Thu, 13 Feb 2014 11:28:17 -0500
8030763: Validate global memory allocation
Summary: Add length checks where necessary
Reviewed-by: coleenp, mschoene
1 /*
2 * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
25 // no precompiled headers
26 #include "classfile/classLoader.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/vmSymbols.hpp"
29 #include "code/icBuffer.hpp"
30 #include "code/vtableStubs.hpp"
31 #include "compiler/compileBroker.hpp"
32 #include "compiler/disassembler.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "jvm_bsd.h"
35 #include "memory/allocation.inline.hpp"
36 #include "memory/filemap.hpp"
37 #include "mutex_bsd.inline.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "os_share_bsd.hpp"
40 #include "prims/jniFastGetField.hpp"
41 #include "prims/jvm.h"
42 #include "prims/jvm_misc.hpp"
43 #include "runtime/arguments.hpp"
44 #include "runtime/extendedPC.hpp"
45 #include "runtime/globals.hpp"
46 #include "runtime/interfaceSupport.hpp"
47 #include "runtime/java.hpp"
48 #include "runtime/javaCalls.hpp"
49 #include "runtime/mutexLocker.hpp"
50 #include "runtime/objectMonitor.hpp"
51 #include "runtime/osThread.hpp"
52 #include "runtime/perfMemory.hpp"
53 #include "runtime/sharedRuntime.hpp"
54 #include "runtime/statSampler.hpp"
55 #include "runtime/stubRoutines.hpp"
56 #include "runtime/thread.inline.hpp"
57 #include "runtime/threadCritical.hpp"
58 #include "runtime/timer.hpp"
59 #include "services/attachListener.hpp"
60 #include "services/memTracker.hpp"
61 #include "services/runtimeService.hpp"
62 #include "utilities/decoder.hpp"
63 #include "utilities/defaultStream.hpp"
64 #include "utilities/events.hpp"
65 #include "utilities/growableArray.hpp"
66 #include "utilities/vmError.hpp"
68 // put OS-includes here
69 # include <sys/types.h>
70 # include <sys/mman.h>
71 # include <sys/stat.h>
72 # include <sys/select.h>
73 # include <pthread.h>
74 # include <signal.h>
75 # include <errno.h>
76 # include <dlfcn.h>
77 # include <stdio.h>
78 # include <unistd.h>
79 # include <sys/resource.h>
80 # include <pthread.h>
81 # include <sys/stat.h>
82 # include <sys/time.h>
83 # include <sys/times.h>
84 # include <sys/utsname.h>
85 # include <sys/socket.h>
86 # include <sys/wait.h>
87 # include <time.h>
88 # include <pwd.h>
89 # include <poll.h>
90 # include <semaphore.h>
91 # include <fcntl.h>
92 # include <string.h>
93 # include <sys/param.h>
94 # include <sys/sysctl.h>
95 # include <sys/ipc.h>
96 # include <sys/shm.h>
97 #ifndef __APPLE__
98 # include <link.h>
99 #endif
100 # include <stdint.h>
101 # include <inttypes.h>
102 # include <sys/ioctl.h>
103 # include <sys/syscall.h>
105 #if defined(__FreeBSD__) || defined(__NetBSD__)
106 # include <elf.h>
107 #endif
109 #ifdef __APPLE__
110 # include <mach/mach.h> // semaphore_* API
111 # include <mach-o/dyld.h>
112 # include <sys/proc_info.h>
113 # include <objc/objc-auto.h>
114 #endif
116 #ifndef MAP_ANONYMOUS
117 #define MAP_ANONYMOUS MAP_ANON
118 #endif
120 #define MAX_PATH (2 * K)
122 // for timer info max values which include all bits
123 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
125 #define LARGEPAGES_BIT (1 << 6)
126 ////////////////////////////////////////////////////////////////////////////////
127 // global variables
128 julong os::Bsd::_physical_memory = 0;
131 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
132 pthread_t os::Bsd::_main_thread;
133 int os::Bsd::_page_size = -1;
135 static jlong initial_time_count=0;
137 static int clock_tics_per_sec = 100;
139 // For diagnostics to print a message once. see run_periodic_checks
140 static sigset_t check_signal_done;
141 static bool check_signals = true;
143 static pid_t _initial_pid = 0;
145 /* Signal number used to suspend/resume a thread */
147 /* do not use any signal number less than SIGSEGV, see 4355769 */
148 static int SR_signum = SIGUSR2;
149 sigset_t SR_sigset;
152 ////////////////////////////////////////////////////////////////////////////////
153 // utility functions
155 static int SR_initialize();
156 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
158 julong os::available_memory() {
159 return Bsd::available_memory();
160 }
162 // available here means free
163 julong os::Bsd::available_memory() {
164 uint64_t available = physical_memory() >> 2;
165 #ifdef __APPLE__
166 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
167 vm_statistics64_data_t vmstat;
168 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
169 (host_info64_t)&vmstat, &count);
170 assert(kerr == KERN_SUCCESS,
171 "host_statistics64 failed - check mach_host_self() and count");
172 if (kerr == KERN_SUCCESS) {
173 available = vmstat.free_count * os::vm_page_size();
174 }
175 #endif
176 return available;
177 }
179 julong os::physical_memory() {
180 return Bsd::physical_memory();
181 }
183 ////////////////////////////////////////////////////////////////////////////////
184 // environment support
186 bool os::getenv(const char* name, char* buf, int len) {
187 const char* val = ::getenv(name);
188 if (val != NULL && strlen(val) < (size_t)len) {
189 strcpy(buf, val);
190 return true;
191 }
192 if (len > 0) buf[0] = 0; // return a null string
193 return false;
194 }
197 // Return true if user is running as root.
199 bool os::have_special_privileges() {
200 static bool init = false;
201 static bool privileges = false;
202 if (!init) {
203 privileges = (getuid() != geteuid()) || (getgid() != getegid());
204 init = true;
205 }
206 return privileges;
207 }
211 // Cpu architecture string
212 #if defined(ZERO)
213 static char cpu_arch[] = ZERO_LIBARCH;
214 #elif defined(IA64)
215 static char cpu_arch[] = "ia64";
216 #elif defined(IA32)
217 static char cpu_arch[] = "i386";
218 #elif defined(AMD64)
219 static char cpu_arch[] = "amd64";
220 #elif defined(ARM)
221 static char cpu_arch[] = "arm";
222 #elif defined(PPC)
223 static char cpu_arch[] = "ppc";
224 #elif defined(SPARC)
225 # ifdef _LP64
226 static char cpu_arch[] = "sparcv9";
227 # else
228 static char cpu_arch[] = "sparc";
229 # endif
230 #else
231 #error Add appropriate cpu_arch setting
232 #endif
234 // Compiler variant
235 #ifdef COMPILER2
236 #define COMPILER_VARIANT "server"
237 #else
238 #define COMPILER_VARIANT "client"
239 #endif
242 void os::Bsd::initialize_system_info() {
243 int mib[2];
244 size_t len;
245 int cpu_val;
246 julong mem_val;
248 /* get processors count via hw.ncpus sysctl */
249 mib[0] = CTL_HW;
250 mib[1] = HW_NCPU;
251 len = sizeof(cpu_val);
252 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
253 assert(len == sizeof(cpu_val), "unexpected data size");
254 set_processor_count(cpu_val);
255 }
256 else {
257 set_processor_count(1); // fallback
258 }
260 /* get physical memory via hw.memsize sysctl (hw.memsize is used
261 * since it returns a 64 bit value)
262 */
263 mib[0] = CTL_HW;
265 #if defined (HW_MEMSIZE) // Apple
266 mib[1] = HW_MEMSIZE;
267 #elif defined(HW_PHYSMEM) // Most of BSD
268 mib[1] = HW_PHYSMEM;
269 #elif defined(HW_REALMEM) // Old FreeBSD
270 mib[1] = HW_REALMEM;
271 #else
272 #error No ways to get physmem
273 #endif
275 len = sizeof(mem_val);
276 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
277 assert(len == sizeof(mem_val), "unexpected data size");
278 _physical_memory = mem_val;
279 } else {
280 _physical_memory = 256*1024*1024; // fallback (XXXBSD?)
281 }
283 #ifdef __OpenBSD__
284 {
285 // limit _physical_memory memory view on OpenBSD since
286 // datasize rlimit restricts us anyway.
287 struct rlimit limits;
288 getrlimit(RLIMIT_DATA, &limits);
289 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
290 }
291 #endif
292 }
294 #ifdef __APPLE__
295 static const char *get_home() {
296 const char *home_dir = ::getenv("HOME");
297 if ((home_dir == NULL) || (*home_dir == '\0')) {
298 struct passwd *passwd_info = getpwuid(geteuid());
299 if (passwd_info != NULL) {
300 home_dir = passwd_info->pw_dir;
301 }
302 }
304 return home_dir;
305 }
306 #endif
308 void os::init_system_properties_values() {
309 // char arch[12];
310 // sysinfo(SI_ARCHITECTURE, arch, sizeof(arch));
312 // The next steps are taken in the product version:
313 //
314 // Obtain the JAVA_HOME value from the location of libjvm.so.
315 // This library should be located at:
316 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
317 //
318 // If "/jre/lib/" appears at the right place in the path, then we
319 // assume libjvm.so is installed in a JDK and we use this path.
320 //
321 // Otherwise exit with message: "Could not create the Java virtual machine."
322 //
323 // The following extra steps are taken in the debugging version:
324 //
325 // If "/jre/lib/" does NOT appear at the right place in the path
326 // instead of exit check for $JAVA_HOME environment variable.
327 //
328 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
329 // then we append a fake suffix "hotspot/libjvm.so" to this path so
330 // it looks like libjvm.so is installed there
331 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
332 //
333 // Otherwise exit.
334 //
335 // Important note: if the location of libjvm.so changes this
336 // code needs to be changed accordingly.
338 // The next few definitions allow the code to be verbatim:
339 #define malloc(n) (char*)NEW_C_HEAP_ARRAY(char, (n), mtInternal)
340 #define getenv(n) ::getenv(n)
342 /*
343 * See ld(1):
344 * The linker uses the following search paths to locate required
345 * shared libraries:
346 * 1: ...
347 * ...
348 * 7: The default directories, normally /lib and /usr/lib.
349 */
350 #ifndef DEFAULT_LIBPATH
351 #define DEFAULT_LIBPATH "/lib:/usr/lib"
352 #endif
354 #define EXTENSIONS_DIR "/lib/ext"
355 #define ENDORSED_DIR "/lib/endorsed"
356 #define REG_DIR "/usr/java/packages"
358 #ifdef __APPLE__
359 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions"
360 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
361 const char *user_home_dir = get_home();
362 // the null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir
363 int system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
364 sizeof(SYS_EXTENSIONS_DIRS);
365 #endif
367 {
368 /* sysclasspath, java_home, dll_dir */
369 {
370 char *home_path;
371 char *dll_path;
372 char *pslash;
373 char buf[MAXPATHLEN];
374 os::jvm_path(buf, sizeof(buf));
376 // Found the full path to libjvm.so.
377 // Now cut the path to <java_home>/jre if we can.
378 *(strrchr(buf, '/')) = '\0'; /* get rid of /libjvm.so */
379 pslash = strrchr(buf, '/');
380 if (pslash != NULL)
381 *pslash = '\0'; /* get rid of /{client|server|hotspot} */
382 dll_path = malloc(strlen(buf) + 1);
383 if (dll_path == NULL)
384 return;
385 strcpy(dll_path, buf);
386 Arguments::set_dll_dir(dll_path);
388 if (pslash != NULL) {
389 pslash = strrchr(buf, '/');
390 if (pslash != NULL) {
391 *pslash = '\0'; /* get rid of /<arch> (/lib on macosx) */
392 #ifndef __APPLE__
393 pslash = strrchr(buf, '/');
394 if (pslash != NULL)
395 *pslash = '\0'; /* get rid of /lib */
396 #endif
397 }
398 }
400 home_path = malloc(strlen(buf) + 1);
401 if (home_path == NULL)
402 return;
403 strcpy(home_path, buf);
404 Arguments::set_java_home(home_path);
406 if (!set_boot_path('/', ':'))
407 return;
408 }
410 /*
411 * Where to look for native libraries
412 *
413 * Note: Due to a legacy implementation, most of the library path
414 * is set in the launcher. This was to accomodate linking restrictions
415 * on legacy Bsd implementations (which are no longer supported).
416 * Eventually, all the library path setting will be done here.
417 *
418 * However, to prevent the proliferation of improperly built native
419 * libraries, the new path component /usr/java/packages is added here.
420 * Eventually, all the library path setting will be done here.
421 */
422 {
423 char *ld_library_path;
425 /*
426 * Construct the invariant part of ld_library_path. Note that the
427 * space for the colon and the trailing null are provided by the
428 * nulls included by the sizeof operator (so actually we allocate
429 * a byte more than necessary).
430 */
431 #ifdef __APPLE__
432 ld_library_path = (char *) malloc(system_ext_size);
433 sprintf(ld_library_path, "%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS, user_home_dir);
434 #else
435 ld_library_path = (char *) malloc(sizeof(REG_DIR) + sizeof("/lib/") +
436 strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH));
437 sprintf(ld_library_path, REG_DIR "/lib/%s:" DEFAULT_LIBPATH, cpu_arch);
438 #endif
440 /*
441 * Get the user setting of LD_LIBRARY_PATH, and prepended it. It
442 * should always exist (until the legacy problem cited above is
443 * addressed).
444 */
445 #ifdef __APPLE__
446 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code can specify a directory inside an app wrapper
447 char *l = getenv("JAVA_LIBRARY_PATH");
448 if (l != NULL) {
449 char *t = ld_library_path;
450 /* That's +1 for the colon and +1 for the trailing '\0' */
451 ld_library_path = (char *) malloc(strlen(l) + 1 + strlen(t) + 1);
452 sprintf(ld_library_path, "%s:%s", l, t);
453 free(t);
454 }
456 char *v = getenv("DYLD_LIBRARY_PATH");
457 #else
458 char *v = getenv("LD_LIBRARY_PATH");
459 #endif
460 if (v != NULL) {
461 char *t = ld_library_path;
462 /* That's +1 for the colon and +1 for the trailing '\0' */
463 ld_library_path = (char *) malloc(strlen(v) + 1 + strlen(t) + 1);
464 sprintf(ld_library_path, "%s:%s", v, t);
465 free(t);
466 }
468 #ifdef __APPLE__
469 // Apple's Java6 has "." at the beginning of java.library.path.
470 // OpenJDK on Windows has "." at the end of java.library.path.
471 // OpenJDK on Linux and Solaris don't have "." in java.library.path
472 // at all. To ease the transition from Apple's Java6 to OpenJDK7,
473 // "." is appended to the end of java.library.path. Yes, this
474 // could cause a change in behavior, but Apple's Java6 behavior
475 // can be achieved by putting "." at the beginning of the
476 // JAVA_LIBRARY_PATH environment variable.
477 {
478 char *t = ld_library_path;
479 // that's +3 for appending ":." and the trailing '\0'
480 ld_library_path = (char *) malloc(strlen(t) + 3);
481 sprintf(ld_library_path, "%s:%s", t, ".");
482 free(t);
483 }
484 #endif
486 Arguments::set_library_path(ld_library_path);
487 }
489 /*
490 * Extensions directories.
491 *
492 * Note that the space for the colon and the trailing null are provided
493 * by the nulls included by the sizeof operator (so actually one byte more
494 * than necessary is allocated).
495 */
496 {
497 #ifdef __APPLE__
498 char *buf = malloc(strlen(Arguments::get_java_home()) +
499 sizeof(EXTENSIONS_DIR) + system_ext_size);
500 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":"
501 SYS_EXTENSIONS_DIRS, user_home_dir, Arguments::get_java_home());
502 #else
503 char *buf = malloc(strlen(Arguments::get_java_home()) +
504 sizeof(EXTENSIONS_DIR) + sizeof(REG_DIR) + sizeof(EXTENSIONS_DIR));
505 sprintf(buf, "%s" EXTENSIONS_DIR ":" REG_DIR EXTENSIONS_DIR,
506 Arguments::get_java_home());
507 #endif
509 Arguments::set_ext_dirs(buf);
510 }
512 /* Endorsed standards default directory. */
513 {
514 char * buf;
515 buf = malloc(strlen(Arguments::get_java_home()) + sizeof(ENDORSED_DIR));
516 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
517 Arguments::set_endorsed_dirs(buf);
518 }
519 }
521 #ifdef __APPLE__
522 #undef SYS_EXTENSIONS_DIR
523 #endif
524 #undef malloc
525 #undef getenv
526 #undef EXTENSIONS_DIR
527 #undef ENDORSED_DIR
529 // Done
530 return;
531 }
533 ////////////////////////////////////////////////////////////////////////////////
534 // breakpoint support
536 void os::breakpoint() {
537 BREAKPOINT;
538 }
540 extern "C" void breakpoint() {
541 // use debugger to set breakpoint here
542 }
544 ////////////////////////////////////////////////////////////////////////////////
545 // signal support
547 debug_only(static bool signal_sets_initialized = false);
548 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
550 bool os::Bsd::is_sig_ignored(int sig) {
551 struct sigaction oact;
552 sigaction(sig, (struct sigaction*)NULL, &oact);
553 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
554 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
555 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
556 return true;
557 else
558 return false;
559 }
561 void os::Bsd::signal_sets_init() {
562 // Should also have an assertion stating we are still single-threaded.
563 assert(!signal_sets_initialized, "Already initialized");
564 // Fill in signals that are necessarily unblocked for all threads in
565 // the VM. Currently, we unblock the following signals:
566 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
567 // by -Xrs (=ReduceSignalUsage));
568 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
569 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
570 // the dispositions or masks wrt these signals.
571 // Programs embedding the VM that want to use the above signals for their
572 // own purposes must, at this time, use the "-Xrs" option to prevent
573 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
574 // (See bug 4345157, and other related bugs).
575 // In reality, though, unblocking these signals is really a nop, since
576 // these signals are not blocked by default.
577 sigemptyset(&unblocked_sigs);
578 sigemptyset(&allowdebug_blocked_sigs);
579 sigaddset(&unblocked_sigs, SIGILL);
580 sigaddset(&unblocked_sigs, SIGSEGV);
581 sigaddset(&unblocked_sigs, SIGBUS);
582 sigaddset(&unblocked_sigs, SIGFPE);
583 sigaddset(&unblocked_sigs, SR_signum);
585 if (!ReduceSignalUsage) {
586 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
587 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
588 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
589 }
590 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
591 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
592 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
593 }
594 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
595 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
596 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
597 }
598 }
599 // Fill in signals that are blocked by all but the VM thread.
600 sigemptyset(&vm_sigs);
601 if (!ReduceSignalUsage)
602 sigaddset(&vm_sigs, BREAK_SIGNAL);
603 debug_only(signal_sets_initialized = true);
605 }
607 // These are signals that are unblocked while a thread is running Java.
608 // (For some reason, they get blocked by default.)
609 sigset_t* os::Bsd::unblocked_signals() {
610 assert(signal_sets_initialized, "Not initialized");
611 return &unblocked_sigs;
612 }
614 // These are the signals that are blocked while a (non-VM) thread is
615 // running Java. Only the VM thread handles these signals.
616 sigset_t* os::Bsd::vm_signals() {
617 assert(signal_sets_initialized, "Not initialized");
618 return &vm_sigs;
619 }
621 // These are signals that are blocked during cond_wait to allow debugger in
622 sigset_t* os::Bsd::allowdebug_blocked_signals() {
623 assert(signal_sets_initialized, "Not initialized");
624 return &allowdebug_blocked_sigs;
625 }
627 void os::Bsd::hotspot_sigmask(Thread* thread) {
629 //Save caller's signal mask before setting VM signal mask
630 sigset_t caller_sigmask;
631 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
633 OSThread* osthread = thread->osthread();
634 osthread->set_caller_sigmask(caller_sigmask);
636 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
638 if (!ReduceSignalUsage) {
639 if (thread->is_VM_thread()) {
640 // Only the VM thread handles BREAK_SIGNAL ...
641 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
642 } else {
643 // ... all other threads block BREAK_SIGNAL
644 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
645 }
646 }
647 }
650 //////////////////////////////////////////////////////////////////////////////
651 // create new thread
653 // check if it's safe to start a new thread
654 static bool _thread_safety_check(Thread* thread) {
655 return true;
656 }
658 #ifdef __APPLE__
659 // library handle for calling objc_registerThreadWithCollector()
660 // without static linking to the libobjc library
661 #define OBJC_LIB "/usr/lib/libobjc.dylib"
662 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
663 typedef void (*objc_registerThreadWithCollector_t)();
664 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
665 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
666 #endif
668 #ifdef __APPLE__
669 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
670 // Additional thread_id used to correlate threads in SA
671 thread_identifier_info_data_t m_ident_info;
672 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT;
674 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
675 (thread_info_t) &m_ident_info, &count);
677 return m_ident_info.thread_id;
678 }
679 #endif
681 // Thread start routine for all newly created threads
682 static void *java_start(Thread *thread) {
683 // Try to randomize the cache line index of hot stack frames.
684 // This helps when threads of the same stack traces evict each other's
685 // cache lines. The threads can be either from the same JVM instance, or
686 // from different JVM instances. The benefit is especially true for
687 // processors with hyperthreading technology.
688 static int counter = 0;
689 int pid = os::current_process_id();
690 alloca(((pid ^ counter++) & 7) * 128);
692 ThreadLocalStorage::set_thread(thread);
694 OSThread* osthread = thread->osthread();
695 Monitor* sync = osthread->startThread_lock();
697 // non floating stack BsdThreads needs extra check, see above
698 if (!_thread_safety_check(thread)) {
699 // notify parent thread
700 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
701 osthread->set_state(ZOMBIE);
702 sync->notify_all();
703 return NULL;
704 }
706 osthread->set_thread_id(os::Bsd::gettid());
708 #ifdef __APPLE__
709 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
710 guarantee(unique_thread_id != 0, "unique thread id was not found");
711 osthread->set_unique_thread_id(unique_thread_id);
712 #endif
713 // initialize signal mask for this thread
714 os::Bsd::hotspot_sigmask(thread);
716 // initialize floating point control register
717 os::Bsd::init_thread_fpu_state();
719 #ifdef __APPLE__
720 // register thread with objc gc
721 if (objc_registerThreadWithCollectorFunction != NULL) {
722 objc_registerThreadWithCollectorFunction();
723 }
724 #endif
726 // handshaking with parent thread
727 {
728 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
730 // notify parent thread
731 osthread->set_state(INITIALIZED);
732 sync->notify_all();
734 // wait until os::start_thread()
735 while (osthread->get_state() == INITIALIZED) {
736 sync->wait(Mutex::_no_safepoint_check_flag);
737 }
738 }
740 // call one more level start routine
741 thread->run();
743 return 0;
744 }
746 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
747 assert(thread->osthread() == NULL, "caller responsible");
749 // Allocate the OSThread object
750 OSThread* osthread = new OSThread(NULL, NULL);
751 if (osthread == NULL) {
752 return false;
753 }
755 // set the correct thread state
756 osthread->set_thread_type(thr_type);
758 // Initial state is ALLOCATED but not INITIALIZED
759 osthread->set_state(ALLOCATED);
761 thread->set_osthread(osthread);
763 // init thread attributes
764 pthread_attr_t attr;
765 pthread_attr_init(&attr);
766 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
768 // stack size
769 if (os::Bsd::supports_variable_stack_size()) {
770 // calculate stack size if it's not specified by caller
771 if (stack_size == 0) {
772 stack_size = os::Bsd::default_stack_size(thr_type);
774 switch (thr_type) {
775 case os::java_thread:
776 // Java threads use ThreadStackSize which default value can be
777 // changed with the flag -Xss
778 assert (JavaThread::stack_size_at_create() > 0, "this should be set");
779 stack_size = JavaThread::stack_size_at_create();
780 break;
781 case os::compiler_thread:
782 if (CompilerThreadStackSize > 0) {
783 stack_size = (size_t)(CompilerThreadStackSize * K);
784 break;
785 } // else fall through:
786 // use VMThreadStackSize if CompilerThreadStackSize is not defined
787 case os::vm_thread:
788 case os::pgc_thread:
789 case os::cgc_thread:
790 case os::watcher_thread:
791 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
792 break;
793 }
794 }
796 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
797 pthread_attr_setstacksize(&attr, stack_size);
798 } else {
799 // let pthread_create() pick the default value.
800 }
802 ThreadState state;
804 {
805 pthread_t tid;
806 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
808 pthread_attr_destroy(&attr);
810 if (ret != 0) {
811 if (PrintMiscellaneous && (Verbose || WizardMode)) {
812 perror("pthread_create()");
813 }
814 // Need to clean up stuff we've allocated so far
815 thread->set_osthread(NULL);
816 delete osthread;
817 return false;
818 }
820 // Store pthread info into the OSThread
821 osthread->set_pthread_id(tid);
823 // Wait until child thread is either initialized or aborted
824 {
825 Monitor* sync_with_child = osthread->startThread_lock();
826 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
827 while ((state = osthread->get_state()) == ALLOCATED) {
828 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
829 }
830 }
832 }
834 // Aborted due to thread limit being reached
835 if (state == ZOMBIE) {
836 thread->set_osthread(NULL);
837 delete osthread;
838 return false;
839 }
841 // The thread is returned suspended (in state INITIALIZED),
842 // and is started higher up in the call chain
843 assert(state == INITIALIZED, "race condition");
844 return true;
845 }
847 /////////////////////////////////////////////////////////////////////////////
848 // attach existing thread
850 // bootstrap the main thread
851 bool os::create_main_thread(JavaThread* thread) {
852 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
853 return create_attached_thread(thread);
854 }
856 bool os::create_attached_thread(JavaThread* thread) {
857 #ifdef ASSERT
858 thread->verify_not_published();
859 #endif
861 // Allocate the OSThread object
862 OSThread* osthread = new OSThread(NULL, NULL);
864 if (osthread == NULL) {
865 return false;
866 }
868 osthread->set_thread_id(os::Bsd::gettid());
870 // Store pthread info into the OSThread
871 #ifdef __APPLE__
872 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
873 guarantee(unique_thread_id != 0, "just checking");
874 osthread->set_unique_thread_id(unique_thread_id);
875 #endif
876 osthread->set_pthread_id(::pthread_self());
878 // initialize floating point control register
879 os::Bsd::init_thread_fpu_state();
881 // Initial thread state is RUNNABLE
882 osthread->set_state(RUNNABLE);
884 thread->set_osthread(osthread);
886 // initialize signal mask for this thread
887 // and save the caller's signal mask
888 os::Bsd::hotspot_sigmask(thread);
890 return true;
891 }
893 void os::pd_start_thread(Thread* thread) {
894 OSThread * osthread = thread->osthread();
895 assert(osthread->get_state() != INITIALIZED, "just checking");
896 Monitor* sync_with_child = osthread->startThread_lock();
897 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
898 sync_with_child->notify();
899 }
901 // Free Bsd resources related to the OSThread
902 void os::free_thread(OSThread* osthread) {
903 assert(osthread != NULL, "osthread not set");
905 if (Thread::current()->osthread() == osthread) {
906 // Restore caller's signal mask
907 sigset_t sigmask = osthread->caller_sigmask();
908 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
909 }
911 delete osthread;
912 }
914 //////////////////////////////////////////////////////////////////////////////
915 // thread local storage
917 int os::allocate_thread_local_storage() {
918 pthread_key_t key;
919 int rslt = pthread_key_create(&key, NULL);
920 assert(rslt == 0, "cannot allocate thread local storage");
921 return (int)key;
922 }
924 // Note: This is currently not used by VM, as we don't destroy TLS key
925 // on VM exit.
926 void os::free_thread_local_storage(int index) {
927 int rslt = pthread_key_delete((pthread_key_t)index);
928 assert(rslt == 0, "invalid index");
929 }
931 void os::thread_local_storage_at_put(int index, void* value) {
932 int rslt = pthread_setspecific((pthread_key_t)index, value);
933 assert(rslt == 0, "pthread_setspecific failed");
934 }
936 extern "C" Thread* get_thread() {
937 return ThreadLocalStorage::thread();
938 }
941 ////////////////////////////////////////////////////////////////////////////////
942 // time support
944 // Time since start-up in seconds to a fine granularity.
945 // Used by VMSelfDestructTimer and the MemProfiler.
946 double os::elapsedTime() {
948 return ((double)os::elapsed_counter()) / os::elapsed_frequency();
949 }
951 jlong os::elapsed_counter() {
952 return javaTimeNanos() - initial_time_count;
953 }
955 jlong os::elapsed_frequency() {
956 return NANOSECS_PER_SEC; // nanosecond resolution
957 }
959 bool os::supports_vtime() { return true; }
960 bool os::enable_vtime() { return false; }
961 bool os::vtime_enabled() { return false; }
963 double os::elapsedVTime() {
964 // better than nothing, but not much
965 return elapsedTime();
966 }
968 jlong os::javaTimeMillis() {
969 timeval time;
970 int status = gettimeofday(&time, NULL);
971 assert(status != -1, "bsd error");
972 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
973 }
975 #ifndef CLOCK_MONOTONIC
976 #define CLOCK_MONOTONIC (1)
977 #endif
979 #ifdef __APPLE__
980 void os::Bsd::clock_init() {
981 // XXXDARWIN: Investigate replacement monotonic clock
982 }
983 #else
984 void os::Bsd::clock_init() {
985 struct timespec res;
986 struct timespec tp;
987 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
988 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
989 // yes, monotonic clock is supported
990 _clock_gettime = ::clock_gettime;
991 }
992 }
993 #endif
996 jlong os::javaTimeNanos() {
997 if (Bsd::supports_monotonic_clock()) {
998 struct timespec tp;
999 int status = Bsd::clock_gettime(CLOCK_MONOTONIC, &tp);
1000 assert(status == 0, "gettime error");
1001 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1002 return result;
1003 } else {
1004 timeval time;
1005 int status = gettimeofday(&time, NULL);
1006 assert(status != -1, "bsd error");
1007 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1008 return 1000 * usecs;
1009 }
1010 }
1012 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1013 if (Bsd::supports_monotonic_clock()) {
1014 info_ptr->max_value = ALL_64_BITS;
1016 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1017 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1018 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1019 } else {
1020 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1021 info_ptr->max_value = ALL_64_BITS;
1023 // gettimeofday is a real time clock so it skips
1024 info_ptr->may_skip_backward = true;
1025 info_ptr->may_skip_forward = true;
1026 }
1028 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1029 }
1031 // Return the real, user, and system times in seconds from an
1032 // arbitrary fixed point in the past.
1033 bool os::getTimesSecs(double* process_real_time,
1034 double* process_user_time,
1035 double* process_system_time) {
1036 struct tms ticks;
1037 clock_t real_ticks = times(&ticks);
1039 if (real_ticks == (clock_t) (-1)) {
1040 return false;
1041 } else {
1042 double ticks_per_second = (double) clock_tics_per_sec;
1043 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1044 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1045 *process_real_time = ((double) real_ticks) / ticks_per_second;
1047 return true;
1048 }
1049 }
1052 char * os::local_time_string(char *buf, size_t buflen) {
1053 struct tm t;
1054 time_t long_time;
1055 time(&long_time);
1056 localtime_r(&long_time, &t);
1057 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1058 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1059 t.tm_hour, t.tm_min, t.tm_sec);
1060 return buf;
1061 }
1063 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1064 return localtime_r(clock, res);
1065 }
1067 ////////////////////////////////////////////////////////////////////////////////
1068 // runtime exit support
1070 // Note: os::shutdown() might be called very early during initialization, or
1071 // called from signal handler. Before adding something to os::shutdown(), make
1072 // sure it is async-safe and can handle partially initialized VM.
1073 void os::shutdown() {
1075 // allow PerfMemory to attempt cleanup of any persistent resources
1076 perfMemory_exit();
1078 // needs to remove object in file system
1079 AttachListener::abort();
1081 // flush buffered output, finish log files
1082 ostream_abort();
1084 // Check for abort hook
1085 abort_hook_t abort_hook = Arguments::abort_hook();
1086 if (abort_hook != NULL) {
1087 abort_hook();
1088 }
1090 }
1092 // Note: os::abort() might be called very early during initialization, or
1093 // called from signal handler. Before adding something to os::abort(), make
1094 // sure it is async-safe and can handle partially initialized VM.
1095 void os::abort(bool dump_core) {
1096 os::shutdown();
1097 if (dump_core) {
1098 #ifndef PRODUCT
1099 fdStream out(defaultStream::output_fd());
1100 out.print_raw("Current thread is ");
1101 char buf[16];
1102 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1103 out.print_raw_cr(buf);
1104 out.print_raw_cr("Dumping core ...");
1105 #endif
1106 ::abort(); // dump core
1107 }
1109 ::exit(1);
1110 }
1112 // Die immediately, no exit hook, no abort hook, no cleanup.
1113 void os::die() {
1114 // _exit() on BsdThreads only kills current thread
1115 ::abort();
1116 }
1118 // This method is a copy of JDK's sysGetLastErrorString
1119 // from src/solaris/hpi/src/system_md.c
1121 size_t os::lasterror(char *buf, size_t len) {
1123 if (errno == 0) return 0;
1125 const char *s = ::strerror(errno);
1126 size_t n = ::strlen(s);
1127 if (n >= len) {
1128 n = len - 1;
1129 }
1130 ::strncpy(buf, s, n);
1131 buf[n] = '\0';
1132 return n;
1133 }
1135 // Information of current thread in variety of formats
1136 pid_t os::Bsd::gettid() {
1137 int retval = -1;
1139 #ifdef __APPLE__ //XNU kernel
1140 // despite the fact mach port is actually not a thread id use it
1141 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1142 retval = ::pthread_mach_thread_np(::pthread_self());
1143 guarantee(retval != 0, "just checking");
1144 return retval;
1146 #elif __FreeBSD__
1147 retval = syscall(SYS_thr_self);
1148 #elif __OpenBSD__
1149 retval = syscall(SYS_getthrid);
1150 #elif __NetBSD__
1151 retval = (pid_t) syscall(SYS__lwp_self);
1152 #endif
1154 if (retval == -1) {
1155 return getpid();
1156 }
1157 }
1159 intx os::current_thread_id() {
1160 #ifdef __APPLE__
1161 return (intx)::pthread_mach_thread_np(::pthread_self());
1162 #else
1163 return (intx)::pthread_self();
1164 #endif
1165 }
1167 int os::current_process_id() {
1169 // Under the old bsd thread library, bsd gives each thread
1170 // its own process id. Because of this each thread will return
1171 // a different pid if this method were to return the result
1172 // of getpid(2). Bsd provides no api that returns the pid
1173 // of the launcher thread for the vm. This implementation
1174 // returns a unique pid, the pid of the launcher thread
1175 // that starts the vm 'process'.
1177 // Under the NPTL, getpid() returns the same pid as the
1178 // launcher thread rather than a unique pid per thread.
1179 // Use gettid() if you want the old pre NPTL behaviour.
1181 // if you are looking for the result of a call to getpid() that
1182 // returns a unique pid for the calling thread, then look at the
1183 // OSThread::thread_id() method in osThread_bsd.hpp file
1185 return (int)(_initial_pid ? _initial_pid : getpid());
1186 }
1188 // DLL functions
1190 #define JNI_LIB_PREFIX "lib"
1191 #ifdef __APPLE__
1192 #define JNI_LIB_SUFFIX ".dylib"
1193 #else
1194 #define JNI_LIB_SUFFIX ".so"
1195 #endif
1197 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1199 // This must be hard coded because it's the system's temporary
1200 // directory not the java application's temp directory, ala java.io.tmpdir.
1201 #ifdef __APPLE__
1202 // macosx has a secure per-user temporary directory
1203 char temp_path_storage[PATH_MAX];
1204 const char* os::get_temp_directory() {
1205 static char *temp_path = NULL;
1206 if (temp_path == NULL) {
1207 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1208 if (pathSize == 0 || pathSize > PATH_MAX) {
1209 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1210 }
1211 temp_path = temp_path_storage;
1212 }
1213 return temp_path;
1214 }
1215 #else /* __APPLE__ */
1216 const char* os::get_temp_directory() { return "/tmp"; }
1217 #endif /* __APPLE__ */
1219 static bool file_exists(const char* filename) {
1220 struct stat statbuf;
1221 if (filename == NULL || strlen(filename) == 0) {
1222 return false;
1223 }
1224 return os::stat(filename, &statbuf) == 0;
1225 }
1227 bool os::dll_build_name(char* buffer, size_t buflen,
1228 const char* pname, const char* fname) {
1229 bool retval = false;
1230 // Copied from libhpi
1231 const size_t pnamelen = pname ? strlen(pname) : 0;
1233 // Return error on buffer overflow.
1234 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1235 return retval;
1236 }
1238 if (pnamelen == 0) {
1239 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1240 retval = true;
1241 } else if (strchr(pname, *os::path_separator()) != NULL) {
1242 int n;
1243 char** pelements = split_path(pname, &n);
1244 if (pelements == NULL) {
1245 return false;
1246 }
1247 for (int i = 0 ; i < n ; i++) {
1248 // Really shouldn't be NULL, but check can't hurt
1249 if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1250 continue; // skip the empty path values
1251 }
1252 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1253 pelements[i], fname);
1254 if (file_exists(buffer)) {
1255 retval = true;
1256 break;
1257 }
1258 }
1259 // release the storage
1260 for (int i = 0 ; i < n ; i++) {
1261 if (pelements[i] != NULL) {
1262 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
1263 }
1264 }
1265 if (pelements != NULL) {
1266 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
1267 }
1268 } else {
1269 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1270 retval = true;
1271 }
1272 return retval;
1273 }
1275 // check if addr is inside libjvm.so
1276 bool os::address_is_in_vm(address addr) {
1277 static address libjvm_base_addr;
1278 Dl_info dlinfo;
1280 if (libjvm_base_addr == NULL) {
1281 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1282 libjvm_base_addr = (address)dlinfo.dli_fbase;
1283 }
1284 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1285 }
1287 if (dladdr((void *)addr, &dlinfo) != 0) {
1288 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1289 }
1291 return false;
1292 }
1295 #define MACH_MAXSYMLEN 256
1297 bool os::dll_address_to_function_name(address addr, char *buf,
1298 int buflen, int *offset) {
1299 // buf is not optional, but offset is optional
1300 assert(buf != NULL, "sanity check");
1302 Dl_info dlinfo;
1303 char localbuf[MACH_MAXSYMLEN];
1305 if (dladdr((void*)addr, &dlinfo) != 0) {
1306 // see if we have a matching symbol
1307 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1308 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1309 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1310 }
1311 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1312 return true;
1313 }
1314 // no matching symbol so try for just file info
1315 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1316 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1317 buf, buflen, offset, dlinfo.dli_fname)) {
1318 return true;
1319 }
1320 }
1322 // Handle non-dynamic manually:
1323 if (dlinfo.dli_fbase != NULL &&
1324 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1325 dlinfo.dli_fbase)) {
1326 if (!Decoder::demangle(localbuf, buf, buflen)) {
1327 jio_snprintf(buf, buflen, "%s", localbuf);
1328 }
1329 return true;
1330 }
1331 }
1332 buf[0] = '\0';
1333 if (offset != NULL) *offset = -1;
1334 return false;
1335 }
1337 // ported from solaris version
1338 bool os::dll_address_to_library_name(address addr, char* buf,
1339 int buflen, int* offset) {
1340 // buf is not optional, but offset is optional
1341 assert(buf != NULL, "sanity check");
1343 Dl_info dlinfo;
1345 if (dladdr((void*)addr, &dlinfo) != 0) {
1346 if (dlinfo.dli_fname != NULL) {
1347 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1348 }
1349 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1350 *offset = addr - (address)dlinfo.dli_fbase;
1351 }
1352 return true;
1353 }
1355 buf[0] = '\0';
1356 if (offset) *offset = -1;
1357 return false;
1358 }
1360 // Loads .dll/.so and
1361 // in case of error it checks if .dll/.so was built for the
1362 // same architecture as Hotspot is running on
1364 #ifdef __APPLE__
1365 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1366 void * result= ::dlopen(filename, RTLD_LAZY);
1367 if (result != NULL) {
1368 // Successful loading
1369 return result;
1370 }
1372 // Read system error message into ebuf
1373 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1374 ebuf[ebuflen-1]='\0';
1376 return NULL;
1377 }
1378 #else
1379 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
1380 {
1381 void * result= ::dlopen(filename, RTLD_LAZY);
1382 if (result != NULL) {
1383 // Successful loading
1384 return result;
1385 }
1387 Elf32_Ehdr elf_head;
1389 // Read system error message into ebuf
1390 // It may or may not be overwritten below
1391 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1392 ebuf[ebuflen-1]='\0';
1393 int diag_msg_max_length=ebuflen-strlen(ebuf);
1394 char* diag_msg_buf=ebuf+strlen(ebuf);
1396 if (diag_msg_max_length==0) {
1397 // No more space in ebuf for additional diagnostics message
1398 return NULL;
1399 }
1402 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1404 if (file_descriptor < 0) {
1405 // Can't open library, report dlerror() message
1406 return NULL;
1407 }
1409 bool failed_to_read_elf_head=
1410 (sizeof(elf_head)!=
1411 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
1413 ::close(file_descriptor);
1414 if (failed_to_read_elf_head) {
1415 // file i/o error - report dlerror() msg
1416 return NULL;
1417 }
1419 typedef struct {
1420 Elf32_Half code; // Actual value as defined in elf.h
1421 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1422 char elf_class; // 32 or 64 bit
1423 char endianess; // MSB or LSB
1424 char* name; // String representation
1425 } arch_t;
1427 #ifndef EM_486
1428 #define EM_486 6 /* Intel 80486 */
1429 #endif
1431 #ifndef EM_MIPS_RS3_LE
1432 #define EM_MIPS_RS3_LE 10 /* MIPS */
1433 #endif
1435 #ifndef EM_PPC64
1436 #define EM_PPC64 21 /* PowerPC64 */
1437 #endif
1439 #ifndef EM_S390
1440 #define EM_S390 22 /* IBM System/390 */
1441 #endif
1443 #ifndef EM_IA_64
1444 #define EM_IA_64 50 /* HP/Intel IA-64 */
1445 #endif
1447 #ifndef EM_X86_64
1448 #define EM_X86_64 62 /* AMD x86-64 */
1449 #endif
1451 static const arch_t arch_array[]={
1452 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1453 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1454 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1455 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1456 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1457 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1458 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1459 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1460 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1461 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1462 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1463 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1464 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1465 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1466 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1467 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1468 };
1470 #if (defined IA32)
1471 static Elf32_Half running_arch_code=EM_386;
1472 #elif (defined AMD64)
1473 static Elf32_Half running_arch_code=EM_X86_64;
1474 #elif (defined IA64)
1475 static Elf32_Half running_arch_code=EM_IA_64;
1476 #elif (defined __sparc) && (defined _LP64)
1477 static Elf32_Half running_arch_code=EM_SPARCV9;
1478 #elif (defined __sparc) && (!defined _LP64)
1479 static Elf32_Half running_arch_code=EM_SPARC;
1480 #elif (defined __powerpc64__)
1481 static Elf32_Half running_arch_code=EM_PPC64;
1482 #elif (defined __powerpc__)
1483 static Elf32_Half running_arch_code=EM_PPC;
1484 #elif (defined ARM)
1485 static Elf32_Half running_arch_code=EM_ARM;
1486 #elif (defined S390)
1487 static Elf32_Half running_arch_code=EM_S390;
1488 #elif (defined ALPHA)
1489 static Elf32_Half running_arch_code=EM_ALPHA;
1490 #elif (defined MIPSEL)
1491 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1492 #elif (defined PARISC)
1493 static Elf32_Half running_arch_code=EM_PARISC;
1494 #elif (defined MIPS)
1495 static Elf32_Half running_arch_code=EM_MIPS;
1496 #elif (defined M68K)
1497 static Elf32_Half running_arch_code=EM_68K;
1498 #else
1499 #error Method os::dll_load requires that one of following is defined:\
1500 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1501 #endif
1503 // Identify compatability class for VM's architecture and library's architecture
1504 // Obtain string descriptions for architectures
1506 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1507 int running_arch_index=-1;
1509 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
1510 if (running_arch_code == arch_array[i].code) {
1511 running_arch_index = i;
1512 }
1513 if (lib_arch.code == arch_array[i].code) {
1514 lib_arch.compat_class = arch_array[i].compat_class;
1515 lib_arch.name = arch_array[i].name;
1516 }
1517 }
1519 assert(running_arch_index != -1,
1520 "Didn't find running architecture code (running_arch_code) in arch_array");
1521 if (running_arch_index == -1) {
1522 // Even though running architecture detection failed
1523 // we may still continue with reporting dlerror() message
1524 return NULL;
1525 }
1527 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1528 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1529 return NULL;
1530 }
1532 #ifndef S390
1533 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1534 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1535 return NULL;
1536 }
1537 #endif // !S390
1539 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1540 if ( lib_arch.name!=NULL ) {
1541 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1542 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1543 lib_arch.name, arch_array[running_arch_index].name);
1544 } else {
1545 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1546 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1547 lib_arch.code,
1548 arch_array[running_arch_index].name);
1549 }
1550 }
1552 return NULL;
1553 }
1554 #endif /* !__APPLE__ */
1556 // XXX: Do we need a lock around this as per Linux?
1557 void* os::dll_lookup(void* handle, const char* name) {
1558 return dlsym(handle, name);
1559 }
1562 static bool _print_ascii_file(const char* filename, outputStream* st) {
1563 int fd = ::open(filename, O_RDONLY);
1564 if (fd == -1) {
1565 return false;
1566 }
1568 char buf[32];
1569 int bytes;
1570 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1571 st->print_raw(buf, bytes);
1572 }
1574 ::close(fd);
1576 return true;
1577 }
1579 void os::print_dll_info(outputStream *st) {
1580 st->print_cr("Dynamic libraries:");
1581 #ifdef RTLD_DI_LINKMAP
1582 Dl_info dli;
1583 void *handle;
1584 Link_map *map;
1585 Link_map *p;
1587 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1588 dli.dli_fname == NULL) {
1589 st->print_cr("Error: Cannot print dynamic libraries.");
1590 return;
1591 }
1592 handle = dlopen(dli.dli_fname, RTLD_LAZY);
1593 if (handle == NULL) {
1594 st->print_cr("Error: Cannot print dynamic libraries.");
1595 return;
1596 }
1597 dlinfo(handle, RTLD_DI_LINKMAP, &map);
1598 if (map == NULL) {
1599 st->print_cr("Error: Cannot print dynamic libraries.");
1600 return;
1601 }
1603 while (map->l_prev != NULL)
1604 map = map->l_prev;
1606 while (map != NULL) {
1607 st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
1608 map = map->l_next;
1609 }
1611 dlclose(handle);
1612 #elif defined(__APPLE__)
1613 uint32_t count;
1614 uint32_t i;
1616 count = _dyld_image_count();
1617 for (i = 1; i < count; i++) {
1618 const char *name = _dyld_get_image_name(i);
1619 intptr_t slide = _dyld_get_image_vmaddr_slide(i);
1620 st->print_cr(PTR_FORMAT " \t%s", slide, name);
1621 }
1622 #else
1623 st->print_cr("Error: Cannot print dynamic libraries.");
1624 #endif
1625 }
1627 void os::print_os_info_brief(outputStream* st) {
1628 st->print("Bsd");
1630 os::Posix::print_uname_info(st);
1631 }
1633 void os::print_os_info(outputStream* st) {
1634 st->print("OS:");
1635 st->print("Bsd");
1637 os::Posix::print_uname_info(st);
1639 os::Posix::print_rlimit_info(st);
1641 os::Posix::print_load_average(st);
1642 }
1644 void os::pd_print_cpu_info(outputStream* st) {
1645 // Nothing to do for now.
1646 }
1648 void os::print_memory_info(outputStream* st) {
1650 st->print("Memory:");
1651 st->print(" %dk page", os::vm_page_size()>>10);
1653 st->print(", physical " UINT64_FORMAT "k",
1654 os::physical_memory() >> 10);
1655 st->print("(" UINT64_FORMAT "k free)",
1656 os::available_memory() >> 10);
1657 st->cr();
1659 // meminfo
1660 st->print("\n/proc/meminfo:\n");
1661 _print_ascii_file("/proc/meminfo", st);
1662 st->cr();
1663 }
1665 // Taken from /usr/include/bits/siginfo.h Supposed to be architecture specific
1666 // but they're the same for all the bsd arch that we support
1667 // and they're the same for solaris but there's no common place to put this.
1668 const char *ill_names[] = { "ILL0", "ILL_ILLOPC", "ILL_ILLOPN", "ILL_ILLADR",
1669 "ILL_ILLTRP", "ILL_PRVOPC", "ILL_PRVREG",
1670 "ILL_COPROC", "ILL_BADSTK" };
1672 const char *fpe_names[] = { "FPE0", "FPE_INTDIV", "FPE_INTOVF", "FPE_FLTDIV",
1673 "FPE_FLTOVF", "FPE_FLTUND", "FPE_FLTRES",
1674 "FPE_FLTINV", "FPE_FLTSUB", "FPE_FLTDEN" };
1676 const char *segv_names[] = { "SEGV0", "SEGV_MAPERR", "SEGV_ACCERR" };
1678 const char *bus_names[] = { "BUS0", "BUS_ADRALN", "BUS_ADRERR", "BUS_OBJERR" };
1680 void os::print_siginfo(outputStream* st, void* siginfo) {
1681 st->print("siginfo:");
1683 const int buflen = 100;
1684 char buf[buflen];
1685 siginfo_t *si = (siginfo_t*)siginfo;
1686 st->print("si_signo=%s: ", os::exception_name(si->si_signo, buf, buflen));
1687 if (si->si_errno != 0 && strerror_r(si->si_errno, buf, buflen) == 0) {
1688 st->print("si_errno=%s", buf);
1689 } else {
1690 st->print("si_errno=%d", si->si_errno);
1691 }
1692 const int c = si->si_code;
1693 assert(c > 0, "unexpected si_code");
1694 switch (si->si_signo) {
1695 case SIGILL:
1696 st->print(", si_code=%d (%s)", c, c > 8 ? "" : ill_names[c]);
1697 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1698 break;
1699 case SIGFPE:
1700 st->print(", si_code=%d (%s)", c, c > 9 ? "" : fpe_names[c]);
1701 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1702 break;
1703 case SIGSEGV:
1704 st->print(", si_code=%d (%s)", c, c > 2 ? "" : segv_names[c]);
1705 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1706 break;
1707 case SIGBUS:
1708 st->print(", si_code=%d (%s)", c, c > 3 ? "" : bus_names[c]);
1709 st->print(", si_addr=" PTR_FORMAT, si->si_addr);
1710 break;
1711 default:
1712 st->print(", si_code=%d", si->si_code);
1713 // no si_addr
1714 }
1716 if ((si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1717 UseSharedSpaces) {
1718 FileMapInfo* mapinfo = FileMapInfo::current_info();
1719 if (mapinfo->is_in_shared_space(si->si_addr)) {
1720 st->print("\n\nError accessing class data sharing archive." \
1721 " Mapped file inaccessible during execution, " \
1722 " possible disk/network problem.");
1723 }
1724 }
1725 st->cr();
1726 }
1729 static void print_signal_handler(outputStream* st, int sig,
1730 char* buf, size_t buflen);
1732 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1733 st->print_cr("Signal Handlers:");
1734 print_signal_handler(st, SIGSEGV, buf, buflen);
1735 print_signal_handler(st, SIGBUS , buf, buflen);
1736 print_signal_handler(st, SIGFPE , buf, buflen);
1737 print_signal_handler(st, SIGPIPE, buf, buflen);
1738 print_signal_handler(st, SIGXFSZ, buf, buflen);
1739 print_signal_handler(st, SIGILL , buf, buflen);
1740 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1741 print_signal_handler(st, SR_signum, buf, buflen);
1742 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1743 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1744 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1745 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1746 }
1748 static char saved_jvm_path[MAXPATHLEN] = {0};
1750 // Find the full path to the current module, libjvm
1751 void os::jvm_path(char *buf, jint buflen) {
1752 // Error checking.
1753 if (buflen < MAXPATHLEN) {
1754 assert(false, "must use a large-enough buffer");
1755 buf[0] = '\0';
1756 return;
1757 }
1758 // Lazy resolve the path to current module.
1759 if (saved_jvm_path[0] != 0) {
1760 strcpy(buf, saved_jvm_path);
1761 return;
1762 }
1764 char dli_fname[MAXPATHLEN];
1765 bool ret = dll_address_to_library_name(
1766 CAST_FROM_FN_PTR(address, os::jvm_path),
1767 dli_fname, sizeof(dli_fname), NULL);
1768 assert(ret, "cannot locate libjvm");
1769 char *rp = NULL;
1770 if (ret && dli_fname[0] != '\0') {
1771 rp = realpath(dli_fname, buf);
1772 }
1773 if (rp == NULL)
1774 return;
1776 if (Arguments::created_by_gamma_launcher()) {
1777 // Support for the gamma launcher. Typical value for buf is
1778 // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm". If "/jre/lib/" appears at
1779 // the right place in the string, then assume we are installed in a JDK and
1780 // we're done. Otherwise, check for a JAVA_HOME environment variable and
1781 // construct a path to the JVM being overridden.
1783 const char *p = buf + strlen(buf) - 1;
1784 for (int count = 0; p > buf && count < 5; ++count) {
1785 for (--p; p > buf && *p != '/'; --p)
1786 /* empty */ ;
1787 }
1789 if (strncmp(p, "/jre/lib/", 9) != 0) {
1790 // Look for JAVA_HOME in the environment.
1791 char* java_home_var = ::getenv("JAVA_HOME");
1792 if (java_home_var != NULL && java_home_var[0] != 0) {
1793 char* jrelib_p;
1794 int len;
1796 // Check the current module name "libjvm"
1797 p = strrchr(buf, '/');
1798 assert(strstr(p, "/libjvm") == p, "invalid library name");
1800 rp = realpath(java_home_var, buf);
1801 if (rp == NULL)
1802 return;
1804 // determine if this is a legacy image or modules image
1805 // modules image doesn't have "jre" subdirectory
1806 len = strlen(buf);
1807 assert(len < buflen, "Ran out of buffer space");
1808 jrelib_p = buf + len;
1810 // Add the appropriate library subdir
1811 snprintf(jrelib_p, buflen-len, "/jre/lib");
1812 if (0 != access(buf, F_OK)) {
1813 snprintf(jrelib_p, buflen-len, "/lib");
1814 }
1816 // Add the appropriate client or server subdir
1817 len = strlen(buf);
1818 jrelib_p = buf + len;
1819 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1820 if (0 != access(buf, F_OK)) {
1821 snprintf(jrelib_p, buflen-len, "");
1822 }
1824 // If the path exists within JAVA_HOME, add the JVM library name
1825 // to complete the path to JVM being overridden. Otherwise fallback
1826 // to the path to the current library.
1827 if (0 == access(buf, F_OK)) {
1828 // Use current module name "libjvm"
1829 len = strlen(buf);
1830 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1831 } else {
1832 // Fall back to path of current library
1833 rp = realpath(dli_fname, buf);
1834 if (rp == NULL)
1835 return;
1836 }
1837 }
1838 }
1839 }
1841 strncpy(saved_jvm_path, buf, MAXPATHLEN);
1842 }
1844 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1845 // no prefix required, not even "_"
1846 }
1848 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1849 // no suffix required
1850 }
1852 ////////////////////////////////////////////////////////////////////////////////
1853 // sun.misc.Signal support
1855 static volatile jint sigint_count = 0;
1857 static void
1858 UserHandler(int sig, void *siginfo, void *context) {
1859 // 4511530 - sem_post is serialized and handled by the manager thread. When
1860 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1861 // don't want to flood the manager thread with sem_post requests.
1862 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
1863 return;
1865 // Ctrl-C is pressed during error reporting, likely because the error
1866 // handler fails to abort. Let VM die immediately.
1867 if (sig == SIGINT && is_error_reported()) {
1868 os::die();
1869 }
1871 os::signal_notify(sig);
1872 }
1874 void* os::user_handler() {
1875 return CAST_FROM_FN_PTR(void*, UserHandler);
1876 }
1878 extern "C" {
1879 typedef void (*sa_handler_t)(int);
1880 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1881 }
1883 void* os::signal(int signal_number, void* handler) {
1884 struct sigaction sigAct, oldSigAct;
1886 sigfillset(&(sigAct.sa_mask));
1887 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
1888 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1890 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1891 // -1 means registration failed
1892 return (void *)-1;
1893 }
1895 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1896 }
1898 void os::signal_raise(int signal_number) {
1899 ::raise(signal_number);
1900 }
1902 /*
1903 * The following code is moved from os.cpp for making this
1904 * code platform specific, which it is by its very nature.
1905 */
1907 // Will be modified when max signal is changed to be dynamic
1908 int os::sigexitnum_pd() {
1909 return NSIG;
1910 }
1912 // a counter for each possible signal value
1913 static volatile jint pending_signals[NSIG+1] = { 0 };
1915 // Bsd(POSIX) specific hand shaking semaphore.
1916 #ifdef __APPLE__
1917 typedef semaphore_t os_semaphore_t;
1918 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1919 #define SEM_WAIT(sem) semaphore_wait(sem)
1920 #define SEM_POST(sem) semaphore_signal(sem)
1921 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem)
1922 #else
1923 typedef sem_t os_semaphore_t;
1924 #define SEM_INIT(sem, value) sem_init(&sem, 0, value)
1925 #define SEM_WAIT(sem) sem_wait(&sem)
1926 #define SEM_POST(sem) sem_post(&sem)
1927 #define SEM_DESTROY(sem) sem_destroy(&sem)
1928 #endif
1930 class Semaphore : public StackObj {
1931 public:
1932 Semaphore();
1933 ~Semaphore();
1934 void signal();
1935 void wait();
1936 bool trywait();
1937 bool timedwait(unsigned int sec, int nsec);
1938 private:
1939 jlong currenttime() const;
1940 os_semaphore_t _semaphore;
1941 };
1943 Semaphore::Semaphore() : _semaphore(0) {
1944 SEM_INIT(_semaphore, 0);
1945 }
1947 Semaphore::~Semaphore() {
1948 SEM_DESTROY(_semaphore);
1949 }
1951 void Semaphore::signal() {
1952 SEM_POST(_semaphore);
1953 }
1955 void Semaphore::wait() {
1956 SEM_WAIT(_semaphore);
1957 }
1959 jlong Semaphore::currenttime() const {
1960 struct timeval tv;
1961 gettimeofday(&tv, NULL);
1962 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
1963 }
1965 #ifdef __APPLE__
1966 bool Semaphore::trywait() {
1967 return timedwait(0, 0);
1968 }
1970 bool Semaphore::timedwait(unsigned int sec, int nsec) {
1971 kern_return_t kr = KERN_ABORTED;
1972 mach_timespec_t waitspec;
1973 waitspec.tv_sec = sec;
1974 waitspec.tv_nsec = nsec;
1976 jlong starttime = currenttime();
1978 kr = semaphore_timedwait(_semaphore, waitspec);
1979 while (kr == KERN_ABORTED) {
1980 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
1982 jlong current = currenttime();
1983 jlong passedtime = current - starttime;
1985 if (passedtime >= totalwait) {
1986 waitspec.tv_sec = 0;
1987 waitspec.tv_nsec = 0;
1988 } else {
1989 jlong waittime = totalwait - (current - starttime);
1990 waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
1991 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
1992 }
1994 kr = semaphore_timedwait(_semaphore, waitspec);
1995 }
1997 return kr == KERN_SUCCESS;
1998 }
2000 #else
2002 bool Semaphore::trywait() {
2003 return sem_trywait(&_semaphore) == 0;
2004 }
2006 bool Semaphore::timedwait(unsigned int sec, int nsec) {
2007 struct timespec ts;
2008 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2010 while (1) {
2011 int result = sem_timedwait(&_semaphore, &ts);
2012 if (result == 0) {
2013 return true;
2014 } else if (errno == EINTR) {
2015 continue;
2016 } else if (errno == ETIMEDOUT) {
2017 return false;
2018 } else {
2019 return false;
2020 }
2021 }
2022 }
2024 #endif // __APPLE__
2026 static os_semaphore_t sig_sem;
2027 static Semaphore sr_semaphore;
2029 void os::signal_init_pd() {
2030 // Initialize signal structures
2031 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2033 // Initialize signal semaphore
2034 ::SEM_INIT(sig_sem, 0);
2035 }
2037 void os::signal_notify(int sig) {
2038 Atomic::inc(&pending_signals[sig]);
2039 ::SEM_POST(sig_sem);
2040 }
2042 static int check_pending_signals(bool wait) {
2043 Atomic::store(0, &sigint_count);
2044 for (;;) {
2045 for (int i = 0; i < NSIG + 1; i++) {
2046 jint n = pending_signals[i];
2047 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2048 return i;
2049 }
2050 }
2051 if (!wait) {
2052 return -1;
2053 }
2054 JavaThread *thread = JavaThread::current();
2055 ThreadBlockInVM tbivm(thread);
2057 bool threadIsSuspended;
2058 do {
2059 thread->set_suspend_equivalent();
2060 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2061 ::SEM_WAIT(sig_sem);
2063 // were we externally suspended while we were waiting?
2064 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2065 if (threadIsSuspended) {
2066 //
2067 // The semaphore has been incremented, but while we were waiting
2068 // another thread suspended us. We don't want to continue running
2069 // while suspended because that would surprise the thread that
2070 // suspended us.
2071 //
2072 ::SEM_POST(sig_sem);
2074 thread->java_suspend_self();
2075 }
2076 } while (threadIsSuspended);
2077 }
2078 }
2080 int os::signal_lookup() {
2081 return check_pending_signals(false);
2082 }
2084 int os::signal_wait() {
2085 return check_pending_signals(true);
2086 }
2088 ////////////////////////////////////////////////////////////////////////////////
2089 // Virtual Memory
2091 int os::vm_page_size() {
2092 // Seems redundant as all get out
2093 assert(os::Bsd::page_size() != -1, "must call os::init");
2094 return os::Bsd::page_size();
2095 }
2097 // Solaris allocates memory by pages.
2098 int os::vm_allocation_granularity() {
2099 assert(os::Bsd::page_size() != -1, "must call os::init");
2100 return os::Bsd::page_size();
2101 }
2103 // Rationale behind this function:
2104 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2105 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2106 // samples for JITted code. Here we create private executable mapping over the code cache
2107 // and then we can use standard (well, almost, as mapping can change) way to provide
2108 // info for the reporting script by storing timestamp and location of symbol
2109 void bsd_wrap_code(char* base, size_t size) {
2110 static volatile jint cnt = 0;
2112 if (!UseOprofile) {
2113 return;
2114 }
2116 char buf[PATH_MAX + 1];
2117 int num = Atomic::add(1, &cnt);
2119 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2120 os::get_temp_directory(), os::current_process_id(), num);
2121 unlink(buf);
2123 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2125 if (fd != -1) {
2126 off_t rv = ::lseek(fd, size-2, SEEK_SET);
2127 if (rv != (off_t)-1) {
2128 if (::write(fd, "", 1) == 1) {
2129 mmap(base, size,
2130 PROT_READ|PROT_WRITE|PROT_EXEC,
2131 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2132 }
2133 }
2134 ::close(fd);
2135 unlink(buf);
2136 }
2137 }
2139 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2140 int err) {
2141 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2142 ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2143 strerror(err), err);
2144 }
2146 // NOTE: Bsd kernel does not really reserve the pages for us.
2147 // All it does is to check if there are enough free pages
2148 // left at the time of mmap(). This could be a potential
2149 // problem.
2150 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2151 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2152 #ifdef __OpenBSD__
2153 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2154 if (::mprotect(addr, size, prot) == 0) {
2155 return true;
2156 }
2157 #else
2158 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2159 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2160 if (res != (uintptr_t) MAP_FAILED) {
2161 return true;
2162 }
2163 #endif
2165 // Warn about any commit errors we see in non-product builds just
2166 // in case mmap() doesn't work as described on the man page.
2167 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2169 return false;
2170 }
2172 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2173 bool exec) {
2174 // alignment_hint is ignored on this OS
2175 return pd_commit_memory(addr, size, exec);
2176 }
2178 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2179 const char* mesg) {
2180 assert(mesg != NULL, "mesg must be specified");
2181 if (!pd_commit_memory(addr, size, exec)) {
2182 // add extra info in product mode for vm_exit_out_of_memory():
2183 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2184 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
2185 }
2186 }
2188 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2189 size_t alignment_hint, bool exec,
2190 const char* mesg) {
2191 // alignment_hint is ignored on this OS
2192 pd_commit_memory_or_exit(addr, size, exec, mesg);
2193 }
2195 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2196 }
2198 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2199 ::madvise(addr, bytes, MADV_DONTNEED);
2200 }
2202 void os::numa_make_global(char *addr, size_t bytes) {
2203 }
2205 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2206 }
2208 bool os::numa_topology_changed() { return false; }
2210 size_t os::numa_get_groups_num() {
2211 return 1;
2212 }
2214 int os::numa_get_group_id() {
2215 return 0;
2216 }
2218 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2219 if (size > 0) {
2220 ids[0] = 0;
2221 return 1;
2222 }
2223 return 0;
2224 }
2226 bool os::get_page_info(char *start, page_info* info) {
2227 return false;
2228 }
2230 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2231 return end;
2232 }
2235 bool os::pd_uncommit_memory(char* addr, size_t size) {
2236 #ifdef __OpenBSD__
2237 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2238 return ::mprotect(addr, size, PROT_NONE) == 0;
2239 #else
2240 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2241 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2242 return res != (uintptr_t) MAP_FAILED;
2243 #endif
2244 }
2246 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2247 return os::commit_memory(addr, size, !ExecMem);
2248 }
2250 // If this is a growable mapping, remove the guard pages entirely by
2251 // munmap()ping them. If not, just call uncommit_memory().
2252 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2253 return os::uncommit_memory(addr, size);
2254 }
2256 static address _highest_vm_reserved_address = NULL;
2258 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2259 // at 'requested_addr'. If there are existing memory mappings at the same
2260 // location, however, they will be overwritten. If 'fixed' is false,
2261 // 'requested_addr' is only treated as a hint, the return value may or
2262 // may not start from the requested address. Unlike Bsd mmap(), this
2263 // function returns NULL to indicate failure.
2264 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2265 char * addr;
2266 int flags;
2268 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2269 if (fixed) {
2270 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2271 flags |= MAP_FIXED;
2272 }
2274 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2275 // touch an uncommitted page. Otherwise, the read/write might
2276 // succeed if we have enough swap space to back the physical page.
2277 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2278 flags, -1, 0);
2280 if (addr != MAP_FAILED) {
2281 // anon_mmap() should only get called during VM initialization,
2282 // don't need lock (actually we can skip locking even it can be called
2283 // from multiple threads, because _highest_vm_reserved_address is just a
2284 // hint about the upper limit of non-stack memory regions.)
2285 if ((address)addr + bytes > _highest_vm_reserved_address) {
2286 _highest_vm_reserved_address = (address)addr + bytes;
2287 }
2288 }
2290 return addr == MAP_FAILED ? NULL : addr;
2291 }
2293 // Don't update _highest_vm_reserved_address, because there might be memory
2294 // regions above addr + size. If so, releasing a memory region only creates
2295 // a hole in the address space, it doesn't help prevent heap-stack collision.
2296 //
2297 static int anon_munmap(char * addr, size_t size) {
2298 return ::munmap(addr, size) == 0;
2299 }
2301 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2302 size_t alignment_hint) {
2303 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2304 }
2306 bool os::pd_release_memory(char* addr, size_t size) {
2307 return anon_munmap(addr, size);
2308 }
2310 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2311 // Bsd wants the mprotect address argument to be page aligned.
2312 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2314 // According to SUSv3, mprotect() should only be used with mappings
2315 // established by mmap(), and mmap() always maps whole pages. Unaligned
2316 // 'addr' likely indicates problem in the VM (e.g. trying to change
2317 // protection of malloc'ed or statically allocated memory). Check the
2318 // caller if you hit this assert.
2319 assert(addr == bottom, "sanity check");
2321 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2322 return ::mprotect(bottom, size, prot) == 0;
2323 }
2325 // Set protections specified
2326 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2327 bool is_committed) {
2328 unsigned int p = 0;
2329 switch (prot) {
2330 case MEM_PROT_NONE: p = PROT_NONE; break;
2331 case MEM_PROT_READ: p = PROT_READ; break;
2332 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
2333 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2334 default:
2335 ShouldNotReachHere();
2336 }
2337 // is_committed is unused.
2338 return bsd_mprotect(addr, bytes, p);
2339 }
2341 bool os::guard_memory(char* addr, size_t size) {
2342 return bsd_mprotect(addr, size, PROT_NONE);
2343 }
2345 bool os::unguard_memory(char* addr, size_t size) {
2346 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2347 }
2349 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2350 return false;
2351 }
2353 // Large page support
2355 static size_t _large_page_size = 0;
2357 void os::large_page_init() {
2358 }
2361 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2362 fatal("This code is not used or maintained.");
2364 // "exec" is passed in but not used. Creating the shared image for
2365 // the code cache doesn't have an SHM_X executable permission to check.
2366 assert(UseLargePages && UseSHM, "only for SHM large pages");
2368 key_t key = IPC_PRIVATE;
2369 char *addr;
2371 bool warn_on_failure = UseLargePages &&
2372 (!FLAG_IS_DEFAULT(UseLargePages) ||
2373 !FLAG_IS_DEFAULT(LargePageSizeInBytes)
2374 );
2375 char msg[128];
2377 // Create a large shared memory region to attach to based on size.
2378 // Currently, size is the total size of the heap
2379 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2380 if (shmid == -1) {
2381 // Possible reasons for shmget failure:
2382 // 1. shmmax is too small for Java heap.
2383 // > check shmmax value: cat /proc/sys/kernel/shmmax
2384 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2385 // 2. not enough large page memory.
2386 // > check available large pages: cat /proc/meminfo
2387 // > increase amount of large pages:
2388 // echo new_value > /proc/sys/vm/nr_hugepages
2389 // Note 1: different Bsd may use different name for this property,
2390 // e.g. on Redhat AS-3 it is "hugetlb_pool".
2391 // Note 2: it's possible there's enough physical memory available but
2392 // they are so fragmented after a long run that they can't
2393 // coalesce into large pages. Try to reserve large pages when
2394 // the system is still "fresh".
2395 if (warn_on_failure) {
2396 jio_snprintf(msg, sizeof(msg), "Failed to reserve shared memory (errno = %d).", errno);
2397 warning(msg);
2398 }
2399 return NULL;
2400 }
2402 // attach to the region
2403 addr = (char*)shmat(shmid, req_addr, 0);
2404 int err = errno;
2406 // Remove shmid. If shmat() is successful, the actual shared memory segment
2407 // will be deleted when it's detached by shmdt() or when the process
2408 // terminates. If shmat() is not successful this will remove the shared
2409 // segment immediately.
2410 shmctl(shmid, IPC_RMID, NULL);
2412 if ((intptr_t)addr == -1) {
2413 if (warn_on_failure) {
2414 jio_snprintf(msg, sizeof(msg), "Failed to attach shared memory (errno = %d).", err);
2415 warning(msg);
2416 }
2417 return NULL;
2418 }
2420 // The memory is committed
2421 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, mtNone, CALLER_PC);
2423 return addr;
2424 }
2426 bool os::release_memory_special(char* base, size_t bytes) {
2427 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2428 // detaching the SHM segment will also delete it, see reserve_memory_special()
2429 int rslt = shmdt(base);
2430 if (rslt == 0) {
2431 tkr.record((address)base, bytes);
2432 return true;
2433 } else {
2434 tkr.discard();
2435 return false;
2436 }
2438 }
2440 size_t os::large_page_size() {
2441 return _large_page_size;
2442 }
2444 // HugeTLBFS allows application to commit large page memory on demand;
2445 // with SysV SHM the entire memory region must be allocated as shared
2446 // memory.
2447 bool os::can_commit_large_page_memory() {
2448 return UseHugeTLBFS;
2449 }
2451 bool os::can_execute_large_page_memory() {
2452 return UseHugeTLBFS;
2453 }
2455 // Reserve memory at an arbitrary address, only if that area is
2456 // available (and not reserved for something else).
2458 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2459 const int max_tries = 10;
2460 char* base[max_tries];
2461 size_t size[max_tries];
2462 const size_t gap = 0x000000;
2464 // Assert only that the size is a multiple of the page size, since
2465 // that's all that mmap requires, and since that's all we really know
2466 // about at this low abstraction level. If we need higher alignment,
2467 // we can either pass an alignment to this method or verify alignment
2468 // in one of the methods further up the call chain. See bug 5044738.
2469 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2471 // Repeatedly allocate blocks until the block is allocated at the
2472 // right spot. Give up after max_tries. Note that reserve_memory() will
2473 // automatically update _highest_vm_reserved_address if the call is
2474 // successful. The variable tracks the highest memory address every reserved
2475 // by JVM. It is used to detect heap-stack collision if running with
2476 // fixed-stack BsdThreads. Because here we may attempt to reserve more
2477 // space than needed, it could confuse the collision detecting code. To
2478 // solve the problem, save current _highest_vm_reserved_address and
2479 // calculate the correct value before return.
2480 address old_highest = _highest_vm_reserved_address;
2482 // Bsd mmap allows caller to pass an address as hint; give it a try first,
2483 // if kernel honors the hint then we can return immediately.
2484 char * addr = anon_mmap(requested_addr, bytes, false);
2485 if (addr == requested_addr) {
2486 return requested_addr;
2487 }
2489 if (addr != NULL) {
2490 // mmap() is successful but it fails to reserve at the requested address
2491 anon_munmap(addr, bytes);
2492 }
2494 int i;
2495 for (i = 0; i < max_tries; ++i) {
2496 base[i] = reserve_memory(bytes);
2498 if (base[i] != NULL) {
2499 // Is this the block we wanted?
2500 if (base[i] == requested_addr) {
2501 size[i] = bytes;
2502 break;
2503 }
2505 // Does this overlap the block we wanted? Give back the overlapped
2506 // parts and try again.
2508 size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2509 if (top_overlap >= 0 && top_overlap < bytes) {
2510 unmap_memory(base[i], top_overlap);
2511 base[i] += top_overlap;
2512 size[i] = bytes - top_overlap;
2513 } else {
2514 size_t bottom_overlap = base[i] + bytes - requested_addr;
2515 if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2516 unmap_memory(requested_addr, bottom_overlap);
2517 size[i] = bytes - bottom_overlap;
2518 } else {
2519 size[i] = bytes;
2520 }
2521 }
2522 }
2523 }
2525 // Give back the unused reserved pieces.
2527 for (int j = 0; j < i; ++j) {
2528 if (base[j] != NULL) {
2529 unmap_memory(base[j], size[j]);
2530 }
2531 }
2533 if (i < max_tries) {
2534 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2535 return requested_addr;
2536 } else {
2537 _highest_vm_reserved_address = old_highest;
2538 return NULL;
2539 }
2540 }
2542 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2543 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2544 }
2546 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
2547 // Solaris uses poll(), bsd uses park().
2548 // Poll() is likely a better choice, assuming that Thread.interrupt()
2549 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
2550 // SIGSEGV, see 4355769.
2552 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
2553 assert(thread == Thread::current(), "thread consistency check");
2555 ParkEvent * const slp = thread->_SleepEvent ;
2556 slp->reset() ;
2557 OrderAccess::fence() ;
2559 if (interruptible) {
2560 jlong prevtime = javaTimeNanos();
2562 for (;;) {
2563 if (os::is_interrupted(thread, true)) {
2564 return OS_INTRPT;
2565 }
2567 jlong newtime = javaTimeNanos();
2569 if (newtime - prevtime < 0) {
2570 // time moving backwards, should only happen if no monotonic clock
2571 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2572 assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2573 } else {
2574 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2575 }
2577 if(millis <= 0) {
2578 return OS_OK;
2579 }
2581 prevtime = newtime;
2583 {
2584 assert(thread->is_Java_thread(), "sanity check");
2585 JavaThread *jt = (JavaThread *) thread;
2586 ThreadBlockInVM tbivm(jt);
2587 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
2589 jt->set_suspend_equivalent();
2590 // cleared by handle_special_suspend_equivalent_condition() or
2591 // java_suspend_self() via check_and_wait_while_suspended()
2593 slp->park(millis);
2595 // were we externally suspended while we were waiting?
2596 jt->check_and_wait_while_suspended();
2597 }
2598 }
2599 } else {
2600 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2601 jlong prevtime = javaTimeNanos();
2603 for (;;) {
2604 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
2605 // the 1st iteration ...
2606 jlong newtime = javaTimeNanos();
2608 if (newtime - prevtime < 0) {
2609 // time moving backwards, should only happen if no monotonic clock
2610 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2611 assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2612 } else {
2613 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2614 }
2616 if(millis <= 0) break ;
2618 prevtime = newtime;
2619 slp->park(millis);
2620 }
2621 return OS_OK ;
2622 }
2623 }
2625 int os::naked_sleep() {
2626 // %% make the sleep time an integer flag. for now use 1 millisec.
2627 return os::sleep(Thread::current(), 1, false);
2628 }
2630 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2631 void os::infinite_sleep() {
2632 while (true) { // sleep forever ...
2633 ::sleep(100); // ... 100 seconds at a time
2634 }
2635 }
2637 // Used to convert frequent JVM_Yield() to nops
2638 bool os::dont_yield() {
2639 return DontYieldALot;
2640 }
2642 void os::yield() {
2643 sched_yield();
2644 }
2646 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
2648 void os::yield_all(int attempts) {
2649 // Yields to all threads, including threads with lower priorities
2650 // Threads on Bsd are all with same priority. The Solaris style
2651 // os::yield_all() with nanosleep(1ms) is not necessary.
2652 sched_yield();
2653 }
2655 // Called from the tight loops to possibly influence time-sharing heuristics
2656 void os::loop_breaker(int attempts) {
2657 os::yield_all(attempts);
2658 }
2660 ////////////////////////////////////////////////////////////////////////////////
2661 // thread priority support
2663 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2664 // only supports dynamic priority, static priority must be zero. For real-time
2665 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2666 // However, for large multi-threaded applications, SCHED_RR is not only slower
2667 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2668 // of 5 runs - Sep 2005).
2669 //
2670 // The following code actually changes the niceness of kernel-thread/LWP. It
2671 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2672 // not the entire user process, and user level threads are 1:1 mapped to kernel
2673 // threads. It has always been the case, but could change in the future. For
2674 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2675 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2677 #if !defined(__APPLE__)
2678 int os::java_to_os_priority[CriticalPriority + 1] = {
2679 19, // 0 Entry should never be used
2681 0, // 1 MinPriority
2682 3, // 2
2683 6, // 3
2685 10, // 4
2686 15, // 5 NormPriority
2687 18, // 6
2689 21, // 7
2690 25, // 8
2691 28, // 9 NearMaxPriority
2693 31, // 10 MaxPriority
2695 31 // 11 CriticalPriority
2696 };
2697 #else
2698 /* Using Mach high-level priority assignments */
2699 int os::java_to_os_priority[CriticalPriority + 1] = {
2700 0, // 0 Entry should never be used (MINPRI_USER)
2702 27, // 1 MinPriority
2703 28, // 2
2704 29, // 3
2706 30, // 4
2707 31, // 5 NormPriority (BASEPRI_DEFAULT)
2708 32, // 6
2710 33, // 7
2711 34, // 8
2712 35, // 9 NearMaxPriority
2714 36, // 10 MaxPriority
2716 36 // 11 CriticalPriority
2717 };
2718 #endif
2720 static int prio_init() {
2721 if (ThreadPriorityPolicy == 1) {
2722 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2723 // if effective uid is not root. Perhaps, a more elegant way of doing
2724 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2725 if (geteuid() != 0) {
2726 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2727 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2728 }
2729 ThreadPriorityPolicy = 0;
2730 }
2731 }
2732 if (UseCriticalJavaThreadPriority) {
2733 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2734 }
2735 return 0;
2736 }
2738 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2739 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
2741 #ifdef __OpenBSD__
2742 // OpenBSD pthread_setprio starves low priority threads
2743 return OS_OK;
2744 #elif defined(__FreeBSD__)
2745 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2746 #elif defined(__APPLE__) || defined(__NetBSD__)
2747 struct sched_param sp;
2748 int policy;
2749 pthread_t self = pthread_self();
2751 if (pthread_getschedparam(self, &policy, &sp) != 0)
2752 return OS_ERR;
2754 sp.sched_priority = newpri;
2755 if (pthread_setschedparam(self, policy, &sp) != 0)
2756 return OS_ERR;
2758 return OS_OK;
2759 #else
2760 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2761 return (ret == 0) ? OS_OK : OS_ERR;
2762 #endif
2763 }
2765 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2766 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
2767 *priority_ptr = java_to_os_priority[NormPriority];
2768 return OS_OK;
2769 }
2771 errno = 0;
2772 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2773 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2774 #elif defined(__APPLE__) || defined(__NetBSD__)
2775 int policy;
2776 struct sched_param sp;
2778 pthread_getschedparam(pthread_self(), &policy, &sp);
2779 *priority_ptr = sp.sched_priority;
2780 #else
2781 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2782 #endif
2783 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2784 }
2786 // Hint to the underlying OS that a task switch would not be good.
2787 // Void return because it's a hint and can fail.
2788 void os::hint_no_preempt() {}
2790 ////////////////////////////////////////////////////////////////////////////////
2791 // suspend/resume support
2793 // the low-level signal-based suspend/resume support is a remnant from the
2794 // old VM-suspension that used to be for java-suspension, safepoints etc,
2795 // within hotspot. Now there is a single use-case for this:
2796 // - calling get_thread_pc() on the VMThread by the flat-profiler task
2797 // that runs in the watcher thread.
2798 // The remaining code is greatly simplified from the more general suspension
2799 // code that used to be used.
2800 //
2801 // The protocol is quite simple:
2802 // - suspend:
2803 // - sends a signal to the target thread
2804 // - polls the suspend state of the osthread using a yield loop
2805 // - target thread signal handler (SR_handler) sets suspend state
2806 // and blocks in sigsuspend until continued
2807 // - resume:
2808 // - sets target osthread state to continue
2809 // - sends signal to end the sigsuspend loop in the SR_handler
2810 //
2811 // Note that the SR_lock plays no role in this suspend/resume protocol.
2812 //
2814 static void resume_clear_context(OSThread *osthread) {
2815 osthread->set_ucontext(NULL);
2816 osthread->set_siginfo(NULL);
2817 }
2819 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2820 osthread->set_ucontext(context);
2821 osthread->set_siginfo(siginfo);
2822 }
2824 //
2825 // Handler function invoked when a thread's execution is suspended or
2826 // resumed. We have to be careful that only async-safe functions are
2827 // called here (Note: most pthread functions are not async safe and
2828 // should be avoided.)
2829 //
2830 // Note: sigwait() is a more natural fit than sigsuspend() from an
2831 // interface point of view, but sigwait() prevents the signal hander
2832 // from being run. libpthread would get very confused by not having
2833 // its signal handlers run and prevents sigwait()'s use with the
2834 // mutex granting granting signal.
2835 //
2836 // Currently only ever called on the VMThread or JavaThread
2837 //
2838 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2839 // Save and restore errno to avoid confusing native code with EINTR
2840 // after sigsuspend.
2841 int old_errno = errno;
2843 Thread* thread = Thread::current();
2844 OSThread* osthread = thread->osthread();
2845 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2847 os::SuspendResume::State current = osthread->sr.state();
2848 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2849 suspend_save_context(osthread, siginfo, context);
2851 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2852 os::SuspendResume::State state = osthread->sr.suspended();
2853 if (state == os::SuspendResume::SR_SUSPENDED) {
2854 sigset_t suspend_set; // signals for sigsuspend()
2856 // get current set of blocked signals and unblock resume signal
2857 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2858 sigdelset(&suspend_set, SR_signum);
2860 sr_semaphore.signal();
2861 // wait here until we are resumed
2862 while (1) {
2863 sigsuspend(&suspend_set);
2865 os::SuspendResume::State result = osthread->sr.running();
2866 if (result == os::SuspendResume::SR_RUNNING) {
2867 sr_semaphore.signal();
2868 break;
2869 } else if (result != os::SuspendResume::SR_SUSPENDED) {
2870 ShouldNotReachHere();
2871 }
2872 }
2874 } else if (state == os::SuspendResume::SR_RUNNING) {
2875 // request was cancelled, continue
2876 } else {
2877 ShouldNotReachHere();
2878 }
2880 resume_clear_context(osthread);
2881 } else if (current == os::SuspendResume::SR_RUNNING) {
2882 // request was cancelled, continue
2883 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2884 // ignore
2885 } else {
2886 // ignore
2887 }
2889 errno = old_errno;
2890 }
2893 static int SR_initialize() {
2894 struct sigaction act;
2895 char *s;
2896 /* Get signal number to use for suspend/resume */
2897 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2898 int sig = ::strtol(s, 0, 10);
2899 if (sig > 0 || sig < NSIG) {
2900 SR_signum = sig;
2901 }
2902 }
2904 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2905 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2907 sigemptyset(&SR_sigset);
2908 sigaddset(&SR_sigset, SR_signum);
2910 /* Set up signal handler for suspend/resume */
2911 act.sa_flags = SA_RESTART|SA_SIGINFO;
2912 act.sa_handler = (void (*)(int)) SR_handler;
2914 // SR_signum is blocked by default.
2915 // 4528190 - We also need to block pthread restart signal (32 on all
2916 // supported Bsd platforms). Note that BsdThreads need to block
2917 // this signal for all threads to work properly. So we don't have
2918 // to use hard-coded signal number when setting up the mask.
2919 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2921 if (sigaction(SR_signum, &act, 0) == -1) {
2922 return -1;
2923 }
2925 // Save signal flag
2926 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2927 return 0;
2928 }
2930 static int sr_notify(OSThread* osthread) {
2931 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2932 assert_status(status == 0, status, "pthread_kill");
2933 return status;
2934 }
2936 // "Randomly" selected value for how long we want to spin
2937 // before bailing out on suspending a thread, also how often
2938 // we send a signal to a thread we want to resume
2939 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2940 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2942 // returns true on success and false on error - really an error is fatal
2943 // but this seems the normal response to library errors
2944 static bool do_suspend(OSThread* osthread) {
2945 assert(osthread->sr.is_running(), "thread should be running");
2946 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2948 // mark as suspended and send signal
2949 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2950 // failed to switch, state wasn't running?
2951 ShouldNotReachHere();
2952 return false;
2953 }
2955 if (sr_notify(osthread) != 0) {
2956 ShouldNotReachHere();
2957 }
2959 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2960 while (true) {
2961 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2962 break;
2963 } else {
2964 // timeout
2965 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2966 if (cancelled == os::SuspendResume::SR_RUNNING) {
2967 return false;
2968 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2969 // make sure that we consume the signal on the semaphore as well
2970 sr_semaphore.wait();
2971 break;
2972 } else {
2973 ShouldNotReachHere();
2974 return false;
2975 }
2976 }
2977 }
2979 guarantee(osthread->sr.is_suspended(), "Must be suspended");
2980 return true;
2981 }
2983 static void do_resume(OSThread* osthread) {
2984 assert(osthread->sr.is_suspended(), "thread should be suspended");
2985 assert(!sr_semaphore.trywait(), "invalid semaphore state");
2987 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2988 // failed to switch to WAKEUP_REQUEST
2989 ShouldNotReachHere();
2990 return;
2991 }
2993 while (true) {
2994 if (sr_notify(osthread) == 0) {
2995 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2996 if (osthread->sr.is_running()) {
2997 return;
2998 }
2999 }
3000 } else {
3001 ShouldNotReachHere();
3002 }
3003 }
3005 guarantee(osthread->sr.is_running(), "Must be running!");
3006 }
3008 ////////////////////////////////////////////////////////////////////////////////
3009 // interrupt support
3011 void os::interrupt(Thread* thread) {
3012 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
3013 "possibility of dangling Thread pointer");
3015 OSThread* osthread = thread->osthread();
3017 if (!osthread->interrupted()) {
3018 osthread->set_interrupted(true);
3019 // More than one thread can get here with the same value of osthread,
3020 // resulting in multiple notifications. We do, however, want the store
3021 // to interrupted() to be visible to other threads before we execute unpark().
3022 OrderAccess::fence();
3023 ParkEvent * const slp = thread->_SleepEvent ;
3024 if (slp != NULL) slp->unpark() ;
3025 }
3027 // For JSR166. Unpark even if interrupt status already was set
3028 if (thread->is_Java_thread())
3029 ((JavaThread*)thread)->parker()->unpark();
3031 ParkEvent * ev = thread->_ParkEvent ;
3032 if (ev != NULL) ev->unpark() ;
3034 }
3036 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
3037 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
3038 "possibility of dangling Thread pointer");
3040 OSThread* osthread = thread->osthread();
3042 bool interrupted = osthread->interrupted();
3044 if (interrupted && clear_interrupted) {
3045 osthread->set_interrupted(false);
3046 // consider thread->_SleepEvent->reset() ... optional optimization
3047 }
3049 return interrupted;
3050 }
3052 ///////////////////////////////////////////////////////////////////////////////////
3053 // signal handling (except suspend/resume)
3055 // This routine may be used by user applications as a "hook" to catch signals.
3056 // The user-defined signal handler must pass unrecognized signals to this
3057 // routine, and if it returns true (non-zero), then the signal handler must
3058 // return immediately. If the flag "abort_if_unrecognized" is true, then this
3059 // routine will never retun false (zero), but instead will execute a VM panic
3060 // routine kill the process.
3061 //
3062 // If this routine returns false, it is OK to call it again. This allows
3063 // the user-defined signal handler to perform checks either before or after
3064 // the VM performs its own checks. Naturally, the user code would be making
3065 // a serious error if it tried to handle an exception (such as a null check
3066 // or breakpoint) that the VM was generating for its own correct operation.
3067 //
3068 // This routine may recognize any of the following kinds of signals:
3069 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
3070 // It should be consulted by handlers for any of those signals.
3071 //
3072 // The caller of this routine must pass in the three arguments supplied
3073 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
3074 // field of the structure passed to sigaction(). This routine assumes that
3075 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
3076 //
3077 // Note that the VM will print warnings if it detects conflicting signal
3078 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
3079 //
3080 extern "C" JNIEXPORT int
3081 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
3082 void* ucontext, int abort_if_unrecognized);
3084 void signalHandler(int sig, siginfo_t* info, void* uc) {
3085 assert(info != NULL && uc != NULL, "it must be old kernel");
3086 int orig_errno = errno; // Preserve errno value over signal handler.
3087 JVM_handle_bsd_signal(sig, info, uc, true);
3088 errno = orig_errno;
3089 }
3092 // This boolean allows users to forward their own non-matching signals
3093 // to JVM_handle_bsd_signal, harmlessly.
3094 bool os::Bsd::signal_handlers_are_installed = false;
3096 // For signal-chaining
3097 struct sigaction os::Bsd::sigact[MAXSIGNUM];
3098 unsigned int os::Bsd::sigs = 0;
3099 bool os::Bsd::libjsig_is_loaded = false;
3100 typedef struct sigaction *(*get_signal_t)(int);
3101 get_signal_t os::Bsd::get_signal_action = NULL;
3103 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
3104 struct sigaction *actp = NULL;
3106 if (libjsig_is_loaded) {
3107 // Retrieve the old signal handler from libjsig
3108 actp = (*get_signal_action)(sig);
3109 }
3110 if (actp == NULL) {
3111 // Retrieve the preinstalled signal handler from jvm
3112 actp = get_preinstalled_handler(sig);
3113 }
3115 return actp;
3116 }
3118 static bool call_chained_handler(struct sigaction *actp, int sig,
3119 siginfo_t *siginfo, void *context) {
3120 // Call the old signal handler
3121 if (actp->sa_handler == SIG_DFL) {
3122 // It's more reasonable to let jvm treat it as an unexpected exception
3123 // instead of taking the default action.
3124 return false;
3125 } else if (actp->sa_handler != SIG_IGN) {
3126 if ((actp->sa_flags & SA_NODEFER) == 0) {
3127 // automaticlly block the signal
3128 sigaddset(&(actp->sa_mask), sig);
3129 }
3131 sa_handler_t hand;
3132 sa_sigaction_t sa;
3133 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3134 // retrieve the chained handler
3135 if (siginfo_flag_set) {
3136 sa = actp->sa_sigaction;
3137 } else {
3138 hand = actp->sa_handler;
3139 }
3141 if ((actp->sa_flags & SA_RESETHAND) != 0) {
3142 actp->sa_handler = SIG_DFL;
3143 }
3145 // try to honor the signal mask
3146 sigset_t oset;
3147 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3149 // call into the chained handler
3150 if (siginfo_flag_set) {
3151 (*sa)(sig, siginfo, context);
3152 } else {
3153 (*hand)(sig);
3154 }
3156 // restore the signal mask
3157 pthread_sigmask(SIG_SETMASK, &oset, 0);
3158 }
3159 // Tell jvm's signal handler the signal is taken care of.
3160 return true;
3161 }
3163 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3164 bool chained = false;
3165 // signal-chaining
3166 if (UseSignalChaining) {
3167 struct sigaction *actp = get_chained_signal_action(sig);
3168 if (actp != NULL) {
3169 chained = call_chained_handler(actp, sig, siginfo, context);
3170 }
3171 }
3172 return chained;
3173 }
3175 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3176 if ((( (unsigned int)1 << sig ) & sigs) != 0) {
3177 return &sigact[sig];
3178 }
3179 return NULL;
3180 }
3182 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3183 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3184 sigact[sig] = oldAct;
3185 sigs |= (unsigned int)1 << sig;
3186 }
3188 // for diagnostic
3189 int os::Bsd::sigflags[MAXSIGNUM];
3191 int os::Bsd::get_our_sigflags(int sig) {
3192 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3193 return sigflags[sig];
3194 }
3196 void os::Bsd::set_our_sigflags(int sig, int flags) {
3197 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3198 sigflags[sig] = flags;
3199 }
3201 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3202 // Check for overwrite.
3203 struct sigaction oldAct;
3204 sigaction(sig, (struct sigaction*)NULL, &oldAct);
3206 void* oldhand = oldAct.sa_sigaction
3207 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3208 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3209 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3210 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3211 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3212 if (AllowUserSignalHandlers || !set_installed) {
3213 // Do not overwrite; user takes responsibility to forward to us.
3214 return;
3215 } else if (UseSignalChaining) {
3216 // save the old handler in jvm
3217 save_preinstalled_handler(sig, oldAct);
3218 // libjsig also interposes the sigaction() call below and saves the
3219 // old sigaction on it own.
3220 } else {
3221 fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3222 "%#lx for signal %d.", (long)oldhand, sig));
3223 }
3224 }
3226 struct sigaction sigAct;
3227 sigfillset(&(sigAct.sa_mask));
3228 sigAct.sa_handler = SIG_DFL;
3229 if (!set_installed) {
3230 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3231 } else {
3232 sigAct.sa_sigaction = signalHandler;
3233 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3234 }
3235 #if __APPLE__
3236 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3237 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3238 // if the signal handler declares it will handle it on alternate stack.
3239 // Notice we only declare we will handle it on alt stack, but we are not
3240 // actually going to use real alt stack - this is just a workaround.
3241 // Please see ux_exception.c, method catch_mach_exception_raise for details
3242 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3243 if (sig == SIGSEGV) {
3244 sigAct.sa_flags |= SA_ONSTACK;
3245 }
3246 #endif
3248 // Save flags, which are set by ours
3249 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3250 sigflags[sig] = sigAct.sa_flags;
3252 int ret = sigaction(sig, &sigAct, &oldAct);
3253 assert(ret == 0, "check");
3255 void* oldhand2 = oldAct.sa_sigaction
3256 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3257 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3258 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3259 }
3261 // install signal handlers for signals that HotSpot needs to
3262 // handle in order to support Java-level exception handling.
3264 void os::Bsd::install_signal_handlers() {
3265 if (!signal_handlers_are_installed) {
3266 signal_handlers_are_installed = true;
3268 // signal-chaining
3269 typedef void (*signal_setting_t)();
3270 signal_setting_t begin_signal_setting = NULL;
3271 signal_setting_t end_signal_setting = NULL;
3272 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3273 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3274 if (begin_signal_setting != NULL) {
3275 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3276 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3277 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3278 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3279 libjsig_is_loaded = true;
3280 assert(UseSignalChaining, "should enable signal-chaining");
3281 }
3282 if (libjsig_is_loaded) {
3283 // Tell libjsig jvm is setting signal handlers
3284 (*begin_signal_setting)();
3285 }
3287 set_signal_handler(SIGSEGV, true);
3288 set_signal_handler(SIGPIPE, true);
3289 set_signal_handler(SIGBUS, true);
3290 set_signal_handler(SIGILL, true);
3291 set_signal_handler(SIGFPE, true);
3292 set_signal_handler(SIGXFSZ, true);
3294 #if defined(__APPLE__)
3295 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3296 // signals caught and handled by the JVM. To work around this, we reset the mach task
3297 // signal handler that's placed on our process by CrashReporter. This disables
3298 // CrashReporter-based reporting.
3299 //
3300 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3301 // on caught fatal signals.
3302 //
3303 // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3304 // handlers. By replacing the existing task exception handler, we disable gdb's mach
3305 // exception handling, while leaving the standard BSD signal handlers functional.
3306 kern_return_t kr;
3307 kr = task_set_exception_ports(mach_task_self(),
3308 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3309 MACH_PORT_NULL,
3310 EXCEPTION_STATE_IDENTITY,
3311 MACHINE_THREAD_STATE);
3313 assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3314 #endif
3316 if (libjsig_is_loaded) {
3317 // Tell libjsig jvm finishes setting signal handlers
3318 (*end_signal_setting)();
3319 }
3321 // We don't activate signal checker if libjsig is in place, we trust ourselves
3322 // and if UserSignalHandler is installed all bets are off
3323 if (CheckJNICalls) {
3324 if (libjsig_is_loaded) {
3325 if (PrintJNIResolving) {
3326 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3327 }
3328 check_signals = false;
3329 }
3330 if (AllowUserSignalHandlers) {
3331 if (PrintJNIResolving) {
3332 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3333 }
3334 check_signals = false;
3335 }
3336 }
3337 }
3338 }
3341 /////
3342 // glibc on Bsd platform uses non-documented flag
3343 // to indicate, that some special sort of signal
3344 // trampoline is used.
3345 // We will never set this flag, and we should
3346 // ignore this flag in our diagnostic
3347 #ifdef SIGNIFICANT_SIGNAL_MASK
3348 #undef SIGNIFICANT_SIGNAL_MASK
3349 #endif
3350 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3352 static const char* get_signal_handler_name(address handler,
3353 char* buf, int buflen) {
3354 int offset;
3355 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3356 if (found) {
3357 // skip directory names
3358 const char *p1, *p2;
3359 p1 = buf;
3360 size_t len = strlen(os::file_separator());
3361 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3362 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3363 } else {
3364 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3365 }
3366 return buf;
3367 }
3369 static void print_signal_handler(outputStream* st, int sig,
3370 char* buf, size_t buflen) {
3371 struct sigaction sa;
3373 sigaction(sig, NULL, &sa);
3375 // See comment for SIGNIFICANT_SIGNAL_MASK define
3376 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3378 st->print("%s: ", os::exception_name(sig, buf, buflen));
3380 address handler = (sa.sa_flags & SA_SIGINFO)
3381 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3382 : CAST_FROM_FN_PTR(address, sa.sa_handler);
3384 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3385 st->print("SIG_DFL");
3386 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3387 st->print("SIG_IGN");
3388 } else {
3389 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3390 }
3392 st->print(", sa_mask[0]=" PTR32_FORMAT, *(uint32_t*)&sa.sa_mask);
3394 address rh = VMError::get_resetted_sighandler(sig);
3395 // May be, handler was resetted by VMError?
3396 if(rh != NULL) {
3397 handler = rh;
3398 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3399 }
3401 st->print(", sa_flags=" PTR32_FORMAT, sa.sa_flags);
3403 // Check: is it our handler?
3404 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3405 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3406 // It is our signal handler
3407 // check for flags, reset system-used one!
3408 if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3409 st->print(
3410 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3411 os::Bsd::get_our_sigflags(sig));
3412 }
3413 }
3414 st->cr();
3415 }
3418 #define DO_SIGNAL_CHECK(sig) \
3419 if (!sigismember(&check_signal_done, sig)) \
3420 os::Bsd::check_signal_handler(sig)
3422 // This method is a periodic task to check for misbehaving JNI applications
3423 // under CheckJNI, we can add any periodic checks here
3425 void os::run_periodic_checks() {
3427 if (check_signals == false) return;
3429 // SEGV and BUS if overridden could potentially prevent
3430 // generation of hs*.log in the event of a crash, debugging
3431 // such a case can be very challenging, so we absolutely
3432 // check the following for a good measure:
3433 DO_SIGNAL_CHECK(SIGSEGV);
3434 DO_SIGNAL_CHECK(SIGILL);
3435 DO_SIGNAL_CHECK(SIGFPE);
3436 DO_SIGNAL_CHECK(SIGBUS);
3437 DO_SIGNAL_CHECK(SIGPIPE);
3438 DO_SIGNAL_CHECK(SIGXFSZ);
3441 // ReduceSignalUsage allows the user to override these handlers
3442 // see comments at the very top and jvm_solaris.h
3443 if (!ReduceSignalUsage) {
3444 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3445 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3446 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3447 DO_SIGNAL_CHECK(BREAK_SIGNAL);
3448 }
3450 DO_SIGNAL_CHECK(SR_signum);
3451 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3452 }
3454 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3456 static os_sigaction_t os_sigaction = NULL;
3458 void os::Bsd::check_signal_handler(int sig) {
3459 char buf[O_BUFLEN];
3460 address jvmHandler = NULL;
3463 struct sigaction act;
3464 if (os_sigaction == NULL) {
3465 // only trust the default sigaction, in case it has been interposed
3466 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3467 if (os_sigaction == NULL) return;
3468 }
3470 os_sigaction(sig, (struct sigaction*)NULL, &act);
3473 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3475 address thisHandler = (act.sa_flags & SA_SIGINFO)
3476 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3477 : CAST_FROM_FN_PTR(address, act.sa_handler) ;
3480 switch(sig) {
3481 case SIGSEGV:
3482 case SIGBUS:
3483 case SIGFPE:
3484 case SIGPIPE:
3485 case SIGILL:
3486 case SIGXFSZ:
3487 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3488 break;
3490 case SHUTDOWN1_SIGNAL:
3491 case SHUTDOWN2_SIGNAL:
3492 case SHUTDOWN3_SIGNAL:
3493 case BREAK_SIGNAL:
3494 jvmHandler = (address)user_handler();
3495 break;
3497 case INTERRUPT_SIGNAL:
3498 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3499 break;
3501 default:
3502 if (sig == SR_signum) {
3503 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3504 } else {
3505 return;
3506 }
3507 break;
3508 }
3510 if (thisHandler != jvmHandler) {
3511 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3512 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3513 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3514 // No need to check this sig any longer
3515 sigaddset(&check_signal_done, sig);
3516 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3517 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3518 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3519 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags);
3520 // No need to check this sig any longer
3521 sigaddset(&check_signal_done, sig);
3522 }
3524 // Dump all the signal
3525 if (sigismember(&check_signal_done, sig)) {
3526 print_signal_handlers(tty, buf, O_BUFLEN);
3527 }
3528 }
3530 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
3532 extern bool signal_name(int signo, char* buf, size_t len);
3534 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3535 if (0 < exception_code && exception_code <= SIGRTMAX) {
3536 // signal
3537 if (!signal_name(exception_code, buf, size)) {
3538 jio_snprintf(buf, size, "SIG%d", exception_code);
3539 }
3540 return buf;
3541 } else {
3542 return NULL;
3543 }
3544 }
3546 // this is called _before_ the most of global arguments have been parsed
3547 void os::init(void) {
3548 char dummy; /* used to get a guess on initial stack address */
3549 // first_hrtime = gethrtime();
3551 // With BsdThreads the JavaMain thread pid (primordial thread)
3552 // is different than the pid of the java launcher thread.
3553 // So, on Bsd, the launcher thread pid is passed to the VM
3554 // via the sun.java.launcher.pid property.
3555 // Use this property instead of getpid() if it was correctly passed.
3556 // See bug 6351349.
3557 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3559 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3561 clock_tics_per_sec = CLK_TCK;
3563 init_random(1234567);
3565 ThreadCritical::initialize();
3567 Bsd::set_page_size(getpagesize());
3568 if (Bsd::page_size() == -1) {
3569 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3570 strerror(errno)));
3571 }
3572 init_page_sizes((size_t) Bsd::page_size());
3574 Bsd::initialize_system_info();
3576 // main_thread points to the aboriginal thread
3577 Bsd::_main_thread = pthread_self();
3579 Bsd::clock_init();
3580 initial_time_count = javaTimeNanos();
3582 #ifdef __APPLE__
3583 // XXXDARWIN
3584 // Work around the unaligned VM callbacks in hotspot's
3585 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3586 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3587 // alignment when doing symbol lookup. To work around this, we force early
3588 // binding of all symbols now, thus binding when alignment is known-good.
3589 _dyld_bind_fully_image_containing_address((const void *) &os::init);
3590 #endif
3591 }
3593 // To install functions for atexit system call
3594 extern "C" {
3595 static void perfMemory_exit_helper() {
3596 perfMemory_exit();
3597 }
3598 }
3600 // this is called _after_ the global arguments have been parsed
3601 jint os::init_2(void)
3602 {
3603 // Allocate a single page and mark it as readable for safepoint polling
3604 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3605 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
3607 os::set_polling_page( polling_page );
3609 #ifndef PRODUCT
3610 if(Verbose && PrintMiscellaneous)
3611 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
3612 #endif
3614 if (!UseMembar) {
3615 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3616 guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3617 os::set_memory_serialize_page( mem_serialize_page );
3619 #ifndef PRODUCT
3620 if(Verbose && PrintMiscellaneous)
3621 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
3622 #endif
3623 }
3625 // initialize suspend/resume support - must do this before signal_sets_init()
3626 if (SR_initialize() != 0) {
3627 perror("SR_initialize failed");
3628 return JNI_ERR;
3629 }
3631 Bsd::signal_sets_init();
3632 Bsd::install_signal_handlers();
3634 // Check minimum allowable stack size for thread creation and to initialize
3635 // the java system classes, including StackOverflowError - depends on page
3636 // size. Add a page for compiler2 recursion in main thread.
3637 // Add in 2*BytesPerWord times page size to account for VM stack during
3638 // class initialization depending on 32 or 64 bit VM.
3639 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3640 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3641 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3643 size_t threadStackSizeInBytes = ThreadStackSize * K;
3644 if (threadStackSizeInBytes != 0 &&
3645 threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3646 tty->print_cr("\nThe stack size specified is too small, "
3647 "Specify at least %dk",
3648 os::Bsd::min_stack_allowed/ K);
3649 return JNI_ERR;
3650 }
3652 // Make the stack size a multiple of the page size so that
3653 // the yellow/red zones can be guarded.
3654 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3655 vm_page_size()));
3657 if (MaxFDLimit) {
3658 // set the number of file descriptors to max. print out error
3659 // if getrlimit/setrlimit fails but continue regardless.
3660 struct rlimit nbr_files;
3661 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3662 if (status != 0) {
3663 if (PrintMiscellaneous && (Verbose || WizardMode))
3664 perror("os::init_2 getrlimit failed");
3665 } else {
3666 nbr_files.rlim_cur = nbr_files.rlim_max;
3668 #ifdef __APPLE__
3669 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3670 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3671 // be used instead
3672 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3673 #endif
3675 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3676 if (status != 0) {
3677 if (PrintMiscellaneous && (Verbose || WizardMode))
3678 perror("os::init_2 setrlimit failed");
3679 }
3680 }
3681 }
3683 // at-exit methods are called in the reverse order of their registration.
3684 // atexit functions are called on return from main or as a result of a
3685 // call to exit(3C). There can be only 32 of these functions registered
3686 // and atexit() does not set errno.
3688 if (PerfAllowAtExitRegistration) {
3689 // only register atexit functions if PerfAllowAtExitRegistration is set.
3690 // atexit functions can be delayed until process exit time, which
3691 // can be problematic for embedded VM situations. Embedded VMs should
3692 // call DestroyJavaVM() to assure that VM resources are released.
3694 // note: perfMemory_exit_helper atexit function may be removed in
3695 // the future if the appropriate cleanup code can be added to the
3696 // VM_Exit VMOperation's doit method.
3697 if (atexit(perfMemory_exit_helper) != 0) {
3698 warning("os::init2 atexit(perfMemory_exit_helper) failed");
3699 }
3700 }
3702 // initialize thread priority policy
3703 prio_init();
3705 #ifdef __APPLE__
3706 // dynamically link to objective c gc registration
3707 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3708 if (handleLibObjc != NULL) {
3709 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3710 }
3711 #endif
3713 return JNI_OK;
3714 }
3716 // this is called at the end of vm_initialization
3717 void os::init_3(void) { }
3719 // Mark the polling page as unreadable
3720 void os::make_polling_page_unreadable(void) {
3721 if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
3722 fatal("Could not disable polling page");
3723 };
3725 // Mark the polling page as readable
3726 void os::make_polling_page_readable(void) {
3727 if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3728 fatal("Could not enable polling page");
3729 }
3730 };
3732 int os::active_processor_count() {
3733 return _processor_count;
3734 }
3736 void os::set_native_thread_name(const char *name) {
3737 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3738 // This is only supported in Snow Leopard and beyond
3739 if (name != NULL) {
3740 // Add a "Java: " prefix to the name
3741 char buf[MAXTHREADNAMESIZE];
3742 snprintf(buf, sizeof(buf), "Java: %s", name);
3743 pthread_setname_np(buf);
3744 }
3745 #endif
3746 }
3748 bool os::distribute_processes(uint length, uint* distribution) {
3749 // Not yet implemented.
3750 return false;
3751 }
3753 bool os::bind_to_processor(uint processor_id) {
3754 // Not yet implemented.
3755 return false;
3756 }
3758 void os::SuspendedThreadTask::internal_do_task() {
3759 if (do_suspend(_thread->osthread())) {
3760 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3761 do_task(context);
3762 do_resume(_thread->osthread());
3763 }
3764 }
3766 ///
3767 class PcFetcher : public os::SuspendedThreadTask {
3768 public:
3769 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3770 ExtendedPC result();
3771 protected:
3772 void do_task(const os::SuspendedThreadTaskContext& context);
3773 private:
3774 ExtendedPC _epc;
3775 };
3777 ExtendedPC PcFetcher::result() {
3778 guarantee(is_done(), "task is not done yet.");
3779 return _epc;
3780 }
3782 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3783 Thread* thread = context.thread();
3784 OSThread* osthread = thread->osthread();
3785 if (osthread->ucontext() != NULL) {
3786 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
3787 } else {
3788 // NULL context is unexpected, double-check this is the VMThread
3789 guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3790 }
3791 }
3793 // Suspends the target using the signal mechanism and then grabs the PC before
3794 // resuming the target. Used by the flat-profiler only
3795 ExtendedPC os::get_thread_pc(Thread* thread) {
3796 // Make sure that it is called by the watcher for the VMThread
3797 assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3798 assert(thread->is_VM_thread(), "Can only be called for VMThread");
3800 PcFetcher fetcher(thread);
3801 fetcher.run();
3802 return fetcher.result();
3803 }
3805 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
3806 {
3807 return pthread_cond_timedwait(_cond, _mutex, _abstime);
3808 }
3810 ////////////////////////////////////////////////////////////////////////////////
3811 // debug support
3813 bool os::find(address addr, outputStream* st) {
3814 Dl_info dlinfo;
3815 memset(&dlinfo, 0, sizeof(dlinfo));
3816 if (dladdr(addr, &dlinfo) != 0) {
3817 st->print(PTR_FORMAT ": ", addr);
3818 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3819 st->print("%s+%#x", dlinfo.dli_sname,
3820 addr - (intptr_t)dlinfo.dli_saddr);
3821 } else if (dlinfo.dli_fbase != NULL) {
3822 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3823 } else {
3824 st->print("<absolute address>");
3825 }
3826 if (dlinfo.dli_fname != NULL) {
3827 st->print(" in %s", dlinfo.dli_fname);
3828 }
3829 if (dlinfo.dli_fbase != NULL) {
3830 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3831 }
3832 st->cr();
3834 if (Verbose) {
3835 // decode some bytes around the PC
3836 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3837 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3838 address lowest = (address) dlinfo.dli_sname;
3839 if (!lowest) lowest = (address) dlinfo.dli_fbase;
3840 if (begin < lowest) begin = lowest;
3841 Dl_info dlinfo2;
3842 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3843 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
3844 end = (address) dlinfo2.dli_saddr;
3845 Disassembler::decode(begin, end, st);
3846 }
3847 return true;
3848 }
3849 return false;
3850 }
3852 ////////////////////////////////////////////////////////////////////////////////
3853 // misc
3855 // This does not do anything on Bsd. This is basically a hook for being
3856 // able to use structured exception handling (thread-local exception filters)
3857 // on, e.g., Win32.
3858 void
3859 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
3860 JavaCallArguments* args, Thread* thread) {
3861 f(value, method, args, thread);
3862 }
3864 void os::print_statistics() {
3865 }
3867 int os::message_box(const char* title, const char* message) {
3868 int i;
3869 fdStream err(defaultStream::error_fd());
3870 for (i = 0; i < 78; i++) err.print_raw("=");
3871 err.cr();
3872 err.print_raw_cr(title);
3873 for (i = 0; i < 78; i++) err.print_raw("-");
3874 err.cr();
3875 err.print_raw_cr(message);
3876 for (i = 0; i < 78; i++) err.print_raw("=");
3877 err.cr();
3879 char buf[16];
3880 // Prevent process from exiting upon "read error" without consuming all CPU
3881 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3883 return buf[0] == 'y' || buf[0] == 'Y';
3884 }
3886 int os::stat(const char *path, struct stat *sbuf) {
3887 char pathbuf[MAX_PATH];
3888 if (strlen(path) > MAX_PATH - 1) {
3889 errno = ENAMETOOLONG;
3890 return -1;
3891 }
3892 os::native_path(strcpy(pathbuf, path));
3893 return ::stat(pathbuf, sbuf);
3894 }
3896 bool os::check_heap(bool force) {
3897 return true;
3898 }
3900 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
3901 return ::vsnprintf(buf, count, format, args);
3902 }
3904 // Is a (classpath) directory empty?
3905 bool os::dir_is_empty(const char* path) {
3906 DIR *dir = NULL;
3907 struct dirent *ptr;
3909 dir = opendir(path);
3910 if (dir == NULL) return true;
3912 /* Scan the directory */
3913 bool result = true;
3914 char buf[sizeof(struct dirent) + MAX_PATH];
3915 while (result && (ptr = ::readdir(dir)) != NULL) {
3916 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3917 result = false;
3918 }
3919 }
3920 closedir(dir);
3921 return result;
3922 }
3924 // This code originates from JDK's sysOpen and open64_w
3925 // from src/solaris/hpi/src/system_md.c
3927 #ifndef O_DELETE
3928 #define O_DELETE 0x10000
3929 #endif
3931 // Open a file. Unlink the file immediately after open returns
3932 // if the specified oflag has the O_DELETE flag set.
3933 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
3935 int os::open(const char *path, int oflag, int mode) {
3937 if (strlen(path) > MAX_PATH - 1) {
3938 errno = ENAMETOOLONG;
3939 return -1;
3940 }
3941 int fd;
3942 int o_delete = (oflag & O_DELETE);
3943 oflag = oflag & ~O_DELETE;
3945 fd = ::open(path, oflag, mode);
3946 if (fd == -1) return -1;
3948 //If the open succeeded, the file might still be a directory
3949 {
3950 struct stat buf;
3951 int ret = ::fstat(fd, &buf);
3952 int st_mode = buf.st_mode;
3954 if (ret != -1) {
3955 if ((st_mode & S_IFMT) == S_IFDIR) {
3956 errno = EISDIR;
3957 ::close(fd);
3958 return -1;
3959 }
3960 } else {
3961 ::close(fd);
3962 return -1;
3963 }
3964 }
3966 /*
3967 * All file descriptors that are opened in the JVM and not
3968 * specifically destined for a subprocess should have the
3969 * close-on-exec flag set. If we don't set it, then careless 3rd
3970 * party native code might fork and exec without closing all
3971 * appropriate file descriptors (e.g. as we do in closeDescriptors in
3972 * UNIXProcess.c), and this in turn might:
3973 *
3974 * - cause end-of-file to fail to be detected on some file
3975 * descriptors, resulting in mysterious hangs, or
3976 *
3977 * - might cause an fopen in the subprocess to fail on a system
3978 * suffering from bug 1085341.
3979 *
3980 * (Yes, the default setting of the close-on-exec flag is a Unix
3981 * design flaw)
3982 *
3983 * See:
3984 * 1085341: 32-bit stdio routines should support file descriptors >255
3985 * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3986 * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3987 */
3988 #ifdef FD_CLOEXEC
3989 {
3990 int flags = ::fcntl(fd, F_GETFD);
3991 if (flags != -1)
3992 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3993 }
3994 #endif
3996 if (o_delete != 0) {
3997 ::unlink(path);
3998 }
3999 return fd;
4000 }
4003 // create binary file, rewriting existing file if required
4004 int os::create_binary_file(const char* path, bool rewrite_existing) {
4005 int oflags = O_WRONLY | O_CREAT;
4006 if (!rewrite_existing) {
4007 oflags |= O_EXCL;
4008 }
4009 return ::open(path, oflags, S_IREAD | S_IWRITE);
4010 }
4012 // return current position of file pointer
4013 jlong os::current_file_offset(int fd) {
4014 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
4015 }
4017 // move file pointer to the specified offset
4018 jlong os::seek_to_file_offset(int fd, jlong offset) {
4019 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
4020 }
4022 // This code originates from JDK's sysAvailable
4023 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
4025 int os::available(int fd, jlong *bytes) {
4026 jlong cur, end;
4027 int mode;
4028 struct stat buf;
4030 if (::fstat(fd, &buf) >= 0) {
4031 mode = buf.st_mode;
4032 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
4033 /*
4034 * XXX: is the following call interruptible? If so, this might
4035 * need to go through the INTERRUPT_IO() wrapper as for other
4036 * blocking, interruptible calls in this file.
4037 */
4038 int n;
4039 if (::ioctl(fd, FIONREAD, &n) >= 0) {
4040 *bytes = n;
4041 return 1;
4042 }
4043 }
4044 }
4045 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
4046 return 0;
4047 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
4048 return 0;
4049 } else if (::lseek(fd, cur, SEEK_SET) == -1) {
4050 return 0;
4051 }
4052 *bytes = end - cur;
4053 return 1;
4054 }
4056 int os::socket_available(int fd, jint *pbytes) {
4057 if (fd < 0)
4058 return OS_OK;
4060 int ret;
4062 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
4064 //%% note ioctl can return 0 when successful, JVM_SocketAvailable
4065 // is expected to return 0 on failure and 1 on success to the jdk.
4067 return (ret == OS_ERR) ? 0 : 1;
4068 }
4070 // Map a block of memory.
4071 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
4072 char *addr, size_t bytes, bool read_only,
4073 bool allow_exec) {
4074 int prot;
4075 int flags;
4077 if (read_only) {
4078 prot = PROT_READ;
4079 flags = MAP_SHARED;
4080 } else {
4081 prot = PROT_READ | PROT_WRITE;
4082 flags = MAP_PRIVATE;
4083 }
4085 if (allow_exec) {
4086 prot |= PROT_EXEC;
4087 }
4089 if (addr != NULL) {
4090 flags |= MAP_FIXED;
4091 }
4093 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
4094 fd, file_offset);
4095 if (mapped_address == MAP_FAILED) {
4096 return NULL;
4097 }
4098 return mapped_address;
4099 }
4102 // Remap a block of memory.
4103 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
4104 char *addr, size_t bytes, bool read_only,
4105 bool allow_exec) {
4106 // same as map_memory() on this OS
4107 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
4108 allow_exec);
4109 }
4112 // Unmap a block of memory.
4113 bool os::pd_unmap_memory(char* addr, size_t bytes) {
4114 return munmap(addr, bytes) == 0;
4115 }
4117 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
4118 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4119 // of a thread.
4120 //
4121 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4122 // the fast estimate available on the platform.
4124 jlong os::current_thread_cpu_time() {
4125 #ifdef __APPLE__
4126 return os::thread_cpu_time(Thread::current(), true /* user + sys */);
4127 #else
4128 Unimplemented();
4129 return 0;
4130 #endif
4131 }
4133 jlong os::thread_cpu_time(Thread* thread) {
4134 #ifdef __APPLE__
4135 return os::thread_cpu_time(thread, true /* user + sys */);
4136 #else
4137 Unimplemented();
4138 return 0;
4139 #endif
4140 }
4142 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4143 #ifdef __APPLE__
4144 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4145 #else
4146 Unimplemented();
4147 return 0;
4148 #endif
4149 }
4151 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4152 #ifdef __APPLE__
4153 struct thread_basic_info tinfo;
4154 mach_msg_type_number_t tcount = THREAD_INFO_MAX;
4155 kern_return_t kr;
4156 thread_t mach_thread;
4158 mach_thread = thread->osthread()->thread_id();
4159 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
4160 if (kr != KERN_SUCCESS)
4161 return -1;
4163 if (user_sys_cpu_time) {
4164 jlong nanos;
4165 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4166 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4167 return nanos;
4168 } else {
4169 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4170 }
4171 #else
4172 Unimplemented();
4173 return 0;
4174 #endif
4175 }
4178 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4179 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
4180 info_ptr->may_skip_backward = false; // elapsed time not wall time
4181 info_ptr->may_skip_forward = false; // elapsed time not wall time
4182 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
4183 }
4185 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4186 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
4187 info_ptr->may_skip_backward = false; // elapsed time not wall time
4188 info_ptr->may_skip_forward = false; // elapsed time not wall time
4189 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
4190 }
4192 bool os::is_thread_cpu_time_supported() {
4193 #ifdef __APPLE__
4194 return true;
4195 #else
4196 return false;
4197 #endif
4198 }
4200 // System loadavg support. Returns -1 if load average cannot be obtained.
4201 // Bsd doesn't yet have a (official) notion of processor sets,
4202 // so just return the system wide load average.
4203 int os::loadavg(double loadavg[], int nelem) {
4204 return ::getloadavg(loadavg, nelem);
4205 }
4207 void os::pause() {
4208 char filename[MAX_PATH];
4209 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4210 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4211 } else {
4212 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4213 }
4215 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4216 if (fd != -1) {
4217 struct stat buf;
4218 ::close(fd);
4219 while (::stat(filename, &buf) == 0) {
4220 (void)::poll(NULL, 0, 100);
4221 }
4222 } else {
4223 jio_fprintf(stderr,
4224 "Could not open pause file '%s', continuing immediately.\n", filename);
4225 }
4226 }
4229 // Refer to the comments in os_solaris.cpp park-unpark.
4230 //
4231 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4232 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4233 // For specifics regarding the bug see GLIBC BUGID 261237 :
4234 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4235 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4236 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4237 // is used. (The simple C test-case provided in the GLIBC bug report manifests the
4238 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4239 // and monitorenter when we're using 1-0 locking. All those operations may result in
4240 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version
4241 // of libpthread avoids the problem, but isn't practical.
4242 //
4243 // Possible remedies:
4244 //
4245 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work.
4246 // This is palliative and probabilistic, however. If the thread is preempted
4247 // between the call to compute_abstime() and pthread_cond_timedwait(), more
4248 // than the minimum period may have passed, and the abstime may be stale (in the
4249 // past) resultin in a hang. Using this technique reduces the odds of a hang
4250 // but the JVM is still vulnerable, particularly on heavily loaded systems.
4251 //
4252 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4253 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set
4254 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4255 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant
4256 // thread.
4257 //
4258 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread
4259 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing
4260 // a timeout request to the chron thread and then blocking via pthread_cond_wait().
4261 // This also works well. In fact it avoids kernel-level scalability impediments
4262 // on certain platforms that don't handle lots of active pthread_cond_timedwait()
4263 // timers in a graceful fashion.
4264 //
4265 // 4. When the abstime value is in the past it appears that control returns
4266 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4267 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we
4268 // can avoid the problem by reinitializing the condvar -- by cond_destroy()
4269 // followed by cond_init() -- after all calls to pthread_cond_timedwait().
4270 // It may be possible to avoid reinitialization by checking the return
4271 // value from pthread_cond_timedwait(). In addition to reinitializing the
4272 // condvar we must establish the invariant that cond_signal() is only called
4273 // within critical sections protected by the adjunct mutex. This prevents
4274 // cond_signal() from "seeing" a condvar that's in the midst of being
4275 // reinitialized or that is corrupt. Sadly, this invariant obviates the
4276 // desirable signal-after-unlock optimization that avoids futile context switching.
4277 //
4278 // I'm also concerned that some versions of NTPL might allocate an auxilliary
4279 // structure when a condvar is used or initialized. cond_destroy() would
4280 // release the helper structure. Our reinitialize-after-timedwait fix
4281 // put excessive stress on malloc/free and locks protecting the c-heap.
4282 //
4283 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag.
4284 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4285 // and only enabling the work-around for vulnerable environments.
4287 // utility to compute the abstime argument to timedwait:
4288 // millis is the relative timeout time
4289 // abstime will be the absolute timeout time
4290 // TODO: replace compute_abstime() with unpackTime()
4292 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
4293 if (millis < 0) millis = 0;
4294 struct timeval now;
4295 int status = gettimeofday(&now, NULL);
4296 assert(status == 0, "gettimeofday");
4297 jlong seconds = millis / 1000;
4298 millis %= 1000;
4299 if (seconds > 50000000) { // see man cond_timedwait(3T)
4300 seconds = 50000000;
4301 }
4302 abstime->tv_sec = now.tv_sec + seconds;
4303 long usec = now.tv_usec + millis * 1000;
4304 if (usec >= 1000000) {
4305 abstime->tv_sec += 1;
4306 usec -= 1000000;
4307 }
4308 abstime->tv_nsec = usec * 1000;
4309 return abstime;
4310 }
4313 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
4314 // Conceptually TryPark() should be equivalent to park(0).
4316 int os::PlatformEvent::TryPark() {
4317 for (;;) {
4318 const int v = _Event ;
4319 guarantee ((v == 0) || (v == 1), "invariant") ;
4320 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ;
4321 }
4322 }
4324 void os::PlatformEvent::park() { // AKA "down()"
4325 // Invariant: Only the thread associated with the Event/PlatformEvent
4326 // may call park().
4327 // TODO: assert that _Assoc != NULL or _Assoc == Self
4328 int v ;
4329 for (;;) {
4330 v = _Event ;
4331 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4332 }
4333 guarantee (v >= 0, "invariant") ;
4334 if (v == 0) {
4335 // Do this the hard way by blocking ...
4336 int status = pthread_mutex_lock(_mutex);
4337 assert_status(status == 0, status, "mutex_lock");
4338 guarantee (_nParked == 0, "invariant") ;
4339 ++ _nParked ;
4340 while (_Event < 0) {
4341 status = pthread_cond_wait(_cond, _mutex);
4342 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4343 // Treat this the same as if the wait was interrupted
4344 if (status == ETIMEDOUT) { status = EINTR; }
4345 assert_status(status == 0 || status == EINTR, status, "cond_wait");
4346 }
4347 -- _nParked ;
4349 _Event = 0 ;
4350 status = pthread_mutex_unlock(_mutex);
4351 assert_status(status == 0, status, "mutex_unlock");
4352 // Paranoia to ensure our locked and lock-free paths interact
4353 // correctly with each other.
4354 OrderAccess::fence();
4355 }
4356 guarantee (_Event >= 0, "invariant") ;
4357 }
4359 int os::PlatformEvent::park(jlong millis) {
4360 guarantee (_nParked == 0, "invariant") ;
4362 int v ;
4363 for (;;) {
4364 v = _Event ;
4365 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4366 }
4367 guarantee (v >= 0, "invariant") ;
4368 if (v != 0) return OS_OK ;
4370 // We do this the hard way, by blocking the thread.
4371 // Consider enforcing a minimum timeout value.
4372 struct timespec abst;
4373 compute_abstime(&abst, millis);
4375 int ret = OS_TIMEOUT;
4376 int status = pthread_mutex_lock(_mutex);
4377 assert_status(status == 0, status, "mutex_lock");
4378 guarantee (_nParked == 0, "invariant") ;
4379 ++_nParked ;
4381 // Object.wait(timo) will return because of
4382 // (a) notification
4383 // (b) timeout
4384 // (c) thread.interrupt
4385 //
4386 // Thread.interrupt and object.notify{All} both call Event::set.
4387 // That is, we treat thread.interrupt as a special case of notification.
4388 // The underlying Solaris implementation, cond_timedwait, admits
4389 // spurious/premature wakeups, but the JLS/JVM spec prevents the
4390 // JVM from making those visible to Java code. As such, we must
4391 // filter out spurious wakeups. We assume all ETIME returns are valid.
4392 //
4393 // TODO: properly differentiate simultaneous notify+interrupt.
4394 // In that case, we should propagate the notify to another waiter.
4396 while (_Event < 0) {
4397 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4398 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4399 pthread_cond_destroy (_cond);
4400 pthread_cond_init (_cond, NULL) ;
4401 }
4402 assert_status(status == 0 || status == EINTR ||
4403 status == ETIMEDOUT,
4404 status, "cond_timedwait");
4405 if (!FilterSpuriousWakeups) break ; // previous semantics
4406 if (status == ETIMEDOUT) break ;
4407 // We consume and ignore EINTR and spurious wakeups.
4408 }
4409 --_nParked ;
4410 if (_Event >= 0) {
4411 ret = OS_OK;
4412 }
4413 _Event = 0 ;
4414 status = pthread_mutex_unlock(_mutex);
4415 assert_status(status == 0, status, "mutex_unlock");
4416 assert (_nParked == 0, "invariant") ;
4417 // Paranoia to ensure our locked and lock-free paths interact
4418 // correctly with each other.
4419 OrderAccess::fence();
4420 return ret;
4421 }
4423 void os::PlatformEvent::unpark() {
4424 // Transitions for _Event:
4425 // 0 :=> 1
4426 // 1 :=> 1
4427 // -1 :=> either 0 or 1; must signal target thread
4428 // That is, we can safely transition _Event from -1 to either
4429 // 0 or 1. Forcing 1 is slightly more efficient for back-to-back
4430 // unpark() calls.
4431 // See also: "Semaphores in Plan 9" by Mullender & Cox
4432 //
4433 // Note: Forcing a transition from "-1" to "1" on an unpark() means
4434 // that it will take two back-to-back park() calls for the owning
4435 // thread to block. This has the benefit of forcing a spurious return
4436 // from the first park() call after an unpark() call which will help
4437 // shake out uses of park() and unpark() without condition variables.
4439 if (Atomic::xchg(1, &_Event) >= 0) return;
4441 // Wait for the thread associated with the event to vacate
4442 int status = pthread_mutex_lock(_mutex);
4443 assert_status(status == 0, status, "mutex_lock");
4444 int AnyWaiters = _nParked;
4445 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4446 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4447 AnyWaiters = 0;
4448 pthread_cond_signal(_cond);
4449 }
4450 status = pthread_mutex_unlock(_mutex);
4451 assert_status(status == 0, status, "mutex_unlock");
4452 if (AnyWaiters != 0) {
4453 status = pthread_cond_signal(_cond);
4454 assert_status(status == 0, status, "cond_signal");
4455 }
4457 // Note that we signal() _after dropping the lock for "immortal" Events.
4458 // This is safe and avoids a common class of futile wakeups. In rare
4459 // circumstances this can cause a thread to return prematurely from
4460 // cond_{timed}wait() but the spurious wakeup is benign and the victim will
4461 // simply re-test the condition and re-park itself.
4462 }
4465 // JSR166
4466 // -------------------------------------------------------
4468 /*
4469 * The solaris and bsd implementations of park/unpark are fairly
4470 * conservative for now, but can be improved. They currently use a
4471 * mutex/condvar pair, plus a a count.
4472 * Park decrements count if > 0, else does a condvar wait. Unpark
4473 * sets count to 1 and signals condvar. Only one thread ever waits
4474 * on the condvar. Contention seen when trying to park implies that someone
4475 * is unparking you, so don't wait. And spurious returns are fine, so there
4476 * is no need to track notifications.
4477 */
4479 #define MAX_SECS 100000000
4480 /*
4481 * This code is common to bsd and solaris and will be moved to a
4482 * common place in dolphin.
4483 *
4484 * The passed in time value is either a relative time in nanoseconds
4485 * or an absolute time in milliseconds. Either way it has to be unpacked
4486 * into suitable seconds and nanoseconds components and stored in the
4487 * given timespec structure.
4488 * Given time is a 64-bit value and the time_t used in the timespec is only
4489 * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4490 * overflow if times way in the future are given. Further on Solaris versions
4491 * prior to 10 there is a restriction (see cond_timedwait) that the specified
4492 * number of seconds, in abstime, is less than current_time + 100,000,000.
4493 * As it will be 28 years before "now + 100000000" will overflow we can
4494 * ignore overflow and just impose a hard-limit on seconds using the value
4495 * of "now + 100,000,000". This places a limit on the timeout of about 3.17
4496 * years from "now".
4497 */
4499 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4500 assert (time > 0, "convertTime");
4502 struct timeval now;
4503 int status = gettimeofday(&now, NULL);
4504 assert(status == 0, "gettimeofday");
4506 time_t max_secs = now.tv_sec + MAX_SECS;
4508 if (isAbsolute) {
4509 jlong secs = time / 1000;
4510 if (secs > max_secs) {
4511 absTime->tv_sec = max_secs;
4512 }
4513 else {
4514 absTime->tv_sec = secs;
4515 }
4516 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4517 }
4518 else {
4519 jlong secs = time / NANOSECS_PER_SEC;
4520 if (secs >= MAX_SECS) {
4521 absTime->tv_sec = max_secs;
4522 absTime->tv_nsec = 0;
4523 }
4524 else {
4525 absTime->tv_sec = now.tv_sec + secs;
4526 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4527 if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4528 absTime->tv_nsec -= NANOSECS_PER_SEC;
4529 ++absTime->tv_sec; // note: this must be <= max_secs
4530 }
4531 }
4532 }
4533 assert(absTime->tv_sec >= 0, "tv_sec < 0");
4534 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4535 assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4536 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4537 }
4539 void Parker::park(bool isAbsolute, jlong time) {
4540 // Ideally we'd do something useful while spinning, such
4541 // as calling unpackTime().
4543 // Optional fast-path check:
4544 // Return immediately if a permit is available.
4545 // We depend on Atomic::xchg() having full barrier semantics
4546 // since we are doing a lock-free update to _counter.
4547 if (Atomic::xchg(0, &_counter) > 0) return;
4549 Thread* thread = Thread::current();
4550 assert(thread->is_Java_thread(), "Must be JavaThread");
4551 JavaThread *jt = (JavaThread *)thread;
4553 // Optional optimization -- avoid state transitions if there's an interrupt pending.
4554 // Check interrupt before trying to wait
4555 if (Thread::is_interrupted(thread, false)) {
4556 return;
4557 }
4559 // Next, demultiplex/decode time arguments
4560 struct timespec absTime;
4561 if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
4562 return;
4563 }
4564 if (time > 0) {
4565 unpackTime(&absTime, isAbsolute, time);
4566 }
4569 // Enter safepoint region
4570 // Beware of deadlocks such as 6317397.
4571 // The per-thread Parker:: mutex is a classic leaf-lock.
4572 // In particular a thread must never block on the Threads_lock while
4573 // holding the Parker:: mutex. If safepoints are pending both the
4574 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4575 ThreadBlockInVM tbivm(jt);
4577 // Don't wait if cannot get lock since interference arises from
4578 // unblocking. Also. check interrupt before trying wait
4579 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4580 return;
4581 }
4583 int status ;
4584 if (_counter > 0) { // no wait needed
4585 _counter = 0;
4586 status = pthread_mutex_unlock(_mutex);
4587 assert (status == 0, "invariant") ;
4588 // Paranoia to ensure our locked and lock-free paths interact
4589 // correctly with each other and Java-level accesses.
4590 OrderAccess::fence();
4591 return;
4592 }
4594 #ifdef ASSERT
4595 // Don't catch signals while blocked; let the running threads have the signals.
4596 // (This allows a debugger to break into the running thread.)
4597 sigset_t oldsigs;
4598 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4599 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4600 #endif
4602 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4603 jt->set_suspend_equivalent();
4604 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4606 if (time == 0) {
4607 status = pthread_cond_wait (_cond, _mutex) ;
4608 } else {
4609 status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
4610 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4611 pthread_cond_destroy (_cond) ;
4612 pthread_cond_init (_cond, NULL);
4613 }
4614 }
4615 assert_status(status == 0 || status == EINTR ||
4616 status == ETIMEDOUT,
4617 status, "cond_timedwait");
4619 #ifdef ASSERT
4620 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4621 #endif
4623 _counter = 0 ;
4624 status = pthread_mutex_unlock(_mutex) ;
4625 assert_status(status == 0, status, "invariant") ;
4626 // Paranoia to ensure our locked and lock-free paths interact
4627 // correctly with each other and Java-level accesses.
4628 OrderAccess::fence();
4630 // If externally suspended while waiting, re-suspend
4631 if (jt->handle_special_suspend_equivalent_condition()) {
4632 jt->java_suspend_self();
4633 }
4634 }
4636 void Parker::unpark() {
4637 int s, status ;
4638 status = pthread_mutex_lock(_mutex);
4639 assert (status == 0, "invariant") ;
4640 s = _counter;
4641 _counter = 1;
4642 if (s < 1) {
4643 if (WorkAroundNPTLTimedWaitHang) {
4644 status = pthread_cond_signal (_cond) ;
4645 assert (status == 0, "invariant") ;
4646 status = pthread_mutex_unlock(_mutex);
4647 assert (status == 0, "invariant") ;
4648 } else {
4649 status = pthread_mutex_unlock(_mutex);
4650 assert (status == 0, "invariant") ;
4651 status = pthread_cond_signal (_cond) ;
4652 assert (status == 0, "invariant") ;
4653 }
4654 } else {
4655 pthread_mutex_unlock(_mutex);
4656 assert (status == 0, "invariant") ;
4657 }
4658 }
4661 /* Darwin has no "environ" in a dynamic library. */
4662 #ifdef __APPLE__
4663 #include <crt_externs.h>
4664 #define environ (*_NSGetEnviron())
4665 #else
4666 extern char** environ;
4667 #endif
4669 // Run the specified command in a separate process. Return its exit value,
4670 // or -1 on failure (e.g. can't fork a new process).
4671 // Unlike system(), this function can be called from signal handler. It
4672 // doesn't block SIGINT et al.
4673 int os::fork_and_exec(char* cmd) {
4674 const char * argv[4] = {"sh", "-c", cmd, NULL};
4676 // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4677 // pthread_atfork handlers and reset pthread library. All we need is a
4678 // separate process to execve. Make a direct syscall to fork process.
4679 // On IA64 there's no fork syscall, we have to use fork() and hope for
4680 // the best...
4681 pid_t pid = fork();
4683 if (pid < 0) {
4684 // fork failed
4685 return -1;
4687 } else if (pid == 0) {
4688 // child process
4690 // execve() in BsdThreads will call pthread_kill_other_threads_np()
4691 // first to kill every thread on the thread list. Because this list is
4692 // not reset by fork() (see notes above), execve() will instead kill
4693 // every thread in the parent process. We know this is the only thread
4694 // in the new process, so make a system call directly.
4695 // IA64 should use normal execve() from glibc to match the glibc fork()
4696 // above.
4697 execve("/bin/sh", (char* const*)argv, environ);
4699 // execve failed
4700 _exit(-1);
4702 } else {
4703 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4704 // care about the actual exit code, for now.
4706 int status;
4708 // Wait for the child process to exit. This returns immediately if
4709 // the child has already exited. */
4710 while (waitpid(pid, &status, 0) < 0) {
4711 switch (errno) {
4712 case ECHILD: return 0;
4713 case EINTR: break;
4714 default: return -1;
4715 }
4716 }
4718 if (WIFEXITED(status)) {
4719 // The child exited normally; get its exit code.
4720 return WEXITSTATUS(status);
4721 } else if (WIFSIGNALED(status)) {
4722 // The child exited because of a signal
4723 // The best value to return is 0x80 + signal number,
4724 // because that is what all Unix shells do, and because
4725 // it allows callers to distinguish between process exit and
4726 // process death by signal.
4727 return 0x80 + WTERMSIG(status);
4728 } else {
4729 // Unknown exit code; pass it through
4730 return status;
4731 }
4732 }
4733 }
4735 // is_headless_jre()
4736 //
4737 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4738 // in order to report if we are running in a headless jre
4739 //
4740 // Since JDK8 xawt/libmawt.so was moved into the same directory
4741 // as libawt.so, and renamed libawt_xawt.so
4742 //
4743 bool os::is_headless_jre() {
4744 #ifdef __APPLE__
4745 // We no longer build headless-only on Mac OS X
4746 return false;
4747 #else
4748 struct stat statbuf;
4749 char buf[MAXPATHLEN];
4750 char libmawtpath[MAXPATHLEN];
4751 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX;
4752 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4753 char *p;
4755 // Get path to libjvm.so
4756 os::jvm_path(buf, sizeof(buf));
4758 // Get rid of libjvm.so
4759 p = strrchr(buf, '/');
4760 if (p == NULL) return false;
4761 else *p = '\0';
4763 // Get rid of client or server
4764 p = strrchr(buf, '/');
4765 if (p == NULL) return false;
4766 else *p = '\0';
4768 // check xawt/libmawt.so
4769 strcpy(libmawtpath, buf);
4770 strcat(libmawtpath, xawtstr);
4771 if (::stat(libmawtpath, &statbuf) == 0) return false;
4773 // check libawt_xawt.so
4774 strcpy(libmawtpath, buf);
4775 strcat(libmawtpath, new_xawtstr);
4776 if (::stat(libmawtpath, &statbuf) == 0) return false;
4778 return true;
4779 #endif
4780 }
4782 // Get the default path to the core file
4783 // Returns the length of the string
4784 int os::get_core_path(char* buffer, size_t bufferSize) {
4785 int n = jio_snprintf(buffer, bufferSize, "/cores");
4787 // Truncate if theoretical string was longer than bufferSize
4788 n = MIN2(n, (int)bufferSize);
4790 return n;
4791 }
4793 #ifndef PRODUCT
4794 void TestReserveMemorySpecial_test() {
4795 // No tests available for this platform
4796 }
4797 #endif