1 /*
2 * Copyright (c) 1999, 2019, 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 "jvm.h"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/icBuffer.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "compiler/compileBroker.hpp"
33 #include "compiler/disassembler.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "logging/log.hpp"
36 #include "logging/logStream.hpp"
37 #include "memory/allocation.inline.hpp"
38 #include "memory/filemap.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "os_bsd.inline.hpp"
41 #include "os_posix.inline.hpp"
42 #include "os_share_bsd.hpp"
43 #include "prims/jniFastGetField.hpp"
44 #include "prims/jvm_misc.hpp"
45 #include "runtime/arguments.hpp"
46 #include "runtime/atomic.hpp"
47 #include "runtime/extendedPC.hpp"
48 #include "runtime/globals.hpp"
49 #include "runtime/interfaceSupport.inline.hpp"
50 #include "runtime/java.hpp"
51 #include "runtime/javaCalls.hpp"
52 #include "runtime/mutexLocker.hpp"
53 #include "runtime/objectMonitor.hpp"
54 #include "runtime/orderAccess.hpp"
55 #include "runtime/osThread.hpp"
56 #include "runtime/perfMemory.hpp"
57 #include "runtime/semaphore.hpp"
58 #include "runtime/sharedRuntime.hpp"
59 #include "runtime/statSampler.hpp"
60 #include "runtime/stubRoutines.hpp"
61 #include "runtime/thread.inline.hpp"
62 #include "runtime/threadCritical.hpp"
63 #include "runtime/timer.hpp"
64 #include "services/attachListener.hpp"
65 #include "services/memTracker.hpp"
66 #include "services/runtimeService.hpp"
67 #include "utilities/align.hpp"
68 #include "utilities/decoder.hpp"
69 #include "utilities/defaultStream.hpp"
70 #include "utilities/events.hpp"
71 #include "utilities/growableArray.hpp"
72 #include "utilities/vmError.hpp"
73
74 // put OS-includes here
75 # include <dlfcn.h>
76 # include <errno.h>
77 # include <fcntl.h>
78 # include <inttypes.h>
79 # include <poll.h>
80 # include <pthread.h>
81 # include <pwd.h>
82 # include <signal.h>
83 # include <stdint.h>
84 # include <stdio.h>
85 # include <string.h>
86 # include <sys/ioctl.h>
87 # include <sys/mman.h>
88 # include <sys/param.h>
89 # include <sys/resource.h>
90 # include <sys/socket.h>
91 # include <sys/stat.h>
92 # include <sys/syscall.h>
93 # include <sys/sysctl.h>
94 # include <sys/time.h>
95 # include <sys/times.h>
96 # include <sys/types.h>
97 # include <sys/wait.h>
98 # include <time.h>
99 # include <unistd.h>
100
101 #if defined(__FreeBSD__) || defined(__NetBSD__)
102 #include <elf.h>
103 #endif
104
105 #ifdef __APPLE__
106 #include <mach-o/dyld.h>
107 #endif
108
109 #ifndef MAP_ANONYMOUS
110 #define MAP_ANONYMOUS MAP_ANON
111 #endif
112
113 #define MAX_PATH (2 * K)
114
115 // for timer info max values which include all bits
116 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
117
118 ////////////////////////////////////////////////////////////////////////////////
119 // global variables
120 julong os::Bsd::_physical_memory = 0;
121
122 #ifdef __APPLE__
123 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
124 volatile uint64_t os::Bsd::_max_abstime = 0;
125 #else
126 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
127 #endif
128 pthread_t os::Bsd::_main_thread;
129 int os::Bsd::_page_size = -1;
130
131 static jlong initial_time_count=0;
132
133 static int clock_tics_per_sec = 100;
134
135 // For diagnostics to print a message once. see run_periodic_checks
136 static sigset_t check_signal_done;
137 static bool check_signals = true;
138
139 // Signal number used to suspend/resume a thread
140
141 // do not use any signal number less than SIGSEGV, see 4355769
142 static int SR_signum = SIGUSR2;
143 sigset_t SR_sigset;
144
145
146 ////////////////////////////////////////////////////////////////////////////////
147 // utility functions
148
149 static int SR_initialize();
150
151 julong os::available_memory() {
152 return Bsd::available_memory();
153 }
154
155 // available here means free
156 julong os::Bsd::available_memory() {
157 uint64_t available = physical_memory() >> 2;
158 #ifdef __APPLE__
159 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
160 vm_statistics64_data_t vmstat;
161 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
162 (host_info64_t)&vmstat, &count);
163 assert(kerr == KERN_SUCCESS,
164 "host_statistics64 failed - check mach_host_self() and count");
165 if (kerr == KERN_SUCCESS) {
166 available = vmstat.free_count * os::vm_page_size();
167 }
168 #endif
169 return available;
170 }
171
172 julong os::physical_memory() {
173 return Bsd::physical_memory();
174 }
175
176 // Return true if user is running as root.
177
178 bool os::have_special_privileges() {
179 static bool init = false;
180 static bool privileges = false;
181 if (!init) {
182 privileges = (getuid() != geteuid()) || (getgid() != getegid());
183 init = true;
184 }
185 return privileges;
186 }
187
188
189
190 // Cpu architecture string
191 #if defined(ZERO)
192 static char cpu_arch[] = ZERO_LIBARCH;
193 #elif defined(IA64)
194 static char cpu_arch[] = "ia64";
195 #elif defined(IA32)
196 static char cpu_arch[] = "i386";
197 #elif defined(AMD64)
198 static char cpu_arch[] = "amd64";
199 #elif defined(ARM)
200 static char cpu_arch[] = "arm";
201 #elif defined(PPC32)
202 static char cpu_arch[] = "ppc";
203 #elif defined(SPARC)
204 #ifdef _LP64
205 static char cpu_arch[] = "sparcv9";
206 #else
207 static char cpu_arch[] = "sparc";
208 #endif
209 #else
210 #error Add appropriate cpu_arch setting
211 #endif
212
213 // Compiler variant
214 #ifdef COMPILER2
215 #define COMPILER_VARIANT "server"
216 #else
217 #define COMPILER_VARIANT "client"
218 #endif
219
220
221 void os::Bsd::initialize_system_info() {
222 int mib[2];
223 size_t len;
224 int cpu_val;
225 julong mem_val;
226
227 // get processors count via hw.ncpus sysctl
228 mib[0] = CTL_HW;
229 mib[1] = HW_NCPU;
230 len = sizeof(cpu_val);
231 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
232 assert(len == sizeof(cpu_val), "unexpected data size");
233 set_processor_count(cpu_val);
234 } else {
235 set_processor_count(1); // fallback
236 }
237
238 // get physical memory via hw.memsize sysctl (hw.memsize is used
239 // since it returns a 64 bit value)
240 mib[0] = CTL_HW;
241
242 #if defined (HW_MEMSIZE) // Apple
243 mib[1] = HW_MEMSIZE;
244 #elif defined(HW_PHYSMEM) // Most of BSD
245 mib[1] = HW_PHYSMEM;
246 #elif defined(HW_REALMEM) // Old FreeBSD
247 mib[1] = HW_REALMEM;
248 #else
249 #error No ways to get physmem
250 #endif
251
252 len = sizeof(mem_val);
253 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
254 assert(len == sizeof(mem_val), "unexpected data size");
255 _physical_memory = mem_val;
256 } else {
257 _physical_memory = 256 * 1024 * 1024; // fallback (XXXBSD?)
258 }
259
260 #ifdef __OpenBSD__
261 {
262 // limit _physical_memory memory view on OpenBSD since
263 // datasize rlimit restricts us anyway.
264 struct rlimit limits;
265 getrlimit(RLIMIT_DATA, &limits);
266 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
267 }
268 #endif
269 }
270
271 #ifdef __APPLE__
272 static const char *get_home() {
273 const char *home_dir = ::getenv("HOME");
274 if ((home_dir == NULL) || (*home_dir == '\0')) {
275 struct passwd *passwd_info = getpwuid(geteuid());
276 if (passwd_info != NULL) {
277 home_dir = passwd_info->pw_dir;
278 }
279 }
280
281 return home_dir;
282 }
283 #endif
284
285 void os::init_system_properties_values() {
286 // The next steps are taken in the product version:
287 //
288 // Obtain the JAVA_HOME value from the location of libjvm.so.
289 // This library should be located at:
290 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
291 //
292 // If "/jre/lib/" appears at the right place in the path, then we
293 // assume libjvm.so is installed in a JDK and we use this path.
294 //
295 // Otherwise exit with message: "Could not create the Java virtual machine."
296 //
297 // The following extra steps are taken in the debugging version:
298 //
299 // If "/jre/lib/" does NOT appear at the right place in the path
300 // instead of exit check for $JAVA_HOME environment variable.
301 //
302 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
303 // then we append a fake suffix "hotspot/libjvm.so" to this path so
304 // it looks like libjvm.so is installed there
305 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
306 //
307 // Otherwise exit.
308 //
309 // Important note: if the location of libjvm.so changes this
310 // code needs to be changed accordingly.
311
312 // See ld(1):
313 // The linker uses the following search paths to locate required
314 // shared libraries:
315 // 1: ...
316 // ...
317 // 7: The default directories, normally /lib and /usr/lib.
318 #ifndef DEFAULT_LIBPATH
319 #ifndef OVERRIDE_LIBPATH
320 #define DEFAULT_LIBPATH "/lib:/usr/lib"
321 #else
322 #define DEFAULT_LIBPATH OVERRIDE_LIBPATH
323 #endif
324 #endif
325
326 // Base path of extensions installed on the system.
327 #define SYS_EXT_DIR "/usr/java/packages"
328 #define EXTENSIONS_DIR "/lib/ext"
329
330 #ifndef __APPLE__
331
332 // Buffer that fits several sprintfs.
333 // Note that the space for the colon and the trailing null are provided
334 // by the nulls included by the sizeof operator.
335 const size_t bufsize =
336 MAX2((size_t)MAXPATHLEN, // For dll_dir & friends.
337 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR)); // extensions dir
338 char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
339
340 // sysclasspath, java_home, dll_dir
341 {
342 char *pslash;
343 os::jvm_path(buf, bufsize);
344
345 // Found the full path to libjvm.so.
346 // Now cut the path to <java_home>/jre if we can.
347 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
348 pslash = strrchr(buf, '/');
349 if (pslash != NULL) {
350 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
351 }
352 Arguments::set_dll_dir(buf);
353
354 if (pslash != NULL) {
355 pslash = strrchr(buf, '/');
356 if (pslash != NULL) {
357 *pslash = '\0'; // Get rid of /<arch>.
358 pslash = strrchr(buf, '/');
359 if (pslash != NULL) {
360 *pslash = '\0'; // Get rid of /lib.
361 }
362 }
363 }
364 Arguments::set_java_home(buf);
365 if (!set_boot_path('/', ':')) {
366 vm_exit_during_initialization("Failed setting boot class path.", NULL);
367 }
368 }
369
370 // Where to look for native libraries.
371 //
372 // Note: Due to a legacy implementation, most of the library path
373 // is set in the launcher. This was to accomodate linking restrictions
374 // on legacy Bsd implementations (which are no longer supported).
375 // Eventually, all the library path setting will be done here.
376 //
377 // However, to prevent the proliferation of improperly built native
378 // libraries, the new path component /usr/java/packages is added here.
379 // Eventually, all the library path setting will be done here.
380 {
381 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
382 // should always exist (until the legacy problem cited above is
383 // addressed).
384 const char *v = ::getenv("LD_LIBRARY_PATH");
385 const char *v_colon = ":";
386 if (v == NULL) { v = ""; v_colon = ""; }
387 // That's +1 for the colon and +1 for the trailing '\0'.
388 char *ld_library_path = NEW_C_HEAP_ARRAY(char,
389 strlen(v) + 1 +
390 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
391 mtInternal);
392 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
393 Arguments::set_library_path(ld_library_path);
394 FREE_C_HEAP_ARRAY(char, ld_library_path);
395 }
396
397 // Extensions directories.
398 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
399 Arguments::set_ext_dirs(buf);
400
401 FREE_C_HEAP_ARRAY(char, buf);
402
403 #else // __APPLE__
404
405 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions"
406 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
407
408 const char *user_home_dir = get_home();
409 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
410 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
411 sizeof(SYS_EXTENSIONS_DIRS);
412
413 // Buffer that fits several sprintfs.
414 // Note that the space for the colon and the trailing null are provided
415 // by the nulls included by the sizeof operator.
416 const size_t bufsize =
417 MAX2((size_t)MAXPATHLEN, // for dll_dir & friends.
418 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size); // extensions dir
419 char *buf = NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
420
421 // sysclasspath, java_home, dll_dir
422 {
423 char *pslash;
424 os::jvm_path(buf, bufsize);
425
426 // Found the full path to libjvm.so.
427 // Now cut the path to <java_home>/jre if we can.
428 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
429 pslash = strrchr(buf, '/');
430 if (pslash != NULL) {
431 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
432 }
433 #ifdef STATIC_BUILD
434 strcat(buf, "/lib");
435 #endif
436
437 Arguments::set_dll_dir(buf);
438
439 if (pslash != NULL) {
440 pslash = strrchr(buf, '/');
441 if (pslash != NULL) {
442 *pslash = '\0'; // Get rid of /lib.
443 }
444 }
445 Arguments::set_java_home(buf);
446 set_boot_path('/', ':');
447 }
448
449 // Where to look for native libraries.
450 //
451 // Note: Due to a legacy implementation, most of the library path
452 // is set in the launcher. This was to accomodate linking restrictions
453 // on legacy Bsd implementations (which are no longer supported).
454 // Eventually, all the library path setting will be done here.
455 //
456 // However, to prevent the proliferation of improperly built native
457 // libraries, the new path component /usr/java/packages is added here.
458 // Eventually, all the library path setting will be done here.
459 {
460 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
461 // should always exist (until the legacy problem cited above is
462 // addressed).
463 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
464 // can specify a directory inside an app wrapper
465 const char *l = ::getenv("JAVA_LIBRARY_PATH");
466 const char *l_colon = ":";
467 if (l == NULL) { l = ""; l_colon = ""; }
468
469 const char *v = ::getenv("DYLD_LIBRARY_PATH");
470 const char *v_colon = ":";
471 if (v == NULL) { v = ""; v_colon = ""; }
472
473 // Apple's Java6 has "." at the beginning of java.library.path.
474 // OpenJDK on Windows has "." at the end of java.library.path.
475 // OpenJDK on Linux and Solaris don't have "." in java.library.path
476 // at all. To ease the transition from Apple's Java6 to OpenJDK7,
477 // "." is appended to the end of java.library.path. Yes, this
478 // could cause a change in behavior, but Apple's Java6 behavior
479 // can be achieved by putting "." at the beginning of the
480 // JAVA_LIBRARY_PATH environment variable.
481 char *ld_library_path = NEW_C_HEAP_ARRAY(char,
482 strlen(v) + 1 + strlen(l) + 1 +
483 system_ext_size + 3,
484 mtInternal);
485 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
486 v, v_colon, l, l_colon, user_home_dir);
487 Arguments::set_library_path(ld_library_path);
488 FREE_C_HEAP_ARRAY(char, ld_library_path);
489 }
490
491 // Extensions directories.
492 //
493 // Note that the space for the colon and the trailing null are provided
494 // by the nulls included by the sizeof operator (so actually one byte more
495 // than necessary is allocated).
496 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
497 user_home_dir, Arguments::get_java_home());
498 Arguments::set_ext_dirs(buf);
499
500 FREE_C_HEAP_ARRAY(char, buf);
501
502 #undef SYS_EXTENSIONS_DIR
503 #undef SYS_EXTENSIONS_DIRS
504
505 #endif // __APPLE__
506
507 #undef SYS_EXT_DIR
508 #undef EXTENSIONS_DIR
509 }
510
511 ////////////////////////////////////////////////////////////////////////////////
512 // breakpoint support
513
514 void os::breakpoint() {
515 BREAKPOINT;
516 }
517
518 extern "C" void breakpoint() {
519 // use debugger to set breakpoint here
520 }
521
522 ////////////////////////////////////////////////////////////////////////////////
523 // signal support
524
525 debug_only(static bool signal_sets_initialized = false);
526 static sigset_t unblocked_sigs, vm_sigs;
527
528 void os::Bsd::signal_sets_init() {
529 // Should also have an assertion stating we are still single-threaded.
530 assert(!signal_sets_initialized, "Already initialized");
531 // Fill in signals that are necessarily unblocked for all threads in
532 // the VM. Currently, we unblock the following signals:
533 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
534 // by -Xrs (=ReduceSignalUsage));
535 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
536 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
537 // the dispositions or masks wrt these signals.
538 // Programs embedding the VM that want to use the above signals for their
539 // own purposes must, at this time, use the "-Xrs" option to prevent
540 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
541 // (See bug 4345157, and other related bugs).
542 // In reality, though, unblocking these signals is really a nop, since
543 // these signals are not blocked by default.
544 sigemptyset(&unblocked_sigs);
545 sigaddset(&unblocked_sigs, SIGILL);
546 sigaddset(&unblocked_sigs, SIGSEGV);
547 sigaddset(&unblocked_sigs, SIGBUS);
548 sigaddset(&unblocked_sigs, SIGFPE);
549 sigaddset(&unblocked_sigs, SR_signum);
550
551 if (!ReduceSignalUsage) {
552 if (!os::Posix::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
553 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
554
555 }
556 if (!os::Posix::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
557 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
558 }
559 if (!os::Posix::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
560 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
561 }
562 }
563 // Fill in signals that are blocked by all but the VM thread.
564 sigemptyset(&vm_sigs);
565 if (!ReduceSignalUsage) {
566 sigaddset(&vm_sigs, BREAK_SIGNAL);
567 }
568 debug_only(signal_sets_initialized = true);
569
570 }
571
572 // These are signals that are unblocked while a thread is running Java.
573 // (For some reason, they get blocked by default.)
574 sigset_t* os::Bsd::unblocked_signals() {
575 assert(signal_sets_initialized, "Not initialized");
576 return &unblocked_sigs;
577 }
578
579 // These are the signals that are blocked while a (non-VM) thread is
580 // running Java. Only the VM thread handles these signals.
581 sigset_t* os::Bsd::vm_signals() {
582 assert(signal_sets_initialized, "Not initialized");
583 return &vm_sigs;
584 }
585
586 void os::Bsd::hotspot_sigmask(Thread* thread) {
587
588 //Save caller's signal mask before setting VM signal mask
589 sigset_t caller_sigmask;
590 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
591
592 OSThread* osthread = thread->osthread();
593 osthread->set_caller_sigmask(caller_sigmask);
594
595 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
596
597 if (!ReduceSignalUsage) {
598 if (thread->is_VM_thread()) {
599 // Only the VM thread handles BREAK_SIGNAL ...
600 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
601 } else {
602 // ... all other threads block BREAK_SIGNAL
603 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
604 }
605 }
606 }
607
608
609 //////////////////////////////////////////////////////////////////////////////
610 // create new thread
611
612 #ifdef __APPLE__
613 // library handle for calling objc_registerThreadWithCollector()
614 // without static linking to the libobjc library
615 #define OBJC_LIB "/usr/lib/libobjc.dylib"
616 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
617 typedef void (*objc_registerThreadWithCollector_t)();
618 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
619 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
620 #endif
621
622 #ifdef __APPLE__
623 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
624 // Additional thread_id used to correlate threads in SA
625 thread_identifier_info_data_t m_ident_info;
626 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT;
627
628 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
629 (thread_info_t) &m_ident_info, &count);
630
631 return m_ident_info.thread_id;
632 }
633 #endif
634
635 // Thread start routine for all newly created threads
636 static void *thread_native_entry(Thread *thread) {
637
638 thread->record_stack_base_and_size();
639
640 // Try to randomize the cache line index of hot stack frames.
641 // This helps when threads of the same stack traces evict each other's
642 // cache lines. The threads can be either from the same JVM instance, or
643 // from different JVM instances. The benefit is especially true for
644 // processors with hyperthreading technology.
645 static int counter = 0;
646 int pid = os::current_process_id();
647 alloca(((pid ^ counter++) & 7) * 128);
648
649 thread->initialize_thread_current();
650
651 OSThread* osthread = thread->osthread();
652 Monitor* sync = osthread->startThread_lock();
653
654 osthread->set_thread_id(os::Bsd::gettid());
655
656 log_info(os, thread)("Thread is alive (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
657 os::current_thread_id(), (uintx) pthread_self());
658
659 #ifdef __APPLE__
660 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
661 guarantee(unique_thread_id != 0, "unique thread id was not found");
662 osthread->set_unique_thread_id(unique_thread_id);
663 #endif
664 // initialize signal mask for this thread
665 os::Bsd::hotspot_sigmask(thread);
666
667 // initialize floating point control register
668 os::Bsd::init_thread_fpu_state();
669
670 #ifdef __APPLE__
671 // register thread with objc gc
672 if (objc_registerThreadWithCollectorFunction != NULL) {
673 objc_registerThreadWithCollectorFunction();
674 }
675 #endif
676
677 // handshaking with parent thread
678 {
679 MutexLocker ml(sync, Mutex::_no_safepoint_check_flag);
680
681 // notify parent thread
682 osthread->set_state(INITIALIZED);
683 sync->notify_all();
684
685 // wait until os::start_thread()
686 while (osthread->get_state() == INITIALIZED) {
687 sync->wait_without_safepoint_check();
688 }
689 }
690
691 // call one more level start routine
692 thread->call_run();
693
694 // Note: at this point the thread object may already have deleted itself.
695 // Prevent dereferencing it from here on out.
696 thread = NULL;
697
698 log_info(os, thread)("Thread finished (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
699 os::current_thread_id(), (uintx) pthread_self());
700
701 return 0;
702 }
703
704 bool os::create_thread(Thread* thread, ThreadType thr_type,
705 size_t req_stack_size) {
706 assert(thread->osthread() == NULL, "caller responsible");
707
708 // Allocate the OSThread object
709 OSThread* osthread = new OSThread(NULL, NULL);
710 if (osthread == NULL) {
711 return false;
712 }
713
714 // set the correct thread state
715 osthread->set_thread_type(thr_type);
716
717 // Initial state is ALLOCATED but not INITIALIZED
718 osthread->set_state(ALLOCATED);
719
720 thread->set_osthread(osthread);
721
722 // init thread attributes
723 pthread_attr_t attr;
724 pthread_attr_init(&attr);
725 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
726
727 // calculate stack size if it's not specified by caller
728 size_t stack_size = os::Posix::get_initial_stack_size(thr_type, req_stack_size);
729 int status = pthread_attr_setstacksize(&attr, stack_size);
730 assert_status(status == 0, status, "pthread_attr_setstacksize");
731
732 ThreadState state;
733
734 {
735 pthread_t tid;
736 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) thread_native_entry, thread);
737
738 char buf[64];
739 if (ret == 0) {
740 log_info(os, thread)("Thread started (pthread id: " UINTX_FORMAT ", attributes: %s). ",
741 (uintx) tid, os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
742 } else {
743 log_warning(os, thread)("Failed to start thread - pthread_create failed (%s) for attributes: %s.",
744 os::errno_name(ret), os::Posix::describe_pthread_attr(buf, sizeof(buf), &attr));
745 // Log some OS information which might explain why creating the thread failed.
746 log_info(os, thread)("Number of threads approx. running in the VM: %d", Threads::number_of_threads());
747 LogStream st(Log(os, thread)::info());
748 os::Posix::print_rlimit_info(&st);
749 os::print_memory_info(&st);
750 }
751
752 pthread_attr_destroy(&attr);
753
754 if (ret != 0) {
755 // Need to clean up stuff we've allocated so far
756 thread->set_osthread(NULL);
757 delete osthread;
758 return false;
759 }
760
761 // Store pthread info into the OSThread
762 osthread->set_pthread_id(tid);
763
764 // Wait until child thread is either initialized or aborted
765 {
766 Monitor* sync_with_child = osthread->startThread_lock();
767 MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
768 while ((state = osthread->get_state()) == ALLOCATED) {
769 sync_with_child->wait_without_safepoint_check();
770 }
771 }
772
773 }
774
775 // Aborted due to thread limit being reached
776 if (state == ZOMBIE) {
777 thread->set_osthread(NULL);
778 delete osthread;
779 return false;
780 }
781
782 // The thread is returned suspended (in state INITIALIZED),
783 // and is started higher up in the call chain
784 assert(state == INITIALIZED, "race condition");
785 return true;
786 }
787
788 /////////////////////////////////////////////////////////////////////////////
789 // attach existing thread
790
791 // bootstrap the main thread
792 bool os::create_main_thread(JavaThread* thread) {
793 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
794 return create_attached_thread(thread);
795 }
796
797 bool os::create_attached_thread(JavaThread* thread) {
798 #ifdef ASSERT
799 thread->verify_not_published();
800 #endif
801
802 // Allocate the OSThread object
803 OSThread* osthread = new OSThread(NULL, NULL);
804
805 if (osthread == NULL) {
806 return false;
807 }
808
809 osthread->set_thread_id(os::Bsd::gettid());
810
811 // Store pthread info into the OSThread
812 #ifdef __APPLE__
813 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
814 guarantee(unique_thread_id != 0, "just checking");
815 osthread->set_unique_thread_id(unique_thread_id);
816 #endif
817 osthread->set_pthread_id(::pthread_self());
818
819 // initialize floating point control register
820 os::Bsd::init_thread_fpu_state();
821
822 // Initial thread state is RUNNABLE
823 osthread->set_state(RUNNABLE);
824
825 thread->set_osthread(osthread);
826
827 // initialize signal mask for this thread
828 // and save the caller's signal mask
829 os::Bsd::hotspot_sigmask(thread);
830
831 log_info(os, thread)("Thread attached (tid: " UINTX_FORMAT ", pthread id: " UINTX_FORMAT ").",
832 os::current_thread_id(), (uintx) pthread_self());
833
834 return true;
835 }
836
837 void os::pd_start_thread(Thread* thread) {
838 OSThread * osthread = thread->osthread();
839 assert(osthread->get_state() != INITIALIZED, "just checking");
840 Monitor* sync_with_child = osthread->startThread_lock();
841 MutexLocker ml(sync_with_child, Mutex::_no_safepoint_check_flag);
842 sync_with_child->notify();
843 }
844
845 // Free Bsd resources related to the OSThread
846 void os::free_thread(OSThread* osthread) {
847 assert(osthread != NULL, "osthread not set");
848
849 // We are told to free resources of the argument thread,
850 // but we can only really operate on the current thread.
851 assert(Thread::current()->osthread() == osthread,
852 "os::free_thread but not current thread");
853
854 // Restore caller's signal mask
855 sigset_t sigmask = osthread->caller_sigmask();
856 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
857
858 delete osthread;
859 }
860
861 ////////////////////////////////////////////////////////////////////////////////
862 // time support
863
864 // Time since start-up in seconds to a fine granularity.
865 // Used by VMSelfDestructTimer and the MemProfiler.
866 double os::elapsedTime() {
867
868 return ((double)os::elapsed_counter()) / os::elapsed_frequency();
869 }
870
871 jlong os::elapsed_counter() {
872 return javaTimeNanos() - initial_time_count;
873 }
874
875 jlong os::elapsed_frequency() {
876 return NANOSECS_PER_SEC; // nanosecond resolution
877 }
878
879 bool os::supports_vtime() { return true; }
880 bool os::enable_vtime() { return false; }
881 bool os::vtime_enabled() { return false; }
882
883 double os::elapsedVTime() {
884 // better than nothing, but not much
885 return elapsedTime();
886 }
887
888 jlong os::javaTimeMillis() {
889 timeval time;
890 int status = gettimeofday(&time, NULL);
891 assert(status != -1, "bsd error");
892 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
893 }
894
895 void os::javaTimeSystemUTC(jlong &seconds, jlong &nanos) {
896 timeval time;
897 int status = gettimeofday(&time, NULL);
898 assert(status != -1, "bsd error");
899 seconds = jlong(time.tv_sec);
900 nanos = jlong(time.tv_usec) * 1000;
901 }
902
903 #ifndef __APPLE__
904 #ifndef CLOCK_MONOTONIC
905 #define CLOCK_MONOTONIC (1)
906 #endif
907 #endif
908
909 #ifdef __APPLE__
910 void os::Bsd::clock_init() {
911 mach_timebase_info(&_timebase_info);
912 }
913 #else
914 void os::Bsd::clock_init() {
915 struct timespec res;
916 struct timespec tp;
917 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
918 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
919 // yes, monotonic clock is supported
920 _clock_gettime = ::clock_gettime;
921 }
922 }
923 #endif
924
925
926
927 #ifdef __APPLE__
928
929 jlong os::javaTimeNanos() {
930 const uint64_t tm = mach_absolute_time();
931 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
932 const uint64_t prev = Bsd::_max_abstime;
933 if (now <= prev) {
934 return prev; // same or retrograde time;
935 }
936 const uint64_t obsv = Atomic::cmpxchg(now, &Bsd::_max_abstime, prev);
937 assert(obsv >= prev, "invariant"); // Monotonicity
938 // If the CAS succeeded then we're done and return "now".
939 // If the CAS failed and the observed value "obsv" is >= now then
940 // we should return "obsv". If the CAS failed and now > obsv > prv then
941 // some other thread raced this thread and installed a new value, in which case
942 // we could either (a) retry the entire operation, (b) retry trying to install now
943 // or (c) just return obsv. We use (c). No loop is required although in some cases
944 // we might discard a higher "now" value in deference to a slightly lower but freshly
945 // installed obsv value. That's entirely benign -- it admits no new orderings compared
946 // to (a) or (b) -- and greatly reduces coherence traffic.
947 // We might also condition (c) on the magnitude of the delta between obsv and now.
948 // Avoiding excessive CAS operations to hot RW locations is critical.
949 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
950 return (prev == obsv) ? now : obsv;
951 }
952
953 #else // __APPLE__
954
955 jlong os::javaTimeNanos() {
956 if (os::supports_monotonic_clock()) {
957 struct timespec tp;
958 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
959 assert(status == 0, "gettime error");
960 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
961 return result;
962 } else {
963 timeval time;
964 int status = gettimeofday(&time, NULL);
965 assert(status != -1, "bsd error");
966 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
967 return 1000 * usecs;
968 }
969 }
970
971 #endif // __APPLE__
972
973 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
974 if (os::supports_monotonic_clock()) {
975 info_ptr->max_value = ALL_64_BITS;
976
977 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
978 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
979 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
980 } else {
981 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
982 info_ptr->max_value = ALL_64_BITS;
983
984 // gettimeofday is a real time clock so it skips
985 info_ptr->may_skip_backward = true;
986 info_ptr->may_skip_forward = true;
987 }
988
989 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
990 }
991
992 // Return the real, user, and system times in seconds from an
993 // arbitrary fixed point in the past.
994 bool os::getTimesSecs(double* process_real_time,
995 double* process_user_time,
996 double* process_system_time) {
997 struct tms ticks;
998 clock_t real_ticks = times(&ticks);
999
1000 if (real_ticks == (clock_t) (-1)) {
1001 return false;
1002 } else {
1003 double ticks_per_second = (double) clock_tics_per_sec;
1004 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1005 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1006 *process_real_time = ((double) real_ticks) / ticks_per_second;
1007
1008 return true;
1009 }
1010 }
1011
1012
1013 char * os::local_time_string(char *buf, size_t buflen) {
1014 struct tm t;
1015 time_t long_time;
1016 time(&long_time);
1017 localtime_r(&long_time, &t);
1018 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1019 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1020 t.tm_hour, t.tm_min, t.tm_sec);
1021 return buf;
1022 }
1023
1024 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1025 return localtime_r(clock, res);
1026 }
1027
1028 ////////////////////////////////////////////////////////////////////////////////
1029 // runtime exit support
1030
1031 // Note: os::shutdown() might be called very early during initialization, or
1032 // called from signal handler. Before adding something to os::shutdown(), make
1033 // sure it is async-safe and can handle partially initialized VM.
1034 void os::shutdown() {
1035
1036 // allow PerfMemory to attempt cleanup of any persistent resources
1037 perfMemory_exit();
1038
1039 // needs to remove object in file system
1040 AttachListener::abort();
1041
1042 // flush buffered output, finish log files
1043 ostream_abort();
1044
1045 // Check for abort hook
1046 abort_hook_t abort_hook = Arguments::abort_hook();
1047 if (abort_hook != NULL) {
1048 abort_hook();
1049 }
1050
1051 }
1052
1053 // Note: os::abort() might be called very early during initialization, or
1054 // called from signal handler. Before adding something to os::abort(), make
1055 // sure it is async-safe and can handle partially initialized VM.
1056 void os::abort(bool dump_core, void* siginfo, const void* context) {
1057 os::shutdown();
1058 if (dump_core) {
1059 #ifndef PRODUCT
1060 fdStream out(defaultStream::output_fd());
1061 out.print_raw("Current thread is ");
1062 char buf[16];
1063 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1064 out.print_raw_cr(buf);
1065 out.print_raw_cr("Dumping core ...");
1066 #endif
1067 ::abort(); // dump core
1068 }
1069
1070 ::exit(1);
1071 }
1072
1073 // Die immediately, no exit hook, no abort hook, no cleanup.
1074 // Dump a core file, if possible, for debugging.
1075 void os::die() {
1076 if (TestUnresponsiveErrorHandler && !CreateCoredumpOnCrash) {
1077 // For TimeoutInErrorHandlingTest.java, we just kill the VM
1078 // and don't take the time to generate a core file.
1079 os::signal_raise(SIGKILL);
1080 } else {
1081 // _exit() on BsdThreads only kills current thread
1082 ::abort();
1083 }
1084 }
1085
1086 // Information of current thread in variety of formats
1087 pid_t os::Bsd::gettid() {
1088 int retval = -1;
1089
1090 #ifdef __APPLE__ //XNU kernel
1091 // despite the fact mach port is actually not a thread id use it
1092 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1093 retval = ::pthread_mach_thread_np(::pthread_self());
1094 guarantee(retval != 0, "just checking");
1095 return retval;
1096
1097 #else
1098 #ifdef __FreeBSD__
1099 retval = syscall(SYS_thr_self);
1100 #else
1101 #ifdef __OpenBSD__
1102 retval = syscall(SYS_getthrid);
1103 #else
1104 #ifdef __NetBSD__
1105 retval = (pid_t) syscall(SYS__lwp_self);
1106 #endif
1107 #endif
1108 #endif
1109 #endif
1110
1111 if (retval == -1) {
1112 return getpid();
1113 }
1114 }
1115
1116 intx os::current_thread_id() {
1117 #ifdef __APPLE__
1118 return (intx)::pthread_mach_thread_np(::pthread_self());
1119 #else
1120 return (intx)::pthread_self();
1121 #endif
1122 }
1123
1124 int os::current_process_id() {
1125 return (int)(getpid());
1126 }
1127
1128 // DLL functions
1129
1130 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1131
1132 // This must be hard coded because it's the system's temporary
1133 // directory not the java application's temp directory, ala java.io.tmpdir.
1134 #ifdef __APPLE__
1135 // macosx has a secure per-user temporary directory
1136 char temp_path_storage[PATH_MAX];
1137 const char* os::get_temp_directory() {
1138 static char *temp_path = NULL;
1139 if (temp_path == NULL) {
1140 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1141 if (pathSize == 0 || pathSize > PATH_MAX) {
1142 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1143 }
1144 temp_path = temp_path_storage;
1145 }
1146 return temp_path;
1147 }
1148 #else // __APPLE__
1149 const char* os::get_temp_directory() { return "/tmp"; }
1150 #endif // __APPLE__
1151
1152 // check if addr is inside libjvm.so
1153 bool os::address_is_in_vm(address addr) {
1154 static address libjvm_base_addr;
1155 Dl_info dlinfo;
1156
1157 if (libjvm_base_addr == NULL) {
1158 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1159 libjvm_base_addr = (address)dlinfo.dli_fbase;
1160 }
1161 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1162 }
1163
1164 if (dladdr((void *)addr, &dlinfo) != 0) {
1165 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1166 }
1167
1168 return false;
1169 }
1170
1171
1172 #define MACH_MAXSYMLEN 256
1173
1174 bool os::dll_address_to_function_name(address addr, char *buf,
1175 int buflen, int *offset,
1176 bool demangle) {
1177 // buf is not optional, but offset is optional
1178 assert(buf != NULL, "sanity check");
1179
1180 Dl_info dlinfo;
1181 char localbuf[MACH_MAXSYMLEN];
1182
1183 if (dladdr((void*)addr, &dlinfo) != 0) {
1184 // see if we have a matching symbol
1185 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1186 if (!(demangle && Decoder::demangle(dlinfo.dli_sname, buf, buflen))) {
1187 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1188 }
1189 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1190 return true;
1191 }
1192 // no matching symbol so try for just file info
1193 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1194 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1195 buf, buflen, offset, dlinfo.dli_fname, demangle)) {
1196 return true;
1197 }
1198 }
1199
1200 // Handle non-dynamic manually:
1201 if (dlinfo.dli_fbase != NULL &&
1202 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1203 dlinfo.dli_fbase)) {
1204 if (!(demangle && Decoder::demangle(localbuf, buf, buflen))) {
1205 jio_snprintf(buf, buflen, "%s", localbuf);
1206 }
1207 return true;
1208 }
1209 }
1210 buf[0] = '\0';
1211 if (offset != NULL) *offset = -1;
1212 return false;
1213 }
1214
1215 // ported from solaris version
1216 bool os::dll_address_to_library_name(address addr, char* buf,
1217 int buflen, int* offset) {
1218 // buf is not optional, but offset is optional
1219 assert(buf != NULL, "sanity check");
1220
1221 Dl_info dlinfo;
1222
1223 if (dladdr((void*)addr, &dlinfo) != 0) {
1224 if (dlinfo.dli_fname != NULL) {
1225 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1226 }
1227 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1228 *offset = addr - (address)dlinfo.dli_fbase;
1229 }
1230 return true;
1231 }
1232
1233 buf[0] = '\0';
1234 if (offset) *offset = -1;
1235 return false;
1236 }
1237
1238 // Loads .dll/.so and
1239 // in case of error it checks if .dll/.so was built for the
1240 // same architecture as Hotspot is running on
1241
1242 #ifdef __APPLE__
1243 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1244 #ifdef STATIC_BUILD
1245 return os::get_default_process_handle();
1246 #else
1247 log_info(os)("attempting shared library load of %s", filename);
1248
1249 void * result= ::dlopen(filename, RTLD_LAZY);
1250 if (result != NULL) {
1251 Events::log(NULL, "Loaded shared library %s", filename);
1252 // Successful loading
1253 log_info(os)("shared library load of %s was successful", filename);
1254 return result;
1255 }
1256
1257 const char* error_report = ::dlerror();
1258 if (error_report == NULL) {
1259 error_report = "dlerror returned no error description";
1260 }
1261 if (ebuf != NULL && ebuflen > 0) {
1262 // Read system error message into ebuf
1263 ::strncpy(ebuf, error_report, ebuflen-1);
1264 ebuf[ebuflen-1]='\0';
1265 }
1266 Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
1267 log_info(os)("shared library load of %s failed, %s", filename, error_report);
1268
1269 return NULL;
1270 #endif // STATIC_BUILD
1271 }
1272 #else
1273 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1274 #ifdef STATIC_BUILD
1275 return os::get_default_process_handle();
1276 #else
1277 log_info(os)("attempting shared library load of %s", filename);
1278 void * result= ::dlopen(filename, RTLD_LAZY);
1279 if (result != NULL) {
1280 Events::log(NULL, "Loaded shared library %s", filename);
1281 // Successful loading
1282 log_info(os)("shared library load of %s was successful", filename);
1283 return result;
1284 }
1285
1286 Elf32_Ehdr elf_head;
1287
1288 const char* const error_report = ::dlerror();
1289 if (error_report == NULL) {
1290 error_report = "dlerror returned no error description";
1291 }
1292 if (ebuf != NULL && ebuflen > 0) {
1293 // Read system error message into ebuf
1294 ::strncpy(ebuf, error_report, ebuflen-1);
1295 ebuf[ebuflen-1]='\0';
1296 }
1297 Events::log(NULL, "Loading shared library %s failed, %s", filename, error_report);
1298 log_info(os)("shared library load of %s failed, %s", filename, error_report);
1299
1300 int diag_msg_max_length=ebuflen-strlen(ebuf);
1301 char* diag_msg_buf=ebuf+strlen(ebuf);
1302
1303 if (diag_msg_max_length==0) {
1304 // No more space in ebuf for additional diagnostics message
1305 return NULL;
1306 }
1307
1308
1309 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1310
1311 if (file_descriptor < 0) {
1312 // Can't open library, report dlerror() message
1313 return NULL;
1314 }
1315
1316 bool failed_to_read_elf_head=
1317 (sizeof(elf_head)!=
1318 (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1319
1320 ::close(file_descriptor);
1321 if (failed_to_read_elf_head) {
1322 // file i/o error - report dlerror() msg
1323 return NULL;
1324 }
1325
1326 typedef struct {
1327 Elf32_Half code; // Actual value as defined in elf.h
1328 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1329 char elf_class; // 32 or 64 bit
1330 char endianess; // MSB or LSB
1331 char* name; // String representation
1332 } arch_t;
1333
1334 #ifndef EM_486
1335 #define EM_486 6 /* Intel 80486 */
1336 #endif
1337
1338 #ifndef EM_MIPS_RS3_LE
1339 #define EM_MIPS_RS3_LE 10 /* MIPS */
1340 #endif
1341
1342 #ifndef EM_PPC64
1343 #define EM_PPC64 21 /* PowerPC64 */
1344 #endif
1345
1346 #ifndef EM_S390
1347 #define EM_S390 22 /* IBM System/390 */
1348 #endif
1349
1350 #ifndef EM_IA_64
1351 #define EM_IA_64 50 /* HP/Intel IA-64 */
1352 #endif
1353
1354 #ifndef EM_X86_64
1355 #define EM_X86_64 62 /* AMD x86-64 */
1356 #endif
1357
1358 static const arch_t arch_array[]={
1359 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1360 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1361 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1362 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1363 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1364 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1365 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1366 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1367 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1368 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1369 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1370 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1371 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1372 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1373 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1374 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1375 };
1376
1377 #if (defined IA32)
1378 static Elf32_Half running_arch_code=EM_386;
1379 #elif (defined AMD64)
1380 static Elf32_Half running_arch_code=EM_X86_64;
1381 #elif (defined IA64)
1382 static Elf32_Half running_arch_code=EM_IA_64;
1383 #elif (defined __sparc) && (defined _LP64)
1384 static Elf32_Half running_arch_code=EM_SPARCV9;
1385 #elif (defined __sparc) && (!defined _LP64)
1386 static Elf32_Half running_arch_code=EM_SPARC;
1387 #elif (defined __powerpc64__)
1388 static Elf32_Half running_arch_code=EM_PPC64;
1389 #elif (defined __powerpc__)
1390 static Elf32_Half running_arch_code=EM_PPC;
1391 #elif (defined ARM)
1392 static Elf32_Half running_arch_code=EM_ARM;
1393 #elif (defined S390)
1394 static Elf32_Half running_arch_code=EM_S390;
1395 #elif (defined ALPHA)
1396 static Elf32_Half running_arch_code=EM_ALPHA;
1397 #elif (defined MIPSEL)
1398 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1399 #elif (defined PARISC)
1400 static Elf32_Half running_arch_code=EM_PARISC;
1401 #elif (defined MIPS)
1402 static Elf32_Half running_arch_code=EM_MIPS;
1403 #elif (defined M68K)
1404 static Elf32_Half running_arch_code=EM_68K;
1405 #else
1406 #error Method os::dll_load requires that one of following is defined:\
1407 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1408 #endif
1409
1410 // Identify compatability class for VM's architecture and library's architecture
1411 // Obtain string descriptions for architectures
1412
1413 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1414 int running_arch_index=-1;
1415
1416 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1417 if (running_arch_code == arch_array[i].code) {
1418 running_arch_index = i;
1419 }
1420 if (lib_arch.code == arch_array[i].code) {
1421 lib_arch.compat_class = arch_array[i].compat_class;
1422 lib_arch.name = arch_array[i].name;
1423 }
1424 }
1425
1426 assert(running_arch_index != -1,
1427 "Didn't find running architecture code (running_arch_code) in arch_array");
1428 if (running_arch_index == -1) {
1429 // Even though running architecture detection failed
1430 // we may still continue with reporting dlerror() message
1431 return NULL;
1432 }
1433
1434 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1435 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1436 return NULL;
1437 }
1438
1439 #ifndef S390
1440 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1441 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1442 return NULL;
1443 }
1444 #endif // !S390
1445
1446 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1447 if (lib_arch.name!=NULL) {
1448 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1449 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1450 lib_arch.name, arch_array[running_arch_index].name);
1451 } else {
1452 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1453 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1454 lib_arch.code,
1455 arch_array[running_arch_index].name);
1456 }
1457 }
1458
1459 return NULL;
1460 #endif // STATIC_BUILD
1461 }
1462 #endif // !__APPLE__
1463
1464 void* os::get_default_process_handle() {
1465 #ifdef __APPLE__
1466 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1467 // to avoid finding unexpected symbols on second (or later)
1468 // loads of a library.
1469 return (void*)::dlopen(NULL, RTLD_FIRST);
1470 #else
1471 return (void*)::dlopen(NULL, RTLD_LAZY);
1472 #endif
1473 }
1474
1475 // XXX: Do we need a lock around this as per Linux?
1476 void* os::dll_lookup(void* handle, const char* name) {
1477 return dlsym(handle, name);
1478 }
1479
1480 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1481 outputStream * out = (outputStream *) param;
1482 out->print_cr(INTPTR_FORMAT " \t%s", (intptr_t)base_address, name);
1483 return 0;
1484 }
1485
1486 void os::print_dll_info(outputStream *st) {
1487 st->print_cr("Dynamic libraries:");
1488 if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1489 st->print_cr("Error: Cannot print dynamic libraries.");
1490 }
1491 }
1492
1493 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1494 #ifdef RTLD_DI_LINKMAP
1495 Dl_info dli;
1496 void *handle;
1497 Link_map *map;
1498 Link_map *p;
1499
1500 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1501 dli.dli_fname == NULL) {
1502 return 1;
1503 }
1504 handle = dlopen(dli.dli_fname, RTLD_LAZY);
1505 if (handle == NULL) {
1506 return 1;
1507 }
1508 dlinfo(handle, RTLD_DI_LINKMAP, &map);
1509 if (map == NULL) {
1510 dlclose(handle);
1511 return 1;
1512 }
1513
1514 while (map->l_prev != NULL)
1515 map = map->l_prev;
1516
1517 while (map != NULL) {
1518 // Value for top_address is returned as 0 since we don't have any information about module size
1519 if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1520 dlclose(handle);
1521 return 1;
1522 }
1523 map = map->l_next;
1524 }
1525
1526 dlclose(handle);
1527 #elif defined(__APPLE__)
1528 for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1529 // Value for top_address is returned as 0 since we don't have any information about module size
1530 if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1531 return 1;
1532 }
1533 }
1534 return 0;
1535 #else
1536 return 1;
1537 #endif
1538 }
1539
1540 void os::get_summary_os_info(char* buf, size_t buflen) {
1541 // These buffers are small because we want this to be brief
1542 // and not use a lot of stack while generating the hs_err file.
1543 char os[100];
1544 size_t size = sizeof(os);
1545 int mib_kern[] = { CTL_KERN, KERN_OSTYPE };
1546 if (sysctl(mib_kern, 2, os, &size, NULL, 0) < 0) {
1547 #ifdef __APPLE__
1548 strncpy(os, "Darwin", sizeof(os));
1549 #elif __OpenBSD__
1550 strncpy(os, "OpenBSD", sizeof(os));
1551 #else
1552 strncpy(os, "BSD", sizeof(os));
1553 #endif
1554 }
1555
1556 char release[100];
1557 size = sizeof(release);
1558 int mib_release[] = { CTL_KERN, KERN_OSRELEASE };
1559 if (sysctl(mib_release, 2, release, &size, NULL, 0) < 0) {
1560 // if error, leave blank
1561 strncpy(release, "", sizeof(release));
1562 }
1563 snprintf(buf, buflen, "%s %s", os, release);
1564 }
1565
1566 void os::print_os_info_brief(outputStream* st) {
1567 os::Posix::print_uname_info(st);
1568 }
1569
1570 void os::print_os_info(outputStream* st) {
1571 st->print("OS:");
1572
1573 os::Posix::print_uname_info(st);
1574
1575 os::Posix::print_rlimit_info(st);
1576
1577 os::Posix::print_load_average(st);
1578 }
1579
1580 void os::pd_print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1581 // Nothing to do for now.
1582 }
1583
1584 void os::get_summary_cpu_info(char* buf, size_t buflen) {
1585 unsigned int mhz;
1586 size_t size = sizeof(mhz);
1587 int mib[] = { CTL_HW, HW_CPU_FREQ };
1588 if (sysctl(mib, 2, &mhz, &size, NULL, 0) < 0) {
1589 mhz = 1; // looks like an error but can be divided by
1590 } else {
1591 mhz /= 1000000; // reported in millions
1592 }
1593
1594 char model[100];
1595 size = sizeof(model);
1596 int mib_model[] = { CTL_HW, HW_MODEL };
1597 if (sysctl(mib_model, 2, model, &size, NULL, 0) < 0) {
1598 strncpy(model, cpu_arch, sizeof(model));
1599 }
1600
1601 char machine[100];
1602 size = sizeof(machine);
1603 int mib_machine[] = { CTL_HW, HW_MACHINE };
1604 if (sysctl(mib_machine, 2, machine, &size, NULL, 0) < 0) {
1605 strncpy(machine, "", sizeof(machine));
1606 }
1607
1608 snprintf(buf, buflen, "%s %s %d MHz", model, machine, mhz);
1609 }
1610
1611 void os::print_memory_info(outputStream* st) {
1612 xsw_usage swap_usage;
1613 size_t size = sizeof(swap_usage);
1614
1615 st->print("Memory:");
1616 st->print(" %dk page", os::vm_page_size()>>10);
1617
1618 st->print(", physical " UINT64_FORMAT "k",
1619 os::physical_memory() >> 10);
1620 st->print("(" UINT64_FORMAT "k free)",
1621 os::available_memory() >> 10);
1622
1623 if((sysctlbyname("vm.swapusage", &swap_usage, &size, NULL, 0) == 0) || (errno == ENOMEM)) {
1624 if (size >= offset_of(xsw_usage, xsu_used)) {
1625 st->print(", swap " UINT64_FORMAT "k",
1626 ((julong) swap_usage.xsu_total) >> 10);
1627 st->print("(" UINT64_FORMAT "k free)",
1628 ((julong) swap_usage.xsu_avail) >> 10);
1629 }
1630 }
1631
1632 st->cr();
1633 }
1634
1635 static void print_signal_handler(outputStream* st, int sig,
1636 char* buf, size_t buflen);
1637
1638 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1639 st->print_cr("Signal Handlers:");
1640 print_signal_handler(st, SIGSEGV, buf, buflen);
1641 print_signal_handler(st, SIGBUS , buf, buflen);
1642 print_signal_handler(st, SIGFPE , buf, buflen);
1643 print_signal_handler(st, SIGPIPE, buf, buflen);
1644 print_signal_handler(st, SIGXFSZ, buf, buflen);
1645 print_signal_handler(st, SIGILL , buf, buflen);
1646 print_signal_handler(st, SR_signum, buf, buflen);
1647 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1648 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1649 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1650 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1651 }
1652
1653 static char saved_jvm_path[MAXPATHLEN] = {0};
1654
1655 // Find the full path to the current module, libjvm
1656 void os::jvm_path(char *buf, jint buflen) {
1657 // Error checking.
1658 if (buflen < MAXPATHLEN) {
1659 assert(false, "must use a large-enough buffer");
1660 buf[0] = '\0';
1661 return;
1662 }
1663 // Lazy resolve the path to current module.
1664 if (saved_jvm_path[0] != 0) {
1665 strcpy(buf, saved_jvm_path);
1666 return;
1667 }
1668
1669 char dli_fname[MAXPATHLEN];
1670 bool ret = dll_address_to_library_name(
1671 CAST_FROM_FN_PTR(address, os::jvm_path),
1672 dli_fname, sizeof(dli_fname), NULL);
1673 assert(ret, "cannot locate libjvm");
1674 char *rp = NULL;
1675 if (ret && dli_fname[0] != '\0') {
1676 rp = os::Posix::realpath(dli_fname, buf, buflen);
1677 }
1678 if (rp == NULL) {
1679 return;
1680 }
1681
1682 if (Arguments::sun_java_launcher_is_altjvm()) {
1683 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1684 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1685 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1686 // appears at the right place in the string, then assume we are
1687 // installed in a JDK and we're done. Otherwise, check for a
1688 // JAVA_HOME environment variable and construct a path to the JVM
1689 // being overridden.
1690
1691 const char *p = buf + strlen(buf) - 1;
1692 for (int count = 0; p > buf && count < 5; ++count) {
1693 for (--p; p > buf && *p != '/'; --p)
1694 /* empty */ ;
1695 }
1696
1697 if (strncmp(p, "/jre/lib/", 9) != 0) {
1698 // Look for JAVA_HOME in the environment.
1699 char* java_home_var = ::getenv("JAVA_HOME");
1700 if (java_home_var != NULL && java_home_var[0] != 0) {
1701 char* jrelib_p;
1702 int len;
1703
1704 // Check the current module name "libjvm"
1705 p = strrchr(buf, '/');
1706 assert(strstr(p, "/libjvm") == p, "invalid library name");
1707
1708 rp = os::Posix::realpath(java_home_var, buf, buflen);
1709 if (rp == NULL) {
1710 return;
1711 }
1712
1713 // determine if this is a legacy image or modules image
1714 // modules image doesn't have "jre" subdirectory
1715 len = strlen(buf);
1716 assert(len < buflen, "Ran out of buffer space");
1717 jrelib_p = buf + len;
1718
1719 // Add the appropriate library subdir
1720 snprintf(jrelib_p, buflen-len, "/jre/lib");
1721 if (0 != access(buf, F_OK)) {
1722 snprintf(jrelib_p, buflen-len, "/lib");
1723 }
1724
1725 // Add the appropriate client or server subdir
1726 len = strlen(buf);
1727 jrelib_p = buf + len;
1728 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1729 if (0 != access(buf, F_OK)) {
1730 snprintf(jrelib_p, buflen-len, "%s", "");
1731 }
1732
1733 // If the path exists within JAVA_HOME, add the JVM library name
1734 // to complete the path to JVM being overridden. Otherwise fallback
1735 // to the path to the current library.
1736 if (0 == access(buf, F_OK)) {
1737 // Use current module name "libjvm"
1738 len = strlen(buf);
1739 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1740 } else {
1741 // Fall back to path of current library
1742 rp = os::Posix::realpath(dli_fname, buf, buflen);
1743 if (rp == NULL) {
1744 return;
1745 }
1746 }
1747 }
1748 }
1749 }
1750
1751 strncpy(saved_jvm_path, buf, MAXPATHLEN);
1752 saved_jvm_path[MAXPATHLEN - 1] = '\0';
1753 }
1754
1755 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1756 // no prefix required, not even "_"
1757 }
1758
1759 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1760 // no suffix required
1761 }
1762
1763 ////////////////////////////////////////////////////////////////////////////////
1764 // sun.misc.Signal support
1765
1766 static void UserHandler(int sig, void *siginfo, void *context) {
1767 // Ctrl-C is pressed during error reporting, likely because the error
1768 // handler fails to abort. Let VM die immediately.
1769 if (sig == SIGINT && VMError::is_error_reported()) {
1770 os::die();
1771 }
1772
1773 os::signal_notify(sig);
1774 }
1775
1776 void* os::user_handler() {
1777 return CAST_FROM_FN_PTR(void*, UserHandler);
1778 }
1779
1780 extern "C" {
1781 typedef void (*sa_handler_t)(int);
1782 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1783 }
1784
1785 void* os::signal(int signal_number, void* handler) {
1786 struct sigaction sigAct, oldSigAct;
1787
1788 sigfillset(&(sigAct.sa_mask));
1789 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
1790 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1791
1792 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1793 // -1 means registration failed
1794 return (void *)-1;
1795 }
1796
1797 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1798 }
1799
1800 void os::signal_raise(int signal_number) {
1801 ::raise(signal_number);
1802 }
1803
1804 // The following code is moved from os.cpp for making this
1805 // code platform specific, which it is by its very nature.
1806
1807 // Will be modified when max signal is changed to be dynamic
1808 int os::sigexitnum_pd() {
1809 return NSIG;
1810 }
1811
1812 // a counter for each possible signal value
1813 static volatile jint pending_signals[NSIG+1] = { 0 };
1814 static Semaphore* sig_sem = NULL;
1815
1816 static void jdk_misc_signal_init() {
1817 // Initialize signal structures
1818 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
1819
1820 // Initialize signal semaphore
1821 sig_sem = new Semaphore();
1822 }
1823
1824 void os::signal_notify(int sig) {
1825 if (sig_sem != NULL) {
1826 Atomic::inc(&pending_signals[sig]);
1827 sig_sem->signal();
1828 } else {
1829 // Signal thread is not created with ReduceSignalUsage and jdk_misc_signal_init
1830 // initialization isn't called.
1831 assert(ReduceSignalUsage, "signal semaphore should be created");
1832 }
1833 }
1834
1835 static int check_pending_signals() {
1836 for (;;) {
1837 for (int i = 0; i < NSIG + 1; i++) {
1838 jint n = pending_signals[i];
1839 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
1840 return i;
1841 }
1842 }
1843 JavaThread *thread = JavaThread::current();
1844 ThreadBlockInVM tbivm(thread);
1845
1846 bool threadIsSuspended;
1847 do {
1848 thread->set_suspend_equivalent();
1849 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
1850 sig_sem->wait();
1851
1852 // were we externally suspended while we were waiting?
1853 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
1854 if (threadIsSuspended) {
1855 // The semaphore has been incremented, but while we were waiting
1856 // another thread suspended us. We don't want to continue running
1857 // while suspended because that would surprise the thread that
1858 // suspended us.
1859 sig_sem->signal();
1860
1861 thread->java_suspend_self();
1862 }
1863 } while (threadIsSuspended);
1864 }
1865 }
1866
1867 int os::signal_wait() {
1868 return check_pending_signals();
1869 }
1870
1871 ////////////////////////////////////////////////////////////////////////////////
1872 // Virtual Memory
1873
1874 int os::vm_page_size() {
1875 // Seems redundant as all get out
1876 assert(os::Bsd::page_size() != -1, "must call os::init");
1877 return os::Bsd::page_size();
1878 }
1879
1880 // Solaris allocates memory by pages.
1881 int os::vm_allocation_granularity() {
1882 assert(os::Bsd::page_size() != -1, "must call os::init");
1883 return os::Bsd::page_size();
1884 }
1885
1886 // Rationale behind this function:
1887 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
1888 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
1889 // samples for JITted code. Here we create private executable mapping over the code cache
1890 // and then we can use standard (well, almost, as mapping can change) way to provide
1891 // info for the reporting script by storing timestamp and location of symbol
1892 void bsd_wrap_code(char* base, size_t size) {
1893 static volatile jint cnt = 0;
1894
1895 if (!UseOprofile) {
1896 return;
1897 }
1898
1899 char buf[PATH_MAX + 1];
1900 int num = Atomic::add(1, &cnt);
1901
1902 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
1903 os::get_temp_directory(), os::current_process_id(), num);
1904 unlink(buf);
1905
1906 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
1907
1908 if (fd != -1) {
1909 off_t rv = ::lseek(fd, size-2, SEEK_SET);
1910 if (rv != (off_t)-1) {
1911 if (::write(fd, "", 1) == 1) {
1912 mmap(base, size,
1913 PROT_READ|PROT_WRITE|PROT_EXEC,
1914 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
1915 }
1916 }
1917 ::close(fd);
1918 unlink(buf);
1919 }
1920 }
1921
1922 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
1923 int err) {
1924 warning("INFO: os::commit_memory(" INTPTR_FORMAT ", " SIZE_FORMAT
1925 ", %d) failed; error='%s' (errno=%d)", (intptr_t)addr, size, exec,
1926 os::errno_name(err), err);
1927 }
1928
1929 // NOTE: Bsd kernel does not really reserve the pages for us.
1930 // All it does is to check if there are enough free pages
1931 // left at the time of mmap(). This could be a potential
1932 // problem.
1933 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
1934 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
1935 #ifdef __OpenBSD__
1936 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
1937 Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(addr), p2i(addr+size), prot);
1938 if (::mprotect(addr, size, prot) == 0) {
1939 return true;
1940 }
1941 #else
1942 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
1943 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
1944 if (res != (uintptr_t) MAP_FAILED) {
1945 return true;
1946 }
1947 #endif
1948
1949 // Warn about any commit errors we see in non-product builds just
1950 // in case mmap() doesn't work as described on the man page.
1951 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
1952
1953 return false;
1954 }
1955
1956 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
1957 bool exec) {
1958 // alignment_hint is ignored on this OS
1959 return pd_commit_memory(addr, size, exec);
1960 }
1961
1962 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
1963 const char* mesg) {
1964 assert(mesg != NULL, "mesg must be specified");
1965 if (!pd_commit_memory(addr, size, exec)) {
1966 // add extra info in product mode for vm_exit_out_of_memory():
1967 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
1968 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, "%s", mesg);
1969 }
1970 }
1971
1972 void os::pd_commit_memory_or_exit(char* addr, size_t size,
1973 size_t alignment_hint, bool exec,
1974 const char* mesg) {
1975 // alignment_hint is ignored on this OS
1976 pd_commit_memory_or_exit(addr, size, exec, mesg);
1977 }
1978
1979 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1980 }
1981
1982 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1983 ::madvise(addr, bytes, MADV_DONTNEED);
1984 }
1985
1986 void os::numa_make_global(char *addr, size_t bytes) {
1987 }
1988
1989 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
1990 }
1991
1992 bool os::numa_topology_changed() { return false; }
1993
1994 size_t os::numa_get_groups_num() {
1995 return 1;
1996 }
1997
1998 int os::numa_get_group_id() {
1999 return 0;
2000 }
2001
2002 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2003 if (size > 0) {
2004 ids[0] = 0;
2005 return 1;
2006 }
2007 return 0;
2008 }
2009
2010 bool os::get_page_info(char *start, page_info* info) {
2011 return false;
2012 }
2013
2014 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2015 return end;
2016 }
2017
2018
2019 bool os::pd_uncommit_memory(char* addr, size_t size) {
2020 #ifdef __OpenBSD__
2021 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2022 Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with PROT_NONE", p2i(addr), p2i(addr+size));
2023 return ::mprotect(addr, size, PROT_NONE) == 0;
2024 #else
2025 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2026 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2027 return res != (uintptr_t) MAP_FAILED;
2028 #endif
2029 }
2030
2031 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2032 return os::commit_memory(addr, size, !ExecMem);
2033 }
2034
2035 // If this is a growable mapping, remove the guard pages entirely by
2036 // munmap()ping them. If not, just call uncommit_memory().
2037 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2038 return os::uncommit_memory(addr, size);
2039 }
2040
2041 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2042 // at 'requested_addr'. If there are existing memory mappings at the same
2043 // location, however, they will be overwritten. If 'fixed' is false,
2044 // 'requested_addr' is only treated as a hint, the return value may or
2045 // may not start from the requested address. Unlike Bsd mmap(), this
2046 // function returns NULL to indicate failure.
2047 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2048 char * addr;
2049 int flags;
2050
2051 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2052 if (fixed) {
2053 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2054 flags |= MAP_FIXED;
2055 }
2056
2057 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2058 // touch an uncommitted page. Otherwise, the read/write might
2059 // succeed if we have enough swap space to back the physical page.
2060 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2061 flags, -1, 0);
2062
2063 return addr == MAP_FAILED ? NULL : addr;
2064 }
2065
2066 static int anon_munmap(char * addr, size_t size) {
2067 return ::munmap(addr, size) == 0;
2068 }
2069
2070 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2071 size_t alignment_hint) {
2072 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2073 }
2074
2075 bool os::pd_release_memory(char* addr, size_t size) {
2076 return anon_munmap(addr, size);
2077 }
2078
2079 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2080 // Bsd wants the mprotect address argument to be page aligned.
2081 char* bottom = (char*)align_down((intptr_t)addr, os::Bsd::page_size());
2082
2083 // According to SUSv3, mprotect() should only be used with mappings
2084 // established by mmap(), and mmap() always maps whole pages. Unaligned
2085 // 'addr' likely indicates problem in the VM (e.g. trying to change
2086 // protection of malloc'ed or statically allocated memory). Check the
2087 // caller if you hit this assert.
2088 assert(addr == bottom, "sanity check");
2089
2090 size = align_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2091 Events::log(NULL, "Protecting memory [" INTPTR_FORMAT "," INTPTR_FORMAT "] with protection modes %x", p2i(bottom), p2i(bottom+size), prot);
2092 return ::mprotect(bottom, size, prot) == 0;
2093 }
2094
2095 // Set protections specified
2096 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2097 bool is_committed) {
2098 unsigned int p = 0;
2099 switch (prot) {
2100 case MEM_PROT_NONE: p = PROT_NONE; break;
2101 case MEM_PROT_READ: p = PROT_READ; break;
2102 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
2103 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2104 default:
2105 ShouldNotReachHere();
2106 }
2107 // is_committed is unused.
2108 return bsd_mprotect(addr, bytes, p);
2109 }
2110
2111 bool os::guard_memory(char* addr, size_t size) {
2112 return bsd_mprotect(addr, size, PROT_NONE);
2113 }
2114
2115 bool os::unguard_memory(char* addr, size_t size) {
2116 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2117 }
2118
2119 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2120 return false;
2121 }
2122
2123 // Large page support
2124
2125 static size_t _large_page_size = 0;
2126
2127 void os::large_page_init() {
2128 }
2129
2130
2131 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2132 fatal("os::reserve_memory_special should not be called on BSD.");
2133 return NULL;
2134 }
2135
2136 bool os::release_memory_special(char* base, size_t bytes) {
2137 fatal("os::release_memory_special should not be called on BSD.");
2138 return false;
2139 }
2140
2141 size_t os::large_page_size() {
2142 return _large_page_size;
2143 }
2144
2145 bool os::can_commit_large_page_memory() {
2146 // Does not matter, we do not support huge pages.
2147 return false;
2148 }
2149
2150 bool os::can_execute_large_page_memory() {
2151 // Does not matter, we do not support huge pages.
2152 return false;
2153 }
2154
2155 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr, int file_desc) {
2156 assert(file_desc >= 0, "file_desc is not valid");
2157 char* result = pd_attempt_reserve_memory_at(bytes, requested_addr);
2158 if (result != NULL) {
2159 if (replace_existing_mapping_with_file_mapping(result, bytes, file_desc) == NULL) {
2160 vm_exit_during_initialization(err_msg("Error in mapping Java heap at the given filesystem directory"));
2161 }
2162 }
2163 return result;
2164 }
2165
2166 // Reserve memory at an arbitrary address, only if that area is
2167 // available (and not reserved for something else).
2168
2169 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2170 // Assert only that the size is a multiple of the page size, since
2171 // that's all that mmap requires, and since that's all we really know
2172 // about at this low abstraction level. If we need higher alignment,
2173 // we can either pass an alignment to this method or verify alignment
2174 // in one of the methods further up the call chain. See bug 5044738.
2175 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2176
2177 // Repeatedly allocate blocks until the block is allocated at the
2178 // right spot.
2179
2180 // Bsd mmap allows caller to pass an address as hint; give it a try first,
2181 // if kernel honors the hint then we can return immediately.
2182 char * addr = anon_mmap(requested_addr, bytes, false);
2183 if (addr == requested_addr) {
2184 return requested_addr;
2185 }
2186
2187 if (addr != NULL) {
2188 // mmap() is successful but it fails to reserve at the requested address
2189 anon_munmap(addr, bytes);
2190 }
2191
2192 return NULL;
2193 }
2194
2195 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2196 void os::infinite_sleep() {
2197 while (true) { // sleep forever ...
2198 ::sleep(100); // ... 100 seconds at a time
2199 }
2200 }
2201
2202 // Used to convert frequent JVM_Yield() to nops
2203 bool os::dont_yield() {
2204 return DontYieldALot;
2205 }
2206
2207 void os::naked_yield() {
2208 sched_yield();
2209 }
2210
2211 ////////////////////////////////////////////////////////////////////////////////
2212 // thread priority support
2213
2214 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2215 // only supports dynamic priority, static priority must be zero. For real-time
2216 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2217 // However, for large multi-threaded applications, SCHED_RR is not only slower
2218 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2219 // of 5 runs - Sep 2005).
2220 //
2221 // The following code actually changes the niceness of kernel-thread/LWP. It
2222 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2223 // not the entire user process, and user level threads are 1:1 mapped to kernel
2224 // threads. It has always been the case, but could change in the future. For
2225 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2226 // It is only used when ThreadPriorityPolicy=1 and may require system level permission
2227 // (e.g., root privilege or CAP_SYS_NICE capability).
2228
2229 #if !defined(__APPLE__)
2230 int os::java_to_os_priority[CriticalPriority + 1] = {
2231 19, // 0 Entry should never be used
2232
2233 0, // 1 MinPriority
2234 3, // 2
2235 6, // 3
2236
2237 10, // 4
2238 15, // 5 NormPriority
2239 18, // 6
2240
2241 21, // 7
2242 25, // 8
2243 28, // 9 NearMaxPriority
2244
2245 31, // 10 MaxPriority
2246
2247 31 // 11 CriticalPriority
2248 };
2249 #else
2250 // Using Mach high-level priority assignments
2251 int os::java_to_os_priority[CriticalPriority + 1] = {
2252 0, // 0 Entry should never be used (MINPRI_USER)
2253
2254 27, // 1 MinPriority
2255 28, // 2
2256 29, // 3
2257
2258 30, // 4
2259 31, // 5 NormPriority (BASEPRI_DEFAULT)
2260 32, // 6
2261
2262 33, // 7
2263 34, // 8
2264 35, // 9 NearMaxPriority
2265
2266 36, // 10 MaxPriority
2267
2268 36 // 11 CriticalPriority
2269 };
2270 #endif
2271
2272 static int prio_init() {
2273 if (ThreadPriorityPolicy == 1) {
2274 if (geteuid() != 0) {
2275 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2276 warning("-XX:ThreadPriorityPolicy=1 may require system level permission, " \
2277 "e.g., being the root user. If the necessary permission is not " \
2278 "possessed, changes to priority will be silently ignored.");
2279 }
2280 }
2281 }
2282 if (UseCriticalJavaThreadPriority) {
2283 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2284 }
2285 return 0;
2286 }
2287
2288 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2289 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2290
2291 #ifdef __OpenBSD__
2292 // OpenBSD pthread_setprio starves low priority threads
2293 return OS_OK;
2294 #elif defined(__FreeBSD__)
2295 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2296 return (ret == 0) ? OS_OK : OS_ERR;
2297 #elif defined(__APPLE__) || defined(__NetBSD__)
2298 struct sched_param sp;
2299 int policy;
2300
2301 if (pthread_getschedparam(thread->osthread()->pthread_id(), &policy, &sp) != 0) {
2302 return OS_ERR;
2303 }
2304
2305 sp.sched_priority = newpri;
2306 if (pthread_setschedparam(thread->osthread()->pthread_id(), policy, &sp) != 0) {
2307 return OS_ERR;
2308 }
2309
2310 return OS_OK;
2311 #else
2312 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2313 return (ret == 0) ? OS_OK : OS_ERR;
2314 #endif
2315 }
2316
2317 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2318 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2319 *priority_ptr = java_to_os_priority[NormPriority];
2320 return OS_OK;
2321 }
2322
2323 errno = 0;
2324 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2325 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2326 #elif defined(__APPLE__) || defined(__NetBSD__)
2327 int policy;
2328 struct sched_param sp;
2329
2330 int res = pthread_getschedparam(thread->osthread()->pthread_id(), &policy, &sp);
2331 if (res != 0) {
2332 *priority_ptr = -1;
2333 return OS_ERR;
2334 } else {
2335 *priority_ptr = sp.sched_priority;
2336 return OS_OK;
2337 }
2338 #else
2339 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2340 #endif
2341 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2342 }
2343
2344 ////////////////////////////////////////////////////////////////////////////////
2345 // suspend/resume support
2346
2347 // The low-level signal-based suspend/resume support is a remnant from the
2348 // old VM-suspension that used to be for java-suspension, safepoints etc,
2349 // within hotspot. Currently used by JFR's OSThreadSampler
2350 //
2351 // The remaining code is greatly simplified from the more general suspension
2352 // code that used to be used.
2353 //
2354 // The protocol is quite simple:
2355 // - suspend:
2356 // - sends a signal to the target thread
2357 // - polls the suspend state of the osthread using a yield loop
2358 // - target thread signal handler (SR_handler) sets suspend state
2359 // and blocks in sigsuspend until continued
2360 // - resume:
2361 // - sets target osthread state to continue
2362 // - sends signal to end the sigsuspend loop in the SR_handler
2363 //
2364 // Note that the SR_lock plays no role in this suspend/resume protocol,
2365 // but is checked for NULL in SR_handler as a thread termination indicator.
2366 // The SR_lock is, however, used by JavaThread::java_suspend()/java_resume() APIs.
2367 //
2368 // Note that resume_clear_context() and suspend_save_context() are needed
2369 // by SR_handler(), so that fetch_frame_from_ucontext() works,
2370 // which in part is used by:
2371 // - Forte Analyzer: AsyncGetCallTrace()
2372 // - StackBanging: get_frame_at_stack_banging_point()
2373
2374 static void resume_clear_context(OSThread *osthread) {
2375 osthread->set_ucontext(NULL);
2376 osthread->set_siginfo(NULL);
2377 }
2378
2379 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2380 osthread->set_ucontext(context);
2381 osthread->set_siginfo(siginfo);
2382 }
2383
2384 // Handler function invoked when a thread's execution is suspended or
2385 // resumed. We have to be careful that only async-safe functions are
2386 // called here (Note: most pthread functions are not async safe and
2387 // should be avoided.)
2388 //
2389 // Note: sigwait() is a more natural fit than sigsuspend() from an
2390 // interface point of view, but sigwait() prevents the signal hander
2391 // from being run. libpthread would get very confused by not having
2392 // its signal handlers run and prevents sigwait()'s use with the
2393 // mutex granting granting signal.
2394 //
2395 // Currently only ever called on the VMThread or JavaThread
2396 //
2397 #ifdef __APPLE__
2398 static OSXSemaphore sr_semaphore;
2399 #else
2400 static PosixSemaphore sr_semaphore;
2401 #endif
2402
2403 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2404 // Save and restore errno to avoid confusing native code with EINTR
2405 // after sigsuspend.
2406 int old_errno = errno;
2407
2408 Thread* thread = Thread::current_or_null_safe();
2409 assert(thread != NULL, "Missing current thread in SR_handler");
2410
2411 // On some systems we have seen signal delivery get "stuck" until the signal
2412 // mask is changed as part of thread termination. Check that the current thread
2413 // has not already terminated (via SR_lock()) - else the following assertion
2414 // will fail because the thread is no longer a JavaThread as the ~JavaThread
2415 // destructor has completed.
2416
2417 if (thread->SR_lock() == NULL) {
2418 return;
2419 }
2420
2421 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2422
2423 OSThread* osthread = thread->osthread();
2424
2425 os::SuspendResume::State current = osthread->sr.state();
2426 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2427 suspend_save_context(osthread, siginfo, context);
2428
2429 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2430 os::SuspendResume::State state = osthread->sr.suspended();
2431 if (state == os::SuspendResume::SR_SUSPENDED) {
2432 sigset_t suspend_set; // signals for sigsuspend()
2433
2434 // get current set of blocked signals and unblock resume signal
2435 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2436 sigdelset(&suspend_set, SR_signum);
2437
2438 sr_semaphore.signal();
2439 // wait here until we are resumed
2440 while (1) {
2441 sigsuspend(&suspend_set);
2442
2443 os::SuspendResume::State result = osthread->sr.running();
2444 if (result == os::SuspendResume::SR_RUNNING) {
2445 sr_semaphore.signal();
2446 break;
2447 } else if (result != os::SuspendResume::SR_SUSPENDED) {
2448 ShouldNotReachHere();
2449 }
2450 }
2451
2452 } else if (state == os::SuspendResume::SR_RUNNING) {
2453 // request was cancelled, continue
2454 } else {
2455 ShouldNotReachHere();
2456 }
2457
2458 resume_clear_context(osthread);
2459 } else if (current == os::SuspendResume::SR_RUNNING) {
2460 // request was cancelled, continue
2461 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2462 // ignore
2463 } else {
2464 // ignore
2465 }
2466
2467 errno = old_errno;
2468 }
2469
2470
2471 static int SR_initialize() {
2472 struct sigaction act;
2473 char *s;
2474 // Get signal number to use for suspend/resume
2475 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2476 int sig = ::strtol(s, 0, 10);
2477 if (sig > MAX2(SIGSEGV, SIGBUS) && // See 4355769.
2478 sig < NSIG) { // Must be legal signal and fit into sigflags[].
2479 SR_signum = sig;
2480 } else {
2481 warning("You set _JAVA_SR_SIGNUM=%d. It must be in range [%d, %d]. Using %d instead.",
2482 sig, MAX2(SIGSEGV, SIGBUS)+1, NSIG-1, SR_signum);
2483 }
2484 }
2485
2486 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2487 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2488
2489 sigemptyset(&SR_sigset);
2490 sigaddset(&SR_sigset, SR_signum);
2491
2492 // Set up signal handler for suspend/resume
2493 act.sa_flags = SA_RESTART|SA_SIGINFO;
2494 act.sa_handler = (void (*)(int)) SR_handler;
2495
2496 // SR_signum is blocked by default.
2497 // 4528190 - We also need to block pthread restart signal (32 on all
2498 // supported Bsd platforms). Note that BsdThreads need to block
2499 // this signal for all threads to work properly. So we don't have
2500 // to use hard-coded signal number when setting up the mask.
2501 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2502
2503 if (sigaction(SR_signum, &act, 0) == -1) {
2504 return -1;
2505 }
2506
2507 // Save signal flag
2508 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2509 return 0;
2510 }
2511
2512 static int sr_notify(OSThread* osthread) {
2513 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2514 assert_status(status == 0, status, "pthread_kill");
2515 return status;
2516 }
2517
2518 // "Randomly" selected value for how long we want to spin
2519 // before bailing out on suspending a thread, also how often
2520 // we send a signal to a thread we want to resume
2521 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2522 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2523
2524 // returns true on success and false on error - really an error is fatal
2525 // but this seems the normal response to library errors
2526 static bool do_suspend(OSThread* osthread) {
2527 assert(osthread->sr.is_running(), "thread should be running");
2528 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2529
2530 // mark as suspended and send signal
2531 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2532 // failed to switch, state wasn't running?
2533 ShouldNotReachHere();
2534 return false;
2535 }
2536
2537 if (sr_notify(osthread) != 0) {
2538 ShouldNotReachHere();
2539 }
2540
2541 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2542 while (true) {
2543 if (sr_semaphore.timedwait(2)) {
2544 break;
2545 } else {
2546 // timeout
2547 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2548 if (cancelled == os::SuspendResume::SR_RUNNING) {
2549 return false;
2550 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2551 // make sure that we consume the signal on the semaphore as well
2552 sr_semaphore.wait();
2553 break;
2554 } else {
2555 ShouldNotReachHere();
2556 return false;
2557 }
2558 }
2559 }
2560
2561 guarantee(osthread->sr.is_suspended(), "Must be suspended");
2562 return true;
2563 }
2564
2565 static void do_resume(OSThread* osthread) {
2566 assert(osthread->sr.is_suspended(), "thread should be suspended");
2567 assert(!sr_semaphore.trywait(), "invalid semaphore state");
2568
2569 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2570 // failed to switch to WAKEUP_REQUEST
2571 ShouldNotReachHere();
2572 return;
2573 }
2574
2575 while (true) {
2576 if (sr_notify(osthread) == 0) {
2577 if (sr_semaphore.timedwait(2)) {
2578 if (osthread->sr.is_running()) {
2579 return;
2580 }
2581 }
2582 } else {
2583 ShouldNotReachHere();
2584 }
2585 }
2586
2587 guarantee(osthread->sr.is_running(), "Must be running!");
2588 }
2589
2590 ///////////////////////////////////////////////////////////////////////////////////
2591 // signal handling (except suspend/resume)
2592
2593 // This routine may be used by user applications as a "hook" to catch signals.
2594 // The user-defined signal handler must pass unrecognized signals to this
2595 // routine, and if it returns true (non-zero), then the signal handler must
2596 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2597 // routine will never retun false (zero), but instead will execute a VM panic
2598 // routine kill the process.
2599 //
2600 // If this routine returns false, it is OK to call it again. This allows
2601 // the user-defined signal handler to perform checks either before or after
2602 // the VM performs its own checks. Naturally, the user code would be making
2603 // a serious error if it tried to handle an exception (such as a null check
2604 // or breakpoint) that the VM was generating for its own correct operation.
2605 //
2606 // This routine may recognize any of the following kinds of signals:
2607 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2608 // It should be consulted by handlers for any of those signals.
2609 //
2610 // The caller of this routine must pass in the three arguments supplied
2611 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2612 // field of the structure passed to sigaction(). This routine assumes that
2613 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2614 //
2615 // Note that the VM will print warnings if it detects conflicting signal
2616 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2617 //
2618 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2619 void* ucontext,
2620 int abort_if_unrecognized);
2621
2622 static void signalHandler(int sig, siginfo_t* info, void* uc) {
2623 assert(info != NULL && uc != NULL, "it must be old kernel");
2624 int orig_errno = errno; // Preserve errno value over signal handler.
2625 JVM_handle_bsd_signal(sig, info, uc, true);
2626 errno = orig_errno;
2627 }
2628
2629
2630 // This boolean allows users to forward their own non-matching signals
2631 // to JVM_handle_bsd_signal, harmlessly.
2632 bool os::Bsd::signal_handlers_are_installed = false;
2633
2634 // For signal-chaining
2635 bool os::Bsd::libjsig_is_loaded = false;
2636 typedef struct sigaction *(*get_signal_t)(int);
2637 get_signal_t os::Bsd::get_signal_action = NULL;
2638
2639 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
2640 struct sigaction *actp = NULL;
2641
2642 if (libjsig_is_loaded) {
2643 // Retrieve the old signal handler from libjsig
2644 actp = (*get_signal_action)(sig);
2645 }
2646 if (actp == NULL) {
2647 // Retrieve the preinstalled signal handler from jvm
2648 actp = os::Posix::get_preinstalled_handler(sig);
2649 }
2650
2651 return actp;
2652 }
2653
2654 static bool call_chained_handler(struct sigaction *actp, int sig,
2655 siginfo_t *siginfo, void *context) {
2656 // Call the old signal handler
2657 if (actp->sa_handler == SIG_DFL) {
2658 // It's more reasonable to let jvm treat it as an unexpected exception
2659 // instead of taking the default action.
2660 return false;
2661 } else if (actp->sa_handler != SIG_IGN) {
2662 if ((actp->sa_flags & SA_NODEFER) == 0) {
2663 // automaticlly block the signal
2664 sigaddset(&(actp->sa_mask), sig);
2665 }
2666
2667 sa_handler_t hand;
2668 sa_sigaction_t sa;
2669 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
2670 // retrieve the chained handler
2671 if (siginfo_flag_set) {
2672 sa = actp->sa_sigaction;
2673 } else {
2674 hand = actp->sa_handler;
2675 }
2676
2677 if ((actp->sa_flags & SA_RESETHAND) != 0) {
2678 actp->sa_handler = SIG_DFL;
2679 }
2680
2681 // try to honor the signal mask
2682 sigset_t oset;
2683 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
2684
2685 // call into the chained handler
2686 if (siginfo_flag_set) {
2687 (*sa)(sig, siginfo, context);
2688 } else {
2689 (*hand)(sig);
2690 }
2691
2692 // restore the signal mask
2693 pthread_sigmask(SIG_SETMASK, &oset, 0);
2694 }
2695 // Tell jvm's signal handler the signal is taken care of.
2696 return true;
2697 }
2698
2699 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
2700 bool chained = false;
2701 // signal-chaining
2702 if (UseSignalChaining) {
2703 struct sigaction *actp = get_chained_signal_action(sig);
2704 if (actp != NULL) {
2705 chained = call_chained_handler(actp, sig, siginfo, context);
2706 }
2707 }
2708 return chained;
2709 }
2710
2711 // for diagnostic
2712 int sigflags[NSIG];
2713
2714 int os::Bsd::get_our_sigflags(int sig) {
2715 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2716 return sigflags[sig];
2717 }
2718
2719 void os::Bsd::set_our_sigflags(int sig, int flags) {
2720 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2721 if (sig > 0 && sig < NSIG) {
2722 sigflags[sig] = flags;
2723 }
2724 }
2725
2726 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
2727 // Check for overwrite.
2728 struct sigaction oldAct;
2729 sigaction(sig, (struct sigaction*)NULL, &oldAct);
2730
2731 void* oldhand = oldAct.sa_sigaction
2732 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
2733 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
2734 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
2735 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
2736 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
2737 if (AllowUserSignalHandlers || !set_installed) {
2738 // Do not overwrite; user takes responsibility to forward to us.
2739 return;
2740 } else if (UseSignalChaining) {
2741 // save the old handler in jvm
2742 os::Posix::save_preinstalled_handler(sig, oldAct);
2743 // libjsig also interposes the sigaction() call below and saves the
2744 // old sigaction on it own.
2745 } else {
2746 fatal("Encountered unexpected pre-existing sigaction handler "
2747 "%#lx for signal %d.", (long)oldhand, sig);
2748 }
2749 }
2750
2751 struct sigaction sigAct;
2752 sigfillset(&(sigAct.sa_mask));
2753 sigAct.sa_handler = SIG_DFL;
2754 if (!set_installed) {
2755 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
2756 } else {
2757 sigAct.sa_sigaction = signalHandler;
2758 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
2759 }
2760 #ifdef __APPLE__
2761 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
2762 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
2763 // if the signal handler declares it will handle it on alternate stack.
2764 // Notice we only declare we will handle it on alt stack, but we are not
2765 // actually going to use real alt stack - this is just a workaround.
2766 // Please see ux_exception.c, method catch_mach_exception_raise for details
2767 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
2768 if (sig == SIGSEGV) {
2769 sigAct.sa_flags |= SA_ONSTACK;
2770 }
2771 #endif
2772
2773 // Save flags, which are set by ours
2774 assert(sig > 0 && sig < NSIG, "vm signal out of expected range");
2775 sigflags[sig] = sigAct.sa_flags;
2776
2777 int ret = sigaction(sig, &sigAct, &oldAct);
2778 assert(ret == 0, "check");
2779
2780 void* oldhand2 = oldAct.sa_sigaction
2781 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
2782 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
2783 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
2784 }
2785
2786 // install signal handlers for signals that HotSpot needs to
2787 // handle in order to support Java-level exception handling.
2788
2789 void os::Bsd::install_signal_handlers() {
2790 if (!signal_handlers_are_installed) {
2791 signal_handlers_are_installed = true;
2792
2793 // signal-chaining
2794 typedef void (*signal_setting_t)();
2795 signal_setting_t begin_signal_setting = NULL;
2796 signal_setting_t end_signal_setting = NULL;
2797 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
2798 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
2799 if (begin_signal_setting != NULL) {
2800 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
2801 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
2802 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
2803 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
2804 libjsig_is_loaded = true;
2805 assert(UseSignalChaining, "should enable signal-chaining");
2806 }
2807 if (libjsig_is_loaded) {
2808 // Tell libjsig jvm is setting signal handlers
2809 (*begin_signal_setting)();
2810 }
2811
2812 set_signal_handler(SIGSEGV, true);
2813 set_signal_handler(SIGPIPE, true);
2814 set_signal_handler(SIGBUS, true);
2815 set_signal_handler(SIGILL, true);
2816 set_signal_handler(SIGFPE, true);
2817 set_signal_handler(SIGXFSZ, true);
2818
2819 #if defined(__APPLE__)
2820 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
2821 // signals caught and handled by the JVM. To work around this, we reset the mach task
2822 // signal handler that's placed on our process by CrashReporter. This disables
2823 // CrashReporter-based reporting.
2824 //
2825 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
2826 // on caught fatal signals.
2827 //
2828 // Additionally, gdb installs both standard BSD signal handlers, and mach exception
2829 // handlers. By replacing the existing task exception handler, we disable gdb's mach
2830 // exception handling, while leaving the standard BSD signal handlers functional.
2831 kern_return_t kr;
2832 kr = task_set_exception_ports(mach_task_self(),
2833 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
2834 MACH_PORT_NULL,
2835 EXCEPTION_STATE_IDENTITY,
2836 MACHINE_THREAD_STATE);
2837
2838 assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
2839 #endif
2840
2841 if (libjsig_is_loaded) {
2842 // Tell libjsig jvm finishes setting signal handlers
2843 (*end_signal_setting)();
2844 }
2845
2846 // We don't activate signal checker if libjsig is in place, we trust ourselves
2847 // and if UserSignalHandler is installed all bets are off
2848 if (CheckJNICalls) {
2849 if (libjsig_is_loaded) {
2850 if (PrintJNIResolving) {
2851 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
2852 }
2853 check_signals = false;
2854 }
2855 if (AllowUserSignalHandlers) {
2856 if (PrintJNIResolving) {
2857 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
2858 }
2859 check_signals = false;
2860 }
2861 }
2862 }
2863 }
2864
2865
2866 /////
2867 // glibc on Bsd platform uses non-documented flag
2868 // to indicate, that some special sort of signal
2869 // trampoline is used.
2870 // We will never set this flag, and we should
2871 // ignore this flag in our diagnostic
2872 #ifdef SIGNIFICANT_SIGNAL_MASK
2873 #undef SIGNIFICANT_SIGNAL_MASK
2874 #endif
2875 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
2876
2877 static const char* get_signal_handler_name(address handler,
2878 char* buf, int buflen) {
2879 int offset;
2880 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
2881 if (found) {
2882 // skip directory names
2883 const char *p1, *p2;
2884 p1 = buf;
2885 size_t len = strlen(os::file_separator());
2886 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
2887 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
2888 } else {
2889 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
2890 }
2891 return buf;
2892 }
2893
2894 static void print_signal_handler(outputStream* st, int sig,
2895 char* buf, size_t buflen) {
2896 struct sigaction sa;
2897
2898 sigaction(sig, NULL, &sa);
2899
2900 // See comment for SIGNIFICANT_SIGNAL_MASK define
2901 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
2902
2903 st->print("%s: ", os::exception_name(sig, buf, buflen));
2904
2905 address handler = (sa.sa_flags & SA_SIGINFO)
2906 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
2907 : CAST_FROM_FN_PTR(address, sa.sa_handler);
2908
2909 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
2910 st->print("SIG_DFL");
2911 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
2912 st->print("SIG_IGN");
2913 } else {
2914 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
2915 }
2916
2917 st->print(", sa_mask[0]=");
2918 os::Posix::print_signal_set_short(st, &sa.sa_mask);
2919
2920 address rh = VMError::get_resetted_sighandler(sig);
2921 // May be, handler was resetted by VMError?
2922 if (rh != NULL) {
2923 handler = rh;
2924 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
2925 }
2926
2927 st->print(", sa_flags=");
2928 os::Posix::print_sa_flags(st, sa.sa_flags);
2929
2930 // Check: is it our handler?
2931 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
2932 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
2933 // It is our signal handler
2934 // check for flags, reset system-used one!
2935 if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
2936 st->print(
2937 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
2938 os::Bsd::get_our_sigflags(sig));
2939 }
2940 }
2941 st->cr();
2942 }
2943
2944
2945 #define DO_SIGNAL_CHECK(sig) \
2946 do { \
2947 if (!sigismember(&check_signal_done, sig)) { \
2948 os::Bsd::check_signal_handler(sig); \
2949 } \
2950 } while (0)
2951
2952 // This method is a periodic task to check for misbehaving JNI applications
2953 // under CheckJNI, we can add any periodic checks here
2954
2955 void os::run_periodic_checks() {
2956
2957 if (check_signals == false) return;
2958
2959 // SEGV and BUS if overridden could potentially prevent
2960 // generation of hs*.log in the event of a crash, debugging
2961 // such a case can be very challenging, so we absolutely
2962 // check the following for a good measure:
2963 DO_SIGNAL_CHECK(SIGSEGV);
2964 DO_SIGNAL_CHECK(SIGILL);
2965 DO_SIGNAL_CHECK(SIGFPE);
2966 DO_SIGNAL_CHECK(SIGBUS);
2967 DO_SIGNAL_CHECK(SIGPIPE);
2968 DO_SIGNAL_CHECK(SIGXFSZ);
2969
2970
2971 // ReduceSignalUsage allows the user to override these handlers
2972 // see comments at the very top and jvm_md.h
2973 if (!ReduceSignalUsage) {
2974 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
2975 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
2976 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
2977 DO_SIGNAL_CHECK(BREAK_SIGNAL);
2978 }
2979
2980 DO_SIGNAL_CHECK(SR_signum);
2981 }
2982
2983 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
2984
2985 static os_sigaction_t os_sigaction = NULL;
2986
2987 void os::Bsd::check_signal_handler(int sig) {
2988 char buf[O_BUFLEN];
2989 address jvmHandler = NULL;
2990
2991
2992 struct sigaction act;
2993 if (os_sigaction == NULL) {
2994 // only trust the default sigaction, in case it has been interposed
2995 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
2996 if (os_sigaction == NULL) return;
2997 }
2998
2999 os_sigaction(sig, (struct sigaction*)NULL, &act);
3000
3001
3002 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3003
3004 address thisHandler = (act.sa_flags & SA_SIGINFO)
3005 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3006 : CAST_FROM_FN_PTR(address, act.sa_handler);
3007
3008
3009 switch (sig) {
3010 case SIGSEGV:
3011 case SIGBUS:
3012 case SIGFPE:
3013 case SIGPIPE:
3014 case SIGILL:
3015 case SIGXFSZ:
3016 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3017 break;
3018
3019 case SHUTDOWN1_SIGNAL:
3020 case SHUTDOWN2_SIGNAL:
3021 case SHUTDOWN3_SIGNAL:
3022 case BREAK_SIGNAL:
3023 jvmHandler = (address)user_handler();
3024 break;
3025
3026 default:
3027 if (sig == SR_signum) {
3028 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3029 } else {
3030 return;
3031 }
3032 break;
3033 }
3034
3035 if (thisHandler != jvmHandler) {
3036 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3037 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3038 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3039 // No need to check this sig any longer
3040 sigaddset(&check_signal_done, sig);
3041 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3042 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3043 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3044 exception_name(sig, buf, O_BUFLEN));
3045 }
3046 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3047 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3048 tty->print("expected:");
3049 os::Posix::print_sa_flags(tty, os::Bsd::get_our_sigflags(sig));
3050 tty->cr();
3051 tty->print(" found:");
3052 os::Posix::print_sa_flags(tty, act.sa_flags);
3053 tty->cr();
3054 // No need to check this sig any longer
3055 sigaddset(&check_signal_done, sig);
3056 }
3057
3058 // Dump all the signal
3059 if (sigismember(&check_signal_done, sig)) {
3060 print_signal_handlers(tty, buf, O_BUFLEN);
3061 }
3062 }
3063
3064 extern void report_error(char* file_name, int line_no, char* title,
3065 char* format, ...);
3066
3067 // this is called _before_ the most of global arguments have been parsed
3068 void os::init(void) {
3069 char dummy; // used to get a guess on initial stack address
3070
3071 clock_tics_per_sec = CLK_TCK;
3072
3073 init_random(1234567);
3074
3075 Bsd::set_page_size(getpagesize());
3076 if (Bsd::page_size() == -1) {
3077 fatal("os_bsd.cpp: os::init: sysconf failed (%s)", os::strerror(errno));
3078 }
3079 init_page_sizes((size_t) Bsd::page_size());
3080
3081 Bsd::initialize_system_info();
3082
3083 // _main_thread points to the thread that created/loaded the JVM.
3084 Bsd::_main_thread = pthread_self();
3085
3086 Bsd::clock_init();
3087 initial_time_count = javaTimeNanos();
3088
3089 os::Posix::init();
3090 }
3091
3092 // To install functions for atexit system call
3093 extern "C" {
3094 static void perfMemory_exit_helper() {
3095 perfMemory_exit();
3096 }
3097 }
3098
3099 // this is called _after_ the global arguments have been parsed
3100 jint os::init_2(void) {
3101
3102 // This could be set after os::Posix::init() but all platforms
3103 // have to set it the same so we have to mirror Solaris.
3104 DEBUG_ONLY(os::set_mutex_init_done();)
3105
3106 os::Posix::init_2();
3107
3108 // initialize suspend/resume support - must do this before signal_sets_init()
3109 if (SR_initialize() != 0) {
3110 perror("SR_initialize failed");
3111 return JNI_ERR;
3112 }
3113
3114 Bsd::signal_sets_init();
3115 Bsd::install_signal_handlers();
3116 // Initialize data for jdk.internal.misc.Signal
3117 if (!ReduceSignalUsage) {
3118 jdk_misc_signal_init();
3119 }
3120
3121 // Check and sets minimum stack sizes against command line options
3122 if (Posix::set_minimum_stack_sizes() == JNI_ERR) {
3123 return JNI_ERR;
3124 }
3125
3126 if (MaxFDLimit) {
3127 // set the number of file descriptors to max. print out error
3128 // if getrlimit/setrlimit fails but continue regardless.
3129 struct rlimit nbr_files;
3130 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3131 if (status != 0) {
3132 log_info(os)("os::init_2 getrlimit failed: %s", os::strerror(errno));
3133 } else {
3134 nbr_files.rlim_cur = nbr_files.rlim_max;
3135
3136 #ifdef __APPLE__
3137 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3138 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3139 // be used instead
3140 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3141 #endif
3142
3143 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3144 if (status != 0) {
3145 log_info(os)("os::init_2 setrlimit failed: %s", os::strerror(errno));
3146 }
3147 }
3148 }
3149
3150 // at-exit methods are called in the reverse order of their registration.
3151 // atexit functions are called on return from main or as a result of a
3152 // call to exit(3C). There can be only 32 of these functions registered
3153 // and atexit() does not set errno.
3154
3155 if (PerfAllowAtExitRegistration) {
3156 // only register atexit functions if PerfAllowAtExitRegistration is set.
3157 // atexit functions can be delayed until process exit time, which
3158 // can be problematic for embedded VM situations. Embedded VMs should
3159 // call DestroyJavaVM() to assure that VM resources are released.
3160
3161 // note: perfMemory_exit_helper atexit function may be removed in
3162 // the future if the appropriate cleanup code can be added to the
3163 // VM_Exit VMOperation's doit method.
3164 if (atexit(perfMemory_exit_helper) != 0) {
3165 warning("os::init_2 atexit(perfMemory_exit_helper) failed");
3166 }
3167 }
3168
3169 // initialize thread priority policy
3170 prio_init();
3171
3172 #ifdef __APPLE__
3173 // dynamically link to objective c gc registration
3174 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3175 if (handleLibObjc != NULL) {
3176 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3177 }
3178 #endif
3179
3180 return JNI_OK;
3181 }
3182
3183 // Mark the polling page as unreadable
3184 void os::make_polling_page_unreadable(void) {
3185 if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3186 fatal("Could not disable polling page");
3187 }
3188 }
3189
3190 // Mark the polling page as readable
3191 void os::make_polling_page_readable(void) {
3192 if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3193 fatal("Could not enable polling page");
3194 }
3195 }
3196
3197 int os::active_processor_count() {
3198 // User has overridden the number of active processors
3199 if (ActiveProcessorCount > 0) {
3200 log_trace(os)("active_processor_count: "
3201 "active processor count set by user : %d",
3202 ActiveProcessorCount);
3203 return ActiveProcessorCount;
3204 }
3205
3206 return _processor_count;
3207 }
3208
3209 #ifdef __APPLE__
3210 uint os::processor_id() {
3211 static volatile int* volatile apic_to_cpu_mapping = NULL;
3212 static volatile int next_cpu_id = 0;
3213
3214 volatile int* mapping = OrderAccess::load_acquire(&apic_to_cpu_mapping);
3215 if (mapping == NULL) {
3216 // Calculate possible number space for APIC ids. This space is not necessarily
3217 // in the range [0, number_of_cpus).
3218 uint total_bits = 0;
3219 for (uint i = 0;; ++i) {
3220 uint eax = 0xb; // Query topology leaf
3221 uint ebx;
3222 uint ecx = i;
3223 uint edx;
3224
3225 __asm__ ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
3226
3227 uint level_type = (ecx >> 8) & 0xFF;
3228 if (level_type == 0) {
3229 // Invalid level; end of topology
3230 break;
3231 }
3232 uint level_apic_id_shift = eax & ((1u << 5) - 1);
3233 total_bits += level_apic_id_shift;
3234 }
3235
3236 uint max_apic_ids = 1u << total_bits;
3237 mapping = NEW_C_HEAP_ARRAY(int, max_apic_ids, mtInternal);
3238
3239 for (uint i = 0; i < max_apic_ids; ++i) {
3240 mapping[i] = -1;
3241 }
3242
3243 if (!Atomic::replace_if_null(mapping, &apic_to_cpu_mapping)) {
3244 FREE_C_HEAP_ARRAY(int, mapping);
3245 mapping = OrderAccess::load_acquire(&apic_to_cpu_mapping);
3246 }
3247 }
3248
3249 uint eax = 0xb;
3250 uint ebx;
3251 uint ecx = 0;
3252 uint edx;
3253
3254 asm ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
3255
3256 // Map from APIC id to a unique logical processor ID in the expected
3257 // [0, num_processors) range.
3258
3259 uint apic_id = edx;
3260 int cpu_id = Atomic::load(&mapping[apic_id]);
3261
3262 while (cpu_id < 0) {
3263 if (Atomic::cmpxchg(-2, &mapping[apic_id], -1)) {
3264 Atomic::store(Atomic::add(1, &next_cpu_id) - 1, &mapping[apic_id]);
3265 }
3266 cpu_id = Atomic::load(&mapping[apic_id]);
3267 }
3268
3269 return (uint)cpu_id;
3270 }
3271 #endif
3272
3273 void os::set_native_thread_name(const char *name) {
3274 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3275 // This is only supported in Snow Leopard and beyond
3276 if (name != NULL) {
3277 // Add a "Java: " prefix to the name
3278 char buf[MAXTHREADNAMESIZE];
3279 snprintf(buf, sizeof(buf), "Java: %s", name);
3280 pthread_setname_np(buf);
3281 }
3282 #endif
3283 }
3284
3285 bool os::distribute_processes(uint length, uint* distribution) {
3286 // Not yet implemented.
3287 return false;
3288 }
3289
3290 bool os::bind_to_processor(uint processor_id) {
3291 // Not yet implemented.
3292 return false;
3293 }
3294
3295 void os::SuspendedThreadTask::internal_do_task() {
3296 if (do_suspend(_thread->osthread())) {
3297 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3298 do_task(context);
3299 do_resume(_thread->osthread());
3300 }
3301 }
3302
3303 ////////////////////////////////////////////////////////////////////////////////
3304 // debug support
3305
3306 bool os::find(address addr, outputStream* st) {
3307 Dl_info dlinfo;
3308 memset(&dlinfo, 0, sizeof(dlinfo));
3309 if (dladdr(addr, &dlinfo) != 0) {
3310 st->print(INTPTR_FORMAT ": ", (intptr_t)addr);
3311 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3312 st->print("%s+%#x", dlinfo.dli_sname,
3313 (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_saddr));
3314 } else if (dlinfo.dli_fbase != NULL) {
3315 st->print("<offset %#x>", (uint)((uintptr_t)addr - (uintptr_t)dlinfo.dli_fbase));
3316 } else {
3317 st->print("<absolute address>");
3318 }
3319 if (dlinfo.dli_fname != NULL) {
3320 st->print(" in %s", dlinfo.dli_fname);
3321 }
3322 if (dlinfo.dli_fbase != NULL) {
3323 st->print(" at " INTPTR_FORMAT, (intptr_t)dlinfo.dli_fbase);
3324 }
3325 st->cr();
3326
3327 if (Verbose) {
3328 // decode some bytes around the PC
3329 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3330 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3331 address lowest = (address) dlinfo.dli_sname;
3332 if (!lowest) lowest = (address) dlinfo.dli_fbase;
3333 if (begin < lowest) begin = lowest;
3334 Dl_info dlinfo2;
3335 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3336 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3337 end = (address) dlinfo2.dli_saddr;
3338 }
3339 Disassembler::decode(begin, end, st);
3340 }
3341 return true;
3342 }
3343 return false;
3344 }
3345
3346 ////////////////////////////////////////////////////////////////////////////////
3347 // misc
3348
3349 // This does not do anything on Bsd. This is basically a hook for being
3350 // able to use structured exception handling (thread-local exception filters)
3351 // on, e.g., Win32.
3352 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3353 const methodHandle& method, JavaCallArguments* args,
3354 Thread* thread) {
3355 f(value, method, args, thread);
3356 }
3357
3358 void os::print_statistics() {
3359 }
3360
3361 bool os::message_box(const char* title, const char* message) {
3362 int i;
3363 fdStream err(defaultStream::error_fd());
3364 for (i = 0; i < 78; i++) err.print_raw("=");
3365 err.cr();
3366 err.print_raw_cr(title);
3367 for (i = 0; i < 78; i++) err.print_raw("-");
3368 err.cr();
3369 err.print_raw_cr(message);
3370 for (i = 0; i < 78; i++) err.print_raw("=");
3371 err.cr();
3372
3373 char buf[16];
3374 // Prevent process from exiting upon "read error" without consuming all CPU
3375 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3376
3377 return buf[0] == 'y' || buf[0] == 'Y';
3378 }
3379
3380 static inline struct timespec get_mtime(const char* filename) {
3381 struct stat st;
3382 int ret = os::stat(filename, &st);
3383 assert(ret == 0, "failed to stat() file '%s': %s", filename, os::strerror(errno));
3384 #ifdef __APPLE__
3385 return st.st_mtimespec;
3386 #else
3387 return st.st_mtim;
3388 #endif
3389 }
3390
3391 int os::compare_file_modified_times(const char* file1, const char* file2) {
3392 struct timespec filetime1 = get_mtime(file1);
3393 struct timespec filetime2 = get_mtime(file2);
3394 int diff = filetime1.tv_sec - filetime2.tv_sec;
3395 if (diff == 0) {
3396 return filetime1.tv_nsec - filetime2.tv_nsec;
3397 }
3398 return diff;
3399 }
3400
3401 // Is a (classpath) directory empty?
3402 bool os::dir_is_empty(const char* path) {
3403 DIR *dir = NULL;
3404 struct dirent *ptr;
3405
3406 dir = opendir(path);
3407 if (dir == NULL) return true;
3408
3409 // Scan the directory
3410 bool result = true;
3411 while (result && (ptr = readdir(dir)) != NULL) {
3412 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3413 result = false;
3414 }
3415 }
3416 closedir(dir);
3417 return result;
3418 }
3419
3420 // This code originates from JDK's sysOpen and open64_w
3421 // from src/solaris/hpi/src/system_md.c
3422
3423 int os::open(const char *path, int oflag, int mode) {
3424 if (strlen(path) > MAX_PATH - 1) {
3425 errno = ENAMETOOLONG;
3426 return -1;
3427 }
3428 int fd;
3429
3430 fd = ::open(path, oflag, mode);
3431 if (fd == -1) return -1;
3432
3433 // If the open succeeded, the file might still be a directory
3434 {
3435 struct stat buf;
3436 int ret = ::fstat(fd, &buf);
3437 int st_mode = buf.st_mode;
3438
3439 if (ret != -1) {
3440 if ((st_mode & S_IFMT) == S_IFDIR) {
3441 errno = EISDIR;
3442 ::close(fd);
3443 return -1;
3444 }
3445 } else {
3446 ::close(fd);
3447 return -1;
3448 }
3449 }
3450
3451 // All file descriptors that are opened in the JVM and not
3452 // specifically destined for a subprocess should have the
3453 // close-on-exec flag set. If we don't set it, then careless 3rd
3454 // party native code might fork and exec without closing all
3455 // appropriate file descriptors (e.g. as we do in closeDescriptors in
3456 // UNIXProcess.c), and this in turn might:
3457 //
3458 // - cause end-of-file to fail to be detected on some file
3459 // descriptors, resulting in mysterious hangs, or
3460 //
3461 // - might cause an fopen in the subprocess to fail on a system
3462 // suffering from bug 1085341.
3463 //
3464 // (Yes, the default setting of the close-on-exec flag is a Unix
3465 // design flaw)
3466 //
3467 // See:
3468 // 1085341: 32-bit stdio routines should support file descriptors >255
3469 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3470 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3471 //
3472 #ifdef FD_CLOEXEC
3473 {
3474 int flags = ::fcntl(fd, F_GETFD);
3475 if (flags != -1) {
3476 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3477 }
3478 }
3479 #endif
3480
3481 return fd;
3482 }
3483
3484
3485 // create binary file, rewriting existing file if required
3486 int os::create_binary_file(const char* path, bool rewrite_existing) {
3487 int oflags = O_WRONLY | O_CREAT;
3488 if (!rewrite_existing) {
3489 oflags |= O_EXCL;
3490 }
3491 return ::open(path, oflags, S_IREAD | S_IWRITE);
3492 }
3493
3494 // return current position of file pointer
3495 jlong os::current_file_offset(int fd) {
3496 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3497 }
3498
3499 // move file pointer to the specified offset
3500 jlong os::seek_to_file_offset(int fd, jlong offset) {
3501 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3502 }
3503
3504 // This code originates from JDK's sysAvailable
3505 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3506
3507 int os::available(int fd, jlong *bytes) {
3508 jlong cur, end;
3509 int mode;
3510 struct stat buf;
3511
3512 if (::fstat(fd, &buf) >= 0) {
3513 mode = buf.st_mode;
3514 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3515 int n;
3516 if (::ioctl(fd, FIONREAD, &n) >= 0) {
3517 *bytes = n;
3518 return 1;
3519 }
3520 }
3521 }
3522 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3523 return 0;
3524 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3525 return 0;
3526 } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3527 return 0;
3528 }
3529 *bytes = end - cur;
3530 return 1;
3531 }
3532
3533 // Map a block of memory.
3534 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3535 char *addr, size_t bytes, bool read_only,
3536 bool allow_exec) {
3537 int prot;
3538 int flags;
3539
3540 if (read_only) {
3541 prot = PROT_READ;
3542 flags = MAP_SHARED;
3543 } else {
3544 prot = PROT_READ | PROT_WRITE;
3545 flags = MAP_PRIVATE;
3546 }
3547
3548 if (allow_exec) {
3549 prot |= PROT_EXEC;
3550 }
3551
3552 if (addr != NULL) {
3553 flags |= MAP_FIXED;
3554 }
3555
3556 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
3557 fd, file_offset);
3558 if (mapped_address == MAP_FAILED) {
3559 return NULL;
3560 }
3561 return mapped_address;
3562 }
3563
3564
3565 // Remap a block of memory.
3566 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
3567 char *addr, size_t bytes, bool read_only,
3568 bool allow_exec) {
3569 // same as map_memory() on this OS
3570 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
3571 allow_exec);
3572 }
3573
3574
3575 // Unmap a block of memory.
3576 bool os::pd_unmap_memory(char* addr, size_t bytes) {
3577 return munmap(addr, bytes) == 0;
3578 }
3579
3580 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
3581 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
3582 // of a thread.
3583 //
3584 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
3585 // the fast estimate available on the platform.
3586
3587 jlong os::current_thread_cpu_time() {
3588 #ifdef __APPLE__
3589 return os::thread_cpu_time(Thread::current(), true /* user + sys */);
3590 #else
3591 Unimplemented();
3592 return 0;
3593 #endif
3594 }
3595
3596 jlong os::thread_cpu_time(Thread* thread) {
3597 #ifdef __APPLE__
3598 return os::thread_cpu_time(thread, true /* user + sys */);
3599 #else
3600 Unimplemented();
3601 return 0;
3602 #endif
3603 }
3604
3605 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
3606 #ifdef __APPLE__
3607 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
3608 #else
3609 Unimplemented();
3610 return 0;
3611 #endif
3612 }
3613
3614 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
3615 #ifdef __APPLE__
3616 struct thread_basic_info tinfo;
3617 mach_msg_type_number_t tcount = THREAD_INFO_MAX;
3618 kern_return_t kr;
3619 thread_t mach_thread;
3620
3621 mach_thread = thread->osthread()->thread_id();
3622 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
3623 if (kr != KERN_SUCCESS) {
3624 return -1;
3625 }
3626
3627 if (user_sys_cpu_time) {
3628 jlong nanos;
3629 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
3630 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
3631 return nanos;
3632 } else {
3633 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
3634 }
3635 #else
3636 Unimplemented();
3637 return 0;
3638 #endif
3639 }
3640
3641
3642 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3643 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
3644 info_ptr->may_skip_backward = false; // elapsed time not wall time
3645 info_ptr->may_skip_forward = false; // elapsed time not wall time
3646 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
3647 }
3648
3649 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
3650 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
3651 info_ptr->may_skip_backward = false; // elapsed time not wall time
3652 info_ptr->may_skip_forward = false; // elapsed time not wall time
3653 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
3654 }
3655
3656 bool os::is_thread_cpu_time_supported() {
3657 #ifdef __APPLE__
3658 return true;
3659 #else
3660 return false;
3661 #endif
3662 }
3663
3664 // System loadavg support. Returns -1 if load average cannot be obtained.
3665 // Bsd doesn't yet have a (official) notion of processor sets,
3666 // so just return the system wide load average.
3667 int os::loadavg(double loadavg[], int nelem) {
3668 return ::getloadavg(loadavg, nelem);
3669 }
3670
3671 void os::pause() {
3672 char filename[MAX_PATH];
3673 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
3674 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
3675 } else {
3676 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
3677 }
3678
3679 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
3680 if (fd != -1) {
3681 struct stat buf;
3682 ::close(fd);
3683 while (::stat(filename, &buf) == 0) {
3684 (void)::poll(NULL, 0, 100);
3685 }
3686 } else {
3687 jio_fprintf(stderr,
3688 "Could not open pause file '%s', continuing immediately.\n", filename);
3689 }
3690 }
3691
3692 // Darwin has no "environ" in a dynamic library.
3693 #ifdef __APPLE__
3694 #include <crt_externs.h>
3695 #define environ (*_NSGetEnviron())
3696 #else
3697 extern char** environ;
3698 #endif
3699
3700 // Run the specified command in a separate process. Return its exit value,
3701 // or -1 on failure (e.g. can't fork a new process).
3702 // Unlike system(), this function can be called from signal handler. It
3703 // doesn't block SIGINT et al.
3704 int os::fork_and_exec(char* cmd, bool use_vfork_if_available) {
3705 const char * argv[4] = {"sh", "-c", cmd, NULL};
3706
3707 // fork() in BsdThreads/NPTL is not async-safe. It needs to run
3708 // pthread_atfork handlers and reset pthread library. All we need is a
3709 // separate process to execve. Make a direct syscall to fork process.
3710 // On IA64 there's no fork syscall, we have to use fork() and hope for
3711 // the best...
3712 pid_t pid = fork();
3713
3714 if (pid < 0) {
3715 // fork failed
3716 return -1;
3717
3718 } else if (pid == 0) {
3719 // child process
3720
3721 // execve() in BsdThreads will call pthread_kill_other_threads_np()
3722 // first to kill every thread on the thread list. Because this list is
3723 // not reset by fork() (see notes above), execve() will instead kill
3724 // every thread in the parent process. We know this is the only thread
3725 // in the new process, so make a system call directly.
3726 // IA64 should use normal execve() from glibc to match the glibc fork()
3727 // above.
3728 execve("/bin/sh", (char* const*)argv, environ);
3729
3730 // execve failed
3731 _exit(-1);
3732
3733 } else {
3734 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
3735 // care about the actual exit code, for now.
3736
3737 int status;
3738
3739 // Wait for the child process to exit. This returns immediately if
3740 // the child has already exited. */
3741 while (waitpid(pid, &status, 0) < 0) {
3742 switch (errno) {
3743 case ECHILD: return 0;
3744 case EINTR: break;
3745 default: return -1;
3746 }
3747 }
3748
3749 if (WIFEXITED(status)) {
3750 // The child exited normally; get its exit code.
3751 return WEXITSTATUS(status);
3752 } else if (WIFSIGNALED(status)) {
3753 // The child exited because of a signal
3754 // The best value to return is 0x80 + signal number,
3755 // because that is what all Unix shells do, and because
3756 // it allows callers to distinguish between process exit and
3757 // process death by signal.
3758 return 0x80 + WTERMSIG(status);
3759 } else {
3760 // Unknown exit code; pass it through
3761 return status;
3762 }
3763 }
3764 }
3765
3766 // Get the default path to the core file
3767 // Returns the length of the string
3768 int os::get_core_path(char* buffer, size_t bufferSize) {
3769 int n = jio_snprintf(buffer, bufferSize, "/cores/core.%d", current_process_id());
3770
3771 // Truncate if theoretical string was longer than bufferSize
3772 n = MIN2(n, (int)bufferSize);
3773
3774 return n;
3775 }
3776
3777 bool os::supports_map_sync() {
3778 return false;
3779 }
3780
3781 #ifndef PRODUCT
3782 void TestReserveMemorySpecial_test() {
3783 // No tests available for this platform
3784 }
3785 #endif
3786
3787 bool os::start_debugging(char *buf, int buflen) {
3788 int len = (int)strlen(buf);
3789 char *p = &buf[len];
3790
3791 jio_snprintf(p, buflen-len,
3792 "\n\n"
3793 "Do you want to debug the problem?\n\n"
3794 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT " (" INTPTR_FORMAT ")\n"
3795 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
3796 "Otherwise, press RETURN to abort...",
3797 os::current_process_id(), os::current_process_id(),
3798 os::current_thread_id(), os::current_thread_id());
3799
3800 bool yes = os::message_box("Unexpected Error", buf);
3801
3802 if (yes) {
3803 // yes, user asked VM to launch debugger
3804 jio_snprintf(buf, sizeof(buf), "gdb /proc/%d/exe %d",
3805 os::current_process_id(), os::current_process_id());
3806
3807 os::fork_and_exec(buf);
3808 yes = false;
3809 }
3810 return yes;
3811 }