1 /*
   2  * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // no precompiled headers
  26 #include "classfile/classLoader.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/icBuffer.hpp"
  30 #include "code/vtableStubs.hpp"
  31 #include "compiler/compileBroker.hpp"
  32 #include "compiler/disassembler.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "jvm_bsd.h"
  35 #include "memory/allocation.inline.hpp"
  36 #include "memory/filemap.hpp"
  37 #include "mutex_bsd.inline.hpp"
  38 #include "oops/oop.inline.hpp"
  39 #include "os_bsd.inline.hpp"
  40 #include "os_share_bsd.hpp"
  41 #include "prims/jniFastGetField.hpp"
  42 #include "prims/jvm.h"
  43 #include "prims/jvm_misc.hpp"
  44 #include "runtime/arguments.hpp"
  45 #include "runtime/atomic.inline.hpp"
  46 #include "runtime/extendedPC.hpp"
  47 #include "runtime/globals.hpp"
  48 #include "runtime/interfaceSupport.hpp"
  49 #include "runtime/java.hpp"
  50 #include "runtime/javaCalls.hpp"
  51 #include "runtime/mutexLocker.hpp"
  52 #include "runtime/objectMonitor.hpp"
  53 #include "runtime/orderAccess.inline.hpp"
  54 #include "runtime/osThread.hpp"
  55 #include "runtime/perfMemory.hpp"
  56 #include "runtime/sharedRuntime.hpp"
  57 #include "runtime/statSampler.hpp"
  58 #include "runtime/stubRoutines.hpp"
  59 #include "runtime/thread.inline.hpp"
  60 #include "runtime/threadCritical.hpp"
  61 #include "runtime/timer.hpp"
  62 #include "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 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 132 
 133 ////////////////////////////////////////////////////////////////////////////////
 134 // global variables
 135 julong os::Bsd::_physical_memory = 0;
 136 
 137 #ifdef __APPLE__
 138 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
 139 volatile uint64_t         os::Bsd::_max_abstime   = 0;
 140 #else
 141 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 142 #endif
 143 pthread_t os::Bsd::_main_thread;
 144 int os::Bsd::_page_size = -1;
 145 
 146 static jlong initial_time_count=0;
 147 
 148 static int clock_tics_per_sec = 100;
 149 
 150 // For diagnostics to print a message once. see run_periodic_checks
 151 static sigset_t check_signal_done;
 152 static bool check_signals = true;
 153 
 154 static pid_t _initial_pid = 0;
 155 
 156 // Signal number used to suspend/resume a thread
 157 
 158 // do not use any signal number less than SIGSEGV, see 4355769
 159 static int SR_signum = SIGUSR2;
 160 sigset_t SR_sigset;
 161 
 162 
 163 ////////////////////////////////////////////////////////////////////////////////
 164 // utility functions
 165 
 166 static int SR_initialize();
 167 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
 168 
 169 julong os::available_memory() {
 170   return Bsd::available_memory();
 171 }
 172 
 173 // available here means free
 174 julong os::Bsd::available_memory() {
 175   uint64_t available = physical_memory() >> 2;
 176 #ifdef __APPLE__
 177   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
 178   vm_statistics64_data_t vmstat;
 179   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
 180                                          (host_info64_t)&vmstat, &count);
 181   assert(kerr == KERN_SUCCESS,
 182          "host_statistics64 failed - check mach_host_self() and count");
 183   if (kerr == KERN_SUCCESS) {
 184     available = vmstat.free_count * os::vm_page_size();
 185   }
 186 #endif
 187   return available;
 188 }
 189 
 190 julong os::physical_memory() {
 191   return Bsd::physical_memory();
 192 }
 193 
 194 // Return true if user is running as root.
 195 
 196 bool os::have_special_privileges() {
 197   static bool init = false;
 198   static bool privileges = false;
 199   if (!init) {
 200     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 201     init = true;
 202   }
 203   return privileges;
 204 }
 205 
 206 
 207 
 208 // Cpu architecture string
 209 #if   defined(ZERO)
 210 static char cpu_arch[] = ZERO_LIBARCH;
 211 #elif defined(IA64)
 212 static char cpu_arch[] = "ia64";
 213 #elif defined(IA32)
 214 static char cpu_arch[] = "i386";
 215 #elif defined(AMD64)
 216 static char cpu_arch[] = "amd64";
 217 #elif defined(ARM)
 218 static char cpu_arch[] = "arm";
 219 #elif defined(PPC32)
 220 static char cpu_arch[] = "ppc";
 221 #elif defined(SPARC)
 222   #ifdef _LP64
 223 static char cpu_arch[] = "sparcv9";
 224   #else
 225 static char cpu_arch[] = "sparc";
 226   #endif
 227 #else
 228   #error Add appropriate cpu_arch setting
 229 #endif
 230 
 231 // Compiler variant
 232 #ifdef COMPILER2
 233   #define COMPILER_VARIANT "server"
 234 #else
 235   #define COMPILER_VARIANT "client"
 236 #endif
 237 
 238 
 239 void os::Bsd::initialize_system_info() {
 240   int mib[2];
 241   size_t len;
 242   int cpu_val;
 243   julong mem_val;
 244 
 245   // get processors count via hw.ncpus sysctl
 246   mib[0] = CTL_HW;
 247   mib[1] = HW_NCPU;
 248   len = sizeof(cpu_val);
 249   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 250     assert(len == sizeof(cpu_val), "unexpected data size");
 251     set_processor_count(cpu_val);
 252   } else {
 253     set_processor_count(1);   // fallback
 254   }
 255 
 256   // get physical memory via hw.memsize sysctl (hw.memsize is used
 257   // since it returns a 64 bit value)
 258   mib[0] = CTL_HW;
 259 
 260 #if defined (HW_MEMSIZE) // Apple
 261   mib[1] = HW_MEMSIZE;
 262 #elif defined(HW_PHYSMEM) // Most of BSD
 263   mib[1] = HW_PHYSMEM;
 264 #elif defined(HW_REALMEM) // Old FreeBSD
 265   mib[1] = HW_REALMEM;
 266 #else
 267   #error No ways to get physmem
 268 #endif
 269 
 270   len = sizeof(mem_val);
 271   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 272     assert(len == sizeof(mem_val), "unexpected data size");
 273     _physical_memory = mem_val;
 274   } else {
 275     _physical_memory = 256 * 1024 * 1024;       // fallback (XXXBSD?)
 276   }
 277 
 278 #ifdef __OpenBSD__
 279   {
 280     // limit _physical_memory memory view on OpenBSD since
 281     // datasize rlimit restricts us anyway.
 282     struct rlimit limits;
 283     getrlimit(RLIMIT_DATA, &limits);
 284     _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 285   }
 286 #endif
 287 }
 288 
 289 #ifdef __APPLE__
 290 static const char *get_home() {
 291   const char *home_dir = ::getenv("HOME");
 292   if ((home_dir == NULL) || (*home_dir == '\0')) {
 293     struct passwd *passwd_info = getpwuid(geteuid());
 294     if (passwd_info != NULL) {
 295       home_dir = passwd_info->pw_dir;
 296     }
 297   }
 298 
 299   return home_dir;
 300 }
 301 #endif
 302 
 303 void os::init_system_properties_values() {
 304   // The next steps are taken in the product version:
 305   //
 306   // Obtain the JAVA_HOME value from the location of libjvm.so.
 307   // This library should be located at:
 308   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 309   //
 310   // If "/jre/lib/" appears at the right place in the path, then we
 311   // assume libjvm.so is installed in a JDK and we use this path.
 312   //
 313   // Otherwise exit with message: "Could not create the Java virtual machine."
 314   //
 315   // The following extra steps are taken in the debugging version:
 316   //
 317   // If "/jre/lib/" does NOT appear at the right place in the path
 318   // instead of exit check for $JAVA_HOME environment variable.
 319   //
 320   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 321   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 322   // it looks like libjvm.so is installed there
 323   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 324   //
 325   // Otherwise exit.
 326   //
 327   // Important note: if the location of libjvm.so changes this
 328   // code needs to be changed accordingly.
 329 
 330   // See ld(1):
 331   //      The linker uses the following search paths to locate required
 332   //      shared libraries:
 333   //        1: ...
 334   //        ...
 335   //        7: The default directories, normally /lib and /usr/lib.
 336 #ifndef DEFAULT_LIBPATH
 337   #define DEFAULT_LIBPATH "/lib:/usr/lib"
 338 #endif
 339 
 340 // Base path of extensions installed on the system.
 341 #define SYS_EXT_DIR     "/usr/java/packages"
 342 #define EXTENSIONS_DIR  "/lib/ext"
 343 
 344 #ifndef __APPLE__
 345 
 346   // Buffer that fits several sprintfs.
 347   // Note that the space for the colon and the trailing null are provided
 348   // by the nulls included by the sizeof operator.
 349   const size_t bufsize =
 350     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 351          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
 352   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 353 
 354   // sysclasspath, java_home, dll_dir
 355   {
 356     char *pslash;
 357     os::jvm_path(buf, bufsize);
 358 
 359     // Found the full path to libjvm.so.
 360     // Now cut the path to <java_home>/jre if we can.
 361     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 362     pslash = strrchr(buf, '/');
 363     if (pslash != NULL) {
 364       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 365     }
 366     Arguments::set_dll_dir(buf);
 367 
 368     if (pslash != NULL) {
 369       pslash = strrchr(buf, '/');
 370       if (pslash != NULL) {
 371         *pslash = '\0';          // Get rid of /<arch>.
 372         pslash = strrchr(buf, '/');
 373         if (pslash != NULL) {
 374           *pslash = '\0';        // Get rid of /lib.
 375         }
 376       }
 377     }
 378     Arguments::set_java_home(buf);
 379     set_boot_path('/', ':');
 380   }
 381 
 382   // Where to look for native libraries.
 383   //
 384   // Note: Due to a legacy implementation, most of the library path
 385   // is set in the launcher. This was to accomodate linking restrictions
 386   // on legacy Bsd implementations (which are no longer supported).
 387   // Eventually, all the library path setting will be done here.
 388   //
 389   // However, to prevent the proliferation of improperly built native
 390   // libraries, the new path component /usr/java/packages is added here.
 391   // Eventually, all the library path setting will be done here.
 392   {
 393     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 394     // should always exist (until the legacy problem cited above is
 395     // addressed).
 396     const char *v = ::getenv("LD_LIBRARY_PATH");
 397     const char *v_colon = ":";
 398     if (v == NULL) { v = ""; v_colon = ""; }
 399     // That's +1 for the colon and +1 for the trailing '\0'.
 400     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 401                                                      strlen(v) + 1 +
 402                                                      sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
 403                                                      mtInternal);
 404     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
 405     Arguments::set_library_path(ld_library_path);
 406     FREE_C_HEAP_ARRAY(char, ld_library_path);
 407   }
 408 
 409   // Extensions directories.
 410   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
 411   Arguments::set_ext_dirs(buf);
 412 
 413   FREE_C_HEAP_ARRAY(char, buf);
 414 
 415 #else // __APPLE__
 416 
 417   #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 418   #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 419 
 420   const char *user_home_dir = get_home();
 421   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
 422   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 423     sizeof(SYS_EXTENSIONS_DIRS);
 424 
 425   // Buffer that fits several sprintfs.
 426   // Note that the space for the colon and the trailing null are provided
 427   // by the nulls included by the sizeof operator.
 428   const size_t bufsize =
 429     MAX2((size_t)MAXPATHLEN,  // for dll_dir & friends.
 430          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
 431   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 432 
 433   // sysclasspath, java_home, dll_dir
 434   {
 435     char *pslash;
 436     os::jvm_path(buf, bufsize);
 437 
 438     // Found the full path to libjvm.so.
 439     // Now cut the path to <java_home>/jre if we can.
 440     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 441     pslash = strrchr(buf, '/');
 442     if (pslash != NULL) {
 443       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 444     }
 445     Arguments::set_dll_dir(buf);
 446 
 447     if (pslash != NULL) {
 448       pslash = strrchr(buf, '/');
 449       if (pslash != NULL) {
 450         *pslash = '\0';          // Get rid of /lib.
 451       }
 452     }
 453     Arguments::set_java_home(buf);
 454     set_boot_path('/', ':');
 455   }
 456 
 457   // Where to look for native libraries.
 458   //
 459   // Note: Due to a legacy implementation, most of the library path
 460   // is set in the launcher. This was to accomodate linking restrictions
 461   // on legacy Bsd implementations (which are no longer supported).
 462   // Eventually, all the library path setting will be done here.
 463   //
 464   // However, to prevent the proliferation of improperly built native
 465   // libraries, the new path component /usr/java/packages is added here.
 466   // Eventually, all the library path setting will be done here.
 467   {
 468     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 469     // should always exist (until the legacy problem cited above is
 470     // addressed).
 471     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
 472     // can specify a directory inside an app wrapper
 473     const char *l = ::getenv("JAVA_LIBRARY_PATH");
 474     const char *l_colon = ":";
 475     if (l == NULL) { l = ""; l_colon = ""; }
 476 
 477     const char *v = ::getenv("DYLD_LIBRARY_PATH");
 478     const char *v_colon = ":";
 479     if (v == NULL) { v = ""; v_colon = ""; }
 480 
 481     // Apple's Java6 has "." at the beginning of java.library.path.
 482     // OpenJDK on Windows has "." at the end of java.library.path.
 483     // OpenJDK on Linux and Solaris don't have "." in java.library.path
 484     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 485     // "." is appended to the end of java.library.path. Yes, this
 486     // could cause a change in behavior, but Apple's Java6 behavior
 487     // can be achieved by putting "." at the beginning of the
 488     // JAVA_LIBRARY_PATH environment variable.
 489     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 490                                                      strlen(v) + 1 + strlen(l) + 1 +
 491                                                      system_ext_size + 3,
 492                                                      mtInternal);
 493     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
 494             v, v_colon, l, l_colon, user_home_dir);
 495     Arguments::set_library_path(ld_library_path);
 496     FREE_C_HEAP_ARRAY(char, ld_library_path);
 497   }
 498 
 499   // Extensions directories.
 500   //
 501   // Note that the space for the colon and the trailing null are provided
 502   // by the nulls included by the sizeof operator (so actually one byte more
 503   // than necessary is allocated).
 504   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
 505           user_home_dir, Arguments::get_java_home());
 506   Arguments::set_ext_dirs(buf);
 507 
 508   FREE_C_HEAP_ARRAY(char, buf);
 509 
 510 #undef SYS_EXTENSIONS_DIR
 511 #undef SYS_EXTENSIONS_DIRS
 512 
 513 #endif // __APPLE__
 514 
 515 #undef SYS_EXT_DIR
 516 #undef EXTENSIONS_DIR
 517 }
 518 
 519 ////////////////////////////////////////////////////////////////////////////////
 520 // breakpoint support
 521 
 522 void os::breakpoint() {
 523   BREAKPOINT;
 524 }
 525 
 526 extern "C" void breakpoint() {
 527   // use debugger to set breakpoint here
 528 }
 529 
 530 ////////////////////////////////////////////////////////////////////////////////
 531 // signal support
 532 
 533 debug_only(static bool signal_sets_initialized = false);
 534 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
 535 
 536 bool os::Bsd::is_sig_ignored(int sig) {
 537   struct sigaction oact;
 538   sigaction(sig, (struct sigaction*)NULL, &oact);
 539   void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
 540                                  : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
 541   if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
 542     return true;
 543   } else {
 544     return false;
 545   }
 546 }
 547 
 548 void os::Bsd::signal_sets_init() {
 549   // Should also have an assertion stating we are still single-threaded.
 550   assert(!signal_sets_initialized, "Already initialized");
 551   // Fill in signals that are necessarily unblocked for all threads in
 552   // the VM. Currently, we unblock the following signals:
 553   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 554   //                         by -Xrs (=ReduceSignalUsage));
 555   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 556   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 557   // the dispositions or masks wrt these signals.
 558   // Programs embedding the VM that want to use the above signals for their
 559   // own purposes must, at this time, use the "-Xrs" option to prevent
 560   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 561   // (See bug 4345157, and other related bugs).
 562   // In reality, though, unblocking these signals is really a nop, since
 563   // these signals are not blocked by default.
 564   sigemptyset(&unblocked_sigs);
 565   sigemptyset(&allowdebug_blocked_sigs);
 566   sigaddset(&unblocked_sigs, SIGILL);
 567   sigaddset(&unblocked_sigs, SIGSEGV);
 568   sigaddset(&unblocked_sigs, SIGBUS);
 569   sigaddset(&unblocked_sigs, SIGFPE);
 570   sigaddset(&unblocked_sigs, SR_signum);
 571 
 572   if (!ReduceSignalUsage) {
 573     if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 574       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 575       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
 576     }
 577     if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 578       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 579       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
 580     }
 581     if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 582       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 583       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
 584     }
 585   }
 586   // Fill in signals that are blocked by all but the VM thread.
 587   sigemptyset(&vm_sigs);
 588   if (!ReduceSignalUsage) {
 589     sigaddset(&vm_sigs, BREAK_SIGNAL);
 590   }
 591   debug_only(signal_sets_initialized = true);
 592 
 593 }
 594 
 595 // These are signals that are unblocked while a thread is running Java.
 596 // (For some reason, they get blocked by default.)
 597 sigset_t* os::Bsd::unblocked_signals() {
 598   assert(signal_sets_initialized, "Not initialized");
 599   return &unblocked_sigs;
 600 }
 601 
 602 // These are the signals that are blocked while a (non-VM) thread is
 603 // running Java. Only the VM thread handles these signals.
 604 sigset_t* os::Bsd::vm_signals() {
 605   assert(signal_sets_initialized, "Not initialized");
 606   return &vm_sigs;
 607 }
 608 
 609 // These are signals that are blocked during cond_wait to allow debugger in
 610 sigset_t* os::Bsd::allowdebug_blocked_signals() {
 611   assert(signal_sets_initialized, "Not initialized");
 612   return &allowdebug_blocked_sigs;
 613 }
 614 
 615 void os::Bsd::hotspot_sigmask(Thread* thread) {
 616 
 617   //Save caller's signal mask before setting VM signal mask
 618   sigset_t caller_sigmask;
 619   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 620 
 621   OSThread* osthread = thread->osthread();
 622   osthread->set_caller_sigmask(caller_sigmask);
 623 
 624   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 625 
 626   if (!ReduceSignalUsage) {
 627     if (thread->is_VM_thread()) {
 628       // Only the VM thread handles BREAK_SIGNAL ...
 629       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 630     } else {
 631       // ... all other threads block BREAK_SIGNAL
 632       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 633     }
 634   }
 635 }
 636 
 637 
 638 //////////////////////////////////////////////////////////////////////////////
 639 // create new thread
 640 
 641 #ifdef __APPLE__
 642 // library handle for calling objc_registerThreadWithCollector()
 643 // without static linking to the libobjc library
 644   #define OBJC_LIB "/usr/lib/libobjc.dylib"
 645   #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 646 typedef void (*objc_registerThreadWithCollector_t)();
 647 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 648 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 649 #endif
 650 
 651 #ifdef __APPLE__
 652 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 653   // Additional thread_id used to correlate threads in SA
 654   thread_identifier_info_data_t     m_ident_info;
 655   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 656 
 657   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 658               (thread_info_t) &m_ident_info, &count);
 659 
 660   return m_ident_info.thread_id;
 661 }
 662 #endif
 663 
 664 // Thread start routine for all newly created threads
 665 static void *java_start(Thread *thread) {
 666   // Try to randomize the cache line index of hot stack frames.
 667   // This helps when threads of the same stack traces evict each other's
 668   // cache lines. The threads can be either from the same JVM instance, or
 669   // from different JVM instances. The benefit is especially true for
 670   // processors with hyperthreading technology.
 671   static int counter = 0;
 672   int pid = os::current_process_id();
 673   alloca(((pid ^ counter++) & 7) * 128);
 674 
 675   ThreadLocalStorage::set_thread(thread);
 676 
 677   OSThread* osthread = thread->osthread();
 678   Monitor* sync = osthread->startThread_lock();
 679 
 680   osthread->set_thread_id(os::Bsd::gettid());
 681 
 682 #ifdef __APPLE__
 683   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 684   guarantee(unique_thread_id != 0, "unique thread id was not found");
 685   osthread->set_unique_thread_id(unique_thread_id);
 686 #endif
 687   // initialize signal mask for this thread
 688   os::Bsd::hotspot_sigmask(thread);
 689 
 690   // initialize floating point control register
 691   os::Bsd::init_thread_fpu_state();
 692 
 693 #ifdef __APPLE__
 694   // register thread with objc gc
 695   if (objc_registerThreadWithCollectorFunction != NULL) {
 696     objc_registerThreadWithCollectorFunction();
 697   }
 698 #endif
 699 
 700   // handshaking with parent thread
 701   {
 702     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 703 
 704     // notify parent thread
 705     osthread->set_state(INITIALIZED);
 706     sync->notify_all();
 707 
 708     // wait until os::start_thread()
 709     while (osthread->get_state() == INITIALIZED) {
 710       sync->wait(Mutex::_no_safepoint_check_flag);
 711     }
 712   }
 713 
 714   // call one more level start routine
 715   thread->run();
 716 
 717   return 0;
 718 }
 719 
 720 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
 721   assert(thread->osthread() == NULL, "caller responsible");
 722 
 723   // Allocate the OSThread object
 724   OSThread* osthread = new OSThread(NULL, NULL);
 725   if (osthread == NULL) {
 726     return false;
 727   }
 728 
 729   // set the correct thread state
 730   osthread->set_thread_type(thr_type);
 731 
 732   // Initial state is ALLOCATED but not INITIALIZED
 733   osthread->set_state(ALLOCATED);
 734 
 735   thread->set_osthread(osthread);
 736 
 737   // init thread attributes
 738   pthread_attr_t attr;
 739   pthread_attr_init(&attr);
 740   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 741 
 742   // stack size
 743   if (os::Bsd::supports_variable_stack_size()) {
 744     // calculate stack size if it's not specified by caller
 745     if (stack_size == 0) {
 746       stack_size = os::Bsd::default_stack_size(thr_type);
 747 
 748       switch (thr_type) {
 749       case os::java_thread:
 750         // Java threads use ThreadStackSize which default value can be
 751         // changed with the flag -Xss
 752         assert(JavaThread::stack_size_at_create() > 0, "this should be set");
 753         stack_size = JavaThread::stack_size_at_create();
 754         break;
 755       case os::compiler_thread:
 756         if (CompilerThreadStackSize > 0) {
 757           stack_size = (size_t)(CompilerThreadStackSize * K);
 758           break;
 759         } // else fall through:
 760           // use VMThreadStackSize if CompilerThreadStackSize is not defined
 761       case os::vm_thread:
 762       case os::pgc_thread:
 763       case os::cgc_thread:
 764       case os::watcher_thread:
 765         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 766         break;
 767       }
 768     }
 769 
 770     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
 771     pthread_attr_setstacksize(&attr, stack_size);
 772   } else {
 773     // let pthread_create() pick the default value.
 774   }
 775 
 776   ThreadState state;
 777 
 778   {
 779     pthread_t tid;
 780     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
 781 
 782     pthread_attr_destroy(&attr);
 783 
 784     if (ret != 0) {
 785       if (PrintMiscellaneous && (Verbose || WizardMode)) {
 786         perror("pthread_create()");
 787       }
 788       // Need to clean up stuff we've allocated so far
 789       thread->set_osthread(NULL);
 790       delete osthread;
 791       return false;
 792     }
 793 
 794     // Store pthread info into the OSThread
 795     osthread->set_pthread_id(tid);
 796 
 797     // Wait until child thread is either initialized or aborted
 798     {
 799       Monitor* sync_with_child = osthread->startThread_lock();
 800       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 801       while ((state = osthread->get_state()) == ALLOCATED) {
 802         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 803       }
 804     }
 805 
 806   }
 807 
 808   // Aborted due to thread limit being reached
 809   if (state == ZOMBIE) {
 810     thread->set_osthread(NULL);
 811     delete osthread;
 812     return false;
 813   }
 814 
 815   // The thread is returned suspended (in state INITIALIZED),
 816   // and is started higher up in the call chain
 817   assert(state == INITIALIZED, "race condition");
 818   return true;
 819 }
 820 
 821 /////////////////////////////////////////////////////////////////////////////
 822 // attach existing thread
 823 
 824 // bootstrap the main thread
 825 bool os::create_main_thread(JavaThread* thread) {
 826   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 827   return create_attached_thread(thread);
 828 }
 829 
 830 bool os::create_attached_thread(JavaThread* thread) {
 831 #ifdef ASSERT
 832   thread->verify_not_published();
 833 #endif
 834 
 835   // Allocate the OSThread object
 836   OSThread* osthread = new OSThread(NULL, NULL);
 837 
 838   if (osthread == NULL) {
 839     return false;
 840   }
 841 
 842   osthread->set_thread_id(os::Bsd::gettid());
 843 
 844   // Store pthread info into the OSThread
 845 #ifdef __APPLE__
 846   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 847   guarantee(unique_thread_id != 0, "just checking");
 848   osthread->set_unique_thread_id(unique_thread_id);
 849 #endif
 850   osthread->set_pthread_id(::pthread_self());
 851 
 852   // initialize floating point control register
 853   os::Bsd::init_thread_fpu_state();
 854 
 855   // Initial thread state is RUNNABLE
 856   osthread->set_state(RUNNABLE);
 857 
 858   thread->set_osthread(osthread);
 859 
 860   // initialize signal mask for this thread
 861   // and save the caller's signal mask
 862   os::Bsd::hotspot_sigmask(thread);
 863 
 864   return true;
 865 }
 866 
 867 void os::pd_start_thread(Thread* thread) {
 868   OSThread * osthread = thread->osthread();
 869   assert(osthread->get_state() != INITIALIZED, "just checking");
 870   Monitor* sync_with_child = osthread->startThread_lock();
 871   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 872   sync_with_child->notify();
 873 }
 874 
 875 // Free Bsd resources related to the OSThread
 876 void os::free_thread(OSThread* osthread) {
 877   assert(osthread != NULL, "osthread not set");
 878 
 879   if (Thread::current()->osthread() == osthread) {
 880     // Restore caller's signal mask
 881     sigset_t sigmask = osthread->caller_sigmask();
 882     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 883   }
 884 
 885   delete osthread;
 886 }
 887 
 888 //////////////////////////////////////////////////////////////////////////////
 889 // thread local storage
 890 
 891 // Restore the thread pointer if the destructor is called. This is in case
 892 // someone from JNI code sets up a destructor with pthread_key_create to run
 893 // detachCurrentThread on thread death. Unless we restore the thread pointer we
 894 // will hang or crash. When detachCurrentThread is called the key will be set
 895 // to null and we will not be called again. If detachCurrentThread is never
 896 // called we could loop forever depending on the pthread implementation.
 897 static void restore_thread_pointer(void* p) {
 898   Thread* thread = (Thread*) p;
 899   os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
 900 }
 901 
 902 int os::allocate_thread_local_storage() {
 903   pthread_key_t key;
 904   int rslt = pthread_key_create(&key, restore_thread_pointer);
 905   assert(rslt == 0, "cannot allocate thread local storage");
 906   return (int)key;
 907 }
 908 
 909 // Note: This is currently not used by VM, as we don't destroy TLS key
 910 // on VM exit.
 911 void os::free_thread_local_storage(int index) {
 912   int rslt = pthread_key_delete((pthread_key_t)index);
 913   assert(rslt == 0, "invalid index");
 914 }
 915 
 916 void os::thread_local_storage_at_put(int index, void* value) {
 917   int rslt = pthread_setspecific((pthread_key_t)index, value);
 918   assert(rslt == 0, "pthread_setspecific failed");
 919 }
 920 
 921 extern "C" Thread* get_thread() {
 922   return ThreadLocalStorage::thread();
 923 }
 924 
 925 
 926 ////////////////////////////////////////////////////////////////////////////////
 927 // time support
 928 
 929 // Time since start-up in seconds to a fine granularity.
 930 // Used by VMSelfDestructTimer and the MemProfiler.
 931 double os::elapsedTime() {
 932 
 933   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 934 }
 935 
 936 jlong os::elapsed_counter() {
 937   return javaTimeNanos() - initial_time_count;
 938 }
 939 
 940 jlong os::elapsed_frequency() {
 941   return NANOSECS_PER_SEC; // nanosecond resolution
 942 }
 943 
 944 bool os::supports_vtime() { return true; }
 945 bool os::enable_vtime()   { return false; }
 946 bool os::vtime_enabled()  { return false; }
 947 
 948 double os::elapsedVTime() {
 949   // better than nothing, but not much
 950   return elapsedTime();
 951 }
 952 
 953 jlong os::javaTimeMillis() {
 954   timeval time;
 955   int status = gettimeofday(&time, NULL);
 956   assert(status != -1, "bsd error");
 957   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 958 }
 959 
 960 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
 961   timeval time;
 962   int status = gettimeofday(&time, NULL);
 963   assert(status != -1, "bsd error");
 964   seconds = jlong(time.tv_sec);
 965   nanos = jlong(time.tv_usec) * 1000;
 966 }
 967 
 968 #ifndef __APPLE__
 969   #ifndef CLOCK_MONOTONIC
 970     #define CLOCK_MONOTONIC (1)
 971   #endif
 972 #endif
 973 
 974 #ifdef __APPLE__
 975 void os::Bsd::clock_init() {
 976   mach_timebase_info(&_timebase_info);
 977 }
 978 #else
 979 void os::Bsd::clock_init() {
 980   struct timespec res;
 981   struct timespec tp;
 982   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
 983       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
 984     // yes, monotonic clock is supported
 985     _clock_gettime = ::clock_gettime;
 986   }
 987 }
 988 #endif
 989 
 990 
 991 
 992 #ifdef __APPLE__
 993 
 994 jlong os::javaTimeNanos() {
 995   const uint64_t tm = mach_absolute_time();
 996   const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
 997   const uint64_t prev = Bsd::_max_abstime;
 998   if (now <= prev) {
 999     return prev;   // same or retrograde time;
1000   }
1001   const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
1002   assert(obsv >= prev, "invariant");   // Monotonicity
1003   // If the CAS succeeded then we're done and return "now".
1004   // If the CAS failed and the observed value "obsv" is >= now then
1005   // we should return "obsv".  If the CAS failed and now > obsv > prv then
1006   // some other thread raced this thread and installed a new value, in which case
1007   // we could either (a) retry the entire operation, (b) retry trying to install now
1008   // or (c) just return obsv.  We use (c).   No loop is required although in some cases
1009   // we might discard a higher "now" value in deference to a slightly lower but freshly
1010   // installed obsv value.   That's entirely benign -- it admits no new orderings compared
1011   // to (a) or (b) -- and greatly reduces coherence traffic.
1012   // We might also condition (c) on the magnitude of the delta between obsv and now.
1013   // Avoiding excessive CAS operations to hot RW locations is critical.
1014   // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1015   return (prev == obsv) ? now : obsv;
1016 }
1017 
1018 #else // __APPLE__
1019 
1020 jlong os::javaTimeNanos() {
1021   if (os::supports_monotonic_clock()) {
1022     struct timespec tp;
1023     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
1024     assert(status == 0, "gettime error");
1025     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1026     return result;
1027   } else {
1028     timeval time;
1029     int status = gettimeofday(&time, NULL);
1030     assert(status != -1, "bsd error");
1031     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1032     return 1000 * usecs;
1033   }
1034 }
1035 
1036 #endif // __APPLE__
1037 
1038 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1039   if (os::supports_monotonic_clock()) {
1040     info_ptr->max_value = ALL_64_BITS;
1041 
1042     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1043     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
1044     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
1045   } else {
1046     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1047     info_ptr->max_value = ALL_64_BITS;
1048 
1049     // gettimeofday is a real time clock so it skips
1050     info_ptr->may_skip_backward = true;
1051     info_ptr->may_skip_forward = true;
1052   }
1053 
1054   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
1055 }
1056 
1057 // Return the real, user, and system times in seconds from an
1058 // arbitrary fixed point in the past.
1059 bool os::getTimesSecs(double* process_real_time,
1060                       double* process_user_time,
1061                       double* process_system_time) {
1062   struct tms ticks;
1063   clock_t real_ticks = times(&ticks);
1064 
1065   if (real_ticks == (clock_t) (-1)) {
1066     return false;
1067   } else {
1068     double ticks_per_second = (double) clock_tics_per_sec;
1069     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1070     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1071     *process_real_time = ((double) real_ticks) / ticks_per_second;
1072 
1073     return true;
1074   }
1075 }
1076 
1077 
1078 char * os::local_time_string(char *buf, size_t buflen) {
1079   struct tm t;
1080   time_t long_time;
1081   time(&long_time);
1082   localtime_r(&long_time, &t);
1083   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1084                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1085                t.tm_hour, t.tm_min, t.tm_sec);
1086   return buf;
1087 }
1088 
1089 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1090   return localtime_r(clock, res);
1091 }
1092 
1093 ////////////////////////////////////////////////////////////////////////////////
1094 // runtime exit support
1095 
1096 // Note: os::shutdown() might be called very early during initialization, or
1097 // called from signal handler. Before adding something to os::shutdown(), make
1098 // sure it is async-safe and can handle partially initialized VM.
1099 void os::shutdown() {
1100 
1101   // allow PerfMemory to attempt cleanup of any persistent resources
1102   perfMemory_exit();
1103 
1104   // needs to remove object in file system
1105   AttachListener::abort();
1106 
1107   // flush buffered output, finish log files
1108   ostream_abort();
1109 
1110   // Check for abort hook
1111   abort_hook_t abort_hook = Arguments::abort_hook();
1112   if (abort_hook != NULL) {
1113     abort_hook();
1114   }
1115 
1116 }
1117 
1118 // Note: os::abort() might be called very early during initialization, or
1119 // called from signal handler. Before adding something to os::abort(), make
1120 // sure it is async-safe and can handle partially initialized VM.
1121 void os::abort(bool dump_core, void* siginfo, void* context) {
1122   os::shutdown();
1123   if (dump_core) {
1124 #ifndef PRODUCT
1125     fdStream out(defaultStream::output_fd());
1126     out.print_raw("Current thread is ");
1127     char buf[16];
1128     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1129     out.print_raw_cr(buf);
1130     out.print_raw_cr("Dumping core ...");
1131 #endif
1132     ::abort(); // dump core
1133   }
1134 
1135   ::exit(1);
1136 }
1137 
1138 // Die immediately, no exit hook, no abort hook, no cleanup.
1139 void os::die() {
1140   // _exit() on BsdThreads only kills current thread
1141   ::abort();
1142 }
1143 
1144 // This method is a copy of JDK's sysGetLastErrorString
1145 // from src/solaris/hpi/src/system_md.c
1146 
1147 size_t os::lasterror(char *buf, size_t len) {
1148   if (errno == 0)  return 0;
1149 
1150   const char *s = ::strerror(errno);
1151   size_t n = ::strlen(s);
1152   if (n >= len) {
1153     n = len - 1;
1154   }
1155   ::strncpy(buf, s, n);
1156   buf[n] = '\0';
1157   return n;
1158 }
1159 
1160 // Information of current thread in variety of formats
1161 pid_t os::Bsd::gettid() {
1162   int retval = -1;
1163 
1164 #ifdef __APPLE__ //XNU kernel
1165   // despite the fact mach port is actually not a thread id use it
1166   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1167   retval = ::pthread_mach_thread_np(::pthread_self());
1168   guarantee(retval != 0, "just checking");
1169   return retval;
1170 
1171 #else
1172   #ifdef __FreeBSD__
1173   retval = syscall(SYS_thr_self);
1174   #else
1175     #ifdef __OpenBSD__
1176   retval = syscall(SYS_getthrid);
1177     #else
1178       #ifdef __NetBSD__
1179   retval = (pid_t) syscall(SYS__lwp_self);
1180       #endif
1181     #endif
1182   #endif
1183 #endif
1184 
1185   if (retval == -1) {
1186     return getpid();
1187   }
1188 }
1189 
1190 intx os::current_thread_id() {
1191 #ifdef __APPLE__
1192   return (intx)::pthread_mach_thread_np(::pthread_self());
1193 #else
1194   return (intx)::pthread_self();
1195 #endif
1196 }
1197 
1198 int os::current_process_id() {
1199 
1200   // Under the old bsd thread library, bsd gives each thread
1201   // its own process id. Because of this each thread will return
1202   // a different pid if this method were to return the result
1203   // of getpid(2). Bsd provides no api that returns the pid
1204   // of the launcher thread for the vm. This implementation
1205   // returns a unique pid, the pid of the launcher thread
1206   // that starts the vm 'process'.
1207 
1208   // Under the NPTL, getpid() returns the same pid as the
1209   // launcher thread rather than a unique pid per thread.
1210   // Use gettid() if you want the old pre NPTL behaviour.
1211 
1212   // if you are looking for the result of a call to getpid() that
1213   // returns a unique pid for the calling thread, then look at the
1214   // OSThread::thread_id() method in osThread_bsd.hpp file
1215 
1216   return (int)(_initial_pid ? _initial_pid : getpid());
1217 }
1218 
1219 // DLL functions
1220 
1221 #define JNI_LIB_PREFIX "lib"
1222 #ifdef __APPLE__
1223   #define JNI_LIB_SUFFIX ".dylib"
1224 #else
1225   #define JNI_LIB_SUFFIX ".so"
1226 #endif
1227 
1228 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1229 
1230 // This must be hard coded because it's the system's temporary
1231 // directory not the java application's temp directory, ala java.io.tmpdir.
1232 #ifdef __APPLE__
1233 // macosx has a secure per-user temporary directory
1234 char temp_path_storage[PATH_MAX];
1235 const char* os::get_temp_directory() {
1236   static char *temp_path = NULL;
1237   if (temp_path == NULL) {
1238     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1239     if (pathSize == 0 || pathSize > PATH_MAX) {
1240       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1241     }
1242     temp_path = temp_path_storage;
1243   }
1244   return temp_path;
1245 }
1246 #else // __APPLE__
1247 const char* os::get_temp_directory() { return "/tmp"; }
1248 #endif // __APPLE__
1249 
1250 static bool file_exists(const char* filename) {
1251   struct stat statbuf;
1252   if (filename == NULL || strlen(filename) == 0) {
1253     return false;
1254   }
1255   return os::stat(filename, &statbuf) == 0;
1256 }
1257 
1258 bool os::dll_build_name(char* buffer, size_t buflen,
1259                         const char* pname, const char* fname) {
1260   bool retval = false;
1261   // Copied from libhpi
1262   const size_t pnamelen = pname ? strlen(pname) : 0;
1263 
1264   // Return error on buffer overflow.
1265   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1266     return retval;
1267   }
1268 
1269   if (pnamelen == 0) {
1270     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1271     retval = true;
1272   } else if (strchr(pname, *os::path_separator()) != NULL) {
1273     int n;
1274     char** pelements = split_path(pname, &n);
1275     if (pelements == NULL) {
1276       return false;
1277     }
1278     for (int i = 0; i < n; i++) {
1279       // Really shouldn't be NULL, but check can't hurt
1280       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1281         continue; // skip the empty path values
1282       }
1283       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1284                pelements[i], fname);
1285       if (file_exists(buffer)) {
1286         retval = true;
1287         break;
1288       }
1289     }
1290     // release the storage
1291     for (int i = 0; i < n; i++) {
1292       if (pelements[i] != NULL) {
1293         FREE_C_HEAP_ARRAY(char, pelements[i]);
1294       }
1295     }
1296     if (pelements != NULL) {
1297       FREE_C_HEAP_ARRAY(char*, pelements);
1298     }
1299   } else {
1300     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1301     retval = true;
1302   }
1303   return retval;
1304 }
1305 
1306 // check if addr is inside libjvm.so
1307 bool os::address_is_in_vm(address addr) {
1308   static address libjvm_base_addr;
1309   Dl_info dlinfo;
1310 
1311   if (libjvm_base_addr == NULL) {
1312     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1313       libjvm_base_addr = (address)dlinfo.dli_fbase;
1314     }
1315     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1316   }
1317 
1318   if (dladdr((void *)addr, &dlinfo) != 0) {
1319     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1320   }
1321 
1322   return false;
1323 }
1324 
1325 
1326 #define MACH_MAXSYMLEN 256
1327 
1328 bool os::dll_address_to_function_name(address addr, char *buf,
1329                                       int buflen, int *offset,
1330                                       bool demangle) {
1331   // buf is not optional, but offset is optional
1332   assert(buf != NULL, "sanity check");
1333 
1334   Dl_info dlinfo;
1335   char localbuf[MACH_MAXSYMLEN];
1336 
1337   if (dladdr((void*)addr, &dlinfo) != 0) {
1338     // see if we have a matching symbol
1339     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1340       if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1341         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1342       }
1343       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1344       return true;
1345     }
1346     // no matching symbol so try for just file info
1347     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1348       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1349                           buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1350         return true;
1351       }
1352     }
1353 
1354     // Handle non-dynamic manually:
1355     if (dlinfo.dli_fbase != NULL &&
1356         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1357                         dlinfo.dli_fbase)) {
1358       if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) {
1359         jio_snprintf(buf, buflen, "%s", localbuf);
1360       }
1361       return true;
1362     }
1363   }
1364   buf[0] = '\0';
1365   if (offset != NULL) *offset = -1;
1366   return false;
1367 }
1368 
1369 // ported from solaris version
1370 bool os::dll_address_to_library_name(address addr, char* buf,
1371                                      int buflen, int* offset) {
1372   // buf is not optional, but offset is optional
1373   assert(buf != NULL, "sanity check");
1374 
1375   Dl_info dlinfo;
1376 
1377   if (dladdr((void*)addr, &dlinfo) != 0) {
1378     if (dlinfo.dli_fname != NULL) {
1379       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1380     }
1381     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1382       *offset = addr - (address)dlinfo.dli_fbase;
1383     }
1384     return true;
1385   }
1386 
1387   buf[0] = '\0';
1388   if (offset) *offset = -1;
1389   return false;
1390 }
1391 
1392 // Loads .dll/.so and
1393 // in case of error it checks if .dll/.so was built for the
1394 // same architecture as Hotspot is running on
1395 
1396 #ifdef __APPLE__
1397 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1398   void * result= ::dlopen(filename, RTLD_LAZY);
1399   if (result != NULL) {
1400     // Successful loading
1401     return result;
1402   }
1403 
1404   // Read system error message into ebuf
1405   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1406   ebuf[ebuflen-1]='\0';
1407 
1408   return NULL;
1409 }
1410 #else
1411 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1412   void * result= ::dlopen(filename, RTLD_LAZY);
1413   if (result != NULL) {
1414     // Successful loading
1415     return result;
1416   }
1417 
1418   Elf32_Ehdr elf_head;
1419 
1420   // Read system error message into ebuf
1421   // It may or may not be overwritten below
1422   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1423   ebuf[ebuflen-1]='\0';
1424   int diag_msg_max_length=ebuflen-strlen(ebuf);
1425   char* diag_msg_buf=ebuf+strlen(ebuf);
1426 
1427   if (diag_msg_max_length==0) {
1428     // No more space in ebuf for additional diagnostics message
1429     return NULL;
1430   }
1431 
1432 
1433   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1434 
1435   if (file_descriptor < 0) {
1436     // Can't open library, report dlerror() message
1437     return NULL;
1438   }
1439 
1440   bool failed_to_read_elf_head=
1441     (sizeof(elf_head)!=
1442      (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1443 
1444   ::close(file_descriptor);
1445   if (failed_to_read_elf_head) {
1446     // file i/o error - report dlerror() msg
1447     return NULL;
1448   }
1449 
1450   typedef struct {
1451     Elf32_Half  code;         // Actual value as defined in elf.h
1452     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1453     char        elf_class;    // 32 or 64 bit
1454     char        endianess;    // MSB or LSB
1455     char*       name;         // String representation
1456   } arch_t;
1457 
1458   #ifndef EM_486
1459     #define EM_486          6               /* Intel 80486 */
1460   #endif
1461 
1462   #ifndef EM_MIPS_RS3_LE
1463     #define EM_MIPS_RS3_LE  10              /* MIPS */
1464   #endif
1465 
1466   #ifndef EM_PPC64
1467     #define EM_PPC64        21              /* PowerPC64 */
1468   #endif
1469 
1470   #ifndef EM_S390
1471     #define EM_S390         22              /* IBM System/390 */
1472   #endif
1473 
1474   #ifndef EM_IA_64
1475     #define EM_IA_64        50              /* HP/Intel IA-64 */
1476   #endif
1477 
1478   #ifndef EM_X86_64
1479     #define EM_X86_64       62              /* AMD x86-64 */
1480   #endif
1481 
1482   static const arch_t arch_array[]={
1483     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1484     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1485     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1486     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1487     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1488     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1489     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1490     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1491     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1492     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1493     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1494     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1495     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1496     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1497     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1498     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1499   };
1500 
1501   #if  (defined IA32)
1502   static  Elf32_Half running_arch_code=EM_386;
1503   #elif   (defined AMD64)
1504   static  Elf32_Half running_arch_code=EM_X86_64;
1505   #elif  (defined IA64)
1506   static  Elf32_Half running_arch_code=EM_IA_64;
1507   #elif  (defined __sparc) && (defined _LP64)
1508   static  Elf32_Half running_arch_code=EM_SPARCV9;
1509   #elif  (defined __sparc) && (!defined _LP64)
1510   static  Elf32_Half running_arch_code=EM_SPARC;
1511   #elif  (defined __powerpc64__)
1512   static  Elf32_Half running_arch_code=EM_PPC64;
1513   #elif  (defined __powerpc__)
1514   static  Elf32_Half running_arch_code=EM_PPC;
1515   #elif  (defined ARM)
1516   static  Elf32_Half running_arch_code=EM_ARM;
1517   #elif  (defined S390)
1518   static  Elf32_Half running_arch_code=EM_S390;
1519   #elif  (defined ALPHA)
1520   static  Elf32_Half running_arch_code=EM_ALPHA;
1521   #elif  (defined MIPSEL)
1522   static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1523   #elif  (defined PARISC)
1524   static  Elf32_Half running_arch_code=EM_PARISC;
1525   #elif  (defined MIPS)
1526   static  Elf32_Half running_arch_code=EM_MIPS;
1527   #elif  (defined M68K)
1528   static  Elf32_Half running_arch_code=EM_68K;
1529   #else
1530     #error Method os::dll_load requires that one of following is defined:\
1531          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1532   #endif
1533 
1534   // Identify compatability class for VM's architecture and library's architecture
1535   // Obtain string descriptions for architectures
1536 
1537   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1538   int running_arch_index=-1;
1539 
1540   for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1541     if (running_arch_code == arch_array[i].code) {
1542       running_arch_index    = i;
1543     }
1544     if (lib_arch.code == arch_array[i].code) {
1545       lib_arch.compat_class = arch_array[i].compat_class;
1546       lib_arch.name         = arch_array[i].name;
1547     }
1548   }
1549 
1550   assert(running_arch_index != -1,
1551          "Didn't find running architecture code (running_arch_code) in arch_array");
1552   if (running_arch_index == -1) {
1553     // Even though running architecture detection failed
1554     // we may still continue with reporting dlerror() message
1555     return NULL;
1556   }
1557 
1558   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1559     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1560     return NULL;
1561   }
1562 
1563 #ifndef S390
1564   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1565     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1566     return NULL;
1567   }
1568 #endif // !S390
1569 
1570   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1571     if (lib_arch.name!=NULL) {
1572       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1573                  " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1574                  lib_arch.name, arch_array[running_arch_index].name);
1575     } else {
1576       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1577                  " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1578                  lib_arch.code,
1579                  arch_array[running_arch_index].name);
1580     }
1581   }
1582 
1583   return NULL;
1584 }
1585 #endif // !__APPLE__
1586 
1587 void* os::get_default_process_handle() {
1588 #ifdef __APPLE__
1589   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1590   // to avoid finding unexpected symbols on second (or later)
1591   // loads of a library.
1592   return (void*)::dlopen(NULL, RTLD_FIRST);
1593 #else
1594   return (void*)::dlopen(NULL, RTLD_LAZY);
1595 #endif
1596 }
1597 
1598 // XXX: Do we need a lock around this as per Linux?
1599 void* os::dll_lookup(void* handle, const char* name) {
1600   return dlsym(handle, name);
1601 }
1602 
1603 
1604 static bool _print_ascii_file(const char* filename, outputStream* st) {
1605   int fd = ::open(filename, O_RDONLY);
1606   if (fd == -1) {
1607     return false;
1608   }
1609 
1610   char buf[32];
1611   int bytes;
1612   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1613     st->print_raw(buf, bytes);
1614   }
1615 
1616   ::close(fd);
1617 
1618   return true;
1619 }
1620 
1621 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1622   outputStream * out = (outputStream *) param;
1623   out->print_cr(PTR_FORMAT " \t%s", base_address, name);
1624   return 0;
1625 }
1626 
1627 void os::print_dll_info(outputStream *st) {
1628   st->print_cr("Dynamic libraries:");
1629   if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1630     st->print_cr("Error: Cannot print dynamic libraries.");
1631   }
1632 }
1633 
1634 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1635 #ifdef RTLD_DI_LINKMAP
1636   Dl_info dli;
1637   void *handle;
1638   Link_map *map;
1639   Link_map *p;
1640 
1641   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1642       dli.dli_fname == NULL) {
1643     return 1;
1644   }
1645   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1646   if (handle == NULL) {
1647     return 1;
1648   }
1649   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1650   if (map == NULL) {
1651     dlclose(handle);
1652     return 1;
1653   }
1654 
1655   while (map->l_prev != NULL)
1656     map = map->l_prev;
1657 
1658   while (map != NULL) {
1659     // Value for top_address is returned as 0 since we don't have any information about module size
1660     if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1661       dlclose(handle);
1662       return 1;
1663     }
1664     map = map->l_next;
1665   }
1666 
1667   dlclose(handle);
1668 #elif defined(__APPLE__)
1669   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1670     // Value for top_address is returned as 0 since we don't have any information about module size
1671     if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1672       return 1;
1673     }
1674   }
1675   return 0;
1676 #else
1677   return 1;
1678 #endif
1679 }
1680 
1681 void os::print_os_info_brief(outputStream* st) {
1682   st->print("Bsd");













1683 











1684   os::Posix::print_uname_info(st);
1685 }
1686 
1687 void os::print_os_info(outputStream* st) {
1688   st->print("OS:");
1689   st->print("Bsd");
1690 
1691   os::Posix::print_uname_info(st);
1692 
1693   os::Posix::print_rlimit_info(st);
1694 
1695   os::Posix::print_load_average(st);
1696 }
1697 
1698 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1699   // Nothing to do for now.
1700 }
1701 



























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