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