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