1 /*
   2  * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 // no precompiled headers
  26 #include "classfile/classLoader.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/vmSymbols.hpp"
  29 #include "code/icBuffer.hpp"
  30 #include "code/vtableStubs.hpp"
  31 #include "compiler/compileBroker.hpp"
  32 #include "compiler/disassembler.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "jvm_bsd.h"
  35 #include "memory/allocation.inline.hpp"
  36 #include "memory/filemap.hpp"
  37 #include "mutex_bsd.inline.hpp"
  38 #include "oops/oop.inline.hpp"
  39 #include "os_share_bsd.hpp"
  40 #include "prims/jniFastGetField.hpp"
  41 #include "prims/jvm.h"
  42 #include "prims/jvm_misc.hpp"
  43 #include "runtime/arguments.hpp"
  44 #include "runtime/extendedPC.hpp"
  45 #include "runtime/globals.hpp"
  46 #include "runtime/interfaceSupport.hpp"
  47 #include "runtime/java.hpp"
  48 #include "runtime/javaCalls.hpp"
  49 #include "runtime/mutexLocker.hpp"
  50 #include "runtime/objectMonitor.hpp"
  51 #include "runtime/osThread.hpp"
  52 #include "runtime/perfMemory.hpp"
  53 #include "runtime/sharedRuntime.hpp"
  54 #include "runtime/statSampler.hpp"
  55 #include "runtime/stubRoutines.hpp"
  56 #include "runtime/thread.inline.hpp"
  57 #include "runtime/threadCritical.hpp"
  58 #include "runtime/timer.hpp"
  59 #include "services/attachListener.hpp"
  60 #include "services/memTracker.hpp"
  61 #include "services/runtimeService.hpp"
  62 #include "utilities/decoder.hpp"
  63 #include "utilities/defaultStream.hpp"
  64 #include "utilities/events.hpp"
  65 #include "utilities/growableArray.hpp"
  66 #include "utilities/vmError.hpp"
  67 
  68 // put OS-includes here
  69 # include <sys/types.h>
  70 # include <sys/mman.h>
  71 # include <sys/stat.h>
  72 # include <sys/select.h>
  73 # include <pthread.h>
  74 # include <signal.h>
  75 # include <errno.h>
  76 # include <dlfcn.h>
  77 # include <stdio.h>
  78 # include <unistd.h>
  79 # include <sys/resource.h>
  80 # include <pthread.h>
  81 # include <sys/stat.h>
  82 # include <sys/time.h>
  83 # include <sys/times.h>
  84 # include <sys/utsname.h>
  85 # include <sys/socket.h>
  86 # include <sys/wait.h>
  87 # include <time.h>
  88 # include <pwd.h>
  89 # include <poll.h>
  90 # include <semaphore.h>
  91 # include <fcntl.h>
  92 # include <string.h>
  93 # include <sys/param.h>
  94 # include <sys/sysctl.h>
  95 # include <sys/ipc.h>
  96 # include <sys/shm.h>
  97 #ifndef __APPLE__
  98 # include <link.h>
  99 #endif
 100 # include <stdint.h>
 101 # include <inttypes.h>
 102 # include <sys/ioctl.h>
 103 # include <sys/syscall.h>
 104 
 105 #if defined(__FreeBSD__) || defined(__NetBSD__)
 106 # include <elf.h>
 107 #endif
 108 
 109 #ifdef __APPLE__
 110 # include <mach/mach.h> // semaphore_* API
 111 # include <mach-o/dyld.h>
 112 # include <sys/proc_info.h>
 113 # include <objc/objc-auto.h>
 114 #endif
 115 
 116 #ifndef MAP_ANONYMOUS
 117 #define MAP_ANONYMOUS MAP_ANON
 118 #endif
 119 
 120 #define MAX_PATH    (2 * K)
 121 
 122 // for timer info max values which include all bits
 123 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
 124 
 125 #define LARGEPAGES_BIT (1 << 6)
 126 ////////////////////////////////////////////////////////////////////////////////
 127 // global variables
 128 julong os::Bsd::_physical_memory = 0;
 129 
 130 
 131 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
 132 pthread_t os::Bsd::_main_thread;
 133 int os::Bsd::_page_size = -1;
 134 
 135 static jlong initial_time_count=0;
 136 
 137 static int clock_tics_per_sec = 100;
 138 
 139 // For diagnostics to print a message once. see run_periodic_checks
 140 static sigset_t check_signal_done;
 141 static bool check_signals = true;
 142 
 143 static pid_t _initial_pid = 0;
 144 
 145 /* Signal number used to suspend/resume a thread */
 146 
 147 /* do not use any signal number less than SIGSEGV, see 4355769 */
 148 static int SR_signum = SIGUSR2;
 149 sigset_t SR_sigset;
 150 
 151 
 152 ////////////////////////////////////////////////////////////////////////////////
 153 // utility functions
 154 
 155 static int SR_initialize();
 156 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
 157 
 158 julong os::available_memory() {
 159   return Bsd::available_memory();
 160 }
 161 
 162 // available here means free
 163 julong os::Bsd::available_memory() {
 164   uint64_t available = physical_memory() >> 2;
 165 #ifdef __APPLE__
 166   mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
 167   vm_statistics64_data_t vmstat;
 168   kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
 169                                          (host_info64_t)&vmstat, &count);
 170   assert(kerr == KERN_SUCCESS,
 171          "host_statistics64 failed - check mach_host_self() and count");
 172   if (kerr == KERN_SUCCESS) {
 173     available = vmstat.free_count * os::vm_page_size();
 174   }
 175 #endif
 176   return available;
 177 }
 178 
 179 julong os::physical_memory() {
 180   return Bsd::physical_memory();
 181 }
 182 
 183 ////////////////////////////////////////////////////////////////////////////////
 184 // environment support
 185 
 186 bool os::getenv(const char* name, char* buf, int len) {
 187   const char* val = ::getenv(name);
 188   if (val != NULL && strlen(val) < (size_t)len) {
 189     strcpy(buf, val);
 190     return true;
 191   }
 192   if (len > 0) buf[0] = 0;  // return a null string
 193   return false;
 194 }
 195 
 196 
 197 // Return true if user is running as root.
 198 
 199 bool os::have_special_privileges() {
 200   static bool init = false;
 201   static bool privileges = false;
 202   if (!init) {
 203     privileges = (getuid() != geteuid()) || (getgid() != getegid());
 204     init = true;
 205   }
 206   return privileges;
 207 }
 208 
 209 
 210 
 211 // Cpu architecture string
 212 #if   defined(ZERO)
 213 static char cpu_arch[] = ZERO_LIBARCH;
 214 #elif defined(IA64)
 215 static char cpu_arch[] = "ia64";
 216 #elif defined(IA32)
 217 static char cpu_arch[] = "i386";
 218 #elif defined(AMD64)
 219 static char cpu_arch[] = "amd64";
 220 #elif defined(ARM)
 221 static char cpu_arch[] = "arm";
 222 #elif defined(PPC)
 223 static char cpu_arch[] = "ppc";
 224 #elif defined(SPARC)
 225 #  ifdef _LP64
 226 static char cpu_arch[] = "sparcv9";
 227 #  else
 228 static char cpu_arch[] = "sparc";
 229 #  endif
 230 #else
 231 #error Add appropriate cpu_arch setting
 232 #endif
 233 
 234 // Compiler variant
 235 #ifdef COMPILER2
 236 #define COMPILER_VARIANT "server"
 237 #else
 238 #define COMPILER_VARIANT "client"
 239 #endif
 240 
 241 
 242 void os::Bsd::initialize_system_info() {
 243   int mib[2];
 244   size_t len;
 245   int cpu_val;
 246   julong mem_val;
 247 
 248   /* get processors count via hw.ncpus sysctl */
 249   mib[0] = CTL_HW;
 250   mib[1] = HW_NCPU;
 251   len = sizeof(cpu_val);
 252   if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
 253        assert(len == sizeof(cpu_val), "unexpected data size");
 254        set_processor_count(cpu_val);
 255   }
 256   else {
 257        set_processor_count(1);   // fallback
 258   }
 259 
 260   /* get physical memory via hw.memsize sysctl (hw.memsize is used
 261    * since it returns a 64 bit value)
 262    */
 263   mib[0] = CTL_HW;
 264 
 265 #if defined (HW_MEMSIZE) // Apple
 266   mib[1] = HW_MEMSIZE;
 267 #elif defined(HW_PHYSMEM) // Most of BSD
 268   mib[1] = HW_PHYSMEM;
 269 #elif defined(HW_REALMEM) // Old FreeBSD
 270   mib[1] = HW_REALMEM;
 271 #else
 272   #error No ways to get physmem
 273 #endif
 274 
 275   len = sizeof(mem_val);
 276   if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
 277        assert(len == sizeof(mem_val), "unexpected data size");
 278        _physical_memory = mem_val;
 279   } else {
 280        _physical_memory = 256*1024*1024;       // fallback (XXXBSD?)
 281   }
 282 
 283 #ifdef __OpenBSD__
 284   {
 285        // limit _physical_memory memory view on OpenBSD since
 286        // datasize rlimit restricts us anyway.
 287        struct rlimit limits;
 288        getrlimit(RLIMIT_DATA, &limits);
 289        _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
 290   }
 291 #endif
 292 }
 293 
 294 #ifdef __APPLE__
 295 static const char *get_home() {
 296   const char *home_dir = ::getenv("HOME");
 297   if ((home_dir == NULL) || (*home_dir == '\0')) {
 298     struct passwd *passwd_info = getpwuid(geteuid());
 299     if (passwd_info != NULL) {
 300       home_dir = passwd_info->pw_dir;
 301     }
 302   }
 303 
 304   return home_dir;
 305 }
 306 #endif
 307 
 308 void os::init_system_properties_values() {
 309 //  char arch[12];
 310 //  sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
 311 
 312   // The next steps are taken in the product version:
 313   //
 314   // Obtain the JAVA_HOME value from the location of libjvm.so.
 315   // This library should be located at:
 316   // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
 317   //
 318   // If "/jre/lib/" appears at the right place in the path, then we
 319   // assume libjvm.so is installed in a JDK and we use this path.
 320   //
 321   // Otherwise exit with message: "Could not create the Java virtual machine."
 322   //
 323   // The following extra steps are taken in the debugging version:
 324   //
 325   // If "/jre/lib/" does NOT appear at the right place in the path
 326   // instead of exit check for $JAVA_HOME environment variable.
 327   //
 328   // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
 329   // then we append a fake suffix "hotspot/libjvm.so" to this path so
 330   // it looks like libjvm.so is installed there
 331   // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
 332   //
 333   // Otherwise exit.
 334   //
 335   // Important note: if the location of libjvm.so changes this
 336   // code needs to be changed accordingly.
 337 
 338   // The next few definitions allow the code to be verbatim:
 339 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal)
 340 #define getenv(n) ::getenv(n)
 341 
 342 /*
 343  * See ld(1):
 344  *      The linker uses the following search paths to locate required
 345  *      shared libraries:
 346  *        1: ...
 347  *        ...
 348  *        7: The default directories, normally /lib and /usr/lib.
 349  */
 350 #ifndef DEFAULT_LIBPATH
 351 #define DEFAULT_LIBPATH "/lib:/usr/lib"
 352 #endif
 353 
 354 #define EXTENSIONS_DIR  "/lib/ext"
 355 #define ENDORSED_DIR    "/lib/endorsed"
 356 #define REG_DIR         "/usr/java/packages"
 357 
 358 #ifdef __APPLE__
 359 #define SYS_EXTENSIONS_DIR   "/Library/Java/Extensions"
 360 #define SYS_EXTENSIONS_DIRS  SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
 361         const char *user_home_dir = get_home();
 362         // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir
 363         int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
 364             sizeof(SYS_EXTENSIONS_DIRS);
 365 #endif
 366 
 367   {
 368     /* sysclasspath, java_home, dll_dir */
 369     {
 370         char *home_path;
 371         char *dll_path;
 372         char *pslash;
 373         char buf[MAXPATHLEN];
 374         os::jvm_path(buf, sizeof(buf));
 375 
 376         // Found the full path to libjvm.so.
 377         // Now cut the path to <java_home>/jre if we can.
 378         *(strrchr(buf, '/')) = '\0';  /* get rid of /libjvm.so */
 379         pslash = strrchr(buf, '/');
 380         if (pslash != NULL)
 381             *pslash = '\0';           /* get rid of /{client|server|hotspot} */
 382         dll_path = malloc(strlen(buf) + 1);
 383         if (dll_path == NULL)
 384             return;
 385         strcpy(dll_path, buf);
 386         Arguments::set_dll_dir(dll_path);
 387 
 388         if (pslash != NULL) {
 389             pslash = strrchr(buf, '/');
 390             if (pslash != NULL) {
 391                 *pslash = '\0';       /* get rid of /<arch> (/lib on macosx) */
 392 #ifndef __APPLE__
 393                 pslash = strrchr(buf, '/');
 394                 if (pslash != NULL)
 395                     *pslash = '\0';   /* get rid of /lib */
 396 #endif
 397             }
 398         }
 399 
 400         home_path = malloc(strlen(buf) + 1);
 401         if (home_path == NULL)
 402             return;
 403         strcpy(home_path, buf);
 404         Arguments::set_java_home(home_path);
 405 
 406         if (!set_boot_path('/', ':'))
 407             return;
 408     }
 409 
 410     /*
 411      * Where to look for native libraries
 412      *
 413      * Note: Due to a legacy implementation, most of the library path
 414      * is set in the launcher.  This was to accomodate linking restrictions
 415      * on legacy Bsd implementations (which are no longer supported).
 416      * Eventually, all the library path setting will be done here.
 417      *
 418      * However, to prevent the proliferation of improperly built native
 419      * libraries, the new path component /usr/java/packages is added here.
 420      * Eventually, all the library path setting will be done here.
 421      */
 422     {
 423         char *ld_library_path;
 424 
 425         /*
 426          * Construct the invariant part of ld_library_path. Note that the
 427          * space for the colon and the trailing null are provided by the
 428          * nulls included by the sizeof operator (so actually we allocate
 429          * a byte more than necessary).
 430          */
 431 #ifdef __APPLE__
 432         ld_library_path = (char *) malloc(system_ext_size);
 433         sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir);
 434 #else
 435         ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
 436             strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
 437         sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
 438 #endif
 439 
 440         /*
 441          * Get the user setting of LD_LIBRARY_PATH, and prepended it.  It
 442          * should always exist (until the legacy problem cited above is
 443          * addressed).
 444          */
 445 #ifdef __APPLE__
 446         // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper
 447         char *l = getenv("JAVA_LIBRARY_PATH");
 448         if (l != NULL) {
 449             char *t = ld_library_path;
 450             /* That's +1 for the colon and +1 for the trailing '\0' */
 451             ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1);
 452             sprintf(ld_library_path, "%s:%s", l, t);
 453             free(t);
 454         }
 455 
 456         char *v = getenv("DYLD_LIBRARY_PATH");
 457 #else
 458         char *v = getenv("LD_LIBRARY_PATH");
 459 #endif
 460         if (v != NULL) {
 461             char *t = ld_library_path;
 462             /* That's +1 for the colon and +1 for the trailing '\0' */
 463             ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
 464             sprintf(ld_library_path, "%s:%s", v, t);
 465             free(t);
 466         }
 467 
 468 #ifdef __APPLE__
 469         // Apple's Java6 has "." at the beginning of java.library.path.
 470         // OpenJDK on Windows has "." at the end of java.library.path.
 471         // OpenJDK on Linux and Solaris don't have "." in java.library.path
 472         // at all. To ease the transition from Apple's Java6 to OpenJDK7,
 473         // "." is appended to the end of java.library.path. Yes, this
 474         // could cause a change in behavior, but Apple's Java6 behavior
 475         // can be achieved by putting "." at the beginning of the
 476         // JAVA_LIBRARY_PATH environment variable.
 477         {
 478             char *t = ld_library_path;
 479             // that's +3 for appending ":." and the trailing '\0'
 480             ld_library_path = (char *) malloc(strlen(t) + 3);
 481             sprintf(ld_library_path, "%s:%s", t, ".");
 482             free(t);
 483         }
 484 #endif
 485 
 486         Arguments::set_library_path(ld_library_path);
 487     }
 488 
 489     /*
 490      * Extensions directories.
 491      *
 492      * Note that the space for the colon and the trailing null are provided
 493      * by the nulls included by the sizeof operator (so actually one byte more
 494      * than necessary is allocated).
 495      */
 496     {
 497 #ifdef __APPLE__
 498         char *buf = malloc(strlen(Arguments::get_java_home()) +
 499             sizeof(EXTENSIONS_DIR) + system_ext_size);
 500         sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":"
 501             SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home());
 502 #else
 503         char *buf = malloc(strlen(Arguments::get_java_home()) +
 504             sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
 505         sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
 506             Arguments::get_java_home());
 507 #endif
 508 
 509         Arguments::set_ext_dirs(buf);
 510     }
 511 
 512     /* Endorsed standards default directory. */
 513     {
 514         char * buf;
 515         buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
 516         sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
 517         Arguments::set_endorsed_dirs(buf);
 518     }
 519   }
 520 
 521 #ifdef __APPLE__
 522 #undef SYS_EXTENSIONS_DIR
 523 #endif
 524 #undef malloc
 525 #undef getenv
 526 #undef EXTENSIONS_DIR
 527 #undef ENDORSED_DIR
 528 
 529   // Done
 530   return;
 531 }
 532 
 533 ////////////////////////////////////////////////////////////////////////////////
 534 // breakpoint support
 535 
 536 void os::breakpoint() {
 537   BREAKPOINT;
 538 }
 539 
 540 extern "C" void breakpoint() {
 541   // use debugger to set breakpoint here
 542 }
 543 
 544 ////////////////////////////////////////////////////////////////////////////////
 545 // signal support
 546 
 547 debug_only(static bool signal_sets_initialized = false);
 548 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
 549 
 550 bool os::Bsd::is_sig_ignored(int sig) {
 551       struct sigaction oact;
 552       sigaction(sig, (struct sigaction*)NULL, &oact);
 553       void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*,  oact.sa_sigaction)
 554                                      : CAST_FROM_FN_PTR(void*,  oact.sa_handler);
 555       if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
 556            return true;
 557       else
 558            return false;
 559 }
 560 
 561 void os::Bsd::signal_sets_init() {
 562   // Should also have an assertion stating we are still single-threaded.
 563   assert(!signal_sets_initialized, "Already initialized");
 564   // Fill in signals that are necessarily unblocked for all threads in
 565   // the VM. Currently, we unblock the following signals:
 566   // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
 567   //                         by -Xrs (=ReduceSignalUsage));
 568   // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
 569   // other threads. The "ReduceSignalUsage" boolean tells us not to alter
 570   // the dispositions or masks wrt these signals.
 571   // Programs embedding the VM that want to use the above signals for their
 572   // own purposes must, at this time, use the "-Xrs" option to prevent
 573   // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
 574   // (See bug 4345157, and other related bugs).
 575   // In reality, though, unblocking these signals is really a nop, since
 576   // these signals are not blocked by default.
 577   sigemptyset(&unblocked_sigs);
 578   sigemptyset(&allowdebug_blocked_sigs);
 579   sigaddset(&unblocked_sigs, SIGILL);
 580   sigaddset(&unblocked_sigs, SIGSEGV);
 581   sigaddset(&unblocked_sigs, SIGBUS);
 582   sigaddset(&unblocked_sigs, SIGFPE);
 583   sigaddset(&unblocked_sigs, SR_signum);
 584 
 585   if (!ReduceSignalUsage) {
 586    if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
 587       sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
 588       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
 589    }
 590    if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
 591       sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
 592       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
 593    }
 594    if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
 595       sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
 596       sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
 597    }
 598   }
 599   // Fill in signals that are blocked by all but the VM thread.
 600   sigemptyset(&vm_sigs);
 601   if (!ReduceSignalUsage)
 602     sigaddset(&vm_sigs, BREAK_SIGNAL);
 603   debug_only(signal_sets_initialized = true);
 604 
 605 }
 606 
 607 // These are signals that are unblocked while a thread is running Java.
 608 // (For some reason, they get blocked by default.)
 609 sigset_t* os::Bsd::unblocked_signals() {
 610   assert(signal_sets_initialized, "Not initialized");
 611   return &unblocked_sigs;
 612 }
 613 
 614 // These are the signals that are blocked while a (non-VM) thread is
 615 // running Java. Only the VM thread handles these signals.
 616 sigset_t* os::Bsd::vm_signals() {
 617   assert(signal_sets_initialized, "Not initialized");
 618   return &vm_sigs;
 619 }
 620 
 621 // These are signals that are blocked during cond_wait to allow debugger in
 622 sigset_t* os::Bsd::allowdebug_blocked_signals() {
 623   assert(signal_sets_initialized, "Not initialized");
 624   return &allowdebug_blocked_sigs;
 625 }
 626 
 627 void os::Bsd::hotspot_sigmask(Thread* thread) {
 628 
 629   //Save caller's signal mask before setting VM signal mask
 630   sigset_t caller_sigmask;
 631   pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
 632 
 633   OSThread* osthread = thread->osthread();
 634   osthread->set_caller_sigmask(caller_sigmask);
 635 
 636   pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
 637 
 638   if (!ReduceSignalUsage) {
 639     if (thread->is_VM_thread()) {
 640       // Only the VM thread handles BREAK_SIGNAL ...
 641       pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
 642     } else {
 643       // ... all other threads block BREAK_SIGNAL
 644       pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
 645     }
 646   }
 647 }
 648 
 649 
 650 //////////////////////////////////////////////////////////////////////////////
 651 // create new thread
 652 
 653 // check if it's safe to start a new thread
 654 static bool _thread_safety_check(Thread* thread) {
 655   return true;
 656 }
 657 
 658 #ifdef __APPLE__
 659 // library handle for calling objc_registerThreadWithCollector()
 660 // without static linking to the libobjc library
 661 #define OBJC_LIB "/usr/lib/libobjc.dylib"
 662 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
 663 typedef void (*objc_registerThreadWithCollector_t)();
 664 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
 665 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
 666 #endif
 667 
 668 #ifdef __APPLE__
 669 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
 670   // Additional thread_id used to correlate threads in SA
 671   thread_identifier_info_data_t     m_ident_info;
 672   mach_msg_type_number_t            count = THREAD_IDENTIFIER_INFO_COUNT;
 673 
 674   thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
 675               (thread_info_t) &m_ident_info, &count);
 676 
 677   return m_ident_info.thread_id;
 678 }
 679 #endif
 680 
 681 // Thread start routine for all newly created threads
 682 static void *java_start(Thread *thread) {
 683   // Try to randomize the cache line index of hot stack frames.
 684   // This helps when threads of the same stack traces evict each other's
 685   // cache lines. The threads can be either from the same JVM instance, or
 686   // from different JVM instances. The benefit is especially true for
 687   // processors with hyperthreading technology.
 688   static int counter = 0;
 689   int pid = os::current_process_id();
 690   alloca(((pid ^ counter++) & 7) * 128);
 691 
 692   ThreadLocalStorage::set_thread(thread);
 693 
 694   OSThread* osthread = thread->osthread();
 695   Monitor* sync = osthread->startThread_lock();
 696 
 697   // non floating stack BsdThreads needs extra check, see above
 698   if (!_thread_safety_check(thread)) {
 699     // notify parent thread
 700     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 701     osthread->set_state(ZOMBIE);
 702     sync->notify_all();
 703     return NULL;
 704   }
 705 
 706   osthread->set_thread_id(os::Bsd::gettid());
 707 
 708 #ifdef __APPLE__
 709   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 710   guarantee(unique_thread_id != 0, "unique thread id was not found");
 711   osthread->set_unique_thread_id(unique_thread_id);
 712 #endif
 713   // initialize signal mask for this thread
 714   os::Bsd::hotspot_sigmask(thread);
 715 
 716   // initialize floating point control register
 717   os::Bsd::init_thread_fpu_state();
 718 
 719 #ifdef __APPLE__
 720   // register thread with objc gc
 721   if (objc_registerThreadWithCollectorFunction != NULL) {
 722     objc_registerThreadWithCollectorFunction();
 723   }
 724 #endif
 725 
 726   // handshaking with parent thread
 727   {
 728     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
 729 
 730     // notify parent thread
 731     osthread->set_state(INITIALIZED);
 732     sync->notify_all();
 733 
 734     // wait until os::start_thread()
 735     while (osthread->get_state() == INITIALIZED) {
 736       sync->wait(Mutex::_no_safepoint_check_flag);
 737     }
 738   }
 739 
 740   // call one more level start routine
 741   thread->run();
 742 
 743   return 0;
 744 }
 745 
 746 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
 747   assert(thread->osthread() == NULL, "caller responsible");
 748 
 749   // Allocate the OSThread object
 750   OSThread* osthread = new OSThread(NULL, NULL);
 751   if (osthread == NULL) {
 752     return false;
 753   }
 754 
 755   // set the correct thread state
 756   osthread->set_thread_type(thr_type);
 757 
 758   // Initial state is ALLOCATED but not INITIALIZED
 759   osthread->set_state(ALLOCATED);
 760 
 761   thread->set_osthread(osthread);
 762 
 763   // init thread attributes
 764   pthread_attr_t attr;
 765   pthread_attr_init(&attr);
 766   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 767 
 768   // stack size
 769   if (os::Bsd::supports_variable_stack_size()) {
 770     // calculate stack size if it's not specified by caller
 771     if (stack_size == 0) {
 772       stack_size = os::Bsd::default_stack_size(thr_type);
 773 
 774       switch (thr_type) {
 775       case os::java_thread:
 776         // Java threads use ThreadStackSize which default value can be
 777         // changed with the flag -Xss
 778         assert (JavaThread::stack_size_at_create() > 0, "this should be set");
 779         stack_size = JavaThread::stack_size_at_create();
 780         break;
 781       case os::compiler_thread:
 782         if (CompilerThreadStackSize > 0) {
 783           stack_size = (size_t)(CompilerThreadStackSize * K);
 784           break;
 785         } // else fall through:
 786           // use VMThreadStackSize if CompilerThreadStackSize is not defined
 787       case os::vm_thread:
 788       case os::pgc_thread:
 789       case os::cgc_thread:
 790       case os::watcher_thread:
 791         if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
 792         break;
 793       }
 794     }
 795 
 796     stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
 797     pthread_attr_setstacksize(&attr, stack_size);
 798   } else {
 799     // let pthread_create() pick the default value.
 800   }
 801 
 802   ThreadState state;
 803 
 804   {
 805     pthread_t tid;
 806     int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
 807 
 808     pthread_attr_destroy(&attr);
 809 
 810     if (ret != 0) {
 811       if (PrintMiscellaneous && (Verbose || WizardMode)) {
 812         perror("pthread_create()");
 813       }
 814       // Need to clean up stuff we've allocated so far
 815       thread->set_osthread(NULL);
 816       delete osthread;
 817       return false;
 818     }
 819 
 820     // Store pthread info into the OSThread
 821     osthread->set_pthread_id(tid);
 822 
 823     // Wait until child thread is either initialized or aborted
 824     {
 825       Monitor* sync_with_child = osthread->startThread_lock();
 826       MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 827       while ((state = osthread->get_state()) == ALLOCATED) {
 828         sync_with_child->wait(Mutex::_no_safepoint_check_flag);
 829       }
 830     }
 831 
 832   }
 833 
 834   // Aborted due to thread limit being reached
 835   if (state == ZOMBIE) {
 836       thread->set_osthread(NULL);
 837       delete osthread;
 838       return false;
 839   }
 840 
 841   // The thread is returned suspended (in state INITIALIZED),
 842   // and is started higher up in the call chain
 843   assert(state == INITIALIZED, "race condition");
 844   return true;
 845 }
 846 
 847 /////////////////////////////////////////////////////////////////////////////
 848 // attach existing thread
 849 
 850 // bootstrap the main thread
 851 bool os::create_main_thread(JavaThread* thread) {
 852   assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
 853   return create_attached_thread(thread);
 854 }
 855 
 856 bool os::create_attached_thread(JavaThread* thread) {
 857 #ifdef ASSERT
 858     thread->verify_not_published();
 859 #endif
 860 
 861   // Allocate the OSThread object
 862   OSThread* osthread = new OSThread(NULL, NULL);
 863 
 864   if (osthread == NULL) {
 865     return false;
 866   }
 867 
 868   osthread->set_thread_id(os::Bsd::gettid());
 869 
 870   // Store pthread info into the OSThread
 871 #ifdef __APPLE__
 872   uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
 873   guarantee(unique_thread_id != 0, "just checking");
 874   osthread->set_unique_thread_id(unique_thread_id);
 875 #endif
 876   osthread->set_pthread_id(::pthread_self());
 877 
 878   // initialize floating point control register
 879   os::Bsd::init_thread_fpu_state();
 880 
 881   // Initial thread state is RUNNABLE
 882   osthread->set_state(RUNNABLE);
 883 
 884   thread->set_osthread(osthread);
 885 
 886   // initialize signal mask for this thread
 887   // and save the caller's signal mask
 888   os::Bsd::hotspot_sigmask(thread);
 889 
 890   return true;
 891 }
 892 
 893 void os::pd_start_thread(Thread* thread) {
 894   OSThread * osthread = thread->osthread();
 895   assert(osthread->get_state() != INITIALIZED, "just checking");
 896   Monitor* sync_with_child = osthread->startThread_lock();
 897   MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
 898   sync_with_child->notify();
 899 }
 900 
 901 // Free Bsd resources related to the OSThread
 902 void os::free_thread(OSThread* osthread) {
 903   assert(osthread != NULL, "osthread not set");
 904 
 905   if (Thread::current()->osthread() == osthread) {
 906     // Restore caller's signal mask
 907     sigset_t sigmask = osthread->caller_sigmask();
 908     pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
 909    }
 910 
 911   delete osthread;
 912 }
 913 
 914 //////////////////////////////////////////////////////////////////////////////
 915 // thread local storage
 916 
 917 int os::allocate_thread_local_storage() {
 918   pthread_key_t key;
 919   int rslt = pthread_key_create(&key, NULL);
 920   assert(rslt == 0, "cannot allocate thread local storage");
 921   return (int)key;
 922 }
 923 
 924 // Note: This is currently not used by VM, as we don't destroy TLS key
 925 // on VM exit.
 926 void os::free_thread_local_storage(int index) {
 927   int rslt = pthread_key_delete((pthread_key_t)index);
 928   assert(rslt == 0, "invalid index");
 929 }
 930 
 931 void os::thread_local_storage_at_put(int index, void* value) {
 932   int rslt = pthread_setspecific((pthread_key_t)index, value);
 933   assert(rslt == 0, "pthread_setspecific failed");
 934 }
 935 
 936 extern "C" Thread* get_thread() {
 937   return ThreadLocalStorage::thread();
 938 }
 939 
 940 
 941 ////////////////////////////////////////////////////////////////////////////////
 942 // time support
 943 
 944 // Time since start-up in seconds to a fine granularity.
 945 // Used by VMSelfDestructTimer and the MemProfiler.
 946 double os::elapsedTime() {
 947 
 948   return ((double)os::elapsed_counter()) / os::elapsed_frequency();
 949 }
 950 
 951 jlong os::elapsed_counter() {
 952   return javaTimeNanos() - initial_time_count;
 953 }
 954 
 955 jlong os::elapsed_frequency() {
 956   return NANOSECS_PER_SEC; // nanosecond resolution
 957 }
 958 
 959 bool os::supports_vtime() { return true; }
 960 bool os::enable_vtime()   { return false; }
 961 bool os::vtime_enabled()  { return false; }
 962 
 963 double os::elapsedVTime() {
 964   // better than nothing, but not much
 965   return elapsedTime();
 966 }
 967 
 968 jlong os::javaTimeMillis() {
 969   timeval time;
 970   int status = gettimeofday(&time, NULL);
 971   assert(status != -1, "bsd error");
 972   return jlong(time.tv_sec) * 1000  +  jlong(time.tv_usec / 1000);
 973 }
 974 
 975 #ifndef CLOCK_MONOTONIC
 976 #define CLOCK_MONOTONIC (1)
 977 #endif
 978 
 979 #ifdef __APPLE__
 980 void os::Bsd::clock_init() {
 981         // XXXDARWIN: Investigate replacement monotonic clock
 982 }
 983 #else
 984 void os::Bsd::clock_init() {
 985   struct timespec res;
 986   struct timespec tp;
 987   if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
 988       ::clock_gettime(CLOCK_MONOTONIC, &tp)  == 0) {
 989     // yes, monotonic clock is supported
 990     _clock_gettime = ::clock_gettime;
 991   }
 992 }
 993 #endif
 994 
 995 
 996 jlong os::javaTimeNanos() {
 997   if (Bsd::supports_monotonic_clock()) {
 998     struct timespec tp;
 999     int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp);
1000     assert(status == 0, "gettime error");
1001     jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1002     return result;
1003   } else {
1004     timeval time;
1005     int status = gettimeofday(&time, NULL);
1006     assert(status != -1, "bsd error");
1007     jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1008     return 1000 * usecs;
1009   }
1010 }
1011 
1012 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1013   if (Bsd::supports_monotonic_clock()) {
1014     info_ptr->max_value = ALL_64_BITS;
1015 
1016     // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1017     info_ptr->may_skip_backward = false;      // not subject to resetting or drifting
1018     info_ptr->may_skip_forward = false;       // not subject to resetting or drifting
1019   } else {
1020     // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1021     info_ptr->max_value = ALL_64_BITS;
1022 
1023     // gettimeofday is a real time clock so it skips
1024     info_ptr->may_skip_backward = true;
1025     info_ptr->may_skip_forward = true;
1026   }
1027 
1028   info_ptr->kind = JVMTI_TIMER_ELAPSED;                // elapsed not CPU time
1029 }
1030 
1031 // Return the real, user, and system times in seconds from an
1032 // arbitrary fixed point in the past.
1033 bool os::getTimesSecs(double* process_real_time,
1034                       double* process_user_time,
1035                       double* process_system_time) {
1036   struct tms ticks;
1037   clock_t real_ticks = times(&ticks);
1038 
1039   if (real_ticks == (clock_t) (-1)) {
1040     return false;
1041   } else {
1042     double ticks_per_second = (double) clock_tics_per_sec;
1043     *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1044     *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1045     *process_real_time = ((double) real_ticks) / ticks_per_second;
1046 
1047     return true;
1048   }
1049 }
1050 
1051 
1052 char * os::local_time_string(char *buf, size_t buflen) {
1053   struct tm t;
1054   time_t long_time;
1055   time(&long_time);
1056   localtime_r(&long_time, &t);
1057   jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1058                t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1059                t.tm_hour, t.tm_min, t.tm_sec);
1060   return buf;
1061 }
1062 
1063 struct tm* os::localtime_pd(const time_t* clock, struct tm*  res) {
1064   return localtime_r(clock, res);
1065 }
1066 
1067 ////////////////////////////////////////////////////////////////////////////////
1068 // runtime exit support
1069 
1070 // Note: os::shutdown() might be called very early during initialization, or
1071 // called from signal handler. Before adding something to os::shutdown(), make
1072 // sure it is async-safe and can handle partially initialized VM.
1073 void os::shutdown() {
1074 
1075   // allow PerfMemory to attempt cleanup of any persistent resources
1076   perfMemory_exit();
1077 
1078   // needs to remove object in file system
1079   AttachListener::abort();
1080 
1081   // flush buffered output, finish log files
1082   ostream_abort();
1083 
1084   // Check for abort hook
1085   abort_hook_t abort_hook = Arguments::abort_hook();
1086   if (abort_hook != NULL) {
1087     abort_hook();
1088   }
1089 
1090 }
1091 
1092 // Note: os::abort() might be called very early during initialization, or
1093 // called from signal handler. Before adding something to os::abort(), make
1094 // sure it is async-safe and can handle partially initialized VM.
1095 void os::abort(bool dump_core) {
1096   os::shutdown();
1097   if (dump_core) {
1098 #ifndef PRODUCT
1099     fdStream out(defaultStream::output_fd());
1100     out.print_raw("Current thread is ");
1101     char buf[16];
1102     jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1103     out.print_raw_cr(buf);
1104     out.print_raw_cr("Dumping core ...");
1105 #endif
1106     ::abort(); // dump core
1107   }
1108 
1109   ::exit(1);
1110 }
1111 
1112 // Die immediately, no exit hook, no abort hook, no cleanup.
1113 void os::die() {
1114   // _exit() on BsdThreads only kills current thread
1115   ::abort();
1116 }
1117 
1118 // unused on bsd for now.
1119 void os::set_error_file(const char *logfile) {}
1120 
1121 
1122 // This method is a copy of JDK's sysGetLastErrorString
1123 // from src/solaris/hpi/src/system_md.c
1124 
1125 size_t os::lasterror(char *buf, size_t len) {
1126 
1127   if (errno == 0)  return 0;
1128 
1129   const char *s = ::strerror(errno);
1130   size_t n = ::strlen(s);
1131   if (n >= len) {
1132     n = len - 1;
1133   }
1134   ::strncpy(buf, s, n);
1135   buf[n] = '\0';
1136   return n;
1137 }
1138 
1139 // Information of current thread in variety of formats
1140 pid_t os::Bsd::gettid() {
1141   int retval = -1;
1142 
1143 #ifdef __APPLE__ //XNU kernel
1144   // despite the fact mach port is actually not a thread id use it
1145   // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1146   retval = ::pthread_mach_thread_np(::pthread_self());
1147   guarantee(retval != 0, "just checking");
1148   return retval;
1149 
1150 #elif __FreeBSD__
1151   retval = syscall(SYS_thr_self);
1152 #elif __OpenBSD__
1153   retval = syscall(SYS_getthrid);
1154 #elif __NetBSD__
1155   retval = (pid_t) syscall(SYS__lwp_self);
1156 #endif
1157 
1158   if (retval == -1) {
1159     return getpid();
1160   }
1161 }
1162 
1163 intx os::current_thread_id() {
1164 #ifdef __APPLE__
1165   return (intx)::pthread_mach_thread_np(::pthread_self());
1166 #else
1167   return (intx)::pthread_self();
1168 #endif
1169 }
1170 
1171 int os::current_process_id() {
1172 
1173   // Under the old bsd thread library, bsd gives each thread
1174   // its own process id. Because of this each thread will return
1175   // a different pid if this method were to return the result
1176   // of getpid(2). Bsd provides no api that returns the pid
1177   // of the launcher thread for the vm. This implementation
1178   // returns a unique pid, the pid of the launcher thread
1179   // that starts the vm 'process'.
1180 
1181   // Under the NPTL, getpid() returns the same pid as the
1182   // launcher thread rather than a unique pid per thread.
1183   // Use gettid() if you want the old pre NPTL behaviour.
1184 
1185   // if you are looking for the result of a call to getpid() that
1186   // returns a unique pid for the calling thread, then look at the
1187   // OSThread::thread_id() method in osThread_bsd.hpp file
1188 
1189   return (int)(_initial_pid ? _initial_pid : getpid());
1190 }
1191 
1192 // DLL functions
1193 
1194 #define JNI_LIB_PREFIX "lib"
1195 #ifdef __APPLE__
1196 #define JNI_LIB_SUFFIX ".dylib"
1197 #else
1198 #define JNI_LIB_SUFFIX ".so"
1199 #endif
1200 
1201 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1202 
1203 // This must be hard coded because it's the system's temporary
1204 // directory not the java application's temp directory, ala java.io.tmpdir.
1205 #ifdef __APPLE__
1206 // macosx has a secure per-user temporary directory
1207 char temp_path_storage[PATH_MAX];
1208 const char* os::get_temp_directory() {
1209   static char *temp_path = NULL;
1210   if (temp_path == NULL) {
1211     int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1212     if (pathSize == 0 || pathSize > PATH_MAX) {
1213       strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1214     }
1215     temp_path = temp_path_storage;
1216   }
1217   return temp_path;
1218 }
1219 #else /* __APPLE__ */
1220 const char* os::get_temp_directory() { return "/tmp"; }
1221 #endif /* __APPLE__ */
1222 
1223 static bool file_exists(const char* filename) {
1224   struct stat statbuf;
1225   if (filename == NULL || strlen(filename) == 0) {
1226     return false;
1227   }
1228   return os::stat(filename, &statbuf) == 0;
1229 }
1230 
1231 bool os::dll_build_name(char* buffer, size_t buflen,
1232                         const char* pname, const char* fname) {
1233   bool retval = false;
1234   // Copied from libhpi
1235   const size_t pnamelen = pname ? strlen(pname) : 0;
1236 
1237   // Return error on buffer overflow.
1238   if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1239     return retval;
1240   }
1241 
1242   if (pnamelen == 0) {
1243     snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1244     retval = true;
1245   } else if (strchr(pname, *os::path_separator()) != NULL) {
1246     int n;
1247     char** pelements = split_path(pname, &n);
1248     if (pelements == NULL) {
1249       return false;
1250     }
1251     for (int i = 0 ; i < n ; i++) {
1252       // Really shouldn't be NULL, but check can't hurt
1253       if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1254         continue; // skip the empty path values
1255       }
1256       snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1257           pelements[i], fname);
1258       if (file_exists(buffer)) {
1259         retval = true;
1260         break;
1261       }
1262     }
1263     // release the storage
1264     for (int i = 0 ; i < n ; i++) {
1265       if (pelements[i] != NULL) {
1266         FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
1267       }
1268     }
1269     if (pelements != NULL) {
1270       FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
1271     }
1272   } else {
1273     snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1274     retval = true;
1275   }
1276   return retval;
1277 }
1278 
1279 // check if addr is inside libjvm.so
1280 bool os::address_is_in_vm(address addr) {
1281   static address libjvm_base_addr;
1282   Dl_info dlinfo;
1283 
1284   if (libjvm_base_addr == NULL) {
1285     if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1286       libjvm_base_addr = (address)dlinfo.dli_fbase;
1287     }
1288     assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1289   }
1290 
1291   if (dladdr((void *)addr, &dlinfo) != 0) {
1292     if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1293   }
1294 
1295   return false;
1296 }
1297 
1298 
1299 #define MACH_MAXSYMLEN 256
1300 
1301 bool os::dll_address_to_function_name(address addr, char *buf,
1302                                       int buflen, int *offset) {
1303   // buf is not optional, but offset is optional
1304   assert(buf != NULL, "sanity check");
1305 
1306   Dl_info dlinfo;
1307   char localbuf[MACH_MAXSYMLEN];
1308 
1309   if (dladdr((void*)addr, &dlinfo) != 0) {
1310     // see if we have a matching symbol
1311     if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1312       if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1313         jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1314       }
1315       if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1316       return true;
1317     }
1318     // no matching symbol so try for just file info
1319     if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1320       if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1321                           buf, buflen, offset, dlinfo.dli_fname)) {
1322          return true;
1323       }
1324     }
1325 
1326     // Handle non-dynamic manually:
1327     if (dlinfo.dli_fbase != NULL &&
1328         Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1329                         dlinfo.dli_fbase)) {
1330       if (!Decoder::demangle(localbuf, buf, buflen)) {
1331         jio_snprintf(buf, buflen, "%s", localbuf);
1332       }
1333       return true;
1334     }
1335   }
1336   buf[0] = '\0';
1337   if (offset != NULL) *offset = -1;
1338   return false;
1339 }
1340 
1341 // ported from solaris version
1342 bool os::dll_address_to_library_name(address addr, char* buf,
1343                                      int buflen, int* offset) {
1344   // buf is not optional, but offset is optional
1345   assert(buf != NULL, "sanity check");
1346 
1347   Dl_info dlinfo;
1348 
1349   if (dladdr((void*)addr, &dlinfo) != 0) {
1350     if (dlinfo.dli_fname != NULL) {
1351       jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1352     }
1353     if (dlinfo.dli_fbase != NULL && offset != NULL) {
1354       *offset = addr - (address)dlinfo.dli_fbase;
1355     }
1356     return true;
1357   }
1358 
1359   buf[0] = '\0';
1360   if (offset) *offset = -1;
1361   return false;
1362 }
1363 
1364 // Loads .dll/.so and
1365 // in case of error it checks if .dll/.so was built for the
1366 // same architecture as Hotspot is running on
1367 
1368 #ifdef __APPLE__
1369 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1370   void * result= ::dlopen(filename, RTLD_LAZY);
1371   if (result != NULL) {
1372     // Successful loading
1373     return result;
1374   }
1375 
1376   // Read system error message into ebuf
1377   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1378   ebuf[ebuflen-1]='\0';
1379 
1380   return NULL;
1381 }
1382 #else
1383 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
1384 {
1385   void * result= ::dlopen(filename, RTLD_LAZY);
1386   if (result != NULL) {
1387     // Successful loading
1388     return result;
1389   }
1390 
1391   Elf32_Ehdr elf_head;
1392 
1393   // Read system error message into ebuf
1394   // It may or may not be overwritten below
1395   ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1396   ebuf[ebuflen-1]='\0';
1397   int diag_msg_max_length=ebuflen-strlen(ebuf);
1398   char* diag_msg_buf=ebuf+strlen(ebuf);
1399 
1400   if (diag_msg_max_length==0) {
1401     // No more space in ebuf for additional diagnostics message
1402     return NULL;
1403   }
1404 
1405 
1406   int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1407 
1408   if (file_descriptor < 0) {
1409     // Can't open library, report dlerror() message
1410     return NULL;
1411   }
1412 
1413   bool failed_to_read_elf_head=
1414     (sizeof(elf_head)!=
1415         (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
1416 
1417   ::close(file_descriptor);
1418   if (failed_to_read_elf_head) {
1419     // file i/o error - report dlerror() msg
1420     return NULL;
1421   }
1422 
1423   typedef struct {
1424     Elf32_Half  code;         // Actual value as defined in elf.h
1425     Elf32_Half  compat_class; // Compatibility of archs at VM's sense
1426     char        elf_class;    // 32 or 64 bit
1427     char        endianess;    // MSB or LSB
1428     char*       name;         // String representation
1429   } arch_t;
1430 
1431   #ifndef EM_486
1432   #define EM_486          6               /* Intel 80486 */
1433   #endif
1434 
1435   #ifndef EM_MIPS_RS3_LE
1436   #define EM_MIPS_RS3_LE  10              /* MIPS */
1437   #endif
1438 
1439   #ifndef EM_PPC64
1440   #define EM_PPC64        21              /* PowerPC64 */
1441   #endif
1442 
1443   #ifndef EM_S390
1444   #define EM_S390         22              /* IBM System/390 */
1445   #endif
1446 
1447   #ifndef EM_IA_64
1448   #define EM_IA_64        50              /* HP/Intel IA-64 */
1449   #endif
1450 
1451   #ifndef EM_X86_64
1452   #define EM_X86_64       62              /* AMD x86-64 */
1453   #endif
1454 
1455   static const arch_t arch_array[]={
1456     {EM_386,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1457     {EM_486,         EM_386,     ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1458     {EM_IA_64,       EM_IA_64,   ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1459     {EM_X86_64,      EM_X86_64,  ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1460     {EM_SPARC,       EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1461     {EM_SPARC32PLUS, EM_SPARC,   ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1462     {EM_SPARCV9,     EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1463     {EM_PPC,         EM_PPC,     ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1464     {EM_PPC64,       EM_PPC64,   ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1465     {EM_ARM,         EM_ARM,     ELFCLASS32,   ELFDATA2LSB, (char*)"ARM"},
1466     {EM_S390,        EM_S390,    ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1467     {EM_ALPHA,       EM_ALPHA,   ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1468     {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1469     {EM_MIPS,        EM_MIPS,    ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1470     {EM_PARISC,      EM_PARISC,  ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1471     {EM_68K,         EM_68K,     ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1472   };
1473 
1474   #if  (defined IA32)
1475     static  Elf32_Half running_arch_code=EM_386;
1476   #elif   (defined AMD64)
1477     static  Elf32_Half running_arch_code=EM_X86_64;
1478   #elif  (defined IA64)
1479     static  Elf32_Half running_arch_code=EM_IA_64;
1480   #elif  (defined __sparc) && (defined _LP64)
1481     static  Elf32_Half running_arch_code=EM_SPARCV9;
1482   #elif  (defined __sparc) && (!defined _LP64)
1483     static  Elf32_Half running_arch_code=EM_SPARC;
1484   #elif  (defined __powerpc64__)
1485     static  Elf32_Half running_arch_code=EM_PPC64;
1486   #elif  (defined __powerpc__)
1487     static  Elf32_Half running_arch_code=EM_PPC;
1488   #elif  (defined ARM)
1489     static  Elf32_Half running_arch_code=EM_ARM;
1490   #elif  (defined S390)
1491     static  Elf32_Half running_arch_code=EM_S390;
1492   #elif  (defined ALPHA)
1493     static  Elf32_Half running_arch_code=EM_ALPHA;
1494   #elif  (defined MIPSEL)
1495     static  Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1496   #elif  (defined PARISC)
1497     static  Elf32_Half running_arch_code=EM_PARISC;
1498   #elif  (defined MIPS)
1499     static  Elf32_Half running_arch_code=EM_MIPS;
1500   #elif  (defined M68K)
1501     static  Elf32_Half running_arch_code=EM_68K;
1502   #else
1503     #error Method os::dll_load requires that one of following is defined:\
1504          IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1505   #endif
1506 
1507   // Identify compatability class for VM's architecture and library's architecture
1508   // Obtain string descriptions for architectures
1509 
1510   arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1511   int running_arch_index=-1;
1512 
1513   for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
1514     if (running_arch_code == arch_array[i].code) {
1515       running_arch_index    = i;
1516     }
1517     if (lib_arch.code == arch_array[i].code) {
1518       lib_arch.compat_class = arch_array[i].compat_class;
1519       lib_arch.name         = arch_array[i].name;
1520     }
1521   }
1522 
1523   assert(running_arch_index != -1,
1524     "Didn't find running architecture code (running_arch_code) in arch_array");
1525   if (running_arch_index == -1) {
1526     // Even though running architecture detection failed
1527     // we may still continue with reporting dlerror() message
1528     return NULL;
1529   }
1530 
1531   if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1532     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1533     return NULL;
1534   }
1535 
1536 #ifndef S390
1537   if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1538     ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1539     return NULL;
1540   }
1541 #endif // !S390
1542 
1543   if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1544     if ( lib_arch.name!=NULL ) {
1545       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1546         " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1547         lib_arch.name, arch_array[running_arch_index].name);
1548     } else {
1549       ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1550       " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1551         lib_arch.code,
1552         arch_array[running_arch_index].name);
1553     }
1554   }
1555 
1556   return NULL;
1557 }
1558 #endif /* !__APPLE__ */
1559 
1560 // XXX: Do we need a lock around this as per Linux?
1561 void* os::dll_lookup(void* handle, const char* name) {
1562   return dlsym(handle, name);
1563 }
1564 
1565 
1566 static bool _print_ascii_file(const char* filename, outputStream* st) {
1567   int fd = ::open(filename, O_RDONLY);
1568   if (fd == -1) {
1569      return false;
1570   }
1571 
1572   char buf[32];
1573   int bytes;
1574   while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1575     st->print_raw(buf, bytes);
1576   }
1577 
1578   ::close(fd);
1579 
1580   return true;
1581 }
1582 
1583 void os::print_dll_info(outputStream *st) {
1584   st->print_cr("Dynamic libraries:");
1585 #ifdef RTLD_DI_LINKMAP
1586   Dl_info dli;
1587   void *handle;
1588   Link_map *map;
1589   Link_map *p;
1590 
1591   if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1592       dli.dli_fname == NULL) {
1593     st->print_cr("Error: Cannot print dynamic libraries.");
1594     return;
1595   }
1596   handle = dlopen(dli.dli_fname, RTLD_LAZY);
1597   if (handle == NULL) {
1598     st->print_cr("Error: Cannot print dynamic libraries.");
1599     return;
1600   }
1601   dlinfo(handle, RTLD_DI_LINKMAP, &map);
1602   if (map == NULL) {
1603     st->print_cr("Error: Cannot print dynamic libraries.");
1604     return;
1605   }
1606 
1607   while (map->l_prev != NULL)
1608     map = map->l_prev;
1609 
1610   while (map != NULL) {
1611     st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
1612     map = map->l_next;
1613   }
1614 
1615   dlclose(handle);
1616 #elif defined(__APPLE__)
1617   uint32_t count;
1618   uint32_t i;
1619 
1620   count = _dyld_image_count();
1621   for (i = 1; i < count; i++) {
1622     const char *name = _dyld_get_image_name(i);
1623     intptr_t slide = _dyld_get_image_vmaddr_slide(i);
1624     st->print_cr(PTR_FORMAT " \t%s", slide, name);
1625   }
1626 #else
1627   st->print_cr("Error: Cannot print dynamic libraries.");
1628 #endif
1629 }
1630 
1631 void os::print_os_info_brief(outputStream* st) {
1632   st->print("Bsd");
1633 
1634   os::Posix::print_uname_info(st);
1635 }
1636 
1637 void os::print_os_info(outputStream* st) {
1638   st->print("OS:");
1639   st->print("Bsd");
1640 
1641   os::Posix::print_uname_info(st);
1642 
1643   os::Posix::print_rlimit_info(st);
1644 
1645   os::Posix::print_load_average(st);
1646 }
1647 
1648 void os::pd_print_cpu_info(outputStream* st) {
1649   // Nothing to do for now.
1650 }
1651 
1652 void os::print_memory_info(outputStream* st) {
1653 
1654   st->print("Memory:");
1655   st->print(" %dk page", os::vm_page_size()>>10);
1656 
1657   st->print(", physical " UINT64_FORMAT "k",
1658             os::physical_memory() >> 10);
1659   st->print("(" UINT64_FORMAT "k free)",
1660             os::available_memory() >> 10);
1661   st->cr();
1662 
1663   // meminfo
1664   st->print("\n/proc/meminfo:\n");
1665   _print_ascii_file("/proc/meminfo", st);
1666   st->cr();
1667 }
1668 
1669 // Taken from /usr/include/bits/siginfo.h  Supposed to be architecture specific
1670 // but they're the same for all the bsd arch that we support
1671 // and they're the same for solaris but there's no common place to put this.
1672 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
1673                           "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
1674                           "ILL_COPROC", "ILL_BADSTK" };
1675 
1676 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
1677                           "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
1678                           "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
1679 
1680 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
1681 
1682 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
1683 
1684 void os::print_siginfo(outputStream* st, void* siginfo) {
1685   st->print("siginfo:");
1686 
1687   const int buflen = 100;
1688   char buf[buflen];
1689   siginfo_t *si = (siginfo_t*)siginfo;
1690   st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
1691   if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
1692     st->print("si_errno=%s", buf);
1693   } else {
1694     st->print("si_errno=%d", si->si_errno);
1695   }
1696   const int c = si->si_code;
1697   assert(c > 0, "unexpected si_code");
1698   switch (si->si_signo) {
1699   case SIGILL:
1700     st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
1701     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1702     break;
1703   case SIGFPE:
1704     st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
1705     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1706     break;
1707   case SIGSEGV:
1708     st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
1709     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1710     break;
1711   case SIGBUS:
1712     st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
1713     st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1714     break;
1715   default:
1716     st->print(", si_code=%d", si->si_code);
1717     // no si_addr
1718   }
1719 
1720   if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1721       UseSharedSpaces) {
1722     FileMapInfo* mapinfo = FileMapInfo::current_info();
1723     if (mapinfo->is_in_shared_space(si->si_addr)) {
1724       st->print("\n\nError accessing class data sharing archive."   \
1725                 " Mapped file inaccessible during execution, "      \
1726                 " possible disk/network problem.");
1727     }
1728   }
1729   st->cr();
1730 }
1731 
1732 
1733 static void print_signal_handler(outputStream* st, int sig,
1734                                  char* buf, size_t buflen);
1735 
1736 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1737   st->print_cr("Signal Handlers:");
1738   print_signal_handler(st, SIGSEGV, buf, buflen);
1739   print_signal_handler(st, SIGBUS , buf, buflen);
1740   print_signal_handler(st, SIGFPE , buf, buflen);
1741   print_signal_handler(st, SIGPIPE, buf, buflen);
1742   print_signal_handler(st, SIGXFSZ, buf, buflen);
1743   print_signal_handler(st, SIGILL , buf, buflen);
1744   print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1745   print_signal_handler(st, SR_signum, buf, buflen);
1746   print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1747   print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1748   print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1749   print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1750 }
1751 
1752 static char saved_jvm_path[MAXPATHLEN] = {0};
1753 
1754 // Find the full path to the current module, libjvm
1755 void os::jvm_path(char *buf, jint buflen) {
1756   // Error checking.
1757   if (buflen < MAXPATHLEN) {
1758     assert(false, "must use a large-enough buffer");
1759     buf[0] = '\0';
1760     return;
1761   }
1762   // Lazy resolve the path to current module.
1763   if (saved_jvm_path[0] != 0) {
1764     strcpy(buf, saved_jvm_path);
1765     return;
1766   }
1767 
1768   char dli_fname[MAXPATHLEN];
1769   bool ret = dll_address_to_library_name(
1770                 CAST_FROM_FN_PTR(address, os::jvm_path),
1771                 dli_fname, sizeof(dli_fname), NULL);
1772   assert(ret, "cannot locate libjvm");
1773   char *rp = NULL;
1774   if (ret && dli_fname[0] != '\0') {
1775     rp = realpath(dli_fname, buf);
1776   }
1777   if (rp == NULL)
1778     return;
1779 
1780   if (Arguments::created_by_gamma_launcher()) {
1781     // Support for the gamma launcher.  Typical value for buf is
1782     // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm".  If "/jre/lib/" appears at
1783     // the right place in the string, then assume we are installed in a JDK and
1784     // we're done.  Otherwise, check for a JAVA_HOME environment variable and
1785     // construct a path to the JVM being overridden.
1786 
1787     const char *p = buf + strlen(buf) - 1;
1788     for (int count = 0; p > buf && count < 5; ++count) {
1789       for (--p; p > buf && *p != '/'; --p)
1790         /* empty */ ;
1791     }
1792 
1793     if (strncmp(p, "/jre/lib/", 9) != 0) {
1794       // Look for JAVA_HOME in the environment.
1795       char* java_home_var = ::getenv("JAVA_HOME");
1796       if (java_home_var != NULL && java_home_var[0] != 0) {
1797         char* jrelib_p;
1798         int len;
1799 
1800         // Check the current module name "libjvm"
1801         p = strrchr(buf, '/');
1802         assert(strstr(p, "/libjvm") == p, "invalid library name");
1803 
1804         rp = realpath(java_home_var, buf);
1805         if (rp == NULL)
1806           return;
1807 
1808         // determine if this is a legacy image or modules image
1809         // modules image doesn't have "jre" subdirectory
1810         len = strlen(buf);
1811         jrelib_p = buf + len;
1812 
1813         // Add the appropriate library subdir
1814         snprintf(jrelib_p, buflen-len, "/jre/lib");
1815         if (0 != access(buf, F_OK)) {
1816           snprintf(jrelib_p, buflen-len, "/lib");
1817         }
1818 
1819         // Add the appropriate client or server subdir
1820         len = strlen(buf);
1821         jrelib_p = buf + len;
1822         snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1823         if (0 != access(buf, F_OK)) {
1824           snprintf(jrelib_p, buflen-len, "");
1825         }
1826 
1827         // If the path exists within JAVA_HOME, add the JVM library name
1828         // to complete the path to JVM being overridden.  Otherwise fallback
1829         // to the path to the current library.
1830         if (0 == access(buf, F_OK)) {
1831           // Use current module name "libjvm"
1832           len = strlen(buf);
1833           snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1834         } else {
1835           // Fall back to path of current library
1836           rp = realpath(dli_fname, buf);
1837           if (rp == NULL)
1838             return;
1839         }
1840       }
1841     }
1842   }
1843 
1844   strcpy(saved_jvm_path, buf);
1845 }
1846 
1847 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1848   // no prefix required, not even "_"
1849 }
1850 
1851 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1852   // no suffix required
1853 }
1854 
1855 ////////////////////////////////////////////////////////////////////////////////
1856 // sun.misc.Signal support
1857 
1858 static volatile jint sigint_count = 0;
1859 
1860 static void
1861 UserHandler(int sig, void *siginfo, void *context) {
1862   // 4511530 - sem_post is serialized and handled by the manager thread. When
1863   // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1864   // don't want to flood the manager thread with sem_post requests.
1865   if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
1866       return;
1867 
1868   // Ctrl-C is pressed during error reporting, likely because the error
1869   // handler fails to abort. Let VM die immediately.
1870   if (sig == SIGINT && is_error_reported()) {
1871      os::die();
1872   }
1873 
1874   os::signal_notify(sig);
1875 }
1876 
1877 void* os::user_handler() {
1878   return CAST_FROM_FN_PTR(void*, UserHandler);
1879 }
1880 
1881 extern "C" {
1882   typedef void (*sa_handler_t)(int);
1883   typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1884 }
1885 
1886 void* os::signal(int signal_number, void* handler) {
1887   struct sigaction sigAct, oldSigAct;
1888 
1889   sigfillset(&(sigAct.sa_mask));
1890   sigAct.sa_flags   = SA_RESTART|SA_SIGINFO;
1891   sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1892 
1893   if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1894     // -1 means registration failed
1895     return (void *)-1;
1896   }
1897 
1898   return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1899 }
1900 
1901 void os::signal_raise(int signal_number) {
1902   ::raise(signal_number);
1903 }
1904 
1905 /*
1906  * The following code is moved from os.cpp for making this
1907  * code platform specific, which it is by its very nature.
1908  */
1909 
1910 // Will be modified when max signal is changed to be dynamic
1911 int os::sigexitnum_pd() {
1912   return NSIG;
1913 }
1914 
1915 // a counter for each possible signal value
1916 static volatile jint pending_signals[NSIG+1] = { 0 };
1917 
1918 // Bsd(POSIX) specific hand shaking semaphore.
1919 #ifdef __APPLE__
1920 typedef semaphore_t os_semaphore_t;
1921 #define SEM_INIT(sem, value)    semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1922 #define SEM_WAIT(sem)           semaphore_wait(sem)
1923 #define SEM_POST(sem)           semaphore_signal(sem)
1924 #define SEM_DESTROY(sem)        semaphore_destroy(mach_task_self(), sem)
1925 #else
1926 typedef sem_t os_semaphore_t;
1927 #define SEM_INIT(sem, value)    sem_init(&sem, 0, value)
1928 #define SEM_WAIT(sem)           sem_wait(&sem)
1929 #define SEM_POST(sem)           sem_post(&sem)
1930 #define SEM_DESTROY(sem)        sem_destroy(&sem)
1931 #endif
1932 
1933 class Semaphore : public StackObj {
1934   public:
1935     Semaphore();
1936     ~Semaphore();
1937     void signal();
1938     void wait();
1939     bool trywait();
1940     bool timedwait(unsigned int sec, int nsec);
1941   private:
1942     jlong currenttime() const;
1943     os_semaphore_t _semaphore;
1944 };
1945 
1946 Semaphore::Semaphore() : _semaphore(0) {
1947   SEM_INIT(_semaphore, 0);
1948 }
1949 
1950 Semaphore::~Semaphore() {
1951   SEM_DESTROY(_semaphore);
1952 }
1953 
1954 void Semaphore::signal() {
1955   SEM_POST(_semaphore);
1956 }
1957 
1958 void Semaphore::wait() {
1959   SEM_WAIT(_semaphore);
1960 }
1961 
1962 jlong Semaphore::currenttime() const {
1963     struct timeval tv;
1964     gettimeofday(&tv, NULL);
1965     return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
1966 }
1967 
1968 #ifdef __APPLE__
1969 bool Semaphore::trywait() {
1970   return timedwait(0, 0);
1971 }
1972 
1973 bool Semaphore::timedwait(unsigned int sec, int nsec) {
1974   kern_return_t kr = KERN_ABORTED;
1975   mach_timespec_t waitspec;
1976   waitspec.tv_sec = sec;
1977   waitspec.tv_nsec = nsec;
1978 
1979   jlong starttime = currenttime();
1980 
1981   kr = semaphore_timedwait(_semaphore, waitspec);
1982   while (kr == KERN_ABORTED) {
1983     jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
1984 
1985     jlong current = currenttime();
1986     jlong passedtime = current - starttime;
1987 
1988     if (passedtime >= totalwait) {
1989       waitspec.tv_sec = 0;
1990       waitspec.tv_nsec = 0;
1991     } else {
1992       jlong waittime = totalwait - (current - starttime);
1993       waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
1994       waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
1995     }
1996 
1997     kr = semaphore_timedwait(_semaphore, waitspec);
1998   }
1999 
2000   return kr == KERN_SUCCESS;
2001 }
2002 
2003 #else
2004 
2005 bool Semaphore::trywait() {
2006   return sem_trywait(&_semaphore) == 0;
2007 }
2008 
2009 bool Semaphore::timedwait(unsigned int sec, int nsec) {
2010   struct timespec ts;
2011   unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2012 
2013   while (1) {
2014     int result = sem_timedwait(&_semaphore, &ts);
2015     if (result == 0) {
2016       return true;
2017     } else if (errno == EINTR) {
2018       continue;
2019     } else if (errno == ETIMEDOUT) {
2020       return false;
2021     } else {
2022       return false;
2023     }
2024   }
2025 }
2026 
2027 #endif // __APPLE__
2028 
2029 static os_semaphore_t sig_sem;
2030 static Semaphore sr_semaphore;
2031 
2032 void os::signal_init_pd() {
2033   // Initialize signal structures
2034   ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2035 
2036   // Initialize signal semaphore
2037   ::SEM_INIT(sig_sem, 0);
2038 }
2039 
2040 void os::signal_notify(int sig) {
2041   Atomic::inc(&pending_signals[sig]);
2042   ::SEM_POST(sig_sem);
2043 }
2044 
2045 static int check_pending_signals(bool wait) {
2046   Atomic::store(0, &sigint_count);
2047   for (;;) {
2048     for (int i = 0; i < NSIG + 1; i++) {
2049       jint n = pending_signals[i];
2050       if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2051         return i;
2052       }
2053     }
2054     if (!wait) {
2055       return -1;
2056     }
2057     JavaThread *thread = JavaThread::current();
2058     ThreadBlockInVM tbivm(thread);
2059 
2060     bool threadIsSuspended;
2061     do {
2062       thread->set_suspend_equivalent();
2063       // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2064       ::SEM_WAIT(sig_sem);
2065 
2066       // were we externally suspended while we were waiting?
2067       threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2068       if (threadIsSuspended) {
2069         //
2070         // The semaphore has been incremented, but while we were waiting
2071         // another thread suspended us. We don't want to continue running
2072         // while suspended because that would surprise the thread that
2073         // suspended us.
2074         //
2075         ::SEM_POST(sig_sem);
2076 
2077         thread->java_suspend_self();
2078       }
2079     } while (threadIsSuspended);
2080   }
2081 }
2082 
2083 int os::signal_lookup() {
2084   return check_pending_signals(false);
2085 }
2086 
2087 int os::signal_wait() {
2088   return check_pending_signals(true);
2089 }
2090 
2091 ////////////////////////////////////////////////////////////////////////////////
2092 // Virtual Memory
2093 
2094 int os::vm_page_size() {
2095   // Seems redundant as all get out
2096   assert(os::Bsd::page_size() != -1, "must call os::init");
2097   return os::Bsd::page_size();
2098 }
2099 
2100 // Solaris allocates memory by pages.
2101 int os::vm_allocation_granularity() {
2102   assert(os::Bsd::page_size() != -1, "must call os::init");
2103   return os::Bsd::page_size();
2104 }
2105 
2106 // Rationale behind this function:
2107 //  current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2108 //  mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2109 //  samples for JITted code. Here we create private executable mapping over the code cache
2110 //  and then we can use standard (well, almost, as mapping can change) way to provide
2111 //  info for the reporting script by storing timestamp and location of symbol
2112 void bsd_wrap_code(char* base, size_t size) {
2113   static volatile jint cnt = 0;
2114 
2115   if (!UseOprofile) {
2116     return;
2117   }
2118 
2119   char buf[PATH_MAX + 1];
2120   int num = Atomic::add(1, &cnt);
2121 
2122   snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2123            os::get_temp_directory(), os::current_process_id(), num);
2124   unlink(buf);
2125 
2126   int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2127 
2128   if (fd != -1) {
2129     off_t rv = ::lseek(fd, size-2, SEEK_SET);
2130     if (rv != (off_t)-1) {
2131       if (::write(fd, "", 1) == 1) {
2132         mmap(base, size,
2133              PROT_READ|PROT_WRITE|PROT_EXEC,
2134              MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2135       }
2136     }
2137     ::close(fd);
2138     unlink(buf);
2139   }
2140 }
2141 
2142 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2143                                     int err) {
2144   warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2145           ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2146           strerror(err), err);
2147 }
2148 
2149 // NOTE: Bsd kernel does not really reserve the pages for us.
2150 //       All it does is to check if there are enough free pages
2151 //       left at the time of mmap(). This could be a potential
2152 //       problem.
2153 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2154   int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2155 #ifdef __OpenBSD__
2156   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2157   if (::mprotect(addr, size, prot) == 0) {
2158     return true;
2159   }
2160 #else
2161   uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2162                                    MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2163   if (res != (uintptr_t) MAP_FAILED) {
2164     return true;
2165   }
2166 #endif
2167 
2168   // Warn about any commit errors we see in non-product builds just
2169   // in case mmap() doesn't work as described on the man page.
2170   NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2171 
2172   return false;
2173 }
2174 
2175 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2176                        bool exec) {
2177   // alignment_hint is ignored on this OS
2178   return pd_commit_memory(addr, size, exec);
2179 }
2180 
2181 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2182                                   const char* mesg) {
2183   assert(mesg != NULL, "mesg must be specified");
2184   if (!pd_commit_memory(addr, size, exec)) {
2185     // add extra info in product mode for vm_exit_out_of_memory():
2186     PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2187     vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
2188   }
2189 }
2190 
2191 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2192                                   size_t alignment_hint, bool exec,
2193                                   const char* mesg) {
2194   // alignment_hint is ignored on this OS
2195   pd_commit_memory_or_exit(addr, size, exec, mesg);
2196 }
2197 
2198 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2199 }
2200 
2201 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2202   ::madvise(addr, bytes, MADV_DONTNEED);
2203 }
2204 
2205 void os::numa_make_global(char *addr, size_t bytes) {
2206 }
2207 
2208 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2209 }
2210 
2211 bool os::numa_topology_changed()   { return false; }
2212 
2213 size_t os::numa_get_groups_num() {
2214   return 1;
2215 }
2216 
2217 int os::numa_get_group_id() {
2218   return 0;
2219 }
2220 
2221 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2222   if (size > 0) {
2223     ids[0] = 0;
2224     return 1;
2225   }
2226   return 0;
2227 }
2228 
2229 bool os::get_page_info(char *start, page_info* info) {
2230   return false;
2231 }
2232 
2233 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2234   return end;
2235 }
2236 
2237 
2238 bool os::pd_uncommit_memory(char* addr, size_t size) {
2239 #ifdef __OpenBSD__
2240   // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2241   return ::mprotect(addr, size, PROT_NONE) == 0;
2242 #else
2243   uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2244                 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2245   return res  != (uintptr_t) MAP_FAILED;
2246 #endif
2247 }
2248 
2249 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2250   return os::commit_memory(addr, size, !ExecMem);
2251 }
2252 
2253 // If this is a growable mapping, remove the guard pages entirely by
2254 // munmap()ping them.  If not, just call uncommit_memory().
2255 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2256   return os::uncommit_memory(addr, size);
2257 }
2258 
2259 static address _highest_vm_reserved_address = NULL;
2260 
2261 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2262 // at 'requested_addr'. If there are existing memory mappings at the same
2263 // location, however, they will be overwritten. If 'fixed' is false,
2264 // 'requested_addr' is only treated as a hint, the return value may or
2265 // may not start from the requested address. Unlike Bsd mmap(), this
2266 // function returns NULL to indicate failure.
2267 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2268   char * addr;
2269   int flags;
2270 
2271   flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2272   if (fixed) {
2273     assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2274     flags |= MAP_FIXED;
2275   }
2276 
2277   // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2278   // touch an uncommitted page. Otherwise, the read/write might
2279   // succeed if we have enough swap space to back the physical page.
2280   addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2281                        flags, -1, 0);
2282 
2283   if (addr != MAP_FAILED) {
2284     // anon_mmap() should only get called during VM initialization,
2285     // don't need lock (actually we can skip locking even it can be called
2286     // from multiple threads, because _highest_vm_reserved_address is just a
2287     // hint about the upper limit of non-stack memory regions.)
2288     if ((address)addr + bytes > _highest_vm_reserved_address) {
2289       _highest_vm_reserved_address = (address)addr + bytes;
2290     }
2291   }
2292 
2293   return addr == MAP_FAILED ? NULL : addr;
2294 }
2295 
2296 // Don't update _highest_vm_reserved_address, because there might be memory
2297 // regions above addr + size. If so, releasing a memory region only creates
2298 // a hole in the address space, it doesn't help prevent heap-stack collision.
2299 //
2300 static int anon_munmap(char * addr, size_t size) {
2301   return ::munmap(addr, size) == 0;
2302 }
2303 
2304 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2305                          size_t alignment_hint) {
2306   return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2307 }
2308 
2309 bool os::pd_release_memory(char* addr, size_t size) {
2310   return anon_munmap(addr, size);
2311 }
2312 
2313 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2314   // Bsd wants the mprotect address argument to be page aligned.
2315   char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2316 
2317   // According to SUSv3, mprotect() should only be used with mappings
2318   // established by mmap(), and mmap() always maps whole pages. Unaligned
2319   // 'addr' likely indicates problem in the VM (e.g. trying to change
2320   // protection of malloc'ed or statically allocated memory). Check the
2321   // caller if you hit this assert.
2322   assert(addr == bottom, "sanity check");
2323 
2324   size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2325   return ::mprotect(bottom, size, prot) == 0;
2326 }
2327 
2328 // Set protections specified
2329 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2330                         bool is_committed) {
2331   unsigned int p = 0;
2332   switch (prot) {
2333   case MEM_PROT_NONE: p = PROT_NONE; break;
2334   case MEM_PROT_READ: p = PROT_READ; break;
2335   case MEM_PROT_RW:   p = PROT_READ|PROT_WRITE; break;
2336   case MEM_PROT_RWX:  p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2337   default:
2338     ShouldNotReachHere();
2339   }
2340   // is_committed is unused.
2341   return bsd_mprotect(addr, bytes, p);
2342 }
2343 
2344 bool os::guard_memory(char* addr, size_t size) {
2345   return bsd_mprotect(addr, size, PROT_NONE);
2346 }
2347 
2348 bool os::unguard_memory(char* addr, size_t size) {
2349   return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2350 }
2351 
2352 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2353   return false;
2354 }
2355 
2356 // Large page support
2357 
2358 static size_t _large_page_size = 0;
2359 
2360 void os::large_page_init() {
2361 }
2362 
2363 
2364 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2365   fatal("This code is not used or maintained.");
2366 
2367   // "exec" is passed in but not used.  Creating the shared image for
2368   // the code cache doesn't have an SHM_X executable permission to check.
2369   assert(UseLargePages && UseSHM, "only for SHM large pages");
2370 
2371   key_t key = IPC_PRIVATE;
2372   char *addr;
2373 
2374   bool warn_on_failure = UseLargePages &&
2375                         (!FLAG_IS_DEFAULT(UseLargePages) ||
2376                          !FLAG_IS_DEFAULT(LargePageSizeInBytes)
2377                         );
2378   char msg[128];
2379 
2380   // Create a large shared memory region to attach to based on size.
2381   // Currently, size is the total size of the heap
2382   int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2383   if (shmid == -1) {
2384      // Possible reasons for shmget failure:
2385      // 1. shmmax is too small for Java heap.
2386      //    > check shmmax value: cat /proc/sys/kernel/shmmax
2387      //    > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2388      // 2. not enough large page memory.
2389      //    > check available large pages: cat /proc/meminfo
2390      //    > increase amount of large pages:
2391      //          echo new_value > /proc/sys/vm/nr_hugepages
2392      //      Note 1: different Bsd may use different name for this property,
2393      //            e.g. on Redhat AS-3 it is "hugetlb_pool".
2394      //      Note 2: it's possible there's enough physical memory available but
2395      //            they are so fragmented after a long run that they can't
2396      //            coalesce into large pages. Try to reserve large pages when
2397      //            the system is still "fresh".
2398      if (warn_on_failure) {
2399        jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
2400        warning(msg);
2401      }
2402      return NULL;
2403   }
2404 
2405   // attach to the region
2406   addr = (char*)shmat(shmid, req_addr, 0);
2407   int err = errno;
2408 
2409   // Remove shmid. If shmat() is successful, the actual shared memory segment
2410   // will be deleted when it's detached by shmdt() or when the process
2411   // terminates. If shmat() is not successful this will remove the shared
2412   // segment immediately.
2413   shmctl(shmid, IPC_RMID, NULL);
2414 
2415   if ((intptr_t)addr == -1) {
2416      if (warn_on_failure) {
2417        jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
2418        warning(msg);
2419      }
2420      return NULL;
2421   }
2422 
2423   // The memory is committed
2424   MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, mtNone, CALLER_PC);
2425 
2426   return addr;
2427 }
2428 
2429 bool os::release_memory_special(char* base, size_t bytes) {
2430   MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2431   // detaching the SHM segment will also delete it, see reserve_memory_special()
2432   int rslt = shmdt(base);
2433   if (rslt == 0) {
2434     tkr.record((address)base, bytes);
2435     return true;
2436   } else {
2437     tkr.discard();
2438     return false;
2439   }
2440 
2441 }
2442 
2443 size_t os::large_page_size() {
2444   return _large_page_size;
2445 }
2446 
2447 // HugeTLBFS allows application to commit large page memory on demand;
2448 // with SysV SHM the entire memory region must be allocated as shared
2449 // memory.
2450 bool os::can_commit_large_page_memory() {
2451   return UseHugeTLBFS;
2452 }
2453 
2454 bool os::can_execute_large_page_memory() {
2455   return UseHugeTLBFS;
2456 }
2457 
2458 // Reserve memory at an arbitrary address, only if that area is
2459 // available (and not reserved for something else).
2460 
2461 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2462   const int max_tries = 10;
2463   char* base[max_tries];
2464   size_t size[max_tries];
2465   const size_t gap = 0x000000;
2466 
2467   // Assert only that the size is a multiple of the page size, since
2468   // that's all that mmap requires, and since that's all we really know
2469   // about at this low abstraction level.  If we need higher alignment,
2470   // we can either pass an alignment to this method or verify alignment
2471   // in one of the methods further up the call chain.  See bug 5044738.
2472   assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2473 
2474   // Repeatedly allocate blocks until the block is allocated at the
2475   // right spot. Give up after max_tries. Note that reserve_memory() will
2476   // automatically update _highest_vm_reserved_address if the call is
2477   // successful. The variable tracks the highest memory address every reserved
2478   // by JVM. It is used to detect heap-stack collision if running with
2479   // fixed-stack BsdThreads. Because here we may attempt to reserve more
2480   // space than needed, it could confuse the collision detecting code. To
2481   // solve the problem, save current _highest_vm_reserved_address and
2482   // calculate the correct value before return.
2483   address old_highest = _highest_vm_reserved_address;
2484 
2485   // Bsd mmap allows caller to pass an address as hint; give it a try first,
2486   // if kernel honors the hint then we can return immediately.
2487   char * addr = anon_mmap(requested_addr, bytes, false);
2488   if (addr == requested_addr) {
2489      return requested_addr;
2490   }
2491 
2492   if (addr != NULL) {
2493      // mmap() is successful but it fails to reserve at the requested address
2494      anon_munmap(addr, bytes);
2495   }
2496 
2497   int i;
2498   for (i = 0; i < max_tries; ++i) {
2499     base[i] = reserve_memory(bytes);
2500 
2501     if (base[i] != NULL) {
2502       // Is this the block we wanted?
2503       if (base[i] == requested_addr) {
2504         size[i] = bytes;
2505         break;
2506       }
2507 
2508       // Does this overlap the block we wanted? Give back the overlapped
2509       // parts and try again.
2510 
2511       size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2512       if (top_overlap >= 0 && top_overlap < bytes) {
2513         unmap_memory(base[i], top_overlap);
2514         base[i] += top_overlap;
2515         size[i] = bytes - top_overlap;
2516       } else {
2517         size_t bottom_overlap = base[i] + bytes - requested_addr;
2518         if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2519           unmap_memory(requested_addr, bottom_overlap);
2520           size[i] = bytes - bottom_overlap;
2521         } else {
2522           size[i] = bytes;
2523         }
2524       }
2525     }
2526   }
2527 
2528   // Give back the unused reserved pieces.
2529 
2530   for (int j = 0; j < i; ++j) {
2531     if (base[j] != NULL) {
2532       unmap_memory(base[j], size[j]);
2533     }
2534   }
2535 
2536   if (i < max_tries) {
2537     _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2538     return requested_addr;
2539   } else {
2540     _highest_vm_reserved_address = old_highest;
2541     return NULL;
2542   }
2543 }
2544 
2545 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2546   RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2547 }
2548 
2549 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
2550 // Solaris uses poll(), bsd uses park().
2551 // Poll() is likely a better choice, assuming that Thread.interrupt()
2552 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
2553 // SIGSEGV, see 4355769.
2554 
2555 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
2556   assert(thread == Thread::current(),  "thread consistency check");
2557 
2558   ParkEvent * const slp = thread->_SleepEvent ;
2559   slp->reset() ;
2560   OrderAccess::fence() ;
2561 
2562   if (interruptible) {
2563     jlong prevtime = javaTimeNanos();
2564 
2565     for (;;) {
2566       if (os::is_interrupted(thread, true)) {
2567         return OS_INTRPT;
2568       }
2569 
2570       jlong newtime = javaTimeNanos();
2571 
2572       if (newtime - prevtime < 0) {
2573         // time moving backwards, should only happen if no monotonic clock
2574         // not a guarantee() because JVM should not abort on kernel/glibc bugs
2575         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2576       } else {
2577         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2578       }
2579 
2580       if(millis <= 0) {
2581         return OS_OK;
2582       }
2583 
2584       prevtime = newtime;
2585 
2586       {
2587         assert(thread->is_Java_thread(), "sanity check");
2588         JavaThread *jt = (JavaThread *) thread;
2589         ThreadBlockInVM tbivm(jt);
2590         OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
2591 
2592         jt->set_suspend_equivalent();
2593         // cleared by handle_special_suspend_equivalent_condition() or
2594         // java_suspend_self() via check_and_wait_while_suspended()
2595 
2596         slp->park(millis);
2597 
2598         // were we externally suspended while we were waiting?
2599         jt->check_and_wait_while_suspended();
2600       }
2601     }
2602   } else {
2603     OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2604     jlong prevtime = javaTimeNanos();
2605 
2606     for (;;) {
2607       // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
2608       // the 1st iteration ...
2609       jlong newtime = javaTimeNanos();
2610 
2611       if (newtime - prevtime < 0) {
2612         // time moving backwards, should only happen if no monotonic clock
2613         // not a guarantee() because JVM should not abort on kernel/glibc bugs
2614         assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2615       } else {
2616         millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2617       }
2618 
2619       if(millis <= 0) break ;
2620 
2621       prevtime = newtime;
2622       slp->park(millis);
2623     }
2624     return OS_OK ;
2625   }
2626 }
2627 
2628 int os::naked_sleep() {
2629   // %% make the sleep time an integer flag. for now use 1 millisec.
2630   return os::sleep(Thread::current(), 1, false);
2631 }
2632 
2633 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2634 void os::infinite_sleep() {
2635   while (true) {    // sleep forever ...
2636     ::sleep(100);   // ... 100 seconds at a time
2637   }
2638 }
2639 
2640 // Used to convert frequent JVM_Yield() to nops
2641 bool os::dont_yield() {
2642   return DontYieldALot;
2643 }
2644 
2645 void os::yield() {
2646   sched_yield();
2647 }
2648 
2649 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
2650 
2651 void os::yield_all(int attempts) {
2652   // Yields to all threads, including threads with lower priorities
2653   // Threads on Bsd are all with same priority. The Solaris style
2654   // os::yield_all() with nanosleep(1ms) is not necessary.
2655   sched_yield();
2656 }
2657 
2658 // Called from the tight loops to possibly influence time-sharing heuristics
2659 void os::loop_breaker(int attempts) {
2660   os::yield_all(attempts);
2661 }
2662 
2663 ////////////////////////////////////////////////////////////////////////////////
2664 // thread priority support
2665 
2666 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2667 // only supports dynamic priority, static priority must be zero. For real-time
2668 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2669 // However, for large multi-threaded applications, SCHED_RR is not only slower
2670 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2671 // of 5 runs - Sep 2005).
2672 //
2673 // The following code actually changes the niceness of kernel-thread/LWP. It
2674 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2675 // not the entire user process, and user level threads are 1:1 mapped to kernel
2676 // threads. It has always been the case, but could change in the future. For
2677 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2678 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2679 
2680 #if !defined(__APPLE__)
2681 int os::java_to_os_priority[CriticalPriority + 1] = {
2682   19,              // 0 Entry should never be used
2683 
2684    0,              // 1 MinPriority
2685    3,              // 2
2686    6,              // 3
2687 
2688   10,              // 4
2689   15,              // 5 NormPriority
2690   18,              // 6
2691 
2692   21,              // 7
2693   25,              // 8
2694   28,              // 9 NearMaxPriority
2695 
2696   31,              // 10 MaxPriority
2697 
2698   31               // 11 CriticalPriority
2699 };
2700 #else
2701 /* Using Mach high-level priority assignments */
2702 int os::java_to_os_priority[CriticalPriority + 1] = {
2703    0,              // 0 Entry should never be used (MINPRI_USER)
2704 
2705   27,              // 1 MinPriority
2706   28,              // 2
2707   29,              // 3
2708 
2709   30,              // 4
2710   31,              // 5 NormPriority (BASEPRI_DEFAULT)
2711   32,              // 6
2712 
2713   33,              // 7
2714   34,              // 8
2715   35,              // 9 NearMaxPriority
2716 
2717   36,              // 10 MaxPriority
2718 
2719   36               // 11 CriticalPriority
2720 };
2721 #endif
2722 
2723 static int prio_init() {
2724   if (ThreadPriorityPolicy == 1) {
2725     // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2726     // if effective uid is not root. Perhaps, a more elegant way of doing
2727     // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2728     if (geteuid() != 0) {
2729       if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2730         warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2731       }
2732       ThreadPriorityPolicy = 0;
2733     }
2734   }
2735   if (UseCriticalJavaThreadPriority) {
2736     os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2737   }
2738   return 0;
2739 }
2740 
2741 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2742   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
2743 
2744 #ifdef __OpenBSD__
2745   // OpenBSD pthread_setprio starves low priority threads
2746   return OS_OK;
2747 #elif defined(__FreeBSD__)
2748   int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2749 #elif defined(__APPLE__) || defined(__NetBSD__)
2750   struct sched_param sp;
2751   int policy;
2752   pthread_t self = pthread_self();
2753 
2754   if (pthread_getschedparam(self, &policy, &sp) != 0)
2755     return OS_ERR;
2756 
2757   sp.sched_priority = newpri;
2758   if (pthread_setschedparam(self, policy, &sp) != 0)
2759     return OS_ERR;
2760 
2761   return OS_OK;
2762 #else
2763   int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2764   return (ret == 0) ? OS_OK : OS_ERR;
2765 #endif
2766 }
2767 
2768 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2769   if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
2770     *priority_ptr = java_to_os_priority[NormPriority];
2771     return OS_OK;
2772   }
2773 
2774   errno = 0;
2775 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2776   *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2777 #elif defined(__APPLE__) || defined(__NetBSD__)
2778   int policy;
2779   struct sched_param sp;
2780 
2781   pthread_getschedparam(pthread_self(), &policy, &sp);
2782   *priority_ptr = sp.sched_priority;
2783 #else
2784   *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2785 #endif
2786   return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2787 }
2788 
2789 // Hint to the underlying OS that a task switch would not be good.
2790 // Void return because it's a hint and can fail.
2791 void os::hint_no_preempt() {}
2792 
2793 ////////////////////////////////////////////////////////////////////////////////
2794 // suspend/resume support
2795 
2796 //  the low-level signal-based suspend/resume support is a remnant from the
2797 //  old VM-suspension that used to be for java-suspension, safepoints etc,
2798 //  within hotspot. Now there is a single use-case for this:
2799 //    - calling get_thread_pc() on the VMThread by the flat-profiler task
2800 //      that runs in the watcher thread.
2801 //  The remaining code is greatly simplified from the more general suspension
2802 //  code that used to be used.
2803 //
2804 //  The protocol is quite simple:
2805 //  - suspend:
2806 //      - sends a signal to the target thread
2807 //      - polls the suspend state of the osthread using a yield loop
2808 //      - target thread signal handler (SR_handler) sets suspend state
2809 //        and blocks in sigsuspend until continued
2810 //  - resume:
2811 //      - sets target osthread state to continue
2812 //      - sends signal to end the sigsuspend loop in the SR_handler
2813 //
2814 //  Note that the SR_lock plays no role in this suspend/resume protocol.
2815 //
2816 
2817 static void resume_clear_context(OSThread *osthread) {
2818   osthread->set_ucontext(NULL);
2819   osthread->set_siginfo(NULL);
2820 }
2821 
2822 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2823   osthread->set_ucontext(context);
2824   osthread->set_siginfo(siginfo);
2825 }
2826 
2827 //
2828 // Handler function invoked when a thread's execution is suspended or
2829 // resumed. We have to be careful that only async-safe functions are
2830 // called here (Note: most pthread functions are not async safe and
2831 // should be avoided.)
2832 //
2833 // Note: sigwait() is a more natural fit than sigsuspend() from an
2834 // interface point of view, but sigwait() prevents the signal hander
2835 // from being run. libpthread would get very confused by not having
2836 // its signal handlers run and prevents sigwait()'s use with the
2837 // mutex granting granting signal.
2838 //
2839 // Currently only ever called on the VMThread or JavaThread
2840 //
2841 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2842   // Save and restore errno to avoid confusing native code with EINTR
2843   // after sigsuspend.
2844   int old_errno = errno;
2845 
2846   Thread* thread = Thread::current();
2847   OSThread* osthread = thread->osthread();
2848   assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2849 
2850   os::SuspendResume::State current = osthread->sr.state();
2851   if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2852     suspend_save_context(osthread, siginfo, context);
2853 
2854     // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2855     os::SuspendResume::State state = osthread->sr.suspended();
2856     if (state == os::SuspendResume::SR_SUSPENDED) {
2857       sigset_t suspend_set;  // signals for sigsuspend()
2858 
2859       // get current set of blocked signals and unblock resume signal
2860       pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2861       sigdelset(&suspend_set, SR_signum);
2862 
2863       sr_semaphore.signal();
2864       // wait here until we are resumed
2865       while (1) {
2866         sigsuspend(&suspend_set);
2867 
2868         os::SuspendResume::State result = osthread->sr.running();
2869         if (result == os::SuspendResume::SR_RUNNING) {
2870           sr_semaphore.signal();
2871           break;
2872         } else if (result != os::SuspendResume::SR_SUSPENDED) {
2873           ShouldNotReachHere();
2874         }
2875       }
2876 
2877     } else if (state == os::SuspendResume::SR_RUNNING) {
2878       // request was cancelled, continue
2879     } else {
2880       ShouldNotReachHere();
2881     }
2882 
2883     resume_clear_context(osthread);
2884   } else if (current == os::SuspendResume::SR_RUNNING) {
2885     // request was cancelled, continue
2886   } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2887     // ignore
2888   } else {
2889     // ignore
2890   }
2891 
2892   errno = old_errno;
2893 }
2894 
2895 
2896 static int SR_initialize() {
2897   struct sigaction act;
2898   char *s;
2899   /* Get signal number to use for suspend/resume */
2900   if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2901     int sig = ::strtol(s, 0, 10);
2902     if (sig > 0 || sig < NSIG) {
2903         SR_signum = sig;
2904     }
2905   }
2906 
2907   assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2908         "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2909 
2910   sigemptyset(&SR_sigset);
2911   sigaddset(&SR_sigset, SR_signum);
2912 
2913   /* Set up signal handler for suspend/resume */
2914   act.sa_flags = SA_RESTART|SA_SIGINFO;
2915   act.sa_handler = (void (*)(int)) SR_handler;
2916 
2917   // SR_signum is blocked by default.
2918   // 4528190 - We also need to block pthread restart signal (32 on all
2919   // supported Bsd platforms). Note that BsdThreads need to block
2920   // this signal for all threads to work properly. So we don't have
2921   // to use hard-coded signal number when setting up the mask.
2922   pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2923 
2924   if (sigaction(SR_signum, &act, 0) == -1) {
2925     return -1;
2926   }
2927 
2928   // Save signal flag
2929   os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2930   return 0;
2931 }
2932 
2933 static int sr_notify(OSThread* osthread) {
2934   int status = pthread_kill(osthread->pthread_id(), SR_signum);
2935   assert_status(status == 0, status, "pthread_kill");
2936   return status;
2937 }
2938 
2939 // "Randomly" selected value for how long we want to spin
2940 // before bailing out on suspending a thread, also how often
2941 // we send a signal to a thread we want to resume
2942 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2943 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2944 
2945 // returns true on success and false on error - really an error is fatal
2946 // but this seems the normal response to library errors
2947 static bool do_suspend(OSThread* osthread) {
2948   assert(osthread->sr.is_running(), "thread should be running");
2949   assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2950 
2951   // mark as suspended and send signal
2952   if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2953     // failed to switch, state wasn't running?
2954     ShouldNotReachHere();
2955     return false;
2956   }
2957 
2958   if (sr_notify(osthread) != 0) {
2959     ShouldNotReachHere();
2960   }
2961 
2962   // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2963   while (true) {
2964     if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2965       break;
2966     } else {
2967       // timeout
2968       os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2969       if (cancelled == os::SuspendResume::SR_RUNNING) {
2970         return false;
2971       } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2972         // make sure that we consume the signal on the semaphore as well
2973         sr_semaphore.wait();
2974         break;
2975       } else {
2976         ShouldNotReachHere();
2977         return false;
2978       }
2979     }
2980   }
2981 
2982   guarantee(osthread->sr.is_suspended(), "Must be suspended");
2983   return true;
2984 }
2985 
2986 static void do_resume(OSThread* osthread) {
2987   assert(osthread->sr.is_suspended(), "thread should be suspended");
2988   assert(!sr_semaphore.trywait(), "invalid semaphore state");
2989 
2990   if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2991     // failed to switch to WAKEUP_REQUEST
2992     ShouldNotReachHere();
2993     return;
2994   }
2995 
2996   while (true) {
2997     if (sr_notify(osthread) == 0) {
2998       if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2999         if (osthread->sr.is_running()) {
3000           return;
3001         }
3002       }
3003     } else {
3004       ShouldNotReachHere();
3005     }
3006   }
3007 
3008   guarantee(osthread->sr.is_running(), "Must be running!");
3009 }
3010 
3011 ////////////////////////////////////////////////////////////////////////////////
3012 // interrupt support
3013 
3014 void os::interrupt(Thread* thread) {
3015   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
3016     "possibility of dangling Thread pointer");
3017 
3018   OSThread* osthread = thread->osthread();
3019 
3020   if (!osthread->interrupted()) {
3021     osthread->set_interrupted(true);
3022     // More than one thread can get here with the same value of osthread,
3023     // resulting in multiple notifications.  We do, however, want the store
3024     // to interrupted() to be visible to other threads before we execute unpark().
3025     OrderAccess::fence();
3026     ParkEvent * const slp = thread->_SleepEvent ;
3027     if (slp != NULL) slp->unpark() ;
3028   }
3029 
3030   // For JSR166. Unpark even if interrupt status already was set
3031   if (thread->is_Java_thread())
3032     ((JavaThread*)thread)->parker()->unpark();
3033 
3034   ParkEvent * ev = thread->_ParkEvent ;
3035   if (ev != NULL) ev->unpark() ;
3036 
3037 }
3038 
3039 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
3040   assert(Thread::current() == thread || Threads_lock->owned_by_self(),
3041     "possibility of dangling Thread pointer");
3042 
3043   OSThread* osthread = thread->osthread();
3044 
3045   bool interrupted = osthread->interrupted();
3046 
3047   if (interrupted && clear_interrupted) {
3048     osthread->set_interrupted(false);
3049     // consider thread->_SleepEvent->reset() ... optional optimization
3050   }
3051 
3052   return interrupted;
3053 }
3054 
3055 ///////////////////////////////////////////////////////////////////////////////////
3056 // signal handling (except suspend/resume)
3057 
3058 // This routine may be used by user applications as a "hook" to catch signals.
3059 // The user-defined signal handler must pass unrecognized signals to this
3060 // routine, and if it returns true (non-zero), then the signal handler must
3061 // return immediately.  If the flag "abort_if_unrecognized" is true, then this
3062 // routine will never retun false (zero), but instead will execute a VM panic
3063 // routine kill the process.
3064 //
3065 // If this routine returns false, it is OK to call it again.  This allows
3066 // the user-defined signal handler to perform checks either before or after
3067 // the VM performs its own checks.  Naturally, the user code would be making
3068 // a serious error if it tried to handle an exception (such as a null check
3069 // or breakpoint) that the VM was generating for its own correct operation.
3070 //
3071 // This routine may recognize any of the following kinds of signals:
3072 //    SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
3073 // It should be consulted by handlers for any of those signals.
3074 //
3075 // The caller of this routine must pass in the three arguments supplied
3076 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
3077 // field of the structure passed to sigaction().  This routine assumes that
3078 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
3079 //
3080 // Note that the VM will print warnings if it detects conflicting signal
3081 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
3082 //
3083 extern "C" JNIEXPORT int
3084 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
3085                         void* ucontext, int abort_if_unrecognized);
3086 
3087 void signalHandler(int sig, siginfo_t* info, void* uc) {
3088   assert(info != NULL && uc != NULL, "it must be old kernel");
3089   int orig_errno = errno;  // Preserve errno value over signal handler.
3090   JVM_handle_bsd_signal(sig, info, uc, true);
3091   errno = orig_errno;
3092 }
3093 
3094 
3095 // This boolean allows users to forward their own non-matching signals
3096 // to JVM_handle_bsd_signal, harmlessly.
3097 bool os::Bsd::signal_handlers_are_installed = false;
3098 
3099 // For signal-chaining
3100 struct sigaction os::Bsd::sigact[MAXSIGNUM];
3101 unsigned int os::Bsd::sigs = 0;
3102 bool os::Bsd::libjsig_is_loaded = false;
3103 typedef struct sigaction *(*get_signal_t)(int);
3104 get_signal_t os::Bsd::get_signal_action = NULL;
3105 
3106 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
3107   struct sigaction *actp = NULL;
3108 
3109   if (libjsig_is_loaded) {
3110     // Retrieve the old signal handler from libjsig
3111     actp = (*get_signal_action)(sig);
3112   }
3113   if (actp == NULL) {
3114     // Retrieve the preinstalled signal handler from jvm
3115     actp = get_preinstalled_handler(sig);
3116   }
3117 
3118   return actp;
3119 }
3120 
3121 static bool call_chained_handler(struct sigaction *actp, int sig,
3122                                  siginfo_t *siginfo, void *context) {
3123   // Call the old signal handler
3124   if (actp->sa_handler == SIG_DFL) {
3125     // It's more reasonable to let jvm treat it as an unexpected exception
3126     // instead of taking the default action.
3127     return false;
3128   } else if (actp->sa_handler != SIG_IGN) {
3129     if ((actp->sa_flags & SA_NODEFER) == 0) {
3130       // automaticlly block the signal
3131       sigaddset(&(actp->sa_mask), sig);
3132     }
3133 
3134     sa_handler_t hand;
3135     sa_sigaction_t sa;
3136     bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3137     // retrieve the chained handler
3138     if (siginfo_flag_set) {
3139       sa = actp->sa_sigaction;
3140     } else {
3141       hand = actp->sa_handler;
3142     }
3143 
3144     if ((actp->sa_flags & SA_RESETHAND) != 0) {
3145       actp->sa_handler = SIG_DFL;
3146     }
3147 
3148     // try to honor the signal mask
3149     sigset_t oset;
3150     pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3151 
3152     // call into the chained handler
3153     if (siginfo_flag_set) {
3154       (*sa)(sig, siginfo, context);
3155     } else {
3156       (*hand)(sig);
3157     }
3158 
3159     // restore the signal mask
3160     pthread_sigmask(SIG_SETMASK, &oset, 0);
3161   }
3162   // Tell jvm's signal handler the signal is taken care of.
3163   return true;
3164 }
3165 
3166 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3167   bool chained = false;
3168   // signal-chaining
3169   if (UseSignalChaining) {
3170     struct sigaction *actp = get_chained_signal_action(sig);
3171     if (actp != NULL) {
3172       chained = call_chained_handler(actp, sig, siginfo, context);
3173     }
3174   }
3175   return chained;
3176 }
3177 
3178 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3179   if ((( (unsigned int)1 << sig ) & sigs) != 0) {
3180     return &sigact[sig];
3181   }
3182   return NULL;
3183 }
3184 
3185 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3186   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3187   sigact[sig] = oldAct;
3188   sigs |= (unsigned int)1 << sig;
3189 }
3190 
3191 // for diagnostic
3192 int os::Bsd::sigflags[MAXSIGNUM];
3193 
3194 int os::Bsd::get_our_sigflags(int sig) {
3195   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3196   return sigflags[sig];
3197 }
3198 
3199 void os::Bsd::set_our_sigflags(int sig, int flags) {
3200   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3201   sigflags[sig] = flags;
3202 }
3203 
3204 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3205   // Check for overwrite.
3206   struct sigaction oldAct;
3207   sigaction(sig, (struct sigaction*)NULL, &oldAct);
3208 
3209   void* oldhand = oldAct.sa_sigaction
3210                 ? CAST_FROM_FN_PTR(void*,  oldAct.sa_sigaction)
3211                 : CAST_FROM_FN_PTR(void*,  oldAct.sa_handler);
3212   if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3213       oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3214       oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3215     if (AllowUserSignalHandlers || !set_installed) {
3216       // Do not overwrite; user takes responsibility to forward to us.
3217       return;
3218     } else if (UseSignalChaining) {
3219       // save the old handler in jvm
3220       save_preinstalled_handler(sig, oldAct);
3221       // libjsig also interposes the sigaction() call below and saves the
3222       // old sigaction on it own.
3223     } else {
3224       fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3225                     "%#lx for signal %d.", (long)oldhand, sig));
3226     }
3227   }
3228 
3229   struct sigaction sigAct;
3230   sigfillset(&(sigAct.sa_mask));
3231   sigAct.sa_handler = SIG_DFL;
3232   if (!set_installed) {
3233     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3234   } else {
3235     sigAct.sa_sigaction = signalHandler;
3236     sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3237   }
3238 #if __APPLE__
3239   // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3240   // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3241   // if the signal handler declares it will handle it on alternate stack.
3242   // Notice we only declare we will handle it on alt stack, but we are not
3243   // actually going to use real alt stack - this is just a workaround.
3244   // Please see ux_exception.c, method catch_mach_exception_raise for details
3245   // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3246   if (sig == SIGSEGV) {
3247     sigAct.sa_flags |= SA_ONSTACK;
3248   }
3249 #endif
3250 
3251   // Save flags, which are set by ours
3252   assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3253   sigflags[sig] = sigAct.sa_flags;
3254 
3255   int ret = sigaction(sig, &sigAct, &oldAct);
3256   assert(ret == 0, "check");
3257 
3258   void* oldhand2  = oldAct.sa_sigaction
3259                   ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3260                   : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3261   assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3262 }
3263 
3264 // install signal handlers for signals that HotSpot needs to
3265 // handle in order to support Java-level exception handling.
3266 
3267 void os::Bsd::install_signal_handlers() {
3268   if (!signal_handlers_are_installed) {
3269     signal_handlers_are_installed = true;
3270 
3271     // signal-chaining
3272     typedef void (*signal_setting_t)();
3273     signal_setting_t begin_signal_setting = NULL;
3274     signal_setting_t end_signal_setting = NULL;
3275     begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3276                              dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3277     if (begin_signal_setting != NULL) {
3278       end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3279                              dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3280       get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3281                             dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3282       libjsig_is_loaded = true;
3283       assert(UseSignalChaining, "should enable signal-chaining");
3284     }
3285     if (libjsig_is_loaded) {
3286       // Tell libjsig jvm is setting signal handlers
3287       (*begin_signal_setting)();
3288     }
3289 
3290     set_signal_handler(SIGSEGV, true);
3291     set_signal_handler(SIGPIPE, true);
3292     set_signal_handler(SIGBUS, true);
3293     set_signal_handler(SIGILL, true);
3294     set_signal_handler(SIGFPE, true);
3295     set_signal_handler(SIGXFSZ, true);
3296 
3297 #if defined(__APPLE__)
3298     // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3299     // signals caught and handled by the JVM. To work around this, we reset the mach task
3300     // signal handler that's placed on our process by CrashReporter. This disables
3301     // CrashReporter-based reporting.
3302     //
3303     // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3304     // on caught fatal signals.
3305     //
3306     // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3307     // handlers. By replacing the existing task exception handler, we disable gdb's mach
3308     // exception handling, while leaving the standard BSD signal handlers functional.
3309     kern_return_t kr;
3310     kr = task_set_exception_ports(mach_task_self(),
3311         EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3312         MACH_PORT_NULL,
3313         EXCEPTION_STATE_IDENTITY,
3314         MACHINE_THREAD_STATE);
3315 
3316     assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3317 #endif
3318 
3319     if (libjsig_is_loaded) {
3320       // Tell libjsig jvm finishes setting signal handlers
3321       (*end_signal_setting)();
3322     }
3323 
3324     // We don't activate signal checker if libjsig is in place, we trust ourselves
3325     // and if UserSignalHandler is installed all bets are off
3326     if (CheckJNICalls) {
3327       if (libjsig_is_loaded) {
3328         if (PrintJNIResolving) {
3329           tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3330         }
3331         check_signals = false;
3332       }
3333       if (AllowUserSignalHandlers) {
3334         if (PrintJNIResolving) {
3335           tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3336         }
3337         check_signals = false;
3338       }
3339     }
3340   }
3341 }
3342 
3343 
3344 /////
3345 // glibc on Bsd platform uses non-documented flag
3346 // to indicate, that some special sort of signal
3347 // trampoline is used.
3348 // We will never set this flag, and we should
3349 // ignore this flag in our diagnostic
3350 #ifdef SIGNIFICANT_SIGNAL_MASK
3351 #undef SIGNIFICANT_SIGNAL_MASK
3352 #endif
3353 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3354 
3355 static const char* get_signal_handler_name(address handler,
3356                                            char* buf, int buflen) {
3357   int offset;
3358   bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3359   if (found) {
3360     // skip directory names
3361     const char *p1, *p2;
3362     p1 = buf;
3363     size_t len = strlen(os::file_separator());
3364     while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3365     jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3366   } else {
3367     jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3368   }
3369   return buf;
3370 }
3371 
3372 static void print_signal_handler(outputStream* st, int sig,
3373                                  char* buf, size_t buflen) {
3374   struct sigaction sa;
3375 
3376   sigaction(sig, NULL, &sa);
3377 
3378   // See comment for SIGNIFICANT_SIGNAL_MASK define
3379   sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3380 
3381   st->print("%s: ", os::exception_name(sig, buf, buflen));
3382 
3383   address handler = (sa.sa_flags & SA_SIGINFO)
3384     ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3385     : CAST_FROM_FN_PTR(address, sa.sa_handler);
3386 
3387   if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3388     st->print("SIG_DFL");
3389   } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3390     st->print("SIG_IGN");
3391   } else {
3392     st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3393   }
3394 
3395   st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask);
3396 
3397   address rh = VMError::get_resetted_sighandler(sig);
3398   // May be, handler was resetted by VMError?
3399   if(rh != NULL) {
3400     handler = rh;
3401     sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3402   }
3403 
3404   st->print(", sa_flags="   PTR32_FORMAT, sa.sa_flags);
3405 
3406   // Check: is it our handler?
3407   if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3408      handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3409     // It is our signal handler
3410     // check for flags, reset system-used one!
3411     if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3412       st->print(
3413                 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3414                 os::Bsd::get_our_sigflags(sig));
3415     }
3416   }
3417   st->cr();
3418 }
3419 
3420 
3421 #define DO_SIGNAL_CHECK(sig) \
3422   if (!sigismember(&check_signal_done, sig)) \
3423     os::Bsd::check_signal_handler(sig)
3424 
3425 // This method is a periodic task to check for misbehaving JNI applications
3426 // under CheckJNI, we can add any periodic checks here
3427 
3428 void os::run_periodic_checks() {
3429 
3430   if (check_signals == false) return;
3431 
3432   // SEGV and BUS if overridden could potentially prevent
3433   // generation of hs*.log in the event of a crash, debugging
3434   // such a case can be very challenging, so we absolutely
3435   // check the following for a good measure:
3436   DO_SIGNAL_CHECK(SIGSEGV);
3437   DO_SIGNAL_CHECK(SIGILL);
3438   DO_SIGNAL_CHECK(SIGFPE);
3439   DO_SIGNAL_CHECK(SIGBUS);
3440   DO_SIGNAL_CHECK(SIGPIPE);
3441   DO_SIGNAL_CHECK(SIGXFSZ);
3442 
3443 
3444   // ReduceSignalUsage allows the user to override these handlers
3445   // see comments at the very top and jvm_solaris.h
3446   if (!ReduceSignalUsage) {
3447     DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3448     DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3449     DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3450     DO_SIGNAL_CHECK(BREAK_SIGNAL);
3451   }
3452 
3453   DO_SIGNAL_CHECK(SR_signum);
3454   DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3455 }
3456 
3457 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3458 
3459 static os_sigaction_t os_sigaction = NULL;
3460 
3461 void os::Bsd::check_signal_handler(int sig) {
3462   char buf[O_BUFLEN];
3463   address jvmHandler = NULL;
3464 
3465 
3466   struct sigaction act;
3467   if (os_sigaction == NULL) {
3468     // only trust the default sigaction, in case it has been interposed
3469     os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3470     if (os_sigaction == NULL) return;
3471   }
3472 
3473   os_sigaction(sig, (struct sigaction*)NULL, &act);
3474 
3475 
3476   act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3477 
3478   address thisHandler = (act.sa_flags & SA_SIGINFO)
3479     ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3480     : CAST_FROM_FN_PTR(address, act.sa_handler) ;
3481 
3482 
3483   switch(sig) {
3484   case SIGSEGV:
3485   case SIGBUS:
3486   case SIGFPE:
3487   case SIGPIPE:
3488   case SIGILL:
3489   case SIGXFSZ:
3490     jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3491     break;
3492 
3493   case SHUTDOWN1_SIGNAL:
3494   case SHUTDOWN2_SIGNAL:
3495   case SHUTDOWN3_SIGNAL:
3496   case BREAK_SIGNAL:
3497     jvmHandler = (address)user_handler();
3498     break;
3499 
3500   case INTERRUPT_SIGNAL:
3501     jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3502     break;
3503 
3504   default:
3505     if (sig == SR_signum) {
3506       jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3507     } else {
3508       return;
3509     }
3510     break;
3511   }
3512 
3513   if (thisHandler != jvmHandler) {
3514     tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3515     tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3516     tty->print_cr("  found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3517     // No need to check this sig any longer
3518     sigaddset(&check_signal_done, sig);
3519   } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3520     tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3521     tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3522     tty->print_cr("  found:" PTR32_FORMAT, act.sa_flags);
3523     // No need to check this sig any longer
3524     sigaddset(&check_signal_done, sig);
3525   }
3526 
3527   // Dump all the signal
3528   if (sigismember(&check_signal_done, sig)) {
3529     print_signal_handlers(tty, buf, O_BUFLEN);
3530   }
3531 }
3532 
3533 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
3534 
3535 extern bool signal_name(int signo, char* buf, size_t len);
3536 
3537 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3538   if (0 < exception_code && exception_code <= SIGRTMAX) {
3539     // signal
3540     if (!signal_name(exception_code, buf, size)) {
3541       jio_snprintf(buf, size, "SIG%d", exception_code);
3542     }
3543     return buf;
3544   } else {
3545     return NULL;
3546   }
3547 }
3548 
3549 // this is called _before_ the most of global arguments have been parsed
3550 void os::init(void) {
3551   char dummy;   /* used to get a guess on initial stack address */
3552 //  first_hrtime = gethrtime();
3553 
3554   // With BsdThreads the JavaMain thread pid (primordial thread)
3555   // is different than the pid of the java launcher thread.
3556   // So, on Bsd, the launcher thread pid is passed to the VM
3557   // via the sun.java.launcher.pid property.
3558   // Use this property instead of getpid() if it was correctly passed.
3559   // See bug 6351349.
3560   pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3561 
3562   _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3563 
3564   clock_tics_per_sec = CLK_TCK;
3565 
3566   init_random(1234567);
3567 
3568   ThreadCritical::initialize();
3569 
3570   Bsd::set_page_size(getpagesize());
3571   if (Bsd::page_size() == -1) {
3572     fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3573                   strerror(errno)));
3574   }
3575   init_page_sizes((size_t) Bsd::page_size());
3576 
3577   Bsd::initialize_system_info();
3578 
3579   // main_thread points to the aboriginal thread
3580   Bsd::_main_thread = pthread_self();
3581 
3582   Bsd::clock_init();
3583   initial_time_count = javaTimeNanos();
3584 
3585 #ifdef __APPLE__
3586   // XXXDARWIN
3587   // Work around the unaligned VM callbacks in hotspot's
3588   // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3589   // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3590   // alignment when doing symbol lookup. To work around this, we force early
3591   // binding of all symbols now, thus binding when alignment is known-good.
3592   _dyld_bind_fully_image_containing_address((const void *) &os::init);
3593 #endif
3594 }
3595 
3596 // To install functions for atexit system call
3597 extern "C" {
3598   static void perfMemory_exit_helper() {
3599     perfMemory_exit();
3600   }
3601 }
3602 
3603 // this is called _after_ the global arguments have been parsed
3604 jint os::init_2(void)
3605 {
3606   // Allocate a single page and mark it as readable for safepoint polling
3607   address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3608   guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
3609 
3610   os::set_polling_page( polling_page );
3611 
3612 #ifndef PRODUCT
3613   if(Verbose && PrintMiscellaneous)
3614     tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
3615 #endif
3616 
3617   if (!UseMembar) {
3618     address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3619     guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3620     os::set_memory_serialize_page( mem_serialize_page );
3621 
3622 #ifndef PRODUCT
3623     if(Verbose && PrintMiscellaneous)
3624       tty->print("[Memory Serialize  Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
3625 #endif
3626   }
3627 
3628   // initialize suspend/resume support - must do this before signal_sets_init()
3629   if (SR_initialize() != 0) {
3630     perror("SR_initialize failed");
3631     return JNI_ERR;
3632   }
3633 
3634   Bsd::signal_sets_init();
3635   Bsd::install_signal_handlers();
3636 
3637   // Check minimum allowable stack size for thread creation and to initialize
3638   // the java system classes, including StackOverflowError - depends on page
3639   // size.  Add a page for compiler2 recursion in main thread.
3640   // Add in 2*BytesPerWord times page size to account for VM stack during
3641   // class initialization depending on 32 or 64 bit VM.
3642   os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3643             (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3644                     2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3645 
3646   size_t threadStackSizeInBytes = ThreadStackSize * K;
3647   if (threadStackSizeInBytes != 0 &&
3648       threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3649         tty->print_cr("\nThe stack size specified is too small, "
3650                       "Specify at least %dk",
3651                       os::Bsd::min_stack_allowed/ K);
3652         return JNI_ERR;
3653   }
3654 
3655   // Make the stack size a multiple of the page size so that
3656   // the yellow/red zones can be guarded.
3657   JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3658         vm_page_size()));
3659 
3660   if (MaxFDLimit) {
3661     // set the number of file descriptors to max. print out error
3662     // if getrlimit/setrlimit fails but continue regardless.
3663     struct rlimit nbr_files;
3664     int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3665     if (status != 0) {
3666       if (PrintMiscellaneous && (Verbose || WizardMode))
3667         perror("os::init_2 getrlimit failed");
3668     } else {
3669       nbr_files.rlim_cur = nbr_files.rlim_max;
3670 
3671 #ifdef __APPLE__
3672       // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3673       // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3674       // be used instead
3675       nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3676 #endif
3677 
3678       status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3679       if (status != 0) {
3680         if (PrintMiscellaneous && (Verbose || WizardMode))
3681           perror("os::init_2 setrlimit failed");
3682       }
3683     }
3684   }
3685 
3686   // at-exit methods are called in the reverse order of their registration.
3687   // atexit functions are called on return from main or as a result of a
3688   // call to exit(3C). There can be only 32 of these functions registered
3689   // and atexit() does not set errno.
3690 
3691   if (PerfAllowAtExitRegistration) {
3692     // only register atexit functions if PerfAllowAtExitRegistration is set.
3693     // atexit functions can be delayed until process exit time, which
3694     // can be problematic for embedded VM situations. Embedded VMs should
3695     // call DestroyJavaVM() to assure that VM resources are released.
3696 
3697     // note: perfMemory_exit_helper atexit function may be removed in
3698     // the future if the appropriate cleanup code can be added to the
3699     // VM_Exit VMOperation's doit method.
3700     if (atexit(perfMemory_exit_helper) != 0) {
3701       warning("os::init2 atexit(perfMemory_exit_helper) failed");
3702     }
3703   }
3704 
3705   // initialize thread priority policy
3706   prio_init();
3707 
3708 #ifdef __APPLE__
3709   // dynamically link to objective c gc registration
3710   void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3711   if (handleLibObjc != NULL) {
3712     objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3713   }
3714 #endif
3715 
3716   return JNI_OK;
3717 }
3718 
3719 // this is called at the end of vm_initialization
3720 void os::init_3(void) { }
3721 
3722 // Mark the polling page as unreadable
3723 void os::make_polling_page_unreadable(void) {
3724   if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
3725     fatal("Could not disable polling page");
3726 };
3727 
3728 // Mark the polling page as readable
3729 void os::make_polling_page_readable(void) {
3730   if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3731     fatal("Could not enable polling page");
3732   }
3733 };
3734 
3735 int os::active_processor_count() {
3736   return _processor_count;
3737 }
3738 
3739 void os::set_native_thread_name(const char *name) {
3740 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3741   // This is only supported in Snow Leopard and beyond
3742   if (name != NULL) {
3743     // Add a "Java: " prefix to the name
3744     char buf[MAXTHREADNAMESIZE];
3745     snprintf(buf, sizeof(buf), "Java: %s", name);
3746     pthread_setname_np(buf);
3747   }
3748 #endif
3749 }
3750 
3751 bool os::distribute_processes(uint length, uint* distribution) {
3752   // Not yet implemented.
3753   return false;
3754 }
3755 
3756 bool os::bind_to_processor(uint processor_id) {
3757   // Not yet implemented.
3758   return false;
3759 }
3760 
3761 void os::SuspendedThreadTask::internal_do_task() {
3762   if (do_suspend(_thread->osthread())) {
3763     SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3764     do_task(context);
3765     do_resume(_thread->osthread());
3766   }
3767 }
3768 
3769 ///
3770 class PcFetcher : public os::SuspendedThreadTask {
3771 public:
3772   PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3773   ExtendedPC result();
3774 protected:
3775   void do_task(const os::SuspendedThreadTaskContext& context);
3776 private:
3777   ExtendedPC _epc;
3778 };
3779 
3780 ExtendedPC PcFetcher::result() {
3781   guarantee(is_done(), "task is not done yet.");
3782   return _epc;
3783 }
3784 
3785 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3786   Thread* thread = context.thread();
3787   OSThread* osthread = thread->osthread();
3788   if (osthread->ucontext() != NULL) {
3789     _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
3790   } else {
3791     // NULL context is unexpected, double-check this is the VMThread
3792     guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3793   }
3794 }
3795 
3796 // Suspends the target using the signal mechanism and then grabs the PC before
3797 // resuming the target. Used by the flat-profiler only
3798 ExtendedPC os::get_thread_pc(Thread* thread) {
3799   // Make sure that it is called by the watcher for the VMThread
3800   assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3801   assert(thread->is_VM_thread(), "Can only be called for VMThread");
3802 
3803   PcFetcher fetcher(thread);
3804   fetcher.run();
3805   return fetcher.result();
3806 }
3807 
3808 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
3809 {
3810   return pthread_cond_timedwait(_cond, _mutex, _abstime);
3811 }
3812 
3813 ////////////////////////////////////////////////////////////////////////////////
3814 // debug support
3815 
3816 bool os::find(address addr, outputStream* st) {
3817   Dl_info dlinfo;
3818   memset(&dlinfo, 0, sizeof(dlinfo));
3819   if (dladdr(addr, &dlinfo) != 0) {
3820     st->print(PTR_FORMAT ": ", addr);
3821     if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3822       st->print("%s+%#x", dlinfo.dli_sname,
3823                  addr - (intptr_t)dlinfo.dli_saddr);
3824     } else if (dlinfo.dli_fbase != NULL) {
3825       st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3826     } else {
3827       st->print("<absolute address>");
3828     }
3829     if (dlinfo.dli_fname != NULL) {
3830       st->print(" in %s", dlinfo.dli_fname);
3831     }
3832     if (dlinfo.dli_fbase != NULL) {
3833       st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3834     }
3835     st->cr();
3836 
3837     if (Verbose) {
3838       // decode some bytes around the PC
3839       address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3840       address end   = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3841       address       lowest = (address) dlinfo.dli_sname;
3842       if (!lowest)  lowest = (address) dlinfo.dli_fbase;
3843       if (begin < lowest)  begin = lowest;
3844       Dl_info dlinfo2;
3845       if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3846           && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
3847         end = (address) dlinfo2.dli_saddr;
3848       Disassembler::decode(begin, end, st);
3849     }
3850     return true;
3851   }
3852   return false;
3853 }
3854 
3855 ////////////////////////////////////////////////////////////////////////////////
3856 // misc
3857 
3858 // This does not do anything on Bsd. This is basically a hook for being
3859 // able to use structured exception handling (thread-local exception filters)
3860 // on, e.g., Win32.
3861 void
3862 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
3863                          JavaCallArguments* args, Thread* thread) {
3864   f(value, method, args, thread);
3865 }
3866 
3867 void os::print_statistics() {
3868 }
3869 
3870 int os::message_box(const char* title, const char* message) {
3871   int i;
3872   fdStream err(defaultStream::error_fd());
3873   for (i = 0; i < 78; i++) err.print_raw("=");
3874   err.cr();
3875   err.print_raw_cr(title);
3876   for (i = 0; i < 78; i++) err.print_raw("-");
3877   err.cr();
3878   err.print_raw_cr(message);
3879   for (i = 0; i < 78; i++) err.print_raw("=");
3880   err.cr();
3881 
3882   char buf[16];
3883   // Prevent process from exiting upon "read error" without consuming all CPU
3884   while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3885 
3886   return buf[0] == 'y' || buf[0] == 'Y';
3887 }
3888 
3889 int os::stat(const char *path, struct stat *sbuf) {
3890   char pathbuf[MAX_PATH];
3891   if (strlen(path) > MAX_PATH - 1) {
3892     errno = ENAMETOOLONG;
3893     return -1;
3894   }
3895   os::native_path(strcpy(pathbuf, path));
3896   return ::stat(pathbuf, sbuf);
3897 }
3898 
3899 bool os::check_heap(bool force) {
3900   return true;
3901 }
3902 
3903 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
3904   return ::vsnprintf(buf, count, format, args);
3905 }
3906 
3907 // Is a (classpath) directory empty?
3908 bool os::dir_is_empty(const char* path) {
3909   DIR *dir = NULL;
3910   struct dirent *ptr;
3911 
3912   dir = opendir(path);
3913   if (dir == NULL) return true;
3914 
3915   /* Scan the directory */
3916   bool result = true;
3917   char buf[sizeof(struct dirent) + MAX_PATH];
3918   while (result && (ptr = ::readdir(dir)) != NULL) {
3919     if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3920       result = false;
3921     }
3922   }
3923   closedir(dir);
3924   return result;
3925 }
3926 
3927 // This code originates from JDK's sysOpen and open64_w
3928 // from src/solaris/hpi/src/system_md.c
3929 
3930 #ifndef O_DELETE
3931 #define O_DELETE 0x10000
3932 #endif
3933 
3934 // Open a file. Unlink the file immediately after open returns
3935 // if the specified oflag has the O_DELETE flag set.
3936 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
3937 
3938 int os::open(const char *path, int oflag, int mode) {
3939 
3940   if (strlen(path) > MAX_PATH - 1) {
3941     errno = ENAMETOOLONG;
3942     return -1;
3943   }
3944   int fd;
3945   int o_delete = (oflag & O_DELETE);
3946   oflag = oflag & ~O_DELETE;
3947 
3948   fd = ::open(path, oflag, mode);
3949   if (fd == -1) return -1;
3950 
3951   //If the open succeeded, the file might still be a directory
3952   {
3953     struct stat buf;
3954     int ret = ::fstat(fd, &buf);
3955     int st_mode = buf.st_mode;
3956 
3957     if (ret != -1) {
3958       if ((st_mode & S_IFMT) == S_IFDIR) {
3959         errno = EISDIR;
3960         ::close(fd);
3961         return -1;
3962       }
3963     } else {
3964       ::close(fd);
3965       return -1;
3966     }
3967   }
3968 
3969     /*
3970      * All file descriptors that are opened in the JVM and not
3971      * specifically destined for a subprocess should have the
3972      * close-on-exec flag set.  If we don't set it, then careless 3rd
3973      * party native code might fork and exec without closing all
3974      * appropriate file descriptors (e.g. as we do in closeDescriptors in
3975      * UNIXProcess.c), and this in turn might:
3976      *
3977      * - cause end-of-file to fail to be detected on some file
3978      *   descriptors, resulting in mysterious hangs, or
3979      *
3980      * - might cause an fopen in the subprocess to fail on a system
3981      *   suffering from bug 1085341.
3982      *
3983      * (Yes, the default setting of the close-on-exec flag is a Unix
3984      * design flaw)
3985      *
3986      * See:
3987      * 1085341: 32-bit stdio routines should support file descriptors >255
3988      * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3989      * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3990      */
3991 #ifdef FD_CLOEXEC
3992     {
3993         int flags = ::fcntl(fd, F_GETFD);
3994         if (flags != -1)
3995             ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3996     }
3997 #endif
3998 
3999   if (o_delete != 0) {
4000     ::unlink(path);
4001   }
4002   return fd;
4003 }
4004 
4005 
4006 // create binary file, rewriting existing file if required
4007 int os::create_binary_file(const char* path, bool rewrite_existing) {
4008   int oflags = O_WRONLY | O_CREAT;
4009   if (!rewrite_existing) {
4010     oflags |= O_EXCL;
4011   }
4012   return ::open(path, oflags, S_IREAD | S_IWRITE);
4013 }
4014 
4015 // return current position of file pointer
4016 jlong os::current_file_offset(int fd) {
4017   return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
4018 }
4019 
4020 // move file pointer to the specified offset
4021 jlong os::seek_to_file_offset(int fd, jlong offset) {
4022   return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
4023 }
4024 
4025 // This code originates from JDK's sysAvailable
4026 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
4027 
4028 int os::available(int fd, jlong *bytes) {
4029   jlong cur, end;
4030   int mode;
4031   struct stat buf;
4032 
4033   if (::fstat(fd, &buf) >= 0) {
4034     mode = buf.st_mode;
4035     if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
4036       /*
4037       * XXX: is the following call interruptible? If so, this might
4038       * need to go through the INTERRUPT_IO() wrapper as for other
4039       * blocking, interruptible calls in this file.
4040       */
4041       int n;
4042       if (::ioctl(fd, FIONREAD, &n) >= 0) {
4043         *bytes = n;
4044         return 1;
4045       }
4046     }
4047   }
4048   if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
4049     return 0;
4050   } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
4051     return 0;
4052   } else if (::lseek(fd, cur, SEEK_SET) == -1) {
4053     return 0;
4054   }
4055   *bytes = end - cur;
4056   return 1;
4057 }
4058 
4059 int os::socket_available(int fd, jint *pbytes) {
4060    if (fd < 0)
4061      return OS_OK;
4062 
4063    int ret;
4064 
4065    RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
4066 
4067    //%% note ioctl can return 0 when successful, JVM_SocketAvailable
4068    // is expected to return 0 on failure and 1 on success to the jdk.
4069 
4070    return (ret == OS_ERR) ? 0 : 1;
4071 }
4072 
4073 // Map a block of memory.
4074 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
4075                      char *addr, size_t bytes, bool read_only,
4076                      bool allow_exec) {
4077   int prot;
4078   int flags;
4079 
4080   if (read_only) {
4081     prot = PROT_READ;
4082     flags = MAP_SHARED;
4083   } else {
4084     prot = PROT_READ | PROT_WRITE;
4085     flags = MAP_PRIVATE;
4086   }
4087 
4088   if (allow_exec) {
4089     prot |= PROT_EXEC;
4090   }
4091 
4092   if (addr != NULL) {
4093     flags |= MAP_FIXED;
4094   }
4095 
4096   char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
4097                                      fd, file_offset);
4098   if (mapped_address == MAP_FAILED) {
4099     return NULL;
4100   }
4101   return mapped_address;
4102 }
4103 
4104 
4105 // Remap a block of memory.
4106 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
4107                        char *addr, size_t bytes, bool read_only,
4108                        bool allow_exec) {
4109   // same as map_memory() on this OS
4110   return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
4111                         allow_exec);
4112 }
4113 
4114 
4115 // Unmap a block of memory.
4116 bool os::pd_unmap_memory(char* addr, size_t bytes) {
4117   return munmap(addr, bytes) == 0;
4118 }
4119 
4120 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
4121 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4122 // of a thread.
4123 //
4124 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4125 // the fast estimate available on the platform.
4126 
4127 jlong os::current_thread_cpu_time() {
4128 #ifdef __APPLE__
4129   return os::thread_cpu_time(Thread::current(), true /* user + sys */);
4130 #else
4131   Unimplemented();
4132   return 0;
4133 #endif
4134 }
4135 
4136 jlong os::thread_cpu_time(Thread* thread) {
4137 #ifdef __APPLE__
4138   return os::thread_cpu_time(thread, true /* user + sys */);
4139 #else
4140   Unimplemented();
4141   return 0;
4142 #endif
4143 }
4144 
4145 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4146 #ifdef __APPLE__
4147   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4148 #else
4149   Unimplemented();
4150   return 0;
4151 #endif
4152 }
4153 
4154 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4155 #ifdef __APPLE__
4156   struct thread_basic_info tinfo;
4157   mach_msg_type_number_t tcount = THREAD_INFO_MAX;
4158   kern_return_t kr;
4159   thread_t mach_thread;
4160 
4161   mach_thread = thread->osthread()->thread_id();
4162   kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
4163   if (kr != KERN_SUCCESS)
4164     return -1;
4165 
4166   if (user_sys_cpu_time) {
4167     jlong nanos;
4168     nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4169     nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4170     return nanos;
4171   } else {
4172     return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4173   }
4174 #else
4175   Unimplemented();
4176   return 0;
4177 #endif
4178 }
4179 
4180 
4181 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4182   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4183   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4184   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4185   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4186 }
4187 
4188 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4189   info_ptr->max_value = ALL_64_BITS;       // will not wrap in less than 64 bits
4190   info_ptr->may_skip_backward = false;     // elapsed time not wall time
4191   info_ptr->may_skip_forward = false;      // elapsed time not wall time
4192   info_ptr->kind = JVMTI_TIMER_TOTAL_CPU;  // user+system time is returned
4193 }
4194 
4195 bool os::is_thread_cpu_time_supported() {
4196 #ifdef __APPLE__
4197   return true;
4198 #else
4199   return false;
4200 #endif
4201 }
4202 
4203 // System loadavg support.  Returns -1 if load average cannot be obtained.
4204 // Bsd doesn't yet have a (official) notion of processor sets,
4205 // so just return the system wide load average.
4206 int os::loadavg(double loadavg[], int nelem) {
4207   return ::getloadavg(loadavg, nelem);
4208 }
4209 
4210 void os::pause() {
4211   char filename[MAX_PATH];
4212   if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4213     jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4214   } else {
4215     jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4216   }
4217 
4218   int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4219   if (fd != -1) {
4220     struct stat buf;
4221     ::close(fd);
4222     while (::stat(filename, &buf) == 0) {
4223       (void)::poll(NULL, 0, 100);
4224     }
4225   } else {
4226     jio_fprintf(stderr,
4227       "Could not open pause file '%s', continuing immediately.\n", filename);
4228   }
4229 }
4230 
4231 
4232 // Refer to the comments in os_solaris.cpp park-unpark.
4233 //
4234 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4235 // hang indefinitely.  For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4236 // For specifics regarding the bug see GLIBC BUGID 261237 :
4237 //    http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4238 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4239 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4240 // is used.  (The simple C test-case provided in the GLIBC bug report manifests the
4241 // hang).  The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4242 // and monitorenter when we're using 1-0 locking.  All those operations may result in
4243 // calls to pthread_cond_timedwait().  Using LD_ASSUME_KERNEL to use an older version
4244 // of libpthread avoids the problem, but isn't practical.
4245 //
4246 // Possible remedies:
4247 //
4248 // 1.   Establish a minimum relative wait time.  50 to 100 msecs seems to work.
4249 //      This is palliative and probabilistic, however.  If the thread is preempted
4250 //      between the call to compute_abstime() and pthread_cond_timedwait(), more
4251 //      than the minimum period may have passed, and the abstime may be stale (in the
4252 //      past) resultin in a hang.   Using this technique reduces the odds of a hang
4253 //      but the JVM is still vulnerable, particularly on heavily loaded systems.
4254 //
4255 // 2.   Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4256 //      of the usual flag-condvar-mutex idiom.  The write side of the pipe is set
4257 //      NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4258 //      reduces to poll()+read().  This works well, but consumes 2 FDs per extant
4259 //      thread.
4260 //
4261 // 3.   Embargo pthread_cond_timedwait() and implement a native "chron" thread
4262 //      that manages timeouts.  We'd emulate pthread_cond_timedwait() by enqueuing
4263 //      a timeout request to the chron thread and then blocking via pthread_cond_wait().
4264 //      This also works well.  In fact it avoids kernel-level scalability impediments
4265 //      on certain platforms that don't handle lots of active pthread_cond_timedwait()
4266 //      timers in a graceful fashion.
4267 //
4268 // 4.   When the abstime value is in the past it appears that control returns
4269 //      correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4270 //      Subsequent timedwait/wait calls may hang indefinitely.  Given that, we
4271 //      can avoid the problem by reinitializing the condvar -- by cond_destroy()
4272 //      followed by cond_init() -- after all calls to pthread_cond_timedwait().
4273 //      It may be possible to avoid reinitialization by checking the return
4274 //      value from pthread_cond_timedwait().  In addition to reinitializing the
4275 //      condvar we must establish the invariant that cond_signal() is only called
4276 //      within critical sections protected by the adjunct mutex.  This prevents
4277 //      cond_signal() from "seeing" a condvar that's in the midst of being
4278 //      reinitialized or that is corrupt.  Sadly, this invariant obviates the
4279 //      desirable signal-after-unlock optimization that avoids futile context switching.
4280 //
4281 //      I'm also concerned that some versions of NTPL might allocate an auxilliary
4282 //      structure when a condvar is used or initialized.  cond_destroy()  would
4283 //      release the helper structure.  Our reinitialize-after-timedwait fix
4284 //      put excessive stress on malloc/free and locks protecting the c-heap.
4285 //
4286 // We currently use (4).  See the WorkAroundNTPLTimedWaitHang flag.
4287 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4288 // and only enabling the work-around for vulnerable environments.
4289 
4290 // utility to compute the abstime argument to timedwait:
4291 // millis is the relative timeout time
4292 // abstime will be the absolute timeout time
4293 // TODO: replace compute_abstime() with unpackTime()
4294 
4295 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
4296   if (millis < 0)  millis = 0;
4297   struct timeval now;
4298   int status = gettimeofday(&now, NULL);
4299   assert(status == 0, "gettimeofday");
4300   jlong seconds = millis / 1000;
4301   millis %= 1000;
4302   if (seconds > 50000000) { // see man cond_timedwait(3T)
4303     seconds = 50000000;
4304   }
4305   abstime->tv_sec = now.tv_sec  + seconds;
4306   long       usec = now.tv_usec + millis * 1000;
4307   if (usec >= 1000000) {
4308     abstime->tv_sec += 1;
4309     usec -= 1000000;
4310   }
4311   abstime->tv_nsec = usec * 1000;
4312   return abstime;
4313 }
4314 
4315 
4316 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
4317 // Conceptually TryPark() should be equivalent to park(0).
4318 
4319 int os::PlatformEvent::TryPark() {
4320   for (;;) {
4321     const int v = _Event ;
4322     guarantee ((v == 0) || (v == 1), "invariant") ;
4323     if (Atomic::cmpxchg (0, &_Event, v) == v) return v  ;
4324   }
4325 }
4326 
4327 void os::PlatformEvent::park() {       // AKA "down()"
4328   // Invariant: Only the thread associated with the Event/PlatformEvent
4329   // may call park().
4330   // TODO: assert that _Assoc != NULL or _Assoc == Self
4331   int v ;
4332   for (;;) {
4333       v = _Event ;
4334       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4335   }
4336   guarantee (v >= 0, "invariant") ;
4337   if (v == 0) {
4338      // Do this the hard way by blocking ...
4339      int status = pthread_mutex_lock(_mutex);
4340      assert_status(status == 0, status, "mutex_lock");
4341      guarantee (_nParked == 0, "invariant") ;
4342      ++ _nParked ;
4343      while (_Event < 0) {
4344         status = pthread_cond_wait(_cond, _mutex);
4345         // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4346         // Treat this the same as if the wait was interrupted
4347         if (status == ETIMEDOUT) { status = EINTR; }
4348         assert_status(status == 0 || status == EINTR, status, "cond_wait");
4349      }
4350      -- _nParked ;
4351 
4352     _Event = 0 ;
4353      status = pthread_mutex_unlock(_mutex);
4354      assert_status(status == 0, status, "mutex_unlock");
4355     // Paranoia to ensure our locked and lock-free paths interact
4356     // correctly with each other.
4357     OrderAccess::fence();
4358   }
4359   guarantee (_Event >= 0, "invariant") ;
4360 }
4361 
4362 int os::PlatformEvent::park(jlong millis) {
4363   guarantee (_nParked == 0, "invariant") ;
4364 
4365   int v ;
4366   for (;;) {
4367       v = _Event ;
4368       if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4369   }
4370   guarantee (v >= 0, "invariant") ;
4371   if (v != 0) return OS_OK ;
4372 
4373   // We do this the hard way, by blocking the thread.
4374   // Consider enforcing a minimum timeout value.
4375   struct timespec abst;
4376   compute_abstime(&abst, millis);
4377 
4378   int ret = OS_TIMEOUT;
4379   int status = pthread_mutex_lock(_mutex);
4380   assert_status(status == 0, status, "mutex_lock");
4381   guarantee (_nParked == 0, "invariant") ;
4382   ++_nParked ;
4383 
4384   // Object.wait(timo) will return because of
4385   // (a) notification
4386   // (b) timeout
4387   // (c) thread.interrupt
4388   //
4389   // Thread.interrupt and object.notify{All} both call Event::set.
4390   // That is, we treat thread.interrupt as a special case of notification.
4391   // The underlying Solaris implementation, cond_timedwait, admits
4392   // spurious/premature wakeups, but the JLS/JVM spec prevents the
4393   // JVM from making those visible to Java code.  As such, we must
4394   // filter out spurious wakeups.  We assume all ETIME returns are valid.
4395   //
4396   // TODO: properly differentiate simultaneous notify+interrupt.
4397   // In that case, we should propagate the notify to another waiter.
4398 
4399   while (_Event < 0) {
4400     status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4401     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4402       pthread_cond_destroy (_cond);
4403       pthread_cond_init (_cond, NULL) ;
4404     }
4405     assert_status(status == 0 || status == EINTR ||
4406                   status == ETIMEDOUT,
4407                   status, "cond_timedwait");
4408     if (!FilterSpuriousWakeups) break ;                 // previous semantics
4409     if (status == ETIMEDOUT) break ;
4410     // We consume and ignore EINTR and spurious wakeups.
4411   }
4412   --_nParked ;
4413   if (_Event >= 0) {
4414      ret = OS_OK;
4415   }
4416   _Event = 0 ;
4417   status = pthread_mutex_unlock(_mutex);
4418   assert_status(status == 0, status, "mutex_unlock");
4419   assert (_nParked == 0, "invariant") ;
4420   // Paranoia to ensure our locked and lock-free paths interact
4421   // correctly with each other.
4422   OrderAccess::fence();
4423   return ret;
4424 }
4425 
4426 void os::PlatformEvent::unpark() {
4427   // Transitions for _Event:
4428   //    0 :=> 1
4429   //    1 :=> 1
4430   //   -1 :=> either 0 or 1; must signal target thread
4431   //          That is, we can safely transition _Event from -1 to either
4432   //          0 or 1. Forcing 1 is slightly more efficient for back-to-back
4433   //          unpark() calls.
4434   // See also: "Semaphores in Plan 9" by Mullender & Cox
4435   //
4436   // Note: Forcing a transition from "-1" to "1" on an unpark() means
4437   // that it will take two back-to-back park() calls for the owning
4438   // thread to block. This has the benefit of forcing a spurious return
4439   // from the first park() call after an unpark() call which will help
4440   // shake out uses of park() and unpark() without condition variables.
4441 
4442   if (Atomic::xchg(1, &_Event) >= 0) return;
4443 
4444   // Wait for the thread associated with the event to vacate
4445   int status = pthread_mutex_lock(_mutex);
4446   assert_status(status == 0, status, "mutex_lock");
4447   int AnyWaiters = _nParked;
4448   assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4449   if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4450     AnyWaiters = 0;
4451     pthread_cond_signal(_cond);
4452   }
4453   status = pthread_mutex_unlock(_mutex);
4454   assert_status(status == 0, status, "mutex_unlock");
4455   if (AnyWaiters != 0) {
4456     status = pthread_cond_signal(_cond);
4457     assert_status(status == 0, status, "cond_signal");
4458   }
4459 
4460   // Note that we signal() _after dropping the lock for "immortal" Events.
4461   // This is safe and avoids a common class of  futile wakeups.  In rare
4462   // circumstances this can cause a thread to return prematurely from
4463   // cond_{timed}wait() but the spurious wakeup is benign and the victim will
4464   // simply re-test the condition and re-park itself.
4465 }
4466 
4467 
4468 // JSR166
4469 // -------------------------------------------------------
4470 
4471 /*
4472  * The solaris and bsd implementations of park/unpark are fairly
4473  * conservative for now, but can be improved. They currently use a
4474  * mutex/condvar pair, plus a a count.
4475  * Park decrements count if > 0, else does a condvar wait.  Unpark
4476  * sets count to 1 and signals condvar.  Only one thread ever waits
4477  * on the condvar. Contention seen when trying to park implies that someone
4478  * is unparking you, so don't wait. And spurious returns are fine, so there
4479  * is no need to track notifications.
4480  */
4481 
4482 #define MAX_SECS 100000000
4483 /*
4484  * This code is common to bsd and solaris and will be moved to a
4485  * common place in dolphin.
4486  *
4487  * The passed in time value is either a relative time in nanoseconds
4488  * or an absolute time in milliseconds. Either way it has to be unpacked
4489  * into suitable seconds and nanoseconds components and stored in the
4490  * given timespec structure.
4491  * Given time is a 64-bit value and the time_t used in the timespec is only
4492  * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4493  * overflow if times way in the future are given. Further on Solaris versions
4494  * prior to 10 there is a restriction (see cond_timedwait) that the specified
4495  * number of seconds, in abstime, is less than current_time  + 100,000,000.
4496  * As it will be 28 years before "now + 100000000" will overflow we can
4497  * ignore overflow and just impose a hard-limit on seconds using the value
4498  * of "now + 100,000,000". This places a limit on the timeout of about 3.17
4499  * years from "now".
4500  */
4501 
4502 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4503   assert (time > 0, "convertTime");
4504 
4505   struct timeval now;
4506   int status = gettimeofday(&now, NULL);
4507   assert(status == 0, "gettimeofday");
4508 
4509   time_t max_secs = now.tv_sec + MAX_SECS;
4510 
4511   if (isAbsolute) {
4512     jlong secs = time / 1000;
4513     if (secs > max_secs) {
4514       absTime->tv_sec = max_secs;
4515     }
4516     else {
4517       absTime->tv_sec = secs;
4518     }
4519     absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4520   }
4521   else {
4522     jlong secs = time / NANOSECS_PER_SEC;
4523     if (secs >= MAX_SECS) {
4524       absTime->tv_sec = max_secs;
4525       absTime->tv_nsec = 0;
4526     }
4527     else {
4528       absTime->tv_sec = now.tv_sec + secs;
4529       absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4530       if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4531         absTime->tv_nsec -= NANOSECS_PER_SEC;
4532         ++absTime->tv_sec; // note: this must be <= max_secs
4533       }
4534     }
4535   }
4536   assert(absTime->tv_sec >= 0, "tv_sec < 0");
4537   assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4538   assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4539   assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4540 }
4541 
4542 void Parker::park(bool isAbsolute, jlong time) {
4543   // Ideally we'd do something useful while spinning, such
4544   // as calling unpackTime().
4545 
4546   // Optional fast-path check:
4547   // Return immediately if a permit is available.
4548   // We depend on Atomic::xchg() having full barrier semantics
4549   // since we are doing a lock-free update to _counter.
4550   if (Atomic::xchg(0, &_counter) > 0) return;
4551 
4552   Thread* thread = Thread::current();
4553   assert(thread->is_Java_thread(), "Must be JavaThread");
4554   JavaThread *jt = (JavaThread *)thread;
4555 
4556   // Optional optimization -- avoid state transitions if there's an interrupt pending.
4557   // Check interrupt before trying to wait
4558   if (Thread::is_interrupted(thread, false)) {
4559     return;
4560   }
4561 
4562   // Next, demultiplex/decode time arguments
4563   struct timespec absTime;
4564   if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
4565     return;
4566   }
4567   if (time > 0) {
4568     unpackTime(&absTime, isAbsolute, time);
4569   }
4570 
4571 
4572   // Enter safepoint region
4573   // Beware of deadlocks such as 6317397.
4574   // The per-thread Parker:: mutex is a classic leaf-lock.
4575   // In particular a thread must never block on the Threads_lock while
4576   // holding the Parker:: mutex.  If safepoints are pending both the
4577   // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4578   ThreadBlockInVM tbivm(jt);
4579 
4580   // Don't wait if cannot get lock since interference arises from
4581   // unblocking.  Also. check interrupt before trying wait
4582   if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4583     return;
4584   }
4585 
4586   int status ;
4587   if (_counter > 0)  { // no wait needed
4588     _counter = 0;
4589     status = pthread_mutex_unlock(_mutex);
4590     assert (status == 0, "invariant") ;
4591     // Paranoia to ensure our locked and lock-free paths interact
4592     // correctly with each other and Java-level accesses.
4593     OrderAccess::fence();
4594     return;
4595   }
4596 
4597 #ifdef ASSERT
4598   // Don't catch signals while blocked; let the running threads have the signals.
4599   // (This allows a debugger to break into the running thread.)
4600   sigset_t oldsigs;
4601   sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4602   pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4603 #endif
4604 
4605   OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4606   jt->set_suspend_equivalent();
4607   // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4608 
4609   if (time == 0) {
4610     status = pthread_cond_wait (_cond, _mutex) ;
4611   } else {
4612     status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
4613     if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4614       pthread_cond_destroy (_cond) ;
4615       pthread_cond_init    (_cond, NULL);
4616     }
4617   }
4618   assert_status(status == 0 || status == EINTR ||
4619                 status == ETIMEDOUT,
4620                 status, "cond_timedwait");
4621 
4622 #ifdef ASSERT
4623   pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4624 #endif
4625 
4626   _counter = 0 ;
4627   status = pthread_mutex_unlock(_mutex) ;
4628   assert_status(status == 0, status, "invariant") ;
4629   // Paranoia to ensure our locked and lock-free paths interact
4630   // correctly with each other and Java-level accesses.
4631   OrderAccess::fence();
4632 
4633   // If externally suspended while waiting, re-suspend
4634   if (jt->handle_special_suspend_equivalent_condition()) {
4635     jt->java_suspend_self();
4636   }
4637 }
4638 
4639 void Parker::unpark() {
4640   int s, status ;
4641   status = pthread_mutex_lock(_mutex);
4642   assert (status == 0, "invariant") ;
4643   s = _counter;
4644   _counter = 1;
4645   if (s < 1) {
4646      if (WorkAroundNPTLTimedWaitHang) {
4647         status = pthread_cond_signal (_cond) ;
4648         assert (status == 0, "invariant") ;
4649         status = pthread_mutex_unlock(_mutex);
4650         assert (status == 0, "invariant") ;
4651      } else {
4652         status = pthread_mutex_unlock(_mutex);
4653         assert (status == 0, "invariant") ;
4654         status = pthread_cond_signal (_cond) ;
4655         assert (status == 0, "invariant") ;
4656      }
4657   } else {
4658     pthread_mutex_unlock(_mutex);
4659     assert (status == 0, "invariant") ;
4660   }
4661 }
4662 
4663 
4664 /* Darwin has no "environ" in a dynamic library. */
4665 #ifdef __APPLE__
4666 #include <crt_externs.h>
4667 #define environ (*_NSGetEnviron())
4668 #else
4669 extern char** environ;
4670 #endif
4671 
4672 // Run the specified command in a separate process. Return its exit value,
4673 // or -1 on failure (e.g. can't fork a new process).
4674 // Unlike system(), this function can be called from signal handler. It
4675 // doesn't block SIGINT et al.
4676 int os::fork_and_exec(char* cmd) {
4677   const char * argv[4] = {"sh", "-c", cmd, NULL};
4678 
4679   // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4680   // pthread_atfork handlers and reset pthread library. All we need is a
4681   // separate process to execve. Make a direct syscall to fork process.
4682   // On IA64 there's no fork syscall, we have to use fork() and hope for
4683   // the best...
4684   pid_t pid = fork();
4685 
4686   if (pid < 0) {
4687     // fork failed
4688     return -1;
4689 
4690   } else if (pid == 0) {
4691     // child process
4692 
4693     // execve() in BsdThreads will call pthread_kill_other_threads_np()
4694     // first to kill every thread on the thread list. Because this list is
4695     // not reset by fork() (see notes above), execve() will instead kill
4696     // every thread in the parent process. We know this is the only thread
4697     // in the new process, so make a system call directly.
4698     // IA64 should use normal execve() from glibc to match the glibc fork()
4699     // above.
4700     execve("/bin/sh", (char* const*)argv, environ);
4701 
4702     // execve failed
4703     _exit(-1);
4704 
4705   } else  {
4706     // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4707     // care about the actual exit code, for now.
4708 
4709     int status;
4710 
4711     // Wait for the child process to exit.  This returns immediately if
4712     // the child has already exited. */
4713     while (waitpid(pid, &status, 0) < 0) {
4714         switch (errno) {
4715         case ECHILD: return 0;
4716         case EINTR: break;
4717         default: return -1;
4718         }
4719     }
4720 
4721     if (WIFEXITED(status)) {
4722        // The child exited normally; get its exit code.
4723        return WEXITSTATUS(status);
4724     } else if (WIFSIGNALED(status)) {
4725        // The child exited because of a signal
4726        // The best value to return is 0x80 + signal number,
4727        // because that is what all Unix shells do, and because
4728        // it allows callers to distinguish between process exit and
4729        // process death by signal.
4730        return 0x80 + WTERMSIG(status);
4731     } else {
4732        // Unknown exit code; pass it through
4733        return status;
4734     }
4735   }
4736 }
4737 
4738 // is_headless_jre()
4739 //
4740 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4741 // in order to report if we are running in a headless jre
4742 //
4743 // Since JDK8 xawt/libmawt.so was moved into the same directory
4744 // as libawt.so, and renamed libawt_xawt.so
4745 //
4746 bool os::is_headless_jre() {
4747 #ifdef __APPLE__
4748     // We no longer build headless-only on Mac OS X
4749     return false;
4750 #else
4751     struct stat statbuf;
4752     char buf[MAXPATHLEN];
4753     char libmawtpath[MAXPATHLEN];
4754     const char *xawtstr  = "/xawt/libmawt" JNI_LIB_SUFFIX;
4755     const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4756     char *p;
4757 
4758     // Get path to libjvm.so
4759     os::jvm_path(buf, sizeof(buf));
4760 
4761     // Get rid of libjvm.so
4762     p = strrchr(buf, '/');
4763     if (p == NULL) return false;
4764     else *p = '\0';
4765 
4766     // Get rid of client or server
4767     p = strrchr(buf, '/');
4768     if (p == NULL) return false;
4769     else *p = '\0';
4770 
4771     // check xawt/libmawt.so
4772     strcpy(libmawtpath, buf);
4773     strcat(libmawtpath, xawtstr);
4774     if (::stat(libmawtpath, &statbuf) == 0) return false;
4775 
4776     // check libawt_xawt.so
4777     strcpy(libmawtpath, buf);
4778     strcat(libmawtpath, new_xawtstr);
4779     if (::stat(libmawtpath, &statbuf) == 0) return false;
4780 
4781     return true;
4782 #endif
4783 }
4784 
4785 // Get the default path to the core file
4786 // Returns the length of the string
4787 int os::get_core_path(char* buffer, size_t bufferSize) {
4788   int n = jio_snprintf(buffer, bufferSize, "/cores");
4789 
4790   // Truncate if theoretical string was longer than bufferSize
4791   n = MIN2(n, (int)bufferSize);
4792 
4793   return n;
4794 }
4795 
4796 #ifndef PRODUCT
4797 void TestReserveMemorySpecial_test() {
4798   // No tests available for this platform
4799 }
4800 #endif