Wed, 05 Jun 2013 14:12:49 -0400
8009302: Mac OS X: JVM crash on infinite recursion on Appkit Thread
Summary: Use SA_ONSTACK flag to ensure signal gets delivered properly.
Reviewed-by: dholmes, coleenp
Contributed-by: gerard.ziemski@oracle.com
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 */
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"
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>
104 #if defined(__FreeBSD__) || defined(__NetBSD__)
105 # include <elf.h>
106 #endif
108 #ifdef __APPLE__
109 # include <mach/mach.h> // semaphore_* API
110 # include <mach-o/dyld.h>
111 # include <sys/proc_info.h>
112 # include <objc/objc-auto.h>
113 #endif
115 #ifndef MAP_ANONYMOUS
116 #define MAP_ANONYMOUS MAP_ANON
117 #endif
119 #define MAX_PATH (2 * K)
121 // for timer info max values which include all bits
122 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
124 #define LARGEPAGES_BIT (1 << 6)
125 ////////////////////////////////////////////////////////////////////////////////
126 // global variables
127 julong os::Bsd::_physical_memory = 0;
130 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
131 pthread_t os::Bsd::_main_thread;
132 int os::Bsd::_page_size = -1;
134 static jlong initial_time_count=0;
136 static int clock_tics_per_sec = 100;
138 // For diagnostics to print a message once. see run_periodic_checks
139 static sigset_t check_signal_done;
140 static bool check_signals = true;
142 static pid_t _initial_pid = 0;
144 /* Signal number used to suspend/resume a thread */
146 /* do not use any signal number less than SIGSEGV, see 4355769 */
147 static int SR_signum = SIGUSR2;
148 sigset_t SR_sigset;
151 ////////////////////////////////////////////////////////////////////////////////
152 // utility functions
154 static int SR_initialize();
156 julong os::available_memory() {
157 return Bsd::available_memory();
158 }
160 julong os::Bsd::available_memory() {
161 // XXXBSD: this is just a stopgap implementation
162 return physical_memory() >> 2;
163 }
165 julong os::physical_memory() {
166 return Bsd::physical_memory();
167 }
169 ////////////////////////////////////////////////////////////////////////////////
170 // environment support
172 bool os::getenv(const char* name, char* buf, int len) {
173 const char* val = ::getenv(name);
174 if (val != NULL && strlen(val) < (size_t)len) {
175 strcpy(buf, val);
176 return true;
177 }
178 if (len > 0) buf[0] = 0; // return a null string
179 return false;
180 }
183 // Return true if user is running as root.
185 bool os::have_special_privileges() {
186 static bool init = false;
187 static bool privileges = false;
188 if (!init) {
189 privileges = (getuid() != geteuid()) || (getgid() != getegid());
190 init = true;
191 }
192 return privileges;
193 }
197 // Cpu architecture string
198 #if defined(ZERO)
199 static char cpu_arch[] = ZERO_LIBARCH;
200 #elif defined(IA64)
201 static char cpu_arch[] = "ia64";
202 #elif defined(IA32)
203 static char cpu_arch[] = "i386";
204 #elif defined(AMD64)
205 static char cpu_arch[] = "amd64";
206 #elif defined(ARM)
207 static char cpu_arch[] = "arm";
208 #elif defined(PPC)
209 static char cpu_arch[] = "ppc";
210 #elif defined(SPARC)
211 # ifdef _LP64
212 static char cpu_arch[] = "sparcv9";
213 # else
214 static char cpu_arch[] = "sparc";
215 # endif
216 #else
217 #error Add appropriate cpu_arch setting
218 #endif
220 // Compiler variant
221 #ifdef COMPILER2
222 #define COMPILER_VARIANT "server"
223 #else
224 #define COMPILER_VARIANT "client"
225 #endif
228 void os::Bsd::initialize_system_info() {
229 int mib[2];
230 size_t len;
231 int cpu_val;
232 julong mem_val;
234 /* get processors count via hw.ncpus sysctl */
235 mib[0] = CTL_HW;
236 mib[1] = HW_NCPU;
237 len = sizeof(cpu_val);
238 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
239 assert(len == sizeof(cpu_val), "unexpected data size");
240 set_processor_count(cpu_val);
241 }
242 else {
243 set_processor_count(1); // fallback
244 }
246 /* get physical memory via hw.memsize sysctl (hw.memsize is used
247 * since it returns a 64 bit value)
248 */
249 mib[0] = CTL_HW;
250 mib[1] = HW_MEMSIZE;
251 len = sizeof(mem_val);
252 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
253 assert(len == sizeof(mem_val), "unexpected data size");
254 _physical_memory = mem_val;
255 } else {
256 _physical_memory = 256*1024*1024; // fallback (XXXBSD?)
257 }
259 #ifdef __OpenBSD__
260 {
261 // limit _physical_memory memory view on OpenBSD since
262 // datasize rlimit restricts us anyway.
263 struct rlimit limits;
264 getrlimit(RLIMIT_DATA, &limits);
265 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
266 }
267 #endif
268 }
270 #ifdef __APPLE__
271 static const char *get_home() {
272 const char *home_dir = ::getenv("HOME");
273 if ((home_dir == NULL) || (*home_dir == '\0')) {
274 struct passwd *passwd_info = getpwuid(geteuid());
275 if (passwd_info != NULL) {
276 home_dir = passwd_info->pw_dir;
277 }
278 }
280 return home_dir;
281 }
282 #endif
284 void os::init_system_properties_values() {
285 // char arch[12];
286 // sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
288 // The next steps are taken in the product version:
289 //
290 // Obtain the JAVA_HOME value from the location of libjvm.so.
291 // This library should be located at:
292 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
293 //
294 // If "/jre/lib/" appears at the right place in the path, then we
295 // assume libjvm.so is installed in a JDK and we use this path.
296 //
297 // Otherwise exit with message: "Could not create the Java virtual machine."
298 //
299 // The following extra steps are taken in the debugging version:
300 //
301 // If "/jre/lib/" does NOT appear at the right place in the path
302 // instead of exit check for $JAVA_HOME environment variable.
303 //
304 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
305 // then we append a fake suffix "hotspot/libjvm.so" to this path so
306 // it looks like libjvm.so is installed there
307 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
308 //
309 // Otherwise exit.
310 //
311 // Important note: if the location of libjvm.so changes this
312 // code needs to be changed accordingly.
314 // The next few definitions allow the code to be verbatim:
315 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal)
316 #define getenv(n) ::getenv(n)
318 /*
319 * See ld(1):
320 * The linker uses the following search paths to locate required
321 * shared libraries:
322 * 1: ...
323 * ...
324 * 7: The default directories, normally /lib and /usr/lib.
325 */
326 #ifndef DEFAULT_LIBPATH
327 #define DEFAULT_LIBPATH "/lib:/usr/lib"
328 #endif
330 #define EXTENSIONS_DIR "/lib/ext"
331 #define ENDORSED_DIR "/lib/endorsed"
332 #define REG_DIR "/usr/java/packages"
334 #ifdef __APPLE__
335 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions"
336 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
337 const char *user_home_dir = get_home();
338 // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir
339 int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
340 sizeof(SYS_EXTENSIONS_DIRS);
341 #endif
343 {
344 /* sysclasspath, java_home, dll_dir */
345 {
346 char *home_path;
347 char *dll_path;
348 char *pslash;
349 char buf[MAXPATHLEN];
350 os::jvm_path(buf, sizeof(buf));
352 // Found the full path to libjvm.so.
353 // Now cut the path to <java_home>/jre if we can.
354 *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */
355 pslash = strrchr(buf, '/');
356 if (pslash != NULL)
357 *pslash = '\0'; /* get rid of /{client|server|hotspot} */
358 dll_path = malloc(strlen(buf) + 1);
359 if (dll_path == NULL)
360 return;
361 strcpy(dll_path, buf);
362 Arguments::set_dll_dir(dll_path);
364 if (pslash != NULL) {
365 pslash = strrchr(buf, '/');
366 if (pslash != NULL) {
367 *pslash = '\0'; /* get rid of /<arch> (/lib on macosx) */
368 #ifndef __APPLE__
369 pslash = strrchr(buf, '/');
370 if (pslash != NULL)
371 *pslash = '\0'; /* get rid of /lib */
372 #endif
373 }
374 }
376 home_path = malloc(strlen(buf) + 1);
377 if (home_path == NULL)
378 return;
379 strcpy(home_path, buf);
380 Arguments::set_java_home(home_path);
382 if (!set_boot_path('/', ':'))
383 return;
384 }
386 /*
387 * Where to look for native libraries
388 *
389 * Note: Due to a legacy implementation, most of the library path
390 * is set in the launcher. This was to accomodate linking restrictions
391 * on legacy Bsd implementations (which are no longer supported).
392 * Eventually, all the library path setting will be done here.
393 *
394 * However, to prevent the proliferation of improperly built native
395 * libraries, the new path component /usr/java/packages is added here.
396 * Eventually, all the library path setting will be done here.
397 */
398 {
399 char *ld_library_path;
401 /*
402 * Construct the invariant part of ld_library_path. Note that the
403 * space for the colon and the trailing null are provided by the
404 * nulls included by the sizeof operator (so actually we allocate
405 * a byte more than necessary).
406 */
407 #ifdef __APPLE__
408 ld_library_path = (char *) malloc(system_ext_size);
409 sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir);
410 #else
411 ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
412 strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
413 sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
414 #endif
416 /*
417 * Get the user setting of LD_LIBRARY_PATH, and prepended it. It
418 * should always exist (until the legacy problem cited above is
419 * addressed).
420 */
421 #ifdef __APPLE__
422 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper
423 char *l = getenv("JAVA_LIBRARY_PATH");
424 if (l != NULL) {
425 char *t = ld_library_path;
426 /* That's +1 for the colon and +1 for the trailing '\0' */
427 ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1);
428 sprintf(ld_library_path, "%s:%s", l, t);
429 free(t);
430 }
432 char *v = getenv("DYLD_LIBRARY_PATH");
433 #else
434 char *v = getenv("LD_LIBRARY_PATH");
435 #endif
436 if (v != NULL) {
437 char *t = ld_library_path;
438 /* That's +1 for the colon and +1 for the trailing '\0' */
439 ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
440 sprintf(ld_library_path, "%s:%s", v, t);
441 free(t);
442 }
444 #ifdef __APPLE__
445 // Apple's Java6 has "." at the beginning of java.library.path.
446 // OpenJDK on Windows has "." at the end of java.library.path.
447 // OpenJDK on Linux and Solaris don't have "." in java.library.path
448 // at all. To ease the transition from Apple's Java6 to OpenJDK7,
449 // "." is appended to the end of java.library.path. Yes, this
450 // could cause a change in behavior, but Apple's Java6 behavior
451 // can be achieved by putting "." at the beginning of the
452 // JAVA_LIBRARY_PATH environment variable.
453 {
454 char *t = ld_library_path;
455 // that's +3 for appending ":." and the trailing '\0'
456 ld_library_path = (char *) malloc(strlen(t) + 3);
457 sprintf(ld_library_path, "%s:%s", t, ".");
458 free(t);
459 }
460 #endif
462 Arguments::set_library_path(ld_library_path);
463 }
465 /*
466 * Extensions directories.
467 *
468 * Note that the space for the colon and the trailing null are provided
469 * by the nulls included by the sizeof operator (so actually one byte more
470 * than necessary is allocated).
471 */
472 {
473 #ifdef __APPLE__
474 char *buf = malloc(strlen(Arguments::get_java_home()) +
475 sizeof(EXTENSIONS_DIR) + system_ext_size);
476 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":"
477 SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home());
478 #else
479 char *buf = malloc(strlen(Arguments::get_java_home()) +
480 sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
481 sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
482 Arguments::get_java_home());
483 #endif
485 Arguments::set_ext_dirs(buf);
486 }
488 /* Endorsed standards default directory. */
489 {
490 char * buf;
491 buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
492 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
493 Arguments::set_endorsed_dirs(buf);
494 }
495 }
497 #ifdef __APPLE__
498 #undef SYS_EXTENSIONS_DIR
499 #endif
500 #undef malloc
501 #undef getenv
502 #undef EXTENSIONS_DIR
503 #undef ENDORSED_DIR
505 // Done
506 return;
507 }
509 ////////////////////////////////////////////////////////////////////////////////
510 // breakpoint support
512 void os::breakpoint() {
513 BREAKPOINT;
514 }
516 extern "C" void breakpoint() {
517 // use debugger to set breakpoint here
518 }
520 ////////////////////////////////////////////////////////////////////////////////
521 // signal support
523 debug_only(static bool signal_sets_initialized = false);
524 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
526 bool os::Bsd::is_sig_ignored(int sig) {
527 struct sigaction oact;
528 sigaction(sig, (struct sigaction*)NULL, &oact);
529 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
530 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
531 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
532 return true;
533 else
534 return false;
535 }
537 void os::Bsd::signal_sets_init() {
538 // Should also have an assertion stating we are still single-threaded.
539 assert(!signal_sets_initialized, "Already initialized");
540 // Fill in signals that are necessarily unblocked for all threads in
541 // the VM. Currently, we unblock the following signals:
542 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
543 // by -Xrs (=ReduceSignalUsage));
544 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
545 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
546 // the dispositions or masks wrt these signals.
547 // Programs embedding the VM that want to use the above signals for their
548 // own purposes must, at this time, use the "-Xrs" option to prevent
549 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
550 // (See bug 4345157, and other related bugs).
551 // In reality, though, unblocking these signals is really a nop, since
552 // these signals are not blocked by default.
553 sigemptyset(&unblocked_sigs);
554 sigemptyset(&allowdebug_blocked_sigs);
555 sigaddset(&unblocked_sigs, SIGILL);
556 sigaddset(&unblocked_sigs, SIGSEGV);
557 sigaddset(&unblocked_sigs, SIGBUS);
558 sigaddset(&unblocked_sigs, SIGFPE);
559 sigaddset(&unblocked_sigs, SR_signum);
561 if (!ReduceSignalUsage) {
562 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
563 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
564 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
565 }
566 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
567 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
568 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
569 }
570 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
571 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
572 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
573 }
574 }
575 // Fill in signals that are blocked by all but the VM thread.
576 sigemptyset(&vm_sigs);
577 if (!ReduceSignalUsage)
578 sigaddset(&vm_sigs, BREAK_SIGNAL);
579 debug_only(signal_sets_initialized = true);
581 }
583 // These are signals that are unblocked while a thread is running Java.
584 // (For some reason, they get blocked by default.)
585 sigset_t* os::Bsd::unblocked_signals() {
586 assert(signal_sets_initialized, "Not initialized");
587 return &unblocked_sigs;
588 }
590 // These are the signals that are blocked while a (non-VM) thread is
591 // running Java. Only the VM thread handles these signals.
592 sigset_t* os::Bsd::vm_signals() {
593 assert(signal_sets_initialized, "Not initialized");
594 return &vm_sigs;
595 }
597 // These are signals that are blocked during cond_wait to allow debugger in
598 sigset_t* os::Bsd::allowdebug_blocked_signals() {
599 assert(signal_sets_initialized, "Not initialized");
600 return &allowdebug_blocked_sigs;
601 }
603 void os::Bsd::hotspot_sigmask(Thread* thread) {
605 //Save caller's signal mask before setting VM signal mask
606 sigset_t caller_sigmask;
607 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
609 OSThread* osthread = thread->osthread();
610 osthread->set_caller_sigmask(caller_sigmask);
612 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
614 if (!ReduceSignalUsage) {
615 if (thread->is_VM_thread()) {
616 // Only the VM thread handles BREAK_SIGNAL ...
617 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
618 } else {
619 // ... all other threads block BREAK_SIGNAL
620 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
621 }
622 }
623 }
626 //////////////////////////////////////////////////////////////////////////////
627 // create new thread
629 static address highest_vm_reserved_address();
631 // check if it's safe to start a new thread
632 static bool _thread_safety_check(Thread* thread) {
633 return true;
634 }
636 #ifdef __APPLE__
637 // library handle for calling objc_registerThreadWithCollector()
638 // without static linking to the libobjc library
639 #define OBJC_LIB "/usr/lib/libobjc.dylib"
640 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
641 typedef void (*objc_registerThreadWithCollector_t)();
642 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
643 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
644 #endif
646 #ifdef __APPLE__
647 static uint64_t locate_unique_thread_id() {
648 // Additional thread_id used to correlate threads in SA
649 thread_identifier_info_data_t m_ident_info;
650 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT;
652 thread_info(::mach_thread_self(), THREAD_IDENTIFIER_INFO,
653 (thread_info_t) &m_ident_info, &count);
654 return m_ident_info.thread_id;
655 }
656 #endif
658 // Thread start routine for all newly created threads
659 static void *java_start(Thread *thread) {
660 // Try to randomize the cache line index of hot stack frames.
661 // This helps when threads of the same stack traces evict each other's
662 // cache lines. The threads can be either from the same JVM instance, or
663 // from different JVM instances. The benefit is especially true for
664 // processors with hyperthreading technology.
665 static int counter = 0;
666 int pid = os::current_process_id();
667 alloca(((pid ^ counter++) & 7) * 128);
669 ThreadLocalStorage::set_thread(thread);
671 OSThread* osthread = thread->osthread();
672 Monitor* sync = osthread->startThread_lock();
674 // non floating stack BsdThreads needs extra check, see above
675 if (!_thread_safety_check(thread)) {
676 // notify parent thread
677 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
678 osthread->set_state(ZOMBIE);
679 sync->notify_all();
680 return NULL;
681 }
683 #ifdef __APPLE__
684 // thread_id is mach thread on macos
685 osthread->set_thread_id(::mach_thread_self());
686 osthread->set_unique_thread_id(locate_unique_thread_id());
687 #else
688 // thread_id is pthread_id on BSD
689 osthread->set_thread_id(::pthread_self());
690 #endif
691 // initialize signal mask for this thread
692 os::Bsd::hotspot_sigmask(thread);
694 // initialize floating point control register
695 os::Bsd::init_thread_fpu_state();
697 #ifdef __APPLE__
698 // register thread with objc gc
699 if (objc_registerThreadWithCollectorFunction != NULL) {
700 objc_registerThreadWithCollectorFunction();
701 }
702 #endif
704 // handshaking with parent thread
705 {
706 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
708 // notify parent thread
709 osthread->set_state(INITIALIZED);
710 sync->notify_all();
712 // wait until os::start_thread()
713 while (osthread->get_state() == INITIALIZED) {
714 sync->wait(Mutex::_no_safepoint_check_flag);
715 }
716 }
718 // call one more level start routine
719 thread->run();
721 return 0;
722 }
724 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
725 assert(thread->osthread() == NULL, "caller responsible");
727 // Allocate the OSThread object
728 OSThread* osthread = new OSThread(NULL, NULL);
729 if (osthread == NULL) {
730 return false;
731 }
733 // set the correct thread state
734 osthread->set_thread_type(thr_type);
736 // Initial state is ALLOCATED but not INITIALIZED
737 osthread->set_state(ALLOCATED);
739 thread->set_osthread(osthread);
741 // init thread attributes
742 pthread_attr_t attr;
743 pthread_attr_init(&attr);
744 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
746 // stack size
747 if (os::Bsd::supports_variable_stack_size()) {
748 // calculate stack size if it's not specified by caller
749 if (stack_size == 0) {
750 stack_size = os::Bsd::default_stack_size(thr_type);
752 switch (thr_type) {
753 case os::java_thread:
754 // Java threads use ThreadStackSize which default value can be
755 // changed with the flag -Xss
756 assert (JavaThread::stack_size_at_create() > 0, "this should be set");
757 stack_size = JavaThread::stack_size_at_create();
758 break;
759 case os::compiler_thread:
760 if (CompilerThreadStackSize > 0) {
761 stack_size = (size_t)(CompilerThreadStackSize * K);
762 break;
763 } // else fall through:
764 // use VMThreadStackSize if CompilerThreadStackSize is not defined
765 case os::vm_thread:
766 case os::pgc_thread:
767 case os::cgc_thread:
768 case os::watcher_thread:
769 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
770 break;
771 }
772 }
774 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
775 pthread_attr_setstacksize(&attr, stack_size);
776 } else {
777 // let pthread_create() pick the default value.
778 }
780 ThreadState state;
782 {
783 pthread_t tid;
784 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
786 pthread_attr_destroy(&attr);
788 if (ret != 0) {
789 if (PrintMiscellaneous && (Verbose || WizardMode)) {
790 perror("pthread_create()");
791 }
792 // Need to clean up stuff we've allocated so far
793 thread->set_osthread(NULL);
794 delete osthread;
795 return false;
796 }
798 // Store pthread info into the OSThread
799 osthread->set_pthread_id(tid);
801 // Wait until child thread is either initialized or aborted
802 {
803 Monitor* sync_with_child = osthread->startThread_lock();
804 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
805 while ((state = osthread->get_state()) == ALLOCATED) {
806 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
807 }
808 }
810 }
812 // Aborted due to thread limit being reached
813 if (state == ZOMBIE) {
814 thread->set_osthread(NULL);
815 delete osthread;
816 return false;
817 }
819 // The thread is returned suspended (in state INITIALIZED),
820 // and is started higher up in the call chain
821 assert(state == INITIALIZED, "race condition");
822 return true;
823 }
825 /////////////////////////////////////////////////////////////////////////////
826 // attach existing thread
828 // bootstrap the main thread
829 bool os::create_main_thread(JavaThread* thread) {
830 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
831 return create_attached_thread(thread);
832 }
834 bool os::create_attached_thread(JavaThread* thread) {
835 #ifdef ASSERT
836 thread->verify_not_published();
837 #endif
839 // Allocate the OSThread object
840 OSThread* osthread = new OSThread(NULL, NULL);
842 if (osthread == NULL) {
843 return false;
844 }
846 // Store pthread info into the OSThread
847 #ifdef __APPLE__
848 osthread->set_thread_id(::mach_thread_self());
849 osthread->set_unique_thread_id(locate_unique_thread_id());
850 #else
851 osthread->set_thread_id(::pthread_self());
852 #endif
853 osthread->set_pthread_id(::pthread_self());
855 // initialize floating point control register
856 os::Bsd::init_thread_fpu_state();
858 // Initial thread state is RUNNABLE
859 osthread->set_state(RUNNABLE);
861 thread->set_osthread(osthread);
863 // initialize signal mask for this thread
864 // and save the caller's signal mask
865 os::Bsd::hotspot_sigmask(thread);
867 return true;
868 }
870 void os::pd_start_thread(Thread* thread) {
871 OSThread * osthread = thread->osthread();
872 assert(osthread->get_state() != INITIALIZED, "just checking");
873 Monitor* sync_with_child = osthread->startThread_lock();
874 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
875 sync_with_child->notify();
876 }
878 // Free Bsd resources related to the OSThread
879 void os::free_thread(OSThread* osthread) {
880 assert(osthread != NULL, "osthread not set");
882 if (Thread::current()->osthread() == osthread) {
883 // Restore caller's signal mask
884 sigset_t sigmask = osthread->caller_sigmask();
885 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
886 }
888 delete osthread;
889 }
891 //////////////////////////////////////////////////////////////////////////////
892 // thread local storage
894 int os::allocate_thread_local_storage() {
895 pthread_key_t key;
896 int rslt = pthread_key_create(&key, NULL);
897 assert(rslt == 0, "cannot allocate thread local storage");
898 return (int)key;
899 }
901 // Note: This is currently not used by VM, as we don't destroy TLS key
902 // on VM exit.
903 void os::free_thread_local_storage(int index) {
904 int rslt = pthread_key_delete((pthread_key_t)index);
905 assert(rslt == 0, "invalid index");
906 }
908 void os::thread_local_storage_at_put(int index, void* value) {
909 int rslt = pthread_setspecific((pthread_key_t)index, value);
910 assert(rslt == 0, "pthread_setspecific failed");
911 }
913 extern "C" Thread* get_thread() {
914 return ThreadLocalStorage::thread();
915 }
918 ////////////////////////////////////////////////////////////////////////////////
919 // time support
921 // Time since start-up in seconds to a fine granularity.
922 // Used by VMSelfDestructTimer and the MemProfiler.
923 double os::elapsedTime() {
925 return (double)(os::elapsed_counter()) * 0.000001;
926 }
928 jlong os::elapsed_counter() {
929 timeval time;
930 int status = gettimeofday(&time, NULL);
931 return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count;
932 }
934 jlong os::elapsed_frequency() {
935 return (1000 * 1000);
936 }
938 // XXX: For now, code this as if BSD does not support vtime.
939 bool os::supports_vtime() { return false; }
940 bool os::enable_vtime() { return false; }
941 bool os::vtime_enabled() { return false; }
942 double os::elapsedVTime() {
943 // better than nothing, but not much
944 return elapsedTime();
945 }
947 jlong os::javaTimeMillis() {
948 timeval time;
949 int status = gettimeofday(&time, NULL);
950 assert(status != -1, "bsd error");
951 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
952 }
954 #ifndef CLOCK_MONOTONIC
955 #define CLOCK_MONOTONIC (1)
956 #endif
958 #ifdef __APPLE__
959 void os::Bsd::clock_init() {
960 // XXXDARWIN: Investigate replacement monotonic clock
961 }
962 #else
963 void os::Bsd::clock_init() {
964 struct timespec res;
965 struct timespec tp;
966 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
967 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
968 // yes, monotonic clock is supported
969 _clock_gettime = ::clock_gettime;
970 }
971 }
972 #endif
975 jlong os::javaTimeNanos() {
976 if (Bsd::supports_monotonic_clock()) {
977 struct timespec tp;
978 int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp);
979 assert(status == 0, "gettime error");
980 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
981 return result;
982 } else {
983 timeval time;
984 int status = gettimeofday(&time, NULL);
985 assert(status != -1, "bsd error");
986 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
987 return 1000 * usecs;
988 }
989 }
991 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
992 if (Bsd::supports_monotonic_clock()) {
993 info_ptr->max_value = ALL_64_BITS;
995 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
996 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
997 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
998 } else {
999 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1000 info_ptr->max_value = ALL_64_BITS;
1002 // gettimeofday is a real time clock so it skips
1003 info_ptr->may_skip_backward = true;
1004 info_ptr->may_skip_forward = true;
1005 }
1007 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1008 }
1010 // Return the real, user, and system times in seconds from an
1011 // arbitrary fixed point in the past.
1012 bool os::getTimesSecs(double* process_real_time,
1013 double* process_user_time,
1014 double* process_system_time) {
1015 struct tms ticks;
1016 clock_t real_ticks = times(&ticks);
1018 if (real_ticks == (clock_t) (-1)) {
1019 return false;
1020 } else {
1021 double ticks_per_second = (double) clock_tics_per_sec;
1022 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1023 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1024 *process_real_time = ((double) real_ticks) / ticks_per_second;
1026 return true;
1027 }
1028 }
1031 char * os::local_time_string(char *buf, size_t buflen) {
1032 struct tm t;
1033 time_t long_time;
1034 time(&long_time);
1035 localtime_r(&long_time, &t);
1036 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1037 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1038 t.tm_hour, t.tm_min, t.tm_sec);
1039 return buf;
1040 }
1042 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1043 return localtime_r(clock, res);
1044 }
1046 ////////////////////////////////////////////////////////////////////////////////
1047 // runtime exit support
1049 // Note: os::shutdown() might be called very early during initialization, or
1050 // called from signal handler. Before adding something to os::shutdown(), make
1051 // sure it is async-safe and can handle partially initialized VM.
1052 void os::shutdown() {
1054 // allow PerfMemory to attempt cleanup of any persistent resources
1055 perfMemory_exit();
1057 // needs to remove object in file system
1058 AttachListener::abort();
1060 // flush buffered output, finish log files
1061 ostream_abort();
1063 // Check for abort hook
1064 abort_hook_t abort_hook = Arguments::abort_hook();
1065 if (abort_hook != NULL) {
1066 abort_hook();
1067 }
1069 }
1071 // Note: os::abort() might be called very early during initialization, or
1072 // called from signal handler. Before adding something to os::abort(), make
1073 // sure it is async-safe and can handle partially initialized VM.
1074 void os::abort(bool dump_core) {
1075 os::shutdown();
1076 if (dump_core) {
1077 #ifndef PRODUCT
1078 fdStream out(defaultStream::output_fd());
1079 out.print_raw("Current thread is ");
1080 char buf[16];
1081 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1082 out.print_raw_cr(buf);
1083 out.print_raw_cr("Dumping core ...");
1084 #endif
1085 ::abort(); // dump core
1086 }
1088 ::exit(1);
1089 }
1091 // Die immediately, no exit hook, no abort hook, no cleanup.
1092 void os::die() {
1093 // _exit() on BsdThreads only kills current thread
1094 ::abort();
1095 }
1097 // unused on bsd for now.
1098 void os::set_error_file(const char *logfile) {}
1101 // This method is a copy of JDK's sysGetLastErrorString
1102 // from src/solaris/hpi/src/system_md.c
1104 size_t os::lasterror(char *buf, size_t len) {
1106 if (errno == 0) return 0;
1108 const char *s = ::strerror(errno);
1109 size_t n = ::strlen(s);
1110 if (n >= len) {
1111 n = len - 1;
1112 }
1113 ::strncpy(buf, s, n);
1114 buf[n] = '\0';
1115 return n;
1116 }
1118 intx os::current_thread_id() {
1119 #ifdef __APPLE__
1120 return (intx)::mach_thread_self();
1121 #else
1122 return (intx)::pthread_self();
1123 #endif
1124 }
1125 int os::current_process_id() {
1127 // Under the old bsd thread library, bsd gives each thread
1128 // its own process id. Because of this each thread will return
1129 // a different pid if this method were to return the result
1130 // of getpid(2). Bsd provides no api that returns the pid
1131 // of the launcher thread for the vm. This implementation
1132 // returns a unique pid, the pid of the launcher thread
1133 // that starts the vm 'process'.
1135 // Under the NPTL, getpid() returns the same pid as the
1136 // launcher thread rather than a unique pid per thread.
1137 // Use gettid() if you want the old pre NPTL behaviour.
1139 // if you are looking for the result of a call to getpid() that
1140 // returns a unique pid for the calling thread, then look at the
1141 // OSThread::thread_id() method in osThread_bsd.hpp file
1143 return (int)(_initial_pid ? _initial_pid : getpid());
1144 }
1146 // DLL functions
1148 #define JNI_LIB_PREFIX "lib"
1149 #ifdef __APPLE__
1150 #define JNI_LIB_SUFFIX ".dylib"
1151 #else
1152 #define JNI_LIB_SUFFIX ".so"
1153 #endif
1155 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1157 // This must be hard coded because it's the system's temporary
1158 // directory not the java application's temp directory, ala java.io.tmpdir.
1159 #ifdef __APPLE__
1160 // macosx has a secure per-user temporary directory
1161 char temp_path_storage[PATH_MAX];
1162 const char* os::get_temp_directory() {
1163 static char *temp_path = NULL;
1164 if (temp_path == NULL) {
1165 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1166 if (pathSize == 0 || pathSize > PATH_MAX) {
1167 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1168 }
1169 temp_path = temp_path_storage;
1170 }
1171 return temp_path;
1172 }
1173 #else /* __APPLE__ */
1174 const char* os::get_temp_directory() { return "/tmp"; }
1175 #endif /* __APPLE__ */
1177 static bool file_exists(const char* filename) {
1178 struct stat statbuf;
1179 if (filename == NULL || strlen(filename) == 0) {
1180 return false;
1181 }
1182 return os::stat(filename, &statbuf) == 0;
1183 }
1185 bool os::dll_build_name(char* buffer, size_t buflen,
1186 const char* pname, const char* fname) {
1187 bool retval = false;
1188 // Copied from libhpi
1189 const size_t pnamelen = pname ? strlen(pname) : 0;
1191 // Return error on buffer overflow.
1192 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1193 return retval;
1194 }
1196 if (pnamelen == 0) {
1197 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1198 retval = true;
1199 } else if (strchr(pname, *os::path_separator()) != NULL) {
1200 int n;
1201 char** pelements = split_path(pname, &n);
1202 if (pelements == NULL) {
1203 return false;
1204 }
1205 for (int i = 0 ; i < n ; i++) {
1206 // Really shouldn't be NULL, but check can't hurt
1207 if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1208 continue; // skip the empty path values
1209 }
1210 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1211 pelements[i], fname);
1212 if (file_exists(buffer)) {
1213 retval = true;
1214 break;
1215 }
1216 }
1217 // release the storage
1218 for (int i = 0 ; i < n ; i++) {
1219 if (pelements[i] != NULL) {
1220 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
1221 }
1222 }
1223 if (pelements != NULL) {
1224 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
1225 }
1226 } else {
1227 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1228 retval = true;
1229 }
1230 return retval;
1231 }
1233 // check if addr is inside libjvm.so
1234 bool os::address_is_in_vm(address addr) {
1235 static address libjvm_base_addr;
1236 Dl_info dlinfo;
1238 if (libjvm_base_addr == NULL) {
1239 dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo);
1240 libjvm_base_addr = (address)dlinfo.dli_fbase;
1241 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1242 }
1244 if (dladdr((void *)addr, &dlinfo)) {
1245 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1246 }
1248 return false;
1249 }
1252 #define MACH_MAXSYMLEN 256
1254 bool os::dll_address_to_function_name(address addr, char *buf,
1255 int buflen, int *offset) {
1256 Dl_info dlinfo;
1257 char localbuf[MACH_MAXSYMLEN];
1259 // dladdr will find names of dynamic functions only, but does
1260 // it set dli_fbase with mach_header address when it "fails" ?
1261 if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) {
1262 if (buf != NULL) {
1263 if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1264 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1265 }
1266 }
1267 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1268 return true;
1269 } else if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != 0) {
1270 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1271 buf, buflen, offset, dlinfo.dli_fname)) {
1272 return true;
1273 }
1274 }
1276 // Handle non-dymanic manually:
1277 if (dlinfo.dli_fbase != NULL &&
1278 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
1279 if(!Decoder::demangle(localbuf, buf, buflen)) {
1280 jio_snprintf(buf, buflen, "%s", localbuf);
1281 }
1282 return true;
1283 }
1284 if (buf != NULL) buf[0] = '\0';
1285 if (offset != NULL) *offset = -1;
1286 return false;
1287 }
1289 // ported from solaris version
1290 bool os::dll_address_to_library_name(address addr, char* buf,
1291 int buflen, int* offset) {
1292 Dl_info dlinfo;
1294 if (dladdr((void*)addr, &dlinfo)){
1295 if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1296 if (offset) *offset = addr - (address)dlinfo.dli_fbase;
1297 return true;
1298 } else {
1299 if (buf) buf[0] = '\0';
1300 if (offset) *offset = -1;
1301 return false;
1302 }
1303 }
1305 // Loads .dll/.so and
1306 // in case of error it checks if .dll/.so was built for the
1307 // same architecture as Hotspot is running on
1309 #ifdef __APPLE__
1310 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1311 void * result= ::dlopen(filename, RTLD_LAZY);
1312 if (result != NULL) {
1313 // Successful loading
1314 return result;
1315 }
1317 // Read system error message into ebuf
1318 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1319 ebuf[ebuflen-1]='\0';
1321 return NULL;
1322 }
1323 #else
1324 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
1325 {
1326 void * result= ::dlopen(filename, RTLD_LAZY);
1327 if (result != NULL) {
1328 // Successful loading
1329 return result;
1330 }
1332 Elf32_Ehdr elf_head;
1334 // Read system error message into ebuf
1335 // It may or may not be overwritten below
1336 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1337 ebuf[ebuflen-1]='\0';
1338 int diag_msg_max_length=ebuflen-strlen(ebuf);
1339 char* diag_msg_buf=ebuf+strlen(ebuf);
1341 if (diag_msg_max_length==0) {
1342 // No more space in ebuf for additional diagnostics message
1343 return NULL;
1344 }
1347 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1349 if (file_descriptor < 0) {
1350 // Can't open library, report dlerror() message
1351 return NULL;
1352 }
1354 bool failed_to_read_elf_head=
1355 (sizeof(elf_head)!=
1356 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
1358 ::close(file_descriptor);
1359 if (failed_to_read_elf_head) {
1360 // file i/o error - report dlerror() msg
1361 return NULL;
1362 }
1364 typedef struct {
1365 Elf32_Half code; // Actual value as defined in elf.h
1366 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1367 char elf_class; // 32 or 64 bit
1368 char endianess; // MSB or LSB
1369 char* name; // String representation
1370 } arch_t;
1372 #ifndef EM_486
1373 #define EM_486 6 /* Intel 80486 */
1374 #endif
1376 #ifndef EM_MIPS_RS3_LE
1377 #define EM_MIPS_RS3_LE 10 /* MIPS */
1378 #endif
1380 #ifndef EM_PPC64
1381 #define EM_PPC64 21 /* PowerPC64 */
1382 #endif
1384 #ifndef EM_S390
1385 #define EM_S390 22 /* IBM System/390 */
1386 #endif
1388 #ifndef EM_IA_64
1389 #define EM_IA_64 50 /* HP/Intel IA-64 */
1390 #endif
1392 #ifndef EM_X86_64
1393 #define EM_X86_64 62 /* AMD x86-64 */
1394 #endif
1396 static const arch_t arch_array[]={
1397 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1398 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1399 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1400 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1401 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1402 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1403 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1404 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1405 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1406 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1407 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1408 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1409 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1410 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1411 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1412 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1413 };
1415 #if (defined IA32)
1416 static Elf32_Half running_arch_code=EM_386;
1417 #elif (defined AMD64)
1418 static Elf32_Half running_arch_code=EM_X86_64;
1419 #elif (defined IA64)
1420 static Elf32_Half running_arch_code=EM_IA_64;
1421 #elif (defined __sparc) && (defined _LP64)
1422 static Elf32_Half running_arch_code=EM_SPARCV9;
1423 #elif (defined __sparc) && (!defined _LP64)
1424 static Elf32_Half running_arch_code=EM_SPARC;
1425 #elif (defined __powerpc64__)
1426 static Elf32_Half running_arch_code=EM_PPC64;
1427 #elif (defined __powerpc__)
1428 static Elf32_Half running_arch_code=EM_PPC;
1429 #elif (defined ARM)
1430 static Elf32_Half running_arch_code=EM_ARM;
1431 #elif (defined S390)
1432 static Elf32_Half running_arch_code=EM_S390;
1433 #elif (defined ALPHA)
1434 static Elf32_Half running_arch_code=EM_ALPHA;
1435 #elif (defined MIPSEL)
1436 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1437 #elif (defined PARISC)
1438 static Elf32_Half running_arch_code=EM_PARISC;
1439 #elif (defined MIPS)
1440 static Elf32_Half running_arch_code=EM_MIPS;
1441 #elif (defined M68K)
1442 static Elf32_Half running_arch_code=EM_68K;
1443 #else
1444 #error Method os::dll_load requires that one of following is defined:\
1445 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1446 #endif
1448 // Identify compatability class for VM's architecture and library's architecture
1449 // Obtain string descriptions for architectures
1451 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1452 int running_arch_index=-1;
1454 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
1455 if (running_arch_code == arch_array[i].code) {
1456 running_arch_index = i;
1457 }
1458 if (lib_arch.code == arch_array[i].code) {
1459 lib_arch.compat_class = arch_array[i].compat_class;
1460 lib_arch.name = arch_array[i].name;
1461 }
1462 }
1464 assert(running_arch_index != -1,
1465 "Didn't find running architecture code (running_arch_code) in arch_array");
1466 if (running_arch_index == -1) {
1467 // Even though running architecture detection failed
1468 // we may still continue with reporting dlerror() message
1469 return NULL;
1470 }
1472 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1473 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1474 return NULL;
1475 }
1477 #ifndef S390
1478 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1479 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1480 return NULL;
1481 }
1482 #endif // !S390
1484 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1485 if ( lib_arch.name!=NULL ) {
1486 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1487 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1488 lib_arch.name, arch_array[running_arch_index].name);
1489 } else {
1490 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1491 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1492 lib_arch.code,
1493 arch_array[running_arch_index].name);
1494 }
1495 }
1497 return NULL;
1498 }
1499 #endif /* !__APPLE__ */
1501 // XXX: Do we need a lock around this as per Linux?
1502 void* os::dll_lookup(void* handle, const char* name) {
1503 return dlsym(handle, name);
1504 }
1507 static bool _print_ascii_file(const char* filename, outputStream* st) {
1508 int fd = ::open(filename, O_RDONLY);
1509 if (fd == -1) {
1510 return false;
1511 }
1513 char buf[32];
1514 int bytes;
1515 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1516 st->print_raw(buf, bytes);
1517 }
1519 ::close(fd);
1521 return true;
1522 }
1524 void os::print_dll_info(outputStream *st) {
1525 st->print_cr("Dynamic libraries:");
1526 #ifdef RTLD_DI_LINKMAP
1527 Dl_info dli;
1528 void *handle;
1529 Link_map *map;
1530 Link_map *p;
1532 if (!dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli)) {
1533 st->print_cr("Error: Cannot print dynamic libraries.");
1534 return;
1535 }
1536 handle = dlopen(dli.dli_fname, RTLD_LAZY);
1537 if (handle == NULL) {
1538 st->print_cr("Error: Cannot print dynamic libraries.");
1539 return;
1540 }
1541 dlinfo(handle, RTLD_DI_LINKMAP, &map);
1542 if (map == NULL) {
1543 st->print_cr("Error: Cannot print dynamic libraries.");
1544 return;
1545 }
1547 while (map->l_prev != NULL)
1548 map = map->l_prev;
1550 while (map != NULL) {
1551 st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
1552 map = map->l_next;
1553 }
1555 dlclose(handle);
1556 #elif defined(__APPLE__)
1557 uint32_t count;
1558 uint32_t i;
1560 count = _dyld_image_count();
1561 for (i = 1; i < count; i++) {
1562 const char *name = _dyld_get_image_name(i);
1563 intptr_t slide = _dyld_get_image_vmaddr_slide(i);
1564 st->print_cr(PTR_FORMAT " \t%s", slide, name);
1565 }
1566 #else
1567 st->print_cr("Error: Cannot print dynamic libraries.");
1568 #endif
1569 }
1571 void os::print_os_info_brief(outputStream* st) {
1572 st->print("Bsd");
1574 os::Posix::print_uname_info(st);
1575 }
1577 void os::print_os_info(outputStream* st) {
1578 st->print("OS:");
1579 st->print("Bsd");
1581 os::Posix::print_uname_info(st);
1583 os::Posix::print_rlimit_info(st);
1585 os::Posix::print_load_average(st);
1586 }
1588 void os::pd_print_cpu_info(outputStream* st) {
1589 // Nothing to do for now.
1590 }
1592 void os::print_memory_info(outputStream* st) {
1594 st->print("Memory:");
1595 st->print(" %dk page", os::vm_page_size()>>10);
1597 st->print(", physical " UINT64_FORMAT "k",
1598 os::physical_memory() >> 10);
1599 st->print("(" UINT64_FORMAT "k free)",
1600 os::available_memory() >> 10);
1601 st->cr();
1603 // meminfo
1604 st->print("\n/proc/meminfo:\n");
1605 _print_ascii_file("/proc/meminfo", st);
1606 st->cr();
1607 }
1609 // Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific
1610 // but they're the same for all the bsd arch that we support
1611 // and they're the same for solaris but there's no common place to put this.
1612 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
1613 "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
1614 "ILL_COPROC", "ILL_BADSTK" };
1616 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
1617 "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
1618 "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
1620 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
1622 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
1624 void os::print_siginfo(outputStream* st, void* siginfo) {
1625 st->print("siginfo:");
1627 const int buflen = 100;
1628 char buf[buflen];
1629 siginfo_t *si = (siginfo_t*)siginfo;
1630 st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
1631 if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
1632 st->print("si_errno=%s", buf);
1633 } else {
1634 st->print("si_errno=%d", si->si_errno);
1635 }
1636 const int c = si->si_code;
1637 assert(c > 0, "unexpected si_code");
1638 switch (si->si_signo) {
1639 case SIGILL:
1640 st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
1641 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1642 break;
1643 case SIGFPE:
1644 st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
1645 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1646 break;
1647 case SIGSEGV:
1648 st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
1649 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1650 break;
1651 case SIGBUS:
1652 st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
1653 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1654 break;
1655 default:
1656 st->print(", si_code=%d", si->si_code);
1657 // no si_addr
1658 }
1660 if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1661 UseSharedSpaces) {
1662 FileMapInfo* mapinfo = FileMapInfo::current_info();
1663 if (mapinfo->is_in_shared_space(si->si_addr)) {
1664 st->print("\n\nError accessing class data sharing archive." \
1665 " Mapped file inaccessible during execution, " \
1666 " possible disk/network problem.");
1667 }
1668 }
1669 st->cr();
1670 }
1673 static void print_signal_handler(outputStream* st, int sig,
1674 char* buf, size_t buflen);
1676 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1677 st->print_cr("Signal Handlers:");
1678 print_signal_handler(st, SIGSEGV, buf, buflen);
1679 print_signal_handler(st, SIGBUS , buf, buflen);
1680 print_signal_handler(st, SIGFPE , buf, buflen);
1681 print_signal_handler(st, SIGPIPE, buf, buflen);
1682 print_signal_handler(st, SIGXFSZ, buf, buflen);
1683 print_signal_handler(st, SIGILL , buf, buflen);
1684 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1685 print_signal_handler(st, SR_signum, buf, buflen);
1686 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1687 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1688 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1689 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1690 }
1692 static char saved_jvm_path[MAXPATHLEN] = {0};
1694 // Find the full path to the current module, libjvm
1695 void os::jvm_path(char *buf, jint buflen) {
1696 // Error checking.
1697 if (buflen < MAXPATHLEN) {
1698 assert(false, "must use a large-enough buffer");
1699 buf[0] = '\0';
1700 return;
1701 }
1702 // Lazy resolve the path to current module.
1703 if (saved_jvm_path[0] != 0) {
1704 strcpy(buf, saved_jvm_path);
1705 return;
1706 }
1708 char dli_fname[MAXPATHLEN];
1709 bool ret = dll_address_to_library_name(
1710 CAST_FROM_FN_PTR(address, os::jvm_path),
1711 dli_fname, sizeof(dli_fname), NULL);
1712 assert(ret != 0, "cannot locate libjvm");
1713 char *rp = realpath(dli_fname, buf);
1714 if (rp == NULL)
1715 return;
1717 if (Arguments::created_by_gamma_launcher()) {
1718 // Support for the gamma launcher. Typical value for buf is
1719 // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm". If "/jre/lib/" appears at
1720 // the right place in the string, then assume we are installed in a JDK and
1721 // we're done. Otherwise, check for a JAVA_HOME environment variable and
1722 // construct a path to the JVM being overridden.
1724 const char *p = buf + strlen(buf) - 1;
1725 for (int count = 0; p > buf && count < 5; ++count) {
1726 for (--p; p > buf && *p != '/'; --p)
1727 /* empty */ ;
1728 }
1730 if (strncmp(p, "/jre/lib/", 9) != 0) {
1731 // Look for JAVA_HOME in the environment.
1732 char* java_home_var = ::getenv("JAVA_HOME");
1733 if (java_home_var != NULL && java_home_var[0] != 0) {
1734 char* jrelib_p;
1735 int len;
1737 // Check the current module name "libjvm"
1738 p = strrchr(buf, '/');
1739 assert(strstr(p, "/libjvm") == p, "invalid library name");
1741 rp = realpath(java_home_var, buf);
1742 if (rp == NULL)
1743 return;
1745 // determine if this is a legacy image or modules image
1746 // modules image doesn't have "jre" subdirectory
1747 len = strlen(buf);
1748 jrelib_p = buf + len;
1750 // Add the appropriate library subdir
1751 snprintf(jrelib_p, buflen-len, "/jre/lib");
1752 if (0 != access(buf, F_OK)) {
1753 snprintf(jrelib_p, buflen-len, "/lib");
1754 }
1756 // Add the appropriate client or server subdir
1757 len = strlen(buf);
1758 jrelib_p = buf + len;
1759 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1760 if (0 != access(buf, F_OK)) {
1761 snprintf(jrelib_p, buflen-len, "");
1762 }
1764 // If the path exists within JAVA_HOME, add the JVM library name
1765 // to complete the path to JVM being overridden. Otherwise fallback
1766 // to the path to the current library.
1767 if (0 == access(buf, F_OK)) {
1768 // Use current module name "libjvm"
1769 len = strlen(buf);
1770 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1771 } else {
1772 // Fall back to path of current library
1773 rp = realpath(dli_fname, buf);
1774 if (rp == NULL)
1775 return;
1776 }
1777 }
1778 }
1779 }
1781 strcpy(saved_jvm_path, buf);
1782 }
1784 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1785 // no prefix required, not even "_"
1786 }
1788 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1789 // no suffix required
1790 }
1792 ////////////////////////////////////////////////////////////////////////////////
1793 // sun.misc.Signal support
1795 static volatile jint sigint_count = 0;
1797 static void
1798 UserHandler(int sig, void *siginfo, void *context) {
1799 // 4511530 - sem_post is serialized and handled by the manager thread. When
1800 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1801 // don't want to flood the manager thread with sem_post requests.
1802 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
1803 return;
1805 // Ctrl-C is pressed during error reporting, likely because the error
1806 // handler fails to abort. Let VM die immediately.
1807 if (sig == SIGINT && is_error_reported()) {
1808 os::die();
1809 }
1811 os::signal_notify(sig);
1812 }
1814 void* os::user_handler() {
1815 return CAST_FROM_FN_PTR(void*, UserHandler);
1816 }
1818 extern "C" {
1819 typedef void (*sa_handler_t)(int);
1820 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1821 }
1823 void* os::signal(int signal_number, void* handler) {
1824 struct sigaction sigAct, oldSigAct;
1826 sigfillset(&(sigAct.sa_mask));
1827 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
1828 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1830 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1831 // -1 means registration failed
1832 return (void *)-1;
1833 }
1835 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1836 }
1838 void os::signal_raise(int signal_number) {
1839 ::raise(signal_number);
1840 }
1842 /*
1843 * The following code is moved from os.cpp for making this
1844 * code platform specific, which it is by its very nature.
1845 */
1847 // Will be modified when max signal is changed to be dynamic
1848 int os::sigexitnum_pd() {
1849 return NSIG;
1850 }
1852 // a counter for each possible signal value
1853 static volatile jint pending_signals[NSIG+1] = { 0 };
1855 // Bsd(POSIX) specific hand shaking semaphore.
1856 #ifdef __APPLE__
1857 static semaphore_t sig_sem;
1858 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1859 #define SEM_WAIT(sem) semaphore_wait(sem);
1860 #define SEM_POST(sem) semaphore_signal(sem);
1861 #else
1862 static sem_t sig_sem;
1863 #define SEM_INIT(sem, value) sem_init(&sem, 0, value)
1864 #define SEM_WAIT(sem) sem_wait(&sem);
1865 #define SEM_POST(sem) sem_post(&sem);
1866 #endif
1868 void os::signal_init_pd() {
1869 // Initialize signal structures
1870 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1872 // Initialize signal semaphore
1873 ::SEM_INIT(sig_sem, 0);
1874 }
1876 void os::signal_notify(int sig) {
1877 Atomic::inc(&pending_signals[sig]);
1878 ::SEM_POST(sig_sem);
1879 }
1881 static int check_pending_signals(bool wait) {
1882 Atomic::store(0, &sigint_count);
1883 for (;;) {
1884 for (int i = 0; i < NSIG + 1; i++) {
1885 jint n = pending_signals[i];
1886 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1887 return i;
1888 }
1889 }
1890 if (!wait) {
1891 return -1;
1892 }
1893 JavaThread *thread = JavaThread::current();
1894 ThreadBlockInVM tbivm(thread);
1896 bool threadIsSuspended;
1897 do {
1898 thread->set_suspend_equivalent();
1899 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1900 ::SEM_WAIT(sig_sem);
1902 // were we externally suspended while we were waiting?
1903 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1904 if (threadIsSuspended) {
1905 //
1906 // The semaphore has been incremented, but while we were waiting
1907 // another thread suspended us. We don't want to continue running
1908 // while suspended because that would surprise the thread that
1909 // suspended us.
1910 //
1911 ::SEM_POST(sig_sem);
1913 thread->java_suspend_self();
1914 }
1915 } while (threadIsSuspended);
1916 }
1917 }
1919 int os::signal_lookup() {
1920 return check_pending_signals(false);
1921 }
1923 int os::signal_wait() {
1924 return check_pending_signals(true);
1925 }
1927 ////////////////////////////////////////////////////////////////////////////////
1928 // Virtual Memory
1930 int os::vm_page_size() {
1931 // Seems redundant as all get out
1932 assert(os::Bsd::page_size() != -1, "must call os::init");
1933 return os::Bsd::page_size();
1934 }
1936 // Solaris allocates memory by pages.
1937 int os::vm_allocation_granularity() {
1938 assert(os::Bsd::page_size() != -1, "must call os::init");
1939 return os::Bsd::page_size();
1940 }
1942 // Rationale behind this function:
1943 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
1944 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
1945 // samples for JITted code. Here we create private executable mapping over the code cache
1946 // and then we can use standard (well, almost, as mapping can change) way to provide
1947 // info for the reporting script by storing timestamp and location of symbol
1948 void bsd_wrap_code(char* base, size_t size) {
1949 static volatile jint cnt = 0;
1951 if (!UseOprofile) {
1952 return;
1953 }
1955 char buf[PATH_MAX + 1];
1956 int num = Atomic::add(1, &cnt);
1958 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
1959 os::get_temp_directory(), os::current_process_id(), num);
1960 unlink(buf);
1962 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
1964 if (fd != -1) {
1965 off_t rv = ::lseek(fd, size-2, SEEK_SET);
1966 if (rv != (off_t)-1) {
1967 if (::write(fd, "", 1) == 1) {
1968 mmap(base, size,
1969 PROT_READ|PROT_WRITE|PROT_EXEC,
1970 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
1971 }
1972 }
1973 ::close(fd);
1974 unlink(buf);
1975 }
1976 }
1978 // NOTE: Bsd kernel does not really reserve the pages for us.
1979 // All it does is to check if there are enough free pages
1980 // left at the time of mmap(). This could be a potential
1981 // problem.
1982 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
1983 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
1984 #ifdef __OpenBSD__
1985 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
1986 return ::mprotect(addr, size, prot) == 0;
1987 #else
1988 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
1989 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
1990 return res != (uintptr_t) MAP_FAILED;
1991 #endif
1992 }
1995 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
1996 bool exec) {
1997 return commit_memory(addr, size, exec);
1998 }
2000 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2001 }
2003 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2004 ::madvise(addr, bytes, MADV_DONTNEED);
2005 }
2007 void os::numa_make_global(char *addr, size_t bytes) {
2008 }
2010 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2011 }
2013 bool os::numa_topology_changed() { return false; }
2015 size_t os::numa_get_groups_num() {
2016 return 1;
2017 }
2019 int os::numa_get_group_id() {
2020 return 0;
2021 }
2023 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2024 if (size > 0) {
2025 ids[0] = 0;
2026 return 1;
2027 }
2028 return 0;
2029 }
2031 bool os::get_page_info(char *start, page_info* info) {
2032 return false;
2033 }
2035 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2036 return end;
2037 }
2040 bool os::pd_uncommit_memory(char* addr, size_t size) {
2041 #ifdef __OpenBSD__
2042 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2043 return ::mprotect(addr, size, PROT_NONE) == 0;
2044 #else
2045 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2046 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2047 return res != (uintptr_t) MAP_FAILED;
2048 #endif
2049 }
2051 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2052 return os::commit_memory(addr, size);
2053 }
2055 // If this is a growable mapping, remove the guard pages entirely by
2056 // munmap()ping them. If not, just call uncommit_memory().
2057 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2058 return os::uncommit_memory(addr, size);
2059 }
2061 static address _highest_vm_reserved_address = NULL;
2063 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2064 // at 'requested_addr'. If there are existing memory mappings at the same
2065 // location, however, they will be overwritten. If 'fixed' is false,
2066 // 'requested_addr' is only treated as a hint, the return value may or
2067 // may not start from the requested address. Unlike Bsd mmap(), this
2068 // function returns NULL to indicate failure.
2069 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2070 char * addr;
2071 int flags;
2073 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2074 if (fixed) {
2075 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2076 flags |= MAP_FIXED;
2077 }
2079 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2080 // touch an uncommitted page. Otherwise, the read/write might
2081 // succeed if we have enough swap space to back the physical page.
2082 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2083 flags, -1, 0);
2085 if (addr != MAP_FAILED) {
2086 // anon_mmap() should only get called during VM initialization,
2087 // don't need lock (actually we can skip locking even it can be called
2088 // from multiple threads, because _highest_vm_reserved_address is just a
2089 // hint about the upper limit of non-stack memory regions.)
2090 if ((address)addr + bytes > _highest_vm_reserved_address) {
2091 _highest_vm_reserved_address = (address)addr + bytes;
2092 }
2093 }
2095 return addr == MAP_FAILED ? NULL : addr;
2096 }
2098 // Don't update _highest_vm_reserved_address, because there might be memory
2099 // regions above addr + size. If so, releasing a memory region only creates
2100 // a hole in the address space, it doesn't help prevent heap-stack collision.
2101 //
2102 static int anon_munmap(char * addr, size_t size) {
2103 return ::munmap(addr, size) == 0;
2104 }
2106 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2107 size_t alignment_hint) {
2108 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2109 }
2111 bool os::pd_release_memory(char* addr, size_t size) {
2112 return anon_munmap(addr, size);
2113 }
2115 static address highest_vm_reserved_address() {
2116 return _highest_vm_reserved_address;
2117 }
2119 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2120 // Bsd wants the mprotect address argument to be page aligned.
2121 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2123 // According to SUSv3, mprotect() should only be used with mappings
2124 // established by mmap(), and mmap() always maps whole pages. Unaligned
2125 // 'addr' likely indicates problem in the VM (e.g. trying to change
2126 // protection of malloc'ed or statically allocated memory). Check the
2127 // caller if you hit this assert.
2128 assert(addr == bottom, "sanity check");
2130 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2131 return ::mprotect(bottom, size, prot) == 0;
2132 }
2134 // Set protections specified
2135 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2136 bool is_committed) {
2137 unsigned int p = 0;
2138 switch (prot) {
2139 case MEM_PROT_NONE: p = PROT_NONE; break;
2140 case MEM_PROT_READ: p = PROT_READ; break;
2141 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
2142 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2143 default:
2144 ShouldNotReachHere();
2145 }
2146 // is_committed is unused.
2147 return bsd_mprotect(addr, bytes, p);
2148 }
2150 bool os::guard_memory(char* addr, size_t size) {
2151 return bsd_mprotect(addr, size, PROT_NONE);
2152 }
2154 bool os::unguard_memory(char* addr, size_t size) {
2155 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2156 }
2158 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2159 return false;
2160 }
2162 /*
2163 * Set the coredump_filter bits to include largepages in core dump (bit 6)
2164 *
2165 * From the coredump_filter documentation:
2166 *
2167 * - (bit 0) anonymous private memory
2168 * - (bit 1) anonymous shared memory
2169 * - (bit 2) file-backed private memory
2170 * - (bit 3) file-backed shared memory
2171 * - (bit 4) ELF header pages in file-backed private memory areas (it is
2172 * effective only if the bit 2 is cleared)
2173 * - (bit 5) hugetlb private memory
2174 * - (bit 6) hugetlb shared memory
2175 */
2176 static void set_coredump_filter(void) {
2177 FILE *f;
2178 long cdm;
2180 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
2181 return;
2182 }
2184 if (fscanf(f, "%lx", &cdm) != 1) {
2185 fclose(f);
2186 return;
2187 }
2189 rewind(f);
2191 if ((cdm & LARGEPAGES_BIT) == 0) {
2192 cdm |= LARGEPAGES_BIT;
2193 fprintf(f, "%#lx", cdm);
2194 }
2196 fclose(f);
2197 }
2199 // Large page support
2201 static size_t _large_page_size = 0;
2203 void os::large_page_init() {
2204 }
2207 char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) {
2208 // "exec" is passed in but not used. Creating the shared image for
2209 // the code cache doesn't have an SHM_X executable permission to check.
2210 assert(UseLargePages && UseSHM, "only for SHM large pages");
2212 key_t key = IPC_PRIVATE;
2213 char *addr;
2215 bool warn_on_failure = UseLargePages &&
2216 (!FLAG_IS_DEFAULT(UseLargePages) ||
2217 !FLAG_IS_DEFAULT(LargePageSizeInBytes)
2218 );
2219 char msg[128];
2221 // Create a large shared memory region to attach to based on size.
2222 // Currently, size is the total size of the heap
2223 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2224 if (shmid == -1) {
2225 // Possible reasons for shmget failure:
2226 // 1. shmmax is too small for Java heap.
2227 // > check shmmax value: cat /proc/sys/kernel/shmmax
2228 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2229 // 2. not enough large page memory.
2230 // > check available large pages: cat /proc/meminfo
2231 // > increase amount of large pages:
2232 // echo new_value > /proc/sys/vm/nr_hugepages
2233 // Note 1: different Bsd may use different name for this property,
2234 // e.g. on Redhat AS-3 it is "hugetlb_pool".
2235 // Note 2: it's possible there's enough physical memory available but
2236 // they are so fragmented after a long run that they can't
2237 // coalesce into large pages. Try to reserve large pages when
2238 // the system is still "fresh".
2239 if (warn_on_failure) {
2240 jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
2241 warning(msg);
2242 }
2243 return NULL;
2244 }
2246 // attach to the region
2247 addr = (char*)shmat(shmid, req_addr, 0);
2248 int err = errno;
2250 // Remove shmid. If shmat() is successful, the actual shared memory segment
2251 // will be deleted when it's detached by shmdt() or when the process
2252 // terminates. If shmat() is not successful this will remove the shared
2253 // segment immediately.
2254 shmctl(shmid, IPC_RMID, NULL);
2256 if ((intptr_t)addr == -1) {
2257 if (warn_on_failure) {
2258 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
2259 warning(msg);
2260 }
2261 return NULL;
2262 }
2264 // The memory is committed
2265 address pc = CALLER_PC;
2266 MemTracker::record_virtual_memory_reserve((address)addr, bytes, pc);
2267 MemTracker::record_virtual_memory_commit((address)addr, bytes, pc);
2269 return addr;
2270 }
2272 bool os::release_memory_special(char* base, size_t bytes) {
2273 // detaching the SHM segment will also delete it, see reserve_memory_special()
2274 int rslt = shmdt(base);
2275 if (rslt == 0) {
2276 MemTracker::record_virtual_memory_uncommit((address)base, bytes);
2277 MemTracker::record_virtual_memory_release((address)base, bytes);
2278 return true;
2279 } else {
2280 return false;
2281 }
2283 }
2285 size_t os::large_page_size() {
2286 return _large_page_size;
2287 }
2289 // HugeTLBFS allows application to commit large page memory on demand;
2290 // with SysV SHM the entire memory region must be allocated as shared
2291 // memory.
2292 bool os::can_commit_large_page_memory() {
2293 return UseHugeTLBFS;
2294 }
2296 bool os::can_execute_large_page_memory() {
2297 return UseHugeTLBFS;
2298 }
2300 // Reserve memory at an arbitrary address, only if that area is
2301 // available (and not reserved for something else).
2303 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2304 const int max_tries = 10;
2305 char* base[max_tries];
2306 size_t size[max_tries];
2307 const size_t gap = 0x000000;
2309 // Assert only that the size is a multiple of the page size, since
2310 // that's all that mmap requires, and since that's all we really know
2311 // about at this low abstraction level. If we need higher alignment,
2312 // we can either pass an alignment to this method or verify alignment
2313 // in one of the methods further up the call chain. See bug 5044738.
2314 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2316 // Repeatedly allocate blocks until the block is allocated at the
2317 // right spot. Give up after max_tries. Note that reserve_memory() will
2318 // automatically update _highest_vm_reserved_address if the call is
2319 // successful. The variable tracks the highest memory address every reserved
2320 // by JVM. It is used to detect heap-stack collision if running with
2321 // fixed-stack BsdThreads. Because here we may attempt to reserve more
2322 // space than needed, it could confuse the collision detecting code. To
2323 // solve the problem, save current _highest_vm_reserved_address and
2324 // calculate the correct value before return.
2325 address old_highest = _highest_vm_reserved_address;
2327 // Bsd mmap allows caller to pass an address as hint; give it a try first,
2328 // if kernel honors the hint then we can return immediately.
2329 char * addr = anon_mmap(requested_addr, bytes, false);
2330 if (addr == requested_addr) {
2331 return requested_addr;
2332 }
2334 if (addr != NULL) {
2335 // mmap() is successful but it fails to reserve at the requested address
2336 anon_munmap(addr, bytes);
2337 }
2339 int i;
2340 for (i = 0; i < max_tries; ++i) {
2341 base[i] = reserve_memory(bytes);
2343 if (base[i] != NULL) {
2344 // Is this the block we wanted?
2345 if (base[i] == requested_addr) {
2346 size[i] = bytes;
2347 break;
2348 }
2350 // Does this overlap the block we wanted? Give back the overlapped
2351 // parts and try again.
2353 size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2354 if (top_overlap >= 0 && top_overlap < bytes) {
2355 unmap_memory(base[i], top_overlap);
2356 base[i] += top_overlap;
2357 size[i] = bytes - top_overlap;
2358 } else {
2359 size_t bottom_overlap = base[i] + bytes - requested_addr;
2360 if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2361 unmap_memory(requested_addr, bottom_overlap);
2362 size[i] = bytes - bottom_overlap;
2363 } else {
2364 size[i] = bytes;
2365 }
2366 }
2367 }
2368 }
2370 // Give back the unused reserved pieces.
2372 for (int j = 0; j < i; ++j) {
2373 if (base[j] != NULL) {
2374 unmap_memory(base[j], size[j]);
2375 }
2376 }
2378 if (i < max_tries) {
2379 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2380 return requested_addr;
2381 } else {
2382 _highest_vm_reserved_address = old_highest;
2383 return NULL;
2384 }
2385 }
2387 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2388 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2389 }
2391 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
2392 // Solaris uses poll(), bsd uses park().
2393 // Poll() is likely a better choice, assuming that Thread.interrupt()
2394 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
2395 // SIGSEGV, see 4355769.
2397 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
2398 assert(thread == Thread::current(), "thread consistency check");
2400 ParkEvent * const slp = thread->_SleepEvent ;
2401 slp->reset() ;
2402 OrderAccess::fence() ;
2404 if (interruptible) {
2405 jlong prevtime = javaTimeNanos();
2407 for (;;) {
2408 if (os::is_interrupted(thread, true)) {
2409 return OS_INTRPT;
2410 }
2412 jlong newtime = javaTimeNanos();
2414 if (newtime - prevtime < 0) {
2415 // time moving backwards, should only happen if no monotonic clock
2416 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2417 assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2418 } else {
2419 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2420 }
2422 if(millis <= 0) {
2423 return OS_OK;
2424 }
2426 prevtime = newtime;
2428 {
2429 assert(thread->is_Java_thread(), "sanity check");
2430 JavaThread *jt = (JavaThread *) thread;
2431 ThreadBlockInVM tbivm(jt);
2432 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
2434 jt->set_suspend_equivalent();
2435 // cleared by handle_special_suspend_equivalent_condition() or
2436 // java_suspend_self() via check_and_wait_while_suspended()
2438 slp->park(millis);
2440 // were we externally suspended while we were waiting?
2441 jt->check_and_wait_while_suspended();
2442 }
2443 }
2444 } else {
2445 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2446 jlong prevtime = javaTimeNanos();
2448 for (;;) {
2449 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
2450 // the 1st iteration ...
2451 jlong newtime = javaTimeNanos();
2453 if (newtime - prevtime < 0) {
2454 // time moving backwards, should only happen if no monotonic clock
2455 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2456 assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2457 } else {
2458 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2459 }
2461 if(millis <= 0) break ;
2463 prevtime = newtime;
2464 slp->park(millis);
2465 }
2466 return OS_OK ;
2467 }
2468 }
2470 int os::naked_sleep() {
2471 // %% make the sleep time an integer flag. for now use 1 millisec.
2472 return os::sleep(Thread::current(), 1, false);
2473 }
2475 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2476 void os::infinite_sleep() {
2477 while (true) { // sleep forever ...
2478 ::sleep(100); // ... 100 seconds at a time
2479 }
2480 }
2482 // Used to convert frequent JVM_Yield() to nops
2483 bool os::dont_yield() {
2484 return DontYieldALot;
2485 }
2487 void os::yield() {
2488 sched_yield();
2489 }
2491 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
2493 void os::yield_all(int attempts) {
2494 // Yields to all threads, including threads with lower priorities
2495 // Threads on Bsd are all with same priority. The Solaris style
2496 // os::yield_all() with nanosleep(1ms) is not necessary.
2497 sched_yield();
2498 }
2500 // Called from the tight loops to possibly influence time-sharing heuristics
2501 void os::loop_breaker(int attempts) {
2502 os::yield_all(attempts);
2503 }
2505 ////////////////////////////////////////////////////////////////////////////////
2506 // thread priority support
2508 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2509 // only supports dynamic priority, static priority must be zero. For real-time
2510 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2511 // However, for large multi-threaded applications, SCHED_RR is not only slower
2512 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2513 // of 5 runs - Sep 2005).
2514 //
2515 // The following code actually changes the niceness of kernel-thread/LWP. It
2516 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2517 // not the entire user process, and user level threads are 1:1 mapped to kernel
2518 // threads. It has always been the case, but could change in the future. For
2519 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2520 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2522 #if !defined(__APPLE__)
2523 int os::java_to_os_priority[CriticalPriority + 1] = {
2524 19, // 0 Entry should never be used
2526 0, // 1 MinPriority
2527 3, // 2
2528 6, // 3
2530 10, // 4
2531 15, // 5 NormPriority
2532 18, // 6
2534 21, // 7
2535 25, // 8
2536 28, // 9 NearMaxPriority
2538 31, // 10 MaxPriority
2540 31 // 11 CriticalPriority
2541 };
2542 #else
2543 /* Using Mach high-level priority assignments */
2544 int os::java_to_os_priority[CriticalPriority + 1] = {
2545 0, // 0 Entry should never be used (MINPRI_USER)
2547 27, // 1 MinPriority
2548 28, // 2
2549 29, // 3
2551 30, // 4
2552 31, // 5 NormPriority (BASEPRI_DEFAULT)
2553 32, // 6
2555 33, // 7
2556 34, // 8
2557 35, // 9 NearMaxPriority
2559 36, // 10 MaxPriority
2561 36 // 11 CriticalPriority
2562 };
2563 #endif
2565 static int prio_init() {
2566 if (ThreadPriorityPolicy == 1) {
2567 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2568 // if effective uid is not root. Perhaps, a more elegant way of doing
2569 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2570 if (geteuid() != 0) {
2571 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2572 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2573 }
2574 ThreadPriorityPolicy = 0;
2575 }
2576 }
2577 if (UseCriticalJavaThreadPriority) {
2578 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2579 }
2580 return 0;
2581 }
2583 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2584 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
2586 #ifdef __OpenBSD__
2587 // OpenBSD pthread_setprio starves low priority threads
2588 return OS_OK;
2589 #elif defined(__FreeBSD__)
2590 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2591 #elif defined(__APPLE__) || defined(__NetBSD__)
2592 struct sched_param sp;
2593 int policy;
2594 pthread_t self = pthread_self();
2596 if (pthread_getschedparam(self, &policy, &sp) != 0)
2597 return OS_ERR;
2599 sp.sched_priority = newpri;
2600 if (pthread_setschedparam(self, policy, &sp) != 0)
2601 return OS_ERR;
2603 return OS_OK;
2604 #else
2605 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2606 return (ret == 0) ? OS_OK : OS_ERR;
2607 #endif
2608 }
2610 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2611 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
2612 *priority_ptr = java_to_os_priority[NormPriority];
2613 return OS_OK;
2614 }
2616 errno = 0;
2617 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2618 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2619 #elif defined(__APPLE__) || defined(__NetBSD__)
2620 int policy;
2621 struct sched_param sp;
2623 pthread_getschedparam(pthread_self(), &policy, &sp);
2624 *priority_ptr = sp.sched_priority;
2625 #else
2626 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2627 #endif
2628 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2629 }
2631 // Hint to the underlying OS that a task switch would not be good.
2632 // Void return because it's a hint and can fail.
2633 void os::hint_no_preempt() {}
2635 ////////////////////////////////////////////////////////////////////////////////
2636 // suspend/resume support
2638 // the low-level signal-based suspend/resume support is a remnant from the
2639 // old VM-suspension that used to be for java-suspension, safepoints etc,
2640 // within hotspot. Now there is a single use-case for this:
2641 // - calling get_thread_pc() on the VMThread by the flat-profiler task
2642 // that runs in the watcher thread.
2643 // The remaining code is greatly simplified from the more general suspension
2644 // code that used to be used.
2645 //
2646 // The protocol is quite simple:
2647 // - suspend:
2648 // - sends a signal to the target thread
2649 // - polls the suspend state of the osthread using a yield loop
2650 // - target thread signal handler (SR_handler) sets suspend state
2651 // and blocks in sigsuspend until continued
2652 // - resume:
2653 // - sets target osthread state to continue
2654 // - sends signal to end the sigsuspend loop in the SR_handler
2655 //
2656 // Note that the SR_lock plays no role in this suspend/resume protocol.
2657 //
2659 static void resume_clear_context(OSThread *osthread) {
2660 osthread->set_ucontext(NULL);
2661 osthread->set_siginfo(NULL);
2663 // notify the suspend action is completed, we have now resumed
2664 osthread->sr.clear_suspended();
2665 }
2667 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2668 osthread->set_ucontext(context);
2669 osthread->set_siginfo(siginfo);
2670 }
2672 //
2673 // Handler function invoked when a thread's execution is suspended or
2674 // resumed. We have to be careful that only async-safe functions are
2675 // called here (Note: most pthread functions are not async safe and
2676 // should be avoided.)
2677 //
2678 // Note: sigwait() is a more natural fit than sigsuspend() from an
2679 // interface point of view, but sigwait() prevents the signal hander
2680 // from being run. libpthread would get very confused by not having
2681 // its signal handlers run and prevents sigwait()'s use with the
2682 // mutex granting granting signal.
2683 //
2684 // Currently only ever called on the VMThread
2685 //
2686 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2687 // Save and restore errno to avoid confusing native code with EINTR
2688 // after sigsuspend.
2689 int old_errno = errno;
2691 Thread* thread = Thread::current();
2692 OSThread* osthread = thread->osthread();
2693 assert(thread->is_VM_thread(), "Must be VMThread");
2694 // read current suspend action
2695 int action = osthread->sr.suspend_action();
2696 if (action == os::Bsd::SuspendResume::SR_SUSPEND) {
2697 suspend_save_context(osthread, siginfo, context);
2699 // Notify the suspend action is about to be completed. do_suspend()
2700 // waits until SR_SUSPENDED is set and then returns. We will wait
2701 // here for a resume signal and that completes the suspend-other
2702 // action. do_suspend/do_resume is always called as a pair from
2703 // the same thread - so there are no races
2705 // notify the caller
2706 osthread->sr.set_suspended();
2708 sigset_t suspend_set; // signals for sigsuspend()
2710 // get current set of blocked signals and unblock resume signal
2711 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2712 sigdelset(&suspend_set, SR_signum);
2714 // wait here until we are resumed
2715 do {
2716 sigsuspend(&suspend_set);
2717 // ignore all returns until we get a resume signal
2718 } while (osthread->sr.suspend_action() != os::Bsd::SuspendResume::SR_CONTINUE);
2720 resume_clear_context(osthread);
2722 } else {
2723 assert(action == os::Bsd::SuspendResume::SR_CONTINUE, "unexpected sr action");
2724 // nothing special to do - just leave the handler
2725 }
2727 errno = old_errno;
2728 }
2731 static int SR_initialize() {
2732 struct sigaction act;
2733 char *s;
2734 /* Get signal number to use for suspend/resume */
2735 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2736 int sig = ::strtol(s, 0, 10);
2737 if (sig > 0 || sig < NSIG) {
2738 SR_signum = sig;
2739 }
2740 }
2742 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2743 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2745 sigemptyset(&SR_sigset);
2746 sigaddset(&SR_sigset, SR_signum);
2748 /* Set up signal handler for suspend/resume */
2749 act.sa_flags = SA_RESTART|SA_SIGINFO;
2750 act.sa_handler = (void (*)(int)) SR_handler;
2752 // SR_signum is blocked by default.
2753 // 4528190 - We also need to block pthread restart signal (32 on all
2754 // supported Bsd platforms). Note that BsdThreads need to block
2755 // this signal for all threads to work properly. So we don't have
2756 // to use hard-coded signal number when setting up the mask.
2757 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2759 if (sigaction(SR_signum, &act, 0) == -1) {
2760 return -1;
2761 }
2763 // Save signal flag
2764 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2765 return 0;
2766 }
2769 // returns true on success and false on error - really an error is fatal
2770 // but this seems the normal response to library errors
2771 static bool do_suspend(OSThread* osthread) {
2772 // mark as suspended and send signal
2773 osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_SUSPEND);
2774 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2775 assert_status(status == 0, status, "pthread_kill");
2777 // check status and wait until notified of suspension
2778 if (status == 0) {
2779 for (int i = 0; !osthread->sr.is_suspended(); i++) {
2780 os::yield_all(i);
2781 }
2782 osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
2783 return true;
2784 }
2785 else {
2786 osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
2787 return false;
2788 }
2789 }
2791 static void do_resume(OSThread* osthread) {
2792 assert(osthread->sr.is_suspended(), "thread should be suspended");
2793 osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_CONTINUE);
2795 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2796 assert_status(status == 0, status, "pthread_kill");
2797 // check status and wait unit notified of resumption
2798 if (status == 0) {
2799 for (int i = 0; osthread->sr.is_suspended(); i++) {
2800 os::yield_all(i);
2801 }
2802 }
2803 osthread->sr.set_suspend_action(os::Bsd::SuspendResume::SR_NONE);
2804 }
2806 ////////////////////////////////////////////////////////////////////////////////
2807 // interrupt support
2809 void os::interrupt(Thread* thread) {
2810 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
2811 "possibility of dangling Thread pointer");
2813 OSThread* osthread = thread->osthread();
2815 if (!osthread->interrupted()) {
2816 osthread->set_interrupted(true);
2817 // More than one thread can get here with the same value of osthread,
2818 // resulting in multiple notifications. We do, however, want the store
2819 // to interrupted() to be visible to other threads before we execute unpark().
2820 OrderAccess::fence();
2821 ParkEvent * const slp = thread->_SleepEvent ;
2822 if (slp != NULL) slp->unpark() ;
2823 }
2825 // For JSR166. Unpark even if interrupt status already was set
2826 if (thread->is_Java_thread())
2827 ((JavaThread*)thread)->parker()->unpark();
2829 ParkEvent * ev = thread->_ParkEvent ;
2830 if (ev != NULL) ev->unpark() ;
2832 }
2834 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
2835 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
2836 "possibility of dangling Thread pointer");
2838 OSThread* osthread = thread->osthread();
2840 bool interrupted = osthread->interrupted();
2842 if (interrupted && clear_interrupted) {
2843 osthread->set_interrupted(false);
2844 // consider thread->_SleepEvent->reset() ... optional optimization
2845 }
2847 return interrupted;
2848 }
2850 ///////////////////////////////////////////////////////////////////////////////////
2851 // signal handling (except suspend/resume)
2853 // This routine may be used by user applications as a "hook" to catch signals.
2854 // The user-defined signal handler must pass unrecognized signals to this
2855 // routine, and if it returns true (non-zero), then the signal handler must
2856 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2857 // routine will never retun false (zero), but instead will execute a VM panic
2858 // routine kill the process.
2859 //
2860 // If this routine returns false, it is OK to call it again. This allows
2861 // the user-defined signal handler to perform checks either before or after
2862 // the VM performs its own checks. Naturally, the user code would be making
2863 // a serious error if it tried to handle an exception (such as a null check
2864 // or breakpoint) that the VM was generating for its own correct operation.
2865 //
2866 // This routine may recognize any of the following kinds of signals:
2867 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2868 // It should be consulted by handlers for any of those signals.
2869 //
2870 // The caller of this routine must pass in the three arguments supplied
2871 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2872 // field of the structure passed to sigaction(). This routine assumes that
2873 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2874 //
2875 // Note that the VM will print warnings if it detects conflicting signal
2876 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2877 //
2878 extern "C" JNIEXPORT int
2879 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2880 void* ucontext, int abort_if_unrecognized);
2882 void signalHandler(int sig, siginfo_t* info, void* uc) {
2883 assert(info != NULL && uc != NULL, "it must be old kernel");
2884 int orig_errno = errno; // Preserve errno value over signal handler.
2885 JVM_handle_bsd_signal(sig, info, uc, true);
2886 errno = orig_errno;
2887 }
2890 // This boolean allows users to forward their own non-matching signals
2891 // to JVM_handle_bsd_signal, harmlessly.
2892 bool os::Bsd::signal_handlers_are_installed = false;
2894 // For signal-chaining
2895 struct sigaction os::Bsd::sigact[MAXSIGNUM];
2896 unsigned int os::Bsd::sigs = 0;
2897 bool os::Bsd::libjsig_is_loaded = false;
2898 typedef struct sigaction *(*get_signal_t)(int);
2899 get_signal_t os::Bsd::get_signal_action = NULL;
2901 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2902 struct sigaction *actp = NULL;
2904 if (libjsig_is_loaded) {
2905 // Retrieve the old signal handler from libjsig
2906 actp = (*get_signal_action)(sig);
2907 }
2908 if (actp == NULL) {
2909 // Retrieve the preinstalled signal handler from jvm
2910 actp = get_preinstalled_handler(sig);
2911 }
2913 return actp;
2914 }
2916 static bool call_chained_handler(struct sigaction *actp, int sig,
2917 siginfo_t *siginfo, void *context) {
2918 // Call the old signal handler
2919 if (actp->sa_handler == SIG_DFL) {
2920 // It's more reasonable to let jvm treat it as an unexpected exception
2921 // instead of taking the default action.
2922 return false;
2923 } else if (actp->sa_handler != SIG_IGN) {
2924 if ((actp->sa_flags & SA_NODEFER) == 0) {
2925 // automaticlly block the signal
2926 sigaddset(&(actp->sa_mask), sig);
2927 }
2929 sa_handler_t hand;
2930 sa_sigaction_t sa;
2931 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
2932 // retrieve the chained handler
2933 if (siginfo_flag_set) {
2934 sa = actp->sa_sigaction;
2935 } else {
2936 hand = actp->sa_handler;
2937 }
2939 if ((actp->sa_flags & SA_RESETHAND) != 0) {
2940 actp->sa_handler = SIG_DFL;
2941 }
2943 // try to honor the signal mask
2944 sigset_t oset;
2945 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
2947 // call into the chained handler
2948 if (siginfo_flag_set) {
2949 (*sa)(sig, siginfo, context);
2950 } else {
2951 (*hand)(sig);
2952 }
2954 // restore the signal mask
2955 pthread_sigmask(SIG_SETMASK, &oset, 0);
2956 }
2957 // Tell jvm's signal handler the signal is taken care of.
2958 return true;
2959 }
2961 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
2962 bool chained = false;
2963 // signal-chaining
2964 if (UseSignalChaining) {
2965 struct sigaction *actp = get_chained_signal_action(sig);
2966 if (actp != NULL) {
2967 chained = call_chained_handler(actp, sig, siginfo, context);
2968 }
2969 }
2970 return chained;
2971 }
2973 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
2974 if ((( (unsigned int)1 << sig ) & sigs) != 0) {
2975 return &sigact[sig];
2976 }
2977 return NULL;
2978 }
2980 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
2981 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2982 sigact[sig] = oldAct;
2983 sigs |= (unsigned int)1 << sig;
2984 }
2986 // for diagnostic
2987 int os::Bsd::sigflags[MAXSIGNUM];
2989 int os::Bsd::get_our_sigflags(int sig) {
2990 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2991 return sigflags[sig];
2992 }
2994 void os::Bsd::set_our_sigflags(int sig, int flags) {
2995 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2996 sigflags[sig] = flags;
2997 }
2999 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3000 // Check for overwrite.
3001 struct sigaction oldAct;
3002 sigaction(sig, (struct sigaction*)NULL, &oldAct);
3004 void* oldhand = oldAct.sa_sigaction
3005 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3006 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3007 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3008 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3009 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3010 if (AllowUserSignalHandlers || !set_installed) {
3011 // Do not overwrite; user takes responsibility to forward to us.
3012 return;
3013 } else if (UseSignalChaining) {
3014 // save the old handler in jvm
3015 save_preinstalled_handler(sig, oldAct);
3016 // libjsig also interposes the sigaction() call below and saves the
3017 // old sigaction on it own.
3018 } else {
3019 fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3020 "%#lx for signal %d.", (long)oldhand, sig));
3021 }
3022 }
3024 struct sigaction sigAct;
3025 sigfillset(&(sigAct.sa_mask));
3026 sigAct.sa_handler = SIG_DFL;
3027 if (!set_installed) {
3028 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3029 } else {
3030 sigAct.sa_sigaction = signalHandler;
3031 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3032 }
3033 #if __APPLE__
3034 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3035 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3036 // if the signal handler declares it will handle it on alternate stack.
3037 // Notice we only declare we will handle it on alt stack, but we are not
3038 // actually going to use real alt stack - this is just a workaround.
3039 // Please see ux_exception.c, method catch_mach_exception_raise for details
3040 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3041 if (sig == SIGSEGV) {
3042 sigAct.sa_flags |= SA_ONSTACK;
3043 }
3044 #endif
3046 // Save flags, which are set by ours
3047 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3048 sigflags[sig] = sigAct.sa_flags;
3050 int ret = sigaction(sig, &sigAct, &oldAct);
3051 assert(ret == 0, "check");
3053 void* oldhand2 = oldAct.sa_sigaction
3054 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3055 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3056 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3057 }
3059 // install signal handlers for signals that HotSpot needs to
3060 // handle in order to support Java-level exception handling.
3062 void os::Bsd::install_signal_handlers() {
3063 if (!signal_handlers_are_installed) {
3064 signal_handlers_are_installed = true;
3066 // signal-chaining
3067 typedef void (*signal_setting_t)();
3068 signal_setting_t begin_signal_setting = NULL;
3069 signal_setting_t end_signal_setting = NULL;
3070 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3071 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3072 if (begin_signal_setting != NULL) {
3073 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3074 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3075 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3076 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3077 libjsig_is_loaded = true;
3078 assert(UseSignalChaining, "should enable signal-chaining");
3079 }
3080 if (libjsig_is_loaded) {
3081 // Tell libjsig jvm is setting signal handlers
3082 (*begin_signal_setting)();
3083 }
3085 set_signal_handler(SIGSEGV, true);
3086 set_signal_handler(SIGPIPE, true);
3087 set_signal_handler(SIGBUS, true);
3088 set_signal_handler(SIGILL, true);
3089 set_signal_handler(SIGFPE, true);
3090 set_signal_handler(SIGXFSZ, true);
3092 #if defined(__APPLE__)
3093 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3094 // signals caught and handled by the JVM. To work around this, we reset the mach task
3095 // signal handler that's placed on our process by CrashReporter. This disables
3096 // CrashReporter-based reporting.
3097 //
3098 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3099 // on caught fatal signals.
3100 //
3101 // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3102 // handlers. By replacing the existing task exception handler, we disable gdb's mach
3103 // exception handling, while leaving the standard BSD signal handlers functional.
3104 kern_return_t kr;
3105 kr = task_set_exception_ports(mach_task_self(),
3106 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3107 MACH_PORT_NULL,
3108 EXCEPTION_STATE_IDENTITY,
3109 MACHINE_THREAD_STATE);
3111 assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3112 #endif
3114 if (libjsig_is_loaded) {
3115 // Tell libjsig jvm finishes setting signal handlers
3116 (*end_signal_setting)();
3117 }
3119 // We don't activate signal checker if libjsig is in place, we trust ourselves
3120 // and if UserSignalHandler is installed all bets are off
3121 if (CheckJNICalls) {
3122 if (libjsig_is_loaded) {
3123 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3124 check_signals = false;
3125 }
3126 if (AllowUserSignalHandlers) {
3127 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3128 check_signals = false;
3129 }
3130 }
3131 }
3132 }
3135 /////
3136 // glibc on Bsd platform uses non-documented flag
3137 // to indicate, that some special sort of signal
3138 // trampoline is used.
3139 // We will never set this flag, and we should
3140 // ignore this flag in our diagnostic
3141 #ifdef SIGNIFICANT_SIGNAL_MASK
3142 #undef SIGNIFICANT_SIGNAL_MASK
3143 #endif
3144 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3146 static const char* get_signal_handler_name(address handler,
3147 char* buf, int buflen) {
3148 int offset;
3149 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3150 if (found) {
3151 // skip directory names
3152 const char *p1, *p2;
3153 p1 = buf;
3154 size_t len = strlen(os::file_separator());
3155 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3156 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3157 } else {
3158 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3159 }
3160 return buf;
3161 }
3163 static void print_signal_handler(outputStream* st, int sig,
3164 char* buf, size_t buflen) {
3165 struct sigaction sa;
3167 sigaction(sig, NULL, &sa);
3169 // See comment for SIGNIFICANT_SIGNAL_MASK define
3170 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3172 st->print("%s: ", os::exception_name(sig, buf, buflen));
3174 address handler = (sa.sa_flags & SA_SIGINFO)
3175 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3176 : CAST_FROM_FN_PTR(address, sa.sa_handler);
3178 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3179 st->print("SIG_DFL");
3180 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3181 st->print("SIG_IGN");
3182 } else {
3183 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3184 }
3186 st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask);
3188 address rh = VMError::get_resetted_sighandler(sig);
3189 // May be, handler was resetted by VMError?
3190 if(rh != NULL) {
3191 handler = rh;
3192 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3193 }
3195 st->print(", sa_flags=" PTR32_FORMAT, sa.sa_flags);
3197 // Check: is it our handler?
3198 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3199 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3200 // It is our signal handler
3201 // check for flags, reset system-used one!
3202 if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3203 st->print(
3204 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3205 os::Bsd::get_our_sigflags(sig));
3206 }
3207 }
3208 st->cr();
3209 }
3212 #define DO_SIGNAL_CHECK(sig) \
3213 if (!sigismember(&check_signal_done, sig)) \
3214 os::Bsd::check_signal_handler(sig)
3216 // This method is a periodic task to check for misbehaving JNI applications
3217 // under CheckJNI, we can add any periodic checks here
3219 void os::run_periodic_checks() {
3221 if (check_signals == false) return;
3223 // SEGV and BUS if overridden could potentially prevent
3224 // generation of hs*.log in the event of a crash, debugging
3225 // such a case can be very challenging, so we absolutely
3226 // check the following for a good measure:
3227 DO_SIGNAL_CHECK(SIGSEGV);
3228 DO_SIGNAL_CHECK(SIGILL);
3229 DO_SIGNAL_CHECK(SIGFPE);
3230 DO_SIGNAL_CHECK(SIGBUS);
3231 DO_SIGNAL_CHECK(SIGPIPE);
3232 DO_SIGNAL_CHECK(SIGXFSZ);
3235 // ReduceSignalUsage allows the user to override these handlers
3236 // see comments at the very top and jvm_solaris.h
3237 if (!ReduceSignalUsage) {
3238 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3239 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3240 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3241 DO_SIGNAL_CHECK(BREAK_SIGNAL);
3242 }
3244 DO_SIGNAL_CHECK(SR_signum);
3245 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3246 }
3248 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3250 static os_sigaction_t os_sigaction = NULL;
3252 void os::Bsd::check_signal_handler(int sig) {
3253 char buf[O_BUFLEN];
3254 address jvmHandler = NULL;
3257 struct sigaction act;
3258 if (os_sigaction == NULL) {
3259 // only trust the default sigaction, in case it has been interposed
3260 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3261 if (os_sigaction == NULL) return;
3262 }
3264 os_sigaction(sig, (struct sigaction*)NULL, &act);
3267 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3269 address thisHandler = (act.sa_flags & SA_SIGINFO)
3270 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3271 : CAST_FROM_FN_PTR(address, act.sa_handler) ;
3274 switch(sig) {
3275 case SIGSEGV:
3276 case SIGBUS:
3277 case SIGFPE:
3278 case SIGPIPE:
3279 case SIGILL:
3280 case SIGXFSZ:
3281 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3282 break;
3284 case SHUTDOWN1_SIGNAL:
3285 case SHUTDOWN2_SIGNAL:
3286 case SHUTDOWN3_SIGNAL:
3287 case BREAK_SIGNAL:
3288 jvmHandler = (address)user_handler();
3289 break;
3291 case INTERRUPT_SIGNAL:
3292 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3293 break;
3295 default:
3296 if (sig == SR_signum) {
3297 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3298 } else {
3299 return;
3300 }
3301 break;
3302 }
3304 if (thisHandler != jvmHandler) {
3305 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3306 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3307 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3308 // No need to check this sig any longer
3309 sigaddset(&check_signal_done, sig);
3310 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3311 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3312 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3313 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags);
3314 // No need to check this sig any longer
3315 sigaddset(&check_signal_done, sig);
3316 }
3318 // Dump all the signal
3319 if (sigismember(&check_signal_done, sig)) {
3320 print_signal_handlers(tty, buf, O_BUFLEN);
3321 }
3322 }
3324 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
3326 extern bool signal_name(int signo, char* buf, size_t len);
3328 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3329 if (0 < exception_code && exception_code <= SIGRTMAX) {
3330 // signal
3331 if (!signal_name(exception_code, buf, size)) {
3332 jio_snprintf(buf, size, "SIG%d", exception_code);
3333 }
3334 return buf;
3335 } else {
3336 return NULL;
3337 }
3338 }
3340 // this is called _before_ the most of global arguments have been parsed
3341 void os::init(void) {
3342 char dummy; /* used to get a guess on initial stack address */
3343 // first_hrtime = gethrtime();
3345 // With BsdThreads the JavaMain thread pid (primordial thread)
3346 // is different than the pid of the java launcher thread.
3347 // So, on Bsd, the launcher thread pid is passed to the VM
3348 // via the sun.java.launcher.pid property.
3349 // Use this property instead of getpid() if it was correctly passed.
3350 // See bug 6351349.
3351 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3353 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3355 clock_tics_per_sec = CLK_TCK;
3357 init_random(1234567);
3359 ThreadCritical::initialize();
3361 Bsd::set_page_size(getpagesize());
3362 if (Bsd::page_size() == -1) {
3363 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3364 strerror(errno)));
3365 }
3366 init_page_sizes((size_t) Bsd::page_size());
3368 Bsd::initialize_system_info();
3370 // main_thread points to the aboriginal thread
3371 Bsd::_main_thread = pthread_self();
3373 Bsd::clock_init();
3374 initial_time_count = os::elapsed_counter();
3376 #ifdef __APPLE__
3377 // XXXDARWIN
3378 // Work around the unaligned VM callbacks in hotspot's
3379 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3380 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3381 // alignment when doing symbol lookup. To work around this, we force early
3382 // binding of all symbols now, thus binding when alignment is known-good.
3383 _dyld_bind_fully_image_containing_address((const void *) &os::init);
3384 #endif
3385 }
3387 // To install functions for atexit system call
3388 extern "C" {
3389 static void perfMemory_exit_helper() {
3390 perfMemory_exit();
3391 }
3392 }
3394 // this is called _after_ the global arguments have been parsed
3395 jint os::init_2(void)
3396 {
3397 // Allocate a single page and mark it as readable for safepoint polling
3398 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3399 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
3401 os::set_polling_page( polling_page );
3403 #ifndef PRODUCT
3404 if(Verbose && PrintMiscellaneous)
3405 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
3406 #endif
3408 if (!UseMembar) {
3409 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3410 guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page");
3411 os::set_memory_serialize_page( mem_serialize_page );
3413 #ifndef PRODUCT
3414 if(Verbose && PrintMiscellaneous)
3415 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
3416 #endif
3417 }
3419 os::large_page_init();
3421 // initialize suspend/resume support - must do this before signal_sets_init()
3422 if (SR_initialize() != 0) {
3423 perror("SR_initialize failed");
3424 return JNI_ERR;
3425 }
3427 Bsd::signal_sets_init();
3428 Bsd::install_signal_handlers();
3430 // Check minimum allowable stack size for thread creation and to initialize
3431 // the java system classes, including StackOverflowError - depends on page
3432 // size. Add a page for compiler2 recursion in main thread.
3433 // Add in 2*BytesPerWord times page size to account for VM stack during
3434 // class initialization depending on 32 or 64 bit VM.
3435 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3436 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3437 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3439 size_t threadStackSizeInBytes = ThreadStackSize * K;
3440 if (threadStackSizeInBytes != 0 &&
3441 threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3442 tty->print_cr("\nThe stack size specified is too small, "
3443 "Specify at least %dk",
3444 os::Bsd::min_stack_allowed/ K);
3445 return JNI_ERR;
3446 }
3448 // Make the stack size a multiple of the page size so that
3449 // the yellow/red zones can be guarded.
3450 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3451 vm_page_size()));
3453 if (MaxFDLimit) {
3454 // set the number of file descriptors to max. print out error
3455 // if getrlimit/setrlimit fails but continue regardless.
3456 struct rlimit nbr_files;
3457 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3458 if (status != 0) {
3459 if (PrintMiscellaneous && (Verbose || WizardMode))
3460 perror("os::init_2 getrlimit failed");
3461 } else {
3462 nbr_files.rlim_cur = nbr_files.rlim_max;
3464 #ifdef __APPLE__
3465 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3466 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3467 // be used instead
3468 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3469 #endif
3471 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3472 if (status != 0) {
3473 if (PrintMiscellaneous && (Verbose || WizardMode))
3474 perror("os::init_2 setrlimit failed");
3475 }
3476 }
3477 }
3479 // at-exit methods are called in the reverse order of their registration.
3480 // atexit functions are called on return from main or as a result of a
3481 // call to exit(3C). There can be only 32 of these functions registered
3482 // and atexit() does not set errno.
3484 if (PerfAllowAtExitRegistration) {
3485 // only register atexit functions if PerfAllowAtExitRegistration is set.
3486 // atexit functions can be delayed until process exit time, which
3487 // can be problematic for embedded VM situations. Embedded VMs should
3488 // call DestroyJavaVM() to assure that VM resources are released.
3490 // note: perfMemory_exit_helper atexit function may be removed in
3491 // the future if the appropriate cleanup code can be added to the
3492 // VM_Exit VMOperation's doit method.
3493 if (atexit(perfMemory_exit_helper) != 0) {
3494 warning("os::init2 atexit(perfMemory_exit_helper) failed");
3495 }
3496 }
3498 // initialize thread priority policy
3499 prio_init();
3501 #ifdef __APPLE__
3502 // dynamically link to objective c gc registration
3503 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3504 if (handleLibObjc != NULL) {
3505 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3506 }
3507 #endif
3509 return JNI_OK;
3510 }
3512 // this is called at the end of vm_initialization
3513 void os::init_3(void) { }
3515 // Mark the polling page as unreadable
3516 void os::make_polling_page_unreadable(void) {
3517 if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
3518 fatal("Could not disable polling page");
3519 };
3521 // Mark the polling page as readable
3522 void os::make_polling_page_readable(void) {
3523 if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3524 fatal("Could not enable polling page");
3525 }
3526 };
3528 int os::active_processor_count() {
3529 return _processor_count;
3530 }
3532 void os::set_native_thread_name(const char *name) {
3533 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3534 // This is only supported in Snow Leopard and beyond
3535 if (name != NULL) {
3536 // Add a "Java: " prefix to the name
3537 char buf[MAXTHREADNAMESIZE];
3538 snprintf(buf, sizeof(buf), "Java: %s", name);
3539 pthread_setname_np(buf);
3540 }
3541 #endif
3542 }
3544 bool os::distribute_processes(uint length, uint* distribution) {
3545 // Not yet implemented.
3546 return false;
3547 }
3549 bool os::bind_to_processor(uint processor_id) {
3550 // Not yet implemented.
3551 return false;
3552 }
3554 ///
3556 // Suspends the target using the signal mechanism and then grabs the PC before
3557 // resuming the target. Used by the flat-profiler only
3558 ExtendedPC os::get_thread_pc(Thread* thread) {
3559 // Make sure that it is called by the watcher for the VMThread
3560 assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3561 assert(thread->is_VM_thread(), "Can only be called for VMThread");
3563 ExtendedPC epc;
3565 OSThread* osthread = thread->osthread();
3566 if (do_suspend(osthread)) {
3567 if (osthread->ucontext() != NULL) {
3568 epc = os::Bsd::ucontext_get_pc(osthread->ucontext());
3569 } else {
3570 // NULL context is unexpected, double-check this is the VMThread
3571 guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3572 }
3573 do_resume(osthread);
3574 }
3575 // failure means pthread_kill failed for some reason - arguably this is
3576 // a fatal problem, but such problems are ignored elsewhere
3578 return epc;
3579 }
3581 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
3582 {
3583 return pthread_cond_timedwait(_cond, _mutex, _abstime);
3584 }
3586 ////////////////////////////////////////////////////////////////////////////////
3587 // debug support
3589 bool os::find(address addr, outputStream* st) {
3590 Dl_info dlinfo;
3591 memset(&dlinfo, 0, sizeof(dlinfo));
3592 if (dladdr(addr, &dlinfo)) {
3593 st->print(PTR_FORMAT ": ", addr);
3594 if (dlinfo.dli_sname != NULL) {
3595 st->print("%s+%#x", dlinfo.dli_sname,
3596 addr - (intptr_t)dlinfo.dli_saddr);
3597 } else if (dlinfo.dli_fname) {
3598 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3599 } else {
3600 st->print("<absolute address>");
3601 }
3602 if (dlinfo.dli_fname) {
3603 st->print(" in %s", dlinfo.dli_fname);
3604 }
3605 if (dlinfo.dli_fbase) {
3606 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3607 }
3608 st->cr();
3610 if (Verbose) {
3611 // decode some bytes around the PC
3612 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3613 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3614 address lowest = (address) dlinfo.dli_sname;
3615 if (!lowest) lowest = (address) dlinfo.dli_fbase;
3616 if (begin < lowest) begin = lowest;
3617 Dl_info dlinfo2;
3618 if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr
3619 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
3620 end = (address) dlinfo2.dli_saddr;
3621 Disassembler::decode(begin, end, st);
3622 }
3623 return true;
3624 }
3625 return false;
3626 }
3628 ////////////////////////////////////////////////////////////////////////////////
3629 // misc
3631 // This does not do anything on Bsd. This is basically a hook for being
3632 // able to use structured exception handling (thread-local exception filters)
3633 // on, e.g., Win32.
3634 void
3635 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
3636 JavaCallArguments* args, Thread* thread) {
3637 f(value, method, args, thread);
3638 }
3640 void os::print_statistics() {
3641 }
3643 int os::message_box(const char* title, const char* message) {
3644 int i;
3645 fdStream err(defaultStream::error_fd());
3646 for (i = 0; i < 78; i++) err.print_raw("=");
3647 err.cr();
3648 err.print_raw_cr(title);
3649 for (i = 0; i < 78; i++) err.print_raw("-");
3650 err.cr();
3651 err.print_raw_cr(message);
3652 for (i = 0; i < 78; i++) err.print_raw("=");
3653 err.cr();
3655 char buf[16];
3656 // Prevent process from exiting upon "read error" without consuming all CPU
3657 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3659 return buf[0] == 'y' || buf[0] == 'Y';
3660 }
3662 int os::stat(const char *path, struct stat *sbuf) {
3663 char pathbuf[MAX_PATH];
3664 if (strlen(path) > MAX_PATH - 1) {
3665 errno = ENAMETOOLONG;
3666 return -1;
3667 }
3668 os::native_path(strcpy(pathbuf, path));
3669 return ::stat(pathbuf, sbuf);
3670 }
3672 bool os::check_heap(bool force) {
3673 return true;
3674 }
3676 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
3677 return ::vsnprintf(buf, count, format, args);
3678 }
3680 // Is a (classpath) directory empty?
3681 bool os::dir_is_empty(const char* path) {
3682 DIR *dir = NULL;
3683 struct dirent *ptr;
3685 dir = opendir(path);
3686 if (dir == NULL) return true;
3688 /* Scan the directory */
3689 bool result = true;
3690 char buf[sizeof(struct dirent) + MAX_PATH];
3691 while (result && (ptr = ::readdir(dir)) != NULL) {
3692 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3693 result = false;
3694 }
3695 }
3696 closedir(dir);
3697 return result;
3698 }
3700 // This code originates from JDK's sysOpen and open64_w
3701 // from src/solaris/hpi/src/system_md.c
3703 #ifndef O_DELETE
3704 #define O_DELETE 0x10000
3705 #endif
3707 // Open a file. Unlink the file immediately after open returns
3708 // if the specified oflag has the O_DELETE flag set.
3709 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
3711 int os::open(const char *path, int oflag, int mode) {
3713 if (strlen(path) > MAX_PATH - 1) {
3714 errno = ENAMETOOLONG;
3715 return -1;
3716 }
3717 int fd;
3718 int o_delete = (oflag & O_DELETE);
3719 oflag = oflag & ~O_DELETE;
3721 fd = ::open(path, oflag, mode);
3722 if (fd == -1) return -1;
3724 //If the open succeeded, the file might still be a directory
3725 {
3726 struct stat buf;
3727 int ret = ::fstat(fd, &buf);
3728 int st_mode = buf.st_mode;
3730 if (ret != -1) {
3731 if ((st_mode & S_IFMT) == S_IFDIR) {
3732 errno = EISDIR;
3733 ::close(fd);
3734 return -1;
3735 }
3736 } else {
3737 ::close(fd);
3738 return -1;
3739 }
3740 }
3742 /*
3743 * All file descriptors that are opened in the JVM and not
3744 * specifically destined for a subprocess should have the
3745 * close-on-exec flag set. If we don't set it, then careless 3rd
3746 * party native code might fork and exec without closing all
3747 * appropriate file descriptors (e.g. as we do in closeDescriptors in
3748 * UNIXProcess.c), and this in turn might:
3749 *
3750 * - cause end-of-file to fail to be detected on some file
3751 * descriptors, resulting in mysterious hangs, or
3752 *
3753 * - might cause an fopen in the subprocess to fail on a system
3754 * suffering from bug 1085341.
3755 *
3756 * (Yes, the default setting of the close-on-exec flag is a Unix
3757 * design flaw)
3758 *
3759 * See:
3760 * 1085341: 32-bit stdio routines should support file descriptors >255
3761 * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3762 * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3763 */
3764 #ifdef FD_CLOEXEC
3765 {
3766 int flags = ::fcntl(fd, F_GETFD);
3767 if (flags != -1)
3768 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3769 }
3770 #endif
3772 if (o_delete != 0) {
3773 ::unlink(path);
3774 }
3775 return fd;
3776 }
3779 // create binary file, rewriting existing file if required
3780 int os::create_binary_file(const char* path, bool rewrite_existing) {
3781 int oflags = O_WRONLY | O_CREAT;
3782 if (!rewrite_existing) {
3783 oflags |= O_EXCL;
3784 }
3785 return ::open(path, oflags, S_IREAD | S_IWRITE);
3786 }
3788 // return current position of file pointer
3789 jlong os::current_file_offset(int fd) {
3790 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3791 }
3793 // move file pointer to the specified offset
3794 jlong os::seek_to_file_offset(int fd, jlong offset) {
3795 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3796 }
3798 // This code originates from JDK's sysAvailable
3799 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3801 int os::available(int fd, jlong *bytes) {
3802 jlong cur, end;
3803 int mode;
3804 struct stat buf;
3806 if (::fstat(fd, &buf) >= 0) {
3807 mode = buf.st_mode;
3808 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3809 /*
3810 * XXX: is the following call interruptible? If so, this might
3811 * need to go through the INTERRUPT_IO() wrapper as for other
3812 * blocking, interruptible calls in this file.
3813 */
3814 int n;
3815 if (::ioctl(fd, FIONREAD, &n) >= 0) {
3816 *bytes = n;
3817 return 1;
3818 }
3819 }
3820 }
3821 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3822 return 0;
3823 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3824 return 0;
3825 } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3826 return 0;
3827 }
3828 *bytes = end - cur;
3829 return 1;
3830 }
3832 int os::socket_available(int fd, jint *pbytes) {
3833 if (fd < 0)
3834 return OS_OK;
3836 int ret;
3838 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
3840 //%% note ioctl can return 0 when successful, JVM_SocketAvailable
3841 // is expected to return 0 on failure and 1 on success to the jdk.
3843 return (ret == OS_ERR) ? 0 : 1;
3844 }
3846 // Map a block of memory.
3847 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3848 char *addr, size_t bytes, bool read_only,
3849 bool allow_exec) {
3850 int prot;
3851 int flags;
3853 if (read_only) {
3854 prot = PROT_READ;
3855 flags = MAP_SHARED;
3856 } else {
3857 prot = PROT_READ | PROT_WRITE;
3858 flags = MAP_PRIVATE;
3859 }
3861 if (allow_exec) {
3862 prot |= PROT_EXEC;
3863 }
3865 if (addr != NULL) {
3866 flags |= MAP_FIXED;
3867 }
3869 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3870 fd, file_offset);
3871 if (mapped_address == MAP_FAILED) {
3872 return NULL;
3873 }
3874 return mapped_address;
3875 }
3878 // Remap a block of memory.
3879 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3880 char *addr, size_t bytes, bool read_only,
3881 bool allow_exec) {
3882 // same as map_memory() on this OS
3883 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3884 allow_exec);
3885 }
3888 // Unmap a block of memory.
3889 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3890 return munmap(addr, bytes) == 0;
3891 }
3893 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3894 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3895 // of a thread.
3896 //
3897 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3898 // the fast estimate available on the platform.
3900 jlong os::current_thread_cpu_time() {
3901 #ifdef __APPLE__
3902 return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3903 #else
3904 Unimplemented();
3905 return 0;
3906 #endif
3907 }
3909 jlong os::thread_cpu_time(Thread* thread) {
3910 #ifdef __APPLE__
3911 return os::thread_cpu_time(thread, true /* user + sys */);
3912 #else
3913 Unimplemented();
3914 return 0;
3915 #endif
3916 }
3918 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3919 #ifdef __APPLE__
3920 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3921 #else
3922 Unimplemented();
3923 return 0;
3924 #endif
3925 }
3927 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3928 #ifdef __APPLE__
3929 struct thread_basic_info tinfo;
3930 mach_msg_type_number_t tcount = THREAD_INFO_MAX;
3931 kern_return_t kr;
3932 thread_t mach_thread;
3934 mach_thread = thread->osthread()->thread_id();
3935 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
3936 if (kr != KERN_SUCCESS)
3937 return -1;
3939 if (user_sys_cpu_time) {
3940 jlong nanos;
3941 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
3942 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
3943 return nanos;
3944 } else {
3945 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
3946 }
3947 #else
3948 Unimplemented();
3949 return 0;
3950 #endif
3951 }
3954 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3955 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
3956 info_ptr->may_skip_backward = false; // elapsed time not wall time
3957 info_ptr->may_skip_forward = false; // elapsed time not wall time
3958 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
3959 }
3961 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3962 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
3963 info_ptr->may_skip_backward = false; // elapsed time not wall time
3964 info_ptr->may_skip_forward = false; // elapsed time not wall time
3965 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
3966 }
3968 bool os::is_thread_cpu_time_supported() {
3969 #ifdef __APPLE__
3970 return true;
3971 #else
3972 return false;
3973 #endif
3974 }
3976 // System loadavg support. Returns -1 if load average cannot be obtained.
3977 // Bsd doesn't yet have a (official) notion of processor sets,
3978 // so just return the system wide load average.
3979 int os::loadavg(double loadavg[], int nelem) {
3980 return ::getloadavg(loadavg, nelem);
3981 }
3983 void os::pause() {
3984 char filename[MAX_PATH];
3985 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
3986 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
3987 } else {
3988 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
3989 }
3991 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
3992 if (fd != -1) {
3993 struct stat buf;
3994 ::close(fd);
3995 while (::stat(filename, &buf) == 0) {
3996 (void)::poll(NULL, 0, 100);
3997 }
3998 } else {
3999 jio_fprintf(stderr,
4000 "Could not open pause file '%s', continuing immediately.\n", filename);
4001 }
4002 }
4005 // Refer to the comments in os_solaris.cpp park-unpark.
4006 //
4007 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4008 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4009 // For specifics regarding the bug see GLIBC BUGID 261237 :
4010 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4011 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4012 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4013 // is used. (The simple C test-case provided in the GLIBC bug report manifests the
4014 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4015 // and monitorenter when we're using 1-0 locking. All those operations may result in
4016 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version
4017 // of libpthread avoids the problem, but isn't practical.
4018 //
4019 // Possible remedies:
4020 //
4021 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work.
4022 // This is palliative and probabilistic, however. If the thread is preempted
4023 // between the call to compute_abstime() and pthread_cond_timedwait(), more
4024 // than the minimum period may have passed, and the abstime may be stale (in the
4025 // past) resultin in a hang. Using this technique reduces the odds of a hang
4026 // but the JVM is still vulnerable, particularly on heavily loaded systems.
4027 //
4028 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4029 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set
4030 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4031 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant
4032 // thread.
4033 //
4034 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread
4035 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing
4036 // a timeout request to the chron thread and then blocking via pthread_cond_wait().
4037 // This also works well. In fact it avoids kernel-level scalability impediments
4038 // on certain platforms that don't handle lots of active pthread_cond_timedwait()
4039 // timers in a graceful fashion.
4040 //
4041 // 4. When the abstime value is in the past it appears that control returns
4042 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4043 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we
4044 // can avoid the problem by reinitializing the condvar -- by cond_destroy()
4045 // followed by cond_init() -- after all calls to pthread_cond_timedwait().
4046 // It may be possible to avoid reinitialization by checking the return
4047 // value from pthread_cond_timedwait(). In addition to reinitializing the
4048 // condvar we must establish the invariant that cond_signal() is only called
4049 // within critical sections protected by the adjunct mutex. This prevents
4050 // cond_signal() from "seeing" a condvar that's in the midst of being
4051 // reinitialized or that is corrupt. Sadly, this invariant obviates the
4052 // desirable signal-after-unlock optimization that avoids futile context switching.
4053 //
4054 // I'm also concerned that some versions of NTPL might allocate an auxilliary
4055 // structure when a condvar is used or initialized. cond_destroy() would
4056 // release the helper structure. Our reinitialize-after-timedwait fix
4057 // put excessive stress on malloc/free and locks protecting the c-heap.
4058 //
4059 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag.
4060 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4061 // and only enabling the work-around for vulnerable environments.
4063 // utility to compute the abstime argument to timedwait:
4064 // millis is the relative timeout time
4065 // abstime will be the absolute timeout time
4066 // TODO: replace compute_abstime() with unpackTime()
4068 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
4069 if (millis < 0) millis = 0;
4070 struct timeval now;
4071 int status = gettimeofday(&now, NULL);
4072 assert(status == 0, "gettimeofday");
4073 jlong seconds = millis / 1000;
4074 millis %= 1000;
4075 if (seconds > 50000000) { // see man cond_timedwait(3T)
4076 seconds = 50000000;
4077 }
4078 abstime->tv_sec = now.tv_sec + seconds;
4079 long usec = now.tv_usec + millis * 1000;
4080 if (usec >= 1000000) {
4081 abstime->tv_sec += 1;
4082 usec -= 1000000;
4083 }
4084 abstime->tv_nsec = usec * 1000;
4085 return abstime;
4086 }
4089 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
4090 // Conceptually TryPark() should be equivalent to park(0).
4092 int os::PlatformEvent::TryPark() {
4093 for (;;) {
4094 const int v = _Event ;
4095 guarantee ((v == 0) || (v == 1), "invariant") ;
4096 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ;
4097 }
4098 }
4100 void os::PlatformEvent::park() { // AKA "down()"
4101 // Invariant: Only the thread associated with the Event/PlatformEvent
4102 // may call park().
4103 // TODO: assert that _Assoc != NULL or _Assoc == Self
4104 int v ;
4105 for (;;) {
4106 v = _Event ;
4107 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4108 }
4109 guarantee (v >= 0, "invariant") ;
4110 if (v == 0) {
4111 // Do this the hard way by blocking ...
4112 int status = pthread_mutex_lock(_mutex);
4113 assert_status(status == 0, status, "mutex_lock");
4114 guarantee (_nParked == 0, "invariant") ;
4115 ++ _nParked ;
4116 while (_Event < 0) {
4117 status = pthread_cond_wait(_cond, _mutex);
4118 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4119 // Treat this the same as if the wait was interrupted
4120 if (status == ETIMEDOUT) { status = EINTR; }
4121 assert_status(status == 0 || status == EINTR, status, "cond_wait");
4122 }
4123 -- _nParked ;
4125 _Event = 0 ;
4126 status = pthread_mutex_unlock(_mutex);
4127 assert_status(status == 0, status, "mutex_unlock");
4128 // Paranoia to ensure our locked and lock-free paths interact
4129 // correctly with each other.
4130 OrderAccess::fence();
4131 }
4132 guarantee (_Event >= 0, "invariant") ;
4133 }
4135 int os::PlatformEvent::park(jlong millis) {
4136 guarantee (_nParked == 0, "invariant") ;
4138 int v ;
4139 for (;;) {
4140 v = _Event ;
4141 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4142 }
4143 guarantee (v >= 0, "invariant") ;
4144 if (v != 0) return OS_OK ;
4146 // We do this the hard way, by blocking the thread.
4147 // Consider enforcing a minimum timeout value.
4148 struct timespec abst;
4149 compute_abstime(&abst, millis);
4151 int ret = OS_TIMEOUT;
4152 int status = pthread_mutex_lock(_mutex);
4153 assert_status(status == 0, status, "mutex_lock");
4154 guarantee (_nParked == 0, "invariant") ;
4155 ++_nParked ;
4157 // Object.wait(timo) will return because of
4158 // (a) notification
4159 // (b) timeout
4160 // (c) thread.interrupt
4161 //
4162 // Thread.interrupt and object.notify{All} both call Event::set.
4163 // That is, we treat thread.interrupt as a special case of notification.
4164 // The underlying Solaris implementation, cond_timedwait, admits
4165 // spurious/premature wakeups, but the JLS/JVM spec prevents the
4166 // JVM from making those visible to Java code. As such, we must
4167 // filter out spurious wakeups. We assume all ETIME returns are valid.
4168 //
4169 // TODO: properly differentiate simultaneous notify+interrupt.
4170 // In that case, we should propagate the notify to another waiter.
4172 while (_Event < 0) {
4173 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4174 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4175 pthread_cond_destroy (_cond);
4176 pthread_cond_init (_cond, NULL) ;
4177 }
4178 assert_status(status == 0 || status == EINTR ||
4179 status == ETIMEDOUT,
4180 status, "cond_timedwait");
4181 if (!FilterSpuriousWakeups) break ; // previous semantics
4182 if (status == ETIMEDOUT) break ;
4183 // We consume and ignore EINTR and spurious wakeups.
4184 }
4185 --_nParked ;
4186 if (_Event >= 0) {
4187 ret = OS_OK;
4188 }
4189 _Event = 0 ;
4190 status = pthread_mutex_unlock(_mutex);
4191 assert_status(status == 0, status, "mutex_unlock");
4192 assert (_nParked == 0, "invariant") ;
4193 // Paranoia to ensure our locked and lock-free paths interact
4194 // correctly with each other.
4195 OrderAccess::fence();
4196 return ret;
4197 }
4199 void os::PlatformEvent::unpark() {
4200 // Transitions for _Event:
4201 // 0 :=> 1
4202 // 1 :=> 1
4203 // -1 :=> either 0 or 1; must signal target thread
4204 // That is, we can safely transition _Event from -1 to either
4205 // 0 or 1. Forcing 1 is slightly more efficient for back-to-back
4206 // unpark() calls.
4207 // See also: "Semaphores in Plan 9" by Mullender & Cox
4208 //
4209 // Note: Forcing a transition from "-1" to "1" on an unpark() means
4210 // that it will take two back-to-back park() calls for the owning
4211 // thread to block. This has the benefit of forcing a spurious return
4212 // from the first park() call after an unpark() call which will help
4213 // shake out uses of park() and unpark() without condition variables.
4215 if (Atomic::xchg(1, &_Event) >= 0) return;
4217 // Wait for the thread associated with the event to vacate
4218 int status = pthread_mutex_lock(_mutex);
4219 assert_status(status == 0, status, "mutex_lock");
4220 int AnyWaiters = _nParked;
4221 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4222 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4223 AnyWaiters = 0;
4224 pthread_cond_signal(_cond);
4225 }
4226 status = pthread_mutex_unlock(_mutex);
4227 assert_status(status == 0, status, "mutex_unlock");
4228 if (AnyWaiters != 0) {
4229 status = pthread_cond_signal(_cond);
4230 assert_status(status == 0, status, "cond_signal");
4231 }
4233 // Note that we signal() _after dropping the lock for "immortal" Events.
4234 // This is safe and avoids a common class of futile wakeups. In rare
4235 // circumstances this can cause a thread to return prematurely from
4236 // cond_{timed}wait() but the spurious wakeup is benign and the victim will
4237 // simply re-test the condition and re-park itself.
4238 }
4241 // JSR166
4242 // -------------------------------------------------------
4244 /*
4245 * The solaris and bsd implementations of park/unpark are fairly
4246 * conservative for now, but can be improved. They currently use a
4247 * mutex/condvar pair, plus a a count.
4248 * Park decrements count if > 0, else does a condvar wait. Unpark
4249 * sets count to 1 and signals condvar. Only one thread ever waits
4250 * on the condvar. Contention seen when trying to park implies that someone
4251 * is unparking you, so don't wait. And spurious returns are fine, so there
4252 * is no need to track notifications.
4253 */
4255 #define MAX_SECS 100000000
4256 /*
4257 * This code is common to bsd and solaris and will be moved to a
4258 * common place in dolphin.
4259 *
4260 * The passed in time value is either a relative time in nanoseconds
4261 * or an absolute time in milliseconds. Either way it has to be unpacked
4262 * into suitable seconds and nanoseconds components and stored in the
4263 * given timespec structure.
4264 * Given time is a 64-bit value and the time_t used in the timespec is only
4265 * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4266 * overflow if times way in the future are given. Further on Solaris versions
4267 * prior to 10 there is a restriction (see cond_timedwait) that the specified
4268 * number of seconds, in abstime, is less than current_time + 100,000,000.
4269 * As it will be 28 years before "now + 100000000" will overflow we can
4270 * ignore overflow and just impose a hard-limit on seconds using the value
4271 * of "now + 100,000,000". This places a limit on the timeout of about 3.17
4272 * years from "now".
4273 */
4275 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4276 assert (time > 0, "convertTime");
4278 struct timeval now;
4279 int status = gettimeofday(&now, NULL);
4280 assert(status == 0, "gettimeofday");
4282 time_t max_secs = now.tv_sec + MAX_SECS;
4284 if (isAbsolute) {
4285 jlong secs = time / 1000;
4286 if (secs > max_secs) {
4287 absTime->tv_sec = max_secs;
4288 }
4289 else {
4290 absTime->tv_sec = secs;
4291 }
4292 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4293 }
4294 else {
4295 jlong secs = time / NANOSECS_PER_SEC;
4296 if (secs >= MAX_SECS) {
4297 absTime->tv_sec = max_secs;
4298 absTime->tv_nsec = 0;
4299 }
4300 else {
4301 absTime->tv_sec = now.tv_sec + secs;
4302 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4303 if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4304 absTime->tv_nsec -= NANOSECS_PER_SEC;
4305 ++absTime->tv_sec; // note: this must be <= max_secs
4306 }
4307 }
4308 }
4309 assert(absTime->tv_sec >= 0, "tv_sec < 0");
4310 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4311 assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4312 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4313 }
4315 void Parker::park(bool isAbsolute, jlong time) {
4316 // Ideally we'd do something useful while spinning, such
4317 // as calling unpackTime().
4319 // Optional fast-path check:
4320 // Return immediately if a permit is available.
4321 // We depend on Atomic::xchg() having full barrier semantics
4322 // since we are doing a lock-free update to _counter.
4323 if (Atomic::xchg(0, &_counter) > 0) return;
4325 Thread* thread = Thread::current();
4326 assert(thread->is_Java_thread(), "Must be JavaThread");
4327 JavaThread *jt = (JavaThread *)thread;
4329 // Optional optimization -- avoid state transitions if there's an interrupt pending.
4330 // Check interrupt before trying to wait
4331 if (Thread::is_interrupted(thread, false)) {
4332 return;
4333 }
4335 // Next, demultiplex/decode time arguments
4336 struct timespec absTime;
4337 if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
4338 return;
4339 }
4340 if (time > 0) {
4341 unpackTime(&absTime, isAbsolute, time);
4342 }
4345 // Enter safepoint region
4346 // Beware of deadlocks such as 6317397.
4347 // The per-thread Parker:: mutex is a classic leaf-lock.
4348 // In particular a thread must never block on the Threads_lock while
4349 // holding the Parker:: mutex. If safepoints are pending both the
4350 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4351 ThreadBlockInVM tbivm(jt);
4353 // Don't wait if cannot get lock since interference arises from
4354 // unblocking. Also. check interrupt before trying wait
4355 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4356 return;
4357 }
4359 int status ;
4360 if (_counter > 0) { // no wait needed
4361 _counter = 0;
4362 status = pthread_mutex_unlock(_mutex);
4363 assert (status == 0, "invariant") ;
4364 // Paranoia to ensure our locked and lock-free paths interact
4365 // correctly with each other and Java-level accesses.
4366 OrderAccess::fence();
4367 return;
4368 }
4370 #ifdef ASSERT
4371 // Don't catch signals while blocked; let the running threads have the signals.
4372 // (This allows a debugger to break into the running thread.)
4373 sigset_t oldsigs;
4374 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4375 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4376 #endif
4378 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4379 jt->set_suspend_equivalent();
4380 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4382 if (time == 0) {
4383 status = pthread_cond_wait (_cond, _mutex) ;
4384 } else {
4385 status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
4386 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4387 pthread_cond_destroy (_cond) ;
4388 pthread_cond_init (_cond, NULL);
4389 }
4390 }
4391 assert_status(status == 0 || status == EINTR ||
4392 status == ETIMEDOUT,
4393 status, "cond_timedwait");
4395 #ifdef ASSERT
4396 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4397 #endif
4399 _counter = 0 ;
4400 status = pthread_mutex_unlock(_mutex) ;
4401 assert_status(status == 0, status, "invariant") ;
4402 // Paranoia to ensure our locked and lock-free paths interact
4403 // correctly with each other and Java-level accesses.
4404 OrderAccess::fence();
4406 // If externally suspended while waiting, re-suspend
4407 if (jt->handle_special_suspend_equivalent_condition()) {
4408 jt->java_suspend_self();
4409 }
4410 }
4412 void Parker::unpark() {
4413 int s, status ;
4414 status = pthread_mutex_lock(_mutex);
4415 assert (status == 0, "invariant") ;
4416 s = _counter;
4417 _counter = 1;
4418 if (s < 1) {
4419 if (WorkAroundNPTLTimedWaitHang) {
4420 status = pthread_cond_signal (_cond) ;
4421 assert (status == 0, "invariant") ;
4422 status = pthread_mutex_unlock(_mutex);
4423 assert (status == 0, "invariant") ;
4424 } else {
4425 status = pthread_mutex_unlock(_mutex);
4426 assert (status == 0, "invariant") ;
4427 status = pthread_cond_signal (_cond) ;
4428 assert (status == 0, "invariant") ;
4429 }
4430 } else {
4431 pthread_mutex_unlock(_mutex);
4432 assert (status == 0, "invariant") ;
4433 }
4434 }
4437 /* Darwin has no "environ" in a dynamic library. */
4438 #ifdef __APPLE__
4439 #include <crt_externs.h>
4440 #define environ (*_NSGetEnviron())
4441 #else
4442 extern char** environ;
4443 #endif
4445 // Run the specified command in a separate process. Return its exit value,
4446 // or -1 on failure (e.g. can't fork a new process).
4447 // Unlike system(), this function can be called from signal handler. It
4448 // doesn't block SIGINT et al.
4449 int os::fork_and_exec(char* cmd) {
4450 const char * argv[4] = {"sh", "-c", cmd, NULL};
4452 // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4453 // pthread_atfork handlers and reset pthread library. All we need is a
4454 // separate process to execve. Make a direct syscall to fork process.
4455 // On IA64 there's no fork syscall, we have to use fork() and hope for
4456 // the best...
4457 pid_t pid = fork();
4459 if (pid < 0) {
4460 // fork failed
4461 return -1;
4463 } else if (pid == 0) {
4464 // child process
4466 // execve() in BsdThreads will call pthread_kill_other_threads_np()
4467 // first to kill every thread on the thread list. Because this list is
4468 // not reset by fork() (see notes above), execve() will instead kill
4469 // every thread in the parent process. We know this is the only thread
4470 // in the new process, so make a system call directly.
4471 // IA64 should use normal execve() from glibc to match the glibc fork()
4472 // above.
4473 execve("/bin/sh", (char* const*)argv, environ);
4475 // execve failed
4476 _exit(-1);
4478 } else {
4479 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4480 // care about the actual exit code, for now.
4482 int status;
4484 // Wait for the child process to exit. This returns immediately if
4485 // the child has already exited. */
4486 while (waitpid(pid, &status, 0) < 0) {
4487 switch (errno) {
4488 case ECHILD: return 0;
4489 case EINTR: break;
4490 default: return -1;
4491 }
4492 }
4494 if (WIFEXITED(status)) {
4495 // The child exited normally; get its exit code.
4496 return WEXITSTATUS(status);
4497 } else if (WIFSIGNALED(status)) {
4498 // The child exited because of a signal
4499 // The best value to return is 0x80 + signal number,
4500 // because that is what all Unix shells do, and because
4501 // it allows callers to distinguish between process exit and
4502 // process death by signal.
4503 return 0x80 + WTERMSIG(status);
4504 } else {
4505 // Unknown exit code; pass it through
4506 return status;
4507 }
4508 }
4509 }
4511 // is_headless_jre()
4512 //
4513 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4514 // in order to report if we are running in a headless jre
4515 //
4516 // Since JDK8 xawt/libmawt.so was moved into the same directory
4517 // as libawt.so, and renamed libawt_xawt.so
4518 //
4519 bool os::is_headless_jre() {
4520 struct stat statbuf;
4521 char buf[MAXPATHLEN];
4522 char libmawtpath[MAXPATHLEN];
4523 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX;
4524 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4525 char *p;
4527 // Get path to libjvm.so
4528 os::jvm_path(buf, sizeof(buf));
4530 // Get rid of libjvm.so
4531 p = strrchr(buf, '/');
4532 if (p == NULL) return false;
4533 else *p = '\0';
4535 // Get rid of client or server
4536 p = strrchr(buf, '/');
4537 if (p == NULL) return false;
4538 else *p = '\0';
4540 // check xawt/libmawt.so
4541 strcpy(libmawtpath, buf);
4542 strcat(libmawtpath, xawtstr);
4543 if (::stat(libmawtpath, &statbuf) == 0) return false;
4545 // check libawt_xawt.so
4546 strcpy(libmawtpath, buf);
4547 strcat(libmawtpath, new_xawtstr);
4548 if (::stat(libmawtpath, &statbuf) == 0) return false;
4550 return true;
4551 }
4553 // Get the default path to the core file
4554 // Returns the length of the string
4555 int os::get_core_path(char* buffer, size_t bufferSize) {
4556 int n = jio_snprintf(buffer, bufferSize, "/cores");
4558 // Truncate if theoretical string was longer than bufferSize
4559 n = MIN2(n, (int)bufferSize);
4561 return n;
4562 }