1 /*
   2  * Copyright (c) 1999, 2016, 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 "logging/log.hpp"
  36 #include "memory/allocation.inline.hpp"
  37 #include "memory/filemap.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 "semaphore_bsd.hpp"
  63 #include "services/attachListener.hpp"
  64 #include "services/memTracker.hpp"
  65 #include "services/runtimeService.hpp"
  66 #include "utilities/decoder.hpp"
  67 #include "utilities/defaultStream.hpp"
  68 #include "utilities/events.hpp"
  69 #include "utilities/growableArray.hpp"
  70 #include "utilities/vmError.hpp"
  71 
  72 // put OS-includes here
  73 # include <sys/types.h>
  74 # include <sys/mman.h>
  75 # include <sys/stat.h>
  76 # include <sys/select.h>
  77 # include <pthread.h>
  78 # include <signal.h>
  79 # include <errno.h>
  80 # include <dlfcn.h>
  81 # include <stdio.h>
  82 # include <unistd.h>
  83 # include <sys/resource.h>
  84 # include <pthread.h>
  85 # include <sys/stat.h>
  86 # include <sys/time.h>
  87 # include <sys/times.h>
  88 # include <sys/utsname.h>
  89 # include <sys/socket.h>
  90 # include <sys/wait.h>
  91 # include <time.h>
  92 # include <pwd.h>
  93 # include <poll.h>
  94 # include <semaphore.h>
  95 # include <fcntl.h>
  96 # include <string.h>
  97 # include <sys/param.h>
  98 # include <sys/sysctl.h>
  99 # include <sys/ipc.h>
 100 # include <sys/shm.h>
 101 #ifndef __APPLE__
 102 # include <link.h>
 103 #endif
 104 # include <stdint.h>
 105 # include <inttypes.h>
 106 # include <sys/ioctl.h>
 107 # include <sys/syscall.h>
 108 
 109 #if defined(__FreeBSD__) || defined(__NetBSD__)
 110   #include <elf.h>
 111 #endif
 112 
 113 #ifdef __APPLE__
 114   #include <mach/mach.h> // semaphore_* API
 115   #include <mach-o/dyld.h>
 116   #include <sys/proc_info.h>
 117   #include <objc/objc-auto.h>
 118 #endif
 119 
 120 #ifndef MAP_ANONYMOUS
 121   #define MAP_ANONYMOUS MAP_ANON
 122 #endif
 123 
 124 #define MAX_PATH    (2 * K)
 125 
 126 // for timer info max values which include all bits
 127 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 128 
 129 #define LARGEPAGES_BIT (1 << 6)
 130 
 131 ////////////////////////////////////////////////////////////////////////////////
 132 // global variables
 133 julong os::Bsd::_physical_memory = 0;
 134 
 135 #ifdef __APPLE__
 136 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
 137 volatile uint64_t         os::Bsd::_max_abstime   = 0;
 138 #else
 139 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 140 #endif
 141 pthread_t os::Bsd::_main_thread;
 142 int os::Bsd::_page_size = -1;
 143 
 144 static jlong initial_time_count=0;
 145 
 146 static int clock_tics_per_sec = 100;
 147 
 148 // For diagnostics to print a message once. see run_periodic_checks
 149 static sigset_t check_signal_done;
 150 static bool check_signals = true;
 151 
 152 static pid_t _initial_pid = 0;
 153 
 154 // Signal number used to suspend/resume a thread
 155 
 156 // do not use any signal number less than SIGSEGV, see 4355769
 157 static int SR_signum = SIGUSR2;
 158 sigset_t SR_sigset;
 159 
 160 
 161 ////////////////////////////////////////////////////////////////////////////////
 162 // utility functions
 163 
 164 static int SR_initialize();
 165 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
 166 
 167 julong os::available_memory() {
 168   return Bsd::available_memory();
 169 }
 170 
 171 // available here means free
 172 julong os::Bsd::available_memory() {
 173   uint64_t available = physical_memory() >> 2;
 174 #ifdef __APPLE__
 175   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
 176   vm_statistics64_data_t vmstat;
 177   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
 178                                          (host_info64_t)&vmstat, &count);
 179   assert(kerr == KERN_SUCCESS,
 180          "host_statistics64 failed - check mach_host_self() and count");
 181   if (kerr == KERN_SUCCESS) {
 182     available = vmstat.free_count * os::vm_page_size();
 183   }
 184 #endif
 185   return available;
 186 }
 187 
 188 julong os::physical_memory() {
 189   return Bsd::physical_memory();
 190 }
 191 
 192 // Return true if user is running as root.
 193 
 194 bool os::have_special_privileges() {
 195   static bool init = false;
 196   static bool privileges = false;
 197   if (!init) {
 198     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 199     init = true;
 200   }
 201   return privileges;
 202 }
 203 
 204 
 205 
 206 // Cpu architecture string
 207 #if   defined(ZERO)
 208 static char cpu_arch[] = ZERO_LIBARCH;
 209 #elif defined(IA64)
 210 static char cpu_arch[] = "ia64";
 211 #elif defined(IA32)
 212 static char cpu_arch[] = "i386";
 213 #elif defined(AMD64)
 214 static char cpu_arch[] = "amd64";
 215 #elif defined(ARM)
 216 static char cpu_arch[] = "arm";
 217 #elif defined(PPC32)
 218 static char cpu_arch[] = "ppc";
 219 #elif defined(SPARC)
 220   #ifdef _LP64
 221 static char cpu_arch[] = "sparcv9";
 222   #else
 223 static char cpu_arch[] = "sparc";
 224   #endif
 225 #else
 226   #error Add appropriate cpu_arch setting
 227 #endif
 228 
 229 // Compiler variant
 230 #ifdef COMPILER2
 231   #define COMPILER_VARIANT "server"
 232 #else
 233   #define COMPILER_VARIANT "client"
 234 #endif
 235 
 236 
 237 void os::Bsd::initialize_system_info() {
 238   int mib[2];
 239   size_t len;
 240   int cpu_val;
 241   julong mem_val;
 242 
 243   // get processors count via hw.ncpus sysctl
 244   mib[0] = CTL_HW;
 245   mib[1] = HW_NCPU;
 246   len = sizeof(cpu_val);
 247   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 248     assert(len == sizeof(cpu_val), "unexpected data size");
 249     set_processor_count(cpu_val);
 250   } else {
 251     set_processor_count(1);   // fallback
 252   }
 253 
 254   // get physical memory via hw.memsize sysctl (hw.memsize is used
 255   // since it returns a 64 bit value)
 256   mib[0] = CTL_HW;
 257 
 258 #if defined (HW_MEMSIZE) // Apple
 259   mib[1] = HW_MEMSIZE;
 260 #elif defined(HW_PHYSMEM) // Most of BSD
 261   mib[1] = HW_PHYSMEM;
 262 #elif defined(HW_REALMEM) // Old FreeBSD
 263   mib[1] = HW_REALMEM;
 264 #else
 265   #error No ways to get physmem
 266 #endif
 267 
 268   len = sizeof(mem_val);
 269   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 270     assert(len == sizeof(mem_val), "unexpected data size");
 271     _physical_memory = mem_val;
 272   } else {
 273     _physical_memory = 256 * 1024 * 1024;       // fallback (XXXBSD?)
 274   }
 275 
 276 #ifdef __OpenBSD__
 277   {
 278     // limit _physical_memory memory view on OpenBSD since
 279     // datasize rlimit restricts us anyway.
 280     struct rlimit limits;
 281     getrlimit(RLIMIT_DATA, &limits);
 282     _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 283   }
 284 #endif
 285 }
 286 
 287 #ifdef __APPLE__
 288 static const char *get_home() {
 289   const char *home_dir = ::getenv("HOME");
 290   if ((home_dir == NULL) || (*home_dir == '\0')) {
 291     struct passwd *passwd_info = getpwuid(geteuid());
 292     if (passwd_info != NULL) {
 293       home_dir = passwd_info->pw_dir;
 294     }
 295   }
 296 
 297   return home_dir;
 298 }
 299 #endif
 300 
 301 void os::init_system_properties_values() {
 302   // The next steps are taken in the product version:
 303   //
 304   // Obtain the JAVA_HOME value from the location of libjvm.so.
 305   // This library should be located at:
 306   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 307   //
 308   // If "/jre/lib/" appears at the right place in the path, then we
 309   // assume libjvm.so is installed in a JDK and we use this path.
 310   //
 311   // Otherwise exit with message: "Could not create the Java virtual machine."
 312   //
 313   // The following extra steps are taken in the debugging version:
 314   //
 315   // If "/jre/lib/" does NOT appear at the right place in the path
 316   // instead of exit check for $JAVA_HOME environment variable.
 317   //
 318   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 319   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 320   // it looks like libjvm.so is installed there
 321   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 322   //
 323   // Otherwise exit.
 324   //
 325   // Important note: if the location of libjvm.so changes this
 326   // code needs to be changed accordingly.
 327 
 328   // See ld(1):
 329   //      The linker uses the following search paths to locate required
 330   //      shared libraries:
 331   //        1: ...
 332   //        ...
 333   //        7: The default directories, normally /lib and /usr/lib.
 334 #ifndef DEFAULT_LIBPATH
 335   #define DEFAULT_LIBPATH "/lib:/usr/lib"
 336 #endif
 337 
 338 // Base path of extensions installed on the system.
 339 #define SYS_EXT_DIR     "/usr/java/packages"
 340 #define EXTENSIONS_DIR  "/lib/ext"
 341 
 342 #ifndef __APPLE__
 343 
 344   // Buffer that fits several sprintfs.
 345   // Note that the space for the colon and the trailing null are provided
 346   // by the nulls included by the sizeof operator.
 347   const size_t bufsize =
 348     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 349          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
 350   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 351 
 352   // sysclasspath, java_home, dll_dir
 353   {
 354     char *pslash;
 355     os::jvm_path(buf, bufsize);
 356 
 357     // Found the full path to libjvm.so.
 358     // Now cut the path to <java_home>/jre if we can.
 359     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 360     pslash = strrchr(buf, '/');
 361     if (pslash != NULL) {
 362       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 363     }
 364     Arguments::set_dll_dir(buf);
 365 
 366     if (pslash != NULL) {
 367       pslash = strrchr(buf, '/');
 368       if (pslash != NULL) {
 369         *pslash = '\0';          // Get rid of /<arch>.
 370         pslash = strrchr(buf, '/');
 371         if (pslash != NULL) {
 372           *pslash = '\0';        // Get rid of /lib.
 373         }
 374       }
 375     }
 376     Arguments::set_java_home(buf);
 377     set_boot_path('/', ':');
 378   }
 379 
 380   // Where to look for native libraries.
 381   //
 382   // Note: Due to a legacy implementation, most of the library path
 383   // is set in the launcher. This was to accomodate linking restrictions
 384   // on legacy Bsd implementations (which are no longer supported).
 385   // Eventually, all the library path setting will be done here.
 386   //
 387   // However, to prevent the proliferation of improperly built native
 388   // libraries, the new path component /usr/java/packages is added here.
 389   // Eventually, all the library path setting will be done here.
 390   {
 391     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 392     // should always exist (until the legacy problem cited above is
 393     // addressed).
 394     const char *v = ::getenv("LD_LIBRARY_PATH");
 395     const char *v_colon = ":";
 396     if (v == NULL) { v = ""; v_colon = ""; }
 397     // That's +1 for the colon and +1 for the trailing '\0'.
 398     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 399                                                      strlen(v) + 1 +
 400                                                      sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
 401                                                      mtInternal);
 402     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
 403     Arguments::set_library_path(ld_library_path);
 404     FREE_C_HEAP_ARRAY(char, ld_library_path);
 405   }
 406 
 407   // Extensions directories.
 408   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
 409   Arguments::set_ext_dirs(buf);
 410 
 411   FREE_C_HEAP_ARRAY(char, buf);
 412 
 413 #else // __APPLE__
 414 
 415   #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 416   #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 417 
 418   const char *user_home_dir = get_home();
 419   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
 420   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 421     sizeof(SYS_EXTENSIONS_DIRS);
 422 
 423   // Buffer that fits several sprintfs.
 424   // Note that the space for the colon and the trailing null are provided
 425   // by the nulls included by the sizeof operator.
 426   const size_t bufsize =
 427     MAX2((size_t)MAXPATHLEN,  // for dll_dir & friends.
 428          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
 429   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 430 
 431   // sysclasspath, java_home, dll_dir
 432   {
 433     char *pslash;
 434     os::jvm_path(buf, bufsize);
 435 
 436     // Found the full path to libjvm.so.
 437     // Now cut the path to <java_home>/jre if we can.
 438     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 439     pslash = strrchr(buf, '/');
 440     if (pslash != NULL) {
 441       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 442     }
 443 #ifdef STATIC_BUILD
 444     strcat(buf, "/lib");
 445 #endif
 446 
 447     Arguments::set_dll_dir(buf);
 448 
 449     if (pslash != NULL) {
 450       pslash = strrchr(buf, '/');
 451       if (pslash != NULL) {
 452         *pslash = '\0';          // Get rid of /lib.
 453       }
 454     }
 455     Arguments::set_java_home(buf);
 456     set_boot_path('/', ':');
 457   }
 458 
 459   // Where to look for native libraries.
 460   //
 461   // Note: Due to a legacy implementation, most of the library path
 462   // is set in the launcher. This was to accomodate linking restrictions
 463   // on legacy Bsd implementations (which are no longer supported).
 464   // Eventually, all the library path setting will be done here.
 465   //
 466   // However, to prevent the proliferation of improperly built native
 467   // libraries, the new path component /usr/java/packages is added here.
 468   // Eventually, all the library path setting will be done here.
 469   {
 470     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 471     // should always exist (until the legacy problem cited above is
 472     // addressed).
 473     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
 474     // can specify a directory inside an app wrapper
 475     const char *l = ::getenv("JAVA_LIBRARY_PATH");
 476     const char *l_colon = ":";
 477     if (l == NULL) { l = ""; l_colon = ""; }
 478 
 479     const char *v = ::getenv("DYLD_LIBRARY_PATH");
 480     const char *v_colon = ":";
 481     if (v == NULL) { v = ""; v_colon = ""; }
 482 
 483     // Apple's Java6 has "." at the beginning of java.library.path.
 484     // OpenJDK on Windows has "." at the end of java.library.path.
 485     // OpenJDK on Linux and Solaris don't have "." in java.library.path
 486     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 487     // "." is appended to the end of java.library.path. Yes, this
 488     // could cause a change in behavior, but Apple's Java6 behavior
 489     // can be achieved by putting "." at the beginning of the
 490     // JAVA_LIBRARY_PATH environment variable.
 491     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 492                                                      strlen(v) + 1 + strlen(l) + 1 +
 493                                                      system_ext_size + 3,
 494                                                      mtInternal);
 495     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
 496             v, v_colon, l, l_colon, user_home_dir);
 497     Arguments::set_library_path(ld_library_path);
 498     FREE_C_HEAP_ARRAY(char, ld_library_path);
 499   }
 500 
 501   // Extensions directories.
 502   //
 503   // Note that the space for the colon and the trailing null are provided
 504   // by the nulls included by the sizeof operator (so actually one byte more
 505   // than necessary is allocated).
 506   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
 507           user_home_dir, Arguments::get_java_home());
 508   Arguments::set_ext_dirs(buf);
 509 
 510   FREE_C_HEAP_ARRAY(char, buf);
 511 
 512 #undef SYS_EXTENSIONS_DIR
 513 #undef SYS_EXTENSIONS_DIRS
 514 
 515 #endif // __APPLE__
 516 
 517 #undef SYS_EXT_DIR
 518 #undef EXTENSIONS_DIR
 519 }
 520 
 521 ////////////////////////////////////////////////////////////////////////////////
 522 // breakpoint support
 523 
 524 void os::breakpoint() {
 525   BREAKPOINT;
 526 }
 527 
 528 extern "C" void breakpoint() {
 529   // use debugger to set breakpoint here
 530 }
 531 
 532 ////////////////////////////////////////////////////////////////////////////////
 533 // signal support
 534 
 535 debug_only(static bool signal_sets_initialized = false);
 536 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
 537 
 538 bool os::Bsd::is_sig_ignored(int sig) {
 539   struct sigaction oact;
 540   sigaction(sig, (struct sigaction*)NULL, &oact);
 541   void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
 542                                  : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
 543   if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
 544     return true;
 545   } else {
 546     return false;
 547   }
 548 }
 549 
 550 void os::Bsd::signal_sets_init() {
 551   // Should also have an assertion stating we are still single-threaded.
 552   assert(!signal_sets_initialized, "Already initialized");
 553   // Fill in signals that are necessarily unblocked for all threads in
 554   // the VM. Currently, we unblock the following signals:
 555   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 556   //                         by -Xrs (=ReduceSignalUsage));
 557   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 558   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 559   // the dispositions or masks wrt these signals.
 560   // Programs embedding the VM that want to use the above signals for their
 561   // own purposes must, at this time, use the "-Xrs" option to prevent
 562   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 563   // (See bug 4345157, and other related bugs).
 564   // In reality, though, unblocking these signals is really a nop, since
 565   // these signals are not blocked by default.
 566   sigemptyset(&unblocked_sigs);
 567   sigemptyset(&allowdebug_blocked_sigs);
 568   sigaddset(&unblocked_sigs, SIGILL);
 569   sigaddset(&unblocked_sigs, SIGSEGV);
 570   sigaddset(&unblocked_sigs, SIGBUS);
 571   sigaddset(&unblocked_sigs, SIGFPE);
 572   sigaddset(&unblocked_sigs, SR_signum);
 573 
 574   if (!ReduceSignalUsage) {
 575     if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 576       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 577       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
 578     }
 579     if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 580       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 581       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
 582     }
 583     if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 584       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 585       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
 586     }
 587   }
 588   // Fill in signals that are blocked by all but the VM thread.
 589   sigemptyset(&vm_sigs);
 590   if (!ReduceSignalUsage) {
 591     sigaddset(&vm_sigs, BREAK_SIGNAL);
 592   }
 593   debug_only(signal_sets_initialized = true);
 594 
 595 }
 596 
 597 // These are signals that are unblocked while a thread is running Java.
 598 // (For some reason, they get blocked by default.)
 599 sigset_t* os::Bsd::unblocked_signals() {
 600   assert(signal_sets_initialized, "Not initialized");
 601   return &unblocked_sigs;
 602 }
 603 
 604 // These are the signals that are blocked while a (non-VM) thread is
 605 // running Java. Only the VM thread handles these signals.
 606 sigset_t* os::Bsd::vm_signals() {
 607   assert(signal_sets_initialized, "Not initialized");
 608   return &vm_sigs;
 609 }
 610 
 611 // These are signals that are blocked during cond_wait to allow debugger in
 612 sigset_t* os::Bsd::allowdebug_blocked_signals() {
 613   assert(signal_sets_initialized, "Not initialized");
 614   return &allowdebug_blocked_sigs;
 615 }
 616 
 617 void os::Bsd::hotspot_sigmask(Thread* thread) {
 618 
 619   //Save caller's signal mask before setting VM signal mask
 620   sigset_t caller_sigmask;
 621   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 622 
 623   OSThread* osthread = thread->osthread();
 624   osthread->set_caller_sigmask(caller_sigmask);
 625 
 626   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 627 
 628   if (!ReduceSignalUsage) {
 629     if (thread->is_VM_thread()) {
 630       // Only the VM thread handles BREAK_SIGNAL ...
 631       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 632     } else {
 633       // ... all other threads block BREAK_SIGNAL
 634       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 635     }
 636   }
 637 }
 638 
 639 
 640 //////////////////////////////////////////////////////////////////////////////
 641 // create new thread
 642 
 643 #ifdef __APPLE__
 644 // library handle for calling objc_registerThreadWithCollector()
 645 // without static linking to the libobjc library
 646   #define OBJC_LIB "/usr/lib/libobjc.dylib"
 647   #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 648 typedef void (*objc_registerThreadWithCollector_t)();
 649 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 650 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 651 #endif
 652 
 653 #ifdef __APPLE__
 654 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 655   // Additional thread_id used to correlate threads in SA
 656   thread_identifier_info_data_t     m_ident_info;
 657   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 658 
 659   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 660               (thread_info_t) &m_ident_info, &count);
 661 
 662   return m_ident_info.thread_id;
 663 }
 664 #endif
 665 
 666 // Thread start routine for all newly created threads
 667 static void *thread_native_entry(Thread *thread) {
 668   // Try to randomize the cache line index of hot stack frames.
 669   // This helps when threads of the same stack traces evict each other's
 670   // cache lines. The threads can be either from the same JVM instance, or
 671   // from different JVM instances. The benefit is especially true for
 672   // processors with hyperthreading technology.
 673   static int counter = 0;
 674   int pid = os::current_process_id();
 675   alloca(((pid ^ counter++) & 7) * 128);
 676 
 677   thread->initialize_thread_current();
 678 
 679   OSThread* osthread = thread->osthread();
 680   Monitor* sync = osthread->startThread_lock();
 681 
 682   osthread->set_thread_id(os::Bsd::gettid());
 683 
 684   log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 685     os::current_thread_id(), (uintx) pthread_self());
 686 
 687 #ifdef __APPLE__
 688   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 689   guarantee(unique_thread_id != 0, "unique thread id was not found");
 690   osthread->set_unique_thread_id(unique_thread_id);
 691 #endif
 692   // initialize signal mask for this thread
 693   os::Bsd::hotspot_sigmask(thread);
 694 
 695   // initialize floating point control register
 696   os::Bsd::init_thread_fpu_state();
 697 
 698 #ifdef __APPLE__
 699   // register thread with objc gc
 700   if (objc_registerThreadWithCollectorFunction != NULL) {
 701     objc_registerThreadWithCollectorFunction();
 702   }
 703 #endif
 704 
 705   // handshaking with parent thread
 706   {
 707     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 708 
 709     // notify parent thread
 710     osthread->set_state(INITIALIZED);
 711     sync->notify_all();
 712 
 713     // wait until os::start_thread()
 714     while (osthread->get_state() == INITIALIZED) {
 715       sync->wait(Mutex::_no_safepoint_check_flag);
 716     }
 717   }
 718 
 719   // call one more level start routine
 720   thread->run();
 721 
 722   log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 723     os::current_thread_id(), (uintx) pthread_self());
 724 
 725   // If a thread has not deleted itself ("delete this") as part of its
 726   // termination sequence, we have to ensure thread-local-storage is
 727   // cleared before we actually terminate. No threads should ever be
 728   // deleted asynchronously with respect to their termination.
 729   if (Thread::current_or_null_safe() != NULL) {
 730     assert(Thread::current_or_null_safe() == thread, "current thread is wrong");
 731     thread->clear_thread_current();
 732   }
 733 
 734   return 0;
 735 }
 736 
 737 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
 738   assert(thread->osthread() == NULL, "caller responsible");
 739 
 740   // Allocate the OSThread object
 741   OSThread* osthread = new OSThread(NULL, NULL);
 742   if (osthread == NULL) {
 743     return false;
 744   }
 745 
 746   // set the correct thread state
 747   osthread->set_thread_type(thr_type);
 748 
 749   // Initial state is ALLOCATED but not INITIALIZED
 750   osthread->set_state(ALLOCATED);
 751 
 752   thread->set_osthread(osthread);
 753 
 754   // init thread attributes
 755   pthread_attr_t attr;
 756   pthread_attr_init(&attr);
 757   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 758 
 759   // calculate stack size if it's not specified by caller
 760   if (stack_size == 0) {
 761     stack_size = os::Bsd::default_stack_size(thr_type);
 762 
 763     switch (thr_type) {
 764     case os::java_thread:
 765       // Java threads use ThreadStackSize which default value can be
 766       // changed with the flag -Xss
 767       assert(JavaThread::stack_size_at_create() > 0, "this should be set");
 768       stack_size = JavaThread::stack_size_at_create();
 769       break;
 770     case os::compiler_thread:
 771       if (CompilerThreadStackSize > 0) {
 772         stack_size = (size_t)(CompilerThreadStackSize * K);
 773         break;
 774       } // else fall through:
 775         // use VMThreadStackSize if CompilerThreadStackSize is not defined
 776     case os::vm_thread:
 777     case os::pgc_thread:
 778     case os::cgc_thread:
 779     case os::watcher_thread:
 780       if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 781       break;
 782     }
 783   }
 784 
 785   stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
 786   pthread_attr_setstacksize(&attr, stack_size);
 787 
 788   ThreadState state;
 789 
 790   {
 791     pthread_t tid;
 792     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
 793 
 794     char buf[64];
 795     if (ret == 0) {
 796       log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
 797         (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 798     } else {
 799       log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
 800         os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 801     }
 802 
 803     pthread_attr_destroy(&attr);
 804 
 805     if (ret != 0) {
 806       // Need to clean up stuff we've allocated so far
 807       thread->set_osthread(NULL);
 808       delete osthread;
 809       return false;
 810     }
 811 
 812     // Store pthread info into the OSThread
 813     osthread->set_pthread_id(tid);
 814 
 815     // Wait until child thread is either initialized or aborted
 816     {
 817       Monitor* sync_with_child = osthread->startThread_lock();
 818       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 819       while ((state = osthread->get_state()) == ALLOCATED) {
 820         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 821       }
 822     }
 823 
 824   }
 825 
 826   // Aborted due to thread limit being reached
 827   if (state == ZOMBIE) {
 828     thread->set_osthread(NULL);
 829     delete osthread;
 830     return false;
 831   }
 832 
 833   // The thread is returned suspended (in state INITIALIZED),
 834   // and is started higher up in the call chain
 835   assert(state == INITIALIZED, "race condition");
 836   return true;
 837 }
 838 
 839 /////////////////////////////////////////////////////////////////////////////
 840 // attach existing thread
 841 
 842 // bootstrap the main thread
 843 bool os::create_main_thread(JavaThread* thread) {
 844   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 845   return create_attached_thread(thread);
 846 }
 847 
 848 bool os::create_attached_thread(JavaThread* thread) {
 849 #ifdef ASSERT
 850   thread->verify_not_published();
 851 #endif
 852 
 853   // Allocate the OSThread object
 854   OSThread* osthread = new OSThread(NULL, NULL);
 855 
 856   if (osthread == NULL) {
 857     return false;
 858   }
 859 
 860   osthread->set_thread_id(os::Bsd::gettid());
 861 
 862   // Store pthread info into the OSThread
 863 #ifdef __APPLE__
 864   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 865   guarantee(unique_thread_id != 0, "just checking");
 866   osthread->set_unique_thread_id(unique_thread_id);
 867 #endif
 868   osthread->set_pthread_id(::pthread_self());
 869 
 870   // initialize floating point control register
 871   os::Bsd::init_thread_fpu_state();
 872 
 873   // Initial thread state is RUNNABLE
 874   osthread->set_state(RUNNABLE);
 875 
 876   thread->set_osthread(osthread);
 877 
 878   // initialize signal mask for this thread
 879   // and save the caller's signal mask
 880   os::Bsd::hotspot_sigmask(thread);
 881 
 882   log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 883     os::current_thread_id(), (uintx) pthread_self());
 884 
 885   return true;
 886 }
 887 
 888 void os::pd_start_thread(Thread* thread) {
 889   OSThread * osthread = thread->osthread();
 890   assert(osthread->get_state() != INITIALIZED, "just checking");
 891   Monitor* sync_with_child = osthread->startThread_lock();
 892   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 893   sync_with_child->notify();
 894 }
 895 
 896 // Free Bsd resources related to the OSThread
 897 void os::free_thread(OSThread* osthread) {
 898   assert(osthread != NULL, "osthread not set");
 899 
 900   // We are told to free resources of the argument thread,
 901   // but we can only really operate on the current thread.
 902   assert(Thread::current()->osthread() == osthread,
 903          "os::free_thread but not current thread");
 904 
 905   // Restore caller's signal mask
 906   sigset_t sigmask = osthread->caller_sigmask();
 907   pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 908 
 909   delete osthread;
 910 }
 911 
 912 ////////////////////////////////////////////////////////////////////////////////
 913 // time support
 914 
 915 // Time since start-up in seconds to a fine granularity.
 916 // Used by VMSelfDestructTimer and the MemProfiler.
 917 double os::elapsedTime() {
 918 
 919   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 920 }
 921 
 922 jlong os::elapsed_counter() {
 923   return javaTimeNanos() - initial_time_count;
 924 }
 925 
 926 jlong os::elapsed_frequency() {
 927   return NANOSECS_PER_SEC; // nanosecond resolution
 928 }
 929 
 930 bool os::supports_vtime() { return true; }
 931 bool os::enable_vtime()   { return false; }
 932 bool os::vtime_enabled()  { return false; }
 933 
 934 double os::elapsedVTime() {
 935   // better than nothing, but not much
 936   return elapsedTime();
 937 }
 938 
 939 jlong os::javaTimeMillis() {
 940   timeval time;
 941   int status = gettimeofday(&time, NULL);
 942   assert(status != -1, "bsd error");
 943   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 944 }
 945 
 946 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
 947   timeval time;
 948   int status = gettimeofday(&time, NULL);
 949   assert(status != -1, "bsd error");
 950   seconds = jlong(time.tv_sec);
 951   nanos = jlong(time.tv_usec) * 1000;
 952 }
 953 
 954 #ifndef __APPLE__
 955   #ifndef CLOCK_MONOTONIC
 956     #define CLOCK_MONOTONIC (1)
 957   #endif
 958 #endif
 959 
 960 #ifdef __APPLE__
 961 void os::Bsd::clock_init() {
 962   mach_timebase_info(&_timebase_info);
 963 }
 964 #else
 965 void os::Bsd::clock_init() {
 966   struct timespec res;
 967   struct timespec tp;
 968   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
 969       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
 970     // yes, monotonic clock is supported
 971     _clock_gettime = ::clock_gettime;
 972   }
 973 }
 974 #endif
 975 
 976 
 977 
 978 #ifdef __APPLE__
 979 
 980 jlong os::javaTimeNanos() {
 981   const uint64_t tm = mach_absolute_time();
 982   const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
 983   const uint64_t prev = Bsd::_max_abstime;
 984   if (now <= prev) {
 985     return prev;   // same or retrograde time;
 986   }
 987   const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
 988   assert(obsv >= prev, "invariant");   // Monotonicity
 989   // If the CAS succeeded then we're done and return "now".
 990   // If the CAS failed and the observed value "obsv" is >= now then
 991   // we should return "obsv".  If the CAS failed and now > obsv > prv then
 992   // some other thread raced this thread and installed a new value, in which case
 993   // we could either (a) retry the entire operation, (b) retry trying to install now
 994   // or (c) just return obsv.  We use (c).   No loop is required although in some cases
 995   // we might discard a higher "now" value in deference to a slightly lower but freshly
 996   // installed obsv value.   That's entirely benign -- it admits no new orderings compared
 997   // to (a) or (b) -- and greatly reduces coherence traffic.
 998   // We might also condition (c) on the magnitude of the delta between obsv and now.
 999   // Avoiding excessive CAS operations to hot RW locations is critical.
1000   // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1001   return (prev == obsv) ? now : obsv;
1002 }
1003 
1004 #else // __APPLE__
1005 
1006 jlong os::javaTimeNanos() {
1007   if (os::supports_monotonic_clock()) {
1008     struct timespec tp;
1009     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
1010     assert(status == 0, "gettime error");
1011     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1012     return result;
1013   } else {
1014     timeval time;
1015     int status = gettimeofday(&time, NULL);
1016     assert(status != -1, "bsd error");
1017     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1018     return 1000 * usecs;
1019   }
1020 }
1021 
1022 #endif // __APPLE__
1023 
1024 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1025   if (os::supports_monotonic_clock()) {
1026     info_ptr->max_value = ALL_64_BITS;
1027 
1028     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1029     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
1030     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
1031   } else {
1032     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1033     info_ptr->max_value = ALL_64_BITS;
1034 
1035     // gettimeofday is a real time clock so it skips
1036     info_ptr->may_skip_backward = true;
1037     info_ptr->may_skip_forward = true;
1038   }
1039 
1040   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
1041 }
1042 
1043 // Return the real, user, and system times in seconds from an
1044 // arbitrary fixed point in the past.
1045 bool os::getTimesSecs(double* process_real_time,
1046                       double* process_user_time,
1047                       double* process_system_time) {
1048   struct tms ticks;
1049   clock_t real_ticks = times(&ticks);
1050 
1051   if (real_ticks == (clock_t) (-1)) {
1052     return false;
1053   } else {
1054     double ticks_per_second = (double) clock_tics_per_sec;
1055     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1056     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1057     *process_real_time = ((double) real_ticks) / ticks_per_second;
1058 
1059     return true;
1060   }
1061 }
1062 
1063 
1064 char * os::local_time_string(char *buf, size_t buflen) {
1065   struct tm t;
1066   time_t long_time;
1067   time(&long_time);
1068   localtime_r(&long_time, &t);
1069   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1070                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1071                t.tm_hour, t.tm_min, t.tm_sec);
1072   return buf;
1073 }
1074 
1075 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1076   return localtime_r(clock, res);
1077 }
1078 
1079 ////////////////////////////////////////////////////////////////////////////////
1080 // runtime exit support
1081 
1082 // Note: os::shutdown() might be called very early during initialization, or
1083 // called from signal handler. Before adding something to os::shutdown(), make
1084 // sure it is async-safe and can handle partially initialized VM.
1085 void os::shutdown() {
1086 
1087   // allow PerfMemory to attempt cleanup of any persistent resources
1088   perfMemory_exit();
1089 
1090   // needs to remove object in file system
1091   AttachListener::abort();
1092 
1093   // flush buffered output, finish log files
1094   ostream_abort();
1095 
1096   // Check for abort hook
1097   abort_hook_t abort_hook = Arguments::abort_hook();
1098   if (abort_hook != NULL) {
1099     abort_hook();
1100   }
1101 
1102 }
1103 
1104 // Note: os::abort() might be called very early during initialization, or
1105 // called from signal handler. Before adding something to os::abort(), make
1106 // sure it is async-safe and can handle partially initialized VM.
1107 void os::abort(bool dump_core, void* siginfo, const void* context) {
1108   os::shutdown();
1109   if (dump_core) {
1110 #ifndef PRODUCT
1111     fdStream out(defaultStream::output_fd());
1112     out.print_raw("Current thread is ");
1113     char buf[16];
1114     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1115     out.print_raw_cr(buf);
1116     out.print_raw_cr("Dumping core ...");
1117 #endif
1118     ::abort(); // dump core
1119   }
1120 
1121   ::exit(1);
1122 }
1123 
1124 // Die immediately, no exit hook, no abort hook, no cleanup.
1125 void os::die() {
1126   // _exit() on BsdThreads only kills current thread
1127   ::abort();
1128 }
1129 
1130 // This method is a copy of JDK's sysGetLastErrorString
1131 // from src/solaris/hpi/src/system_md.c
1132 
1133 size_t os::lasterror(char *buf, size_t len) {
1134   if (errno == 0)  return 0;
1135 
1136   const char *s = os::strerror(errno);
1137   size_t n = ::strlen(s);
1138   if (n >= len) {
1139     n = len - 1;
1140   }
1141   ::strncpy(buf, s, n);
1142   buf[n] = '\0';
1143   return n;
1144 }
1145 
1146 // Information of current thread in variety of formats
1147 pid_t os::Bsd::gettid() {
1148   int retval = -1;
1149 
1150 #ifdef __APPLE__ //XNU kernel
1151   // despite the fact mach port is actually not a thread id use it
1152   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1153   retval = ::pthread_mach_thread_np(::pthread_self());
1154   guarantee(retval != 0, "just checking");
1155   return retval;
1156 
1157 #else
1158   #ifdef __FreeBSD__
1159   retval = syscall(SYS_thr_self);
1160   #else
1161     #ifdef __OpenBSD__
1162   retval = syscall(SYS_getthrid);
1163     #else
1164       #ifdef __NetBSD__
1165   retval = (pid_t) syscall(SYS__lwp_self);
1166       #endif
1167     #endif
1168   #endif
1169 #endif
1170 
1171   if (retval == -1) {
1172     return getpid();
1173   }
1174 }
1175 
1176 intx os::current_thread_id() {
1177 #ifdef __APPLE__
1178   return (intx)::pthread_mach_thread_np(::pthread_self());
1179 #else
1180   return (intx)::pthread_self();
1181 #endif
1182 }
1183 
1184 int os::current_process_id() {
1185 
1186   // Under the old bsd thread library, bsd gives each thread
1187   // its own process id. Because of this each thread will return
1188   // a different pid if this method were to return the result
1189   // of getpid(2). Bsd provides no api that returns the pid
1190   // of the launcher thread for the vm. This implementation
1191   // returns a unique pid, the pid of the launcher thread
1192   // that starts the vm 'process'.
1193 
1194   // Under the NPTL, getpid() returns the same pid as the
1195   // launcher thread rather than a unique pid per thread.
1196   // Use gettid() if you want the old pre NPTL behaviour.
1197 
1198   // if you are looking for the result of a call to getpid() that
1199   // returns a unique pid for the calling thread, then look at the
1200   // OSThread::thread_id() method in osThread_bsd.hpp file
1201 
1202   return (int)(_initial_pid ? _initial_pid : getpid());
1203 }
1204 
1205 // DLL functions
1206 
1207 #define JNI_LIB_PREFIX "lib"
1208 #ifdef __APPLE__
1209   #define JNI_LIB_SUFFIX ".dylib"
1210 #else
1211   #define JNI_LIB_SUFFIX ".so"
1212 #endif
1213 
1214 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1215 
1216 // This must be hard coded because it's the system's temporary
1217 // directory not the java application's temp directory, ala java.io.tmpdir.
1218 #ifdef __APPLE__
1219 // macosx has a secure per-user temporary directory
1220 char temp_path_storage[PATH_MAX];
1221 const char* os::get_temp_directory() {
1222   static char *temp_path = NULL;
1223   if (temp_path == NULL) {
1224     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1225     if (pathSize == 0 || pathSize > PATH_MAX) {
1226       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1227     }
1228     temp_path = temp_path_storage;
1229   }
1230   return temp_path;
1231 }
1232 #else // __APPLE__
1233 const char* os::get_temp_directory() { return "/tmp"; }
1234 #endif // __APPLE__
1235 
1236 static bool file_exists(const char* filename) {
1237   struct stat statbuf;
1238   if (filename == NULL || strlen(filename) == 0) {
1239     return false;
1240   }
1241   return os::stat(filename, &statbuf) == 0;
1242 }
1243 
1244 bool os::dll_build_name(char* buffer, size_t buflen,
1245                         const char* pname, const char* fname) {
1246   bool retval = false;
1247   // Copied from libhpi
1248   const size_t pnamelen = pname ? strlen(pname) : 0;
1249 
1250   // Return error on buffer overflow.
1251   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1252     return retval;
1253   }
1254 
1255   if (pnamelen == 0) {
1256     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1257     retval = true;
1258   } else if (strchr(pname, *os::path_separator()) != NULL) {
1259     int n;
1260     char** pelements = split_path(pname, &n);
1261     if (pelements == NULL) {
1262       return false;
1263     }
1264     for (int i = 0; i < n; i++) {
1265       // Really shouldn't be NULL, but check can't hurt
1266       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1267         continue; // skip the empty path values
1268       }
1269       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1270                pelements[i], fname);
1271       if (file_exists(buffer)) {
1272         retval = true;
1273         break;
1274       }
1275     }
1276     // release the storage
1277     for (int i = 0; i < n; i++) {
1278       if (pelements[i] != NULL) {
1279         FREE_C_HEAP_ARRAY(char, pelements[i]);
1280       }
1281     }
1282     if (pelements != NULL) {
1283       FREE_C_HEAP_ARRAY(char*, pelements);
1284     }
1285   } else {
1286     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1287     retval = true;
1288   }
1289   return retval;
1290 }
1291 
1292 // check if addr is inside libjvm.so
1293 bool os::address_is_in_vm(address addr) {
1294   static address libjvm_base_addr;
1295   Dl_info dlinfo;
1296 
1297   if (libjvm_base_addr == NULL) {
1298     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1299       libjvm_base_addr = (address)dlinfo.dli_fbase;
1300     }
1301     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1302   }
1303 
1304   if (dladdr((void *)addr, &dlinfo) != 0) {
1305     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1306   }
1307 
1308   return false;
1309 }
1310 
1311 
1312 #define MACH_MAXSYMLEN 256
1313 
1314 bool os::dll_address_to_function_name(address addr, char *buf,
1315                                       int buflen, int *offset,
1316                                       bool demangle) {
1317   // buf is not optional, but offset is optional
1318   assert(buf != NULL, "sanity check");
1319 
1320   Dl_info dlinfo;
1321   char localbuf[MACH_MAXSYMLEN];
1322 
1323   if (dladdr((void*)addr, &dlinfo) != 0) {
1324     // see if we have a matching symbol
1325     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1326       if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1327         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1328       }
1329       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1330       return true;
1331     }
1332     // no matching symbol so try for just file info
1333     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1334       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1335                           buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1336         return true;
1337       }
1338     }
1339 
1340     // Handle non-dynamic manually:
1341     if (dlinfo.dli_fbase != NULL &&
1342         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1343                         dlinfo.dli_fbase)) {
1344       if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) {
1345         jio_snprintf(buf, buflen, "%s", localbuf);
1346       }
1347       return true;
1348     }
1349   }
1350   buf[0] = '\0';
1351   if (offset != NULL) *offset = -1;
1352   return false;
1353 }
1354 
1355 // ported from solaris version
1356 bool os::dll_address_to_library_name(address addr, char* buf,
1357                                      int buflen, int* offset) {
1358   // buf is not optional, but offset is optional
1359   assert(buf != NULL, "sanity check");
1360 
1361   Dl_info dlinfo;
1362 
1363   if (dladdr((void*)addr, &dlinfo) != 0) {
1364     if (dlinfo.dli_fname != NULL) {
1365       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1366     }
1367     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1368       *offset = addr - (address)dlinfo.dli_fbase;
1369     }
1370     return true;
1371   }
1372 
1373   buf[0] = '\0';
1374   if (offset) *offset = -1;
1375   return false;
1376 }
1377 
1378 // Loads .dll/.so and
1379 // in case of error it checks if .dll/.so was built for the
1380 // same architecture as Hotspot is running on
1381 
1382 #ifdef __APPLE__
1383 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1384 #ifdef STATIC_BUILD
1385   return os::get_default_process_handle();
1386 #else
1387   void * result= ::dlopen(filename, RTLD_LAZY);
1388   if (result != NULL) {
1389     // Successful loading
1390     return result;
1391   }
1392 
1393   // Read system error message into ebuf
1394   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1395   ebuf[ebuflen-1]='\0';
1396 
1397   return NULL;
1398 #endif // STATIC_BUILD
1399 }
1400 #else
1401 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1402 #ifdef STATIC_BUILD
1403   return os::get_default_process_handle();
1404 #else
1405   void * result= ::dlopen(filename, RTLD_LAZY);
1406   if (result != NULL) {
1407     // Successful loading
1408     return result;
1409   }
1410 
1411   Elf32_Ehdr elf_head;
1412 
1413   // Read system error message into ebuf
1414   // It may or may not be overwritten below
1415   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1416   ebuf[ebuflen-1]='\0';
1417   int diag_msg_max_length=ebuflen-strlen(ebuf);
1418   char* diag_msg_buf=ebuf+strlen(ebuf);
1419 
1420   if (diag_msg_max_length==0) {
1421     // No more space in ebuf for additional diagnostics message
1422     return NULL;
1423   }
1424 
1425 
1426   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1427 
1428   if (file_descriptor < 0) {
1429     // Can't open library, report dlerror() message
1430     return NULL;
1431   }
1432 
1433   bool failed_to_read_elf_head=
1434     (sizeof(elf_head)!=
1435      (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1436 
1437   ::close(file_descriptor);
1438   if (failed_to_read_elf_head) {
1439     // file i/o error - report dlerror() msg
1440     return NULL;
1441   }
1442 
1443   typedef struct {
1444     Elf32_Half  code;         // Actual value as defined in elf.h
1445     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1446     char        elf_class;    // 32 or 64 bit
1447     char        endianess;    // MSB or LSB
1448     char*       name;         // String representation
1449   } arch_t;
1450 
1451   #ifndef EM_486
1452     #define EM_486          6               /* Intel 80486 */
1453   #endif
1454 
1455   #ifndef EM_MIPS_RS3_LE
1456     #define EM_MIPS_RS3_LE  10              /* MIPS */
1457   #endif
1458 
1459   #ifndef EM_PPC64
1460     #define EM_PPC64        21              /* PowerPC64 */
1461   #endif
1462 
1463   #ifndef EM_S390
1464     #define EM_S390         22              /* IBM System/390 */
1465   #endif
1466 
1467   #ifndef EM_IA_64
1468     #define EM_IA_64        50              /* HP/Intel IA-64 */
1469   #endif
1470 
1471   #ifndef EM_X86_64
1472     #define EM_X86_64       62              /* AMD x86-64 */
1473   #endif
1474 
1475   static const arch_t arch_array[]={
1476     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1477     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1478     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1479     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1480     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1481     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1482     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1483     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1484     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1485     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1486     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1487     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1488     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1489     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1490     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1491     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1492   };
1493 
1494   #if  (defined IA32)
1495   static  Elf32_Half running_arch_code=EM_386;
1496   #elif   (defined AMD64)
1497   static  Elf32_Half running_arch_code=EM_X86_64;
1498   #elif  (defined IA64)
1499   static  Elf32_Half running_arch_code=EM_IA_64;
1500   #elif  (defined __sparc) && (defined _LP64)
1501   static  Elf32_Half running_arch_code=EM_SPARCV9;
1502   #elif  (defined __sparc) && (!defined _LP64)
1503   static  Elf32_Half running_arch_code=EM_SPARC;
1504   #elif  (defined __powerpc64__)
1505   static  Elf32_Half running_arch_code=EM_PPC64;
1506   #elif  (defined __powerpc__)
1507   static  Elf32_Half running_arch_code=EM_PPC;
1508   #elif  (defined ARM)
1509   static  Elf32_Half running_arch_code=EM_ARM;
1510   #elif  (defined S390)
1511   static  Elf32_Half running_arch_code=EM_S390;
1512   #elif  (defined ALPHA)
1513   static  Elf32_Half running_arch_code=EM_ALPHA;
1514   #elif  (defined MIPSEL)
1515   static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1516   #elif  (defined PARISC)
1517   static  Elf32_Half running_arch_code=EM_PARISC;
1518   #elif  (defined MIPS)
1519   static  Elf32_Half running_arch_code=EM_MIPS;
1520   #elif  (defined M68K)
1521   static  Elf32_Half running_arch_code=EM_68K;
1522   #else
1523     #error Method os::dll_load requires that one of following is defined:\
1524          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1525   #endif
1526 
1527   // Identify compatability class for VM's architecture and library's architecture
1528   // Obtain string descriptions for architectures
1529 
1530   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1531   int running_arch_index=-1;
1532 
1533   for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1534     if (running_arch_code == arch_array[i].code) {
1535       running_arch_index    = i;
1536     }
1537     if (lib_arch.code == arch_array[i].code) {
1538       lib_arch.compat_class = arch_array[i].compat_class;
1539       lib_arch.name         = arch_array[i].name;
1540     }
1541   }
1542 
1543   assert(running_arch_index != -1,
1544          "Didn't find running architecture code (running_arch_code) in arch_array");
1545   if (running_arch_index == -1) {
1546     // Even though running architecture detection failed
1547     // we may still continue with reporting dlerror() message
1548     return NULL;
1549   }
1550 
1551   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1552     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1553     return NULL;
1554   }
1555 
1556 #ifndef S390
1557   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1558     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1559     return NULL;
1560   }
1561 #endif // !S390
1562 
1563   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1564     if (lib_arch.name!=NULL) {
1565       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1566                  " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1567                  lib_arch.name, arch_array[running_arch_index].name);
1568     } else {
1569       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1570                  " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1571                  lib_arch.code,
1572                  arch_array[running_arch_index].name);
1573     }
1574   }
1575 
1576   return NULL;
1577 #endif // STATIC_BUILD
1578 }
1579 #endif // !__APPLE__
1580 
1581 void* os::get_default_process_handle() {
1582 #ifdef __APPLE__
1583   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1584   // to avoid finding unexpected symbols on second (or later)
1585   // loads of a library.
1586   return (void*)::dlopen(NULL, RTLD_FIRST);
1587 #else
1588   return (void*)::dlopen(NULL, RTLD_LAZY);
1589 #endif
1590 }
1591 
1592 // XXX: Do we need a lock around this as per Linux?
1593 void* os::dll_lookup(void* handle, const char* name) {
1594   return dlsym(handle, name);
1595 }
1596 
1597 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1598   outputStream * out = (outputStream *) param;
1599   out->print_cr(PTR_FORMAT " \t%s", base_address, name);
1600   return 0;
1601 }
1602 
1603 void os::print_dll_info(outputStream *st) {
1604   st->print_cr("Dynamic libraries:");
1605   if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1606     st->print_cr("Error: Cannot print dynamic libraries.");
1607   }
1608 }
1609 
1610 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1611 #ifdef RTLD_DI_LINKMAP
1612   Dl_info dli;
1613   void *handle;
1614   Link_map *map;
1615   Link_map *p;
1616 
1617   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1618       dli.dli_fname == NULL) {
1619     return 1;
1620   }
1621   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1622   if (handle == NULL) {
1623     return 1;
1624   }
1625   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1626   if (map == NULL) {
1627     dlclose(handle);
1628     return 1;
1629   }
1630 
1631   while (map->l_prev != NULL)
1632     map = map->l_prev;
1633 
1634   while (map != NULL) {
1635     // Value for top_address is returned as 0 since we don't have any information about module size
1636     if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1637       dlclose(handle);
1638       return 1;
1639     }
1640     map = map->l_next;
1641   }
1642 
1643   dlclose(handle);
1644 #elif defined(__APPLE__)
1645   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1646     // Value for top_address is returned as 0 since we don't have any information about module size
1647     if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1648       return 1;
1649     }
1650   }
1651   return 0;
1652 #else
1653   return 1;
1654 #endif
1655 }
1656 
1657 void os::get_summary_os_info(char* buf, size_t buflen) {
1658   // These buffers are small because we want this to be brief
1659   // and not use a lot of stack while generating the hs_err file.
1660   char os[100];
1661   size_t size = sizeof(os);
1662   int mib_kern[] = { CTL_KERN, KERN_OSTYPE };
1663   if (sysctl(mib_kern, 2, os, &size, NULL, 0) < 0) {
1664 #ifdef __APPLE__
1665       strncpy(os, "Darwin", sizeof(os));
1666 #elif __OpenBSD__
1667       strncpy(os, "OpenBSD", sizeof(os));
1668 #else
1669       strncpy(os, "BSD", sizeof(os));
1670 #endif
1671   }
1672 
1673   char release[100];
1674   size = sizeof(release);
1675   int mib_release[] = { CTL_KERN, KERN_OSRELEASE };
1676   if (sysctl(mib_release, 2, release, &size, NULL, 0) < 0) {
1677       // if error, leave blank
1678       strncpy(release, "", sizeof(release));
1679   }
1680   snprintf(buf, buflen, "%s %s", os, release);
1681 }
1682 
1683 void os::print_os_info_brief(outputStream* st) {
1684   os::Posix::print_uname_info(st);
1685 }
1686 
1687 void os::print_os_info(outputStream* st) {
1688   st->print("OS:");
1689 
1690   os::Posix::print_uname_info(st);
1691 
1692   os::Posix::print_rlimit_info(st);
1693 
1694   os::Posix::print_load_average(st);
1695 }
1696 
1697 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1698   // Nothing to do for now.
1699 }
1700 
1701 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1702   unsigned int mhz;
1703   size_t size = sizeof(mhz);
1704   int mib[] = { CTL_HW, HW_CPU_FREQ };
1705   if (sysctl(mib, 2, &mhz, &size, NULL, 0) < 0) {
1706     mhz = 1;  // looks like an error but can be divided by
1707   } else {
1708     mhz /= 1000000;  // reported in millions
1709   }
1710 
1711   char model[100];
1712   size = sizeof(model);
1713   int mib_model[] = { CTL_HW, HW_MODEL };
1714   if (sysctl(mib_model, 2, model, &size, NULL, 0) < 0) {
1715     strncpy(model, cpu_arch, sizeof(model));
1716   }
1717 
1718   char machine[100];
1719   size = sizeof(machine);
1720   int mib_machine[] = { CTL_HW, HW_MACHINE };
1721   if (sysctl(mib_machine, 2, machine, &size, NULL, 0) < 0) {
1722       strncpy(machine, "", sizeof(machine));
1723   }
1724 
1725   snprintf(buf, buflen, "%s %s %d MHz", model, machine, mhz);
1726 }
1727 
1728 void os::print_memory_info(outputStream* st) {
1729 
1730   st->print("Memory:");
1731   st->print(" %dk page", os::vm_page_size()>>10);
1732 
1733   st->print(", physical " UINT64_FORMAT "k",
1734             os::physical_memory() >> 10);
1735   st->print("(" UINT64_FORMAT "k free)",
1736             os::available_memory() >> 10);
1737   st->cr();
1738 }
1739 
1740 static void print_signal_handler(outputStream* st, int sig,
1741                                  char* buf, size_t buflen);
1742 
1743 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1744   st->print_cr("Signal Handlers:");
1745   print_signal_handler(st, SIGSEGV, buf, buflen);
1746   print_signal_handler(st, SIGBUS , buf, buflen);
1747   print_signal_handler(st, SIGFPE , buf, buflen);
1748   print_signal_handler(st, SIGPIPE, buf, buflen);
1749   print_signal_handler(st, SIGXFSZ, buf, buflen);
1750   print_signal_handler(st, SIGILL , buf, buflen);
1751   print_signal_handler(st, SR_signum, buf, buflen);
1752   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1753   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1754   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1755   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1756 }
1757 
1758 static char saved_jvm_path[MAXPATHLEN] = {0};
1759 
1760 // Find the full path to the current module, libjvm
1761 void os::jvm_path(char *buf, jint buflen) {
1762   // Error checking.
1763   if (buflen < MAXPATHLEN) {
1764     assert(false, "must use a large-enough buffer");
1765     buf[0] = '\0';
1766     return;
1767   }
1768   // Lazy resolve the path to current module.
1769   if (saved_jvm_path[0] != 0) {
1770     strcpy(buf, saved_jvm_path);
1771     return;
1772   }
1773 
1774   char dli_fname[MAXPATHLEN];
1775   bool ret = dll_address_to_library_name(
1776                                          CAST_FROM_FN_PTR(address, os::jvm_path),
1777                                          dli_fname, sizeof(dli_fname), NULL);
1778   assert(ret, "cannot locate libjvm");
1779   char *rp = NULL;
1780   if (ret && dli_fname[0] != '\0') {
1781     rp = realpath(dli_fname, buf);
1782   }
1783   if (rp == NULL) {
1784     return;
1785   }
1786 
1787   if (Arguments::sun_java_launcher_is_altjvm()) {
1788     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1789     // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1790     // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1791     // appears at the right place in the string, then assume we are
1792     // installed in a JDK and we're done. Otherwise, check for a
1793     // JAVA_HOME environment variable and construct a path to the JVM
1794     // being overridden.
1795 
1796     const char *p = buf + strlen(buf) - 1;
1797     for (int count = 0; p > buf && count < 5; ++count) {
1798       for (--p; p > buf && *p != '/'; --p)
1799         /* empty */ ;
1800     }
1801 
1802     if (strncmp(p, "/jre/lib/", 9) != 0) {
1803       // Look for JAVA_HOME in the environment.
1804       char* java_home_var = ::getenv("JAVA_HOME");
1805       if (java_home_var != NULL && java_home_var[0] != 0) {
1806         char* jrelib_p;
1807         int len;
1808 
1809         // Check the current module name "libjvm"
1810         p = strrchr(buf, '/');
1811         assert(strstr(p, "/libjvm") == p, "invalid library name");
1812 
1813         rp = realpath(java_home_var, buf);
1814         if (rp == NULL) {
1815           return;
1816         }
1817 
1818         // determine if this is a legacy image or modules image
1819         // modules image doesn't have "jre" subdirectory
1820         len = strlen(buf);
1821         assert(len < buflen, "Ran out of buffer space");
1822         jrelib_p = buf + len;
1823 
1824         // Add the appropriate library subdir
1825         snprintf(jrelib_p, buflen-len, "/jre/lib");
1826         if (0 != access(buf, F_OK)) {
1827           snprintf(jrelib_p, buflen-len, "/lib");
1828         }
1829 
1830         // Add the appropriate client or server subdir
1831         len = strlen(buf);
1832         jrelib_p = buf + len;
1833         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1834         if (0 != access(buf, F_OK)) {
1835           snprintf(jrelib_p, buflen-len, "%s", "");
1836         }
1837 
1838         // If the path exists within JAVA_HOME, add the JVM library name
1839         // to complete the path to JVM being overridden.  Otherwise fallback
1840         // to the path to the current library.
1841         if (0 == access(buf, F_OK)) {
1842           // Use current module name "libjvm"
1843           len = strlen(buf);
1844           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1845         } else {
1846           // Fall back to path of current library
1847           rp = realpath(dli_fname, buf);
1848           if (rp == NULL) {
1849             return;
1850           }
1851         }
1852       }
1853     }
1854   }
1855 
1856   strncpy(saved_jvm_path, buf, MAXPATHLEN);
1857   saved_jvm_path[MAXPATHLEN - 1] = '\0';
1858 }
1859 
1860 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1861   // no prefix required, not even "_"
1862 }
1863 
1864 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1865   // no suffix required
1866 }
1867 
1868 ////////////////////////////////////////////////////////////////////////////////
1869 // sun.misc.Signal support
1870 
1871 static volatile jint sigint_count = 0;
1872 
1873 static void UserHandler(int sig, void *siginfo, void *context) {
1874   // 4511530 - sem_post is serialized and handled by the manager thread. When
1875   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1876   // don't want to flood the manager thread with sem_post requests.
1877   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
1878     return;
1879   }
1880 
1881   // Ctrl-C is pressed during error reporting, likely because the error
1882   // handler fails to abort. Let VM die immediately.
1883   if (sig == SIGINT && is_error_reported()) {
1884     os::die();
1885   }
1886 
1887   os::signal_notify(sig);
1888 }
1889 
1890 void* os::user_handler() {
1891   return CAST_FROM_FN_PTR(void*, UserHandler);
1892 }
1893 
1894 extern "C" {
1895   typedef void (*sa_handler_t)(int);
1896   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1897 }
1898 
1899 void* os::signal(int signal_number, void* handler) {
1900   struct sigaction sigAct, oldSigAct;
1901 
1902   sigfillset(&(sigAct.sa_mask));
1903   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1904   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1905 
1906   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1907     // -1 means registration failed
1908     return (void *)-1;
1909   }
1910 
1911   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1912 }
1913 
1914 void os::signal_raise(int signal_number) {
1915   ::raise(signal_number);
1916 }
1917 
1918 // The following code is moved from os.cpp for making this
1919 // code platform specific, which it is by its very nature.
1920 
1921 // Will be modified when max signal is changed to be dynamic
1922 int os::sigexitnum_pd() {
1923   return NSIG;
1924 }
1925 
1926 // a counter for each possible signal value
1927 static volatile jint pending_signals[NSIG+1] = { 0 };
1928 
1929 // Bsd(POSIX) specific hand shaking semaphore.
1930 #ifdef __APPLE__
1931 typedef semaphore_t os_semaphore_t;
1932 
1933   #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1934   #define SEM_WAIT(sem)           semaphore_wait(sem)
1935   #define SEM_POST(sem)           semaphore_signal(sem)
1936   #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
1937 #else
1938 typedef sem_t os_semaphore_t;
1939 
1940   #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
1941   #define SEM_WAIT(sem)           sem_wait(&sem)
1942   #define SEM_POST(sem)           sem_post(&sem)
1943   #define SEM_DESTROY(sem)        sem_destroy(&sem)
1944 #endif
1945 
1946 #ifdef __APPLE__
1947 // OS X doesn't support unamed POSIX semaphores, so the implementation in os_posix.cpp can't be used.
1948 
1949 static const char* sem_init_strerror(kern_return_t value) {
1950   switch (value) {
1951     case KERN_INVALID_ARGUMENT:  return "Invalid argument";
1952     case KERN_RESOURCE_SHORTAGE: return "Resource shortage";
1953     default:                     return "Unknown";
1954   }
1955 }
1956 
1957 OSXSemaphore::OSXSemaphore(uint value) {
1958   kern_return_t ret = SEM_INIT(_semaphore, value);
1959 
1960   guarantee(ret == KERN_SUCCESS, "Failed to create semaphore: %s", sem_init_strerror(ret));
1961 }
1962 
1963 OSXSemaphore::~OSXSemaphore() {
1964   SEM_DESTROY(_semaphore);
1965 }
1966 
1967 void OSXSemaphore::signal(uint count) {
1968   for (uint i = 0; i < count; i++) {
1969     kern_return_t ret = SEM_POST(_semaphore);
1970 
1971     assert(ret == KERN_SUCCESS, "Failed to signal semaphore");
1972   }
1973 }
1974 
1975 void OSXSemaphore::wait() {
1976   kern_return_t ret;
1977   while ((ret = SEM_WAIT(_semaphore)) == KERN_ABORTED) {
1978     // Semaphore was interrupted. Retry.
1979   }
1980   assert(ret == KERN_SUCCESS, "Failed to wait on semaphore");
1981 }
1982 
1983 jlong OSXSemaphore::currenttime() {
1984   struct timeval tv;
1985   gettimeofday(&tv, NULL);
1986   return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
1987 }
1988 
1989 bool OSXSemaphore::trywait() {
1990   return timedwait(0, 0);
1991 }
1992 
1993 bool OSXSemaphore::timedwait(unsigned int sec, int nsec) {
1994   kern_return_t kr = KERN_ABORTED;
1995   mach_timespec_t waitspec;
1996   waitspec.tv_sec = sec;
1997   waitspec.tv_nsec = nsec;
1998 
1999   jlong starttime = currenttime();
2000 
2001   kr = semaphore_timedwait(_semaphore, waitspec);
2002   while (kr == KERN_ABORTED) {
2003     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
2004 
2005     jlong current = currenttime();
2006     jlong passedtime = current - starttime;
2007 
2008     if (passedtime >= totalwait) {
2009       waitspec.tv_sec = 0;
2010       waitspec.tv_nsec = 0;
2011     } else {
2012       jlong waittime = totalwait - (current - starttime);
2013       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
2014       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
2015     }
2016 
2017     kr = semaphore_timedwait(_semaphore, waitspec);
2018   }
2019 
2020   return kr == KERN_SUCCESS;
2021 }
2022 
2023 #else
2024 // Use POSIX implementation of semaphores.
2025 
2026 struct timespec PosixSemaphore::create_timespec(unsigned int sec, int nsec) {
2027   struct timespec ts;
2028   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2029 
2030   return ts;
2031 }
2032 
2033 #endif // __APPLE__
2034 
2035 static os_semaphore_t sig_sem;
2036 
2037 #ifdef __APPLE__
2038 static OSXSemaphore sr_semaphore;
2039 #else
2040 static PosixSemaphore sr_semaphore;
2041 #endif
2042 
2043 void os::signal_init_pd() {
2044   // Initialize signal structures
2045   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2046 
2047   // Initialize signal semaphore
2048   ::SEM_INIT(sig_sem, 0);
2049 }
2050 
2051 void os::signal_notify(int sig) {
2052   Atomic::inc(&pending_signals[sig]);
2053   ::SEM_POST(sig_sem);
2054 }
2055 
2056 static int check_pending_signals(bool wait) {
2057   Atomic::store(0, &sigint_count);
2058   for (;;) {
2059     for (int i = 0; i < NSIG + 1; i++) {
2060       jint n = pending_signals[i];
2061       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2062         return i;
2063       }
2064     }
2065     if (!wait) {
2066       return -1;
2067     }
2068     JavaThread *thread = JavaThread::current();
2069     ThreadBlockInVM tbivm(thread);
2070 
2071     bool threadIsSuspended;
2072     do {
2073       thread->set_suspend_equivalent();
2074       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2075       ::SEM_WAIT(sig_sem);
2076 
2077       // were we externally suspended while we were waiting?
2078       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2079       if (threadIsSuspended) {
2080         // The semaphore has been incremented, but while we were waiting
2081         // another thread suspended us. We don't want to continue running
2082         // while suspended because that would surprise the thread that
2083         // suspended us.
2084         ::SEM_POST(sig_sem);
2085 
2086         thread->java_suspend_self();
2087       }
2088     } while (threadIsSuspended);
2089   }
2090 }
2091 
2092 int os::signal_lookup() {
2093   return check_pending_signals(false);
2094 }
2095 
2096 int os::signal_wait() {
2097   return check_pending_signals(true);
2098 }
2099 
2100 ////////////////////////////////////////////////////////////////////////////////
2101 // Virtual Memory
2102 
2103 int os::vm_page_size() {
2104   // Seems redundant as all get out
2105   assert(os::Bsd::page_size() != -1, "must call os::init");
2106   return os::Bsd::page_size();
2107 }
2108 
2109 // Solaris allocates memory by pages.
2110 int os::vm_allocation_granularity() {
2111   assert(os::Bsd::page_size() != -1, "must call os::init");
2112   return os::Bsd::page_size();
2113 }
2114 
2115 // Rationale behind this function:
2116 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2117 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2118 //  samples for JITted code. Here we create private executable mapping over the code cache
2119 //  and then we can use standard (well, almost, as mapping can change) way to provide
2120 //  info for the reporting script by storing timestamp and location of symbol
2121 void bsd_wrap_code(char* base, size_t size) {
2122   static volatile jint cnt = 0;
2123 
2124   if (!UseOprofile) {
2125     return;
2126   }
2127 
2128   char buf[PATH_MAX + 1];
2129   int num = Atomic::add(1, &cnt);
2130 
2131   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2132            os::get_temp_directory(), os::current_process_id(), num);
2133   unlink(buf);
2134 
2135   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2136 
2137   if (fd != -1) {
2138     off_t rv = ::lseek(fd, size-2, SEEK_SET);
2139     if (rv != (off_t)-1) {
2140       if (::write(fd, "", 1) == 1) {
2141         mmap(base, size,
2142              PROT_READ|PROT_WRITE|PROT_EXEC,
2143              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2144       }
2145     }
2146     ::close(fd);
2147     unlink(buf);
2148   }
2149 }
2150 
2151 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2152                                     int err) {
2153   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2154           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2155           os::errno_name(err), err);
2156 }
2157 
2158 // NOTE: Bsd kernel does not really reserve the pages for us.
2159 //       All it does is to check if there are enough free pages
2160 //       left at the time of mmap(). This could be a potential
2161 //       problem.
2162 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2163   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2164 #ifdef __OpenBSD__
2165   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2166   if (::mprotect(addr, size, prot) == 0) {
2167     return true;
2168   }
2169 #else
2170   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2171                                      MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2172   if (res != (uintptr_t) MAP_FAILED) {
2173     return true;
2174   }
2175 #endif
2176 
2177   // Warn about any commit errors we see in non-product builds just
2178   // in case mmap() doesn't work as described on the man page.
2179   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2180 
2181   return false;
2182 }
2183 
2184 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2185                           bool exec) {
2186   // alignment_hint is ignored on this OS
2187   return pd_commit_memory(addr, size, exec);
2188 }
2189 
2190 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2191                                   const char* mesg) {
2192   assert(mesg != NULL, "mesg must be specified");
2193   if (!pd_commit_memory(addr, size, exec)) {
2194     // add extra info in product mode for vm_exit_out_of_memory():
2195     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2196     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2197   }
2198 }
2199 
2200 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2201                                   size_t alignment_hint, bool exec,
2202                                   const char* mesg) {
2203   // alignment_hint is ignored on this OS
2204   pd_commit_memory_or_exit(addr, size, exec, mesg);
2205 }
2206 
2207 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2208 }
2209 
2210 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2211   ::madvise(addr, bytes, MADV_DONTNEED);
2212 }
2213 
2214 void os::numa_make_global(char *addr, size_t bytes) {
2215 }
2216 
2217 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2218 }
2219 
2220 bool os::numa_topology_changed()   { return false; }
2221 
2222 size_t os::numa_get_groups_num() {
2223   return 1;
2224 }
2225 
2226 int os::numa_get_group_id() {
2227   return 0;
2228 }
2229 
2230 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2231   if (size > 0) {
2232     ids[0] = 0;
2233     return 1;
2234   }
2235   return 0;
2236 }
2237 
2238 bool os::get_page_info(char *start, page_info* info) {
2239   return false;
2240 }
2241 
2242 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2243   return end;
2244 }
2245 
2246 
2247 bool os::pd_uncommit_memory(char* addr, size_t size) {
2248 #ifdef __OpenBSD__
2249   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2250   return ::mprotect(addr, size, PROT_NONE) == 0;
2251 #else
2252   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2253                                      MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2254   return res  != (uintptr_t) MAP_FAILED;
2255 #endif
2256 }
2257 
2258 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2259   return os::commit_memory(addr, size, !ExecMem);
2260 }
2261 
2262 // If this is a growable mapping, remove the guard pages entirely by
2263 // munmap()ping them.  If not, just call uncommit_memory().
2264 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2265   return os::uncommit_memory(addr, size);
2266 }
2267 
2268 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2269 // at 'requested_addr'. If there are existing memory mappings at the same
2270 // location, however, they will be overwritten. If 'fixed' is false,
2271 // 'requested_addr' is only treated as a hint, the return value may or
2272 // may not start from the requested address. Unlike Bsd mmap(), this
2273 // function returns NULL to indicate failure.
2274 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2275   char * addr;
2276   int flags;
2277 
2278   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2279   if (fixed) {
2280     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2281     flags |= MAP_FIXED;
2282   }
2283 
2284   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2285   // touch an uncommitted page. Otherwise, the read/write might
2286   // succeed if we have enough swap space to back the physical page.
2287   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2288                        flags, -1, 0);
2289 
2290   return addr == MAP_FAILED ? NULL : addr;
2291 }
2292 
2293 static int anon_munmap(char * addr, size_t size) {
2294   return ::munmap(addr, size) == 0;
2295 }
2296 
2297 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2298                             size_t alignment_hint) {
2299   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2300 }
2301 
2302 bool os::pd_release_memory(char* addr, size_t size) {
2303   return anon_munmap(addr, size);
2304 }
2305 
2306 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2307   // Bsd wants the mprotect address argument to be page aligned.
2308   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2309 
2310   // According to SUSv3, mprotect() should only be used with mappings
2311   // established by mmap(), and mmap() always maps whole pages. Unaligned
2312   // 'addr' likely indicates problem in the VM (e.g. trying to change
2313   // protection of malloc'ed or statically allocated memory). Check the
2314   // caller if you hit this assert.
2315   assert(addr == bottom, "sanity check");
2316 
2317   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2318   return ::mprotect(bottom, size, prot) == 0;
2319 }
2320 
2321 // Set protections specified
2322 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2323                         bool is_committed) {
2324   unsigned int p = 0;
2325   switch (prot) {
2326   case MEM_PROT_NONE: p = PROT_NONE; break;
2327   case MEM_PROT_READ: p = PROT_READ; break;
2328   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2329   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2330   default:
2331     ShouldNotReachHere();
2332   }
2333   // is_committed is unused.
2334   return bsd_mprotect(addr, bytes, p);
2335 }
2336 
2337 bool os::guard_memory(char* addr, size_t size) {
2338   return bsd_mprotect(addr, size, PROT_NONE);
2339 }
2340 
2341 bool os::unguard_memory(char* addr, size_t size) {
2342   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2343 }
2344 
2345 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2346   return false;
2347 }
2348 
2349 // Large page support
2350 
2351 static size_t _large_page_size = 0;
2352 
2353 void os::large_page_init() {
2354 }
2355 
2356 
2357 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2358   fatal("This code is not used or maintained.");
2359 
2360   // "exec" is passed in but not used.  Creating the shared image for
2361   // the code cache doesn't have an SHM_X executable permission to check.
2362   assert(UseLargePages && UseSHM, "only for SHM large pages");
2363 
2364   key_t key = IPC_PRIVATE;
2365   char *addr;
2366 
2367   bool warn_on_failure = UseLargePages &&
2368                          (!FLAG_IS_DEFAULT(UseLargePages) ||
2369                           !FLAG_IS_DEFAULT(LargePageSizeInBytes));
2370 
2371   // Create a large shared memory region to attach to based on size.
2372   // Currently, size is the total size of the heap
2373   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2374   if (shmid == -1) {
2375     // Possible reasons for shmget failure:
2376     // 1. shmmax is too small for Java heap.
2377     //    > check shmmax value: cat /proc/sys/kernel/shmmax
2378     //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2379     // 2. not enough large page memory.
2380     //    > check available large pages: cat /proc/meminfo
2381     //    > increase amount of large pages:
2382     //          echo new_value > /proc/sys/vm/nr_hugepages
2383     //      Note 1: different Bsd may use different name for this property,
2384     //            e.g. on Redhat AS-3 it is "hugetlb_pool".
2385     //      Note 2: it's possible there's enough physical memory available but
2386     //            they are so fragmented after a long run that they can't
2387     //            coalesce into large pages. Try to reserve large pages when
2388     //            the system is still "fresh".
2389     if (warn_on_failure) {
2390       warning("Failed to reserve shared memory (errno = %d).", errno);
2391     }
2392     return NULL;
2393   }
2394 
2395   // attach to the region
2396   addr = (char*)shmat(shmid, req_addr, 0);
2397   int err = errno;
2398 
2399   // Remove shmid. If shmat() is successful, the actual shared memory segment
2400   // will be deleted when it's detached by shmdt() or when the process
2401   // terminates. If shmat() is not successful this will remove the shared
2402   // segment immediately.
2403   shmctl(shmid, IPC_RMID, NULL);
2404 
2405   if ((intptr_t)addr == -1) {
2406     if (warn_on_failure) {
2407       warning("Failed to attach shared memory (errno = %d).", err);
2408     }
2409     return NULL;
2410   }
2411 
2412   // The memory is committed
2413   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
2414 
2415   return addr;
2416 }
2417 
2418 bool os::release_memory_special(char* base, size_t bytes) {
2419   if (MemTracker::tracking_level() > NMT_minimal) {
2420     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2421     // detaching the SHM segment will also delete it, see reserve_memory_special()
2422     int rslt = shmdt(base);
2423     if (rslt == 0) {
2424       tkr.record((address)base, bytes);
2425       return true;
2426     } else {
2427       return false;
2428     }
2429   } else {
2430     return shmdt(base) == 0;
2431   }
2432 }
2433 
2434 size_t os::large_page_size() {
2435   return _large_page_size;
2436 }
2437 
2438 // HugeTLBFS allows application to commit large page memory on demand;
2439 // with SysV SHM the entire memory region must be allocated as shared
2440 // memory.
2441 bool os::can_commit_large_page_memory() {
2442   return UseHugeTLBFS;
2443 }
2444 
2445 bool os::can_execute_large_page_memory() {
2446   return UseHugeTLBFS;
2447 }
2448 
2449 // Reserve memory at an arbitrary address, only if that area is
2450 // available (and not reserved for something else).
2451 
2452 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2453   const int max_tries = 10;
2454   char* base[max_tries];
2455   size_t size[max_tries];
2456   const size_t gap = 0x000000;
2457 
2458   // Assert only that the size is a multiple of the page size, since
2459   // that's all that mmap requires, and since that's all we really know
2460   // about at this low abstraction level.  If we need higher alignment,
2461   // we can either pass an alignment to this method or verify alignment
2462   // in one of the methods further up the call chain.  See bug 5044738.
2463   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2464 
2465   // Repeatedly allocate blocks until the block is allocated at the
2466   // right spot.
2467 
2468   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2469   // if kernel honors the hint then we can return immediately.
2470   char * addr = anon_mmap(requested_addr, bytes, false);
2471   if (addr == requested_addr) {
2472     return requested_addr;
2473   }
2474 
2475   if (addr != NULL) {
2476     // mmap() is successful but it fails to reserve at the requested address
2477     anon_munmap(addr, bytes);
2478   }
2479 
2480   int i;
2481   for (i = 0; i < max_tries; ++i) {
2482     base[i] = reserve_memory(bytes);
2483 
2484     if (base[i] != NULL) {
2485       // Is this the block we wanted?
2486       if (base[i] == requested_addr) {
2487         size[i] = bytes;
2488         break;
2489       }
2490 
2491       // Does this overlap the block we wanted? Give back the overlapped
2492       // parts and try again.
2493 
2494       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2495       if (top_overlap >= 0 && top_overlap < bytes) {
2496         unmap_memory(base[i], top_overlap);
2497         base[i] += top_overlap;
2498         size[i] = bytes - top_overlap;
2499       } else {
2500         size_t bottom_overlap = base[i] + bytes - requested_addr;
2501         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2502           unmap_memory(requested_addr, bottom_overlap);
2503           size[i] = bytes - bottom_overlap;
2504         } else {
2505           size[i] = bytes;
2506         }
2507       }
2508     }
2509   }
2510 
2511   // Give back the unused reserved pieces.
2512 
2513   for (int j = 0; j < i; ++j) {
2514     if (base[j] != NULL) {
2515       unmap_memory(base[j], size[j]);
2516     }
2517   }
2518 
2519   if (i < max_tries) {
2520     return requested_addr;
2521   } else {
2522     return NULL;
2523   }
2524 }
2525 
2526 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2527   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2528 }
2529 
2530 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
2531   RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset));
2532 }
2533 
2534 void os::naked_short_sleep(jlong ms) {
2535   struct timespec req;
2536 
2537   assert(ms < 1000, "Un-interruptable sleep, short time use only");
2538   req.tv_sec = 0;
2539   if (ms > 0) {
2540     req.tv_nsec = (ms % 1000) * 1000000;
2541   } else {
2542     req.tv_nsec = 1;
2543   }
2544 
2545   nanosleep(&req, NULL);
2546 
2547   return;
2548 }
2549 
2550 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2551 void os::infinite_sleep() {
2552   while (true) {    // sleep forever ...
2553     ::sleep(100);   // ... 100 seconds at a time
2554   }
2555 }
2556 
2557 // Used to convert frequent JVM_Yield() to nops
2558 bool os::dont_yield() {
2559   return DontYieldALot;
2560 }
2561 
2562 void os::naked_yield() {
2563   sched_yield();
2564 }
2565 
2566 ////////////////////////////////////////////////////////////////////////////////
2567 // thread priority support
2568 
2569 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2570 // only supports dynamic priority, static priority must be zero. For real-time
2571 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2572 // However, for large multi-threaded applications, SCHED_RR is not only slower
2573 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2574 // of 5 runs - Sep 2005).
2575 //
2576 // The following code actually changes the niceness of kernel-thread/LWP. It
2577 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2578 // not the entire user process, and user level threads are 1:1 mapped to kernel
2579 // threads. It has always been the case, but could change in the future. For
2580 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2581 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2582 
2583 #if !defined(__APPLE__)
2584 int os::java_to_os_priority[CriticalPriority + 1] = {
2585   19,              // 0 Entry should never be used
2586 
2587    0,              // 1 MinPriority
2588    3,              // 2
2589    6,              // 3
2590 
2591   10,              // 4
2592   15,              // 5 NormPriority
2593   18,              // 6
2594 
2595   21,              // 7
2596   25,              // 8
2597   28,              // 9 NearMaxPriority
2598 
2599   31,              // 10 MaxPriority
2600 
2601   31               // 11 CriticalPriority
2602 };
2603 #else
2604 // Using Mach high-level priority assignments
2605 int os::java_to_os_priority[CriticalPriority + 1] = {
2606    0,              // 0 Entry should never be used (MINPRI_USER)
2607 
2608   27,              // 1 MinPriority
2609   28,              // 2
2610   29,              // 3
2611 
2612   30,              // 4
2613   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2614   32,              // 6
2615 
2616   33,              // 7
2617   34,              // 8
2618   35,              // 9 NearMaxPriority
2619 
2620   36,              // 10 MaxPriority
2621 
2622   36               // 11 CriticalPriority
2623 };
2624 #endif
2625 
2626 static int prio_init() {
2627   if (ThreadPriorityPolicy == 1) {
2628     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2629     // if effective uid is not root. Perhaps, a more elegant way of doing
2630     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2631     if (geteuid() != 0) {
2632       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2633         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2634       }
2635       ThreadPriorityPolicy = 0;
2636     }
2637   }
2638   if (UseCriticalJavaThreadPriority) {
2639     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2640   }
2641   return 0;
2642 }
2643 
2644 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2645   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2646 
2647 #ifdef __OpenBSD__
2648   // OpenBSD pthread_setprio starves low priority threads
2649   return OS_OK;
2650 #elif defined(__FreeBSD__)
2651   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2652 #elif defined(__APPLE__) || defined(__NetBSD__)
2653   struct sched_param sp;
2654   int policy;
2655   pthread_t self = pthread_self();
2656 
2657   if (pthread_getschedparam(self, &policy, &sp) != 0) {
2658     return OS_ERR;
2659   }
2660 
2661   sp.sched_priority = newpri;
2662   if (pthread_setschedparam(self, policy, &sp) != 0) {
2663     return OS_ERR;
2664   }
2665 
2666   return OS_OK;
2667 #else
2668   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2669   return (ret == 0) ? OS_OK : OS_ERR;
2670 #endif
2671 }
2672 
2673 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2674   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2675     *priority_ptr = java_to_os_priority[NormPriority];
2676     return OS_OK;
2677   }
2678 
2679   errno = 0;
2680 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2681   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2682 #elif defined(__APPLE__) || defined(__NetBSD__)
2683   int policy;
2684   struct sched_param sp;
2685 
2686   pthread_getschedparam(pthread_self(), &policy, &sp);
2687   *priority_ptr = sp.sched_priority;
2688 #else
2689   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2690 #endif
2691   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2692 }
2693 
2694 // Hint to the underlying OS that a task switch would not be good.
2695 // Void return because it's a hint and can fail.
2696 void os::hint_no_preempt() {}
2697 
2698 ////////////////////////////////////////////////////////////////////////////////
2699 // suspend/resume support
2700 
2701 //  the low-level signal-based suspend/resume support is a remnant from the
2702 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2703 //  within hotspot. Now there is a single use-case for this:
2704 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
2705 //      that runs in the watcher thread.
2706 //  The remaining code is greatly simplified from the more general suspension
2707 //  code that used to be used.
2708 //
2709 //  The protocol is quite simple:
2710 //  - suspend:
2711 //      - sends a signal to the target thread
2712 //      - polls the suspend state of the osthread using a yield loop
2713 //      - target thread signal handler (SR_handler) sets suspend state
2714 //        and blocks in sigsuspend until continued
2715 //  - resume:
2716 //      - sets target osthread state to continue
2717 //      - sends signal to end the sigsuspend loop in the SR_handler
2718 //
2719 //  Note that the SR_lock plays no role in this suspend/resume protocol.
2720 
2721 static void resume_clear_context(OSThread *osthread) {
2722   osthread->set_ucontext(NULL);
2723   osthread->set_siginfo(NULL);
2724 }
2725 
2726 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2727   osthread->set_ucontext(context);
2728   osthread->set_siginfo(siginfo);
2729 }
2730 
2731 // Handler function invoked when a thread's execution is suspended or
2732 // resumed. We have to be careful that only async-safe functions are
2733 // called here (Note: most pthread functions are not async safe and
2734 // should be avoided.)
2735 //
2736 // Note: sigwait() is a more natural fit than sigsuspend() from an
2737 // interface point of view, but sigwait() prevents the signal hander
2738 // from being run. libpthread would get very confused by not having
2739 // its signal handlers run and prevents sigwait()'s use with the
2740 // mutex granting granting signal.
2741 //
2742 // Currently only ever called on the VMThread or JavaThread
2743 //
2744 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2745   // Save and restore errno to avoid confusing native code with EINTR
2746   // after sigsuspend.
2747   int old_errno = errno;
2748 
2749   Thread* thread = Thread::current();
2750   OSThread* osthread = thread->osthread();
2751   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2752 
2753   os::SuspendResume::State current = osthread->sr.state();
2754   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2755     suspend_save_context(osthread, siginfo, context);
2756 
2757     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2758     os::SuspendResume::State state = osthread->sr.suspended();
2759     if (state == os::SuspendResume::SR_SUSPENDED) {
2760       sigset_t suspend_set;  // signals for sigsuspend()
2761 
2762       // get current set of blocked signals and unblock resume signal
2763       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2764       sigdelset(&suspend_set, SR_signum);
2765 
2766       sr_semaphore.signal();
2767       // wait here until we are resumed
2768       while (1) {
2769         sigsuspend(&suspend_set);
2770 
2771         os::SuspendResume::State result = osthread->sr.running();
2772         if (result == os::SuspendResume::SR_RUNNING) {
2773           sr_semaphore.signal();
2774           break;
2775         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2776           ShouldNotReachHere();
2777         }
2778       }
2779 
2780     } else if (state == os::SuspendResume::SR_RUNNING) {
2781       // request was cancelled, continue
2782     } else {
2783       ShouldNotReachHere();
2784     }
2785 
2786     resume_clear_context(osthread);
2787   } else if (current == os::SuspendResume::SR_RUNNING) {
2788     // request was cancelled, continue
2789   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2790     // ignore
2791   } else {
2792     // ignore
2793   }
2794 
2795   errno = old_errno;
2796 }
2797 
2798 
2799 static int SR_initialize() {
2800   struct sigaction act;
2801   char *s;
2802   // Get signal number to use for suspend/resume
2803   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2804     int sig = ::strtol(s, 0, 10);
2805     if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
2806         sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
2807       SR_signum = sig;
2808     } else {
2809       warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2810               sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2811     }
2812   }
2813 
2814   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2815          "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2816 
2817   sigemptyset(&SR_sigset);
2818   sigaddset(&SR_sigset, SR_signum);
2819 
2820   // Set up signal handler for suspend/resume
2821   act.sa_flags = SA_RESTART|SA_SIGINFO;
2822   act.sa_handler = (void (*)(int)) SR_handler;
2823 
2824   // SR_signum is blocked by default.
2825   // 4528190 - We also need to block pthread restart signal (32 on all
2826   // supported Bsd platforms). Note that BsdThreads need to block
2827   // this signal for all threads to work properly. So we don't have
2828   // to use hard-coded signal number when setting up the mask.
2829   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2830 
2831   if (sigaction(SR_signum, &act, 0) == -1) {
2832     return -1;
2833   }
2834 
2835   // Save signal flag
2836   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2837   return 0;
2838 }
2839 
2840 static int sr_notify(OSThread* osthread) {
2841   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2842   assert_status(status == 0, status, "pthread_kill");
2843   return status;
2844 }
2845 
2846 // "Randomly" selected value for how long we want to spin
2847 // before bailing out on suspending a thread, also how often
2848 // we send a signal to a thread we want to resume
2849 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2850 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2851 
2852 // returns true on success and false on error - really an error is fatal
2853 // but this seems the normal response to library errors
2854 static bool do_suspend(OSThread* osthread) {
2855   assert(osthread->sr.is_running(), "thread should be running");
2856   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2857 
2858   // mark as suspended and send signal
2859   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2860     // failed to switch, state wasn't running?
2861     ShouldNotReachHere();
2862     return false;
2863   }
2864 
2865   if (sr_notify(osthread) != 0) {
2866     ShouldNotReachHere();
2867   }
2868 
2869   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2870   while (true) {
2871     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2872       break;
2873     } else {
2874       // timeout
2875       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2876       if (cancelled == os::SuspendResume::SR_RUNNING) {
2877         return false;
2878       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2879         // make sure that we consume the signal on the semaphore as well
2880         sr_semaphore.wait();
2881         break;
2882       } else {
2883         ShouldNotReachHere();
2884         return false;
2885       }
2886     }
2887   }
2888 
2889   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2890   return true;
2891 }
2892 
2893 static void do_resume(OSThread* osthread) {
2894   assert(osthread->sr.is_suspended(), "thread should be suspended");
2895   assert(!sr_semaphore.trywait(), "invalid semaphore state");
2896 
2897   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2898     // failed to switch to WAKEUP_REQUEST
2899     ShouldNotReachHere();
2900     return;
2901   }
2902 
2903   while (true) {
2904     if (sr_notify(osthread) == 0) {
2905       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2906         if (osthread->sr.is_running()) {
2907           return;
2908         }
2909       }
2910     } else {
2911       ShouldNotReachHere();
2912     }
2913   }
2914 
2915   guarantee(osthread->sr.is_running(), "Must be running!");
2916 }
2917 
2918 ///////////////////////////////////////////////////////////////////////////////////
2919 // signal handling (except suspend/resume)
2920 
2921 // This routine may be used by user applications as a "hook" to catch signals.
2922 // The user-defined signal handler must pass unrecognized signals to this
2923 // routine, and if it returns true (non-zero), then the signal handler must
2924 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
2925 // routine will never retun false (zero), but instead will execute a VM panic
2926 // routine kill the process.
2927 //
2928 // If this routine returns false, it is OK to call it again.  This allows
2929 // the user-defined signal handler to perform checks either before or after
2930 // the VM performs its own checks.  Naturally, the user code would be making
2931 // a serious error if it tried to handle an exception (such as a null check
2932 // or breakpoint) that the VM was generating for its own correct operation.
2933 //
2934 // This routine may recognize any of the following kinds of signals:
2935 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2936 // It should be consulted by handlers for any of those signals.
2937 //
2938 // The caller of this routine must pass in the three arguments supplied
2939 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2940 // field of the structure passed to sigaction().  This routine assumes that
2941 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2942 //
2943 // Note that the VM will print warnings if it detects conflicting signal
2944 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2945 //
2946 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2947                                                void* ucontext,
2948                                                int abort_if_unrecognized);
2949 
2950 void signalHandler(int sig, siginfo_t* info, void* uc) {
2951   assert(info != NULL && uc != NULL, "it must be old kernel");
2952   int orig_errno = errno;  // Preserve errno value over signal handler.
2953   JVM_handle_bsd_signal(sig, info, uc, true);
2954   errno = orig_errno;
2955 }
2956 
2957 
2958 // This boolean allows users to forward their own non-matching signals
2959 // to JVM_handle_bsd_signal, harmlessly.
2960 bool os::Bsd::signal_handlers_are_installed = false;
2961 
2962 // For signal-chaining
2963 struct sigaction sigact[NSIG];
2964 uint32_t sigs = 0;
2965 #if (32 < NSIG-1)
2966 #error "Not all signals can be encoded in sigs. Adapt its type!"
2967 #endif
2968 bool os::Bsd::libjsig_is_loaded = false;
2969 typedef struct sigaction *(*get_signal_t)(int);
2970 get_signal_t os::Bsd::get_signal_action = NULL;
2971 
2972 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2973   struct sigaction *actp = NULL;
2974 
2975   if (libjsig_is_loaded) {
2976     // Retrieve the old signal handler from libjsig
2977     actp = (*get_signal_action)(sig);
2978   }
2979   if (actp == NULL) {
2980     // Retrieve the preinstalled signal handler from jvm
2981     actp = get_preinstalled_handler(sig);
2982   }
2983 
2984   return actp;
2985 }
2986 
2987 static bool call_chained_handler(struct sigaction *actp, int sig,
2988                                  siginfo_t *siginfo, void *context) {
2989   // Call the old signal handler
2990   if (actp->sa_handler == SIG_DFL) {
2991     // It's more reasonable to let jvm treat it as an unexpected exception
2992     // instead of taking the default action.
2993     return false;
2994   } else if (actp->sa_handler != SIG_IGN) {
2995     if ((actp->sa_flags & SA_NODEFER) == 0) {
2996       // automaticlly block the signal
2997       sigaddset(&(actp->sa_mask), sig);
2998     }
2999 
3000     sa_handler_t hand;
3001     sa_sigaction_t sa;
3002     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3003     // retrieve the chained handler
3004     if (siginfo_flag_set) {
3005       sa = actp->sa_sigaction;
3006     } else {
3007       hand = actp->sa_handler;
3008     }
3009 
3010     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3011       actp->sa_handler = SIG_DFL;
3012     }
3013 
3014     // try to honor the signal mask
3015     sigset_t oset;
3016     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3017 
3018     // call into the chained handler
3019     if (siginfo_flag_set) {
3020       (*sa)(sig, siginfo, context);
3021     } else {
3022       (*hand)(sig);
3023     }
3024 
3025     // restore the signal mask
3026     pthread_sigmask(SIG_SETMASK, &oset, 0);
3027   }
3028   // Tell jvm's signal handler the signal is taken care of.
3029   return true;
3030 }
3031 
3032 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3033   bool chained = false;
3034   // signal-chaining
3035   if (UseSignalChaining) {
3036     struct sigaction *actp = get_chained_signal_action(sig);
3037     if (actp != NULL) {
3038       chained = call_chained_handler(actp, sig, siginfo, context);
3039     }
3040   }
3041   return chained;
3042 }
3043 
3044 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3045   if ((((uint32_t)1 << (sig-1)) & sigs) != 0) {
3046     return &sigact[sig];
3047   }
3048   return NULL;
3049 }
3050 
3051 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3052   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3053   sigact[sig] = oldAct;
3054   sigs |= (uint32_t)1 << (sig-1);
3055 }
3056 
3057 // for diagnostic
3058 int sigflags[NSIG];
3059 
3060 int os::Bsd::get_our_sigflags(int sig) {
3061   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3062   return sigflags[sig];
3063 }
3064 
3065 void os::Bsd::set_our_sigflags(int sig, int flags) {
3066   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3067   if (sig > 0 && sig < NSIG) {
3068     sigflags[sig] = flags;
3069   }
3070 }
3071 
3072 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3073   // Check for overwrite.
3074   struct sigaction oldAct;
3075   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3076 
3077   void* oldhand = oldAct.sa_sigaction
3078                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
3079                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
3080   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3081       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3082       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3083     if (AllowUserSignalHandlers || !set_installed) {
3084       // Do not overwrite; user takes responsibility to forward to us.
3085       return;
3086     } else if (UseSignalChaining) {
3087       // save the old handler in jvm
3088       save_preinstalled_handler(sig, oldAct);
3089       // libjsig also interposes the sigaction() call below and saves the
3090       // old sigaction on it own.
3091     } else {
3092       fatal("Encountered unexpected pre-existing sigaction handler "
3093             "%#lx for signal %d.", (long)oldhand, sig);
3094     }
3095   }
3096 
3097   struct sigaction sigAct;
3098   sigfillset(&(sigAct.sa_mask));
3099   sigAct.sa_handler = SIG_DFL;
3100   if (!set_installed) {
3101     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3102   } else {
3103     sigAct.sa_sigaction = signalHandler;
3104     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3105   }
3106 #ifdef __APPLE__
3107   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3108   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3109   // if the signal handler declares it will handle it on alternate stack.
3110   // Notice we only declare we will handle it on alt stack, but we are not
3111   // actually going to use real alt stack - this is just a workaround.
3112   // Please see ux_exception.c, method catch_mach_exception_raise for details
3113   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3114   if (sig == SIGSEGV) {
3115     sigAct.sa_flags |= SA_ONSTACK;
3116   }
3117 #endif
3118 
3119   // Save flags, which are set by ours
3120   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3121   sigflags[sig] = sigAct.sa_flags;
3122 
3123   int ret = sigaction(sig, &sigAct, &oldAct);
3124   assert(ret == 0, "check");
3125 
3126   void* oldhand2  = oldAct.sa_sigaction
3127                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3128                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3129   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3130 }
3131 
3132 // install signal handlers for signals that HotSpot needs to
3133 // handle in order to support Java-level exception handling.
3134 
3135 void os::Bsd::install_signal_handlers() {
3136   if (!signal_handlers_are_installed) {
3137     signal_handlers_are_installed = true;
3138 
3139     // signal-chaining
3140     typedef void (*signal_setting_t)();
3141     signal_setting_t begin_signal_setting = NULL;
3142     signal_setting_t end_signal_setting = NULL;
3143     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3144                                           dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3145     if (begin_signal_setting != NULL) {
3146       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3147                                           dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3148       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3149                                          dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3150       libjsig_is_loaded = true;
3151       assert(UseSignalChaining, "should enable signal-chaining");
3152     }
3153     if (libjsig_is_loaded) {
3154       // Tell libjsig jvm is setting signal handlers
3155       (*begin_signal_setting)();
3156     }
3157 
3158     set_signal_handler(SIGSEGV, true);
3159     set_signal_handler(SIGPIPE, true);
3160     set_signal_handler(SIGBUS, true);
3161     set_signal_handler(SIGILL, true);
3162     set_signal_handler(SIGFPE, true);
3163     set_signal_handler(SIGXFSZ, true);
3164 
3165 #if defined(__APPLE__)
3166     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3167     // signals caught and handled by the JVM. To work around this, we reset the mach task
3168     // signal handler that's placed on our process by CrashReporter. This disables
3169     // CrashReporter-based reporting.
3170     //
3171     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3172     // on caught fatal signals.
3173     //
3174     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3175     // handlers. By replacing the existing task exception handler, we disable gdb's mach
3176     // exception handling, while leaving the standard BSD signal handlers functional.
3177     kern_return_t kr;
3178     kr = task_set_exception_ports(mach_task_self(),
3179                                   EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3180                                   MACH_PORT_NULL,
3181                                   EXCEPTION_STATE_IDENTITY,
3182                                   MACHINE_THREAD_STATE);
3183 
3184     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3185 #endif
3186 
3187     if (libjsig_is_loaded) {
3188       // Tell libjsig jvm finishes setting signal handlers
3189       (*end_signal_setting)();
3190     }
3191 
3192     // We don't activate signal checker if libjsig is in place, we trust ourselves
3193     // and if UserSignalHandler is installed all bets are off
3194     if (CheckJNICalls) {
3195       if (libjsig_is_loaded) {
3196         if (PrintJNIResolving) {
3197           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3198         }
3199         check_signals = false;
3200       }
3201       if (AllowUserSignalHandlers) {
3202         if (PrintJNIResolving) {
3203           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3204         }
3205         check_signals = false;
3206       }
3207     }
3208   }
3209 }
3210 
3211 
3212 /////
3213 // glibc on Bsd platform uses non-documented flag
3214 // to indicate, that some special sort of signal
3215 // trampoline is used.
3216 // We will never set this flag, and we should
3217 // ignore this flag in our diagnostic
3218 #ifdef SIGNIFICANT_SIGNAL_MASK
3219   #undef SIGNIFICANT_SIGNAL_MASK
3220 #endif
3221 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3222 
3223 static const char* get_signal_handler_name(address handler,
3224                                            char* buf, int buflen) {
3225   int offset;
3226   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3227   if (found) {
3228     // skip directory names
3229     const char *p1, *p2;
3230     p1 = buf;
3231     size_t len = strlen(os::file_separator());
3232     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3233     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3234   } else {
3235     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3236   }
3237   return buf;
3238 }
3239 
3240 static void print_signal_handler(outputStream* st, int sig,
3241                                  char* buf, size_t buflen) {
3242   struct sigaction sa;
3243 
3244   sigaction(sig, NULL, &sa);
3245 
3246   // See comment for SIGNIFICANT_SIGNAL_MASK define
3247   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3248 
3249   st->print("%s: ", os::exception_name(sig, buf, buflen));
3250 
3251   address handler = (sa.sa_flags & SA_SIGINFO)
3252     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3253     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3254 
3255   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3256     st->print("SIG_DFL");
3257   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3258     st->print("SIG_IGN");
3259   } else {
3260     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3261   }
3262 
3263   st->print(", sa_mask[0]=");
3264   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3265 
3266   address rh = VMError::get_resetted_sighandler(sig);
3267   // May be, handler was resetted by VMError?
3268   if (rh != NULL) {
3269     handler = rh;
3270     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3271   }
3272 
3273   st->print(", sa_flags=");
3274   os::Posix::print_sa_flags(st, sa.sa_flags);
3275 
3276   // Check: is it our handler?
3277   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3278       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3279     // It is our signal handler
3280     // check for flags, reset system-used one!
3281     if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3282       st->print(
3283                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3284                 os::Bsd::get_our_sigflags(sig));
3285     }
3286   }
3287   st->cr();
3288 }
3289 
3290 
3291 #define DO_SIGNAL_CHECK(sig)                      \
3292   do {                                            \
3293     if (!sigismember(&check_signal_done, sig)) {  \
3294       os::Bsd::check_signal_handler(sig);         \
3295     }                                             \
3296   } while (0)
3297 
3298 // This method is a periodic task to check for misbehaving JNI applications
3299 // under CheckJNI, we can add any periodic checks here
3300 
3301 void os::run_periodic_checks() {
3302 
3303   if (check_signals == false) return;
3304 
3305   // SEGV and BUS if overridden could potentially prevent
3306   // generation of hs*.log in the event of a crash, debugging
3307   // such a case can be very challenging, so we absolutely
3308   // check the following for a good measure:
3309   DO_SIGNAL_CHECK(SIGSEGV);
3310   DO_SIGNAL_CHECK(SIGILL);
3311   DO_SIGNAL_CHECK(SIGFPE);
3312   DO_SIGNAL_CHECK(SIGBUS);
3313   DO_SIGNAL_CHECK(SIGPIPE);
3314   DO_SIGNAL_CHECK(SIGXFSZ);
3315 
3316 
3317   // ReduceSignalUsage allows the user to override these handlers
3318   // see comments at the very top and jvm_solaris.h
3319   if (!ReduceSignalUsage) {
3320     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3321     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3322     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3323     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3324   }
3325 
3326   DO_SIGNAL_CHECK(SR_signum);
3327 }
3328 
3329 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3330 
3331 static os_sigaction_t os_sigaction = NULL;
3332 
3333 void os::Bsd::check_signal_handler(int sig) {
3334   char buf[O_BUFLEN];
3335   address jvmHandler = NULL;
3336 
3337 
3338   struct sigaction act;
3339   if (os_sigaction == NULL) {
3340     // only trust the default sigaction, in case it has been interposed
3341     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3342     if (os_sigaction == NULL) return;
3343   }
3344 
3345   os_sigaction(sig, (struct sigaction*)NULL, &act);
3346 
3347 
3348   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3349 
3350   address thisHandler = (act.sa_flags & SA_SIGINFO)
3351     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3352     : CAST_FROM_FN_PTR(address, act.sa_handler);
3353 
3354 
3355   switch (sig) {
3356   case SIGSEGV:
3357   case SIGBUS:
3358   case SIGFPE:
3359   case SIGPIPE:
3360   case SIGILL:
3361   case SIGXFSZ:
3362     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3363     break;
3364 
3365   case SHUTDOWN1_SIGNAL:
3366   case SHUTDOWN2_SIGNAL:
3367   case SHUTDOWN3_SIGNAL:
3368   case BREAK_SIGNAL:
3369     jvmHandler = (address)user_handler();
3370     break;
3371 
3372   default:
3373     if (sig == SR_signum) {
3374       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3375     } else {
3376       return;
3377     }
3378     break;
3379   }
3380 
3381   if (thisHandler != jvmHandler) {
3382     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3383     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3384     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3385     // No need to check this sig any longer
3386     sigaddset(&check_signal_done, sig);
3387     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3388     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3389       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3390                     exception_name(sig, buf, O_BUFLEN));
3391     }
3392   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3393     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3394     tty->print("expected:");
3395     os::Posix::print_sa_flags(tty, os::Bsd::get_our_sigflags(sig));
3396     tty->cr();
3397     tty->print("  found:");
3398     os::Posix::print_sa_flags(tty, act.sa_flags);
3399     tty->cr();
3400     // No need to check this sig any longer
3401     sigaddset(&check_signal_done, sig);
3402   }
3403 
3404   // Dump all the signal
3405   if (sigismember(&check_signal_done, sig)) {
3406     print_signal_handlers(tty, buf, O_BUFLEN);
3407   }
3408 }
3409 
3410 extern void report_error(char* file_name, int line_no, char* title,
3411                          char* format, ...);
3412 
3413 // this is called _before_ the most of global arguments have been parsed
3414 void os::init(void) {
3415   char dummy;   // used to get a guess on initial stack address
3416 //  first_hrtime = gethrtime();
3417 
3418   // With BsdThreads the JavaMain thread pid (primordial thread)
3419   // is different than the pid of the java launcher thread.
3420   // So, on Bsd, the launcher thread pid is passed to the VM
3421   // via the sun.java.launcher.pid property.
3422   // Use this property instead of getpid() if it was correctly passed.
3423   // See bug 6351349.
3424   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3425 
3426   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3427 
3428   clock_tics_per_sec = CLK_TCK;
3429 
3430   init_random(1234567);
3431 
3432   ThreadCritical::initialize();
3433 
3434   Bsd::set_page_size(getpagesize());
3435   if (Bsd::page_size() == -1) {
3436     fatal("os_bsd.cpp: os::init: sysconf failed (%s)", os::strerror(errno));
3437   }
3438   init_page_sizes((size_t) Bsd::page_size());
3439 
3440   Bsd::initialize_system_info();
3441 
3442   // main_thread points to the aboriginal thread
3443   Bsd::_main_thread = pthread_self();
3444 
3445   Bsd::clock_init();
3446   initial_time_count = javaTimeNanos();
3447 
3448 #ifdef __APPLE__
3449   // XXXDARWIN
3450   // Work around the unaligned VM callbacks in hotspot's
3451   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3452   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3453   // alignment when doing symbol lookup. To work around this, we force early
3454   // binding of all symbols now, thus binding when alignment is known-good.
3455   _dyld_bind_fully_image_containing_address((const void *) &os::init);
3456 #endif
3457 }
3458 
3459 // To install functions for atexit system call
3460 extern "C" {
3461   static void perfMemory_exit_helper() {
3462     perfMemory_exit();
3463   }
3464 }
3465 
3466 // this is called _after_ the global arguments have been parsed
3467 jint os::init_2(void) {
3468   // Allocate a single page and mark it as readable for safepoint polling
3469   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3470   guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page");
3471 
3472   os::set_polling_page(polling_page);
3473   log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
3474 
3475   if (!UseMembar) {
3476     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3477     guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3478     os::set_memory_serialize_page(mem_serialize_page);
3479     log_info(os)("Memory Serialize Page address: " INTPTR_FORMAT, p2i(mem_serialize_page));
3480   }
3481 
3482   // initialize suspend/resume support - must do this before signal_sets_init()
3483   if (SR_initialize() != 0) {
3484     perror("SR_initialize failed");
3485     return JNI_ERR;
3486   }
3487 
3488   Bsd::signal_sets_init();
3489   Bsd::install_signal_handlers();
3490 
3491   // Check minimum allowable stack size for thread creation and to initialize
3492   // the java system classes, including StackOverflowError - depends on page
3493   // size.  Add two 4K pages for compiler2 recursion in main thread.
3494   // Add in 4*BytesPerWord 4K pages to account for VM stack during
3495   // class initialization depending on 32 or 64 bit VM.
3496   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3497                                     JavaThread::stack_guard_zone_size() +
3498                                     JavaThread::stack_shadow_zone_size() +
3499                                     (4*BytesPerWord COMPILER2_PRESENT(+2)) * 4 * K);
3500 
3501   os::Bsd::min_stack_allowed = align_size_up(os::Bsd::min_stack_allowed, os::vm_page_size());
3502 
3503   size_t threadStackSizeInBytes = ThreadStackSize * K;
3504   if (threadStackSizeInBytes != 0 &&
3505       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3506     tty->print_cr("\nThe stack size specified is too small, "
3507                   "Specify at least %dk",
3508                   os::Bsd::min_stack_allowed/ K);
3509     return JNI_ERR;
3510   }
3511 
3512   // Make the stack size a multiple of the page size so that
3513   // the yellow/red zones can be guarded.
3514   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3515                                                 vm_page_size()));
3516 
3517   if (MaxFDLimit) {
3518     // set the number of file descriptors to max. print out error
3519     // if getrlimit/setrlimit fails but continue regardless.
3520     struct rlimit nbr_files;
3521     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3522     if (status != 0) {
3523       log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3524     } else {
3525       nbr_files.rlim_cur = nbr_files.rlim_max;
3526 
3527 #ifdef __APPLE__
3528       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3529       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3530       // be used instead
3531       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3532 #endif
3533 
3534       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3535       if (status != 0) {
3536         log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3537       }
3538     }
3539   }
3540 
3541   // at-exit methods are called in the reverse order of their registration.
3542   // atexit functions are called on return from main or as a result of a
3543   // call to exit(3C). There can be only 32 of these functions registered
3544   // and atexit() does not set errno.
3545 
3546   if (PerfAllowAtExitRegistration) {
3547     // only register atexit functions if PerfAllowAtExitRegistration is set.
3548     // atexit functions can be delayed until process exit time, which
3549     // can be problematic for embedded VM situations. Embedded VMs should
3550     // call DestroyJavaVM() to assure that VM resources are released.
3551 
3552     // note: perfMemory_exit_helper atexit function may be removed in
3553     // the future if the appropriate cleanup code can be added to the
3554     // VM_Exit VMOperation's doit method.
3555     if (atexit(perfMemory_exit_helper) != 0) {
3556       warning("os::init2 atexit(perfMemory_exit_helper) failed");
3557     }
3558   }
3559 
3560   // initialize thread priority policy
3561   prio_init();
3562 
3563 #ifdef __APPLE__
3564   // dynamically link to objective c gc registration
3565   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3566   if (handleLibObjc != NULL) {
3567     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3568   }
3569 #endif
3570 
3571   return JNI_OK;
3572 }
3573 
3574 // Mark the polling page as unreadable
3575 void os::make_polling_page_unreadable(void) {
3576   if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3577     fatal("Could not disable polling page");
3578   }
3579 }
3580 
3581 // Mark the polling page as readable
3582 void os::make_polling_page_readable(void) {
3583   if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3584     fatal("Could not enable polling page");
3585   }
3586 }
3587 
3588 int os::active_processor_count() {
3589   return _processor_count;
3590 }
3591 
3592 void os::set_native_thread_name(const char *name) {
3593 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3594   // This is only supported in Snow Leopard and beyond
3595   if (name != NULL) {
3596     // Add a "Java: " prefix to the name
3597     char buf[MAXTHREADNAMESIZE];
3598     snprintf(buf, sizeof(buf), "Java: %s", name);
3599     pthread_setname_np(buf);
3600   }
3601 #endif
3602 }
3603 
3604 bool os::distribute_processes(uint length, uint* distribution) {
3605   // Not yet implemented.
3606   return false;
3607 }
3608 
3609 bool os::bind_to_processor(uint processor_id) {
3610   // Not yet implemented.
3611   return false;
3612 }
3613 
3614 void os::SuspendedThreadTask::internal_do_task() {
3615   if (do_suspend(_thread->osthread())) {
3616     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3617     do_task(context);
3618     do_resume(_thread->osthread());
3619   }
3620 }
3621 
3622 ///
3623 class PcFetcher : public os::SuspendedThreadTask {
3624  public:
3625   PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3626   ExtendedPC result();
3627  protected:
3628   void do_task(const os::SuspendedThreadTaskContext& context);
3629  private:
3630   ExtendedPC _epc;
3631 };
3632 
3633 ExtendedPC PcFetcher::result() {
3634   guarantee(is_done(), "task is not done yet.");
3635   return _epc;
3636 }
3637 
3638 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3639   Thread* thread = context.thread();
3640   OSThread* osthread = thread->osthread();
3641   if (osthread->ucontext() != NULL) {
3642     _epc = os::Bsd::ucontext_get_pc((const ucontext_t *) context.ucontext());
3643   } else {
3644     // NULL context is unexpected, double-check this is the VMThread
3645     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3646   }
3647 }
3648 
3649 // Suspends the target using the signal mechanism and then grabs the PC before
3650 // resuming the target. Used by the flat-profiler only
3651 ExtendedPC os::get_thread_pc(Thread* thread) {
3652   // Make sure that it is called by the watcher for the VMThread
3653   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3654   assert(thread->is_VM_thread(), "Can only be called for VMThread");
3655 
3656   PcFetcher fetcher(thread);
3657   fetcher.run();
3658   return fetcher.result();
3659 }
3660 
3661 ////////////////////////////////////////////////////////////////////////////////
3662 // debug support
3663 
3664 bool os::find(address addr, outputStream* st) {
3665   Dl_info dlinfo;
3666   memset(&dlinfo, 0, sizeof(dlinfo));
3667   if (dladdr(addr, &dlinfo) != 0) {
3668     st->print(PTR_FORMAT ": ", addr);
3669     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3670       st->print("%s+%#x", dlinfo.dli_sname,
3671                 addr - (intptr_t)dlinfo.dli_saddr);
3672     } else if (dlinfo.dli_fbase != NULL) {
3673       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3674     } else {
3675       st->print("<absolute address>");
3676     }
3677     if (dlinfo.dli_fname != NULL) {
3678       st->print(" in %s", dlinfo.dli_fname);
3679     }
3680     if (dlinfo.dli_fbase != NULL) {
3681       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3682     }
3683     st->cr();
3684 
3685     if (Verbose) {
3686       // decode some bytes around the PC
3687       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3688       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3689       address       lowest = (address) dlinfo.dli_sname;
3690       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3691       if (begin < lowest)  begin = lowest;
3692       Dl_info dlinfo2;
3693       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3694           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3695         end = (address) dlinfo2.dli_saddr;
3696       }
3697       Disassembler::decode(begin, end, st);
3698     }
3699     return true;
3700   }
3701   return false;
3702 }
3703 
3704 ////////////////////////////////////////////////////////////////////////////////
3705 // misc
3706 
3707 // This does not do anything on Bsd. This is basically a hook for being
3708 // able to use structured exception handling (thread-local exception filters)
3709 // on, e.g., Win32.
3710 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3711                               const methodHandle& method, JavaCallArguments* args,
3712                               Thread* thread) {
3713   f(value, method, args, thread);
3714 }
3715 
3716 void os::print_statistics() {
3717 }
3718 
3719 bool os::message_box(const char* title, const char* message) {
3720   int i;
3721   fdStream err(defaultStream::error_fd());
3722   for (i = 0; i < 78; i++) err.print_raw("=");
3723   err.cr();
3724   err.print_raw_cr(title);
3725   for (i = 0; i < 78; i++) err.print_raw("-");
3726   err.cr();
3727   err.print_raw_cr(message);
3728   for (i = 0; i < 78; i++) err.print_raw("=");
3729   err.cr();
3730 
3731   char buf[16];
3732   // Prevent process from exiting upon "read error" without consuming all CPU
3733   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3734 
3735   return buf[0] == 'y' || buf[0] == 'Y';
3736 }
3737 
3738 int os::stat(const char *path, struct stat *sbuf) {
3739   char pathbuf[MAX_PATH];
3740   if (strlen(path) > MAX_PATH - 1) {
3741     errno = ENAMETOOLONG;
3742     return -1;
3743   }
3744   os::native_path(strcpy(pathbuf, path));
3745   return ::stat(pathbuf, sbuf);
3746 }
3747 
3748 static inline struct timespec get_mtime(const char* filename) {
3749   struct stat st;
3750   int ret = os::stat(filename, &st);
3751   assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
3752 #ifdef __APPLE__
3753   return st.st_mtimespec;
3754 #else
3755   return st.st_mtim;
3756 #endif
3757 }
3758 
3759 int os::compare_file_modified_times(const char* file1, const char* file2) {
3760   struct timespec filetime1 = get_mtime(file1);
3761   struct timespec filetime2 = get_mtime(file2);
3762   int diff = filetime1.tv_sec - filetime2.tv_sec;
3763   if (diff == 0) {
3764     return filetime1.tv_nsec - filetime2.tv_nsec;
3765   }
3766   return diff;
3767 }
3768 
3769 
3770 bool os::check_heap(bool force) {
3771   return true;
3772 }
3773 
3774 // Is a (classpath) directory empty?
3775 bool os::dir_is_empty(const char* path) {
3776   DIR *dir = NULL;
3777   struct dirent *ptr;
3778 
3779   dir = opendir(path);
3780   if (dir == NULL) return true;
3781 
3782   // Scan the directory
3783   bool result = true;
3784   char buf[sizeof(struct dirent) + MAX_PATH];
3785   while (result && (ptr = ::readdir(dir)) != NULL) {
3786     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3787       result = false;
3788     }
3789   }
3790   closedir(dir);
3791   return result;
3792 }
3793 
3794 // This code originates from JDK's sysOpen and open64_w
3795 // from src/solaris/hpi/src/system_md.c
3796 
3797 int os::open(const char *path, int oflag, int mode) {
3798   if (strlen(path) > MAX_PATH - 1) {
3799     errno = ENAMETOOLONG;
3800     return -1;
3801   }
3802   int fd;
3803 
3804   fd = ::open(path, oflag, mode);
3805   if (fd == -1) return -1;
3806 
3807   // If the open succeeded, the file might still be a directory
3808   {
3809     struct stat buf;
3810     int ret = ::fstat(fd, &buf);
3811     int st_mode = buf.st_mode;
3812 
3813     if (ret != -1) {
3814       if ((st_mode & S_IFMT) == S_IFDIR) {
3815         errno = EISDIR;
3816         ::close(fd);
3817         return -1;
3818       }
3819     } else {
3820       ::close(fd);
3821       return -1;
3822     }
3823   }
3824 
3825   // All file descriptors that are opened in the JVM and not
3826   // specifically destined for a subprocess should have the
3827   // close-on-exec flag set.  If we don't set it, then careless 3rd
3828   // party native code might fork and exec without closing all
3829   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3830   // UNIXProcess.c), and this in turn might:
3831   //
3832   // - cause end-of-file to fail to be detected on some file
3833   //   descriptors, resulting in mysterious hangs, or
3834   //
3835   // - might cause an fopen in the subprocess to fail on a system
3836   //   suffering from bug 1085341.
3837   //
3838   // (Yes, the default setting of the close-on-exec flag is a Unix
3839   // design flaw)
3840   //
3841   // See:
3842   // 1085341: 32-bit stdio routines should support file descriptors >255
3843   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3844   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3845   //
3846 #ifdef FD_CLOEXEC
3847   {
3848     int flags = ::fcntl(fd, F_GETFD);
3849     if (flags != -1) {
3850       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3851     }
3852   }
3853 #endif
3854 
3855   return fd;
3856 }
3857 
3858 
3859 // create binary file, rewriting existing file if required
3860 int os::create_binary_file(const char* path, bool rewrite_existing) {
3861   int oflags = O_WRONLY | O_CREAT;
3862   if (!rewrite_existing) {
3863     oflags |= O_EXCL;
3864   }
3865   return ::open(path, oflags, S_IREAD | S_IWRITE);
3866 }
3867 
3868 // return current position of file pointer
3869 jlong os::current_file_offset(int fd) {
3870   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3871 }
3872 
3873 // move file pointer to the specified offset
3874 jlong os::seek_to_file_offset(int fd, jlong offset) {
3875   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3876 }
3877 
3878 // This code originates from JDK's sysAvailable
3879 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3880 
3881 int os::available(int fd, jlong *bytes) {
3882   jlong cur, end;
3883   int mode;
3884   struct stat buf;
3885 
3886   if (::fstat(fd, &buf) >= 0) {
3887     mode = buf.st_mode;
3888     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3889       int n;
3890       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3891         *bytes = n;
3892         return 1;
3893       }
3894     }
3895   }
3896   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3897     return 0;
3898   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3899     return 0;
3900   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3901     return 0;
3902   }
3903   *bytes = end - cur;
3904   return 1;
3905 }
3906 
3907 // Map a block of memory.
3908 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3909                         char *addr, size_t bytes, bool read_only,
3910                         bool allow_exec) {
3911   int prot;
3912   int flags;
3913 
3914   if (read_only) {
3915     prot = PROT_READ;
3916     flags = MAP_SHARED;
3917   } else {
3918     prot = PROT_READ | PROT_WRITE;
3919     flags = MAP_PRIVATE;
3920   }
3921 
3922   if (allow_exec) {
3923     prot |= PROT_EXEC;
3924   }
3925 
3926   if (addr != NULL) {
3927     flags |= MAP_FIXED;
3928   }
3929 
3930   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3931                                      fd, file_offset);
3932   if (mapped_address == MAP_FAILED) {
3933     return NULL;
3934   }
3935   return mapped_address;
3936 }
3937 
3938 
3939 // Remap a block of memory.
3940 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3941                           char *addr, size_t bytes, bool read_only,
3942                           bool allow_exec) {
3943   // same as map_memory() on this OS
3944   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3945                         allow_exec);
3946 }
3947 
3948 
3949 // Unmap a block of memory.
3950 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3951   return munmap(addr, bytes) == 0;
3952 }
3953 
3954 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3955 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3956 // of a thread.
3957 //
3958 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3959 // the fast estimate available on the platform.
3960 
3961 jlong os::current_thread_cpu_time() {
3962 #ifdef __APPLE__
3963   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3964 #else
3965   Unimplemented();
3966   return 0;
3967 #endif
3968 }
3969 
3970 jlong os::thread_cpu_time(Thread* thread) {
3971 #ifdef __APPLE__
3972   return os::thread_cpu_time(thread, true /* user + sys */);
3973 #else
3974   Unimplemented();
3975   return 0;
3976 #endif
3977 }
3978 
3979 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3980 #ifdef __APPLE__
3981   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3982 #else
3983   Unimplemented();
3984   return 0;
3985 #endif
3986 }
3987 
3988 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3989 #ifdef __APPLE__
3990   struct thread_basic_info tinfo;
3991   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
3992   kern_return_t kr;
3993   thread_t mach_thread;
3994 
3995   mach_thread = thread->osthread()->thread_id();
3996   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
3997   if (kr != KERN_SUCCESS) {
3998     return -1;
3999   }
4000 
4001   if (user_sys_cpu_time) {
4002     jlong nanos;
4003     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4004     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4005     return nanos;
4006   } else {
4007     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4008   }
4009 #else
4010   Unimplemented();
4011   return 0;
4012 #endif
4013 }
4014 
4015 
4016 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4017   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4018   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4019   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4020   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4021 }
4022 
4023 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4024   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4025   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4026   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4027   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4028 }
4029 
4030 bool os::is_thread_cpu_time_supported() {
4031 #ifdef __APPLE__
4032   return true;
4033 #else
4034   return false;
4035 #endif
4036 }
4037 
4038 // System loadavg support.  Returns -1 if load average cannot be obtained.
4039 // Bsd doesn't yet have a (official) notion of processor sets,
4040 // so just return the system wide load average.
4041 int os::loadavg(double loadavg[], int nelem) {
4042   return ::getloadavg(loadavg, nelem);
4043 }
4044 
4045 void os::pause() {
4046   char filename[MAX_PATH];
4047   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4048     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4049   } else {
4050     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4051   }
4052 
4053   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4054   if (fd != -1) {
4055     struct stat buf;
4056     ::close(fd);
4057     while (::stat(filename, &buf) == 0) {
4058       (void)::poll(NULL, 0, 100);
4059     }
4060   } else {
4061     jio_fprintf(stderr,
4062                 "Could not open pause file '%s', continuing immediately.\n", filename);
4063   }
4064 }
4065 
4066 
4067 // Refer to the comments in os_solaris.cpp park-unpark. The next two
4068 // comment paragraphs are worth repeating here:
4069 //
4070 // Assumption:
4071 //    Only one parker can exist on an event, which is why we allocate
4072 //    them per-thread. Multiple unparkers can coexist.
4073 //
4074 // _Event serves as a restricted-range semaphore.
4075 //   -1 : thread is blocked, i.e. there is a waiter
4076 //    0 : neutral: thread is running or ready,
4077 //        could have been signaled after a wait started
4078 //    1 : signaled - thread is running or ready
4079 //
4080 
4081 // utility to compute the abstime argument to timedwait:
4082 // millis is the relative timeout time
4083 // abstime will be the absolute timeout time
4084 // TODO: replace compute_abstime() with unpackTime()
4085 
4086 static struct timespec* compute_abstime(struct timespec* abstime,
4087                                         jlong millis) {
4088   if (millis < 0)  millis = 0;
4089   struct timeval now;
4090   int status = gettimeofday(&now, NULL);
4091   assert(status == 0, "gettimeofday");
4092   jlong seconds = millis / 1000;
4093   millis %= 1000;
4094   if (seconds > 50000000) { // see man cond_timedwait(3T)
4095     seconds = 50000000;
4096   }
4097   abstime->tv_sec = now.tv_sec  + seconds;
4098   long       usec = now.tv_usec + millis * 1000;
4099   if (usec >= 1000000) {
4100     abstime->tv_sec += 1;
4101     usec -= 1000000;
4102   }
4103   abstime->tv_nsec = usec * 1000;
4104   return abstime;
4105 }
4106 
4107 void os::PlatformEvent::park() {       // AKA "down()"
4108   // Transitions for _Event:
4109   //   -1 => -1 : illegal
4110   //    1 =>  0 : pass - return immediately
4111   //    0 => -1 : block; then set _Event to 0 before returning
4112 
4113   // Invariant: Only the thread associated with the Event/PlatformEvent
4114   // may call park().
4115   // TODO: assert that _Assoc != NULL or _Assoc == Self
4116   assert(_nParked == 0, "invariant");
4117 
4118   int v;
4119   for (;;) {
4120     v = _Event;
4121     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4122   }
4123   guarantee(v >= 0, "invariant");
4124   if (v == 0) {
4125     // Do this the hard way by blocking ...
4126     int status = pthread_mutex_lock(_mutex);
4127     assert_status(status == 0, status, "mutex_lock");
4128     guarantee(_nParked == 0, "invariant");
4129     ++_nParked;
4130     while (_Event < 0) {
4131       status = pthread_cond_wait(_cond, _mutex);
4132       // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4133       // Treat this the same as if the wait was interrupted
4134       if (status == ETIMEDOUT) { status = EINTR; }
4135       assert_status(status == 0 || status == EINTR, status, "cond_wait");
4136     }
4137     --_nParked;
4138 
4139     _Event = 0;
4140     status = pthread_mutex_unlock(_mutex);
4141     assert_status(status == 0, status, "mutex_unlock");
4142     // Paranoia to ensure our locked and lock-free paths interact
4143     // correctly with each other.
4144     OrderAccess::fence();
4145   }
4146   guarantee(_Event >= 0, "invariant");
4147 }
4148 
4149 int os::PlatformEvent::park(jlong millis) {
4150   // Transitions for _Event:
4151   //   -1 => -1 : illegal
4152   //    1 =>  0 : pass - return immediately
4153   //    0 => -1 : block; then set _Event to 0 before returning
4154 
4155   guarantee(_nParked == 0, "invariant");
4156 
4157   int v;
4158   for (;;) {
4159     v = _Event;
4160     if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4161   }
4162   guarantee(v >= 0, "invariant");
4163   if (v != 0) return OS_OK;
4164 
4165   // We do this the hard way, by blocking the thread.
4166   // Consider enforcing a minimum timeout value.
4167   struct timespec abst;
4168   compute_abstime(&abst, millis);
4169 
4170   int ret = OS_TIMEOUT;
4171   int status = pthread_mutex_lock(_mutex);
4172   assert_status(status == 0, status, "mutex_lock");
4173   guarantee(_nParked == 0, "invariant");
4174   ++_nParked;
4175 
4176   // Object.wait(timo) will return because of
4177   // (a) notification
4178   // (b) timeout
4179   // (c) thread.interrupt
4180   //
4181   // Thread.interrupt and object.notify{All} both call Event::set.
4182   // That is, we treat thread.interrupt as a special case of notification.
4183   // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false.
4184   // We assume all ETIME returns are valid.
4185   //
4186   // TODO: properly differentiate simultaneous notify+interrupt.
4187   // In that case, we should propagate the notify to another waiter.
4188 
4189   while (_Event < 0) {
4190     status = pthread_cond_timedwait(_cond, _mutex, &abst);
4191     assert_status(status == 0 || status == EINTR ||
4192                   status == ETIMEDOUT,
4193                   status, "cond_timedwait");
4194     if (!FilterSpuriousWakeups) break;                 // previous semantics
4195     if (status == ETIMEDOUT) break;
4196     // We consume and ignore EINTR and spurious wakeups.
4197   }
4198   --_nParked;
4199   if (_Event >= 0) {
4200     ret = OS_OK;
4201   }
4202   _Event = 0;
4203   status = pthread_mutex_unlock(_mutex);
4204   assert_status(status == 0, status, "mutex_unlock");
4205   assert(_nParked == 0, "invariant");
4206   // Paranoia to ensure our locked and lock-free paths interact
4207   // correctly with each other.
4208   OrderAccess::fence();
4209   return ret;
4210 }
4211 
4212 void os::PlatformEvent::unpark() {
4213   // Transitions for _Event:
4214   //    0 => 1 : just return
4215   //    1 => 1 : just return
4216   //   -1 => either 0 or 1; must signal target thread
4217   //         That is, we can safely transition _Event from -1 to either
4218   //         0 or 1.
4219   // See also: "Semaphores in Plan 9" by Mullender & Cox
4220   //
4221   // Note: Forcing a transition from "-1" to "1" on an unpark() means
4222   // that it will take two back-to-back park() calls for the owning
4223   // thread to block. This has the benefit of forcing a spurious return
4224   // from the first park() call after an unpark() call which will help
4225   // shake out uses of park() and unpark() without condition variables.
4226 
4227   if (Atomic::xchg(1, &_Event) >= 0) return;
4228 
4229   // Wait for the thread associated with the event to vacate
4230   int status = pthread_mutex_lock(_mutex);
4231   assert_status(status == 0, status, "mutex_lock");
4232   int AnyWaiters = _nParked;
4233   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4234   status = pthread_mutex_unlock(_mutex);
4235   assert_status(status == 0, status, "mutex_unlock");
4236   if (AnyWaiters != 0) {
4237     // Note that we signal() *after* dropping the lock for "immortal" Events.
4238     // This is safe and avoids a common class of  futile wakeups.  In rare
4239     // circumstances this can cause a thread to return prematurely from
4240     // cond_{timed}wait() but the spurious wakeup is benign and the victim
4241     // will simply re-test the condition and re-park itself.
4242     // This provides particular benefit if the underlying platform does not
4243     // provide wait morphing.
4244     status = pthread_cond_signal(_cond);
4245     assert_status(status == 0, status, "cond_signal");
4246   }
4247 }
4248 
4249 
4250 // JSR166
4251 // -------------------------------------------------------
4252 
4253 // The solaris and bsd implementations of park/unpark are fairly
4254 // conservative for now, but can be improved. They currently use a
4255 // mutex/condvar pair, plus a a count.
4256 // Park decrements count if > 0, else does a condvar wait.  Unpark
4257 // sets count to 1 and signals condvar.  Only one thread ever waits
4258 // on the condvar. Contention seen when trying to park implies that someone
4259 // is unparking you, so don't wait. And spurious returns are fine, so there
4260 // is no need to track notifications.
4261 
4262 #define MAX_SECS 100000000
4263 
4264 // This code is common to bsd and solaris and will be moved to a
4265 // common place in dolphin.
4266 //
4267 // The passed in time value is either a relative time in nanoseconds
4268 // or an absolute time in milliseconds. Either way it has to be unpacked
4269 // into suitable seconds and nanoseconds components and stored in the
4270 // given timespec structure.
4271 // Given time is a 64-bit value and the time_t used in the timespec is only
4272 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4273 // overflow if times way in the future are given. Further on Solaris versions
4274 // prior to 10 there is a restriction (see cond_timedwait) that the specified
4275 // number of seconds, in abstime, is less than current_time  + 100,000,000.
4276 // As it will be 28 years before "now + 100000000" will overflow we can
4277 // ignore overflow and just impose a hard-limit on seconds using the value
4278 // of "now + 100,000,000". This places a limit on the timeout of about 3.17
4279 // years from "now".
4280 
4281 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4282   assert(time > 0, "convertTime");
4283 
4284   struct timeval now;
4285   int status = gettimeofday(&now, NULL);
4286   assert(status == 0, "gettimeofday");
4287 
4288   time_t max_secs = now.tv_sec + MAX_SECS;
4289 
4290   if (isAbsolute) {
4291     jlong secs = time / 1000;
4292     if (secs > max_secs) {
4293       absTime->tv_sec = max_secs;
4294     } else {
4295       absTime->tv_sec = secs;
4296     }
4297     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4298   } else {
4299     jlong secs = time / NANOSECS_PER_SEC;
4300     if (secs >= MAX_SECS) {
4301       absTime->tv_sec = max_secs;
4302       absTime->tv_nsec = 0;
4303     } else {
4304       absTime->tv_sec = now.tv_sec + secs;
4305       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4306       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4307         absTime->tv_nsec -= NANOSECS_PER_SEC;
4308         ++absTime->tv_sec; // note: this must be <= max_secs
4309       }
4310     }
4311   }
4312   assert(absTime->tv_sec >= 0, "tv_sec < 0");
4313   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4314   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4315   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4316 }
4317 
4318 void Parker::park(bool isAbsolute, jlong time) {
4319   // Ideally we'd do something useful while spinning, such
4320   // as calling unpackTime().
4321 
4322   // Optional fast-path check:
4323   // Return immediately if a permit is available.
4324   // We depend on Atomic::xchg() having full barrier semantics
4325   // since we are doing a lock-free update to _counter.
4326   if (Atomic::xchg(0, &_counter) > 0) return;
4327 
4328   Thread* thread = Thread::current();
4329   assert(thread->is_Java_thread(), "Must be JavaThread");
4330   JavaThread *jt = (JavaThread *)thread;
4331 
4332   // Optional optimization -- avoid state transitions if there's an interrupt pending.
4333   // Check interrupt before trying to wait
4334   if (Thread::is_interrupted(thread, false)) {
4335     return;
4336   }
4337 
4338   // Next, demultiplex/decode time arguments
4339   struct timespec absTime;
4340   if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
4341     return;
4342   }
4343   if (time > 0) {
4344     unpackTime(&absTime, isAbsolute, time);
4345   }
4346 
4347 
4348   // Enter safepoint region
4349   // Beware of deadlocks such as 6317397.
4350   // The per-thread Parker:: mutex is a classic leaf-lock.
4351   // In particular a thread must never block on the Threads_lock while
4352   // holding the Parker:: mutex.  If safepoints are pending both the
4353   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4354   ThreadBlockInVM tbivm(jt);
4355 
4356   // Don't wait if cannot get lock since interference arises from
4357   // unblocking.  Also. check interrupt before trying wait
4358   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4359     return;
4360   }
4361 
4362   int status;
4363   if (_counter > 0)  { // no wait needed
4364     _counter = 0;
4365     status = pthread_mutex_unlock(_mutex);
4366     assert_status(status == 0, status, "invariant");
4367     // Paranoia to ensure our locked and lock-free paths interact
4368     // correctly with each other and Java-level accesses.
4369     OrderAccess::fence();
4370     return;
4371   }
4372 
4373 #ifdef ASSERT
4374   // Don't catch signals while blocked; let the running threads have the signals.
4375   // (This allows a debugger to break into the running thread.)
4376   sigset_t oldsigs;
4377   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4378   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4379 #endif
4380 
4381   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4382   jt->set_suspend_equivalent();
4383   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4384 
4385   if (time == 0) {
4386     status = pthread_cond_wait(_cond, _mutex);
4387   } else {
4388     status = pthread_cond_timedwait(_cond, _mutex, &absTime);
4389   }
4390   assert_status(status == 0 || status == EINTR ||
4391                 status == ETIMEDOUT,
4392                 status, "cond_timedwait");
4393 
4394 #ifdef ASSERT
4395   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4396 #endif
4397 
4398   _counter = 0;
4399   status = pthread_mutex_unlock(_mutex);
4400   assert_status(status == 0, status, "invariant");
4401   // Paranoia to ensure our locked and lock-free paths interact
4402   // correctly with each other and Java-level accesses.
4403   OrderAccess::fence();
4404 
4405   // If externally suspended while waiting, re-suspend
4406   if (jt->handle_special_suspend_equivalent_condition()) {
4407     jt->java_suspend_self();
4408   }
4409 }
4410 
4411 void Parker::unpark() {
4412   int status = pthread_mutex_lock(_mutex);
4413   assert_status(status == 0, status, "invariant");
4414   const int s = _counter;
4415   _counter = 1;
4416   status = pthread_mutex_unlock(_mutex);
4417   assert_status(status == 0, status, "invariant");
4418   if (s < 1) {
4419     status = pthread_cond_signal(_cond);
4420     assert_status(status == 0, status, "invariant");
4421   }
4422 }
4423 
4424 
4425 // Darwin has no "environ" in a dynamic library.
4426 #ifdef __APPLE__
4427   #include <crt_externs.h>
4428   #define environ (*_NSGetEnviron())
4429 #else
4430 extern char** environ;
4431 #endif
4432 
4433 // Run the specified command in a separate process. Return its exit value,
4434 // or -1 on failure (e.g. can't fork a new process).
4435 // Unlike system(), this function can be called from signal handler. It
4436 // doesn't block SIGINT et al.
4437 int os::fork_and_exec(char* cmd) {
4438   const char * argv[4] = {"sh", "-c", cmd, NULL};
4439 
4440   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4441   // pthread_atfork handlers and reset pthread library. All we need is a
4442   // separate process to execve. Make a direct syscall to fork process.
4443   // On IA64 there's no fork syscall, we have to use fork() and hope for
4444   // the best...
4445   pid_t pid = fork();
4446 
4447   if (pid < 0) {
4448     // fork failed
4449     return -1;
4450 
4451   } else if (pid == 0) {
4452     // child process
4453 
4454     // execve() in BsdThreads will call pthread_kill_other_threads_np()
4455     // first to kill every thread on the thread list. Because this list is
4456     // not reset by fork() (see notes above), execve() will instead kill
4457     // every thread in the parent process. We know this is the only thread
4458     // in the new process, so make a system call directly.
4459     // IA64 should use normal execve() from glibc to match the glibc fork()
4460     // above.
4461     execve("/bin/sh", (char* const*)argv, environ);
4462 
4463     // execve failed
4464     _exit(-1);
4465 
4466   } else  {
4467     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4468     // care about the actual exit code, for now.
4469 
4470     int status;
4471 
4472     // Wait for the child process to exit.  This returns immediately if
4473     // the child has already exited. */
4474     while (waitpid(pid, &status, 0) < 0) {
4475       switch (errno) {
4476       case ECHILD: return 0;
4477       case EINTR: break;
4478       default: return -1;
4479       }
4480     }
4481 
4482     if (WIFEXITED(status)) {
4483       // The child exited normally; get its exit code.
4484       return WEXITSTATUS(status);
4485     } else if (WIFSIGNALED(status)) {
4486       // The child exited because of a signal
4487       // The best value to return is 0x80 + signal number,
4488       // because that is what all Unix shells do, and because
4489       // it allows callers to distinguish between process exit and
4490       // process death by signal.
4491       return 0x80 + WTERMSIG(status);
4492     } else {
4493       // Unknown exit code; pass it through
4494       return status;
4495     }
4496   }
4497 }
4498 
4499 // is_headless_jre()
4500 //
4501 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4502 // in order to report if we are running in a headless jre
4503 //
4504 // Since JDK8 xawt/libmawt.so was moved into the same directory
4505 // as libawt.so, and renamed libawt_xawt.so
4506 //
4507 bool os::is_headless_jre() {
4508 #ifdef __APPLE__
4509   // We no longer build headless-only on Mac OS X
4510   return false;
4511 #else
4512   struct stat statbuf;
4513   char buf[MAXPATHLEN];
4514   char libmawtpath[MAXPATHLEN];
4515   const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
4516   const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4517   char *p;
4518 
4519   // Get path to libjvm.so
4520   os::jvm_path(buf, sizeof(buf));
4521 
4522   // Get rid of libjvm.so
4523   p = strrchr(buf, '/');
4524   if (p == NULL) {
4525     return false;
4526   } else {
4527     *p = '\0';
4528   }
4529 
4530   // Get rid of client or server
4531   p = strrchr(buf, '/');
4532   if (p == NULL) {
4533     return false;
4534   } else {
4535     *p = '\0';
4536   }
4537 
4538   // check xawt/libmawt.so
4539   strcpy(libmawtpath, buf);
4540   strcat(libmawtpath, xawtstr);
4541   if (::stat(libmawtpath, &statbuf) == 0) return false;
4542 
4543   // check libawt_xawt.so
4544   strcpy(libmawtpath, buf);
4545   strcat(libmawtpath, new_xawtstr);
4546   if (::stat(libmawtpath, &statbuf) == 0) return false;
4547 
4548   return true;
4549 #endif
4550 }
4551 
4552 // Get the default path to the core file
4553 // Returns the length of the string
4554 int os::get_core_path(char* buffer, size_t bufferSize) {
4555   int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
4556 
4557   // Truncate if theoretical string was longer than bufferSize
4558   n = MIN2(n, (int)bufferSize);
4559 
4560   return n;
4561 }
4562 
4563 #ifndef PRODUCT
4564 void TestReserveMemorySpecial_test() {
4565   // No tests available for this platform
4566 }
4567 #endif
4568 
4569 bool os::start_debugging(char *buf, int buflen) {
4570   int len = (int)strlen(buf);
4571   char *p = &buf[len];
4572 
4573   jio_snprintf(p, buflen-len,
4574              "\n\n"
4575              "Do you want to debug the problem?\n\n"
4576              "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT " (" INTPTR_FORMAT ")\n"
4577              "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
4578              "Otherwise, press RETURN to abort...",
4579              os::current_process_id(), os::current_process_id(),
4580              os::current_thread_id(), os::current_thread_id());
4581 
4582   bool yes = os::message_box("Unexpected Error", buf);
4583 
4584   if (yes) {
4585     // yes, user asked VM to launch debugger
4586     jio_snprintf(buf, sizeof(buf), "gdb /proc/%d/exe %d",
4587                      os::current_process_id(), os::current_process_id());
4588 
4589     os::fork_and_exec(buf);
4590     yes = false;
4591   }
4592   return yes;
4593 }