1 /*
   2  * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // no precompiled headers
  26 #include "jvm.h"
  27 #include "classfile/classLoader.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "classfile/vmSymbols.hpp"
  30 #include "code/icBuffer.hpp"
  31 #include "code/vtableStubs.hpp"
  32 #include "compiler/compileBroker.hpp"
  33 #include "compiler/disassembler.hpp"
  34 #include "interpreter/interpreter.hpp"
  35 #include "logging/log.hpp"
  36 #include "memory/allocation.inline.hpp"
  37 #include "memory/filemap.hpp"
  38 #include "oops/oop.inline.hpp"
  39 #include "os_bsd.inline.hpp"
  40 #include "os_share_bsd.hpp"
  41 #include "prims/jniFastGetField.hpp"
  42 #include "prims/jvm_misc.hpp"
  43 #include "runtime/arguments.hpp"
  44 #include "runtime/atomic.hpp"
  45 #include "runtime/extendedPC.hpp"
  46 #include "runtime/globals.hpp"
  47 #include "runtime/interfaceSupport.hpp"
  48 #include "runtime/java.hpp"
  49 #include "runtime/javaCalls.hpp"
  50 #include "runtime/mutexLocker.hpp"
  51 #include "runtime/objectMonitor.hpp"
  52 #include "runtime/orderAccess.inline.hpp"
  53 #include "runtime/osThread.hpp"
  54 #include "runtime/perfMemory.hpp"
  55 #include "runtime/sharedRuntime.hpp"
  56 #include "runtime/statSampler.hpp"
  57 #include "runtime/stubRoutines.hpp"
  58 #include "runtime/thread.inline.hpp"
  59 #include "runtime/threadCritical.hpp"
  60 #include "runtime/timer.hpp"
  61 #include "semaphore_bsd.hpp"
  62 #include "services/attachListener.hpp"
  63 #include "services/memTracker.hpp"
  64 #include "services/runtimeService.hpp"
  65 #include "utilities/align.hpp"
  66 #include "utilities/decoder.hpp"
  67 #include "utilities/defaultStream.hpp"
  68 #include "utilities/events.hpp"
  69 #include "utilities/growableArray.hpp"
  70 #include "utilities/vmError.hpp"
  71 
  72 // put OS-includes here
  73 # include <sys/types.h>
  74 # include <sys/mman.h>
  75 # include <sys/stat.h>
  76 # include <sys/select.h>
  77 # include <pthread.h>
  78 # include <signal.h>
  79 # include <errno.h>
  80 # include <dlfcn.h>
  81 # include <stdio.h>
  82 # include <unistd.h>
  83 # include <sys/resource.h>
  84 # include <pthread.h>
  85 # include <sys/stat.h>
  86 # include <sys/time.h>
  87 # include <sys/times.h>
  88 # include <sys/utsname.h>
  89 # include <sys/socket.h>
  90 # include <sys/wait.h>
  91 # include <time.h>
  92 # include <pwd.h>
  93 # include <poll.h>
  94 # include <semaphore.h>
  95 # include <fcntl.h>
  96 # include <string.h>
  97 # include <sys/param.h>
  98 # include <sys/sysctl.h>
  99 # include <sys/ipc.h>
 100 # include <sys/shm.h>
 101 #ifndef __APPLE__
 102 # include <link.h>
 103 #endif
 104 # include <stdint.h>
 105 # include <inttypes.h>
 106 # include <sys/ioctl.h>
 107 # include <sys/syscall.h>
 108 
 109 #if defined(__FreeBSD__) || defined(__NetBSD__)
 110   #include <elf.h>
 111 #endif
 112 
 113 #ifdef __APPLE__
 114   #include <mach/mach.h> // semaphore_* API
 115   #include <mach-o/dyld.h>
 116   #include <sys/proc_info.h>
 117   #include <objc/objc-auto.h>
 118 #endif
 119 
 120 #ifndef MAP_ANONYMOUS
 121   #define MAP_ANONYMOUS MAP_ANON
 122 #endif
 123 
 124 #define MAX_PATH    (2 * K)
 125 
 126 // for timer info max values which include all bits
 127 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 128 
 129 #define LARGEPAGES_BIT (1 << 6)
 130 
 131 ////////////////////////////////////////////////////////////////////////////////
 132 // global variables
 133 julong os::Bsd::_physical_memory = 0;
 134 
 135 #ifdef __APPLE__
 136 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
 137 volatile uint64_t         os::Bsd::_max_abstime   = 0;
 138 #else
 139 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 140 #endif
 141 pthread_t os::Bsd::_main_thread;
 142 int os::Bsd::_page_size = -1;
 143 
 144 static jlong initial_time_count=0;
 145 
 146 static int clock_tics_per_sec = 100;
 147 
 148 // For diagnostics to print a message once. see run_periodic_checks
 149 static sigset_t check_signal_done;
 150 static bool check_signals = true;
 151 
 152 static pid_t _initial_pid = 0;
 153 
 154 // Signal number used to suspend/resume a thread
 155 
 156 // do not use any signal number less than SIGSEGV, see 4355769
 157 static int SR_signum = SIGUSR2;
 158 sigset_t SR_sigset;
 159 
 160 
 161 ////////////////////////////////////////////////////////////////////////////////
 162 // utility functions
 163 
 164 static int SR_initialize();
 165 
 166 julong os::available_memory() {
 167   return Bsd::available_memory();
 168 }
 169 
 170 // available here means free
 171 julong os::Bsd::available_memory() {
 172   uint64_t available = physical_memory() >> 2;
 173 #ifdef __APPLE__
 174   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
 175   vm_statistics64_data_t vmstat;
 176   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
 177                                          (host_info64_t)&vmstat, &count);
 178   assert(kerr == KERN_SUCCESS,
 179          "host_statistics64 failed - check mach_host_self() and count");
 180   if (kerr == KERN_SUCCESS) {
 181     available = vmstat.free_count * os::vm_page_size();
 182   }
 183 #endif
 184   return available;
 185 }
 186 
 187 julong os::physical_memory() {
 188   return Bsd::physical_memory();
 189 }
 190 
 191 // Return true if user is running as root.
 192 
 193 bool os::have_special_privileges() {
 194   static bool init = false;
 195   static bool privileges = false;
 196   if (!init) {
 197     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 198     init = true;
 199   }
 200   return privileges;
 201 }
 202 
 203 
 204 
 205 // Cpu architecture string
 206 #if   defined(ZERO)
 207 static char cpu_arch[] = ZERO_LIBARCH;
 208 #elif defined(IA64)
 209 static char cpu_arch[] = "ia64";
 210 #elif defined(IA32)
 211 static char cpu_arch[] = "i386";
 212 #elif defined(AMD64)
 213 static char cpu_arch[] = "amd64";
 214 #elif defined(ARM)
 215 static char cpu_arch[] = "arm";
 216 #elif defined(PPC32)
 217 static char cpu_arch[] = "ppc";
 218 #elif defined(SPARC)
 219   #ifdef _LP64
 220 static char cpu_arch[] = "sparcv9";
 221   #else
 222 static char cpu_arch[] = "sparc";
 223   #endif
 224 #else
 225   #error Add appropriate cpu_arch setting
 226 #endif
 227 
 228 // Compiler variant
 229 #ifdef COMPILER2
 230   #define COMPILER_VARIANT "server"
 231 #else
 232   #define COMPILER_VARIANT "client"
 233 #endif
 234 
 235 
 236 void os::Bsd::initialize_system_info() {
 237   int mib[2];
 238   size_t len;
 239   int cpu_val;
 240   julong mem_val;
 241 
 242   // get processors count via hw.ncpus sysctl
 243   mib[0] = CTL_HW;
 244   mib[1] = HW_NCPU;
 245   len = sizeof(cpu_val);
 246   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 247     assert(len == sizeof(cpu_val), "unexpected data size");
 248     set_processor_count(cpu_val);
 249   } else {
 250     set_processor_count(1);   // fallback
 251   }
 252 
 253   // get physical memory via hw.memsize sysctl (hw.memsize is used
 254   // since it returns a 64 bit value)
 255   mib[0] = CTL_HW;
 256 
 257 #if defined (HW_MEMSIZE) // Apple
 258   mib[1] = HW_MEMSIZE;
 259 #elif defined(HW_PHYSMEM) // Most of BSD
 260   mib[1] = HW_PHYSMEM;
 261 #elif defined(HW_REALMEM) // Old FreeBSD
 262   mib[1] = HW_REALMEM;
 263 #else
 264   #error No ways to get physmem
 265 #endif
 266 
 267   len = sizeof(mem_val);
 268   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 269     assert(len == sizeof(mem_val), "unexpected data size");
 270     _physical_memory = mem_val;
 271   } else {
 272     _physical_memory = 256 * 1024 * 1024;       // fallback (XXXBSD?)
 273   }
 274 
 275 #ifdef __OpenBSD__
 276   {
 277     // limit _physical_memory memory view on OpenBSD since
 278     // datasize rlimit restricts us anyway.
 279     struct rlimit limits;
 280     getrlimit(RLIMIT_DATA, &limits);
 281     _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 282   }
 283 #endif
 284 }
 285 
 286 #ifdef __APPLE__
 287 static const char *get_home() {
 288   const char *home_dir = ::getenv("HOME");
 289   if ((home_dir == NULL) || (*home_dir == '\0')) {
 290     struct passwd *passwd_info = getpwuid(geteuid());
 291     if (passwd_info != NULL) {
 292       home_dir = passwd_info->pw_dir;
 293     }
 294   }
 295 
 296   return home_dir;
 297 }
 298 #endif
 299 
 300 void os::init_system_properties_values() {
 301   // The next steps are taken in the product version:
 302   //
 303   // Obtain the JAVA_HOME value from the location of libjvm.so.
 304   // This library should be located at:
 305   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 306   //
 307   // If "/jre/lib/" appears at the right place in the path, then we
 308   // assume libjvm.so is installed in a JDK and we use this path.
 309   //
 310   // Otherwise exit with message: "Could not create the Java virtual machine."
 311   //
 312   // The following extra steps are taken in the debugging version:
 313   //
 314   // If "/jre/lib/" does NOT appear at the right place in the path
 315   // instead of exit check for $JAVA_HOME environment variable.
 316   //
 317   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 318   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 319   // it looks like libjvm.so is installed there
 320   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 321   //
 322   // Otherwise exit.
 323   //
 324   // Important note: if the location of libjvm.so changes this
 325   // code needs to be changed accordingly.
 326 
 327   // See ld(1):
 328   //      The linker uses the following search paths to locate required
 329   //      shared libraries:
 330   //        1: ...
 331   //        ...
 332   //        7: The default directories, normally /lib and /usr/lib.
 333 #ifndef DEFAULT_LIBPATH
 334   #define DEFAULT_LIBPATH "/lib:/usr/lib"
 335 #endif
 336 
 337 // Base path of extensions installed on the system.
 338 #define SYS_EXT_DIR     "/usr/java/packages"
 339 #define EXTENSIONS_DIR  "/lib/ext"
 340 
 341 #ifndef __APPLE__
 342 
 343   // Buffer that fits several sprintfs.
 344   // Note that the space for the colon and the trailing null are provided
 345   // by the nulls included by the sizeof operator.
 346   const size_t bufsize =
 347     MAX2((size_t)MAXPATHLEN,  // For dll_dir & friends.
 348          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
 349   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 350 
 351   // sysclasspath, java_home, dll_dir
 352   {
 353     char *pslash;
 354     os::jvm_path(buf, bufsize);
 355 
 356     // Found the full path to libjvm.so.
 357     // Now cut the path to <java_home>/jre if we can.
 358     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 359     pslash = strrchr(buf, '/');
 360     if (pslash != NULL) {
 361       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 362     }
 363     Arguments::set_dll_dir(buf);
 364 
 365     if (pslash != NULL) {
 366       pslash = strrchr(buf, '/');
 367       if (pslash != NULL) {
 368         *pslash = '\0';          // Get rid of /<arch>.
 369         pslash = strrchr(buf, '/');
 370         if (pslash != NULL) {
 371           *pslash = '\0';        // Get rid of /lib.
 372         }
 373       }
 374     }
 375     Arguments::set_java_home(buf);
 376     set_boot_path('/', ':');
 377   }
 378 
 379   // Where to look for native libraries.
 380   //
 381   // Note: Due to a legacy implementation, most of the library path
 382   // is set in the launcher. This was to accomodate linking restrictions
 383   // on legacy Bsd implementations (which are no longer supported).
 384   // Eventually, all the library path setting will be done here.
 385   //
 386   // However, to prevent the proliferation of improperly built native
 387   // libraries, the new path component /usr/java/packages is added here.
 388   // Eventually, all the library path setting will be done here.
 389   {
 390     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 391     // should always exist (until the legacy problem cited above is
 392     // addressed).
 393     const char *v = ::getenv("LD_LIBRARY_PATH");
 394     const char *v_colon = ":";
 395     if (v == NULL) { v = ""; v_colon = ""; }
 396     // That's +1 for the colon and +1 for the trailing '\0'.
 397     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 398                                                      strlen(v) + 1 +
 399                                                      sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
 400                                                      mtInternal);
 401     sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
 402     Arguments::set_library_path(ld_library_path);
 403     FREE_C_HEAP_ARRAY(char, ld_library_path);
 404   }
 405 
 406   // Extensions directories.
 407   sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
 408   Arguments::set_ext_dirs(buf);
 409 
 410   FREE_C_HEAP_ARRAY(char, buf);
 411 
 412 #else // __APPLE__
 413 
 414   #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 415   #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 416 
 417   const char *user_home_dir = get_home();
 418   // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
 419   size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 420     sizeof(SYS_EXTENSIONS_DIRS);
 421 
 422   // Buffer that fits several sprintfs.
 423   // Note that the space for the colon and the trailing null are provided
 424   // by the nulls included by the sizeof operator.
 425   const size_t bufsize =
 426     MAX2((size_t)MAXPATHLEN,  // for dll_dir & friends.
 427          (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
 428   char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
 429 
 430   // sysclasspath, java_home, dll_dir
 431   {
 432     char *pslash;
 433     os::jvm_path(buf, bufsize);
 434 
 435     // Found the full path to libjvm.so.
 436     // Now cut the path to <java_home>/jre if we can.
 437     *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
 438     pslash = strrchr(buf, '/');
 439     if (pslash != NULL) {
 440       *pslash = '\0';            // Get rid of /{client|server|hotspot}.
 441     }
 442 #ifdef STATIC_BUILD
 443     strcat(buf, "/lib");
 444 #endif
 445 
 446     Arguments::set_dll_dir(buf);
 447 
 448     if (pslash != NULL) {
 449       pslash = strrchr(buf, '/');
 450       if (pslash != NULL) {
 451         *pslash = '\0';          // Get rid of /lib.
 452       }
 453     }
 454     Arguments::set_java_home(buf);
 455     set_boot_path('/', ':');
 456   }
 457 
 458   // Where to look for native libraries.
 459   //
 460   // Note: Due to a legacy implementation, most of the library path
 461   // is set in the launcher. This was to accomodate linking restrictions
 462   // on legacy Bsd implementations (which are no longer supported).
 463   // Eventually, all the library path setting will be done here.
 464   //
 465   // However, to prevent the proliferation of improperly built native
 466   // libraries, the new path component /usr/java/packages is added here.
 467   // Eventually, all the library path setting will be done here.
 468   {
 469     // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
 470     // should always exist (until the legacy problem cited above is
 471     // addressed).
 472     // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
 473     // can specify a directory inside an app wrapper
 474     const char *l = ::getenv("JAVA_LIBRARY_PATH");
 475     const char *l_colon = ":";
 476     if (l == NULL) { l = ""; l_colon = ""; }
 477 
 478     const char *v = ::getenv("DYLD_LIBRARY_PATH");
 479     const char *v_colon = ":";
 480     if (v == NULL) { v = ""; v_colon = ""; }
 481 
 482     // Apple's Java6 has "." at the beginning of java.library.path.
 483     // OpenJDK on Windows has "." at the end of java.library.path.
 484     // OpenJDK on Linux and Solaris don't have "." in java.library.path
 485     // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 486     // "." is appended to the end of java.library.path. Yes, this
 487     // could cause a change in behavior, but Apple's Java6 behavior
 488     // can be achieved by putting "." at the beginning of the
 489     // JAVA_LIBRARY_PATH environment variable.
 490     char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
 491                                                      strlen(v) + 1 + strlen(l) + 1 +
 492                                                      system_ext_size + 3,
 493                                                      mtInternal);
 494     sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
 495             v, v_colon, l, l_colon, user_home_dir);
 496     Arguments::set_library_path(ld_library_path);
 497     FREE_C_HEAP_ARRAY(char, ld_library_path);
 498   }
 499 
 500   // Extensions directories.
 501   //
 502   // Note that the space for the colon and the trailing null are provided
 503   // by the nulls included by the sizeof operator (so actually one byte more
 504   // than necessary is allocated).
 505   sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
 506           user_home_dir, Arguments::get_java_home());
 507   Arguments::set_ext_dirs(buf);
 508 
 509   FREE_C_HEAP_ARRAY(char, buf);
 510 
 511 #undef SYS_EXTENSIONS_DIR
 512 #undef SYS_EXTENSIONS_DIRS
 513 
 514 #endif // __APPLE__
 515 
 516 #undef SYS_EXT_DIR
 517 #undef EXTENSIONS_DIR
 518 }
 519 
 520 ////////////////////////////////////////////////////////////////////////////////
 521 // breakpoint support
 522 
 523 void os::breakpoint() {
 524   BREAKPOINT;
 525 }
 526 
 527 extern "C" void breakpoint() {
 528   // use debugger to set breakpoint here
 529 }
 530 
 531 ////////////////////////////////////////////////////////////////////////////////
 532 // signal support
 533 
 534 debug_only(static bool signal_sets_initialized = false);
 535 static sigset_t unblocked_sigs, vm_sigs;
 536 
 537 bool os::Bsd::is_sig_ignored(int sig) {
 538   struct sigaction oact;
 539   sigaction(sig, (struct sigaction*)NULL, &oact);
 540   void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
 541                                  : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
 542   if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
 543     return true;
 544   } else {
 545     return false;
 546   }
 547 }
 548 
 549 void os::Bsd::signal_sets_init() {
 550   // Should also have an assertion stating we are still single-threaded.
 551   assert(!signal_sets_initialized, "Already initialized");
 552   // Fill in signals that are necessarily unblocked for all threads in
 553   // the VM. Currently, we unblock the following signals:
 554   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 555   //                         by -Xrs (=ReduceSignalUsage));
 556   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 557   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 558   // the dispositions or masks wrt these signals.
 559   // Programs embedding the VM that want to use the above signals for their
 560   // own purposes must, at this time, use the "-Xrs" option to prevent
 561   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 562   // (See bug 4345157, and other related bugs).
 563   // In reality, though, unblocking these signals is really a nop, since
 564   // these signals are not blocked by default.
 565   sigemptyset(&unblocked_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 
 576     }
 577     if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 578       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 579     }
 580     if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 581       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 582     }
 583   }
 584   // Fill in signals that are blocked by all but the VM thread.
 585   sigemptyset(&vm_sigs);
 586   if (!ReduceSignalUsage) {
 587     sigaddset(&vm_sigs, BREAK_SIGNAL);
 588   }
 589   debug_only(signal_sets_initialized = true);
 590 
 591 }
 592 
 593 // These are signals that are unblocked while a thread is running Java.
 594 // (For some reason, they get blocked by default.)
 595 sigset_t* os::Bsd::unblocked_signals() {
 596   assert(signal_sets_initialized, "Not initialized");
 597   return &unblocked_sigs;
 598 }
 599 
 600 // These are the signals that are blocked while a (non-VM) thread is
 601 // running Java. Only the VM thread handles these signals.
 602 sigset_t* os::Bsd::vm_signals() {
 603   assert(signal_sets_initialized, "Not initialized");
 604   return &vm_sigs;
 605 }
 606 
 607 void os::Bsd::hotspot_sigmask(Thread* thread) {
 608 
 609   //Save caller's signal mask before setting VM signal mask
 610   sigset_t caller_sigmask;
 611   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 612 
 613   OSThread* osthread = thread->osthread();
 614   osthread->set_caller_sigmask(caller_sigmask);
 615 
 616   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 617 
 618   if (!ReduceSignalUsage) {
 619     if (thread->is_VM_thread()) {
 620       // Only the VM thread handles BREAK_SIGNAL ...
 621       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 622     } else {
 623       // ... all other threads block BREAK_SIGNAL
 624       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 625     }
 626   }
 627 }
 628 
 629 
 630 //////////////////////////////////////////////////////////////////////////////
 631 // create new thread
 632 
 633 #ifdef __APPLE__
 634 // library handle for calling objc_registerThreadWithCollector()
 635 // without static linking to the libobjc library
 636   #define OBJC_LIB "/usr/lib/libobjc.dylib"
 637   #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 638 typedef void (*objc_registerThreadWithCollector_t)();
 639 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 640 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 641 #endif
 642 
 643 #ifdef __APPLE__
 644 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 645   // Additional thread_id used to correlate threads in SA
 646   thread_identifier_info_data_t     m_ident_info;
 647   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 648 
 649   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 650               (thread_info_t) &m_ident_info, &count);
 651 
 652   return m_ident_info.thread_id;
 653 }
 654 #endif
 655 
 656 // Thread start routine for all newly created threads
 657 static void *thread_native_entry(Thread *thread) {
 658   // Try to randomize the cache line index of hot stack frames.
 659   // This helps when threads of the same stack traces evict each other's
 660   // cache lines. The threads can be either from the same JVM instance, or
 661   // from different JVM instances. The benefit is especially true for
 662   // processors with hyperthreading technology.
 663   static int counter = 0;
 664   int pid = os::current_process_id();
 665   alloca(((pid ^ counter++) & 7) * 128);
 666 
 667   thread->initialize_thread_current();
 668 
 669   OSThread* osthread = thread->osthread();
 670   Monitor* sync = osthread->startThread_lock();
 671 
 672   osthread->set_thread_id(os::Bsd::gettid());
 673 
 674   log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 675     os::current_thread_id(), (uintx) pthread_self());
 676 
 677 #ifdef __APPLE__
 678   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 679   guarantee(unique_thread_id != 0, "unique thread id was not found");
 680   osthread->set_unique_thread_id(unique_thread_id);
 681 #endif
 682   // initialize signal mask for this thread
 683   os::Bsd::hotspot_sigmask(thread);
 684 
 685   // initialize floating point control register
 686   os::Bsd::init_thread_fpu_state();
 687 
 688 #ifdef __APPLE__
 689   // register thread with objc gc
 690   if (objc_registerThreadWithCollectorFunction != NULL) {
 691     objc_registerThreadWithCollectorFunction();
 692   }
 693 #endif
 694 
 695   // handshaking with parent thread
 696   {
 697     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 698 
 699     // notify parent thread
 700     osthread->set_state(INITIALIZED);
 701     sync->notify_all();
 702 
 703     // wait until os::start_thread()
 704     while (osthread->get_state() == INITIALIZED) {
 705       sync->wait(Mutex::_no_safepoint_check_flag);
 706     }
 707   }
 708 
 709   // call one more level start routine
 710   thread->run();
 711 
 712   log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 713     os::current_thread_id(), (uintx) pthread_self());
 714 
 715   // If a thread has not deleted itself ("delete this") as part of its
 716   // termination sequence, we have to ensure thread-local-storage is
 717   // cleared before we actually terminate. No threads should ever be
 718   // deleted asynchronously with respect to their termination.
 719   if (Thread::current_or_null_safe() != NULL) {
 720     assert(Thread::current_or_null_safe() == thread, "current thread is wrong");
 721     thread->clear_thread_current();
 722   }
 723 
 724   return 0;
 725 }
 726 
 727 bool os::create_thread(Thread* thread, ThreadType thr_type,
 728                        size_t req_stack_size) {
 729   assert(thread->osthread() == NULL, "caller responsible");
 730 
 731   // Allocate the OSThread object
 732   OSThread* osthread = new OSThread(NULL, NULL);
 733   if (osthread == NULL) {
 734     return false;
 735   }
 736 
 737   // set the correct thread state
 738   osthread->set_thread_type(thr_type);
 739 
 740   // Initial state is ALLOCATED but not INITIALIZED
 741   osthread->set_state(ALLOCATED);
 742 
 743   thread->set_osthread(osthread);
 744 
 745   // init thread attributes
 746   pthread_attr_t attr;
 747   pthread_attr_init(&attr);
 748   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 749 
 750   // calculate stack size if it's not specified by caller
 751   size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
 752   int status = pthread_attr_setstacksize(&attr, stack_size);
 753   assert_status(status == 0, status, "pthread_attr_setstacksize");
 754 
 755   ThreadState state;
 756 
 757   {
 758     pthread_t tid;
 759     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
 760 
 761     char buf[64];
 762     if (ret == 0) {
 763       log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
 764         (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 765     } else {
 766       log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
 767         os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
 768     }
 769 
 770     pthread_attr_destroy(&attr);
 771 
 772     if (ret != 0) {
 773       // Need to clean up stuff we've allocated so far
 774       thread->set_osthread(NULL);
 775       delete osthread;
 776       return false;
 777     }
 778 
 779     // Store pthread info into the OSThread
 780     osthread->set_pthread_id(tid);
 781 
 782     // Wait until child thread is either initialized or aborted
 783     {
 784       Monitor* sync_with_child = osthread->startThread_lock();
 785       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 786       while ((state = osthread->get_state()) == ALLOCATED) {
 787         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 788       }
 789     }
 790 
 791   }
 792 
 793   // Aborted due to thread limit being reached
 794   if (state == ZOMBIE) {
 795     thread->set_osthread(NULL);
 796     delete osthread;
 797     return false;
 798   }
 799 
 800   // The thread is returned suspended (in state INITIALIZED),
 801   // and is started higher up in the call chain
 802   assert(state == INITIALIZED, "race condition");
 803   return true;
 804 }
 805 
 806 /////////////////////////////////////////////////////////////////////////////
 807 // attach existing thread
 808 
 809 // bootstrap the main thread
 810 bool os::create_main_thread(JavaThread* thread) {
 811   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 812   return create_attached_thread(thread);
 813 }
 814 
 815 bool os::create_attached_thread(JavaThread* thread) {
 816 #ifdef ASSERT
 817   thread->verify_not_published();
 818 #endif
 819 
 820   // Allocate the OSThread object
 821   OSThread* osthread = new OSThread(NULL, NULL);
 822 
 823   if (osthread == NULL) {
 824     return false;
 825   }
 826 
 827   osthread->set_thread_id(os::Bsd::gettid());
 828 
 829   // Store pthread info into the OSThread
 830 #ifdef __APPLE__
 831   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 832   guarantee(unique_thread_id != 0, "just checking");
 833   osthread->set_unique_thread_id(unique_thread_id);
 834 #endif
 835   osthread->set_pthread_id(::pthread_self());
 836 
 837   // initialize floating point control register
 838   os::Bsd::init_thread_fpu_state();
 839 
 840   // Initial thread state is RUNNABLE
 841   osthread->set_state(RUNNABLE);
 842 
 843   thread->set_osthread(osthread);
 844 
 845   // initialize signal mask for this thread
 846   // and save the caller's signal mask
 847   os::Bsd::hotspot_sigmask(thread);
 848 
 849   log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
 850     os::current_thread_id(), (uintx) pthread_self());
 851 
 852   return true;
 853 }
 854 
 855 void os::pd_start_thread(Thread* thread) {
 856   OSThread * osthread = thread->osthread();
 857   assert(osthread->get_state() != INITIALIZED, "just checking");
 858   Monitor* sync_with_child = osthread->startThread_lock();
 859   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 860   sync_with_child->notify();
 861 }
 862 
 863 // Free Bsd resources related to the OSThread
 864 void os::free_thread(OSThread* osthread) {
 865   assert(osthread != NULL, "osthread not set");
 866 
 867   // We are told to free resources of the argument thread,
 868   // but we can only really operate on the current thread.
 869   assert(Thread::current()->osthread() == osthread,
 870          "os::free_thread but not current thread");
 871 
 872   // Restore caller's signal mask
 873   sigset_t sigmask = osthread->caller_sigmask();
 874   pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 875 
 876   delete osthread;
 877 }
 878 
 879 ////////////////////////////////////////////////////////////////////////////////
 880 // time support
 881 
 882 // Time since start-up in seconds to a fine granularity.
 883 // Used by VMSelfDestructTimer and the MemProfiler.
 884 double os::elapsedTime() {
 885 
 886   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 887 }
 888 
 889 jlong os::elapsed_counter() {
 890   return javaTimeNanos() - initial_time_count;
 891 }
 892 
 893 jlong os::elapsed_frequency() {
 894   return NANOSECS_PER_SEC; // nanosecond resolution
 895 }
 896 
 897 bool os::supports_vtime() { return true; }
 898 bool os::enable_vtime()   { return false; }
 899 bool os::vtime_enabled()  { return false; }
 900 
 901 double os::elapsedVTime() {
 902   // better than nothing, but not much
 903   return elapsedTime();
 904 }
 905 
 906 jlong os::javaTimeMillis() {
 907   timeval time;
 908   int status = gettimeofday(&time, NULL);
 909   assert(status != -1, "bsd error");
 910   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 911 }
 912 
 913 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
 914   timeval time;
 915   int status = gettimeofday(&time, NULL);
 916   assert(status != -1, "bsd error");
 917   seconds = jlong(time.tv_sec);
 918   nanos = jlong(time.tv_usec) * 1000;
 919 }
 920 
 921 #ifndef __APPLE__
 922   #ifndef CLOCK_MONOTONIC
 923     #define CLOCK_MONOTONIC (1)
 924   #endif
 925 #endif
 926 
 927 #ifdef __APPLE__
 928 void os::Bsd::clock_init() {
 929   mach_timebase_info(&_timebase_info);
 930 }
 931 #else
 932 void os::Bsd::clock_init() {
 933   struct timespec res;
 934   struct timespec tp;
 935   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
 936       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
 937     // yes, monotonic clock is supported
 938     _clock_gettime = ::clock_gettime;
 939   }
 940 }
 941 #endif
 942 
 943 
 944 
 945 #ifdef __APPLE__
 946 
 947 jlong os::javaTimeNanos() {
 948   const uint64_t tm = mach_absolute_time();
 949   const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
 950   const uint64_t prev = Bsd::_max_abstime;
 951   if (now <= prev) {
 952     return prev;   // same or retrograde time;
 953   }
 954   const uint64_t obsv = Atomic::cmpxchg(now, &Bsd::_max_abstime, prev);
 955   assert(obsv >= prev, "invariant");   // Monotonicity
 956   // If the CAS succeeded then we're done and return "now".
 957   // If the CAS failed and the observed value "obsv" is >= now then
 958   // we should return "obsv".  If the CAS failed and now > obsv > prv then
 959   // some other thread raced this thread and installed a new value, in which case
 960   // we could either (a) retry the entire operation, (b) retry trying to install now
 961   // or (c) just return obsv.  We use (c).   No loop is required although in some cases
 962   // we might discard a higher "now" value in deference to a slightly lower but freshly
 963   // installed obsv value.   That's entirely benign -- it admits no new orderings compared
 964   // to (a) or (b) -- and greatly reduces coherence traffic.
 965   // We might also condition (c) on the magnitude of the delta between obsv and now.
 966   // Avoiding excessive CAS operations to hot RW locations is critical.
 967   // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
 968   return (prev == obsv) ? now : obsv;
 969 }
 970 
 971 #else // __APPLE__
 972 
 973 jlong os::javaTimeNanos() {
 974   if (os::supports_monotonic_clock()) {
 975     struct timespec tp;
 976     int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
 977     assert(status == 0, "gettime error");
 978     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
 979     return result;
 980   } else {
 981     timeval time;
 982     int status = gettimeofday(&time, NULL);
 983     assert(status != -1, "bsd error");
 984     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
 985     return 1000 * usecs;
 986   }
 987 }
 988 
 989 #endif // __APPLE__
 990 
 991 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
 992   if (os::supports_monotonic_clock()) {
 993     info_ptr->max_value = ALL_64_BITS;
 994 
 995     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
 996     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
 997     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
 998   } else {
 999     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1000     info_ptr->max_value = ALL_64_BITS;
1001 
1002     // gettimeofday is a real time clock so it skips
1003     info_ptr->may_skip_backward = true;
1004     info_ptr->may_skip_forward = true;
1005   }
1006 
1007   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
1008 }
1009 
1010 // Return the real, user, and system times in seconds from an
1011 // arbitrary fixed point in the past.
1012 bool os::getTimesSecs(double* process_real_time,
1013                       double* process_user_time,
1014                       double* process_system_time) {
1015   struct tms ticks;
1016   clock_t real_ticks = times(&ticks);
1017 
1018   if (real_ticks == (clock_t) (-1)) {
1019     return false;
1020   } else {
1021     double ticks_per_second = (double) clock_tics_per_sec;
1022     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1023     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1024     *process_real_time = ((double) real_ticks) / ticks_per_second;
1025 
1026     return true;
1027   }
1028 }
1029 
1030 
1031 char * os::local_time_string(char *buf, size_t buflen) {
1032   struct tm t;
1033   time_t long_time;
1034   time(&long_time);
1035   localtime_r(&long_time, &t);
1036   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1037                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1038                t.tm_hour, t.tm_min, t.tm_sec);
1039   return buf;
1040 }
1041 
1042 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1043   return localtime_r(clock, res);
1044 }
1045 
1046 ////////////////////////////////////////////////////////////////////////////////
1047 // runtime exit support
1048 
1049 // Note: os::shutdown() might be called very early during initialization, or
1050 // called from signal handler. Before adding something to os::shutdown(), make
1051 // sure it is async-safe and can handle partially initialized VM.
1052 void os::shutdown() {
1053 
1054   // allow PerfMemory to attempt cleanup of any persistent resources
1055   perfMemory_exit();
1056 
1057   // needs to remove object in file system
1058   AttachListener::abort();
1059 
1060   // flush buffered output, finish log files
1061   ostream_abort();
1062 
1063   // Check for abort hook
1064   abort_hook_t abort_hook = Arguments::abort_hook();
1065   if (abort_hook != NULL) {
1066     abort_hook();
1067   }
1068 
1069 }
1070 
1071 // Note: os::abort() might be called very early during initialization, or
1072 // called from signal handler. Before adding something to os::abort(), make
1073 // sure it is async-safe and can handle partially initialized VM.
1074 void os::abort(bool dump_core, void* siginfo, const void* context) {
1075   os::shutdown();
1076   if (dump_core) {
1077 #ifndef PRODUCT
1078     fdStream out(defaultStream::output_fd());
1079     out.print_raw("Current thread is ");
1080     char buf[16];
1081     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1082     out.print_raw_cr(buf);
1083     out.print_raw_cr("Dumping core ...");
1084 #endif
1085     ::abort(); // dump core
1086   }
1087 
1088   ::exit(1);
1089 }
1090 
1091 // Die immediately, no exit hook, no abort hook, no cleanup.
1092 void os::die() {
1093   // _exit() on BsdThreads only kills current thread
1094   ::abort();
1095 }
1096 
1097 // This method is a copy of JDK's sysGetLastErrorString
1098 // from src/solaris/hpi/src/system_md.c
1099 
1100 size_t os::lasterror(char *buf, size_t len) {
1101   if (errno == 0)  return 0;
1102 
1103   const char *s = os::strerror(errno);
1104   size_t n = ::strlen(s);
1105   if (n >= len) {
1106     n = len - 1;
1107   }
1108   ::strncpy(buf, s, n);
1109   buf[n] = '\0';
1110   return n;
1111 }
1112 
1113 // Information of current thread in variety of formats
1114 pid_t os::Bsd::gettid() {
1115   int retval = -1;
1116 
1117 #ifdef __APPLE__ //XNU kernel
1118   // despite the fact mach port is actually not a thread id use it
1119   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1120   retval = ::pthread_mach_thread_np(::pthread_self());
1121   guarantee(retval != 0, "just checking");
1122   return retval;
1123 
1124 #else
1125   #ifdef __FreeBSD__
1126   retval = syscall(SYS_thr_self);
1127   #else
1128     #ifdef __OpenBSD__
1129   retval = syscall(SYS_getthrid);
1130     #else
1131       #ifdef __NetBSD__
1132   retval = (pid_t) syscall(SYS__lwp_self);
1133       #endif
1134     #endif
1135   #endif
1136 #endif
1137 
1138   if (retval == -1) {
1139     return getpid();
1140   }
1141 }
1142 
1143 intx os::current_thread_id() {
1144 #ifdef __APPLE__
1145   return (intx)::pthread_mach_thread_np(::pthread_self());
1146 #else
1147   return (intx)::pthread_self();
1148 #endif
1149 }
1150 
1151 int os::current_process_id() {
1152 
1153   // Under the old bsd thread library, bsd gives each thread
1154   // its own process id. Because of this each thread will return
1155   // a different pid if this method were to return the result
1156   // of getpid(2). Bsd provides no api that returns the pid
1157   // of the launcher thread for the vm. This implementation
1158   // returns a unique pid, the pid of the launcher thread
1159   // that starts the vm 'process'.
1160 
1161   // Under the NPTL, getpid() returns the same pid as the
1162   // launcher thread rather than a unique pid per thread.
1163   // Use gettid() if you want the old pre NPTL behaviour.
1164 
1165   // if you are looking for the result of a call to getpid() that
1166   // returns a unique pid for the calling thread, then look at the
1167   // OSThread::thread_id() method in osThread_bsd.hpp file
1168 
1169   return (int)(_initial_pid ? _initial_pid : getpid());
1170 }
1171 
1172 // DLL functions
1173 
1174 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1175 
1176 // This must be hard coded because it's the system's temporary
1177 // directory not the java application's temp directory, ala java.io.tmpdir.
1178 #ifdef __APPLE__
1179 // macosx has a secure per-user temporary directory
1180 char temp_path_storage[PATH_MAX];
1181 const char* os::get_temp_directory() {
1182   static char *temp_path = NULL;
1183   if (temp_path == NULL) {
1184     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1185     if (pathSize == 0 || pathSize > PATH_MAX) {
1186       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1187     }
1188     temp_path = temp_path_storage;
1189   }
1190   return temp_path;
1191 }
1192 #else // __APPLE__
1193 const char* os::get_temp_directory() { return "/tmp"; }
1194 #endif // __APPLE__
1195 
1196 // check if addr is inside libjvm.so
1197 bool os::address_is_in_vm(address addr) {
1198   static address libjvm_base_addr;
1199   Dl_info dlinfo;
1200 
1201   if (libjvm_base_addr == NULL) {
1202     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1203       libjvm_base_addr = (address)dlinfo.dli_fbase;
1204     }
1205     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1206   }
1207 
1208   if (dladdr((void *)addr, &dlinfo) != 0) {
1209     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1210   }
1211 
1212   return false;
1213 }
1214 
1215 
1216 #define MACH_MAXSYMLEN 256
1217 
1218 bool os::dll_address_to_function_name(address addr, char *buf,
1219                                       int buflen, int *offset,
1220                                       bool demangle) {
1221   // buf is not optional, but offset is optional
1222   assert(buf != NULL, "sanity check");
1223 
1224   Dl_info dlinfo;
1225   char localbuf[MACH_MAXSYMLEN];
1226 
1227   if (dladdr((void*)addr, &dlinfo) != 0) {
1228     // see if we have a matching symbol
1229     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1230       if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1231         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1232       }
1233       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1234       return true;
1235     }
1236     // no matching symbol so try for just file info
1237     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1238       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1239                           buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1240         return true;
1241       }
1242     }
1243 
1244     // Handle non-dynamic manually:
1245     if (dlinfo.dli_fbase != NULL &&
1246         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1247                         dlinfo.dli_fbase)) {
1248       if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) {
1249         jio_snprintf(buf, buflen, "%s", localbuf);
1250       }
1251       return true;
1252     }
1253   }
1254   buf[0] = '\0';
1255   if (offset != NULL) *offset = -1;
1256   return false;
1257 }
1258 
1259 // ported from solaris version
1260 bool os::dll_address_to_library_name(address addr, char* buf,
1261                                      int buflen, int* offset) {
1262   // buf is not optional, but offset is optional
1263   assert(buf != NULL, "sanity check");
1264 
1265   Dl_info dlinfo;
1266 
1267   if (dladdr((void*)addr, &dlinfo) != 0) {
1268     if (dlinfo.dli_fname != NULL) {
1269       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1270     }
1271     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1272       *offset = addr - (address)dlinfo.dli_fbase;
1273     }
1274     return true;
1275   }
1276 
1277   buf[0] = '\0';
1278   if (offset) *offset = -1;
1279   return false;
1280 }
1281 
1282 // Loads .dll/.so and
1283 // in case of error it checks if .dll/.so was built for the
1284 // same architecture as Hotspot is running on
1285 
1286 #ifdef __APPLE__
1287 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1288 #ifdef STATIC_BUILD
1289   return os::get_default_process_handle();
1290 #else
1291   void * result= ::dlopen(filename, RTLD_LAZY);
1292   if (result != NULL) {
1293     // Successful loading
1294     return result;
1295   }
1296 
1297   // Read system error message into ebuf
1298   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1299   ebuf[ebuflen-1]='\0';
1300 
1301   return NULL;
1302 #endif // STATIC_BUILD
1303 }
1304 #else
1305 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1306 #ifdef STATIC_BUILD
1307   return os::get_default_process_handle();
1308 #else
1309   void * result= ::dlopen(filename, RTLD_LAZY);
1310   if (result != NULL) {
1311     // Successful loading
1312     return result;
1313   }
1314 
1315   Elf32_Ehdr elf_head;
1316 
1317   // Read system error message into ebuf
1318   // It may or may not be overwritten below
1319   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1320   ebuf[ebuflen-1]='\0';
1321   int diag_msg_max_length=ebuflen-strlen(ebuf);
1322   char* diag_msg_buf=ebuf+strlen(ebuf);
1323 
1324   if (diag_msg_max_length==0) {
1325     // No more space in ebuf for additional diagnostics message
1326     return NULL;
1327   }
1328 
1329 
1330   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1331 
1332   if (file_descriptor < 0) {
1333     // Can't open library, report dlerror() message
1334     return NULL;
1335   }
1336 
1337   bool failed_to_read_elf_head=
1338     (sizeof(elf_head)!=
1339      (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1340 
1341   ::close(file_descriptor);
1342   if (failed_to_read_elf_head) {
1343     // file i/o error - report dlerror() msg
1344     return NULL;
1345   }
1346 
1347   typedef struct {
1348     Elf32_Half  code;         // Actual value as defined in elf.h
1349     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1350     char        elf_class;    // 32 or 64 bit
1351     char        endianess;    // MSB or LSB
1352     char*       name;         // String representation
1353   } arch_t;
1354 
1355   #ifndef EM_486
1356     #define EM_486          6               /* Intel 80486 */
1357   #endif
1358 
1359   #ifndef EM_MIPS_RS3_LE
1360     #define EM_MIPS_RS3_LE  10              /* MIPS */
1361   #endif
1362 
1363   #ifndef EM_PPC64
1364     #define EM_PPC64        21              /* PowerPC64 */
1365   #endif
1366 
1367   #ifndef EM_S390
1368     #define EM_S390         22              /* IBM System/390 */
1369   #endif
1370 
1371   #ifndef EM_IA_64
1372     #define EM_IA_64        50              /* HP/Intel IA-64 */
1373   #endif
1374 
1375   #ifndef EM_X86_64
1376     #define EM_X86_64       62              /* AMD x86-64 */
1377   #endif
1378 
1379   static const arch_t arch_array[]={
1380     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1381     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1382     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1383     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1384     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1385     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1386     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1387     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1388     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1389     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1390     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1391     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1392     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1393     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1394     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1395     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1396   };
1397 
1398   #if  (defined IA32)
1399   static  Elf32_Half running_arch_code=EM_386;
1400   #elif   (defined AMD64)
1401   static  Elf32_Half running_arch_code=EM_X86_64;
1402   #elif  (defined IA64)
1403   static  Elf32_Half running_arch_code=EM_IA_64;
1404   #elif  (defined __sparc) && (defined _LP64)
1405   static  Elf32_Half running_arch_code=EM_SPARCV9;
1406   #elif  (defined __sparc) && (!defined _LP64)
1407   static  Elf32_Half running_arch_code=EM_SPARC;
1408   #elif  (defined __powerpc64__)
1409   static  Elf32_Half running_arch_code=EM_PPC64;
1410   #elif  (defined __powerpc__)
1411   static  Elf32_Half running_arch_code=EM_PPC;
1412   #elif  (defined ARM)
1413   static  Elf32_Half running_arch_code=EM_ARM;
1414   #elif  (defined S390)
1415   static  Elf32_Half running_arch_code=EM_S390;
1416   #elif  (defined ALPHA)
1417   static  Elf32_Half running_arch_code=EM_ALPHA;
1418   #elif  (defined MIPSEL)
1419   static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1420   #elif  (defined PARISC)
1421   static  Elf32_Half running_arch_code=EM_PARISC;
1422   #elif  (defined MIPS)
1423   static  Elf32_Half running_arch_code=EM_MIPS;
1424   #elif  (defined M68K)
1425   static  Elf32_Half running_arch_code=EM_68K;
1426   #else
1427     #error Method os::dll_load requires that one of following is defined:\
1428          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1429   #endif
1430 
1431   // Identify compatability class for VM's architecture and library's architecture
1432   // Obtain string descriptions for architectures
1433 
1434   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1435   int running_arch_index=-1;
1436 
1437   for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1438     if (running_arch_code == arch_array[i].code) {
1439       running_arch_index    = i;
1440     }
1441     if (lib_arch.code == arch_array[i].code) {
1442       lib_arch.compat_class = arch_array[i].compat_class;
1443       lib_arch.name         = arch_array[i].name;
1444     }
1445   }
1446 
1447   assert(running_arch_index != -1,
1448          "Didn't find running architecture code (running_arch_code) in arch_array");
1449   if (running_arch_index == -1) {
1450     // Even though running architecture detection failed
1451     // we may still continue with reporting dlerror() message
1452     return NULL;
1453   }
1454 
1455   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1456     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1457     return NULL;
1458   }
1459 
1460 #ifndef S390
1461   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1462     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1463     return NULL;
1464   }
1465 #endif // !S390
1466 
1467   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1468     if (lib_arch.name!=NULL) {
1469       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1470                  " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1471                  lib_arch.name, arch_array[running_arch_index].name);
1472     } else {
1473       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1474                  " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1475                  lib_arch.code,
1476                  arch_array[running_arch_index].name);
1477     }
1478   }
1479 
1480   return NULL;
1481 #endif // STATIC_BUILD
1482 }
1483 #endif // !__APPLE__
1484 
1485 void* os::get_default_process_handle() {
1486 #ifdef __APPLE__
1487   // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1488   // to avoid finding unexpected symbols on second (or later)
1489   // loads of a library.
1490   return (void*)::dlopen(NULL, RTLD_FIRST);
1491 #else
1492   return (void*)::dlopen(NULL, RTLD_LAZY);
1493 #endif
1494 }
1495 
1496 // XXX: Do we need a lock around this as per Linux?
1497 void* os::dll_lookup(void* handle, const char* name) {
1498   return dlsym(handle, name);
1499 }
1500 
1501 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1502   outputStream * out = (outputStream *) param;
1503   out->print_cr(INTPTR_FORMAT " \t%s", (intptr_t)base_address, name);
1504   return 0;
1505 }
1506 
1507 void os::print_dll_info(outputStream *st) {
1508   st->print_cr("Dynamic libraries:");
1509   if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1510     st->print_cr("Error: Cannot print dynamic libraries.");
1511   }
1512 }
1513 
1514 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1515 #ifdef RTLD_DI_LINKMAP
1516   Dl_info dli;
1517   void *handle;
1518   Link_map *map;
1519   Link_map *p;
1520 
1521   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1522       dli.dli_fname == NULL) {
1523     return 1;
1524   }
1525   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1526   if (handle == NULL) {
1527     return 1;
1528   }
1529   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1530   if (map == NULL) {
1531     dlclose(handle);
1532     return 1;
1533   }
1534 
1535   while (map->l_prev != NULL)
1536     map = map->l_prev;
1537 
1538   while (map != NULL) {
1539     // Value for top_address is returned as 0 since we don't have any information about module size
1540     if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1541       dlclose(handle);
1542       return 1;
1543     }
1544     map = map->l_next;
1545   }
1546 
1547   dlclose(handle);
1548 #elif defined(__APPLE__)
1549   for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1550     // Value for top_address is returned as 0 since we don't have any information about module size
1551     if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1552       return 1;
1553     }
1554   }
1555   return 0;
1556 #else
1557   return 1;
1558 #endif
1559 }
1560 
1561 void os::get_summary_os_info(char* buf, size_t buflen) {
1562   // These buffers are small because we want this to be brief
1563   // and not use a lot of stack while generating the hs_err file.
1564   char os[100];
1565   size_t size = sizeof(os);
1566   int mib_kern[] = { CTL_KERN, KERN_OSTYPE };
1567   if (sysctl(mib_kern, 2, os, &size, NULL, 0) < 0) {
1568 #ifdef __APPLE__
1569       strncpy(os, "Darwin", sizeof(os));
1570 #elif __OpenBSD__
1571       strncpy(os, "OpenBSD", sizeof(os));
1572 #else
1573       strncpy(os, "BSD", sizeof(os));
1574 #endif
1575   }
1576 
1577   char release[100];
1578   size = sizeof(release);
1579   int mib_release[] = { CTL_KERN, KERN_OSRELEASE };
1580   if (sysctl(mib_release, 2, release, &size, NULL, 0) < 0) {
1581       // if error, leave blank
1582       strncpy(release, "", sizeof(release));
1583   }
1584   snprintf(buf, buflen, "%s %s", os, release);
1585 }
1586 
1587 void os::print_os_info_brief(outputStream* st) {
1588   os::Posix::print_uname_info(st);
1589 }
1590 
1591 void os::print_os_info(outputStream* st) {
1592   st->print("OS:");
1593 
1594   os::Posix::print_uname_info(st);
1595 
1596   os::Posix::print_rlimit_info(st);
1597 
1598   os::Posix::print_load_average(st);
1599 }
1600 
1601 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1602   // Nothing to do for now.
1603 }
1604 
1605 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1606   unsigned int mhz;
1607   size_t size = sizeof(mhz);
1608   int mib[] = { CTL_HW, HW_CPU_FREQ };
1609   if (sysctl(mib, 2, &mhz, &size, NULL, 0) < 0) {
1610     mhz = 1;  // looks like an error but can be divided by
1611   } else {
1612     mhz /= 1000000;  // reported in millions
1613   }
1614 
1615   char model[100];
1616   size = sizeof(model);
1617   int mib_model[] = { CTL_HW, HW_MODEL };
1618   if (sysctl(mib_model, 2, model, &size, NULL, 0) < 0) {
1619     strncpy(model, cpu_arch, sizeof(model));
1620   }
1621 
1622   char machine[100];
1623   size = sizeof(machine);
1624   int mib_machine[] = { CTL_HW, HW_MACHINE };
1625   if (sysctl(mib_machine, 2, machine, &size, NULL, 0) < 0) {
1626       strncpy(machine, "", sizeof(machine));
1627   }
1628 
1629   snprintf(buf, buflen, "%s %s %d MHz", model, machine, mhz);
1630 }
1631 
1632 void os::print_memory_info(outputStream* st) {
1633 
1634   st->print("Memory:");
1635   st->print(" %dk page", os::vm_page_size()>>10);
1636 
1637   st->print(", physical " UINT64_FORMAT "k",
1638             os::physical_memory() >> 10);
1639   st->print("(" UINT64_FORMAT "k free)",
1640             os::available_memory() >> 10);
1641   st->cr();
1642 }
1643 
1644 static void print_signal_handler(outputStream* st, int sig,
1645                                  char* buf, size_t buflen);
1646 
1647 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1648   st->print_cr("Signal Handlers:");
1649   print_signal_handler(st, SIGSEGV, buf, buflen);
1650   print_signal_handler(st, SIGBUS , buf, buflen);
1651   print_signal_handler(st, SIGFPE , buf, buflen);
1652   print_signal_handler(st, SIGPIPE, buf, buflen);
1653   print_signal_handler(st, SIGXFSZ, buf, buflen);
1654   print_signal_handler(st, SIGILL , buf, buflen);
1655   print_signal_handler(st, SR_signum, buf, buflen);
1656   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1657   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1658   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1659   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1660 }
1661 
1662 static char saved_jvm_path[MAXPATHLEN] = {0};
1663 
1664 // Find the full path to the current module, libjvm
1665 void os::jvm_path(char *buf, jint buflen) {
1666   // Error checking.
1667   if (buflen < MAXPATHLEN) {
1668     assert(false, "must use a large-enough buffer");
1669     buf[0] = '\0';
1670     return;
1671   }
1672   // Lazy resolve the path to current module.
1673   if (saved_jvm_path[0] != 0) {
1674     strcpy(buf, saved_jvm_path);
1675     return;
1676   }
1677 
1678   char dli_fname[MAXPATHLEN];
1679   bool ret = dll_address_to_library_name(
1680                                          CAST_FROM_FN_PTR(address, os::jvm_path),
1681                                          dli_fname, sizeof(dli_fname), NULL);
1682   assert(ret, "cannot locate libjvm");
1683   char *rp = NULL;
1684   if (ret && dli_fname[0] != '\0') {
1685     rp = os::Posix::realpath(dli_fname, buf, buflen);
1686   }
1687   if (rp == NULL) {
1688     return;
1689   }
1690 
1691   if (Arguments::sun_java_launcher_is_altjvm()) {
1692     // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1693     // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1694     // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1695     // appears at the right place in the string, then assume we are
1696     // installed in a JDK and we're done. Otherwise, check for a
1697     // JAVA_HOME environment variable and construct a path to the JVM
1698     // being overridden.
1699 
1700     const char *p = buf + strlen(buf) - 1;
1701     for (int count = 0; p > buf && count < 5; ++count) {
1702       for (--p; p > buf && *p != '/'; --p)
1703         /* empty */ ;
1704     }
1705 
1706     if (strncmp(p, "/jre/lib/", 9) != 0) {
1707       // Look for JAVA_HOME in the environment.
1708       char* java_home_var = ::getenv("JAVA_HOME");
1709       if (java_home_var != NULL && java_home_var[0] != 0) {
1710         char* jrelib_p;
1711         int len;
1712 
1713         // Check the current module name "libjvm"
1714         p = strrchr(buf, '/');
1715         assert(strstr(p, "/libjvm") == p, "invalid library name");
1716 
1717         rp = os::Posix::realpath(java_home_var, buf, buflen);
1718         if (rp == NULL) {
1719           return;
1720         }
1721 
1722         // determine if this is a legacy image or modules image
1723         // modules image doesn't have "jre" subdirectory
1724         len = strlen(buf);
1725         assert(len < buflen, "Ran out of buffer space");
1726         jrelib_p = buf + len;
1727 
1728         // Add the appropriate library subdir
1729         snprintf(jrelib_p, buflen-len, "/jre/lib");
1730         if (0 != access(buf, F_OK)) {
1731           snprintf(jrelib_p, buflen-len, "/lib");
1732         }
1733 
1734         // Add the appropriate client or server subdir
1735         len = strlen(buf);
1736         jrelib_p = buf + len;
1737         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1738         if (0 != access(buf, F_OK)) {
1739           snprintf(jrelib_p, buflen-len, "%s", "");
1740         }
1741 
1742         // If the path exists within JAVA_HOME, add the JVM library name
1743         // to complete the path to JVM being overridden.  Otherwise fallback
1744         // to the path to the current library.
1745         if (0 == access(buf, F_OK)) {
1746           // Use current module name "libjvm"
1747           len = strlen(buf);
1748           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1749         } else {
1750           // Fall back to path of current library
1751           rp = os::Posix::realpath(dli_fname, buf, buflen);
1752           if (rp == NULL) {
1753             return;
1754           }
1755         }
1756       }
1757     }
1758   }
1759 
1760   strncpy(saved_jvm_path, buf, MAXPATHLEN);
1761   saved_jvm_path[MAXPATHLEN - 1] = '\0';
1762 }
1763 
1764 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1765   // no prefix required, not even "_"
1766 }
1767 
1768 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1769   // no suffix required
1770 }
1771 
1772 ////////////////////////////////////////////////////////////////////////////////
1773 // sun.misc.Signal support
1774 
1775 static volatile jint sigint_count = 0;
1776 
1777 static void UserHandler(int sig, void *siginfo, void *context) {
1778   // 4511530 - sem_post is serialized and handled by the manager thread. When
1779   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1780   // don't want to flood the manager thread with sem_post requests.
1781   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
1782     return;
1783   }
1784 
1785   // Ctrl-C is pressed during error reporting, likely because the error
1786   // handler fails to abort. Let VM die immediately.
1787   if (sig == SIGINT && VMError::is_error_reported()) {
1788     os::die();
1789   }
1790 
1791   os::signal_notify(sig);
1792 }
1793 
1794 void* os::user_handler() {
1795   return CAST_FROM_FN_PTR(void*, UserHandler);
1796 }
1797 
1798 extern "C" {
1799   typedef void (*sa_handler_t)(int);
1800   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1801 }
1802 
1803 void* os::signal(int signal_number, void* handler) {
1804   struct sigaction sigAct, oldSigAct;
1805 
1806   sigfillset(&(sigAct.sa_mask));
1807   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1808   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1809 
1810   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1811     // -1 means registration failed
1812     return (void *)-1;
1813   }
1814 
1815   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1816 }
1817 
1818 void os::signal_raise(int signal_number) {
1819   ::raise(signal_number);
1820 }
1821 
1822 // The following code is moved from os.cpp for making this
1823 // code platform specific, which it is by its very nature.
1824 
1825 // Will be modified when max signal is changed to be dynamic
1826 int os::sigexitnum_pd() {
1827   return NSIG;
1828 }
1829 
1830 // a counter for each possible signal value
1831 static volatile jint pending_signals[NSIG+1] = { 0 };
1832 
1833 // Bsd(POSIX) specific hand shaking semaphore.
1834 #ifdef __APPLE__
1835 typedef semaphore_t os_semaphore_t;
1836 
1837   #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1838   #define SEM_WAIT(sem)           semaphore_wait(sem)
1839   #define SEM_POST(sem)           semaphore_signal(sem)
1840   #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
1841 #else
1842 typedef sem_t os_semaphore_t;
1843 
1844   #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
1845   #define SEM_WAIT(sem)           sem_wait(&sem)
1846   #define SEM_POST(sem)           sem_post(&sem)
1847   #define SEM_DESTROY(sem)        sem_destroy(&sem)
1848 #endif
1849 
1850 #ifdef __APPLE__
1851 // OS X doesn't support unamed POSIX semaphores, so the implementation in os_posix.cpp can't be used.
1852 
1853 static const char* sem_init_strerror(kern_return_t value) {
1854   switch (value) {
1855     case KERN_INVALID_ARGUMENT:  return "Invalid argument";
1856     case KERN_RESOURCE_SHORTAGE: return "Resource shortage";
1857     default:                     return "Unknown";
1858   }
1859 }
1860 
1861 OSXSemaphore::OSXSemaphore(uint value) {
1862   kern_return_t ret = SEM_INIT(_semaphore, value);
1863 
1864   guarantee(ret == KERN_SUCCESS, "Failed to create semaphore: %s", sem_init_strerror(ret));
1865 }
1866 
1867 OSXSemaphore::~OSXSemaphore() {
1868   SEM_DESTROY(_semaphore);
1869 }
1870 
1871 void OSXSemaphore::signal(uint count) {
1872   for (uint i = 0; i < count; i++) {
1873     kern_return_t ret = SEM_POST(_semaphore);
1874 
1875     assert(ret == KERN_SUCCESS, "Failed to signal semaphore");
1876   }
1877 }
1878 
1879 void OSXSemaphore::wait() {
1880   kern_return_t ret;
1881   while ((ret = SEM_WAIT(_semaphore)) == KERN_ABORTED) {
1882     // Semaphore was interrupted. Retry.
1883   }
1884   assert(ret == KERN_SUCCESS, "Failed to wait on semaphore");
1885 }
1886 
1887 jlong OSXSemaphore::currenttime() {
1888   struct timeval tv;
1889   gettimeofday(&tv, NULL);
1890   return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
1891 }
1892 
1893 bool OSXSemaphore::trywait() {
1894   return timedwait(0, 0);
1895 }
1896 
1897 bool OSXSemaphore::timedwait(unsigned int sec, int nsec) {
1898   kern_return_t kr = KERN_ABORTED;
1899   mach_timespec_t waitspec;
1900   waitspec.tv_sec = sec;
1901   waitspec.tv_nsec = nsec;
1902 
1903   jlong starttime = currenttime();
1904 
1905   kr = semaphore_timedwait(_semaphore, waitspec);
1906   while (kr == KERN_ABORTED) {
1907     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
1908 
1909     jlong current = currenttime();
1910     jlong passedtime = current - starttime;
1911 
1912     if (passedtime >= totalwait) {
1913       waitspec.tv_sec = 0;
1914       waitspec.tv_nsec = 0;
1915     } else {
1916       jlong waittime = totalwait - (current - starttime);
1917       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
1918       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
1919     }
1920 
1921     kr = semaphore_timedwait(_semaphore, waitspec);
1922   }
1923 
1924   return kr == KERN_SUCCESS;
1925 }
1926 
1927 #else
1928 // Use POSIX implementation of semaphores.
1929 
1930 struct timespec PosixSemaphore::create_timespec(unsigned int sec, int nsec) {
1931   struct timespec ts;
1932   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
1933 
1934   return ts;
1935 }
1936 
1937 #endif // __APPLE__
1938 
1939 static os_semaphore_t sig_sem;
1940 
1941 #ifdef __APPLE__
1942 static OSXSemaphore sr_semaphore;
1943 #else
1944 static PosixSemaphore sr_semaphore;
1945 #endif
1946 
1947 void os::signal_init_pd() {
1948   // Initialize signal structures
1949   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1950 
1951   // Initialize signal semaphore
1952   ::SEM_INIT(sig_sem, 0);
1953 }
1954 
1955 void os::signal_notify(int sig) {
1956   Atomic::inc(&pending_signals[sig]);
1957   ::SEM_POST(sig_sem);
1958 }
1959 
1960 static int check_pending_signals(bool wait) {
1961   Atomic::store(0, &sigint_count);
1962   for (;;) {
1963     for (int i = 0; i < NSIG + 1; i++) {
1964       jint n = pending_signals[i];
1965       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1966         return i;
1967       }
1968     }
1969     if (!wait) {
1970       return -1;
1971     }
1972     JavaThread *thread = JavaThread::current();
1973     ThreadBlockInVM tbivm(thread);
1974 
1975     bool threadIsSuspended;
1976     do {
1977       thread->set_suspend_equivalent();
1978       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1979       ::SEM_WAIT(sig_sem);
1980 
1981       // were we externally suspended while we were waiting?
1982       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1983       if (threadIsSuspended) {
1984         // The semaphore has been incremented, but while we were waiting
1985         // another thread suspended us. We don't want to continue running
1986         // while suspended because that would surprise the thread that
1987         // suspended us.
1988         ::SEM_POST(sig_sem);
1989 
1990         thread->java_suspend_self();
1991       }
1992     } while (threadIsSuspended);
1993   }
1994 }
1995 
1996 int os::signal_lookup() {
1997   return check_pending_signals(false);
1998 }
1999 
2000 int os::signal_wait() {
2001   return check_pending_signals(true);
2002 }
2003 
2004 ////////////////////////////////////////////////////////////////////////////////
2005 // Virtual Memory
2006 
2007 int os::vm_page_size() {
2008   // Seems redundant as all get out
2009   assert(os::Bsd::page_size() != -1, "must call os::init");
2010   return os::Bsd::page_size();
2011 }
2012 
2013 // Solaris allocates memory by pages.
2014 int os::vm_allocation_granularity() {
2015   assert(os::Bsd::page_size() != -1, "must call os::init");
2016   return os::Bsd::page_size();
2017 }
2018 
2019 // Rationale behind this function:
2020 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2021 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2022 //  samples for JITted code. Here we create private executable mapping over the code cache
2023 //  and then we can use standard (well, almost, as mapping can change) way to provide
2024 //  info for the reporting script by storing timestamp and location of symbol
2025 void bsd_wrap_code(char* base, size_t size) {
2026   static volatile jint cnt = 0;
2027 
2028   if (!UseOprofile) {
2029     return;
2030   }
2031 
2032   char buf[PATH_MAX + 1];
2033   int num = Atomic::add(1, &cnt);
2034 
2035   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2036            os::get_temp_directory(), os::current_process_id(), num);
2037   unlink(buf);
2038 
2039   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2040 
2041   if (fd != -1) {
2042     off_t rv = ::lseek(fd, size-2, SEEK_SET);
2043     if (rv != (off_t)-1) {
2044       if (::write(fd, "", 1) == 1) {
2045         mmap(base, size,
2046              PROT_READ|PROT_WRITE|PROT_EXEC,
2047              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2048       }
2049     }
2050     ::close(fd);
2051     unlink(buf);
2052   }
2053 }
2054 
2055 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2056                                     int err) {
2057   warning("INFO: os::commit_memory(" INTPTR_FORMAT ", " SIZE_FORMAT
2058           ", %d) failed; error='%s' (errno=%d)", (intptr_t)addr, size, exec,
2059            os::errno_name(err), err);
2060 }
2061 
2062 // NOTE: Bsd kernel does not really reserve the pages for us.
2063 //       All it does is to check if there are enough free pages
2064 //       left at the time of mmap(). This could be a potential
2065 //       problem.
2066 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2067   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2068 #ifdef __OpenBSD__
2069   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2070   if (::mprotect(addr, size, prot) == 0) {
2071     return true;
2072   }
2073 #else
2074   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2075                                      MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2076   if (res != (uintptr_t) MAP_FAILED) {
2077     return true;
2078   }
2079 #endif
2080 
2081   // Warn about any commit errors we see in non-product builds just
2082   // in case mmap() doesn't work as described on the man page.
2083   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2084 
2085   return false;
2086 }
2087 
2088 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2089                           bool exec) {
2090   // alignment_hint is ignored on this OS
2091   return pd_commit_memory(addr, size, exec);
2092 }
2093 
2094 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2095                                   const char* mesg) {
2096   assert(mesg != NULL, "mesg must be specified");
2097   if (!pd_commit_memory(addr, size, exec)) {
2098     // add extra info in product mode for vm_exit_out_of_memory():
2099     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2100     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
2101   }
2102 }
2103 
2104 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2105                                   size_t alignment_hint, bool exec,
2106                                   const char* mesg) {
2107   // alignment_hint is ignored on this OS
2108   pd_commit_memory_or_exit(addr, size, exec, mesg);
2109 }
2110 
2111 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2112 }
2113 
2114 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2115   ::madvise(addr, bytes, MADV_DONTNEED);
2116 }
2117 
2118 void os::numa_make_global(char *addr, size_t bytes) {
2119 }
2120 
2121 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2122 }
2123 
2124 bool os::numa_topology_changed()   { return false; }
2125 
2126 size_t os::numa_get_groups_num() {
2127   return 1;
2128 }
2129 
2130 int os::numa_get_group_id() {
2131   return 0;
2132 }
2133 
2134 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2135   if (size > 0) {
2136     ids[0] = 0;
2137     return 1;
2138   }
2139   return 0;
2140 }
2141 
2142 bool os::get_page_info(char *start, page_info* info) {
2143   return false;
2144 }
2145 
2146 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2147   return end;
2148 }
2149 
2150 
2151 bool os::pd_uncommit_memory(char* addr, size_t size) {
2152 #ifdef __OpenBSD__
2153   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2154   return ::mprotect(addr, size, PROT_NONE) == 0;
2155 #else
2156   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2157                                      MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2158   return res  != (uintptr_t) MAP_FAILED;
2159 #endif
2160 }
2161 
2162 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2163   return os::commit_memory(addr, size, !ExecMem);
2164 }
2165 
2166 // If this is a growable mapping, remove the guard pages entirely by
2167 // munmap()ping them.  If not, just call uncommit_memory().
2168 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2169   return os::uncommit_memory(addr, size);
2170 }
2171 
2172 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2173 // at 'requested_addr'. If there are existing memory mappings at the same
2174 // location, however, they will be overwritten. If 'fixed' is false,
2175 // 'requested_addr' is only treated as a hint, the return value may or
2176 // may not start from the requested address. Unlike Bsd mmap(), this
2177 // function returns NULL to indicate failure.
2178 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2179   char * addr;
2180   int flags;
2181 
2182   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2183   if (fixed) {
2184     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2185     flags |= MAP_FIXED;
2186   }
2187 
2188   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2189   // touch an uncommitted page. Otherwise, the read/write might
2190   // succeed if we have enough swap space to back the physical page.
2191   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2192                        flags, -1, 0);
2193 
2194   return addr == MAP_FAILED ? NULL : addr;
2195 }
2196 
2197 static int anon_munmap(char * addr, size_t size) {
2198   return ::munmap(addr, size) == 0;
2199 }
2200 
2201 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2202                             size_t alignment_hint) {
2203   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2204 }
2205 
2206 bool os::pd_release_memory(char* addr, size_t size) {
2207   return anon_munmap(addr, size);
2208 }
2209 
2210 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2211   // Bsd wants the mprotect address argument to be page aligned.
2212   char* bottom = (char*)align_down((intptr_t)addr, os::Bsd::page_size());
2213 
2214   // According to SUSv3, mprotect() should only be used with mappings
2215   // established by mmap(), and mmap() always maps whole pages. Unaligned
2216   // 'addr' likely indicates problem in the VM (e.g. trying to change
2217   // protection of malloc'ed or statically allocated memory). Check the
2218   // caller if you hit this assert.
2219   assert(addr == bottom, "sanity check");
2220 
2221   size = align_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2222   return ::mprotect(bottom, size, prot) == 0;
2223 }
2224 
2225 // Set protections specified
2226 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2227                         bool is_committed) {
2228   unsigned int p = 0;
2229   switch (prot) {
2230   case MEM_PROT_NONE: p = PROT_NONE; break;
2231   case MEM_PROT_READ: p = PROT_READ; break;
2232   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2233   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2234   default:
2235     ShouldNotReachHere();
2236   }
2237   // is_committed is unused.
2238   return bsd_mprotect(addr, bytes, p);
2239 }
2240 
2241 bool os::guard_memory(char* addr, size_t size) {
2242   return bsd_mprotect(addr, size, PROT_NONE);
2243 }
2244 
2245 bool os::unguard_memory(char* addr, size_t size) {
2246   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2247 }
2248 
2249 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2250   return false;
2251 }
2252 
2253 // Large page support
2254 
2255 static size_t _large_page_size = 0;
2256 
2257 void os::large_page_init() {
2258 }
2259 
2260 
2261 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2262   fatal("This code is not used or maintained.");
2263 
2264   // "exec" is passed in but not used.  Creating the shared image for
2265   // the code cache doesn't have an SHM_X executable permission to check.
2266   assert(UseLargePages && UseSHM, "only for SHM large pages");
2267 
2268   key_t key = IPC_PRIVATE;
2269   char *addr;
2270 
2271   bool warn_on_failure = UseLargePages &&
2272                          (!FLAG_IS_DEFAULT(UseLargePages) ||
2273                           !FLAG_IS_DEFAULT(LargePageSizeInBytes));
2274 
2275   // Create a large shared memory region to attach to based on size.
2276   // Currently, size is the total size of the heap
2277   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2278   if (shmid == -1) {
2279     // Possible reasons for shmget failure:
2280     // 1. shmmax is too small for Java heap.
2281     //    > check shmmax value: cat /proc/sys/kernel/shmmax
2282     //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2283     // 2. not enough large page memory.
2284     //    > check available large pages: cat /proc/meminfo
2285     //    > increase amount of large pages:
2286     //          echo new_value > /proc/sys/vm/nr_hugepages
2287     //      Note 1: different Bsd may use different name for this property,
2288     //            e.g. on Redhat AS-3 it is "hugetlb_pool".
2289     //      Note 2: it's possible there's enough physical memory available but
2290     //            they are so fragmented after a long run that they can't
2291     //            coalesce into large pages. Try to reserve large pages when
2292     //            the system is still "fresh".
2293     if (warn_on_failure) {
2294       warning("Failed to reserve shared memory (errno = %d).", errno);
2295     }
2296     return NULL;
2297   }
2298 
2299   // attach to the region
2300   addr = (char*)shmat(shmid, req_addr, 0);
2301   int err = errno;
2302 
2303   // Remove shmid. If shmat() is successful, the actual shared memory segment
2304   // will be deleted when it's detached by shmdt() or when the process
2305   // terminates. If shmat() is not successful this will remove the shared
2306   // segment immediately.
2307   shmctl(shmid, IPC_RMID, NULL);
2308 
2309   if ((intptr_t)addr == -1) {
2310     if (warn_on_failure) {
2311       warning("Failed to attach shared memory (errno = %d).", err);
2312     }
2313     return NULL;
2314   }
2315 
2316   // The memory is committed
2317   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
2318 
2319   return addr;
2320 }
2321 
2322 bool os::release_memory_special(char* base, size_t bytes) {
2323   if (MemTracker::tracking_level() > NMT_minimal) {
2324     Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2325     // detaching the SHM segment will also delete it, see reserve_memory_special()
2326     int rslt = shmdt(base);
2327     if (rslt == 0) {
2328       tkr.record((address)base, bytes);
2329       return true;
2330     } else {
2331       return false;
2332     }
2333   } else {
2334     return shmdt(base) == 0;
2335   }
2336 }
2337 
2338 size_t os::large_page_size() {
2339   return _large_page_size;
2340 }
2341 
2342 // HugeTLBFS allows application to commit large page memory on demand;
2343 // with SysV SHM the entire memory region must be allocated as shared
2344 // memory.
2345 bool os::can_commit_large_page_memory() {
2346   return UseHugeTLBFS;
2347 }
2348 
2349 bool os::can_execute_large_page_memory() {
2350   return UseHugeTLBFS;
2351 }
2352 
2353 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2354   assert(file_desc >= 0, "file_desc is not valid");
2355   char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
2356   if (result != NULL) {
2357     if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2358       vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2359     }
2360   }
2361   return result;
2362 }
2363 
2364 // Reserve memory at an arbitrary address, only if that area is
2365 // available (and not reserved for something else).
2366 
2367 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2368   const int max_tries = 10;
2369   char* base[max_tries];
2370   size_t size[max_tries];
2371   const size_t gap = 0x000000;
2372 
2373   // Assert only that the size is a multiple of the page size, since
2374   // that's all that mmap requires, and since that's all we really know
2375   // about at this low abstraction level.  If we need higher alignment,
2376   // we can either pass an alignment to this method or verify alignment
2377   // in one of the methods further up the call chain.  See bug 5044738.
2378   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2379 
2380   // Repeatedly allocate blocks until the block is allocated at the
2381   // right spot.
2382 
2383   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2384   // if kernel honors the hint then we can return immediately.
2385   char * addr = anon_mmap(requested_addr, bytes, false);
2386   if (addr == requested_addr) {
2387     return requested_addr;
2388   }
2389 
2390   if (addr != NULL) {
2391     // mmap() is successful but it fails to reserve at the requested address
2392     anon_munmap(addr, bytes);
2393   }
2394 
2395   int i;
2396   for (i = 0; i < max_tries; ++i) {
2397     base[i] = reserve_memory(bytes);
2398 
2399     if (base[i] != NULL) {
2400       // Is this the block we wanted?
2401       if (base[i] == requested_addr) {
2402         size[i] = bytes;
2403         break;
2404       }
2405 
2406       // Does this overlap the block we wanted? Give back the overlapped
2407       // parts and try again.
2408 
2409       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2410       if (top_overlap >= 0 && top_overlap < bytes) {
2411         unmap_memory(base[i], top_overlap);
2412         base[i] += top_overlap;
2413         size[i] = bytes - top_overlap;
2414       } else {
2415         size_t bottom_overlap = base[i] + bytes - requested_addr;
2416         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2417           unmap_memory(requested_addr, bottom_overlap);
2418           size[i] = bytes - bottom_overlap;
2419         } else {
2420           size[i] = bytes;
2421         }
2422       }
2423     }
2424   }
2425 
2426   // Give back the unused reserved pieces.
2427 
2428   for (int j = 0; j < i; ++j) {
2429     if (base[j] != NULL) {
2430       unmap_memory(base[j], size[j]);
2431     }
2432   }
2433 
2434   if (i < max_tries) {
2435     return requested_addr;
2436   } else {
2437     return NULL;
2438   }
2439 }
2440 
2441 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2442   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2443 }
2444 
2445 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
2446   RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset));
2447 }
2448 
2449 void os::naked_short_sleep(jlong ms) {
2450   struct timespec req;
2451 
2452   assert(ms < 1000, "Un-interruptable sleep, short time use only");
2453   req.tv_sec = 0;
2454   if (ms > 0) {
2455     req.tv_nsec = (ms % 1000) * 1000000;
2456   } else {
2457     req.tv_nsec = 1;
2458   }
2459 
2460   nanosleep(&req, NULL);
2461 
2462   return;
2463 }
2464 
2465 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2466 void os::infinite_sleep() {
2467   while (true) {    // sleep forever ...
2468     ::sleep(100);   // ... 100 seconds at a time
2469   }
2470 }
2471 
2472 // Used to convert frequent JVM_Yield() to nops
2473 bool os::dont_yield() {
2474   return DontYieldALot;
2475 }
2476 
2477 void os::naked_yield() {
2478   sched_yield();
2479 }
2480 
2481 ////////////////////////////////////////////////////////////////////////////////
2482 // thread priority support
2483 
2484 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2485 // only supports dynamic priority, static priority must be zero. For real-time
2486 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2487 // However, for large multi-threaded applications, SCHED_RR is not only slower
2488 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2489 // of 5 runs - Sep 2005).
2490 //
2491 // The following code actually changes the niceness of kernel-thread/LWP. It
2492 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2493 // not the entire user process, and user level threads are 1:1 mapped to kernel
2494 // threads. It has always been the case, but could change in the future. For
2495 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2496 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2497 
2498 #if !defined(__APPLE__)
2499 int os::java_to_os_priority[CriticalPriority + 1] = {
2500   19,              // 0 Entry should never be used
2501 
2502    0,              // 1 MinPriority
2503    3,              // 2
2504    6,              // 3
2505 
2506   10,              // 4
2507   15,              // 5 NormPriority
2508   18,              // 6
2509 
2510   21,              // 7
2511   25,              // 8
2512   28,              // 9 NearMaxPriority
2513 
2514   31,              // 10 MaxPriority
2515 
2516   31               // 11 CriticalPriority
2517 };
2518 #else
2519 // Using Mach high-level priority assignments
2520 int os::java_to_os_priority[CriticalPriority + 1] = {
2521    0,              // 0 Entry should never be used (MINPRI_USER)
2522 
2523   27,              // 1 MinPriority
2524   28,              // 2
2525   29,              // 3
2526 
2527   30,              // 4
2528   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2529   32,              // 6
2530 
2531   33,              // 7
2532   34,              // 8
2533   35,              // 9 NearMaxPriority
2534 
2535   36,              // 10 MaxPriority
2536 
2537   36               // 11 CriticalPriority
2538 };
2539 #endif
2540 
2541 static int prio_init() {
2542   if (ThreadPriorityPolicy == 1) {
2543     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2544     // if effective uid is not root. Perhaps, a more elegant way of doing
2545     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2546     if (geteuid() != 0) {
2547       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2548         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2549       }
2550       ThreadPriorityPolicy = 0;
2551     }
2552   }
2553   if (UseCriticalJavaThreadPriority) {
2554     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2555   }
2556   return 0;
2557 }
2558 
2559 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2560   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2561 
2562 #ifdef __OpenBSD__
2563   // OpenBSD pthread_setprio starves low priority threads
2564   return OS_OK;
2565 #elif defined(__FreeBSD__)
2566   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2567 #elif defined(__APPLE__) || defined(__NetBSD__)
2568   struct sched_param sp;
2569   int policy;
2570   pthread_t self = pthread_self();
2571 
2572   if (pthread_getschedparam(self, &policy, &sp) != 0) {
2573     return OS_ERR;
2574   }
2575 
2576   sp.sched_priority = newpri;
2577   if (pthread_setschedparam(self, policy, &sp) != 0) {
2578     return OS_ERR;
2579   }
2580 
2581   return OS_OK;
2582 #else
2583   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2584   return (ret == 0) ? OS_OK : OS_ERR;
2585 #endif
2586 }
2587 
2588 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2589   if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2590     *priority_ptr = java_to_os_priority[NormPriority];
2591     return OS_OK;
2592   }
2593 
2594   errno = 0;
2595 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2596   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2597 #elif defined(__APPLE__) || defined(__NetBSD__)
2598   int policy;
2599   struct sched_param sp;
2600 
2601   pthread_getschedparam(pthread_self(), &policy, &sp);
2602   *priority_ptr = sp.sched_priority;
2603 #else
2604   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2605 #endif
2606   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2607 }
2608 
2609 // Hint to the underlying OS that a task switch would not be good.
2610 // Void return because it's a hint and can fail.
2611 void os::hint_no_preempt() {}
2612 
2613 ////////////////////////////////////////////////////////////////////////////////
2614 // suspend/resume support
2615 
2616 //  The low-level signal-based suspend/resume support is a remnant from the
2617 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2618 //  within hotspot. Currently used by JFR's OSThreadSampler
2619 //
2620 //  The remaining code is greatly simplified from the more general suspension
2621 //  code that used to be used.
2622 //
2623 //  The protocol is quite simple:
2624 //  - suspend:
2625 //      - sends a signal to the target thread
2626 //      - polls the suspend state of the osthread using a yield loop
2627 //      - target thread signal handler (SR_handler) sets suspend state
2628 //        and blocks in sigsuspend until continued
2629 //  - resume:
2630 //      - sets target osthread state to continue
2631 //      - sends signal to end the sigsuspend loop in the SR_handler
2632 //
2633 //  Note that the SR_lock plays no role in this suspend/resume protocol,
2634 //  but is checked for NULL in SR_handler as a thread termination indicator.
2635 //  The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
2636 //
2637 //  Note that resume_clear_context() and suspend_save_context() are needed
2638 //  by SR_handler(), so that fetch_frame_from_ucontext() works,
2639 //  which in part is used by:
2640 //    - Forte Analyzer: AsyncGetCallTrace()
2641 //    - StackBanging: get_frame_at_stack_banging_point()
2642 
2643 static void resume_clear_context(OSThread *osthread) {
2644   osthread->set_ucontext(NULL);
2645   osthread->set_siginfo(NULL);
2646 }
2647 
2648 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2649   osthread->set_ucontext(context);
2650   osthread->set_siginfo(siginfo);
2651 }
2652 
2653 // Handler function invoked when a thread's execution is suspended or
2654 // resumed. We have to be careful that only async-safe functions are
2655 // called here (Note: most pthread functions are not async safe and
2656 // should be avoided.)
2657 //
2658 // Note: sigwait() is a more natural fit than sigsuspend() from an
2659 // interface point of view, but sigwait() prevents the signal hander
2660 // from being run. libpthread would get very confused by not having
2661 // its signal handlers run and prevents sigwait()'s use with the
2662 // mutex granting granting signal.
2663 //
2664 // Currently only ever called on the VMThread or JavaThread
2665 //
2666 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2667   // Save and restore errno to avoid confusing native code with EINTR
2668   // after sigsuspend.
2669   int old_errno = errno;
2670 
2671   Thread* thread = Thread::current_or_null_safe();
2672   assert(thread != NULL, "Missing current thread in SR_handler");
2673 
2674   // On some systems we have seen signal delivery get "stuck" until the signal
2675   // mask is changed as part of thread termination. Check that the current thread
2676   // has not already terminated (via SR_lock()) - else the following assertion
2677   // will fail because the thread is no longer a JavaThread as the ~JavaThread
2678   // destructor has completed.
2679 
2680   if (thread->SR_lock() == NULL) {
2681     return;
2682   }
2683 
2684   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2685 
2686   OSThread* osthread = thread->osthread();
2687 
2688   os::SuspendResume::State current = osthread->sr.state();
2689   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2690     suspend_save_context(osthread, siginfo, context);
2691 
2692     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2693     os::SuspendResume::State state = osthread->sr.suspended();
2694     if (state == os::SuspendResume::SR_SUSPENDED) {
2695       sigset_t suspend_set;  // signals for sigsuspend()
2696 
2697       // get current set of blocked signals and unblock resume signal
2698       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2699       sigdelset(&suspend_set, SR_signum);
2700 
2701       sr_semaphore.signal();
2702       // wait here until we are resumed
2703       while (1) {
2704         sigsuspend(&suspend_set);
2705 
2706         os::SuspendResume::State result = osthread->sr.running();
2707         if (result == os::SuspendResume::SR_RUNNING) {
2708           sr_semaphore.signal();
2709           break;
2710         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2711           ShouldNotReachHere();
2712         }
2713       }
2714 
2715     } else if (state == os::SuspendResume::SR_RUNNING) {
2716       // request was cancelled, continue
2717     } else {
2718       ShouldNotReachHere();
2719     }
2720 
2721     resume_clear_context(osthread);
2722   } else if (current == os::SuspendResume::SR_RUNNING) {
2723     // request was cancelled, continue
2724   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2725     // ignore
2726   } else {
2727     // ignore
2728   }
2729 
2730   errno = old_errno;
2731 }
2732 
2733 
2734 static int SR_initialize() {
2735   struct sigaction act;
2736   char *s;
2737   // Get signal number to use for suspend/resume
2738   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2739     int sig = ::strtol(s, 0, 10);
2740     if (sig > MAX2(SIGSEGV, SIGBUS) &&  // See 4355769.
2741         sig < NSIG) {                   // Must be legal signal and fit into sigflags[].
2742       SR_signum = sig;
2743     } else {
2744       warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2745               sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2746     }
2747   }
2748 
2749   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2750          "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2751 
2752   sigemptyset(&SR_sigset);
2753   sigaddset(&SR_sigset, SR_signum);
2754 
2755   // Set up signal handler for suspend/resume
2756   act.sa_flags = SA_RESTART|SA_SIGINFO;
2757   act.sa_handler = (void (*)(int)) SR_handler;
2758 
2759   // SR_signum is blocked by default.
2760   // 4528190 - We also need to block pthread restart signal (32 on all
2761   // supported Bsd platforms). Note that BsdThreads need to block
2762   // this signal for all threads to work properly. So we don't have
2763   // to use hard-coded signal number when setting up the mask.
2764   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2765 
2766   if (sigaction(SR_signum, &act, 0) == -1) {
2767     return -1;
2768   }
2769 
2770   // Save signal flag
2771   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2772   return 0;
2773 }
2774 
2775 static int sr_notify(OSThread* osthread) {
2776   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2777   assert_status(status == 0, status, "pthread_kill");
2778   return status;
2779 }
2780 
2781 // "Randomly" selected value for how long we want to spin
2782 // before bailing out on suspending a thread, also how often
2783 // we send a signal to a thread we want to resume
2784 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2785 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2786 
2787 // returns true on success and false on error - really an error is fatal
2788 // but this seems the normal response to library errors
2789 static bool do_suspend(OSThread* osthread) {
2790   assert(osthread->sr.is_running(), "thread should be running");
2791   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2792 
2793   // mark as suspended and send signal
2794   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2795     // failed to switch, state wasn't running?
2796     ShouldNotReachHere();
2797     return false;
2798   }
2799 
2800   if (sr_notify(osthread) != 0) {
2801     ShouldNotReachHere();
2802   }
2803 
2804   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2805   while (true) {
2806     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2807       break;
2808     } else {
2809       // timeout
2810       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2811       if (cancelled == os::SuspendResume::SR_RUNNING) {
2812         return false;
2813       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2814         // make sure that we consume the signal on the semaphore as well
2815         sr_semaphore.wait();
2816         break;
2817       } else {
2818         ShouldNotReachHere();
2819         return false;
2820       }
2821     }
2822   }
2823 
2824   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2825   return true;
2826 }
2827 
2828 static void do_resume(OSThread* osthread) {
2829   assert(osthread->sr.is_suspended(), "thread should be suspended");
2830   assert(!sr_semaphore.trywait(), "invalid semaphore state");
2831 
2832   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2833     // failed to switch to WAKEUP_REQUEST
2834     ShouldNotReachHere();
2835     return;
2836   }
2837 
2838   while (true) {
2839     if (sr_notify(osthread) == 0) {
2840       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2841         if (osthread->sr.is_running()) {
2842           return;
2843         }
2844       }
2845     } else {
2846       ShouldNotReachHere();
2847     }
2848   }
2849 
2850   guarantee(osthread->sr.is_running(), "Must be running!");
2851 }
2852 
2853 ///////////////////////////////////////////////////////////////////////////////////
2854 // signal handling (except suspend/resume)
2855 
2856 // This routine may be used by user applications as a "hook" to catch signals.
2857 // The user-defined signal handler must pass unrecognized signals to this
2858 // routine, and if it returns true (non-zero), then the signal handler must
2859 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
2860 // routine will never retun false (zero), but instead will execute a VM panic
2861 // routine kill the process.
2862 //
2863 // If this routine returns false, it is OK to call it again.  This allows
2864 // the user-defined signal handler to perform checks either before or after
2865 // the VM performs its own checks.  Naturally, the user code would be making
2866 // a serious error if it tried to handle an exception (such as a null check
2867 // or breakpoint) that the VM was generating for its own correct operation.
2868 //
2869 // This routine may recognize any of the following kinds of signals:
2870 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2871 // It should be consulted by handlers for any of those signals.
2872 //
2873 // The caller of this routine must pass in the three arguments supplied
2874 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2875 // field of the structure passed to sigaction().  This routine assumes that
2876 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2877 //
2878 // Note that the VM will print warnings if it detects conflicting signal
2879 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2880 //
2881 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2882                                                void* ucontext,
2883                                                int abort_if_unrecognized);
2884 
2885 void signalHandler(int sig, siginfo_t* info, void* uc) {
2886   assert(info != NULL && uc != NULL, "it must be old kernel");
2887   int orig_errno = errno;  // Preserve errno value over signal handler.
2888   JVM_handle_bsd_signal(sig, info, uc, true);
2889   errno = orig_errno;
2890 }
2891 
2892 
2893 // This boolean allows users to forward their own non-matching signals
2894 // to JVM_handle_bsd_signal, harmlessly.
2895 bool os::Bsd::signal_handlers_are_installed = false;
2896 
2897 // For signal-chaining
2898 struct sigaction sigact[NSIG];
2899 uint32_t sigs = 0;
2900 #if (32 < NSIG-1)
2901 #error "Not all signals can be encoded in sigs. Adapt its type!"
2902 #endif
2903 bool os::Bsd::libjsig_is_loaded = false;
2904 typedef struct sigaction *(*get_signal_t)(int);
2905 get_signal_t os::Bsd::get_signal_action = NULL;
2906 
2907 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2908   struct sigaction *actp = NULL;
2909 
2910   if (libjsig_is_loaded) {
2911     // Retrieve the old signal handler from libjsig
2912     actp = (*get_signal_action)(sig);
2913   }
2914   if (actp == NULL) {
2915     // Retrieve the preinstalled signal handler from jvm
2916     actp = get_preinstalled_handler(sig);
2917   }
2918 
2919   return actp;
2920 }
2921 
2922 static bool call_chained_handler(struct sigaction *actp, int sig,
2923                                  siginfo_t *siginfo, void *context) {
2924   // Call the old signal handler
2925   if (actp->sa_handler == SIG_DFL) {
2926     // It's more reasonable to let jvm treat it as an unexpected exception
2927     // instead of taking the default action.
2928     return false;
2929   } else if (actp->sa_handler != SIG_IGN) {
2930     if ((actp->sa_flags & SA_NODEFER) == 0) {
2931       // automaticlly block the signal
2932       sigaddset(&(actp->sa_mask), sig);
2933     }
2934 
2935     sa_handler_t hand;
2936     sa_sigaction_t sa;
2937     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
2938     // retrieve the chained handler
2939     if (siginfo_flag_set) {
2940       sa = actp->sa_sigaction;
2941     } else {
2942       hand = actp->sa_handler;
2943     }
2944 
2945     if ((actp->sa_flags & SA_RESETHAND) != 0) {
2946       actp->sa_handler = SIG_DFL;
2947     }
2948 
2949     // try to honor the signal mask
2950     sigset_t oset;
2951     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
2952 
2953     // call into the chained handler
2954     if (siginfo_flag_set) {
2955       (*sa)(sig, siginfo, context);
2956     } else {
2957       (*hand)(sig);
2958     }
2959 
2960     // restore the signal mask
2961     pthread_sigmask(SIG_SETMASK, &oset, 0);
2962   }
2963   // Tell jvm's signal handler the signal is taken care of.
2964   return true;
2965 }
2966 
2967 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
2968   bool chained = false;
2969   // signal-chaining
2970   if (UseSignalChaining) {
2971     struct sigaction *actp = get_chained_signal_action(sig);
2972     if (actp != NULL) {
2973       chained = call_chained_handler(actp, sig, siginfo, context);
2974     }
2975   }
2976   return chained;
2977 }
2978 
2979 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
2980   if ((((uint32_t)1 << (sig-1)) & sigs) != 0) {
2981     return &sigact[sig];
2982   }
2983   return NULL;
2984 }
2985 
2986 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
2987   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2988   sigact[sig] = oldAct;
2989   sigs |= (uint32_t)1 << (sig-1);
2990 }
2991 
2992 // for diagnostic
2993 int sigflags[NSIG];
2994 
2995 int os::Bsd::get_our_sigflags(int sig) {
2996   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2997   return sigflags[sig];
2998 }
2999 
3000 void os::Bsd::set_our_sigflags(int sig, int flags) {
3001   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3002   if (sig > 0 && sig < NSIG) {
3003     sigflags[sig] = flags;
3004   }
3005 }
3006 
3007 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3008   // Check for overwrite.
3009   struct sigaction oldAct;
3010   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3011 
3012   void* oldhand = oldAct.sa_sigaction
3013                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
3014                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
3015   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3016       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3017       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3018     if (AllowUserSignalHandlers || !set_installed) {
3019       // Do not overwrite; user takes responsibility to forward to us.
3020       return;
3021     } else if (UseSignalChaining) {
3022       // save the old handler in jvm
3023       save_preinstalled_handler(sig, oldAct);
3024       // libjsig also interposes the sigaction() call below and saves the
3025       // old sigaction on it own.
3026     } else {
3027       fatal("Encountered unexpected pre-existing sigaction handler "
3028             "%#lx for signal %d.", (long)oldhand, sig);
3029     }
3030   }
3031 
3032   struct sigaction sigAct;
3033   sigfillset(&(sigAct.sa_mask));
3034   sigAct.sa_handler = SIG_DFL;
3035   if (!set_installed) {
3036     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3037   } else {
3038     sigAct.sa_sigaction = signalHandler;
3039     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3040   }
3041 #ifdef __APPLE__
3042   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3043   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3044   // if the signal handler declares it will handle it on alternate stack.
3045   // Notice we only declare we will handle it on alt stack, but we are not
3046   // actually going to use real alt stack - this is just a workaround.
3047   // Please see ux_exception.c, method catch_mach_exception_raise for details
3048   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3049   if (sig == SIGSEGV) {
3050     sigAct.sa_flags |= SA_ONSTACK;
3051   }
3052 #endif
3053 
3054   // Save flags, which are set by ours
3055   assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
3056   sigflags[sig] = sigAct.sa_flags;
3057 
3058   int ret = sigaction(sig, &sigAct, &oldAct);
3059   assert(ret == 0, "check");
3060 
3061   void* oldhand2  = oldAct.sa_sigaction
3062                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3063                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3064   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3065 }
3066 
3067 // install signal handlers for signals that HotSpot needs to
3068 // handle in order to support Java-level exception handling.
3069 
3070 void os::Bsd::install_signal_handlers() {
3071   if (!signal_handlers_are_installed) {
3072     signal_handlers_are_installed = true;
3073 
3074     // signal-chaining
3075     typedef void (*signal_setting_t)();
3076     signal_setting_t begin_signal_setting = NULL;
3077     signal_setting_t end_signal_setting = NULL;
3078     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3079                                           dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3080     if (begin_signal_setting != NULL) {
3081       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3082                                           dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3083       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3084                                          dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3085       libjsig_is_loaded = true;
3086       assert(UseSignalChaining, "should enable signal-chaining");
3087     }
3088     if (libjsig_is_loaded) {
3089       // Tell libjsig jvm is setting signal handlers
3090       (*begin_signal_setting)();
3091     }
3092 
3093     set_signal_handler(SIGSEGV, true);
3094     set_signal_handler(SIGPIPE, true);
3095     set_signal_handler(SIGBUS, true);
3096     set_signal_handler(SIGILL, true);
3097     set_signal_handler(SIGFPE, true);
3098     set_signal_handler(SIGXFSZ, true);
3099 
3100 #if defined(__APPLE__)
3101     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3102     // signals caught and handled by the JVM. To work around this, we reset the mach task
3103     // signal handler that's placed on our process by CrashReporter. This disables
3104     // CrashReporter-based reporting.
3105     //
3106     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3107     // on caught fatal signals.
3108     //
3109     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3110     // handlers. By replacing the existing task exception handler, we disable gdb's mach
3111     // exception handling, while leaving the standard BSD signal handlers functional.
3112     kern_return_t kr;
3113     kr = task_set_exception_ports(mach_task_self(),
3114                                   EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3115                                   MACH_PORT_NULL,
3116                                   EXCEPTION_STATE_IDENTITY,
3117                                   MACHINE_THREAD_STATE);
3118 
3119     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3120 #endif
3121 
3122     if (libjsig_is_loaded) {
3123       // Tell libjsig jvm finishes setting signal handlers
3124       (*end_signal_setting)();
3125     }
3126 
3127     // We don't activate signal checker if libjsig is in place, we trust ourselves
3128     // and if UserSignalHandler is installed all bets are off
3129     if (CheckJNICalls) {
3130       if (libjsig_is_loaded) {
3131         if (PrintJNIResolving) {
3132           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3133         }
3134         check_signals = false;
3135       }
3136       if (AllowUserSignalHandlers) {
3137         if (PrintJNIResolving) {
3138           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3139         }
3140         check_signals = false;
3141       }
3142     }
3143   }
3144 }
3145 
3146 
3147 /////
3148 // glibc on Bsd platform uses non-documented flag
3149 // to indicate, that some special sort of signal
3150 // trampoline is used.
3151 // We will never set this flag, and we should
3152 // ignore this flag in our diagnostic
3153 #ifdef SIGNIFICANT_SIGNAL_MASK
3154   #undef SIGNIFICANT_SIGNAL_MASK
3155 #endif
3156 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3157 
3158 static const char* get_signal_handler_name(address handler,
3159                                            char* buf, int buflen) {
3160   int offset;
3161   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3162   if (found) {
3163     // skip directory names
3164     const char *p1, *p2;
3165     p1 = buf;
3166     size_t len = strlen(os::file_separator());
3167     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3168     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3169   } else {
3170     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3171   }
3172   return buf;
3173 }
3174 
3175 static void print_signal_handler(outputStream* st, int sig,
3176                                  char* buf, size_t buflen) {
3177   struct sigaction sa;
3178 
3179   sigaction(sig, NULL, &sa);
3180 
3181   // See comment for SIGNIFICANT_SIGNAL_MASK define
3182   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3183 
3184   st->print("%s: ", os::exception_name(sig, buf, buflen));
3185 
3186   address handler = (sa.sa_flags & SA_SIGINFO)
3187     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3188     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3189 
3190   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3191     st->print("SIG_DFL");
3192   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3193     st->print("SIG_IGN");
3194   } else {
3195     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3196   }
3197 
3198   st->print(", sa_mask[0]=");
3199   os::Posix::print_signal_set_short(st, &sa.sa_mask);
3200 
3201   address rh = VMError::get_resetted_sighandler(sig);
3202   // May be, handler was resetted by VMError?
3203   if (rh != NULL) {
3204     handler = rh;
3205     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3206   }
3207 
3208   st->print(", sa_flags=");
3209   os::Posix::print_sa_flags(st, sa.sa_flags);
3210 
3211   // Check: is it our handler?
3212   if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3213       handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3214     // It is our signal handler
3215     // check for flags, reset system-used one!
3216     if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3217       st->print(
3218                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3219                 os::Bsd::get_our_sigflags(sig));
3220     }
3221   }
3222   st->cr();
3223 }
3224 
3225 
3226 #define DO_SIGNAL_CHECK(sig)                      \
3227   do {                                            \
3228     if (!sigismember(&check_signal_done, sig)) {  \
3229       os::Bsd::check_signal_handler(sig);         \
3230     }                                             \
3231   } while (0)
3232 
3233 // This method is a periodic task to check for misbehaving JNI applications
3234 // under CheckJNI, we can add any periodic checks here
3235 
3236 void os::run_periodic_checks() {
3237 
3238   if (check_signals == false) return;
3239 
3240   // SEGV and BUS if overridden could potentially prevent
3241   // generation of hs*.log in the event of a crash, debugging
3242   // such a case can be very challenging, so we absolutely
3243   // check the following for a good measure:
3244   DO_SIGNAL_CHECK(SIGSEGV);
3245   DO_SIGNAL_CHECK(SIGILL);
3246   DO_SIGNAL_CHECK(SIGFPE);
3247   DO_SIGNAL_CHECK(SIGBUS);
3248   DO_SIGNAL_CHECK(SIGPIPE);
3249   DO_SIGNAL_CHECK(SIGXFSZ);
3250 
3251 
3252   // ReduceSignalUsage allows the user to override these handlers
3253   // see comments at the very top and jvm_md.h
3254   if (!ReduceSignalUsage) {
3255     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3256     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3257     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3258     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3259   }
3260 
3261   DO_SIGNAL_CHECK(SR_signum);
3262 }
3263 
3264 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3265 
3266 static os_sigaction_t os_sigaction = NULL;
3267 
3268 void os::Bsd::check_signal_handler(int sig) {
3269   char buf[O_BUFLEN];
3270   address jvmHandler = NULL;
3271 
3272 
3273   struct sigaction act;
3274   if (os_sigaction == NULL) {
3275     // only trust the default sigaction, in case it has been interposed
3276     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3277     if (os_sigaction == NULL) return;
3278   }
3279 
3280   os_sigaction(sig, (struct sigaction*)NULL, &act);
3281 
3282 
3283   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3284 
3285   address thisHandler = (act.sa_flags & SA_SIGINFO)
3286     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3287     : CAST_FROM_FN_PTR(address, act.sa_handler);
3288 
3289 
3290   switch (sig) {
3291   case SIGSEGV:
3292   case SIGBUS:
3293   case SIGFPE:
3294   case SIGPIPE:
3295   case SIGILL:
3296   case SIGXFSZ:
3297     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3298     break;
3299 
3300   case SHUTDOWN1_SIGNAL:
3301   case SHUTDOWN2_SIGNAL:
3302   case SHUTDOWN3_SIGNAL:
3303   case BREAK_SIGNAL:
3304     jvmHandler = (address)user_handler();
3305     break;
3306 
3307   default:
3308     if (sig == SR_signum) {
3309       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3310     } else {
3311       return;
3312     }
3313     break;
3314   }
3315 
3316   if (thisHandler != jvmHandler) {
3317     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3318     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3319     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3320     // No need to check this sig any longer
3321     sigaddset(&check_signal_done, sig);
3322     // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3323     if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3324       tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3325                     exception_name(sig, buf, O_BUFLEN));
3326     }
3327   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3328     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3329     tty->print("expected:");
3330     os::Posix::print_sa_flags(tty, os::Bsd::get_our_sigflags(sig));
3331     tty->cr();
3332     tty->print("  found:");
3333     os::Posix::print_sa_flags(tty, act.sa_flags);
3334     tty->cr();
3335     // No need to check this sig any longer
3336     sigaddset(&check_signal_done, sig);
3337   }
3338 
3339   // Dump all the signal
3340   if (sigismember(&check_signal_done, sig)) {
3341     print_signal_handlers(tty, buf, O_BUFLEN);
3342   }
3343 }
3344 
3345 extern void report_error(char* file_name, int line_no, char* title,
3346                          char* format, ...);
3347 
3348 // this is called _before_ the most of global arguments have been parsed
3349 void os::init(void) {
3350   char dummy;   // used to get a guess on initial stack address
3351 
3352   // With BsdThreads the JavaMain thread pid (primordial thread)
3353   // is different than the pid of the java launcher thread.
3354   // So, on Bsd, the launcher thread pid is passed to the VM
3355   // via the sun.java.launcher.pid property.
3356   // Use this property instead of getpid() if it was correctly passed.
3357   // See bug 6351349.
3358   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3359 
3360   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3361 
3362   clock_tics_per_sec = CLK_TCK;
3363 
3364   init_random(1234567);
3365 
3366   Bsd::set_page_size(getpagesize());
3367   if (Bsd::page_size() == -1) {
3368     fatal("os_bsd.cpp: os::init: sysconf failed (%s)", os::strerror(errno));
3369   }
3370   init_page_sizes((size_t) Bsd::page_size());
3371 
3372   Bsd::initialize_system_info();
3373 
3374   // main_thread points to the aboriginal thread
3375   Bsd::_main_thread = pthread_self();
3376 
3377   Bsd::clock_init();
3378   initial_time_count = javaTimeNanos();
3379 
3380 #ifdef __APPLE__
3381   // XXXDARWIN
3382   // Work around the unaligned VM callbacks in hotspot's
3383   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3384   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3385   // alignment when doing symbol lookup. To work around this, we force early
3386   // binding of all symbols now, thus binding when alignment is known-good.
3387   _dyld_bind_fully_image_containing_address((const void *) &os::init);
3388 #endif
3389 
3390   os::Posix::init();
3391 }
3392 
3393 // To install functions for atexit system call
3394 extern "C" {
3395   static void perfMemory_exit_helper() {
3396     perfMemory_exit();
3397   }
3398 }
3399 
3400 // this is called _after_ the global arguments have been parsed
3401 jint os::init_2(void) {
3402 
3403   os::Posix::init_2();
3404 
3405   // Allocate a single page and mark it as readable for safepoint polling
3406   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3407   guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page");
3408 
3409   os::set_polling_page(polling_page);
3410   log_info(os)("SafePoint Polling address: " INTPTR_FORMAT, p2i(polling_page));
3411 
3412   if (!UseMembar) {
3413     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3414     guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3415     os::set_memory_serialize_page(mem_serialize_page);
3416     log_info(os)("Memory Serialize Page address: " INTPTR_FORMAT, p2i(mem_serialize_page));
3417   }
3418 
3419   // initialize suspend/resume support - must do this before signal_sets_init()
3420   if (SR_initialize() != 0) {
3421     perror("SR_initialize failed");
3422     return JNI_ERR;
3423   }
3424 
3425   Bsd::signal_sets_init();
3426   Bsd::install_signal_handlers();
3427 
3428   // Check and sets minimum stack sizes against command line options
3429   if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
3430     return JNI_ERR;
3431   }
3432 
3433   if (MaxFDLimit) {
3434     // set the number of file descriptors to max. print out error
3435     // if getrlimit/setrlimit fails but continue regardless.
3436     struct rlimit nbr_files;
3437     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3438     if (status != 0) {
3439       log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3440     } else {
3441       nbr_files.rlim_cur = nbr_files.rlim_max;
3442 
3443 #ifdef __APPLE__
3444       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3445       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3446       // be used instead
3447       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3448 #endif
3449 
3450       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3451       if (status != 0) {
3452         log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3453       }
3454     }
3455   }
3456 
3457   // at-exit methods are called in the reverse order of their registration.
3458   // atexit functions are called on return from main or as a result of a
3459   // call to exit(3C). There can be only 32 of these functions registered
3460   // and atexit() does not set errno.
3461 
3462   if (PerfAllowAtExitRegistration) {
3463     // only register atexit functions if PerfAllowAtExitRegistration is set.
3464     // atexit functions can be delayed until process exit time, which
3465     // can be problematic for embedded VM situations. Embedded VMs should
3466     // call DestroyJavaVM() to assure that VM resources are released.
3467 
3468     // note: perfMemory_exit_helper atexit function may be removed in
3469     // the future if the appropriate cleanup code can be added to the
3470     // VM_Exit VMOperation's doit method.
3471     if (atexit(perfMemory_exit_helper) != 0) {
3472       warning("os::init_2 atexit(perfMemory_exit_helper) failed");
3473     }
3474   }
3475 
3476   // initialize thread priority policy
3477   prio_init();
3478 
3479 #ifdef __APPLE__
3480   // dynamically link to objective c gc registration
3481   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3482   if (handleLibObjc != NULL) {
3483     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3484   }
3485 #endif
3486 
3487   return JNI_OK;
3488 }
3489 
3490 // Mark the polling page as unreadable
3491 void os::make_polling_page_unreadable(void) {
3492   if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3493     fatal("Could not disable polling page");
3494   }
3495 }
3496 
3497 // Mark the polling page as readable
3498 void os::make_polling_page_readable(void) {
3499   if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3500     fatal("Could not enable polling page");
3501   }
3502 }
3503 
3504 int os::active_processor_count() {
3505   return _processor_count;
3506 }
3507 
3508 void os::set_native_thread_name(const char *name) {
3509 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3510   // This is only supported in Snow Leopard and beyond
3511   if (name != NULL) {
3512     // Add a "Java: " prefix to the name
3513     char buf[MAXTHREADNAMESIZE];
3514     snprintf(buf, sizeof(buf), "Java: %s", name);
3515     pthread_setname_np(buf);
3516   }
3517 #endif
3518 }
3519 
3520 bool os::distribute_processes(uint length, uint* distribution) {
3521   // Not yet implemented.
3522   return false;
3523 }
3524 
3525 bool os::bind_to_processor(uint processor_id) {
3526   // Not yet implemented.
3527   return false;
3528 }
3529 
3530 void os::SuspendedThreadTask::internal_do_task() {
3531   if (do_suspend(_thread->osthread())) {
3532     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3533     do_task(context);
3534     do_resume(_thread->osthread());
3535   }
3536 }
3537 
3538 ////////////////////////////////////////////////////////////////////////////////
3539 // debug support
3540 
3541 bool os::find(address addr, outputStream* st) {
3542   Dl_info dlinfo;
3543   memset(&dlinfo, 0, sizeof(dlinfo));
3544   if (dladdr(addr, &dlinfo) != 0) {
3545     st->print(INTPTR_FORMAT ": ", (intptr_t)addr);
3546     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3547       st->print("%s+%#x", dlinfo.dli_sname,
3548                 (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_saddr));
3549     } else if (dlinfo.dli_fbase != NULL) {
3550       st->print("<offset %#x>", (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_fbase));
3551     } else {
3552       st->print("<absolute address>");
3553     }
3554     if (dlinfo.dli_fname != NULL) {
3555       st->print(" in %s", dlinfo.dli_fname);
3556     }
3557     if (dlinfo.dli_fbase != NULL) {
3558       st->print(" at " INTPTR_FORMAT, (intptr_t)dlinfo.dli_fbase);
3559     }
3560     st->cr();
3561 
3562     if (Verbose) {
3563       // decode some bytes around the PC
3564       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3565       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3566       address       lowest = (address) dlinfo.dli_sname;
3567       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3568       if (begin < lowest)  begin = lowest;
3569       Dl_info dlinfo2;
3570       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3571           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3572         end = (address) dlinfo2.dli_saddr;
3573       }
3574       Disassembler::decode(begin, end, st);
3575     }
3576     return true;
3577   }
3578   return false;
3579 }
3580 
3581 ////////////////////////////////////////////////////////////////////////////////
3582 // misc
3583 
3584 // This does not do anything on Bsd. This is basically a hook for being
3585 // able to use structured exception handling (thread-local exception filters)
3586 // on, e.g., Win32.
3587 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3588                               const methodHandle& method, JavaCallArguments* args,
3589                               Thread* thread) {
3590   f(value, method, args, thread);
3591 }
3592 
3593 void os::print_statistics() {
3594 }
3595 
3596 bool os::message_box(const char* title, const char* message) {
3597   int i;
3598   fdStream err(defaultStream::error_fd());
3599   for (i = 0; i < 78; i++) err.print_raw("=");
3600   err.cr();
3601   err.print_raw_cr(title);
3602   for (i = 0; i < 78; i++) err.print_raw("-");
3603   err.cr();
3604   err.print_raw_cr(message);
3605   for (i = 0; i < 78; i++) err.print_raw("=");
3606   err.cr();
3607 
3608   char buf[16];
3609   // Prevent process from exiting upon "read error" without consuming all CPU
3610   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3611 
3612   return buf[0] == 'y' || buf[0] == 'Y';
3613 }
3614 
3615 int os::stat(const char *path, struct stat *sbuf) {
3616   char pathbuf[MAX_PATH];
3617   if (strlen(path) > MAX_PATH - 1) {
3618     errno = ENAMETOOLONG;
3619     return -1;
3620   }
3621   os::native_path(strcpy(pathbuf, path));
3622   return ::stat(pathbuf, sbuf);
3623 }
3624 
3625 static inline struct timespec get_mtime(const char* filename) {
3626   struct stat st;
3627   int ret = os::stat(filename, &st);
3628   assert(ret == 0, "failed to stat() file '%s': %s", filename, strerror(errno));
3629 #ifdef __APPLE__
3630   return st.st_mtimespec;
3631 #else
3632   return st.st_mtim;
3633 #endif
3634 }
3635 
3636 int os::compare_file_modified_times(const char* file1, const char* file2) {
3637   struct timespec filetime1 = get_mtime(file1);
3638   struct timespec filetime2 = get_mtime(file2);
3639   int diff = filetime1.tv_sec - filetime2.tv_sec;
3640   if (diff == 0) {
3641     return filetime1.tv_nsec - filetime2.tv_nsec;
3642   }
3643   return diff;
3644 }
3645 
3646 // Is a (classpath) directory empty?
3647 bool os::dir_is_empty(const char* path) {
3648   DIR *dir = NULL;
3649   struct dirent *ptr;
3650 
3651   dir = opendir(path);
3652   if (dir == NULL) return true;
3653 
3654   // Scan the directory
3655   bool result = true;
3656   char buf[sizeof(struct dirent) + MAX_PATH];
3657   while (result && (ptr = ::readdir(dir)) != NULL) {
3658     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3659       result = false;
3660     }
3661   }
3662   closedir(dir);
3663   return result;
3664 }
3665 
3666 // This code originates from JDK's sysOpen and open64_w
3667 // from src/solaris/hpi/src/system_md.c
3668 
3669 int os::open(const char *path, int oflag, int mode) {
3670   if (strlen(path) > MAX_PATH - 1) {
3671     errno = ENAMETOOLONG;
3672     return -1;
3673   }
3674   int fd;
3675 
3676   fd = ::open(path, oflag, mode);
3677   if (fd == -1) return -1;
3678 
3679   // If the open succeeded, the file might still be a directory
3680   {
3681     struct stat buf;
3682     int ret = ::fstat(fd, &buf);
3683     int st_mode = buf.st_mode;
3684 
3685     if (ret != -1) {
3686       if ((st_mode & S_IFMT) == S_IFDIR) {
3687         errno = EISDIR;
3688         ::close(fd);
3689         return -1;
3690       }
3691     } else {
3692       ::close(fd);
3693       return -1;
3694     }
3695   }
3696 
3697   // All file descriptors that are opened in the JVM and not
3698   // specifically destined for a subprocess should have the
3699   // close-on-exec flag set.  If we don't set it, then careless 3rd
3700   // party native code might fork and exec without closing all
3701   // appropriate file descriptors (e.g. as we do in closeDescriptors in
3702   // UNIXProcess.c), and this in turn might:
3703   //
3704   // - cause end-of-file to fail to be detected on some file
3705   //   descriptors, resulting in mysterious hangs, or
3706   //
3707   // - might cause an fopen in the subprocess to fail on a system
3708   //   suffering from bug 1085341.
3709   //
3710   // (Yes, the default setting of the close-on-exec flag is a Unix
3711   // design flaw)
3712   //
3713   // See:
3714   // 1085341: 32-bit stdio routines should support file descriptors >255
3715   // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3716   // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3717   //
3718 #ifdef FD_CLOEXEC
3719   {
3720     int flags = ::fcntl(fd, F_GETFD);
3721     if (flags != -1) {
3722       ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3723     }
3724   }
3725 #endif
3726 
3727   return fd;
3728 }
3729 
3730 
3731 // create binary file, rewriting existing file if required
3732 int os::create_binary_file(const char* path, bool rewrite_existing) {
3733   int oflags = O_WRONLY | O_CREAT;
3734   if (!rewrite_existing) {
3735     oflags |= O_EXCL;
3736   }
3737   return ::open(path, oflags, S_IREAD | S_IWRITE);
3738 }
3739 
3740 // return current position of file pointer
3741 jlong os::current_file_offset(int fd) {
3742   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3743 }
3744 
3745 // move file pointer to the specified offset
3746 jlong os::seek_to_file_offset(int fd, jlong offset) {
3747   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3748 }
3749 
3750 // This code originates from JDK's sysAvailable
3751 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3752 
3753 int os::available(int fd, jlong *bytes) {
3754   jlong cur, end;
3755   int mode;
3756   struct stat buf;
3757 
3758   if (::fstat(fd, &buf) >= 0) {
3759     mode = buf.st_mode;
3760     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3761       int n;
3762       if (::ioctl(fd, FIONREAD, &n) >= 0) {
3763         *bytes = n;
3764         return 1;
3765       }
3766     }
3767   }
3768   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3769     return 0;
3770   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3771     return 0;
3772   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3773     return 0;
3774   }
3775   *bytes = end - cur;
3776   return 1;
3777 }
3778 
3779 // Map a block of memory.
3780 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3781                         char *addr, size_t bytes, bool read_only,
3782                         bool allow_exec) {
3783   int prot;
3784   int flags;
3785 
3786   if (read_only) {
3787     prot = PROT_READ;
3788     flags = MAP_SHARED;
3789   } else {
3790     prot = PROT_READ | PROT_WRITE;
3791     flags = MAP_PRIVATE;
3792   }
3793 
3794   if (allow_exec) {
3795     prot |= PROT_EXEC;
3796   }
3797 
3798   if (addr != NULL) {
3799     flags |= MAP_FIXED;
3800   }
3801 
3802   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3803                                      fd, file_offset);
3804   if (mapped_address == MAP_FAILED) {
3805     return NULL;
3806   }
3807   return mapped_address;
3808 }
3809 
3810 
3811 // Remap a block of memory.
3812 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3813                           char *addr, size_t bytes, bool read_only,
3814                           bool allow_exec) {
3815   // same as map_memory() on this OS
3816   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3817                         allow_exec);
3818 }
3819 
3820 
3821 // Unmap a block of memory.
3822 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3823   return munmap(addr, bytes) == 0;
3824 }
3825 
3826 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3827 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3828 // of a thread.
3829 //
3830 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3831 // the fast estimate available on the platform.
3832 
3833 jlong os::current_thread_cpu_time() {
3834 #ifdef __APPLE__
3835   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3836 #else
3837   Unimplemented();
3838   return 0;
3839 #endif
3840 }
3841 
3842 jlong os::thread_cpu_time(Thread* thread) {
3843 #ifdef __APPLE__
3844   return os::thread_cpu_time(thread, true /* user + sys */);
3845 #else
3846   Unimplemented();
3847   return 0;
3848 #endif
3849 }
3850 
3851 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3852 #ifdef __APPLE__
3853   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3854 #else
3855   Unimplemented();
3856   return 0;
3857 #endif
3858 }
3859 
3860 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3861 #ifdef __APPLE__
3862   struct thread_basic_info tinfo;
3863   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
3864   kern_return_t kr;
3865   thread_t mach_thread;
3866 
3867   mach_thread = thread->osthread()->thread_id();
3868   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
3869   if (kr != KERN_SUCCESS) {
3870     return -1;
3871   }
3872 
3873   if (user_sys_cpu_time) {
3874     jlong nanos;
3875     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
3876     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
3877     return nanos;
3878   } else {
3879     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
3880   }
3881 #else
3882   Unimplemented();
3883   return 0;
3884 #endif
3885 }
3886 
3887 
3888 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3889   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3890   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3891   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3892   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3893 }
3894 
3895 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3896   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
3897   info_ptr->may_skip_backward = false;     // elapsed time not wall time
3898   info_ptr->may_skip_forward = false;      // elapsed time not wall time
3899   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
3900 }
3901 
3902 bool os::is_thread_cpu_time_supported() {
3903 #ifdef __APPLE__
3904   return true;
3905 #else
3906   return false;
3907 #endif
3908 }
3909 
3910 // System loadavg support.  Returns -1 if load average cannot be obtained.
3911 // Bsd doesn't yet have a (official) notion of processor sets,
3912 // so just return the system wide load average.
3913 int os::loadavg(double loadavg[], int nelem) {
3914   return ::getloadavg(loadavg, nelem);
3915 }
3916 
3917 void os::pause() {
3918   char filename[MAX_PATH];
3919   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
3920     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
3921   } else {
3922     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
3923   }
3924 
3925   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
3926   if (fd != -1) {
3927     struct stat buf;
3928     ::close(fd);
3929     while (::stat(filename, &buf) == 0) {
3930       (void)::poll(NULL, 0, 100);
3931     }
3932   } else {
3933     jio_fprintf(stderr,
3934                 "Could not open pause file '%s', continuing immediately.\n", filename);
3935   }
3936 }
3937 
3938 // Darwin has no "environ" in a dynamic library.
3939 #ifdef __APPLE__
3940   #include <crt_externs.h>
3941   #define environ (*_NSGetEnviron())
3942 #else
3943 extern char** environ;
3944 #endif
3945 
3946 // Run the specified command in a separate process. Return its exit value,
3947 // or -1 on failure (e.g. can't fork a new process).
3948 // Unlike system(), this function can be called from signal handler. It
3949 // doesn't block SIGINT et al.
3950 int os::fork_and_exec(char* cmd) {
3951   const char * argv[4] = {"sh", "-c", cmd, NULL};
3952 
3953   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
3954   // pthread_atfork handlers and reset pthread library. All we need is a
3955   // separate process to execve. Make a direct syscall to fork process.
3956   // On IA64 there's no fork syscall, we have to use fork() and hope for
3957   // the best...
3958   pid_t pid = fork();
3959 
3960   if (pid < 0) {
3961     // fork failed
3962     return -1;
3963 
3964   } else if (pid == 0) {
3965     // child process
3966 
3967     // execve() in BsdThreads will call pthread_kill_other_threads_np()
3968     // first to kill every thread on the thread list. Because this list is
3969     // not reset by fork() (see notes above), execve() will instead kill
3970     // every thread in the parent process. We know this is the only thread
3971     // in the new process, so make a system call directly.
3972     // IA64 should use normal execve() from glibc to match the glibc fork()
3973     // above.
3974     execve("/bin/sh", (char* const*)argv, environ);
3975 
3976     // execve failed
3977     _exit(-1);
3978 
3979   } else  {
3980     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
3981     // care about the actual exit code, for now.
3982 
3983     int status;
3984 
3985     // Wait for the child process to exit.  This returns immediately if
3986     // the child has already exited. */
3987     while (waitpid(pid, &status, 0) < 0) {
3988       switch (errno) {
3989       case ECHILD: return 0;
3990       case EINTR: break;
3991       default: return -1;
3992       }
3993     }
3994 
3995     if (WIFEXITED(status)) {
3996       // The child exited normally; get its exit code.
3997       return WEXITSTATUS(status);
3998     } else if (WIFSIGNALED(status)) {
3999       // The child exited because of a signal
4000       // The best value to return is 0x80 + signal number,
4001       // because that is what all Unix shells do, and because
4002       // it allows callers to distinguish between process exit and
4003       // process death by signal.
4004       return 0x80 + WTERMSIG(status);
4005     } else {
4006       // Unknown exit code; pass it through
4007       return status;
4008     }
4009   }
4010 }
4011 
4012 // is_headless_jre()
4013 //
4014 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4015 // in order to report if we are running in a headless jre
4016 //
4017 // Since JDK8 xawt/libmawt.so was moved into the same directory
4018 // as libawt.so, and renamed libawt_xawt.so
4019 //
4020 bool os::is_headless_jre() {
4021 #ifdef __APPLE__
4022   // We no longer build headless-only on Mac OS X
4023   return false;
4024 #else
4025   struct stat statbuf;
4026   char buf[MAXPATHLEN];
4027   char libmawtpath[MAXPATHLEN];
4028   const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
4029   const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4030   char *p;
4031 
4032   // Get path to libjvm.so
4033   os::jvm_path(buf, sizeof(buf));
4034 
4035   // Get rid of libjvm.so
4036   p = strrchr(buf, '/');
4037   if (p == NULL) {
4038     return false;
4039   } else {
4040     *p = '\0';
4041   }
4042 
4043   // Get rid of client or server
4044   p = strrchr(buf, '/');
4045   if (p == NULL) {
4046     return false;
4047   } else {
4048     *p = '\0';
4049   }
4050 
4051   // check xawt/libmawt.so
4052   strcpy(libmawtpath, buf);
4053   strcat(libmawtpath, xawtstr);
4054   if (::stat(libmawtpath, &statbuf) == 0) return false;
4055 
4056   // check libawt_xawt.so
4057   strcpy(libmawtpath, buf);
4058   strcat(libmawtpath, new_xawtstr);
4059   if (::stat(libmawtpath, &statbuf) == 0) return false;
4060 
4061   return true;
4062 #endif
4063 }
4064 
4065 // Get the default path to the core file
4066 // Returns the length of the string
4067 int os::get_core_path(char* buffer, size_t bufferSize) {
4068   int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
4069 
4070   // Truncate if theoretical string was longer than bufferSize
4071   n = MIN2(n, (int)bufferSize);
4072 
4073   return n;
4074 }
4075 
4076 #ifndef PRODUCT
4077 void TestReserveMemorySpecial_test() {
4078   // No tests available for this platform
4079 }
4080 #endif
4081 
4082 bool os::start_debugging(char *buf, int buflen) {
4083   int len = (int)strlen(buf);
4084   char *p = &buf[len];
4085 
4086   jio_snprintf(p, buflen-len,
4087              "\n\n"
4088              "Do you want to debug the problem?\n\n"
4089              "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT " (" INTPTR_FORMAT ")\n"
4090              "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
4091              "Otherwise, press RETURN to abort...",
4092              os::current_process_id(), os::current_process_id(),
4093              os::current_thread_id(), os::current_thread_id());
4094 
4095   bool yes = os::message_box("Unexpected Error", buf);
4096 
4097   if (yes) {
4098     // yes, user asked VM to launch debugger
4099     jio_snprintf(buf, sizeof(buf), "gdb /proc/%d/exe %d",
4100                      os::current_process_id(), os::current_process_id());
4101 
4102     os::fork_and_exec(buf);
4103     yes = false;
4104   }
4105   return yes;
4106 }