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