1 /*
2 * Copyright (c) 1999, 2015, 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_bsd.inline.hpp"
40 #include "os_share_bsd.hpp"
41 #include "prims/jniFastGetField.hpp"
42 #include "prims/jvm.h"
43 #include "prims/jvm_misc.hpp"
44 #include "runtime/arguments.hpp"
45 #include "runtime/atomic.inline.hpp"
46 #include "runtime/extendedPC.hpp"
47 #include "runtime/globals.hpp"
48 #include "runtime/interfaceSupport.hpp"
49 #include "runtime/java.hpp"
50 #include "runtime/javaCalls.hpp"
51 #include "runtime/mutexLocker.hpp"
52 #include "runtime/objectMonitor.hpp"
53 #include "runtime/orderAccess.inline.hpp"
54 #include "runtime/osThread.hpp"
55 #include "runtime/perfMemory.hpp"
56 #include "runtime/sharedRuntime.hpp"
57 #include "runtime/statSampler.hpp"
58 #include "runtime/stubRoutines.hpp"
59 #include "runtime/thread.inline.hpp"
60 #include "runtime/threadCritical.hpp"
61 #include "runtime/timer.hpp"
62 #include "semaphore_bsd.hpp"
63 #include "services/attachListener.hpp"
64 #include "services/memTracker.hpp"
65 #include "services/runtimeService.hpp"
66 #include "utilities/decoder.hpp"
67 #include "utilities/defaultStream.hpp"
68 #include "utilities/events.hpp"
69 #include "utilities/growableArray.hpp"
70 #include "utilities/vmError.hpp"
71
72 // put OS-includes here
73 # include <sys/types.h>
74 # include <sys/mman.h>
75 # include <sys/stat.h>
76 # include <sys/select.h>
77 # include <pthread.h>
78 # include <signal.h>
79 # include <errno.h>
80 # include <dlfcn.h>
81 # include <stdio.h>
82 # include <unistd.h>
83 # include <sys/resource.h>
84 # include <pthread.h>
85 # include <sys/stat.h>
86 # include <sys/time.h>
87 # include <sys/times.h>
88 # include <sys/utsname.h>
89 # include <sys/socket.h>
90 # include <sys/wait.h>
91 # include <time.h>
92 # include <pwd.h>
93 # include <poll.h>
94 # include <semaphore.h>
95 # include <fcntl.h>
96 # include <string.h>
97 # include <sys/param.h>
98 # include <sys/sysctl.h>
99 # include <sys/ipc.h>
100 # include <sys/shm.h>
101 #ifndef __APPLE__
102 # include <link.h>
103 #endif
104 # include <stdint.h>
105 # include <inttypes.h>
106 # include <sys/ioctl.h>
107 # include <sys/syscall.h>
108
109 #if defined(__FreeBSD__) || defined(__NetBSD__)
110 #include <elf.h>
111 #endif
112
113 #ifdef __APPLE__
114 #include <mach/mach.h> // semaphore_* API
115 #include <mach-o/dyld.h>
116 #include <sys/proc_info.h>
117 #include <objc/objc-auto.h>
118 #endif
119
120 #ifndef MAP_ANONYMOUS
121 #define MAP_ANONYMOUS MAP_ANON
122 #endif
123
124 #define MAX_PATH (2 * K)
125
126 // for timer info max values which include all bits
127 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
128
129 #define LARGEPAGES_BIT (1 << 6)
130
131 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
132
133 ////////////////////////////////////////////////////////////////////////////////
134 // global variables
135 julong os::Bsd::_physical_memory = 0;
136
137 #ifdef __APPLE__
138 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
139 volatile uint64_t os::Bsd::_max_abstime = 0;
140 #else
141 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
142 #endif
143 pthread_t os::Bsd::_main_thread;
144 int os::Bsd::_page_size = -1;
145
146 static jlong initial_time_count=0;
147
148 static int clock_tics_per_sec = 100;
149
150 // For diagnostics to print a message once. see run_periodic_checks
151 static sigset_t check_signal_done;
152 static bool check_signals = true;
153
154 static pid_t _initial_pid = 0;
155
156 // Signal number used to suspend/resume a thread
157
158 // do not use any signal number less than SIGSEGV, see 4355769
159 static int SR_signum = SIGUSR2;
160 sigset_t SR_sigset;
161
162
163 ////////////////////////////////////////////////////////////////////////////////
164 // utility functions
165
166 static int SR_initialize();
167 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
168
169 julong os::available_memory() {
170 return Bsd::available_memory();
171 }
172
173 // available here means free
174 julong os::Bsd::available_memory() {
175 uint64_t available = physical_memory() >> 2;
176 #ifdef __APPLE__
177 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
178 vm_statistics64_data_t vmstat;
179 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
180 (host_info64_t)&vmstat, &count);
181 assert(kerr == KERN_SUCCESS,
182 "host_statistics64 failed - check mach_host_self() and count");
183 if (kerr == KERN_SUCCESS) {
184 available = vmstat.free_count * os::vm_page_size();
185 }
186 #endif
187 return available;
188 }
189
190 julong os::physical_memory() {
191 return Bsd::physical_memory();
192 }
193
194 // Return true if user is running as root.
195
196 bool os::have_special_privileges() {
197 static bool init = false;
198 static bool privileges = false;
199 if (!init) {
200 privileges = (getuid() != geteuid()) || (getgid() != getegid());
201 init = true;
202 }
203 return privileges;
204 }
205
206
207
208 // Cpu architecture string
209 #if defined(ZERO)
210 static char cpu_arch[] = ZERO_LIBARCH;
211 #elif defined(IA64)
212 static char cpu_arch[] = "ia64";
213 #elif defined(IA32)
214 static char cpu_arch[] = "i386";
215 #elif defined(AMD64)
216 static char cpu_arch[] = "amd64";
217 #elif defined(ARM)
218 static char cpu_arch[] = "arm";
219 #elif defined(PPC32)
220 static char cpu_arch[] = "ppc";
221 #elif defined(SPARC)
222 #ifdef _LP64
223 static char cpu_arch[] = "sparcv9";
224 #else
225 static char cpu_arch[] = "sparc";
226 #endif
227 #else
228 #error Add appropriate cpu_arch setting
229 #endif
230
231 // Compiler variant
232 #ifdef COMPILER2
233 #define COMPILER_VARIANT "server"
234 #else
235 #define COMPILER_VARIANT "client"
236 #endif
237
238
239 void os::Bsd::initialize_system_info() {
240 int mib[2];
241 size_t len;
242 int cpu_val;
243 julong mem_val;
244
245 // get processors count via hw.ncpus sysctl
246 mib[0] = CTL_HW;
247 mib[1] = HW_NCPU;
248 len = sizeof(cpu_val);
249 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
250 assert(len == sizeof(cpu_val), "unexpected data size");
251 set_processor_count(cpu_val);
252 } else {
253 set_processor_count(1); // fallback
254 }
255
256 // get physical memory via hw.memsize sysctl (hw.memsize is used
257 // since it returns a 64 bit value)
258 mib[0] = CTL_HW;
259
260 #if defined (HW_MEMSIZE) // Apple
261 mib[1] = HW_MEMSIZE;
262 #elif defined(HW_PHYSMEM) // Most of BSD
263 mib[1] = HW_PHYSMEM;
264 #elif defined(HW_REALMEM) // Old FreeBSD
265 mib[1] = HW_REALMEM;
266 #else
267 #error No ways to get physmem
268 #endif
269
270 len = sizeof(mem_val);
271 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
272 assert(len == sizeof(mem_val), "unexpected data size");
273 _physical_memory = mem_val;
274 } else {
275 _physical_memory = 256 * 1024 * 1024; // fallback (XXXBSD?)
276 }
277
278 #ifdef __OpenBSD__
279 {
280 // limit _physical_memory memory view on OpenBSD since
281 // datasize rlimit restricts us anyway.
282 struct rlimit limits;
283 getrlimit(RLIMIT_DATA, &limits);
284 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
285 }
286 #endif
287 }
288
289 #ifdef __APPLE__
290 static const char *get_home() {
291 const char *home_dir = ::getenv("HOME");
292 if ((home_dir == NULL) || (*home_dir == '\0')) {
293 struct passwd *passwd_info = getpwuid(geteuid());
294 if (passwd_info != NULL) {
295 home_dir = passwd_info->pw_dir;
296 }
297 }
298
299 return home_dir;
300 }
301 #endif
302
303 void os::init_system_properties_values() {
304 // The next steps are taken in the product version:
305 //
306 // Obtain the JAVA_HOME value from the location of libjvm.so.
307 // This library should be located at:
308 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
309 //
310 // If "/jre/lib/" appears at the right place in the path, then we
311 // assume libjvm.so is installed in a JDK and we use this path.
312 //
313 // Otherwise exit with message: "Could not create the Java virtual machine."
314 //
315 // The following extra steps are taken in the debugging version:
316 //
317 // If "/jre/lib/" does NOT appear at the right place in the path
318 // instead of exit check for $JAVA_HOME environment variable.
319 //
320 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
321 // then we append a fake suffix "hotspot/libjvm.so" to this path so
322 // it looks like libjvm.so is installed there
323 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
324 //
325 // Otherwise exit.
326 //
327 // Important note: if the location of libjvm.so changes this
328 // code needs to be changed accordingly.
329
330 // See ld(1):
331 // The linker uses the following search paths to locate required
332 // shared libraries:
333 // 1: ...
334 // ...
335 // 7: The default directories, normally /lib and /usr/lib.
336 #ifndef DEFAULT_LIBPATH
337 #define DEFAULT_LIBPATH "/lib:/usr/lib"
338 #endif
339
340 // Base path of extensions installed on the system.
341 #define SYS_EXT_DIR "/usr/java/packages"
342 #define EXTENSIONS_DIR "/lib/ext"
343
344 #ifndef __APPLE__
345
346 // Buffer that fits several sprintfs.
347 // Note that the space for the colon and the trailing null are provided
348 // by the nulls included by the sizeof operator.
349 const size_t bufsize =
350 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
351 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
352 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
353
354 // sysclasspath, java_home, dll_dir
355 {
356 char *pslash;
357 os::jvm_path(buf, bufsize);
358
359 // Found the full path to libjvm.so.
360 // Now cut the path to <java_home>/jre if we can.
361 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
362 pslash = strrchr(buf, '/');
363 if (pslash != NULL) {
364 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
365 }
366 Arguments::set_dll_dir(buf);
367
368 if (pslash != NULL) {
369 pslash = strrchr(buf, '/');
370 if (pslash != NULL) {
371 *pslash = '\0'; // Get rid of /<arch>.
372 pslash = strrchr(buf, '/');
373 if (pslash != NULL) {
374 *pslash = '\0'; // Get rid of /lib.
375 }
376 }
377 }
378 Arguments::set_java_home(buf);
379 set_boot_path('/', ':');
380 }
381
382 // Where to look for native libraries.
383 //
384 // Note: Due to a legacy implementation, most of the library path
385 // is set in the launcher. This was to accomodate linking restrictions
386 // on legacy Bsd implementations (which are no longer supported).
387 // Eventually, all the library path setting will be done here.
388 //
389 // However, to prevent the proliferation of improperly built native
390 // libraries, the new path component /usr/java/packages is added here.
391 // Eventually, all the library path setting will be done here.
392 {
393 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
394 // should always exist (until the legacy problem cited above is
395 // addressed).
396 const char *v = ::getenv("LD_LIBRARY_PATH");
397 const char *v_colon = ":";
398 if (v == NULL) { v = ""; v_colon = ""; }
399 // That's +1 for the colon and +1 for the trailing '\0'.
400 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
401 strlen(v) + 1 +
402 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
403 mtInternal);
404 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
405 Arguments::set_library_path(ld_library_path);
406 FREE_C_HEAP_ARRAY(char, ld_library_path);
407 }
408
409 // Extensions directories.
410 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
411 Arguments::set_ext_dirs(buf);
412
413 FREE_C_HEAP_ARRAY(char, buf);
414
415 #else // __APPLE__
416
417 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions"
418 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
419
420 const char *user_home_dir = get_home();
421 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
422 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
423 sizeof(SYS_EXTENSIONS_DIRS);
424
425 // Buffer that fits several sprintfs.
426 // Note that the space for the colon and the trailing null are provided
427 // by the nulls included by the sizeof operator.
428 const size_t bufsize =
429 MAX2((size_t)MAXPATHLEN, // for dll_dir & friends.
430 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
431 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
432
433 // sysclasspath, java_home, dll_dir
434 {
435 char *pslash;
436 os::jvm_path(buf, bufsize);
437
438 // Found the full path to libjvm.so.
439 // Now cut the path to <java_home>/jre if we can.
440 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
441 pslash = strrchr(buf, '/');
442 if (pslash != NULL) {
443 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
444 }
445 Arguments::set_dll_dir(buf);
446
447 if (pslash != NULL) {
448 pslash = strrchr(buf, '/');
449 if (pslash != NULL) {
450 *pslash = '\0'; // Get rid of /lib.
451 }
452 }
453 Arguments::set_java_home(buf);
454 set_boot_path('/', ':');
455 }
456
457 // Where to look for native libraries.
458 //
459 // Note: Due to a legacy implementation, most of the library path
460 // is set in the launcher. This was to accomodate linking restrictions
461 // on legacy Bsd implementations (which are no longer supported).
462 // Eventually, all the library path setting will be done here.
463 //
464 // However, to prevent the proliferation of improperly built native
465 // libraries, the new path component /usr/java/packages is added here.
466 // Eventually, all the library path setting will be done here.
467 {
468 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
469 // should always exist (until the legacy problem cited above is
470 // addressed).
471 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
472 // can specify a directory inside an app wrapper
473 const char *l = ::getenv("JAVA_LIBRARY_PATH");
474 const char *l_colon = ":";
475 if (l == NULL) { l = ""; l_colon = ""; }
476
477 const char *v = ::getenv("DYLD_LIBRARY_PATH");
478 const char *v_colon = ":";
479 if (v == NULL) { v = ""; v_colon = ""; }
480
481 // Apple's Java6 has "." at the beginning of java.library.path.
482 // OpenJDK on Windows has "." at the end of java.library.path.
483 // OpenJDK on Linux and Solaris don't have "." in java.library.path
484 // at all. To ease the transition from Apple's Java6 to OpenJDK7,
485 // "." is appended to the end of java.library.path. Yes, this
486 // could cause a change in behavior, but Apple's Java6 behavior
487 // can be achieved by putting "." at the beginning of the
488 // JAVA_LIBRARY_PATH environment variable.
489 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
490 strlen(v) + 1 + strlen(l) + 1 +
491 system_ext_size + 3,
492 mtInternal);
493 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
494 v, v_colon, l, l_colon, user_home_dir);
495 Arguments::set_library_path(ld_library_path);
496 FREE_C_HEAP_ARRAY(char, ld_library_path);
497 }
498
499 // Extensions directories.
500 //
501 // Note that the space for the colon and the trailing null are provided
502 // by the nulls included by the sizeof operator (so actually one byte more
503 // than necessary is allocated).
504 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
505 user_home_dir, Arguments::get_java_home());
506 Arguments::set_ext_dirs(buf);
507
508 FREE_C_HEAP_ARRAY(char, buf);
509
510 #undef SYS_EXTENSIONS_DIR
511 #undef SYS_EXTENSIONS_DIRS
512
513 #endif // __APPLE__
514
515 #undef SYS_EXT_DIR
516 #undef EXTENSIONS_DIR
517 }
518
519 ////////////////////////////////////////////////////////////////////////////////
520 // breakpoint support
521
522 void os::breakpoint() {
523 BREAKPOINT;
524 }
525
526 extern "C" void breakpoint() {
527 // use debugger to set breakpoint here
528 }
529
530 ////////////////////////////////////////////////////////////////////////////////
531 // signal support
532
533 debug_only(static bool signal_sets_initialized = false);
534 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
535
536 bool os::Bsd::is_sig_ignored(int sig) {
537 struct sigaction oact;
538 sigaction(sig, (struct sigaction*)NULL, &oact);
539 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
540 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
541 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
542 return true;
543 } else {
544 return false;
545 }
546 }
547
548 void os::Bsd::signal_sets_init() {
549 // Should also have an assertion stating we are still single-threaded.
550 assert(!signal_sets_initialized, "Already initialized");
551 // Fill in signals that are necessarily unblocked for all threads in
552 // the VM. Currently, we unblock the following signals:
553 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
554 // by -Xrs (=ReduceSignalUsage));
555 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
556 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
557 // the dispositions or masks wrt these signals.
558 // Programs embedding the VM that want to use the above signals for their
559 // own purposes must, at this time, use the "-Xrs" option to prevent
560 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
561 // (See bug 4345157, and other related bugs).
562 // In reality, though, unblocking these signals is really a nop, since
563 // these signals are not blocked by default.
564 sigemptyset(&unblocked_sigs);
565 sigemptyset(&allowdebug_blocked_sigs);
566 sigaddset(&unblocked_sigs, SIGILL);
567 sigaddset(&unblocked_sigs, SIGSEGV);
568 sigaddset(&unblocked_sigs, SIGBUS);
569 sigaddset(&unblocked_sigs, SIGFPE);
570 sigaddset(&unblocked_sigs, SR_signum);
571
572 if (!ReduceSignalUsage) {
573 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
574 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
575 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
576 }
577 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
578 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
579 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
580 }
581 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
582 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
583 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
584 }
585 }
586 // Fill in signals that are blocked by all but the VM thread.
587 sigemptyset(&vm_sigs);
588 if (!ReduceSignalUsage) {
589 sigaddset(&vm_sigs, BREAK_SIGNAL);
590 }
591 debug_only(signal_sets_initialized = true);
592
593 }
594
595 // These are signals that are unblocked while a thread is running Java.
596 // (For some reason, they get blocked by default.)
597 sigset_t* os::Bsd::unblocked_signals() {
598 assert(signal_sets_initialized, "Not initialized");
599 return &unblocked_sigs;
600 }
601
602 // These are the signals that are blocked while a (non-VM) thread is
603 // running Java. Only the VM thread handles these signals.
604 sigset_t* os::Bsd::vm_signals() {
605 assert(signal_sets_initialized, "Not initialized");
606 return &vm_sigs;
607 }
608
609 // These are signals that are blocked during cond_wait to allow debugger in
610 sigset_t* os::Bsd::allowdebug_blocked_signals() {
611 assert(signal_sets_initialized, "Not initialized");
612 return &allowdebug_blocked_sigs;
613 }
614
615 void os::Bsd::hotspot_sigmask(Thread* thread) {
616
617 //Save caller's signal mask before setting VM signal mask
618 sigset_t caller_sigmask;
619 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
620
621 OSThread* osthread = thread->osthread();
622 osthread->set_caller_sigmask(caller_sigmask);
623
624 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
625
626 if (!ReduceSignalUsage) {
627 if (thread->is_VM_thread()) {
628 // Only the VM thread handles BREAK_SIGNAL ...
629 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
630 } else {
631 // ... all other threads block BREAK_SIGNAL
632 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
633 }
634 }
635 }
636
637
638 //////////////////////////////////////////////////////////////////////////////
639 // create new thread
640
641 // check if it's safe to start a new thread
642 static bool _thread_safety_check(Thread* thread) {
643 return true;
644 }
645
646 #ifdef __APPLE__
647 // library handle for calling objc_registerThreadWithCollector()
648 // without static linking to the libobjc library
649 #define OBJC_LIB "/usr/lib/libobjc.dylib"
650 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
651 typedef void (*objc_registerThreadWithCollector_t)();
652 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
653 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
654 #endif
655
656 #ifdef __APPLE__
657 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
658 // Additional thread_id used to correlate threads in SA
659 thread_identifier_info_data_t m_ident_info;
660 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT;
661
662 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
663 (thread_info_t) &m_ident_info, &count);
664
665 return m_ident_info.thread_id;
666 }
667 #endif
668
669 // Thread start routine for all newly created threads
670 static void *java_start(Thread *thread) {
671 // Try to randomize the cache line index of hot stack frames.
672 // This helps when threads of the same stack traces evict each other's
673 // cache lines. The threads can be either from the same JVM instance, or
674 // from different JVM instances. The benefit is especially true for
675 // processors with hyperthreading technology.
676 static int counter = 0;
677 int pid = os::current_process_id();
678 alloca(((pid ^ counter++) & 7) * 128);
679
680 ThreadLocalStorage::set_thread(thread);
681
682 OSThread* osthread = thread->osthread();
683 Monitor* sync = osthread->startThread_lock();
684
685 // non floating stack BsdThreads needs extra check, see above
686 if (!_thread_safety_check(thread)) {
687 // notify parent thread
688 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
689 osthread->set_state(ZOMBIE);
690 sync->notify_all();
691 return NULL;
692 }
693
694 osthread->set_thread_id(os::Bsd::gettid());
695
696 #ifdef __APPLE__
697 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
698 guarantee(unique_thread_id != 0, "unique thread id was not found");
699 osthread->set_unique_thread_id(unique_thread_id);
700 #endif
701 // initialize signal mask for this thread
702 os::Bsd::hotspot_sigmask(thread);
703
704 // initialize floating point control register
705 os::Bsd::init_thread_fpu_state();
706
707 #ifdef __APPLE__
708 // register thread with objc gc
709 if (objc_registerThreadWithCollectorFunction != NULL) {
710 objc_registerThreadWithCollectorFunction();
711 }
712 #endif
713
714 // handshaking with parent thread
715 {
716 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
717
718 // notify parent thread
719 osthread->set_state(INITIALIZED);
720 sync->notify_all();
721
722 // wait until os::start_thread()
723 while (osthread->get_state() == INITIALIZED) {
724 sync->wait(Mutex::_no_safepoint_check_flag);
725 }
726 }
727
728 // call one more level start routine
729 thread->run();
730
731 return 0;
732 }
733
734 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
735 assert(thread->osthread() == NULL, "caller responsible");
736
737 // Allocate the OSThread object
738 OSThread* osthread = new OSThread(NULL, NULL);
739 if (osthread == NULL) {
740 return false;
741 }
742
743 // set the correct thread state
744 osthread->set_thread_type(thr_type);
745
746 // Initial state is ALLOCATED but not INITIALIZED
747 osthread->set_state(ALLOCATED);
748
749 thread->set_osthread(osthread);
750
751 // init thread attributes
752 pthread_attr_t attr;
753 pthread_attr_init(&attr);
754 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
755
756 // stack size
757 if (os::Bsd::supports_variable_stack_size()) {
758 // calculate stack size if it's not specified by caller
759 if (stack_size == 0) {
760 stack_size = os::Bsd::default_stack_size(thr_type);
761
762 switch (thr_type) {
763 case os::java_thread:
764 // Java threads use ThreadStackSize which default value can be
765 // changed with the flag -Xss
766 assert(JavaThread::stack_size_at_create() > 0, "this should be set");
767 stack_size = JavaThread::stack_size_at_create();
768 break;
769 case os::compiler_thread:
770 if (CompilerThreadStackSize > 0) {
771 stack_size = (size_t)(CompilerThreadStackSize * K);
772 break;
773 } // else fall through:
774 // use VMThreadStackSize if CompilerThreadStackSize is not defined
775 case os::vm_thread:
776 case os::pgc_thread:
777 case os::cgc_thread:
778 case os::watcher_thread:
779 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
780 break;
781 }
782 }
783
784 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
785 pthread_attr_setstacksize(&attr, stack_size);
786 } else {
787 // let pthread_create() pick the default value.
788 }
789
790 ThreadState state;
791
792 {
793 pthread_t tid;
794 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
795
796 pthread_attr_destroy(&attr);
797
798 if (ret != 0) {
799 if (PrintMiscellaneous && (Verbose || WizardMode)) {
800 perror("pthread_create()");
801 }
802 // Need to clean up stuff we've allocated so far
803 thread->set_osthread(NULL);
804 delete osthread;
805 return false;
806 }
807
808 // Store pthread info into the OSThread
809 osthread->set_pthread_id(tid);
810
811 // Wait until child thread is either initialized or aborted
812 {
813 Monitor* sync_with_child = osthread->startThread_lock();
814 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
815 while ((state = osthread->get_state()) == ALLOCATED) {
816 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
817 }
818 }
819
820 }
821
822 // Aborted due to thread limit being reached
823 if (state == ZOMBIE) {
824 thread->set_osthread(NULL);
825 delete osthread;
826 return false;
827 }
828
829 // The thread is returned suspended (in state INITIALIZED),
830 // and is started higher up in the call chain
831 assert(state == INITIALIZED, "race condition");
832 return true;
833 }
834
835 /////////////////////////////////////////////////////////////////////////////
836 // attach existing thread
837
838 // bootstrap the main thread
839 bool os::create_main_thread(JavaThread* thread) {
840 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
841 return create_attached_thread(thread);
842 }
843
844 bool os::create_attached_thread(JavaThread* thread) {
845 #ifdef ASSERT
846 thread->verify_not_published();
847 #endif
848
849 // Allocate the OSThread object
850 OSThread* osthread = new OSThread(NULL, NULL);
851
852 if (osthread == NULL) {
853 return false;
854 }
855
856 osthread->set_thread_id(os::Bsd::gettid());
857
858 // Store pthread info into the OSThread
859 #ifdef __APPLE__
860 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
861 guarantee(unique_thread_id != 0, "just checking");
862 osthread->set_unique_thread_id(unique_thread_id);
863 #endif
864 osthread->set_pthread_id(::pthread_self());
865
866 // initialize floating point control register
867 os::Bsd::init_thread_fpu_state();
868
869 // Initial thread state is RUNNABLE
870 osthread->set_state(RUNNABLE);
871
872 thread->set_osthread(osthread);
873
874 // initialize signal mask for this thread
875 // and save the caller's signal mask
876 os::Bsd::hotspot_sigmask(thread);
877
878 return true;
879 }
880
881 void os::pd_start_thread(Thread* thread) {
882 OSThread * osthread = thread->osthread();
883 assert(osthread->get_state() != INITIALIZED, "just checking");
884 Monitor* sync_with_child = osthread->startThread_lock();
885 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
886 sync_with_child->notify();
887 }
888
889 // Free Bsd resources related to the OSThread
890 void os::free_thread(OSThread* osthread) {
891 assert(osthread != NULL, "osthread not set");
892
893 if (Thread::current()->osthread() == osthread) {
894 // Restore caller's signal mask
895 sigset_t sigmask = osthread->caller_sigmask();
896 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
897 }
898
899 delete osthread;
900 }
901
902 //////////////////////////////////////////////////////////////////////////////
903 // thread local storage
904
905 // Restore the thread pointer if the destructor is called. This is in case
906 // someone from JNI code sets up a destructor with pthread_key_create to run
907 // detachCurrentThread on thread death. Unless we restore the thread pointer we
908 // will hang or crash. When detachCurrentThread is called the key will be set
909 // to null and we will not be called again. If detachCurrentThread is never
910 // called we could loop forever depending on the pthread implementation.
911 static void restore_thread_pointer(void* p) {
912 Thread* thread = (Thread*) p;
913 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
914 }
915
916 int os::allocate_thread_local_storage() {
917 pthread_key_t key;
918 int rslt = pthread_key_create(&key, restore_thread_pointer);
919 assert(rslt == 0, "cannot allocate thread local storage");
920 return (int)key;
921 }
922
923 // Note: This is currently not used by VM, as we don't destroy TLS key
924 // on VM exit.
925 void os::free_thread_local_storage(int index) {
926 int rslt = pthread_key_delete((pthread_key_t)index);
927 assert(rslt == 0, "invalid index");
928 }
929
930 void os::thread_local_storage_at_put(int index, void* value) {
931 int rslt = pthread_setspecific((pthread_key_t)index, value);
932 assert(rslt == 0, "pthread_setspecific failed");
933 }
934
935 extern "C" Thread* get_thread() {
936 return ThreadLocalStorage::thread();
937 }
938
939
940 ////////////////////////////////////////////////////////////////////////////////
941 // time support
942
943 // Time since start-up in seconds to a fine granularity.
944 // Used by VMSelfDestructTimer and the MemProfiler.
945 double os::elapsedTime() {
946
947 return ((double)os::elapsed_counter()) / os::elapsed_frequency();
948 }
949
950 jlong os::elapsed_counter() {
951 return javaTimeNanos() - initial_time_count;
952 }
953
954 jlong os::elapsed_frequency() {
955 return NANOSECS_PER_SEC; // nanosecond resolution
956 }
957
958 bool os::supports_vtime() { return true; }
959 bool os::enable_vtime() { return false; }
960 bool os::vtime_enabled() { return false; }
961
962 double os::elapsedVTime() {
963 // better than nothing, but not much
964 return elapsedTime();
965 }
966
967 jlong os::javaTimeMillis() {
968 timeval time;
969 int status = gettimeofday(&time, NULL);
970 assert(status != -1, "bsd error");
971 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
972 }
973
974 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
975 timeval time;
976 int status = gettimeofday(&time, NULL);
977 assert(status != -1, "bsd error");
978 seconds = jlong(time.tv_sec);
979 nanos = jlong(time.tv_usec) * 1000;
980 }
981
982 #ifndef __APPLE__
983 #ifndef CLOCK_MONOTONIC
984 #define CLOCK_MONOTONIC (1)
985 #endif
986 #endif
987
988 #ifdef __APPLE__
989 void os::Bsd::clock_init() {
990 mach_timebase_info(&_timebase_info);
991 }
992 #else
993 void os::Bsd::clock_init() {
994 struct timespec res;
995 struct timespec tp;
996 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
997 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
998 // yes, monotonic clock is supported
999 _clock_gettime = ::clock_gettime;
1000 }
1001 }
1002 #endif
1003
1004
1005
1006 #ifdef __APPLE__
1007
1008 jlong os::javaTimeNanos() {
1009 const uint64_t tm = mach_absolute_time();
1010 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
1011 const uint64_t prev = Bsd::_max_abstime;
1012 if (now <= prev) {
1013 return prev; // same or retrograde time;
1014 }
1015 const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
1016 assert(obsv >= prev, "invariant"); // Monotonicity
1017 // If the CAS succeeded then we're done and return "now".
1018 // If the CAS failed and the observed value "obsv" is >= now then
1019 // we should return "obsv". If the CAS failed and now > obsv > prv then
1020 // some other thread raced this thread and installed a new value, in which case
1021 // we could either (a) retry the entire operation, (b) retry trying to install now
1022 // or (c) just return obsv. We use (c). No loop is required although in some cases
1023 // we might discard a higher "now" value in deference to a slightly lower but freshly
1024 // installed obsv value. That's entirely benign -- it admits no new orderings compared
1025 // to (a) or (b) -- and greatly reduces coherence traffic.
1026 // We might also condition (c) on the magnitude of the delta between obsv and now.
1027 // Avoiding excessive CAS operations to hot RW locations is critical.
1028 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1029 return (prev == obsv) ? now : obsv;
1030 }
1031
1032 #else // __APPLE__
1033
1034 jlong os::javaTimeNanos() {
1035 if (os::supports_monotonic_clock()) {
1036 struct timespec tp;
1037 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
1038 assert(status == 0, "gettime error");
1039 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1040 return result;
1041 } else {
1042 timeval time;
1043 int status = gettimeofday(&time, NULL);
1044 assert(status != -1, "bsd error");
1045 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1046 return 1000 * usecs;
1047 }
1048 }
1049
1050 #endif // __APPLE__
1051
1052 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1053 if (os::supports_monotonic_clock()) {
1054 info_ptr->max_value = ALL_64_BITS;
1055
1056 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1057 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1058 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1059 } else {
1060 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1061 info_ptr->max_value = ALL_64_BITS;
1062
1063 // gettimeofday is a real time clock so it skips
1064 info_ptr->may_skip_backward = true;
1065 info_ptr->may_skip_forward = true;
1066 }
1067
1068 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1069 }
1070
1071 // Return the real, user, and system times in seconds from an
1072 // arbitrary fixed point in the past.
1073 bool os::getTimesSecs(double* process_real_time,
1074 double* process_user_time,
1075 double* process_system_time) {
1076 struct tms ticks;
1077 clock_t real_ticks = times(&ticks);
1078
1079 if (real_ticks == (clock_t) (-1)) {
1080 return false;
1081 } else {
1082 double ticks_per_second = (double) clock_tics_per_sec;
1083 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1084 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1085 *process_real_time = ((double) real_ticks) / ticks_per_second;
1086
1087 return true;
1088 }
1089 }
1090
1091
1092 char * os::local_time_string(char *buf, size_t buflen) {
1093 struct tm t;
1094 time_t long_time;
1095 time(&long_time);
1096 localtime_r(&long_time, &t);
1097 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1098 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1099 t.tm_hour, t.tm_min, t.tm_sec);
1100 return buf;
1101 }
1102
1103 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1104 return localtime_r(clock, res);
1105 }
1106
1107 ////////////////////////////////////////////////////////////////////////////////
1108 // runtime exit support
1109
1110 // Note: os::shutdown() might be called very early during initialization, or
1111 // called from signal handler. Before adding something to os::shutdown(), make
1112 // sure it is async-safe and can handle partially initialized VM.
1113 void os::shutdown() {
1114
1115 // allow PerfMemory to attempt cleanup of any persistent resources
1116 perfMemory_exit();
1117
1118 // needs to remove object in file system
1119 AttachListener::abort();
1120
1121 // flush buffered output, finish log files
1122 ostream_abort();
1123
1124 // Check for abort hook
1125 abort_hook_t abort_hook = Arguments::abort_hook();
1126 if (abort_hook != NULL) {
1127 abort_hook();
1128 }
1129
1130 }
1131
1132 // Note: os::abort() might be called very early during initialization, or
1133 // called from signal handler. Before adding something to os::abort(), make
1134 // sure it is async-safe and can handle partially initialized VM.
1135 void os::abort(bool dump_core) {
1136 abort(dump_core, NULL, NULL);
1137 }
1138
1139 void os::abort(bool dump_core, void* siginfo, void* context) {
1140 os::shutdown();
1141 if (dump_core) {
1142 #ifndef PRODUCT
1143 fdStream out(defaultStream::output_fd());
1144 out.print_raw("Current thread is ");
1145 char buf[16];
1146 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1147 out.print_raw_cr(buf);
1148 out.print_raw_cr("Dumping core ...");
1149 #endif
1150 ::abort(); // dump core
1151 }
1152
1153 ::exit(1);
1154 }
1155
1156 // Die immediately, no exit hook, no abort hook, no cleanup.
1157 void os::die() {
1158 // _exit() on BsdThreads only kills current thread
1159 ::abort();
1160 }
1161
1162 // This method is a copy of JDK's sysGetLastErrorString
1163 // from src/solaris/hpi/src/system_md.c
1164
1165 size_t os::lasterror(char *buf, size_t len) {
1166 if (errno == 0) return 0;
1167
1168 const char *s = ::strerror(errno);
1169 size_t n = ::strlen(s);
1170 if (n >= len) {
1171 n = len - 1;
1172 }
1173 ::strncpy(buf, s, n);
1174 buf[n] = '\0';
1175 return n;
1176 }
1177
1178 // Information of current thread in variety of formats
1179 pid_t os::Bsd::gettid() {
1180 int retval = -1;
1181
1182 #ifdef __APPLE__ //XNU kernel
1183 // despite the fact mach port is actually not a thread id use it
1184 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1185 retval = ::pthread_mach_thread_np(::pthread_self());
1186 guarantee(retval != 0, "just checking");
1187 return retval;
1188
1189 #else
1190 #ifdef __FreeBSD__
1191 retval = syscall(SYS_thr_self);
1192 #else
1193 #ifdef __OpenBSD__
1194 retval = syscall(SYS_getthrid);
1195 #else
1196 #ifdef __NetBSD__
1197 retval = (pid_t) syscall(SYS__lwp_self);
1198 #endif
1199 #endif
1200 #endif
1201 #endif
1202
1203 if (retval == -1) {
1204 return getpid();
1205 }
1206 }
1207
1208 intx os::current_thread_id() {
1209 #ifdef __APPLE__
1210 return (intx)::pthread_mach_thread_np(::pthread_self());
1211 #else
1212 return (intx)::pthread_self();
1213 #endif
1214 }
1215
1216 int os::current_process_id() {
1217
1218 // Under the old bsd thread library, bsd gives each thread
1219 // its own process id. Because of this each thread will return
1220 // a different pid if this method were to return the result
1221 // of getpid(2). Bsd provides no api that returns the pid
1222 // of the launcher thread for the vm. This implementation
1223 // returns a unique pid, the pid of the launcher thread
1224 // that starts the vm 'process'.
1225
1226 // Under the NPTL, getpid() returns the same pid as the
1227 // launcher thread rather than a unique pid per thread.
1228 // Use gettid() if you want the old pre NPTL behaviour.
1229
1230 // if you are looking for the result of a call to getpid() that
1231 // returns a unique pid for the calling thread, then look at the
1232 // OSThread::thread_id() method in osThread_bsd.hpp file
1233
1234 return (int)(_initial_pid ? _initial_pid : getpid());
1235 }
1236
1237 // DLL functions
1238
1239 #define JNI_LIB_PREFIX "lib"
1240 #ifdef __APPLE__
1241 #define JNI_LIB_SUFFIX ".dylib"
1242 #else
1243 #define JNI_LIB_SUFFIX ".so"
1244 #endif
1245
1246 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1247
1248 // This must be hard coded because it's the system's temporary
1249 // directory not the java application's temp directory, ala java.io.tmpdir.
1250 #ifdef __APPLE__
1251 // macosx has a secure per-user temporary directory
1252 char temp_path_storage[PATH_MAX];
1253 const char* os::get_temp_directory() {
1254 static char *temp_path = NULL;
1255 if (temp_path == NULL) {
1256 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1257 if (pathSize == 0 || pathSize > PATH_MAX) {
1258 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1259 }
1260 temp_path = temp_path_storage;
1261 }
1262 return temp_path;
1263 }
1264 #else // __APPLE__
1265 const char* os::get_temp_directory() { return "/tmp"; }
1266 #endif // __APPLE__
1267
1268 static bool file_exists(const char* filename) {
1269 struct stat statbuf;
1270 if (filename == NULL || strlen(filename) == 0) {
1271 return false;
1272 }
1273 return os::stat(filename, &statbuf) == 0;
1274 }
1275
1276 bool os::dll_build_name(char* buffer, size_t buflen,
1277 const char* pname, const char* fname) {
1278 bool retval = false;
1279 // Copied from libhpi
1280 const size_t pnamelen = pname ? strlen(pname) : 0;
1281
1282 // Return error on buffer overflow.
1283 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1284 return retval;
1285 }
1286
1287 if (pnamelen == 0) {
1288 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1289 retval = true;
1290 } else if (strchr(pname, *os::path_separator()) != NULL) {
1291 int n;
1292 char** pelements = split_path(pname, &n);
1293 if (pelements == NULL) {
1294 return false;
1295 }
1296 for (int i = 0; i < n; i++) {
1297 // Really shouldn't be NULL, but check can't hurt
1298 if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1299 continue; // skip the empty path values
1300 }
1301 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1302 pelements[i], fname);
1303 if (file_exists(buffer)) {
1304 retval = true;
1305 break;
1306 }
1307 }
1308 // release the storage
1309 for (int i = 0; i < n; i++) {
1310 if (pelements[i] != NULL) {
1311 FREE_C_HEAP_ARRAY(char, pelements[i]);
1312 }
1313 }
1314 if (pelements != NULL) {
1315 FREE_C_HEAP_ARRAY(char*, pelements);
1316 }
1317 } else {
1318 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1319 retval = true;
1320 }
1321 return retval;
1322 }
1323
1324 // check if addr is inside libjvm.so
1325 bool os::address_is_in_vm(address addr) {
1326 static address libjvm_base_addr;
1327 Dl_info dlinfo;
1328
1329 if (libjvm_base_addr == NULL) {
1330 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1331 libjvm_base_addr = (address)dlinfo.dli_fbase;
1332 }
1333 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1334 }
1335
1336 if (dladdr((void *)addr, &dlinfo) != 0) {
1337 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1338 }
1339
1340 return false;
1341 }
1342
1343
1344 #define MACH_MAXSYMLEN 256
1345
1346 bool os::dll_address_to_function_name(address addr, char *buf,
1347 int buflen, int *offset) {
1348 // buf is not optional, but offset is optional
1349 assert(buf != NULL, "sanity check");
1350
1351 Dl_info dlinfo;
1352 char localbuf[MACH_MAXSYMLEN];
1353
1354 if (dladdr((void*)addr, &dlinfo) != 0) {
1355 // see if we have a matching symbol
1356 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1357 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1358 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1359 }
1360 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1361 return true;
1362 }
1363 // no matching symbol so try for just file info
1364 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1365 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1366 buf, buflen, offset, dlinfo.dli_fname)) {
1367 return true;
1368 }
1369 }
1370
1371 // Handle non-dynamic manually:
1372 if (dlinfo.dli_fbase != NULL &&
1373 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
1374 if (!Decoder::demangle(localbuf, buf, buflen)) {
1375 jio_snprintf(buf, buflen, "%s", localbuf);
1376 }
1377 return true;
1378 }
1379 }
1380 buf[0] = '\0';
1381 if (offset != NULL) *offset = -1;
1382 return false;
1383 }
1384
1385 // ported from solaris version
1386 bool os::dll_address_to_library_name(address addr, char* buf,
1387 int buflen, int* offset) {
1388 // buf is not optional, but offset is optional
1389 assert(buf != NULL, "sanity check");
1390
1391 Dl_info dlinfo;
1392
1393 if (dladdr((void*)addr, &dlinfo) != 0) {
1394 if (dlinfo.dli_fname != NULL) {
1395 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1396 }
1397 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1398 *offset = addr - (address)dlinfo.dli_fbase;
1399 }
1400 return true;
1401 }
1402
1403 buf[0] = '\0';
1404 if (offset) *offset = -1;
1405 return false;
1406 }
1407
1408 // Loads .dll/.so and
1409 // in case of error it checks if .dll/.so was built for the
1410 // same architecture as Hotspot is running on
1411
1412 #ifdef __APPLE__
1413 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1414 void * result= ::dlopen(filename, RTLD_LAZY);
1415 if (result != NULL) {
1416 // Successful loading
1417 return result;
1418 }
1419
1420 // Read system error message into ebuf
1421 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1422 ebuf[ebuflen-1]='\0';
1423
1424 return NULL;
1425 }
1426 #else
1427 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1428 void * result= ::dlopen(filename, RTLD_LAZY);
1429 if (result != NULL) {
1430 // Successful loading
1431 return result;
1432 }
1433
1434 Elf32_Ehdr elf_head;
1435
1436 // Read system error message into ebuf
1437 // It may or may not be overwritten below
1438 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1439 ebuf[ebuflen-1]='\0';
1440 int diag_msg_max_length=ebuflen-strlen(ebuf);
1441 char* diag_msg_buf=ebuf+strlen(ebuf);
1442
1443 if (diag_msg_max_length==0) {
1444 // No more space in ebuf for additional diagnostics message
1445 return NULL;
1446 }
1447
1448
1449 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1450
1451 if (file_descriptor < 0) {
1452 // Can't open library, report dlerror() message
1453 return NULL;
1454 }
1455
1456 bool failed_to_read_elf_head=
1457 (sizeof(elf_head)!=
1458 (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1459
1460 ::close(file_descriptor);
1461 if (failed_to_read_elf_head) {
1462 // file i/o error - report dlerror() msg
1463 return NULL;
1464 }
1465
1466 typedef struct {
1467 Elf32_Half code; // Actual value as defined in elf.h
1468 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1469 char elf_class; // 32 or 64 bit
1470 char endianess; // MSB or LSB
1471 char* name; // String representation
1472 } arch_t;
1473
1474 #ifndef EM_486
1475 #define EM_486 6 /* Intel 80486 */
1476 #endif
1477
1478 #ifndef EM_MIPS_RS3_LE
1479 #define EM_MIPS_RS3_LE 10 /* MIPS */
1480 #endif
1481
1482 #ifndef EM_PPC64
1483 #define EM_PPC64 21 /* PowerPC64 */
1484 #endif
1485
1486 #ifndef EM_S390
1487 #define EM_S390 22 /* IBM System/390 */
1488 #endif
1489
1490 #ifndef EM_IA_64
1491 #define EM_IA_64 50 /* HP/Intel IA-64 */
1492 #endif
1493
1494 #ifndef EM_X86_64
1495 #define EM_X86_64 62 /* AMD x86-64 */
1496 #endif
1497
1498 static const arch_t arch_array[]={
1499 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1500 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1501 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1502 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1503 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1504 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1505 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1506 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1507 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1508 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1509 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1510 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1511 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1512 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1513 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1514 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1515 };
1516
1517 #if (defined IA32)
1518 static Elf32_Half running_arch_code=EM_386;
1519 #elif (defined AMD64)
1520 static Elf32_Half running_arch_code=EM_X86_64;
1521 #elif (defined IA64)
1522 static Elf32_Half running_arch_code=EM_IA_64;
1523 #elif (defined __sparc) && (defined _LP64)
1524 static Elf32_Half running_arch_code=EM_SPARCV9;
1525 #elif (defined __sparc) && (!defined _LP64)
1526 static Elf32_Half running_arch_code=EM_SPARC;
1527 #elif (defined __powerpc64__)
1528 static Elf32_Half running_arch_code=EM_PPC64;
1529 #elif (defined __powerpc__)
1530 static Elf32_Half running_arch_code=EM_PPC;
1531 #elif (defined ARM)
1532 static Elf32_Half running_arch_code=EM_ARM;
1533 #elif (defined S390)
1534 static Elf32_Half running_arch_code=EM_S390;
1535 #elif (defined ALPHA)
1536 static Elf32_Half running_arch_code=EM_ALPHA;
1537 #elif (defined MIPSEL)
1538 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1539 #elif (defined PARISC)
1540 static Elf32_Half running_arch_code=EM_PARISC;
1541 #elif (defined MIPS)
1542 static Elf32_Half running_arch_code=EM_MIPS;
1543 #elif (defined M68K)
1544 static Elf32_Half running_arch_code=EM_68K;
1545 #else
1546 #error Method os::dll_load requires that one of following is defined:\
1547 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1548 #endif
1549
1550 // Identify compatability class for VM's architecture and library's architecture
1551 // Obtain string descriptions for architectures
1552
1553 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1554 int running_arch_index=-1;
1555
1556 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1557 if (running_arch_code == arch_array[i].code) {
1558 running_arch_index = i;
1559 }
1560 if (lib_arch.code == arch_array[i].code) {
1561 lib_arch.compat_class = arch_array[i].compat_class;
1562 lib_arch.name = arch_array[i].name;
1563 }
1564 }
1565
1566 assert(running_arch_index != -1,
1567 "Didn't find running architecture code (running_arch_code) in arch_array");
1568 if (running_arch_index == -1) {
1569 // Even though running architecture detection failed
1570 // we may still continue with reporting dlerror() message
1571 return NULL;
1572 }
1573
1574 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1575 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1576 return NULL;
1577 }
1578
1579 #ifndef S390
1580 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1581 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1582 return NULL;
1583 }
1584 #endif // !S390
1585
1586 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1587 if (lib_arch.name!=NULL) {
1588 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1589 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1590 lib_arch.name, arch_array[running_arch_index].name);
1591 } else {
1592 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1593 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1594 lib_arch.code,
1595 arch_array[running_arch_index].name);
1596 }
1597 }
1598
1599 return NULL;
1600 }
1601 #endif // !__APPLE__
1602
1603 void* os::get_default_process_handle() {
1604 #ifdef __APPLE__
1605 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1606 // to avoid finding unexpected symbols on second (or later)
1607 // loads of a library.
1608 return (void*)::dlopen(NULL, RTLD_FIRST);
1609 #else
1610 return (void*)::dlopen(NULL, RTLD_LAZY);
1611 #endif
1612 }
1613
1614 // XXX: Do we need a lock around this as per Linux?
1615 void* os::dll_lookup(void* handle, const char* name) {
1616 return dlsym(handle, name);
1617 }
1618
1619
1620 static bool _print_ascii_file(const char* filename, outputStream* st) {
1621 int fd = ::open(filename, O_RDONLY);
1622 if (fd == -1) {
1623 return false;
1624 }
1625
1626 char buf[32];
1627 int bytes;
1628 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1629 st->print_raw(buf, bytes);
1630 }
1631
1632 ::close(fd);
1633
1634 return true;
1635 }
1636
1637 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1638 outputStream * out = (outputStream *) param;
1639 out->print_cr(PTR_FORMAT " \t%s", base_address, name);
1640 return 0;
1641 }
1642
1643 void os::print_dll_info(outputStream *st) {
1644 st->print_cr("Dynamic libraries:");
1645 if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1646 st->print_cr("Error: Cannot print dynamic libraries.");
1647 }
1648 }
1649
1650 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1651 #ifdef RTLD_DI_LINKMAP
1652 Dl_info dli;
1653 void *handle;
1654 Link_map *map;
1655 Link_map *p;
1656
1657 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1658 dli.dli_fname == NULL) {
1659 return 1;
1660 }
1661 handle = dlopen(dli.dli_fname, RTLD_LAZY);
1662 if (handle == NULL) {
1663 return 1;
1664 }
1665 dlinfo(handle, RTLD_DI_LINKMAP, &map);
1666 if (map == NULL) {
1667 dlclose(handle);
1668 return 1;
1669 }
1670
1671 while (map->l_prev != NULL)
1672 map = map->l_prev;
1673
1674 while (map != NULL) {
1675 // Value for top_address is returned as 0 since we don't have any information about module size
1676 if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1677 dlclose(handle);
1678 return 1;
1679 }
1680 map = map->l_next;
1681 }
1682
1683 dlclose(handle);
1684 #elif defined(__APPLE__)
1685 for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1686 // Value for top_address is returned as 0 since we don't have any information about module size
1687 if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1688 return 1;
1689 }
1690 }
1691 return 0;
1692 #else
1693 return 1;
1694 #endif
1695 }
1696
1697 void os::print_os_info_brief(outputStream* st) {
1698 st->print("Bsd");
1699
1700 os::Posix::print_uname_info(st);
1701 }
1702
1703 void os::print_os_info(outputStream* st) {
1704 st->print("OS:");
1705 st->print("Bsd");
1706
1707 os::Posix::print_uname_info(st);
1708
1709 os::Posix::print_rlimit_info(st);
1710
1711 os::Posix::print_load_average(st);
1712 }
1713
1714 void os::pd_print_cpu_info(outputStream* st) {
1715 // Nothing to do for now.
1716 }
1717
1718 void os::print_memory_info(outputStream* st) {
1719
1720 st->print("Memory:");
1721 st->print(" %dk page", os::vm_page_size()>>10);
1722
1723 st->print(", physical " UINT64_FORMAT "k",
1724 os::physical_memory() >> 10);
1725 st->print("(" UINT64_FORMAT "k free)",
1726 os::available_memory() >> 10);
1727 st->cr();
1728
1729 // meminfo
1730 st->print("\n/proc/meminfo:\n");
1731 _print_ascii_file("/proc/meminfo", st);
1732 st->cr();
1733 }
1734
1735 void os::print_siginfo(outputStream* st, void* siginfo) {
1736 const siginfo_t* si = (const siginfo_t*)siginfo;
1737
1738 os::Posix::print_siginfo_brief(st, si);
1739
1740 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1741 UseSharedSpaces) {
1742 FileMapInfo* mapinfo = FileMapInfo::current_info();
1743 if (mapinfo->is_in_shared_space(si->si_addr)) {
1744 st->print("\n\nError accessing class data sharing archive." \
1745 " Mapped file inaccessible during execution, " \
1746 " possible disk/network problem.");
1747 }
1748 }
1749 st->cr();
1750 }
1751
1752
1753 static void print_signal_handler(outputStream* st, int sig,
1754 char* buf, size_t buflen);
1755
1756 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1757 st->print_cr("Signal Handlers:");
1758 print_signal_handler(st, SIGSEGV, buf, buflen);
1759 print_signal_handler(st, SIGBUS , buf, buflen);
1760 print_signal_handler(st, SIGFPE , buf, buflen);
1761 print_signal_handler(st, SIGPIPE, buf, buflen);
1762 print_signal_handler(st, SIGXFSZ, buf, buflen);
1763 print_signal_handler(st, SIGILL , buf, buflen);
1764 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1765 print_signal_handler(st, SR_signum, buf, buflen);
1766 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1767 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1768 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1769 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1770 }
1771
1772 static char saved_jvm_path[MAXPATHLEN] = {0};
1773
1774 // Find the full path to the current module, libjvm
1775 void os::jvm_path(char *buf, jint buflen) {
1776 // Error checking.
1777 if (buflen < MAXPATHLEN) {
1778 assert(false, "must use a large-enough buffer");
1779 buf[0] = '\0';
1780 return;
1781 }
1782 // Lazy resolve the path to current module.
1783 if (saved_jvm_path[0] != 0) {
1784 strcpy(buf, saved_jvm_path);
1785 return;
1786 }
1787
1788 char dli_fname[MAXPATHLEN];
1789 bool ret = dll_address_to_library_name(
1790 CAST_FROM_FN_PTR(address, os::jvm_path),
1791 dli_fname, sizeof(dli_fname), NULL);
1792 assert(ret, "cannot locate libjvm");
1793 char *rp = NULL;
1794 if (ret && dli_fname[0] != '\0') {
1795 rp = realpath(dli_fname, buf);
1796 }
1797 if (rp == NULL) {
1798 return;
1799 }
1800
1801 if (Arguments::sun_java_launcher_is_altjvm()) {
1802 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1803 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1804 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1805 // appears at the right place in the string, then assume we are
1806 // installed in a JDK and we're done. Otherwise, check for a
1807 // JAVA_HOME environment variable and construct a path to the JVM
1808 // being overridden.
1809
1810 const char *p = buf + strlen(buf) - 1;
1811 for (int count = 0; p > buf && count < 5; ++count) {
1812 for (--p; p > buf && *p != '/'; --p)
1813 /* empty */ ;
1814 }
1815
1816 if (strncmp(p, "/jre/lib/", 9) != 0) {
1817 // Look for JAVA_HOME in the environment.
1818 char* java_home_var = ::getenv("JAVA_HOME");
1819 if (java_home_var != NULL && java_home_var[0] != 0) {
1820 char* jrelib_p;
1821 int len;
1822
1823 // Check the current module name "libjvm"
1824 p = strrchr(buf, '/');
1825 assert(strstr(p, "/libjvm") == p, "invalid library name");
1826
1827 rp = realpath(java_home_var, buf);
1828 if (rp == NULL) {
1829 return;
1830 }
1831
1832 // determine if this is a legacy image or modules image
1833 // modules image doesn't have "jre" subdirectory
1834 len = strlen(buf);
1835 assert(len < buflen, "Ran out of buffer space");
1836 jrelib_p = buf + len;
1837
1838 // Add the appropriate library subdir
1839 snprintf(jrelib_p, buflen-len, "/jre/lib");
1840 if (0 != access(buf, F_OK)) {
1841 snprintf(jrelib_p, buflen-len, "/lib");
1842 }
1843
1844 // Add the appropriate client or server subdir
1845 len = strlen(buf);
1846 jrelib_p = buf + len;
1847 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1848 if (0 != access(buf, F_OK)) {
1849 snprintf(jrelib_p, buflen-len, "%s", "");
1850 }
1851
1852 // If the path exists within JAVA_HOME, add the JVM library name
1853 // to complete the path to JVM being overridden. Otherwise fallback
1854 // to the path to the current library.
1855 if (0 == access(buf, F_OK)) {
1856 // Use current module name "libjvm"
1857 len = strlen(buf);
1858 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1859 } else {
1860 // Fall back to path of current library
1861 rp = realpath(dli_fname, buf);
1862 if (rp == NULL) {
1863 return;
1864 }
1865 }
1866 }
1867 }
1868 }
1869
1870 strncpy(saved_jvm_path, buf, MAXPATHLEN);
1871 saved_jvm_path[MAXPATHLEN - 1] = '\0';
1872 }
1873
1874 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1875 // no prefix required, not even "_"
1876 }
1877
1878 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1879 // no suffix required
1880 }
1881
1882 ////////////////////////////////////////////////////////////////////////////////
1883 // sun.misc.Signal support
1884
1885 static volatile jint sigint_count = 0;
1886
1887 static void UserHandler(int sig, void *siginfo, void *context) {
1888 // 4511530 - sem_post is serialized and handled by the manager thread. When
1889 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1890 // don't want to flood the manager thread with sem_post requests.
1891 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
1892 return;
1893 }
1894
1895 // Ctrl-C is pressed during error reporting, likely because the error
1896 // handler fails to abort. Let VM die immediately.
1897 if (sig == SIGINT && is_error_reported()) {
1898 os::die();
1899 }
1900
1901 os::signal_notify(sig);
1902 }
1903
1904 void* os::user_handler() {
1905 return CAST_FROM_FN_PTR(void*, UserHandler);
1906 }
1907
1908 extern "C" {
1909 typedef void (*sa_handler_t)(int);
1910 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1911 }
1912
1913 void* os::signal(int signal_number, void* handler) {
1914 struct sigaction sigAct, oldSigAct;
1915
1916 sigfillset(&(sigAct.sa_mask));
1917 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
1918 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1919
1920 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1921 // -1 means registration failed
1922 return (void *)-1;
1923 }
1924
1925 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1926 }
1927
1928 void os::signal_raise(int signal_number) {
1929 ::raise(signal_number);
1930 }
1931
1932 // The following code is moved from os.cpp for making this
1933 // code platform specific, which it is by its very nature.
1934
1935 // Will be modified when max signal is changed to be dynamic
1936 int os::sigexitnum_pd() {
1937 return NSIG;
1938 }
1939
1940 // a counter for each possible signal value
1941 static volatile jint pending_signals[NSIG+1] = { 0 };
1942
1943 // Bsd(POSIX) specific hand shaking semaphore.
1944 #ifdef __APPLE__
1945 typedef semaphore_t os_semaphore_t;
1946
1947 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1948 #define SEM_WAIT(sem) semaphore_wait(sem)
1949 #define SEM_POST(sem) semaphore_signal(sem)
1950 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem)
1951 #else
1952 typedef sem_t os_semaphore_t;
1953
1954 #define SEM_INIT(sem, value) sem_init(&sem, 0, value)
1955 #define SEM_WAIT(sem) sem_wait(&sem)
1956 #define SEM_POST(sem) sem_post(&sem)
1957 #define SEM_DESTROY(sem) sem_destroy(&sem)
1958 #endif
1959
1960 #ifdef __APPLE__
1961 // OS X doesn't support unamed POSIX semaphores, so the implementation in os_posix.cpp can't be used.
1962
1963 static const char* sem_init_strerror(kern_return_t value) {
1964 switch (value) {
1965 case KERN_INVALID_ARGUMENT: return "Invalid argument";
1966 case KERN_RESOURCE_SHORTAGE: return "Resource shortage";
1967 default: return "Unknown";
1968 }
1969 }
1970
1971 OSXSemaphore::OSXSemaphore(uint value) {
1972 kern_return_t ret = SEM_INIT(_semaphore, value);
1973
1974 guarantee(ret == KERN_SUCCESS, err_msg("Failed to create semaphore: %s", sem_init_strerror(ret)));
1975 }
1976
1977 OSXSemaphore::~OSXSemaphore() {
1978 SEM_DESTROY(_semaphore);
1979 }
1980
1981 void OSXSemaphore::signal(uint count) {
1982 for (uint i = 0; i < count; i++) {
1983 kern_return_t ret = SEM_POST(_semaphore);
1984
1985 assert(ret == KERN_SUCCESS, "Failed to signal semaphore");
1986 }
1987 }
1988
1989 void OSXSemaphore::wait() {
1990 kern_return_t ret;
1991 while ((ret = SEM_WAIT(_semaphore)) == KERN_ABORTED) {
1992 // Semaphore was interrupted. Retry.
1993 }
1994 assert(ret == KERN_SUCCESS, "Failed to wait on semaphore");
1995 }
1996
1997 jlong OSXSemaphore::currenttime() {
1998 struct timeval tv;
1999 gettimeofday(&tv, NULL);
2000 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
2001 }
2002
2003 bool OSXSemaphore::trywait() {
2004 return timedwait(0, 0);
2005 }
2006
2007 bool OSXSemaphore::timedwait(unsigned int sec, int nsec) {
2008 kern_return_t kr = KERN_ABORTED;
2009 mach_timespec_t waitspec;
2010 waitspec.tv_sec = sec;
2011 waitspec.tv_nsec = nsec;
2012
2013 jlong starttime = currenttime();
2014
2015 kr = semaphore_timedwait(_semaphore, waitspec);
2016 while (kr == KERN_ABORTED) {
2017 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
2018
2019 jlong current = currenttime();
2020 jlong passedtime = current - starttime;
2021
2022 if (passedtime >= totalwait) {
2023 waitspec.tv_sec = 0;
2024 waitspec.tv_nsec = 0;
2025 } else {
2026 jlong waittime = totalwait - (current - starttime);
2027 waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
2028 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
2029 }
2030
2031 kr = semaphore_timedwait(_semaphore, waitspec);
2032 }
2033
2034 return kr == KERN_SUCCESS;
2035 }
2036
2037 #else
2038 // Use POSIX implementation of semaphores.
2039
2040 struct timespec PosixSemaphore::create_timespec(unsigned int sec, int nsec) {
2041 struct timespec ts;
2042 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2043
2044 return ts;
2045 }
2046
2047 #endif // __APPLE__
2048
2049 static os_semaphore_t sig_sem;
2050
2051 #ifdef __APPLE__
2052 static OSXSemaphore sr_semaphore;
2053 #else
2054 static PosixSemaphore sr_semaphore;
2055 #endif
2056
2057 void os::signal_init_pd() {
2058 // Initialize signal structures
2059 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2060
2061 // Initialize signal semaphore
2062 ::SEM_INIT(sig_sem, 0);
2063 }
2064
2065 void os::signal_notify(int sig) {
2066 Atomic::inc(&pending_signals[sig]);
2067 ::SEM_POST(sig_sem);
2068 }
2069
2070 static int check_pending_signals(bool wait) {
2071 Atomic::store(0, &sigint_count);
2072 for (;;) {
2073 for (int i = 0; i < NSIG + 1; i++) {
2074 jint n = pending_signals[i];
2075 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2076 return i;
2077 }
2078 }
2079 if (!wait) {
2080 return -1;
2081 }
2082 JavaThread *thread = JavaThread::current();
2083 ThreadBlockInVM tbivm(thread);
2084
2085 bool threadIsSuspended;
2086 do {
2087 thread->set_suspend_equivalent();
2088 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2089 ::SEM_WAIT(sig_sem);
2090
2091 // were we externally suspended while we were waiting?
2092 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2093 if (threadIsSuspended) {
2094 // The semaphore has been incremented, but while we were waiting
2095 // another thread suspended us. We don't want to continue running
2096 // while suspended because that would surprise the thread that
2097 // suspended us.
2098 ::SEM_POST(sig_sem);
2099
2100 thread->java_suspend_self();
2101 }
2102 } while (threadIsSuspended);
2103 }
2104 }
2105
2106 int os::signal_lookup() {
2107 return check_pending_signals(false);
2108 }
2109
2110 int os::signal_wait() {
2111 return check_pending_signals(true);
2112 }
2113
2114 ////////////////////////////////////////////////////////////////////////////////
2115 // Virtual Memory
2116
2117 int os::vm_page_size() {
2118 // Seems redundant as all get out
2119 assert(os::Bsd::page_size() != -1, "must call os::init");
2120 return os::Bsd::page_size();
2121 }
2122
2123 // Solaris allocates memory by pages.
2124 int os::vm_allocation_granularity() {
2125 assert(os::Bsd::page_size() != -1, "must call os::init");
2126 return os::Bsd::page_size();
2127 }
2128
2129 // Rationale behind this function:
2130 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2131 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2132 // samples for JITted code. Here we create private executable mapping over the code cache
2133 // and then we can use standard (well, almost, as mapping can change) way to provide
2134 // info for the reporting script by storing timestamp and location of symbol
2135 void bsd_wrap_code(char* base, size_t size) {
2136 static volatile jint cnt = 0;
2137
2138 if (!UseOprofile) {
2139 return;
2140 }
2141
2142 char buf[PATH_MAX + 1];
2143 int num = Atomic::add(1, &cnt);
2144
2145 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2146 os::get_temp_directory(), os::current_process_id(), num);
2147 unlink(buf);
2148
2149 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2150
2151 if (fd != -1) {
2152 off_t rv = ::lseek(fd, size-2, SEEK_SET);
2153 if (rv != (off_t)-1) {
2154 if (::write(fd, "", 1) == 1) {
2155 mmap(base, size,
2156 PROT_READ|PROT_WRITE|PROT_EXEC,
2157 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2158 }
2159 }
2160 ::close(fd);
2161 unlink(buf);
2162 }
2163 }
2164
2165 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2166 int err) {
2167 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2168 ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2169 strerror(err), err);
2170 }
2171
2172 // NOTE: Bsd kernel does not really reserve the pages for us.
2173 // All it does is to check if there are enough free pages
2174 // left at the time of mmap(). This could be a potential
2175 // problem.
2176 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2177 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2178 #ifdef __OpenBSD__
2179 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2180 if (::mprotect(addr, size, prot) == 0) {
2181 return true;
2182 }
2183 #else
2184 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2185 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2186 if (res != (uintptr_t) MAP_FAILED) {
2187 return true;
2188 }
2189 #endif
2190
2191 // Warn about any commit errors we see in non-product builds just
2192 // in case mmap() doesn't work as described on the man page.
2193 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2194
2195 return false;
2196 }
2197
2198 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2199 bool exec) {
2200 // alignment_hint is ignored on this OS
2201 return pd_commit_memory(addr, size, exec);
2202 }
2203
2204 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2205 const char* mesg) {
2206 assert(mesg != NULL, "mesg must be specified");
2207 if (!pd_commit_memory(addr, size, exec)) {
2208 // add extra info in product mode for vm_exit_out_of_memory():
2209 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2210 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
2211 }
2212 }
2213
2214 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2215 size_t alignment_hint, bool exec,
2216 const char* mesg) {
2217 // alignment_hint is ignored on this OS
2218 pd_commit_memory_or_exit(addr, size, exec, mesg);
2219 }
2220
2221 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2222 }
2223
2224 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2225 ::madvise(addr, bytes, MADV_DONTNEED);
2226 }
2227
2228 void os::numa_make_global(char *addr, size_t bytes) {
2229 }
2230
2231 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2232 }
2233
2234 bool os::numa_topology_changed() { return false; }
2235
2236 size_t os::numa_get_groups_num() {
2237 return 1;
2238 }
2239
2240 int os::numa_get_group_id() {
2241 return 0;
2242 }
2243
2244 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2245 if (size > 0) {
2246 ids[0] = 0;
2247 return 1;
2248 }
2249 return 0;
2250 }
2251
2252 bool os::get_page_info(char *start, page_info* info) {
2253 return false;
2254 }
2255
2256 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2257 return end;
2258 }
2259
2260
2261 bool os::pd_uncommit_memory(char* addr, size_t size) {
2262 #ifdef __OpenBSD__
2263 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2264 return ::mprotect(addr, size, PROT_NONE) == 0;
2265 #else
2266 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2267 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2268 return res != (uintptr_t) MAP_FAILED;
2269 #endif
2270 }
2271
2272 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2273 return os::commit_memory(addr, size, !ExecMem);
2274 }
2275
2276 // If this is a growable mapping, remove the guard pages entirely by
2277 // munmap()ping them. If not, just call uncommit_memory().
2278 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2279 return os::uncommit_memory(addr, size);
2280 }
2281
2282 static address _highest_vm_reserved_address = NULL;
2283
2284 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2285 // at 'requested_addr'. If there are existing memory mappings at the same
2286 // location, however, they will be overwritten. If 'fixed' is false,
2287 // 'requested_addr' is only treated as a hint, the return value may or
2288 // may not start from the requested address. Unlike Bsd mmap(), this
2289 // function returns NULL to indicate failure.
2290 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2291 char * addr;
2292 int flags;
2293
2294 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2295 if (fixed) {
2296 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2297 flags |= MAP_FIXED;
2298 }
2299
2300 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2301 // touch an uncommitted page. Otherwise, the read/write might
2302 // succeed if we have enough swap space to back the physical page.
2303 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2304 flags, -1, 0);
2305
2306 if (addr != MAP_FAILED) {
2307 // anon_mmap() should only get called during VM initialization,
2308 // don't need lock (actually we can skip locking even it can be called
2309 // from multiple threads, because _highest_vm_reserved_address is just a
2310 // hint about the upper limit of non-stack memory regions.)
2311 if ((address)addr + bytes > _highest_vm_reserved_address) {
2312 _highest_vm_reserved_address = (address)addr + bytes;
2313 }
2314 }
2315
2316 return addr == MAP_FAILED ? NULL : addr;
2317 }
2318
2319 // Don't update _highest_vm_reserved_address, because there might be memory
2320 // regions above addr + size. If so, releasing a memory region only creates
2321 // a hole in the address space, it doesn't help prevent heap-stack collision.
2322 //
2323 static int anon_munmap(char * addr, size_t size) {
2324 return ::munmap(addr, size) == 0;
2325 }
2326
2327 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2328 size_t alignment_hint) {
2329 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2330 }
2331
2332 bool os::pd_release_memory(char* addr, size_t size) {
2333 return anon_munmap(addr, size);
2334 }
2335
2336 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2337 // Bsd wants the mprotect address argument to be page aligned.
2338 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2339
2340 // According to SUSv3, mprotect() should only be used with mappings
2341 // established by mmap(), and mmap() always maps whole pages. Unaligned
2342 // 'addr' likely indicates problem in the VM (e.g. trying to change
2343 // protection of malloc'ed or statically allocated memory). Check the
2344 // caller if you hit this assert.
2345 assert(addr == bottom, "sanity check");
2346
2347 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2348 return ::mprotect(bottom, size, prot) == 0;
2349 }
2350
2351 // Set protections specified
2352 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2353 bool is_committed) {
2354 unsigned int p = 0;
2355 switch (prot) {
2356 case MEM_PROT_NONE: p = PROT_NONE; break;
2357 case MEM_PROT_READ: p = PROT_READ; break;
2358 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
2359 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2360 default:
2361 ShouldNotReachHere();
2362 }
2363 // is_committed is unused.
2364 return bsd_mprotect(addr, bytes, p);
2365 }
2366
2367 bool os::guard_memory(char* addr, size_t size) {
2368 return bsd_mprotect(addr, size, PROT_NONE);
2369 }
2370
2371 bool os::unguard_memory(char* addr, size_t size) {
2372 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2373 }
2374
2375 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2376 return false;
2377 }
2378
2379 // Large page support
2380
2381 static size_t _large_page_size = 0;
2382
2383 void os::large_page_init() {
2384 }
2385
2386
2387 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2388 fatal("This code is not used or maintained.");
2389
2390 // "exec" is passed in but not used. Creating the shared image for
2391 // the code cache doesn't have an SHM_X executable permission to check.
2392 assert(UseLargePages && UseSHM, "only for SHM large pages");
2393
2394 key_t key = IPC_PRIVATE;
2395 char *addr;
2396
2397 bool warn_on_failure = UseLargePages &&
2398 (!FLAG_IS_DEFAULT(UseLargePages) ||
2399 !FLAG_IS_DEFAULT(LargePageSizeInBytes));
2400
2401 // Create a large shared memory region to attach to based on size.
2402 // Currently, size is the total size of the heap
2403 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2404 if (shmid == -1) {
2405 // Possible reasons for shmget failure:
2406 // 1. shmmax is too small for Java heap.
2407 // > check shmmax value: cat /proc/sys/kernel/shmmax
2408 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2409 // 2. not enough large page memory.
2410 // > check available large pages: cat /proc/meminfo
2411 // > increase amount of large pages:
2412 // echo new_value > /proc/sys/vm/nr_hugepages
2413 // Note 1: different Bsd may use different name for this property,
2414 // e.g. on Redhat AS-3 it is "hugetlb_pool".
2415 // Note 2: it's possible there's enough physical memory available but
2416 // they are so fragmented after a long run that they can't
2417 // coalesce into large pages. Try to reserve large pages when
2418 // the system is still "fresh".
2419 if (warn_on_failure) {
2420 warning("Failed to reserve shared memory (errno = %d).", errno);
2421 }
2422 return NULL;
2423 }
2424
2425 // attach to the region
2426 addr = (char*)shmat(shmid, req_addr, 0);
2427 int err = errno;
2428
2429 // Remove shmid. If shmat() is successful, the actual shared memory segment
2430 // will be deleted when it's detached by shmdt() or when the process
2431 // terminates. If shmat() is not successful this will remove the shared
2432 // segment immediately.
2433 shmctl(shmid, IPC_RMID, NULL);
2434
2435 if ((intptr_t)addr == -1) {
2436 if (warn_on_failure) {
2437 warning("Failed to attach shared memory (errno = %d).", err);
2438 }
2439 return NULL;
2440 }
2441
2442 // The memory is committed
2443 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
2444
2445 return addr;
2446 }
2447
2448 bool os::release_memory_special(char* base, size_t bytes) {
2449 if (MemTracker::tracking_level() > NMT_minimal) {
2450 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2451 // detaching the SHM segment will also delete it, see reserve_memory_special()
2452 int rslt = shmdt(base);
2453 if (rslt == 0) {
2454 tkr.record((address)base, bytes);
2455 return true;
2456 } else {
2457 return false;
2458 }
2459 } else {
2460 return shmdt(base) == 0;
2461 }
2462 }
2463
2464 size_t os::large_page_size() {
2465 return _large_page_size;
2466 }
2467
2468 // HugeTLBFS allows application to commit large page memory on demand;
2469 // with SysV SHM the entire memory region must be allocated as shared
2470 // memory.
2471 bool os::can_commit_large_page_memory() {
2472 return UseHugeTLBFS;
2473 }
2474
2475 bool os::can_execute_large_page_memory() {
2476 return UseHugeTLBFS;
2477 }
2478
2479 // Reserve memory at an arbitrary address, only if that area is
2480 // available (and not reserved for something else).
2481
2482 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2483 const int max_tries = 10;
2484 char* base[max_tries];
2485 size_t size[max_tries];
2486 const size_t gap = 0x000000;
2487
2488 // Assert only that the size is a multiple of the page size, since
2489 // that's all that mmap requires, and since that's all we really know
2490 // about at this low abstraction level. If we need higher alignment,
2491 // we can either pass an alignment to this method or verify alignment
2492 // in one of the methods further up the call chain. See bug 5044738.
2493 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2494
2495 // Repeatedly allocate blocks until the block is allocated at the
2496 // right spot. Give up after max_tries. Note that reserve_memory() will
2497 // automatically update _highest_vm_reserved_address if the call is
2498 // successful. The variable tracks the highest memory address every reserved
2499 // by JVM. It is used to detect heap-stack collision if running with
2500 // fixed-stack BsdThreads. Because here we may attempt to reserve more
2501 // space than needed, it could confuse the collision detecting code. To
2502 // solve the problem, save current _highest_vm_reserved_address and
2503 // calculate the correct value before return.
2504 address old_highest = _highest_vm_reserved_address;
2505
2506 // Bsd mmap allows caller to pass an address as hint; give it a try first,
2507 // if kernel honors the hint then we can return immediately.
2508 char * addr = anon_mmap(requested_addr, bytes, false);
2509 if (addr == requested_addr) {
2510 return requested_addr;
2511 }
2512
2513 if (addr != NULL) {
2514 // mmap() is successful but it fails to reserve at the requested address
2515 anon_munmap(addr, bytes);
2516 }
2517
2518 int i;
2519 for (i = 0; i < max_tries; ++i) {
2520 base[i] = reserve_memory(bytes);
2521
2522 if (base[i] != NULL) {
2523 // Is this the block we wanted?
2524 if (base[i] == requested_addr) {
2525 size[i] = bytes;
2526 break;
2527 }
2528
2529 // Does this overlap the block we wanted? Give back the overlapped
2530 // parts and try again.
2531
2532 size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2533 if (top_overlap >= 0 && top_overlap < bytes) {
2534 unmap_memory(base[i], top_overlap);
2535 base[i] += top_overlap;
2536 size[i] = bytes - top_overlap;
2537 } else {
2538 size_t bottom_overlap = base[i] + bytes - requested_addr;
2539 if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2540 unmap_memory(requested_addr, bottom_overlap);
2541 size[i] = bytes - bottom_overlap;
2542 } else {
2543 size[i] = bytes;
2544 }
2545 }
2546 }
2547 }
2548
2549 // Give back the unused reserved pieces.
2550
2551 for (int j = 0; j < i; ++j) {
2552 if (base[j] != NULL) {
2553 unmap_memory(base[j], size[j]);
2554 }
2555 }
2556
2557 if (i < max_tries) {
2558 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2559 return requested_addr;
2560 } else {
2561 _highest_vm_reserved_address = old_highest;
2562 return NULL;
2563 }
2564 }
2565
2566 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2567 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2568 }
2569
2570 size_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
2571 RESTARTABLE_RETURN_INT(::pread(fd, buf, nBytes, offset));
2572 }
2573
2574 void os::naked_short_sleep(jlong ms) {
2575 struct timespec req;
2576
2577 assert(ms < 1000, "Un-interruptable sleep, short time use only");
2578 req.tv_sec = 0;
2579 if (ms > 0) {
2580 req.tv_nsec = (ms % 1000) * 1000000;
2581 } else {
2582 req.tv_nsec = 1;
2583 }
2584
2585 nanosleep(&req, NULL);
2586
2587 return;
2588 }
2589
2590 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2591 void os::infinite_sleep() {
2592 while (true) { // sleep forever ...
2593 ::sleep(100); // ... 100 seconds at a time
2594 }
2595 }
2596
2597 // Used to convert frequent JVM_Yield() to nops
2598 bool os::dont_yield() {
2599 return DontYieldALot;
2600 }
2601
2602 void os::naked_yield() {
2603 sched_yield();
2604 }
2605
2606 ////////////////////////////////////////////////////////////////////////////////
2607 // thread priority support
2608
2609 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2610 // only supports dynamic priority, static priority must be zero. For real-time
2611 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2612 // However, for large multi-threaded applications, SCHED_RR is not only slower
2613 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2614 // of 5 runs - Sep 2005).
2615 //
2616 // The following code actually changes the niceness of kernel-thread/LWP. It
2617 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2618 // not the entire user process, and user level threads are 1:1 mapped to kernel
2619 // threads. It has always been the case, but could change in the future. For
2620 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2621 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2622
2623 #if !defined(__APPLE__)
2624 int os::java_to_os_priority[CriticalPriority + 1] = {
2625 19, // 0 Entry should never be used
2626
2627 0, // 1 MinPriority
2628 3, // 2
2629 6, // 3
2630
2631 10, // 4
2632 15, // 5 NormPriority
2633 18, // 6
2634
2635 21, // 7
2636 25, // 8
2637 28, // 9 NearMaxPriority
2638
2639 31, // 10 MaxPriority
2640
2641 31 // 11 CriticalPriority
2642 };
2643 #else
2644 // Using Mach high-level priority assignments
2645 int os::java_to_os_priority[CriticalPriority + 1] = {
2646 0, // 0 Entry should never be used (MINPRI_USER)
2647
2648 27, // 1 MinPriority
2649 28, // 2
2650 29, // 3
2651
2652 30, // 4
2653 31, // 5 NormPriority (BASEPRI_DEFAULT)
2654 32, // 6
2655
2656 33, // 7
2657 34, // 8
2658 35, // 9 NearMaxPriority
2659
2660 36, // 10 MaxPriority
2661
2662 36 // 11 CriticalPriority
2663 };
2664 #endif
2665
2666 static int prio_init() {
2667 if (ThreadPriorityPolicy == 1) {
2668 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2669 // if effective uid is not root. Perhaps, a more elegant way of doing
2670 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2671 if (geteuid() != 0) {
2672 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2673 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2674 }
2675 ThreadPriorityPolicy = 0;
2676 }
2677 }
2678 if (UseCriticalJavaThreadPriority) {
2679 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2680 }
2681 return 0;
2682 }
2683
2684 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2685 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2686
2687 #ifdef __OpenBSD__
2688 // OpenBSD pthread_setprio starves low priority threads
2689 return OS_OK;
2690 #elif defined(__FreeBSD__)
2691 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2692 #elif defined(__APPLE__) || defined(__NetBSD__)
2693 struct sched_param sp;
2694 int policy;
2695 pthread_t self = pthread_self();
2696
2697 if (pthread_getschedparam(self, &policy, &sp) != 0) {
2698 return OS_ERR;
2699 }
2700
2701 sp.sched_priority = newpri;
2702 if (pthread_setschedparam(self, policy, &sp) != 0) {
2703 return OS_ERR;
2704 }
2705
2706 return OS_OK;
2707 #else
2708 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2709 return (ret == 0) ? OS_OK : OS_ERR;
2710 #endif
2711 }
2712
2713 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2714 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2715 *priority_ptr = java_to_os_priority[NormPriority];
2716 return OS_OK;
2717 }
2718
2719 errno = 0;
2720 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2721 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2722 #elif defined(__APPLE__) || defined(__NetBSD__)
2723 int policy;
2724 struct sched_param sp;
2725
2726 pthread_getschedparam(pthread_self(), &policy, &sp);
2727 *priority_ptr = sp.sched_priority;
2728 #else
2729 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2730 #endif
2731 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2732 }
2733
2734 // Hint to the underlying OS that a task switch would not be good.
2735 // Void return because it's a hint and can fail.
2736 void os::hint_no_preempt() {}
2737
2738 ////////////////////////////////////////////////////////////////////////////////
2739 // suspend/resume support
2740
2741 // the low-level signal-based suspend/resume support is a remnant from the
2742 // old VM-suspension that used to be for java-suspension, safepoints etc,
2743 // within hotspot. Now there is a single use-case for this:
2744 // - calling get_thread_pc() on the VMThread by the flat-profiler task
2745 // that runs in the watcher thread.
2746 // The remaining code is greatly simplified from the more general suspension
2747 // code that used to be used.
2748 //
2749 // The protocol is quite simple:
2750 // - suspend:
2751 // - sends a signal to the target thread
2752 // - polls the suspend state of the osthread using a yield loop
2753 // - target thread signal handler (SR_handler) sets suspend state
2754 // and blocks in sigsuspend until continued
2755 // - resume:
2756 // - sets target osthread state to continue
2757 // - sends signal to end the sigsuspend loop in the SR_handler
2758 //
2759 // Note that the SR_lock plays no role in this suspend/resume protocol.
2760
2761 static void resume_clear_context(OSThread *osthread) {
2762 osthread->set_ucontext(NULL);
2763 osthread->set_siginfo(NULL);
2764 }
2765
2766 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2767 osthread->set_ucontext(context);
2768 osthread->set_siginfo(siginfo);
2769 }
2770
2771 // Handler function invoked when a thread's execution is suspended or
2772 // resumed. We have to be careful that only async-safe functions are
2773 // called here (Note: most pthread functions are not async safe and
2774 // should be avoided.)
2775 //
2776 // Note: sigwait() is a more natural fit than sigsuspend() from an
2777 // interface point of view, but sigwait() prevents the signal hander
2778 // from being run. libpthread would get very confused by not having
2779 // its signal handlers run and prevents sigwait()'s use with the
2780 // mutex granting granting signal.
2781 //
2782 // Currently only ever called on the VMThread or JavaThread
2783 //
2784 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2785 // Save and restore errno to avoid confusing native code with EINTR
2786 // after sigsuspend.
2787 int old_errno = errno;
2788
2789 Thread* thread = Thread::current();
2790 OSThread* osthread = thread->osthread();
2791 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2792
2793 os::SuspendResume::State current = osthread->sr.state();
2794 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2795 suspend_save_context(osthread, siginfo, context);
2796
2797 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2798 os::SuspendResume::State state = osthread->sr.suspended();
2799 if (state == os::SuspendResume::SR_SUSPENDED) {
2800 sigset_t suspend_set; // signals for sigsuspend()
2801
2802 // get current set of blocked signals and unblock resume signal
2803 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2804 sigdelset(&suspend_set, SR_signum);
2805
2806 sr_semaphore.signal();
2807 // wait here until we are resumed
2808 while (1) {
2809 sigsuspend(&suspend_set);
2810
2811 os::SuspendResume::State result = osthread->sr.running();
2812 if (result == os::SuspendResume::SR_RUNNING) {
2813 sr_semaphore.signal();
2814 break;
2815 } else if (result != os::SuspendResume::SR_SUSPENDED) {
2816 ShouldNotReachHere();
2817 }
2818 }
2819
2820 } else if (state == os::SuspendResume::SR_RUNNING) {
2821 // request was cancelled, continue
2822 } else {
2823 ShouldNotReachHere();
2824 }
2825
2826 resume_clear_context(osthread);
2827 } else if (current == os::SuspendResume::SR_RUNNING) {
2828 // request was cancelled, continue
2829 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2830 // ignore
2831 } else {
2832 // ignore
2833 }
2834
2835 errno = old_errno;
2836 }
2837
2838
2839 static int SR_initialize() {
2840 struct sigaction act;
2841 char *s;
2842 // Get signal number to use for suspend/resume
2843 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2844 int sig = ::strtol(s, 0, 10);
2845 if (sig > 0 || sig < NSIG) {
2846 SR_signum = sig;
2847 }
2848 }
2849
2850 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2851 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2852
2853 sigemptyset(&SR_sigset);
2854 sigaddset(&SR_sigset, SR_signum);
2855
2856 // Set up signal handler for suspend/resume
2857 act.sa_flags = SA_RESTART|SA_SIGINFO;
2858 act.sa_handler = (void (*)(int)) SR_handler;
2859
2860 // SR_signum is blocked by default.
2861 // 4528190 - We also need to block pthread restart signal (32 on all
2862 // supported Bsd platforms). Note that BsdThreads need to block
2863 // this signal for all threads to work properly. So we don't have
2864 // to use hard-coded signal number when setting up the mask.
2865 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2866
2867 if (sigaction(SR_signum, &act, 0) == -1) {
2868 return -1;
2869 }
2870
2871 // Save signal flag
2872 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2873 return 0;
2874 }
2875
2876 static int sr_notify(OSThread* osthread) {
2877 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2878 assert_status(status == 0, status, "pthread_kill");
2879 return status;
2880 }
2881
2882 // "Randomly" selected value for how long we want to spin
2883 // before bailing out on suspending a thread, also how often
2884 // we send a signal to a thread we want to resume
2885 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2886 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2887
2888 // returns true on success and false on error - really an error is fatal
2889 // but this seems the normal response to library errors
2890 static bool do_suspend(OSThread* osthread) {
2891 assert(osthread->sr.is_running(), "thread should be running");
2892 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2893
2894 // mark as suspended and send signal
2895 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2896 // failed to switch, state wasn't running?
2897 ShouldNotReachHere();
2898 return false;
2899 }
2900
2901 if (sr_notify(osthread) != 0) {
2902 ShouldNotReachHere();
2903 }
2904
2905 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2906 while (true) {
2907 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2908 break;
2909 } else {
2910 // timeout
2911 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2912 if (cancelled == os::SuspendResume::SR_RUNNING) {
2913 return false;
2914 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2915 // make sure that we consume the signal on the semaphore as well
2916 sr_semaphore.wait();
2917 break;
2918 } else {
2919 ShouldNotReachHere();
2920 return false;
2921 }
2922 }
2923 }
2924
2925 guarantee(osthread->sr.is_suspended(), "Must be suspended");
2926 return true;
2927 }
2928
2929 static void do_resume(OSThread* osthread) {
2930 assert(osthread->sr.is_suspended(), "thread should be suspended");
2931 assert(!sr_semaphore.trywait(), "invalid semaphore state");
2932
2933 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2934 // failed to switch to WAKEUP_REQUEST
2935 ShouldNotReachHere();
2936 return;
2937 }
2938
2939 while (true) {
2940 if (sr_notify(osthread) == 0) {
2941 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2942 if (osthread->sr.is_running()) {
2943 return;
2944 }
2945 }
2946 } else {
2947 ShouldNotReachHere();
2948 }
2949 }
2950
2951 guarantee(osthread->sr.is_running(), "Must be running!");
2952 }
2953
2954 ///////////////////////////////////////////////////////////////////////////////////
2955 // signal handling (except suspend/resume)
2956
2957 // This routine may be used by user applications as a "hook" to catch signals.
2958 // The user-defined signal handler must pass unrecognized signals to this
2959 // routine, and if it returns true (non-zero), then the signal handler must
2960 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2961 // routine will never retun false (zero), but instead will execute a VM panic
2962 // routine kill the process.
2963 //
2964 // If this routine returns false, it is OK to call it again. This allows
2965 // the user-defined signal handler to perform checks either before or after
2966 // the VM performs its own checks. Naturally, the user code would be making
2967 // a serious error if it tried to handle an exception (such as a null check
2968 // or breakpoint) that the VM was generating for its own correct operation.
2969 //
2970 // This routine may recognize any of the following kinds of signals:
2971 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2972 // It should be consulted by handlers for any of those signals.
2973 //
2974 // The caller of this routine must pass in the three arguments supplied
2975 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2976 // field of the structure passed to sigaction(). This routine assumes that
2977 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2978 //
2979 // Note that the VM will print warnings if it detects conflicting signal
2980 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2981 //
2982 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2983 void* ucontext,
2984 int abort_if_unrecognized);
2985
2986 void signalHandler(int sig, siginfo_t* info, void* uc) {
2987 assert(info != NULL && uc != NULL, "it must be old kernel");
2988 int orig_errno = errno; // Preserve errno value over signal handler.
2989 JVM_handle_bsd_signal(sig, info, uc, true);
2990 errno = orig_errno;
2991 }
2992
2993
2994 // This boolean allows users to forward their own non-matching signals
2995 // to JVM_handle_bsd_signal, harmlessly.
2996 bool os::Bsd::signal_handlers_are_installed = false;
2997
2998 // For signal-chaining
2999 struct sigaction os::Bsd::sigact[MAXSIGNUM];
3000 unsigned int os::Bsd::sigs = 0;
3001 bool os::Bsd::libjsig_is_loaded = false;
3002 typedef struct sigaction *(*get_signal_t)(int);
3003 get_signal_t os::Bsd::get_signal_action = NULL;
3004
3005 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
3006 struct sigaction *actp = NULL;
3007
3008 if (libjsig_is_loaded) {
3009 // Retrieve the old signal handler from libjsig
3010 actp = (*get_signal_action)(sig);
3011 }
3012 if (actp == NULL) {
3013 // Retrieve the preinstalled signal handler from jvm
3014 actp = get_preinstalled_handler(sig);
3015 }
3016
3017 return actp;
3018 }
3019
3020 static bool call_chained_handler(struct sigaction *actp, int sig,
3021 siginfo_t *siginfo, void *context) {
3022 // Call the old signal handler
3023 if (actp->sa_handler == SIG_DFL) {
3024 // It's more reasonable to let jvm treat it as an unexpected exception
3025 // instead of taking the default action.
3026 return false;
3027 } else if (actp->sa_handler != SIG_IGN) {
3028 if ((actp->sa_flags & SA_NODEFER) == 0) {
3029 // automaticlly block the signal
3030 sigaddset(&(actp->sa_mask), sig);
3031 }
3032
3033 sa_handler_t hand;
3034 sa_sigaction_t sa;
3035 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3036 // retrieve the chained handler
3037 if (siginfo_flag_set) {
3038 sa = actp->sa_sigaction;
3039 } else {
3040 hand = actp->sa_handler;
3041 }
3042
3043 if ((actp->sa_flags & SA_RESETHAND) != 0) {
3044 actp->sa_handler = SIG_DFL;
3045 }
3046
3047 // try to honor the signal mask
3048 sigset_t oset;
3049 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3050
3051 // call into the chained handler
3052 if (siginfo_flag_set) {
3053 (*sa)(sig, siginfo, context);
3054 } else {
3055 (*hand)(sig);
3056 }
3057
3058 // restore the signal mask
3059 pthread_sigmask(SIG_SETMASK, &oset, 0);
3060 }
3061 // Tell jvm's signal handler the signal is taken care of.
3062 return true;
3063 }
3064
3065 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3066 bool chained = false;
3067 // signal-chaining
3068 if (UseSignalChaining) {
3069 struct sigaction *actp = get_chained_signal_action(sig);
3070 if (actp != NULL) {
3071 chained = call_chained_handler(actp, sig, siginfo, context);
3072 }
3073 }
3074 return chained;
3075 }
3076
3077 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3078 if ((((unsigned int)1 << sig) & sigs) != 0) {
3079 return &sigact[sig];
3080 }
3081 return NULL;
3082 }
3083
3084 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3085 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3086 sigact[sig] = oldAct;
3087 sigs |= (unsigned int)1 << sig;
3088 }
3089
3090 // for diagnostic
3091 int os::Bsd::sigflags[MAXSIGNUM];
3092
3093 int os::Bsd::get_our_sigflags(int sig) {
3094 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3095 return sigflags[sig];
3096 }
3097
3098 void os::Bsd::set_our_sigflags(int sig, int flags) {
3099 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3100 sigflags[sig] = flags;
3101 }
3102
3103 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3104 // Check for overwrite.
3105 struct sigaction oldAct;
3106 sigaction(sig, (struct sigaction*)NULL, &oldAct);
3107
3108 void* oldhand = oldAct.sa_sigaction
3109 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3110 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3111 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3112 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3113 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3114 if (AllowUserSignalHandlers || !set_installed) {
3115 // Do not overwrite; user takes responsibility to forward to us.
3116 return;
3117 } else if (UseSignalChaining) {
3118 // save the old handler in jvm
3119 save_preinstalled_handler(sig, oldAct);
3120 // libjsig also interposes the sigaction() call below and saves the
3121 // old sigaction on it own.
3122 } else {
3123 fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3124 "%#lx for signal %d.", (long)oldhand, sig));
3125 }
3126 }
3127
3128 struct sigaction sigAct;
3129 sigfillset(&(sigAct.sa_mask));
3130 sigAct.sa_handler = SIG_DFL;
3131 if (!set_installed) {
3132 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3133 } else {
3134 sigAct.sa_sigaction = signalHandler;
3135 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3136 }
3137 #ifdef __APPLE__
3138 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3139 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3140 // if the signal handler declares it will handle it on alternate stack.
3141 // Notice we only declare we will handle it on alt stack, but we are not
3142 // actually going to use real alt stack - this is just a workaround.
3143 // Please see ux_exception.c, method catch_mach_exception_raise for details
3144 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3145 if (sig == SIGSEGV) {
3146 sigAct.sa_flags |= SA_ONSTACK;
3147 }
3148 #endif
3149
3150 // Save flags, which are set by ours
3151 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3152 sigflags[sig] = sigAct.sa_flags;
3153
3154 int ret = sigaction(sig, &sigAct, &oldAct);
3155 assert(ret == 0, "check");
3156
3157 void* oldhand2 = oldAct.sa_sigaction
3158 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3159 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3160 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3161 }
3162
3163 // install signal handlers for signals that HotSpot needs to
3164 // handle in order to support Java-level exception handling.
3165
3166 void os::Bsd::install_signal_handlers() {
3167 if (!signal_handlers_are_installed) {
3168 signal_handlers_are_installed = true;
3169
3170 // signal-chaining
3171 typedef void (*signal_setting_t)();
3172 signal_setting_t begin_signal_setting = NULL;
3173 signal_setting_t end_signal_setting = NULL;
3174 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3175 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3176 if (begin_signal_setting != NULL) {
3177 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3178 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3179 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3180 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3181 libjsig_is_loaded = true;
3182 assert(UseSignalChaining, "should enable signal-chaining");
3183 }
3184 if (libjsig_is_loaded) {
3185 // Tell libjsig jvm is setting signal handlers
3186 (*begin_signal_setting)();
3187 }
3188
3189 set_signal_handler(SIGSEGV, true);
3190 set_signal_handler(SIGPIPE, true);
3191 set_signal_handler(SIGBUS, true);
3192 set_signal_handler(SIGILL, true);
3193 set_signal_handler(SIGFPE, true);
3194 set_signal_handler(SIGXFSZ, true);
3195
3196 #if defined(__APPLE__)
3197 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3198 // signals caught and handled by the JVM. To work around this, we reset the mach task
3199 // signal handler that's placed on our process by CrashReporter. This disables
3200 // CrashReporter-based reporting.
3201 //
3202 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3203 // on caught fatal signals.
3204 //
3205 // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3206 // handlers. By replacing the existing task exception handler, we disable gdb's mach
3207 // exception handling, while leaving the standard BSD signal handlers functional.
3208 kern_return_t kr;
3209 kr = task_set_exception_ports(mach_task_self(),
3210 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3211 MACH_PORT_NULL,
3212 EXCEPTION_STATE_IDENTITY,
3213 MACHINE_THREAD_STATE);
3214
3215 assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3216 #endif
3217
3218 if (libjsig_is_loaded) {
3219 // Tell libjsig jvm finishes setting signal handlers
3220 (*end_signal_setting)();
3221 }
3222
3223 // We don't activate signal checker if libjsig is in place, we trust ourselves
3224 // and if UserSignalHandler is installed all bets are off
3225 if (CheckJNICalls) {
3226 if (libjsig_is_loaded) {
3227 if (PrintJNIResolving) {
3228 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3229 }
3230 check_signals = false;
3231 }
3232 if (AllowUserSignalHandlers) {
3233 if (PrintJNIResolving) {
3234 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3235 }
3236 check_signals = false;
3237 }
3238 }
3239 }
3240 }
3241
3242
3243 /////
3244 // glibc on Bsd platform uses non-documented flag
3245 // to indicate, that some special sort of signal
3246 // trampoline is used.
3247 // We will never set this flag, and we should
3248 // ignore this flag in our diagnostic
3249 #ifdef SIGNIFICANT_SIGNAL_MASK
3250 #undef SIGNIFICANT_SIGNAL_MASK
3251 #endif
3252 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3253
3254 static const char* get_signal_handler_name(address handler,
3255 char* buf, int buflen) {
3256 int offset;
3257 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3258 if (found) {
3259 // skip directory names
3260 const char *p1, *p2;
3261 p1 = buf;
3262 size_t len = strlen(os::file_separator());
3263 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3264 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3265 } else {
3266 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3267 }
3268 return buf;
3269 }
3270
3271 static void print_signal_handler(outputStream* st, int sig,
3272 char* buf, size_t buflen) {
3273 struct sigaction sa;
3274
3275 sigaction(sig, NULL, &sa);
3276
3277 // See comment for SIGNIFICANT_SIGNAL_MASK define
3278 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3279
3280 st->print("%s: ", os::exception_name(sig, buf, buflen));
3281
3282 address handler = (sa.sa_flags & SA_SIGINFO)
3283 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3284 : CAST_FROM_FN_PTR(address, sa.sa_handler);
3285
3286 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3287 st->print("SIG_DFL");
3288 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3289 st->print("SIG_IGN");
3290 } else {
3291 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3292 }
3293
3294 st->print(", sa_mask[0]=");
3295 os::Posix::print_signal_set_short(st, &sa.sa_mask);
3296
3297 address rh = VMError::get_resetted_sighandler(sig);
3298 // May be, handler was resetted by VMError?
3299 if (rh != NULL) {
3300 handler = rh;
3301 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3302 }
3303
3304 st->print(", sa_flags=");
3305 os::Posix::print_sa_flags(st, sa.sa_flags);
3306
3307 // Check: is it our handler?
3308 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3309 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3310 // It is our signal handler
3311 // check for flags, reset system-used one!
3312 if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3313 st->print(
3314 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3315 os::Bsd::get_our_sigflags(sig));
3316 }
3317 }
3318 st->cr();
3319 }
3320
3321
3322 #define DO_SIGNAL_CHECK(sig) \
3323 do { \
3324 if (!sigismember(&check_signal_done, sig)) { \
3325 os::Bsd::check_signal_handler(sig); \
3326 } \
3327 } while (0)
3328
3329 // This method is a periodic task to check for misbehaving JNI applications
3330 // under CheckJNI, we can add any periodic checks here
3331
3332 void os::run_periodic_checks() {
3333
3334 if (check_signals == false) return;
3335
3336 // SEGV and BUS if overridden could potentially prevent
3337 // generation of hs*.log in the event of a crash, debugging
3338 // such a case can be very challenging, so we absolutely
3339 // check the following for a good measure:
3340 DO_SIGNAL_CHECK(SIGSEGV);
3341 DO_SIGNAL_CHECK(SIGILL);
3342 DO_SIGNAL_CHECK(SIGFPE);
3343 DO_SIGNAL_CHECK(SIGBUS);
3344 DO_SIGNAL_CHECK(SIGPIPE);
3345 DO_SIGNAL_CHECK(SIGXFSZ);
3346
3347
3348 // ReduceSignalUsage allows the user to override these handlers
3349 // see comments at the very top and jvm_solaris.h
3350 if (!ReduceSignalUsage) {
3351 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3352 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3353 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3354 DO_SIGNAL_CHECK(BREAK_SIGNAL);
3355 }
3356
3357 DO_SIGNAL_CHECK(SR_signum);
3358 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3359 }
3360
3361 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3362
3363 static os_sigaction_t os_sigaction = NULL;
3364
3365 void os::Bsd::check_signal_handler(int sig) {
3366 char buf[O_BUFLEN];
3367 address jvmHandler = NULL;
3368
3369
3370 struct sigaction act;
3371 if (os_sigaction == NULL) {
3372 // only trust the default sigaction, in case it has been interposed
3373 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3374 if (os_sigaction == NULL) return;
3375 }
3376
3377 os_sigaction(sig, (struct sigaction*)NULL, &act);
3378
3379
3380 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3381
3382 address thisHandler = (act.sa_flags & SA_SIGINFO)
3383 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3384 : CAST_FROM_FN_PTR(address, act.sa_handler);
3385
3386
3387 switch (sig) {
3388 case SIGSEGV:
3389 case SIGBUS:
3390 case SIGFPE:
3391 case SIGPIPE:
3392 case SIGILL:
3393 case SIGXFSZ:
3394 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3395 break;
3396
3397 case SHUTDOWN1_SIGNAL:
3398 case SHUTDOWN2_SIGNAL:
3399 case SHUTDOWN3_SIGNAL:
3400 case BREAK_SIGNAL:
3401 jvmHandler = (address)user_handler();
3402 break;
3403
3404 case INTERRUPT_SIGNAL:
3405 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3406 break;
3407
3408 default:
3409 if (sig == SR_signum) {
3410 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3411 } else {
3412 return;
3413 }
3414 break;
3415 }
3416
3417 if (thisHandler != jvmHandler) {
3418 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3419 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3420 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3421 // No need to check this sig any longer
3422 sigaddset(&check_signal_done, sig);
3423 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3424 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3425 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3426 exception_name(sig, buf, O_BUFLEN));
3427 }
3428 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3429 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3430 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3431 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags);
3432 // No need to check this sig any longer
3433 sigaddset(&check_signal_done, sig);
3434 }
3435
3436 // Dump all the signal
3437 if (sigismember(&check_signal_done, sig)) {
3438 print_signal_handlers(tty, buf, O_BUFLEN);
3439 }
3440 }
3441
3442 extern void report_error(char* file_name, int line_no, char* title,
3443 char* format, ...);
3444
3445 extern bool signal_name(int signo, char* buf, size_t len);
3446
3447 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3448 if (0 < exception_code && exception_code <= SIGRTMAX) {
3449 // signal
3450 if (!signal_name(exception_code, buf, size)) {
3451 jio_snprintf(buf, size, "SIG%d", exception_code);
3452 }
3453 return buf;
3454 } else {
3455 return NULL;
3456 }
3457 }
3458
3459 // this is called _before_ the most of global arguments have been parsed
3460 void os::init(void) {
3461 char dummy; // used to get a guess on initial stack address
3462 // first_hrtime = gethrtime();
3463
3464 // With BsdThreads the JavaMain thread pid (primordial thread)
3465 // is different than the pid of the java launcher thread.
3466 // So, on Bsd, the launcher thread pid is passed to the VM
3467 // via the sun.java.launcher.pid property.
3468 // Use this property instead of getpid() if it was correctly passed.
3469 // See bug 6351349.
3470 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3471
3472 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3473
3474 clock_tics_per_sec = CLK_TCK;
3475
3476 init_random(1234567);
3477
3478 ThreadCritical::initialize();
3479
3480 Bsd::set_page_size(getpagesize());
3481 if (Bsd::page_size() == -1) {
3482 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3483 strerror(errno)));
3484 }
3485 init_page_sizes((size_t) Bsd::page_size());
3486
3487 Bsd::initialize_system_info();
3488
3489 // main_thread points to the aboriginal thread
3490 Bsd::_main_thread = pthread_self();
3491
3492 Bsd::clock_init();
3493 initial_time_count = javaTimeNanos();
3494
3495 #ifdef __APPLE__
3496 // XXXDARWIN
3497 // Work around the unaligned VM callbacks in hotspot's
3498 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3499 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3500 // alignment when doing symbol lookup. To work around this, we force early
3501 // binding of all symbols now, thus binding when alignment is known-good.
3502 _dyld_bind_fully_image_containing_address((const void *) &os::init);
3503 #endif
3504 }
3505
3506 // To install functions for atexit system call
3507 extern "C" {
3508 static void perfMemory_exit_helper() {
3509 perfMemory_exit();
3510 }
3511 }
3512
3513 // this is called _after_ the global arguments have been parsed
3514 jint os::init_2(void) {
3515 // Allocate a single page and mark it as readable for safepoint polling
3516 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3517 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page");
3518
3519 os::set_polling_page(polling_page);
3520
3521 #ifndef PRODUCT
3522 if (Verbose && PrintMiscellaneous) {
3523 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n",
3524 (intptr_t)polling_page);
3525 }
3526 #endif
3527
3528 if (!UseMembar) {
3529 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3530 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3531 os::set_memory_serialize_page(mem_serialize_page);
3532
3533 #ifndef PRODUCT
3534 if (Verbose && PrintMiscellaneous) {
3535 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n",
3536 (intptr_t)mem_serialize_page);
3537 }
3538 #endif
3539 }
3540
3541 // initialize suspend/resume support - must do this before signal_sets_init()
3542 if (SR_initialize() != 0) {
3543 perror("SR_initialize failed");
3544 return JNI_ERR;
3545 }
3546
3547 Bsd::signal_sets_init();
3548 Bsd::install_signal_handlers();
3549
3550 // Check minimum allowable stack size for thread creation and to initialize
3551 // the java system classes, including StackOverflowError - depends on page
3552 // size. Add a page for compiler2 recursion in main thread.
3553 // Add in 2*BytesPerWord times page size to account for VM stack during
3554 // class initialization depending on 32 or 64 bit VM.
3555 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3556 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3557 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3558
3559 size_t threadStackSizeInBytes = ThreadStackSize * K;
3560 if (threadStackSizeInBytes != 0 &&
3561 threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3562 tty->print_cr("\nThe stack size specified is too small, "
3563 "Specify at least %dk",
3564 os::Bsd::min_stack_allowed/ K);
3565 return JNI_ERR;
3566 }
3567
3568 // Make the stack size a multiple of the page size so that
3569 // the yellow/red zones can be guarded.
3570 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3571 vm_page_size()));
3572
3573 if (MaxFDLimit) {
3574 // set the number of file descriptors to max. print out error
3575 // if getrlimit/setrlimit fails but continue regardless.
3576 struct rlimit nbr_files;
3577 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3578 if (status != 0) {
3579 if (PrintMiscellaneous && (Verbose || WizardMode)) {
3580 perror("os::init_2 getrlimit failed");
3581 }
3582 } else {
3583 nbr_files.rlim_cur = nbr_files.rlim_max;
3584
3585 #ifdef __APPLE__
3586 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3587 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3588 // be used instead
3589 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3590 #endif
3591
3592 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3593 if (status != 0) {
3594 if (PrintMiscellaneous && (Verbose || WizardMode)) {
3595 perror("os::init_2 setrlimit failed");
3596 }
3597 }
3598 }
3599 }
3600
3601 // at-exit methods are called in the reverse order of their registration.
3602 // atexit functions are called on return from main or as a result of a
3603 // call to exit(3C). There can be only 32 of these functions registered
3604 // and atexit() does not set errno.
3605
3606 if (PerfAllowAtExitRegistration) {
3607 // only register atexit functions if PerfAllowAtExitRegistration is set.
3608 // atexit functions can be delayed until process exit time, which
3609 // can be problematic for embedded VM situations. Embedded VMs should
3610 // call DestroyJavaVM() to assure that VM resources are released.
3611
3612 // note: perfMemory_exit_helper atexit function may be removed in
3613 // the future if the appropriate cleanup code can be added to the
3614 // VM_Exit VMOperation's doit method.
3615 if (atexit(perfMemory_exit_helper) != 0) {
3616 warning("os::init2 atexit(perfMemory_exit_helper) failed");
3617 }
3618 }
3619
3620 // initialize thread priority policy
3621 prio_init();
3622
3623 #ifdef __APPLE__
3624 // dynamically link to objective c gc registration
3625 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3626 if (handleLibObjc != NULL) {
3627 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3628 }
3629 #endif
3630
3631 return JNI_OK;
3632 }
3633
3634 // Mark the polling page as unreadable
3635 void os::make_polling_page_unreadable(void) {
3636 if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3637 fatal("Could not disable polling page");
3638 }
3639 }
3640
3641 // Mark the polling page as readable
3642 void os::make_polling_page_readable(void) {
3643 if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3644 fatal("Could not enable polling page");
3645 }
3646 }
3647
3648 int os::active_processor_count() {
3649 return _processor_count;
3650 }
3651
3652 void os::set_native_thread_name(const char *name) {
3653 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3654 // This is only supported in Snow Leopard and beyond
3655 if (name != NULL) {
3656 // Add a "Java: " prefix to the name
3657 char buf[MAXTHREADNAMESIZE];
3658 snprintf(buf, sizeof(buf), "Java: %s", name);
3659 pthread_setname_np(buf);
3660 }
3661 #endif
3662 }
3663
3664 bool os::distribute_processes(uint length, uint* distribution) {
3665 // Not yet implemented.
3666 return false;
3667 }
3668
3669 bool os::bind_to_processor(uint processor_id) {
3670 // Not yet implemented.
3671 return false;
3672 }
3673
3674 void os::SuspendedThreadTask::internal_do_task() {
3675 if (do_suspend(_thread->osthread())) {
3676 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3677 do_task(context);
3678 do_resume(_thread->osthread());
3679 }
3680 }
3681
3682 ///
3683 class PcFetcher : public os::SuspendedThreadTask {
3684 public:
3685 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3686 ExtendedPC result();
3687 protected:
3688 void do_task(const os::SuspendedThreadTaskContext& context);
3689 private:
3690 ExtendedPC _epc;
3691 };
3692
3693 ExtendedPC PcFetcher::result() {
3694 guarantee(is_done(), "task is not done yet.");
3695 return _epc;
3696 }
3697
3698 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3699 Thread* thread = context.thread();
3700 OSThread* osthread = thread->osthread();
3701 if (osthread->ucontext() != NULL) {
3702 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
3703 } else {
3704 // NULL context is unexpected, double-check this is the VMThread
3705 guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3706 }
3707 }
3708
3709 // Suspends the target using the signal mechanism and then grabs the PC before
3710 // resuming the target. Used by the flat-profiler only
3711 ExtendedPC os::get_thread_pc(Thread* thread) {
3712 // Make sure that it is called by the watcher for the VMThread
3713 assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3714 assert(thread->is_VM_thread(), "Can only be called for VMThread");
3715
3716 PcFetcher fetcher(thread);
3717 fetcher.run();
3718 return fetcher.result();
3719 }
3720
3721 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond,
3722 pthread_mutex_t *_mutex,
3723 const struct timespec *_abstime) {
3724 return pthread_cond_timedwait(_cond, _mutex, _abstime);
3725 }
3726
3727 ////////////////////////////////////////////////////////////////////////////////
3728 // debug support
3729
3730 bool os::find(address addr, outputStream* st) {
3731 Dl_info dlinfo;
3732 memset(&dlinfo, 0, sizeof(dlinfo));
3733 if (dladdr(addr, &dlinfo) != 0) {
3734 st->print(PTR_FORMAT ": ", addr);
3735 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3736 st->print("%s+%#x", dlinfo.dli_sname,
3737 addr - (intptr_t)dlinfo.dli_saddr);
3738 } else if (dlinfo.dli_fbase != NULL) {
3739 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3740 } else {
3741 st->print("<absolute address>");
3742 }
3743 if (dlinfo.dli_fname != NULL) {
3744 st->print(" in %s", dlinfo.dli_fname);
3745 }
3746 if (dlinfo.dli_fbase != NULL) {
3747 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3748 }
3749 st->cr();
3750
3751 if (Verbose) {
3752 // decode some bytes around the PC
3753 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3754 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3755 address lowest = (address) dlinfo.dli_sname;
3756 if (!lowest) lowest = (address) dlinfo.dli_fbase;
3757 if (begin < lowest) begin = lowest;
3758 Dl_info dlinfo2;
3759 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3760 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3761 end = (address) dlinfo2.dli_saddr;
3762 }
3763 Disassembler::decode(begin, end, st);
3764 }
3765 return true;
3766 }
3767 return false;
3768 }
3769
3770 ////////////////////////////////////////////////////////////////////////////////
3771 // misc
3772
3773 // This does not do anything on Bsd. This is basically a hook for being
3774 // able to use structured exception handling (thread-local exception filters)
3775 // on, e.g., Win32.
3776 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3777 methodHandle* method, JavaCallArguments* args,
3778 Thread* thread) {
3779 f(value, method, args, thread);
3780 }
3781
3782 void os::print_statistics() {
3783 }
3784
3785 int os::message_box(const char* title, const char* message) {
3786 int i;
3787 fdStream err(defaultStream::error_fd());
3788 for (i = 0; i < 78; i++) err.print_raw("=");
3789 err.cr();
3790 err.print_raw_cr(title);
3791 for (i = 0; i < 78; i++) err.print_raw("-");
3792 err.cr();
3793 err.print_raw_cr(message);
3794 for (i = 0; i < 78; i++) err.print_raw("=");
3795 err.cr();
3796
3797 char buf[16];
3798 // Prevent process from exiting upon "read error" without consuming all CPU
3799 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3800
3801 return buf[0] == 'y' || buf[0] == 'Y';
3802 }
3803
3804 int os::stat(const char *path, struct stat *sbuf) {
3805 char pathbuf[MAX_PATH];
3806 if (strlen(path) > MAX_PATH - 1) {
3807 errno = ENAMETOOLONG;
3808 return -1;
3809 }
3810 os::native_path(strcpy(pathbuf, path));
3811 return ::stat(pathbuf, sbuf);
3812 }
3813
3814 bool os::check_heap(bool force) {
3815 return true;
3816 }
3817
3818 // Is a (classpath) directory empty?
3819 bool os::dir_is_empty(const char* path) {
3820 DIR *dir = NULL;
3821 struct dirent *ptr;
3822
3823 dir = opendir(path);
3824 if (dir == NULL) return true;
3825
3826 // Scan the directory
3827 bool result = true;
3828 char buf[sizeof(struct dirent) + MAX_PATH];
3829 while (result && (ptr = ::readdir(dir)) != NULL) {
3830 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3831 result = false;
3832 }
3833 }
3834 closedir(dir);
3835 return result;
3836 }
3837
3838 // This code originates from JDK's sysOpen and open64_w
3839 // from src/solaris/hpi/src/system_md.c
3840
3841 int os::open(const char *path, int oflag, int mode) {
3842 if (strlen(path) > MAX_PATH - 1) {
3843 errno = ENAMETOOLONG;
3844 return -1;
3845 }
3846 int fd;
3847
3848 fd = ::open(path, oflag, mode);
3849 if (fd == -1) return -1;
3850
3851 // If the open succeeded, the file might still be a directory
3852 {
3853 struct stat buf;
3854 int ret = ::fstat(fd, &buf);
3855 int st_mode = buf.st_mode;
3856
3857 if (ret != -1) {
3858 if ((st_mode & S_IFMT) == S_IFDIR) {
3859 errno = EISDIR;
3860 ::close(fd);
3861 return -1;
3862 }
3863 } else {
3864 ::close(fd);
3865 return -1;
3866 }
3867 }
3868
3869 // All file descriptors that are opened in the JVM and not
3870 // specifically destined for a subprocess should have the
3871 // close-on-exec flag set. If we don't set it, then careless 3rd
3872 // party native code might fork and exec without closing all
3873 // appropriate file descriptors (e.g. as we do in closeDescriptors in
3874 // UNIXProcess.c), and this in turn might:
3875 //
3876 // - cause end-of-file to fail to be detected on some file
3877 // descriptors, resulting in mysterious hangs, or
3878 //
3879 // - might cause an fopen in the subprocess to fail on a system
3880 // suffering from bug 1085341.
3881 //
3882 // (Yes, the default setting of the close-on-exec flag is a Unix
3883 // design flaw)
3884 //
3885 // See:
3886 // 1085341: 32-bit stdio routines should support file descriptors >255
3887 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3888 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3889 //
3890 #ifdef FD_CLOEXEC
3891 {
3892 int flags = ::fcntl(fd, F_GETFD);
3893 if (flags != -1) {
3894 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3895 }
3896 }
3897 #endif
3898
3899 return fd;
3900 }
3901
3902
3903 // create binary file, rewriting existing file if required
3904 int os::create_binary_file(const char* path, bool rewrite_existing) {
3905 int oflags = O_WRONLY | O_CREAT;
3906 if (!rewrite_existing) {
3907 oflags |= O_EXCL;
3908 }
3909 return ::open(path, oflags, S_IREAD | S_IWRITE);
3910 }
3911
3912 // return current position of file pointer
3913 jlong os::current_file_offset(int fd) {
3914 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3915 }
3916
3917 // move file pointer to the specified offset
3918 jlong os::seek_to_file_offset(int fd, jlong offset) {
3919 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3920 }
3921
3922 // This code originates from JDK's sysAvailable
3923 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3924
3925 int os::available(int fd, jlong *bytes) {
3926 jlong cur, end;
3927 int mode;
3928 struct stat buf;
3929
3930 if (::fstat(fd, &buf) >= 0) {
3931 mode = buf.st_mode;
3932 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3933 // XXX: is the following call interruptible? If so, this might
3934 // need to go through the INTERRUPT_IO() wrapper as for other
3935 // blocking, interruptible calls in this file.
3936 int n;
3937 if (::ioctl(fd, FIONREAD, &n) >= 0) {
3938 *bytes = n;
3939 return 1;
3940 }
3941 }
3942 }
3943 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3944 return 0;
3945 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3946 return 0;
3947 } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3948 return 0;
3949 }
3950 *bytes = end - cur;
3951 return 1;
3952 }
3953
3954 // Map a block of memory.
3955 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3956 char *addr, size_t bytes, bool read_only,
3957 bool allow_exec) {
3958 int prot;
3959 int flags;
3960
3961 if (read_only) {
3962 prot = PROT_READ;
3963 flags = MAP_SHARED;
3964 } else {
3965 prot = PROT_READ | PROT_WRITE;
3966 flags = MAP_PRIVATE;
3967 }
3968
3969 if (allow_exec) {
3970 prot |= PROT_EXEC;
3971 }
3972
3973 if (addr != NULL) {
3974 flags |= MAP_FIXED;
3975 }
3976
3977 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3978 fd, file_offset);
3979 if (mapped_address == MAP_FAILED) {
3980 return NULL;
3981 }
3982 return mapped_address;
3983 }
3984
3985
3986 // Remap a block of memory.
3987 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3988 char *addr, size_t bytes, bool read_only,
3989 bool allow_exec) {
3990 // same as map_memory() on this OS
3991 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3992 allow_exec);
3993 }
3994
3995
3996 // Unmap a block of memory.
3997 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3998 return munmap(addr, bytes) == 0;
3999 }
4000
4001 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
4002 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4003 // of a thread.
4004 //
4005 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4006 // the fast estimate available on the platform.
4007
4008 jlong os::current_thread_cpu_time() {
4009 #ifdef __APPLE__
4010 return os::thread_cpu_time(Thread::current(), true /* user + sys */);
4011 #else
4012 Unimplemented();
4013 return 0;
4014 #endif
4015 }
4016
4017 jlong os::thread_cpu_time(Thread* thread) {
4018 #ifdef __APPLE__
4019 return os::thread_cpu_time(thread, true /* user + sys */);
4020 #else
4021 Unimplemented();
4022 return 0;
4023 #endif
4024 }
4025
4026 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4027 #ifdef __APPLE__
4028 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4029 #else
4030 Unimplemented();
4031 return 0;
4032 #endif
4033 }
4034
4035 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4036 #ifdef __APPLE__
4037 struct thread_basic_info tinfo;
4038 mach_msg_type_number_t tcount = THREAD_INFO_MAX;
4039 kern_return_t kr;
4040 thread_t mach_thread;
4041
4042 mach_thread = thread->osthread()->thread_id();
4043 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
4044 if (kr != KERN_SUCCESS) {
4045 return -1;
4046 }
4047
4048 if (user_sys_cpu_time) {
4049 jlong nanos;
4050 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4051 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4052 return nanos;
4053 } else {
4054 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4055 }
4056 #else
4057 Unimplemented();
4058 return 0;
4059 #endif
4060 }
4061
4062
4063 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4064 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
4065 info_ptr->may_skip_backward = false; // elapsed time not wall time
4066 info_ptr->may_skip_forward = false; // elapsed time not wall time
4067 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
4068 }
4069
4070 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4071 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
4072 info_ptr->may_skip_backward = false; // elapsed time not wall time
4073 info_ptr->may_skip_forward = false; // elapsed time not wall time
4074 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
4075 }
4076
4077 bool os::is_thread_cpu_time_supported() {
4078 #ifdef __APPLE__
4079 return true;
4080 #else
4081 return false;
4082 #endif
4083 }
4084
4085 // System loadavg support. Returns -1 if load average cannot be obtained.
4086 // Bsd doesn't yet have a (official) notion of processor sets,
4087 // so just return the system wide load average.
4088 int os::loadavg(double loadavg[], int nelem) {
4089 return ::getloadavg(loadavg, nelem);
4090 }
4091
4092 void os::pause() {
4093 char filename[MAX_PATH];
4094 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4095 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4096 } else {
4097 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4098 }
4099
4100 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4101 if (fd != -1) {
4102 struct stat buf;
4103 ::close(fd);
4104 while (::stat(filename, &buf) == 0) {
4105 (void)::poll(NULL, 0, 100);
4106 }
4107 } else {
4108 jio_fprintf(stderr,
4109 "Could not open pause file '%s', continuing immediately.\n", filename);
4110 }
4111 }
4112
4113
4114 // Refer to the comments in os_solaris.cpp park-unpark. The next two
4115 // comment paragraphs are worth repeating here:
4116 //
4117 // Assumption:
4118 // Only one parker can exist on an event, which is why we allocate
4119 // them per-thread. Multiple unparkers can coexist.
4120 //
4121 // _Event serves as a restricted-range semaphore.
4122 // -1 : thread is blocked, i.e. there is a waiter
4123 // 0 : neutral: thread is running or ready,
4124 // could have been signaled after a wait started
4125 // 1 : signaled - thread is running or ready
4126 //
4127 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4128 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4129 // For specifics regarding the bug see GLIBC BUGID 261237 :
4130 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4131 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4132 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4133 // is used. (The simple C test-case provided in the GLIBC bug report manifests the
4134 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4135 // and monitorenter when we're using 1-0 locking. All those operations may result in
4136 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version
4137 // of libpthread avoids the problem, but isn't practical.
4138 //
4139 // Possible remedies:
4140 //
4141 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work.
4142 // This is palliative and probabilistic, however. If the thread is preempted
4143 // between the call to compute_abstime() and pthread_cond_timedwait(), more
4144 // than the minimum period may have passed, and the abstime may be stale (in the
4145 // past) resultin in a hang. Using this technique reduces the odds of a hang
4146 // but the JVM is still vulnerable, particularly on heavily loaded systems.
4147 //
4148 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4149 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set
4150 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4151 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant
4152 // thread.
4153 //
4154 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread
4155 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing
4156 // a timeout request to the chron thread and then blocking via pthread_cond_wait().
4157 // This also works well. In fact it avoids kernel-level scalability impediments
4158 // on certain platforms that don't handle lots of active pthread_cond_timedwait()
4159 // timers in a graceful fashion.
4160 //
4161 // 4. When the abstime value is in the past it appears that control returns
4162 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4163 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we
4164 // can avoid the problem by reinitializing the condvar -- by cond_destroy()
4165 // followed by cond_init() -- after all calls to pthread_cond_timedwait().
4166 // It may be possible to avoid reinitialization by checking the return
4167 // value from pthread_cond_timedwait(). In addition to reinitializing the
4168 // condvar we must establish the invariant that cond_signal() is only called
4169 // within critical sections protected by the adjunct mutex. This prevents
4170 // cond_signal() from "seeing" a condvar that's in the midst of being
4171 // reinitialized or that is corrupt. Sadly, this invariant obviates the
4172 // desirable signal-after-unlock optimization that avoids futile context switching.
4173 //
4174 // I'm also concerned that some versions of NTPL might allocate an auxilliary
4175 // structure when a condvar is used or initialized. cond_destroy() would
4176 // release the helper structure. Our reinitialize-after-timedwait fix
4177 // put excessive stress on malloc/free and locks protecting the c-heap.
4178 //
4179 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag.
4180 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4181 // and only enabling the work-around for vulnerable environments.
4182
4183 // utility to compute the abstime argument to timedwait:
4184 // millis is the relative timeout time
4185 // abstime will be the absolute timeout time
4186 // TODO: replace compute_abstime() with unpackTime()
4187
4188 static struct timespec* compute_abstime(struct timespec* abstime,
4189 jlong millis) {
4190 if (millis < 0) millis = 0;
4191 struct timeval now;
4192 int status = gettimeofday(&now, NULL);
4193 assert(status == 0, "gettimeofday");
4194 jlong seconds = millis / 1000;
4195 millis %= 1000;
4196 if (seconds > 50000000) { // see man cond_timedwait(3T)
4197 seconds = 50000000;
4198 }
4199 abstime->tv_sec = now.tv_sec + seconds;
4200 long usec = now.tv_usec + millis * 1000;
4201 if (usec >= 1000000) {
4202 abstime->tv_sec += 1;
4203 usec -= 1000000;
4204 }
4205 abstime->tv_nsec = usec * 1000;
4206 return abstime;
4207 }
4208
4209 void os::PlatformEvent::park() { // AKA "down()"
4210 // Transitions for _Event:
4211 // -1 => -1 : illegal
4212 // 1 => 0 : pass - return immediately
4213 // 0 => -1 : block; then set _Event to 0 before returning
4214
4215 // Invariant: Only the thread associated with the Event/PlatformEvent
4216 // may call park().
4217 // TODO: assert that _Assoc != NULL or _Assoc == Self
4218 assert(_nParked == 0, "invariant");
4219
4220 int v;
4221 for (;;) {
4222 v = _Event;
4223 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4224 }
4225 guarantee(v >= 0, "invariant");
4226 if (v == 0) {
4227 // Do this the hard way by blocking ...
4228 int status = pthread_mutex_lock(_mutex);
4229 assert_status(status == 0, status, "mutex_lock");
4230 guarantee(_nParked == 0, "invariant");
4231 ++_nParked;
4232 while (_Event < 0) {
4233 status = pthread_cond_wait(_cond, _mutex);
4234 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4235 // Treat this the same as if the wait was interrupted
4236 if (status == ETIMEDOUT) { status = EINTR; }
4237 assert_status(status == 0 || status == EINTR, status, "cond_wait");
4238 }
4239 --_nParked;
4240
4241 _Event = 0;
4242 status = pthread_mutex_unlock(_mutex);
4243 assert_status(status == 0, status, "mutex_unlock");
4244 // Paranoia to ensure our locked and lock-free paths interact
4245 // correctly with each other.
4246 OrderAccess::fence();
4247 }
4248 guarantee(_Event >= 0, "invariant");
4249 }
4250
4251 int os::PlatformEvent::park(jlong millis) {
4252 // Transitions for _Event:
4253 // -1 => -1 : illegal
4254 // 1 => 0 : pass - return immediately
4255 // 0 => -1 : block; then set _Event to 0 before returning
4256
4257 guarantee(_nParked == 0, "invariant");
4258
4259 int v;
4260 for (;;) {
4261 v = _Event;
4262 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4263 }
4264 guarantee(v >= 0, "invariant");
4265 if (v != 0) return OS_OK;
4266
4267 // We do this the hard way, by blocking the thread.
4268 // Consider enforcing a minimum timeout value.
4269 struct timespec abst;
4270 compute_abstime(&abst, millis);
4271
4272 int ret = OS_TIMEOUT;
4273 int status = pthread_mutex_lock(_mutex);
4274 assert_status(status == 0, status, "mutex_lock");
4275 guarantee(_nParked == 0, "invariant");
4276 ++_nParked;
4277
4278 // Object.wait(timo) will return because of
4279 // (a) notification
4280 // (b) timeout
4281 // (c) thread.interrupt
4282 //
4283 // Thread.interrupt and object.notify{All} both call Event::set.
4284 // That is, we treat thread.interrupt as a special case of notification.
4285 // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false.
4286 // We assume all ETIME returns are valid.
4287 //
4288 // TODO: properly differentiate simultaneous notify+interrupt.
4289 // In that case, we should propagate the notify to another waiter.
4290
4291 while (_Event < 0) {
4292 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4293 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4294 pthread_cond_destroy(_cond);
4295 pthread_cond_init(_cond, NULL);
4296 }
4297 assert_status(status == 0 || status == EINTR ||
4298 status == ETIMEDOUT,
4299 status, "cond_timedwait");
4300 if (!FilterSpuriousWakeups) break; // previous semantics
4301 if (status == ETIMEDOUT) break;
4302 // We consume and ignore EINTR and spurious wakeups.
4303 }
4304 --_nParked;
4305 if (_Event >= 0) {
4306 ret = OS_OK;
4307 }
4308 _Event = 0;
4309 status = pthread_mutex_unlock(_mutex);
4310 assert_status(status == 0, status, "mutex_unlock");
4311 assert(_nParked == 0, "invariant");
4312 // Paranoia to ensure our locked and lock-free paths interact
4313 // correctly with each other.
4314 OrderAccess::fence();
4315 return ret;
4316 }
4317
4318 void os::PlatformEvent::unpark() {
4319 // Transitions for _Event:
4320 // 0 => 1 : just return
4321 // 1 => 1 : just return
4322 // -1 => either 0 or 1; must signal target thread
4323 // That is, we can safely transition _Event from -1 to either
4324 // 0 or 1.
4325 // See also: "Semaphores in Plan 9" by Mullender & Cox
4326 //
4327 // Note: Forcing a transition from "-1" to "1" on an unpark() means
4328 // that it will take two back-to-back park() calls for the owning
4329 // thread to block. This has the benefit of forcing a spurious return
4330 // from the first park() call after an unpark() call which will help
4331 // shake out uses of park() and unpark() without condition variables.
4332
4333 if (Atomic::xchg(1, &_Event) >= 0) return;
4334
4335 // Wait for the thread associated with the event to vacate
4336 int status = pthread_mutex_lock(_mutex);
4337 assert_status(status == 0, status, "mutex_lock");
4338 int AnyWaiters = _nParked;
4339 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4340 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4341 AnyWaiters = 0;
4342 pthread_cond_signal(_cond);
4343 }
4344 status = pthread_mutex_unlock(_mutex);
4345 assert_status(status == 0, status, "mutex_unlock");
4346 if (AnyWaiters != 0) {
4347 // Note that we signal() *after* dropping the lock for "immortal" Events.
4348 // This is safe and avoids a common class of futile wakeups. In rare
4349 // circumstances this can cause a thread to return prematurely from
4350 // cond_{timed}wait() but the spurious wakeup is benign and the victim
4351 // will simply re-test the condition and re-park itself.
4352 // This provides particular benefit if the underlying platform does not
4353 // provide wait morphing.
4354 status = pthread_cond_signal(_cond);
4355 assert_status(status == 0, status, "cond_signal");
4356 }
4357 }
4358
4359
4360 // JSR166
4361 // -------------------------------------------------------
4362
4363 // The solaris and bsd implementations of park/unpark are fairly
4364 // conservative for now, but can be improved. They currently use a
4365 // mutex/condvar pair, plus a a count.
4366 // Park decrements count if > 0, else does a condvar wait. Unpark
4367 // sets count to 1 and signals condvar. Only one thread ever waits
4368 // on the condvar. Contention seen when trying to park implies that someone
4369 // is unparking you, so don't wait. And spurious returns are fine, so there
4370 // is no need to track notifications.
4371
4372 #define MAX_SECS 100000000
4373
4374 // This code is common to bsd and solaris and will be moved to a
4375 // common place in dolphin.
4376 //
4377 // The passed in time value is either a relative time in nanoseconds
4378 // or an absolute time in milliseconds. Either way it has to be unpacked
4379 // into suitable seconds and nanoseconds components and stored in the
4380 // given timespec structure.
4381 // Given time is a 64-bit value and the time_t used in the timespec is only
4382 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4383 // overflow if times way in the future are given. Further on Solaris versions
4384 // prior to 10 there is a restriction (see cond_timedwait) that the specified
4385 // number of seconds, in abstime, is less than current_time + 100,000,000.
4386 // As it will be 28 years before "now + 100000000" will overflow we can
4387 // ignore overflow and just impose a hard-limit on seconds using the value
4388 // of "now + 100,000,000". This places a limit on the timeout of about 3.17
4389 // years from "now".
4390
4391 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4392 assert(time > 0, "convertTime");
4393
4394 struct timeval now;
4395 int status = gettimeofday(&now, NULL);
4396 assert(status == 0, "gettimeofday");
4397
4398 time_t max_secs = now.tv_sec + MAX_SECS;
4399
4400 if (isAbsolute) {
4401 jlong secs = time / 1000;
4402 if (secs > max_secs) {
4403 absTime->tv_sec = max_secs;
4404 } else {
4405 absTime->tv_sec = secs;
4406 }
4407 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4408 } else {
4409 jlong secs = time / NANOSECS_PER_SEC;
4410 if (secs >= MAX_SECS) {
4411 absTime->tv_sec = max_secs;
4412 absTime->tv_nsec = 0;
4413 } else {
4414 absTime->tv_sec = now.tv_sec + secs;
4415 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4416 if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4417 absTime->tv_nsec -= NANOSECS_PER_SEC;
4418 ++absTime->tv_sec; // note: this must be <= max_secs
4419 }
4420 }
4421 }
4422 assert(absTime->tv_sec >= 0, "tv_sec < 0");
4423 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4424 assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4425 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4426 }
4427
4428 void Parker::park(bool isAbsolute, jlong time) {
4429 // Ideally we'd do something useful while spinning, such
4430 // as calling unpackTime().
4431
4432 // Optional fast-path check:
4433 // Return immediately if a permit is available.
4434 // We depend on Atomic::xchg() having full barrier semantics
4435 // since we are doing a lock-free update to _counter.
4436 if (Atomic::xchg(0, &_counter) > 0) return;
4437
4438 Thread* thread = Thread::current();
4439 assert(thread->is_Java_thread(), "Must be JavaThread");
4440 JavaThread *jt = (JavaThread *)thread;
4441
4442 // Optional optimization -- avoid state transitions if there's an interrupt pending.
4443 // Check interrupt before trying to wait
4444 if (Thread::is_interrupted(thread, false)) {
4445 return;
4446 }
4447
4448 // Next, demultiplex/decode time arguments
4449 struct timespec absTime;
4450 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
4451 return;
4452 }
4453 if (time > 0) {
4454 unpackTime(&absTime, isAbsolute, time);
4455 }
4456
4457
4458 // Enter safepoint region
4459 // Beware of deadlocks such as 6317397.
4460 // The per-thread Parker:: mutex is a classic leaf-lock.
4461 // In particular a thread must never block on the Threads_lock while
4462 // holding the Parker:: mutex. If safepoints are pending both the
4463 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4464 ThreadBlockInVM tbivm(jt);
4465
4466 // Don't wait if cannot get lock since interference arises from
4467 // unblocking. Also. check interrupt before trying wait
4468 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4469 return;
4470 }
4471
4472 int status;
4473 if (_counter > 0) { // no wait needed
4474 _counter = 0;
4475 status = pthread_mutex_unlock(_mutex);
4476 assert(status == 0, "invariant");
4477 // Paranoia to ensure our locked and lock-free paths interact
4478 // correctly with each other and Java-level accesses.
4479 OrderAccess::fence();
4480 return;
4481 }
4482
4483 #ifdef ASSERT
4484 // Don't catch signals while blocked; let the running threads have the signals.
4485 // (This allows a debugger to break into the running thread.)
4486 sigset_t oldsigs;
4487 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4488 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4489 #endif
4490
4491 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4492 jt->set_suspend_equivalent();
4493 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4494
4495 if (time == 0) {
4496 status = pthread_cond_wait(_cond, _mutex);
4497 } else {
4498 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &absTime);
4499 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4500 pthread_cond_destroy(_cond);
4501 pthread_cond_init(_cond, NULL);
4502 }
4503 }
4504 assert_status(status == 0 || status == EINTR ||
4505 status == ETIMEDOUT,
4506 status, "cond_timedwait");
4507
4508 #ifdef ASSERT
4509 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4510 #endif
4511
4512 _counter = 0;
4513 status = pthread_mutex_unlock(_mutex);
4514 assert_status(status == 0, status, "invariant");
4515 // Paranoia to ensure our locked and lock-free paths interact
4516 // correctly with each other and Java-level accesses.
4517 OrderAccess::fence();
4518
4519 // If externally suspended while waiting, re-suspend
4520 if (jt->handle_special_suspend_equivalent_condition()) {
4521 jt->java_suspend_self();
4522 }
4523 }
4524
4525 void Parker::unpark() {
4526 int status = pthread_mutex_lock(_mutex);
4527 assert(status == 0, "invariant");
4528 const int s = _counter;
4529 _counter = 1;
4530 if (s < 1) {
4531 if (WorkAroundNPTLTimedWaitHang) {
4532 status = pthread_cond_signal(_cond);
4533 assert(status == 0, "invariant");
4534 status = pthread_mutex_unlock(_mutex);
4535 assert(status == 0, "invariant");
4536 } else {
4537 status = pthread_mutex_unlock(_mutex);
4538 assert(status == 0, "invariant");
4539 status = pthread_cond_signal(_cond);
4540 assert(status == 0, "invariant");
4541 }
4542 } else {
4543 pthread_mutex_unlock(_mutex);
4544 assert(status == 0, "invariant");
4545 }
4546 }
4547
4548
4549 // Darwin has no "environ" in a dynamic library.
4550 #ifdef __APPLE__
4551 #include <crt_externs.h>
4552 #define environ (*_NSGetEnviron())
4553 #else
4554 extern char** environ;
4555 #endif
4556
4557 // Run the specified command in a separate process. Return its exit value,
4558 // or -1 on failure (e.g. can't fork a new process).
4559 // Unlike system(), this function can be called from signal handler. It
4560 // doesn't block SIGINT et al.
4561 int os::fork_and_exec(char* cmd) {
4562 const char * argv[4] = {"sh", "-c", cmd, NULL};
4563
4564 // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4565 // pthread_atfork handlers and reset pthread library. All we need is a
4566 // separate process to execve. Make a direct syscall to fork process.
4567 // On IA64 there's no fork syscall, we have to use fork() and hope for
4568 // the best...
4569 pid_t pid = fork();
4570
4571 if (pid < 0) {
4572 // fork failed
4573 return -1;
4574
4575 } else if (pid == 0) {
4576 // child process
4577
4578 // execve() in BsdThreads will call pthread_kill_other_threads_np()
4579 // first to kill every thread on the thread list. Because this list is
4580 // not reset by fork() (see notes above), execve() will instead kill
4581 // every thread in the parent process. We know this is the only thread
4582 // in the new process, so make a system call directly.
4583 // IA64 should use normal execve() from glibc to match the glibc fork()
4584 // above.
4585 execve("/bin/sh", (char* const*)argv, environ);
4586
4587 // execve failed
4588 _exit(-1);
4589
4590 } else {
4591 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4592 // care about the actual exit code, for now.
4593
4594 int status;
4595
4596 // Wait for the child process to exit. This returns immediately if
4597 // the child has already exited. */
4598 while (waitpid(pid, &status, 0) < 0) {
4599 switch (errno) {
4600 case ECHILD: return 0;
4601 case EINTR: break;
4602 default: return -1;
4603 }
4604 }
4605
4606 if (WIFEXITED(status)) {
4607 // The child exited normally; get its exit code.
4608 return WEXITSTATUS(status);
4609 } else if (WIFSIGNALED(status)) {
4610 // The child exited because of a signal
4611 // The best value to return is 0x80 + signal number,
4612 // because that is what all Unix shells do, and because
4613 // it allows callers to distinguish between process exit and
4614 // process death by signal.
4615 return 0x80 + WTERMSIG(status);
4616 } else {
4617 // Unknown exit code; pass it through
4618 return status;
4619 }
4620 }
4621 }
4622
4623 // is_headless_jre()
4624 //
4625 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4626 // in order to report if we are running in a headless jre
4627 //
4628 // Since JDK8 xawt/libmawt.so was moved into the same directory
4629 // as libawt.so, and renamed libawt_xawt.so
4630 //
4631 bool os::is_headless_jre() {
4632 #ifdef __APPLE__
4633 // We no longer build headless-only on Mac OS X
4634 return false;
4635 #else
4636 struct stat statbuf;
4637 char buf[MAXPATHLEN];
4638 char libmawtpath[MAXPATHLEN];
4639 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX;
4640 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4641 char *p;
4642
4643 // Get path to libjvm.so
4644 os::jvm_path(buf, sizeof(buf));
4645
4646 // Get rid of libjvm.so
4647 p = strrchr(buf, '/');
4648 if (p == NULL) {
4649 return false;
4650 } else {
4651 *p = '\0';
4652 }
4653
4654 // Get rid of client or server
4655 p = strrchr(buf, '/');
4656 if (p == NULL) {
4657 return false;
4658 } else {
4659 *p = '\0';
4660 }
4661
4662 // check xawt/libmawt.so
4663 strcpy(libmawtpath, buf);
4664 strcat(libmawtpath, xawtstr);
4665 if (::stat(libmawtpath, &statbuf) == 0) return false;
4666
4667 // check libawt_xawt.so
4668 strcpy(libmawtpath, buf);
4669 strcat(libmawtpath, new_xawtstr);
4670 if (::stat(libmawtpath, &statbuf) == 0) return false;
4671
4672 return true;
4673 #endif
4674 }
4675
4676 // Get the default path to the core file
4677 // Returns the length of the string
4678 int os::get_core_path(char* buffer, size_t bufferSize) {
4679 int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
4680
4681 // Truncate if theoretical string was longer than bufferSize
4682 n = MIN2(n, (int)bufferSize);
4683
4684 return n;
4685 }
4686
4687 #ifndef PRODUCT
4688 void TestReserveMemorySpecial_test() {
4689 // No tests available for this platform
4690 }
4691 #endif