Wed, 19 Dec 2012 10:35:08 -0800
8005044: remove crufty '_g' support from HS runtime code
Summary: Phase 2 is removing '_g' support from the Runtime code.
Reviewed-by: dcubed, coleenp, hseigel
Contributed-by: ron.durbin@oracle.com
1 /*
2 * Copyright (c) 1999, 2012, 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 u_long 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 set_processor_count(cpu_val);
254 }
255 else {
256 set_processor_count(1); // fallback
257 }
259 /* get physical memory via hw.usermem sysctl (hw.usermem is used
260 * instead of hw.physmem because we need size of allocatable memory
261 */
262 mib[0] = CTL_HW;
263 mib[1] = HW_USERMEM;
264 len = sizeof(mem_val);
265 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1)
266 _physical_memory = mem_val;
267 else
268 _physical_memory = 256*1024*1024; // fallback (XXXBSD?)
270 #ifdef __OpenBSD__
271 {
272 // limit _physical_memory memory view on OpenBSD since
273 // datasize rlimit restricts us anyway.
274 struct rlimit limits;
275 getrlimit(RLIMIT_DATA, &limits);
276 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
277 }
278 #endif
279 }
281 #ifdef __APPLE__
282 static const char *get_home() {
283 const char *home_dir = ::getenv("HOME");
284 if ((home_dir == NULL) || (*home_dir == '\0')) {
285 struct passwd *passwd_info = getpwuid(geteuid());
286 if (passwd_info != NULL) {
287 home_dir = passwd_info->pw_dir;
288 }
289 }
291 return home_dir;
292 }
293 #endif
295 void os::init_system_properties_values() {
296 // char arch[12];
297 // sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
299 // The next steps are taken in the product version:
300 //
301 // Obtain the JAVA_HOME value from the location of libjvm.so.
302 // This library should be located at:
303 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
304 //
305 // If "/jre/lib/" appears at the right place in the path, then we
306 // assume libjvm.so is installed in a JDK and we use this path.
307 //
308 // Otherwise exit with message: "Could not create the Java virtual machine."
309 //
310 // The following extra steps are taken in the debugging version:
311 //
312 // If "/jre/lib/" does NOT appear at the right place in the path
313 // instead of exit check for $JAVA_HOME environment variable.
314 //
315 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
316 // then we append a fake suffix "hotspot/libjvm.so" to this path so
317 // it looks like libjvm.so is installed there
318 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
319 //
320 // Otherwise exit.
321 //
322 // Important note: if the location of libjvm.so changes this
323 // code needs to be changed accordingly.
325 // The next few definitions allow the code to be verbatim:
326 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal)
327 #define getenv(n) ::getenv(n)
329 /*
330 * See ld(1):
331 * The linker uses the following search paths to locate required
332 * shared libraries:
333 * 1: ...
334 * ...
335 * 7: The default directories, normally /lib and /usr/lib.
336 */
337 #ifndef DEFAULT_LIBPATH
338 #define DEFAULT_LIBPATH "/lib:/usr/lib"
339 #endif
341 #define EXTENSIONS_DIR "/lib/ext"
342 #define ENDORSED_DIR "/lib/endorsed"
343 #define REG_DIR "/usr/java/packages"
345 #ifdef __APPLE__
346 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions"
347 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
348 const char *user_home_dir = get_home();
349 // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir
350 int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
351 sizeof(SYS_EXTENSIONS_DIRS);
352 #endif
354 {
355 /* sysclasspath, java_home, dll_dir */
356 {
357 char *home_path;
358 char *dll_path;
359 char *pslash;
360 char buf[MAXPATHLEN];
361 os::jvm_path(buf, sizeof(buf));
363 // Found the full path to libjvm.so.
364 // Now cut the path to <java_home>/jre if we can.
365 *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */
366 pslash = strrchr(buf, '/');
367 if (pslash != NULL)
368 *pslash = '\0'; /* get rid of /{client|server|hotspot} */
369 dll_path = malloc(strlen(buf) + 1);
370 if (dll_path == NULL)
371 return;
372 strcpy(dll_path, buf);
373 Arguments::set_dll_dir(dll_path);
375 if (pslash != NULL) {
376 pslash = strrchr(buf, '/');
377 if (pslash != NULL) {
378 *pslash = '\0'; /* get rid of /<arch> (/lib on macosx) */
379 #ifndef __APPLE__
380 pslash = strrchr(buf, '/');
381 if (pslash != NULL)
382 *pslash = '\0'; /* get rid of /lib */
383 #endif
384 }
385 }
387 home_path = malloc(strlen(buf) + 1);
388 if (home_path == NULL)
389 return;
390 strcpy(home_path, buf);
391 Arguments::set_java_home(home_path);
393 if (!set_boot_path('/', ':'))
394 return;
395 }
397 /*
398 * Where to look for native libraries
399 *
400 * Note: Due to a legacy implementation, most of the library path
401 * is set in the launcher. This was to accomodate linking restrictions
402 * on legacy Bsd implementations (which are no longer supported).
403 * Eventually, all the library path setting will be done here.
404 *
405 * However, to prevent the proliferation of improperly built native
406 * libraries, the new path component /usr/java/packages is added here.
407 * Eventually, all the library path setting will be done here.
408 */
409 {
410 char *ld_library_path;
412 /*
413 * Construct the invariant part of ld_library_path. Note that the
414 * space for the colon and the trailing null are provided by the
415 * nulls included by the sizeof operator (so actually we allocate
416 * a byte more than necessary).
417 */
418 #ifdef __APPLE__
419 ld_library_path = (char *) malloc(system_ext_size);
420 sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir);
421 #else
422 ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
423 strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
424 sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
425 #endif
427 /*
428 * Get the user setting of LD_LIBRARY_PATH, and prepended it. It
429 * should always exist (until the legacy problem cited above is
430 * addressed).
431 */
432 #ifdef __APPLE__
433 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper
434 char *l = getenv("JAVA_LIBRARY_PATH");
435 if (l != NULL) {
436 char *t = ld_library_path;
437 /* That's +1 for the colon and +1 for the trailing '\0' */
438 ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1);
439 sprintf(ld_library_path, "%s:%s", l, t);
440 free(t);
441 }
443 char *v = getenv("DYLD_LIBRARY_PATH");
444 #else
445 char *v = getenv("LD_LIBRARY_PATH");
446 #endif
447 if (v != NULL) {
448 char *t = ld_library_path;
449 /* That's +1 for the colon and +1 for the trailing '\0' */
450 ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
451 sprintf(ld_library_path, "%s:%s", v, t);
452 free(t);
453 }
455 #ifdef __APPLE__
456 // Apple's Java6 has "." at the beginning of java.library.path.
457 // OpenJDK on Windows has "." at the end of java.library.path.
458 // OpenJDK on Linux and Solaris don't have "." in java.library.path
459 // at all. To ease the transition from Apple's Java6 to OpenJDK7,
460 // "." is appended to the end of java.library.path. Yes, this
461 // could cause a change in behavior, but Apple's Java6 behavior
462 // can be achieved by putting "." at the beginning of the
463 // JAVA_LIBRARY_PATH environment variable.
464 {
465 char *t = ld_library_path;
466 // that's +3 for appending ":." and the trailing '\0'
467 ld_library_path = (char *) malloc(strlen(t) + 3);
468 sprintf(ld_library_path, "%s:%s", t, ".");
469 free(t);
470 }
471 #endif
473 Arguments::set_library_path(ld_library_path);
474 }
476 /*
477 * Extensions directories.
478 *
479 * Note that the space for the colon and the trailing null are provided
480 * by the nulls included by the sizeof operator (so actually one byte more
481 * than necessary is allocated).
482 */
483 {
484 #ifdef __APPLE__
485 char *buf = malloc(strlen(Arguments::get_java_home()) +
486 sizeof(EXTENSIONS_DIR) + system_ext_size);
487 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":"
488 SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home());
489 #else
490 char *buf = malloc(strlen(Arguments::get_java_home()) +
491 sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
492 sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
493 Arguments::get_java_home());
494 #endif
496 Arguments::set_ext_dirs(buf);
497 }
499 /* Endorsed standards default directory. */
500 {
501 char * buf;
502 buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
503 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
504 Arguments::set_endorsed_dirs(buf);
505 }
506 }
508 #ifdef __APPLE__
509 #undef SYS_EXTENSIONS_DIR
510 #endif
511 #undef malloc
512 #undef getenv
513 #undef EXTENSIONS_DIR
514 #undef ENDORSED_DIR
516 // Done
517 return;
518 }
520 ////////////////////////////////////////////////////////////////////////////////
521 // breakpoint support
523 void os::breakpoint() {
524 BREAKPOINT;
525 }
527 extern "C" void breakpoint() {
528 // use debugger to set breakpoint here
529 }
531 ////////////////////////////////////////////////////////////////////////////////
532 // signal support
534 debug_only(static bool signal_sets_initialized = false);
535 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
537 bool os::Bsd::is_sig_ignored(int sig) {
538 struct sigaction oact;
539 sigaction(sig, (struct sigaction*)NULL, &oact);
540 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
541 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
542 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
543 return true;
544 else
545 return false;
546 }
548 void os::Bsd::signal_sets_init() {
549 // Should also have an assertion stating we are still single-threaded.
550 assert(!signal_sets_initialized, "Already initialized");
551 // Fill in signals that are necessarily unblocked for all threads in
552 // the VM. Currently, we unblock the following signals:
553 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
554 // by -Xrs (=ReduceSignalUsage));
555 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
556 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
557 // the dispositions or masks wrt these signals.
558 // Programs embedding the VM that want to use the above signals for their
559 // own purposes must, at this time, use the "-Xrs" option to prevent
560 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
561 // (See bug 4345157, and other related bugs).
562 // In reality, though, unblocking these signals is really a nop, since
563 // these signals are not blocked by default.
564 sigemptyset(&unblocked_sigs);
565 sigemptyset(&allowdebug_blocked_sigs);
566 sigaddset(&unblocked_sigs, SIGILL);
567 sigaddset(&unblocked_sigs, SIGSEGV);
568 sigaddset(&unblocked_sigs, SIGBUS);
569 sigaddset(&unblocked_sigs, SIGFPE);
570 sigaddset(&unblocked_sigs, SR_signum);
572 if (!ReduceSignalUsage) {
573 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
574 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
575 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
576 }
577 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
578 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
579 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
580 }
581 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
582 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
583 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
584 }
585 }
586 // Fill in signals that are blocked by all but the VM thread.
587 sigemptyset(&vm_sigs);
588 if (!ReduceSignalUsage)
589 sigaddset(&vm_sigs, BREAK_SIGNAL);
590 debug_only(signal_sets_initialized = true);
592 }
594 // These are signals that are unblocked while a thread is running Java.
595 // (For some reason, they get blocked by default.)
596 sigset_t* os::Bsd::unblocked_signals() {
597 assert(signal_sets_initialized, "Not initialized");
598 return &unblocked_sigs;
599 }
601 // These are the signals that are blocked while a (non-VM) thread is
602 // running Java. Only the VM thread handles these signals.
603 sigset_t* os::Bsd::vm_signals() {
604 assert(signal_sets_initialized, "Not initialized");
605 return &vm_sigs;
606 }
608 // These are signals that are blocked during cond_wait to allow debugger in
609 sigset_t* os::Bsd::allowdebug_blocked_signals() {
610 assert(signal_sets_initialized, "Not initialized");
611 return &allowdebug_blocked_sigs;
612 }
614 void os::Bsd::hotspot_sigmask(Thread* thread) {
616 //Save caller's signal mask before setting VM signal mask
617 sigset_t caller_sigmask;
618 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
620 OSThread* osthread = thread->osthread();
621 osthread->set_caller_sigmask(caller_sigmask);
623 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
625 if (!ReduceSignalUsage) {
626 if (thread->is_VM_thread()) {
627 // Only the VM thread handles BREAK_SIGNAL ...
628 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
629 } else {
630 // ... all other threads block BREAK_SIGNAL
631 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
632 }
633 }
634 }
637 //////////////////////////////////////////////////////////////////////////////
638 // create new thread
640 static address highest_vm_reserved_address();
642 // check if it's safe to start a new thread
643 static bool _thread_safety_check(Thread* thread) {
644 return true;
645 }
647 #ifdef __APPLE__
648 // library handle for calling objc_registerThreadWithCollector()
649 // without static linking to the libobjc library
650 #define OBJC_LIB "/usr/lib/libobjc.dylib"
651 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
652 typedef void (*objc_registerThreadWithCollector_t)();
653 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
654 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
655 #endif
657 // Thread start routine for all newly created threads
658 static void *java_start(Thread *thread) {
659 // Try to randomize the cache line index of hot stack frames.
660 // This helps when threads of the same stack traces evict each other's
661 // cache lines. The threads can be either from the same JVM instance, or
662 // from different JVM instances. The benefit is especially true for
663 // processors with hyperthreading technology.
664 static int counter = 0;
665 int pid = os::current_process_id();
666 alloca(((pid ^ counter++) & 7) * 128);
668 ThreadLocalStorage::set_thread(thread);
670 OSThread* osthread = thread->osthread();
671 Monitor* sync = osthread->startThread_lock();
673 // non floating stack BsdThreads needs extra check, see above
674 if (!_thread_safety_check(thread)) {
675 // notify parent thread
676 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
677 osthread->set_state(ZOMBIE);
678 sync->notify_all();
679 return NULL;
680 }
682 #ifdef __APPLE__
683 // thread_id is mach thread on macos
684 osthread->set_thread_id(::mach_thread_self());
685 #else
686 // thread_id is pthread_id on BSD
687 osthread->set_thread_id(::pthread_self());
688 #endif
689 // initialize signal mask for this thread
690 os::Bsd::hotspot_sigmask(thread);
692 // initialize floating point control register
693 os::Bsd::init_thread_fpu_state();
695 #ifdef __APPLE__
696 // register thread with objc gc
697 if (objc_registerThreadWithCollectorFunction != NULL) {
698 objc_registerThreadWithCollectorFunction();
699 }
700 #endif
702 // handshaking with parent thread
703 {
704 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
706 // notify parent thread
707 osthread->set_state(INITIALIZED);
708 sync->notify_all();
710 // wait until os::start_thread()
711 while (osthread->get_state() == INITIALIZED) {
712 sync->wait(Mutex::_no_safepoint_check_flag);
713 }
714 }
716 // call one more level start routine
717 thread->run();
719 return 0;
720 }
722 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
723 assert(thread->osthread() == NULL, "caller responsible");
725 // Allocate the OSThread object
726 OSThread* osthread = new OSThread(NULL, NULL);
727 if (osthread == NULL) {
728 return false;
729 }
731 // set the correct thread state
732 osthread->set_thread_type(thr_type);
734 // Initial state is ALLOCATED but not INITIALIZED
735 osthread->set_state(ALLOCATED);
737 thread->set_osthread(osthread);
739 // init thread attributes
740 pthread_attr_t attr;
741 pthread_attr_init(&attr);
742 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
744 // stack size
745 if (os::Bsd::supports_variable_stack_size()) {
746 // calculate stack size if it's not specified by caller
747 if (stack_size == 0) {
748 stack_size = os::Bsd::default_stack_size(thr_type);
750 switch (thr_type) {
751 case os::java_thread:
752 // Java threads use ThreadStackSize which default value can be
753 // changed with the flag -Xss
754 assert (JavaThread::stack_size_at_create() > 0, "this should be set");
755 stack_size = JavaThread::stack_size_at_create();
756 break;
757 case os::compiler_thread:
758 if (CompilerThreadStackSize > 0) {
759 stack_size = (size_t)(CompilerThreadStackSize * K);
760 break;
761 } // else fall through:
762 // use VMThreadStackSize if CompilerThreadStackSize is not defined
763 case os::vm_thread:
764 case os::pgc_thread:
765 case os::cgc_thread:
766 case os::watcher_thread:
767 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
768 break;
769 }
770 }
772 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
773 pthread_attr_setstacksize(&attr, stack_size);
774 } else {
775 // let pthread_create() pick the default value.
776 }
778 ThreadState state;
780 {
781 pthread_t tid;
782 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
784 pthread_attr_destroy(&attr);
786 if (ret != 0) {
787 if (PrintMiscellaneous && (Verbose || WizardMode)) {
788 perror("pthread_create()");
789 }
790 // Need to clean up stuff we've allocated so far
791 thread->set_osthread(NULL);
792 delete osthread;
793 return false;
794 }
796 // Store pthread info into the OSThread
797 osthread->set_pthread_id(tid);
799 // Wait until child thread is either initialized or aborted
800 {
801 Monitor* sync_with_child = osthread->startThread_lock();
802 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
803 while ((state = osthread->get_state()) == ALLOCATED) {
804 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
805 }
806 }
808 }
810 // Aborted due to thread limit being reached
811 if (state == ZOMBIE) {
812 thread->set_osthread(NULL);
813 delete osthread;
814 return false;
815 }
817 // The thread is returned suspended (in state INITIALIZED),
818 // and is started higher up in the call chain
819 assert(state == INITIALIZED, "race condition");
820 return true;
821 }
823 /////////////////////////////////////////////////////////////////////////////
824 // attach existing thread
826 // bootstrap the main thread
827 bool os::create_main_thread(JavaThread* thread) {
828 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
829 return create_attached_thread(thread);
830 }
832 bool os::create_attached_thread(JavaThread* thread) {
833 #ifdef ASSERT
834 thread->verify_not_published();
835 #endif
837 // Allocate the OSThread object
838 OSThread* osthread = new OSThread(NULL, NULL);
840 if (osthread == NULL) {
841 return false;
842 }
844 // Store pthread info into the OSThread
845 #ifdef __APPLE__
846 osthread->set_thread_id(::mach_thread_self());
847 #else
848 osthread->set_thread_id(::pthread_self());
849 #endif
850 osthread->set_pthread_id(::pthread_self());
852 // initialize floating point control register
853 os::Bsd::init_thread_fpu_state();
855 // Initial thread state is RUNNABLE
856 osthread->set_state(RUNNABLE);
858 thread->set_osthread(osthread);
860 // initialize signal mask for this thread
861 // and save the caller's signal mask
862 os::Bsd::hotspot_sigmask(thread);
864 return true;
865 }
867 void os::pd_start_thread(Thread* thread) {
868 OSThread * osthread = thread->osthread();
869 assert(osthread->get_state() != INITIALIZED, "just checking");
870 Monitor* sync_with_child = osthread->startThread_lock();
871 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
872 sync_with_child->notify();
873 }
875 // Free Bsd resources related to the OSThread
876 void os::free_thread(OSThread* osthread) {
877 assert(osthread != NULL, "osthread not set");
879 if (Thread::current()->osthread() == osthread) {
880 // Restore caller's signal mask
881 sigset_t sigmask = osthread->caller_sigmask();
882 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
883 }
885 delete osthread;
886 }
888 //////////////////////////////////////////////////////////////////////////////
889 // thread local storage
891 int os::allocate_thread_local_storage() {
892 pthread_key_t key;
893 int rslt = pthread_key_create(&key, NULL);
894 assert(rslt == 0, "cannot allocate thread local storage");
895 return (int)key;
896 }
898 // Note: This is currently not used by VM, as we don't destroy TLS key
899 // on VM exit.
900 void os::free_thread_local_storage(int index) {
901 int rslt = pthread_key_delete((pthread_key_t)index);
902 assert(rslt == 0, "invalid index");
903 }
905 void os::thread_local_storage_at_put(int index, void* value) {
906 int rslt = pthread_setspecific((pthread_key_t)index, value);
907 assert(rslt == 0, "pthread_setspecific failed");
908 }
910 extern "C" Thread* get_thread() {
911 return ThreadLocalStorage::thread();
912 }
915 ////////////////////////////////////////////////////////////////////////////////
916 // time support
918 // Time since start-up in seconds to a fine granularity.
919 // Used by VMSelfDestructTimer and the MemProfiler.
920 double os::elapsedTime() {
922 return (double)(os::elapsed_counter()) * 0.000001;
923 }
925 jlong os::elapsed_counter() {
926 timeval time;
927 int status = gettimeofday(&time, NULL);
928 return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count;
929 }
931 jlong os::elapsed_frequency() {
932 return (1000 * 1000);
933 }
935 // XXX: For now, code this as if BSD does not support vtime.
936 bool os::supports_vtime() { return false; }
937 bool os::enable_vtime() { return false; }
938 bool os::vtime_enabled() { return false; }
939 double os::elapsedVTime() {
940 // better than nothing, but not much
941 return elapsedTime();
942 }
944 jlong os::javaTimeMillis() {
945 timeval time;
946 int status = gettimeofday(&time, NULL);
947 assert(status != -1, "bsd error");
948 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
949 }
951 #ifndef CLOCK_MONOTONIC
952 #define CLOCK_MONOTONIC (1)
953 #endif
955 #ifdef __APPLE__
956 void os::Bsd::clock_init() {
957 // XXXDARWIN: Investigate replacement monotonic clock
958 }
959 #else
960 void os::Bsd::clock_init() {
961 struct timespec res;
962 struct timespec tp;
963 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
964 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
965 // yes, monotonic clock is supported
966 _clock_gettime = ::clock_gettime;
967 }
968 }
969 #endif
972 jlong os::javaTimeNanos() {
973 if (Bsd::supports_monotonic_clock()) {
974 struct timespec tp;
975 int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp);
976 assert(status == 0, "gettime error");
977 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
978 return result;
979 } else {
980 timeval time;
981 int status = gettimeofday(&time, NULL);
982 assert(status != -1, "bsd error");
983 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
984 return 1000 * usecs;
985 }
986 }
988 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
989 if (Bsd::supports_monotonic_clock()) {
990 info_ptr->max_value = ALL_64_BITS;
992 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
993 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
994 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
995 } else {
996 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
997 info_ptr->max_value = ALL_64_BITS;
999 // gettimeofday is a real time clock so it skips
1000 info_ptr->may_skip_backward = true;
1001 info_ptr->may_skip_forward = true;
1002 }
1004 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1005 }
1007 // Return the real, user, and system times in seconds from an
1008 // arbitrary fixed point in the past.
1009 bool os::getTimesSecs(double* process_real_time,
1010 double* process_user_time,
1011 double* process_system_time) {
1012 struct tms ticks;
1013 clock_t real_ticks = times(&ticks);
1015 if (real_ticks == (clock_t) (-1)) {
1016 return false;
1017 } else {
1018 double ticks_per_second = (double) clock_tics_per_sec;
1019 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1020 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1021 *process_real_time = ((double) real_ticks) / ticks_per_second;
1023 return true;
1024 }
1025 }
1028 char * os::local_time_string(char *buf, size_t buflen) {
1029 struct tm t;
1030 time_t long_time;
1031 time(&long_time);
1032 localtime_r(&long_time, &t);
1033 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1034 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1035 t.tm_hour, t.tm_min, t.tm_sec);
1036 return buf;
1037 }
1039 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1040 return localtime_r(clock, res);
1041 }
1043 ////////////////////////////////////////////////////////////////////////////////
1044 // runtime exit support
1046 // Note: os::shutdown() might be called very early during initialization, or
1047 // called from signal handler. Before adding something to os::shutdown(), make
1048 // sure it is async-safe and can handle partially initialized VM.
1049 void os::shutdown() {
1051 // allow PerfMemory to attempt cleanup of any persistent resources
1052 perfMemory_exit();
1054 // needs to remove object in file system
1055 AttachListener::abort();
1057 // flush buffered output, finish log files
1058 ostream_abort();
1060 // Check for abort hook
1061 abort_hook_t abort_hook = Arguments::abort_hook();
1062 if (abort_hook != NULL) {
1063 abort_hook();
1064 }
1066 }
1068 // Note: os::abort() might be called very early during initialization, or
1069 // called from signal handler. Before adding something to os::abort(), make
1070 // sure it is async-safe and can handle partially initialized VM.
1071 void os::abort(bool dump_core) {
1072 os::shutdown();
1073 if (dump_core) {
1074 #ifndef PRODUCT
1075 fdStream out(defaultStream::output_fd());
1076 out.print_raw("Current thread is ");
1077 char buf[16];
1078 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1079 out.print_raw_cr(buf);
1080 out.print_raw_cr("Dumping core ...");
1081 #endif
1082 ::abort(); // dump core
1083 }
1085 ::exit(1);
1086 }
1088 // Die immediately, no exit hook, no abort hook, no cleanup.
1089 void os::die() {
1090 // _exit() on BsdThreads only kills current thread
1091 ::abort();
1092 }
1094 // unused on bsd for now.
1095 void os::set_error_file(const char *logfile) {}
1098 // This method is a copy of JDK's sysGetLastErrorString
1099 // from src/solaris/hpi/src/system_md.c
1101 size_t os::lasterror(char *buf, size_t len) {
1103 if (errno == 0) return 0;
1105 const char *s = ::strerror(errno);
1106 size_t n = ::strlen(s);
1107 if (n >= len) {
1108 n = len - 1;
1109 }
1110 ::strncpy(buf, s, n);
1111 buf[n] = '\0';
1112 return n;
1113 }
1115 intx os::current_thread_id() {
1116 #ifdef __APPLE__
1117 return (intx)::mach_thread_self();
1118 #else
1119 return (intx)::pthread_self();
1120 #endif
1121 }
1122 int os::current_process_id() {
1124 // Under the old bsd thread library, bsd gives each thread
1125 // its own process id. Because of this each thread will return
1126 // a different pid if this method were to return the result
1127 // of getpid(2). Bsd provides no api that returns the pid
1128 // of the launcher thread for the vm. This implementation
1129 // returns a unique pid, the pid of the launcher thread
1130 // that starts the vm 'process'.
1132 // Under the NPTL, getpid() returns the same pid as the
1133 // launcher thread rather than a unique pid per thread.
1134 // Use gettid() if you want the old pre NPTL behaviour.
1136 // if you are looking for the result of a call to getpid() that
1137 // returns a unique pid for the calling thread, then look at the
1138 // OSThread::thread_id() method in osThread_bsd.hpp file
1140 return (int)(_initial_pid ? _initial_pid : getpid());
1141 }
1143 // DLL functions
1145 #define JNI_LIB_PREFIX "lib"
1146 #ifdef __APPLE__
1147 #define JNI_LIB_SUFFIX ".dylib"
1148 #else
1149 #define JNI_LIB_SUFFIX ".so"
1150 #endif
1152 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1154 // This must be hard coded because it's the system's temporary
1155 // directory not the java application's temp directory, ala java.io.tmpdir.
1156 #ifdef __APPLE__
1157 // macosx has a secure per-user temporary directory
1158 char temp_path_storage[PATH_MAX];
1159 const char* os::get_temp_directory() {
1160 static char *temp_path = NULL;
1161 if (temp_path == NULL) {
1162 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1163 if (pathSize == 0 || pathSize > PATH_MAX) {
1164 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1165 }
1166 temp_path = temp_path_storage;
1167 }
1168 return temp_path;
1169 }
1170 #else /* __APPLE__ */
1171 const char* os::get_temp_directory() { return "/tmp"; }
1172 #endif /* __APPLE__ */
1174 static bool file_exists(const char* filename) {
1175 struct stat statbuf;
1176 if (filename == NULL || strlen(filename) == 0) {
1177 return false;
1178 }
1179 return os::stat(filename, &statbuf) == 0;
1180 }
1182 bool os::dll_build_name(char* buffer, size_t buflen,
1183 const char* pname, const char* fname) {
1184 bool retval = false;
1185 // Copied from libhpi
1186 const size_t pnamelen = pname ? strlen(pname) : 0;
1188 // Return error on buffer overflow.
1189 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1190 return retval;
1191 }
1193 if (pnamelen == 0) {
1194 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1195 retval = true;
1196 } else if (strchr(pname, *os::path_separator()) != NULL) {
1197 int n;
1198 char** pelements = split_path(pname, &n);
1199 for (int i = 0 ; i < n ; i++) {
1200 // Really shouldn't be NULL, but check can't hurt
1201 if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1202 continue; // skip the empty path values
1203 }
1204 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1205 pelements[i], fname);
1206 if (file_exists(buffer)) {
1207 retval = true;
1208 break;
1209 }
1210 }
1211 // release the storage
1212 for (int i = 0 ; i < n ; i++) {
1213 if (pelements[i] != NULL) {
1214 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
1215 }
1216 }
1217 if (pelements != NULL) {
1218 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
1219 }
1220 } else {
1221 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1222 retval = true;
1223 }
1224 return retval;
1225 }
1227 const char* os::get_current_directory(char *buf, int buflen) {
1228 return getcwd(buf, buflen);
1229 }
1231 // check if addr is inside libjvm.so
1232 bool os::address_is_in_vm(address addr) {
1233 static address libjvm_base_addr;
1234 Dl_info dlinfo;
1236 if (libjvm_base_addr == NULL) {
1237 dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo);
1238 libjvm_base_addr = (address)dlinfo.dli_fbase;
1239 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1240 }
1242 if (dladdr((void *)addr, &dlinfo)) {
1243 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1244 }
1246 return false;
1247 }
1250 #define MACH_MAXSYMLEN 256
1252 bool os::dll_address_to_function_name(address addr, char *buf,
1253 int buflen, int *offset) {
1254 Dl_info dlinfo;
1255 char localbuf[MACH_MAXSYMLEN];
1257 // dladdr will find names of dynamic functions only, but does
1258 // it set dli_fbase with mach_header address when it "fails" ?
1259 if (dladdr((void*)addr, &dlinfo) && dlinfo.dli_sname != NULL) {
1260 if (buf != NULL) {
1261 if(!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1262 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1263 }
1264 }
1265 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1266 return true;
1267 } else if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != 0) {
1268 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1269 buf, buflen, offset, dlinfo.dli_fname)) {
1270 return true;
1271 }
1272 }
1274 // Handle non-dymanic manually:
1275 if (dlinfo.dli_fbase != NULL &&
1276 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
1277 if(!Decoder::demangle(localbuf, buf, buflen)) {
1278 jio_snprintf(buf, buflen, "%s", localbuf);
1279 }
1280 return true;
1281 }
1282 if (buf != NULL) buf[0] = '\0';
1283 if (offset != NULL) *offset = -1;
1284 return false;
1285 }
1287 // ported from solaris version
1288 bool os::dll_address_to_library_name(address addr, char* buf,
1289 int buflen, int* offset) {
1290 Dl_info dlinfo;
1292 if (dladdr((void*)addr, &dlinfo)){
1293 if (buf) jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1294 if (offset) *offset = addr - (address)dlinfo.dli_fbase;
1295 return true;
1296 } else {
1297 if (buf) buf[0] = '\0';
1298 if (offset) *offset = -1;
1299 return false;
1300 }
1301 }
1303 // Loads .dll/.so and
1304 // in case of error it checks if .dll/.so was built for the
1305 // same architecture as Hotspot is running on
1307 #ifdef __APPLE__
1308 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1309 void * result= ::dlopen(filename, RTLD_LAZY);
1310 if (result != NULL) {
1311 // Successful loading
1312 return result;
1313 }
1315 // Read system error message into ebuf
1316 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1317 ebuf[ebuflen-1]='\0';
1319 return NULL;
1320 }
1321 #else
1322 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
1323 {
1324 void * result= ::dlopen(filename, RTLD_LAZY);
1325 if (result != NULL) {
1326 // Successful loading
1327 return result;
1328 }
1330 Elf32_Ehdr elf_head;
1332 // Read system error message into ebuf
1333 // It may or may not be overwritten below
1334 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1335 ebuf[ebuflen-1]='\0';
1336 int diag_msg_max_length=ebuflen-strlen(ebuf);
1337 char* diag_msg_buf=ebuf+strlen(ebuf);
1339 if (diag_msg_max_length==0) {
1340 // No more space in ebuf for additional diagnostics message
1341 return NULL;
1342 }
1345 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1347 if (file_descriptor < 0) {
1348 // Can't open library, report dlerror() message
1349 return NULL;
1350 }
1352 bool failed_to_read_elf_head=
1353 (sizeof(elf_head)!=
1354 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
1356 ::close(file_descriptor);
1357 if (failed_to_read_elf_head) {
1358 // file i/o error - report dlerror() msg
1359 return NULL;
1360 }
1362 typedef struct {
1363 Elf32_Half code; // Actual value as defined in elf.h
1364 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1365 char elf_class; // 32 or 64 bit
1366 char endianess; // MSB or LSB
1367 char* name; // String representation
1368 } arch_t;
1370 #ifndef EM_486
1371 #define EM_486 6 /* Intel 80486 */
1372 #endif
1374 #ifndef EM_MIPS_RS3_LE
1375 #define EM_MIPS_RS3_LE 10 /* MIPS */
1376 #endif
1378 #ifndef EM_PPC64
1379 #define EM_PPC64 21 /* PowerPC64 */
1380 #endif
1382 #ifndef EM_S390
1383 #define EM_S390 22 /* IBM System/390 */
1384 #endif
1386 #ifndef EM_IA_64
1387 #define EM_IA_64 50 /* HP/Intel IA-64 */
1388 #endif
1390 #ifndef EM_X86_64
1391 #define EM_X86_64 62 /* AMD x86-64 */
1392 #endif
1394 static const arch_t arch_array[]={
1395 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1396 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1397 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1398 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1399 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1400 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1401 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1402 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1403 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1404 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1405 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1406 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1407 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1408 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1409 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1410 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1411 };
1413 #if (defined IA32)
1414 static Elf32_Half running_arch_code=EM_386;
1415 #elif (defined AMD64)
1416 static Elf32_Half running_arch_code=EM_X86_64;
1417 #elif (defined IA64)
1418 static Elf32_Half running_arch_code=EM_IA_64;
1419 #elif (defined __sparc) && (defined _LP64)
1420 static Elf32_Half running_arch_code=EM_SPARCV9;
1421 #elif (defined __sparc) && (!defined _LP64)
1422 static Elf32_Half running_arch_code=EM_SPARC;
1423 #elif (defined __powerpc64__)
1424 static Elf32_Half running_arch_code=EM_PPC64;
1425 #elif (defined __powerpc__)
1426 static Elf32_Half running_arch_code=EM_PPC;
1427 #elif (defined ARM)
1428 static Elf32_Half running_arch_code=EM_ARM;
1429 #elif (defined S390)
1430 static Elf32_Half running_arch_code=EM_S390;
1431 #elif (defined ALPHA)
1432 static Elf32_Half running_arch_code=EM_ALPHA;
1433 #elif (defined MIPSEL)
1434 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1435 #elif (defined PARISC)
1436 static Elf32_Half running_arch_code=EM_PARISC;
1437 #elif (defined MIPS)
1438 static Elf32_Half running_arch_code=EM_MIPS;
1439 #elif (defined M68K)
1440 static Elf32_Half running_arch_code=EM_68K;
1441 #else
1442 #error Method os::dll_load requires that one of following is defined:\
1443 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1444 #endif
1446 // Identify compatability class for VM's architecture and library's architecture
1447 // Obtain string descriptions for architectures
1449 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1450 int running_arch_index=-1;
1452 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
1453 if (running_arch_code == arch_array[i].code) {
1454 running_arch_index = i;
1455 }
1456 if (lib_arch.code == arch_array[i].code) {
1457 lib_arch.compat_class = arch_array[i].compat_class;
1458 lib_arch.name = arch_array[i].name;
1459 }
1460 }
1462 assert(running_arch_index != -1,
1463 "Didn't find running architecture code (running_arch_code) in arch_array");
1464 if (running_arch_index == -1) {
1465 // Even though running architecture detection failed
1466 // we may still continue with reporting dlerror() message
1467 return NULL;
1468 }
1470 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1471 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1472 return NULL;
1473 }
1475 #ifndef S390
1476 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1477 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1478 return NULL;
1479 }
1480 #endif // !S390
1482 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1483 if ( lib_arch.name!=NULL ) {
1484 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1485 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1486 lib_arch.name, arch_array[running_arch_index].name);
1487 } else {
1488 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1489 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1490 lib_arch.code,
1491 arch_array[running_arch_index].name);
1492 }
1493 }
1495 return NULL;
1496 }
1497 #endif /* !__APPLE__ */
1499 // XXX: Do we need a lock around this as per Linux?
1500 void* os::dll_lookup(void* handle, const char* name) {
1501 return dlsym(handle, name);
1502 }
1505 static bool _print_ascii_file(const char* filename, outputStream* st) {
1506 int fd = ::open(filename, O_RDONLY);
1507 if (fd == -1) {
1508 return false;
1509 }
1511 char buf[32];
1512 int bytes;
1513 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1514 st->print_raw(buf, bytes);
1515 }
1517 ::close(fd);
1519 return true;
1520 }
1522 void os::print_dll_info(outputStream *st) {
1523 st->print_cr("Dynamic libraries:");
1524 #ifdef RTLD_DI_LINKMAP
1525 Dl_info dli;
1526 void *handle;
1527 Link_map *map;
1528 Link_map *p;
1530 if (!dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli)) {
1531 st->print_cr("Error: Cannot print dynamic libraries.");
1532 return;
1533 }
1534 handle = dlopen(dli.dli_fname, RTLD_LAZY);
1535 if (handle == NULL) {
1536 st->print_cr("Error: Cannot print dynamic libraries.");
1537 return;
1538 }
1539 dlinfo(handle, RTLD_DI_LINKMAP, &map);
1540 if (map == NULL) {
1541 st->print_cr("Error: Cannot print dynamic libraries.");
1542 return;
1543 }
1545 while (map->l_prev != NULL)
1546 map = map->l_prev;
1548 while (map != NULL) {
1549 st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
1550 map = map->l_next;
1551 }
1553 dlclose(handle);
1554 #elif defined(__APPLE__)
1555 uint32_t count;
1556 uint32_t i;
1558 count = _dyld_image_count();
1559 for (i = 1; i < count; i++) {
1560 const char *name = _dyld_get_image_name(i);
1561 intptr_t slide = _dyld_get_image_vmaddr_slide(i);
1562 st->print_cr(PTR_FORMAT " \t%s", slide, name);
1563 }
1564 #else
1565 st->print_cr("Error: Cannot print dynamic libraries.");
1566 #endif
1567 }
1569 void os::print_os_info_brief(outputStream* st) {
1570 st->print("Bsd");
1572 os::Posix::print_uname_info(st);
1573 }
1575 void os::print_os_info(outputStream* st) {
1576 st->print("OS:");
1577 st->print("Bsd");
1579 os::Posix::print_uname_info(st);
1581 os::Posix::print_rlimit_info(st);
1583 os::Posix::print_load_average(st);
1584 }
1586 void os::pd_print_cpu_info(outputStream* st) {
1587 // Nothing to do for now.
1588 }
1590 void os::print_memory_info(outputStream* st) {
1592 st->print("Memory:");
1593 st->print(" %dk page", os::vm_page_size()>>10);
1595 st->print(", physical " UINT64_FORMAT "k",
1596 os::physical_memory() >> 10);
1597 st->print("(" UINT64_FORMAT "k free)",
1598 os::available_memory() >> 10);
1599 st->cr();
1601 // meminfo
1602 st->print("\n/proc/meminfo:\n");
1603 _print_ascii_file("/proc/meminfo", st);
1604 st->cr();
1605 }
1607 // Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific
1608 // but they're the same for all the bsd arch that we support
1609 // and they're the same for solaris but there's no common place to put this.
1610 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
1611 "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
1612 "ILL_COPROC", "ILL_BADSTK" };
1614 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
1615 "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
1616 "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
1618 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
1620 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
1622 void os::print_siginfo(outputStream* st, void* siginfo) {
1623 st->print("siginfo:");
1625 const int buflen = 100;
1626 char buf[buflen];
1627 siginfo_t *si = (siginfo_t*)siginfo;
1628 st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
1629 if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
1630 st->print("si_errno=%s", buf);
1631 } else {
1632 st->print("si_errno=%d", si->si_errno);
1633 }
1634 const int c = si->si_code;
1635 assert(c > 0, "unexpected si_code");
1636 switch (si->si_signo) {
1637 case SIGILL:
1638 st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
1639 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1640 break;
1641 case SIGFPE:
1642 st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
1643 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1644 break;
1645 case SIGSEGV:
1646 st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
1647 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1648 break;
1649 case SIGBUS:
1650 st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
1651 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1652 break;
1653 default:
1654 st->print(", si_code=%d", si->si_code);
1655 // no si_addr
1656 }
1658 if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1659 UseSharedSpaces) {
1660 FileMapInfo* mapinfo = FileMapInfo::current_info();
1661 if (mapinfo->is_in_shared_space(si->si_addr)) {
1662 st->print("\n\nError accessing class data sharing archive." \
1663 " Mapped file inaccessible during execution, " \
1664 " possible disk/network problem.");
1665 }
1666 }
1667 st->cr();
1668 }
1671 static void print_signal_handler(outputStream* st, int sig,
1672 char* buf, size_t buflen);
1674 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1675 st->print_cr("Signal Handlers:");
1676 print_signal_handler(st, SIGSEGV, buf, buflen);
1677 print_signal_handler(st, SIGBUS , buf, buflen);
1678 print_signal_handler(st, SIGFPE , buf, buflen);
1679 print_signal_handler(st, SIGPIPE, buf, buflen);
1680 print_signal_handler(st, SIGXFSZ, buf, buflen);
1681 print_signal_handler(st, SIGILL , buf, buflen);
1682 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1683 print_signal_handler(st, SR_signum, buf, buflen);
1684 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1685 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1686 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1687 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1688 }
1690 static char saved_jvm_path[MAXPATHLEN] = {0};
1692 // Find the full path to the current module, libjvm
1693 void os::jvm_path(char *buf, jint buflen) {
1694 // Error checking.
1695 if (buflen < MAXPATHLEN) {
1696 assert(false, "must use a large-enough buffer");
1697 buf[0] = '\0';
1698 return;
1699 }
1700 // Lazy resolve the path to current module.
1701 if (saved_jvm_path[0] != 0) {
1702 strcpy(buf, saved_jvm_path);
1703 return;
1704 }
1706 char dli_fname[MAXPATHLEN];
1707 bool ret = dll_address_to_library_name(
1708 CAST_FROM_FN_PTR(address, os::jvm_path),
1709 dli_fname, sizeof(dli_fname), NULL);
1710 assert(ret != 0, "cannot locate libjvm");
1711 char *rp = realpath(dli_fname, buf);
1712 if (rp == NULL)
1713 return;
1715 if (Arguments::created_by_gamma_launcher()) {
1716 // Support for the gamma launcher. Typical value for buf is
1717 // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm". If "/jre/lib/" appears at
1718 // the right place in the string, then assume we are installed in a JDK and
1719 // we're done. Otherwise, check for a JAVA_HOME environment variable and
1720 // construct a path to the JVM being overridden.
1722 const char *p = buf + strlen(buf) - 1;
1723 for (int count = 0; p > buf && count < 5; ++count) {
1724 for (--p; p > buf && *p != '/'; --p)
1725 /* empty */ ;
1726 }
1728 if (strncmp(p, "/jre/lib/", 9) != 0) {
1729 // Look for JAVA_HOME in the environment.
1730 char* java_home_var = ::getenv("JAVA_HOME");
1731 if (java_home_var != NULL && java_home_var[0] != 0) {
1732 char* jrelib_p;
1733 int len;
1735 // Check the current module name "libjvm"
1736 p = strrchr(buf, '/');
1737 assert(strstr(p, "/libjvm") == p, "invalid library name");
1739 rp = realpath(java_home_var, buf);
1740 if (rp == NULL)
1741 return;
1743 // determine if this is a legacy image or modules image
1744 // modules image doesn't have "jre" subdirectory
1745 len = strlen(buf);
1746 jrelib_p = buf + len;
1748 // Add the appropriate library subdir
1749 snprintf(jrelib_p, buflen-len, "/jre/lib");
1750 if (0 != access(buf, F_OK)) {
1751 snprintf(jrelib_p, buflen-len, "/lib");
1752 }
1754 // Add the appropriate client or server subdir
1755 len = strlen(buf);
1756 jrelib_p = buf + len;
1757 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1758 if (0 != access(buf, F_OK)) {
1759 snprintf(jrelib_p, buflen-len, "");
1760 }
1762 // If the path exists within JAVA_HOME, add the JVM library name
1763 // to complete the path to JVM being overridden. Otherwise fallback
1764 // to the path to the current library.
1765 if (0 == access(buf, F_OK)) {
1766 // Use current module name "libjvm"
1767 len = strlen(buf);
1768 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1769 } else {
1770 // Fall back to path of current library
1771 rp = realpath(dli_fname, buf);
1772 if (rp == NULL)
1773 return;
1774 }
1775 }
1776 }
1777 }
1779 strcpy(saved_jvm_path, buf);
1780 }
1782 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1783 // no prefix required, not even "_"
1784 }
1786 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1787 // no suffix required
1788 }
1790 ////////////////////////////////////////////////////////////////////////////////
1791 // sun.misc.Signal support
1793 static volatile jint sigint_count = 0;
1795 static void
1796 UserHandler(int sig, void *siginfo, void *context) {
1797 // 4511530 - sem_post is serialized and handled by the manager thread. When
1798 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1799 // don't want to flood the manager thread with sem_post requests.
1800 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
1801 return;
1803 // Ctrl-C is pressed during error reporting, likely because the error
1804 // handler fails to abort. Let VM die immediately.
1805 if (sig == SIGINT && is_error_reported()) {
1806 os::die();
1807 }
1809 os::signal_notify(sig);
1810 }
1812 void* os::user_handler() {
1813 return CAST_FROM_FN_PTR(void*, UserHandler);
1814 }
1816 extern "C" {
1817 typedef void (*sa_handler_t)(int);
1818 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1819 }
1821 void* os::signal(int signal_number, void* handler) {
1822 struct sigaction sigAct, oldSigAct;
1824 sigfillset(&(sigAct.sa_mask));
1825 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
1826 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1828 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1829 // -1 means registration failed
1830 return (void *)-1;
1831 }
1833 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1834 }
1836 void os::signal_raise(int signal_number) {
1837 ::raise(signal_number);
1838 }
1840 /*
1841 * The following code is moved from os.cpp for making this
1842 * code platform specific, which it is by its very nature.
1843 */
1845 // Will be modified when max signal is changed to be dynamic
1846 int os::sigexitnum_pd() {
1847 return NSIG;
1848 }
1850 // a counter for each possible signal value
1851 static volatile jint pending_signals[NSIG+1] = { 0 };
1853 // Bsd(POSIX) specific hand shaking semaphore.
1854 #ifdef __APPLE__
1855 static semaphore_t sig_sem;
1856 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1857 #define SEM_WAIT(sem) semaphore_wait(sem);
1858 #define SEM_POST(sem) semaphore_signal(sem);
1859 #else
1860 static sem_t sig_sem;
1861 #define SEM_INIT(sem, value) sem_init(&sem, 0, value)
1862 #define SEM_WAIT(sem) sem_wait(&sem);
1863 #define SEM_POST(sem) sem_post(&sem);
1864 #endif
1866 void os::signal_init_pd() {
1867 // Initialize signal structures
1868 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1870 // Initialize signal semaphore
1871 ::SEM_INIT(sig_sem, 0);
1872 }
1874 void os::signal_notify(int sig) {
1875 Atomic::inc(&pending_signals[sig]);
1876 ::SEM_POST(sig_sem);
1877 }
1879 static int check_pending_signals(bool wait) {
1880 Atomic::store(0, &sigint_count);
1881 for (;;) {
1882 for (int i = 0; i < NSIG + 1; i++) {
1883 jint n = pending_signals[i];
1884 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1885 return i;
1886 }
1887 }
1888 if (!wait) {
1889 return -1;
1890 }
1891 JavaThread *thread = JavaThread::current();
1892 ThreadBlockInVM tbivm(thread);
1894 bool threadIsSuspended;
1895 do {
1896 thread->set_suspend_equivalent();
1897 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1898 ::SEM_WAIT(sig_sem);
1900 // were we externally suspended while we were waiting?
1901 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1902 if (threadIsSuspended) {
1903 //
1904 // The semaphore has been incremented, but while we were waiting
1905 // another thread suspended us. We don't want to continue running
1906 // while suspended because that would surprise the thread that
1907 // suspended us.
1908 //
1909 ::SEM_POST(sig_sem);
1911 thread->java_suspend_self();
1912 }
1913 } while (threadIsSuspended);
1914 }
1915 }
1917 int os::signal_lookup() {
1918 return check_pending_signals(false);
1919 }
1921 int os::signal_wait() {
1922 return check_pending_signals(true);
1923 }
1925 ////////////////////////////////////////////////////////////////////////////////
1926 // Virtual Memory
1928 int os::vm_page_size() {
1929 // Seems redundant as all get out
1930 assert(os::Bsd::page_size() != -1, "must call os::init");
1931 return os::Bsd::page_size();
1932 }
1934 // Solaris allocates memory by pages.
1935 int os::vm_allocation_granularity() {
1936 assert(os::Bsd::page_size() != -1, "must call os::init");
1937 return os::Bsd::page_size();
1938 }
1940 // Rationale behind this function:
1941 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
1942 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
1943 // samples for JITted code. Here we create private executable mapping over the code cache
1944 // and then we can use standard (well, almost, as mapping can change) way to provide
1945 // info for the reporting script by storing timestamp and location of symbol
1946 void bsd_wrap_code(char* base, size_t size) {
1947 static volatile jint cnt = 0;
1949 if (!UseOprofile) {
1950 return;
1951 }
1953 char buf[PATH_MAX + 1];
1954 int num = Atomic::add(1, &cnt);
1956 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
1957 os::get_temp_directory(), os::current_process_id(), num);
1958 unlink(buf);
1960 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
1962 if (fd != -1) {
1963 off_t rv = ::lseek(fd, size-2, SEEK_SET);
1964 if (rv != (off_t)-1) {
1965 if (::write(fd, "", 1) == 1) {
1966 mmap(base, size,
1967 PROT_READ|PROT_WRITE|PROT_EXEC,
1968 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
1969 }
1970 }
1971 ::close(fd);
1972 unlink(buf);
1973 }
1974 }
1976 // NOTE: Bsd kernel does not really reserve the pages for us.
1977 // All it does is to check if there are enough free pages
1978 // left at the time of mmap(). This could be a potential
1979 // problem.
1980 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
1981 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
1982 #ifdef __OpenBSD__
1983 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
1984 return ::mprotect(addr, size, prot) == 0;
1985 #else
1986 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
1987 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
1988 return res != (uintptr_t) MAP_FAILED;
1989 #endif
1990 }
1993 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
1994 bool exec) {
1995 return commit_memory(addr, size, exec);
1996 }
1998 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1999 }
2001 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2002 ::madvise(addr, bytes, MADV_DONTNEED);
2003 }
2005 void os::numa_make_global(char *addr, size_t bytes) {
2006 }
2008 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2009 }
2011 bool os::numa_topology_changed() { return false; }
2013 size_t os::numa_get_groups_num() {
2014 return 1;
2015 }
2017 int os::numa_get_group_id() {
2018 return 0;
2019 }
2021 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2022 if (size > 0) {
2023 ids[0] = 0;
2024 return 1;
2025 }
2026 return 0;
2027 }
2029 bool os::get_page_info(char *start, page_info* info) {
2030 return false;
2031 }
2033 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2034 return end;
2035 }
2038 bool os::pd_uncommit_memory(char* addr, size_t size) {
2039 #ifdef __OpenBSD__
2040 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2041 return ::mprotect(addr, size, PROT_NONE) == 0;
2042 #else
2043 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2044 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2045 return res != (uintptr_t) MAP_FAILED;
2046 #endif
2047 }
2049 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2050 return os::commit_memory(addr, size);
2051 }
2053 // If this is a growable mapping, remove the guard pages entirely by
2054 // munmap()ping them. If not, just call uncommit_memory().
2055 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2056 return os::uncommit_memory(addr, size);
2057 }
2059 static address _highest_vm_reserved_address = NULL;
2061 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2062 // at 'requested_addr'. If there are existing memory mappings at the same
2063 // location, however, they will be overwritten. If 'fixed' is false,
2064 // 'requested_addr' is only treated as a hint, the return value may or
2065 // may not start from the requested address. Unlike Bsd mmap(), this
2066 // function returns NULL to indicate failure.
2067 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2068 char * addr;
2069 int flags;
2071 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2072 if (fixed) {
2073 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2074 flags |= MAP_FIXED;
2075 }
2077 // Map uncommitted pages PROT_READ and PROT_WRITE, change access
2078 // to PROT_EXEC if executable when we commit the page.
2079 addr = (char*)::mmap(requested_addr, bytes, PROT_READ|PROT_WRITE,
2080 flags, -1, 0);
2082 if (addr != MAP_FAILED) {
2083 // anon_mmap() should only get called during VM initialization,
2084 // don't need lock (actually we can skip locking even it can be called
2085 // from multiple threads, because _highest_vm_reserved_address is just a
2086 // hint about the upper limit of non-stack memory regions.)
2087 if ((address)addr + bytes > _highest_vm_reserved_address) {
2088 _highest_vm_reserved_address = (address)addr + bytes;
2089 }
2090 }
2092 return addr == MAP_FAILED ? NULL : addr;
2093 }
2095 // Don't update _highest_vm_reserved_address, because there might be memory
2096 // regions above addr + size. If so, releasing a memory region only creates
2097 // a hole in the address space, it doesn't help prevent heap-stack collision.
2098 //
2099 static int anon_munmap(char * addr, size_t size) {
2100 return ::munmap(addr, size) == 0;
2101 }
2103 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2104 size_t alignment_hint) {
2105 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2106 }
2108 bool os::pd_release_memory(char* addr, size_t size) {
2109 return anon_munmap(addr, size);
2110 }
2112 static address highest_vm_reserved_address() {
2113 return _highest_vm_reserved_address;
2114 }
2116 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2117 // Bsd wants the mprotect address argument to be page aligned.
2118 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2120 // According to SUSv3, mprotect() should only be used with mappings
2121 // established by mmap(), and mmap() always maps whole pages. Unaligned
2122 // 'addr' likely indicates problem in the VM (e.g. trying to change
2123 // protection of malloc'ed or statically allocated memory). Check the
2124 // caller if you hit this assert.
2125 assert(addr == bottom, "sanity check");
2127 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2128 return ::mprotect(bottom, size, prot) == 0;
2129 }
2131 // Set protections specified
2132 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2133 bool is_committed) {
2134 unsigned int p = 0;
2135 switch (prot) {
2136 case MEM_PROT_NONE: p = PROT_NONE; break;
2137 case MEM_PROT_READ: p = PROT_READ; break;
2138 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
2139 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2140 default:
2141 ShouldNotReachHere();
2142 }
2143 // is_committed is unused.
2144 return bsd_mprotect(addr, bytes, p);
2145 }
2147 bool os::guard_memory(char* addr, size_t size) {
2148 return bsd_mprotect(addr, size, PROT_NONE);
2149 }
2151 bool os::unguard_memory(char* addr, size_t size) {
2152 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2153 }
2155 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2156 return false;
2157 }
2159 /*
2160 * Set the coredump_filter bits to include largepages in core dump (bit 6)
2161 *
2162 * From the coredump_filter documentation:
2163 *
2164 * - (bit 0) anonymous private memory
2165 * - (bit 1) anonymous shared memory
2166 * - (bit 2) file-backed private memory
2167 * - (bit 3) file-backed shared memory
2168 * - (bit 4) ELF header pages in file-backed private memory areas (it is
2169 * effective only if the bit 2 is cleared)
2170 * - (bit 5) hugetlb private memory
2171 * - (bit 6) hugetlb shared memory
2172 */
2173 static void set_coredump_filter(void) {
2174 FILE *f;
2175 long cdm;
2177 if ((f = fopen("/proc/self/coredump_filter", "r+")) == NULL) {
2178 return;
2179 }
2181 if (fscanf(f, "%lx", &cdm) != 1) {
2182 fclose(f);
2183 return;
2184 }
2186 rewind(f);
2188 if ((cdm & LARGEPAGES_BIT) == 0) {
2189 cdm |= LARGEPAGES_BIT;
2190 fprintf(f, "%#lx", cdm);
2191 }
2193 fclose(f);
2194 }
2196 // Large page support
2198 static size_t _large_page_size = 0;
2200 void os::large_page_init() {
2201 }
2204 char* os::reserve_memory_special(size_t bytes, char* req_addr, bool exec) {
2205 // "exec" is passed in but not used. Creating the shared image for
2206 // the code cache doesn't have an SHM_X executable permission to check.
2207 assert(UseLargePages && UseSHM, "only for SHM large pages");
2209 key_t key = IPC_PRIVATE;
2210 char *addr;
2212 bool warn_on_failure = UseLargePages &&
2213 (!FLAG_IS_DEFAULT(UseLargePages) ||
2214 !FLAG_IS_DEFAULT(LargePageSizeInBytes)
2215 );
2216 char msg[128];
2218 // Create a large shared memory region to attach to based on size.
2219 // Currently, size is the total size of the heap
2220 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2221 if (shmid == -1) {
2222 // Possible reasons for shmget failure:
2223 // 1. shmmax is too small for Java heap.
2224 // > check shmmax value: cat /proc/sys/kernel/shmmax
2225 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2226 // 2. not enough large page memory.
2227 // > check available large pages: cat /proc/meminfo
2228 // > increase amount of large pages:
2229 // echo new_value > /proc/sys/vm/nr_hugepages
2230 // Note 1: different Bsd may use different name for this property,
2231 // e.g. on Redhat AS-3 it is "hugetlb_pool".
2232 // Note 2: it's possible there's enough physical memory available but
2233 // they are so fragmented after a long run that they can't
2234 // coalesce into large pages. Try to reserve large pages when
2235 // the system is still "fresh".
2236 if (warn_on_failure) {
2237 jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
2238 warning(msg);
2239 }
2240 return NULL;
2241 }
2243 // attach to the region
2244 addr = (char*)shmat(shmid, req_addr, 0);
2245 int err = errno;
2247 // Remove shmid. If shmat() is successful, the actual shared memory segment
2248 // will be deleted when it's detached by shmdt() or when the process
2249 // terminates. If shmat() is not successful this will remove the shared
2250 // segment immediately.
2251 shmctl(shmid, IPC_RMID, NULL);
2253 if ((intptr_t)addr == -1) {
2254 if (warn_on_failure) {
2255 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
2256 warning(msg);
2257 }
2258 return NULL;
2259 }
2261 return addr;
2262 }
2264 bool os::release_memory_special(char* base, size_t bytes) {
2265 // detaching the SHM segment will also delete it, see reserve_memory_special()
2266 int rslt = shmdt(base);
2267 return rslt == 0;
2268 }
2270 size_t os::large_page_size() {
2271 return _large_page_size;
2272 }
2274 // HugeTLBFS allows application to commit large page memory on demand;
2275 // with SysV SHM the entire memory region must be allocated as shared
2276 // memory.
2277 bool os::can_commit_large_page_memory() {
2278 return UseHugeTLBFS;
2279 }
2281 bool os::can_execute_large_page_memory() {
2282 return UseHugeTLBFS;
2283 }
2285 // Reserve memory at an arbitrary address, only if that area is
2286 // available (and not reserved for something else).
2288 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2289 const int max_tries = 10;
2290 char* base[max_tries];
2291 size_t size[max_tries];
2292 const size_t gap = 0x000000;
2294 // Assert only that the size is a multiple of the page size, since
2295 // that's all that mmap requires, and since that's all we really know
2296 // about at this low abstraction level. If we need higher alignment,
2297 // we can either pass an alignment to this method or verify alignment
2298 // in one of the methods further up the call chain. See bug 5044738.
2299 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2301 // Repeatedly allocate blocks until the block is allocated at the
2302 // right spot. Give up after max_tries. Note that reserve_memory() will
2303 // automatically update _highest_vm_reserved_address if the call is
2304 // successful. The variable tracks the highest memory address every reserved
2305 // by JVM. It is used to detect heap-stack collision if running with
2306 // fixed-stack BsdThreads. Because here we may attempt to reserve more
2307 // space than needed, it could confuse the collision detecting code. To
2308 // solve the problem, save current _highest_vm_reserved_address and
2309 // calculate the correct value before return.
2310 address old_highest = _highest_vm_reserved_address;
2312 // Bsd mmap allows caller to pass an address as hint; give it a try first,
2313 // if kernel honors the hint then we can return immediately.
2314 char * addr = anon_mmap(requested_addr, bytes, false);
2315 if (addr == requested_addr) {
2316 return requested_addr;
2317 }
2319 if (addr != NULL) {
2320 // mmap() is successful but it fails to reserve at the requested address
2321 anon_munmap(addr, bytes);
2322 }
2324 int i;
2325 for (i = 0; i < max_tries; ++i) {
2326 base[i] = reserve_memory(bytes);
2328 if (base[i] != NULL) {
2329 // Is this the block we wanted?
2330 if (base[i] == requested_addr) {
2331 size[i] = bytes;
2332 break;
2333 }
2335 // Does this overlap the block we wanted? Give back the overlapped
2336 // parts and try again.
2338 size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2339 if (top_overlap >= 0 && top_overlap < bytes) {
2340 unmap_memory(base[i], top_overlap);
2341 base[i] += top_overlap;
2342 size[i] = bytes - top_overlap;
2343 } else {
2344 size_t bottom_overlap = base[i] + bytes - requested_addr;
2345 if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2346 unmap_memory(requested_addr, bottom_overlap);
2347 size[i] = bytes - bottom_overlap;
2348 } else {
2349 size[i] = bytes;
2350 }
2351 }
2352 }
2353 }
2355 // Give back the unused reserved pieces.
2357 for (int j = 0; j < i; ++j) {
2358 if (base[j] != NULL) {
2359 unmap_memory(base[j], size[j]);
2360 }
2361 }
2363 if (i < max_tries) {
2364 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2365 return requested_addr;
2366 } else {
2367 _highest_vm_reserved_address = old_highest;
2368 return NULL;
2369 }
2370 }
2372 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2373 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2374 }
2376 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
2377 // Solaris uses poll(), bsd uses park().
2378 // Poll() is likely a better choice, assuming that Thread.interrupt()
2379 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
2380 // SIGSEGV, see 4355769.
2382 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
2383 assert(thread == Thread::current(), "thread consistency check");
2385 ParkEvent * const slp = thread->_SleepEvent ;
2386 slp->reset() ;
2387 OrderAccess::fence() ;
2389 if (interruptible) {
2390 jlong prevtime = javaTimeNanos();
2392 for (;;) {
2393 if (os::is_interrupted(thread, true)) {
2394 return OS_INTRPT;
2395 }
2397 jlong newtime = javaTimeNanos();
2399 if (newtime - prevtime < 0) {
2400 // time moving backwards, should only happen if no monotonic clock
2401 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2402 assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2403 } else {
2404 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2405 }
2407 if(millis <= 0) {
2408 return OS_OK;
2409 }
2411 prevtime = newtime;
2413 {
2414 assert(thread->is_Java_thread(), "sanity check");
2415 JavaThread *jt = (JavaThread *) thread;
2416 ThreadBlockInVM tbivm(jt);
2417 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
2419 jt->set_suspend_equivalent();
2420 // cleared by handle_special_suspend_equivalent_condition() or
2421 // java_suspend_self() via check_and_wait_while_suspended()
2423 slp->park(millis);
2425 // were we externally suspended while we were waiting?
2426 jt->check_and_wait_while_suspended();
2427 }
2428 }
2429 } else {
2430 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2431 jlong prevtime = javaTimeNanos();
2433 for (;;) {
2434 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
2435 // the 1st iteration ...
2436 jlong newtime = javaTimeNanos();
2438 if (newtime - prevtime < 0) {
2439 // time moving backwards, should only happen if no monotonic clock
2440 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2441 assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2442 } else {
2443 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2444 }
2446 if(millis <= 0) break ;
2448 prevtime = newtime;
2449 slp->park(millis);
2450 }
2451 return OS_OK ;
2452 }
2453 }
2455 int os::naked_sleep() {
2456 // %% make the sleep time an integer flag. for now use 1 millisec.
2457 return os::sleep(Thread::current(), 1, false);
2458 }
2460 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2461 void os::infinite_sleep() {
2462 while (true) { // sleep forever ...
2463 ::sleep(100); // ... 100 seconds at a time
2464 }
2465 }
2467 // Used to convert frequent JVM_Yield() to nops
2468 bool os::dont_yield() {
2469 return DontYieldALot;
2470 }
2472 void os::yield() {
2473 sched_yield();
2474 }
2476 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
2478 void os::yield_all(int attempts) {
2479 // Yields to all threads, including threads with lower priorities
2480 // Threads on Bsd are all with same priority. The Solaris style
2481 // os::yield_all() with nanosleep(1ms) is not necessary.
2482 sched_yield();
2483 }
2485 // Called from the tight loops to possibly influence time-sharing heuristics
2486 void os::loop_breaker(int attempts) {
2487 os::yield_all(attempts);
2488 }
2490 ////////////////////////////////////////////////////////////////////////////////
2491 // thread priority support
2493 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2494 // only supports dynamic priority, static priority must be zero. For real-time
2495 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2496 // However, for large multi-threaded applications, SCHED_RR is not only slower
2497 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2498 // of 5 runs - Sep 2005).
2499 //
2500 // The following code actually changes the niceness of kernel-thread/LWP. It
2501 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2502 // not the entire user process, and user level threads are 1:1 mapped to kernel
2503 // threads. It has always been the case, but could change in the future. For
2504 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2505 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2507 #if !defined(__APPLE__)
2508 int os::java_to_os_priority[CriticalPriority + 1] = {
2509 19, // 0 Entry should never be used
2511 0, // 1 MinPriority
2512 3, // 2
2513 6, // 3
2515 10, // 4
2516 15, // 5 NormPriority
2517 18, // 6
2519 21, // 7
2520 25, // 8
2521 28, // 9 NearMaxPriority
2523 31, // 10 MaxPriority
2525 31 // 11 CriticalPriority
2526 };
2527 #else
2528 /* Using Mach high-level priority assignments */
2529 int os::java_to_os_priority[CriticalPriority + 1] = {
2530 0, // 0 Entry should never be used (MINPRI_USER)
2532 27, // 1 MinPriority
2533 28, // 2
2534 29, // 3
2536 30, // 4
2537 31, // 5 NormPriority (BASEPRI_DEFAULT)
2538 32, // 6
2540 33, // 7
2541 34, // 8
2542 35, // 9 NearMaxPriority
2544 36, // 10 MaxPriority
2546 36 // 11 CriticalPriority
2547 };
2548 #endif
2550 static int prio_init() {
2551 if (ThreadPriorityPolicy == 1) {
2552 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2553 // if effective uid is not root. Perhaps, a more elegant way of doing
2554 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2555 if (geteuid() != 0) {
2556 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2557 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2558 }
2559 ThreadPriorityPolicy = 0;
2560 }
2561 }
2562 if (UseCriticalJavaThreadPriority) {
2563 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2564 }
2565 return 0;
2566 }
2568 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2569 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
2571 #ifdef __OpenBSD__
2572 // OpenBSD pthread_setprio starves low priority threads
2573 return OS_OK;
2574 #elif defined(__FreeBSD__)
2575 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2576 #elif defined(__APPLE__) || defined(__NetBSD__)
2577 struct sched_param sp;
2578 int policy;
2579 pthread_t self = pthread_self();
2581 if (pthread_getschedparam(self, &policy, &sp) != 0)
2582 return OS_ERR;
2584 sp.sched_priority = newpri;
2585 if (pthread_setschedparam(self, policy, &sp) != 0)
2586 return OS_ERR;
2588 return OS_OK;
2589 #else
2590 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2591 return (ret == 0) ? OS_OK : OS_ERR;
2592 #endif
2593 }
2595 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2596 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
2597 *priority_ptr = java_to_os_priority[NormPriority];
2598 return OS_OK;
2599 }
2601 errno = 0;
2602 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2603 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2604 #elif defined(__APPLE__) || defined(__NetBSD__)
2605 int policy;
2606 struct sched_param sp;
2608 pthread_getschedparam(pthread_self(), &policy, &sp);
2609 *priority_ptr = sp.sched_priority;
2610 #else
2611 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2612 #endif
2613 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2614 }
2616 // Hint to the underlying OS that a task switch would not be good.
2617 // Void return because it's a hint and can fail.
2618 void os::hint_no_preempt() {}
2620 ////////////////////////////////////////////////////////////////////////////////
2621 // suspend/resume support
2623 // the low-level signal-based suspend/resume support is a remnant from the
2624 // old VM-suspension that used to be for java-suspension, safepoints etc,
2625 // within hotspot. Now there is a single use-case for this:
2626 // - calling get_thread_pc() on the VMThread by the flat-profiler task
2627 // that runs in the watcher thread.
2628 // The remaining code is greatly simplified from the more general suspension
2629 // code that used to be used.
2630 //
2631 // The protocol is quite simple:
2632 // - suspend:
2633 // - sends a signal to the target thread
2634 // - polls the suspend state of the osthread using a yield loop
2635 // - target thread signal handler (SR_handler) sets suspend state
2636 // and blocks in sigsuspend until continued
2637 // - resume:
2638 // - sets target osthread state to continue
2639 // - sends signal to end the sigsuspend loop in the SR_handler
2640 //
2641 // Note that the SR_lock plays no role in this suspend/resume protocol.
2642 //
2644 static void resume_clear_context(OSThread *osthread) {
2645 osthread->set_ucontext(NULL);
2646 osthread->set_siginfo(NULL);
2648 // notify the suspend action is completed, we have now resumed
2649 osthread->sr.clear_suspended();
2650 }
2652 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2653 osthread->set_ucontext(context);
2654 osthread->set_siginfo(siginfo);
2655 }
2657 //
2658 // Handler function invoked when a thread's execution is suspended or
2659 // resumed. We have to be careful that only async-safe functions are
2660 // called here (Note: most pthread functions are not async safe and
2661 // should be avoided.)
2662 //
2663 // Note: sigwait() is a more natural fit than sigsuspend() from an
2664 // interface point of view, but sigwait() prevents the signal hander
2665 // from being run. libpthread would get very confused by not having
2666 // its signal handlers run and prevents sigwait()'s use with the
2667 // mutex granting granting signal.
2668 //
2669 // Currently only ever called on the VMThread
2670 //
2671 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2672 // Save and restore errno to avoid confusing native code with EINTR
2673 // after sigsuspend.
2674 int old_errno = errno;
2676 Thread* thread = Thread::current();
2677 OSThread* osthread = thread->osthread();
2678 assert(thread->is_VM_thread(), "Must be VMThread");
2679 // read current suspend action
2680 int action = osthread->sr.suspend_action();
2681 if (action == SR_SUSPEND) {
2682 suspend_save_context(osthread, siginfo, context);
2684 // Notify the suspend action is about to be completed. do_suspend()
2685 // waits until SR_SUSPENDED is set and then returns. We will wait
2686 // here for a resume signal and that completes the suspend-other
2687 // action. do_suspend/do_resume is always called as a pair from
2688 // the same thread - so there are no races
2690 // notify the caller
2691 osthread->sr.set_suspended();
2693 sigset_t suspend_set; // signals for sigsuspend()
2695 // get current set of blocked signals and unblock resume signal
2696 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2697 sigdelset(&suspend_set, SR_signum);
2699 // wait here until we are resumed
2700 do {
2701 sigsuspend(&suspend_set);
2702 // ignore all returns until we get a resume signal
2703 } while (osthread->sr.suspend_action() != SR_CONTINUE);
2705 resume_clear_context(osthread);
2707 } else {
2708 assert(action == SR_CONTINUE, "unexpected sr action");
2709 // nothing special to do - just leave the handler
2710 }
2712 errno = old_errno;
2713 }
2716 static int SR_initialize() {
2717 struct sigaction act;
2718 char *s;
2719 /* Get signal number to use for suspend/resume */
2720 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2721 int sig = ::strtol(s, 0, 10);
2722 if (sig > 0 || sig < NSIG) {
2723 SR_signum = sig;
2724 }
2725 }
2727 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2728 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2730 sigemptyset(&SR_sigset);
2731 sigaddset(&SR_sigset, SR_signum);
2733 /* Set up signal handler for suspend/resume */
2734 act.sa_flags = SA_RESTART|SA_SIGINFO;
2735 act.sa_handler = (void (*)(int)) SR_handler;
2737 // SR_signum is blocked by default.
2738 // 4528190 - We also need to block pthread restart signal (32 on all
2739 // supported Bsd platforms). Note that BsdThreads need to block
2740 // this signal for all threads to work properly. So we don't have
2741 // to use hard-coded signal number when setting up the mask.
2742 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2744 if (sigaction(SR_signum, &act, 0) == -1) {
2745 return -1;
2746 }
2748 // Save signal flag
2749 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2750 return 0;
2751 }
2753 static int SR_finalize() {
2754 return 0;
2755 }
2758 // returns true on success and false on error - really an error is fatal
2759 // but this seems the normal response to library errors
2760 static bool do_suspend(OSThread* osthread) {
2761 // mark as suspended and send signal
2762 osthread->sr.set_suspend_action(SR_SUSPEND);
2763 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2764 assert_status(status == 0, status, "pthread_kill");
2766 // check status and wait until notified of suspension
2767 if (status == 0) {
2768 for (int i = 0; !osthread->sr.is_suspended(); i++) {
2769 os::yield_all(i);
2770 }
2771 osthread->sr.set_suspend_action(SR_NONE);
2772 return true;
2773 }
2774 else {
2775 osthread->sr.set_suspend_action(SR_NONE);
2776 return false;
2777 }
2778 }
2780 static void do_resume(OSThread* osthread) {
2781 assert(osthread->sr.is_suspended(), "thread should be suspended");
2782 osthread->sr.set_suspend_action(SR_CONTINUE);
2784 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2785 assert_status(status == 0, status, "pthread_kill");
2786 // check status and wait unit notified of resumption
2787 if (status == 0) {
2788 for (int i = 0; osthread->sr.is_suspended(); i++) {
2789 os::yield_all(i);
2790 }
2791 }
2792 osthread->sr.set_suspend_action(SR_NONE);
2793 }
2795 ////////////////////////////////////////////////////////////////////////////////
2796 // interrupt support
2798 void os::interrupt(Thread* thread) {
2799 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
2800 "possibility of dangling Thread pointer");
2802 OSThread* osthread = thread->osthread();
2804 if (!osthread->interrupted()) {
2805 osthread->set_interrupted(true);
2806 // More than one thread can get here with the same value of osthread,
2807 // resulting in multiple notifications. We do, however, want the store
2808 // to interrupted() to be visible to other threads before we execute unpark().
2809 OrderAccess::fence();
2810 ParkEvent * const slp = thread->_SleepEvent ;
2811 if (slp != NULL) slp->unpark() ;
2812 }
2814 // For JSR166. Unpark even if interrupt status already was set
2815 if (thread->is_Java_thread())
2816 ((JavaThread*)thread)->parker()->unpark();
2818 ParkEvent * ev = thread->_ParkEvent ;
2819 if (ev != NULL) ev->unpark() ;
2821 }
2823 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
2824 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
2825 "possibility of dangling Thread pointer");
2827 OSThread* osthread = thread->osthread();
2829 bool interrupted = osthread->interrupted();
2831 if (interrupted && clear_interrupted) {
2832 osthread->set_interrupted(false);
2833 // consider thread->_SleepEvent->reset() ... optional optimization
2834 }
2836 return interrupted;
2837 }
2839 ///////////////////////////////////////////////////////////////////////////////////
2840 // signal handling (except suspend/resume)
2842 // This routine may be used by user applications as a "hook" to catch signals.
2843 // The user-defined signal handler must pass unrecognized signals to this
2844 // routine, and if it returns true (non-zero), then the signal handler must
2845 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2846 // routine will never retun false (zero), but instead will execute a VM panic
2847 // routine kill the process.
2848 //
2849 // If this routine returns false, it is OK to call it again. This allows
2850 // the user-defined signal handler to perform checks either before or after
2851 // the VM performs its own checks. Naturally, the user code would be making
2852 // a serious error if it tried to handle an exception (such as a null check
2853 // or breakpoint) that the VM was generating for its own correct operation.
2854 //
2855 // This routine may recognize any of the following kinds of signals:
2856 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2857 // It should be consulted by handlers for any of those signals.
2858 //
2859 // The caller of this routine must pass in the three arguments supplied
2860 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2861 // field of the structure passed to sigaction(). This routine assumes that
2862 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2863 //
2864 // Note that the VM will print warnings if it detects conflicting signal
2865 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2866 //
2867 extern "C" JNIEXPORT int
2868 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2869 void* ucontext, int abort_if_unrecognized);
2871 void signalHandler(int sig, siginfo_t* info, void* uc) {
2872 assert(info != NULL && uc != NULL, "it must be old kernel");
2873 JVM_handle_bsd_signal(sig, info, uc, true);
2874 }
2877 // This boolean allows users to forward their own non-matching signals
2878 // to JVM_handle_bsd_signal, harmlessly.
2879 bool os::Bsd::signal_handlers_are_installed = false;
2881 // For signal-chaining
2882 struct sigaction os::Bsd::sigact[MAXSIGNUM];
2883 unsigned int os::Bsd::sigs = 0;
2884 bool os::Bsd::libjsig_is_loaded = false;
2885 typedef struct sigaction *(*get_signal_t)(int);
2886 get_signal_t os::Bsd::get_signal_action = NULL;
2888 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2889 struct sigaction *actp = NULL;
2891 if (libjsig_is_loaded) {
2892 // Retrieve the old signal handler from libjsig
2893 actp = (*get_signal_action)(sig);
2894 }
2895 if (actp == NULL) {
2896 // Retrieve the preinstalled signal handler from jvm
2897 actp = get_preinstalled_handler(sig);
2898 }
2900 return actp;
2901 }
2903 static bool call_chained_handler(struct sigaction *actp, int sig,
2904 siginfo_t *siginfo, void *context) {
2905 // Call the old signal handler
2906 if (actp->sa_handler == SIG_DFL) {
2907 // It's more reasonable to let jvm treat it as an unexpected exception
2908 // instead of taking the default action.
2909 return false;
2910 } else if (actp->sa_handler != SIG_IGN) {
2911 if ((actp->sa_flags & SA_NODEFER) == 0) {
2912 // automaticlly block the signal
2913 sigaddset(&(actp->sa_mask), sig);
2914 }
2916 sa_handler_t hand;
2917 sa_sigaction_t sa;
2918 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
2919 // retrieve the chained handler
2920 if (siginfo_flag_set) {
2921 sa = actp->sa_sigaction;
2922 } else {
2923 hand = actp->sa_handler;
2924 }
2926 if ((actp->sa_flags & SA_RESETHAND) != 0) {
2927 actp->sa_handler = SIG_DFL;
2928 }
2930 // try to honor the signal mask
2931 sigset_t oset;
2932 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
2934 // call into the chained handler
2935 if (siginfo_flag_set) {
2936 (*sa)(sig, siginfo, context);
2937 } else {
2938 (*hand)(sig);
2939 }
2941 // restore the signal mask
2942 pthread_sigmask(SIG_SETMASK, &oset, 0);
2943 }
2944 // Tell jvm's signal handler the signal is taken care of.
2945 return true;
2946 }
2948 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
2949 bool chained = false;
2950 // signal-chaining
2951 if (UseSignalChaining) {
2952 struct sigaction *actp = get_chained_signal_action(sig);
2953 if (actp != NULL) {
2954 chained = call_chained_handler(actp, sig, siginfo, context);
2955 }
2956 }
2957 return chained;
2958 }
2960 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
2961 if ((( (unsigned int)1 << sig ) & sigs) != 0) {
2962 return &sigact[sig];
2963 }
2964 return NULL;
2965 }
2967 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
2968 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2969 sigact[sig] = oldAct;
2970 sigs |= (unsigned int)1 << sig;
2971 }
2973 // for diagnostic
2974 int os::Bsd::sigflags[MAXSIGNUM];
2976 int os::Bsd::get_our_sigflags(int sig) {
2977 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2978 return sigflags[sig];
2979 }
2981 void os::Bsd::set_our_sigflags(int sig, int flags) {
2982 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
2983 sigflags[sig] = flags;
2984 }
2986 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
2987 // Check for overwrite.
2988 struct sigaction oldAct;
2989 sigaction(sig, (struct sigaction*)NULL, &oldAct);
2991 void* oldhand = oldAct.sa_sigaction
2992 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
2993 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
2994 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
2995 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
2996 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
2997 if (AllowUserSignalHandlers || !set_installed) {
2998 // Do not overwrite; user takes responsibility to forward to us.
2999 return;
3000 } else if (UseSignalChaining) {
3001 // save the old handler in jvm
3002 save_preinstalled_handler(sig, oldAct);
3003 // libjsig also interposes the sigaction() call below and saves the
3004 // old sigaction on it own.
3005 } else {
3006 fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3007 "%#lx for signal %d.", (long)oldhand, sig));
3008 }
3009 }
3011 struct sigaction sigAct;
3012 sigfillset(&(sigAct.sa_mask));
3013 sigAct.sa_handler = SIG_DFL;
3014 if (!set_installed) {
3015 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3016 } else {
3017 sigAct.sa_sigaction = signalHandler;
3018 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3019 }
3020 // Save flags, which are set by ours
3021 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3022 sigflags[sig] = sigAct.sa_flags;
3024 int ret = sigaction(sig, &sigAct, &oldAct);
3025 assert(ret == 0, "check");
3027 void* oldhand2 = oldAct.sa_sigaction
3028 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3029 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3030 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3031 }
3033 // install signal handlers for signals that HotSpot needs to
3034 // handle in order to support Java-level exception handling.
3036 void os::Bsd::install_signal_handlers() {
3037 if (!signal_handlers_are_installed) {
3038 signal_handlers_are_installed = true;
3040 // signal-chaining
3041 typedef void (*signal_setting_t)();
3042 signal_setting_t begin_signal_setting = NULL;
3043 signal_setting_t end_signal_setting = NULL;
3044 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3045 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3046 if (begin_signal_setting != NULL) {
3047 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3048 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3049 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3050 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3051 libjsig_is_loaded = true;
3052 assert(UseSignalChaining, "should enable signal-chaining");
3053 }
3054 if (libjsig_is_loaded) {
3055 // Tell libjsig jvm is setting signal handlers
3056 (*begin_signal_setting)();
3057 }
3059 set_signal_handler(SIGSEGV, true);
3060 set_signal_handler(SIGPIPE, true);
3061 set_signal_handler(SIGBUS, true);
3062 set_signal_handler(SIGILL, true);
3063 set_signal_handler(SIGFPE, true);
3064 set_signal_handler(SIGXFSZ, true);
3066 #if defined(__APPLE__)
3067 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3068 // signals caught and handled by the JVM. To work around this, we reset the mach task
3069 // signal handler that's placed on our process by CrashReporter. This disables
3070 // CrashReporter-based reporting.
3071 //
3072 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3073 // on caught fatal signals.
3074 //
3075 // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3076 // handlers. By replacing the existing task exception handler, we disable gdb's mach
3077 // exception handling, while leaving the standard BSD signal handlers functional.
3078 kern_return_t kr;
3079 kr = task_set_exception_ports(mach_task_self(),
3080 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3081 MACH_PORT_NULL,
3082 EXCEPTION_STATE_IDENTITY,
3083 MACHINE_THREAD_STATE);
3085 assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3086 #endif
3088 if (libjsig_is_loaded) {
3089 // Tell libjsig jvm finishes setting signal handlers
3090 (*end_signal_setting)();
3091 }
3093 // We don't activate signal checker if libjsig is in place, we trust ourselves
3094 // and if UserSignalHandler is installed all bets are off
3095 if (CheckJNICalls) {
3096 if (libjsig_is_loaded) {
3097 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3098 check_signals = false;
3099 }
3100 if (AllowUserSignalHandlers) {
3101 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3102 check_signals = false;
3103 }
3104 }
3105 }
3106 }
3109 /////
3110 // glibc on Bsd platform uses non-documented flag
3111 // to indicate, that some special sort of signal
3112 // trampoline is used.
3113 // We will never set this flag, and we should
3114 // ignore this flag in our diagnostic
3115 #ifdef SIGNIFICANT_SIGNAL_MASK
3116 #undef SIGNIFICANT_SIGNAL_MASK
3117 #endif
3118 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3120 static const char* get_signal_handler_name(address handler,
3121 char* buf, int buflen) {
3122 int offset;
3123 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3124 if (found) {
3125 // skip directory names
3126 const char *p1, *p2;
3127 p1 = buf;
3128 size_t len = strlen(os::file_separator());
3129 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3130 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3131 } else {
3132 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3133 }
3134 return buf;
3135 }
3137 static void print_signal_handler(outputStream* st, int sig,
3138 char* buf, size_t buflen) {
3139 struct sigaction sa;
3141 sigaction(sig, NULL, &sa);
3143 // See comment for SIGNIFICANT_SIGNAL_MASK define
3144 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3146 st->print("%s: ", os::exception_name(sig, buf, buflen));
3148 address handler = (sa.sa_flags & SA_SIGINFO)
3149 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3150 : CAST_FROM_FN_PTR(address, sa.sa_handler);
3152 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3153 st->print("SIG_DFL");
3154 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3155 st->print("SIG_IGN");
3156 } else {
3157 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3158 }
3160 st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask);
3162 address rh = VMError::get_resetted_sighandler(sig);
3163 // May be, handler was resetted by VMError?
3164 if(rh != NULL) {
3165 handler = rh;
3166 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3167 }
3169 st->print(", sa_flags=" PTR32_FORMAT, sa.sa_flags);
3171 // Check: is it our handler?
3172 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3173 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3174 // It is our signal handler
3175 // check for flags, reset system-used one!
3176 if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3177 st->print(
3178 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3179 os::Bsd::get_our_sigflags(sig));
3180 }
3181 }
3182 st->cr();
3183 }
3186 #define DO_SIGNAL_CHECK(sig) \
3187 if (!sigismember(&check_signal_done, sig)) \
3188 os::Bsd::check_signal_handler(sig)
3190 // This method is a periodic task to check for misbehaving JNI applications
3191 // under CheckJNI, we can add any periodic checks here
3193 void os::run_periodic_checks() {
3195 if (check_signals == false) return;
3197 // SEGV and BUS if overridden could potentially prevent
3198 // generation of hs*.log in the event of a crash, debugging
3199 // such a case can be very challenging, so we absolutely
3200 // check the following for a good measure:
3201 DO_SIGNAL_CHECK(SIGSEGV);
3202 DO_SIGNAL_CHECK(SIGILL);
3203 DO_SIGNAL_CHECK(SIGFPE);
3204 DO_SIGNAL_CHECK(SIGBUS);
3205 DO_SIGNAL_CHECK(SIGPIPE);
3206 DO_SIGNAL_CHECK(SIGXFSZ);
3209 // ReduceSignalUsage allows the user to override these handlers
3210 // see comments at the very top and jvm_solaris.h
3211 if (!ReduceSignalUsage) {
3212 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3213 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3214 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3215 DO_SIGNAL_CHECK(BREAK_SIGNAL);
3216 }
3218 DO_SIGNAL_CHECK(SR_signum);
3219 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3220 }
3222 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3224 static os_sigaction_t os_sigaction = NULL;
3226 void os::Bsd::check_signal_handler(int sig) {
3227 char buf[O_BUFLEN];
3228 address jvmHandler = NULL;
3231 struct sigaction act;
3232 if (os_sigaction == NULL) {
3233 // only trust the default sigaction, in case it has been interposed
3234 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3235 if (os_sigaction == NULL) return;
3236 }
3238 os_sigaction(sig, (struct sigaction*)NULL, &act);
3241 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3243 address thisHandler = (act.sa_flags & SA_SIGINFO)
3244 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3245 : CAST_FROM_FN_PTR(address, act.sa_handler) ;
3248 switch(sig) {
3249 case SIGSEGV:
3250 case SIGBUS:
3251 case SIGFPE:
3252 case SIGPIPE:
3253 case SIGILL:
3254 case SIGXFSZ:
3255 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3256 break;
3258 case SHUTDOWN1_SIGNAL:
3259 case SHUTDOWN2_SIGNAL:
3260 case SHUTDOWN3_SIGNAL:
3261 case BREAK_SIGNAL:
3262 jvmHandler = (address)user_handler();
3263 break;
3265 case INTERRUPT_SIGNAL:
3266 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3267 break;
3269 default:
3270 if (sig == SR_signum) {
3271 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3272 } else {
3273 return;
3274 }
3275 break;
3276 }
3278 if (thisHandler != jvmHandler) {
3279 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3280 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3281 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3282 // No need to check this sig any longer
3283 sigaddset(&check_signal_done, sig);
3284 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3285 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3286 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3287 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags);
3288 // No need to check this sig any longer
3289 sigaddset(&check_signal_done, sig);
3290 }
3292 // Dump all the signal
3293 if (sigismember(&check_signal_done, sig)) {
3294 print_signal_handlers(tty, buf, O_BUFLEN);
3295 }
3296 }
3298 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
3300 extern bool signal_name(int signo, char* buf, size_t len);
3302 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3303 if (0 < exception_code && exception_code <= SIGRTMAX) {
3304 // signal
3305 if (!signal_name(exception_code, buf, size)) {
3306 jio_snprintf(buf, size, "SIG%d", exception_code);
3307 }
3308 return buf;
3309 } else {
3310 return NULL;
3311 }
3312 }
3314 // this is called _before_ the most of global arguments have been parsed
3315 void os::init(void) {
3316 char dummy; /* used to get a guess on initial stack address */
3317 // first_hrtime = gethrtime();
3319 // With BsdThreads the JavaMain thread pid (primordial thread)
3320 // is different than the pid of the java launcher thread.
3321 // So, on Bsd, the launcher thread pid is passed to the VM
3322 // via the sun.java.launcher.pid property.
3323 // Use this property instead of getpid() if it was correctly passed.
3324 // See bug 6351349.
3325 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3327 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3329 clock_tics_per_sec = CLK_TCK;
3331 init_random(1234567);
3333 ThreadCritical::initialize();
3335 Bsd::set_page_size(getpagesize());
3336 if (Bsd::page_size() == -1) {
3337 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3338 strerror(errno)));
3339 }
3340 init_page_sizes((size_t) Bsd::page_size());
3342 Bsd::initialize_system_info();
3344 // main_thread points to the aboriginal thread
3345 Bsd::_main_thread = pthread_self();
3347 Bsd::clock_init();
3348 initial_time_count = os::elapsed_counter();
3350 #ifdef __APPLE__
3351 // XXXDARWIN
3352 // Work around the unaligned VM callbacks in hotspot's
3353 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3354 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3355 // alignment when doing symbol lookup. To work around this, we force early
3356 // binding of all symbols now, thus binding when alignment is known-good.
3357 _dyld_bind_fully_image_containing_address((const void *) &os::init);
3358 #endif
3359 }
3361 // To install functions for atexit system call
3362 extern "C" {
3363 static void perfMemory_exit_helper() {
3364 perfMemory_exit();
3365 }
3366 }
3368 // this is called _after_ the global arguments have been parsed
3369 jint os::init_2(void)
3370 {
3371 // Allocate a single page and mark it as readable for safepoint polling
3372 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3373 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
3375 os::set_polling_page( polling_page );
3377 #ifndef PRODUCT
3378 if(Verbose && PrintMiscellaneous)
3379 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
3380 #endif
3382 if (!UseMembar) {
3383 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3384 guarantee( mem_serialize_page != NULL, "mmap Failed for memory serialize page");
3385 os::set_memory_serialize_page( mem_serialize_page );
3387 #ifndef PRODUCT
3388 if(Verbose && PrintMiscellaneous)
3389 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
3390 #endif
3391 }
3393 os::large_page_init();
3395 // initialize suspend/resume support - must do this before signal_sets_init()
3396 if (SR_initialize() != 0) {
3397 perror("SR_initialize failed");
3398 return JNI_ERR;
3399 }
3401 Bsd::signal_sets_init();
3402 Bsd::install_signal_handlers();
3404 // Check minimum allowable stack size for thread creation and to initialize
3405 // the java system classes, including StackOverflowError - depends on page
3406 // size. Add a page for compiler2 recursion in main thread.
3407 // Add in 2*BytesPerWord times page size to account for VM stack during
3408 // class initialization depending on 32 or 64 bit VM.
3409 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3410 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3411 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3413 size_t threadStackSizeInBytes = ThreadStackSize * K;
3414 if (threadStackSizeInBytes != 0 &&
3415 threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3416 tty->print_cr("\nThe stack size specified is too small, "
3417 "Specify at least %dk",
3418 os::Bsd::min_stack_allowed/ K);
3419 return JNI_ERR;
3420 }
3422 // Make the stack size a multiple of the page size so that
3423 // the yellow/red zones can be guarded.
3424 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3425 vm_page_size()));
3427 if (MaxFDLimit) {
3428 // set the number of file descriptors to max. print out error
3429 // if getrlimit/setrlimit fails but continue regardless.
3430 struct rlimit nbr_files;
3431 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3432 if (status != 0) {
3433 if (PrintMiscellaneous && (Verbose || WizardMode))
3434 perror("os::init_2 getrlimit failed");
3435 } else {
3436 nbr_files.rlim_cur = nbr_files.rlim_max;
3438 #ifdef __APPLE__
3439 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3440 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3441 // be used instead
3442 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3443 #endif
3445 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3446 if (status != 0) {
3447 if (PrintMiscellaneous && (Verbose || WizardMode))
3448 perror("os::init_2 setrlimit failed");
3449 }
3450 }
3451 }
3453 // at-exit methods are called in the reverse order of their registration.
3454 // atexit functions are called on return from main or as a result of a
3455 // call to exit(3C). There can be only 32 of these functions registered
3456 // and atexit() does not set errno.
3458 if (PerfAllowAtExitRegistration) {
3459 // only register atexit functions if PerfAllowAtExitRegistration is set.
3460 // atexit functions can be delayed until process exit time, which
3461 // can be problematic for embedded VM situations. Embedded VMs should
3462 // call DestroyJavaVM() to assure that VM resources are released.
3464 // note: perfMemory_exit_helper atexit function may be removed in
3465 // the future if the appropriate cleanup code can be added to the
3466 // VM_Exit VMOperation's doit method.
3467 if (atexit(perfMemory_exit_helper) != 0) {
3468 warning("os::init2 atexit(perfMemory_exit_helper) failed");
3469 }
3470 }
3472 // initialize thread priority policy
3473 prio_init();
3475 #ifdef __APPLE__
3476 // dynamically link to objective c gc registration
3477 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3478 if (handleLibObjc != NULL) {
3479 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3480 }
3481 #endif
3483 return JNI_OK;
3484 }
3486 // this is called at the end of vm_initialization
3487 void os::init_3(void) { }
3489 // Mark the polling page as unreadable
3490 void os::make_polling_page_unreadable(void) {
3491 if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
3492 fatal("Could not disable polling page");
3493 };
3495 // Mark the polling page as readable
3496 void os::make_polling_page_readable(void) {
3497 if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3498 fatal("Could not enable polling page");
3499 }
3500 };
3502 int os::active_processor_count() {
3503 return _processor_count;
3504 }
3506 void os::set_native_thread_name(const char *name) {
3507 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3508 // This is only supported in Snow Leopard and beyond
3509 if (name != NULL) {
3510 // Add a "Java: " prefix to the name
3511 char buf[MAXTHREADNAMESIZE];
3512 snprintf(buf, sizeof(buf), "Java: %s", name);
3513 pthread_setname_np(buf);
3514 }
3515 #endif
3516 }
3518 bool os::distribute_processes(uint length, uint* distribution) {
3519 // Not yet implemented.
3520 return false;
3521 }
3523 bool os::bind_to_processor(uint processor_id) {
3524 // Not yet implemented.
3525 return false;
3526 }
3528 ///
3530 // Suspends the target using the signal mechanism and then grabs the PC before
3531 // resuming the target. Used by the flat-profiler only
3532 ExtendedPC os::get_thread_pc(Thread* thread) {
3533 // Make sure that it is called by the watcher for the VMThread
3534 assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3535 assert(thread->is_VM_thread(), "Can only be called for VMThread");
3537 ExtendedPC epc;
3539 OSThread* osthread = thread->osthread();
3540 if (do_suspend(osthread)) {
3541 if (osthread->ucontext() != NULL) {
3542 epc = os::Bsd::ucontext_get_pc(osthread->ucontext());
3543 } else {
3544 // NULL context is unexpected, double-check this is the VMThread
3545 guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3546 }
3547 do_resume(osthread);
3548 }
3549 // failure means pthread_kill failed for some reason - arguably this is
3550 // a fatal problem, but such problems are ignored elsewhere
3552 return epc;
3553 }
3555 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
3556 {
3557 return pthread_cond_timedwait(_cond, _mutex, _abstime);
3558 }
3560 ////////////////////////////////////////////////////////////////////////////////
3561 // debug support
3563 static address same_page(address x, address y) {
3564 int page_bits = -os::vm_page_size();
3565 if ((intptr_t(x) & page_bits) == (intptr_t(y) & page_bits))
3566 return x;
3567 else if (x > y)
3568 return (address)(intptr_t(y) | ~page_bits) + 1;
3569 else
3570 return (address)(intptr_t(y) & page_bits);
3571 }
3573 bool os::find(address addr, outputStream* st) {
3574 Dl_info dlinfo;
3575 memset(&dlinfo, 0, sizeof(dlinfo));
3576 if (dladdr(addr, &dlinfo)) {
3577 st->print(PTR_FORMAT ": ", addr);
3578 if (dlinfo.dli_sname != NULL) {
3579 st->print("%s+%#x", dlinfo.dli_sname,
3580 addr - (intptr_t)dlinfo.dli_saddr);
3581 } else if (dlinfo.dli_fname) {
3582 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3583 } else {
3584 st->print("<absolute address>");
3585 }
3586 if (dlinfo.dli_fname) {
3587 st->print(" in %s", dlinfo.dli_fname);
3588 }
3589 if (dlinfo.dli_fbase) {
3590 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3591 }
3592 st->cr();
3594 if (Verbose) {
3595 // decode some bytes around the PC
3596 address begin = same_page(addr-40, addr);
3597 address end = same_page(addr+40, addr);
3598 address lowest = (address) dlinfo.dli_sname;
3599 if (!lowest) lowest = (address) dlinfo.dli_fbase;
3600 if (begin < lowest) begin = lowest;
3601 Dl_info dlinfo2;
3602 if (dladdr(end, &dlinfo2) && dlinfo2.dli_saddr != dlinfo.dli_saddr
3603 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
3604 end = (address) dlinfo2.dli_saddr;
3605 Disassembler::decode(begin, end, st);
3606 }
3607 return true;
3608 }
3609 return false;
3610 }
3612 ////////////////////////////////////////////////////////////////////////////////
3613 // misc
3615 // This does not do anything on Bsd. This is basically a hook for being
3616 // able to use structured exception handling (thread-local exception filters)
3617 // on, e.g., Win32.
3618 void
3619 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
3620 JavaCallArguments* args, Thread* thread) {
3621 f(value, method, args, thread);
3622 }
3624 void os::print_statistics() {
3625 }
3627 int os::message_box(const char* title, const char* message) {
3628 int i;
3629 fdStream err(defaultStream::error_fd());
3630 for (i = 0; i < 78; i++) err.print_raw("=");
3631 err.cr();
3632 err.print_raw_cr(title);
3633 for (i = 0; i < 78; i++) err.print_raw("-");
3634 err.cr();
3635 err.print_raw_cr(message);
3636 for (i = 0; i < 78; i++) err.print_raw("=");
3637 err.cr();
3639 char buf[16];
3640 // Prevent process from exiting upon "read error" without consuming all CPU
3641 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3643 return buf[0] == 'y' || buf[0] == 'Y';
3644 }
3646 int os::stat(const char *path, struct stat *sbuf) {
3647 char pathbuf[MAX_PATH];
3648 if (strlen(path) > MAX_PATH - 1) {
3649 errno = ENAMETOOLONG;
3650 return -1;
3651 }
3652 os::native_path(strcpy(pathbuf, path));
3653 return ::stat(pathbuf, sbuf);
3654 }
3656 bool os::check_heap(bool force) {
3657 return true;
3658 }
3660 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
3661 return ::vsnprintf(buf, count, format, args);
3662 }
3664 // Is a (classpath) directory empty?
3665 bool os::dir_is_empty(const char* path) {
3666 DIR *dir = NULL;
3667 struct dirent *ptr;
3669 dir = opendir(path);
3670 if (dir == NULL) return true;
3672 /* Scan the directory */
3673 bool result = true;
3674 char buf[sizeof(struct dirent) + MAX_PATH];
3675 while (result && (ptr = ::readdir(dir)) != NULL) {
3676 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3677 result = false;
3678 }
3679 }
3680 closedir(dir);
3681 return result;
3682 }
3684 // This code originates from JDK's sysOpen and open64_w
3685 // from src/solaris/hpi/src/system_md.c
3687 #ifndef O_DELETE
3688 #define O_DELETE 0x10000
3689 #endif
3691 // Open a file. Unlink the file immediately after open returns
3692 // if the specified oflag has the O_DELETE flag set.
3693 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
3695 int os::open(const char *path, int oflag, int mode) {
3697 if (strlen(path) > MAX_PATH - 1) {
3698 errno = ENAMETOOLONG;
3699 return -1;
3700 }
3701 int fd;
3702 int o_delete = (oflag & O_DELETE);
3703 oflag = oflag & ~O_DELETE;
3705 fd = ::open(path, oflag, mode);
3706 if (fd == -1) return -1;
3708 //If the open succeeded, the file might still be a directory
3709 {
3710 struct stat buf;
3711 int ret = ::fstat(fd, &buf);
3712 int st_mode = buf.st_mode;
3714 if (ret != -1) {
3715 if ((st_mode & S_IFMT) == S_IFDIR) {
3716 errno = EISDIR;
3717 ::close(fd);
3718 return -1;
3719 }
3720 } else {
3721 ::close(fd);
3722 return -1;
3723 }
3724 }
3726 /*
3727 * All file descriptors that are opened in the JVM and not
3728 * specifically destined for a subprocess should have the
3729 * close-on-exec flag set. If we don't set it, then careless 3rd
3730 * party native code might fork and exec without closing all
3731 * appropriate file descriptors (e.g. as we do in closeDescriptors in
3732 * UNIXProcess.c), and this in turn might:
3733 *
3734 * - cause end-of-file to fail to be detected on some file
3735 * descriptors, resulting in mysterious hangs, or
3736 *
3737 * - might cause an fopen in the subprocess to fail on a system
3738 * suffering from bug 1085341.
3739 *
3740 * (Yes, the default setting of the close-on-exec flag is a Unix
3741 * design flaw)
3742 *
3743 * See:
3744 * 1085341: 32-bit stdio routines should support file descriptors >255
3745 * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3746 * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3747 */
3748 #ifdef FD_CLOEXEC
3749 {
3750 int flags = ::fcntl(fd, F_GETFD);
3751 if (flags != -1)
3752 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3753 }
3754 #endif
3756 if (o_delete != 0) {
3757 ::unlink(path);
3758 }
3759 return fd;
3760 }
3763 // create binary file, rewriting existing file if required
3764 int os::create_binary_file(const char* path, bool rewrite_existing) {
3765 int oflags = O_WRONLY | O_CREAT;
3766 if (!rewrite_existing) {
3767 oflags |= O_EXCL;
3768 }
3769 return ::open(path, oflags, S_IREAD | S_IWRITE);
3770 }
3772 // return current position of file pointer
3773 jlong os::current_file_offset(int fd) {
3774 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3775 }
3777 // move file pointer to the specified offset
3778 jlong os::seek_to_file_offset(int fd, jlong offset) {
3779 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3780 }
3782 // This code originates from JDK's sysAvailable
3783 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3785 int os::available(int fd, jlong *bytes) {
3786 jlong cur, end;
3787 int mode;
3788 struct stat buf;
3790 if (::fstat(fd, &buf) >= 0) {
3791 mode = buf.st_mode;
3792 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3793 /*
3794 * XXX: is the following call interruptible? If so, this might
3795 * need to go through the INTERRUPT_IO() wrapper as for other
3796 * blocking, interruptible calls in this file.
3797 */
3798 int n;
3799 if (::ioctl(fd, FIONREAD, &n) >= 0) {
3800 *bytes = n;
3801 return 1;
3802 }
3803 }
3804 }
3805 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3806 return 0;
3807 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3808 return 0;
3809 } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3810 return 0;
3811 }
3812 *bytes = end - cur;
3813 return 1;
3814 }
3816 int os::socket_available(int fd, jint *pbytes) {
3817 if (fd < 0)
3818 return OS_OK;
3820 int ret;
3822 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
3824 //%% note ioctl can return 0 when successful, JVM_SocketAvailable
3825 // is expected to return 0 on failure and 1 on success to the jdk.
3827 return (ret == OS_ERR) ? 0 : 1;
3828 }
3830 // Map a block of memory.
3831 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3832 char *addr, size_t bytes, bool read_only,
3833 bool allow_exec) {
3834 int prot;
3835 int flags;
3837 if (read_only) {
3838 prot = PROT_READ;
3839 flags = MAP_SHARED;
3840 } else {
3841 prot = PROT_READ | PROT_WRITE;
3842 flags = MAP_PRIVATE;
3843 }
3845 if (allow_exec) {
3846 prot |= PROT_EXEC;
3847 }
3849 if (addr != NULL) {
3850 flags |= MAP_FIXED;
3851 }
3853 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3854 fd, file_offset);
3855 if (mapped_address == MAP_FAILED) {
3856 return NULL;
3857 }
3858 return mapped_address;
3859 }
3862 // Remap a block of memory.
3863 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3864 char *addr, size_t bytes, bool read_only,
3865 bool allow_exec) {
3866 // same as map_memory() on this OS
3867 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3868 allow_exec);
3869 }
3872 // Unmap a block of memory.
3873 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3874 return munmap(addr, bytes) == 0;
3875 }
3877 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3878 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3879 // of a thread.
3880 //
3881 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3882 // the fast estimate available on the platform.
3884 jlong os::current_thread_cpu_time() {
3885 #ifdef __APPLE__
3886 return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3887 #endif
3888 }
3890 jlong os::thread_cpu_time(Thread* thread) {
3891 }
3893 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3894 #ifdef __APPLE__
3895 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3896 #endif
3897 }
3899 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3900 #ifdef __APPLE__
3901 struct thread_basic_info tinfo;
3902 mach_msg_type_number_t tcount = THREAD_INFO_MAX;
3903 kern_return_t kr;
3904 thread_t mach_thread;
3906 mach_thread = thread->osthread()->thread_id();
3907 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
3908 if (kr != KERN_SUCCESS)
3909 return -1;
3911 if (user_sys_cpu_time) {
3912 jlong nanos;
3913 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
3914 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
3915 return nanos;
3916 } else {
3917 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
3918 }
3919 #endif
3920 }
3923 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3924 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
3925 info_ptr->may_skip_backward = false; // elapsed time not wall time
3926 info_ptr->may_skip_forward = false; // elapsed time not wall time
3927 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
3928 }
3930 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3931 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
3932 info_ptr->may_skip_backward = false; // elapsed time not wall time
3933 info_ptr->may_skip_forward = false; // elapsed time not wall time
3934 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
3935 }
3937 bool os::is_thread_cpu_time_supported() {
3938 #ifdef __APPLE__
3939 return true;
3940 #else
3941 return false;
3942 #endif
3943 }
3945 // System loadavg support. Returns -1 if load average cannot be obtained.
3946 // Bsd doesn't yet have a (official) notion of processor sets,
3947 // so just return the system wide load average.
3948 int os::loadavg(double loadavg[], int nelem) {
3949 return ::getloadavg(loadavg, nelem);
3950 }
3952 void os::pause() {
3953 char filename[MAX_PATH];
3954 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
3955 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
3956 } else {
3957 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
3958 }
3960 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
3961 if (fd != -1) {
3962 struct stat buf;
3963 ::close(fd);
3964 while (::stat(filename, &buf) == 0) {
3965 (void)::poll(NULL, 0, 100);
3966 }
3967 } else {
3968 jio_fprintf(stderr,
3969 "Could not open pause file '%s', continuing immediately.\n", filename);
3970 }
3971 }
3974 // Refer to the comments in os_solaris.cpp park-unpark.
3975 //
3976 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
3977 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
3978 // For specifics regarding the bug see GLIBC BUGID 261237 :
3979 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
3980 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
3981 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
3982 // is used. (The simple C test-case provided in the GLIBC bug report manifests the
3983 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
3984 // and monitorenter when we're using 1-0 locking. All those operations may result in
3985 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version
3986 // of libpthread avoids the problem, but isn't practical.
3987 //
3988 // Possible remedies:
3989 //
3990 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work.
3991 // This is palliative and probabilistic, however. If the thread is preempted
3992 // between the call to compute_abstime() and pthread_cond_timedwait(), more
3993 // than the minimum period may have passed, and the abstime may be stale (in the
3994 // past) resultin in a hang. Using this technique reduces the odds of a hang
3995 // but the JVM is still vulnerable, particularly on heavily loaded systems.
3996 //
3997 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
3998 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set
3999 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4000 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant
4001 // thread.
4002 //
4003 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread
4004 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing
4005 // a timeout request to the chron thread and then blocking via pthread_cond_wait().
4006 // This also works well. In fact it avoids kernel-level scalability impediments
4007 // on certain platforms that don't handle lots of active pthread_cond_timedwait()
4008 // timers in a graceful fashion.
4009 //
4010 // 4. When the abstime value is in the past it appears that control returns
4011 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4012 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we
4013 // can avoid the problem by reinitializing the condvar -- by cond_destroy()
4014 // followed by cond_init() -- after all calls to pthread_cond_timedwait().
4015 // It may be possible to avoid reinitialization by checking the return
4016 // value from pthread_cond_timedwait(). In addition to reinitializing the
4017 // condvar we must establish the invariant that cond_signal() is only called
4018 // within critical sections protected by the adjunct mutex. This prevents
4019 // cond_signal() from "seeing" a condvar that's in the midst of being
4020 // reinitialized or that is corrupt. Sadly, this invariant obviates the
4021 // desirable signal-after-unlock optimization that avoids futile context switching.
4022 //
4023 // I'm also concerned that some versions of NTPL might allocate an auxilliary
4024 // structure when a condvar is used or initialized. cond_destroy() would
4025 // release the helper structure. Our reinitialize-after-timedwait fix
4026 // put excessive stress on malloc/free and locks protecting the c-heap.
4027 //
4028 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag.
4029 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4030 // and only enabling the work-around for vulnerable environments.
4032 // utility to compute the abstime argument to timedwait:
4033 // millis is the relative timeout time
4034 // abstime will be the absolute timeout time
4035 // TODO: replace compute_abstime() with unpackTime()
4037 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
4038 if (millis < 0) millis = 0;
4039 struct timeval now;
4040 int status = gettimeofday(&now, NULL);
4041 assert(status == 0, "gettimeofday");
4042 jlong seconds = millis / 1000;
4043 millis %= 1000;
4044 if (seconds > 50000000) { // see man cond_timedwait(3T)
4045 seconds = 50000000;
4046 }
4047 abstime->tv_sec = now.tv_sec + seconds;
4048 long usec = now.tv_usec + millis * 1000;
4049 if (usec >= 1000000) {
4050 abstime->tv_sec += 1;
4051 usec -= 1000000;
4052 }
4053 abstime->tv_nsec = usec * 1000;
4054 return abstime;
4055 }
4058 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
4059 // Conceptually TryPark() should be equivalent to park(0).
4061 int os::PlatformEvent::TryPark() {
4062 for (;;) {
4063 const int v = _Event ;
4064 guarantee ((v == 0) || (v == 1), "invariant") ;
4065 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ;
4066 }
4067 }
4069 void os::PlatformEvent::park() { // AKA "down()"
4070 // Invariant: Only the thread associated with the Event/PlatformEvent
4071 // may call park().
4072 // TODO: assert that _Assoc != NULL or _Assoc == Self
4073 int v ;
4074 for (;;) {
4075 v = _Event ;
4076 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4077 }
4078 guarantee (v >= 0, "invariant") ;
4079 if (v == 0) {
4080 // Do this the hard way by blocking ...
4081 int status = pthread_mutex_lock(_mutex);
4082 assert_status(status == 0, status, "mutex_lock");
4083 guarantee (_nParked == 0, "invariant") ;
4084 ++ _nParked ;
4085 while (_Event < 0) {
4086 status = pthread_cond_wait(_cond, _mutex);
4087 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4088 // Treat this the same as if the wait was interrupted
4089 if (status == ETIMEDOUT) { status = EINTR; }
4090 assert_status(status == 0 || status == EINTR, status, "cond_wait");
4091 }
4092 -- _nParked ;
4094 // In theory we could move the ST of 0 into _Event past the unlock(),
4095 // but then we'd need a MEMBAR after the ST.
4096 _Event = 0 ;
4097 status = pthread_mutex_unlock(_mutex);
4098 assert_status(status == 0, status, "mutex_unlock");
4099 }
4100 guarantee (_Event >= 0, "invariant") ;
4101 }
4103 int os::PlatformEvent::park(jlong millis) {
4104 guarantee (_nParked == 0, "invariant") ;
4106 int v ;
4107 for (;;) {
4108 v = _Event ;
4109 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4110 }
4111 guarantee (v >= 0, "invariant") ;
4112 if (v != 0) return OS_OK ;
4114 // We do this the hard way, by blocking the thread.
4115 // Consider enforcing a minimum timeout value.
4116 struct timespec abst;
4117 compute_abstime(&abst, millis);
4119 int ret = OS_TIMEOUT;
4120 int status = pthread_mutex_lock(_mutex);
4121 assert_status(status == 0, status, "mutex_lock");
4122 guarantee (_nParked == 0, "invariant") ;
4123 ++_nParked ;
4125 // Object.wait(timo) will return because of
4126 // (a) notification
4127 // (b) timeout
4128 // (c) thread.interrupt
4129 //
4130 // Thread.interrupt and object.notify{All} both call Event::set.
4131 // That is, we treat thread.interrupt as a special case of notification.
4132 // The underlying Solaris implementation, cond_timedwait, admits
4133 // spurious/premature wakeups, but the JLS/JVM spec prevents the
4134 // JVM from making those visible to Java code. As such, we must
4135 // filter out spurious wakeups. We assume all ETIME returns are valid.
4136 //
4137 // TODO: properly differentiate simultaneous notify+interrupt.
4138 // In that case, we should propagate the notify to another waiter.
4140 while (_Event < 0) {
4141 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4142 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4143 pthread_cond_destroy (_cond);
4144 pthread_cond_init (_cond, NULL) ;
4145 }
4146 assert_status(status == 0 || status == EINTR ||
4147 status == ETIMEDOUT,
4148 status, "cond_timedwait");
4149 if (!FilterSpuriousWakeups) break ; // previous semantics
4150 if (status == ETIMEDOUT) break ;
4151 // We consume and ignore EINTR and spurious wakeups.
4152 }
4153 --_nParked ;
4154 if (_Event >= 0) {
4155 ret = OS_OK;
4156 }
4157 _Event = 0 ;
4158 status = pthread_mutex_unlock(_mutex);
4159 assert_status(status == 0, status, "mutex_unlock");
4160 assert (_nParked == 0, "invariant") ;
4161 return ret;
4162 }
4164 void os::PlatformEvent::unpark() {
4165 int v, AnyWaiters ;
4166 for (;;) {
4167 v = _Event ;
4168 if (v > 0) {
4169 // The LD of _Event could have reordered or be satisfied
4170 // by a read-aside from this processor's write buffer.
4171 // To avoid problems execute a barrier and then
4172 // ratify the value.
4173 OrderAccess::fence() ;
4174 if (_Event == v) return ;
4175 continue ;
4176 }
4177 if (Atomic::cmpxchg (v+1, &_Event, v) == v) break ;
4178 }
4179 if (v < 0) {
4180 // Wait for the thread associated with the event to vacate
4181 int status = pthread_mutex_lock(_mutex);
4182 assert_status(status == 0, status, "mutex_lock");
4183 AnyWaiters = _nParked ;
4184 assert (AnyWaiters == 0 || AnyWaiters == 1, "invariant") ;
4185 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4186 AnyWaiters = 0 ;
4187 pthread_cond_signal (_cond);
4188 }
4189 status = pthread_mutex_unlock(_mutex);
4190 assert_status(status == 0, status, "mutex_unlock");
4191 if (AnyWaiters != 0) {
4192 status = pthread_cond_signal(_cond);
4193 assert_status(status == 0, status, "cond_signal");
4194 }
4195 }
4197 // Note that we signal() _after dropping the lock for "immortal" Events.
4198 // This is safe and avoids a common class of futile wakeups. In rare
4199 // circumstances this can cause a thread to return prematurely from
4200 // cond_{timed}wait() but the spurious wakeup is benign and the victim will
4201 // simply re-test the condition and re-park itself.
4202 }
4205 // JSR166
4206 // -------------------------------------------------------
4208 /*
4209 * The solaris and bsd implementations of park/unpark are fairly
4210 * conservative for now, but can be improved. They currently use a
4211 * mutex/condvar pair, plus a a count.
4212 * Park decrements count if > 0, else does a condvar wait. Unpark
4213 * sets count to 1 and signals condvar. Only one thread ever waits
4214 * on the condvar. Contention seen when trying to park implies that someone
4215 * is unparking you, so don't wait. And spurious returns are fine, so there
4216 * is no need to track notifications.
4217 */
4219 #define MAX_SECS 100000000
4220 /*
4221 * This code is common to bsd and solaris and will be moved to a
4222 * common place in dolphin.
4223 *
4224 * The passed in time value is either a relative time in nanoseconds
4225 * or an absolute time in milliseconds. Either way it has to be unpacked
4226 * into suitable seconds and nanoseconds components and stored in the
4227 * given timespec structure.
4228 * Given time is a 64-bit value and the time_t used in the timespec is only
4229 * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4230 * overflow if times way in the future are given. Further on Solaris versions
4231 * prior to 10 there is a restriction (see cond_timedwait) that the specified
4232 * number of seconds, in abstime, is less than current_time + 100,000,000.
4233 * As it will be 28 years before "now + 100000000" will overflow we can
4234 * ignore overflow and just impose a hard-limit on seconds using the value
4235 * of "now + 100,000,000". This places a limit on the timeout of about 3.17
4236 * years from "now".
4237 */
4239 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4240 assert (time > 0, "convertTime");
4242 struct timeval now;
4243 int status = gettimeofday(&now, NULL);
4244 assert(status == 0, "gettimeofday");
4246 time_t max_secs = now.tv_sec + MAX_SECS;
4248 if (isAbsolute) {
4249 jlong secs = time / 1000;
4250 if (secs > max_secs) {
4251 absTime->tv_sec = max_secs;
4252 }
4253 else {
4254 absTime->tv_sec = secs;
4255 }
4256 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4257 }
4258 else {
4259 jlong secs = time / NANOSECS_PER_SEC;
4260 if (secs >= MAX_SECS) {
4261 absTime->tv_sec = max_secs;
4262 absTime->tv_nsec = 0;
4263 }
4264 else {
4265 absTime->tv_sec = now.tv_sec + secs;
4266 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4267 if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4268 absTime->tv_nsec -= NANOSECS_PER_SEC;
4269 ++absTime->tv_sec; // note: this must be <= max_secs
4270 }
4271 }
4272 }
4273 assert(absTime->tv_sec >= 0, "tv_sec < 0");
4274 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4275 assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4276 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4277 }
4279 void Parker::park(bool isAbsolute, jlong time) {
4280 // Optional fast-path check:
4281 // Return immediately if a permit is available.
4282 if (_counter > 0) {
4283 _counter = 0 ;
4284 OrderAccess::fence();
4285 return ;
4286 }
4288 Thread* thread = Thread::current();
4289 assert(thread->is_Java_thread(), "Must be JavaThread");
4290 JavaThread *jt = (JavaThread *)thread;
4292 // Optional optimization -- avoid state transitions if there's an interrupt pending.
4293 // Check interrupt before trying to wait
4294 if (Thread::is_interrupted(thread, false)) {
4295 return;
4296 }
4298 // Next, demultiplex/decode time arguments
4299 struct timespec absTime;
4300 if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
4301 return;
4302 }
4303 if (time > 0) {
4304 unpackTime(&absTime, isAbsolute, time);
4305 }
4308 // Enter safepoint region
4309 // Beware of deadlocks such as 6317397.
4310 // The per-thread Parker:: mutex is a classic leaf-lock.
4311 // In particular a thread must never block on the Threads_lock while
4312 // holding the Parker:: mutex. If safepoints are pending both the
4313 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4314 ThreadBlockInVM tbivm(jt);
4316 // Don't wait if cannot get lock since interference arises from
4317 // unblocking. Also. check interrupt before trying wait
4318 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4319 return;
4320 }
4322 int status ;
4323 if (_counter > 0) { // no wait needed
4324 _counter = 0;
4325 status = pthread_mutex_unlock(_mutex);
4326 assert (status == 0, "invariant") ;
4327 OrderAccess::fence();
4328 return;
4329 }
4331 #ifdef ASSERT
4332 // Don't catch signals while blocked; let the running threads have the signals.
4333 // (This allows a debugger to break into the running thread.)
4334 sigset_t oldsigs;
4335 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4336 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4337 #endif
4339 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4340 jt->set_suspend_equivalent();
4341 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4343 if (time == 0) {
4344 status = pthread_cond_wait (_cond, _mutex) ;
4345 } else {
4346 status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
4347 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4348 pthread_cond_destroy (_cond) ;
4349 pthread_cond_init (_cond, NULL);
4350 }
4351 }
4352 assert_status(status == 0 || status == EINTR ||
4353 status == ETIMEDOUT,
4354 status, "cond_timedwait");
4356 #ifdef ASSERT
4357 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4358 #endif
4360 _counter = 0 ;
4361 status = pthread_mutex_unlock(_mutex) ;
4362 assert_status(status == 0, status, "invariant") ;
4363 // If externally suspended while waiting, re-suspend
4364 if (jt->handle_special_suspend_equivalent_condition()) {
4365 jt->java_suspend_self();
4366 }
4368 OrderAccess::fence();
4369 }
4371 void Parker::unpark() {
4372 int s, status ;
4373 status = pthread_mutex_lock(_mutex);
4374 assert (status == 0, "invariant") ;
4375 s = _counter;
4376 _counter = 1;
4377 if (s < 1) {
4378 if (WorkAroundNPTLTimedWaitHang) {
4379 status = pthread_cond_signal (_cond) ;
4380 assert (status == 0, "invariant") ;
4381 status = pthread_mutex_unlock(_mutex);
4382 assert (status == 0, "invariant") ;
4383 } else {
4384 status = pthread_mutex_unlock(_mutex);
4385 assert (status == 0, "invariant") ;
4386 status = pthread_cond_signal (_cond) ;
4387 assert (status == 0, "invariant") ;
4388 }
4389 } else {
4390 pthread_mutex_unlock(_mutex);
4391 assert (status == 0, "invariant") ;
4392 }
4393 }
4396 /* Darwin has no "environ" in a dynamic library. */
4397 #ifdef __APPLE__
4398 #include <crt_externs.h>
4399 #define environ (*_NSGetEnviron())
4400 #else
4401 extern char** environ;
4402 #endif
4404 // Run the specified command in a separate process. Return its exit value,
4405 // or -1 on failure (e.g. can't fork a new process).
4406 // Unlike system(), this function can be called from signal handler. It
4407 // doesn't block SIGINT et al.
4408 int os::fork_and_exec(char* cmd) {
4409 const char * argv[4] = {"sh", "-c", cmd, NULL};
4411 // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4412 // pthread_atfork handlers and reset pthread library. All we need is a
4413 // separate process to execve. Make a direct syscall to fork process.
4414 // On IA64 there's no fork syscall, we have to use fork() and hope for
4415 // the best...
4416 pid_t pid = fork();
4418 if (pid < 0) {
4419 // fork failed
4420 return -1;
4422 } else if (pid == 0) {
4423 // child process
4425 // execve() in BsdThreads will call pthread_kill_other_threads_np()
4426 // first to kill every thread on the thread list. Because this list is
4427 // not reset by fork() (see notes above), execve() will instead kill
4428 // every thread in the parent process. We know this is the only thread
4429 // in the new process, so make a system call directly.
4430 // IA64 should use normal execve() from glibc to match the glibc fork()
4431 // above.
4432 execve("/bin/sh", (char* const*)argv, environ);
4434 // execve failed
4435 _exit(-1);
4437 } else {
4438 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4439 // care about the actual exit code, for now.
4441 int status;
4443 // Wait for the child process to exit. This returns immediately if
4444 // the child has already exited. */
4445 while (waitpid(pid, &status, 0) < 0) {
4446 switch (errno) {
4447 case ECHILD: return 0;
4448 case EINTR: break;
4449 default: return -1;
4450 }
4451 }
4453 if (WIFEXITED(status)) {
4454 // The child exited normally; get its exit code.
4455 return WEXITSTATUS(status);
4456 } else if (WIFSIGNALED(status)) {
4457 // The child exited because of a signal
4458 // The best value to return is 0x80 + signal number,
4459 // because that is what all Unix shells do, and because
4460 // it allows callers to distinguish between process exit and
4461 // process death by signal.
4462 return 0x80 + WTERMSIG(status);
4463 } else {
4464 // Unknown exit code; pass it through
4465 return status;
4466 }
4467 }
4468 }
4470 // is_headless_jre()
4471 //
4472 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4473 // in order to report if we are running in a headless jre
4474 //
4475 // Since JDK8 xawt/libmawt.so was moved into the same directory
4476 // as libawt.so, and renamed libawt_xawt.so
4477 //
4478 bool os::is_headless_jre() {
4479 struct stat statbuf;
4480 char buf[MAXPATHLEN];
4481 char libmawtpath[MAXPATHLEN];
4482 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX;
4483 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4484 char *p;
4486 // Get path to libjvm.so
4487 os::jvm_path(buf, sizeof(buf));
4489 // Get rid of libjvm.so
4490 p = strrchr(buf, '/');
4491 if (p == NULL) return false;
4492 else *p = '\0';
4494 // Get rid of client or server
4495 p = strrchr(buf, '/');
4496 if (p == NULL) return false;
4497 else *p = '\0';
4499 // check xawt/libmawt.so
4500 strcpy(libmawtpath, buf);
4501 strcat(libmawtpath, xawtstr);
4502 if (::stat(libmawtpath, &statbuf) == 0) return false;
4504 // check libawt_xawt.so
4505 strcpy(libmawtpath, buf);
4506 strcat(libmawtpath, new_xawtstr);
4507 if (::stat(libmawtpath, &statbuf) == 0) return false;
4509 return true;
4510 }
4512 // Get the default path to the core file
4513 // Returns the length of the string
4514 int os::get_core_path(char* buffer, size_t bufferSize) {
4515 int n = jio_snprintf(buffer, bufferSize, "/cores");
4517 // Truncate if theoretical string was longer than bufferSize
4518 n = MIN2(n, (int)bufferSize);
4520 return n;
4521 }