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