1 /*
2 * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 // no precompiled headers
26 #include "classfile/classLoader.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/vmSymbols.hpp"
29 #include "code/icBuffer.hpp"
30 #include "code/vtableStubs.hpp"
31 #include "compiler/compileBroker.hpp"
32 #include "compiler/disassembler.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "jvm_bsd.h"
35 #include "memory/allocation.inline.hpp"
36 #include "memory/filemap.hpp"
37 #include "mutex_bsd.inline.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "os_bsd.inline.hpp"
40 #include "os_share_bsd.hpp"
41 #include "prims/jniFastGetField.hpp"
42 #include "prims/jvm.h"
43 #include "prims/jvm_misc.hpp"
44 #include "runtime/arguments.hpp"
45 #include "runtime/atomic.inline.hpp"
46 #include "runtime/extendedPC.hpp"
47 #include "runtime/globals.hpp"
48 #include "runtime/interfaceSupport.hpp"
49 #include "runtime/java.hpp"
50 #include "runtime/javaCalls.hpp"
51 #include "runtime/mutexLocker.hpp"
52 #include "runtime/objectMonitor.hpp"
53 #include "runtime/orderAccess.inline.hpp"
54 #include "runtime/osThread.hpp"
55 #include "runtime/perfMemory.hpp"
56 #include "runtime/sharedRuntime.hpp"
57 #include "runtime/statSampler.hpp"
58 #include "runtime/stubRoutines.hpp"
59 #include "runtime/thread.inline.hpp"
60 #include "runtime/threadCritical.hpp"
61 #include "runtime/timer.hpp"
62 #include "services/attachListener.hpp"
63 #include "services/memTracker.hpp"
64 #include "services/runtimeService.hpp"
65 #include "utilities/decoder.hpp"
66 #include "utilities/defaultStream.hpp"
67 #include "utilities/events.hpp"
68 #include "utilities/growableArray.hpp"
69 #include "utilities/vmError.hpp"
70
71 // put OS-includes here
72 # include <sys/types.h>
73 # include <sys/mman.h>
74 # include <sys/stat.h>
75 # include <sys/select.h>
76 # include <pthread.h>
77 # include <signal.h>
78 # include <errno.h>
79 # include <dlfcn.h>
80 # include <stdio.h>
81 # include <unistd.h>
82 # include <sys/resource.h>
83 # include <pthread.h>
84 # include <sys/stat.h>
85 # include <sys/time.h>
86 # include <sys/times.h>
87 # include <sys/utsname.h>
88 # include <sys/socket.h>
89 # include <sys/wait.h>
90 # include <time.h>
91 # include <pwd.h>
92 # include <poll.h>
93 # include <semaphore.h>
94 # include <fcntl.h>
95 # include <string.h>
96 # include <sys/param.h>
97 # include <sys/sysctl.h>
98 # include <sys/ipc.h>
99 # include <sys/shm.h>
100 #ifndef __APPLE__
101 # include <link.h>
102 #endif
103 # include <stdint.h>
104 # include <inttypes.h>
105 # include <sys/ioctl.h>
106 # include <sys/syscall.h>
107
108 #if defined(__FreeBSD__) || defined(__NetBSD__)
109 #include <elf.h>
110 #endif
111
112 #ifdef __APPLE__
113 #include <mach/mach.h> // semaphore_* API
114 #include <mach-o/dyld.h>
115 #include <sys/proc_info.h>
116 #include <objc/objc-auto.h>
117 #endif
118
119 #ifndef MAP_ANONYMOUS
120 #define MAP_ANONYMOUS MAP_ANON
121 #endif
122
123 #define MAX_PATH (2 * K)
124
125 // for timer info max values which include all bits
126 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
127
128 #define LARGEPAGES_BIT (1 << 6)
129
130 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
131
132 ////////////////////////////////////////////////////////////////////////////////
133 // global variables
134 julong os::Bsd::_physical_memory = 0;
135
136 #ifdef __APPLE__
137 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
138 volatile uint64_t os::Bsd::_max_abstime = 0;
139 #else
140 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
141 #endif
142 pthread_t os::Bsd::_main_thread;
143 int os::Bsd::_page_size = -1;
144
145 static jlong initial_time_count=0;
146
147 static int clock_tics_per_sec = 100;
148
149 // For diagnostics to print a message once. see run_periodic_checks
150 static sigset_t check_signal_done;
151 static bool check_signals = true;
152
153 static pid_t _initial_pid = 0;
154
155 // Signal number used to suspend/resume a thread
156
157 // do not use any signal number less than SIGSEGV, see 4355769
158 static int SR_signum = SIGUSR2;
159 sigset_t SR_sigset;
160
161
162 ////////////////////////////////////////////////////////////////////////////////
163 // utility functions
164
165 static int SR_initialize();
166 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
167
168 julong os::available_memory() {
169 return Bsd::available_memory();
170 }
171
172 // available here means free
173 julong os::Bsd::available_memory() {
174 uint64_t available = physical_memory() >> 2;
175 #ifdef __APPLE__
176 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
177 vm_statistics64_data_t vmstat;
178 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
179 (host_info64_t)&vmstat, &count);
180 assert(kerr == KERN_SUCCESS,
181 "host_statistics64 failed - check mach_host_self() and count");
182 if (kerr == KERN_SUCCESS) {
183 available = vmstat.free_count * os::vm_page_size();
184 }
185 #endif
186 return available;
187 }
188
189 julong os::physical_memory() {
190 return Bsd::physical_memory();
191 }
192
193 ////////////////////////////////////////////////////////////////////////////////
194 // environment support
195
196 bool os::getenv(const char* name, char* buf, int len) {
197 const char* val = ::getenv(name);
198 if (val != NULL && strlen(val) < (size_t)len) {
199 strcpy(buf, val);
200 return true;
201 }
202 if (len > 0) buf[0] = 0; // return a null string
203 return false;
204 }
205
206
207 // Return true if user is running as root.
208
209 bool os::have_special_privileges() {
210 static bool init = false;
211 static bool privileges = false;
212 if (!init) {
213 privileges = (getuid() != geteuid()) || (getgid() != getegid());
214 init = true;
215 }
216 return privileges;
217 }
218
219
220
221 // Cpu architecture string
222 #if defined(ZERO)
223 static char cpu_arch[] = ZERO_LIBARCH;
224 #elif defined(IA64)
225 static char cpu_arch[] = "ia64";
226 #elif defined(IA32)
227 static char cpu_arch[] = "i386";
228 #elif defined(AMD64)
229 static char cpu_arch[] = "amd64";
230 #elif defined(ARM)
231 static char cpu_arch[] = "arm";
232 #elif defined(PPC32)
233 static char cpu_arch[] = "ppc";
234 #elif defined(SPARC)
235 #ifdef _LP64
236 static char cpu_arch[] = "sparcv9";
237 #else
238 static char cpu_arch[] = "sparc";
239 #endif
240 #else
241 #error Add appropriate cpu_arch setting
242 #endif
243
244 // Compiler variant
245 #ifdef COMPILER2
246 #define COMPILER_VARIANT "server"
247 #else
248 #define COMPILER_VARIANT "client"
249 #endif
250
251
252 void os::Bsd::initialize_system_info() {
253 int mib[2];
254 size_t len;
255 int cpu_val;
256 julong mem_val;
257
258 // get processors count via hw.ncpus sysctl
259 mib[0] = CTL_HW;
260 mib[1] = HW_NCPU;
261 len = sizeof(cpu_val);
262 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
263 assert(len == sizeof(cpu_val), "unexpected data size");
264 set_processor_count(cpu_val);
265 } else {
266 set_processor_count(1); // fallback
267 }
268
269 // get physical memory via hw.memsize sysctl (hw.memsize is used
270 // since it returns a 64 bit value)
271 mib[0] = CTL_HW;
272
273 #if defined (HW_MEMSIZE) // Apple
274 mib[1] = HW_MEMSIZE;
275 #elif defined(HW_PHYSMEM) // Most of BSD
276 mib[1] = HW_PHYSMEM;
277 #elif defined(HW_REALMEM) // Old FreeBSD
278 mib[1] = HW_REALMEM;
279 #else
280 #error No ways to get physmem
281 #endif
282
283 len = sizeof(mem_val);
284 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
285 assert(len == sizeof(mem_val), "unexpected data size");
286 _physical_memory = mem_val;
287 } else {
288 _physical_memory = 256 * 1024 * 1024; // fallback (XXXBSD?)
289 }
290
291 #ifdef __OpenBSD__
292 {
293 // limit _physical_memory memory view on OpenBSD since
294 // datasize rlimit restricts us anyway.
295 struct rlimit limits;
296 getrlimit(RLIMIT_DATA, &limits);
297 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
298 }
299 #endif
300 }
301
302 #ifdef __APPLE__
303 static const char *get_home() {
304 const char *home_dir = ::getenv("HOME");
305 if ((home_dir == NULL) || (*home_dir == '\0')) {
306 struct passwd *passwd_info = getpwuid(geteuid());
307 if (passwd_info != NULL) {
308 home_dir = passwd_info->pw_dir;
309 }
310 }
311
312 return home_dir;
313 }
314 #endif
315
316 void os::init_system_properties_values() {
317 // The next steps are taken in the product version:
318 //
319 // Obtain the JAVA_HOME value from the location of libjvm.so.
320 // This library should be located at:
321 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
322 //
323 // If "/jre/lib/" appears at the right place in the path, then we
324 // assume libjvm.so is installed in a JDK and we use this path.
325 //
326 // Otherwise exit with message: "Could not create the Java virtual machine."
327 //
328 // The following extra steps are taken in the debugging version:
329 //
330 // If "/jre/lib/" does NOT appear at the right place in the path
331 // instead of exit check for $JAVA_HOME environment variable.
332 //
333 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
334 // then we append a fake suffix "hotspot/libjvm.so" to this path so
335 // it looks like libjvm.so is installed there
336 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
337 //
338 // Otherwise exit.
339 //
340 // Important note: if the location of libjvm.so changes this
341 // code needs to be changed accordingly.
342
343 // See ld(1):
344 // The linker uses the following search paths to locate required
345 // shared libraries:
346 // 1: ...
347 // ...
348 // 7: The default directories, normally /lib and /usr/lib.
349 #ifndef DEFAULT_LIBPATH
350 #define DEFAULT_LIBPATH "/lib:/usr/lib"
351 #endif
352
353 // Base path of extensions installed on the system.
354 #define SYS_EXT_DIR "/usr/java/packages"
355 #define EXTENSIONS_DIR "/lib/ext"
356 #define ENDORSED_DIR "/lib/endorsed"
357
358 #ifndef __APPLE__
359
360 // Buffer that fits several sprintfs.
361 // Note that the space for the colon and the trailing null are provided
362 // by the nulls included by the sizeof operator.
363 const size_t bufsize =
364 MAX3((size_t)MAXPATHLEN, // For dll_dir & friends.
365 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR), // extensions dir
366 (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir
367 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
368
369 // sysclasspath, java_home, dll_dir
370 {
371 char *pslash;
372 os::jvm_path(buf, bufsize);
373
374 // Found the full path to libjvm.so.
375 // Now cut the path to <java_home>/jre if we can.
376 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
377 pslash = strrchr(buf, '/');
378 if (pslash != NULL) {
379 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
380 }
381 Arguments::set_dll_dir(buf);
382
383 if (pslash != NULL) {
384 pslash = strrchr(buf, '/');
385 if (pslash != NULL) {
386 *pslash = '\0'; // Get rid of /<arch>.
387 pslash = strrchr(buf, '/');
388 if (pslash != NULL) {
389 *pslash = '\0'; // Get rid of /lib.
390 }
391 }
392 }
393 Arguments::set_java_home(buf);
394 set_boot_path('/', ':');
395 }
396
397 // Where to look for native libraries.
398 //
399 // Note: Due to a legacy implementation, most of the library path
400 // is set in the launcher. This was to accomodate linking restrictions
401 // on legacy Bsd implementations (which are no longer supported).
402 // Eventually, all the library path setting will be done here.
403 //
404 // However, to prevent the proliferation of improperly built native
405 // libraries, the new path component /usr/java/packages is added here.
406 // Eventually, all the library path setting will be done here.
407 {
408 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
409 // should always exist (until the legacy problem cited above is
410 // addressed).
411 const char *v = ::getenv("LD_LIBRARY_PATH");
412 const char *v_colon = ":";
413 if (v == NULL) { v = ""; v_colon = ""; }
414 // That's +1 for the colon and +1 for the trailing '\0'.
415 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
416 strlen(v) + 1 +
417 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
418 mtInternal);
419 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
420 Arguments::set_library_path(ld_library_path);
421 FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal);
422 }
423
424 // Extensions directories.
425 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
426 Arguments::set_ext_dirs(buf);
427
428 // Endorsed standards default directory.
429 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
430 Arguments::set_endorsed_dirs(buf);
431
432 FREE_C_HEAP_ARRAY(char, buf, mtInternal);
433
434 #else // __APPLE__
435
436 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions"
437 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
438
439 const char *user_home_dir = get_home();
440 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
441 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
442 sizeof(SYS_EXTENSIONS_DIRS);
443
444 // Buffer that fits several sprintfs.
445 // Note that the space for the colon and the trailing null are provided
446 // by the nulls included by the sizeof operator.
447 const size_t bufsize =
448 MAX3((size_t)MAXPATHLEN, // for dll_dir & friends.
449 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size, // extensions dir
450 (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir
451 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
452
453 // sysclasspath, java_home, dll_dir
454 {
455 char *pslash;
456 os::jvm_path(buf, bufsize);
457
458 // Found the full path to libjvm.so.
459 // Now cut the path to <java_home>/jre if we can.
460 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
461 pslash = strrchr(buf, '/');
462 if (pslash != NULL) {
463 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
464 }
465 Arguments::set_dll_dir(buf);
466
467 if (pslash != NULL) {
468 pslash = strrchr(buf, '/');
469 if (pslash != NULL) {
470 *pslash = '\0'; // Get rid of /lib.
471 }
472 }
473 Arguments::set_java_home(buf);
474 set_boot_path('/', ':');
475 }
476
477 // Where to look for native libraries.
478 //
479 // Note: Due to a legacy implementation, most of the library path
480 // is set in the launcher. This was to accomodate linking restrictions
481 // on legacy Bsd implementations (which are no longer supported).
482 // Eventually, all the library path setting will be done here.
483 //
484 // However, to prevent the proliferation of improperly built native
485 // libraries, the new path component /usr/java/packages is added here.
486 // Eventually, all the library path setting will be done here.
487 {
488 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
489 // should always exist (until the legacy problem cited above is
490 // addressed).
491 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
492 // can specify a directory inside an app wrapper
493 const char *l = ::getenv("JAVA_LIBRARY_PATH");
494 const char *l_colon = ":";
495 if (l == NULL) { l = ""; l_colon = ""; }
496
497 const char *v = ::getenv("DYLD_LIBRARY_PATH");
498 const char *v_colon = ":";
499 if (v == NULL) { v = ""; v_colon = ""; }
500
501 // Apple's Java6 has "." at the beginning of java.library.path.
502 // OpenJDK on Windows has "." at the end of java.library.path.
503 // OpenJDK on Linux and Solaris don't have "." in java.library.path
504 // at all. To ease the transition from Apple's Java6 to OpenJDK7,
505 // "." is appended to the end of java.library.path. Yes, this
506 // could cause a change in behavior, but Apple's Java6 behavior
507 // can be achieved by putting "." at the beginning of the
508 // JAVA_LIBRARY_PATH environment variable.
509 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
510 strlen(v) + 1 + strlen(l) + 1 +
511 system_ext_size + 3,
512 mtInternal);
513 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
514 v, v_colon, l, l_colon, user_home_dir);
515 Arguments::set_library_path(ld_library_path);
516 FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal);
517 }
518
519 // Extensions directories.
520 //
521 // Note that the space for the colon and the trailing null are provided
522 // by the nulls included by the sizeof operator (so actually one byte more
523 // than necessary is allocated).
524 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
525 user_home_dir, Arguments::get_java_home());
526 Arguments::set_ext_dirs(buf);
527
528 // Endorsed standards default directory.
529 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
530 Arguments::set_endorsed_dirs(buf);
531
532 FREE_C_HEAP_ARRAY(char, buf, mtInternal);
533
534 #undef SYS_EXTENSIONS_DIR
535 #undef SYS_EXTENSIONS_DIRS
536
537 #endif // __APPLE__
538
539 #undef SYS_EXT_DIR
540 #undef EXTENSIONS_DIR
541 #undef ENDORSED_DIR
542 }
543
544 ////////////////////////////////////////////////////////////////////////////////
545 // breakpoint support
546
547 void os::breakpoint() {
548 BREAKPOINT;
549 }
550
551 extern "C" void breakpoint() {
552 // use debugger to set breakpoint here
553 }
554
555 ////////////////////////////////////////////////////////////////////////////////
556 // signal support
557
558 debug_only(static bool signal_sets_initialized = false);
559 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
560
561 bool os::Bsd::is_sig_ignored(int sig) {
562 struct sigaction oact;
563 sigaction(sig, (struct sigaction*)NULL, &oact);
564 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
565 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
566 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN)) {
567 return true;
568 } else {
569 return false;
570 }
571 }
572
573 void os::Bsd::signal_sets_init() {
574 // Should also have an assertion stating we are still single-threaded.
575 assert(!signal_sets_initialized, "Already initialized");
576 // Fill in signals that are necessarily unblocked for all threads in
577 // the VM. Currently, we unblock the following signals:
578 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
579 // by -Xrs (=ReduceSignalUsage));
580 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
581 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
582 // the dispositions or masks wrt these signals.
583 // Programs embedding the VM that want to use the above signals for their
584 // own purposes must, at this time, use the "-Xrs" option to prevent
585 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
586 // (See bug 4345157, and other related bugs).
587 // In reality, though, unblocking these signals is really a nop, since
588 // these signals are not blocked by default.
589 sigemptyset(&unblocked_sigs);
590 sigemptyset(&allowdebug_blocked_sigs);
591 sigaddset(&unblocked_sigs, SIGILL);
592 sigaddset(&unblocked_sigs, SIGSEGV);
593 sigaddset(&unblocked_sigs, SIGBUS);
594 sigaddset(&unblocked_sigs, SIGFPE);
595 sigaddset(&unblocked_sigs, SR_signum);
596
597 if (!ReduceSignalUsage) {
598 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
599 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
600 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
601 }
602 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
603 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
604 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
605 }
606 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
607 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
608 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
609 }
610 }
611 // Fill in signals that are blocked by all but the VM thread.
612 sigemptyset(&vm_sigs);
613 if (!ReduceSignalUsage) {
614 sigaddset(&vm_sigs, BREAK_SIGNAL);
615 }
616 debug_only(signal_sets_initialized = true);
617
618 }
619
620 // These are signals that are unblocked while a thread is running Java.
621 // (For some reason, they get blocked by default.)
622 sigset_t* os::Bsd::unblocked_signals() {
623 assert(signal_sets_initialized, "Not initialized");
624 return &unblocked_sigs;
625 }
626
627 // These are the signals that are blocked while a (non-VM) thread is
628 // running Java. Only the VM thread handles these signals.
629 sigset_t* os::Bsd::vm_signals() {
630 assert(signal_sets_initialized, "Not initialized");
631 return &vm_sigs;
632 }
633
634 // These are signals that are blocked during cond_wait to allow debugger in
635 sigset_t* os::Bsd::allowdebug_blocked_signals() {
636 assert(signal_sets_initialized, "Not initialized");
637 return &allowdebug_blocked_sigs;
638 }
639
640 void os::Bsd::hotspot_sigmask(Thread* thread) {
641
642 //Save caller's signal mask before setting VM signal mask
643 sigset_t caller_sigmask;
644 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
645
646 OSThread* osthread = thread->osthread();
647 osthread->set_caller_sigmask(caller_sigmask);
648
649 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
650
651 if (!ReduceSignalUsage) {
652 if (thread->is_VM_thread()) {
653 // Only the VM thread handles BREAK_SIGNAL ...
654 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
655 } else {
656 // ... all other threads block BREAK_SIGNAL
657 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
658 }
659 }
660 }
661
662
663 //////////////////////////////////////////////////////////////////////////////
664 // create new thread
665
666 // check if it's safe to start a new thread
667 static bool _thread_safety_check(Thread* thread) {
668 return true;
669 }
670
671 #ifdef __APPLE__
672 // library handle for calling objc_registerThreadWithCollector()
673 // without static linking to the libobjc library
674 #define OBJC_LIB "/usr/lib/libobjc.dylib"
675 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
676 typedef void (*objc_registerThreadWithCollector_t)();
677 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
678 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
679 #endif
680
681 #ifdef __APPLE__
682 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
683 // Additional thread_id used to correlate threads in SA
684 thread_identifier_info_data_t m_ident_info;
685 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT;
686
687 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
688 (thread_info_t) &m_ident_info, &count);
689
690 return m_ident_info.thread_id;
691 }
692 #endif
693
694 // Thread start routine for all newly created threads
695 static void *java_start(Thread *thread) {
696 // Try to randomize the cache line index of hot stack frames.
697 // This helps when threads of the same stack traces evict each other's
698 // cache lines. The threads can be either from the same JVM instance, or
699 // from different JVM instances. The benefit is especially true for
700 // processors with hyperthreading technology.
701 static int counter = 0;
702 int pid = os::current_process_id();
703 alloca(((pid ^ counter++) & 7) * 128);
704
705 ThreadLocalStorage::set_thread(thread);
706
707 OSThread* osthread = thread->osthread();
708 Monitor* sync = osthread->startThread_lock();
709
710 // non floating stack BsdThreads needs extra check, see above
711 if (!_thread_safety_check(thread)) {
712 // notify parent thread
713 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
714 osthread->set_state(ZOMBIE);
715 sync->notify_all();
716 return NULL;
717 }
718
719 osthread->set_thread_id(os::Bsd::gettid());
720
721 #ifdef __APPLE__
722 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
723 guarantee(unique_thread_id != 0, "unique thread id was not found");
724 osthread->set_unique_thread_id(unique_thread_id);
725 #endif
726 // initialize signal mask for this thread
727 os::Bsd::hotspot_sigmask(thread);
728
729 // initialize floating point control register
730 os::Bsd::init_thread_fpu_state();
731
732 #ifdef __APPLE__
733 // register thread with objc gc
734 if (objc_registerThreadWithCollectorFunction != NULL) {
735 objc_registerThreadWithCollectorFunction();
736 }
737 #endif
738
739 // handshaking with parent thread
740 {
741 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
742
743 // notify parent thread
744 osthread->set_state(INITIALIZED);
745 sync->notify_all();
746
747 // wait until os::start_thread()
748 while (osthread->get_state() == INITIALIZED) {
749 sync->wait(Mutex::_no_safepoint_check_flag);
750 }
751 }
752
753 // call one more level start routine
754 thread->run();
755
756 return 0;
757 }
758
759 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
760 assert(thread->osthread() == NULL, "caller responsible");
761
762 // Allocate the OSThread object
763 OSThread* osthread = new OSThread(NULL, NULL);
764 if (osthread == NULL) {
765 return false;
766 }
767
768 // set the correct thread state
769 osthread->set_thread_type(thr_type);
770
771 // Initial state is ALLOCATED but not INITIALIZED
772 osthread->set_state(ALLOCATED);
773
774 thread->set_osthread(osthread);
775
776 // init thread attributes
777 pthread_attr_t attr;
778 pthread_attr_init(&attr);
779 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
780
781 // stack size
782 if (os::Bsd::supports_variable_stack_size()) {
783 // calculate stack size if it's not specified by caller
784 if (stack_size == 0) {
785 stack_size = os::Bsd::default_stack_size(thr_type);
786
787 switch (thr_type) {
788 case os::java_thread:
789 // Java threads use ThreadStackSize which default value can be
790 // changed with the flag -Xss
791 assert(JavaThread::stack_size_at_create() > 0, "this should be set");
792 stack_size = JavaThread::stack_size_at_create();
793 break;
794 case os::compiler_thread:
795 if (CompilerThreadStackSize > 0) {
796 stack_size = (size_t)(CompilerThreadStackSize * K);
797 break;
798 } // else fall through:
799 // use VMThreadStackSize if CompilerThreadStackSize is not defined
800 case os::vm_thread:
801 case os::pgc_thread:
802 case os::cgc_thread:
803 case os::watcher_thread:
804 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
805 break;
806 }
807 }
808
809 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
810 pthread_attr_setstacksize(&attr, stack_size);
811 } else {
812 // let pthread_create() pick the default value.
813 }
814
815 ThreadState state;
816
817 {
818 pthread_t tid;
819 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
820
821 pthread_attr_destroy(&attr);
822
823 if (ret != 0) {
824 if (PrintMiscellaneous && (Verbose || WizardMode)) {
825 perror("pthread_create()");
826 }
827 // Need to clean up stuff we've allocated so far
828 thread->set_osthread(NULL);
829 delete osthread;
830 return false;
831 }
832
833 // Store pthread info into the OSThread
834 osthread->set_pthread_id(tid);
835
836 // Wait until child thread is either initialized or aborted
837 {
838 Monitor* sync_with_child = osthread->startThread_lock();
839 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
840 while ((state = osthread->get_state()) == ALLOCATED) {
841 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
842 }
843 }
844
845 }
846
847 // Aborted due to thread limit being reached
848 if (state == ZOMBIE) {
849 thread->set_osthread(NULL);
850 delete osthread;
851 return false;
852 }
853
854 // The thread is returned suspended (in state INITIALIZED),
855 // and is started higher up in the call chain
856 assert(state == INITIALIZED, "race condition");
857 return true;
858 }
859
860 /////////////////////////////////////////////////////////////////////////////
861 // attach existing thread
862
863 // bootstrap the main thread
864 bool os::create_main_thread(JavaThread* thread) {
865 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
866 return create_attached_thread(thread);
867 }
868
869 bool os::create_attached_thread(JavaThread* thread) {
870 #ifdef ASSERT
871 thread->verify_not_published();
872 #endif
873
874 // Allocate the OSThread object
875 OSThread* osthread = new OSThread(NULL, NULL);
876
877 if (osthread == NULL) {
878 return false;
879 }
880
881 osthread->set_thread_id(os::Bsd::gettid());
882
883 // Store pthread info into the OSThread
884 #ifdef __APPLE__
885 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
886 guarantee(unique_thread_id != 0, "just checking");
887 osthread->set_unique_thread_id(unique_thread_id);
888 #endif
889 osthread->set_pthread_id(::pthread_self());
890
891 // initialize floating point control register
892 os::Bsd::init_thread_fpu_state();
893
894 // Initial thread state is RUNNABLE
895 osthread->set_state(RUNNABLE);
896
897 thread->set_osthread(osthread);
898
899 // initialize signal mask for this thread
900 // and save the caller's signal mask
901 os::Bsd::hotspot_sigmask(thread);
902
903 return true;
904 }
905
906 void os::pd_start_thread(Thread* thread) {
907 OSThread * osthread = thread->osthread();
908 assert(osthread->get_state() != INITIALIZED, "just checking");
909 Monitor* sync_with_child = osthread->startThread_lock();
910 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
911 sync_with_child->notify();
912 }
913
914 // Free Bsd resources related to the OSThread
915 void os::free_thread(OSThread* osthread) {
916 assert(osthread != NULL, "osthread not set");
917
918 if (Thread::current()->osthread() == osthread) {
919 // Restore caller's signal mask
920 sigset_t sigmask = osthread->caller_sigmask();
921 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
922 }
923
924 delete osthread;
925 }
926
927 //////////////////////////////////////////////////////////////////////////////
928 // thread local storage
929
930 // Restore the thread pointer if the destructor is called. This is in case
931 // someone from JNI code sets up a destructor with pthread_key_create to run
932 // detachCurrentThread on thread death. Unless we restore the thread pointer we
933 // will hang or crash. When detachCurrentThread is called the key will be set
934 // to null and we will not be called again. If detachCurrentThread is never
935 // called we could loop forever depending on the pthread implementation.
936 static void restore_thread_pointer(void* p) {
937 Thread* thread = (Thread*) p;
938 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
939 }
940
941 int os::allocate_thread_local_storage() {
942 pthread_key_t key;
943 int rslt = pthread_key_create(&key, restore_thread_pointer);
944 assert(rslt == 0, "cannot allocate thread local storage");
945 return (int)key;
946 }
947
948 // Note: This is currently not used by VM, as we don't destroy TLS key
949 // on VM exit.
950 void os::free_thread_local_storage(int index) {
951 int rslt = pthread_key_delete((pthread_key_t)index);
952 assert(rslt == 0, "invalid index");
953 }
954
955 void os::thread_local_storage_at_put(int index, void* value) {
956 int rslt = pthread_setspecific((pthread_key_t)index, value);
957 assert(rslt == 0, "pthread_setspecific failed");
958 }
959
960 extern "C" Thread* get_thread() {
961 return ThreadLocalStorage::thread();
962 }
963
964
965 ////////////////////////////////////////////////////////////////////////////////
966 // time support
967
968 // Time since start-up in seconds to a fine granularity.
969 // Used by VMSelfDestructTimer and the MemProfiler.
970 double os::elapsedTime() {
971
972 return ((double)os::elapsed_counter()) / os::elapsed_frequency();
973 }
974
975 jlong os::elapsed_counter() {
976 return javaTimeNanos() - initial_time_count;
977 }
978
979 jlong os::elapsed_frequency() {
980 return NANOSECS_PER_SEC; // nanosecond resolution
981 }
982
983 bool os::supports_vtime() { return true; }
984 bool os::enable_vtime() { return false; }
985 bool os::vtime_enabled() { return false; }
986
987 double os::elapsedVTime() {
988 // better than nothing, but not much
989 return elapsedTime();
990 }
991
992 jlong os::javaTimeMillis() {
993 timeval time;
994 int status = gettimeofday(&time, NULL);
995 assert(status != -1, "bsd error");
996 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
997 }
998
999 #ifndef __APPLE__
1000 #ifndef CLOCK_MONOTONIC
1001 #define CLOCK_MONOTONIC (1)
1002 #endif
1003 #endif
1004
1005 #ifdef __APPLE__
1006 void os::Bsd::clock_init() {
1007 mach_timebase_info(&_timebase_info);
1008 }
1009 #else
1010 void os::Bsd::clock_init() {
1011 struct timespec res;
1012 struct timespec tp;
1013 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
1014 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
1015 // yes, monotonic clock is supported
1016 _clock_gettime = ::clock_gettime;
1017 }
1018 }
1019 #endif
1020
1021
1022
1023 #ifdef __APPLE__
1024
1025 jlong os::javaTimeNanos() {
1026 const uint64_t tm = mach_absolute_time();
1027 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
1028 const uint64_t prev = Bsd::_max_abstime;
1029 if (now <= prev) {
1030 return prev; // same or retrograde time;
1031 }
1032 const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
1033 assert(obsv >= prev, "invariant"); // Monotonicity
1034 // If the CAS succeeded then we're done and return "now".
1035 // If the CAS failed and the observed value "obsv" is >= now then
1036 // we should return "obsv". If the CAS failed and now > obsv > prv then
1037 // some other thread raced this thread and installed a new value, in which case
1038 // we could either (a) retry the entire operation, (b) retry trying to install now
1039 // or (c) just return obsv. We use (c). No loop is required although in some cases
1040 // we might discard a higher "now" value in deference to a slightly lower but freshly
1041 // installed obsv value. That's entirely benign -- it admits no new orderings compared
1042 // to (a) or (b) -- and greatly reduces coherence traffic.
1043 // We might also condition (c) on the magnitude of the delta between obsv and now.
1044 // Avoiding excessive CAS operations to hot RW locations is critical.
1045 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1046 return (prev == obsv) ? now : obsv;
1047 }
1048
1049 #else // __APPLE__
1050
1051 jlong os::javaTimeNanos() {
1052 if (os::supports_monotonic_clock()) {
1053 struct timespec tp;
1054 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
1055 assert(status == 0, "gettime error");
1056 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1057 return result;
1058 } else {
1059 timeval time;
1060 int status = gettimeofday(&time, NULL);
1061 assert(status != -1, "bsd error");
1062 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1063 return 1000 * usecs;
1064 }
1065 }
1066
1067 #endif // __APPLE__
1068
1069 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1070 if (os::supports_monotonic_clock()) {
1071 info_ptr->max_value = ALL_64_BITS;
1072
1073 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1074 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1075 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1076 } else {
1077 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1078 info_ptr->max_value = ALL_64_BITS;
1079
1080 // gettimeofday is a real time clock so it skips
1081 info_ptr->may_skip_backward = true;
1082 info_ptr->may_skip_forward = true;
1083 }
1084
1085 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1086 }
1087
1088 // Return the real, user, and system times in seconds from an
1089 // arbitrary fixed point in the past.
1090 bool os::getTimesSecs(double* process_real_time,
1091 double* process_user_time,
1092 double* process_system_time) {
1093 struct tms ticks;
1094 clock_t real_ticks = times(&ticks);
1095
1096 if (real_ticks == (clock_t) (-1)) {
1097 return false;
1098 } else {
1099 double ticks_per_second = (double) clock_tics_per_sec;
1100 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1101 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1102 *process_real_time = ((double) real_ticks) / ticks_per_second;
1103
1104 return true;
1105 }
1106 }
1107
1108
1109 char * os::local_time_string(char *buf, size_t buflen) {
1110 struct tm t;
1111 time_t long_time;
1112 time(&long_time);
1113 localtime_r(&long_time, &t);
1114 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1115 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1116 t.tm_hour, t.tm_min, t.tm_sec);
1117 return buf;
1118 }
1119
1120 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1121 return localtime_r(clock, res);
1122 }
1123
1124 ////////////////////////////////////////////////////////////////////////////////
1125 // runtime exit support
1126
1127 // Note: os::shutdown() might be called very early during initialization, or
1128 // called from signal handler. Before adding something to os::shutdown(), make
1129 // sure it is async-safe and can handle partially initialized VM.
1130 void os::shutdown() {
1131
1132 // allow PerfMemory to attempt cleanup of any persistent resources
1133 perfMemory_exit();
1134
1135 // needs to remove object in file system
1136 AttachListener::abort();
1137
1138 // flush buffered output, finish log files
1139 ostream_abort();
1140
1141 // Check for abort hook
1142 abort_hook_t abort_hook = Arguments::abort_hook();
1143 if (abort_hook != NULL) {
1144 abort_hook();
1145 }
1146
1147 }
1148
1149 // Note: os::abort() might be called very early during initialization, or
1150 // called from signal handler. Before adding something to os::abort(), make
1151 // sure it is async-safe and can handle partially initialized VM.
1152 void os::abort(bool dump_core) {
1153 os::shutdown();
1154 if (dump_core) {
1155 #ifndef PRODUCT
1156 fdStream out(defaultStream::output_fd());
1157 out.print_raw("Current thread is ");
1158 char buf[16];
1159 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1160 out.print_raw_cr(buf);
1161 out.print_raw_cr("Dumping core ...");
1162 #endif
1163 ::abort(); // dump core
1164 }
1165
1166 ::exit(1);
1167 }
1168
1169 // Die immediately, no exit hook, no abort hook, no cleanup.
1170 void os::die() {
1171 // _exit() on BsdThreads only kills current thread
1172 ::abort();
1173 }
1174
1175 // This method is a copy of JDK's sysGetLastErrorString
1176 // from src/solaris/hpi/src/system_md.c
1177
1178 size_t os::lasterror(char *buf, size_t len) {
1179 if (errno == 0) return 0;
1180
1181 const char *s = ::strerror(errno);
1182 size_t n = ::strlen(s);
1183 if (n >= len) {
1184 n = len - 1;
1185 }
1186 ::strncpy(buf, s, n);
1187 buf[n] = '\0';
1188 return n;
1189 }
1190
1191 // Information of current thread in variety of formats
1192 pid_t os::Bsd::gettid() {
1193 int retval = -1;
1194
1195 #ifdef __APPLE__ //XNU kernel
1196 // despite the fact mach port is actually not a thread id use it
1197 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1198 retval = ::pthread_mach_thread_np(::pthread_self());
1199 guarantee(retval != 0, "just checking");
1200 return retval;
1201
1202 #elif __FreeBSD__
1203 retval = syscall(SYS_thr_self);
1204 #elif __OpenBSD__
1205 retval = syscall(SYS_getthrid);
1206 #elif __NetBSD__
1207 retval = (pid_t) syscall(SYS__lwp_self);
1208 #endif
1209
1210 if (retval == -1) {
1211 return getpid();
1212 }
1213 }
1214
1215 intx os::current_thread_id() {
1216 #ifdef __APPLE__
1217 return (intx)::pthread_mach_thread_np(::pthread_self());
1218 #else
1219 return (intx)::pthread_self();
1220 #endif
1221 }
1222
1223 int os::current_process_id() {
1224
1225 // Under the old bsd thread library, bsd gives each thread
1226 // its own process id. Because of this each thread will return
1227 // a different pid if this method were to return the result
1228 // of getpid(2). Bsd provides no api that returns the pid
1229 // of the launcher thread for the vm. This implementation
1230 // returns a unique pid, the pid of the launcher thread
1231 // that starts the vm 'process'.
1232
1233 // Under the NPTL, getpid() returns the same pid as the
1234 // launcher thread rather than a unique pid per thread.
1235 // Use gettid() if you want the old pre NPTL behaviour.
1236
1237 // if you are looking for the result of a call to getpid() that
1238 // returns a unique pid for the calling thread, then look at the
1239 // OSThread::thread_id() method in osThread_bsd.hpp file
1240
1241 return (int)(_initial_pid ? _initial_pid : getpid());
1242 }
1243
1244 // DLL functions
1245
1246 #define JNI_LIB_PREFIX "lib"
1247 #ifdef __APPLE__
1248 #define JNI_LIB_SUFFIX ".dylib"
1249 #else
1250 #define JNI_LIB_SUFFIX ".so"
1251 #endif
1252
1253 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1254
1255 // This must be hard coded because it's the system's temporary
1256 // directory not the java application's temp directory, ala java.io.tmpdir.
1257 #ifdef __APPLE__
1258 // macosx has a secure per-user temporary directory
1259 char temp_path_storage[PATH_MAX];
1260 const char* os::get_temp_directory() {
1261 static char *temp_path = NULL;
1262 if (temp_path == NULL) {
1263 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1264 if (pathSize == 0 || pathSize > PATH_MAX) {
1265 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1266 }
1267 temp_path = temp_path_storage;
1268 }
1269 return temp_path;
1270 }
1271 #else // __APPLE__
1272 const char* os::get_temp_directory() { return "/tmp"; }
1273 #endif // __APPLE__
1274
1275 static bool file_exists(const char* filename) {
1276 struct stat statbuf;
1277 if (filename == NULL || strlen(filename) == 0) {
1278 return false;
1279 }
1280 return os::stat(filename, &statbuf) == 0;
1281 }
1282
1283 bool os::dll_build_name(char* buffer, size_t buflen,
1284 const char* pname, const char* fname) {
1285 bool retval = false;
1286 // Copied from libhpi
1287 const size_t pnamelen = pname ? strlen(pname) : 0;
1288
1289 // Return error on buffer overflow.
1290 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1291 return retval;
1292 }
1293
1294 if (pnamelen == 0) {
1295 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1296 retval = true;
1297 } else if (strchr(pname, *os::path_separator()) != NULL) {
1298 int n;
1299 char** pelements = split_path(pname, &n);
1300 if (pelements == NULL) {
1301 return false;
1302 }
1303 for (int i = 0; i < n; i++) {
1304 // Really shouldn't be NULL, but check can't hurt
1305 if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1306 continue; // skip the empty path values
1307 }
1308 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1309 pelements[i], fname);
1310 if (file_exists(buffer)) {
1311 retval = true;
1312 break;
1313 }
1314 }
1315 // release the storage
1316 for (int i = 0; i < n; i++) {
1317 if (pelements[i] != NULL) {
1318 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
1319 }
1320 }
1321 if (pelements != NULL) {
1322 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
1323 }
1324 } else {
1325 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1326 retval = true;
1327 }
1328 return retval;
1329 }
1330
1331 // check if addr is inside libjvm.so
1332 bool os::address_is_in_vm(address addr) {
1333 static address libjvm_base_addr;
1334 Dl_info dlinfo;
1335
1336 if (libjvm_base_addr == NULL) {
1337 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1338 libjvm_base_addr = (address)dlinfo.dli_fbase;
1339 }
1340 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1341 }
1342
1343 if (dladdr((void *)addr, &dlinfo) != 0) {
1344 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1345 }
1346
1347 return false;
1348 }
1349
1350
1351 #define MACH_MAXSYMLEN 256
1352
1353 bool os::dll_address_to_function_name(address addr, char *buf,
1354 int buflen, int *offset) {
1355 // buf is not optional, but offset is optional
1356 assert(buf != NULL, "sanity check");
1357
1358 Dl_info dlinfo;
1359 char localbuf[MACH_MAXSYMLEN];
1360
1361 if (dladdr((void*)addr, &dlinfo) != 0) {
1362 // see if we have a matching symbol
1363 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1364 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1365 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1366 }
1367 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1368 return true;
1369 }
1370 // no matching symbol so try for just file info
1371 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1372 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1373 buf, buflen, offset, dlinfo.dli_fname)) {
1374 return true;
1375 }
1376 }
1377
1378 // Handle non-dynamic manually:
1379 if (dlinfo.dli_fbase != NULL &&
1380 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset, dlinfo.dli_fbase)) {
1381 if (!Decoder::demangle(localbuf, buf, buflen)) {
1382 jio_snprintf(buf, buflen, "%s", localbuf);
1383 }
1384 return true;
1385 }
1386 }
1387 buf[0] = '\0';
1388 if (offset != NULL) *offset = -1;
1389 return false;
1390 }
1391
1392 // ported from solaris version
1393 bool os::dll_address_to_library_name(address addr, char* buf,
1394 int buflen, int* offset) {
1395 // buf is not optional, but offset is optional
1396 assert(buf != NULL, "sanity check");
1397
1398 Dl_info dlinfo;
1399
1400 if (dladdr((void*)addr, &dlinfo) != 0) {
1401 if (dlinfo.dli_fname != NULL) {
1402 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1403 }
1404 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1405 *offset = addr - (address)dlinfo.dli_fbase;
1406 }
1407 return true;
1408 }
1409
1410 buf[0] = '\0';
1411 if (offset) *offset = -1;
1412 return false;
1413 }
1414
1415 // Loads .dll/.so and
1416 // in case of error it checks if .dll/.so was built for the
1417 // same architecture as Hotspot is running on
1418
1419 #ifdef __APPLE__
1420 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1421 void * result= ::dlopen(filename, RTLD_LAZY);
1422 if (result != NULL) {
1423 // Successful loading
1424 return result;
1425 }
1426
1427 // Read system error message into ebuf
1428 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1429 ebuf[ebuflen-1]='\0';
1430
1431 return NULL;
1432 }
1433 #else
1434 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1435 void * result= ::dlopen(filename, RTLD_LAZY);
1436 if (result != NULL) {
1437 // Successful loading
1438 return result;
1439 }
1440
1441 Elf32_Ehdr elf_head;
1442
1443 // Read system error message into ebuf
1444 // It may or may not be overwritten below
1445 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1446 ebuf[ebuflen-1]='\0';
1447 int diag_msg_max_length=ebuflen-strlen(ebuf);
1448 char* diag_msg_buf=ebuf+strlen(ebuf);
1449
1450 if (diag_msg_max_length==0) {
1451 // No more space in ebuf for additional diagnostics message
1452 return NULL;
1453 }
1454
1455
1456 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1457
1458 if (file_descriptor < 0) {
1459 // Can't open library, report dlerror() message
1460 return NULL;
1461 }
1462
1463 bool failed_to_read_elf_head=
1464 (sizeof(elf_head)!=
1465 (::read(file_descriptor, &elf_head,sizeof(elf_head))));
1466
1467 ::close(file_descriptor);
1468 if (failed_to_read_elf_head) {
1469 // file i/o error - report dlerror() msg
1470 return NULL;
1471 }
1472
1473 typedef struct {
1474 Elf32_Half code; // Actual value as defined in elf.h
1475 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1476 char elf_class; // 32 or 64 bit
1477 char endianess; // MSB or LSB
1478 char* name; // String representation
1479 } arch_t;
1480
1481 #ifndef EM_486
1482 #define EM_486 6 /* Intel 80486 */
1483 #endif
1484
1485 #ifndef EM_MIPS_RS3_LE
1486 #define EM_MIPS_RS3_LE 10 /* MIPS */
1487 #endif
1488
1489 #ifndef EM_PPC64
1490 #define EM_PPC64 21 /* PowerPC64 */
1491 #endif
1492
1493 #ifndef EM_S390
1494 #define EM_S390 22 /* IBM System/390 */
1495 #endif
1496
1497 #ifndef EM_IA_64
1498 #define EM_IA_64 50 /* HP/Intel IA-64 */
1499 #endif
1500
1501 #ifndef EM_X86_64
1502 #define EM_X86_64 62 /* AMD x86-64 */
1503 #endif
1504
1505 static const arch_t arch_array[]={
1506 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1507 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1508 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1509 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1510 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1511 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1512 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1513 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1514 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1515 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1516 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1517 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1518 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1519 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1520 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1521 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1522 };
1523
1524 #if (defined IA32)
1525 static Elf32_Half running_arch_code=EM_386;
1526 #elif (defined AMD64)
1527 static Elf32_Half running_arch_code=EM_X86_64;
1528 #elif (defined IA64)
1529 static Elf32_Half running_arch_code=EM_IA_64;
1530 #elif (defined __sparc) && (defined _LP64)
1531 static Elf32_Half running_arch_code=EM_SPARCV9;
1532 #elif (defined __sparc) && (!defined _LP64)
1533 static Elf32_Half running_arch_code=EM_SPARC;
1534 #elif (defined __powerpc64__)
1535 static Elf32_Half running_arch_code=EM_PPC64;
1536 #elif (defined __powerpc__)
1537 static Elf32_Half running_arch_code=EM_PPC;
1538 #elif (defined ARM)
1539 static Elf32_Half running_arch_code=EM_ARM;
1540 #elif (defined S390)
1541 static Elf32_Half running_arch_code=EM_S390;
1542 #elif (defined ALPHA)
1543 static Elf32_Half running_arch_code=EM_ALPHA;
1544 #elif (defined MIPSEL)
1545 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1546 #elif (defined PARISC)
1547 static Elf32_Half running_arch_code=EM_PARISC;
1548 #elif (defined MIPS)
1549 static Elf32_Half running_arch_code=EM_MIPS;
1550 #elif (defined M68K)
1551 static Elf32_Half running_arch_code=EM_68K;
1552 #else
1553 #error Method os::dll_load requires that one of following is defined:\
1554 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1555 #endif
1556
1557 // Identify compatability class for VM's architecture and library's architecture
1558 // Obtain string descriptions for architectures
1559
1560 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1561 int running_arch_index=-1;
1562
1563 for (unsigned int i=0; i < ARRAY_SIZE(arch_array); i++) {
1564 if (running_arch_code == arch_array[i].code) {
1565 running_arch_index = i;
1566 }
1567 if (lib_arch.code == arch_array[i].code) {
1568 lib_arch.compat_class = arch_array[i].compat_class;
1569 lib_arch.name = arch_array[i].name;
1570 }
1571 }
1572
1573 assert(running_arch_index != -1,
1574 "Didn't find running architecture code (running_arch_code) in arch_array");
1575 if (running_arch_index == -1) {
1576 // Even though running architecture detection failed
1577 // we may still continue with reporting dlerror() message
1578 return NULL;
1579 }
1580
1581 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1582 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1583 return NULL;
1584 }
1585
1586 #ifndef S390
1587 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1588 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1589 return NULL;
1590 }
1591 #endif // !S390
1592
1593 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1594 if (lib_arch.name!=NULL) {
1595 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1596 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1597 lib_arch.name, arch_array[running_arch_index].name);
1598 } else {
1599 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1600 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1601 lib_arch.code,
1602 arch_array[running_arch_index].name);
1603 }
1604 }
1605
1606 return NULL;
1607 }
1608 #endif // !__APPLE__
1609
1610 void* os::get_default_process_handle() {
1611 #ifdef __APPLE__
1612 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1613 // to avoid finding unexpected symbols on second (or later)
1614 // loads of a library.
1615 return (void*)::dlopen(NULL, RTLD_FIRST);
1616 #else
1617 return (void*)::dlopen(NULL, RTLD_LAZY);
1618 #endif
1619 }
1620
1621 // XXX: Do we need a lock around this as per Linux?
1622 void* os::dll_lookup(void* handle, const char* name) {
1623 return dlsym(handle, name);
1624 }
1625
1626
1627 static bool _print_ascii_file(const char* filename, outputStream* st) {
1628 int fd = ::open(filename, O_RDONLY);
1629 if (fd == -1) {
1630 return false;
1631 }
1632
1633 char buf[32];
1634 int bytes;
1635 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1636 st->print_raw(buf, bytes);
1637 }
1638
1639 ::close(fd);
1640
1641 return true;
1642 }
1643
1644 int _print_dll_info_cb(const char * name, address base_address, address top_address, void * param) {
1645 outputStream * out = (outputStream *) param;
1646 out->print_cr(PTR_FORMAT " \t%s", base_address, name);
1647 return 0;
1648 }
1649
1650 void os::print_dll_info(outputStream *st) {
1651 st->print_cr("Dynamic libraries:");
1652 if (get_loaded_modules_info(_print_dll_info_cb, (void *)st)) {
1653 st->print_cr("Error: Cannot print dynamic libraries.");
1654 }
1655 }
1656
1657 int os::get_loaded_modules_info(os::LoadedModulesCallbackFunc callback, void *param) {
1658 #ifdef RTLD_DI_LINKMAP
1659 Dl_info dli;
1660 void *handle;
1661 Link_map *map;
1662 Link_map *p;
1663
1664 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1665 dli.dli_fname == NULL) {
1666 return 1;
1667 }
1668 handle = dlopen(dli.dli_fname, RTLD_LAZY);
1669 if (handle == NULL) {
1670 return 1;
1671 }
1672 dlinfo(handle, RTLD_DI_LINKMAP, &map);
1673 if (map == NULL) {
1674 dlclose(handle);
1675 return 1;
1676 }
1677
1678 while (map->l_prev != NULL)
1679 map = map->l_prev;
1680
1681 while (map != NULL) {
1682 // Value for top_address is returned as 0 since we don't have any information about module size
1683 if (callback(map->l_name, (address)map->l_addr, (address)0, param)) {
1684 dlclose(handle);
1685 return 1;
1686 }
1687 map = map->l_next;
1688 }
1689
1690 dlclose(handle);
1691 #elif defined(__APPLE__)
1692 for (uint32_t i = 1; i < _dyld_image_count(); i++) {
1693 // Value for top_address is returned as 0 since we don't have any information about module size
1694 if (callback(_dyld_get_image_name(i), (address)_dyld_get_image_header(i), (address)0, param)) {
1695 return 1;
1696 }
1697 }
1698 return 0;
1699 #else
1700 return 1;
1701 #endif
1702 }
1703
1704 void os::print_os_info_brief(outputStream* st) {
1705 st->print("Bsd");
1706
1707 os::Posix::print_uname_info(st);
1708 }
1709
1710 void os::print_os_info(outputStream* st) {
1711 st->print("OS:");
1712 st->print("Bsd");
1713
1714 os::Posix::print_uname_info(st);
1715
1716 os::Posix::print_rlimit_info(st);
1717
1718 os::Posix::print_load_average(st);
1719 }
1720
1721 void os::pd_print_cpu_info(outputStream* st) {
1722 // Nothing to do for now.
1723 }
1724
1725 void os::print_memory_info(outputStream* st) {
1726
1727 st->print("Memory:");
1728 st->print(" %dk page", os::vm_page_size()>>10);
1729
1730 st->print(", physical " UINT64_FORMAT "k",
1731 os::physical_memory() >> 10);
1732 st->print("(" UINT64_FORMAT "k free)",
1733 os::available_memory() >> 10);
1734 st->cr();
1735
1736 // meminfo
1737 st->print("\n/proc/meminfo:\n");
1738 _print_ascii_file("/proc/meminfo", st);
1739 st->cr();
1740 }
1741
1742 void os::print_siginfo(outputStream* st, void* siginfo) {
1743 const siginfo_t* si = (const siginfo_t*)siginfo;
1744
1745 os::Posix::print_siginfo_brief(st, si);
1746
1747 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1748 UseSharedSpaces) {
1749 FileMapInfo* mapinfo = FileMapInfo::current_info();
1750 if (mapinfo->is_in_shared_space(si->si_addr)) {
1751 st->print("\n\nError accessing class data sharing archive." \
1752 " Mapped file inaccessible during execution, " \
1753 " possible disk/network problem.");
1754 }
1755 }
1756 st->cr();
1757 }
1758
1759
1760 static void print_signal_handler(outputStream* st, int sig,
1761 char* buf, size_t buflen);
1762
1763 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1764 st->print_cr("Signal Handlers:");
1765 print_signal_handler(st, SIGSEGV, buf, buflen);
1766 print_signal_handler(st, SIGBUS , buf, buflen);
1767 print_signal_handler(st, SIGFPE , buf, buflen);
1768 print_signal_handler(st, SIGPIPE, buf, buflen);
1769 print_signal_handler(st, SIGXFSZ, buf, buflen);
1770 print_signal_handler(st, SIGILL , buf, buflen);
1771 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1772 print_signal_handler(st, SR_signum, buf, buflen);
1773 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1774 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1775 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1776 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1777 }
1778
1779 static char saved_jvm_path[MAXPATHLEN] = {0};
1780
1781 // Find the full path to the current module, libjvm
1782 void os::jvm_path(char *buf, jint buflen) {
1783 // Error checking.
1784 if (buflen < MAXPATHLEN) {
1785 assert(false, "must use a large-enough buffer");
1786 buf[0] = '\0';
1787 return;
1788 }
1789 // Lazy resolve the path to current module.
1790 if (saved_jvm_path[0] != 0) {
1791 strcpy(buf, saved_jvm_path);
1792 return;
1793 }
1794
1795 char dli_fname[MAXPATHLEN];
1796 bool ret = dll_address_to_library_name(
1797 CAST_FROM_FN_PTR(address, os::jvm_path),
1798 dli_fname, sizeof(dli_fname), NULL);
1799 assert(ret, "cannot locate libjvm");
1800 char *rp = NULL;
1801 if (ret && dli_fname[0] != '\0') {
1802 rp = realpath(dli_fname, buf);
1803 }
1804 if (rp == NULL) {
1805 return;
1806 }
1807
1808 if (Arguments::sun_java_launcher_is_altjvm()) {
1809 // Support for the java launcher's '-XXaltjvm=<path>' option. Typical
1810 // value for buf is "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm.so"
1811 // or "<JAVA_HOME>/jre/lib/<vmtype>/libjvm.dylib". If "/jre/lib/"
1812 // appears at the right place in the string, then assume we are
1813 // installed in a JDK and we're done. Otherwise, check for a
1814 // JAVA_HOME environment variable and construct a path to the JVM
1815 // being overridden.
1816
1817 const char *p = buf + strlen(buf) - 1;
1818 for (int count = 0; p > buf && count < 5; ++count) {
1819 for (--p; p > buf && *p != '/'; --p)
1820 /* empty */ ;
1821 }
1822
1823 if (strncmp(p, "/jre/lib/", 9) != 0) {
1824 // Look for JAVA_HOME in the environment.
1825 char* java_home_var = ::getenv("JAVA_HOME");
1826 if (java_home_var != NULL && java_home_var[0] != 0) {
1827 char* jrelib_p;
1828 int len;
1829
1830 // Check the current module name "libjvm"
1831 p = strrchr(buf, '/');
1832 assert(strstr(p, "/libjvm") == p, "invalid library name");
1833
1834 rp = realpath(java_home_var, buf);
1835 if (rp == NULL) {
1836 return;
1837 }
1838
1839 // determine if this is a legacy image or modules image
1840 // modules image doesn't have "jre" subdirectory
1841 len = strlen(buf);
1842 assert(len < buflen, "Ran out of buffer space");
1843 jrelib_p = buf + len;
1844
1845 // Add the appropriate library subdir
1846 snprintf(jrelib_p, buflen-len, "/jre/lib");
1847 if (0 != access(buf, F_OK)) {
1848 snprintf(jrelib_p, buflen-len, "/lib");
1849 }
1850
1851 // Add the appropriate client or server subdir
1852 len = strlen(buf);
1853 jrelib_p = buf + len;
1854 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1855 if (0 != access(buf, F_OK)) {
1856 snprintf(jrelib_p, buflen-len, "%s", "");
1857 }
1858
1859 // If the path exists within JAVA_HOME, add the JVM library name
1860 // to complete the path to JVM being overridden. Otherwise fallback
1861 // to the path to the current library.
1862 if (0 == access(buf, F_OK)) {
1863 // Use current module name "libjvm"
1864 len = strlen(buf);
1865 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1866 } else {
1867 // Fall back to path of current library
1868 rp = realpath(dli_fname, buf);
1869 if (rp == NULL) {
1870 return;
1871 }
1872 }
1873 }
1874 }
1875 }
1876
1877 strncpy(saved_jvm_path, buf, MAXPATHLEN);
1878 }
1879
1880 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1881 // no prefix required, not even "_"
1882 }
1883
1884 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1885 // no suffix required
1886 }
1887
1888 ////////////////////////////////////////////////////////////////////////////////
1889 // sun.misc.Signal support
1890
1891 static volatile jint sigint_count = 0;
1892
1893 static void UserHandler(int sig, void *siginfo, void *context) {
1894 // 4511530 - sem_post is serialized and handled by the manager thread. When
1895 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1896 // don't want to flood the manager thread with sem_post requests.
1897 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1) {
1898 return;
1899 }
1900
1901 // Ctrl-C is pressed during error reporting, likely because the error
1902 // handler fails to abort. Let VM die immediately.
1903 if (sig == SIGINT && is_error_reported()) {
1904 os::die();
1905 }
1906
1907 os::signal_notify(sig);
1908 }
1909
1910 void* os::user_handler() {
1911 return CAST_FROM_FN_PTR(void*, UserHandler);
1912 }
1913
1914 extern "C" {
1915 typedef void (*sa_handler_t)(int);
1916 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1917 }
1918
1919 void* os::signal(int signal_number, void* handler) {
1920 struct sigaction sigAct, oldSigAct;
1921
1922 sigfillset(&(sigAct.sa_mask));
1923 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
1924 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1925
1926 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1927 // -1 means registration failed
1928 return (void *)-1;
1929 }
1930
1931 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1932 }
1933
1934 void os::signal_raise(int signal_number) {
1935 ::raise(signal_number);
1936 }
1937
1938 // The following code is moved from os.cpp for making this
1939 // code platform specific, which it is by its very nature.
1940
1941 // Will be modified when max signal is changed to be dynamic
1942 int os::sigexitnum_pd() {
1943 return NSIG;
1944 }
1945
1946 // a counter for each possible signal value
1947 static volatile jint pending_signals[NSIG+1] = { 0 };
1948
1949 // Bsd(POSIX) specific hand shaking semaphore.
1950 #ifdef __APPLE__
1951 typedef semaphore_t os_semaphore_t;
1952
1953 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1954 #define SEM_WAIT(sem) semaphore_wait(sem)
1955 #define SEM_POST(sem) semaphore_signal(sem)
1956 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem)
1957 #else
1958 typedef sem_t os_semaphore_t;
1959
1960 #define SEM_INIT(sem, value) sem_init(&sem, 0, value)
1961 #define SEM_WAIT(sem) sem_wait(&sem)
1962 #define SEM_POST(sem) sem_post(&sem)
1963 #define SEM_DESTROY(sem) sem_destroy(&sem)
1964 #endif
1965
1966 class Semaphore : public StackObj {
1967 public:
1968 Semaphore();
1969 ~Semaphore();
1970 void signal();
1971 void wait();
1972 bool trywait();
1973 bool timedwait(unsigned int sec, int nsec);
1974 private:
1975 jlong currenttime() const;
1976 os_semaphore_t _semaphore;
1977 };
1978
1979 Semaphore::Semaphore() : _semaphore(0) {
1980 SEM_INIT(_semaphore, 0);
1981 }
1982
1983 Semaphore::~Semaphore() {
1984 SEM_DESTROY(_semaphore);
1985 }
1986
1987 void Semaphore::signal() {
1988 SEM_POST(_semaphore);
1989 }
1990
1991 void Semaphore::wait() {
1992 SEM_WAIT(_semaphore);
1993 }
1994
1995 jlong Semaphore::currenttime() const {
1996 struct timeval tv;
1997 gettimeofday(&tv, NULL);
1998 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
1999 }
2000
2001 #ifdef __APPLE__
2002 bool Semaphore::trywait() {
2003 return timedwait(0, 0);
2004 }
2005
2006 bool Semaphore::timedwait(unsigned int sec, int nsec) {
2007 kern_return_t kr = KERN_ABORTED;
2008 mach_timespec_t waitspec;
2009 waitspec.tv_sec = sec;
2010 waitspec.tv_nsec = nsec;
2011
2012 jlong starttime = currenttime();
2013
2014 kr = semaphore_timedwait(_semaphore, waitspec);
2015 while (kr == KERN_ABORTED) {
2016 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
2017
2018 jlong current = currenttime();
2019 jlong passedtime = current - starttime;
2020
2021 if (passedtime >= totalwait) {
2022 waitspec.tv_sec = 0;
2023 waitspec.tv_nsec = 0;
2024 } else {
2025 jlong waittime = totalwait - (current - starttime);
2026 waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
2027 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
2028 }
2029
2030 kr = semaphore_timedwait(_semaphore, waitspec);
2031 }
2032
2033 return kr == KERN_SUCCESS;
2034 }
2035
2036 #else
2037
2038 bool Semaphore::trywait() {
2039 return sem_trywait(&_semaphore) == 0;
2040 }
2041
2042 bool Semaphore::timedwait(unsigned int sec, int nsec) {
2043 struct timespec ts;
2044 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2045
2046 while (1) {
2047 int result = sem_timedwait(&_semaphore, &ts);
2048 if (result == 0) {
2049 return true;
2050 } else if (errno == EINTR) {
2051 continue;
2052 } else if (errno == ETIMEDOUT) {
2053 return false;
2054 } else {
2055 return false;
2056 }
2057 }
2058 }
2059
2060 #endif // __APPLE__
2061
2062 static os_semaphore_t sig_sem;
2063 static Semaphore sr_semaphore;
2064
2065 void os::signal_init_pd() {
2066 // Initialize signal structures
2067 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2068
2069 // Initialize signal semaphore
2070 ::SEM_INIT(sig_sem, 0);
2071 }
2072
2073 void os::signal_notify(int sig) {
2074 Atomic::inc(&pending_signals[sig]);
2075 ::SEM_POST(sig_sem);
2076 }
2077
2078 static int check_pending_signals(bool wait) {
2079 Atomic::store(0, &sigint_count);
2080 for (;;) {
2081 for (int i = 0; i < NSIG + 1; i++) {
2082 jint n = pending_signals[i];
2083 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2084 return i;
2085 }
2086 }
2087 if (!wait) {
2088 return -1;
2089 }
2090 JavaThread *thread = JavaThread::current();
2091 ThreadBlockInVM tbivm(thread);
2092
2093 bool threadIsSuspended;
2094 do {
2095 thread->set_suspend_equivalent();
2096 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2097 ::SEM_WAIT(sig_sem);
2098
2099 // were we externally suspended while we were waiting?
2100 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2101 if (threadIsSuspended) {
2102 // The semaphore has been incremented, but while we were waiting
2103 // another thread suspended us. We don't want to continue running
2104 // while suspended because that would surprise the thread that
2105 // suspended us.
2106 ::SEM_POST(sig_sem);
2107
2108 thread->java_suspend_self();
2109 }
2110 } while (threadIsSuspended);
2111 }
2112 }
2113
2114 int os::signal_lookup() {
2115 return check_pending_signals(false);
2116 }
2117
2118 int os::signal_wait() {
2119 return check_pending_signals(true);
2120 }
2121
2122 ////////////////////////////////////////////////////////////////////////////////
2123 // Virtual Memory
2124
2125 int os::vm_page_size() {
2126 // Seems redundant as all get out
2127 assert(os::Bsd::page_size() != -1, "must call os::init");
2128 return os::Bsd::page_size();
2129 }
2130
2131 // Solaris allocates memory by pages.
2132 int os::vm_allocation_granularity() {
2133 assert(os::Bsd::page_size() != -1, "must call os::init");
2134 return os::Bsd::page_size();
2135 }
2136
2137 // Rationale behind this function:
2138 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2139 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2140 // samples for JITted code. Here we create private executable mapping over the code cache
2141 // and then we can use standard (well, almost, as mapping can change) way to provide
2142 // info for the reporting script by storing timestamp and location of symbol
2143 void bsd_wrap_code(char* base, size_t size) {
2144 static volatile jint cnt = 0;
2145
2146 if (!UseOprofile) {
2147 return;
2148 }
2149
2150 char buf[PATH_MAX + 1];
2151 int num = Atomic::add(1, &cnt);
2152
2153 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2154 os::get_temp_directory(), os::current_process_id(), num);
2155 unlink(buf);
2156
2157 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2158
2159 if (fd != -1) {
2160 off_t rv = ::lseek(fd, size-2, SEEK_SET);
2161 if (rv != (off_t)-1) {
2162 if (::write(fd, "", 1) == 1) {
2163 mmap(base, size,
2164 PROT_READ|PROT_WRITE|PROT_EXEC,
2165 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2166 }
2167 }
2168 ::close(fd);
2169 unlink(buf);
2170 }
2171 }
2172
2173 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2174 int err) {
2175 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2176 ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2177 strerror(err), err);
2178 }
2179
2180 // NOTE: Bsd kernel does not really reserve the pages for us.
2181 // All it does is to check if there are enough free pages
2182 // left at the time of mmap(). This could be a potential
2183 // problem.
2184 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2185 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2186 #ifdef __OpenBSD__
2187 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2188 if (::mprotect(addr, size, prot) == 0) {
2189 return true;
2190 }
2191 #else
2192 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2193 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2194 if (res != (uintptr_t) MAP_FAILED) {
2195 return true;
2196 }
2197 #endif
2198
2199 // Warn about any commit errors we see in non-product builds just
2200 // in case mmap() doesn't work as described on the man page.
2201 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2202
2203 return false;
2204 }
2205
2206 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2207 bool exec) {
2208 // alignment_hint is ignored on this OS
2209 return pd_commit_memory(addr, size, exec);
2210 }
2211
2212 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2213 const char* mesg) {
2214 assert(mesg != NULL, "mesg must be specified");
2215 if (!pd_commit_memory(addr, size, exec)) {
2216 // add extra info in product mode for vm_exit_out_of_memory():
2217 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2218 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
2219 }
2220 }
2221
2222 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2223 size_t alignment_hint, bool exec,
2224 const char* mesg) {
2225 // alignment_hint is ignored on this OS
2226 pd_commit_memory_or_exit(addr, size, exec, mesg);
2227 }
2228
2229 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2230 }
2231
2232 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2233 ::madvise(addr, bytes, MADV_DONTNEED);
2234 }
2235
2236 void os::numa_make_global(char *addr, size_t bytes) {
2237 }
2238
2239 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2240 }
2241
2242 bool os::numa_topology_changed() { return false; }
2243
2244 size_t os::numa_get_groups_num() {
2245 return 1;
2246 }
2247
2248 int os::numa_get_group_id() {
2249 return 0;
2250 }
2251
2252 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2253 if (size > 0) {
2254 ids[0] = 0;
2255 return 1;
2256 }
2257 return 0;
2258 }
2259
2260 bool os::get_page_info(char *start, page_info* info) {
2261 return false;
2262 }
2263
2264 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2265 return end;
2266 }
2267
2268
2269 bool os::pd_uncommit_memory(char* addr, size_t size) {
2270 #ifdef __OpenBSD__
2271 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2272 return ::mprotect(addr, size, PROT_NONE) == 0;
2273 #else
2274 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2275 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2276 return res != (uintptr_t) MAP_FAILED;
2277 #endif
2278 }
2279
2280 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2281 return os::commit_memory(addr, size, !ExecMem);
2282 }
2283
2284 // If this is a growable mapping, remove the guard pages entirely by
2285 // munmap()ping them. If not, just call uncommit_memory().
2286 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2287 return os::uncommit_memory(addr, size);
2288 }
2289
2290 static address _highest_vm_reserved_address = NULL;
2291
2292 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2293 // at 'requested_addr'. If there are existing memory mappings at the same
2294 // location, however, they will be overwritten. If 'fixed' is false,
2295 // 'requested_addr' is only treated as a hint, the return value may or
2296 // may not start from the requested address. Unlike Bsd mmap(), this
2297 // function returns NULL to indicate failure.
2298 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2299 char * addr;
2300 int flags;
2301
2302 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2303 if (fixed) {
2304 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2305 flags |= MAP_FIXED;
2306 }
2307
2308 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2309 // touch an uncommitted page. Otherwise, the read/write might
2310 // succeed if we have enough swap space to back the physical page.
2311 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2312 flags, -1, 0);
2313
2314 if (addr != MAP_FAILED) {
2315 // anon_mmap() should only get called during VM initialization,
2316 // don't need lock (actually we can skip locking even it can be called
2317 // from multiple threads, because _highest_vm_reserved_address is just a
2318 // hint about the upper limit of non-stack memory regions.)
2319 if ((address)addr + bytes > _highest_vm_reserved_address) {
2320 _highest_vm_reserved_address = (address)addr + bytes;
2321 }
2322 }
2323
2324 return addr == MAP_FAILED ? NULL : addr;
2325 }
2326
2327 // Don't update _highest_vm_reserved_address, because there might be memory
2328 // regions above addr + size. If so, releasing a memory region only creates
2329 // a hole in the address space, it doesn't help prevent heap-stack collision.
2330 //
2331 static int anon_munmap(char * addr, size_t size) {
2332 return ::munmap(addr, size) == 0;
2333 }
2334
2335 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2336 size_t alignment_hint) {
2337 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2338 }
2339
2340 bool os::pd_release_memory(char* addr, size_t size) {
2341 return anon_munmap(addr, size);
2342 }
2343
2344 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2345 // Bsd wants the mprotect address argument to be page aligned.
2346 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2347
2348 // According to SUSv3, mprotect() should only be used with mappings
2349 // established by mmap(), and mmap() always maps whole pages. Unaligned
2350 // 'addr' likely indicates problem in the VM (e.g. trying to change
2351 // protection of malloc'ed or statically allocated memory). Check the
2352 // caller if you hit this assert.
2353 assert(addr == bottom, "sanity check");
2354
2355 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2356 return ::mprotect(bottom, size, prot) == 0;
2357 }
2358
2359 // Set protections specified
2360 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2361 bool is_committed) {
2362 unsigned int p = 0;
2363 switch (prot) {
2364 case MEM_PROT_NONE: p = PROT_NONE; break;
2365 case MEM_PROT_READ: p = PROT_READ; break;
2366 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
2367 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2368 default:
2369 ShouldNotReachHere();
2370 }
2371 // is_committed is unused.
2372 return bsd_mprotect(addr, bytes, p);
2373 }
2374
2375 bool os::guard_memory(char* addr, size_t size) {
2376 return bsd_mprotect(addr, size, PROT_NONE);
2377 }
2378
2379 bool os::unguard_memory(char* addr, size_t size) {
2380 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2381 }
2382
2383 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2384 return false;
2385 }
2386
2387 // Large page support
2388
2389 static size_t _large_page_size = 0;
2390
2391 void os::large_page_init() {
2392 }
2393
2394
2395 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2396 fatal("This code is not used or maintained.");
2397
2398 // "exec" is passed in but not used. Creating the shared image for
2399 // the code cache doesn't have an SHM_X executable permission to check.
2400 assert(UseLargePages && UseSHM, "only for SHM large pages");
2401
2402 key_t key = IPC_PRIVATE;
2403 char *addr;
2404
2405 bool warn_on_failure = UseLargePages &&
2406 (!FLAG_IS_DEFAULT(UseLargePages) ||
2407 !FLAG_IS_DEFAULT(LargePageSizeInBytes));
2408
2409 // Create a large shared memory region to attach to based on size.
2410 // Currently, size is the total size of the heap
2411 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2412 if (shmid == -1) {
2413 // Possible reasons for shmget failure:
2414 // 1. shmmax is too small for Java heap.
2415 // > check shmmax value: cat /proc/sys/kernel/shmmax
2416 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2417 // 2. not enough large page memory.
2418 // > check available large pages: cat /proc/meminfo
2419 // > increase amount of large pages:
2420 // echo new_value > /proc/sys/vm/nr_hugepages
2421 // Note 1: different Bsd may use different name for this property,
2422 // e.g. on Redhat AS-3 it is "hugetlb_pool".
2423 // Note 2: it's possible there's enough physical memory available but
2424 // they are so fragmented after a long run that they can't
2425 // coalesce into large pages. Try to reserve large pages when
2426 // the system is still "fresh".
2427 if (warn_on_failure) {
2428 warning("Failed to reserve shared memory (errno = %d).", errno);
2429 }
2430 return NULL;
2431 }
2432
2433 // attach to the region
2434 addr = (char*)shmat(shmid, req_addr, 0);
2435 int err = errno;
2436
2437 // Remove shmid. If shmat() is successful, the actual shared memory segment
2438 // will be deleted when it's detached by shmdt() or when the process
2439 // terminates. If shmat() is not successful this will remove the shared
2440 // segment immediately.
2441 shmctl(shmid, IPC_RMID, NULL);
2442
2443 if ((intptr_t)addr == -1) {
2444 if (warn_on_failure) {
2445 warning("Failed to attach shared memory (errno = %d).", err);
2446 }
2447 return NULL;
2448 }
2449
2450 // The memory is committed
2451 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, CALLER_PC);
2452
2453 return addr;
2454 }
2455
2456 bool os::release_memory_special(char* base, size_t bytes) {
2457 if (MemTracker::tracking_level() > NMT_minimal) {
2458 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2459 // detaching the SHM segment will also delete it, see reserve_memory_special()
2460 int rslt = shmdt(base);
2461 if (rslt == 0) {
2462 tkr.record((address)base, bytes);
2463 return true;
2464 } else {
2465 return false;
2466 }
2467 } else {
2468 return shmdt(base) == 0;
2469 }
2470 }
2471
2472 size_t os::large_page_size() {
2473 return _large_page_size;
2474 }
2475
2476 // HugeTLBFS allows application to commit large page memory on demand;
2477 // with SysV SHM the entire memory region must be allocated as shared
2478 // memory.
2479 bool os::can_commit_large_page_memory() {
2480 return UseHugeTLBFS;
2481 }
2482
2483 bool os::can_execute_large_page_memory() {
2484 return UseHugeTLBFS;
2485 }
2486
2487 // Reserve memory at an arbitrary address, only if that area is
2488 // available (and not reserved for something else).
2489
2490 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2491 const int max_tries = 10;
2492 char* base[max_tries];
2493 size_t size[max_tries];
2494 const size_t gap = 0x000000;
2495
2496 // Assert only that the size is a multiple of the page size, since
2497 // that's all that mmap requires, and since that's all we really know
2498 // about at this low abstraction level. If we need higher alignment,
2499 // we can either pass an alignment to this method or verify alignment
2500 // in one of the methods further up the call chain. See bug 5044738.
2501 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2502
2503 // Repeatedly allocate blocks until the block is allocated at the
2504 // right spot. Give up after max_tries. Note that reserve_memory() will
2505 // automatically update _highest_vm_reserved_address if the call is
2506 // successful. The variable tracks the highest memory address every reserved
2507 // by JVM. It is used to detect heap-stack collision if running with
2508 // fixed-stack BsdThreads. Because here we may attempt to reserve more
2509 // space than needed, it could confuse the collision detecting code. To
2510 // solve the problem, save current _highest_vm_reserved_address and
2511 // calculate the correct value before return.
2512 address old_highest = _highest_vm_reserved_address;
2513
2514 // Bsd mmap allows caller to pass an address as hint; give it a try first,
2515 // if kernel honors the hint then we can return immediately.
2516 char * addr = anon_mmap(requested_addr, bytes, false);
2517 if (addr == requested_addr) {
2518 return requested_addr;
2519 }
2520
2521 if (addr != NULL) {
2522 // mmap() is successful but it fails to reserve at the requested address
2523 anon_munmap(addr, bytes);
2524 }
2525
2526 int i;
2527 for (i = 0; i < max_tries; ++i) {
2528 base[i] = reserve_memory(bytes);
2529
2530 if (base[i] != NULL) {
2531 // Is this the block we wanted?
2532 if (base[i] == requested_addr) {
2533 size[i] = bytes;
2534 break;
2535 }
2536
2537 // Does this overlap the block we wanted? Give back the overlapped
2538 // parts and try again.
2539
2540 size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2541 if (top_overlap >= 0 && top_overlap < bytes) {
2542 unmap_memory(base[i], top_overlap);
2543 base[i] += top_overlap;
2544 size[i] = bytes - top_overlap;
2545 } else {
2546 size_t bottom_overlap = base[i] + bytes - requested_addr;
2547 if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2548 unmap_memory(requested_addr, bottom_overlap);
2549 size[i] = bytes - bottom_overlap;
2550 } else {
2551 size[i] = bytes;
2552 }
2553 }
2554 }
2555 }
2556
2557 // Give back the unused reserved pieces.
2558
2559 for (int j = 0; j < i; ++j) {
2560 if (base[j] != NULL) {
2561 unmap_memory(base[j], size[j]);
2562 }
2563 }
2564
2565 if (i < max_tries) {
2566 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2567 return requested_addr;
2568 } else {
2569 _highest_vm_reserved_address = old_highest;
2570 return NULL;
2571 }
2572 }
2573
2574 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2575 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2576 }
2577
2578 void os::naked_short_sleep(jlong ms) {
2579 struct timespec req;
2580
2581 assert(ms < 1000, "Un-interruptable sleep, short time use only");
2582 req.tv_sec = 0;
2583 if (ms > 0) {
2584 req.tv_nsec = (ms % 1000) * 1000000;
2585 } else {
2586 req.tv_nsec = 1;
2587 }
2588
2589 nanosleep(&req, NULL);
2590
2591 return;
2592 }
2593
2594 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2595 void os::infinite_sleep() {
2596 while (true) { // sleep forever ...
2597 ::sleep(100); // ... 100 seconds at a time
2598 }
2599 }
2600
2601 // Used to convert frequent JVM_Yield() to nops
2602 bool os::dont_yield() {
2603 return DontYieldALot;
2604 }
2605
2606 void os::naked_yield() {
2607 sched_yield();
2608 }
2609
2610 ////////////////////////////////////////////////////////////////////////////////
2611 // thread priority support
2612
2613 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2614 // only supports dynamic priority, static priority must be zero. For real-time
2615 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2616 // However, for large multi-threaded applications, SCHED_RR is not only slower
2617 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2618 // of 5 runs - Sep 2005).
2619 //
2620 // The following code actually changes the niceness of kernel-thread/LWP. It
2621 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2622 // not the entire user process, and user level threads are 1:1 mapped to kernel
2623 // threads. It has always been the case, but could change in the future. For
2624 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2625 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2626
2627 #if !defined(__APPLE__)
2628 int os::java_to_os_priority[CriticalPriority + 1] = {
2629 19, // 0 Entry should never be used
2630
2631 0, // 1 MinPriority
2632 3, // 2
2633 6, // 3
2634
2635 10, // 4
2636 15, // 5 NormPriority
2637 18, // 6
2638
2639 21, // 7
2640 25, // 8
2641 28, // 9 NearMaxPriority
2642
2643 31, // 10 MaxPriority
2644
2645 31 // 11 CriticalPriority
2646 };
2647 #else
2648 // Using Mach high-level priority assignments
2649 int os::java_to_os_priority[CriticalPriority + 1] = {
2650 0, // 0 Entry should never be used (MINPRI_USER)
2651
2652 27, // 1 MinPriority
2653 28, // 2
2654 29, // 3
2655
2656 30, // 4
2657 31, // 5 NormPriority (BASEPRI_DEFAULT)
2658 32, // 6
2659
2660 33, // 7
2661 34, // 8
2662 35, // 9 NearMaxPriority
2663
2664 36, // 10 MaxPriority
2665
2666 36 // 11 CriticalPriority
2667 };
2668 #endif
2669
2670 static int prio_init() {
2671 if (ThreadPriorityPolicy == 1) {
2672 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2673 // if effective uid is not root. Perhaps, a more elegant way of doing
2674 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2675 if (geteuid() != 0) {
2676 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2677 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2678 }
2679 ThreadPriorityPolicy = 0;
2680 }
2681 }
2682 if (UseCriticalJavaThreadPriority) {
2683 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2684 }
2685 return 0;
2686 }
2687
2688 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2689 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) return OS_OK;
2690
2691 #ifdef __OpenBSD__
2692 // OpenBSD pthread_setprio starves low priority threads
2693 return OS_OK;
2694 #elif defined(__FreeBSD__)
2695 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2696 #elif defined(__APPLE__) || defined(__NetBSD__)
2697 struct sched_param sp;
2698 int policy;
2699 pthread_t self = pthread_self();
2700
2701 if (pthread_getschedparam(self, &policy, &sp) != 0) {
2702 return OS_ERR;
2703 }
2704
2705 sp.sched_priority = newpri;
2706 if (pthread_setschedparam(self, policy, &sp) != 0) {
2707 return OS_ERR;
2708 }
2709
2710 return OS_OK;
2711 #else
2712 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2713 return (ret == 0) ? OS_OK : OS_ERR;
2714 #endif
2715 }
2716
2717 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2718 if (!UseThreadPriorities || ThreadPriorityPolicy == 0) {
2719 *priority_ptr = java_to_os_priority[NormPriority];
2720 return OS_OK;
2721 }
2722
2723 errno = 0;
2724 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2725 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2726 #elif defined(__APPLE__) || defined(__NetBSD__)
2727 int policy;
2728 struct sched_param sp;
2729
2730 pthread_getschedparam(pthread_self(), &policy, &sp);
2731 *priority_ptr = sp.sched_priority;
2732 #else
2733 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2734 #endif
2735 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2736 }
2737
2738 // Hint to the underlying OS that a task switch would not be good.
2739 // Void return because it's a hint and can fail.
2740 void os::hint_no_preempt() {}
2741
2742 ////////////////////////////////////////////////////////////////////////////////
2743 // suspend/resume support
2744
2745 // the low-level signal-based suspend/resume support is a remnant from the
2746 // old VM-suspension that used to be for java-suspension, safepoints etc,
2747 // within hotspot. Now there is a single use-case for this:
2748 // - calling get_thread_pc() on the VMThread by the flat-profiler task
2749 // that runs in the watcher thread.
2750 // The remaining code is greatly simplified from the more general suspension
2751 // code that used to be used.
2752 //
2753 // The protocol is quite simple:
2754 // - suspend:
2755 // - sends a signal to the target thread
2756 // - polls the suspend state of the osthread using a yield loop
2757 // - target thread signal handler (SR_handler) sets suspend state
2758 // and blocks in sigsuspend until continued
2759 // - resume:
2760 // - sets target osthread state to continue
2761 // - sends signal to end the sigsuspend loop in the SR_handler
2762 //
2763 // Note that the SR_lock plays no role in this suspend/resume protocol.
2764
2765 static void resume_clear_context(OSThread *osthread) {
2766 osthread->set_ucontext(NULL);
2767 osthread->set_siginfo(NULL);
2768 }
2769
2770 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2771 osthread->set_ucontext(context);
2772 osthread->set_siginfo(siginfo);
2773 }
2774
2775 // Handler function invoked when a thread's execution is suspended or
2776 // resumed. We have to be careful that only async-safe functions are
2777 // called here (Note: most pthread functions are not async safe and
2778 // should be avoided.)
2779 //
2780 // Note: sigwait() is a more natural fit than sigsuspend() from an
2781 // interface point of view, but sigwait() prevents the signal hander
2782 // from being run. libpthread would get very confused by not having
2783 // its signal handlers run and prevents sigwait()'s use with the
2784 // mutex granting granting signal.
2785 //
2786 // Currently only ever called on the VMThread or JavaThread
2787 //
2788 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2789 // Save and restore errno to avoid confusing native code with EINTR
2790 // after sigsuspend.
2791 int old_errno = errno;
2792
2793 Thread* thread = Thread::current();
2794 OSThread* osthread = thread->osthread();
2795 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2796
2797 os::SuspendResume::State current = osthread->sr.state();
2798 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2799 suspend_save_context(osthread, siginfo, context);
2800
2801 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2802 os::SuspendResume::State state = osthread->sr.suspended();
2803 if (state == os::SuspendResume::SR_SUSPENDED) {
2804 sigset_t suspend_set; // signals for sigsuspend()
2805
2806 // get current set of blocked signals and unblock resume signal
2807 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2808 sigdelset(&suspend_set, SR_signum);
2809
2810 sr_semaphore.signal();
2811 // wait here until we are resumed
2812 while (1) {
2813 sigsuspend(&suspend_set);
2814
2815 os::SuspendResume::State result = osthread->sr.running();
2816 if (result == os::SuspendResume::SR_RUNNING) {
2817 sr_semaphore.signal();
2818 break;
2819 } else if (result != os::SuspendResume::SR_SUSPENDED) {
2820 ShouldNotReachHere();
2821 }
2822 }
2823
2824 } else if (state == os::SuspendResume::SR_RUNNING) {
2825 // request was cancelled, continue
2826 } else {
2827 ShouldNotReachHere();
2828 }
2829
2830 resume_clear_context(osthread);
2831 } else if (current == os::SuspendResume::SR_RUNNING) {
2832 // request was cancelled, continue
2833 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2834 // ignore
2835 } else {
2836 // ignore
2837 }
2838
2839 errno = old_errno;
2840 }
2841
2842
2843 static int SR_initialize() {
2844 struct sigaction act;
2845 char *s;
2846 // Get signal number to use for suspend/resume
2847 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2848 int sig = ::strtol(s, 0, 10);
2849 if (sig > 0 || sig < NSIG) {
2850 SR_signum = sig;
2851 }
2852 }
2853
2854 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2855 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2856
2857 sigemptyset(&SR_sigset);
2858 sigaddset(&SR_sigset, SR_signum);
2859
2860 // Set up signal handler for suspend/resume
2861 act.sa_flags = SA_RESTART|SA_SIGINFO;
2862 act.sa_handler = (void (*)(int)) SR_handler;
2863
2864 // SR_signum is blocked by default.
2865 // 4528190 - We also need to block pthread restart signal (32 on all
2866 // supported Bsd platforms). Note that BsdThreads need to block
2867 // this signal for all threads to work properly. So we don't have
2868 // to use hard-coded signal number when setting up the mask.
2869 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2870
2871 if (sigaction(SR_signum, &act, 0) == -1) {
2872 return -1;
2873 }
2874
2875 // Save signal flag
2876 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2877 return 0;
2878 }
2879
2880 static int sr_notify(OSThread* osthread) {
2881 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2882 assert_status(status == 0, status, "pthread_kill");
2883 return status;
2884 }
2885
2886 // "Randomly" selected value for how long we want to spin
2887 // before bailing out on suspending a thread, also how often
2888 // we send a signal to a thread we want to resume
2889 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2890 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2891
2892 // returns true on success and false on error - really an error is fatal
2893 // but this seems the normal response to library errors
2894 static bool do_suspend(OSThread* osthread) {
2895 assert(osthread->sr.is_running(), "thread should be running");
2896 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2897
2898 // mark as suspended and send signal
2899 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2900 // failed to switch, state wasn't running?
2901 ShouldNotReachHere();
2902 return false;
2903 }
2904
2905 if (sr_notify(osthread) != 0) {
2906 ShouldNotReachHere();
2907 }
2908
2909 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2910 while (true) {
2911 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2912 break;
2913 } else {
2914 // timeout
2915 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2916 if (cancelled == os::SuspendResume::SR_RUNNING) {
2917 return false;
2918 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2919 // make sure that we consume the signal on the semaphore as well
2920 sr_semaphore.wait();
2921 break;
2922 } else {
2923 ShouldNotReachHere();
2924 return false;
2925 }
2926 }
2927 }
2928
2929 guarantee(osthread->sr.is_suspended(), "Must be suspended");
2930 return true;
2931 }
2932
2933 static void do_resume(OSThread* osthread) {
2934 assert(osthread->sr.is_suspended(), "thread should be suspended");
2935 assert(!sr_semaphore.trywait(), "invalid semaphore state");
2936
2937 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
2938 // failed to switch to WAKEUP_REQUEST
2939 ShouldNotReachHere();
2940 return;
2941 }
2942
2943 while (true) {
2944 if (sr_notify(osthread) == 0) {
2945 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2946 if (osthread->sr.is_running()) {
2947 return;
2948 }
2949 }
2950 } else {
2951 ShouldNotReachHere();
2952 }
2953 }
2954
2955 guarantee(osthread->sr.is_running(), "Must be running!");
2956 }
2957
2958 ///////////////////////////////////////////////////////////////////////////////////
2959 // signal handling (except suspend/resume)
2960
2961 // This routine may be used by user applications as a "hook" to catch signals.
2962 // The user-defined signal handler must pass unrecognized signals to this
2963 // routine, and if it returns true (non-zero), then the signal handler must
2964 // return immediately. If the flag "abort_if_unrecognized" is true, then this
2965 // routine will never retun false (zero), but instead will execute a VM panic
2966 // routine kill the process.
2967 //
2968 // If this routine returns false, it is OK to call it again. This allows
2969 // the user-defined signal handler to perform checks either before or after
2970 // the VM performs its own checks. Naturally, the user code would be making
2971 // a serious error if it tried to handle an exception (such as a null check
2972 // or breakpoint) that the VM was generating for its own correct operation.
2973 //
2974 // This routine may recognize any of the following kinds of signals:
2975 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
2976 // It should be consulted by handlers for any of those signals.
2977 //
2978 // The caller of this routine must pass in the three arguments supplied
2979 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
2980 // field of the structure passed to sigaction(). This routine assumes that
2981 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
2982 //
2983 // Note that the VM will print warnings if it detects conflicting signal
2984 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
2985 //
2986 extern "C" JNIEXPORT int JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
2987 void* ucontext,
2988 int abort_if_unrecognized);
2989
2990 void signalHandler(int sig, siginfo_t* info, void* uc) {
2991 assert(info != NULL && uc != NULL, "it must be old kernel");
2992 int orig_errno = errno; // Preserve errno value over signal handler.
2993 JVM_handle_bsd_signal(sig, info, uc, true);
2994 errno = orig_errno;
2995 }
2996
2997
2998 // This boolean allows users to forward their own non-matching signals
2999 // to JVM_handle_bsd_signal, harmlessly.
3000 bool os::Bsd::signal_handlers_are_installed = false;
3001
3002 // For signal-chaining
3003 struct sigaction os::Bsd::sigact[MAXSIGNUM];
3004 unsigned int os::Bsd::sigs = 0;
3005 bool os::Bsd::libjsig_is_loaded = false;
3006 typedef struct sigaction *(*get_signal_t)(int);
3007 get_signal_t os::Bsd::get_signal_action = NULL;
3008
3009 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
3010 struct sigaction *actp = NULL;
3011
3012 if (libjsig_is_loaded) {
3013 // Retrieve the old signal handler from libjsig
3014 actp = (*get_signal_action)(sig);
3015 }
3016 if (actp == NULL) {
3017 // Retrieve the preinstalled signal handler from jvm
3018 actp = get_preinstalled_handler(sig);
3019 }
3020
3021 return actp;
3022 }
3023
3024 static bool call_chained_handler(struct sigaction *actp, int sig,
3025 siginfo_t *siginfo, void *context) {
3026 // Call the old signal handler
3027 if (actp->sa_handler == SIG_DFL) {
3028 // It's more reasonable to let jvm treat it as an unexpected exception
3029 // instead of taking the default action.
3030 return false;
3031 } else if (actp->sa_handler != SIG_IGN) {
3032 if ((actp->sa_flags & SA_NODEFER) == 0) {
3033 // automaticlly block the signal
3034 sigaddset(&(actp->sa_mask), sig);
3035 }
3036
3037 sa_handler_t hand;
3038 sa_sigaction_t sa;
3039 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3040 // retrieve the chained handler
3041 if (siginfo_flag_set) {
3042 sa = actp->sa_sigaction;
3043 } else {
3044 hand = actp->sa_handler;
3045 }
3046
3047 if ((actp->sa_flags & SA_RESETHAND) != 0) {
3048 actp->sa_handler = SIG_DFL;
3049 }
3050
3051 // try to honor the signal mask
3052 sigset_t oset;
3053 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3054
3055 // call into the chained handler
3056 if (siginfo_flag_set) {
3057 (*sa)(sig, siginfo, context);
3058 } else {
3059 (*hand)(sig);
3060 }
3061
3062 // restore the signal mask
3063 pthread_sigmask(SIG_SETMASK, &oset, 0);
3064 }
3065 // Tell jvm's signal handler the signal is taken care of.
3066 return true;
3067 }
3068
3069 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3070 bool chained = false;
3071 // signal-chaining
3072 if (UseSignalChaining) {
3073 struct sigaction *actp = get_chained_signal_action(sig);
3074 if (actp != NULL) {
3075 chained = call_chained_handler(actp, sig, siginfo, context);
3076 }
3077 }
3078 return chained;
3079 }
3080
3081 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3082 if ((((unsigned int)1 << sig) & sigs) != 0) {
3083 return &sigact[sig];
3084 }
3085 return NULL;
3086 }
3087
3088 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3089 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3090 sigact[sig] = oldAct;
3091 sigs |= (unsigned int)1 << sig;
3092 }
3093
3094 // for diagnostic
3095 int os::Bsd::sigflags[MAXSIGNUM];
3096
3097 int os::Bsd::get_our_sigflags(int sig) {
3098 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3099 return sigflags[sig];
3100 }
3101
3102 void os::Bsd::set_our_sigflags(int sig, int flags) {
3103 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3104 sigflags[sig] = flags;
3105 }
3106
3107 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3108 // Check for overwrite.
3109 struct sigaction oldAct;
3110 sigaction(sig, (struct sigaction*)NULL, &oldAct);
3111
3112 void* oldhand = oldAct.sa_sigaction
3113 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3114 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3115 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3116 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3117 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3118 if (AllowUserSignalHandlers || !set_installed) {
3119 // Do not overwrite; user takes responsibility to forward to us.
3120 return;
3121 } else if (UseSignalChaining) {
3122 // save the old handler in jvm
3123 save_preinstalled_handler(sig, oldAct);
3124 // libjsig also interposes the sigaction() call below and saves the
3125 // old sigaction on it own.
3126 } else {
3127 fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3128 "%#lx for signal %d.", (long)oldhand, sig));
3129 }
3130 }
3131
3132 struct sigaction sigAct;
3133 sigfillset(&(sigAct.sa_mask));
3134 sigAct.sa_handler = SIG_DFL;
3135 if (!set_installed) {
3136 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3137 } else {
3138 sigAct.sa_sigaction = signalHandler;
3139 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3140 }
3141 #ifdef __APPLE__
3142 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3143 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3144 // if the signal handler declares it will handle it on alternate stack.
3145 // Notice we only declare we will handle it on alt stack, but we are not
3146 // actually going to use real alt stack - this is just a workaround.
3147 // Please see ux_exception.c, method catch_mach_exception_raise for details
3148 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3149 if (sig == SIGSEGV) {
3150 sigAct.sa_flags |= SA_ONSTACK;
3151 }
3152 #endif
3153
3154 // Save flags, which are set by ours
3155 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3156 sigflags[sig] = sigAct.sa_flags;
3157
3158 int ret = sigaction(sig, &sigAct, &oldAct);
3159 assert(ret == 0, "check");
3160
3161 void* oldhand2 = oldAct.sa_sigaction
3162 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3163 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3164 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3165 }
3166
3167 // install signal handlers for signals that HotSpot needs to
3168 // handle in order to support Java-level exception handling.
3169
3170 void os::Bsd::install_signal_handlers() {
3171 if (!signal_handlers_are_installed) {
3172 signal_handlers_are_installed = true;
3173
3174 // signal-chaining
3175 typedef void (*signal_setting_t)();
3176 signal_setting_t begin_signal_setting = NULL;
3177 signal_setting_t end_signal_setting = NULL;
3178 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3179 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3180 if (begin_signal_setting != NULL) {
3181 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3182 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3183 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3184 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3185 libjsig_is_loaded = true;
3186 assert(UseSignalChaining, "should enable signal-chaining");
3187 }
3188 if (libjsig_is_loaded) {
3189 // Tell libjsig jvm is setting signal handlers
3190 (*begin_signal_setting)();
3191 }
3192
3193 set_signal_handler(SIGSEGV, true);
3194 set_signal_handler(SIGPIPE, true);
3195 set_signal_handler(SIGBUS, true);
3196 set_signal_handler(SIGILL, true);
3197 set_signal_handler(SIGFPE, true);
3198 set_signal_handler(SIGXFSZ, true);
3199
3200 #if defined(__APPLE__)
3201 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3202 // signals caught and handled by the JVM. To work around this, we reset the mach task
3203 // signal handler that's placed on our process by CrashReporter. This disables
3204 // CrashReporter-based reporting.
3205 //
3206 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3207 // on caught fatal signals.
3208 //
3209 // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3210 // handlers. By replacing the existing task exception handler, we disable gdb's mach
3211 // exception handling, while leaving the standard BSD signal handlers functional.
3212 kern_return_t kr;
3213 kr = task_set_exception_ports(mach_task_self(),
3214 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3215 MACH_PORT_NULL,
3216 EXCEPTION_STATE_IDENTITY,
3217 MACHINE_THREAD_STATE);
3218
3219 assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3220 #endif
3221
3222 if (libjsig_is_loaded) {
3223 // Tell libjsig jvm finishes setting signal handlers
3224 (*end_signal_setting)();
3225 }
3226
3227 // We don't activate signal checker if libjsig is in place, we trust ourselves
3228 // and if UserSignalHandler is installed all bets are off
3229 if (CheckJNICalls) {
3230 if (libjsig_is_loaded) {
3231 if (PrintJNIResolving) {
3232 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3233 }
3234 check_signals = false;
3235 }
3236 if (AllowUserSignalHandlers) {
3237 if (PrintJNIResolving) {
3238 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3239 }
3240 check_signals = false;
3241 }
3242 }
3243 }
3244 }
3245
3246
3247 /////
3248 // glibc on Bsd platform uses non-documented flag
3249 // to indicate, that some special sort of signal
3250 // trampoline is used.
3251 // We will never set this flag, and we should
3252 // ignore this flag in our diagnostic
3253 #ifdef SIGNIFICANT_SIGNAL_MASK
3254 #undef SIGNIFICANT_SIGNAL_MASK
3255 #endif
3256 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3257
3258 static const char* get_signal_handler_name(address handler,
3259 char* buf, int buflen) {
3260 int offset;
3261 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3262 if (found) {
3263 // skip directory names
3264 const char *p1, *p2;
3265 p1 = buf;
3266 size_t len = strlen(os::file_separator());
3267 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3268 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3269 } else {
3270 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3271 }
3272 return buf;
3273 }
3274
3275 static void print_signal_handler(outputStream* st, int sig,
3276 char* buf, size_t buflen) {
3277 struct sigaction sa;
3278
3279 sigaction(sig, NULL, &sa);
3280
3281 // See comment for SIGNIFICANT_SIGNAL_MASK define
3282 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3283
3284 st->print("%s: ", os::exception_name(sig, buf, buflen));
3285
3286 address handler = (sa.sa_flags & SA_SIGINFO)
3287 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3288 : CAST_FROM_FN_PTR(address, sa.sa_handler);
3289
3290 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3291 st->print("SIG_DFL");
3292 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3293 st->print("SIG_IGN");
3294 } else {
3295 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3296 }
3297
3298 st->print(", sa_mask[0]=");
3299 os::Posix::print_signal_set_short(st, &sa.sa_mask);
3300
3301 address rh = VMError::get_resetted_sighandler(sig);
3302 // May be, handler was resetted by VMError?
3303 if (rh != NULL) {
3304 handler = rh;
3305 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3306 }
3307
3308 st->print(", sa_flags=");
3309 os::Posix::print_sa_flags(st, sa.sa_flags);
3310
3311 // Check: is it our handler?
3312 if (handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3313 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3314 // It is our signal handler
3315 // check for flags, reset system-used one!
3316 if ((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3317 st->print(
3318 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3319 os::Bsd::get_our_sigflags(sig));
3320 }
3321 }
3322 st->cr();
3323 }
3324
3325
3326 #define DO_SIGNAL_CHECK(sig) \
3327 do { \
3328 if (!sigismember(&check_signal_done, sig)) { \
3329 os::Bsd::check_signal_handler(sig); \
3330 } \
3331 } while (0)
3332
3333 // This method is a periodic task to check for misbehaving JNI applications
3334 // under CheckJNI, we can add any periodic checks here
3335
3336 void os::run_periodic_checks() {
3337
3338 if (check_signals == false) return;
3339
3340 // SEGV and BUS if overridden could potentially prevent
3341 // generation of hs*.log in the event of a crash, debugging
3342 // such a case can be very challenging, so we absolutely
3343 // check the following for a good measure:
3344 DO_SIGNAL_CHECK(SIGSEGV);
3345 DO_SIGNAL_CHECK(SIGILL);
3346 DO_SIGNAL_CHECK(SIGFPE);
3347 DO_SIGNAL_CHECK(SIGBUS);
3348 DO_SIGNAL_CHECK(SIGPIPE);
3349 DO_SIGNAL_CHECK(SIGXFSZ);
3350
3351
3352 // ReduceSignalUsage allows the user to override these handlers
3353 // see comments at the very top and jvm_solaris.h
3354 if (!ReduceSignalUsage) {
3355 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3356 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3357 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3358 DO_SIGNAL_CHECK(BREAK_SIGNAL);
3359 }
3360
3361 DO_SIGNAL_CHECK(SR_signum);
3362 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3363 }
3364
3365 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3366
3367 static os_sigaction_t os_sigaction = NULL;
3368
3369 void os::Bsd::check_signal_handler(int sig) {
3370 char buf[O_BUFLEN];
3371 address jvmHandler = NULL;
3372
3373
3374 struct sigaction act;
3375 if (os_sigaction == NULL) {
3376 // only trust the default sigaction, in case it has been interposed
3377 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3378 if (os_sigaction == NULL) return;
3379 }
3380
3381 os_sigaction(sig, (struct sigaction*)NULL, &act);
3382
3383
3384 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3385
3386 address thisHandler = (act.sa_flags & SA_SIGINFO)
3387 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3388 : CAST_FROM_FN_PTR(address, act.sa_handler);
3389
3390
3391 switch (sig) {
3392 case SIGSEGV:
3393 case SIGBUS:
3394 case SIGFPE:
3395 case SIGPIPE:
3396 case SIGILL:
3397 case SIGXFSZ:
3398 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3399 break;
3400
3401 case SHUTDOWN1_SIGNAL:
3402 case SHUTDOWN2_SIGNAL:
3403 case SHUTDOWN3_SIGNAL:
3404 case BREAK_SIGNAL:
3405 jvmHandler = (address)user_handler();
3406 break;
3407
3408 case INTERRUPT_SIGNAL:
3409 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3410 break;
3411
3412 default:
3413 if (sig == SR_signum) {
3414 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3415 } else {
3416 return;
3417 }
3418 break;
3419 }
3420
3421 if (thisHandler != jvmHandler) {
3422 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3423 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3424 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3425 // No need to check this sig any longer
3426 sigaddset(&check_signal_done, sig);
3427 // Running under non-interactive shell, SHUTDOWN2_SIGNAL will be reassigned SIG_IGN
3428 if (sig == SHUTDOWN2_SIGNAL && !isatty(fileno(stdin))) {
3429 tty->print_cr("Running in non-interactive shell, %s handler is replaced by shell",
3430 exception_name(sig, buf, O_BUFLEN));
3431 }
3432 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3433 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3434 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3435 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags);
3436 // No need to check this sig any longer
3437 sigaddset(&check_signal_done, sig);
3438 }
3439
3440 // Dump all the signal
3441 if (sigismember(&check_signal_done, sig)) {
3442 print_signal_handlers(tty, buf, O_BUFLEN);
3443 }
3444 }
3445
3446 extern void report_error(char* file_name, int line_no, char* title,
3447 char* format, ...);
3448
3449 extern bool signal_name(int signo, char* buf, size_t len);
3450
3451 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3452 if (0 < exception_code && exception_code <= SIGRTMAX) {
3453 // signal
3454 if (!signal_name(exception_code, buf, size)) {
3455 jio_snprintf(buf, size, "SIG%d", exception_code);
3456 }
3457 return buf;
3458 } else {
3459 return NULL;
3460 }
3461 }
3462
3463 // this is called _before_ the most of global arguments have been parsed
3464 void os::init(void) {
3465 char dummy; // used to get a guess on initial stack address
3466 // first_hrtime = gethrtime();
3467
3468 // With BsdThreads the JavaMain thread pid (primordial thread)
3469 // is different than the pid of the java launcher thread.
3470 // So, on Bsd, the launcher thread pid is passed to the VM
3471 // via the sun.java.launcher.pid property.
3472 // Use this property instead of getpid() if it was correctly passed.
3473 // See bug 6351349.
3474 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3475
3476 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3477
3478 clock_tics_per_sec = CLK_TCK;
3479
3480 init_random(1234567);
3481
3482 ThreadCritical::initialize();
3483
3484 Bsd::set_page_size(getpagesize());
3485 if (Bsd::page_size() == -1) {
3486 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3487 strerror(errno)));
3488 }
3489 init_page_sizes((size_t) Bsd::page_size());
3490
3491 Bsd::initialize_system_info();
3492
3493 // main_thread points to the aboriginal thread
3494 Bsd::_main_thread = pthread_self();
3495
3496 Bsd::clock_init();
3497 initial_time_count = javaTimeNanos();
3498
3499 #ifdef __APPLE__
3500 // XXXDARWIN
3501 // Work around the unaligned VM callbacks in hotspot's
3502 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3503 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3504 // alignment when doing symbol lookup. To work around this, we force early
3505 // binding of all symbols now, thus binding when alignment is known-good.
3506 _dyld_bind_fully_image_containing_address((const void *) &os::init);
3507 #endif
3508 }
3509
3510 // To install functions for atexit system call
3511 extern "C" {
3512 static void perfMemory_exit_helper() {
3513 perfMemory_exit();
3514 }
3515 }
3516
3517 // this is called _after_ the global arguments have been parsed
3518 jint os::init_2(void) {
3519 // Allocate a single page and mark it as readable for safepoint polling
3520 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3521 guarantee(polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page");
3522
3523 os::set_polling_page(polling_page);
3524
3525 #ifndef PRODUCT
3526 if (Verbose && PrintMiscellaneous) {
3527 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n",
3528 (intptr_t)polling_page);
3529 }
3530 #endif
3531
3532 if (!UseMembar) {
3533 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3534 guarantee(mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3535 os::set_memory_serialize_page(mem_serialize_page);
3536
3537 #ifndef PRODUCT
3538 if (Verbose && PrintMiscellaneous) {
3539 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n",
3540 (intptr_t)mem_serialize_page);
3541 }
3542 #endif
3543 }
3544
3545 // initialize suspend/resume support - must do this before signal_sets_init()
3546 if (SR_initialize() != 0) {
3547 perror("SR_initialize failed");
3548 return JNI_ERR;
3549 }
3550
3551 Bsd::signal_sets_init();
3552 Bsd::install_signal_handlers();
3553
3554 // Check minimum allowable stack size for thread creation and to initialize
3555 // the java system classes, including StackOverflowError - depends on page
3556 // size. Add a page for compiler2 recursion in main thread.
3557 // Add in 2*BytesPerWord times page size to account for VM stack during
3558 // class initialization depending on 32 or 64 bit VM.
3559 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3560 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3561 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3562
3563 size_t threadStackSizeInBytes = ThreadStackSize * K;
3564 if (threadStackSizeInBytes != 0 &&
3565 threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3566 tty->print_cr("\nThe stack size specified is too small, "
3567 "Specify at least %dk",
3568 os::Bsd::min_stack_allowed/ K);
3569 return JNI_ERR;
3570 }
3571
3572 // Make the stack size a multiple of the page size so that
3573 // the yellow/red zones can be guarded.
3574 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3575 vm_page_size()));
3576
3577 if (MaxFDLimit) {
3578 // set the number of file descriptors to max. print out error
3579 // if getrlimit/setrlimit fails but continue regardless.
3580 struct rlimit nbr_files;
3581 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3582 if (status != 0) {
3583 if (PrintMiscellaneous && (Verbose || WizardMode)) {
3584 perror("os::init_2 getrlimit failed");
3585 }
3586 } else {
3587 nbr_files.rlim_cur = nbr_files.rlim_max;
3588
3589 #ifdef __APPLE__
3590 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3591 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3592 // be used instead
3593 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3594 #endif
3595
3596 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3597 if (status != 0) {
3598 if (PrintMiscellaneous && (Verbose || WizardMode)) {
3599 perror("os::init_2 setrlimit failed");
3600 }
3601 }
3602 }
3603 }
3604
3605 // at-exit methods are called in the reverse order of their registration.
3606 // atexit functions are called on return from main or as a result of a
3607 // call to exit(3C). There can be only 32 of these functions registered
3608 // and atexit() does not set errno.
3609
3610 if (PerfAllowAtExitRegistration) {
3611 // only register atexit functions if PerfAllowAtExitRegistration is set.
3612 // atexit functions can be delayed until process exit time, which
3613 // can be problematic for embedded VM situations. Embedded VMs should
3614 // call DestroyJavaVM() to assure that VM resources are released.
3615
3616 // note: perfMemory_exit_helper atexit function may be removed in
3617 // the future if the appropriate cleanup code can be added to the
3618 // VM_Exit VMOperation's doit method.
3619 if (atexit(perfMemory_exit_helper) != 0) {
3620 warning("os::init2 atexit(perfMemory_exit_helper) failed");
3621 }
3622 }
3623
3624 // initialize thread priority policy
3625 prio_init();
3626
3627 #ifdef __APPLE__
3628 // dynamically link to objective c gc registration
3629 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3630 if (handleLibObjc != NULL) {
3631 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3632 }
3633 #endif
3634
3635 return JNI_OK;
3636 }
3637
3638 // this is called at the end of vm_initialization
3639 void os::init_3(void) { }
3640
3641 // Mark the polling page as unreadable
3642 void os::make_polling_page_unreadable(void) {
3643 if (!guard_memory((char*)_polling_page, Bsd::page_size())) {
3644 fatal("Could not disable polling page");
3645 }
3646 }
3647
3648 // Mark the polling page as readable
3649 void os::make_polling_page_readable(void) {
3650 if (!bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3651 fatal("Could not enable polling page");
3652 }
3653 }
3654
3655 int os::active_processor_count() {
3656 return _processor_count;
3657 }
3658
3659 void os::set_native_thread_name(const char *name) {
3660 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3661 // This is only supported in Snow Leopard and beyond
3662 if (name != NULL) {
3663 // Add a "Java: " prefix to the name
3664 char buf[MAXTHREADNAMESIZE];
3665 snprintf(buf, sizeof(buf), "Java: %s", name);
3666 pthread_setname_np(buf);
3667 }
3668 #endif
3669 }
3670
3671 bool os::distribute_processes(uint length, uint* distribution) {
3672 // Not yet implemented.
3673 return false;
3674 }
3675
3676 bool os::bind_to_processor(uint processor_id) {
3677 // Not yet implemented.
3678 return false;
3679 }
3680
3681 void os::SuspendedThreadTask::internal_do_task() {
3682 if (do_suspend(_thread->osthread())) {
3683 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3684 do_task(context);
3685 do_resume(_thread->osthread());
3686 }
3687 }
3688
3689 ///
3690 class PcFetcher : public os::SuspendedThreadTask {
3691 public:
3692 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3693 ExtendedPC result();
3694 protected:
3695 void do_task(const os::SuspendedThreadTaskContext& context);
3696 private:
3697 ExtendedPC _epc;
3698 };
3699
3700 ExtendedPC PcFetcher::result() {
3701 guarantee(is_done(), "task is not done yet.");
3702 return _epc;
3703 }
3704
3705 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3706 Thread* thread = context.thread();
3707 OSThread* osthread = thread->osthread();
3708 if (osthread->ucontext() != NULL) {
3709 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
3710 } else {
3711 // NULL context is unexpected, double-check this is the VMThread
3712 guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3713 }
3714 }
3715
3716 // Suspends the target using the signal mechanism and then grabs the PC before
3717 // resuming the target. Used by the flat-profiler only
3718 ExtendedPC os::get_thread_pc(Thread* thread) {
3719 // Make sure that it is called by the watcher for the VMThread
3720 assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3721 assert(thread->is_VM_thread(), "Can only be called for VMThread");
3722
3723 PcFetcher fetcher(thread);
3724 fetcher.run();
3725 return fetcher.result();
3726 }
3727
3728 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond,
3729 pthread_mutex_t *_mutex,
3730 const struct timespec *_abstime) {
3731 return pthread_cond_timedwait(_cond, _mutex, _abstime);
3732 }
3733
3734 ////////////////////////////////////////////////////////////////////////////////
3735 // debug support
3736
3737 bool os::find(address addr, outputStream* st) {
3738 Dl_info dlinfo;
3739 memset(&dlinfo, 0, sizeof(dlinfo));
3740 if (dladdr(addr, &dlinfo) != 0) {
3741 st->print(PTR_FORMAT ": ", addr);
3742 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3743 st->print("%s+%#x", dlinfo.dli_sname,
3744 addr - (intptr_t)dlinfo.dli_saddr);
3745 } else if (dlinfo.dli_fbase != NULL) {
3746 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3747 } else {
3748 st->print("<absolute address>");
3749 }
3750 if (dlinfo.dli_fname != NULL) {
3751 st->print(" in %s", dlinfo.dli_fname);
3752 }
3753 if (dlinfo.dli_fbase != NULL) {
3754 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3755 }
3756 st->cr();
3757
3758 if (Verbose) {
3759 // decode some bytes around the PC
3760 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3761 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3762 address lowest = (address) dlinfo.dli_sname;
3763 if (!lowest) lowest = (address) dlinfo.dli_fbase;
3764 if (begin < lowest) begin = lowest;
3765 Dl_info dlinfo2;
3766 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3767 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin) {
3768 end = (address) dlinfo2.dli_saddr;
3769 }
3770 Disassembler::decode(begin, end, st);
3771 }
3772 return true;
3773 }
3774 return false;
3775 }
3776
3777 ////////////////////////////////////////////////////////////////////////////////
3778 // misc
3779
3780 // This does not do anything on Bsd. This is basically a hook for being
3781 // able to use structured exception handling (thread-local exception filters)
3782 // on, e.g., Win32.
3783 void os::os_exception_wrapper(java_call_t f, JavaValue* value,
3784 methodHandle* method, JavaCallArguments* args,
3785 Thread* thread) {
3786 f(value, method, args, thread);
3787 }
3788
3789 void os::print_statistics() {
3790 }
3791
3792 int os::message_box(const char* title, const char* message) {
3793 int i;
3794 fdStream err(defaultStream::error_fd());
3795 for (i = 0; i < 78; i++) err.print_raw("=");
3796 err.cr();
3797 err.print_raw_cr(title);
3798 for (i = 0; i < 78; i++) err.print_raw("-");
3799 err.cr();
3800 err.print_raw_cr(message);
3801 for (i = 0; i < 78; i++) err.print_raw("=");
3802 err.cr();
3803
3804 char buf[16];
3805 // Prevent process from exiting upon "read error" without consuming all CPU
3806 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3807
3808 return buf[0] == 'y' || buf[0] == 'Y';
3809 }
3810
3811 int os::stat(const char *path, struct stat *sbuf) {
3812 char pathbuf[MAX_PATH];
3813 if (strlen(path) > MAX_PATH - 1) {
3814 errno = ENAMETOOLONG;
3815 return -1;
3816 }
3817 os::native_path(strcpy(pathbuf, path));
3818 return ::stat(pathbuf, sbuf);
3819 }
3820
3821 bool os::check_heap(bool force) {
3822 return true;
3823 }
3824
3825 // Is a (classpath) directory empty?
3826 bool os::dir_is_empty(const char* path) {
3827 DIR *dir = NULL;
3828 struct dirent *ptr;
3829
3830 dir = opendir(path);
3831 if (dir == NULL) return true;
3832
3833 // Scan the directory
3834 bool result = true;
3835 char buf[sizeof(struct dirent) + MAX_PATH];
3836 while (result && (ptr = ::readdir(dir)) != NULL) {
3837 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3838 result = false;
3839 }
3840 }
3841 closedir(dir);
3842 return result;
3843 }
3844
3845 // This code originates from JDK's sysOpen and open64_w
3846 // from src/solaris/hpi/src/system_md.c
3847
3848 #ifndef O_DELETE
3849 #define O_DELETE 0x10000
3850 #endif
3851
3852 // Open a file. Unlink the file immediately after open returns
3853 // if the specified oflag has the O_DELETE flag set.
3854 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
3855
3856 int os::open(const char *path, int oflag, int mode) {
3857 if (strlen(path) > MAX_PATH - 1) {
3858 errno = ENAMETOOLONG;
3859 return -1;
3860 }
3861 int fd;
3862 int o_delete = (oflag & O_DELETE);
3863 oflag = oflag & ~O_DELETE;
3864
3865 fd = ::open(path, oflag, mode);
3866 if (fd == -1) return -1;
3867
3868 // If the open succeeded, the file might still be a directory
3869 {
3870 struct stat buf;
3871 int ret = ::fstat(fd, &buf);
3872 int st_mode = buf.st_mode;
3873
3874 if (ret != -1) {
3875 if ((st_mode & S_IFMT) == S_IFDIR) {
3876 errno = EISDIR;
3877 ::close(fd);
3878 return -1;
3879 }
3880 } else {
3881 ::close(fd);
3882 return -1;
3883 }
3884 }
3885
3886 // All file descriptors that are opened in the JVM and not
3887 // specifically destined for a subprocess should have the
3888 // close-on-exec flag set. If we don't set it, then careless 3rd
3889 // party native code might fork and exec without closing all
3890 // appropriate file descriptors (e.g. as we do in closeDescriptors in
3891 // UNIXProcess.c), and this in turn might:
3892 //
3893 // - cause end-of-file to fail to be detected on some file
3894 // descriptors, resulting in mysterious hangs, or
3895 //
3896 // - might cause an fopen in the subprocess to fail on a system
3897 // suffering from bug 1085341.
3898 //
3899 // (Yes, the default setting of the close-on-exec flag is a Unix
3900 // design flaw)
3901 //
3902 // See:
3903 // 1085341: 32-bit stdio routines should support file descriptors >255
3904 // 4843136: (process) pipe file descriptor from Runtime.exec not being closed
3905 // 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
3906 //
3907 #ifdef FD_CLOEXEC
3908 {
3909 int flags = ::fcntl(fd, F_GETFD);
3910 if (flags != -1) {
3911 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
3912 }
3913 }
3914 #endif
3915
3916 if (o_delete != 0) {
3917 ::unlink(path);
3918 }
3919 return fd;
3920 }
3921
3922
3923 // create binary file, rewriting existing file if required
3924 int os::create_binary_file(const char* path, bool rewrite_existing) {
3925 int oflags = O_WRONLY | O_CREAT;
3926 if (!rewrite_existing) {
3927 oflags |= O_EXCL;
3928 }
3929 return ::open(path, oflags, S_IREAD | S_IWRITE);
3930 }
3931
3932 // return current position of file pointer
3933 jlong os::current_file_offset(int fd) {
3934 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
3935 }
3936
3937 // move file pointer to the specified offset
3938 jlong os::seek_to_file_offset(int fd, jlong offset) {
3939 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
3940 }
3941
3942 // This code originates from JDK's sysAvailable
3943 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
3944
3945 int os::available(int fd, jlong *bytes) {
3946 jlong cur, end;
3947 int mode;
3948 struct stat buf;
3949
3950 if (::fstat(fd, &buf) >= 0) {
3951 mode = buf.st_mode;
3952 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
3953 // XXX: is the following call interruptible? If so, this might
3954 // need to go through the INTERRUPT_IO() wrapper as for other
3955 // blocking, interruptible calls in this file.
3956 int n;
3957 if (::ioctl(fd, FIONREAD, &n) >= 0) {
3958 *bytes = n;
3959 return 1;
3960 }
3961 }
3962 }
3963 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
3964 return 0;
3965 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
3966 return 0;
3967 } else if (::lseek(fd, cur, SEEK_SET) == -1) {
3968 return 0;
3969 }
3970 *bytes = end - cur;
3971 return 1;
3972 }
3973
3974 int os::socket_available(int fd, jint *pbytes) {
3975 if (fd < 0) {
3976 return OS_OK;
3977 }
3978
3979 int ret;
3980
3981 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
3982
3983 //%% note ioctl can return 0 when successful, JVM_SocketAvailable
3984 // is expected to return 0 on failure and 1 on success to the jdk.
3985
3986 return (ret == OS_ERR) ? 0 : 1;
3987 }
3988
3989 // Map a block of memory.
3990 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
3991 char *addr, size_t bytes, bool read_only,
3992 bool allow_exec) {
3993 int prot;
3994 int flags;
3995
3996 if (read_only) {
3997 prot = PROT_READ;
3998 flags = MAP_SHARED;
3999 } else {
4000 prot = PROT_READ | PROT_WRITE;
4001 flags = MAP_PRIVATE;
4002 }
4003
4004 if (allow_exec) {
4005 prot |= PROT_EXEC;
4006 }
4007
4008 if (addr != NULL) {
4009 flags |= MAP_FIXED;
4010 }
4011
4012 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
4013 fd, file_offset);
4014 if (mapped_address == MAP_FAILED) {
4015 return NULL;
4016 }
4017 return mapped_address;
4018 }
4019
4020
4021 // Remap a block of memory.
4022 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
4023 char *addr, size_t bytes, bool read_only,
4024 bool allow_exec) {
4025 // same as map_memory() on this OS
4026 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
4027 allow_exec);
4028 }
4029
4030
4031 // Unmap a block of memory.
4032 bool os::pd_unmap_memory(char* addr, size_t bytes) {
4033 return munmap(addr, bytes) == 0;
4034 }
4035
4036 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
4037 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4038 // of a thread.
4039 //
4040 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4041 // the fast estimate available on the platform.
4042
4043 jlong os::current_thread_cpu_time() {
4044 #ifdef __APPLE__
4045 return os::thread_cpu_time(Thread::current(), true /* user + sys */);
4046 #else
4047 Unimplemented();
4048 return 0;
4049 #endif
4050 }
4051
4052 jlong os::thread_cpu_time(Thread* thread) {
4053 #ifdef __APPLE__
4054 return os::thread_cpu_time(thread, true /* user + sys */);
4055 #else
4056 Unimplemented();
4057 return 0;
4058 #endif
4059 }
4060
4061 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4062 #ifdef __APPLE__
4063 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4064 #else
4065 Unimplemented();
4066 return 0;
4067 #endif
4068 }
4069
4070 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4071 #ifdef __APPLE__
4072 struct thread_basic_info tinfo;
4073 mach_msg_type_number_t tcount = THREAD_INFO_MAX;
4074 kern_return_t kr;
4075 thread_t mach_thread;
4076
4077 mach_thread = thread->osthread()->thread_id();
4078 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
4079 if (kr != KERN_SUCCESS) {
4080 return -1;
4081 }
4082
4083 if (user_sys_cpu_time) {
4084 jlong nanos;
4085 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4086 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4087 return nanos;
4088 } else {
4089 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4090 }
4091 #else
4092 Unimplemented();
4093 return 0;
4094 #endif
4095 }
4096
4097
4098 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4099 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
4100 info_ptr->may_skip_backward = false; // elapsed time not wall time
4101 info_ptr->may_skip_forward = false; // elapsed time not wall time
4102 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
4103 }
4104
4105 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4106 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
4107 info_ptr->may_skip_backward = false; // elapsed time not wall time
4108 info_ptr->may_skip_forward = false; // elapsed time not wall time
4109 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
4110 }
4111
4112 bool os::is_thread_cpu_time_supported() {
4113 #ifdef __APPLE__
4114 return true;
4115 #else
4116 return false;
4117 #endif
4118 }
4119
4120 // System loadavg support. Returns -1 if load average cannot be obtained.
4121 // Bsd doesn't yet have a (official) notion of processor sets,
4122 // so just return the system wide load average.
4123 int os::loadavg(double loadavg[], int nelem) {
4124 return ::getloadavg(loadavg, nelem);
4125 }
4126
4127 void os::pause() {
4128 char filename[MAX_PATH];
4129 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4130 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4131 } else {
4132 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4133 }
4134
4135 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4136 if (fd != -1) {
4137 struct stat buf;
4138 ::close(fd);
4139 while (::stat(filename, &buf) == 0) {
4140 (void)::poll(NULL, 0, 100);
4141 }
4142 } else {
4143 jio_fprintf(stderr,
4144 "Could not open pause file '%s', continuing immediately.\n", filename);
4145 }
4146 }
4147
4148
4149 // Refer to the comments in os_solaris.cpp park-unpark.
4150 //
4151 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4152 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4153 // For specifics regarding the bug see GLIBC BUGID 261237 :
4154 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4155 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4156 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4157 // is used. (The simple C test-case provided in the GLIBC bug report manifests the
4158 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4159 // and monitorenter when we're using 1-0 locking. All those operations may result in
4160 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version
4161 // of libpthread avoids the problem, but isn't practical.
4162 //
4163 // Possible remedies:
4164 //
4165 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work.
4166 // This is palliative and probabilistic, however. If the thread is preempted
4167 // between the call to compute_abstime() and pthread_cond_timedwait(), more
4168 // than the minimum period may have passed, and the abstime may be stale (in the
4169 // past) resultin in a hang. Using this technique reduces the odds of a hang
4170 // but the JVM is still vulnerable, particularly on heavily loaded systems.
4171 //
4172 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4173 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set
4174 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4175 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant
4176 // thread.
4177 //
4178 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread
4179 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing
4180 // a timeout request to the chron thread and then blocking via pthread_cond_wait().
4181 // This also works well. In fact it avoids kernel-level scalability impediments
4182 // on certain platforms that don't handle lots of active pthread_cond_timedwait()
4183 // timers in a graceful fashion.
4184 //
4185 // 4. When the abstime value is in the past it appears that control returns
4186 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4187 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we
4188 // can avoid the problem by reinitializing the condvar -- by cond_destroy()
4189 // followed by cond_init() -- after all calls to pthread_cond_timedwait().
4190 // It may be possible to avoid reinitialization by checking the return
4191 // value from pthread_cond_timedwait(). In addition to reinitializing the
4192 // condvar we must establish the invariant that cond_signal() is only called
4193 // within critical sections protected by the adjunct mutex. This prevents
4194 // cond_signal() from "seeing" a condvar that's in the midst of being
4195 // reinitialized or that is corrupt. Sadly, this invariant obviates the
4196 // desirable signal-after-unlock optimization that avoids futile context switching.
4197 //
4198 // I'm also concerned that some versions of NTPL might allocate an auxilliary
4199 // structure when a condvar is used or initialized. cond_destroy() would
4200 // release the helper structure. Our reinitialize-after-timedwait fix
4201 // put excessive stress on malloc/free and locks protecting the c-heap.
4202 //
4203 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag.
4204 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4205 // and only enabling the work-around for vulnerable environments.
4206
4207 // utility to compute the abstime argument to timedwait:
4208 // millis is the relative timeout time
4209 // abstime will be the absolute timeout time
4210 // TODO: replace compute_abstime() with unpackTime()
4211
4212 static struct timespec* compute_abstime(struct timespec* abstime,
4213 jlong millis) {
4214 if (millis < 0) millis = 0;
4215 struct timeval now;
4216 int status = gettimeofday(&now, NULL);
4217 assert(status == 0, "gettimeofday");
4218 jlong seconds = millis / 1000;
4219 millis %= 1000;
4220 if (seconds > 50000000) { // see man cond_timedwait(3T)
4221 seconds = 50000000;
4222 }
4223 abstime->tv_sec = now.tv_sec + seconds;
4224 long usec = now.tv_usec + millis * 1000;
4225 if (usec >= 1000000) {
4226 abstime->tv_sec += 1;
4227 usec -= 1000000;
4228 }
4229 abstime->tv_nsec = usec * 1000;
4230 return abstime;
4231 }
4232
4233 void os::PlatformEvent::park() { // AKA "down()"
4234 // Invariant: Only the thread associated with the Event/PlatformEvent
4235 // may call park().
4236 // TODO: assert that _Assoc != NULL or _Assoc == Self
4237 assert(_nParked == 0, "invariant");
4238
4239 int v;
4240 for (;;) {
4241 v = _Event;
4242 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4243 }
4244 guarantee(v >= 0, "invariant");
4245 if (v == 0) {
4246 // Do this the hard way by blocking ...
4247 int status = pthread_mutex_lock(_mutex);
4248 assert_status(status == 0, status, "mutex_lock");
4249 guarantee(_nParked == 0, "invariant");
4250 ++_nParked;
4251 while (_Event < 0) {
4252 status = pthread_cond_wait(_cond, _mutex);
4253 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4254 // Treat this the same as if the wait was interrupted
4255 if (status == ETIMEDOUT) { status = EINTR; }
4256 assert_status(status == 0 || status == EINTR, status, "cond_wait");
4257 }
4258 --_nParked;
4259
4260 _Event = 0;
4261 status = pthread_mutex_unlock(_mutex);
4262 assert_status(status == 0, status, "mutex_unlock");
4263 // Paranoia to ensure our locked and lock-free paths interact
4264 // correctly with each other.
4265 OrderAccess::fence();
4266 }
4267 guarantee(_Event >= 0, "invariant");
4268 }
4269
4270 int os::PlatformEvent::park(jlong millis) {
4271 guarantee(_nParked == 0, "invariant");
4272
4273 int v;
4274 for (;;) {
4275 v = _Event;
4276 if (Atomic::cmpxchg(v-1, &_Event, v) == v) break;
4277 }
4278 guarantee(v >= 0, "invariant");
4279 if (v != 0) return OS_OK;
4280
4281 // We do this the hard way, by blocking the thread.
4282 // Consider enforcing a minimum timeout value.
4283 struct timespec abst;
4284 compute_abstime(&abst, millis);
4285
4286 int ret = OS_TIMEOUT;
4287 int status = pthread_mutex_lock(_mutex);
4288 assert_status(status == 0, status, "mutex_lock");
4289 guarantee(_nParked == 0, "invariant");
4290 ++_nParked;
4291
4292 // Object.wait(timo) will return because of
4293 // (a) notification
4294 // (b) timeout
4295 // (c) thread.interrupt
4296 //
4297 // Thread.interrupt and object.notify{All} both call Event::set.
4298 // That is, we treat thread.interrupt as a special case of notification.
4299 // We ignore spurious OS wakeups unless FilterSpuriousWakeups is false.
4300 // We assume all ETIME returns are valid.
4301 //
4302 // TODO: properly differentiate simultaneous notify+interrupt.
4303 // In that case, we should propagate the notify to another waiter.
4304
4305 while (_Event < 0) {
4306 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4307 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4308 pthread_cond_destroy(_cond);
4309 pthread_cond_init(_cond, NULL);
4310 }
4311 assert_status(status == 0 || status == EINTR ||
4312 status == ETIMEDOUT,
4313 status, "cond_timedwait");
4314 if (!FilterSpuriousWakeups) break; // previous semantics
4315 if (status == ETIMEDOUT) break;
4316 // We consume and ignore EINTR and spurious wakeups.
4317 }
4318 --_nParked;
4319 if (_Event >= 0) {
4320 ret = OS_OK;
4321 }
4322 _Event = 0;
4323 status = pthread_mutex_unlock(_mutex);
4324 assert_status(status == 0, status, "mutex_unlock");
4325 assert(_nParked == 0, "invariant");
4326 // Paranoia to ensure our locked and lock-free paths interact
4327 // correctly with each other.
4328 OrderAccess::fence();
4329 return ret;
4330 }
4331
4332 void os::PlatformEvent::unpark() {
4333 // Transitions for _Event:
4334 // 0 :=> 1
4335 // 1 :=> 1
4336 // -1 :=> either 0 or 1; must signal target thread
4337 // That is, we can safely transition _Event from -1 to either
4338 // 0 or 1.
4339 // See also: "Semaphores in Plan 9" by Mullender & Cox
4340 //
4341 // Note: Forcing a transition from "-1" to "1" on an unpark() means
4342 // that it will take two back-to-back park() calls for the owning
4343 // thread to block. This has the benefit of forcing a spurious return
4344 // from the first park() call after an unpark() call which will help
4345 // shake out uses of park() and unpark() without condition variables.
4346
4347 if (Atomic::xchg(1, &_Event) >= 0) return;
4348
4349 // Wait for the thread associated with the event to vacate
4350 int status = pthread_mutex_lock(_mutex);
4351 assert_status(status == 0, status, "mutex_lock");
4352 int AnyWaiters = _nParked;
4353 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4354 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4355 AnyWaiters = 0;
4356 pthread_cond_signal(_cond);
4357 }
4358 status = pthread_mutex_unlock(_mutex);
4359 assert_status(status == 0, status, "mutex_unlock");
4360 if (AnyWaiters != 0) {
4361 status = pthread_cond_signal(_cond);
4362 assert_status(status == 0, status, "cond_signal");
4363 }
4364
4365 // Note that we signal() _after dropping the lock for "immortal" Events.
4366 // This is safe and avoids a common class of futile wakeups. In rare
4367 // circumstances this can cause a thread to return prematurely from
4368 // cond_{timed}wait() but the spurious wakeup is benign and the victim will
4369 // simply re-test the condition and re-park itself.
4370 }
4371
4372
4373 // JSR166
4374 // -------------------------------------------------------
4375
4376 // The solaris and bsd implementations of park/unpark are fairly
4377 // conservative for now, but can be improved. They currently use a
4378 // mutex/condvar pair, plus a a count.
4379 // Park decrements count if > 0, else does a condvar wait. Unpark
4380 // sets count to 1 and signals condvar. Only one thread ever waits
4381 // on the condvar. Contention seen when trying to park implies that someone
4382 // is unparking you, so don't wait. And spurious returns are fine, so there
4383 // is no need to track notifications.
4384
4385 #define MAX_SECS 100000000
4386
4387 // This code is common to bsd and solaris and will be moved to a
4388 // common place in dolphin.
4389 //
4390 // The passed in time value is either a relative time in nanoseconds
4391 // or an absolute time in milliseconds. Either way it has to be unpacked
4392 // into suitable seconds and nanoseconds components and stored in the
4393 // given timespec structure.
4394 // Given time is a 64-bit value and the time_t used in the timespec is only
4395 // a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4396 // overflow if times way in the future are given. Further on Solaris versions
4397 // prior to 10 there is a restriction (see cond_timedwait) that the specified
4398 // number of seconds, in abstime, is less than current_time + 100,000,000.
4399 // As it will be 28 years before "now + 100000000" will overflow we can
4400 // ignore overflow and just impose a hard-limit on seconds using the value
4401 // of "now + 100,000,000". This places a limit on the timeout of about 3.17
4402 // years from "now".
4403
4404 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4405 assert(time > 0, "convertTime");
4406
4407 struct timeval now;
4408 int status = gettimeofday(&now, NULL);
4409 assert(status == 0, "gettimeofday");
4410
4411 time_t max_secs = now.tv_sec + MAX_SECS;
4412
4413 if (isAbsolute) {
4414 jlong secs = time / 1000;
4415 if (secs > max_secs) {
4416 absTime->tv_sec = max_secs;
4417 } else {
4418 absTime->tv_sec = secs;
4419 }
4420 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4421 } else {
4422 jlong secs = time / NANOSECS_PER_SEC;
4423 if (secs >= MAX_SECS) {
4424 absTime->tv_sec = max_secs;
4425 absTime->tv_nsec = 0;
4426 } else {
4427 absTime->tv_sec = now.tv_sec + secs;
4428 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4429 if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4430 absTime->tv_nsec -= NANOSECS_PER_SEC;
4431 ++absTime->tv_sec; // note: this must be <= max_secs
4432 }
4433 }
4434 }
4435 assert(absTime->tv_sec >= 0, "tv_sec < 0");
4436 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4437 assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4438 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4439 }
4440
4441 void Parker::park(bool isAbsolute, jlong time) {
4442 // Ideally we'd do something useful while spinning, such
4443 // as calling unpackTime().
4444
4445 // Optional fast-path check:
4446 // Return immediately if a permit is available.
4447 // We depend on Atomic::xchg() having full barrier semantics
4448 // since we are doing a lock-free update to _counter.
4449 if (Atomic::xchg(0, &_counter) > 0) return;
4450
4451 Thread* thread = Thread::current();
4452 assert(thread->is_Java_thread(), "Must be JavaThread");
4453 JavaThread *jt = (JavaThread *)thread;
4454
4455 // Optional optimization -- avoid state transitions if there's an interrupt pending.
4456 // Check interrupt before trying to wait
4457 if (Thread::is_interrupted(thread, false)) {
4458 return;
4459 }
4460
4461 // Next, demultiplex/decode time arguments
4462 struct timespec absTime;
4463 if (time < 0 || (isAbsolute && time == 0)) { // don't wait at all
4464 return;
4465 }
4466 if (time > 0) {
4467 unpackTime(&absTime, isAbsolute, time);
4468 }
4469
4470
4471 // Enter safepoint region
4472 // Beware of deadlocks such as 6317397.
4473 // The per-thread Parker:: mutex is a classic leaf-lock.
4474 // In particular a thread must never block on the Threads_lock while
4475 // holding the Parker:: mutex. If safepoints are pending both the
4476 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4477 ThreadBlockInVM tbivm(jt);
4478
4479 // Don't wait if cannot get lock since interference arises from
4480 // unblocking. Also. check interrupt before trying wait
4481 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4482 return;
4483 }
4484
4485 int status;
4486 if (_counter > 0) { // no wait needed
4487 _counter = 0;
4488 status = pthread_mutex_unlock(_mutex);
4489 assert(status == 0, "invariant");
4490 // Paranoia to ensure our locked and lock-free paths interact
4491 // correctly with each other and Java-level accesses.
4492 OrderAccess::fence();
4493 return;
4494 }
4495
4496 #ifdef ASSERT
4497 // Don't catch signals while blocked; let the running threads have the signals.
4498 // (This allows a debugger to break into the running thread.)
4499 sigset_t oldsigs;
4500 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4501 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4502 #endif
4503
4504 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4505 jt->set_suspend_equivalent();
4506 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4507
4508 if (time == 0) {
4509 status = pthread_cond_wait(_cond, _mutex);
4510 } else {
4511 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &absTime);
4512 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4513 pthread_cond_destroy(_cond);
4514 pthread_cond_init(_cond, NULL);
4515 }
4516 }
4517 assert_status(status == 0 || status == EINTR ||
4518 status == ETIMEDOUT,
4519 status, "cond_timedwait");
4520
4521 #ifdef ASSERT
4522 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4523 #endif
4524
4525 _counter = 0;
4526 status = pthread_mutex_unlock(_mutex);
4527 assert_status(status == 0, status, "invariant");
4528 // Paranoia to ensure our locked and lock-free paths interact
4529 // correctly with each other and Java-level accesses.
4530 OrderAccess::fence();
4531
4532 // If externally suspended while waiting, re-suspend
4533 if (jt->handle_special_suspend_equivalent_condition()) {
4534 jt->java_suspend_self();
4535 }
4536 }
4537
4538 void Parker::unpark() {
4539 int status = pthread_mutex_lock(_mutex);
4540 assert(status == 0, "invariant");
4541 const int s = _counter;
4542 _counter = 1;
4543 if (s < 1) {
4544 if (WorkAroundNPTLTimedWaitHang) {
4545 status = pthread_cond_signal(_cond);
4546 assert(status == 0, "invariant");
4547 status = pthread_mutex_unlock(_mutex);
4548 assert(status == 0, "invariant");
4549 } else {
4550 status = pthread_mutex_unlock(_mutex);
4551 assert(status == 0, "invariant");
4552 status = pthread_cond_signal(_cond);
4553 assert(status == 0, "invariant");
4554 }
4555 } else {
4556 pthread_mutex_unlock(_mutex);
4557 assert(status == 0, "invariant");
4558 }
4559 }
4560
4561
4562 // Darwin has no "environ" in a dynamic library.
4563 #ifdef __APPLE__
4564 #include <crt_externs.h>
4565 #define environ (*_NSGetEnviron())
4566 #else
4567 extern char** environ;
4568 #endif
4569
4570 // Run the specified command in a separate process. Return its exit value,
4571 // or -1 on failure (e.g. can't fork a new process).
4572 // Unlike system(), this function can be called from signal handler. It
4573 // doesn't block SIGINT et al.
4574 int os::fork_and_exec(char* cmd) {
4575 const char * argv[4] = {"sh", "-c", cmd, NULL};
4576
4577 // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4578 // pthread_atfork handlers and reset pthread library. All we need is a
4579 // separate process to execve. Make a direct syscall to fork process.
4580 // On IA64 there's no fork syscall, we have to use fork() and hope for
4581 // the best...
4582 pid_t pid = fork();
4583
4584 if (pid < 0) {
4585 // fork failed
4586 return -1;
4587
4588 } else if (pid == 0) {
4589 // child process
4590
4591 // execve() in BsdThreads will call pthread_kill_other_threads_np()
4592 // first to kill every thread on the thread list. Because this list is
4593 // not reset by fork() (see notes above), execve() will instead kill
4594 // every thread in the parent process. We know this is the only thread
4595 // in the new process, so make a system call directly.
4596 // IA64 should use normal execve() from glibc to match the glibc fork()
4597 // above.
4598 execve("/bin/sh", (char* const*)argv, environ);
4599
4600 // execve failed
4601 _exit(-1);
4602
4603 } else {
4604 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4605 // care about the actual exit code, for now.
4606
4607 int status;
4608
4609 // Wait for the child process to exit. This returns immediately if
4610 // the child has already exited. */
4611 while (waitpid(pid, &status, 0) < 0) {
4612 switch (errno) {
4613 case ECHILD: return 0;
4614 case EINTR: break;
4615 default: return -1;
4616 }
4617 }
4618
4619 if (WIFEXITED(status)) {
4620 // The child exited normally; get its exit code.
4621 return WEXITSTATUS(status);
4622 } else if (WIFSIGNALED(status)) {
4623 // The child exited because of a signal
4624 // The best value to return is 0x80 + signal number,
4625 // because that is what all Unix shells do, and because
4626 // it allows callers to distinguish between process exit and
4627 // process death by signal.
4628 return 0x80 + WTERMSIG(status);
4629 } else {
4630 // Unknown exit code; pass it through
4631 return status;
4632 }
4633 }
4634 }
4635
4636 // is_headless_jre()
4637 //
4638 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4639 // in order to report if we are running in a headless jre
4640 //
4641 // Since JDK8 xawt/libmawt.so was moved into the same directory
4642 // as libawt.so, and renamed libawt_xawt.so
4643 //
4644 bool os::is_headless_jre() {
4645 #ifdef __APPLE__
4646 // We no longer build headless-only on Mac OS X
4647 return false;
4648 #else
4649 struct stat statbuf;
4650 char buf[MAXPATHLEN];
4651 char libmawtpath[MAXPATHLEN];
4652 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX;
4653 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4654 char *p;
4655
4656 // Get path to libjvm.so
4657 os::jvm_path(buf, sizeof(buf));
4658
4659 // Get rid of libjvm.so
4660 p = strrchr(buf, '/');
4661 if (p == NULL) {
4662 return false;
4663 } else {
4664 *p = '\0';
4665 }
4666
4667 // Get rid of client or server
4668 p = strrchr(buf, '/');
4669 if (p == NULL) {
4670 return false;
4671 } else {
4672 *p = '\0';
4673 }
4674
4675 // check xawt/libmawt.so
4676 strcpy(libmawtpath, buf);
4677 strcat(libmawtpath, xawtstr);
4678 if (::stat(libmawtpath, &statbuf) == 0) return false;
4679
4680 // check libawt_xawt.so
4681 strcpy(libmawtpath, buf);
4682 strcat(libmawtpath, new_xawtstr);
4683 if (::stat(libmawtpath, &statbuf) == 0) return false;
4684
4685 return true;
4686 #endif
4687 }
4688
4689 // Get the default path to the core file
4690 // Returns the length of the string
4691 int os::get_core_path(char* buffer, size_t bufferSize) {
4692 int n = jio_snprintf(buffer, bufferSize, "/cores/core or core.%d", current_process_id());
4693
4694 // Truncate if theoretical string was longer than bufferSize
4695 n = MIN2(n, (int)bufferSize);
4696
4697 return n;
4698 }
4699
4700 #ifndef PRODUCT
4701 void TestReserveMemorySpecial_test() {
4702 // No tests available for this platform
4703 }
4704 #endif