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