #undef SYS_EXTENSIONS_DIRS
 525 
 526 #endif // __APPLE__
 527 
 528 #undef SYS_EXT_DIR
 529 #undef EXTENSIONS_DIR
 530 }
 531 
 532 ////////////////////////////////////////////////////////////////////////////////
 533 // breakpoint support
 534 
 535 void os::breakpoint() {
 536   BREAKPOINT;
 537 }
 538 
 539 extern "C" void breakpoint() {
 540   // use debugger to set breakpoint here
 541 }
 542 
 543 ////////////////////////////////////////////////////////////////////////////////
 544 // signal support
 545 
 546 debug_only(static bool signal_sets_initialized = false);
 547 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
 548 
 549 bool os::Bsd::is_sig_ignored(int sig) {
 550   struct sigaction oact;
 551   sigaction(sig, (struct sigaction*)NULL, &oact);
 552   void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
 553                                  : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
 554   if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
 555     return true;
 556   } else {
 557     return false;
 558   }
 559 }
 560 
 561 void os::Bsd::signal_sets_init() {
 562   // Should also have an assertion stating we are still single-threaded.
 563   assert(!signal_sets_initialized, "Already initialized");
 564   // Fill in signals that are necessarily unblocked for all threads in
 565   // the VM. Currently, we unblock the following signals:
 566   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 567   //                         by -Xrs (=ReduceSignalUsage));
 568   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 569   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 570   // the dispositions or masks wrt these signals.
 571   // Programs embedding the VM that want to use the above signals for their
 572   // own purposes must, at this time, use the "-Xrs" option to prevent
 573   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 574   // (See bug 4345157, and other related bugs).
 575   // In reality, though, unblocking these signals is really a nop, since
 576   // these signals are not blocked by default.
 577   sigemptyset(&unblocked_sigs);
 578   sigemptyset(&allowdebug_blocked_sigs);
 579   sigaddset(&unblocked_sigs, SIGILL);
 580   sigaddset(&unblocked_sigs, SIGSEGV);
 581   sigaddset(&unblocked_sigs, SIGBUS);
 582   sigaddset(&unblocked_sigs, SIGFPE);
 583   sigaddset(&unblocked_sigs, SR_signum);
 584 
 585   if (!ReduceSignalUsage) {
 586     if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 587       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 588       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
 589     }
 590     if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 591       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 592       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
 593     }
 594     if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 595       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 596       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
 597     }
 598   }
 599   // Fill in signals that are blocked by all but the VM thread.
 600   sigemptyset(&vm_sigs);
 601   if (!ReduceSignalUsage) {
 602     sigaddset(&vm_sigs, BREAK_SIGNAL);
 603   }
 604   debug_only(signal_sets_initialized = true);
 605 
 606 }
 607 
 608 // These are signals that are unblocked while a thread is running Java.
 609 // (For some reason, they get blocked by default.)
 610 sigset_t* os::Bsd::unblocked_signals() {
 611   assert(signal_sets_initialized, "Not initialized");
 612   return &unblocked_sigs;
 613 }
 614 
 615 // These are the signals that are blocked while a (non-VM) thread is
 616 // running Java. Only the VM thread handles these signals.
 617 sigset_t* os::Bsd::vm_signals() {
 618   assert(signal_sets_initialized, "Not initialized");
 619   return &vm_sigs;
 620 }
 621 
 622 // These are signals that are blocked during cond_wait to allow debugger in
 623 sigset_t* os::Bsd::allowdebug_blocked_signals() {
 624   assert(signal_sets_initialized, "Not initialized");
 625   return &allowdebug_blocked_sigs;
 626 }
 627 
 628 void os::Bsd::hotspot_sigmask(Thread* thread) {
 629 
 630   //Save caller's signal mask before setting VM signal mask
 631   sigset_t caller_sigmask;
 632   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 633 
 634   OSThread* osthread = thread->osthread();
 635   osthread->set_caller_sigmask(caller_sigmask);
 636 
 637   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 638 
 639   if (!ReduceSignalUsage) {
 640     if (thread->is_VM_thread()) {
 641       // Only the VM thread handles BREAK_SIGNAL ...
 642       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 643     } else {
 644       // ... all other threads block BREAK_SIGNAL
 645       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 646     }
 647   }
 648 }
 649 
 650 
 651 //////////////////////////////////////////////////////////////////////////////
 652 // create new thread
 653 
 654 // check if it's safe to start a new thread
 655 static bool _thread_safety_check(Thread* thread) {
 656   return true;
 657 }
 658 
 659 #ifdef __APPLE__
 660 // library handle for calling objc_registerThreadWithCollector()
 661 // without static linking to the libobjc library
 662   #define OBJC_LIB "/usr/lib/libobjc.dylib"
 663   #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 664 typedef void (*objc_registerThreadWithCollector_t)();
 665 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 666 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 667 #endif
 668 
 669 #ifdef __APPLE__
 670 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 671   // Additional thread_id used to correlate threads in SA
 672   thread_identifier_info_data_t     m_ident_info;
 673   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 674 
 675   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 676               (thread_info_t) &m_ident_info, &count);
 677 
 678   return m_ident_info.thread_id;
 679 }
 680 #endif
 681 
 682 // Thread start routine for all newly created threads
 683 static void *java_start(Thread *thread) {
 684   // Try to randomize the cache line index of hot stack frames.
 685   // This helps when threads of the same stack traces evict each other's
 686   // cache lines. The threads can be either from the same JVM instance, or
 687   // from different JVM instances. The benefit is especially true for
 688   // processors with hyperthreading technology.
 689   static int counter = 0;
 690   int pid = os::current_process_id();
 691   alloca(((pid ^ counter++) & 7) * 128);
 692 
 693   ThreadLocalStorage::set_thread(thread);
 694 
 695   OSThread* osthread = thread->osthread();
 696   Monitor* sync = osthread->startThread_lock();
 697 
 698   // non floating stack BsdThreads needs extra check, see above
 699   if (!_thread_safety_check(thread)) {
 700     // notify parent thread
 701     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 702     osthread->set_state(ZOMBIE);
 703     sync->notify_all();
 704     return NULL;
 705   }
 706 
 707   osthread->set_thread_id(os::Bsd::gettid());
 708 
 709 #ifdef __APPLE__
 710   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 711   guarantee(unique_thread_id != 0, "unique thread id was not found");
 712   osthread->set_unique_thread_id(unique_thread_id);
 713 #endif
 714   // initialize signal mask for this thread
 715   os::Bsd::hotspot_sigmask(thread);
 716 
 717   // initialize floating point control register
 718   os::Bsd::init_thread_fpu_state();
 719 
 720 #ifdef __APPLE__
 721   // register thread with objc gc
 722   if (objc_registerThreadWithCollectorFunction != NULL) {
 723     objc_registerThreadWithCollectorFunction();
 724   }
 725 #endif
 726 
 727   // handshaking with parent thread
 728   {
 729     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 730 
 731     // notify parent thread
 732     osthread->set_state(INITIALIZED);
 733     sync->notify_all();
 734 
 735     // wait until os::start_thread()
 736     while (osthread->get_state() == INITIALIZED) {
 737       sync->wait(Mutex::_no_safepoint_check_flag);
 738     }
 739   }
 740 
 741   // call one more level start routine
 742   thread->run();
 743 
 744   return 0;
 745 }
 746 
 747 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
 748   assert(thread->osthread() == NULL, "caller responsible");
 749 
 750   // Allocate the OSThread object
 751   OSThread* osthread = new OSThread(NULL, NULL);
 752   if (osthread == NULL) {
 753     return false;
 754   }
 755 
 756   // set the correct thread state
 757   osthread->set_thread_type(thr_type);
 758 
 759   // Initial state is ALLOCATED but not INITIALIZED
 760   osthread->set_state(ALLOCATED);
 761 
 762   thread->set_osthread(osthread);
 763 
 764   // init thread attributes
 765   pthread_attr_t attr;
 766   pthread_attr_init(&attr);
 767   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 768 
 769   // stack size
 770   if (os::Bsd::supports_variable_stack_size()) {
 771     // calculate stack size if it's not specified by caller
 772     if (stack_size == 0) {
 773       stack_size = os::Bsd::default_stack_size(thr_type);
 774 
 775       switch (thr_type) {
 776       case os::java_thread:
 777         // Java threads use ThreadStackSize which default value can be
 778         // changed with the flag -Xss
 779         assert(JavaThread::stack_size_at_create() > 0, "this should be set");
 780         stack_size = JavaThread::stack_size_at_create();
 781         break;
 782       case os::compiler_thread:
 783         if (CompilerThreadStackSize > 0) {
 784           stack_size = (size_t)(CompilerThreadStackSize * K);
 785           break;
 786         } // else fall through:
 787           // use VMThreadStackSize if CompilerThreadStackSize is not defined
 788       case os::vm_thread:
 789       case os::pgc_thread:
 790       case os::cgc_thread:
 791       case os::watcher_thread:
 792         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 793         break;
 794       }
 795     }
 796 
 797     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
 798     pthread_attr_setstacksize(&attr, stack_size);
 799   } else {
 800     // let pthread_create() pick the default value.
 801   }
 802 
 803   ThreadState state;
 804 
 805   {
 806     pthread_t tid;
 807     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
 808 
 809     pthread_attr_destroy(&attr);
 810 
 811     if (ret != 0) {
 812       if (PrintMiscellaneous && (Verbose || WizardMode)) {
 813         perror("pthread_create()");
 814       }
 815       // Need to clean up stuff we've allocated so far
 816       thread->set_osthread(NULL);
 817       delete osthread;
 818       return false;
 819     }
 820 
 821     // Store pthread info into the OSThread
 822     osthread->set_pthread_id(tid);
 823 
 824     // Wait until child thread is either initialized or aborted
 825     {
 826       Monitor* sync_with_child = osthread->startThread_lock();
 827       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 828       while ((state = osthread->get_state()) == ALLOCATED) {
 829         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 830       }
 831     }
 832 
 833   }
 834 
 835   // Aborted due to thread limit being reached
 836   if (state == ZOMBIE) {
 837     thread->set_osthread(NULL);
 838     delete osthread;
 839     return false;
 840   }
 841 
 842   // The thread is returned suspended (in state INITIALIZED),
 843   // and is started higher up in the call chain
 844   assert(state == INITIALIZED, "race condition");
 845   return true;
 846 }
 847 
 848 /////////////////////////////////////////////////////////////////////////////
 849 // attach existing thread
 850 
 851 // bootstrap the main thread
 852 bool os::create_main_thread(JavaThread* thread) {
 853   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 854   return create_attached_thread(thread);
 855 }
 856 
 857 bool os::create_attached_thread(JavaThread* thread) {
 858 #ifdef ASSERT
 859   thread->verify_not_published();
 860 #endif
 861 
 862   // Allocate the OSThread object
 863   OSThread* osthread = new OSThread(NULL, NULL);
 864 
 865   if (osthread == NULL) {
 866     return false;
 867   }
 868 
 869   osthread->set_thread_id(os::Bsd::gettid());
 870 
 871   // Store pthread info into the OSThread
 872 #ifdef __APPLE__
 873   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 874   guarantee(unique_thread_id != 0, "just checking");
 875   osthread->set_unique_thread_id(unique_thread_id);
 876 #endif
 877   osthread->set_pthread_id(::pthread_self());
 878 
 879   // initialize floating point control register
 880   os::Bsd::init_thread_fpu_state();
 881 
 882   // Initial thread state is RUNNABLE
 883   osthread->set_state(RUNNABLE);
 884 
 885   thread->set_osthread(osthread);
 886 
 887   // initialize signal mask for this thread
 888   // and save the caller's signal mask
 889   os::Bsd::hotspot_sigmask(thread);
 890 
 891   return true;
 892 }
 893 
 894 void os::pd_start_thread(Thread* thread) {
 895   OSThread * osthread = thread->osthread();
 896   assert(osthread->get_state() != INITIALIZED, "just checking");
 897   Monitor* sync_with_child = osthread->startThread_lock();
 898   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 899   sync_with_child->notify();
 900 }
 901 
 902 // Free Bsd resources related to the OSThread
 903 void os::free_thread(OSThread* osthread) {
 904   assert(osthread != NULL, "osthread not set");
 905 
 906   if (Thread::current()->osthread() == osthread) {
 907     // Restore caller's signal mask
 908     sigset_t sigmask = osthread->caller_sigmask();
 909     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 910   }
 911 
 912   delete osthread;
 913 }
 914 
 915 //////////////////////////////////////////////////////////////////////////////
 916 // thread local storage
 917 
 918 // Restore the thread pointer if the destructor is called. This is in case
 919 // someone from JNI code sets up a destructor with pthread_key_create to run
 920 // detachCurrentThread on thread death. Unless we restore the thread pointer we
 921 // will hang or crash. When detachCurrentThread is called the key will be set
 922 // to null and we will not be called again. If detachCurrentThread is never
 923 // called we could loop forever depending on the pthread implementation.
 924 static void restore_thread_pointer(void* p) {
 925   Thread* thread = (Thread*) p;
 926   os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
 927 }
 928 
 929 int os::allocate_thread_local_storage() {
 930   pthread_key_t key;
 931   int rslt = pthread_key_create(&key, restore_thread_pointer);
 932   assert(rslt == 0, "cannot allocate thread local storage");
 933   return (int)key;
 934 }
 935 
 936 // Note: This is currently not used by VM, as we don't destroy TLS key
 937 // on VM exit.
 938 void os::free_thread_local_storage(int index) {
 939   int rslt = pthread_key_delete((pthread_key_t)index);
 940   assert(rslt == 0, "invalid index");
 941 }
 942 
 943 void os::thread_local_storage_at_put(int index, void* value) {
 944   int rslt = pthread_setspecific((pthread_key_t)index, value);
 945   assert(rslt == 0, "pthread_setspecific failed");
 946 }
 947 
 948 extern "C" Thread* get_thread() {
 949   return ThreadLocalStorage::thread();
 950 }
 951 
 952 
 953 ////////////////////////////////////////////////////////////////////////////////
 954 // time support
 955 
 956 // Time since start-up in seconds to a fine granularity.
 957 // Used by VMSelfDestructTimer and the MemProfiler.
 958 double os::elapsedTime() {
 959 
 960   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 961 }
 962 
 963 jlong os::elapsed_counter() {
 964   return javaTimeNanos() - initial_time_count;
 965 }
 966 
 967 jlong os::elapsed_frequency() {
 968   return NANOSECS_PER_SEC; // nanosecond resolution
 969 }
 970 
 971 bool os::supports_vtime() { return true; }
 972 bool os::enable_vtime()   { return false; }
 973 bool os::vtime_enabled()  { return false; }
 974 
 975 double os::elapsedVTime() {
 976   // better than nothing, but not much
 977   return elapsedTime();
 978 }
 979 
 980 jlong os::javaTimeMillis() {
 981   timeval time;
 982   int status = gettimeofday(&time, NULL);
 983   assert(status != -1, "bsd error");
 984   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 985 }
 986 








 987 #ifndef __APPLE__
 988   #ifndef CLOCK_MONOTONIC
 989     #define CLOCK_MONOTONIC (1)
 990   #endif
 991 #endif
 992 
 993 #ifdef __APPLE__
 994 void os::Bsd::clock_init() {
 995   mach_timebase_info(&_timebase_info);
 996 }
 997 #else
 998 void os::Bsd::clock_init() {
 999   struct timespec res;
1000   struct timespec tp;
1001   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
1002       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
1003     // yes, monotonic clock is supported
1004     _clock_gettime = ::clock_gettime;
1005   }
1006 }
1007 #endif
1008 
1009 
1010 
1011 #ifdef __APPLE__
1012 
1013 jlong os::javaTimeNanos() {
1014   const uint64_t tm = mach_absolute_time();
1015   const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
1016   const uint64_t prev = Bsd::_max_abstime;
1017   if (now <= prev) {
1018     return prev;   // same or retrograde time;
1019   }
1020   const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
1021   assert(obsv >= prev, "invariant");   // Monotonicity
1022   // If the CAS succeeded then we're done and return "now".
1023   // If the CAS failed and the observed value "obsv" is >= now then
1024   // we should return "obsv".  If the CAS failed and now > obsv > prv then
1025   // some other thread raced this thread and installed a new value, in which case
1026   // we could either (a) retry the entire operation, (b) retry trying to install now
1027   // or (c) just return obsv.  We use (c).   No loop is required although in some cases
1028   // we might discard a higher "now" value in deference to a slightly lower but freshly
1029   // installed obsv value.   That's entirely benign -- it admits no new orderings compared
1030   // to (a) or (b) -- and greatly reduces coherence traffic.
1031   // We might also condition (c) on the magnitude of the delta between obsv and now.
1032   // Avoiding excessive CAS operations to hot RW locations is critical.
1033   // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1034   return (prev == obsv) ? now : obsv;
1035 }
1036 
1037 #else // __APPLE__
1038 
1039 jlong os::javaTimeNanos() {
1040   if (os::supports_monotonic_clock()) {
1041     struct timespec tp;
1042     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
1043     assert(status == 0, "gettime error");
1044     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1045     return result;
1046   } else {
1047     timeval time;
1048     int status = gettimeofday(&time, NULL);
1049     assert(status != -1, "bsd error");
1050     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1051     return 1000 * usecs;
1052   }
1053 }
1054 
1055 #endif // __APPLE__
1056 
1057 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1058   if (os::supports_monotonic_clock()) {
1059     info_ptr->max_value = ALL_64_BITS;
1060 
1061     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1062     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
1063     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
1064   } else {
1065     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1066     info_ptr->max_value = ALL_64_BITS;
1067 
1068     // gettimeofday is a real time clock so it skips
1069     info_ptr->may_skip_backward = true;
1070     info_ptr->may_skip_forward = true;
1071   }
1072 
1073   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
1074 }
1075 
1076 // Return the real, user, and system times in seconds from an
1077 // arbitrary fixed point in the past.
1078 bool os::getTimesSecs(double* process_real_time,
1079                       double* process_user_time,
1080                       double* process_system_time) {
1081   struct tms ticks;
1082   clock_t real_ticks = times(&ticks);
1083 
1084   if (real_ticks == (clock_t) (-1)) {
1085     return false;
1086   } else {
1087     double ticks_per_second = (double) clock_tics_per_sec;
1088     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1089     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1090     *process_real_time = ((double) real_ticks) / ticks_per_second;
1091 
1092     return true;
1093   }
1094 }
1095 
1096 
1097 char * os::local_time_string(char *buf, size_t buflen) {
1098   struct tm t;
1099   time_t long_time;
1100   time(&long_time);
1101   localtime_r(&long_time, &t);
1102   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1103                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1104                t.tm_hour, t.tm_min, t.tm_sec);
1105   return buf;
1106 }
1107 
1108 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1109   return localtime_r(clock, res);
1110 }
1111 
1112 ////////////////////////////////////////////////////////////////////////////////
1113 // runtime exit support
1114 
1115 // Note: os::shutdown() might be called very early during initialization, or
1116 // called from signal handler. Before adding something to os::shutdown(), make
1117 // sure it is async-safe and can handle partially initialized VM.
1118 void os::shutdown() {
1119 
1120   // allow PerfMemory to attempt cleanup of any persistent resources
1121   perfMemory_exit();
1122 
1123   // needs to remove object in file system
1124   AttachListener::abort();
1125 
1126   // flush buffered output, finish log files
1127   ostream_abort();
1128 
1129   // Check for abort hook
1130   abort_hook_t abort_hook = Arguments::abort_hook();
1131   if (abort_hook != NULL) {
1132     abort_hook();
1133   }
1134 
1135 }
1136 
1137 // Note: os::abort() might be called very early during initialization, or
1138 // called from signal handler. Before adding something to os::abort(), make
1139 // sure it is async-safe and can handle partially initialized VM.
1140 void os::abort(bool dump_core) {
1141   os::shutdown();
1142   if (dump_core) {
1143 #ifndef PRODUCT
1144     fdStream out(defaultStream::output_fd());
1145     out.print_raw("Current thread is ");
1146     char buf[16];
1147     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1148     out.print_raw_cr(buf);
1149     out.print_raw_cr("Dumping core ...");
1150 #endif
1151     ::abort(); // dump core
1152   }
1153 
1154   ::exit(1);
1155 }
1156 
1157 // Die immediately, no exit hook, no abort hook, no cleanup.
1158 void os::die() {
1159   // _exit() on BsdThreads only kills current thread
1160   ::abort();
1161 }
1162 
1163 // This method is a copy of JDK's sysGetLastErrorString
1164 // from src/solaris/hpi/src/system_md.c
1165 
1166 size_t os::lasterror(char *buf, size_t len) {
1167   if (errno == 0)  return 0;
1168 
1169   const char *s = ::strerror(errno);
1170   size_t n = ::strlen(s);
1171   if (n >= len) {
1172     n = len - 1;
1173   }
1174   ::strncpy(buf, s, n);
1175   buf[n] = '\0';
1176   return n;
1177 }
1178 
1179 // Information of current thread in variety of formats
1180 pid_t os::Bsd::gettid() {
1181   int retval = -1;
1182 
1183 #ifdef __APPLE__ //XNU kernel
1184   // despite the fact mach port is actually not a thread id use it
1185   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1186   retval = ::pthread_mach_thread_np(::pthread_self());
1187   guarantee(retval != 0, "just checking");
1188   return retval;
1189 
1190 #elif __FreeBSD__
1191   retval = syscall(SYS_thr_self);
1192 #elif __OpenBSD__
1193   retval = syscall(SYS_getthrid);
1194 #elif __NetBSD__
1195   retval = (pid_t) syscall(SYS__lwp_self);
1196 #endif
1197 
1198   if (retval == -1) {
1199     return getpid();
1200   }
1201 }
1202 
1203 intx os::current_thread_id() {
1204 #ifdef __APPLE__
1205   return (intx)::pthread_mach_thread_np(::pthread_self());
1206 #else
1207   return (intx)::pthread_self();
1208 #endif
1209 }
1210 
1211 int os::current_process_id() {
1212 
1213   // Under the old bsd thread library, bsd gives each thread
1214   // its own process id. Because of this each thread will return
1215   // a different pid if this method were to return the result
1216   // of getpid(2). Bsd provides no api that returns the pid
1217   // of the launcher thread for the vm. This implementation
1218   // returns a unique pid, the pid of the launcher thread
1219   // that starts the vm 'process'.
1220 
1221   // Under the NPTL, getpid() returns the same pid as the
1222   // launcher thread rather than a unique pid per thread.
1223   // Use gettid() if you want the old pre NPTL behaviour.
1224 
1225   // if you are looking for the result of a call to getpid() that
1226   // returns a unique pid for the calling thread, then look at the
1227   // OSThread::thread_id() method in osThread_bsd.hpp file
1228 
1229   return (int)(_initial_pid ? _initial_pid : getpid());
1230 }
1231 
1232 // DLL functions
1233 
1234 #define JNI_LIB_PREFIX "lib"
1235 #ifdef __APPLE__
1236   #define JNI_LIB_SUFFIX ".dylib"
1237 #else
1238   #define JNI_LIB_SUFFIX ".so"
1239 #endif
1240 
1241 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1242 
1243 // This must be hard coded because it's the system's temporary
1244 // directory not the java application's temp directory, ala java.io.tmpdir.
1245 #ifdef __APPLE__
1246 // macosx has a secure per-user temporary directory
1247 char temp_path_storage[PATH_MAX];
1248 const char* os::get_temp_directory() {
1249   static char *temp_path = NULL;
1250   if (temp_path == NULL) {
1251     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1252     if (pathSize == 0 || pathSize > PATH_MAX) {
1253       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1254     }
1255     temp_path = temp_path_storage;
1256   }
1257   return temp_path;
1258 }
1259 #else // __APPLE__
1260 const char* os::get_temp_directory() { return "/tmp"; }
1261 #endif // __APPLE__
1262 
1263 static bool file_exists(const char* filename) {
1264   struct stat statbuf;
1265   if (filename == NULL || strlen(filename) == 0) {
1266     return false;
1267   }
1268   return os::stat(filename, &statbuf) == 0;
1269 }
1270 
1271 bool os::dll_build_name(char* buffer, size_t buflen,
1272                         const char* pname, const char* fname) {
1273   bool retval = false;
1274   // Copied from libhpi
1275   const size_t pnamelen = pname ? strlen(pname) : 0;
1276 
1277   // Return error on buffer overflow.
1278   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1279     return retval;
1280   }
1281 
1282   if (pnamelen == 0) {
1283     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1284     retval = true;
1285   } else if (strchr(pname, *os::path_separator()) != NULL) {
1286     int n;
1287     char** pelements = split_path(pname, &n);
1288     if (pelements == NULL) {
1289       return false;
1290     }
1291     for (int i = 0; i < n; i++) {
1292       // Really shouldn't be NULL, but check can't hurt
1293       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1294         continue; // skip the empty path values
1295       }
1296       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1297                pelements[i], fname);
1298       if (file_exists(buffer)) {
1299         retval = true;
1300         break;
1301       }
1302     }
1303     // release the storage
1304     for (int i = 0; i < n; i++) {
1305       if (pelements[i] != NULL) {
1306         FREE_C_HEAP_ARRAY(char, pelements[i]);
1307       }
1308     }
1309     if (pelements != NULL) {
1310       FREE_C_HEAP_ARRAY(char*, pelements);
1311     }
1312   } else {
1313     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1314     retval = true;
1315   }
1316   return retval;
1317 }
1318 
1319 // check if addr is inside libjvm.so
1320 bool os::address_is_in_vm(address addr) {
1321   static address libjvm_base_addr;
1322   Dl_info dlinfo;
1323 
1324   if (libjvm_base_addr == NULL) {
1325     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1326       libjvm_base_addr = (address)dlinfo.dli_fbase;
1327     }
1328     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1329   }
1330 
1331   if (dladdr((void *)addr, &dlinfo) != 0) {
1332     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1333   }
1334 
1335   return false;
1336 }
1337 
1338 
1339 #define MACH_MAXSYMLEN 256
1340 
1341 bool os::dll_address_to_function_name(address addr, char *buf,
1342                                       int buflen, int *offset) {
1343   // buf is not optional, but offset is optional
1344   assert(buf != NULL, "sanity check");
1345 
1346   Dl_info dlinfo;
1347   char localbuf[MACH_MAXSYMLEN];
1348 
1349   if (dladdr((void*)addr, &dlinfo) != 0) {
1350     // see if we have a matching symbol
1351     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1352       if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1353         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1354       }
1355       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1356       return true;
1357     }
1358     // no matching symbol so try for just file info
1359     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1360       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1361                           buf, buflen, offset, dlinfo.dli_fname)) {
1362         return true;
1363       }
1364     }
1365 
1366     // Handle non-dynamic manually:
1367     if (dlinfo.dli_fbase != NULL &&
1368         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
1369       if (!Decoder::demangle(localbuf, buf, buflen)) {
1370         jio_snprintf(buf, buflen, "%s", localbuf);
1371       }
1372       return true;
1373     }
1374   }
1375   buf[0] = '\0';
1376   if (offset != NULL) *offset = -1;
1377   return false;
1378 }
1379 
1380 // ported from solaris version
1381 bool os::dll_address_to_library_name(address addr, char* buf,
1382                                      int buflen, int* offset) {
1383   // buf is not optional, but offset is optional
1384   assert(buf != NULL, "sanity check");
1385 
1386   Dl_info dlinfo;
1387 
1388   if (dladdr((void*)addr, &dlinfo) != 0) {
1389     if (dlinfo.dli_fname != NULL) {
1390       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1391     }
1392     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1393       *offset = addr - (address)dlinfo.dli_fbase;
1394     }
1395     return true;
1396   }
1397 
1398   buf[0] = '\0';
1399   if (offset) *offset = -1;
1400   return false;
1401 }
1402 
1403 // Loads .dll/.so and
1404 // in case of error it checks if .dll/.so was built for the
1405 // same architecture as Hotspot is running on
1406 
1407 #ifdef __APPLE__
1408 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1409   void * result= ::dlopen(filename, RTLD_LAZY);
1410   if (result != NULL) {
1411     // Successful loading
1412     return result;
1413   }
1414 
1415   // Read system error message into ebuf
1416   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1417   ebuf[ebuflen-1]='\0';
1418 
1419   return NULL;
1420 }
1421 #else
1422 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1423   void * result= ::dlopen(filename, RTLD_LAZY);
1424   if (result != NULL) {
1425     // Successful loading
1426     return result;
1427   }
1428 
1429   Elf32_Ehdr elf_head;
1430 
1431   // Read system error message into ebuf
1432   // It may or may not be overwritten below
1433   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1434   ebuf[ebuflen-1]='\0';
1435   int diag_msg_max_length=ebuflen-strlen(ebuf);
1436   char* diag_msg_buf=ebuf+strlen(ebuf);
1437 
1438   if (diag_msg_max_length==0) {
1439     // No more space in ebuf for additional diagnostics message
1440     return NULL;
1441   }
1442 
1443 
1444   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1445 
1446   if (file_descriptor < 0) {
1447     // Can't open library, report dlerror() message
1448     return NULL;
1449   }
1450 
1451   bool failed_to_read_elf_head=
1452     (sizeof(elf_head)!=
1453      (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1454 
1455   ::close(file_descriptor);
1456   if (failed_to_read_elf_head) {
1457     // file i/o error - report dlerror() msg
1458     return NULL;
1459   }
1460 
1461   typedef struct {
1462     Elf32_Half  code;         // Actual value as defined in elf.h
1463     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1464     char        elf_class;    // 32 or 64 bit
1465     char        endianess;    // MSB or LSB
1466     char*       name;         // String representation
1467   } arch_t;
1468 
1469   #ifndef EM_486
1470     #define EM_486          6               /* Intel 80486 */
1471   #endif
1472 
1473   #ifndef EM_MIPS_RS3_LE
1474     #define EM_MIPS_RS3_LE  10              /* MIPS */
1475   #endif
1476 
1477   #ifndef EM_PPC64
1478     #define EM_PPC64        21              /* PowerPC64 */
1479   #endif
1480 
1481   #ifndef EM_S390
1482     #define EM_S390         22              /* IBM System/390 */
1483   #endif
1484 
1485   #ifndef EM_IA_64
1486     #define EM_IA_64        50              /* HP/Intel IA-64 */
1487   #endif
1488 
1489   #ifndef EM_X86_64
1490     #define EM_X86_64       62              /* AMD x86-64 */
1491   #endif
1492 
1493   static const arch_t arch_array[]={
1494     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1495     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1496     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1497     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1498     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1499     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1500     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1501     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1502     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1503     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1504     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1505     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1506     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1507     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1508     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1509     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1510   };
1511 
1512   #if  (defined IA32)
1513   static  Elf32_Half running_arch_code=EM_386;
1514   #elif   (defined AMD64)
1515   static  Elf32_Half running_arch_code=EM_X86_64;
1516   #elif  (defined IA64)
1517   static  Elf32_Half running_arch_code=EM_IA_64;
1518   #elif  (defined __sparc) && (defined _LP64)
1519   static  Elf32_Half running_arch_code=EM_SPARCV9;
1520   #elif  (defined __sparc) && (!defined _LP64)
1521   static  Elf32_Half running_arch_code=EM_SPARC;
1522   #elif  (defined __powerpc64__)
1523   static  Elf32_Half running_arch_code=EM_PPC64;
1524   #elif  (defined __powerpc__)
1525   static  Elf32_Half running_arch_code=EM_PPC;
1526   #elif  (defined ARM)
1527   static  Elf32_Half running_arch_code=EM_ARM;
1528   #elif  (defined S390)
1529   static  Elf32_Half running_arch_code=EM_S390;
1530   #elif  (defined ALPHA)
1531   static  Elf32_Half running_arch_code=EM_ALPHA;
1532   #elif  (defined MIPSEL)
1533   static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1534   #elif  (defined PARISC)
1535   static  Elf32_Half running_arch_code=EM_PARISC;
1536   #elif  (defined MIPS)
1537   static  Elf32_Half running_arch_code=EM_MIPS;
1538   #elif  (defined M68K)
1539   static  Elf32_Half running_arch_code=EM_68K;
1540   #else
1541     #error Method os::dll_load requires that one of following is defined:\
1542          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1543   #endif
1544 
1545   // Identify compatability class for VM's architecture and library's architecture
1546   // Obtain string descriptions for architectures
1547 
1548   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1549   int running_arch_index=-1;
1550 
1551   for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1552     if (running_arch_code == arch_array[i].code) {
1553       running_arch_index    = i;
1554     }
1555     if (lib_arch.code == arch_array[i].code) {
1556       lib_arch.compat_class = arch_array[i].compat_class;
1557       lib_arch.name         = arch_array[i].name;
1558     }
1559   }
1560 
1561   assert(running_arch_index != -1,
1562          "Didn't find running architecture code (running_arch_code) in arch_array");
1563   if (running_arch_index == -1) {
1564     // Even though running architecture detection failed
1565     // we may still continue with reporting dlerror() message
1566     return NULL;
1567   }
1568 
1569   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1570     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1571     return NULL;
1572   }
1573 
1574 #ifndef S390
1575   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1576     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1577     return NULL;
1578   }
1579 #endif // !S390
1580 
1581   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1582     if (lib_arch.name!=NULL) {
1583       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1584                  " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1585                  lib_arch.name, arch_array[running_arch_index].name);
1586     } else {
1587       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1588                  " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1589                  lib_arch.code,
1590                  arch_array[running_arch_index].name);
1591     }
1592   }
1593 
1594   return NULL;
1595 }
1596 #endif // !__APPLE__
1597 
1598 void* os::get_default_process_handle() {
1599 #ifdef __APPLE__
1600   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1601   // to avoid finding unexpected symbols on second (or later)
1602   // loads of a library.
1603   return (void*)::dlopen(NULL, RTLD_FIRST);
1604 #else
1605   return (void*)::dlopen(NULL, RTLD_LAZY);
1606 #endif
1607 }
1608 
1609 // XXX: Do we need a lock around this as per Linux?
1610 void* os::dll_lookup(void* handle, const char* name) {
1611   return dlsym(handle, name);
1612 }
1613 
1614 
1615 static bool _print_ascii_file(const char* filename, outputStream* st) {
1616   int fd = ::open(filename, O_RDONLY);
1617   if (fd == -1) {
1618     return false;
1619   }
1620 
1621   char buf[32];
1622   int bytes;
1623   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1624     st->print_raw(buf, bytes);
1625   }
1626 
1627   ::close(fd);
1628 
1629   return true;
1630 }
1631 
1632 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1633   outputStream * out = (outputStream *) param;
1634   out->print_cr(PTR_FORMAT " \t%s", base_address, name);
1635   return 0;
1636 }
1637 
1638 void os::print_dll_info(outputStream *st) {
1639   st->print_cr("Dynamic libraries:");
1640   if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1641     st->print_cr("Error: Cannot print dynamic libraries.");
1642   }
1643 }
1644 
1645 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1646 #ifdef RTLD_DI_LINKMAP
1647   Dl_info dli;
1648   void *handle;
1649   Link_map *map;
1650   Link_map *p;
1651 
1652   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1653       dli.dli_fname == NULL) {
1654     return 1;
1655   }
1656   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1657   if (handle == NULL) {
1658     return 1;
1659   }
1660   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1661   if (map == NULL) {
1662     dlclose(handle);
1663     return 1;
1664   }
1665 
1666   while (map->l_prev != NULL)
1667     map = map->l_prev;
1668 
1669   while (map != NULL) {
1670     // Value for top_address is returned as 0 since we don't have any information about module size
1671     if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1672       dlclose(handle);
1673       return 1;
1674     }
1675     map = map->l_next;
1676   }
1677 
1678   dlclose(handle);
1679 #elif defined(__APPLE__)
1680   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1681     // Value for top_address is returned as 0 since we don't have any information about module size
1682     if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1683       return 1;
1684     }
1685   }
1686   return 0;
1687 #else
1688   return 1;
1689 #endif
1690 }
1691 
1692 void os::print_os_info_brief(outputStream* st) {
1693   st->print("Bsd");
1694 
1695   os::Posix::print_uname_info(st);
1696 }
1697 
1698 void os::print_os_info(outputStream* st) {
1699   st->print("OS:");
1700   st->print("Bsd");
1701 
1702   os::Posix::print_uname_info(st);
1703 
1704   os::Posix::print_rlimit_info(st);
1705 
1706   os::Posix::print_load_average(st);
1707 }
1708 
1709 void os::pd_print_cpu_info(outputStream* st) {
1710   // Nothing to do for now.
1711 }
1712 
1713 void os::print_memory_info(outputStream* st) {
1714 
1715   st->print("Memory:");
1716   st->print(" %dk page", os::vm_page_size()>>10);
1717 
1718   st->print(", physical " UINT64_FORMAT "k",
1719             os::physical_memory() >> 10);
1720   st->print("(" UINT64_FORMAT "k free)",
1721             os::available_memory() >> 10);
1722   st->cr();
1723 
1724   // meminfo
1725   st->print("\n/proc/meminfo:\n");
1726   _print_ascii_file("/proc/meminfo", st);
1727   st->cr();
1728 }
1729 
1730 void os::print_siginfo(outputStream* st, void* siginfo) {
1731   const siginfo_t* si = (const siginfo_t*)siginfo;
1732 
1733   os::Posix::print_siginfo_brief(st, si);
1734 
1735   if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1736       UseSharedSpaces) {
1737     FileMapInfo* mapinfo = FileMapInfo::current_info();
1738     if (mapinfo->is_in_shared_space(si->si_addr)) {
1739       st->print("\n\nError accessing class data sharing archive."   \
1740                 " Mapped file inaccessible during execution, "      \
1741                 " possible disk/network problem.");
1742     }
1743   }
1744   st->cr();
1745 }
1746 
1747 
1748 static void print_signal_handler(outputStream* st, int sig,
1749                                  char* buf, size_t buflen);
1750 
1751 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1752   st->print_cr("Signal Handlers:");
1753   print_signal_handler(st, SIGSEGV, buf, buflen);
1754   print_signal_handler(st, SIGBUS , buf, buflen);
1755   print_signal_handler(st, SIGFPE , buf, buflen);
1756   print_signal_handler(st, SIGPIPE, buf, buflen);
1757   print_signal_handler(st, SIGXFSZ, buf, buflen);
1758   print_signal_handler(st, SIGILL , buf, buflen);
1759   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1760   print_signal_handler(st, SR_signum, buf, buflen);
1761   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1762   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1763   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1764   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1765 }
1766 
1767 static char saved_jvm_path[MAXPATHLEN] = {0};
1768 
1769 // Find the full path to the current module, libjvm
1770 void os::jvm_path(char *buf, jint buflen) {
1771   // Error checking.
1772   if (buflen < MAXPATHLEN) {
1773     assert(false, "must use a large-enough buffer");
1774     buf[0] = '\0';
1775     return;
1776   }
1777   // Lazy resolve the path to current module.
1778   if (saved_jvm_path[0] != 0) {
1779     strcpy(buf, saved_jvm_path);
1780     return;
1781   }
1782 
1783   char dli_fname[MAXPATHLEN];
1784   bool ret = dll_address_to_library_name(
1785                                          CAST_FROM_FN_PTR(address, os::jvm_path),
1786                                          dli_fname, sizeof(dli_fname), NULL);
1787   assert(ret, "cannot locate libjvm");
1788   char *rp = NULL;
1789   if (ret && dli_fname[0] != '\0') {
1790     rp = realpath(dli_fname, buf);
1791   }
1792   if (rp == NULL) {
1793     return;
1794   }
1795 
1796   if (Arguments::sun_java_launcher_is_altjvm()) {
1797     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1798     // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1799     // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1800     // appears at the right place in the string, then assume we are
1801     // installed in a JDK and we're done. Otherwise, check for a
1802     // JAVA_HOME environment variable and construct a path to the JVM
1803     // being overridden.
1804 
1805     const char *p = buf + strlen(buf) - 1;
1806     for (int count = 0; p > buf && count < 5; ++count) {
1807       for (--p; p > buf && *p != '/'; --p)
1808         /* empty */ ;
1809     }
1810 
1811     if (strncmp(p, "/jre/lib/", 9) != 0) {
1812       // Look for JAVA_HOME in the environment.
1813       char* java_home_var = ::getenv("JAVA_HOME");
1814       if (java_home_var != NULL && java_home_var[0] != 0) {
1815         char* jrelib_p;
1816         int len;
1817 
1818         // Check the current module name "libjvm"
1819         p = strrchr(buf, '/');
1820         assert(strstr(p, "/libjvm") == p, "invalid library name");
1821 
1822         rp = realpath(java_home_var, buf);
1823         if (rp == NULL) {
1824           return;
1825         }
1826 
1827         // determine if this is a legacy image or modules image
1828         // modules image doesn't have "jre" subdirectory
1829         len = strlen(buf);
1830         assert(len < buflen, "Ran out of buffer space");
1831         jrelib_p = buf + len;
1832 
1833         // Add the appropriate library subdir
1834         snprintf(jrelib_p, buflen-len, "/jre/lib");
1835         if (0 != access(buf, F_OK)) {
1836           snprintf(jrelib_p, buflen-len, "/lib");
1837         }
1838 
1839         // Add the appropriate client or server subdir
1840         len = strlen(buf);
1841         jrelib_p = buf + len;
1842         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1843         if (0 != access(buf, F_OK)) {
1844           snprintf(jrelib_p, buflen-len, "%s", "");
1845         }
1846 
1847         // If the path exists within JAVA_HOME, add the JVM library name
1848         // to complete the path to JVM being overridden.  Otherwise fallback
1849         // to the path to the current library.
1850         if (0 == access(buf, F_OK)) {
1851           // Use current module name "libjvm"
1852           len = strlen(buf);
1853           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1854         } else {
1855           // Fall back to path of current library
1856           rp = realpath(dli_fname, buf);
1857           if (rp == NULL) {
1858             return;
1859           }
1860         }
1861       }
1862     }
1863   }
1864 
1865   strncpy(saved_jvm_path, buf, MAXPATHLEN);
1866   saved_jvm_path[MAXPATHLEN - 1] = '\0';
1867 }
1868 
1869 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1870   // no prefix required, not even "_"
1871 }
1872 
1873 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1874   // no suffix required
1875 }
1876 
1877 ////////////////////////////////////////////////////////////////////////////////
1878 // sun.misc.Signal support
1879 
1880 static volatile jint sigint_count = 0;
1881 
1882 static void UserHandler(int sig, void *siginfo, void *context) {
1883   // 4511530 - sem_post is serialized and handled by the manager thread. When
1884   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1885   // don't want to flood the manager thread with sem_post requests.
1886   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
1887     return;
1888   }
1889 
1890   // Ctrl-C is pressed during error reporting, likely because the error
1891   // handler fails to abort. Let VM die immediately.
1892   if (sig == SIGINT && is_error_reported()) {
1893     os::die();
1894   }
1895 
1896   os::signal_notify(sig);
1897 }
1898 
1899 void* os::user_handler() {
1900   return CAST_FROM_FN_PTR(void*, UserHandler);
1901 }
1902 
1903 extern "C" {
1904   typedef void (*sa_handler_t)(int);
1905   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1906 }
1907 
1908 void* os::signal(int signal_number, void* handler) {
1909   struct sigaction sigAct, oldSigAct;
1910 
1911   sigfillset(&(sigAct.sa_mask));
1912   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1913   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1914 
1915   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1916     // -1 means registration failed
1917     return (void *)-1;
1918   }
1919 
1920   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1921 }
1922 
1923 void os::signal_raise(int signal_number) {
1924   ::raise(signal_number);
1925 }
1926 
1927 // The following code is moved from os.cpp for making this
1928 // code platform specific, which it is by its very nature.
1929 
1930 // Will be modified when max signal is changed to be dynamic
1931 int os::sigexitnum_pd() {
1932   return NSIG;
1933 }
1934 
1935 // a counter for each possible signal value
1936 static volatile jint pending_signals[NSIG+1] = { 0 };
1937 
1938 // Bsd(POSIX) specific hand shaking semaphore.
1939 #ifdef __APPLE__
1940 typedef semaphore_t os_semaphore_t;
1941 
1942   #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1943   #define SEM_WAIT(sem)           semaphore_wait(sem)
1944   #define SEM_POST(sem)           semaphore_signal(sem)
1945   #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
1946 #else
1947 typedef sem_t os_semaphore_t;
1948 
1949   #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
1950   #define SEM_WAIT(sem)           sem_wait(&sem)
1951   #define SEM_POST(sem)           sem_post(&sem)
1952   #define SEM_DESTROY(sem)        sem_destroy(&sem)
1953 #endif
1954 
1955 class Semaphore : public StackObj {
1956  public:
1957   Semaphore();
1958   ~Semaphore();
1959   void signal();
1960   void wait();
1961   bool trywait();
1962   bool timedwait(unsigned int sec, int nsec);
1963  private:
1964   jlong currenttime() const;
1965   os_semaphore_t _semaphore;
1966 };
1967 
1968 Semaphore::Semaphore() : _semaphore(0) {
1969   SEM_INIT(_semaphore, 0);
1970 }
1971 
1972 Semaphore::~Semaphore() {
1973   SEM_DESTROY(_semaphore);
1974 }
1975 
1976 void Semaphore::signal() {
1977   SEM_POST(_semaphore);
1978 }
1979 
1980 void Semaphore::wait() {
1981   SEM_WAIT(_semaphore);
1982 }
1983 
1984 jlong Semaphore::currenttime() const {
1985   struct timeval tv;
1986   gettimeofday(&tv, NULL);
1987   return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
1988 }
1989 
1990 #ifdef __APPLE__
1991 bool Semaphore::trywait() {
1992   return timedwait(0, 0);
1993 }
1994 
1995 bool Semaphore::timedwait(unsigned int sec, int nsec) {
1996   kern_return_t kr = KERN_ABORTED;
1997   mach_timespec_t waitspec;
1998   waitspec.tv_sec = sec;
1999   waitspec.tv_nsec = nsec;
2000 
2001   jlong starttime = currenttime();
2002 
2003   kr = semaphore_timedwait(_semaphore, waitspec);
2004   while (kr == KERN_ABORTED) {
2005     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
2006 
2007     jlong current = currenttime();
2008     jlong passedtime = current - starttime;
2009 
2010     if (passedtime >= totalwait) {
2011       waitspec.tv_sec = 0;
2012       waitspec.tv_nsec = 0;
2013     } else {
2014       jlong waittime = totalwait - (current - starttime);
2015       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
2016       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
2017     }
2018 
2019     kr = semaphore_timedwait(_semaphore, waitspec);
2020   }
2021 
2022   return kr == KERN_SUCCESS;
2023 }
2024 
2025 #else
2026 
2027 bool Semaphore::trywait() {
2028   return sem_trywait(&_semaphore) == 0;
2029 }
2030 
2031 bool Semaphore::timedwait(unsigned int sec, int nsec) {
2032   struct timespec ts;
2033   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2034 
2035   while (1) {
2036     int result = sem_timedwait(&_semaphore, &ts);
2037     if (result == 0) {
2038       return true;
2039     } else if (errno == EINTR) {
2040       continue;
2041     } else if (errno == ETIMEDOUT) {
2042       return false;
2043     } else {
2044       return false;
2045     }
2046   }
2047 }
2048 
2049 #endif // __APPLE__
2050 
2051 static os_semaphore_t sig_sem;
2052 static Semaphore sr_semaphore;
2053 
2054 void os::signal_init_pd() {
2055   // Initialize signal structures
2056   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2057 
2058   // Initialize signal semaphore
2059   ::SEM_INIT(sig_sem, 0);
2060 }
2061 
2062 void os::signal_notify(int sig) {
2063   Atomic::inc(&pending_signals[sig]);
2064   ::SEM_POST(sig_sem);
2065 }
2066 
2067 static int check_pending_signals(bool wait) {
2068   Atomic::store(0, &sigint_count);
2069   for (;;) {
2070     for (int i = 0; i < NSIG + 1; i++) {
2071       jint n = pending_signals[i];
2072       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2073         return i;
2074       }
2075     }
2076     if (!wait) {
2077       return -1;
2078     }
2079     JavaThread *thread = JavaThread::current();
2080     ThreadBlockInVM tbivm(thread);
2081 
2082     bool threadIsSuspended;
2083     do {
2084       thread->set_suspend_equivalent();
2085       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2086       ::SEM_WAIT(sig_sem);
2087 
2088       // were we externally suspended while we were waiting?
2089       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2090       if (threadIsSuspended) {
2091         // The semaphore has been incremented, but while we were waiting
2092         // another thread suspended us. We don't want to continue running
2093         // while suspended because that would surprise the thread that
2094         // suspended us.
2095         ::SEM_POST(sig_sem);
2096 
2097         thread->java_suspend_self();
2098       }
2099     } while (threadIsSuspended);
2100   }
2101 }
2102 
2103 int os::signal_lookup() {
2104   return check_pending_signals(false);
2105 }
2106 
2107 int os::signal_wait() {
2108   return check_pending_signals(true);
2109 }
2110 
2111 ////////////////////////////////////////////////////////////////////////////////
2112 // Virtual Memory
2113 
2114 int os::vm_page_size() {
2115   // Seems redundant as all get out
2116   assert(os::Bsd::page_size() != -1, "must call os::init");
2117   return os::Bsd::page_size();
2118 }
2119 
2120 // Solaris allocates memory by pages.
2121 int os::vm_allocation_granularity() {
2122   assert(os::Bsd::page_size() != -1, "must call os::init");
2123   return os::Bsd::page_size();
2124 }
2125 
2126 // Rationale behind this function:
2127 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2128 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2129 //  samples for JITted code. Here we create private executable mapping over the code cache
2130 //  and then we can use standard (well, almost, as mapping can change) way to provide
2131 //  info for the reporting script by storing timestamp and location of symbol
2132 void bsd_wrap_code(char* base, size_t size) {
2133   static volatile jint cnt = 0;
2134 
2135   if (!UseOprofile) {
2136     return;
2137   }
2138 
2139   char buf[PATH_MAX + 1];
2140   int num = Atomic::add(1, &cnt);
2141 
2142   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2143            os::get_temp_directory(), os::current_process_id(), num);
2144   unlink(buf);
2145 
2146   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2147 
2148   if (fd != -1) {
2149     off_t rv = ::lseek(fd, size-2, SEEK_SET);
2150     if (rv != (off_t)-1) {
2151       if (::write(fd, "", 1) == 1) {
2152         mmap(base, size,
2153              PROT_READ|PROT_WRITE|PROT_EXEC,
2154              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2155       }
2156     }
2157     ::close(fd);
2158     unlink(buf);
2159   }
2160 }
2161 
2162 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2163                                     int err) {
2164   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2165           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2166           strerror(err), err);
2167 }
2168 
2169 // NOTE: Bsd kernel does not really reserve the pages for us.
2170 //       All it does is to check if there are enough free pages
2171 //       left at the time of mmap(). This could be a potential
2172 //       problem.
2173 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2174   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2175 #ifdef __OpenBSD__
2176   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2177   if (::mprotect(addr, size, prot) == 0) {
2178     return true;
2179   }
2180 #else
2181   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2182                                      MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2183   if (res != (uintptr_t) MAP_FAILED) {
2184     return true;
2185   }
2186 #endif
2187 
2188   // Warn about any commit errors we see in non-product builds just
2189   // in case mmap() doesn't work as described on the man page.
2190   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2191 
2192   return false;
2193 }
2194 
2195 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2196                           bool exec) {
2197   // alignment_hint is ignored on this OS
2198   return pd_commit_memory(addr, size, exec);
2199 }
2200 
2201 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2202                                   const char* mesg) {
2203   assert(mesg != NULL, "mesg must be specified");
2204   if (!pd_commit_memory(addr, size, exec)) {
2205     // add extra info in product mode for vm_exit_out_of_memory():
2206     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2207     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
2208   }
2209 }
2210 
2211 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2212                                   size_t alignment_hint, bool exec,
2213                                   const char* mesg) {
2214   // alignment_hint is ignored on this OS
2215   pd_commit_memory_or_exit(addr, size, exec, mesg);
2216 }
2217 
2218 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2219 }
2220 
2221 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2222   ::madvise(addr, bytes, MADV_DONTNEED);
2223 }
2224 
2225 void os::numa_make_global(char *addr, size_t bytes) {
2226 }
2227 
2228 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2229 }
2230 
2231 bool os::numa_topology_changed()   { return false; }
2232 
2233 size_t os::numa_get_groups_num() {
2234   return 1;
2235 }
2236 
2237 int os::numa_get_group_id() {
2238   return 0;
2239 }
2240 
2241 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2242   if (size > 0) {
2243     ids[0] = 0;
2244     return 1;
2245   }
2246   return 0;
2247 }
2248 
2249 bool os::get_page_info(char *start, page_info* info) {
2250   return false;
2251 }
2252 
2253 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2254   return end;
2255 }
2256 
2257 
2258 bool os::pd_uncommit_memory(char* addr, size_t size) {
2259 #ifdef __OpenBSD__
2260   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2261   return ::mprotect(addr, size, PROT_NONE) == 0;
2262 #else
2263   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2264                                      MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2265   return res  != (uintptr_t) MAP_FAILED;
2266 #endif
2267 }
2268 
2269 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2270   return os::commit_memory(addr, size, !ExecMem);
2271 }
2272 
2273 // If this is a growable mapping, remove the guard pages entirely by
2274 // munmap()ping them.  If not, just call uncommit_memory().
2275 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2276   return os::uncommit_memory(addr, size);
2277 }
2278 
2279 static address _highest_vm_reserved_address = NULL;
2280 
2281 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2282 // at 'requested_addr'. If there are existing memory mappings at the same
2283 // location, however, they will be overwritten. If 'fixed' is false,
2284 // 'requested_addr' is only treated as a hint, the return value may or
2285 // may not start from the requested address. Unlike Bsd mmap(), this
2286 // function returns NULL to indicate failure.
2287 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2288   char * addr;
2289   int flags;
2290 
2291   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2292   if (fixed) {
2293     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2294     flags |= MAP_FIXED;
2295   }
2296 
2297   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2298   // touch an uncommitted page. Otherwise, the read/write might
2299   // succeed if we have enough swap space to back the physical page.
2300   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2301                        flags, -1, 0);
2302 
2303   if (addr != MAP_FAILED) {
2304     // anon_mmap() should only get called during VM initialization,
2305     // don't need lock (actually we can skip locking even it can be called
2306     // from multiple threads, because _highest_vm_reserved_address is just a
2307     // hint about the upper limit of non-stack memory regions.)
2308     if ((address)addr + bytes > _highest_vm_reserved_address) {
2309       _highest_vm_reserved_address = (address)addr + bytes;
2310     }
2311   }
2312 
2313   return addr == MAP_FAILED ? NULL : addr;
2314 }
2315 
2316 // Don't update _highest_vm_reserved_address, because there might be memory
2317 // regions above addr + size. If so, releasing a memory region only creates
2318 // a hole in the address space, it doesn't help prevent heap-stack collision.
2319 //
2320 static int anon_munmap(char * addr, size_t size) {
2321   return ::munmap(addr, size) == 0;
2322 }
2323 
2324 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2325                             size_t alignment_hint) {
2326   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2327 }
2328 
2329 bool os::pd_release_memory(char* addr, size_t size) {
2330   return anon_munmap(addr, size);
2331 }
2332 
2333 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2334   // Bsd wants the mprotect address argument to be page aligned.
2335   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2336 
2337   // According to SUSv3, mprotect() should only be used with mappings
2338   // established by mmap(), and mmap() always maps whole pages. Unaligned
2339   // 'addr' likely indicates problem in the VM (e.g. trying to change
2340   // protection of malloc'ed or statically allocated memory). Check the
2341   // caller if you hit this assert.
2342   assert(addr == bottom, "sanity check");
2343 
2344   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2345   return ::mprotect(bottom, size, prot) == 0;
2346 }
2347 
2348 // Set protections specified
2349 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2350                         bool is_committed) {
2351   unsigned int p = 0;
2352   switch (prot) {
2353   case MEM_PROT_NONE: p = PROT_NONE; break;
2354   case MEM_PROT_READ: p = PROT_READ; break;
2355   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2356   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2357   default:
2358     ShouldNotReachHere();
2359   }
2360   // is_committed is unused.
2361   return bsd_mprotect(addr, bytes, p);
2362 }
2363 
2364 bool os::guard_memory(char* addr, size_t size) {
2365   return bsd_mprotect(addr, size, PROT_NONE);
2366 }
2367 
2368 bool os::unguard_memory(char* addr, size_t size) {
2369   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2370 }
2371 
2372 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2373   return false;
2374 }
2375 
2376 // Large page support
2377 
2378 static size_t _large_page_size = 0;
2379 
2380 void os::large_page_init() {
2381 }
2382 
2383 
2384 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2385   fatal("This code is not used or maintained.");
2386 
2387   // "exec" is passed in but not used.  Creating the shared image for
2388   // the code cache doesn't have an SHM_X executable permission to check.
2389   assert(UseLargePages && UseSHM, "only for SHM large pages");
2390 
2391   key_t key = IPC_PRIVATE;
2392   char *addr;
2393 
2394   bool warn_on_failure = UseLargePages &&
2395                          (!FLAG_IS_DEFAULT(UseLargePages) ||
2396                           !FLAG_IS_DEFAULT(LargePageSizeInBytes));
2397 
2398   // Create a large shared memory region to attach to based on size.
2399   // Currently, size is the total size of the heap
2400   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2401   if (shmid == -1) {
2402     // Possible reasons for shmget failure:
2403     // 1. shmmax is too small for Java heap.
2404     //    > check shmmax value: cat /proc/sys/kernel/shmmax
2405     //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2406     // 2. not enough large page memory.
2407     //    > check available large pages: cat /proc/meminfo
2408     //    > increase amount of large pages:
2409     //          echo new_value > /proc/sys/vm/nr_hugepages
2410     //      Note 1: different Bsd may use different name for this property,
2411     //            e.g. on Redhat AS-3 it is "hugetlb_pool".
2412     //      Note 2: it's possible there's enough physical memory available but
2413     //            they are so fragmented after a long run that they can't
2414     //            coalesce into large pages. Try to reserve large pages when
2415     //            the system is still "fresh".
2416     if (warn_on_failure) {
2417       warning("Failed to reserve shared memory (errno = %d).", errno);
2418     }
2419     return NULL;
2420   }
2421 
2422   // attach to the region
2423   addr = (char*)shmat(shmid, req_addr, 0);
2424   int err = errno;
2425 
2426   // Remove shmid. If shmat() is successful, the actual shared memory segment
2427   // will be deleted when it's detached by shmdt() or when the process
2428   // terminates. If shmat() is not successful this will remove the shared
2429   // segment immediately.
2430   shmctl(shmid, IPC_RMID, NULL);
2431 
2432   if ((intptr_t)addr == -1) {
2433     if (warn_on_failure) {
2434       warning("Failed to attach shared memory (errno = %d).", err);
2435     }
2436     return NULL;
2437   }
2438 
2439   // The memory is committed
2440   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
2441 
2442   return addr;
2443 }
2444 
2445 bool os::release_memory_special(char* base, size_t bytes) {
2446   if (MemTracker::tracking_level() > NMT_minimal) {
2447     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2448     // detaching the SHM segment will also delete it, see reserve_memory_special()
2449     int rslt = shmdt(base);
2450     if (rslt == 0) {
2451       tkr.record((address)base, bytes);
2452       return true;
2453     } else {
2454       return false;
2455     }
2456   } else {
2457     return shmdt(base) == 0;
2458   }
2459 }
2460 
2461 size_t os::large_page_size() {
2462   return _large_page_size;
2463 }
2464 
2465 // HugeTLBFS allows application to commit large page memory on demand;
2466 // with SysV SHM the entire memory region must be allocated as shared
2467 // memory.
2468 bool os::can_commit_large_page_memory() {
2469   return UseHugeTLBFS;
2470 }
2471 
2472 bool os::can_execute_large_page_memory() {
2473   return UseHugeTLBFS;
2474 }
2475 
2476 // Reserve memory at an arbitrary address, only if that area is
2477 // available (and not reserved for something else).
2478 
2479 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2480   const int max_tries = 10;
2481   char* base[max_tries];
2482   size_t size[max_tries];
2483   const size_t gap = 0x000000;
2484 
2485   // Assert only that the size is a multiple of the page size, since
2486   // that's all that mmap requires, and since that's all we really know
2487   // about at this low abstraction level.  If we need higher alignment,
2488   // we can either pass an alignment to this method or verify alignment
2489   // in one of the methods further up the call chain.  See bug 5044738.
2490   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2491 
2492   // Repeatedly allocate blocks until the block is allocated at the
2493   // right spot. Give up after max_tries. Note that reserve_memory() will
2494   // automatically update _highest_vm_reserved_address if the call is
2495   // successful. The variable tracks the highest memory address every reserved
2496   // by JVM. It is used to detect heap-stack collision if running with
2497   // fixed-stack BsdThreads. Because here we may attempt to reserve more
2498   // space than needed, it could confuse the collision detecting code. To
2499   // solve the problem, save current _highest_vm_reserved_address and
2500   // calculate the correct value before return.
2501   address old_highest = _highest_vm_reserved_address;
2502 
2503   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2504   // if kernel honors the hint then we can return immediately.
2505   char * addr = anon_mmap(requested_addr, bytes, false);
2506   if (addr == requested_addr) {
2507     return requested_addr;
2508   }
2509 
2510   if (addr != NULL) {
2511     // mmap() is successful but it fails to reserve at the requested address
2512     anon_munmap(addr, bytes);
2513   }
2514 
2515   int i;
2516   for (i = 0; i < max_tries; ++i) {
2517     base[i] = reserve_memory(bytes);
2518 
2519     if (base[i] != NULL) {
2520       // Is this the block we wanted?
2521       if (base[i] == requested_addr) {
2522         size[i] = bytes;
2523         break;
2524       }
2525 
2526       // Does this overlap the block we wanted? Give back the overlapped
2527       // parts and try again.
2528 
2529       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2530       if (top_overlap >= 0 && top_overlap < bytes) {
2531         unmap_memory(base[i], top_overlap);
2532         base[i] += top_overlap;
2533         size[i] = bytes - top_overlap;
2534       } else {
2535         size_t bottom_overlap = base[i] + bytes - requested_addr;
2536         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2537           unmap_memory(requested_addr, bottom_overlap);
2538           size[i] = bytes - bottom_overlap;
2539         } else {
2540           size[i] = bytes;
2541         }
2542       }
2543     }
2544   }
2545 
2546   // Give back the unused reserved pieces.
2547 
2548   for (int j = 0; j < i; ++j) {
2549     if (base[j] != NULL) {
2550       unmap_memory(base[j], size[j]);
2551     }
2552   }
2553 
2554   if (i < max_tries) {
2555     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2556     return requested_addr;
2557   } else {
2558     _highest_vm_reserved_address = old_highest;
2559     return NULL;
2560   }
2561 }
2562 
2563 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2564   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2565 }
2566 
2567 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
2568   RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset));
2569 }
2570 
2571 void os::naked_short_sleep(jlong ms) {
2572   struct timespec req;
2573 
2574   assert(ms < 1000, "Un-interruptable sleep, short time use only");
2575   req.tv_sec = 0;
2576   if (ms > 0) {
2577     req.tv_nsec = (ms % 1000) * 1000000;
2578   } else {
2579     req.tv_nsec = 1;
2580   }
2581 
2582   nanosleep(&req, NULL);
2583 
2584   return;
2585 }
2586 
2587 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2588 void os::infinite_sleep() {
2589   while (true) {    // sleep forever ...
2590     ::sleep(100);   // ... 100 seconds at a time
2591   }
2592 }
2593 
2594 // Used to convert frequent JVM_Yield() to nops
2595 bool os::dont_yield() {
2596   return DontYieldALot;
2597 }
2598 
2599 void os::naked_yield() {
2600   sched_yield();
2601 }
2602 
2603 ////////////////////////////////////////////////////////////////////////////////
2604 // thread priority support
2605 
2606 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2607 // only supports dynamic priority, static priority must be zero. For real-time
2608 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2609 // However, for large multi-threaded applications, SCHED_RR is not only slower
2610 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2611 // of 5 runs - Sep 2005).
2612 //
2613 // The following code actually changes the niceness of kernel-thread/LWP. It
2614 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2615 // not the entire user process, and user level threads are 1:1 mapped to kernel
2616 // threads. It has always been the case, but could change in the future. For
2617 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2618 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2619 
2620 #if !defined(__APPLE__)
2621 int os::java_to_os_priority[CriticalPriority + 1] = {
2622   19,              // 0 Entry should never be used
2623 
2624    0,              // 1 MinPriority
2625    3,              // 2
2626    6,              // 3
2627 
2628   10,              // 4
2629   15,              // 5 NormPriority
2630   18,              // 6
2631 
2632   21,              // 7
2633   25,              // 8
2634   28,              // 9 NearMaxPriority
2635 
2636   31,              // 10 MaxPriority
2637 
2638   31               // 11 CriticalPriority
2639 };
2640 #else
2641 // Using Mach high-level priority assignments
2642 int os::java_to_os_priority[CriticalPriority + 1] = {
2643    0,              // 0 Entry should never be used (MINPRI_USER)
2644 
2645   27,              // 1 MinPriority
2646   28,              // 2
2647   29,              // 3
2648 
2649   30,              // 4
2650   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2651   32,              // 6
2652 
2653   33,              // 7
2654   34,              // 8
2655   35,              // 9 NearMaxPriority
2656 
2657   36,              // 10 MaxPriority
2658 
2659   36               // 11 CriticalPriority
2660 };
2661 #endif
2662 
2663 static int prio_init() {
2664   if (ThreadPriorityPolicy == 1) {
2665     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2666     // if effective uid is not root. Perhaps, a more elegant way of doing
2667     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2668     if (geteuid() != 0) {
2669       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2670         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2671       }
2672       ThreadPriorityPolicy = 0;
2673     }
2674   }
2675   if (UseCriticalJavaThreadPriority) {
2676     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2677   }
2678   return 0;
2679 }
2680 
2681 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2682   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2683 
2684 #ifdef __OpenBSD__
2685   // OpenBSD pthread_setprio starves low priority threads
2686   return OS_OK;
2687 #elif defined(__FreeBSD__)
2688   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2689 #elif defined(__APPLE__) || defined(__NetBSD__)
2690   struct sched_param sp;
2691   int policy;
2692   pthread_t self = pthread_self();
2693 
2694   if (pthread_getschedparam(self, &policy, &sp) != 0) {
2695     return OS_ERR;
2696   }
2697 
2698   sp.sched_priority = newpri;
2699   if (pthread_setschedparam(self, policy, &sp) != 0) {
2700     return OS_ERR;
2701   }
2702 
2703   return OS_OK;
2704 #else
2705   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2706   return (ret == 0) ? OS_OK : OS_ERR;
2707 #endif
2708 }
2709 
2710 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2711   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2712     *priority_ptr = java_to_os_priority[NormPriority];
2713     return OS_OK;
2714   }
2715 
2716   errno = 0;
2717 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2718   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2719 #elif defined(__APPLE__) || defined(__NetBSD__)
2720   int policy;
2721   struct sched_param sp;
2722 
2723   pthread_getschedparam(pthread_self(), &policy, &sp);
2724   *priority_ptr = sp.sched_priority;
2725 #else
2726   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2727 #endif
2728   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2729 }
2730 
2731 // Hint to the underlying OS that a task switch would not be good.
2732 // Void return because it's a hint and can fail.
2733 void os::hint_no_preempt() {}
2734 
2735 ////////////////////////////////////////////////////////////////////////////////
2736 // suspend/resume support
2737 
2738 //  the low-level signal-based suspend/resume support is a remnant from the
2739 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2740 //  within hotspot. Now there is a single use-case for this:
2741 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
2742 //      that runs in the watcher thread.
2743 //  The remaining code is greatly simplified from the more general suspension
2744 //  code that used to be used.
2745 //
2746 //  The protocol is quite simple:
2747 //  - suspend:
2748 //      - sends a signal to the target thread
2749 //      - polls the suspend state of the osthread using a yield loop
2750 //      - target thread signal handler (SR_handler) sets suspend state
2751 //        and blocks in sigsuspend until continued
2752 //  - resume:
2753 //      - sets target osthread state to continue
2754 //      - sends signal to end the sigsuspend loop in the SR_handler
2755 //
2756 //  Note that the SR_lock plays no role in this suspend/resume protocol.
2757 
2758 static void resume_clear_context(OSThread *osthread) {
2759   osthread->set_ucontext(NULL);
2760   osthread->set_siginfo(NULL);
2761 }
2762 
2763 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2764   osthread->set_ucontext(context);
2765   osthread->set_siginfo(siginfo);
2766 }
2767 
2768 // Handler function invoked when a thread's execution is suspended or
2769 // resumed. We have to be careful that only async-safe functions are
2770 // called here (Note: most pthread functions are not async safe and
2771 // should be avoided.)
2772 //
2773 // Note: sigwait() is a more natural fit than sigsuspend() from an
2774 // interface point of view, but sigwait() prevents the signal hander
2775 // from being run. libpthread would get very confused by not having
2776 // its signal handlers run and prevents sigwait()'s use with the
2777 // mutex granting granting signal.
2778 //
2779 // Currently only ever called on the VMThread or JavaThread
2780 //
2781 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2782   // Save and restore errno to avoid confusing native code with EINTR
2783   // after sigsuspend.
2784   int old_errno = errno;
2785 
2786   Thread* thread = Thread::current();
2787   OSThread* osthread = thread->osthread();
2788   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2789 
2790   os::SuspendResume::State current = osthread->sr.state();
2791   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2792     suspend_save_context(osthread, siginfo, context);
2793 
2794     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2795     os::SuspendResume::State state = osthread->sr.suspended();
2796     if (state == os::SuspendResume::SR_SUSPENDED) {
2797       sigset_t suspend_set;  // signals for sigsuspend()
2798 
2799       // get current set of blocked signals and unblock resume signal
2800       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2801       sigdelset(&suspend_set, SR_signum);
2802 
2803       sr_semaphore.signal();
2804       // wait here until we are resumed
2805       while (1) {
2806         sigsuspend(&suspend_set);
2807 
2808         os::SuspendResume::State result = osthread->sr.running();
2809         if (result == os::SuspendResume::SR_RUNNING) {
2810           sr_semaphore.signal();
2811           break;
2812         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2813           ShouldNotReachHere();
2814         }
2815       }
2816 
2817     } else if (state == os::SuspendResume::SR_RUNNING) {
2818       // request was cancelled, continue
2819     } else {
2820       ShouldNotReachHere();
2821     }
2822 
2823     resume_clear_context(osthread);
2824   } else if (current == os::SuspendResume::SR_RUNNING) {
2825     // request was cancelled, continue
2826   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2827     // ignore
2828   } else {
2829     // ignore
2830   }
2831 
2832   errno = old_errno;
2833 }
2834 
2835 
2836 static int SR_initialize() {
2837   struct sigaction act;
2838   char *s;
2839   // Get signal number to use for suspend/resume
2840   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2841     int sig = ::strtol(s, 0, 10);
2842     if (sig > 0 || sig < NSIG) {
2843       SR_signum = sig;
2844     }
2845   }
2846 
2847   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2848          "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2849 
2850   sigemptyset(&SR_sigset);
2851   sigaddset(&SR_sigset, SR_signum);
2852 
2853   // Set up signal handler for suspend/resume
2854   act.sa_flags = SA_RESTART|SA_SIGINFO;
2855   act.sa_handler = (void (*)(int)) SR_handler;
2856 
2857   // SR_signum is blocked by default.
2858   // 4528190 - We also need to block pthread restart signal (32 on all
2859   // supported Bsd platforms). Note that BsdThreads need to block
2860   // this signal for all threads to work properly. So we don't have
2861   // to use hard-coded signal number when setting up the mask.
2862   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2863 
2864   if (sigaction(SR_signum, &act, 0) == -1) {
2865     return -1;
2866   }
2867 
2868   // Save signal flag
2869   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2870   return 0;
2871 }
2872 
2873 static int sr_notify(OSThread* osthread) {
2874   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2875   assert_status(status == 0, status, "pthread_kill");
2876   return status;
2877 }
2878 
2879 // "Randomly" selected value for how long we want to spin
2880 // before bailing out on suspending a thread, also how often
2881 // we send a signal to a thread we want to resume
2882 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2883 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2884 
2885 // returns true on success and false on error - really an error is fatal
2886 // but this seems the normal response to library errors
2887 static bool do_suspend(OSThread* osthread) {
2888   assert(osthread->sr.is_running(), "thread should be running");
2889   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2890 
2891   // mark as suspended and send signal
2892   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2893     // failed to switch, state wasn't running?
2894     ShouldNotReachHere();
2895     return false;
2896   }
2897 
2898   if (sr_notify(osthread) != 0) {
2899     ShouldNotReachHere();
2900   }
2901 
2902   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2903   while (true) {
2904     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2905       break;
2906     } else {
2907       // timeout
2908       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2909       if (cancelled == os::SuspendResume::SR_RUNNING) {
2910         return false;
2911       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2912         // make sure that we consume the signal on the semaphore as well
2913         sr_semaphore.wait();
2914         break;
2915       } else {
2916         ShouldNotReachHere();
2917         return false;
2918       }
2919     }
2920   }
2921 
2922   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2923   return true;
2924 }
2925 
2926 static void do_resume(OSThread* osthread) {
2927   assert(osthread->sr.is_suspended(), "thread should be suspended");
2928   assert(!sr_semaphore.trywait(), "invalid semaphore state");
2929 
2930   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2931     // failed to switch to WAKEUP_REQUEST
2932     ShouldNotReachHere();
2933     return;
2934   }
2935 
2936   while (true) {
2937     if (sr_notify(osthread) == 0) {
2938       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2939         if (osthread->sr.is_running()) {
2940           return;
2941         }
2942       }
2943     } else {
2944       ShouldNotReachHere();
2945     }
2946   }
2947 
2948   guarantee(osthread->sr.is_running(), "Must be running!");
2949 }
2950 
2951 ///////////////////////////////////////////////////////////////////////////////////
2952 // signal handling (except suspend/resume)
2953 
2954 // This routine may be used by user applications as a "hook" to catch signals.
2955 // The user-defined signal handler must pass unrecognized signals to this
2956 // routine, and if it returns true (non-zero), then the signal handler must
2957 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
2958 // routine will never retun false (zero), but instead will execute a VM panic
2959 // routine kill the process.
2960 //
2961 // If this routine returns false, it is OK to call it again.  This allows
2962 // the user-defined signal handler to perform checks either before or after
2963 // the VM performs its own checks.  Naturally, the user code would be making
2964 // a serious error if it tried to handle an exception (such as a null check
2965 // or breakpoint) that the VM was generating for its own correct operation.
2966 //
2967 // This routine may recognize any of the following kinds of signals:
2968 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2969 // It should be consulted by handlers for any of those signals.
2970 //
2971 // The caller of this routine must pass in the three arguments supplied
2972 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2973 // field of the structure passed to sigaction().  This routine assumes that
2974 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2975 //
2976 // Note that the VM will print warnings if it detects conflicting signal
2977 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2978 //
2979 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2980                                                void* ucontext,
2981                                                int abort_if_unrecognized);
2982 
2983 void signalHandler(int sig, siginfo_t* info, void* uc) {
2984   assert(info != NULL && uc != NULL, "it must be old kernel");
2985   int orig_errno = errno;  // Preserve errno value over signal handler.
2986   JVM_handle_bsd_signal(sig, info, uc, true);
2987   errno = orig_errno;
2988 }
2989 
2990 
2991 // This boolean allows users to forward their own non-matching signals
2992 // to JVM_handle_bsd_signal, harmlessly.
2993 bool os::Bsd::signal_handlers_are_installed = false;
2994 
2995 // For signal-chaining
2996 struct sigaction os::Bsd::sigact[MAXSIGNUM];
2997 unsigned int os::Bsd::sigs = 0;
2998 bool os::Bsd::libjsig_is_loaded = false;
2999 typedef struct sigaction *(*get_signal_t)(int);
3000 get_signal_t os::Bsd::get_signal_action = NULL;
3001 
3002 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
3003   struct sigaction *actp = NULL;
3004 
3005   if (libjsig_is_loaded) {
3006     // Retrieve the old signal handler from libjsig
3007     actp = (*get_signal_action)(sig);
3008   }
3009   if (actp == NULL) {
3010     // Retrieve the preinstalled signal handler from jvm
3011     actp = get_preinstalled_handler(sig);
3012   }
3013 
3014   return actp;
3015 }
3016 
3017 static bool call_chained_handler(struct sigaction *actp, int sig,
3018                                  siginfo_t *siginfo, void *context) {
3019   // Call the old signal handler
3020   if (actp->sa_handler == SIG_DFL) {
3021     // It's more reasonable to let jvm treat it as an unexpected exception
3022     // instead of taking the default action.
3023     return false;
3024   } else if (actp->sa_handler != SIG_IGN) {
3025     if ((actp->sa_flags & SA_NODEFER) == 0) {
3026       // automaticlly block the signal
3027       sigaddset(&(actp->sa_mask), sig);
3028     }
3029 
3030     sa_handler_t hand;
3031     sa_sigaction_t sa;
3032     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3033     // retrieve the chained handler
3034     if (siginfo_flag_set) {
3035       sa = actp->sa_sigaction;
3036     } else {
3037       hand = actp->sa_handler;
3038     }
3039 
3040     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3041       actp->sa_handler = SIG_DFL;
3042     }
3043 
3044     // try to honor the signal mask
3045     sigset_t oset;
3046     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3047 
3048     // call into the chained handler
3049     if (siginfo_flag_set) {
3050       (*sa)(sig, siginfo, context);
3051     } else {
3052       (*hand)(sig);
3053     }
3054 
3055     // restore the signal mask
3056     pthread_sigmask(SIG_SETMASK, &oset, 0);
3057   }
3058   // Tell jvm's signal handler the signal is taken care of.
3059   return true;
3060 }
3061 
3062 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3063   bool chained = false;
3064   // signal-chaining
3065   if (UseSignalChaining) {
3066     struct sigaction *actp = get_chained_signal_action(sig);
3067     if (actp != NULL) {
3068       chained = call_chained_handler(actp, sig, siginfo, context);
3069     }
3070   }
3071   return chained;
3072 }
3073 
3074 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3075   if ((((unsigned int)1 << sig) & sigs) != 0) {
3076     return &sigact[sig];
3077   }
3078   return NULL;
3079 }
3080 
3081 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3082   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3083   sigact[sig] = oldAct;
3084   sigs |= (unsigned int)1 << sig;
3085 }
3086 
3087 // for diagnostic
3088 int os::Bsd::sigflags[MAXSIGNUM];
3089 
3090 int os::Bsd::get_our_sigflags(int sig) {
3091   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3092   return sigflags[sig];
3093 }
3094 
3095 void os::Bsd::set_our_sigflags(int sig, int flags) {
3096   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3097   sigflags[sig] = flags;
3098 }
3099 
3100 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3101   // Check for overwrite.
3102   struct sigaction oldAct;
3103   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3104 
3105   void* oldhand = oldAct.sa_sigaction
3106                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
3107                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
3108   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3109       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3110       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3111     if (AllowUserSignalHandlers || !set_installed) {
3112       // Do not overwrite; user takes responsibility to forward to us.
3113       return;
3114     } else if (UseSignalChaining) {
3115       // save the old handler in jvm
3116       save_preinstalled_handler(sig, oldAct);
3117       // libjsig also interposes the sigaction() call below and saves the
3118       // old sigaction on it own.
3119     } else {
3120       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3121                     "%#lx for signal %d.", (long)oldhand, sig));
3122     }
3123   }
3124 
3125   struct sigaction sigAct;
3126   sigfillset(&(sigAct.sa_mask));
3127   sigAct.sa_handler = SIG_DFL;
3128   if (!set_installed) {
3129     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3130   } else {
3131     sigAct.sa_sigaction = signalHandler;
3132     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3133   }
3134 #ifdef __APPLE__
3135   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3136   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3137   // if the signal handler declares it will handle it on alternate stack.
3138   // Notice we only declare we will handle it on alt stack, but we are not
3139   // actually going to use real alt stack - this is just a workaround.
3140   // Please see ux_exception.c, method catch_mach_exception_raise for details
3141   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3142   if (sig == SIGSEGV) {
3143     sigAct.sa_flags |= SA_ONSTACK;
3144   }
3145 #endif
3146 
3147   // Save flags, which are set by ours
3148   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3149   sigflags[sig] = sigAct.sa_flags;
3150 
3151   int ret = sigaction(sig, &sigAct, &oldAct);
3152   assert(ret == 0, "check");
3153 
3154   void* oldhand2  = oldAct.sa_sigaction
3155                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3156                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3157   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3158 }
3159 
3160 // install signal handlers for signals that HotSpot needs to
3161 // handle in order to support Java-level exception handling.
3162 
3163 void os::Bsd::install_signal_handlers() {
3164   if (!signal_handlers_are_installed) {
3165     signal_handlers_are_installed = true;
3166 
3167     // signal-chaining
3168     typedef void (*signal_setting_t)();
3169     signal_setting_t begin_signal_setting = NULL;
3170     signal_setting_t end_signal_setting = NULL;
3171     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3172                                           dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3173     if (begin_signal_setting != NULL) {
3174       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3175                                           dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3176       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3177                                          dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3178       libjsig_is_loaded = true;
3179       assert(UseSignalChaining, "should enable signal-chaining");
3180     }
3181     if (libjsig_is_loaded) {
3182       // Tell libjsig jvm is setting signal handlers
3183       (*begin_signal_setting)();
3184     }
3185 
3186     set_signal_handler(SIGSEGV, true);
3187     set_signal_handler(SIGPIPE, true);
3188     set_signal_handler(SIGBUS, true);
3189     set_signal_handler(SIGILL, true);
3190     set_signal_handler(SIGFPE, true);
3191     set_signal_handler(SIGXFSZ, true);
3192 
3193 #if defined(__APPLE__)
3194     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3195     // signals caught and handled by the JVM. To work around this, we reset the mach task
3196     // signal handler that's placed on our process by CrashReporter. This disables
3197     // CrashReporter-based reporting.
3198     //
3199     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3200     // on caught fatal signals.
3201     //
3202     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3203     // handlers. By replacing the existing task exception handler, we disable gdb's mach
3204     // exception handling, while leaving the standard BSD signal handlers functional.
3205     kern_return_t kr;
3206     kr = task_set_exception_ports(mach_task_self(),
3207                                   EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3208                                   MACH_PORT_NULL,
3209                                   EXCEPTION_STATE_IDENTITY,
3210                                   MACHINE_THREAD_STATE);
3211 
3212     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3213 #endif
3214 
3215     if (libjsig_is_loaded) {
3216       // Tell libjsig jvm finishes setting signal handlers
3217       (*end_signal_setting)();
3218     }
3219 
3220     // We don't activate signal checker if libjsig is in place, we trust ourselves
3221     // and if UserSignalHandler is installed all bets are off
3222     if (CheckJNICalls) {
3223       if (libjsig_is_loaded) {
3224         if (PrintJNIResolving) {
3225           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3226         }
3227         check_signals = false;
3228       }
3229       if (AllowUserSignalHandlers) {
3230         if (PrintJNIResolving) {
3231           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3232         }
3233         check_signals = false;
3234       }
3235     }
3236   }
3237 }
3238 
3239 
3240 /////
3241 // glibc on Bsd platform uses non-documented flag
3242 // to indicate, that some special sort of signal
3243 // trampoline is used.
3244 // We will never set this flag, and we should
3245 // ignore this flag in our diagnostic
3246 #ifdef SIGNIFICANT_SIGNAL_MASK
3247   #undef SIGNIFICANT_SIGNAL_MASK
3248 #endif
3249 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3250 
3251 static const char* get_signal_handler_name(address handler,
3252                                            char* buf, int buflen) {
3253   int offset;
3254   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3255   if (found) {
3256     // skip directory names
3257     const char *p1, *p2;
3258     p1 = buf;
3259     size_t len = strlen(os::file_separator());
3260     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3261     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3262   } else {
3263     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3264   }
3265   return buf;
3266 }
3267 
3268 static void print_signal_handler(outputStream* st, int sig,
3269                                  char* buf, size_t buflen) {
3270   struct sigaction sa;
3271 
3272   sigaction(sig, NULL, &sa);
3273 
3274   // See comment for SIGNIFICANT_SIGNAL_MASK define
3275   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3276 
3277   st->print("%s: ", os::exception_name(sig, buf, buflen));
3278 
3279   address handler = (sa.sa_flags & SA_SIGINFO)
3280     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3281     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3282 
3283   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3284     st->print("SIG_DFL");
3285   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3286     st->print("SIG_IGN");
3287   } else {
3288     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3289   }
3290 
3291   st->print(", sa_mask[0]=");
3292   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3293 
3294   address rh = VMError::get_resetted_sighandler(sig);
3295   // May be, handler was resetted by VMError?
3296   if (rh != NULL) {
3297     handler = rh;
3298     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3299   }
3300 
3301   st->print(", sa_flags=");
3302   os::Posix::print_sa_flags(st, sa.sa_flags);
3303 
3304   // Check: is it our handler?
3305   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3306       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3307     // It is our signal handler
3308     // check for flags, reset system-used one!
3309     if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3310       st->print(
3311                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3312                 os::Bsd::get_our_sigflags(sig));
3313     }
3314   }
3315   st->cr();
3316 }
3317 
3318 
3319 #define DO_SIGNAL_CHECK(sig)                      \
3320   do {                                            \
3321     if (!sigismember(&check_signal_done, sig)) {  \
3322       os::Bsd::check_signal_handler(sig);         \
3323     }                                             \
3324   } while (0)
3325 
3326 // This method is a periodic task to check for misbehaving JNI applications
3327 // under CheckJNI, we can add any periodic checks here
3328 
3329 void os::run_periodic_checks() {
3330 
3331   if (check_signals == false) return;
3332 
3333   // SEGV and BUS if overridden could potentially prevent
3334   // generation of hs*.log in the event of a crash, debugging
3335   // such a case can be very challenging, so we absolutely
3336   // check the following for a good measure:
3337   DO_SIGNAL_CHECK(SIGSEGV);
3338   DO_SIGNAL_CHECK(SIGILL);
3339   DO_SIGNAL_CHECK(SIGFPE);
3340   DO_SIGNAL_CHECK(SIGBUS);
3341   DO_SIGNAL_CHECK(SIGPIPE);
3342   DO_SIGNAL_CHECK(SIGXFSZ);
3343 
3344 
3345   // ReduceSignalUsage allows the user to override these handlers
3346   // see comments at the very top and jvm_solaris.h
3347   if (!ReduceSignalUsage) {
3348     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3349     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3350     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3351     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3352   }
3353 
3354   DO_SIGNAL_CHECK(SR_signum);
3355   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3356 }
3357 
3358 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3359 
3360 static os_sigaction_t os_sigaction = NULL;
3361 
3362 void os::Bsd::check_signal_handler(int sig) {
3363   char buf[O_BUFLEN];
3364   address jvmHandler = NULL;
3365 
3366 
3367   struct sigaction act;
3368   if (os_sigaction == NULL) {
3369     // only trust the default sigaction, in case it has been interposed
3370     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3371     if (os_sigaction == NULL) return;
3372   }
3373 
3374   os_sigaction(sig, (struct sigaction*)NULL, &act);
3375 
3376 
3377   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3378 
3379   address thisHandler = (act.sa_flags & SA_SIGINFO)
3380     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3381     : CAST_FROM_FN_PTR(address, act.sa_handler);
3382 
3383 
3384   switch (sig) {
3385   case SIGSEGV:
3386   case SIGBUS:
3387   case SIGFPE:
3388   case SIGPIPE:
3389   case SIGILL:
3390   case SIGXFSZ:
3391     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3392     break;
3393 
3394   case SHUTDOWN1_SIGNAL:
3395   case SHUTDOWN2_SIGNAL:
3396   case SHUTDOWN3_SIGNAL:
3397   case BREAK_SIGNAL:
3398     jvmHandler = (address)user_handler();
3399     break;
3400 
3401   case INTERRUPT_SIGNAL:
3402     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3403     break;
3404 
3405   default:
3406     if (sig == SR_signum) {
3407       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3408     } else {
3409       return;
3410     }
3411     break;
3412   }
3413 
3414   if (thisHandler != jvmHandler) {
3415     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3416     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3417     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3418     // No need to check this sig any longer
3419     sigaddset(&check_signal_done, sig);
3420     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3421     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3422       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3423                     exception_name(sig, buf, O_BUFLEN));
3424     }
3425   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3426     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3427     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3428     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
3429     // No need to check this sig any longer
3430     sigaddset(&check_signal_done, sig);
3431   }
3432 
3433   // Dump all the signal
3434   if (sigismember(&check_signal_done, sig)) {
3435     print_signal_handlers(tty, buf, O_BUFLEN);
3436   }
3437 }
3438 
3439 extern void report_error(char* file_name, int line_no, char* title,
3440                          char* format, ...);
3441 
3442 extern bool signal_name(int signo, char* buf, size_t len);
3443 
3444 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3445   if (0 < exception_code && exception_code <= SIGRTMAX) {
3446     // signal
3447     if (!signal_name(exception_code, buf, size)) {
3448       jio_snprintf(buf, size, "SIG%d", exception_code);
3449     }
3450     return buf;
3451   } else {
3452     return NULL;
3453   }
3454 }
3455 
3456 // this is called _before_ the most of global arguments have been parsed
3457 void os::init(void) {
3458   char dummy;   // used to get a guess on initial stack address
3459 //  first_hrtime = gethrtime();
3460 
3461   // With BsdThreads the JavaMain thread pid (primordial thread)
3462   // is different than the pid of the java launcher thread.
3463   // So, on Bsd, the launcher thread pid is passed to the VM
3464   // via the sun.java.launcher.pid property.
3465   // Use this property instead of getpid() if it was correctly passed.
3466   // See bug 6351349.
3467   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3468 
3469   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3470 
3471   clock_tics_per_sec = CLK_TCK;
3472 
3473   init_random(1234567);
3474 
3475   ThreadCritical::initialize();
3476 
3477   Bsd::set_page_size(getpagesize());
3478   if (Bsd::page_size() == -1) {
3479     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3480                   strerror(errno)));
3481   }
3482   init_page_sizes((size_t) Bsd::page_size());
3483 
3484   Bsd::initialize_system_info();
3485 
3486   // main_thread points to the aboriginal thread
3487   Bsd::_main_thread = pthread_self();
3488 
3489   Bsd::clock_init();
3490   initial_time_count = javaTimeNanos();
3491 
3492 #ifdef __APPLE__
3493   // XXXDARWIN
3494   // Work around the unaligned VM callbacks in hotspot's
3495   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3496   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3497   // alignment when doing symbol lookup. To work around this, we force early
3498   // binding of all symbols now, thus binding when alignment is known-good.
3499   _dyld_bind_fully_image_containing_address((const void *) &os::init);
3500 #endif
3501 }
3502 
3503 // To install functions for atexit system call
3504 extern "C" {
3505   static void perfMemory_exit_helper() {
3506     perfMemory_exit();
3507   }
3508 }
3509 
3510 // this is called _after_ the global arguments have been parsed
3511 jint os::init_2(void) {
3512   // Allocate a single page and mark it as readable for safepoint polling
3513   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3514   guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page");
3515 
3516   os::set_polling_page(polling_page);
3517 
3518 #ifndef PRODUCT
3519   if (Verbose && PrintMiscellaneous) {
3520     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n",
3521                (intptr_t)polling_page);
3522   }
3523 #endif
3524 
3525   if (!UseMembar) {
3526     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3527     guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3528     os::set_memory_serialize_page(mem_serialize_page);
3529 
3530 #ifndef PRODUCT
3531     if (Verbose && PrintMiscellaneous) {
3532       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n",
3533                  (intptr_t)mem_serialize_page);
3534     }
3535 #endif
3536   }
3537 
3538   // initialize suspend/resume support - must do this before signal_sets_init()
3539   if (SR_initialize() != 0) {
3540     perror("SR_initialize failed");
3541     return JNI_ERR;
3542   }
3543 
3544   Bsd::signal_sets_init();
3545   Bsd::install_signal_handlers();
3546 
3547   // Check minimum allowable stack size for thread creation and to initialize
3548   // the java system classes, including StackOverflowError - depends on page
3549   // size.  Add a page for compiler2 recursion in main thread.
3550   // Add in 2*BytesPerWord times page size to account for VM stack during
3551   // class initialization depending on 32 or 64 bit VM.
3552   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3553                                     (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3554                                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3555 
3556   size_t threadStackSizeInBytes = ThreadStackSize * K;
3557   if (threadStackSizeInBytes != 0 &&
3558       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3559     tty->print_cr("\nThe stack size specified is too small, "
3560                   "Specify at least %dk",
3561                   os::Bsd::min_stack_allowed/ K);
3562     return JNI_ERR;
3563   }
3564 
3565   // Make the stack size a multiple of the page size so that
3566   // the yellow/red zones can be guarded.
3567   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3568                                                 vm_page_size()));
3569 
3570   if (MaxFDLimit) {
3571     // set the number of file descriptors to max. print out error
3572     // if getrlimit/setrlimit fails but continue regardless.
3573     struct rlimit nbr_files;
3574     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3575     if (status != 0) {
3576       if (PrintMiscellaneous && (Verbose || WizardMode)) {
3577         perror("os::init_2 getrlimit failed");
3578       }
3579     } else {
3580       nbr_files.rlim_cur = nbr_files.rlim_max;
3581 
3582 #ifdef __APPLE__
3583       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3584       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3585       // be used instead
3586       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3587 #endif
3588 
3589       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3590       if (status != 0) {
3591         if (PrintMiscellaneous && (Verbose || WizardMode)) {
3592           perror("os::init_2 setrlimit failed");
3593         }
3594       }
3595     }
3596   }
3597 
3598   // at-exit methods are called in the reverse order of their registration.
3599   // atexit functions are called on return from main or as a result of a
3600   // call to exit(3C). There can be only 32 of these functions registered
3601   // and atexit() does not set errno.
3602 
3603   if (PerfAllowAtExitRegistration) {
3604     // only register atexit functions if PerfAllowAtExitRegistration is set.
3605     // atexit functions can be delayed until process exit time, which
3606     // can be problematic for embedded VM situations. Embedded VMs should
3607     // call DestroyJavaVM() to assure that VM resources are released.
3608 
3609     // note: perfMemory_exit_helper atexit function may be removed in
3610     // the future if the appropriate cleanup code can be added to the
3611     // VM_Exit VMOperation's doit method.
3612     if (atexit(perfMemory_exit_helper) != 0) {
3613       warning("os::init2 atexit(perfMemory_exit_helper) failed");
3614     }
3615   }
3616 
3617   // initialize thread priority policy
3618   prio_init();
3619 
3620 #ifdef __APPLE__
3621   // dynamically link to objective c gc registration
3622   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3623   if (handleLibObjc != NULL) {
3624     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3625   }
3626 #endif
3627 
3628   return JNI_OK;
3629 }
3630 
3631 // Mark the polling page as unreadable
3632 void os::make_polling_page_unreadable(void) {
3633   if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3634     fatal("Could not disable polling page");
3635   }
3636 }
3637 
3638 // Mark the polling page as readable
3639 void os::make_polling_page_readable(void) {
3640   if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3641     fatal("Could not enable polling page");
3642   }
3643 }
3644 
3645 int os::active_processor_count() {
3646   return _processor_count;
3647 }
3648 
3649 void os::set_native_thread_name(const char *name) {
3650 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3651   // This is only supported in Snow Leopard and beyond
3652   if (name != NULL) {
3653     // Add a "Java: " prefix to the name
3654     char buf[MAXTHREADNAMESIZE];
3655     snprintf(buf, sizeof(buf), "Java: %s", name);
3656     pthread_setname_np(buf);
3657   }
3658 #endif
3659 }
3660 
3661 bool os::distribute_processes(uint length, uint* distribution) {
3662   // Not yet implemented.
3663   return false;
3664 }
3665 
3666 bool os::bind_to_processor(uint processor_id) {
3667   // Not yet implemented.
3668   return false;
3669 }
3670 
3671 void os::SuspendedThreadTask::internal_do_task() {
3672   if (do_suspend(_thread->osthread())) {
3673     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3674     do_task(context);
3675     do_resume(_thread->osthread());
3676   }
3677 }
3678 
3679 ///
3680 class PcFetcher : public os::SuspendedThreadTask {
3681  public:
3682   PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3683   ExtendedPC result();
3684  protected:
3685   void do_task(const os::SuspendedThreadTaskContext& context);
3686  private:
3687   ExtendedPC _epc;
3688 };
3689 
3690 ExtendedPC PcFetcher::result() {
3691   guarantee(is_done(), "task is not done yet.");
3692   return _epc;
3693 }
3694 
3695 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3696   Thread* thread = context.thread();
3697   OSThread* osthread = thread->osthread();
3698   if (osthread->ucontext() != NULL) {
3699     _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
3700   } else {
3701     // NULL context is unexpected, double-check this is the VMThread
3702     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3703   }
3704 }
3705 
3706 // Suspends the target using the signal mechanism and then grabs the PC before
3707 // resuming the target. Used by the flat-profiler only
3708 ExtendedPC os::get_thread_pc(Thread* thread) {
3709   // Make sure that it is called by the watcher for the VMThread
3710   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3711   assert(thread->is_VM_thread(), "Can only be called for VMThread");
3712 
3713   PcFetcher fetcher(thread);
3714   fetcher.run();
3715   return fetcher.result();
3716 }
3717 
3718 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond,
3719                                  pthread_mutex_t *_mutex,
3720                                  const struct timespec *_abstime) {
3721   return pthread_cond_timedwait(_cond, _mutex, _abstime);
3722 }
3723 
3724 ////////////////////////////////////////////////////////////////////////////////
3725 // debug support
3726 
3727 bool os::find(address addr, outputStream* st) {
3728   Dl_info dlinfo;
3729   memset(&dlinfo, 0, sizeof(dlinfo));
3730   if (dladdr(addr, &dlinfo) != 0) {
3731     st->print(PTR_FORMAT ": ", addr);
3732     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3733       st->print("%s+%#x", dlinfo.dli_sname,
3734                 addr - (intptr_t)dlinfo.dli_saddr);
3735     } else if (dlinfo.dli_fbase != NULL) {
3736       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3737     } else {
3738       st->print("<absolute address>");
3739     }
3740     if (dlinfo.dli_fname != NULL) {
3741       st->print(" in %s", dlinfo.dli_fname);
3742     }
3743     if (dlinfo.dli_fbase != NULL) {
3744       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3745     }
3746     st->cr();
3747 
3748     if (Verbose) {
3749       // decode some bytes around the PC
3750       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3751       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3752       address       lowest = (address) dlinfo.dli_sname;
3753       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3754       if (begin < lowest)  begin = lowest;
3755       Dl_info dlinfo2;
3756       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3757           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3758         end = (address) dlinfo2.dli_saddr;
3759       }
3760       Disassembler::decode(begin, end, st);
3761     }
3762     return true;
3763   }
3764   return false;
3765 }
3766 
3767 ////////////////////////////////////////////////////////////////////////////////
3768 // misc
3769 
3770 // This does not do anything on Bsd. This is basically a hook for being
3771 // able to use structured exception handling (thread-local exception filters)
3772 // on, e.g., Win32.
3773 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3774                               methodHandle* method, JavaCallArguments* args,
3775                               Thread* thread) {
3776   f(value, method, args, thread);
3777 }
3778 
3779 void os::print_statistics() {
3780 }
3781 
3782 int os::message_box(const char* title, const char* message) {
3783   int i;
3784   fdStream err(defaultStream::error_fd());
3785   for (i = 0; i < 78; i++) err.print_raw("=");
3786   err.cr();
3787   err.print_raw_cr(title);
3788   for (i = 0; i < 78; i++) err.print_raw("-");
3789   err.cr();
3790   err.print_raw_cr(message);
3791   for (i = 0; i < 78; i++) err.print_raw("=");
3792   err.cr();
3793 
3794   char buf[16];
3795   // Prevent process from exiting upon "read error" without consuming all CPU
3796   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3797 
3798   return buf[0] == 'y' || buf[0] == 'Y';
3799 }
3800 
3801 int os::stat(const char *path, struct stat *sbuf) {
3802   char pathbuf[MAX_PATH];
3803   if (strlen(path) > MAX_PATH - 1) {
3804     errno = ENAMETOOLONG;
3805     return -1;
3806   }
3807   os::native_path(strcpy(pathbuf, path));
3808   return ::stat(pathbuf, sbuf);
3809 }
3810 
3811 bool os::check_heap(bool force) {
3812   return true;
3813 }
3814 
3815 // Is a (classpath) directory empty?
3816 bool os::dir_is_empty(const char* path) {
3817   DIR *dir = NULL;
3818   struct dirent *ptr;
3819 
3820   dir = opendir(path);
3821   if (dir == NULL) return true;
3822 
3823   // Scan the directory
3824   bool result = true;
3825   char buf[sizeof(struct dirent) + MAX_PATH];
3826   while (result && (ptr = ::readdir(dir)) != NULL) {
3827     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3828       result = false;
3829     }
3830   }
3831   closedir(dir);
3832   return result;
3833 }
3834 
3835 // This code originates from JDK's sysOpen and open64_w
3836 // from src/solaris/hpi/src/system_md.c
3837 
3838 int os::open(const char *path, int oflag, int mode) {
3839   if (strlen(path) > MAX_PATH - 1) {
3840     errno = ENAMETOOLONG;
3841     return -1;
3842   }
3843   int fd;
3844 
3845   fd = ::open(path, oflag, mode);
3846   if (fd == -1) return -1;
3847 
3848   // If the open succeeded, the file might still be a directory
3849   {
3850     struct stat buf;
3851     int ret = ::fstat(fd, &buf);
3852     int st_mode = buf.st_mode;
3853 
3854     if (ret != -1) {
3855       if ((st_mode & S_IFMT) == S_IFDIR) {
3856         errno = EISDIR;
3857         ::close(fd);
3858         return -1;
3859       }
3860     } else {
3861       ::close(fd);
3862       return -1;
3863     }
3864   }
3865 
3866   // All file descriptors that are opened in the JVM and not
3867   // specifically destined for a subprocess should have the
3868   // close-on-exec flag set.  If we don't set it, then careless 3rd
3869   // party native code might fork and exec without closing all
3870   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3871   // UNIXProcess.c), and this in turn might:
3872   //
3873   // - cause end-of-file to fail to be detected on some file
3874   //   descriptors, resulting in mysterious hangs, or
3875   //
3876   // - might cause an fopen in the subprocess to fail on a system
3877   //   suffering from bug 1085341.
3878   //
3879   // (Yes, the default setting of the close-on-exec flag is a Unix
3880   // design flaw)
3881   //
3882   // See:
3883   // 1085341: 32-bit stdio routines should support file descriptors >255
3884   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3885   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3886   //
3887 #ifdef FD_CLOEXEC
3888   {
3889     int flags = ::fcntl(fd, F_GETFD);
3890     if (flags != -1) {
3891       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3892     }
3893   }
3894 #endif
3895 
3896   return fd;
3897 }
3898 
3899 
3900 // create binary file, rewriting existing file if required
3901 int os::create_binary_file(const char* path, bool rewrite_existing) {
3902   int oflags = O_WRONLY | O_CREAT;
3903   if (!rewrite_existing) {
3904     oflags |= O_EXCL;
3905   }
3906   return ::open(path, oflags, S_IREAD | S_IWRITE);
3907 }
3908 
3909 // return current position of file pointer
3910 jlong os::current_file_offset(int fd) {
3911   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3912 }
3913 
3914 // move file pointer to the specified offset
3915 jlong os::seek_to_file_offset(int fd, jlong offset) {
3916   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3917 }
3918 
3919 // This code originates from JDK's sysAvailable
3920 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3921 
3922 int os::available(int fd, jlong *bytes) {
3923   jlong cur, end;
3924   int mode;
3925   struct stat buf;
3926 
3927   if (::fstat(fd, &buf) >= 0) {
3928     mode = buf.st_mode;
3929     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3930       // XXX: is the following call interruptible? If so, this might
3931       // need to go through the INTERRUPT_IO() wrapper as for other
3932       // blocking, interruptible calls in this file.
3933       int n;
3934       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3935         *bytes = n;
3936         return 1;
3937       }
3938     }
3939   }
3940   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3941     return 0;
3942   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3943     return 0;
3944   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3945     return 0;
3946   }
3947   *bytes = end - cur;
3948   return 1;
3949 }
3950 
3951 // Map a block of memory.
3952 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3953                         char *addr, size_t bytes, bool read_only,
3954                         bool allow_exec) {
3955   int prot;
3956   int flags;
3957 
3958   if (read_only) {
3959     prot = PROT_READ;
3960     flags = MAP_SHARED;
3961   } else {
3962     prot = PROT_READ | PROT_WRITE;
3963     flags = MAP_PRIVATE;
3964   }
3965 
3966   if (allow_exec) {
3967     prot |= PROT_EXEC;
3968   }
3969 
3970   if (addr != NULL) {
3971     flags |= MAP_FIXED;
3972   }
3973 
3974   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3975                                      fd, file_offset);
3976   if (mapped_address == MAP_FAILED) {
3977     return NULL;
3978   }
3979   return mapped_address;
3980 }
3981 
3982 
3983 // Remap a block of memory.
3984 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3985                           char *addr, size_t bytes, bool read_only,
3986                           bool allow_exec) {
3987   // same as map_memory() on this OS
3988   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3989                         allow_exec);
3990 }
3991 
3992 
3993 // Unmap a block of memory.
3994 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3995   return munmap(addr, bytes) == 0;
3996 }
3997 
3998 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3999 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4000 // of a thread.
4001 //
4002 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4003 // the fast estimate available on the platform.
4004 
4005 jlong os::current_thread_cpu_time() {
4006 #ifdef __APPLE__
4007   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
4008 #else
4009   Unimplemented();
4010   return 0;
4011 #endif
4012 }
4013 
4014 jlong os::thread_cpu_time(Thread* thread) {
4015 #ifdef __APPLE__
4016   return os::thread_cpu_time(thread, true /* user + sys */);
4017 #else
4018   Unimplemented();
4019   return 0;
4020 #endif
4021 }
4022 
4023 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4024 #ifdef __APPLE__
4025   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4026 #else
4027   Unimplemented();
4028   return 0;
4029 #endif
4030 }
4031 
4032 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4033 #ifdef __APPLE__
4034   struct thread_basic_info tinfo;
4035   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
4036   kern_return_t kr;
4037   thread_t mach_thread;
4038 
4039   mach_thread = thread->osthread()->thread_id();
4040   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
4041   if (kr != KERN_SUCCESS) {
4042     return -1;
4043   }
4044 
4045   if (user_sys_cpu_time) {
4046     jlong nanos;
4047     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4048     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4049     return nanos;
4050   } else {
4051     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4052   }
4053 #else
4054   Unimplemented();
4055   return 0;
4056 #endif
4057 }
4058 
4059 
4060 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4061   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4062   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4063   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4064   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4065 }
4066 
4067 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4068   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4069   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4070   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4071   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4072 }
4073 
4074 bool os::is_thread_cpu_time_supported() {
4075 #ifdef __APPLE__
4076   return true;
4077 #else
4078   return false;
4079 #endif
4080 }
4081 
4082 // System loadavg support.  Returns -1 if load average cannot be obtained.
4083 // Bsd doesn't yet have a (official) notion of processor sets,
4084 // so just return the system wide load average.
4085 int os::loadavg(double loadavg[], int nelem) {
4086   return ::getloadavg(loadavg, nelem);
4087 }
4088 
4089 void os::pause() {
4090   char filename[MAX_PATH];
4091   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4092     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4093   } else {
4094     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4095   }
4096 
4097   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4098   if (fd != -1) {
4099     struct stat buf;
4100     ::close(fd);
4101     while (::stat(filename, &buf) == 0) {
4102       (void)::poll(NULL, 0, 100);
4103     }
4104   } else {
4105     jio_fprintf(stderr,
4106                 "Could not open pause file '%s', continuing immediately.\n", filename);
4107   }
4108 }
4109 
4110 
4111 // Refer to the comments in os_solaris.cpp park-unpark. The next two
4112 // comment paragraphs are worth repeating here:
4113 //
4114 // Assumption:
4115 //    Only one parker can exist on an event, which is why we allocate
4116 //    them per-thread. Multiple unparkers can coexist.
4117 //
4118 // _Event serves as a restricted-range semaphore.
4119 //   -1 : thread is blocked, i.e. there is a waiter
4120 //    0 : neutral: thread is running or ready,
4121 //        could have been signaled after a wait started
4122 //    1 : signaled - thread is running or ready
4123 //
4124 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4125 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4126 // For specifics regarding the bug see GLIBC BUGID 261237 :
4127 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4128 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4129 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4130 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
4131 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4132 // and monitorenter when we're using 1-0 locking.  All those operations may result in
4133 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
4134 // of libpthread avoids the problem, but isn't practical.
4135 //
4136 // Possible remedies:
4137 //
4138 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
4139 //      This is palliative and probabilistic, however.  If the thread is preempted
4140 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
4141 //      than the minimum period may have passed, and the abstime may be stale (in the
4142 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
4143 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
4144 //
4145 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4146 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
4147 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4148 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
4149 //      thread.
4150 //
4151 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
4152 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
4153 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
4154 //      This also works well.  In fact it avoids kernel-level scalability impediments
4155 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
4156 //      timers in a graceful fashion.
4157 //
4158 // 4.   When the abstime value is in the past it appears that control returns
4159 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4160 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
4161 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
4162 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
4163 //      It may be possible to avoid reinitialization by checking the return
4164 //      value from pthread_cond_timedwait().  In addition to reinitializing the
4165 //      condvar we must establish the invariant that cond_signal() is only called
4166 //      within critical sections protected by the adjunct mutex.  This prevents
4167 //      cond_signal() from "seeing" a condvar that's in the midst of being
4168 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
4169 //      desirable signal-after-unlock optimization that avoids futile context switching.
4170 //
4171 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
4172 //      structure when a condvar is used or initialized.  cond_destroy()  would
4173 //      release the helper structure.  Our reinitialize-after-timedwait fix
4174 //      put excessive stress on malloc/free and locks protecting the c-heap.
4175 //
4176 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
4177 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4178 // and only enabling the work-around for vulnerable environments.
4179 
4180 // utility to compute the abstime argument to timedwait:
4181 // millis is the relative timeout time
4182 // abstime will be the absolute timeout time
4183 // TODO: replace compute_abstime() with unpackTime()
4184 
4185 static struct timespec* compute_abstime(struct timespec* abstime,
4186                                         jlong millis) {
4187   if (millis < 0)  millis = 0;
4188   struct timeval now;
4189   int status = gettimeofday(&now, NULL);
4190   assert(status == 0, "gettimeofday");
4191   jlong seconds = millis / 1000;
4192   millis %= 1000;
4193   if (seconds > 50000000) { // see man cond_timedwait(3T)
4194     seconds = 50000000;
4195   }
4196   abstime->tv_sec = now.tv_sec  + seconds;
4197   long       usec = now.tv_usec + millis * 1000;
4198   if (usec >= 1000000) {
4199     abstime->tv_sec += 1;
4200     usec -= 1000000;
4201   }
4202   abstime->tv_nsec = usec * 1000;
4203   return abstime;
4204 }
4205 
4206 void os::PlatformEvent::park() {       // AKA "down()"
4207   // Transitions for _Event:
4208   //   -1 => -1 : illegal
4209   //    1 =>  0 : pass - return immediately
4210   //    0 => -1 : block; then set _Event to 0 before returning
4211 
4212   // Invariant: Only the thread associated with the Event/PlatformEvent
4213   // may call park().
4214   // TODO: assert that _Assoc != NULL or _Assoc == Self
4215   assert(_nParked == 0, "invariant");
4216 
4217   int v;
4218   for (;;) {
4219     v = _Event;
4220     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4221   }
4222   guarantee(v >= 0, "invariant");
4223   if (v == 0) {
4224     // Do this the hard way by blocking ...
4225     int status = pthread_mutex_lock(_mutex);
4226     assert_status(status == 0, status, "mutex_lock");
4227     guarantee(_nParked == 0, "invariant");
4228     ++_nParked;
4229     while (_Event < 0) {
4230       status = pthread_cond_wait(_cond, _mutex);
4231       // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4232       // Treat this the same as if the wait was interrupted
4233       if (status == ETIMEDOUT) { status = EINTR; }
4234       assert_status(status == 0 || status == EINTR, status, "cond_wait");
4235     }
4236     --_nParked;
4237 
4238     _Event = 0;
4239     status = pthread_mutex_unlock(_mutex);
4240     assert_status(status == 0, status, "mutex_unlock");
4241     // Paranoia to ensure our locked and lock-free paths interact
4242     // correctly with each other.
4243     OrderAccess::fence();
4244   }
4245   guarantee(_Event >= 0, "invariant");
4246 }
4247 
4248 int os::PlatformEvent::park(jlong millis) {
4249   // Transitions for _Event:
4250   //   -1 => -1 : illegal
4251   //    1 =>  0 : pass - return immediately
4252   //    0 => -1 : block; then set _Event to 0 before returning
4253 
4254   guarantee(_nParked == 0, "invariant");
4255 
4256   int v;
4257   for (;;) {
4258     v = _Event;
4259     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4260   }
4261   guarantee(v >= 0, "invariant");
4262   if (v != 0) return OS_OK;
4263 
4264   // We do this the hard way, by blocking the thread.
4265   // Consider enforcing a minimum timeout value.
4266   struct timespec abst;
4267   compute_abstime(&abst, millis);
4268 
4269   int ret = OS_TIMEOUT;
4270   int status = pthread_mutex_lock(_mutex);
4271   assert_status(status == 0, status, "mutex_lock");
4272   guarantee(_nParked == 0, "invariant");
4273   ++_nParked;
4274 
4275   // Object.wait(timo) will return because of
4276   // (a) notification
4277   // (b) timeout
4278   // (c) thread.interrupt
4279   //
4280   // Thread.interrupt and object.notify{All} both call Event::set.
4281   // That is, we treat thread.interrupt as a special case of notification.
4282   // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false.
4283   // We assume all ETIME returns are valid.
4284   //
4285   // TODO: properly differentiate simultaneous notify+interrupt.
4286   // In that case, we should propagate the notify to another waiter.
4287 
4288   while (_Event < 0) {
4289     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4290     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4291       pthread_cond_destroy(_cond);
4292       pthread_cond_init(_cond, NULL);
4293     }
4294     assert_status(status == 0 || status == EINTR ||
4295                   status == ETIMEDOUT,
4296                   status, "cond_timedwait");
4297     if (!FilterSpuriousWakeups) break;                 // previous semantics
4298     if (status == ETIMEDOUT) break;
4299     // We consume and ignore EINTR and spurious wakeups.
4300   }
4301   --_nParked;
4302   if (_Event >= 0) {
4303     ret = OS_OK;
4304   }
4305   _Event = 0;
4306   status = pthread_mutex_unlock(_mutex);
4307   assert_status(status == 0, status, "mutex_unlock");
4308   assert(_nParked == 0, "invariant");
4309   // Paranoia to ensure our locked and lock-free paths interact
4310   // correctly with each other.
4311   OrderAccess::fence();
4312   return ret;
4313 }
4314 
4315 void os::PlatformEvent::unpark() {
4316   // Transitions for _Event:
4317   //    0 => 1 : just return
4318   //    1 => 1 : just return
4319   //   -1 => either 0 or 1; must signal target thread
4320   //         That is, we can safely transition _Event from -1 to either
4321   //         0 or 1.
4322   // See also: "Semaphores in Plan 9" by Mullender & Cox
4323   //
4324   // Note: Forcing a transition from "-1" to "1" on an unpark() means
4325   // that it will take two back-to-back park() calls for the owning
4326   // thread to block. This has the benefit of forcing a spurious return
4327   // from the first park() call after an unpark() call which will help
4328   // shake out uses of park() and unpark() without condition variables.
4329 
4330   if (Atomic::xchg(1, &_Event) >= 0) return;
4331 
4332   // Wait for the thread associated with the event to vacate
4333   int status = pthread_mutex_lock(_mutex);
4334   assert_status(status == 0, status, "mutex_lock");
4335   int AnyWaiters = _nParked;
4336   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4337   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4338     AnyWaiters = 0;
4339     pthread_cond_signal(_cond);
4340   }
4341   status = pthread_mutex_unlock(_mutex);
4342   assert_status(status == 0, status, "mutex_unlock");
4343   if (AnyWaiters != 0) {
4344     // Note that we signal() *after* dropping the lock for "immortal" Events.
4345     // This is safe and avoids a common class of  futile wakeups.  In rare
4346     // circumstances this can cause a thread to return prematurely from
4347     // cond_{timed}wait() but the spurious wakeup is benign and the victim
4348     // will simply re-test the condition and re-park itself.
4349     // This provides particular benefit if the underlying platform does not
4350     // provide wait morphing.
4351     status = pthread_cond_signal(_cond);
4352     assert_status(status == 0, status, "cond_signal");
4353   }
4354 }
4355 
4356 
4357 // JSR166
4358 // -------------------------------------------------------
4359 
4360 // The solaris and bsd implementations of park/unpark are fairly
4361 // conservative for now, but can be improved. They currently use a
4362 // mutex/condvar pair, plus a a count.
4363 // Park decrements count if > 0, else does a condvar wait.  Unpark
4364 // sets count to 1 and signals condvar.  Only one thread ever waits
4365 // on the condvar. Contention seen when trying to park implies that someone
4366 // is unparking you, so don't wait. And spurious returns are fine, so there
4367 // is no need to track notifications.
4368 
4369 #define MAX_SECS 100000000
4370 
4371 // This code is common to bsd and solaris and will be moved to a
4372 // common place in dolphin.
4373 //
4374 // The passed in time value is either a relative time in nanoseconds
4375 // or an absolute time in milliseconds. Either way it has to be unpacked
4376 // into suitable seconds and nanoseconds components and stored in the
4377 // given timespec structure.
4378 // Given time is a 64-bit value and the time_t used in the timespec is only
4379 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4380 // overflow if times way in the future are given. Further on Solaris versions
4381 // prior to 10 there is a restriction (see cond_timedwait) that the specified
4382 // number of seconds, in abstime, is less than current_time  + 100,000,000.
4383 // As it will be 28 years before "now + 100000000" will overflow we can
4384 // ignore overflow and just impose a hard-limit on seconds using the value
4385 // of "now + 100,000,000". This places a limit on the timeout of about 3.17
4386 // years from "now".
4387 
4388 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4389   assert(time > 0, "convertTime");
4390 
4391   struct timeval now;
4392   int status = gettimeofday(&now, NULL);
4393   assert(status == 0, "gettimeofday");
4394 
4395   time_t max_secs = now.tv_sec + MAX_SECS;
4396 
4397   if (isAbsolute) {
4398     jlong secs = time / 1000;
4399     if (secs > max_secs) {
4400       absTime->tv_sec = max_secs;
4401     } else {
4402       absTime->tv_sec = secs;
4403     }
4404     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4405   } else {
4406     jlong secs = time / NANOSECS_PER_SEC;
4407     if (secs >= MAX_SECS) {
4408       absTime->tv_sec = max_secs;
4409       absTime->tv_nsec = 0;
4410     } else {
4411       absTime->tv_sec = now.tv_sec + secs;
4412       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4413       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4414         absTime->tv_nsec -= NANOSECS_PER_SEC;
4415         ++absTime->tv_sec; // note: this must be <= max_secs
4416       }
4417     }
4418   }
4419   assert(absTime->tv_sec >= 0, "tv_sec < 0");
4420   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4421   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4422   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4423 }
4424 
4425 void Parker::park(bool isAbsolute, jlong time) {
4426   // Ideally we'd do something useful while spinning, such
4427   // as calling unpackTime().
4428 
4429   // Optional fast-path check:
4430   // Return immediately if a permit is available.
4431   // We depend on Atomic::xchg() having full barrier semantics
4432   // since we are doing a lock-free update to _counter.
4433   if (Atomic::xchg(0, &_counter) > 0) return;
4434 
4435   Thread* thread = Thread::current();
4436   assert(thread->is_Java_thread(), "Must be JavaThread");
4437   JavaThread *jt = (JavaThread *)thread;
4438 
4439   // Optional optimization -- avoid state transitions if there's an interrupt pending.
4440   // Check interrupt before trying to wait
4441   if (Thread::is_interrupted(thread, false)) {
4442     return;
4443   }
4444 
4445   // Next, demultiplex/decode time arguments
4446   struct timespec absTime;
4447   if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
4448     return;
4449   }
4450   if (time > 0) {
4451     unpackTime(&absTime, isAbsolute, time);
4452   }
4453 
4454 
4455   // Enter safepoint region
4456   // Beware of deadlocks such as 6317397.
4457   // The per-thread Parker:: mutex is a classic leaf-lock.
4458   // In particular a thread must never block on the Threads_lock while
4459   // holding the Parker:: mutex.  If safepoints are pending both the
4460   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4461   ThreadBlockInVM tbivm(jt);
4462 
4463   // Don't wait if cannot get lock since interference arises from
4464   // unblocking.  Also. check interrupt before trying wait
4465   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4466     return;
4467   }
4468 
4469   int status;
4470   if (_counter > 0)  { // no wait needed
4471     _counter = 0;
4472     status = pthread_mutex_unlock(_mutex);
4473     assert(status == 0, "invariant");
4474     // Paranoia to ensure our locked and lock-free paths interact
4475     // correctly with each other and Java-level accesses.
4476     OrderAccess::fence();
4477     return;
4478   }
4479 
4480 #ifdef ASSERT
4481   // Don't catch signals while blocked; let the running threads have the signals.
4482   // (This allows a debugger to break into the running thread.)
4483   sigset_t oldsigs;
4484   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4485   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4486 #endif
4487 
4488   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4489   jt->set_suspend_equivalent();
4490   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4491 
4492   if (time == 0) {
4493     status = pthread_cond_wait(_cond, _mutex);
4494   } else {
4495     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &absTime);
4496     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4497       pthread_cond_destroy(_cond);
4498       pthread_cond_init(_cond, NULL);
4499     }
4500   }
4501   assert_status(status == 0 || status == EINTR ||
4502                 status == ETIMEDOUT,
4503                 status, "cond_timedwait");
4504 
4505 #ifdef ASSERT
4506   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4507 #endif
4508 
4509   _counter = 0;
4510   status = pthread_mutex_unlock(_mutex);
4511   assert_status(status == 0, status, "invariant");
4512   // Paranoia to ensure our locked and lock-free paths interact
4513   // correctly with each other and Java-level accesses.
4514   OrderAccess::fence();
4515 
4516   // If externally suspended while waiting, re-suspend
4517   if (jt->handle_special_suspend_equivalent_condition()) {
4518     jt->java_suspend_self();
4519   }
4520 }
4521 
4522 void Parker::unpark() {
4523   int status = pthread_mutex_lock(_mutex);
4524   assert(status == 0, "invariant");
4525   const int s = _counter;
4526   _counter = 1;
4527   if (s < 1) {
4528     if (WorkAroundNPTLTimedWaitHang) {
4529       status = pthread_cond_signal(_cond);
4530       assert(status == 0, "invariant");
4531       status = pthread_mutex_unlock(_mutex);
4532       assert(status == 0, "invariant");
4533     } else {
4534       status = pthread_mutex_unlock(_mutex);
4535       assert(status == 0, "invariant");
4536       status = pthread_cond_signal(_cond);
4537       assert(status == 0, "invariant");
4538     }
4539   } else {
4540     pthread_mutex_unlock(_mutex);
4541     assert(status == 0, "invariant");
4542   }
4543 }
4544 
4545 
4546 // Darwin has no "environ" in a dynamic library.
4547 #ifdef __APPLE__
4548   #include <crt_externs.h>
4549   #define environ (*_NSGetEnviron())
4550 #else
4551 extern char** environ;
4552 #endif
4553 
4554 // Run the specified command in a separate process. Return its exit value,
4555 // or -1 on failure (e.g. can't fork a new process).
4556 // Unlike system(), this function can be called from signal handler. It
4557 // doesn't block SIGINT et al.
4558 int os::fork_and_exec(char* cmd) {
4559   const char * argv[4] = {"sh", "-c", cmd, NULL};
4560 
4561   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4562   // pthread_atfork handlers and reset pthread library. All we need is a
4563   // separate process to execve. Make a direct syscall to fork process.
4564   // On IA64 there's no fork syscall, we have to use fork() and hope for
4565   // the best...
4566   pid_t pid = fork();
4567 
4568   if (pid < 0) {
4569     // fork failed
4570     return -1;
4571 
4572   } else if (pid == 0) {
4573     // child process
4574 
4575     // execve() in BsdThreads will call pthread_kill_other_threads_np()
4576     // first to kill every thread on the thread list. Because this list is
4577     // not reset by fork() (see notes above), execve() will instead kill
4578     // every thread in the parent process. We know this is the only thread
4579     // in the new process, so make a system call directly.
4580     // IA64 should use normal execve() from glibc to match the glibc fork()
4581     // above.
4582     execve("/bin/sh", (char* const*)argv, environ);
4583 
4584     // execve failed
4585     _exit(-1);
4586 
4587   } else  {
4588     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4589     // care about the actual exit code, for now.
4590 
4591     int status;
4592 
4593     // Wait for the child process to exit.  This returns immediately if
4594     // the child has already exited. */
4595     while (waitpid(pid, &status, 0) < 0) {
4596       switch (errno) {
4597       case ECHILD: return 0;
4598       case EINTR: break;
4599       default: return -1;
4600       }
4601     }
4602 
4603     if (WIFEXITED(status)) {
4604       // The child exited normally; get its exit code.
4605       return WEXITSTATUS(status);
4606     } else if (WIFSIGNALED(status)) {
4607       // The child exited because of a signal
4608       // The best value to return is 0x80 + signal number,
4609       // because that is what all Unix shells do, and because
4610       // it allows callers to distinguish between process exit and
4611       // process death by signal.
4612       return 0x80 + WTERMSIG(status);
4613     } else {
4614       // Unknown exit code; pass it through
4615       return status;
4616     }
4617   }
4618 }
4619 
4620 // is_headless_jre()
4621 //
4622 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4623 // in order to report if we are running in a headless jre
4624 //
4625 // Since JDK8 xawt/libmawt.so was moved into the same directory
4626 // as libawt.so, and renamed libawt_xawt.so
4627 //
4628 bool os::is_headless_jre() {
4629 #ifdef __APPLE__
4630   // We no longer build headless-only on Mac OS X
4631   return false;
4632 #else
4633   struct stat statbuf;
4634   char buf[MAXPATHLEN];
4635   char libmawtpath[MAXPATHLEN];
4636   const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
4637   const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4638   char *p;
4639 
4640   // Get path to libjvm.so
4641   os::jvm_path(buf, sizeof(buf));
4642 
4643   // Get rid of libjvm.so
4644   p = strrchr(buf, '/');
4645   if (p == NULL) {
4646     return false;
4647   } else {
4648     *p = '\0';
4649   }
4650 
4651   // Get rid of client or server
4652   p = strrchr(buf, '/');
4653   if (p == NULL) {
4654     return false;
4655   } else {
4656     *p = '\0';
4657   }
4658 
4659   // check xawt/libmawt.so
4660   strcpy(libmawtpath, buf);
4661   strcat(libmawtpath, xawtstr);
4662   if (::stat(libmawtpath, &statbuf) == 0) return false;
4663 
4664   // check libawt_xawt.so
4665   strcpy(libmawtpath, buf);
4666   strcat(libmawtpath, new_xawtstr);
4667   if (::stat(libmawtpath, &statbuf) == 0) return false;
4668 
4669   return true;
4670 #endif
4671 }
4672 
4673 // Get the default path to the core file
4674 // Returns the length of the string
4675 int os::get_core_path(char* buffer, size_t bufferSize) {
4676   int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
4677 
4678   // Truncate if theoretical string was longer than bufferSize
4679   n = MIN2(n, (int)bufferSize);
4680 
4681   return n;
4682 }
4683 
4684 #ifndef PRODUCT
4685 void TestReserveMemorySpecial_test() {
4686   // No tests available for this platform
4687 }
4688 #endif
--- EOF ---