Fri, 08 Feb 2013 12:48:24 +0100
8006423: SA: NullPointerException in sun.jvm.hotspot.debugger.bsd.BsdThread.getContext(BsdThread.java:67)
Summary: Do not rely on mach thread port names to identify threads from SA
Reviewed-by: dholmes, minqi, rbackman
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/runtimeService.hpp"
61 #include "utilities/decoder.hpp"
62 #include "utilities/defaultStream.hpp"
63 #include "utilities/events.hpp"
64 #include "utilities/growableArray.hpp"
65 #include "utilities/vmError.hpp"
67 // put OS-includes here
68 # include <sys/types.h>
69 # include <sys/mman.h>
70 # include <sys/stat.h>
71 # include <sys/select.h>
72 # include <pthread.h>
73 # include <signal.h>
74 # include <errno.h>
75 # include <dlfcn.h>
76 # include <stdio.h>
77 # include <unistd.h>
78 # include <sys/resource.h>
79 # include <pthread.h>
80 # include <sys/stat.h>
81 # include <sys/time.h>
82 # include <sys/times.h>
83 # include <sys/utsname.h>
84 # include <sys/socket.h>
85 # include <sys/wait.h>
86 # include <time.h>
87 # include <pwd.h>
88 # include <poll.h>
89 # include <semaphore.h>
90 # include <fcntl.h>
91 # include <string.h>
92 # include <sys/param.h>
93 # include <sys/sysctl.h>
94 # include <sys/ipc.h>
95 # include <sys/shm.h>
96 #ifndef __APPLE__
97 # include <link.h>
98 #endif
99 # include <stdint.h>
100 # include <inttypes.h>
101 # include <sys/ioctl.h>
103 #if defined(__FreeBSD__) || defined(__NetBSD__)
104 # include <elf.h>
105 #endif
107 #ifdef __APPLE__
108 # include <mach/mach.h> // semaphore_* API
109 # include <mach-o/dyld.h>
110 # include <sys/proc_info.h>
111 # include <objc/objc-auto.h>
112 #endif
114 #ifndef MAP_ANONYMOUS
115 #define MAP_ANONYMOUS MAP_ANON
116 #endif
118 #define MAX_PATH (2 * K)
120 // for timer info max values which include all bits
121 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
123 #define LARGEPAGES_BIT (1 << 6)
124 ////////////////////////////////////////////////////////////////////////////////
125 // global variables
126 julong os::Bsd::_physical_memory = 0;
129 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
130 pthread_t os::Bsd::_main_thread;
131 int os::Bsd::_page_size = -1;
133 static jlong initial_time_count=0;
135 static int clock_tics_per_sec = 100;
137 // For diagnostics to print a message once. see run_periodic_checks
138 static sigset_t check_signal_done;
139 static bool check_signals = true;
141 static pid_t _initial_pid = 0;
143 /* Signal number used to suspend/resume a thread */
145 /* do not use any signal number less than SIGSEGV, see 4355769 */
146 static int SR_signum = SIGUSR2;
147 sigset_t SR_sigset;
150 ////////////////////////////////////////////////////////////////////////////////
151 // utility functions
153 static int SR_initialize();
154 static int SR_finalize();
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 julong os::allocatable_physical_memory(julong size) {
170 #ifdef _LP64
171 return size;
172 #else
173 julong result = MIN2(size, (julong)3800*M);
174 if (!is_allocatable(result)) {
175 // See comments under solaris for alignment considerations
176 julong reasonable_size = (julong)2*G - 2 * os::vm_page_size();
177 result = MIN2(size, reasonable_size);
178 }
179 return result;
180 #endif // _LP64
181 }
183 ////////////////////////////////////////////////////////////////////////////////
184 // environment support
186 bool os::getenv(const char* name, char* buf, int len) {
187 const char* val = ::getenv(name);
188 if (val != NULL && strlen(val) < (size_t)len) {
189 strcpy(buf, val);
190 return true;
191 }
192 if (len > 0) buf[0] = 0; // return a null string
193 return false;
194 }
197 // Return true if user is running as root.
199 bool os::have_special_privileges() {
200 static bool init = false;
201 static bool privileges = false;
202 if (!init) {
203 privileges = (getuid() != geteuid()) || (getgid() != getegid());
204 init = true;
205 }
206 return privileges;
207 }
211 // Cpu architecture string
212 #if defined(ZERO)
213 static char cpu_arch[] = ZERO_LIBARCH;
214 #elif defined(IA64)
215 static char cpu_arch[] = "ia64";
216 #elif defined(IA32)
217 static char cpu_arch[] = "i386";
218 #elif defined(AMD64)
219 static char cpu_arch[] = "amd64";
220 #elif defined(ARM)
221 static char cpu_arch[] = "arm";
222 #elif defined(PPC)
223 static char cpu_arch[] = "ppc";
224 #elif defined(SPARC)
225 # ifdef _LP64
226 static char cpu_arch[] = "sparcv9";
227 # else
228 static char cpu_arch[] = "sparc";
229 # endif
230 #else
231 #error Add appropriate cpu_arch setting
232 #endif
234 // Compiler variant
235 #ifdef COMPILER2
236 #define COMPILER_VARIANT "server"
237 #else
238 #define COMPILER_VARIANT "client"
239 #endif
242 void os::Bsd::initialize_system_info() {
243 int mib[2];
244 size_t len;
245 int cpu_val;
246 julong mem_val;
248 /* get processors count via hw.ncpus sysctl */
249 mib[0] = CTL_HW;
250 mib[1] = HW_NCPU;
251 len = sizeof(cpu_val);
252 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
253 assert(len == sizeof(cpu_val), "unexpected data size");
254 set_processor_count(cpu_val);
255 }
256 else {
257 set_processor_count(1); // fallback
258 }
260 /* get physical memory via hw.memsize sysctl (hw.memsize is used
261 * since it returns a 64 bit value)
262 */
263 mib[0] = CTL_HW;
264 mib[1] = HW_MEMSIZE;
265 len = sizeof(mem_val);
266 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
267 assert(len == sizeof(mem_val), "unexpected data size");
268 _physical_memory = mem_val;
269 } else {
270 _physical_memory = 256*1024*1024; // fallback (XXXBSD?)
271 }
273 #ifdef __OpenBSD__
274 {
275 // limit _physical_memory memory view on OpenBSD since
276 // datasize rlimit restricts us anyway.
277 struct rlimit limits;
278 getrlimit(RLIMIT_DATA, &limits);
279 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
280 }
281 #endif
282 }
284 #ifdef __APPLE__
285 static const char *get_home() {
286 const char *home_dir = ::getenv("HOME");
287 if ((home_dir == NULL) || (*home_dir == '\0')) {
288 struct passwd *passwd_info = getpwuid(geteuid());
289 if (passwd_info != NULL) {
290 home_dir = passwd_info->pw_dir;
291 }
292 }
294 return home_dir;
295 }
296 #endif
298 void os::init_system_properties_values() {
299 // char arch[12];
300 // sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
302 // The next steps are taken in the product version:
303 //
304 // Obtain the JAVA_HOME value from the location of libjvm.so.
305 // This library should be located at:
306 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
307 //
308 // If "/jre/lib/" appears at the right place in the path, then we
309 // assume libjvm.so is installed in a JDK and we use this path.
310 //
311 // Otherwise exit with message: "Could not create the Java virtual machine."
312 //
313 // The following extra steps are taken in the debugging version:
314 //
315 // If "/jre/lib/" does NOT appear at the right place in the path
316 // instead of exit check for $JAVA_HOME environment variable.
317 //
318 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
319 // then we append a fake suffix "hotspot/libjvm.so" to this path so
320 // it looks like libjvm.so is installed there
321 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
322 //
323 // Otherwise exit.
324 //
325 // Important note: if the location of libjvm.so changes this
326 // code needs to be changed accordingly.
328 // The next few definitions allow the code to be verbatim:
329 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal)
330 #define getenv(n) ::getenv(n)
332 /*
333 * See ld(1):
334 * The linker uses the following search paths to locate required
335 * shared libraries:
336 * 1: ...
337 * ...
338 * 7: The default directories, normally /lib and /usr/lib.
339 */
340 #ifndef DEFAULT_LIBPATH
341 #define DEFAULT_LIBPATH "/lib:/usr/lib"
342 #endif
344 #define EXTENSIONS_DIR "/lib/ext"
345 #define ENDORSED_DIR "/lib/endorsed"
346 #define REG_DIR "/usr/java/packages"
348 #ifdef __APPLE__
349 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions"
350 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
351 const char *user_home_dir = get_home();
352 // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir
353 int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
354 sizeof(SYS_EXTENSIONS_DIRS);
355 #endif
357 {
358 /* sysclasspath, java_home, dll_dir */
359 {
360 char *home_path;
361 char *dll_path;
362 char *pslash;
363 char buf[MAXPATHLEN];
364 os::jvm_path(buf, sizeof(buf));
366 // Found the full path to libjvm.so.
367 // Now cut the path to <java_home>/jre if we can.
368 *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */
369 pslash = strrchr(buf, '/');
370 if (pslash != NULL)
371 *pslash = '\0'; /* get rid of /{client|server|hotspot} */
372 dll_path = malloc(strlen(buf) + 1);
373 if (dll_path == NULL)
374 return;
375 strcpy(dll_path, buf);
376 Arguments::set_dll_dir(dll_path);
378 if (pslash != NULL) {
379 pslash = strrchr(buf, '/');
380 if (pslash != NULL) {
381 *pslash = '\0'; /* get rid of /<arch> (/lib on macosx) */
382 #ifndef __APPLE__
383 pslash = strrchr(buf, '/');
384 if (pslash != NULL)
385 *pslash = '\0'; /* get rid of /lib */
386 #endif
387 }
388 }
390 home_path = malloc(strlen(buf) + 1);
391 if (home_path == NULL)
392 return;
393 strcpy(home_path, buf);
394 Arguments::set_java_home(home_path);
396 if (!set_boot_path('/', ':'))
397 return;
398 }
400 /*
401 * Where to look for native libraries
402 *
403 * Note: Due to a legacy implementation, most of the library path
404 * is set in the launcher. This was to accomodate linking restrictions
405 * on legacy Bsd implementations (which are no longer supported).
406 * Eventually, all the library path setting will be done here.
407 *
408 * However, to prevent the proliferation of improperly built native
409 * libraries, the new path component /usr/java/packages is added here.
410 * Eventually, all the library path setting will be done here.
411 */
412 {
413 char *ld_library_path;
415 /*
416 * Construct the invariant part of ld_library_path. Note that the
417 * space for the colon and the trailing null are provided by the
418 * nulls included by the sizeof operator (so actually we allocate
419 * a byte more than necessary).
420 */
421 #ifdef __APPLE__
422 ld_library_path = (char *) malloc(system_ext_size);
423 sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir);
424 #else
425 ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
426 strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
427 sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
428 #endif
430 /*
431 * Get the user setting of LD_LIBRARY_PATH, and prepended it. It
432 * should always exist (until the legacy problem cited above is
433 * addressed).
434 */
435 #ifdef __APPLE__
436 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper
437 char *l = getenv("JAVA_LIBRARY_PATH");
438 if (l != NULL) {
439 char *t = ld_library_path;
440 /* That's +1 for the colon and +1 for the trailing '\0' */
441 ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1);
442 sprintf(ld_library_path, "%s:%s", l, t);
443 free(t);
444 }
446 char *v = getenv("DYLD_LIBRARY_PATH");
447 #else
448 char *v = getenv("LD_LIBRARY_PATH");
449 #endif
450 if (v != NULL) {
451 char *t = ld_library_path;
452 /* That's +1 for the colon and +1 for the trailing '\0' */
453 ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
454 sprintf(ld_library_path, "%s:%s", v, t);
455 free(t);
456 }
458 #ifdef __APPLE__
459 // Apple's Java6 has "." at the beginning of java.library.path.
460 // OpenJDK on Windows has "." at the end of java.library.path.
461 // OpenJDK on Linux and Solaris don't have "." in java.library.path
462 // at all. To ease the transition from Apple's Java6 to OpenJDK7,
463 // "." is appended to the end of java.library.path. Yes, this
464 // could cause a change in behavior, but Apple's Java6 behavior
465 // can be achieved by putting "." at the beginning of the
466 // JAVA_LIBRARY_PATH environment variable.
467 {
468 char *t = ld_library_path;
469 // that's +3 for appending ":." and the trailing '\0'
470 ld_library_path = (char *) malloc(strlen(t) + 3);
471 sprintf(ld_library_path, "%s:%s", t, ".");
472 free(t);
473 }
474 #endif
476 Arguments::set_library_path(ld_library_path);
477 }
479 /*
480 * Extensions directories.
481 *
482 * Note that the space for the colon and the trailing null are provided
483 * by the nulls included by the sizeof operator (so actually one byte more
484 * than necessary is allocated).
485 */
486 {
487 #ifdef __APPLE__
488 char *buf = malloc(strlen(Arguments::get_java_home()) +
489 sizeof(EXTENSIONS_DIR) + system_ext_size);
490 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":"
491 SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home());
492 #else
493 char *buf = malloc(strlen(Arguments::get_java_home()) +
494 sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
495 sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
496 Arguments::get_java_home());
497 #endif
499 Arguments::set_ext_dirs(buf);
500 }
502 /* Endorsed standards default directory. */
503 {
504 char * buf;
505 buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
506 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
507 Arguments::set_endorsed_dirs(buf);
508 }
509 }
511 #ifdef __APPLE__
512 #undef SYS_EXTENSIONS_DIR
513 #endif
514 #undef malloc
515 #undef getenv
516 #undef EXTENSIONS_DIR
517 #undef ENDORSED_DIR
519 // Done
520 return;
521 }
523 ////////////////////////////////////////////////////////////////////////////////
524 // breakpoint support
526 void os::breakpoint() {
527 BREAKPOINT;
528 }
530 extern "C" void breakpoint() {
531 // use debugger to set breakpoint here
532 }
534 ////////////////////////////////////////////////////////////////////////////////
535 // signal support
537 debug_only(static bool signal_sets_initialized = false);
538 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
540 bool os::Bsd::is_sig_ignored(int sig) {
541 struct sigaction oact;
542 sigaction(sig, (struct sigaction*)NULL, &oact);
543 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
544 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
545 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
546 return true;
547 else
548 return false;
549 }
551 void os::Bsd::signal_sets_init() {
552 // Should also have an assertion stating we are still single-threaded.
553 assert(!signal_sets_initialized, "Already initialized");
554 // Fill in signals that are necessarily unblocked for all threads in
555 // the VM. Currently, we unblock the following signals:
556 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
557 // by -Xrs (=ReduceSignalUsage));
558 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
559 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
560 // the dispositions or masks wrt these signals.
561 // Programs embedding the VM that want to use the above signals for their
562 // own purposes must, at this time, use the "-Xrs" option to prevent
563 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
564 // (See bug 4345157, and other related bugs).
565 // In reality, though, unblocking these signals is really a nop, since
566 // these signals are not blocked by default.
567 sigemptyset(&unblocked_sigs);
568 sigemptyset(&allowdebug_blocked_sigs);
569 sigaddset(&unblocked_sigs, SIGILL);
570 sigaddset(&unblocked_sigs, SIGSEGV);
571 sigaddset(&unblocked_sigs, SIGBUS);
572 sigaddset(&unblocked_sigs, SIGFPE);
573 sigaddset(&unblocked_sigs, SR_signum);
575 if (!ReduceSignalUsage) {
576 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
577 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
578 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
579 }
580 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
581 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
582 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
583 }
584 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
585 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
586 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
587 }
588 }
589 // Fill in signals that are blocked by all but the VM thread.
590 sigemptyset(&vm_sigs);
591 if (!ReduceSignalUsage)
592 sigaddset(&vm_sigs, BREAK_SIGNAL);
593 debug_only(signal_sets_initialized = true);
595 }
597 // These are signals that are unblocked while a thread is running Java.
598 // (For some reason, they get blocked by default.)
599 sigset_t* os::Bsd::unblocked_signals() {
600 assert(signal_sets_initialized, "Not initialized");
601 return &unblocked_sigs;
602 }
604 // These are the signals that are blocked while a (non-VM) thread is
605 // running Java. Only the VM thread handles these signals.
606 sigset_t* os::Bsd::vm_signals() {
607 assert(signal_sets_initialized, "Not initialized");
608 return &vm_sigs;
609 }
611 // These are signals that are blocked during cond_wait to allow debugger in
612 sigset_t* os::Bsd::allowdebug_blocked_signals() {
613 assert(signal_sets_initialized, "Not initialized");
614 return &allowdebug_blocked_sigs;
615 }
617 void os::Bsd::hotspot_sigmask(Thread* thread) {
619 //Save caller's signal mask before setting VM signal mask
620 sigset_t caller_sigmask;
621 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
623 OSThread* osthread = thread->osthread();
624 osthread->set_caller_sigmask(caller_sigmask);
626 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
628 if (!ReduceSignalUsage) {
629 if (thread->is_VM_thread()) {
630 // Only the VM thread handles BREAK_SIGNAL ...
631 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
632 } else {
633 // ... all other threads block BREAK_SIGNAL
634 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
635 }
636 }
637 }
640 //////////////////////////////////////////////////////////////////////////////
641 // create new thread
643 static address highest_vm_reserved_address();
645 // check if it's safe to start a new thread
646 static bool _thread_safety_check(Thread* thread) {
647 return true;
648 }
650 #ifdef __APPLE__
651 // library handle for calling objc_registerThreadWithCollector()
652 // without static linking to the libobjc library
653 #define OBJC_LIB "/usr/lib/libobjc.dylib"
654 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
655 typedef void (*objc_registerThreadWithCollector_t)();
656 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
657 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
658 #endif
660 #ifdef __APPLE__
661 static uint64_t locate_unique_thread_id() {
662 // Additional thread_id used to correlate threads in SA
663 thread_identifier_info_data_t m_ident_info;
664 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT;
666 thread_info(::mach_thread_self(), THREAD_IDENTIFIER_INFO,
667 (thread_info_t) &m_ident_info, &count);
668 return m_ident_info.thread_id;
669 }
670 #endif
672 // Thread start routine for all newly created threads
673 static void *java_start(Thread *thread) {
674 // Try to randomize the cache line index of hot stack frames.
675 // This helps when threads of the same stack traces evict each other's
676 // cache lines. The threads can be either from the same JVM instance, or
677 // from different JVM instances. The benefit is especially true for
678 // processors with hyperthreading technology.
679 static int counter = 0;
680 int pid = os::current_process_id();
681 alloca(((pid ^ counter++) & 7) * 128);
683 ThreadLocalStorage::set_thread(thread);
685 OSThread* osthread = thread->osthread();
686 Monitor* sync = osthread->startThread_lock();
688 // non floating stack BsdThreads needs extra check, see above
689 if (!_thread_safety_check(thread)) {
690 // notify parent thread
691 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
692 osthread->set_state(ZOMBIE);
693 sync->notify_all();
694 return NULL;
695 }
697 #ifdef __APPLE__
698 // thread_id is mach thread on macos
699 osthread->set_thread_id(::mach_thread_self());
700 osthread->set_unique_thread_id(locate_unique_thread_id());
701 #else
702 // thread_id is pthread_id on BSD
703 osthread->set_thread_id(::pthread_self());
704 #endif
705 // initialize signal mask for this thread
706 os::Bsd::hotspot_sigmask(thread);
708 // initialize floating point control register
709 os::Bsd::init_thread_fpu_state();
711 #ifdef __APPLE__
712 // register thread with objc gc
713 if (objc_registerThreadWithCollectorFunction != NULL) {
714 objc_registerThreadWithCollectorFunction();
715 }
716 #endif
718 // handshaking with parent thread
719 {
720 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
722 // notify parent thread
723 osthread->set_state(INITIALIZED);
724 sync->notify_all();
726 // wait until os::start_thread()
727 while (osthread->get_state() == INITIALIZED) {
728 sync->wait(Mutex::_no_safepoint_check_flag);
729 }
730 }
732 // call one more level start routine
733 thread->run();
735 return 0;
736 }
738 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
739 assert(thread->osthread() == NULL, "caller responsible");
741 // Allocate the OSThread object
742 OSThread* osthread = new OSThread(NULL, NULL);
743 if (osthread == NULL) {
744 return false;
745 }
747 // set the correct thread state
748 osthread->set_thread_type(thr_type);
750 // Initial state is ALLOCATED but not INITIALIZED
751 osthread->set_state(ALLOCATED);
753 thread->set_osthread(osthread);
755 // init thread attributes
756 pthread_attr_t attr;
757 pthread_attr_init(&attr);
758 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
760 // stack size
761 if (os::Bsd::supports_variable_stack_size()) {
762 // calculate stack size if it's not specified by caller
763 if (stack_size == 0) {
764 stack_size = os::Bsd::default_stack_size(thr_type);
766 switch (thr_type) {
767 case os::java_thread:
768 // Java threads use ThreadStackSize which default value can be
769 // changed with the flag -Xss
770 assert (JavaThread::stack_size_at_create() > 0, "this should be set");
771 stack_size = JavaThread::stack_size_at_create();
772 break;
773 case os::compiler_thread:
774 if (CompilerThreadStackSize > 0) {
775 stack_size = (size_t)(CompilerThreadStackSize * K);
776 break;
777 } // else fall through:
778 // use VMThreadStackSize if CompilerThreadStackSize is not defined
779 case os::vm_thread:
780 case os::pgc_thread:
781 case os::cgc_thread:
782 case os::watcher_thread:
783 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
784 break;
785 }
786 }
788 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
789 pthread_attr_setstacksize(&attr, stack_size);
790 } else {
791 // let pthread_create() pick the default value.
792 }
794 ThreadState state;
796 {
797 pthread_t tid;
798 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
800 pthread_attr_destroy(&attr);
802 if (ret != 0) {
803 if (PrintMiscellaneous && (Verbose || WizardMode)) {
804 perror("pthread_create()");
805 }
806 // Need to clean up stuff we've allocated so far
807 thread->set_osthread(NULL);
808 delete osthread;
809 return false;
810 }
812 // Store pthread info into the OSThread
813 osthread->set_pthread_id(tid);
815 // Wait until child thread is either initialized or aborted
816 {
817 Monitor* sync_with_child = osthread->startThread_lock();
818 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
819 while ((state = osthread->get_state()) == ALLOCATED) {
820 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
821 }
822 }
824 }
826 // Aborted due to thread limit being reached
827 if (state == ZOMBIE) {
828 thread->set_osthread(NULL);
829 delete osthread;
830 return false;
831 }
833 // The thread is returned suspended (in state INITIALIZED),
834 // and is started higher up in the call chain
835 assert(state == INITIALIZED, "race condition");
836 return true;
837 }
839 /////////////////////////////////////////////////////////////////////////////
840 // attach existing thread
842 // bootstrap the main thread
843 bool os::create_main_thread(JavaThread* thread) {
844 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
845 return create_attached_thread(thread);
846 }
848 bool os::create_attached_thread(JavaThread* thread) {
849 #ifdef ASSERT
850 thread->verify_not_published();
851 #endif
853 // Allocate the OSThread object
854 OSThread* osthread = new OSThread(NULL, NULL);
856 if (osthread == NULL) {
857 return false;
858 }
860 // Store pthread info into the OSThread
861 #ifdef __APPLE__
862 osthread->set_thread_id(::mach_thread_self());
863 osthread->set_unique_thread_id(locate_unique_thread_id());
864 #else
865 osthread->set_thread_id(::pthread_self());
866 #endif
867 osthread->set_pthread_id(::pthread_self());
869 // initialize floating point control register
870 os::Bsd::init_thread_fpu_state();
872 // Initial thread state is RUNNABLE
873 osthread->set_state(RUNNABLE);
875 thread->set_osthread(osthread);
877 // initialize signal mask for this thread
878 // and save the caller's signal mask
879 os::Bsd::hotspot_sigmask(thread);
881 return true;
882 }
884 void os::pd_start_thread(Thread* thread) {
885 OSThread * osthread = thread->osthread();
886 assert(osthread->get_state() != INITIALIZED, "just checking");
887 Monitor* sync_with_child = osthread->startThread_lock();
888 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
889 sync_with_child->notify();
890 }
892 // Free Bsd resources related to the OSThread
893 void os::free_thread(OSThread* osthread) {
894 assert(osthread != NULL, "osthread not set");
896 if (Thread::current()->osthread() == osthread) {
897 // Restore caller's signal mask
898 sigset_t sigmask = osthread->caller_sigmask();
899 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
900 }
902 delete osthread;
903 }
905 //////////////////////////////////////////////////////////////////////////////
906 // thread local storage
908 int os::allocate_thread_local_storage() {
909 pthread_key_t key;
910 int rslt = pthread_key_create(&key, NULL);
911 assert(rslt == 0, "cannot allocate thread local storage");
912 return (int)key;
913 }
915 // Note: This is currently not used by VM, as we don't destroy TLS key
916 // on VM exit.
917 void os::free_thread_local_storage(int index) {
918 int rslt = pthread_key_delete((pthread_key_t)index);
919 assert(rslt == 0, "invalid index");
920 }
922 void os::thread_local_storage_at_put(int index, void* value) {
923 int rslt = pthread_setspecific((pthread_key_t)index, value);
924 assert(rslt == 0, "pthread_setspecific failed");
925 }
927 extern "C" Thread* get_thread() {
928 return ThreadLocalStorage::thread();
929 }
932 ////////////////////////////////////////////////////////////////////////////////
933 // time support
935 // Time since start-up in seconds to a fine granularity.
936 // Used by VMSelfDestructTimer and the MemProfiler.
937 double os::elapsedTime() {
939 return (double)(os::elapsed_counter()) * 0.000001;
940 }
942 jlong os::elapsed_counter() {
943 timeval time;
944 int status = gettimeofday(&time, NULL);
945 return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count;
946 }
948 jlong os::elapsed_frequency() {
949 return (1000 * 1000);
950 }
952 // XXX: For now, code this as if BSD does not support vtime.
953 bool os::supports_vtime() { return false; }
954 bool os::enable_vtime() { return false; }
955 bool os::vtime_enabled() { return false; }
956 double os::elapsedVTime() {
957 // better than nothing, but not much
958 return elapsedTime();
959 }
961 jlong os::javaTimeMillis() {
962 timeval time;
963 int status = gettimeofday(&time, NULL);
964 assert(status != -1, "bsd error");
965 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
966 }
968 #ifndef CLOCK_MONOTONIC
969 #define CLOCK_MONOTONIC (1)
970 #endif
972 #ifdef __APPLE__
973 void os::Bsd::clock_init() {
974 // XXXDARWIN: Investigate replacement monotonic clock
975 }
976 #else
977 void os::Bsd::clock_init() {
978 struct timespec res;
979 struct timespec tp;
980 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
981 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
982 // yes, monotonic clock is supported
983 _clock_gettime = ::clock_gettime;
984 }
985 }
986 #endif
989 jlong os::javaTimeNanos() {
990 if (Bsd::supports_monotonic_clock()) {
991 struct timespec tp;
992 int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp);
993 assert(status == 0, "gettime error");
994 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
995 return result;
996 } else {
997 timeval time;
998 int status = gettimeofday(&time, NULL);
999 assert(status != -1, "bsd error");
1000 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1001 return 1000 * usecs;
1002 }
1003 }
1005 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1006 if (Bsd::supports_monotonic_clock()) {
1007 info_ptr->max_value = ALL_64_BITS;
1009 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1010 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1011 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1012 } else {
1013 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1014 info_ptr->max_value = ALL_64_BITS;
1016 // gettimeofday is a real time clock so it skips
1017 info_ptr->may_skip_backward = true;
1018 info_ptr->may_skip_forward = true;
1019 }
1021 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1022 }
1024 // Return the real, user, and system times in seconds from an
1025 // arbitrary fixed point in the past.
1026 bool os::getTimesSecs(double* process_real_time,
1027 double* process_user_time,
1028 double* process_system_time) {
1029 struct tms ticks;
1030 clock_t real_ticks = times(&ticks);
1032 if (real_ticks == (clock_t) (-1)) {
1033 return false;
1034 } else {
1035 double ticks_per_second = (double) clock_tics_per_sec;
1036 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1037 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1038 *process_real_time = ((double) real_ticks) / ticks_per_second;
1040 return true;
1041 }
1042 }
1045 char * os::local_time_string(char *buf, size_t buflen) {
1046 struct tm t;
1047 time_t long_time;
1048 time(&long_time);
1049 localtime_r(&long_time, &t);
1050 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1051 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1052 t.tm_hour, t.tm_min, t.tm_sec);
1053 return buf;
1054 }
1056 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1057 return localtime_r(clock, res);
1058 }
1060 ////////////////////////////////////////////////////////////////////////////////
1061 // runtime exit support
1063 // Note: os::shutdown() might be called very early during initialization, or
1064 // called from signal handler. Before adding something to os::shutdown(), make
1065 // sure it is async-safe and can handle partially initialized VM.
1066 void os::shutdown() {
1068 // allow PerfMemory to attempt cleanup of any persistent resources
1069 perfMemory_exit();
1071 // needs to remove object in file system
1072 AttachListener::abort();
1074 // flush buffered output, finish log files
1075 ostream_abort();
1077 // Check for abort hook
1078 abort_hook_t abort_hook = Arguments::abort_hook();
1079 if (abort_hook != NULL) {
1080 abort_hook();
1081 }
1083 }
1085 // Note: os::abort() might be called very early during initialization, or
1086 // called from signal handler. Before adding something to os::abort(), make
1087 // sure it is async-safe and can handle partially initialized VM.
1088 void os::abort(bool dump_core) {
1089 os::shutdown();
1090 if (dump_core) {
1091 #ifndef PRODUCT
1092 fdStream out(defaultStream::output_fd());
1093 out.print_raw("Current thread is ");
1094 char buf[16];
1095 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1096 out.print_raw_cr(buf);
1097 out.print_raw_cr("Dumping core ...");
1098 #endif
1099 ::abort(); // dump core
1100 }
1102 ::exit(1);
1103 }
1105 // Die immediately, no exit hook, no abort hook, no cleanup.
1106 void os::die() {
1107 // _exit() on BsdThreads only kills current thread
1108 ::abort();
1109 }
1111 // unused on bsd for now.
1112 void os::set_error_file(const char *logfile) {}
1115 // This method is a copy of JDK's sysGetLastErrorString
1116 // from src/solaris/hpi/src/system_md.c
1118 size_t os::lasterror(char *buf, size_t len) {
1120 if (errno == 0) return 0;
1122 const char *s = ::strerror(errno);
1123 size_t n = ::strlen(s);
1124 if (n >= len) {
1125 n = len - 1;
1126 }
1127 ::strncpy(buf, s, n);
1128 buf[n] = '\0';
1129 return n;
1130 }
1132 intx os::current_thread_id() {
1133 #ifdef __APPLE__
1134 return (intx)::mach_thread_self();
1135 #else
1136 return (intx)::pthread_self();
1137 #endif
1138 }
1139 int os::current_process_id() {
1141 // Under the old bsd thread library, bsd gives each thread
1142 // its own process id. Because of this each thread will return
1143 // a different pid if this method were to return the result
1144 // of getpid(2). Bsd provides no api that returns the pid
1145 // of the launcher thread for the vm. This implementation
1146 // returns a unique pid, the pid of the launcher thread
1147 // that starts the vm 'process'.
1149 // Under the NPTL, getpid() returns the same pid as the
1150 // launcher thread rather than a unique pid per thread.
1151 // Use gettid() if you want the old pre NPTL behaviour.
1153 // if you are looking for the result of a call to getpid() that
1154 // returns a unique pid for the calling thread, then look at the
1155 // OSThread::thread_id() method in osThread_bsd.hpp file
1157 return (int)(_initial_pid ? _initial_pid : getpid());
1158 }
1160 // DLL functions
1162 #define JNI_LIB_PREFIX "lib"
1163 #ifdef __APPLE__
1164 #define JNI_LIB_SUFFIX ".dylib"
1165 #else
1166 #define JNI_LIB_SUFFIX ".so"
1167 #endif
1169 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1171 // This must be hard coded because it's the system's temporary
1172 // directory not the java application's temp directory, ala java.io.tmpdir.
1173 #ifdef __APPLE__
1174 // macosx has a secure per-user temporary directory
1175 char temp_path_storage[PATH_MAX];
1176 const char* os::get_temp_directory() {
1177 static char *temp_path = NULL;
1178 if (temp_path == NULL) {
1179 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1180 if (pathSize == 0 || pathSize > PATH_MAX) {
1181 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1182 }
1183 temp_path = temp_path_storage;
1184 }
1185 return temp_path;
1186 }
1187 #else /* __APPLE__ */
1188 const char* os::get_temp_directory() { return "/tmp"; }
1189 #endif /* __APPLE__ */
1191 static bool file_exists(const char* filename) {
1192 struct stat statbuf;
1193 if (filename == NULL || strlen(filename) == 0) {
1194 return false;
1195 }
1196 return os::stat(filename, &statbuf) == 0;
1197 }
1199 bool os::dll_build_name(char* buffer, size_t buflen,
1200 const char* pname, const char* fname) {
1201 bool retval = false;
1202 // Copied from libhpi
1203 const size_t pnamelen = pname ? strlen(pname) : 0;
1205 // Return error on buffer overflow.
1206 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1207 return retval;
1208 }
1210 if (pnamelen == 0) {
1211 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1212 retval = true;
1213 } else if (strchr(pname, *os::path_separator()) != NULL) {
1214 int n;
1215 char** pelements = split_path(pname, &n);
1216 for (int i = 0 ; i < n ; i++) {
1217 // Really shouldn't be NULL, but check can't hurt
1218 if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1219 continue; // skip the empty path values
1220 }
1221 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1222 pelements[i], fname);
1223 if (file_exists(buffer)) {
1224 retval = true;
1225 break;
1226 }
1227 }
1228 // release the storage
1229 for (int i = 0 ; i < n ; i++) {
1230 if (pelements[i] != NULL) {
1231 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
1232 }
1233 }
1234 if (pelements != NULL) {
1235 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
1236 }
1237 } else {
1238 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1239 retval = true;
1240 }
1241 return retval;
1242 }
1244 const char* os::get_current_directory(char *buf, int buflen) {
1245 return getcwd(buf, buflen);
1246 }
1248 // check if addr is inside libjvm.so
1249 bool os::address_is_in_vm(address addr) {
1250 static address libjvm_base_addr;
1251 Dl_info dlinfo;
1253 if (libjvm_base_addr == NULL) {
1254 dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo);
1255 libjvm_base_addr = (address)dlinfo.dli_fbase;
1256 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1257 }
1259 if (dladdr((void *)addr, &dlinfo)) {
1260 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1261 }
1263 return false;
1264 }
1267 #define MACH_MAXSYMLEN 256
1269 bool os::dll_address_to_function_name(address addr, char *buf,
1270 int buflen, int *offset) {
1271 Dl_info dlinfo;
1272 char localbuf[MACH_MAXSYMLEN];
1274 // dladdr will find names of dynamic functions only, but does
1275 // it set dli_fbase with mach_header address when it "fails" ?
1276 if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) {
1277 if (buf != NULL) {
1278 if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1279 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1280 }
1281 }
1282 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1283 return true;
1284 } else if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != 0) {
1285 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1286 buf, buflen, offset, dlinfo.dli_fname)) {
1287 return true;
1288 }
1289 }
1291 // Handle non-dymanic manually:
1292 if (dlinfo.dli_fbase != NULL &&
1293 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
1294 if(!Decoder::demangle(localbuf, buf, buflen)) {
1295 jio_snprintf(buf, buflen, "%s", localbuf);
1296 }
1297 return true;
1298 }
1299 if (buf != NULL) buf[0] = '\0';
1300 if (offset != NULL) *offset = -1;
1301 return false;
1302 }
1304 // ported from solaris version
1305 bool os::dll_address_to_library_name(address addr, char* buf,
1306 int buflen, int* offset) {
1307 Dl_info dlinfo;
1309 if (dladdr((void*)addr, &dlinfo)){
1310 if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1311 if (offset) *offset = addr - (address)dlinfo.dli_fbase;
1312 return true;
1313 } else {
1314 if (buf) buf[0] = '\0';
1315 if (offset) *offset = -1;
1316 return false;
1317 }
1318 }
1320 // Loads .dll/.so and
1321 // in case of error it checks if .dll/.so was built for the
1322 // same architecture as Hotspot is running on
1324 #ifdef __APPLE__
1325 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1326 void * result= ::dlopen(filename, RTLD_LAZY);
1327 if (result != NULL) {
1328 // Successful loading
1329 return result;
1330 }
1332 // Read system error message into ebuf
1333 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1334 ebuf[ebuflen-1]='\0';
1336 return NULL;
1337 }
1338 #else
1339 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
1340 {
1341 void * result= ::dlopen(filename, RTLD_LAZY);
1342 if (result != NULL) {
1343 // Successful loading
1344 return result;
1345 }
1347 Elf32_Ehdr elf_head;
1349 // Read system error message into ebuf
1350 // It may or may not be overwritten below
1351 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1352 ebuf[ebuflen-1]='\0';
1353 int diag_msg_max_length=ebuflen-strlen(ebuf);
1354 char* diag_msg_buf=ebuf+strlen(ebuf);
1356 if (diag_msg_max_length==0) {
1357 // No more space in ebuf for additional diagnostics message
1358 return NULL;
1359 }
1362 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1364 if (file_descriptor < 0) {
1365 // Can't open library, report dlerror() message
1366 return NULL;
1367 }
1369 bool failed_to_read_elf_head=
1370 (sizeof(elf_head)!=
1371 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
1373 ::close(file_descriptor);
1374 if (failed_to_read_elf_head) {
1375 // file i/o error - report dlerror() msg
1376 return NULL;
1377 }
1379 typedef struct {
1380 Elf32_Half code; // Actual value as defined in elf.h
1381 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1382 char elf_class; // 32 or 64 bit
1383 char endianess; // MSB or LSB
1384 char* name; // String representation
1385 } arch_t;
1387 #ifndef EM_486
1388 #define EM_486 6 /* Intel 80486 */
1389 #endif
1391 #ifndef EM_MIPS_RS3_LE
1392 #define EM_MIPS_RS3_LE 10 /* MIPS */
1393 #endif
1395 #ifndef EM_PPC64
1396 #define EM_PPC64 21 /* PowerPC64 */
1397 #endif
1399 #ifndef EM_S390
1400 #define EM_S390 22 /* IBM System/390 */
1401 #endif
1403 #ifndef EM_IA_64
1404 #define EM_IA_64 50 /* HP/Intel IA-64 */
1405 #endif
1407 #ifndef EM_X86_64
1408 #define EM_X86_64 62 /* AMD x86-64 */
1409 #endif
1411 static const arch_t arch_array[]={
1412 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1413 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1414 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1415 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1416 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1417 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1418 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1419 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1420 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1421 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1422 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1423 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1424 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1425 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1426 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1427 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1428 };
1430 #if (defined IA32)
1431 static Elf32_Half running_arch_code=EM_386;
1432 #elif (defined AMD64)
1433 static Elf32_Half running_arch_code=EM_X86_64;
1434 #elif (defined IA64)
1435 static Elf32_Half running_arch_code=EM_IA_64;
1436 #elif (defined __sparc) && (defined _LP64)
1437 static Elf32_Half running_arch_code=EM_SPARCV9;
1438 #elif (defined __sparc) && (!defined _LP64)
1439 static Elf32_Half running_arch_code=EM_SPARC;
1440 #elif (defined __powerpc64__)
1441 static Elf32_Half running_arch_code=EM_PPC64;
1442 #elif (defined __powerpc__)
1443 static Elf32_Half running_arch_code=EM_PPC;
1444 #elif (defined ARM)
1445 static Elf32_Half running_arch_code=EM_ARM;
1446 #elif (defined S390)
1447 static Elf32_Half running_arch_code=EM_S390;
1448 #elif (defined ALPHA)
1449 static Elf32_Half running_arch_code=EM_ALPHA;
1450 #elif (defined MIPSEL)
1451 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1452 #elif (defined PARISC)
1453 static Elf32_Half running_arch_code=EM_PARISC;
1454 #elif (defined MIPS)
1455 static Elf32_Half running_arch_code=EM_MIPS;
1456 #elif (defined M68K)
1457 static Elf32_Half running_arch_code=EM_68K;
1458 #else
1459 #error Method os::dll_load requires that one of following is defined:\
1460 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1461 #endif
1463 // Identify compatability class for VM's architecture and library's architecture
1464 // Obtain string descriptions for architectures
1466 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1467 int running_arch_index=-1;
1469 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
1470 if (running_arch_code == arch_array[i].code) {
1471 running_arch_index = i;
1472 }
1473 if (lib_arch.code == arch_array[i].code) {
1474 lib_arch.compat_class = arch_array[i].compat_class;
1475 lib_arch.name = arch_array[i].name;
1476 }
1477 }
1479 assert(running_arch_index != -1,
1480 "Didn't find running architecture code (running_arch_code) in arch_array");
1481 if (running_arch_index == -1) {
1482 // Even though running architecture detection failed
1483 // we may still continue with reporting dlerror() message
1484 return NULL;
1485 }
1487 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1488 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1489 return NULL;
1490 }
1492 #ifndef S390
1493 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1494 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1495 return NULL;
1496 }
1497 #endif // !S390
1499 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1500 if ( lib_arch.name!=NULL ) {
1501 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1502 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1503 lib_arch.name, arch_array[running_arch_index].name);
1504 } else {
1505 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1506 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1507 lib_arch.code,
1508 arch_array[running_arch_index].name);
1509 }
1510 }
1512 return NULL;
1513 }
1514 #endif /* !__APPLE__ */
1516 // XXX: Do we need a lock around this as per Linux?
1517 void* os::dll_lookup(void* handle, const char* name) {
1518 return dlsym(handle, name);
1519 }
1522 static bool _print_ascii_file(const char* filename, outputStream* st) {
1523 int fd = ::open(filename, O_RDONLY);
1524 if (fd == -1) {
1525 return false;
1526 }
1528 char buf[32];
1529 int bytes;
1530 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1531 st->print_raw(buf, bytes);
1532 }
1534 ::close(fd);
1536 return true;
1537 }
1539 void os::print_dll_info(outputStream *st) {
1540 st->print_cr("Dynamic libraries:");
1541 #ifdef RTLD_DI_LINKMAP
1542 Dl_info dli;
1543 void *handle;
1544 Link_map *map;
1545 Link_map *p;
1547 if (!dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli)) {
1548 st->print_cr("Error: Cannot print dynamic libraries.");
1549 return;
1550 }
1551 handle = dlopen(dli.dli_fname, RTLD_LAZY);
1552 if (handle == NULL) {
1553 st->print_cr("Error: Cannot print dynamic libraries.");
1554 return;
1555 }
1556 dlinfo(handle, RTLD_DI_LINKMAP, &map);
1557 if (map == NULL) {
1558 st->print_cr("Error: Cannot print dynamic libraries.");
1559 return;
1560 }
1562 while (map->l_prev != NULL)
1563 map = map->l_prev;
1565 while (map != NULL) {
1566 st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
1567 map = map->l_next;
1568 }
1570 dlclose(handle);
1571 #elif defined(__APPLE__)
1572 uint32_t count;
1573 uint32_t i;
1575 count = _dyld_image_count();
1576 for (i = 1; i < count; i++) {
1577 const char *name = _dyld_get_image_name(i);
1578 intptr_t slide = _dyld_get_image_vmaddr_slide(i);
1579 st->print_cr(PTR_FORMAT " \t%s", slide, name);
1580 }
1581 #else
1582 st->print_cr("Error: Cannot print dynamic libraries.");
1583 #endif
1584 }
1586 void os::print_os_info_brief(outputStream* st) {
1587 st->print("Bsd");
1589 os::Posix::print_uname_info(st);
1590 }
1592 void os::print_os_info(outputStream* st) {
1593 st->print("OS:");
1594 st->print("Bsd");
1596 os::Posix::print_uname_info(st);
1598 os::Posix::print_rlimit_info(st);
1600 os::Posix::print_load_average(st);
1601 }
1603 void os::pd_print_cpu_info(outputStream* st) {
1604 // Nothing to do for now.
1605 }
1607 void os::print_memory_info(outputStream* st) {
1609 st->print("Memory:");
1610 st->print(" %dk page", os::vm_page_size()>>10);
1612 st->print(", physical " UINT64_FORMAT "k",
1613 os::physical_memory() >> 10);
1614 st->print("(" UINT64_FORMAT "k free)",
1615 os::available_memory() >> 10);
1616 st->cr();
1618 // meminfo
1619 st->print("\n/proc/meminfo:\n");
1620 _print_ascii_file("/proc/meminfo", st);
1621 st->cr();
1622 }
1624 // Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific
1625 // but they're the same for all the bsd arch that we support
1626 // and they're the same for solaris but there's no common place to put this.
1627 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
1628 "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
1629 "ILL_COPROC", "ILL_BADSTK" };
1631 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
1632 "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
1633 "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
1635 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
1637 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
1639 void os::print_siginfo(outputStream* st, void* siginfo) {
1640 st->print("siginfo:");
1642 const int buflen = 100;
1643 char buf[buflen];
1644 siginfo_t *si = (siginfo_t*)siginfo;
1645 st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
1646 if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
1647 st->print("si_errno=%s", buf);
1648 } else {
1649 st->print("si_errno=%d", si->si_errno);
1650 }
1651 const int c = si->si_code;
1652 assert(c > 0, "unexpected si_code");
1653 switch (si->si_signo) {
1654 case SIGILL:
1655 st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
1656 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1657 break;
1658 case SIGFPE:
1659 st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
1660 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1661 break;
1662 case SIGSEGV:
1663 st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
1664 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1665 break;
1666 case SIGBUS:
1667 st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
1668 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1669 break;
1670 default:
1671 st->print(", si_code=%d", si->si_code);
1672 // no si_addr
1673 }
1675 if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1676 UseSharedSpaces) {
1677 FileMapInfo* mapinfo = FileMapInfo::current_info();
1678 if (mapinfo->is_in_shared_space(si->si_addr)) {
1679 st->print("\n\nError accessing class data sharing archive." \
1680 " Mapped file inaccessible during execution, " \
1681 " possible disk/network problem.");
1682 }
1683 }
1684 st->cr();
1685 }
1688 static void print_signal_handler(outputStream* st, int sig,
1689 char* buf, size_t buflen);
1691 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1692 st->print_cr("Signal Handlers:");
1693 print_signal_handler(st, SIGSEGV, buf, buflen);
1694 print_signal_handler(st, SIGBUS , buf, buflen);
1695 print_signal_handler(st, SIGFPE , buf, buflen);
1696 print_signal_handler(st, SIGPIPE, buf, buflen);
1697 print_signal_handler(st, SIGXFSZ, buf, buflen);
1698 print_signal_handler(st, SIGILL , buf, buflen);
1699 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1700 print_signal_handler(st, SR_signum, buf, buflen);
1701 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1702 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1703 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1704 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1705 }
1707 static char saved_jvm_path[MAXPATHLEN] = {0};
1709 // Find the full path to the current module, libjvm
1710 void os::jvm_path(char *buf, jint buflen) {
1711 // Error checking.
1712 if (buflen < MAXPATHLEN) {
1713 assert(false, "must use a large-enough buffer");
1714 buf[0] = '\0';
1715 return;
1716 }
1717 // Lazy resolve the path to current module.
1718 if (saved_jvm_path[0] != 0) {
1719 strcpy(buf, saved_jvm_path);
1720 return;
1721 }
1723 char dli_fname[MAXPATHLEN];
1724 bool ret = dll_address_to_library_name(
1725 CAST_FROM_FN_PTR(address, os::jvm_path),
1726 dli_fname, sizeof(dli_fname), NULL);
1727 assert(ret != 0, "cannot locate libjvm");
1728 char *rp = realpath(dli_fname, buf);
1729 if (rp == NULL)
1730 return;
1732 if (Arguments::created_by_gamma_launcher()) {
1733 // Support for the gamma launcher. Typical value for buf is
1734 // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm". If "/jre/lib/" appears at
1735 // the right place in the string, then assume we are installed in a JDK and
1736 // we're done. Otherwise, check for a JAVA_HOME environment variable and
1737 // construct a path to the JVM being overridden.
1739 const char *p = buf + strlen(buf) - 1;
1740 for (int count = 0; p > buf && count < 5; ++count) {
1741 for (--p; p > buf && *p != '/'; --p)
1742 /* empty */ ;
1743 }
1745 if (strncmp(p, "/jre/lib/", 9) != 0) {
1746 // Look for JAVA_HOME in the environment.
1747 char* java_home_var = ::getenv("JAVA_HOME");
1748 if (java_home_var != NULL && java_home_var[0] != 0) {
1749 char* jrelib_p;
1750 int len;
1752 // Check the current module name "libjvm"
1753 p = strrchr(buf, '/');
1754 assert(strstr(p, "/libjvm") == p, "invalid library name");
1756 rp = realpath(java_home_var, buf);
1757 if (rp == NULL)
1758 return;
1760 // determine if this is a legacy image or modules image
1761 // modules image doesn't have "jre" subdirectory
1762 len = strlen(buf);
1763 jrelib_p = buf + len;
1765 // Add the appropriate library subdir
1766 snprintf(jrelib_p, buflen-len, "/jre/lib");
1767 if (0 != access(buf, F_OK)) {
1768 snprintf(jrelib_p, buflen-len, "/lib");
1769 }
1771 // Add the appropriate client or server subdir
1772 len = strlen(buf);
1773 jrelib_p = buf + len;
1774 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1775 if (0 != access(buf, F_OK)) {
1776 snprintf(jrelib_p, buflen-len, "");
1777 }
1779 // If the path exists within JAVA_HOME, add the JVM library name
1780 // to complete the path to JVM being overridden. Otherwise fallback
1781 // to the path to the current library.
1782 if (0 == access(buf, F_OK)) {
1783 // Use current module name "libjvm"
1784 len = strlen(buf);
1785 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1786 } else {
1787 // Fall back to path of current library
1788 rp = realpath(dli_fname, buf);
1789 if (rp == NULL)
1790 return;
1791 }
1792 }
1793 }
1794 }
1796 strcpy(saved_jvm_path, buf);
1797 }
1799 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1800 // no prefix required, not even "_"
1801 }
1803 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1804 // no suffix required
1805 }
1807 ////////////////////////////////////////////////////////////////////////////////
1808 // sun.misc.Signal support
1810 static volatile jint sigint_count = 0;
1812 static void
1813 UserHandler(int sig, void *siginfo, void *context) {
1814 // 4511530 - sem_post is serialized and handled by the manager thread. When
1815 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1816 // don't want to flood the manager thread with sem_post requests.
1817 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
1818 return;
1820 // Ctrl-C is pressed during error reporting, likely because the error
1821 // handler fails to abort. Let VM die immediately.
1822 if (sig == SIGINT && is_error_reported()) {
1823 os::die();
1824 }
1826 os::signal_notify(sig);
1827 }
1829 void* os::user_handler() {
1830 return CAST_FROM_FN_PTR(void*, UserHandler);
1831 }
1833 extern "C" {
1834 typedef void (*sa_handler_t)(int);
1835 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1836 }
1838 void* os::signal(int signal_number, void* handler) {
1839 struct sigaction sigAct, oldSigAct;
1841 sigfillset(&(sigAct.sa_mask));
1842 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
1843 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1845 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1846 // -1 means registration failed
1847 return (void *)-1;
1848 }
1850 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1851 }
1853 void os::signal_raise(int signal_number) {
1854 ::raise(signal_number);
1855 }
1857 /*
1858 * The following code is moved from os.cpp for making this
1859 * code platform specific, which it is by its very nature.
1860 */
1862 // Will be modified when max signal is changed to be dynamic
1863 int os::sigexitnum_pd() {
1864 return NSIG;
1865 }
1867 // a counter for each possible signal value
1868 static volatile jint pending_signals[NSIG+1] = { 0 };
1870 // Bsd(POSIX) specific hand shaking semaphore.
1871 #ifdef __APPLE__
1872 static semaphore_t sig_sem;
1873 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1874 #define SEM_WAIT(sem) semaphore_wait(sem);
1875 #define SEM_POST(sem) semaphore_signal(sem);
1876 #else
1877 static sem_t sig_sem;
1878 #define SEM_INIT(sem, value) sem_init(&sem, 0, value)
1879 #define SEM_WAIT(sem) sem_wait(&sem);
1880 #define SEM_POST(sem) sem_post(&sem);
1881 #endif
1883 void os::signal_init_pd() {
1884 // Initialize signal structures
1885 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1887 // Initialize signal semaphore
1888 ::SEM_INIT(sig_sem, 0);
1889 }
1891 void os::signal_notify(int sig) {
1892 Atomic::inc(&pending_signals[sig]);
1893 ::SEM_POST(sig_sem);
1894 }
1896 static int check_pending_signals(bool wait) {
1897 Atomic::store(0, &sigint_count);
1898 for (;;) {
1899 for (int i = 0; i < NSIG + 1; i++) {
1900 jint n = pending_signals[i];
1901 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1902 return i;
1903 }
1904 }
1905 if (!wait) {
1906 return -1;
1907 }
1908 JavaThread *thread = JavaThread::current();
1909 ThreadBlockInVM tbivm(thread);
1911 bool threadIsSuspended;
1912 do {
1913 thread->set_suspend_equivalent();
1914 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1915 ::SEM_WAIT(sig_sem);
1917 // were we externally suspended while we were waiting?
1918 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1919 if (threadIsSuspended) {
1920 //
1921 // The semaphore has been incremented, but while we were waiting
1922 // another thread suspended us. We don't want to continue running
1923 // while suspended because that would surprise the thread that
1924 // suspended us.
1925 //
1926 ::SEM_POST(sig_sem);
1928 thread->java_suspend_self();
1929 }
1930 } while (threadIsSuspended);
1931 }
1932 }
1934 int os::signal_lookup() {
1935 return check_pending_signals(false);
1936 }
1938 int os::signal_wait() {
1939 return check_pending_signals(true);
1940 }
1942 ////////////////////////////////////////////////////////////////////////////////
1943 // Virtual Memory
1945 int os::vm_page_size() {
1946 // Seems redundant as all get out
1947 assert(os::Bsd::page_size() != -1, "must call os::init");
1948 return os::Bsd::page_size();
1949 }
1951 // Solaris allocates memory by pages.
1952 int os::vm_allocation_granularity() {
1953 assert(os::Bsd::page_size() != -1, "must call os::init");
1954 return os::Bsd::page_size();
1955 }
1957 // Rationale behind this function:
1958 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
1959 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
1960 // samples for JITted code. Here we create private executable mapping over the code cache
1961 // and then we can use standard (well, almost, as mapping can change) way to provide
1962 // info for the reporting script by storing timestamp and location of symbol
1963 void bsd_wrap_code(char* base, size_t size) {
1964 static volatile jint cnt = 0;
1966 if (!UseOprofile) {
1967 return;
1968 }
1970 char buf[PATH_MAX + 1];
1971 int num = Atomic::add(1, &cnt);
1973 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
1974 os::get_temp_directory(), os::current_process_id(), num);
1975 unlink(buf);
1977 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
1979 if (fd != -1) {
1980 off_t rv = ::lseek(fd, size-2, SEEK_SET);
1981 if (rv != (off_t)-1) {
1982 if (::write(fd, "", 1) == 1) {
1983 mmap(base, size,
1984 PROT_READ|PROT_WRITE|PROT_EXEC,
1985 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
1986 }
1987 }
1988 ::close(fd);
1989 unlink(buf);
1990 }
1991 }
1993 // NOTE: Bsd kernel does not really reserve the pages for us.
1994 // All it does is to check if there are enough free pages
1995 // left at the time of mmap(). This could be a potential
1996 // problem.
1997 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
1998 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
1999 #ifdef __OpenBSD__
2000 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2001 return ::mprotect(addr, size, prot) == 0;
2002 #else
2003 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2004 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2005 return res != (uintptr_t) MAP_FAILED;
2006 #endif
2007 }
2010 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2011 bool exec) {
2012 return commit_memory(addr, size, exec);
2013 }
2015 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2016 }
2018 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2019 ::madvise(addr, bytes, MADV_DONTNEED);
2020 }
2022 void os::numa_make_global(char *addr, size_t bytes) {
2023 }
2025 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2026 }
2028 bool os::numa_topology_changed() { return false; }
2030 size_t os::numa_get_groups_num() {
2031 return 1;
2032 }
2034 int os::numa_get_group_id() {
2035 return 0;
2036 }
2038 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2039 if (size > 0) {
2040 ids[0] = 0;
2041 return 1;
2042 }
2043 return 0;
2044 }
2046 bool os::get_page_info(char *start, page_info* info) {
2047 return false;
2048 }
2050 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2051 return end;
2052 }
2055 bool os::pd_uncommit_memory(char* addr, size_t size) {
2056 #ifdef __OpenBSD__
2057 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2058 return ::mprotect(addr, size, PROT_NONE) == 0;
2059 #else
2060 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2061 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2062 return res != (uintptr_t) MAP_FAILED;
2063 #endif
2064 }
2066 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2067 return os::commit_memory(addr, size);
2068 }
2070 // If this is a growable mapping, remove the guard pages entirely by
2071 // munmap()ping them. If not, just call uncommit_memory().
2072 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2073 return os::uncommit_memory(addr, size);
2074 }
2076 static address _highest_vm_reserved_address = NULL;
2078 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2079 // at 'requested_addr'. If there are existing memory mappings at the same
2080 // location, however, they will be overwritten. If 'fixed' is false,
2081 // 'requested_addr' is only treated as a hint, the return value may or
2082 // may not start from the requested address. Unlike Bsd mmap(), this
2083 // function returns NULL to indicate failure.
2084 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2085 char * addr;
2086 int flags;
2088 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2089 if (fixed) {
2090 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2091 flags |= MAP_FIXED;
2092 }
2094 // Map uncommitted pages PROT_READ and PROT_WRITE, change access
2095 // to PROT_EXEC if executable when we commit the page.
2096 addr = (char*)::mmap(requested_addr, bytes, PROT_READ|PROT_WRITE,
2097 flags, -1, 0);
2099 if (addr != MAP_FAILED) {
2100 // anon_mmap() should only get called during VM initialization,
2101 // don't need lock (actually we can skip locking even it can be called
2102 // from multiple threads, because _highest_vm_reserved_address is just a
2103 // hint about the upper limit of non-stack memory regions.)
2104 if ((address)addr + bytes > _highest_vm_reserved_address) {
2105 _highest_vm_reserved_address = (address)addr + bytes;
2106 }
2107 }
2109 return addr == MAP_FAILED ? NULL : addr;
2110 }
2112 // Don't update _highest_vm_reserved_address, because there might be memory
2113 // regions above addr + size. If so, releasing a memory region only creates
2114 // a hole in the address space, it doesn't help prevent heap-stack collision.
2115 //
2116 static int anon_munmap(char * addr, size_t size) {
2117 return ::munmap(addr, size) == 0;
2118 }
2120 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2121 size_t alignment_hint) {
2122 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2123 }
2125 bool os::pd_release_memory(char* addr, size_t size) {
2126 return anon_munmap(addr, size);
2127 }
2129 static address highest_vm_reserved_address() {
2130 return _highest_vm_reserved_address;
2131 }
2133 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2134 // Bsd wants the mprotect address argument to be page aligned.
2135 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2137 // According to SUSv3, mprotect() should only be used with mappings
2138 // established by mmap(), and mmap() always maps whole pages. Unaligned
2139 // 'addr' likely indicates problem in the VM (e.g. trying to change
2140 // protection of malloc'ed or statically allocated memory). Check the
2141 // caller if you hit this assert.
2142 assert(addr == bottom, "sanity check");
2144 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2145 return ::mprotect(bottom, size, prot) == 0;
2146 }
2148 // Set protections specified
2149 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2150 bool is_committed) {
2151 unsigned int p = 0;
2152 switch (prot) {
2153 case MEM_PROT_NONE: p = PROT_NONE; break;
2154 case MEM_PROT_READ: p = PROT_READ; break;
2155 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
2156 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2157 default:
2158 ShouldNotReachHere();
2159 }
2160 // is_committed is unused.
2161 return bsd_mprotect(addr, bytes, p);
2162 }
2164 bool os::guard_memory(char* addr, size_t size) {
2165 return bsd_mprotect(addr, size, PROT_NONE);
2166 }
2168 bool os::unguard_memory(char* addr, size_t size) {
2169 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2170 }
2172 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2173 return false;
2174 }
2176 /*
2177 * Set the coredump_filter bits to include largepages in core dump (bit 6)
2178 *
2179 * From the coredump_filter documentation:
2180 *
2181 * - (bit 0) anonymous private memory
2182 * - (bit 1) anonymous shared memory
2183 * - (bit 2) file-backed private memory
2184 * - (bit 3) file-backed shared memory
2185 * - (bit 4) ELF header pages in file-backed private memory areas (it is
2186 * effective only if the bit 2 is cleared)
2187 * - (bit 5) hugetlb private memory
2188 * - (bit 6) hugetlb shared memory
2189 */
2190 static void set_coredump_filter(void) {
2191 FILE *f;
2192 long cdm;
2194 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
2195 return;
2196 }
2198 if (fscanf(f, "%lx", &cdm) != 1) {
2199 fclose(f);
2200 return;
2201 }
2203 rewind(f);
2205 if ((cdm & LARGEPAGES_BIT) == 0) {
2206 cdm |= LARGEPAGES_BIT;
2207 fprintf(f, "%#lx", cdm);
2208 }
2210 fclose(f);
2211 }
2213 // Large page support
2215 static size_t _large_page_size = 0;
2217 void os::large_page_init() {
2218 }
2221 char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) {
2222 // "exec" is passed in but not used. Creating the shared image for
2223 // the code cache doesn't have an SHM_X executable permission to check.
2224 assert(UseLargePages && UseSHM, "only for SHM large pages");
2226 key_t key = IPC_PRIVATE;
2227 char *addr;
2229 bool warn_on_failure = UseLargePages &&
2230 (!FLAG_IS_DEFAULT(UseLargePages) ||
2231 !FLAG_IS_DEFAULT(LargePageSizeInBytes)
2232 );
2233 char msg[128];
2235 // Create a large shared memory region to attach to based on size.
2236 // Currently, size is the total size of the heap
2237 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2238 if (shmid == -1) {
2239 // Possible reasons for shmget failure:
2240 // 1. shmmax is too small for Java heap.
2241 // > check shmmax value: cat /proc/sys/kernel/shmmax
2242 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2243 // 2. not enough large page memory.
2244 // > check available large pages: cat /proc/meminfo
2245 // > increase amount of large pages:
2246 // echo new_value > /proc/sys/vm/nr_hugepages
2247 // Note 1: different Bsd may use different name for this property,
2248 // e.g. on Redhat AS-3 it is "hugetlb_pool".
2249 // Note 2: it's possible there's enough physical memory available but
2250 // they are so fragmented after a long run that they can't
2251 // coalesce into large pages. Try to reserve large pages when
2252 // the system is still "fresh".
2253 if (warn_on_failure) {
2254 jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
2255 warning(msg);
2256 }
2257 return NULL;
2258 }
2260 // attach to the region
2261 addr = (char*)shmat(shmid, req_addr, 0);
2262 int err = errno;
2264 // Remove shmid. If shmat() is successful, the actual shared memory segment
2265 // will be deleted when it's detached by shmdt() or when the process
2266 // terminates. If shmat() is not successful this will remove the shared
2267 // segment immediately.
2268 shmctl(shmid, IPC_RMID, NULL);
2270 if ((intptr_t)addr == -1) {
2271 if (warn_on_failure) {
2272 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
2273 warning(msg);
2274 }
2275 return NULL;
2276 }
2278 return addr;
2279 }
2281 bool os::release_memory_special(char* base, size_t bytes) {
2282 // detaching the SHM segment will also delete it, see reserve_memory_special()
2283 int rslt = shmdt(base);
2284 return rslt == 0;
2285 }
2287 size_t os::large_page_size() {
2288 return _large_page_size;
2289 }
2291 // HugeTLBFS allows application to commit large page memory on demand;
2292 // with SysV SHM the entire memory region must be allocated as shared
2293 // memory.
2294 bool os::can_commit_large_page_memory() {
2295 return UseHugeTLBFS;
2296 }
2298 bool os::can_execute_large_page_memory() {
2299 return UseHugeTLBFS;
2300 }
2302 // Reserve memory at an arbitrary address, only if that area is
2303 // available (and not reserved for something else).
2305 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2306 const int max_tries = 10;
2307 char* base[max_tries];
2308 size_t size[max_tries];
2309 const size_t gap = 0x000000;
2311 // Assert only that the size is a multiple of the page size, since
2312 // that's all that mmap requires, and since that's all we really know
2313 // about at this low abstraction level. If we need higher alignment,
2314 // we can either pass an alignment to this method or verify alignment
2315 // in one of the methods further up the call chain. See bug 5044738.
2316 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2318 // Repeatedly allocate blocks until the block is allocated at the
2319 // right spot. Give up after max_tries. Note that reserve_memory() will
2320 // automatically update _highest_vm_reserved_address if the call is
2321 // successful. The variable tracks the highest memory address every reserved
2322 // by JVM. It is used to detect heap-stack collision if running with
2323 // fixed-stack BsdThreads. Because here we may attempt to reserve more
2324 // space than needed, it could confuse the collision detecting code. To
2325 // solve the problem, save current _highest_vm_reserved_address and
2326 // calculate the correct value before return.
2327 address old_highest = _highest_vm_reserved_address;
2329 // Bsd mmap allows caller to pass an address as hint; give it a try first,
2330 // if kernel honors the hint then we can return immediately.
2331 char * addr = anon_mmap(requested_addr, bytes, false);
2332 if (addr == requested_addr) {
2333 return requested_addr;
2334 }
2336 if (addr != NULL) {
2337 // mmap() is successful but it fails to reserve at the requested address
2338 anon_munmap(addr, bytes);
2339 }
2341 int i;
2342 for (i = 0; i < max_tries; ++i) {
2343 base[i] = reserve_memory(bytes);
2345 if (base[i] != NULL) {
2346 // Is this the block we wanted?
2347 if (base[i] == requested_addr) {
2348 size[i] = bytes;
2349 break;
2350 }
2352 // Does this overlap the block we wanted? Give back the overlapped
2353 // parts and try again.
2355 size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2356 if (top_overlap >= 0 && top_overlap < bytes) {
2357 unmap_memory(base[i], top_overlap);
2358 base[i] += top_overlap;
2359 size[i] = bytes - top_overlap;
2360 } else {
2361 size_t bottom_overlap = base[i] + bytes - requested_addr;
2362 if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2363 unmap_memory(requested_addr, bottom_overlap);
2364 size[i] = bytes - bottom_overlap;
2365 } else {
2366 size[i] = bytes;
2367 }
2368 }
2369 }
2370 }
2372 // Give back the unused reserved pieces.
2374 for (int j = 0; j < i; ++j) {
2375 if (base[j] != NULL) {
2376 unmap_memory(base[j], size[j]);
2377 }
2378 }
2380 if (i < max_tries) {
2381 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2382 return requested_addr;
2383 } else {
2384 _highest_vm_reserved_address = old_highest;
2385 return NULL;
2386 }
2387 }
2389 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2390 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2391 }
2393 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
2394 // Solaris uses poll(), bsd uses park().
2395 // Poll() is likely a better choice, assuming that Thread.interrupt()
2396 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
2397 // SIGSEGV, see 4355769.
2399 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
2400 assert(thread == Thread::current(), "thread consistency check");
2402 ParkEvent * const slp = thread->_SleepEvent ;
2403 slp->reset() ;
2404 OrderAccess::fence() ;
2406 if (interruptible) {
2407 jlong prevtime = javaTimeNanos();
2409 for (;;) {
2410 if (os::is_interrupted(thread, true)) {
2411 return OS_INTRPT;
2412 }
2414 jlong newtime = javaTimeNanos();
2416 if (newtime - prevtime < 0) {
2417 // time moving backwards, should only happen if no monotonic clock
2418 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2419 assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2420 } else {
2421 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2422 }
2424 if(millis <= 0) {
2425 return OS_OK;
2426 }
2428 prevtime = newtime;
2430 {
2431 assert(thread->is_Java_thread(), "sanity check");
2432 JavaThread *jt = (JavaThread *) thread;
2433 ThreadBlockInVM tbivm(jt);
2434 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
2436 jt->set_suspend_equivalent();
2437 // cleared by handle_special_suspend_equivalent_condition() or
2438 // java_suspend_self() via check_and_wait_while_suspended()
2440 slp->park(millis);
2442 // were we externally suspended while we were waiting?
2443 jt->check_and_wait_while_suspended();
2444 }
2445 }
2446 } else {
2447 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2448 jlong prevtime = javaTimeNanos();
2450 for (;;) {
2451 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
2452 // the 1st iteration ...
2453 jlong newtime = javaTimeNanos();
2455 if (newtime - prevtime < 0) {
2456 // time moving backwards, should only happen if no monotonic clock
2457 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2458 assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2459 } else {
2460 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2461 }
2463 if(millis <= 0) break ;
2465 prevtime = newtime;
2466 slp->park(millis);
2467 }
2468 return OS_OK ;
2469 }
2470 }
2472 int os::naked_sleep() {
2473 // %% make the sleep time an integer flag. for now use 1 millisec.
2474 return os::sleep(Thread::current(), 1, false);
2475 }
2477 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2478 void os::infinite_sleep() {
2479 while (true) { // sleep forever ...
2480 ::sleep(100); // ... 100 seconds at a time
2481 }
2482 }
2484 // Used to convert frequent JVM_Yield() to nops
2485 bool os::dont_yield() {
2486 return DontYieldALot;
2487 }
2489 void os::yield() {
2490 sched_yield();
2491 }
2493 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
2495 void os::yield_all(int attempts) {
2496 // Yields to all threads, including threads with lower priorities
2497 // Threads on Bsd are all with same priority. The Solaris style
2498 // os::yield_all() with nanosleep(1ms) is not necessary.
2499 sched_yield();
2500 }
2502 // Called from the tight loops to possibly influence time-sharing heuristics
2503 void os::loop_breaker(int attempts) {
2504 os::yield_all(attempts);
2505 }
2507 ////////////////////////////////////////////////////////////////////////////////
2508 // thread priority support
2510 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2511 // only supports dynamic priority, static priority must be zero. For real-time
2512 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2513 // However, for large multi-threaded applications, SCHED_RR is not only slower
2514 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2515 // of 5 runs - Sep 2005).
2516 //
2517 // The following code actually changes the niceness of kernel-thread/LWP. It
2518 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2519 // not the entire user process, and user level threads are 1:1 mapped to kernel
2520 // threads. It has always been the case, but could change in the future. For
2521 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2522 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2524 #if !defined(__APPLE__)
2525 int os::java_to_os_priority[CriticalPriority + 1] = {
2526 19, // 0 Entry should never be used
2528 0, // 1 MinPriority
2529 3, // 2
2530 6, // 3
2532 10, // 4
2533 15, // 5 NormPriority
2534 18, // 6
2536 21, // 7
2537 25, // 8
2538 28, // 9 NearMaxPriority
2540 31, // 10 MaxPriority
2542 31 // 11 CriticalPriority
2543 };
2544 #else
2545 /* Using Mach high-level priority assignments */
2546 int os::java_to_os_priority[CriticalPriority + 1] = {
2547 0, // 0 Entry should never be used (MINPRI_USER)
2549 27, // 1 MinPriority
2550 28, // 2
2551 29, // 3
2553 30, // 4
2554 31, // 5 NormPriority (BASEPRI_DEFAULT)
2555 32, // 6
2557 33, // 7
2558 34, // 8
2559 35, // 9 NearMaxPriority
2561 36, // 10 MaxPriority
2563 36 // 11 CriticalPriority
2564 };
2565 #endif
2567 static int prio_init() {
2568 if (ThreadPriorityPolicy == 1) {
2569 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2570 // if effective uid is not root. Perhaps, a more elegant way of doing
2571 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2572 if (geteuid() != 0) {
2573 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2574 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2575 }
2576 ThreadPriorityPolicy = 0;
2577 }
2578 }
2579 if (UseCriticalJavaThreadPriority) {
2580 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2581 }
2582 return 0;
2583 }
2585 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2586 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
2588 #ifdef __OpenBSD__
2589 // OpenBSD pthread_setprio starves low priority threads
2590 return OS_OK;
2591 #elif defined(__FreeBSD__)
2592 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2593 #elif defined(__APPLE__) || defined(__NetBSD__)
2594 struct sched_param sp;
2595 int policy;
2596 pthread_t self = pthread_self();
2598 if (pthread_getschedparam(self, &policy, &sp) != 0)
2599 return OS_ERR;
2601 sp.sched_priority = newpri;
2602 if (pthread_setschedparam(self, policy, &sp) != 0)
2603 return OS_ERR;
2605 return OS_OK;
2606 #else
2607 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2608 return (ret == 0) ? OS_OK : OS_ERR;
2609 #endif
2610 }
2612 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2613 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
2614 *priority_ptr = java_to_os_priority[NormPriority];
2615 return OS_OK;
2616 }
2618 errno = 0;
2619 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2620 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2621 #elif defined(__APPLE__) || defined(__NetBSD__)
2622 int policy;
2623 struct sched_param sp;
2625 pthread_getschedparam(pthread_self(), &policy, &sp);
2626 *priority_ptr = sp.sched_priority;
2627 #else
2628 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2629 #endif
2630 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2631 }
2633 // Hint to the underlying OS that a task switch would not be good.
2634 // Void return because it's a hint and can fail.
2635 void os::hint_no_preempt() {}
2637 ////////////////////////////////////////////////////////////////////////////////
2638 // suspend/resume support
2640 // the low-level signal-based suspend/resume support is a remnant from the
2641 // old VM-suspension that used to be for java-suspension, safepoints etc,
2642 // within hotspot. Now there is a single use-case for this:
2643 // - calling get_thread_pc() on the VMThread by the flat-profiler task
2644 // that runs in the watcher thread.
2645 // The remaining code is greatly simplified from the more general suspension
2646 // code that used to be used.
2647 //
2648 // The protocol is quite simple:
2649 // - suspend:
2650 // - sends a signal to the target thread
2651 // - polls the suspend state of the osthread using a yield loop
2652 // - target thread signal handler (SR_handler) sets suspend state
2653 // and blocks in sigsuspend until continued
2654 // - resume:
2655 // - sets target osthread state to continue
2656 // - sends signal to end the sigsuspend loop in the SR_handler
2657 //
2658 // Note that the SR_lock plays no role in this suspend/resume protocol.
2659 //
2661 static void resume_clear_context(OSThread *osthread) {
2662 osthread->set_ucontext(NULL);
2663 osthread->set_siginfo(NULL);
2665 // notify the suspend action is completed, we have now resumed
2666 osthread->sr.clear_suspended();
2667 }
2669 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2670 osthread->set_ucontext(context);
2671 osthread->set_siginfo(siginfo);
2672 }
2674 //
2675 // Handler function invoked when a thread's execution is suspended or
2676 // resumed. We have to be careful that only async-safe functions are
2677 // called here (Note: most pthread functions are not async safe and
2678 // should be avoided.)
2679 //
2680 // Note: sigwait() is a more natural fit than sigsuspend() from an
2681 // interface point of view, but sigwait() prevents the signal hander
2682 // from being run. libpthread would get very confused by not having
2683 // its signal handlers run and prevents sigwait()'s use with the
2684 // mutex granting granting signal.
2685 //
2686 // Currently only ever called on the VMThread
2687 //
2688 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2689 // Save and restore errno to avoid confusing native code with EINTR
2690 // after sigsuspend.
2691 int old_errno = errno;
2693 Thread* thread = Thread::current();
2694 OSThread* osthread = thread->osthread();
2695 assert(thread->is_VM_thread(), "Must be VMThread");
2696 // read current suspend action
2697 int action = osthread->sr.suspend_action();
2698 if (action == SR_SUSPEND) {
2699 suspend_save_context(osthread, siginfo, context);
2701 // Notify the suspend action is about to be completed. do_suspend()
2702 // waits until SR_SUSPENDED is set and then returns. We will wait
2703 // here for a resume signal and that completes the suspend-other
2704 // action. do_suspend/do_resume is always called as a pair from
2705 // the same thread - so there are no races
2707 // notify the caller
2708 osthread->sr.set_suspended();
2710 sigset_t suspend_set; // signals for sigsuspend()
2712 // get current set of blocked signals and unblock resume signal
2713 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2714 sigdelset(&suspend_set, SR_signum);
2716 // wait here until we are resumed
2717 do {
2718 sigsuspend(&suspend_set);
2719 // ignore all returns until we get a resume signal
2720 } while (osthread->sr.suspend_action() != SR_CONTINUE);
2722 resume_clear_context(osthread);
2724 } else {
2725 assert(action == SR_CONTINUE, "unexpected sr action");
2726 // nothing special to do - just leave the handler
2727 }
2729 errno = old_errno;
2730 }
2733 static int SR_initialize() {
2734 struct sigaction act;
2735 char *s;
2736 /* Get signal number to use for suspend/resume */
2737 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2738 int sig = ::strtol(s, 0, 10);
2739 if (sig > 0 || sig < NSIG) {
2740 SR_signum = sig;
2741 }
2742 }
2744 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2745 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2747 sigemptyset(&SR_sigset);
2748 sigaddset(&SR_sigset, SR_signum);
2750 /* Set up signal handler for suspend/resume */
2751 act.sa_flags = SA_RESTART|SA_SIGINFO;
2752 act.sa_handler = (void (*)(int)) SR_handler;
2754 // SR_signum is blocked by default.
2755 // 4528190 - We also need to block pthread restart signal (32 on all
2756 // supported Bsd platforms). Note that BsdThreads need to block
2757 // this signal for all threads to work properly. So we don't have
2758 // to use hard-coded signal number when setting up the mask.
2759 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2761 if (sigaction(SR_signum, &act, 0) == -1) {
2762 return -1;
2763 }
2765 // Save signal flag
2766 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2767 return 0;
2768 }
2770 static int SR_finalize() {
2771 return 0;
2772 }
2775 // returns true on success and false on error - really an error is fatal
2776 // but this seems the normal response to library errors
2777 static bool do_suspend(OSThread* osthread) {
2778 // mark as suspended and send signal
2779 osthread->sr.set_suspend_action(SR_SUSPEND);
2780 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2781 assert_status(status == 0, status, "pthread_kill");
2783 // check status and wait until notified of suspension
2784 if (status == 0) {
2785 for (int i = 0; !osthread->sr.is_suspended(); i++) {
2786 os::yield_all(i);
2787 }
2788 osthread->sr.set_suspend_action(SR_NONE);
2789 return true;
2790 }
2791 else {
2792 osthread->sr.set_suspend_action(SR_NONE);
2793 return false;
2794 }
2795 }
2797 static void do_resume(OSThread* osthread) {
2798 assert(osthread->sr.is_suspended(), "thread should be suspended");
2799 osthread->sr.set_suspend_action(SR_CONTINUE);
2801 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2802 assert_status(status == 0, status, "pthread_kill");
2803 // check status and wait unit notified of resumption
2804 if (status == 0) {
2805 for (int i = 0; osthread->sr.is_suspended(); i++) {
2806 os::yield_all(i);
2807 }
2808 }
2809 osthread->sr.set_suspend_action(SR_NONE);
2810 }
2812 ////////////////////////////////////////////////////////////////////////////////
2813 // interrupt support
2815 void os::interrupt(Thread* thread) {
2816 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
2817 "possibility of dangling Thread pointer");
2819 OSThread* osthread = thread->osthread();
2821 if (!osthread->interrupted()) {
2822 osthread->set_interrupted(true);
2823 // More than one thread can get here with the same value of osthread,
2824 // resulting in multiple notifications. We do, however, want the store
2825 // to interrupted() to be visible to other threads before we execute unpark().
2826 OrderAccess::fence();
2827 ParkEvent * const slp = thread->_SleepEvent ;
2828 if (slp != NULL) slp->unpark() ;
2829 }
2831 // For JSR166. Unpark even if interrupt status already was set
2832 if (thread->is_Java_thread())
2833 ((JavaThread*)thread)->parker()->unpark();
2835 ParkEvent * ev = thread->_ParkEvent ;
2836 if (ev != NULL) ev->unpark() ;
2838 }
2840 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
2841 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
2842 "possibility of dangling Thread pointer");
2844 OSThread* osthread = thread->osthread();
2846 bool interrupted = osthread->interrupted();
2848 if (interrupted && clear_interrupted) {
2849 osthread->set_interrupted(false);
2850 // consider thread->_SleepEvent->reset() ... optional optimization
2851 }
2853 return interrupted;
2854 }
2856 ///////////////////////////////////////////////////////////////////////////////////
2857 // signal handling (except suspend/resume)
2859 // This routine may be used by user applications as a "hook" to catch signals.
2860 // The user-defined signal handler must pass unrecognized signals to this
2861 // routine, and if it returns true (non-zero), then the signal handler must
2862 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2863 // routine will never retun false (zero), but instead will execute a VM panic
2864 // routine kill the process.
2865 //
2866 // If this routine returns false, it is OK to call it again. This allows
2867 // the user-defined signal handler to perform checks either before or after
2868 // the VM performs its own checks. Naturally, the user code would be making
2869 // a serious error if it tried to handle an exception (such as a null check
2870 // or breakpoint) that the VM was generating for its own correct operation.
2871 //
2872 // This routine may recognize any of the following kinds of signals:
2873 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2874 // It should be consulted by handlers for any of those signals.
2875 //
2876 // The caller of this routine must pass in the three arguments supplied
2877 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2878 // field of the structure passed to sigaction(). This routine assumes that
2879 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2880 //
2881 // Note that the VM will print warnings if it detects conflicting signal
2882 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2883 //
2884 extern "C" JNIEXPORT int
2885 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2886 void* ucontext, int abort_if_unrecognized);
2888 void signalHandler(int sig, siginfo_t* info, void* uc) {
2889 assert(info != NULL && uc != NULL, "it must be old kernel");
2890 JVM_handle_bsd_signal(sig, info, uc, true);
2891 }
2894 // This boolean allows users to forward their own non-matching signals
2895 // to JVM_handle_bsd_signal, harmlessly.
2896 bool os::Bsd::signal_handlers_are_installed = false;
2898 // For signal-chaining
2899 struct sigaction os::Bsd::sigact[MAXSIGNUM];
2900 unsigned int os::Bsd::sigs = 0;
2901 bool os::Bsd::libjsig_is_loaded = false;
2902 typedef struct sigaction *(*get_signal_t)(int);
2903 get_signal_t os::Bsd::get_signal_action = NULL;
2905 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2906 struct sigaction *actp = NULL;
2908 if (libjsig_is_loaded) {
2909 // Retrieve the old signal handler from libjsig
2910 actp = (*get_signal_action)(sig);
2911 }
2912 if (actp == NULL) {
2913 // Retrieve the preinstalled signal handler from jvm
2914 actp = get_preinstalled_handler(sig);
2915 }
2917 return actp;
2918 }
2920 static bool call_chained_handler(struct sigaction *actp, int sig,
2921 siginfo_t *siginfo, void *context) {
2922 // Call the old signal handler
2923 if (actp->sa_handler == SIG_DFL) {
2924 // It's more reasonable to let jvm treat it as an unexpected exception
2925 // instead of taking the default action.
2926 return false;
2927 } else if (actp->sa_handler != SIG_IGN) {
2928 if ((actp->sa_flags & SA_NODEFER) == 0) {
2929 // automaticlly block the signal
2930 sigaddset(&(actp->sa_mask), sig);
2931 }
2933 sa_handler_t hand;
2934 sa_sigaction_t sa;
2935 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
2936 // retrieve the chained handler
2937 if (siginfo_flag_set) {
2938 sa = actp->sa_sigaction;
2939 } else {
2940 hand = actp->sa_handler;
2941 }
2943 if ((actp->sa_flags & SA_RESETHAND) != 0) {
2944 actp->sa_handler = SIG_DFL;
2945 }
2947 // try to honor the signal mask
2948 sigset_t oset;
2949 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
2951 // call into the chained handler
2952 if (siginfo_flag_set) {
2953 (*sa)(sig, siginfo, context);
2954 } else {
2955 (*hand)(sig);
2956 }
2958 // restore the signal mask
2959 pthread_sigmask(SIG_SETMASK, &oset, 0);
2960 }
2961 // Tell jvm's signal handler the signal is taken care of.
2962 return true;
2963 }
2965 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
2966 bool chained = false;
2967 // signal-chaining
2968 if (UseSignalChaining) {
2969 struct sigaction *actp = get_chained_signal_action(sig);
2970 if (actp != NULL) {
2971 chained = call_chained_handler(actp, sig, siginfo, context);
2972 }
2973 }
2974 return chained;
2975 }
2977 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
2978 if ((( (unsigned int)1 << sig ) & sigs) != 0) {
2979 return &sigact[sig];
2980 }
2981 return NULL;
2982 }
2984 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
2985 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2986 sigact[sig] = oldAct;
2987 sigs |= (unsigned int)1 << sig;
2988 }
2990 // for diagnostic
2991 int os::Bsd::sigflags[MAXSIGNUM];
2993 int os::Bsd::get_our_sigflags(int sig) {
2994 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2995 return sigflags[sig];
2996 }
2998 void os::Bsd::set_our_sigflags(int sig, int flags) {
2999 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3000 sigflags[sig] = flags;
3001 }
3003 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3004 // Check for overwrite.
3005 struct sigaction oldAct;
3006 sigaction(sig, (struct sigaction*)NULL, &oldAct);
3008 void* oldhand = oldAct.sa_sigaction
3009 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3010 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3011 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3012 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3013 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3014 if (AllowUserSignalHandlers || !set_installed) {
3015 // Do not overwrite; user takes responsibility to forward to us.
3016 return;
3017 } else if (UseSignalChaining) {
3018 // save the old handler in jvm
3019 save_preinstalled_handler(sig, oldAct);
3020 // libjsig also interposes the sigaction() call below and saves the
3021 // old sigaction on it own.
3022 } else {
3023 fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3024 "%#lx for signal %d.", (long)oldhand, sig));
3025 }
3026 }
3028 struct sigaction sigAct;
3029 sigfillset(&(sigAct.sa_mask));
3030 sigAct.sa_handler = SIG_DFL;
3031 if (!set_installed) {
3032 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3033 } else {
3034 sigAct.sa_sigaction = signalHandler;
3035 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3036 }
3037 // Save flags, which are set by ours
3038 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3039 sigflags[sig] = sigAct.sa_flags;
3041 int ret = sigaction(sig, &sigAct, &oldAct);
3042 assert(ret == 0, "check");
3044 void* oldhand2 = oldAct.sa_sigaction
3045 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3046 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3047 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3048 }
3050 // install signal handlers for signals that HotSpot needs to
3051 // handle in order to support Java-level exception handling.
3053 void os::Bsd::install_signal_handlers() {
3054 if (!signal_handlers_are_installed) {
3055 signal_handlers_are_installed = true;
3057 // signal-chaining
3058 typedef void (*signal_setting_t)();
3059 signal_setting_t begin_signal_setting = NULL;
3060 signal_setting_t end_signal_setting = NULL;
3061 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3062 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3063 if (begin_signal_setting != NULL) {
3064 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3065 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3066 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3067 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3068 libjsig_is_loaded = true;
3069 assert(UseSignalChaining, "should enable signal-chaining");
3070 }
3071 if (libjsig_is_loaded) {
3072 // Tell libjsig jvm is setting signal handlers
3073 (*begin_signal_setting)();
3074 }
3076 set_signal_handler(SIGSEGV, true);
3077 set_signal_handler(SIGPIPE, true);
3078 set_signal_handler(SIGBUS, true);
3079 set_signal_handler(SIGILL, true);
3080 set_signal_handler(SIGFPE, true);
3081 set_signal_handler(SIGXFSZ, true);
3083 #if defined(__APPLE__)
3084 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3085 // signals caught and handled by the JVM. To work around this, we reset the mach task
3086 // signal handler that's placed on our process by CrashReporter. This disables
3087 // CrashReporter-based reporting.
3088 //
3089 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3090 // on caught fatal signals.
3091 //
3092 // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3093 // handlers. By replacing the existing task exception handler, we disable gdb's mach
3094 // exception handling, while leaving the standard BSD signal handlers functional.
3095 kern_return_t kr;
3096 kr = task_set_exception_ports(mach_task_self(),
3097 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3098 MACH_PORT_NULL,
3099 EXCEPTION_STATE_IDENTITY,
3100 MACHINE_THREAD_STATE);
3102 assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3103 #endif
3105 if (libjsig_is_loaded) {
3106 // Tell libjsig jvm finishes setting signal handlers
3107 (*end_signal_setting)();
3108 }
3110 // We don't activate signal checker if libjsig is in place, we trust ourselves
3111 // and if UserSignalHandler is installed all bets are off
3112 if (CheckJNICalls) {
3113 if (libjsig_is_loaded) {
3114 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3115 check_signals = false;
3116 }
3117 if (AllowUserSignalHandlers) {
3118 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3119 check_signals = false;
3120 }
3121 }
3122 }
3123 }
3126 /////
3127 // glibc on Bsd platform uses non-documented flag
3128 // to indicate, that some special sort of signal
3129 // trampoline is used.
3130 // We will never set this flag, and we should
3131 // ignore this flag in our diagnostic
3132 #ifdef SIGNIFICANT_SIGNAL_MASK
3133 #undef SIGNIFICANT_SIGNAL_MASK
3134 #endif
3135 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3137 static const char* get_signal_handler_name(address handler,
3138 char* buf, int buflen) {
3139 int offset;
3140 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3141 if (found) {
3142 // skip directory names
3143 const char *p1, *p2;
3144 p1 = buf;
3145 size_t len = strlen(os::file_separator());
3146 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3147 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3148 } else {
3149 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3150 }
3151 return buf;
3152 }
3154 static void print_signal_handler(outputStream* st, int sig,
3155 char* buf, size_t buflen) {
3156 struct sigaction sa;
3158 sigaction(sig, NULL, &sa);
3160 // See comment for SIGNIFICANT_SIGNAL_MASK define
3161 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3163 st->print("%s: ", os::exception_name(sig, buf, buflen));
3165 address handler = (sa.sa_flags & SA_SIGINFO)
3166 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3167 : CAST_FROM_FN_PTR(address, sa.sa_handler);
3169 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3170 st->print("SIG_DFL");
3171 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3172 st->print("SIG_IGN");
3173 } else {
3174 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3175 }
3177 st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask);
3179 address rh = VMError::get_resetted_sighandler(sig);
3180 // May be, handler was resetted by VMError?
3181 if(rh != NULL) {
3182 handler = rh;
3183 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3184 }
3186 st->print(", sa_flags=" PTR32_FORMAT, sa.sa_flags);
3188 // Check: is it our handler?
3189 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3190 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3191 // It is our signal handler
3192 // check for flags, reset system-used one!
3193 if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3194 st->print(
3195 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3196 os::Bsd::get_our_sigflags(sig));
3197 }
3198 }
3199 st->cr();
3200 }
3203 #define DO_SIGNAL_CHECK(sig) \
3204 if (!sigismember(&check_signal_done, sig)) \
3205 os::Bsd::check_signal_handler(sig)
3207 // This method is a periodic task to check for misbehaving JNI applications
3208 // under CheckJNI, we can add any periodic checks here
3210 void os::run_periodic_checks() {
3212 if (check_signals == false) return;
3214 // SEGV and BUS if overridden could potentially prevent
3215 // generation of hs*.log in the event of a crash, debugging
3216 // such a case can be very challenging, so we absolutely
3217 // check the following for a good measure:
3218 DO_SIGNAL_CHECK(SIGSEGV);
3219 DO_SIGNAL_CHECK(SIGILL);
3220 DO_SIGNAL_CHECK(SIGFPE);
3221 DO_SIGNAL_CHECK(SIGBUS);
3222 DO_SIGNAL_CHECK(SIGPIPE);
3223 DO_SIGNAL_CHECK(SIGXFSZ);
3226 // ReduceSignalUsage allows the user to override these handlers
3227 // see comments at the very top and jvm_solaris.h
3228 if (!ReduceSignalUsage) {
3229 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3230 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3231 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3232 DO_SIGNAL_CHECK(BREAK_SIGNAL);
3233 }
3235 DO_SIGNAL_CHECK(SR_signum);
3236 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3237 }
3239 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3241 static os_sigaction_t os_sigaction = NULL;
3243 void os::Bsd::check_signal_handler(int sig) {
3244 char buf[O_BUFLEN];
3245 address jvmHandler = NULL;
3248 struct sigaction act;
3249 if (os_sigaction == NULL) {
3250 // only trust the default sigaction, in case it has been interposed
3251 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3252 if (os_sigaction == NULL) return;
3253 }
3255 os_sigaction(sig, (struct sigaction*)NULL, &act);
3258 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3260 address thisHandler = (act.sa_flags & SA_SIGINFO)
3261 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3262 : CAST_FROM_FN_PTR(address, act.sa_handler) ;
3265 switch(sig) {
3266 case SIGSEGV:
3267 case SIGBUS:
3268 case SIGFPE:
3269 case SIGPIPE:
3270 case SIGILL:
3271 case SIGXFSZ:
3272 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3273 break;
3275 case SHUTDOWN1_SIGNAL:
3276 case SHUTDOWN2_SIGNAL:
3277 case SHUTDOWN3_SIGNAL:
3278 case BREAK_SIGNAL:
3279 jvmHandler = (address)user_handler();
3280 break;
3282 case INTERRUPT_SIGNAL:
3283 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3284 break;
3286 default:
3287 if (sig == SR_signum) {
3288 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3289 } else {
3290 return;
3291 }
3292 break;
3293 }
3295 if (thisHandler != jvmHandler) {
3296 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3297 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3298 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3299 // No need to check this sig any longer
3300 sigaddset(&check_signal_done, sig);
3301 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3302 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3303 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3304 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags);
3305 // No need to check this sig any longer
3306 sigaddset(&check_signal_done, sig);
3307 }
3309 // Dump all the signal
3310 if (sigismember(&check_signal_done, sig)) {
3311 print_signal_handlers(tty, buf, O_BUFLEN);
3312 }
3313 }
3315 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
3317 extern bool signal_name(int signo, char* buf, size_t len);
3319 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3320 if (0 < exception_code && exception_code <= SIGRTMAX) {
3321 // signal
3322 if (!signal_name(exception_code, buf, size)) {
3323 jio_snprintf(buf, size, "SIG%d", exception_code);
3324 }
3325 return buf;
3326 } else {
3327 return NULL;
3328 }
3329 }
3331 // this is called _before_ the most of global arguments have been parsed
3332 void os::init(void) {
3333 char dummy; /* used to get a guess on initial stack address */
3334 // first_hrtime = gethrtime();
3336 // With BsdThreads the JavaMain thread pid (primordial thread)
3337 // is different than the pid of the java launcher thread.
3338 // So, on Bsd, the launcher thread pid is passed to the VM
3339 // via the sun.java.launcher.pid property.
3340 // Use this property instead of getpid() if it was correctly passed.
3341 // See bug 6351349.
3342 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3344 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3346 clock_tics_per_sec = CLK_TCK;
3348 init_random(1234567);
3350 ThreadCritical::initialize();
3352 Bsd::set_page_size(getpagesize());
3353 if (Bsd::page_size() == -1) {
3354 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3355 strerror(errno)));
3356 }
3357 init_page_sizes((size_t) Bsd::page_size());
3359 Bsd::initialize_system_info();
3361 // main_thread points to the aboriginal thread
3362 Bsd::_main_thread = pthread_self();
3364 Bsd::clock_init();
3365 initial_time_count = os::elapsed_counter();
3367 #ifdef __APPLE__
3368 // XXXDARWIN
3369 // Work around the unaligned VM callbacks in hotspot's
3370 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3371 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3372 // alignment when doing symbol lookup. To work around this, we force early
3373 // binding of all symbols now, thus binding when alignment is known-good.
3374 _dyld_bind_fully_image_containing_address((const void *) &os::init);
3375 #endif
3376 }
3378 // To install functions for atexit system call
3379 extern "C" {
3380 static void perfMemory_exit_helper() {
3381 perfMemory_exit();
3382 }
3383 }
3385 // this is called _after_ the global arguments have been parsed
3386 jint os::init_2(void)
3387 {
3388 // Allocate a single page and mark it as readable for safepoint polling
3389 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3390 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
3392 os::set_polling_page( polling_page );
3394 #ifndef PRODUCT
3395 if(Verbose && PrintMiscellaneous)
3396 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
3397 #endif
3399 if (!UseMembar) {
3400 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3401 guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page");
3402 os::set_memory_serialize_page( mem_serialize_page );
3404 #ifndef PRODUCT
3405 if(Verbose && PrintMiscellaneous)
3406 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
3407 #endif
3408 }
3410 os::large_page_init();
3412 // initialize suspend/resume support - must do this before signal_sets_init()
3413 if (SR_initialize() != 0) {
3414 perror("SR_initialize failed");
3415 return JNI_ERR;
3416 }
3418 Bsd::signal_sets_init();
3419 Bsd::install_signal_handlers();
3421 // Check minimum allowable stack size for thread creation and to initialize
3422 // the java system classes, including StackOverflowError - depends on page
3423 // size. Add a page for compiler2 recursion in main thread.
3424 // Add in 2*BytesPerWord times page size to account for VM stack during
3425 // class initialization depending on 32 or 64 bit VM.
3426 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3427 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3428 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3430 size_t threadStackSizeInBytes = ThreadStackSize * K;
3431 if (threadStackSizeInBytes != 0 &&
3432 threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3433 tty->print_cr("\nThe stack size specified is too small, "
3434 "Specify at least %dk",
3435 os::Bsd::min_stack_allowed/ K);
3436 return JNI_ERR;
3437 }
3439 // Make the stack size a multiple of the page size so that
3440 // the yellow/red zones can be guarded.
3441 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3442 vm_page_size()));
3444 if (MaxFDLimit) {
3445 // set the number of file descriptors to max. print out error
3446 // if getrlimit/setrlimit fails but continue regardless.
3447 struct rlimit nbr_files;
3448 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3449 if (status != 0) {
3450 if (PrintMiscellaneous && (Verbose || WizardMode))
3451 perror("os::init_2 getrlimit failed");
3452 } else {
3453 nbr_files.rlim_cur = nbr_files.rlim_max;
3455 #ifdef __APPLE__
3456 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3457 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3458 // be used instead
3459 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3460 #endif
3462 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3463 if (status != 0) {
3464 if (PrintMiscellaneous && (Verbose || WizardMode))
3465 perror("os::init_2 setrlimit failed");
3466 }
3467 }
3468 }
3470 // at-exit methods are called in the reverse order of their registration.
3471 // atexit functions are called on return from main or as a result of a
3472 // call to exit(3C). There can be only 32 of these functions registered
3473 // and atexit() does not set errno.
3475 if (PerfAllowAtExitRegistration) {
3476 // only register atexit functions if PerfAllowAtExitRegistration is set.
3477 // atexit functions can be delayed until process exit time, which
3478 // can be problematic for embedded VM situations. Embedded VMs should
3479 // call DestroyJavaVM() to assure that VM resources are released.
3481 // note: perfMemory_exit_helper atexit function may be removed in
3482 // the future if the appropriate cleanup code can be added to the
3483 // VM_Exit VMOperation's doit method.
3484 if (atexit(perfMemory_exit_helper) != 0) {
3485 warning("os::init2 atexit(perfMemory_exit_helper) failed");
3486 }
3487 }
3489 // initialize thread priority policy
3490 prio_init();
3492 #ifdef __APPLE__
3493 // dynamically link to objective c gc registration
3494 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3495 if (handleLibObjc != NULL) {
3496 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3497 }
3498 #endif
3500 return JNI_OK;
3501 }
3503 // this is called at the end of vm_initialization
3504 void os::init_3(void) { }
3506 // Mark the polling page as unreadable
3507 void os::make_polling_page_unreadable(void) {
3508 if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
3509 fatal("Could not disable polling page");
3510 };
3512 // Mark the polling page as readable
3513 void os::make_polling_page_readable(void) {
3514 if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3515 fatal("Could not enable polling page");
3516 }
3517 };
3519 int os::active_processor_count() {
3520 return _processor_count;
3521 }
3523 void os::set_native_thread_name(const char *name) {
3524 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3525 // This is only supported in Snow Leopard and beyond
3526 if (name != NULL) {
3527 // Add a "Java: " prefix to the name
3528 char buf[MAXTHREADNAMESIZE];
3529 snprintf(buf, sizeof(buf), "Java: %s", name);
3530 pthread_setname_np(buf);
3531 }
3532 #endif
3533 }
3535 bool os::distribute_processes(uint length, uint* distribution) {
3536 // Not yet implemented.
3537 return false;
3538 }
3540 bool os::bind_to_processor(uint processor_id) {
3541 // Not yet implemented.
3542 return false;
3543 }
3545 ///
3547 // Suspends the target using the signal mechanism and then grabs the PC before
3548 // resuming the target. Used by the flat-profiler only
3549 ExtendedPC os::get_thread_pc(Thread* thread) {
3550 // Make sure that it is called by the watcher for the VMThread
3551 assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3552 assert(thread->is_VM_thread(), "Can only be called for VMThread");
3554 ExtendedPC epc;
3556 OSThread* osthread = thread->osthread();
3557 if (do_suspend(osthread)) {
3558 if (osthread->ucontext() != NULL) {
3559 epc = os::Bsd::ucontext_get_pc(osthread->ucontext());
3560 } else {
3561 // NULL context is unexpected, double-check this is the VMThread
3562 guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3563 }
3564 do_resume(osthread);
3565 }
3566 // failure means pthread_kill failed for some reason - arguably this is
3567 // a fatal problem, but such problems are ignored elsewhere
3569 return epc;
3570 }
3572 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
3573 {
3574 return pthread_cond_timedwait(_cond, _mutex, _abstime);
3575 }
3577 ////////////////////////////////////////////////////////////////////////////////
3578 // debug support
3580 static address same_page(address x, address y) {
3581 int page_bits = -os::vm_page_size();
3582 if ((intptr_t(x) & page_bits) == (intptr_t(y) & page_bits))
3583 return x;
3584 else if (x > y)
3585 return (address)(intptr_t(y) | ~page_bits) + 1;
3586 else
3587 return (address)(intptr_t(y) & page_bits);
3588 }
3590 bool os::find(address addr, outputStream* st) {
3591 Dl_info dlinfo;
3592 memset(&dlinfo, 0, sizeof(dlinfo));
3593 if (dladdr(addr, &dlinfo)) {
3594 st->print(PTR_FORMAT ": ", addr);
3595 if (dlinfo.dli_sname != NULL) {
3596 st->print("%s+%#x", dlinfo.dli_sname,
3597 addr - (intptr_t)dlinfo.dli_saddr);
3598 } else if (dlinfo.dli_fname) {
3599 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3600 } else {
3601 st->print("<absolute address>");
3602 }
3603 if (dlinfo.dli_fname) {
3604 st->print(" in %s", dlinfo.dli_fname);
3605 }
3606 if (dlinfo.dli_fbase) {
3607 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3608 }
3609 st->cr();
3611 if (Verbose) {
3612 // decode some bytes around the PC
3613 address begin = same_page(addr-40, addr);
3614 address end = same_page(addr+40, addr);
3615 address lowest = (address) dlinfo.dli_sname;
3616 if (!lowest) lowest = (address) dlinfo.dli_fbase;
3617 if (begin < lowest) begin = lowest;
3618 Dl_info dlinfo2;
3619 if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr
3620 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
3621 end = (address) dlinfo2.dli_saddr;
3622 Disassembler::decode(begin, end, st);
3623 }
3624 return true;
3625 }
3626 return false;
3627 }
3629 ////////////////////////////////////////////////////////////////////////////////
3630 // misc
3632 // This does not do anything on Bsd. This is basically a hook for being
3633 // able to use structured exception handling (thread-local exception filters)
3634 // on, e.g., Win32.
3635 void
3636 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
3637 JavaCallArguments* args, Thread* thread) {
3638 f(value, method, args, thread);
3639 }
3641 void os::print_statistics() {
3642 }
3644 int os::message_box(const char* title, const char* message) {
3645 int i;
3646 fdStream err(defaultStream::error_fd());
3647 for (i = 0; i < 78; i++) err.print_raw("=");
3648 err.cr();
3649 err.print_raw_cr(title);
3650 for (i = 0; i < 78; i++) err.print_raw("-");
3651 err.cr();
3652 err.print_raw_cr(message);
3653 for (i = 0; i < 78; i++) err.print_raw("=");
3654 err.cr();
3656 char buf[16];
3657 // Prevent process from exiting upon "read error" without consuming all CPU
3658 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3660 return buf[0] == 'y' || buf[0] == 'Y';
3661 }
3663 int os::stat(const char *path, struct stat *sbuf) {
3664 char pathbuf[MAX_PATH];
3665 if (strlen(path) > MAX_PATH - 1) {
3666 errno = ENAMETOOLONG;
3667 return -1;
3668 }
3669 os::native_path(strcpy(pathbuf, path));
3670 return ::stat(pathbuf, sbuf);
3671 }
3673 bool os::check_heap(bool force) {
3674 return true;
3675 }
3677 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
3678 return ::vsnprintf(buf, count, format, args);
3679 }
3681 // Is a (classpath) directory empty?
3682 bool os::dir_is_empty(const char* path) {
3683 DIR *dir = NULL;
3684 struct dirent *ptr;
3686 dir = opendir(path);
3687 if (dir == NULL) return true;
3689 /* Scan the directory */
3690 bool result = true;
3691 char buf[sizeof(struct dirent) + MAX_PATH];
3692 while (result && (ptr = ::readdir(dir)) != NULL) {
3693 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3694 result = false;
3695 }
3696 }
3697 closedir(dir);
3698 return result;
3699 }
3701 // This code originates from JDK's sysOpen and open64_w
3702 // from src/solaris/hpi/src/system_md.c
3704 #ifndef O_DELETE
3705 #define O_DELETE 0x10000
3706 #endif
3708 // Open a file. Unlink the file immediately after open returns
3709 // if the specified oflag has the O_DELETE flag set.
3710 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
3712 int os::open(const char *path, int oflag, int mode) {
3714 if (strlen(path) > MAX_PATH - 1) {
3715 errno = ENAMETOOLONG;
3716 return -1;
3717 }
3718 int fd;
3719 int o_delete = (oflag & O_DELETE);
3720 oflag = oflag & ~O_DELETE;
3722 fd = ::open(path, oflag, mode);
3723 if (fd == -1) return -1;
3725 //If the open succeeded, the file might still be a directory
3726 {
3727 struct stat buf;
3728 int ret = ::fstat(fd, &buf);
3729 int st_mode = buf.st_mode;
3731 if (ret != -1) {
3732 if ((st_mode & S_IFMT) == S_IFDIR) {
3733 errno = EISDIR;
3734 ::close(fd);
3735 return -1;
3736 }
3737 } else {
3738 ::close(fd);
3739 return -1;
3740 }
3741 }
3743 /*
3744 * All file descriptors that are opened in the JVM and not
3745 * specifically destined for a subprocess should have the
3746 * close-on-exec flag set. If we don't set it, then careless 3rd
3747 * party native code might fork and exec without closing all
3748 * appropriate file descriptors (e.g. as we do in closeDescriptors in
3749 * UNIXProcess.c), and this in turn might:
3750 *
3751 * - cause end-of-file to fail to be detected on some file
3752 * descriptors, resulting in mysterious hangs, or
3753 *
3754 * - might cause an fopen in the subprocess to fail on a system
3755 * suffering from bug 1085341.
3756 *
3757 * (Yes, the default setting of the close-on-exec flag is a Unix
3758 * design flaw)
3759 *
3760 * See:
3761 * 1085341: 32-bit stdio routines should support file descriptors >255
3762 * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3763 * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3764 */
3765 #ifdef FD_CLOEXEC
3766 {
3767 int flags = ::fcntl(fd, F_GETFD);
3768 if (flags != -1)
3769 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3770 }
3771 #endif
3773 if (o_delete != 0) {
3774 ::unlink(path);
3775 }
3776 return fd;
3777 }
3780 // create binary file, rewriting existing file if required
3781 int os::create_binary_file(const char* path, bool rewrite_existing) {
3782 int oflags = O_WRONLY | O_CREAT;
3783 if (!rewrite_existing) {
3784 oflags |= O_EXCL;
3785 }
3786 return ::open(path, oflags, S_IREAD | S_IWRITE);
3787 }
3789 // return current position of file pointer
3790 jlong os::current_file_offset(int fd) {
3791 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3792 }
3794 // move file pointer to the specified offset
3795 jlong os::seek_to_file_offset(int fd, jlong offset) {
3796 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3797 }
3799 // This code originates from JDK's sysAvailable
3800 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3802 int os::available(int fd, jlong *bytes) {
3803 jlong cur, end;
3804 int mode;
3805 struct stat buf;
3807 if (::fstat(fd, &buf) >= 0) {
3808 mode = buf.st_mode;
3809 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3810 /*
3811 * XXX: is the following call interruptible? If so, this might
3812 * need to go through the INTERRUPT_IO() wrapper as for other
3813 * blocking, interruptible calls in this file.
3814 */
3815 int n;
3816 if (::ioctl(fd, FIONREAD, &n) >= 0) {
3817 *bytes = n;
3818 return 1;
3819 }
3820 }
3821 }
3822 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3823 return 0;
3824 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3825 return 0;
3826 } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3827 return 0;
3828 }
3829 *bytes = end - cur;
3830 return 1;
3831 }
3833 int os::socket_available(int fd, jint *pbytes) {
3834 if (fd < 0)
3835 return OS_OK;
3837 int ret;
3839 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
3841 //%% note ioctl can return 0 when successful, JVM_SocketAvailable
3842 // is expected to return 0 on failure and 1 on success to the jdk.
3844 return (ret == OS_ERR) ? 0 : 1;
3845 }
3847 // Map a block of memory.
3848 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3849 char *addr, size_t bytes, bool read_only,
3850 bool allow_exec) {
3851 int prot;
3852 int flags;
3854 if (read_only) {
3855 prot = PROT_READ;
3856 flags = MAP_SHARED;
3857 } else {
3858 prot = PROT_READ | PROT_WRITE;
3859 flags = MAP_PRIVATE;
3860 }
3862 if (allow_exec) {
3863 prot |= PROT_EXEC;
3864 }
3866 if (addr != NULL) {
3867 flags |= MAP_FIXED;
3868 }
3870 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3871 fd, file_offset);
3872 if (mapped_address == MAP_FAILED) {
3873 return NULL;
3874 }
3875 return mapped_address;
3876 }
3879 // Remap a block of memory.
3880 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3881 char *addr, size_t bytes, bool read_only,
3882 bool allow_exec) {
3883 // same as map_memory() on this OS
3884 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3885 allow_exec);
3886 }
3889 // Unmap a block of memory.
3890 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3891 return munmap(addr, bytes) == 0;
3892 }
3894 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3895 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3896 // of a thread.
3897 //
3898 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3899 // the fast estimate available on the platform.
3901 jlong os::current_thread_cpu_time() {
3902 #ifdef __APPLE__
3903 return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3904 #endif
3905 }
3907 jlong os::thread_cpu_time(Thread* thread) {
3908 }
3910 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3911 #ifdef __APPLE__
3912 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3913 #endif
3914 }
3916 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3917 #ifdef __APPLE__
3918 struct thread_basic_info tinfo;
3919 mach_msg_type_number_t tcount = THREAD_INFO_MAX;
3920 kern_return_t kr;
3921 thread_t mach_thread;
3923 mach_thread = thread->osthread()->thread_id();
3924 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
3925 if (kr != KERN_SUCCESS)
3926 return -1;
3928 if (user_sys_cpu_time) {
3929 jlong nanos;
3930 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
3931 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
3932 return nanos;
3933 } else {
3934 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
3935 }
3936 #endif
3937 }
3940 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3941 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
3942 info_ptr->may_skip_backward = false; // elapsed time not wall time
3943 info_ptr->may_skip_forward = false; // elapsed time not wall time
3944 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
3945 }
3947 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3948 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
3949 info_ptr->may_skip_backward = false; // elapsed time not wall time
3950 info_ptr->may_skip_forward = false; // elapsed time not wall time
3951 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
3952 }
3954 bool os::is_thread_cpu_time_supported() {
3955 #ifdef __APPLE__
3956 return true;
3957 #else
3958 return false;
3959 #endif
3960 }
3962 // System loadavg support. Returns -1 if load average cannot be obtained.
3963 // Bsd doesn't yet have a (official) notion of processor sets,
3964 // so just return the system wide load average.
3965 int os::loadavg(double loadavg[], int nelem) {
3966 return ::getloadavg(loadavg, nelem);
3967 }
3969 void os::pause() {
3970 char filename[MAX_PATH];
3971 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
3972 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
3973 } else {
3974 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
3975 }
3977 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
3978 if (fd != -1) {
3979 struct stat buf;
3980 ::close(fd);
3981 while (::stat(filename, &buf) == 0) {
3982 (void)::poll(NULL, 0, 100);
3983 }
3984 } else {
3985 jio_fprintf(stderr,
3986 "Could not open pause file '%s', continuing immediately.\n", filename);
3987 }
3988 }
3991 // Refer to the comments in os_solaris.cpp park-unpark.
3992 //
3993 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
3994 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
3995 // For specifics regarding the bug see GLIBC BUGID 261237 :
3996 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
3997 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
3998 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
3999 // is used. (The simple C test-case provided in the GLIBC bug report manifests the
4000 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4001 // and monitorenter when we're using 1-0 locking. All those operations may result in
4002 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version
4003 // of libpthread avoids the problem, but isn't practical.
4004 //
4005 // Possible remedies:
4006 //
4007 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work.
4008 // This is palliative and probabilistic, however. If the thread is preempted
4009 // between the call to compute_abstime() and pthread_cond_timedwait(), more
4010 // than the minimum period may have passed, and the abstime may be stale (in the
4011 // past) resultin in a hang. Using this technique reduces the odds of a hang
4012 // but the JVM is still vulnerable, particularly on heavily loaded systems.
4013 //
4014 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4015 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set
4016 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4017 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant
4018 // thread.
4019 //
4020 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread
4021 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing
4022 // a timeout request to the chron thread and then blocking via pthread_cond_wait().
4023 // This also works well. In fact it avoids kernel-level scalability impediments
4024 // on certain platforms that don't handle lots of active pthread_cond_timedwait()
4025 // timers in a graceful fashion.
4026 //
4027 // 4. When the abstime value is in the past it appears that control returns
4028 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4029 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we
4030 // can avoid the problem by reinitializing the condvar -- by cond_destroy()
4031 // followed by cond_init() -- after all calls to pthread_cond_timedwait().
4032 // It may be possible to avoid reinitialization by checking the return
4033 // value from pthread_cond_timedwait(). In addition to reinitializing the
4034 // condvar we must establish the invariant that cond_signal() is only called
4035 // within critical sections protected by the adjunct mutex. This prevents
4036 // cond_signal() from "seeing" a condvar that's in the midst of being
4037 // reinitialized or that is corrupt. Sadly, this invariant obviates the
4038 // desirable signal-after-unlock optimization that avoids futile context switching.
4039 //
4040 // I'm also concerned that some versions of NTPL might allocate an auxilliary
4041 // structure when a condvar is used or initialized. cond_destroy() would
4042 // release the helper structure. Our reinitialize-after-timedwait fix
4043 // put excessive stress on malloc/free and locks protecting the c-heap.
4044 //
4045 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag.
4046 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4047 // and only enabling the work-around for vulnerable environments.
4049 // utility to compute the abstime argument to timedwait:
4050 // millis is the relative timeout time
4051 // abstime will be the absolute timeout time
4052 // TODO: replace compute_abstime() with unpackTime()
4054 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
4055 if (millis < 0) millis = 0;
4056 struct timeval now;
4057 int status = gettimeofday(&now, NULL);
4058 assert(status == 0, "gettimeofday");
4059 jlong seconds = millis / 1000;
4060 millis %= 1000;
4061 if (seconds > 50000000) { // see man cond_timedwait(3T)
4062 seconds = 50000000;
4063 }
4064 abstime->tv_sec = now.tv_sec + seconds;
4065 long usec = now.tv_usec + millis * 1000;
4066 if (usec >= 1000000) {
4067 abstime->tv_sec += 1;
4068 usec -= 1000000;
4069 }
4070 abstime->tv_nsec = usec * 1000;
4071 return abstime;
4072 }
4075 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
4076 // Conceptually TryPark() should be equivalent to park(0).
4078 int os::PlatformEvent::TryPark() {
4079 for (;;) {
4080 const int v = _Event ;
4081 guarantee ((v == 0) || (v == 1), "invariant") ;
4082 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ;
4083 }
4084 }
4086 void os::PlatformEvent::park() { // AKA "down()"
4087 // Invariant: Only the thread associated with the Event/PlatformEvent
4088 // may call park().
4089 // TODO: assert that _Assoc != NULL or _Assoc == Self
4090 int v ;
4091 for (;;) {
4092 v = _Event ;
4093 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4094 }
4095 guarantee (v >= 0, "invariant") ;
4096 if (v == 0) {
4097 // Do this the hard way by blocking ...
4098 int status = pthread_mutex_lock(_mutex);
4099 assert_status(status == 0, status, "mutex_lock");
4100 guarantee (_nParked == 0, "invariant") ;
4101 ++ _nParked ;
4102 while (_Event < 0) {
4103 status = pthread_cond_wait(_cond, _mutex);
4104 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4105 // Treat this the same as if the wait was interrupted
4106 if (status == ETIMEDOUT) { status = EINTR; }
4107 assert_status(status == 0 || status == EINTR, status, "cond_wait");
4108 }
4109 -- _nParked ;
4111 _Event = 0 ;
4112 status = pthread_mutex_unlock(_mutex);
4113 assert_status(status == 0, status, "mutex_unlock");
4114 // Paranoia to ensure our locked and lock-free paths interact
4115 // correctly with each other.
4116 OrderAccess::fence();
4117 }
4118 guarantee (_Event >= 0, "invariant") ;
4119 }
4121 int os::PlatformEvent::park(jlong millis) {
4122 guarantee (_nParked == 0, "invariant") ;
4124 int v ;
4125 for (;;) {
4126 v = _Event ;
4127 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4128 }
4129 guarantee (v >= 0, "invariant") ;
4130 if (v != 0) return OS_OK ;
4132 // We do this the hard way, by blocking the thread.
4133 // Consider enforcing a minimum timeout value.
4134 struct timespec abst;
4135 compute_abstime(&abst, millis);
4137 int ret = OS_TIMEOUT;
4138 int status = pthread_mutex_lock(_mutex);
4139 assert_status(status == 0, status, "mutex_lock");
4140 guarantee (_nParked == 0, "invariant") ;
4141 ++_nParked ;
4143 // Object.wait(timo) will return because of
4144 // (a) notification
4145 // (b) timeout
4146 // (c) thread.interrupt
4147 //
4148 // Thread.interrupt and object.notify{All} both call Event::set.
4149 // That is, we treat thread.interrupt as a special case of notification.
4150 // The underlying Solaris implementation, cond_timedwait, admits
4151 // spurious/premature wakeups, but the JLS/JVM spec prevents the
4152 // JVM from making those visible to Java code. As such, we must
4153 // filter out spurious wakeups. We assume all ETIME returns are valid.
4154 //
4155 // TODO: properly differentiate simultaneous notify+interrupt.
4156 // In that case, we should propagate the notify to another waiter.
4158 while (_Event < 0) {
4159 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4160 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4161 pthread_cond_destroy (_cond);
4162 pthread_cond_init (_cond, NULL) ;
4163 }
4164 assert_status(status == 0 || status == EINTR ||
4165 status == ETIMEDOUT,
4166 status, "cond_timedwait");
4167 if (!FilterSpuriousWakeups) break ; // previous semantics
4168 if (status == ETIMEDOUT) break ;
4169 // We consume and ignore EINTR and spurious wakeups.
4170 }
4171 --_nParked ;
4172 if (_Event >= 0) {
4173 ret = OS_OK;
4174 }
4175 _Event = 0 ;
4176 status = pthread_mutex_unlock(_mutex);
4177 assert_status(status == 0, status, "mutex_unlock");
4178 assert (_nParked == 0, "invariant") ;
4179 // Paranoia to ensure our locked and lock-free paths interact
4180 // correctly with each other.
4181 OrderAccess::fence();
4182 return ret;
4183 }
4185 void os::PlatformEvent::unpark() {
4186 // Transitions for _Event:
4187 // 0 :=> 1
4188 // 1 :=> 1
4189 // -1 :=> either 0 or 1; must signal target thread
4190 // That is, we can safely transition _Event from -1 to either
4191 // 0 or 1. Forcing 1 is slightly more efficient for back-to-back
4192 // unpark() calls.
4193 // See also: "Semaphores in Plan 9" by Mullender & Cox
4194 //
4195 // Note: Forcing a transition from "-1" to "1" on an unpark() means
4196 // that it will take two back-to-back park() calls for the owning
4197 // thread to block. This has the benefit of forcing a spurious return
4198 // from the first park() call after an unpark() call which will help
4199 // shake out uses of park() and unpark() without condition variables.
4201 if (Atomic::xchg(1, &_Event) >= 0) return;
4203 // Wait for the thread associated with the event to vacate
4204 int status = pthread_mutex_lock(_mutex);
4205 assert_status(status == 0, status, "mutex_lock");
4206 int AnyWaiters = _nParked;
4207 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4208 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4209 AnyWaiters = 0;
4210 pthread_cond_signal(_cond);
4211 }
4212 status = pthread_mutex_unlock(_mutex);
4213 assert_status(status == 0, status, "mutex_unlock");
4214 if (AnyWaiters != 0) {
4215 status = pthread_cond_signal(_cond);
4216 assert_status(status == 0, status, "cond_signal");
4217 }
4219 // Note that we signal() _after dropping the lock for "immortal" Events.
4220 // This is safe and avoids a common class of futile wakeups. In rare
4221 // circumstances this can cause a thread to return prematurely from
4222 // cond_{timed}wait() but the spurious wakeup is benign and the victim will
4223 // simply re-test the condition and re-park itself.
4224 }
4227 // JSR166
4228 // -------------------------------------------------------
4230 /*
4231 * The solaris and bsd implementations of park/unpark are fairly
4232 * conservative for now, but can be improved. They currently use a
4233 * mutex/condvar pair, plus a a count.
4234 * Park decrements count if > 0, else does a condvar wait. Unpark
4235 * sets count to 1 and signals condvar. Only one thread ever waits
4236 * on the condvar. Contention seen when trying to park implies that someone
4237 * is unparking you, so don't wait. And spurious returns are fine, so there
4238 * is no need to track notifications.
4239 */
4241 #define MAX_SECS 100000000
4242 /*
4243 * This code is common to bsd and solaris and will be moved to a
4244 * common place in dolphin.
4245 *
4246 * The passed in time value is either a relative time in nanoseconds
4247 * or an absolute time in milliseconds. Either way it has to be unpacked
4248 * into suitable seconds and nanoseconds components and stored in the
4249 * given timespec structure.
4250 * Given time is a 64-bit value and the time_t used in the timespec is only
4251 * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4252 * overflow if times way in the future are given. Further on Solaris versions
4253 * prior to 10 there is a restriction (see cond_timedwait) that the specified
4254 * number of seconds, in abstime, is less than current_time + 100,000,000.
4255 * As it will be 28 years before "now + 100000000" will overflow we can
4256 * ignore overflow and just impose a hard-limit on seconds using the value
4257 * of "now + 100,000,000". This places a limit on the timeout of about 3.17
4258 * years from "now".
4259 */
4261 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4262 assert (time > 0, "convertTime");
4264 struct timeval now;
4265 int status = gettimeofday(&now, NULL);
4266 assert(status == 0, "gettimeofday");
4268 time_t max_secs = now.tv_sec + MAX_SECS;
4270 if (isAbsolute) {
4271 jlong secs = time / 1000;
4272 if (secs > max_secs) {
4273 absTime->tv_sec = max_secs;
4274 }
4275 else {
4276 absTime->tv_sec = secs;
4277 }
4278 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4279 }
4280 else {
4281 jlong secs = time / NANOSECS_PER_SEC;
4282 if (secs >= MAX_SECS) {
4283 absTime->tv_sec = max_secs;
4284 absTime->tv_nsec = 0;
4285 }
4286 else {
4287 absTime->tv_sec = now.tv_sec + secs;
4288 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4289 if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4290 absTime->tv_nsec -= NANOSECS_PER_SEC;
4291 ++absTime->tv_sec; // note: this must be <= max_secs
4292 }
4293 }
4294 }
4295 assert(absTime->tv_sec >= 0, "tv_sec < 0");
4296 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4297 assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4298 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4299 }
4301 void Parker::park(bool isAbsolute, jlong time) {
4302 // Ideally we'd do something useful while spinning, such
4303 // as calling unpackTime().
4305 // Optional fast-path check:
4306 // Return immediately if a permit is available.
4307 // We depend on Atomic::xchg() having full barrier semantics
4308 // since we are doing a lock-free update to _counter.
4309 if (Atomic::xchg(0, &_counter) > 0) return;
4311 Thread* thread = Thread::current();
4312 assert(thread->is_Java_thread(), "Must be JavaThread");
4313 JavaThread *jt = (JavaThread *)thread;
4315 // Optional optimization -- avoid state transitions if there's an interrupt pending.
4316 // Check interrupt before trying to wait
4317 if (Thread::is_interrupted(thread, false)) {
4318 return;
4319 }
4321 // Next, demultiplex/decode time arguments
4322 struct timespec absTime;
4323 if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
4324 return;
4325 }
4326 if (time > 0) {
4327 unpackTime(&absTime, isAbsolute, time);
4328 }
4331 // Enter safepoint region
4332 // Beware of deadlocks such as 6317397.
4333 // The per-thread Parker:: mutex is a classic leaf-lock.
4334 // In particular a thread must never block on the Threads_lock while
4335 // holding the Parker:: mutex. If safepoints are pending both the
4336 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4337 ThreadBlockInVM tbivm(jt);
4339 // Don't wait if cannot get lock since interference arises from
4340 // unblocking. Also. check interrupt before trying wait
4341 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4342 return;
4343 }
4345 int status ;
4346 if (_counter > 0) { // no wait needed
4347 _counter = 0;
4348 status = pthread_mutex_unlock(_mutex);
4349 assert (status == 0, "invariant") ;
4350 // Paranoia to ensure our locked and lock-free paths interact
4351 // correctly with each other and Java-level accesses.
4352 OrderAccess::fence();
4353 return;
4354 }
4356 #ifdef ASSERT
4357 // Don't catch signals while blocked; let the running threads have the signals.
4358 // (This allows a debugger to break into the running thread.)
4359 sigset_t oldsigs;
4360 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4361 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4362 #endif
4364 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4365 jt->set_suspend_equivalent();
4366 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4368 if (time == 0) {
4369 status = pthread_cond_wait (_cond, _mutex) ;
4370 } else {
4371 status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
4372 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4373 pthread_cond_destroy (_cond) ;
4374 pthread_cond_init (_cond, NULL);
4375 }
4376 }
4377 assert_status(status == 0 || status == EINTR ||
4378 status == ETIMEDOUT,
4379 status, "cond_timedwait");
4381 #ifdef ASSERT
4382 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4383 #endif
4385 _counter = 0 ;
4386 status = pthread_mutex_unlock(_mutex) ;
4387 assert_status(status == 0, status, "invariant") ;
4388 // Paranoia to ensure our locked and lock-free paths interact
4389 // correctly with each other and Java-level accesses.
4390 OrderAccess::fence();
4392 // If externally suspended while waiting, re-suspend
4393 if (jt->handle_special_suspend_equivalent_condition()) {
4394 jt->java_suspend_self();
4395 }
4396 }
4398 void Parker::unpark() {
4399 int s, status ;
4400 status = pthread_mutex_lock(_mutex);
4401 assert (status == 0, "invariant") ;
4402 s = _counter;
4403 _counter = 1;
4404 if (s < 1) {
4405 if (WorkAroundNPTLTimedWaitHang) {
4406 status = pthread_cond_signal (_cond) ;
4407 assert (status == 0, "invariant") ;
4408 status = pthread_mutex_unlock(_mutex);
4409 assert (status == 0, "invariant") ;
4410 } else {
4411 status = pthread_mutex_unlock(_mutex);
4412 assert (status == 0, "invariant") ;
4413 status = pthread_cond_signal (_cond) ;
4414 assert (status == 0, "invariant") ;
4415 }
4416 } else {
4417 pthread_mutex_unlock(_mutex);
4418 assert (status == 0, "invariant") ;
4419 }
4420 }
4423 /* Darwin has no "environ" in a dynamic library. */
4424 #ifdef __APPLE__
4425 #include <crt_externs.h>
4426 #define environ (*_NSGetEnviron())
4427 #else
4428 extern char** environ;
4429 #endif
4431 // Run the specified command in a separate process. Return its exit value,
4432 // or -1 on failure (e.g. can't fork a new process).
4433 // Unlike system(), this function can be called from signal handler. It
4434 // doesn't block SIGINT et al.
4435 int os::fork_and_exec(char* cmd) {
4436 const char * argv[4] = {"sh", "-c", cmd, NULL};
4438 // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4439 // pthread_atfork handlers and reset pthread library. All we need is a
4440 // separate process to execve. Make a direct syscall to fork process.
4441 // On IA64 there's no fork syscall, we have to use fork() and hope for
4442 // the best...
4443 pid_t pid = fork();
4445 if (pid < 0) {
4446 // fork failed
4447 return -1;
4449 } else if (pid == 0) {
4450 // child process
4452 // execve() in BsdThreads will call pthread_kill_other_threads_np()
4453 // first to kill every thread on the thread list. Because this list is
4454 // not reset by fork() (see notes above), execve() will instead kill
4455 // every thread in the parent process. We know this is the only thread
4456 // in the new process, so make a system call directly.
4457 // IA64 should use normal execve() from glibc to match the glibc fork()
4458 // above.
4459 execve("/bin/sh", (char* const*)argv, environ);
4461 // execve failed
4462 _exit(-1);
4464 } else {
4465 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4466 // care about the actual exit code, for now.
4468 int status;
4470 // Wait for the child process to exit. This returns immediately if
4471 // the child has already exited. */
4472 while (waitpid(pid, &status, 0) < 0) {
4473 switch (errno) {
4474 case ECHILD: return 0;
4475 case EINTR: break;
4476 default: return -1;
4477 }
4478 }
4480 if (WIFEXITED(status)) {
4481 // The child exited normally; get its exit code.
4482 return WEXITSTATUS(status);
4483 } else if (WIFSIGNALED(status)) {
4484 // The child exited because of a signal
4485 // The best value to return is 0x80 + signal number,
4486 // because that is what all Unix shells do, and because
4487 // it allows callers to distinguish between process exit and
4488 // process death by signal.
4489 return 0x80 + WTERMSIG(status);
4490 } else {
4491 // Unknown exit code; pass it through
4492 return status;
4493 }
4494 }
4495 }
4497 // is_headless_jre()
4498 //
4499 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4500 // in order to report if we are running in a headless jre
4501 //
4502 // Since JDK8 xawt/libmawt.so was moved into the same directory
4503 // as libawt.so, and renamed libawt_xawt.so
4504 //
4505 bool os::is_headless_jre() {
4506 struct stat statbuf;
4507 char buf[MAXPATHLEN];
4508 char libmawtpath[MAXPATHLEN];
4509 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX;
4510 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4511 char *p;
4513 // Get path to libjvm.so
4514 os::jvm_path(buf, sizeof(buf));
4516 // Get rid of libjvm.so
4517 p = strrchr(buf, '/');
4518 if (p == NULL) return false;
4519 else *p = '\0';
4521 // Get rid of client or server
4522 p = strrchr(buf, '/');
4523 if (p == NULL) return false;
4524 else *p = '\0';
4526 // check xawt/libmawt.so
4527 strcpy(libmawtpath, buf);
4528 strcat(libmawtpath, xawtstr);
4529 if (::stat(libmawtpath, &statbuf) == 0) return false;
4531 // check libawt_xawt.so
4532 strcpy(libmawtpath, buf);
4533 strcat(libmawtpath, new_xawtstr);
4534 if (::stat(libmawtpath, &statbuf) == 0) return false;
4536 return true;
4537 }
4539 // Get the default path to the core file
4540 // Returns the length of the string
4541 int os::get_core_path(char* buffer, size_t bufferSize) {
4542 int n = jio_snprintf(buffer, bufferSize, "/cores");
4544 // Truncate if theoretical string was longer than bufferSize
4545 n = MIN2(n, (int)bufferSize);
4547 return n;
4548 }