Fri, 24 Oct 2014 15:02:37 -0400
8050807: Better performing performance data handling
Reviewed-by: dcubed, dholmes, pnauman, ctornqvi, mschoene
Contributed-by: gerald.thornbrugh@oracle.com
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 */
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/osThread.hpp"
52 #include "runtime/perfMemory.hpp"
53 #include "runtime/sharedRuntime.hpp"
54 #include "runtime/statSampler.hpp"
55 #include "runtime/stubRoutines.hpp"
56 #include "runtime/thread.inline.hpp"
57 #include "runtime/threadCritical.hpp"
58 #include "runtime/timer.hpp"
59 #include "services/attachListener.hpp"
60 #include "services/memTracker.hpp"
61 #include "services/runtimeService.hpp"
62 #include "utilities/decoder.hpp"
63 #include "utilities/defaultStream.hpp"
64 #include "utilities/events.hpp"
65 #include "utilities/growableArray.hpp"
66 #include "utilities/vmError.hpp"
68 // put OS-includes here
69 # include <sys/types.h>
70 # include <sys/mman.h>
71 # include <sys/stat.h>
72 # include <sys/select.h>
73 # include <pthread.h>
74 # include <signal.h>
75 # include <errno.h>
76 # include <dlfcn.h>
77 # include <stdio.h>
78 # include <unistd.h>
79 # include <sys/resource.h>
80 # include <pthread.h>
81 # include <sys/stat.h>
82 # include <sys/time.h>
83 # include <sys/times.h>
84 # include <sys/utsname.h>
85 # include <sys/socket.h>
86 # include <sys/wait.h>
87 # include <time.h>
88 # include <pwd.h>
89 # include <poll.h>
90 # include <semaphore.h>
91 # include <fcntl.h>
92 # include <string.h>
93 # include <sys/param.h>
94 # include <sys/sysctl.h>
95 # include <sys/ipc.h>
96 # include <sys/shm.h>
97 #ifndef __APPLE__
98 # include <link.h>
99 #endif
100 # include <stdint.h>
101 # include <inttypes.h>
102 # include <sys/ioctl.h>
103 # include <sys/syscall.h>
105 #if defined(__FreeBSD__) || defined(__NetBSD__)
106 # include <elf.h>
107 #endif
109 #ifdef __APPLE__
110 # include <mach/mach.h> // semaphore_* API
111 # include <mach-o/dyld.h>
112 # include <sys/proc_info.h>
113 # include <objc/objc-auto.h>
114 #endif
116 #ifndef MAP_ANONYMOUS
117 #define MAP_ANONYMOUS MAP_ANON
118 #endif
120 #define MAX_PATH (2 * K)
122 // for timer info max values which include all bits
123 #define ALL_64_BITS CONST64(0xFFFFFFFFFFFFFFFF)
125 #define LARGEPAGES_BIT (1 << 6)
127 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
129 ////////////////////////////////////////////////////////////////////////////////
130 // global variables
131 julong os::Bsd::_physical_memory = 0;
133 #ifdef __APPLE__
134 mach_timebase_info_data_t os::Bsd::_timebase_info = {0, 0};
135 volatile uint64_t os::Bsd::_max_abstime = 0;
136 #else
137 int (*os::Bsd::_clock_gettime)(clockid_t, struct timespec *) = NULL;
138 #endif
139 pthread_t os::Bsd::_main_thread;
140 int os::Bsd::_page_size = -1;
142 static jlong initial_time_count=0;
144 static int clock_tics_per_sec = 100;
146 // For diagnostics to print a message once. see run_periodic_checks
147 static sigset_t check_signal_done;
148 static bool check_signals = true;
150 static pid_t _initial_pid = 0;
152 /* Signal number used to suspend/resume a thread */
154 /* do not use any signal number less than SIGSEGV, see 4355769 */
155 static int SR_signum = SIGUSR2;
156 sigset_t SR_sigset;
159 ////////////////////////////////////////////////////////////////////////////////
160 // utility functions
162 static int SR_initialize();
163 static void unpackTime(timespec* absTime, bool isAbsolute, jlong time);
165 julong os::available_memory() {
166 return Bsd::available_memory();
167 }
169 // available here means free
170 julong os::Bsd::available_memory() {
171 uint64_t available = physical_memory() >> 2;
172 #ifdef __APPLE__
173 mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
174 vm_statistics64_data_t vmstat;
175 kern_return_t kerr = host_statistics64(mach_host_self(), HOST_VM_INFO64,
176 (host_info64_t)&vmstat, &count);
177 assert(kerr == KERN_SUCCESS,
178 "host_statistics64 failed - check mach_host_self() and count");
179 if (kerr == KERN_SUCCESS) {
180 available = vmstat.free_count * os::vm_page_size();
181 }
182 #endif
183 return available;
184 }
186 julong os::physical_memory() {
187 return Bsd::physical_memory();
188 }
190 ////////////////////////////////////////////////////////////////////////////////
191 // environment support
193 bool os::getenv(const char* name, char* buf, int len) {
194 const char* val = ::getenv(name);
195 if (val != NULL && strlen(val) < (size_t)len) {
196 strcpy(buf, val);
197 return true;
198 }
199 if (len > 0) buf[0] = 0; // return a null string
200 return false;
201 }
204 // Return true if user is running as root.
206 bool os::have_special_privileges() {
207 static bool init = false;
208 static bool privileges = false;
209 if (!init) {
210 privileges = (getuid() != geteuid()) || (getgid() != getegid());
211 init = true;
212 }
213 return privileges;
214 }
218 // Cpu architecture string
219 #if defined(ZERO)
220 static char cpu_arch[] = ZERO_LIBARCH;
221 #elif defined(IA64)
222 static char cpu_arch[] = "ia64";
223 #elif defined(IA32)
224 static char cpu_arch[] = "i386";
225 #elif defined(AMD64)
226 static char cpu_arch[] = "amd64";
227 #elif defined(ARM)
228 static char cpu_arch[] = "arm";
229 #elif defined(PPC32)
230 static char cpu_arch[] = "ppc";
231 #elif defined(SPARC)
232 # ifdef _LP64
233 static char cpu_arch[] = "sparcv9";
234 # else
235 static char cpu_arch[] = "sparc";
236 # endif
237 #else
238 #error Add appropriate cpu_arch setting
239 #endif
241 // Compiler variant
242 #ifdef COMPILER2
243 #define COMPILER_VARIANT "server"
244 #else
245 #define COMPILER_VARIANT "client"
246 #endif
249 void os::Bsd::initialize_system_info() {
250 int mib[2];
251 size_t len;
252 int cpu_val;
253 julong mem_val;
255 /* get processors count via hw.ncpus sysctl */
256 mib[0] = CTL_HW;
257 mib[1] = HW_NCPU;
258 len = sizeof(cpu_val);
259 if (sysctl(mib, 2, &cpu_val, &len, NULL, 0) != -1 && cpu_val >= 1) {
260 assert(len == sizeof(cpu_val), "unexpected data size");
261 set_processor_count(cpu_val);
262 }
263 else {
264 set_processor_count(1); // fallback
265 }
267 /* get physical memory via hw.memsize sysctl (hw.memsize is used
268 * since it returns a 64 bit value)
269 */
270 mib[0] = CTL_HW;
272 #if defined (HW_MEMSIZE) // Apple
273 mib[1] = HW_MEMSIZE;
274 #elif defined(HW_PHYSMEM) // Most of BSD
275 mib[1] = HW_PHYSMEM;
276 #elif defined(HW_REALMEM) // Old FreeBSD
277 mib[1] = HW_REALMEM;
278 #else
279 #error No ways to get physmem
280 #endif
282 len = sizeof(mem_val);
283 if (sysctl(mib, 2, &mem_val, &len, NULL, 0) != -1) {
284 assert(len == sizeof(mem_val), "unexpected data size");
285 _physical_memory = mem_val;
286 } else {
287 _physical_memory = 256*1024*1024; // fallback (XXXBSD?)
288 }
290 #ifdef __OpenBSD__
291 {
292 // limit _physical_memory memory view on OpenBSD since
293 // datasize rlimit restricts us anyway.
294 struct rlimit limits;
295 getrlimit(RLIMIT_DATA, &limits);
296 _physical_memory = MIN2(_physical_memory, (julong)limits.rlim_cur);
297 }
298 #endif
299 }
301 #ifdef __APPLE__
302 static const char *get_home() {
303 const char *home_dir = ::getenv("HOME");
304 if ((home_dir == NULL) || (*home_dir == '\0')) {
305 struct passwd *passwd_info = getpwuid(geteuid());
306 if (passwd_info != NULL) {
307 home_dir = passwd_info->pw_dir;
308 }
309 }
311 return home_dir;
312 }
313 #endif
315 void os::init_system_properties_values() {
316 // The next steps are taken in the product version:
317 //
318 // Obtain the JAVA_HOME value from the location of libjvm.so.
319 // This library should be located at:
320 // <JAVA_HOME>/jre/lib/<arch>/{client|server}/libjvm.so.
321 //
322 // If "/jre/lib/" appears at the right place in the path, then we
323 // assume libjvm.so is installed in a JDK and we use this path.
324 //
325 // Otherwise exit with message: "Could not create the Java virtual machine."
326 //
327 // The following extra steps are taken in the debugging version:
328 //
329 // If "/jre/lib/" does NOT appear at the right place in the path
330 // instead of exit check for $JAVA_HOME environment variable.
331 //
332 // If it is defined and we are able to locate $JAVA_HOME/jre/lib/<arch>,
333 // then we append a fake suffix "hotspot/libjvm.so" to this path so
334 // it looks like libjvm.so is installed there
335 // <JAVA_HOME>/jre/lib/<arch>/hotspot/libjvm.so.
336 //
337 // Otherwise exit.
338 //
339 // Important note: if the location of libjvm.so changes this
340 // code needs to be changed accordingly.
342 // See ld(1):
343 // The linker uses the following search paths to locate required
344 // shared libraries:
345 // 1: ...
346 // ...
347 // 7: The default directories, normally /lib and /usr/lib.
348 #ifndef DEFAULT_LIBPATH
349 #define DEFAULT_LIBPATH "/lib:/usr/lib"
350 #endif
352 // Base path of extensions installed on the system.
353 #define SYS_EXT_DIR "/usr/java/packages"
354 #define EXTENSIONS_DIR "/lib/ext"
355 #define ENDORSED_DIR "/lib/endorsed"
357 #ifndef __APPLE__
359 // Buffer that fits several sprintfs.
360 // Note that the space for the colon and the trailing null are provided
361 // by the nulls included by the sizeof operator.
362 const size_t bufsize =
363 MAX3((size_t)MAXPATHLEN, // For dll_dir & friends.
364 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + sizeof(SYS_EXT_DIR) + sizeof(EXTENSIONS_DIR), // extensions dir
365 (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir
366 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
368 // sysclasspath, java_home, dll_dir
369 {
370 char *pslash;
371 os::jvm_path(buf, bufsize);
373 // Found the full path to libjvm.so.
374 // Now cut the path to <java_home>/jre if we can.
375 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
376 pslash = strrchr(buf, '/');
377 if (pslash != NULL) {
378 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
379 }
380 Arguments::set_dll_dir(buf);
382 if (pslash != NULL) {
383 pslash = strrchr(buf, '/');
384 if (pslash != NULL) {
385 *pslash = '\0'; // Get rid of /<arch>.
386 pslash = strrchr(buf, '/');
387 if (pslash != NULL) {
388 *pslash = '\0'; // Get rid of /lib.
389 }
390 }
391 }
392 Arguments::set_java_home(buf);
393 set_boot_path('/', ':');
394 }
396 // Where to look for native libraries.
397 //
398 // Note: Due to a legacy implementation, most of the library path
399 // is set in the launcher. This was to accomodate linking restrictions
400 // on legacy Bsd implementations (which are no longer supported).
401 // Eventually, all the library path setting will be done here.
402 //
403 // However, to prevent the proliferation of improperly built native
404 // libraries, the new path component /usr/java/packages is added here.
405 // Eventually, all the library path setting will be done here.
406 {
407 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
408 // should always exist (until the legacy problem cited above is
409 // addressed).
410 const char *v = ::getenv("LD_LIBRARY_PATH");
411 const char *v_colon = ":";
412 if (v == NULL) { v = ""; v_colon = ""; }
413 // That's +1 for the colon and +1 for the trailing '\0'.
414 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
415 strlen(v) + 1 +
416 sizeof(SYS_EXT_DIR) + sizeof("/lib/") + strlen(cpu_arch) + sizeof(DEFAULT_LIBPATH) + 1,
417 mtInternal);
418 sprintf(ld_library_path, "%s%s" SYS_EXT_DIR "/lib/%s:" DEFAULT_LIBPATH, v, v_colon, cpu_arch);
419 Arguments::set_library_path(ld_library_path);
420 FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal);
421 }
423 // Extensions directories.
424 sprintf(buf, "%s" EXTENSIONS_DIR ":" SYS_EXT_DIR EXTENSIONS_DIR, Arguments::get_java_home());
425 Arguments::set_ext_dirs(buf);
427 // Endorsed standards default directory.
428 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
429 Arguments::set_endorsed_dirs(buf);
431 FREE_C_HEAP_ARRAY(char, buf, mtInternal);
433 #else // __APPLE__
435 #define SYS_EXTENSIONS_DIR "/Library/Java/Extensions"
436 #define SYS_EXTENSIONS_DIRS SYS_EXTENSIONS_DIR ":/Network" SYS_EXTENSIONS_DIR ":/System" SYS_EXTENSIONS_DIR ":/usr/lib/java"
438 const char *user_home_dir = get_home();
439 // The null in SYS_EXTENSIONS_DIRS counts for the size of the colon after user_home_dir.
440 size_t system_ext_size = strlen(user_home_dir) + sizeof(SYS_EXTENSIONS_DIR) +
441 sizeof(SYS_EXTENSIONS_DIRS);
443 // Buffer that fits several sprintfs.
444 // Note that the space for the colon and the trailing null are provided
445 // by the nulls included by the sizeof operator.
446 const size_t bufsize =
447 MAX3((size_t)MAXPATHLEN, // for dll_dir & friends.
448 (size_t)MAXPATHLEN + sizeof(EXTENSIONS_DIR) + system_ext_size, // extensions dir
449 (size_t)MAXPATHLEN + sizeof(ENDORSED_DIR)); // endorsed dir
450 char *buf = (char *)NEW_C_HEAP_ARRAY(char, bufsize, mtInternal);
452 // sysclasspath, java_home, dll_dir
453 {
454 char *pslash;
455 os::jvm_path(buf, bufsize);
457 // Found the full path to libjvm.so.
458 // Now cut the path to <java_home>/jre if we can.
459 *(strrchr(buf, '/')) = '\0'; // Get rid of /libjvm.so.
460 pslash = strrchr(buf, '/');
461 if (pslash != NULL) {
462 *pslash = '\0'; // Get rid of /{client|server|hotspot}.
463 }
464 Arguments::set_dll_dir(buf);
466 if (pslash != NULL) {
467 pslash = strrchr(buf, '/');
468 if (pslash != NULL) {
469 *pslash = '\0'; // Get rid of /lib.
470 }
471 }
472 Arguments::set_java_home(buf);
473 set_boot_path('/', ':');
474 }
476 // Where to look for native libraries.
477 //
478 // Note: Due to a legacy implementation, most of the library path
479 // is set in the launcher. This was to accomodate linking restrictions
480 // on legacy Bsd implementations (which are no longer supported).
481 // Eventually, all the library path setting will be done here.
482 //
483 // However, to prevent the proliferation of improperly built native
484 // libraries, the new path component /usr/java/packages is added here.
485 // Eventually, all the library path setting will be done here.
486 {
487 // Get the user setting of LD_LIBRARY_PATH, and prepended it. It
488 // should always exist (until the legacy problem cited above is
489 // addressed).
490 // Prepend the default path with the JAVA_LIBRARY_PATH so that the app launcher code
491 // can specify a directory inside an app wrapper
492 const char *l = ::getenv("JAVA_LIBRARY_PATH");
493 const char *l_colon = ":";
494 if (l == NULL) { l = ""; l_colon = ""; }
496 const char *v = ::getenv("DYLD_LIBRARY_PATH");
497 const char *v_colon = ":";
498 if (v == NULL) { v = ""; v_colon = ""; }
500 // Apple's Java6 has "." at the beginning of java.library.path.
501 // OpenJDK on Windows has "." at the end of java.library.path.
502 // OpenJDK on Linux and Solaris don't have "." in java.library.path
503 // at all. To ease the transition from Apple's Java6 to OpenJDK7,
504 // "." is appended to the end of java.library.path. Yes, this
505 // could cause a change in behavior, but Apple's Java6 behavior
506 // can be achieved by putting "." at the beginning of the
507 // JAVA_LIBRARY_PATH environment variable.
508 char *ld_library_path = (char *)NEW_C_HEAP_ARRAY(char,
509 strlen(v) + 1 + strlen(l) + 1 +
510 system_ext_size + 3,
511 mtInternal);
512 sprintf(ld_library_path, "%s%s%s%s%s" SYS_EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS ":.",
513 v, v_colon, l, l_colon, user_home_dir);
514 Arguments::set_library_path(ld_library_path);
515 FREE_C_HEAP_ARRAY(char, ld_library_path, mtInternal);
516 }
518 // Extensions directories.
519 //
520 // Note that the space for the colon and the trailing null are provided
521 // by the nulls included by the sizeof operator (so actually one byte more
522 // than necessary is allocated).
523 sprintf(buf, "%s" SYS_EXTENSIONS_DIR ":%s" EXTENSIONS_DIR ":" SYS_EXTENSIONS_DIRS,
524 user_home_dir, Arguments::get_java_home());
525 Arguments::set_ext_dirs(buf);
527 // Endorsed standards default directory.
528 sprintf(buf, "%s" ENDORSED_DIR, Arguments::get_java_home());
529 Arguments::set_endorsed_dirs(buf);
531 FREE_C_HEAP_ARRAY(char, buf, mtInternal);
533 #undef SYS_EXTENSIONS_DIR
534 #undef SYS_EXTENSIONS_DIRS
536 #endif // __APPLE__
538 #undef SYS_EXT_DIR
539 #undef EXTENSIONS_DIR
540 #undef ENDORSED_DIR
541 }
543 ////////////////////////////////////////////////////////////////////////////////
544 // breakpoint support
546 void os::breakpoint() {
547 BREAKPOINT;
548 }
550 extern "C" void breakpoint() {
551 // use debugger to set breakpoint here
552 }
554 ////////////////////////////////////////////////////////////////////////////////
555 // signal support
557 debug_only(static bool signal_sets_initialized = false);
558 static sigset_t unblocked_sigs, vm_sigs, allowdebug_blocked_sigs;
560 bool os::Bsd::is_sig_ignored(int sig) {
561 struct sigaction oact;
562 sigaction(sig, (struct sigaction*)NULL, &oact);
563 void* ohlr = oact.sa_sigaction ? CAST_FROM_FN_PTR(void*, oact.sa_sigaction)
564 : CAST_FROM_FN_PTR(void*, oact.sa_handler);
565 if (ohlr == CAST_FROM_FN_PTR(void*, SIG_IGN))
566 return true;
567 else
568 return false;
569 }
571 void os::Bsd::signal_sets_init() {
572 // Should also have an assertion stating we are still single-threaded.
573 assert(!signal_sets_initialized, "Already initialized");
574 // Fill in signals that are necessarily unblocked for all threads in
575 // the VM. Currently, we unblock the following signals:
576 // SHUTDOWN{1,2,3}_SIGNAL: for shutdown hooks support (unless over-ridden
577 // by -Xrs (=ReduceSignalUsage));
578 // BREAK_SIGNAL which is unblocked only by the VM thread and blocked by all
579 // other threads. The "ReduceSignalUsage" boolean tells us not to alter
580 // the dispositions or masks wrt these signals.
581 // Programs embedding the VM that want to use the above signals for their
582 // own purposes must, at this time, use the "-Xrs" option to prevent
583 // interference with shutdown hooks and BREAK_SIGNAL thread dumping.
584 // (See bug 4345157, and other related bugs).
585 // In reality, though, unblocking these signals is really a nop, since
586 // these signals are not blocked by default.
587 sigemptyset(&unblocked_sigs);
588 sigemptyset(&allowdebug_blocked_sigs);
589 sigaddset(&unblocked_sigs, SIGILL);
590 sigaddset(&unblocked_sigs, SIGSEGV);
591 sigaddset(&unblocked_sigs, SIGBUS);
592 sigaddset(&unblocked_sigs, SIGFPE);
593 sigaddset(&unblocked_sigs, SR_signum);
595 if (!ReduceSignalUsage) {
596 if (!os::Bsd::is_sig_ignored(SHUTDOWN1_SIGNAL)) {
597 sigaddset(&unblocked_sigs, SHUTDOWN1_SIGNAL);
598 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN1_SIGNAL);
599 }
600 if (!os::Bsd::is_sig_ignored(SHUTDOWN2_SIGNAL)) {
601 sigaddset(&unblocked_sigs, SHUTDOWN2_SIGNAL);
602 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN2_SIGNAL);
603 }
604 if (!os::Bsd::is_sig_ignored(SHUTDOWN3_SIGNAL)) {
605 sigaddset(&unblocked_sigs, SHUTDOWN3_SIGNAL);
606 sigaddset(&allowdebug_blocked_sigs, SHUTDOWN3_SIGNAL);
607 }
608 }
609 // Fill in signals that are blocked by all but the VM thread.
610 sigemptyset(&vm_sigs);
611 if (!ReduceSignalUsage)
612 sigaddset(&vm_sigs, BREAK_SIGNAL);
613 debug_only(signal_sets_initialized = true);
615 }
617 // These are signals that are unblocked while a thread is running Java.
618 // (For some reason, they get blocked by default.)
619 sigset_t* os::Bsd::unblocked_signals() {
620 assert(signal_sets_initialized, "Not initialized");
621 return &unblocked_sigs;
622 }
624 // These are the signals that are blocked while a (non-VM) thread is
625 // running Java. Only the VM thread handles these signals.
626 sigset_t* os::Bsd::vm_signals() {
627 assert(signal_sets_initialized, "Not initialized");
628 return &vm_sigs;
629 }
631 // These are signals that are blocked during cond_wait to allow debugger in
632 sigset_t* os::Bsd::allowdebug_blocked_signals() {
633 assert(signal_sets_initialized, "Not initialized");
634 return &allowdebug_blocked_sigs;
635 }
637 void os::Bsd::hotspot_sigmask(Thread* thread) {
639 //Save caller's signal mask before setting VM signal mask
640 sigset_t caller_sigmask;
641 pthread_sigmask(SIG_BLOCK, NULL, &caller_sigmask);
643 OSThread* osthread = thread->osthread();
644 osthread->set_caller_sigmask(caller_sigmask);
646 pthread_sigmask(SIG_UNBLOCK, os::Bsd::unblocked_signals(), NULL);
648 if (!ReduceSignalUsage) {
649 if (thread->is_VM_thread()) {
650 // Only the VM thread handles BREAK_SIGNAL ...
651 pthread_sigmask(SIG_UNBLOCK, vm_signals(), NULL);
652 } else {
653 // ... all other threads block BREAK_SIGNAL
654 pthread_sigmask(SIG_BLOCK, vm_signals(), NULL);
655 }
656 }
657 }
660 //////////////////////////////////////////////////////////////////////////////
661 // create new thread
663 // check if it's safe to start a new thread
664 static bool _thread_safety_check(Thread* thread) {
665 return true;
666 }
668 #ifdef __APPLE__
669 // library handle for calling objc_registerThreadWithCollector()
670 // without static linking to the libobjc library
671 #define OBJC_LIB "/usr/lib/libobjc.dylib"
672 #define OBJC_GCREGISTER "objc_registerThreadWithCollector"
673 typedef void (*objc_registerThreadWithCollector_t)();
674 extern "C" objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction;
675 objc_registerThreadWithCollector_t objc_registerThreadWithCollectorFunction = NULL;
676 #endif
678 #ifdef __APPLE__
679 static uint64_t locate_unique_thread_id(mach_port_t mach_thread_port) {
680 // Additional thread_id used to correlate threads in SA
681 thread_identifier_info_data_t m_ident_info;
682 mach_msg_type_number_t count = THREAD_IDENTIFIER_INFO_COUNT;
684 thread_info(mach_thread_port, THREAD_IDENTIFIER_INFO,
685 (thread_info_t) &m_ident_info, &count);
687 return m_ident_info.thread_id;
688 }
689 #endif
691 // Thread start routine for all newly created threads
692 static void *java_start(Thread *thread) {
693 // Try to randomize the cache line index of hot stack frames.
694 // This helps when threads of the same stack traces evict each other's
695 // cache lines. The threads can be either from the same JVM instance, or
696 // from different JVM instances. The benefit is especially true for
697 // processors with hyperthreading technology.
698 static int counter = 0;
699 int pid = os::current_process_id();
700 alloca(((pid ^ counter++) & 7) * 128);
702 ThreadLocalStorage::set_thread(thread);
704 OSThread* osthread = thread->osthread();
705 Monitor* sync = osthread->startThread_lock();
707 // non floating stack BsdThreads needs extra check, see above
708 if (!_thread_safety_check(thread)) {
709 // notify parent thread
710 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
711 osthread->set_state(ZOMBIE);
712 sync->notify_all();
713 return NULL;
714 }
716 osthread->set_thread_id(os::Bsd::gettid());
718 #ifdef __APPLE__
719 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
720 guarantee(unique_thread_id != 0, "unique thread id was not found");
721 osthread->set_unique_thread_id(unique_thread_id);
722 #endif
723 // initialize signal mask for this thread
724 os::Bsd::hotspot_sigmask(thread);
726 // initialize floating point control register
727 os::Bsd::init_thread_fpu_state();
729 #ifdef __APPLE__
730 // register thread with objc gc
731 if (objc_registerThreadWithCollectorFunction != NULL) {
732 objc_registerThreadWithCollectorFunction();
733 }
734 #endif
736 // handshaking with parent thread
737 {
738 MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
740 // notify parent thread
741 osthread->set_state(INITIALIZED);
742 sync->notify_all();
744 // wait until os::start_thread()
745 while (osthread->get_state() == INITIALIZED) {
746 sync->wait(Mutex::_no_safepoint_check_flag);
747 }
748 }
750 // call one more level start routine
751 thread->run();
753 return 0;
754 }
756 bool os::create_thread(Thread* thread, ThreadType thr_type, size_t stack_size) {
757 assert(thread->osthread() == NULL, "caller responsible");
759 // Allocate the OSThread object
760 OSThread* osthread = new OSThread(NULL, NULL);
761 if (osthread == NULL) {
762 return false;
763 }
765 // set the correct thread state
766 osthread->set_thread_type(thr_type);
768 // Initial state is ALLOCATED but not INITIALIZED
769 osthread->set_state(ALLOCATED);
771 thread->set_osthread(osthread);
773 // init thread attributes
774 pthread_attr_t attr;
775 pthread_attr_init(&attr);
776 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
778 // stack size
779 if (os::Bsd::supports_variable_stack_size()) {
780 // calculate stack size if it's not specified by caller
781 if (stack_size == 0) {
782 stack_size = os::Bsd::default_stack_size(thr_type);
784 switch (thr_type) {
785 case os::java_thread:
786 // Java threads use ThreadStackSize which default value can be
787 // changed with the flag -Xss
788 assert (JavaThread::stack_size_at_create() > 0, "this should be set");
789 stack_size = JavaThread::stack_size_at_create();
790 break;
791 case os::compiler_thread:
792 if (CompilerThreadStackSize > 0) {
793 stack_size = (size_t)(CompilerThreadStackSize * K);
794 break;
795 } // else fall through:
796 // use VMThreadStackSize if CompilerThreadStackSize is not defined
797 case os::vm_thread:
798 case os::pgc_thread:
799 case os::cgc_thread:
800 case os::watcher_thread:
801 if (VMThreadStackSize > 0) stack_size = (size_t)(VMThreadStackSize * K);
802 break;
803 }
804 }
806 stack_size = MAX2(stack_size, os::Bsd::min_stack_allowed);
807 pthread_attr_setstacksize(&attr, stack_size);
808 } else {
809 // let pthread_create() pick the default value.
810 }
812 ThreadState state;
814 {
815 pthread_t tid;
816 int ret = pthread_create(&tid, &attr, (void* (*)(void*)) java_start, thread);
818 pthread_attr_destroy(&attr);
820 if (ret != 0) {
821 if (PrintMiscellaneous && (Verbose || WizardMode)) {
822 perror("pthread_create()");
823 }
824 // Need to clean up stuff we've allocated so far
825 thread->set_osthread(NULL);
826 delete osthread;
827 return false;
828 }
830 // Store pthread info into the OSThread
831 osthread->set_pthread_id(tid);
833 // Wait until child thread is either initialized or aborted
834 {
835 Monitor* sync_with_child = osthread->startThread_lock();
836 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
837 while ((state = osthread->get_state()) == ALLOCATED) {
838 sync_with_child->wait(Mutex::_no_safepoint_check_flag);
839 }
840 }
842 }
844 // Aborted due to thread limit being reached
845 if (state == ZOMBIE) {
846 thread->set_osthread(NULL);
847 delete osthread;
848 return false;
849 }
851 // The thread is returned suspended (in state INITIALIZED),
852 // and is started higher up in the call chain
853 assert(state == INITIALIZED, "race condition");
854 return true;
855 }
857 /////////////////////////////////////////////////////////////////////////////
858 // attach existing thread
860 // bootstrap the main thread
861 bool os::create_main_thread(JavaThread* thread) {
862 assert(os::Bsd::_main_thread == pthread_self(), "should be called inside main thread");
863 return create_attached_thread(thread);
864 }
866 bool os::create_attached_thread(JavaThread* thread) {
867 #ifdef ASSERT
868 thread->verify_not_published();
869 #endif
871 // Allocate the OSThread object
872 OSThread* osthread = new OSThread(NULL, NULL);
874 if (osthread == NULL) {
875 return false;
876 }
878 osthread->set_thread_id(os::Bsd::gettid());
880 // Store pthread info into the OSThread
881 #ifdef __APPLE__
882 uint64_t unique_thread_id = locate_unique_thread_id(osthread->thread_id());
883 guarantee(unique_thread_id != 0, "just checking");
884 osthread->set_unique_thread_id(unique_thread_id);
885 #endif
886 osthread->set_pthread_id(::pthread_self());
888 // initialize floating point control register
889 os::Bsd::init_thread_fpu_state();
891 // Initial thread state is RUNNABLE
892 osthread->set_state(RUNNABLE);
894 thread->set_osthread(osthread);
896 // initialize signal mask for this thread
897 // and save the caller's signal mask
898 os::Bsd::hotspot_sigmask(thread);
900 return true;
901 }
903 void os::pd_start_thread(Thread* thread) {
904 OSThread * osthread = thread->osthread();
905 assert(osthread->get_state() != INITIALIZED, "just checking");
906 Monitor* sync_with_child = osthread->startThread_lock();
907 MutexLockerEx ml(sync_with_child, Mutex::_no_safepoint_check_flag);
908 sync_with_child->notify();
909 }
911 // Free Bsd resources related to the OSThread
912 void os::free_thread(OSThread* osthread) {
913 assert(osthread != NULL, "osthread not set");
915 if (Thread::current()->osthread() == osthread) {
916 // Restore caller's signal mask
917 sigset_t sigmask = osthread->caller_sigmask();
918 pthread_sigmask(SIG_SETMASK, &sigmask, NULL);
919 }
921 delete osthread;
922 }
924 //////////////////////////////////////////////////////////////////////////////
925 // thread local storage
927 // Restore the thread pointer if the destructor is called. This is in case
928 // someone from JNI code sets up a destructor with pthread_key_create to run
929 // detachCurrentThread on thread death. Unless we restore the thread pointer we
930 // will hang or crash. When detachCurrentThread is called the key will be set
931 // to null and we will not be called again. If detachCurrentThread is never
932 // called we could loop forever depending on the pthread implementation.
933 static void restore_thread_pointer(void* p) {
934 Thread* thread = (Thread*) p;
935 os::thread_local_storage_at_put(ThreadLocalStorage::thread_index(), thread);
936 }
938 int os::allocate_thread_local_storage() {
939 pthread_key_t key;
940 int rslt = pthread_key_create(&key, restore_thread_pointer);
941 assert(rslt == 0, "cannot allocate thread local storage");
942 return (int)key;
943 }
945 // Note: This is currently not used by VM, as we don't destroy TLS key
946 // on VM exit.
947 void os::free_thread_local_storage(int index) {
948 int rslt = pthread_key_delete((pthread_key_t)index);
949 assert(rslt == 0, "invalid index");
950 }
952 void os::thread_local_storage_at_put(int index, void* value) {
953 int rslt = pthread_setspecific((pthread_key_t)index, value);
954 assert(rslt == 0, "pthread_setspecific failed");
955 }
957 extern "C" Thread* get_thread() {
958 return ThreadLocalStorage::thread();
959 }
962 ////////////////////////////////////////////////////////////////////////////////
963 // time support
965 // Time since start-up in seconds to a fine granularity.
966 // Used by VMSelfDestructTimer and the MemProfiler.
967 double os::elapsedTime() {
969 return ((double)os::elapsed_counter()) / os::elapsed_frequency();
970 }
972 jlong os::elapsed_counter() {
973 return javaTimeNanos() - initial_time_count;
974 }
976 jlong os::elapsed_frequency() {
977 return NANOSECS_PER_SEC; // nanosecond resolution
978 }
980 bool os::supports_vtime() { return true; }
981 bool os::enable_vtime() { return false; }
982 bool os::vtime_enabled() { return false; }
984 double os::elapsedVTime() {
985 // better than nothing, but not much
986 return elapsedTime();
987 }
989 jlong os::javaTimeMillis() {
990 timeval time;
991 int status = gettimeofday(&time, NULL);
992 assert(status != -1, "bsd error");
993 return jlong(time.tv_sec) * 1000 + jlong(time.tv_usec / 1000);
994 }
996 #ifndef __APPLE__
997 #ifndef CLOCK_MONOTONIC
998 #define CLOCK_MONOTONIC (1)
999 #endif
1000 #endif
1002 #ifdef __APPLE__
1003 void os::Bsd::clock_init() {
1004 mach_timebase_info(&_timebase_info);
1005 }
1006 #else
1007 void os::Bsd::clock_init() {
1008 struct timespec res;
1009 struct timespec tp;
1010 if (::clock_getres(CLOCK_MONOTONIC, &res) == 0 &&
1011 ::clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
1012 // yes, monotonic clock is supported
1013 _clock_gettime = ::clock_gettime;
1014 }
1015 }
1016 #endif
1019 #ifdef __APPLE__
1021 jlong os::javaTimeNanos() {
1022 const uint64_t tm = mach_absolute_time();
1023 const uint64_t now = (tm * Bsd::_timebase_info.numer) / Bsd::_timebase_info.denom;
1024 const uint64_t prev = Bsd::_max_abstime;
1025 if (now <= prev) {
1026 return prev; // same or retrograde time;
1027 }
1028 const uint64_t obsv = Atomic::cmpxchg(now, (volatile jlong*)&Bsd::_max_abstime, prev);
1029 assert(obsv >= prev, "invariant"); // Monotonicity
1030 // If the CAS succeeded then we're done and return "now".
1031 // If the CAS failed and the observed value "obsv" is >= now then
1032 // we should return "obsv". If the CAS failed and now > obsv > prv then
1033 // some other thread raced this thread and installed a new value, in which case
1034 // we could either (a) retry the entire operation, (b) retry trying to install now
1035 // or (c) just return obsv. We use (c). No loop is required although in some cases
1036 // we might discard a higher "now" value in deference to a slightly lower but freshly
1037 // installed obsv value. That's entirely benign -- it admits no new orderings compared
1038 // to (a) or (b) -- and greatly reduces coherence traffic.
1039 // We might also condition (c) on the magnitude of the delta between obsv and now.
1040 // Avoiding excessive CAS operations to hot RW locations is critical.
1041 // See https://blogs.oracle.com/dave/entry/cas_and_cache_trivia_invalidate
1042 return (prev == obsv) ? now : obsv;
1043 }
1045 #else // __APPLE__
1047 jlong os::javaTimeNanos() {
1048 if (Bsd::supports_monotonic_clock()) {
1049 struct timespec tp;
1050 int status = Bsd::_clock_gettime(CLOCK_MONOTONIC, &tp);
1051 assert(status == 0, "gettime error");
1052 jlong result = jlong(tp.tv_sec) * (1000 * 1000 * 1000) + jlong(tp.tv_nsec);
1053 return result;
1054 } else {
1055 timeval time;
1056 int status = gettimeofday(&time, NULL);
1057 assert(status != -1, "bsd error");
1058 jlong usecs = jlong(time.tv_sec) * (1000 * 1000) + jlong(time.tv_usec);
1059 return 1000 * usecs;
1060 }
1061 }
1063 #endif // __APPLE__
1065 void os::javaTimeNanos_info(jvmtiTimerInfo *info_ptr) {
1066 if (Bsd::supports_monotonic_clock()) {
1067 info_ptr->max_value = ALL_64_BITS;
1069 // CLOCK_MONOTONIC - amount of time since some arbitrary point in the past
1070 info_ptr->may_skip_backward = false; // not subject to resetting or drifting
1071 info_ptr->may_skip_forward = false; // not subject to resetting or drifting
1072 } else {
1073 // gettimeofday - based on time in seconds since the Epoch thus does not wrap
1074 info_ptr->max_value = ALL_64_BITS;
1076 // gettimeofday is a real time clock so it skips
1077 info_ptr->may_skip_backward = true;
1078 info_ptr->may_skip_forward = true;
1079 }
1081 info_ptr->kind = JVMTI_TIMER_ELAPSED; // elapsed not CPU time
1082 }
1084 // Return the real, user, and system times in seconds from an
1085 // arbitrary fixed point in the past.
1086 bool os::getTimesSecs(double* process_real_time,
1087 double* process_user_time,
1088 double* process_system_time) {
1089 struct tms ticks;
1090 clock_t real_ticks = times(&ticks);
1092 if (real_ticks == (clock_t) (-1)) {
1093 return false;
1094 } else {
1095 double ticks_per_second = (double) clock_tics_per_sec;
1096 *process_user_time = ((double) ticks.tms_utime) / ticks_per_second;
1097 *process_system_time = ((double) ticks.tms_stime) / ticks_per_second;
1098 *process_real_time = ((double) real_ticks) / ticks_per_second;
1100 return true;
1101 }
1102 }
1105 char * os::local_time_string(char *buf, size_t buflen) {
1106 struct tm t;
1107 time_t long_time;
1108 time(&long_time);
1109 localtime_r(&long_time, &t);
1110 jio_snprintf(buf, buflen, "%d-%02d-%02d %02d:%02d:%02d",
1111 t.tm_year + 1900, t.tm_mon + 1, t.tm_mday,
1112 t.tm_hour, t.tm_min, t.tm_sec);
1113 return buf;
1114 }
1116 struct tm* os::localtime_pd(const time_t* clock, struct tm* res) {
1117 return localtime_r(clock, res);
1118 }
1120 ////////////////////////////////////////////////////////////////////////////////
1121 // runtime exit support
1123 // Note: os::shutdown() might be called very early during initialization, or
1124 // called from signal handler. Before adding something to os::shutdown(), make
1125 // sure it is async-safe and can handle partially initialized VM.
1126 void os::shutdown() {
1128 // allow PerfMemory to attempt cleanup of any persistent resources
1129 perfMemory_exit();
1131 // needs to remove object in file system
1132 AttachListener::abort();
1134 // flush buffered output, finish log files
1135 ostream_abort();
1137 // Check for abort hook
1138 abort_hook_t abort_hook = Arguments::abort_hook();
1139 if (abort_hook != NULL) {
1140 abort_hook();
1141 }
1143 }
1145 // Note: os::abort() might be called very early during initialization, or
1146 // called from signal handler. Before adding something to os::abort(), make
1147 // sure it is async-safe and can handle partially initialized VM.
1148 void os::abort(bool dump_core) {
1149 os::shutdown();
1150 if (dump_core) {
1151 #ifndef PRODUCT
1152 fdStream out(defaultStream::output_fd());
1153 out.print_raw("Current thread is ");
1154 char buf[16];
1155 jio_snprintf(buf, sizeof(buf), UINTX_FORMAT, os::current_thread_id());
1156 out.print_raw_cr(buf);
1157 out.print_raw_cr("Dumping core ...");
1158 #endif
1159 ::abort(); // dump core
1160 }
1162 ::exit(1);
1163 }
1165 // Die immediately, no exit hook, no abort hook, no cleanup.
1166 void os::die() {
1167 // _exit() on BsdThreads only kills current thread
1168 ::abort();
1169 }
1171 // This method is a copy of JDK's sysGetLastErrorString
1172 // from src/solaris/hpi/src/system_md.c
1174 size_t os::lasterror(char *buf, size_t len) {
1176 if (errno == 0) return 0;
1178 const char *s = ::strerror(errno);
1179 size_t n = ::strlen(s);
1180 if (n >= len) {
1181 n = len - 1;
1182 }
1183 ::strncpy(buf, s, n);
1184 buf[n] = '\0';
1185 return n;
1186 }
1188 // Information of current thread in variety of formats
1189 pid_t os::Bsd::gettid() {
1190 int retval = -1;
1192 #ifdef __APPLE__ //XNU kernel
1193 // despite the fact mach port is actually not a thread id use it
1194 // instead of syscall(SYS_thread_selfid) as it certainly fits to u4
1195 retval = ::pthread_mach_thread_np(::pthread_self());
1196 guarantee(retval != 0, "just checking");
1197 return retval;
1199 #elif __FreeBSD__
1200 retval = syscall(SYS_thr_self);
1201 #elif __OpenBSD__
1202 retval = syscall(SYS_getthrid);
1203 #elif __NetBSD__
1204 retval = (pid_t) syscall(SYS__lwp_self);
1205 #endif
1207 if (retval == -1) {
1208 return getpid();
1209 }
1210 }
1212 intx os::current_thread_id() {
1213 #ifdef __APPLE__
1214 return (intx)::pthread_mach_thread_np(::pthread_self());
1215 #else
1216 return (intx)::pthread_self();
1217 #endif
1218 }
1220 int os::current_process_id() {
1222 // Under the old bsd thread library, bsd gives each thread
1223 // its own process id. Because of this each thread will return
1224 // a different pid if this method were to return the result
1225 // of getpid(2). Bsd provides no api that returns the pid
1226 // of the launcher thread for the vm. This implementation
1227 // returns a unique pid, the pid of the launcher thread
1228 // that starts the vm 'process'.
1230 // Under the NPTL, getpid() returns the same pid as the
1231 // launcher thread rather than a unique pid per thread.
1232 // Use gettid() if you want the old pre NPTL behaviour.
1234 // if you are looking for the result of a call to getpid() that
1235 // returns a unique pid for the calling thread, then look at the
1236 // OSThread::thread_id() method in osThread_bsd.hpp file
1238 return (int)(_initial_pid ? _initial_pid : getpid());
1239 }
1241 // DLL functions
1243 #define JNI_LIB_PREFIX "lib"
1244 #ifdef __APPLE__
1245 #define JNI_LIB_SUFFIX ".dylib"
1246 #else
1247 #define JNI_LIB_SUFFIX ".so"
1248 #endif
1250 const char* os::dll_file_extension() { return JNI_LIB_SUFFIX; }
1252 // This must be hard coded because it's the system's temporary
1253 // directory not the java application's temp directory, ala java.io.tmpdir.
1254 #ifdef __APPLE__
1255 // macosx has a secure per-user temporary directory
1256 char temp_path_storage[PATH_MAX];
1257 const char* os::get_temp_directory() {
1258 static char *temp_path = NULL;
1259 if (temp_path == NULL) {
1260 int pathSize = confstr(_CS_DARWIN_USER_TEMP_DIR, temp_path_storage, PATH_MAX);
1261 if (pathSize == 0 || pathSize > PATH_MAX) {
1262 strlcpy(temp_path_storage, "/tmp/", sizeof(temp_path_storage));
1263 }
1264 temp_path = temp_path_storage;
1265 }
1266 return temp_path;
1267 }
1268 #else /* __APPLE__ */
1269 const char* os::get_temp_directory() { return "/tmp"; }
1270 #endif /* __APPLE__ */
1272 static bool file_exists(const char* filename) {
1273 struct stat statbuf;
1274 if (filename == NULL || strlen(filename) == 0) {
1275 return false;
1276 }
1277 return os::stat(filename, &statbuf) == 0;
1278 }
1280 bool os::dll_build_name(char* buffer, size_t buflen,
1281 const char* pname, const char* fname) {
1282 bool retval = false;
1283 // Copied from libhpi
1284 const size_t pnamelen = pname ? strlen(pname) : 0;
1286 // Return error on buffer overflow.
1287 if (pnamelen + strlen(fname) + strlen(JNI_LIB_PREFIX) + strlen(JNI_LIB_SUFFIX) + 2 > buflen) {
1288 return retval;
1289 }
1291 if (pnamelen == 0) {
1292 snprintf(buffer, buflen, JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, fname);
1293 retval = true;
1294 } else if (strchr(pname, *os::path_separator()) != NULL) {
1295 int n;
1296 char** pelements = split_path(pname, &n);
1297 if (pelements == NULL) {
1298 return false;
1299 }
1300 for (int i = 0 ; i < n ; i++) {
1301 // Really shouldn't be NULL, but check can't hurt
1302 if (pelements[i] == NULL || strlen(pelements[i]) == 0) {
1303 continue; // skip the empty path values
1304 }
1305 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX,
1306 pelements[i], fname);
1307 if (file_exists(buffer)) {
1308 retval = true;
1309 break;
1310 }
1311 }
1312 // release the storage
1313 for (int i = 0 ; i < n ; i++) {
1314 if (pelements[i] != NULL) {
1315 FREE_C_HEAP_ARRAY(char, pelements[i], mtInternal);
1316 }
1317 }
1318 if (pelements != NULL) {
1319 FREE_C_HEAP_ARRAY(char*, pelements, mtInternal);
1320 }
1321 } else {
1322 snprintf(buffer, buflen, "%s/" JNI_LIB_PREFIX "%s" JNI_LIB_SUFFIX, pname, fname);
1323 retval = true;
1324 }
1325 return retval;
1326 }
1328 // check if addr is inside libjvm.so
1329 bool os::address_is_in_vm(address addr) {
1330 static address libjvm_base_addr;
1331 Dl_info dlinfo;
1333 if (libjvm_base_addr == NULL) {
1334 if (dladdr(CAST_FROM_FN_PTR(void *, os::address_is_in_vm), &dlinfo) != 0) {
1335 libjvm_base_addr = (address)dlinfo.dli_fbase;
1336 }
1337 assert(libjvm_base_addr !=NULL, "Cannot obtain base address for libjvm");
1338 }
1340 if (dladdr((void *)addr, &dlinfo) != 0) {
1341 if (libjvm_base_addr == (address)dlinfo.dli_fbase) return true;
1342 }
1344 return false;
1345 }
1348 #define MACH_MAXSYMLEN 256
1350 bool os::dll_address_to_function_name(address addr, char *buf,
1351 int buflen, int *offset) {
1352 // buf is not optional, but offset is optional
1353 assert(buf != NULL, "sanity check");
1355 Dl_info dlinfo;
1356 char localbuf[MACH_MAXSYMLEN];
1358 if (dladdr((void*)addr, &dlinfo) != 0) {
1359 // see if we have a matching symbol
1360 if (dlinfo.dli_saddr != NULL && dlinfo.dli_sname != NULL) {
1361 if (!Decoder::demangle(dlinfo.dli_sname, buf, buflen)) {
1362 jio_snprintf(buf, buflen, "%s", dlinfo.dli_sname);
1363 }
1364 if (offset != NULL) *offset = addr - (address)dlinfo.dli_saddr;
1365 return true;
1366 }
1367 // no matching symbol so try for just file info
1368 if (dlinfo.dli_fname != NULL && dlinfo.dli_fbase != NULL) {
1369 if (Decoder::decode((address)(addr - (address)dlinfo.dli_fbase),
1370 buf, buflen, offset, dlinfo.dli_fname)) {
1371 return true;
1372 }
1373 }
1375 // Handle non-dynamic manually:
1376 if (dlinfo.dli_fbase != NULL &&
1377 Decoder::decode(addr, localbuf, MACH_MAXSYMLEN, offset,
1378 dlinfo.dli_fbase)) {
1379 if (!Decoder::demangle(localbuf, buf, buflen)) {
1380 jio_snprintf(buf, buflen, "%s", localbuf);
1381 }
1382 return true;
1383 }
1384 }
1385 buf[0] = '\0';
1386 if (offset != NULL) *offset = -1;
1387 return false;
1388 }
1390 // ported from solaris version
1391 bool os::dll_address_to_library_name(address addr, char* buf,
1392 int buflen, int* offset) {
1393 // buf is not optional, but offset is optional
1394 assert(buf != NULL, "sanity check");
1396 Dl_info dlinfo;
1398 if (dladdr((void*)addr, &dlinfo) != 0) {
1399 if (dlinfo.dli_fname != NULL) {
1400 jio_snprintf(buf, buflen, "%s", dlinfo.dli_fname);
1401 }
1402 if (dlinfo.dli_fbase != NULL && offset != NULL) {
1403 *offset = addr - (address)dlinfo.dli_fbase;
1404 }
1405 return true;
1406 }
1408 buf[0] = '\0';
1409 if (offset) *offset = -1;
1410 return false;
1411 }
1413 // Loads .dll/.so and
1414 // in case of error it checks if .dll/.so was built for the
1415 // same architecture as Hotspot is running on
1417 #ifdef __APPLE__
1418 void * os::dll_load(const char *filename, char *ebuf, int ebuflen) {
1419 void * result= ::dlopen(filename, RTLD_LAZY);
1420 if (result != NULL) {
1421 // Successful loading
1422 return result;
1423 }
1425 // Read system error message into ebuf
1426 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1427 ebuf[ebuflen-1]='\0';
1429 return NULL;
1430 }
1431 #else
1432 void * os::dll_load(const char *filename, char *ebuf, int ebuflen)
1433 {
1434 void * result= ::dlopen(filename, RTLD_LAZY);
1435 if (result != NULL) {
1436 // Successful loading
1437 return result;
1438 }
1440 Elf32_Ehdr elf_head;
1442 // Read system error message into ebuf
1443 // It may or may not be overwritten below
1444 ::strncpy(ebuf, ::dlerror(), ebuflen-1);
1445 ebuf[ebuflen-1]='\0';
1446 int diag_msg_max_length=ebuflen-strlen(ebuf);
1447 char* diag_msg_buf=ebuf+strlen(ebuf);
1449 if (diag_msg_max_length==0) {
1450 // No more space in ebuf for additional diagnostics message
1451 return NULL;
1452 }
1455 int file_descriptor= ::open(filename, O_RDONLY | O_NONBLOCK);
1457 if (file_descriptor < 0) {
1458 // Can't open library, report dlerror() message
1459 return NULL;
1460 }
1462 bool failed_to_read_elf_head=
1463 (sizeof(elf_head)!=
1464 (::read(file_descriptor, &elf_head,sizeof(elf_head)))) ;
1466 ::close(file_descriptor);
1467 if (failed_to_read_elf_head) {
1468 // file i/o error - report dlerror() msg
1469 return NULL;
1470 }
1472 typedef struct {
1473 Elf32_Half code; // Actual value as defined in elf.h
1474 Elf32_Half compat_class; // Compatibility of archs at VM's sense
1475 char elf_class; // 32 or 64 bit
1476 char endianess; // MSB or LSB
1477 char* name; // String representation
1478 } arch_t;
1480 #ifndef EM_486
1481 #define EM_486 6 /* Intel 80486 */
1482 #endif
1484 #ifndef EM_MIPS_RS3_LE
1485 #define EM_MIPS_RS3_LE 10 /* MIPS */
1486 #endif
1488 #ifndef EM_PPC64
1489 #define EM_PPC64 21 /* PowerPC64 */
1490 #endif
1492 #ifndef EM_S390
1493 #define EM_S390 22 /* IBM System/390 */
1494 #endif
1496 #ifndef EM_IA_64
1497 #define EM_IA_64 50 /* HP/Intel IA-64 */
1498 #endif
1500 #ifndef EM_X86_64
1501 #define EM_X86_64 62 /* AMD x86-64 */
1502 #endif
1504 static const arch_t arch_array[]={
1505 {EM_386, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1506 {EM_486, EM_386, ELFCLASS32, ELFDATA2LSB, (char*)"IA 32"},
1507 {EM_IA_64, EM_IA_64, ELFCLASS64, ELFDATA2LSB, (char*)"IA 64"},
1508 {EM_X86_64, EM_X86_64, ELFCLASS64, ELFDATA2LSB, (char*)"AMD 64"},
1509 {EM_SPARC, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1510 {EM_SPARC32PLUS, EM_SPARC, ELFCLASS32, ELFDATA2MSB, (char*)"Sparc 32"},
1511 {EM_SPARCV9, EM_SPARCV9, ELFCLASS64, ELFDATA2MSB, (char*)"Sparc v9 64"},
1512 {EM_PPC, EM_PPC, ELFCLASS32, ELFDATA2MSB, (char*)"Power PC 32"},
1513 {EM_PPC64, EM_PPC64, ELFCLASS64, ELFDATA2MSB, (char*)"Power PC 64"},
1514 {EM_ARM, EM_ARM, ELFCLASS32, ELFDATA2LSB, (char*)"ARM"},
1515 {EM_S390, EM_S390, ELFCLASSNONE, ELFDATA2MSB, (char*)"IBM System/390"},
1516 {EM_ALPHA, EM_ALPHA, ELFCLASS64, ELFDATA2LSB, (char*)"Alpha"},
1517 {EM_MIPS_RS3_LE, EM_MIPS_RS3_LE, ELFCLASS32, ELFDATA2LSB, (char*)"MIPSel"},
1518 {EM_MIPS, EM_MIPS, ELFCLASS32, ELFDATA2MSB, (char*)"MIPS"},
1519 {EM_PARISC, EM_PARISC, ELFCLASS32, ELFDATA2MSB, (char*)"PARISC"},
1520 {EM_68K, EM_68K, ELFCLASS32, ELFDATA2MSB, (char*)"M68k"}
1521 };
1523 #if (defined IA32)
1524 static Elf32_Half running_arch_code=EM_386;
1525 #elif (defined AMD64)
1526 static Elf32_Half running_arch_code=EM_X86_64;
1527 #elif (defined IA64)
1528 static Elf32_Half running_arch_code=EM_IA_64;
1529 #elif (defined __sparc) && (defined _LP64)
1530 static Elf32_Half running_arch_code=EM_SPARCV9;
1531 #elif (defined __sparc) && (!defined _LP64)
1532 static Elf32_Half running_arch_code=EM_SPARC;
1533 #elif (defined __powerpc64__)
1534 static Elf32_Half running_arch_code=EM_PPC64;
1535 #elif (defined __powerpc__)
1536 static Elf32_Half running_arch_code=EM_PPC;
1537 #elif (defined ARM)
1538 static Elf32_Half running_arch_code=EM_ARM;
1539 #elif (defined S390)
1540 static Elf32_Half running_arch_code=EM_S390;
1541 #elif (defined ALPHA)
1542 static Elf32_Half running_arch_code=EM_ALPHA;
1543 #elif (defined MIPSEL)
1544 static Elf32_Half running_arch_code=EM_MIPS_RS3_LE;
1545 #elif (defined PARISC)
1546 static Elf32_Half running_arch_code=EM_PARISC;
1547 #elif (defined MIPS)
1548 static Elf32_Half running_arch_code=EM_MIPS;
1549 #elif (defined M68K)
1550 static Elf32_Half running_arch_code=EM_68K;
1551 #else
1552 #error Method os::dll_load requires that one of following is defined:\
1553 IA32, AMD64, IA64, __sparc, __powerpc__, ARM, S390, ALPHA, MIPS, MIPSEL, PARISC, M68K
1554 #endif
1556 // Identify compatability class for VM's architecture and library's architecture
1557 // Obtain string descriptions for architectures
1559 arch_t lib_arch={elf_head.e_machine,0,elf_head.e_ident[EI_CLASS], elf_head.e_ident[EI_DATA], NULL};
1560 int running_arch_index=-1;
1562 for (unsigned int i=0 ; i < ARRAY_SIZE(arch_array) ; i++ ) {
1563 if (running_arch_code == arch_array[i].code) {
1564 running_arch_index = i;
1565 }
1566 if (lib_arch.code == arch_array[i].code) {
1567 lib_arch.compat_class = arch_array[i].compat_class;
1568 lib_arch.name = arch_array[i].name;
1569 }
1570 }
1572 assert(running_arch_index != -1,
1573 "Didn't find running architecture code (running_arch_code) in arch_array");
1574 if (running_arch_index == -1) {
1575 // Even though running architecture detection failed
1576 // we may still continue with reporting dlerror() message
1577 return NULL;
1578 }
1580 if (lib_arch.endianess != arch_array[running_arch_index].endianess) {
1581 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: endianness mismatch)");
1582 return NULL;
1583 }
1585 #ifndef S390
1586 if (lib_arch.elf_class != arch_array[running_arch_index].elf_class) {
1587 ::snprintf(diag_msg_buf, diag_msg_max_length-1," (Possible cause: architecture word width mismatch)");
1588 return NULL;
1589 }
1590 #endif // !S390
1592 if (lib_arch.compat_class != arch_array[running_arch_index].compat_class) {
1593 if ( lib_arch.name!=NULL ) {
1594 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1595 " (Possible cause: can't load %s-bit .so on a %s-bit platform)",
1596 lib_arch.name, arch_array[running_arch_index].name);
1597 } else {
1598 ::snprintf(diag_msg_buf, diag_msg_max_length-1,
1599 " (Possible cause: can't load this .so (machine code=0x%x) on a %s-bit platform)",
1600 lib_arch.code,
1601 arch_array[running_arch_index].name);
1602 }
1603 }
1605 return NULL;
1606 }
1607 #endif /* !__APPLE__ */
1609 void* os::get_default_process_handle() {
1610 #ifdef __APPLE__
1611 // MacOS X needs to use RTLD_FIRST instead of RTLD_LAZY
1612 // to avoid finding unexpected symbols on second (or later)
1613 // loads of a library.
1614 return (void*)::dlopen(NULL, RTLD_FIRST);
1615 #else
1616 return (void*)::dlopen(NULL, RTLD_LAZY);
1617 #endif
1618 }
1620 // XXX: Do we need a lock around this as per Linux?
1621 void* os::dll_lookup(void* handle, const char* name) {
1622 return dlsym(handle, name);
1623 }
1626 static bool _print_ascii_file(const char* filename, outputStream* st) {
1627 int fd = ::open(filename, O_RDONLY);
1628 if (fd == -1) {
1629 return false;
1630 }
1632 char buf[32];
1633 int bytes;
1634 while ((bytes = ::read(fd, buf, sizeof(buf))) > 0) {
1635 st->print_raw(buf, bytes);
1636 }
1638 ::close(fd);
1640 return true;
1641 }
1643 void os::print_dll_info(outputStream *st) {
1644 st->print_cr("Dynamic libraries:");
1645 #ifdef RTLD_DI_LINKMAP
1646 Dl_info dli;
1647 void *handle;
1648 Link_map *map;
1649 Link_map *p;
1651 if (dladdr(CAST_FROM_FN_PTR(void *, os::print_dll_info), &dli) == 0 ||
1652 dli.dli_fname == NULL) {
1653 st->print_cr("Error: Cannot print dynamic libraries.");
1654 return;
1655 }
1656 handle = dlopen(dli.dli_fname, RTLD_LAZY);
1657 if (handle == NULL) {
1658 st->print_cr("Error: Cannot print dynamic libraries.");
1659 return;
1660 }
1661 dlinfo(handle, RTLD_DI_LINKMAP, &map);
1662 if (map == NULL) {
1663 st->print_cr("Error: Cannot print dynamic libraries.");
1664 return;
1665 }
1667 while (map->l_prev != NULL)
1668 map = map->l_prev;
1670 while (map != NULL) {
1671 st->print_cr(PTR_FORMAT " \t%s", map->l_addr, map->l_name);
1672 map = map->l_next;
1673 }
1675 dlclose(handle);
1676 #elif defined(__APPLE__)
1677 uint32_t count;
1678 uint32_t i;
1680 count = _dyld_image_count();
1681 for (i = 1; i < count; i++) {
1682 const char *name = _dyld_get_image_name(i);
1683 intptr_t slide = _dyld_get_image_vmaddr_slide(i);
1684 st->print_cr(PTR_FORMAT " \t%s", slide, name);
1685 }
1686 #else
1687 st->print_cr("Error: Cannot print dynamic libraries.");
1688 #endif
1689 }
1691 void os::print_os_info_brief(outputStream* st) {
1692 st->print("Bsd");
1694 os::Posix::print_uname_info(st);
1695 }
1697 void os::print_os_info(outputStream* st) {
1698 st->print("OS:");
1699 st->print("Bsd");
1701 os::Posix::print_uname_info(st);
1703 os::Posix::print_rlimit_info(st);
1705 os::Posix::print_load_average(st);
1706 }
1708 void os::pd_print_cpu_info(outputStream* st) {
1709 // Nothing to do for now.
1710 }
1712 void os::print_memory_info(outputStream* st) {
1714 st->print("Memory:");
1715 st->print(" %dk page", os::vm_page_size()>>10);
1717 st->print(", physical " UINT64_FORMAT "k",
1718 os::physical_memory() >> 10);
1719 st->print("(" UINT64_FORMAT "k free)",
1720 os::available_memory() >> 10);
1721 st->cr();
1723 // meminfo
1724 st->print("\n/proc/meminfo:\n");
1725 _print_ascii_file("/proc/meminfo", st);
1726 st->cr();
1727 }
1729 void os::print_siginfo(outputStream* st, void* siginfo) {
1730 const siginfo_t* si = (const siginfo_t*)siginfo;
1732 os::Posix::print_siginfo_brief(st, si);
1734 if (si && (si->si_signo == SIGBUS || si->si_signo == SIGSEGV) &&
1735 UseSharedSpaces) {
1736 FileMapInfo* mapinfo = FileMapInfo::current_info();
1737 if (mapinfo->is_in_shared_space(si->si_addr)) {
1738 st->print("\n\nError accessing class data sharing archive." \
1739 " Mapped file inaccessible during execution, " \
1740 " possible disk/network problem.");
1741 }
1742 }
1743 st->cr();
1744 }
1747 static void print_signal_handler(outputStream* st, int sig,
1748 char* buf, size_t buflen);
1750 void os::print_signal_handlers(outputStream* st, char* buf, size_t buflen) {
1751 st->print_cr("Signal Handlers:");
1752 print_signal_handler(st, SIGSEGV, buf, buflen);
1753 print_signal_handler(st, SIGBUS , buf, buflen);
1754 print_signal_handler(st, SIGFPE , buf, buflen);
1755 print_signal_handler(st, SIGPIPE, buf, buflen);
1756 print_signal_handler(st, SIGXFSZ, buf, buflen);
1757 print_signal_handler(st, SIGILL , buf, buflen);
1758 print_signal_handler(st, INTERRUPT_SIGNAL, buf, buflen);
1759 print_signal_handler(st, SR_signum, buf, buflen);
1760 print_signal_handler(st, SHUTDOWN1_SIGNAL, buf, buflen);
1761 print_signal_handler(st, SHUTDOWN2_SIGNAL , buf, buflen);
1762 print_signal_handler(st, SHUTDOWN3_SIGNAL , buf, buflen);
1763 print_signal_handler(st, BREAK_SIGNAL, buf, buflen);
1764 }
1766 static char saved_jvm_path[MAXPATHLEN] = {0};
1768 // Find the full path to the current module, libjvm
1769 void os::jvm_path(char *buf, jint buflen) {
1770 // Error checking.
1771 if (buflen < MAXPATHLEN) {
1772 assert(false, "must use a large-enough buffer");
1773 buf[0] = '\0';
1774 return;
1775 }
1776 // Lazy resolve the path to current module.
1777 if (saved_jvm_path[0] != 0) {
1778 strcpy(buf, saved_jvm_path);
1779 return;
1780 }
1782 char dli_fname[MAXPATHLEN];
1783 bool ret = dll_address_to_library_name(
1784 CAST_FROM_FN_PTR(address, os::jvm_path),
1785 dli_fname, sizeof(dli_fname), NULL);
1786 assert(ret, "cannot locate libjvm");
1787 char *rp = NULL;
1788 if (ret && dli_fname[0] != '\0') {
1789 rp = realpath(dli_fname, buf);
1790 }
1791 if (rp == NULL)
1792 return;
1794 if (Arguments::created_by_gamma_launcher()) {
1795 // Support for the gamma launcher. Typical value for buf is
1796 // "<JAVA_HOME>/jre/lib/<arch>/<vmtype>/libjvm". If "/jre/lib/" appears at
1797 // the right place in the string, then assume we are installed in a JDK and
1798 // we're done. Otherwise, check for a JAVA_HOME environment variable and
1799 // construct a path to the JVM being overridden.
1801 const char *p = buf + strlen(buf) - 1;
1802 for (int count = 0; p > buf && count < 5; ++count) {
1803 for (--p; p > buf && *p != '/'; --p)
1804 /* empty */ ;
1805 }
1807 if (strncmp(p, "/jre/lib/", 9) != 0) {
1808 // Look for JAVA_HOME in the environment.
1809 char* java_home_var = ::getenv("JAVA_HOME");
1810 if (java_home_var != NULL && java_home_var[0] != 0) {
1811 char* jrelib_p;
1812 int len;
1814 // Check the current module name "libjvm"
1815 p = strrchr(buf, '/');
1816 assert(strstr(p, "/libjvm") == p, "invalid library name");
1818 rp = realpath(java_home_var, buf);
1819 if (rp == NULL)
1820 return;
1822 // determine if this is a legacy image or modules image
1823 // modules image doesn't have "jre" subdirectory
1824 len = strlen(buf);
1825 assert(len < buflen, "Ran out of buffer space");
1826 jrelib_p = buf + len;
1828 // Add the appropriate library subdir
1829 snprintf(jrelib_p, buflen-len, "/jre/lib");
1830 if (0 != access(buf, F_OK)) {
1831 snprintf(jrelib_p, buflen-len, "/lib");
1832 }
1834 // Add the appropriate client or server subdir
1835 len = strlen(buf);
1836 jrelib_p = buf + len;
1837 snprintf(jrelib_p, buflen-len, "/%s", COMPILER_VARIANT);
1838 if (0 != access(buf, F_OK)) {
1839 snprintf(jrelib_p, buflen-len, "");
1840 }
1842 // If the path exists within JAVA_HOME, add the JVM library name
1843 // to complete the path to JVM being overridden. Otherwise fallback
1844 // to the path to the current library.
1845 if (0 == access(buf, F_OK)) {
1846 // Use current module name "libjvm"
1847 len = strlen(buf);
1848 snprintf(buf + len, buflen-len, "/libjvm%s", JNI_LIB_SUFFIX);
1849 } else {
1850 // Fall back to path of current library
1851 rp = realpath(dli_fname, buf);
1852 if (rp == NULL)
1853 return;
1854 }
1855 }
1856 }
1857 }
1859 strncpy(saved_jvm_path, buf, MAXPATHLEN);
1860 }
1862 void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
1863 // no prefix required, not even "_"
1864 }
1866 void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
1867 // no suffix required
1868 }
1870 ////////////////////////////////////////////////////////////////////////////////
1871 // sun.misc.Signal support
1873 static volatile jint sigint_count = 0;
1875 static void
1876 UserHandler(int sig, void *siginfo, void *context) {
1877 // 4511530 - sem_post is serialized and handled by the manager thread. When
1878 // the program is interrupted by Ctrl-C, SIGINT is sent to every thread. We
1879 // don't want to flood the manager thread with sem_post requests.
1880 if (sig == SIGINT && Atomic::add(1, &sigint_count) > 1)
1881 return;
1883 // Ctrl-C is pressed during error reporting, likely because the error
1884 // handler fails to abort. Let VM die immediately.
1885 if (sig == SIGINT && is_error_reported()) {
1886 os::die();
1887 }
1889 os::signal_notify(sig);
1890 }
1892 void* os::user_handler() {
1893 return CAST_FROM_FN_PTR(void*, UserHandler);
1894 }
1896 extern "C" {
1897 typedef void (*sa_handler_t)(int);
1898 typedef void (*sa_sigaction_t)(int, siginfo_t *, void *);
1899 }
1901 void* os::signal(int signal_number, void* handler) {
1902 struct sigaction sigAct, oldSigAct;
1904 sigfillset(&(sigAct.sa_mask));
1905 sigAct.sa_flags = SA_RESTART|SA_SIGINFO;
1906 sigAct.sa_handler = CAST_TO_FN_PTR(sa_handler_t, handler);
1908 if (sigaction(signal_number, &sigAct, &oldSigAct)) {
1909 // -1 means registration failed
1910 return (void *)-1;
1911 }
1913 return CAST_FROM_FN_PTR(void*, oldSigAct.sa_handler);
1914 }
1916 void os::signal_raise(int signal_number) {
1917 ::raise(signal_number);
1918 }
1920 /*
1921 * The following code is moved from os.cpp for making this
1922 * code platform specific, which it is by its very nature.
1923 */
1925 // Will be modified when max signal is changed to be dynamic
1926 int os::sigexitnum_pd() {
1927 return NSIG;
1928 }
1930 // a counter for each possible signal value
1931 static volatile jint pending_signals[NSIG+1] = { 0 };
1933 // Bsd(POSIX) specific hand shaking semaphore.
1934 #ifdef __APPLE__
1935 typedef semaphore_t os_semaphore_t;
1936 #define SEM_INIT(sem, value) semaphore_create(mach_task_self(), &sem, SYNC_POLICY_FIFO, value)
1937 #define SEM_WAIT(sem) semaphore_wait(sem)
1938 #define SEM_POST(sem) semaphore_signal(sem)
1939 #define SEM_DESTROY(sem) semaphore_destroy(mach_task_self(), sem)
1940 #else
1941 typedef sem_t os_semaphore_t;
1942 #define SEM_INIT(sem, value) sem_init(&sem, 0, value)
1943 #define SEM_WAIT(sem) sem_wait(&sem)
1944 #define SEM_POST(sem) sem_post(&sem)
1945 #define SEM_DESTROY(sem) sem_destroy(&sem)
1946 #endif
1948 class Semaphore : public StackObj {
1949 public:
1950 Semaphore();
1951 ~Semaphore();
1952 void signal();
1953 void wait();
1954 bool trywait();
1955 bool timedwait(unsigned int sec, int nsec);
1956 private:
1957 jlong currenttime() const;
1958 os_semaphore_t _semaphore;
1959 };
1961 Semaphore::Semaphore() : _semaphore(0) {
1962 SEM_INIT(_semaphore, 0);
1963 }
1965 Semaphore::~Semaphore() {
1966 SEM_DESTROY(_semaphore);
1967 }
1969 void Semaphore::signal() {
1970 SEM_POST(_semaphore);
1971 }
1973 void Semaphore::wait() {
1974 SEM_WAIT(_semaphore);
1975 }
1977 jlong Semaphore::currenttime() const {
1978 struct timeval tv;
1979 gettimeofday(&tv, NULL);
1980 return (tv.tv_sec * NANOSECS_PER_SEC) + (tv.tv_usec * 1000);
1981 }
1983 #ifdef __APPLE__
1984 bool Semaphore::trywait() {
1985 return timedwait(0, 0);
1986 }
1988 bool Semaphore::timedwait(unsigned int sec, int nsec) {
1989 kern_return_t kr = KERN_ABORTED;
1990 mach_timespec_t waitspec;
1991 waitspec.tv_sec = sec;
1992 waitspec.tv_nsec = nsec;
1994 jlong starttime = currenttime();
1996 kr = semaphore_timedwait(_semaphore, waitspec);
1997 while (kr == KERN_ABORTED) {
1998 jlong totalwait = (sec * NANOSECS_PER_SEC) + nsec;
2000 jlong current = currenttime();
2001 jlong passedtime = current - starttime;
2003 if (passedtime >= totalwait) {
2004 waitspec.tv_sec = 0;
2005 waitspec.tv_nsec = 0;
2006 } else {
2007 jlong waittime = totalwait - (current - starttime);
2008 waitspec.tv_sec = waittime / NANOSECS_PER_SEC;
2009 waitspec.tv_nsec = waittime % NANOSECS_PER_SEC;
2010 }
2012 kr = semaphore_timedwait(_semaphore, waitspec);
2013 }
2015 return kr == KERN_SUCCESS;
2016 }
2018 #else
2020 bool Semaphore::trywait() {
2021 return sem_trywait(&_semaphore) == 0;
2022 }
2024 bool Semaphore::timedwait(unsigned int sec, int nsec) {
2025 struct timespec ts;
2026 unpackTime(&ts, false, (sec * NANOSECS_PER_SEC) + nsec);
2028 while (1) {
2029 int result = sem_timedwait(&_semaphore, &ts);
2030 if (result == 0) {
2031 return true;
2032 } else if (errno == EINTR) {
2033 continue;
2034 } else if (errno == ETIMEDOUT) {
2035 return false;
2036 } else {
2037 return false;
2038 }
2039 }
2040 }
2042 #endif // __APPLE__
2044 static os_semaphore_t sig_sem;
2045 static Semaphore sr_semaphore;
2047 void os::signal_init_pd() {
2048 // Initialize signal structures
2049 ::memset((void*)pending_signals, 0, sizeof(pending_signals));
2051 // Initialize signal semaphore
2052 ::SEM_INIT(sig_sem, 0);
2053 }
2055 void os::signal_notify(int sig) {
2056 Atomic::inc(&pending_signals[sig]);
2057 ::SEM_POST(sig_sem);
2058 }
2060 static int check_pending_signals(bool wait) {
2061 Atomic::store(0, &sigint_count);
2062 for (;;) {
2063 for (int i = 0; i < NSIG + 1; i++) {
2064 jint n = pending_signals[i];
2065 if (n > 0 && n == Atomic::cmpxchg(n - 1, &pending_signals[i], n)) {
2066 return i;
2067 }
2068 }
2069 if (!wait) {
2070 return -1;
2071 }
2072 JavaThread *thread = JavaThread::current();
2073 ThreadBlockInVM tbivm(thread);
2075 bool threadIsSuspended;
2076 do {
2077 thread->set_suspend_equivalent();
2078 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
2079 ::SEM_WAIT(sig_sem);
2081 // were we externally suspended while we were waiting?
2082 threadIsSuspended = thread->handle_special_suspend_equivalent_condition();
2083 if (threadIsSuspended) {
2084 //
2085 // The semaphore has been incremented, but while we were waiting
2086 // another thread suspended us. We don't want to continue running
2087 // while suspended because that would surprise the thread that
2088 // suspended us.
2089 //
2090 ::SEM_POST(sig_sem);
2092 thread->java_suspend_self();
2093 }
2094 } while (threadIsSuspended);
2095 }
2096 }
2098 int os::signal_lookup() {
2099 return check_pending_signals(false);
2100 }
2102 int os::signal_wait() {
2103 return check_pending_signals(true);
2104 }
2106 ////////////////////////////////////////////////////////////////////////////////
2107 // Virtual Memory
2109 int os::vm_page_size() {
2110 // Seems redundant as all get out
2111 assert(os::Bsd::page_size() != -1, "must call os::init");
2112 return os::Bsd::page_size();
2113 }
2115 // Solaris allocates memory by pages.
2116 int os::vm_allocation_granularity() {
2117 assert(os::Bsd::page_size() != -1, "must call os::init");
2118 return os::Bsd::page_size();
2119 }
2121 // Rationale behind this function:
2122 // current (Mon Apr 25 20:12:18 MSD 2005) oprofile drops samples without executable
2123 // mapping for address (see lookup_dcookie() in the kernel module), thus we cannot get
2124 // samples for JITted code. Here we create private executable mapping over the code cache
2125 // and then we can use standard (well, almost, as mapping can change) way to provide
2126 // info for the reporting script by storing timestamp and location of symbol
2127 void bsd_wrap_code(char* base, size_t size) {
2128 static volatile jint cnt = 0;
2130 if (!UseOprofile) {
2131 return;
2132 }
2134 char buf[PATH_MAX + 1];
2135 int num = Atomic::add(1, &cnt);
2137 snprintf(buf, PATH_MAX + 1, "%s/hs-vm-%d-%d",
2138 os::get_temp_directory(), os::current_process_id(), num);
2139 unlink(buf);
2141 int fd = ::open(buf, O_CREAT | O_RDWR, S_IRWXU);
2143 if (fd != -1) {
2144 off_t rv = ::lseek(fd, size-2, SEEK_SET);
2145 if (rv != (off_t)-1) {
2146 if (::write(fd, "", 1) == 1) {
2147 mmap(base, size,
2148 PROT_READ|PROT_WRITE|PROT_EXEC,
2149 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE, fd, 0);
2150 }
2151 }
2152 ::close(fd);
2153 unlink(buf);
2154 }
2155 }
2157 static void warn_fail_commit_memory(char* addr, size_t size, bool exec,
2158 int err) {
2159 warning("INFO: os::commit_memory(" PTR_FORMAT ", " SIZE_FORMAT
2160 ", %d) failed; error='%s' (errno=%d)", addr, size, exec,
2161 strerror(err), err);
2162 }
2164 // NOTE: Bsd kernel does not really reserve the pages for us.
2165 // All it does is to check if there are enough free pages
2166 // left at the time of mmap(). This could be a potential
2167 // problem.
2168 bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
2169 int prot = exec ? PROT_READ|PROT_WRITE|PROT_EXEC : PROT_READ|PROT_WRITE;
2170 #ifdef __OpenBSD__
2171 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2172 if (::mprotect(addr, size, prot) == 0) {
2173 return true;
2174 }
2175 #else
2176 uintptr_t res = (uintptr_t) ::mmap(addr, size, prot,
2177 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
2178 if (res != (uintptr_t) MAP_FAILED) {
2179 return true;
2180 }
2181 #endif
2183 // Warn about any commit errors we see in non-product builds just
2184 // in case mmap() doesn't work as described on the man page.
2185 NOT_PRODUCT(warn_fail_commit_memory(addr, size, exec, errno);)
2187 return false;
2188 }
2190 bool os::pd_commit_memory(char* addr, size_t size, size_t alignment_hint,
2191 bool exec) {
2192 // alignment_hint is ignored on this OS
2193 return pd_commit_memory(addr, size, exec);
2194 }
2196 void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
2197 const char* mesg) {
2198 assert(mesg != NULL, "mesg must be specified");
2199 if (!pd_commit_memory(addr, size, exec)) {
2200 // add extra info in product mode for vm_exit_out_of_memory():
2201 PRODUCT_ONLY(warn_fail_commit_memory(addr, size, exec, errno);)
2202 vm_exit_out_of_memory(size, OOM_MMAP_ERROR, mesg);
2203 }
2204 }
2206 void os::pd_commit_memory_or_exit(char* addr, size_t size,
2207 size_t alignment_hint, bool exec,
2208 const char* mesg) {
2209 // alignment_hint is ignored on this OS
2210 pd_commit_memory_or_exit(addr, size, exec, mesg);
2211 }
2213 void os::pd_realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
2214 }
2216 void os::pd_free_memory(char *addr, size_t bytes, size_t alignment_hint) {
2217 ::madvise(addr, bytes, MADV_DONTNEED);
2218 }
2220 void os::numa_make_global(char *addr, size_t bytes) {
2221 }
2223 void os::numa_make_local(char *addr, size_t bytes, int lgrp_hint) {
2224 }
2226 bool os::numa_topology_changed() { return false; }
2228 size_t os::numa_get_groups_num() {
2229 return 1;
2230 }
2232 int os::numa_get_group_id() {
2233 return 0;
2234 }
2236 size_t os::numa_get_leaf_groups(int *ids, size_t size) {
2237 if (size > 0) {
2238 ids[0] = 0;
2239 return 1;
2240 }
2241 return 0;
2242 }
2244 bool os::get_page_info(char *start, page_info* info) {
2245 return false;
2246 }
2248 char *os::scan_pages(char *start, char* end, page_info* page_expected, page_info* page_found) {
2249 return end;
2250 }
2253 bool os::pd_uncommit_memory(char* addr, size_t size) {
2254 #ifdef __OpenBSD__
2255 // XXX: Work-around mmap/MAP_FIXED bug temporarily on OpenBSD
2256 return ::mprotect(addr, size, PROT_NONE) == 0;
2257 #else
2258 uintptr_t res = (uintptr_t) ::mmap(addr, size, PROT_NONE,
2259 MAP_PRIVATE|MAP_FIXED|MAP_NORESERVE|MAP_ANONYMOUS, -1, 0);
2260 return res != (uintptr_t) MAP_FAILED;
2261 #endif
2262 }
2264 bool os::pd_create_stack_guard_pages(char* addr, size_t size) {
2265 return os::commit_memory(addr, size, !ExecMem);
2266 }
2268 // If this is a growable mapping, remove the guard pages entirely by
2269 // munmap()ping them. If not, just call uncommit_memory().
2270 bool os::remove_stack_guard_pages(char* addr, size_t size) {
2271 return os::uncommit_memory(addr, size);
2272 }
2274 static address _highest_vm_reserved_address = NULL;
2276 // If 'fixed' is true, anon_mmap() will attempt to reserve anonymous memory
2277 // at 'requested_addr'. If there are existing memory mappings at the same
2278 // location, however, they will be overwritten. If 'fixed' is false,
2279 // 'requested_addr' is only treated as a hint, the return value may or
2280 // may not start from the requested address. Unlike Bsd mmap(), this
2281 // function returns NULL to indicate failure.
2282 static char* anon_mmap(char* requested_addr, size_t bytes, bool fixed) {
2283 char * addr;
2284 int flags;
2286 flags = MAP_PRIVATE | MAP_NORESERVE | MAP_ANONYMOUS;
2287 if (fixed) {
2288 assert((uintptr_t)requested_addr % os::Bsd::page_size() == 0, "unaligned address");
2289 flags |= MAP_FIXED;
2290 }
2292 // Map reserved/uncommitted pages PROT_NONE so we fail early if we
2293 // touch an uncommitted page. Otherwise, the read/write might
2294 // succeed if we have enough swap space to back the physical page.
2295 addr = (char*)::mmap(requested_addr, bytes, PROT_NONE,
2296 flags, -1, 0);
2298 if (addr != MAP_FAILED) {
2299 // anon_mmap() should only get called during VM initialization,
2300 // don't need lock (actually we can skip locking even it can be called
2301 // from multiple threads, because _highest_vm_reserved_address is just a
2302 // hint about the upper limit of non-stack memory regions.)
2303 if ((address)addr + bytes > _highest_vm_reserved_address) {
2304 _highest_vm_reserved_address = (address)addr + bytes;
2305 }
2306 }
2308 return addr == MAP_FAILED ? NULL : addr;
2309 }
2311 // Don't update _highest_vm_reserved_address, because there might be memory
2312 // regions above addr + size. If so, releasing a memory region only creates
2313 // a hole in the address space, it doesn't help prevent heap-stack collision.
2314 //
2315 static int anon_munmap(char * addr, size_t size) {
2316 return ::munmap(addr, size) == 0;
2317 }
2319 char* os::pd_reserve_memory(size_t bytes, char* requested_addr,
2320 size_t alignment_hint) {
2321 return anon_mmap(requested_addr, bytes, (requested_addr != NULL));
2322 }
2324 bool os::pd_release_memory(char* addr, size_t size) {
2325 return anon_munmap(addr, size);
2326 }
2328 static bool bsd_mprotect(char* addr, size_t size, int prot) {
2329 // Bsd wants the mprotect address argument to be page aligned.
2330 char* bottom = (char*)align_size_down((intptr_t)addr, os::Bsd::page_size());
2332 // According to SUSv3, mprotect() should only be used with mappings
2333 // established by mmap(), and mmap() always maps whole pages. Unaligned
2334 // 'addr' likely indicates problem in the VM (e.g. trying to change
2335 // protection of malloc'ed or statically allocated memory). Check the
2336 // caller if you hit this assert.
2337 assert(addr == bottom, "sanity check");
2339 size = align_size_up(pointer_delta(addr, bottom, 1) + size, os::Bsd::page_size());
2340 return ::mprotect(bottom, size, prot) == 0;
2341 }
2343 // Set protections specified
2344 bool os::protect_memory(char* addr, size_t bytes, ProtType prot,
2345 bool is_committed) {
2346 unsigned int p = 0;
2347 switch (prot) {
2348 case MEM_PROT_NONE: p = PROT_NONE; break;
2349 case MEM_PROT_READ: p = PROT_READ; break;
2350 case MEM_PROT_RW: p = PROT_READ|PROT_WRITE; break;
2351 case MEM_PROT_RWX: p = PROT_READ|PROT_WRITE|PROT_EXEC; break;
2352 default:
2353 ShouldNotReachHere();
2354 }
2355 // is_committed is unused.
2356 return bsd_mprotect(addr, bytes, p);
2357 }
2359 bool os::guard_memory(char* addr, size_t size) {
2360 return bsd_mprotect(addr, size, PROT_NONE);
2361 }
2363 bool os::unguard_memory(char* addr, size_t size) {
2364 return bsd_mprotect(addr, size, PROT_READ|PROT_WRITE);
2365 }
2367 bool os::Bsd::hugetlbfs_sanity_check(bool warn, size_t page_size) {
2368 return false;
2369 }
2371 // Large page support
2373 static size_t _large_page_size = 0;
2375 void os::large_page_init() {
2376 }
2379 char* os::reserve_memory_special(size_t bytes, size_t alignment, char* req_addr, bool exec) {
2380 fatal("This code is not used or maintained.");
2382 // "exec" is passed in but not used. Creating the shared image for
2383 // the code cache doesn't have an SHM_X executable permission to check.
2384 assert(UseLargePages && UseSHM, "only for SHM large pages");
2386 key_t key = IPC_PRIVATE;
2387 char *addr;
2389 bool warn_on_failure = UseLargePages &&
2390 (!FLAG_IS_DEFAULT(UseLargePages) ||
2391 !FLAG_IS_DEFAULT(LargePageSizeInBytes)
2392 );
2394 // Create a large shared memory region to attach to based on size.
2395 // Currently, size is the total size of the heap
2396 int shmid = shmget(key, bytes, IPC_CREAT|SHM_R|SHM_W);
2397 if (shmid == -1) {
2398 // Possible reasons for shmget failure:
2399 // 1. shmmax is too small for Java heap.
2400 // > check shmmax value: cat /proc/sys/kernel/shmmax
2401 // > increase shmmax value: echo "0xffffffff" > /proc/sys/kernel/shmmax
2402 // 2. not enough large page memory.
2403 // > check available large pages: cat /proc/meminfo
2404 // > increase amount of large pages:
2405 // echo new_value > /proc/sys/vm/nr_hugepages
2406 // Note 1: different Bsd may use different name for this property,
2407 // e.g. on Redhat AS-3 it is "hugetlb_pool".
2408 // Note 2: it's possible there's enough physical memory available but
2409 // they are so fragmented after a long run that they can't
2410 // coalesce into large pages. Try to reserve large pages when
2411 // the system is still "fresh".
2412 if (warn_on_failure) {
2413 warning("Failed to reserve shared memory (errno = %d).", errno);
2414 }
2415 return NULL;
2416 }
2418 // attach to the region
2419 addr = (char*)shmat(shmid, req_addr, 0);
2420 int err = errno;
2422 // Remove shmid. If shmat() is successful, the actual shared memory segment
2423 // will be deleted when it's detached by shmdt() or when the process
2424 // terminates. If shmat() is not successful this will remove the shared
2425 // segment immediately.
2426 shmctl(shmid, IPC_RMID, NULL);
2428 if ((intptr_t)addr == -1) {
2429 if (warn_on_failure) {
2430 warning("Failed to attach shared memory (errno = %d).", err);
2431 }
2432 return NULL;
2433 }
2435 // The memory is committed
2436 MemTracker::record_virtual_memory_reserve_and_commit((address)addr, bytes, mtNone, CALLER_PC);
2438 return addr;
2439 }
2441 bool os::release_memory_special(char* base, size_t bytes) {
2442 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
2443 // detaching the SHM segment will also delete it, see reserve_memory_special()
2444 int rslt = shmdt(base);
2445 if (rslt == 0) {
2446 tkr.record((address)base, bytes);
2447 return true;
2448 } else {
2449 tkr.discard();
2450 return false;
2451 }
2453 }
2455 size_t os::large_page_size() {
2456 return _large_page_size;
2457 }
2459 // HugeTLBFS allows application to commit large page memory on demand;
2460 // with SysV SHM the entire memory region must be allocated as shared
2461 // memory.
2462 bool os::can_commit_large_page_memory() {
2463 return UseHugeTLBFS;
2464 }
2466 bool os::can_execute_large_page_memory() {
2467 return UseHugeTLBFS;
2468 }
2470 // Reserve memory at an arbitrary address, only if that area is
2471 // available (and not reserved for something else).
2473 char* os::pd_attempt_reserve_memory_at(size_t bytes, char* requested_addr) {
2474 const int max_tries = 10;
2475 char* base[max_tries];
2476 size_t size[max_tries];
2477 const size_t gap = 0x000000;
2479 // Assert only that the size is a multiple of the page size, since
2480 // that's all that mmap requires, and since that's all we really know
2481 // about at this low abstraction level. If we need higher alignment,
2482 // we can either pass an alignment to this method or verify alignment
2483 // in one of the methods further up the call chain. See bug 5044738.
2484 assert(bytes % os::vm_page_size() == 0, "reserving unexpected size block");
2486 // Repeatedly allocate blocks until the block is allocated at the
2487 // right spot. Give up after max_tries. Note that reserve_memory() will
2488 // automatically update _highest_vm_reserved_address if the call is
2489 // successful. The variable tracks the highest memory address every reserved
2490 // by JVM. It is used to detect heap-stack collision if running with
2491 // fixed-stack BsdThreads. Because here we may attempt to reserve more
2492 // space than needed, it could confuse the collision detecting code. To
2493 // solve the problem, save current _highest_vm_reserved_address and
2494 // calculate the correct value before return.
2495 address old_highest = _highest_vm_reserved_address;
2497 // Bsd mmap allows caller to pass an address as hint; give it a try first,
2498 // if kernel honors the hint then we can return immediately.
2499 char * addr = anon_mmap(requested_addr, bytes, false);
2500 if (addr == requested_addr) {
2501 return requested_addr;
2502 }
2504 if (addr != NULL) {
2505 // mmap() is successful but it fails to reserve at the requested address
2506 anon_munmap(addr, bytes);
2507 }
2509 int i;
2510 for (i = 0; i < max_tries; ++i) {
2511 base[i] = reserve_memory(bytes);
2513 if (base[i] != NULL) {
2514 // Is this the block we wanted?
2515 if (base[i] == requested_addr) {
2516 size[i] = bytes;
2517 break;
2518 }
2520 // Does this overlap the block we wanted? Give back the overlapped
2521 // parts and try again.
2523 size_t top_overlap = requested_addr + (bytes + gap) - base[i];
2524 if (top_overlap >= 0 && top_overlap < bytes) {
2525 unmap_memory(base[i], top_overlap);
2526 base[i] += top_overlap;
2527 size[i] = bytes - top_overlap;
2528 } else {
2529 size_t bottom_overlap = base[i] + bytes - requested_addr;
2530 if (bottom_overlap >= 0 && bottom_overlap < bytes) {
2531 unmap_memory(requested_addr, bottom_overlap);
2532 size[i] = bytes - bottom_overlap;
2533 } else {
2534 size[i] = bytes;
2535 }
2536 }
2537 }
2538 }
2540 // Give back the unused reserved pieces.
2542 for (int j = 0; j < i; ++j) {
2543 if (base[j] != NULL) {
2544 unmap_memory(base[j], size[j]);
2545 }
2546 }
2548 if (i < max_tries) {
2549 _highest_vm_reserved_address = MAX2(old_highest, (address)requested_addr + bytes);
2550 return requested_addr;
2551 } else {
2552 _highest_vm_reserved_address = old_highest;
2553 return NULL;
2554 }
2555 }
2557 size_t os::read(int fd, void *buf, unsigned int nBytes) {
2558 RESTARTABLE_RETURN_INT(::read(fd, buf, nBytes));
2559 }
2561 // TODO-FIXME: reconcile Solaris' os::sleep with the bsd variation.
2562 // Solaris uses poll(), bsd uses park().
2563 // Poll() is likely a better choice, assuming that Thread.interrupt()
2564 // generates a SIGUSRx signal. Note that SIGUSR1 can interfere with
2565 // SIGSEGV, see 4355769.
2567 int os::sleep(Thread* thread, jlong millis, bool interruptible) {
2568 assert(thread == Thread::current(), "thread consistency check");
2570 ParkEvent * const slp = thread->_SleepEvent ;
2571 slp->reset() ;
2572 OrderAccess::fence() ;
2574 if (interruptible) {
2575 jlong prevtime = javaTimeNanos();
2577 for (;;) {
2578 if (os::is_interrupted(thread, true)) {
2579 return OS_INTRPT;
2580 }
2582 jlong newtime = javaTimeNanos();
2584 if (newtime - prevtime < 0) {
2585 // time moving backwards, should only happen if no monotonic clock
2586 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2587 assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2588 } else {
2589 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2590 }
2592 if(millis <= 0) {
2593 return OS_OK;
2594 }
2596 prevtime = newtime;
2598 {
2599 assert(thread->is_Java_thread(), "sanity check");
2600 JavaThread *jt = (JavaThread *) thread;
2601 ThreadBlockInVM tbivm(jt);
2602 OSThreadWaitState osts(jt->osthread(), false /* not Object.wait() */);
2604 jt->set_suspend_equivalent();
2605 // cleared by handle_special_suspend_equivalent_condition() or
2606 // java_suspend_self() via check_and_wait_while_suspended()
2608 slp->park(millis);
2610 // were we externally suspended while we were waiting?
2611 jt->check_and_wait_while_suspended();
2612 }
2613 }
2614 } else {
2615 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
2616 jlong prevtime = javaTimeNanos();
2618 for (;;) {
2619 // It'd be nice to avoid the back-to-back javaTimeNanos() calls on
2620 // the 1st iteration ...
2621 jlong newtime = javaTimeNanos();
2623 if (newtime - prevtime < 0) {
2624 // time moving backwards, should only happen if no monotonic clock
2625 // not a guarantee() because JVM should not abort on kernel/glibc bugs
2626 assert(!Bsd::supports_monotonic_clock(), "time moving backwards");
2627 } else {
2628 millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
2629 }
2631 if(millis <= 0) break ;
2633 prevtime = newtime;
2634 slp->park(millis);
2635 }
2636 return OS_OK ;
2637 }
2638 }
2640 void os::naked_short_sleep(jlong ms) {
2641 struct timespec req;
2643 assert(ms < 1000, "Un-interruptable sleep, short time use only");
2644 req.tv_sec = 0;
2645 if (ms > 0) {
2646 req.tv_nsec = (ms % 1000) * 1000000;
2647 }
2648 else {
2649 req.tv_nsec = 1;
2650 }
2652 nanosleep(&req, NULL);
2654 return;
2655 }
2657 // Sleep forever; naked call to OS-specific sleep; use with CAUTION
2658 void os::infinite_sleep() {
2659 while (true) { // sleep forever ...
2660 ::sleep(100); // ... 100 seconds at a time
2661 }
2662 }
2664 // Used to convert frequent JVM_Yield() to nops
2665 bool os::dont_yield() {
2666 return DontYieldALot;
2667 }
2669 void os::yield() {
2670 sched_yield();
2671 }
2673 os::YieldResult os::NakedYield() { sched_yield(); return os::YIELD_UNKNOWN ;}
2675 void os::yield_all(int attempts) {
2676 // Yields to all threads, including threads with lower priorities
2677 // Threads on Bsd are all with same priority. The Solaris style
2678 // os::yield_all() with nanosleep(1ms) is not necessary.
2679 sched_yield();
2680 }
2682 // Called from the tight loops to possibly influence time-sharing heuristics
2683 void os::loop_breaker(int attempts) {
2684 os::yield_all(attempts);
2685 }
2687 ////////////////////////////////////////////////////////////////////////////////
2688 // thread priority support
2690 // Note: Normal Bsd applications are run with SCHED_OTHER policy. SCHED_OTHER
2691 // only supports dynamic priority, static priority must be zero. For real-time
2692 // applications, Bsd supports SCHED_RR which allows static priority (1-99).
2693 // However, for large multi-threaded applications, SCHED_RR is not only slower
2694 // than SCHED_OTHER, but also very unstable (my volano tests hang hard 4 out
2695 // of 5 runs - Sep 2005).
2696 //
2697 // The following code actually changes the niceness of kernel-thread/LWP. It
2698 // has an assumption that setpriority() only modifies one kernel-thread/LWP,
2699 // not the entire user process, and user level threads are 1:1 mapped to kernel
2700 // threads. It has always been the case, but could change in the future. For
2701 // this reason, the code should not be used as default (ThreadPriorityPolicy=0).
2702 // It is only used when ThreadPriorityPolicy=1 and requires root privilege.
2704 #if !defined(__APPLE__)
2705 int os::java_to_os_priority[CriticalPriority + 1] = {
2706 19, // 0 Entry should never be used
2708 0, // 1 MinPriority
2709 3, // 2
2710 6, // 3
2712 10, // 4
2713 15, // 5 NormPriority
2714 18, // 6
2716 21, // 7
2717 25, // 8
2718 28, // 9 NearMaxPriority
2720 31, // 10 MaxPriority
2722 31 // 11 CriticalPriority
2723 };
2724 #else
2725 /* Using Mach high-level priority assignments */
2726 int os::java_to_os_priority[CriticalPriority + 1] = {
2727 0, // 0 Entry should never be used (MINPRI_USER)
2729 27, // 1 MinPriority
2730 28, // 2
2731 29, // 3
2733 30, // 4
2734 31, // 5 NormPriority (BASEPRI_DEFAULT)
2735 32, // 6
2737 33, // 7
2738 34, // 8
2739 35, // 9 NearMaxPriority
2741 36, // 10 MaxPriority
2743 36 // 11 CriticalPriority
2744 };
2745 #endif
2747 static int prio_init() {
2748 if (ThreadPriorityPolicy == 1) {
2749 // Only root can raise thread priority. Don't allow ThreadPriorityPolicy=1
2750 // if effective uid is not root. Perhaps, a more elegant way of doing
2751 // this is to test CAP_SYS_NICE capability, but that will require libcap.so
2752 if (geteuid() != 0) {
2753 if (!FLAG_IS_DEFAULT(ThreadPriorityPolicy)) {
2754 warning("-XX:ThreadPriorityPolicy requires root privilege on Bsd");
2755 }
2756 ThreadPriorityPolicy = 0;
2757 }
2758 }
2759 if (UseCriticalJavaThreadPriority) {
2760 os::java_to_os_priority[MaxPriority] = os::java_to_os_priority[CriticalPriority];
2761 }
2762 return 0;
2763 }
2765 OSReturn os::set_native_priority(Thread* thread, int newpri) {
2766 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) return OS_OK;
2768 #ifdef __OpenBSD__
2769 // OpenBSD pthread_setprio starves low priority threads
2770 return OS_OK;
2771 #elif defined(__FreeBSD__)
2772 int ret = pthread_setprio(thread->osthread()->pthread_id(), newpri);
2773 #elif defined(__APPLE__) || defined(__NetBSD__)
2774 struct sched_param sp;
2775 int policy;
2776 pthread_t self = pthread_self();
2778 if (pthread_getschedparam(self, &policy, &sp) != 0)
2779 return OS_ERR;
2781 sp.sched_priority = newpri;
2782 if (pthread_setschedparam(self, policy, &sp) != 0)
2783 return OS_ERR;
2785 return OS_OK;
2786 #else
2787 int ret = setpriority(PRIO_PROCESS, thread->osthread()->thread_id(), newpri);
2788 return (ret == 0) ? OS_OK : OS_ERR;
2789 #endif
2790 }
2792 OSReturn os::get_native_priority(const Thread* const thread, int *priority_ptr) {
2793 if ( !UseThreadPriorities || ThreadPriorityPolicy == 0 ) {
2794 *priority_ptr = java_to_os_priority[NormPriority];
2795 return OS_OK;
2796 }
2798 errno = 0;
2799 #if defined(__OpenBSD__) || defined(__FreeBSD__)
2800 *priority_ptr = pthread_getprio(thread->osthread()->pthread_id());
2801 #elif defined(__APPLE__) || defined(__NetBSD__)
2802 int policy;
2803 struct sched_param sp;
2805 pthread_getschedparam(pthread_self(), &policy, &sp);
2806 *priority_ptr = sp.sched_priority;
2807 #else
2808 *priority_ptr = getpriority(PRIO_PROCESS, thread->osthread()->thread_id());
2809 #endif
2810 return (*priority_ptr != -1 || errno == 0 ? OS_OK : OS_ERR);
2811 }
2813 // Hint to the underlying OS that a task switch would not be good.
2814 // Void return because it's a hint and can fail.
2815 void os::hint_no_preempt() {}
2817 ////////////////////////////////////////////////////////////////////////////////
2818 // suspend/resume support
2820 // the low-level signal-based suspend/resume support is a remnant from the
2821 // old VM-suspension that used to be for java-suspension, safepoints etc,
2822 // within hotspot. Now there is a single use-case for this:
2823 // - calling get_thread_pc() on the VMThread by the flat-profiler task
2824 // that runs in the watcher thread.
2825 // The remaining code is greatly simplified from the more general suspension
2826 // code that used to be used.
2827 //
2828 // The protocol is quite simple:
2829 // - suspend:
2830 // - sends a signal to the target thread
2831 // - polls the suspend state of the osthread using a yield loop
2832 // - target thread signal handler (SR_handler) sets suspend state
2833 // and blocks in sigsuspend until continued
2834 // - resume:
2835 // - sets target osthread state to continue
2836 // - sends signal to end the sigsuspend loop in the SR_handler
2837 //
2838 // Note that the SR_lock plays no role in this suspend/resume protocol.
2839 //
2841 static void resume_clear_context(OSThread *osthread) {
2842 osthread->set_ucontext(NULL);
2843 osthread->set_siginfo(NULL);
2844 }
2846 static void suspend_save_context(OSThread *osthread, siginfo_t* siginfo, ucontext_t* context) {
2847 osthread->set_ucontext(context);
2848 osthread->set_siginfo(siginfo);
2849 }
2851 //
2852 // Handler function invoked when a thread's execution is suspended or
2853 // resumed. We have to be careful that only async-safe functions are
2854 // called here (Note: most pthread functions are not async safe and
2855 // should be avoided.)
2856 //
2857 // Note: sigwait() is a more natural fit than sigsuspend() from an
2858 // interface point of view, but sigwait() prevents the signal hander
2859 // from being run. libpthread would get very confused by not having
2860 // its signal handlers run and prevents sigwait()'s use with the
2861 // mutex granting granting signal.
2862 //
2863 // Currently only ever called on the VMThread or JavaThread
2864 //
2865 static void SR_handler(int sig, siginfo_t* siginfo, ucontext_t* context) {
2866 // Save and restore errno to avoid confusing native code with EINTR
2867 // after sigsuspend.
2868 int old_errno = errno;
2870 Thread* thread = Thread::current();
2871 OSThread* osthread = thread->osthread();
2872 assert(thread->is_VM_thread() || thread->is_Java_thread(), "Must be VMThread or JavaThread");
2874 os::SuspendResume::State current = osthread->sr.state();
2875 if (current == os::SuspendResume::SR_SUSPEND_REQUEST) {
2876 suspend_save_context(osthread, siginfo, context);
2878 // attempt to switch the state, we assume we had a SUSPEND_REQUEST
2879 os::SuspendResume::State state = osthread->sr.suspended();
2880 if (state == os::SuspendResume::SR_SUSPENDED) {
2881 sigset_t suspend_set; // signals for sigsuspend()
2883 // get current set of blocked signals and unblock resume signal
2884 pthread_sigmask(SIG_BLOCK, NULL, &suspend_set);
2885 sigdelset(&suspend_set, SR_signum);
2887 sr_semaphore.signal();
2888 // wait here until we are resumed
2889 while (1) {
2890 sigsuspend(&suspend_set);
2892 os::SuspendResume::State result = osthread->sr.running();
2893 if (result == os::SuspendResume::SR_RUNNING) {
2894 sr_semaphore.signal();
2895 break;
2896 } else if (result != os::SuspendResume::SR_SUSPENDED) {
2897 ShouldNotReachHere();
2898 }
2899 }
2901 } else if (state == os::SuspendResume::SR_RUNNING) {
2902 // request was cancelled, continue
2903 } else {
2904 ShouldNotReachHere();
2905 }
2907 resume_clear_context(osthread);
2908 } else if (current == os::SuspendResume::SR_RUNNING) {
2909 // request was cancelled, continue
2910 } else if (current == os::SuspendResume::SR_WAKEUP_REQUEST) {
2911 // ignore
2912 } else {
2913 // ignore
2914 }
2916 errno = old_errno;
2917 }
2920 static int SR_initialize() {
2921 struct sigaction act;
2922 char *s;
2923 /* Get signal number to use for suspend/resume */
2924 if ((s = ::getenv("_JAVA_SR_SIGNUM")) != 0) {
2925 int sig = ::strtol(s, 0, 10);
2926 if (sig > 0 || sig < NSIG) {
2927 SR_signum = sig;
2928 }
2929 }
2931 assert(SR_signum > SIGSEGV && SR_signum > SIGBUS,
2932 "SR_signum must be greater than max(SIGSEGV, SIGBUS), see 4355769");
2934 sigemptyset(&SR_sigset);
2935 sigaddset(&SR_sigset, SR_signum);
2937 /* Set up signal handler for suspend/resume */
2938 act.sa_flags = SA_RESTART|SA_SIGINFO;
2939 act.sa_handler = (void (*)(int)) SR_handler;
2941 // SR_signum is blocked by default.
2942 // 4528190 - We also need to block pthread restart signal (32 on all
2943 // supported Bsd platforms). Note that BsdThreads need to block
2944 // this signal for all threads to work properly. So we don't have
2945 // to use hard-coded signal number when setting up the mask.
2946 pthread_sigmask(SIG_BLOCK, NULL, &act.sa_mask);
2948 if (sigaction(SR_signum, &act, 0) == -1) {
2949 return -1;
2950 }
2952 // Save signal flag
2953 os::Bsd::set_our_sigflags(SR_signum, act.sa_flags);
2954 return 0;
2955 }
2957 static int sr_notify(OSThread* osthread) {
2958 int status = pthread_kill(osthread->pthread_id(), SR_signum);
2959 assert_status(status == 0, status, "pthread_kill");
2960 return status;
2961 }
2963 // "Randomly" selected value for how long we want to spin
2964 // before bailing out on suspending a thread, also how often
2965 // we send a signal to a thread we want to resume
2966 static const int RANDOMLY_LARGE_INTEGER = 1000000;
2967 static const int RANDOMLY_LARGE_INTEGER2 = 100;
2969 // returns true on success and false on error - really an error is fatal
2970 // but this seems the normal response to library errors
2971 static bool do_suspend(OSThread* osthread) {
2972 assert(osthread->sr.is_running(), "thread should be running");
2973 assert(!sr_semaphore.trywait(), "semaphore has invalid state");
2975 // mark as suspended and send signal
2976 if (osthread->sr.request_suspend() != os::SuspendResume::SR_SUSPEND_REQUEST) {
2977 // failed to switch, state wasn't running?
2978 ShouldNotReachHere();
2979 return false;
2980 }
2982 if (sr_notify(osthread) != 0) {
2983 ShouldNotReachHere();
2984 }
2986 // managed to send the signal and switch to SUSPEND_REQUEST, now wait for SUSPENDED
2987 while (true) {
2988 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
2989 break;
2990 } else {
2991 // timeout
2992 os::SuspendResume::State cancelled = osthread->sr.cancel_suspend();
2993 if (cancelled == os::SuspendResume::SR_RUNNING) {
2994 return false;
2995 } else if (cancelled == os::SuspendResume::SR_SUSPENDED) {
2996 // make sure that we consume the signal on the semaphore as well
2997 sr_semaphore.wait();
2998 break;
2999 } else {
3000 ShouldNotReachHere();
3001 return false;
3002 }
3003 }
3004 }
3006 guarantee(osthread->sr.is_suspended(), "Must be suspended");
3007 return true;
3008 }
3010 static void do_resume(OSThread* osthread) {
3011 assert(osthread->sr.is_suspended(), "thread should be suspended");
3012 assert(!sr_semaphore.trywait(), "invalid semaphore state");
3014 if (osthread->sr.request_wakeup() != os::SuspendResume::SR_WAKEUP_REQUEST) {
3015 // failed to switch to WAKEUP_REQUEST
3016 ShouldNotReachHere();
3017 return;
3018 }
3020 while (true) {
3021 if (sr_notify(osthread) == 0) {
3022 if (sr_semaphore.timedwait(0, 2 * NANOSECS_PER_MILLISEC)) {
3023 if (osthread->sr.is_running()) {
3024 return;
3025 }
3026 }
3027 } else {
3028 ShouldNotReachHere();
3029 }
3030 }
3032 guarantee(osthread->sr.is_running(), "Must be running!");
3033 }
3035 ////////////////////////////////////////////////////////////////////////////////
3036 // interrupt support
3038 void os::interrupt(Thread* thread) {
3039 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
3040 "possibility of dangling Thread pointer");
3042 OSThread* osthread = thread->osthread();
3044 if (!osthread->interrupted()) {
3045 osthread->set_interrupted(true);
3046 // More than one thread can get here with the same value of osthread,
3047 // resulting in multiple notifications. We do, however, want the store
3048 // to interrupted() to be visible to other threads before we execute unpark().
3049 OrderAccess::fence();
3050 ParkEvent * const slp = thread->_SleepEvent ;
3051 if (slp != NULL) slp->unpark() ;
3052 }
3054 // For JSR166. Unpark even if interrupt status already was set
3055 if (thread->is_Java_thread())
3056 ((JavaThread*)thread)->parker()->unpark();
3058 ParkEvent * ev = thread->_ParkEvent ;
3059 if (ev != NULL) ev->unpark() ;
3061 }
3063 bool os::is_interrupted(Thread* thread, bool clear_interrupted) {
3064 assert(Thread::current() == thread || Threads_lock->owned_by_self(),
3065 "possibility of dangling Thread pointer");
3067 OSThread* osthread = thread->osthread();
3069 bool interrupted = osthread->interrupted();
3071 if (interrupted && clear_interrupted) {
3072 osthread->set_interrupted(false);
3073 // consider thread->_SleepEvent->reset() ... optional optimization
3074 }
3076 return interrupted;
3077 }
3079 ///////////////////////////////////////////////////////////////////////////////////
3080 // signal handling (except suspend/resume)
3082 // This routine may be used by user applications as a "hook" to catch signals.
3083 // The user-defined signal handler must pass unrecognized signals to this
3084 // routine, and if it returns true (non-zero), then the signal handler must
3085 // return immediately. If the flag "abort_if_unrecognized" is true, then this
3086 // routine will never retun false (zero), but instead will execute a VM panic
3087 // routine kill the process.
3088 //
3089 // If this routine returns false, it is OK to call it again. This allows
3090 // the user-defined signal handler to perform checks either before or after
3091 // the VM performs its own checks. Naturally, the user code would be making
3092 // a serious error if it tried to handle an exception (such as a null check
3093 // or breakpoint) that the VM was generating for its own correct operation.
3094 //
3095 // This routine may recognize any of the following kinds of signals:
3096 // SIGBUS, SIGSEGV, SIGILL, SIGFPE, SIGQUIT, SIGPIPE, SIGXFSZ, SIGUSR1.
3097 // It should be consulted by handlers for any of those signals.
3098 //
3099 // The caller of this routine must pass in the three arguments supplied
3100 // to the function referred to in the "sa_sigaction" (not the "sa_handler")
3101 // field of the structure passed to sigaction(). This routine assumes that
3102 // the sa_flags field passed to sigaction() includes SA_SIGINFO and SA_RESTART.
3103 //
3104 // Note that the VM will print warnings if it detects conflicting signal
3105 // handlers, unless invoked with the option "-XX:+AllowUserSignalHandlers".
3106 //
3107 extern "C" JNIEXPORT int
3108 JVM_handle_bsd_signal(int signo, siginfo_t* siginfo,
3109 void* ucontext, int abort_if_unrecognized);
3111 void signalHandler(int sig, siginfo_t* info, void* uc) {
3112 assert(info != NULL && uc != NULL, "it must be old kernel");
3113 int orig_errno = errno; // Preserve errno value over signal handler.
3114 JVM_handle_bsd_signal(sig, info, uc, true);
3115 errno = orig_errno;
3116 }
3119 // This boolean allows users to forward their own non-matching signals
3120 // to JVM_handle_bsd_signal, harmlessly.
3121 bool os::Bsd::signal_handlers_are_installed = false;
3123 // For signal-chaining
3124 struct sigaction os::Bsd::sigact[MAXSIGNUM];
3125 unsigned int os::Bsd::sigs = 0;
3126 bool os::Bsd::libjsig_is_loaded = false;
3127 typedef struct sigaction *(*get_signal_t)(int);
3128 get_signal_t os::Bsd::get_signal_action = NULL;
3130 struct sigaction* os::Bsd::get_chained_signal_action(int sig) {
3131 struct sigaction *actp = NULL;
3133 if (libjsig_is_loaded) {
3134 // Retrieve the old signal handler from libjsig
3135 actp = (*get_signal_action)(sig);
3136 }
3137 if (actp == NULL) {
3138 // Retrieve the preinstalled signal handler from jvm
3139 actp = get_preinstalled_handler(sig);
3140 }
3142 return actp;
3143 }
3145 static bool call_chained_handler(struct sigaction *actp, int sig,
3146 siginfo_t *siginfo, void *context) {
3147 // Call the old signal handler
3148 if (actp->sa_handler == SIG_DFL) {
3149 // It's more reasonable to let jvm treat it as an unexpected exception
3150 // instead of taking the default action.
3151 return false;
3152 } else if (actp->sa_handler != SIG_IGN) {
3153 if ((actp->sa_flags & SA_NODEFER) == 0) {
3154 // automaticlly block the signal
3155 sigaddset(&(actp->sa_mask), sig);
3156 }
3158 sa_handler_t hand;
3159 sa_sigaction_t sa;
3160 bool siginfo_flag_set = (actp->sa_flags & SA_SIGINFO) != 0;
3161 // retrieve the chained handler
3162 if (siginfo_flag_set) {
3163 sa = actp->sa_sigaction;
3164 } else {
3165 hand = actp->sa_handler;
3166 }
3168 if ((actp->sa_flags & SA_RESETHAND) != 0) {
3169 actp->sa_handler = SIG_DFL;
3170 }
3172 // try to honor the signal mask
3173 sigset_t oset;
3174 pthread_sigmask(SIG_SETMASK, &(actp->sa_mask), &oset);
3176 // call into the chained handler
3177 if (siginfo_flag_set) {
3178 (*sa)(sig, siginfo, context);
3179 } else {
3180 (*hand)(sig);
3181 }
3183 // restore the signal mask
3184 pthread_sigmask(SIG_SETMASK, &oset, 0);
3185 }
3186 // Tell jvm's signal handler the signal is taken care of.
3187 return true;
3188 }
3190 bool os::Bsd::chained_handler(int sig, siginfo_t* siginfo, void* context) {
3191 bool chained = false;
3192 // signal-chaining
3193 if (UseSignalChaining) {
3194 struct sigaction *actp = get_chained_signal_action(sig);
3195 if (actp != NULL) {
3196 chained = call_chained_handler(actp, sig, siginfo, context);
3197 }
3198 }
3199 return chained;
3200 }
3202 struct sigaction* os::Bsd::get_preinstalled_handler(int sig) {
3203 if ((( (unsigned int)1 << sig ) & sigs) != 0) {
3204 return &sigact[sig];
3205 }
3206 return NULL;
3207 }
3209 void os::Bsd::save_preinstalled_handler(int sig, struct sigaction& oldAct) {
3210 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3211 sigact[sig] = oldAct;
3212 sigs |= (unsigned int)1 << sig;
3213 }
3215 // for diagnostic
3216 int os::Bsd::sigflags[MAXSIGNUM];
3218 int os::Bsd::get_our_sigflags(int sig) {
3219 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3220 return sigflags[sig];
3221 }
3223 void os::Bsd::set_our_sigflags(int sig, int flags) {
3224 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3225 sigflags[sig] = flags;
3226 }
3228 void os::Bsd::set_signal_handler(int sig, bool set_installed) {
3229 // Check for overwrite.
3230 struct sigaction oldAct;
3231 sigaction(sig, (struct sigaction*)NULL, &oldAct);
3233 void* oldhand = oldAct.sa_sigaction
3234 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3235 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3236 if (oldhand != CAST_FROM_FN_PTR(void*, SIG_DFL) &&
3237 oldhand != CAST_FROM_FN_PTR(void*, SIG_IGN) &&
3238 oldhand != CAST_FROM_FN_PTR(void*, (sa_sigaction_t)signalHandler)) {
3239 if (AllowUserSignalHandlers || !set_installed) {
3240 // Do not overwrite; user takes responsibility to forward to us.
3241 return;
3242 } else if (UseSignalChaining) {
3243 // save the old handler in jvm
3244 save_preinstalled_handler(sig, oldAct);
3245 // libjsig also interposes the sigaction() call below and saves the
3246 // old sigaction on it own.
3247 } else {
3248 fatal(err_msg("Encountered unexpected pre-existing sigaction handler "
3249 "%#lx for signal %d.", (long)oldhand, sig));
3250 }
3251 }
3253 struct sigaction sigAct;
3254 sigfillset(&(sigAct.sa_mask));
3255 sigAct.sa_handler = SIG_DFL;
3256 if (!set_installed) {
3257 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3258 } else {
3259 sigAct.sa_sigaction = signalHandler;
3260 sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
3261 }
3262 #ifdef __APPLE__
3263 // Needed for main thread as XNU (Mac OS X kernel) will only deliver SIGSEGV
3264 // (which starts as SIGBUS) on main thread with faulting address inside "stack+guard pages"
3265 // if the signal handler declares it will handle it on alternate stack.
3266 // Notice we only declare we will handle it on alt stack, but we are not
3267 // actually going to use real alt stack - this is just a workaround.
3268 // Please see ux_exception.c, method catch_mach_exception_raise for details
3269 // link http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/uxkern/ux_exception.c
3270 if (sig == SIGSEGV) {
3271 sigAct.sa_flags |= SA_ONSTACK;
3272 }
3273 #endif
3275 // Save flags, which are set by ours
3276 assert(sig > 0 && sig < MAXSIGNUM, "vm signal out of expected range");
3277 sigflags[sig] = sigAct.sa_flags;
3279 int ret = sigaction(sig, &sigAct, &oldAct);
3280 assert(ret == 0, "check");
3282 void* oldhand2 = oldAct.sa_sigaction
3283 ? CAST_FROM_FN_PTR(void*, oldAct.sa_sigaction)
3284 : CAST_FROM_FN_PTR(void*, oldAct.sa_handler);
3285 assert(oldhand2 == oldhand, "no concurrent signal handler installation");
3286 }
3288 // install signal handlers for signals that HotSpot needs to
3289 // handle in order to support Java-level exception handling.
3291 void os::Bsd::install_signal_handlers() {
3292 if (!signal_handlers_are_installed) {
3293 signal_handlers_are_installed = true;
3295 // signal-chaining
3296 typedef void (*signal_setting_t)();
3297 signal_setting_t begin_signal_setting = NULL;
3298 signal_setting_t end_signal_setting = NULL;
3299 begin_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3300 dlsym(RTLD_DEFAULT, "JVM_begin_signal_setting"));
3301 if (begin_signal_setting != NULL) {
3302 end_signal_setting = CAST_TO_FN_PTR(signal_setting_t,
3303 dlsym(RTLD_DEFAULT, "JVM_end_signal_setting"));
3304 get_signal_action = CAST_TO_FN_PTR(get_signal_t,
3305 dlsym(RTLD_DEFAULT, "JVM_get_signal_action"));
3306 libjsig_is_loaded = true;
3307 assert(UseSignalChaining, "should enable signal-chaining");
3308 }
3309 if (libjsig_is_loaded) {
3310 // Tell libjsig jvm is setting signal handlers
3311 (*begin_signal_setting)();
3312 }
3314 set_signal_handler(SIGSEGV, true);
3315 set_signal_handler(SIGPIPE, true);
3316 set_signal_handler(SIGBUS, true);
3317 set_signal_handler(SIGILL, true);
3318 set_signal_handler(SIGFPE, true);
3319 set_signal_handler(SIGXFSZ, true);
3321 #if defined(__APPLE__)
3322 // In Mac OS X 10.4, CrashReporter will write a crash log for all 'fatal' signals, including
3323 // signals caught and handled by the JVM. To work around this, we reset the mach task
3324 // signal handler that's placed on our process by CrashReporter. This disables
3325 // CrashReporter-based reporting.
3326 //
3327 // This work-around is not necessary for 10.5+, as CrashReporter no longer intercedes
3328 // on caught fatal signals.
3329 //
3330 // Additionally, gdb installs both standard BSD signal handlers, and mach exception
3331 // handlers. By replacing the existing task exception handler, we disable gdb's mach
3332 // exception handling, while leaving the standard BSD signal handlers functional.
3333 kern_return_t kr;
3334 kr = task_set_exception_ports(mach_task_self(),
3335 EXC_MASK_BAD_ACCESS | EXC_MASK_ARITHMETIC,
3336 MACH_PORT_NULL,
3337 EXCEPTION_STATE_IDENTITY,
3338 MACHINE_THREAD_STATE);
3340 assert(kr == KERN_SUCCESS, "could not set mach task signal handler");
3341 #endif
3343 if (libjsig_is_loaded) {
3344 // Tell libjsig jvm finishes setting signal handlers
3345 (*end_signal_setting)();
3346 }
3348 // We don't activate signal checker if libjsig is in place, we trust ourselves
3349 // and if UserSignalHandler is installed all bets are off
3350 if (CheckJNICalls) {
3351 if (libjsig_is_loaded) {
3352 if (PrintJNIResolving) {
3353 tty->print_cr("Info: libjsig is activated, all active signal checking is disabled");
3354 }
3355 check_signals = false;
3356 }
3357 if (AllowUserSignalHandlers) {
3358 if (PrintJNIResolving) {
3359 tty->print_cr("Info: AllowUserSignalHandlers is activated, all active signal checking is disabled");
3360 }
3361 check_signals = false;
3362 }
3363 }
3364 }
3365 }
3368 /////
3369 // glibc on Bsd platform uses non-documented flag
3370 // to indicate, that some special sort of signal
3371 // trampoline is used.
3372 // We will never set this flag, and we should
3373 // ignore this flag in our diagnostic
3374 #ifdef SIGNIFICANT_SIGNAL_MASK
3375 #undef SIGNIFICANT_SIGNAL_MASK
3376 #endif
3377 #define SIGNIFICANT_SIGNAL_MASK (~0x04000000)
3379 static const char* get_signal_handler_name(address handler,
3380 char* buf, int buflen) {
3381 int offset;
3382 bool found = os::dll_address_to_library_name(handler, buf, buflen, &offset);
3383 if (found) {
3384 // skip directory names
3385 const char *p1, *p2;
3386 p1 = buf;
3387 size_t len = strlen(os::file_separator());
3388 while ((p2 = strstr(p1, os::file_separator())) != NULL) p1 = p2 + len;
3389 jio_snprintf(buf, buflen, "%s+0x%x", p1, offset);
3390 } else {
3391 jio_snprintf(buf, buflen, PTR_FORMAT, handler);
3392 }
3393 return buf;
3394 }
3396 static void print_signal_handler(outputStream* st, int sig,
3397 char* buf, size_t buflen) {
3398 struct sigaction sa;
3400 sigaction(sig, NULL, &sa);
3402 // See comment for SIGNIFICANT_SIGNAL_MASK define
3403 sa.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3405 st->print("%s: ", os::exception_name(sig, buf, buflen));
3407 address handler = (sa.sa_flags & SA_SIGINFO)
3408 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
3409 : CAST_FROM_FN_PTR(address, sa.sa_handler);
3411 if (handler == CAST_FROM_FN_PTR(address, SIG_DFL)) {
3412 st->print("SIG_DFL");
3413 } else if (handler == CAST_FROM_FN_PTR(address, SIG_IGN)) {
3414 st->print("SIG_IGN");
3415 } else {
3416 st->print("[%s]", get_signal_handler_name(handler, buf, buflen));
3417 }
3419 st->print(", sa_mask[0]=");
3420 os::Posix::print_signal_set_short(st, &sa.sa_mask);
3422 address rh = VMError::get_resetted_sighandler(sig);
3423 // May be, handler was resetted by VMError?
3424 if(rh != NULL) {
3425 handler = rh;
3426 sa.sa_flags = VMError::get_resetted_sigflags(sig) & SIGNIFICANT_SIGNAL_MASK;
3427 }
3429 st->print(", sa_flags=");
3430 os::Posix::print_sa_flags(st, sa.sa_flags);
3432 // Check: is it our handler?
3433 if(handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler) ||
3434 handler == CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler)) {
3435 // It is our signal handler
3436 // check for flags, reset system-used one!
3437 if((int)sa.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3438 st->print(
3439 ", flags was changed from " PTR32_FORMAT ", consider using jsig library",
3440 os::Bsd::get_our_sigflags(sig));
3441 }
3442 }
3443 st->cr();
3444 }
3447 #define DO_SIGNAL_CHECK(sig) \
3448 if (!sigismember(&check_signal_done, sig)) \
3449 os::Bsd::check_signal_handler(sig)
3451 // This method is a periodic task to check for misbehaving JNI applications
3452 // under CheckJNI, we can add any periodic checks here
3454 void os::run_periodic_checks() {
3456 if (check_signals == false) return;
3458 // SEGV and BUS if overridden could potentially prevent
3459 // generation of hs*.log in the event of a crash, debugging
3460 // such a case can be very challenging, so we absolutely
3461 // check the following for a good measure:
3462 DO_SIGNAL_CHECK(SIGSEGV);
3463 DO_SIGNAL_CHECK(SIGILL);
3464 DO_SIGNAL_CHECK(SIGFPE);
3465 DO_SIGNAL_CHECK(SIGBUS);
3466 DO_SIGNAL_CHECK(SIGPIPE);
3467 DO_SIGNAL_CHECK(SIGXFSZ);
3470 // ReduceSignalUsage allows the user to override these handlers
3471 // see comments at the very top and jvm_solaris.h
3472 if (!ReduceSignalUsage) {
3473 DO_SIGNAL_CHECK(SHUTDOWN1_SIGNAL);
3474 DO_SIGNAL_CHECK(SHUTDOWN2_SIGNAL);
3475 DO_SIGNAL_CHECK(SHUTDOWN3_SIGNAL);
3476 DO_SIGNAL_CHECK(BREAK_SIGNAL);
3477 }
3479 DO_SIGNAL_CHECK(SR_signum);
3480 DO_SIGNAL_CHECK(INTERRUPT_SIGNAL);
3481 }
3483 typedef int (*os_sigaction_t)(int, const struct sigaction *, struct sigaction *);
3485 static os_sigaction_t os_sigaction = NULL;
3487 void os::Bsd::check_signal_handler(int sig) {
3488 char buf[O_BUFLEN];
3489 address jvmHandler = NULL;
3492 struct sigaction act;
3493 if (os_sigaction == NULL) {
3494 // only trust the default sigaction, in case it has been interposed
3495 os_sigaction = (os_sigaction_t)dlsym(RTLD_DEFAULT, "sigaction");
3496 if (os_sigaction == NULL) return;
3497 }
3499 os_sigaction(sig, (struct sigaction*)NULL, &act);
3502 act.sa_flags &= SIGNIFICANT_SIGNAL_MASK;
3504 address thisHandler = (act.sa_flags & SA_SIGINFO)
3505 ? CAST_FROM_FN_PTR(address, act.sa_sigaction)
3506 : CAST_FROM_FN_PTR(address, act.sa_handler) ;
3509 switch(sig) {
3510 case SIGSEGV:
3511 case SIGBUS:
3512 case SIGFPE:
3513 case SIGPIPE:
3514 case SIGILL:
3515 case SIGXFSZ:
3516 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)signalHandler);
3517 break;
3519 case SHUTDOWN1_SIGNAL:
3520 case SHUTDOWN2_SIGNAL:
3521 case SHUTDOWN3_SIGNAL:
3522 case BREAK_SIGNAL:
3523 jvmHandler = (address)user_handler();
3524 break;
3526 case INTERRUPT_SIGNAL:
3527 jvmHandler = CAST_FROM_FN_PTR(address, SIG_DFL);
3528 break;
3530 default:
3531 if (sig == SR_signum) {
3532 jvmHandler = CAST_FROM_FN_PTR(address, (sa_sigaction_t)SR_handler);
3533 } else {
3534 return;
3535 }
3536 break;
3537 }
3539 if (thisHandler != jvmHandler) {
3540 tty->print("Warning: %s handler ", exception_name(sig, buf, O_BUFLEN));
3541 tty->print("expected:%s", get_signal_handler_name(jvmHandler, buf, O_BUFLEN));
3542 tty->print_cr(" found:%s", get_signal_handler_name(thisHandler, buf, O_BUFLEN));
3543 // No need to check this sig any longer
3544 sigaddset(&check_signal_done, sig);
3545 } else if(os::Bsd::get_our_sigflags(sig) != 0 && (int)act.sa_flags != os::Bsd::get_our_sigflags(sig)) {
3546 tty->print("Warning: %s handler flags ", exception_name(sig, buf, O_BUFLEN));
3547 tty->print("expected:" PTR32_FORMAT, os::Bsd::get_our_sigflags(sig));
3548 tty->print_cr(" found:" PTR32_FORMAT, act.sa_flags);
3549 // No need to check this sig any longer
3550 sigaddset(&check_signal_done, sig);
3551 }
3553 // Dump all the signal
3554 if (sigismember(&check_signal_done, sig)) {
3555 print_signal_handlers(tty, buf, O_BUFLEN);
3556 }
3557 }
3559 extern void report_error(char* file_name, int line_no, char* title, char* format, ...);
3561 extern bool signal_name(int signo, char* buf, size_t len);
3563 const char* os::exception_name(int exception_code, char* buf, size_t size) {
3564 if (0 < exception_code && exception_code <= SIGRTMAX) {
3565 // signal
3566 if (!signal_name(exception_code, buf, size)) {
3567 jio_snprintf(buf, size, "SIG%d", exception_code);
3568 }
3569 return buf;
3570 } else {
3571 return NULL;
3572 }
3573 }
3575 // this is called _before_ the most of global arguments have been parsed
3576 void os::init(void) {
3577 char dummy; /* used to get a guess on initial stack address */
3578 // first_hrtime = gethrtime();
3580 // With BsdThreads the JavaMain thread pid (primordial thread)
3581 // is different than the pid of the java launcher thread.
3582 // So, on Bsd, the launcher thread pid is passed to the VM
3583 // via the sun.java.launcher.pid property.
3584 // Use this property instead of getpid() if it was correctly passed.
3585 // See bug 6351349.
3586 pid_t java_launcher_pid = (pid_t) Arguments::sun_java_launcher_pid();
3588 _initial_pid = (java_launcher_pid > 0) ? java_launcher_pid : getpid();
3590 clock_tics_per_sec = CLK_TCK;
3592 init_random(1234567);
3594 ThreadCritical::initialize();
3596 Bsd::set_page_size(getpagesize());
3597 if (Bsd::page_size() == -1) {
3598 fatal(err_msg("os_bsd.cpp: os::init: sysconf failed (%s)",
3599 strerror(errno)));
3600 }
3601 init_page_sizes((size_t) Bsd::page_size());
3603 Bsd::initialize_system_info();
3605 // main_thread points to the aboriginal thread
3606 Bsd::_main_thread = pthread_self();
3608 Bsd::clock_init();
3609 initial_time_count = javaTimeNanos();
3611 #ifdef __APPLE__
3612 // XXXDARWIN
3613 // Work around the unaligned VM callbacks in hotspot's
3614 // sharedRuntime. The callbacks don't use SSE2 instructions, and work on
3615 // Linux, Solaris, and FreeBSD. On Mac OS X, dyld (rightly so) enforces
3616 // alignment when doing symbol lookup. To work around this, we force early
3617 // binding of all symbols now, thus binding when alignment is known-good.
3618 _dyld_bind_fully_image_containing_address((const void *) &os::init);
3619 #endif
3620 }
3622 // To install functions for atexit system call
3623 extern "C" {
3624 static void perfMemory_exit_helper() {
3625 perfMemory_exit();
3626 }
3627 }
3629 // this is called _after_ the global arguments have been parsed
3630 jint os::init_2(void)
3631 {
3632 // Allocate a single page and mark it as readable for safepoint polling
3633 address polling_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3634 guarantee( polling_page != MAP_FAILED, "os::init_2: failed to allocate polling page" );
3636 os::set_polling_page( polling_page );
3638 #ifndef PRODUCT
3639 if(Verbose && PrintMiscellaneous)
3640 tty->print("[SafePoint Polling address: " INTPTR_FORMAT "]\n", (intptr_t)polling_page);
3641 #endif
3643 if (!UseMembar) {
3644 address mem_serialize_page = (address) ::mmap(NULL, Bsd::page_size(), PROT_READ | PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
3645 guarantee( mem_serialize_page != MAP_FAILED, "mmap Failed for memory serialize page");
3646 os::set_memory_serialize_page( mem_serialize_page );
3648 #ifndef PRODUCT
3649 if(Verbose && PrintMiscellaneous)
3650 tty->print("[Memory Serialize Page address: " INTPTR_FORMAT "]\n", (intptr_t)mem_serialize_page);
3651 #endif
3652 }
3654 // initialize suspend/resume support - must do this before signal_sets_init()
3655 if (SR_initialize() != 0) {
3656 perror("SR_initialize failed");
3657 return JNI_ERR;
3658 }
3660 Bsd::signal_sets_init();
3661 Bsd::install_signal_handlers();
3663 // Check minimum allowable stack size for thread creation and to initialize
3664 // the java system classes, including StackOverflowError - depends on page
3665 // size. Add a page for compiler2 recursion in main thread.
3666 // Add in 2*BytesPerWord times page size to account for VM stack during
3667 // class initialization depending on 32 or 64 bit VM.
3668 os::Bsd::min_stack_allowed = MAX2(os::Bsd::min_stack_allowed,
3669 (size_t)(StackYellowPages+StackRedPages+StackShadowPages+
3670 2*BytesPerWord COMPILER2_PRESENT(+1)) * Bsd::page_size());
3672 size_t threadStackSizeInBytes = ThreadStackSize * K;
3673 if (threadStackSizeInBytes != 0 &&
3674 threadStackSizeInBytes < os::Bsd::min_stack_allowed) {
3675 tty->print_cr("\nThe stack size specified is too small, "
3676 "Specify at least %dk",
3677 os::Bsd::min_stack_allowed/ K);
3678 return JNI_ERR;
3679 }
3681 // Make the stack size a multiple of the page size so that
3682 // the yellow/red zones can be guarded.
3683 JavaThread::set_stack_size_at_create(round_to(threadStackSizeInBytes,
3684 vm_page_size()));
3686 if (MaxFDLimit) {
3687 // set the number of file descriptors to max. print out error
3688 // if getrlimit/setrlimit fails but continue regardless.
3689 struct rlimit nbr_files;
3690 int status = getrlimit(RLIMIT_NOFILE, &nbr_files);
3691 if (status != 0) {
3692 if (PrintMiscellaneous && (Verbose || WizardMode))
3693 perror("os::init_2 getrlimit failed");
3694 } else {
3695 nbr_files.rlim_cur = nbr_files.rlim_max;
3697 #ifdef __APPLE__
3698 // Darwin returns RLIM_INFINITY for rlim_max, but fails with EINVAL if
3699 // you attempt to use RLIM_INFINITY. As per setrlimit(2), OPEN_MAX must
3700 // be used instead
3701 nbr_files.rlim_cur = MIN(OPEN_MAX, nbr_files.rlim_cur);
3702 #endif
3704 status = setrlimit(RLIMIT_NOFILE, &nbr_files);
3705 if (status != 0) {
3706 if (PrintMiscellaneous && (Verbose || WizardMode))
3707 perror("os::init_2 setrlimit failed");
3708 }
3709 }
3710 }
3712 // at-exit methods are called in the reverse order of their registration.
3713 // atexit functions are called on return from main or as a result of a
3714 // call to exit(3C). There can be only 32 of these functions registered
3715 // and atexit() does not set errno.
3717 if (PerfAllowAtExitRegistration) {
3718 // only register atexit functions if PerfAllowAtExitRegistration is set.
3719 // atexit functions can be delayed until process exit time, which
3720 // can be problematic for embedded VM situations. Embedded VMs should
3721 // call DestroyJavaVM() to assure that VM resources are released.
3723 // note: perfMemory_exit_helper atexit function may be removed in
3724 // the future if the appropriate cleanup code can be added to the
3725 // VM_Exit VMOperation's doit method.
3726 if (atexit(perfMemory_exit_helper) != 0) {
3727 warning("os::init2 atexit(perfMemory_exit_helper) failed");
3728 }
3729 }
3731 // initialize thread priority policy
3732 prio_init();
3734 #ifdef __APPLE__
3735 // dynamically link to objective c gc registration
3736 void *handleLibObjc = dlopen(OBJC_LIB, RTLD_LAZY);
3737 if (handleLibObjc != NULL) {
3738 objc_registerThreadWithCollectorFunction = (objc_registerThreadWithCollector_t) dlsym(handleLibObjc, OBJC_GCREGISTER);
3739 }
3740 #endif
3742 return JNI_OK;
3743 }
3745 // this is called at the end of vm_initialization
3746 void os::init_3(void) { }
3748 // Mark the polling page as unreadable
3749 void os::make_polling_page_unreadable(void) {
3750 if( !guard_memory((char*)_polling_page, Bsd::page_size()) )
3751 fatal("Could not disable polling page");
3752 };
3754 // Mark the polling page as readable
3755 void os::make_polling_page_readable(void) {
3756 if( !bsd_mprotect((char *)_polling_page, Bsd::page_size(), PROT_READ)) {
3757 fatal("Could not enable polling page");
3758 }
3759 };
3761 int os::active_processor_count() {
3762 return _processor_count;
3763 }
3765 void os::set_native_thread_name(const char *name) {
3766 #if defined(__APPLE__) && MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_5
3767 // This is only supported in Snow Leopard and beyond
3768 if (name != NULL) {
3769 // Add a "Java: " prefix to the name
3770 char buf[MAXTHREADNAMESIZE];
3771 snprintf(buf, sizeof(buf), "Java: %s", name);
3772 pthread_setname_np(buf);
3773 }
3774 #endif
3775 }
3777 bool os::distribute_processes(uint length, uint* distribution) {
3778 // Not yet implemented.
3779 return false;
3780 }
3782 bool os::bind_to_processor(uint processor_id) {
3783 // Not yet implemented.
3784 return false;
3785 }
3787 void os::SuspendedThreadTask::internal_do_task() {
3788 if (do_suspend(_thread->osthread())) {
3789 SuspendedThreadTaskContext context(_thread, _thread->osthread()->ucontext());
3790 do_task(context);
3791 do_resume(_thread->osthread());
3792 }
3793 }
3795 ///
3796 class PcFetcher : public os::SuspendedThreadTask {
3797 public:
3798 PcFetcher(Thread* thread) : os::SuspendedThreadTask(thread) {}
3799 ExtendedPC result();
3800 protected:
3801 void do_task(const os::SuspendedThreadTaskContext& context);
3802 private:
3803 ExtendedPC _epc;
3804 };
3806 ExtendedPC PcFetcher::result() {
3807 guarantee(is_done(), "task is not done yet.");
3808 return _epc;
3809 }
3811 void PcFetcher::do_task(const os::SuspendedThreadTaskContext& context) {
3812 Thread* thread = context.thread();
3813 OSThread* osthread = thread->osthread();
3814 if (osthread->ucontext() != NULL) {
3815 _epc = os::Bsd::ucontext_get_pc((ucontext_t *) context.ucontext());
3816 } else {
3817 // NULL context is unexpected, double-check this is the VMThread
3818 guarantee(thread->is_VM_thread(), "can only be called for VMThread");
3819 }
3820 }
3822 // Suspends the target using the signal mechanism and then grabs the PC before
3823 // resuming the target. Used by the flat-profiler only
3824 ExtendedPC os::get_thread_pc(Thread* thread) {
3825 // Make sure that it is called by the watcher for the VMThread
3826 assert(Thread::current()->is_Watcher_thread(), "Must be watcher");
3827 assert(thread->is_VM_thread(), "Can only be called for VMThread");
3829 PcFetcher fetcher(thread);
3830 fetcher.run();
3831 return fetcher.result();
3832 }
3834 int os::Bsd::safe_cond_timedwait(pthread_cond_t *_cond, pthread_mutex_t *_mutex, const struct timespec *_abstime)
3835 {
3836 return pthread_cond_timedwait(_cond, _mutex, _abstime);
3837 }
3839 ////////////////////////////////////////////////////////////////////////////////
3840 // debug support
3842 bool os::find(address addr, outputStream* st) {
3843 Dl_info dlinfo;
3844 memset(&dlinfo, 0, sizeof(dlinfo));
3845 if (dladdr(addr, &dlinfo) != 0) {
3846 st->print(PTR_FORMAT ": ", addr);
3847 if (dlinfo.dli_sname != NULL && dlinfo.dli_saddr != NULL) {
3848 st->print("%s+%#x", dlinfo.dli_sname,
3849 addr - (intptr_t)dlinfo.dli_saddr);
3850 } else if (dlinfo.dli_fbase != NULL) {
3851 st->print("<offset %#x>", addr - (intptr_t)dlinfo.dli_fbase);
3852 } else {
3853 st->print("<absolute address>");
3854 }
3855 if (dlinfo.dli_fname != NULL) {
3856 st->print(" in %s", dlinfo.dli_fname);
3857 }
3858 if (dlinfo.dli_fbase != NULL) {
3859 st->print(" at " PTR_FORMAT, dlinfo.dli_fbase);
3860 }
3861 st->cr();
3863 if (Verbose) {
3864 // decode some bytes around the PC
3865 address begin = clamp_address_in_page(addr-40, addr, os::vm_page_size());
3866 address end = clamp_address_in_page(addr+40, addr, os::vm_page_size());
3867 address lowest = (address) dlinfo.dli_sname;
3868 if (!lowest) lowest = (address) dlinfo.dli_fbase;
3869 if (begin < lowest) begin = lowest;
3870 Dl_info dlinfo2;
3871 if (dladdr(end, &dlinfo2) != 0 && dlinfo2.dli_saddr != dlinfo.dli_saddr
3872 && end > dlinfo2.dli_saddr && dlinfo2.dli_saddr > begin)
3873 end = (address) dlinfo2.dli_saddr;
3874 Disassembler::decode(begin, end, st);
3875 }
3876 return true;
3877 }
3878 return false;
3879 }
3881 ////////////////////////////////////////////////////////////////////////////////
3882 // misc
3884 // This does not do anything on Bsd. This is basically a hook for being
3885 // able to use structured exception handling (thread-local exception filters)
3886 // on, e.g., Win32.
3887 void
3888 os::os_exception_wrapper(java_call_t f, JavaValue* value, methodHandle* method,
3889 JavaCallArguments* args, Thread* thread) {
3890 f(value, method, args, thread);
3891 }
3893 void os::print_statistics() {
3894 }
3896 int os::message_box(const char* title, const char* message) {
3897 int i;
3898 fdStream err(defaultStream::error_fd());
3899 for (i = 0; i < 78; i++) err.print_raw("=");
3900 err.cr();
3901 err.print_raw_cr(title);
3902 for (i = 0; i < 78; i++) err.print_raw("-");
3903 err.cr();
3904 err.print_raw_cr(message);
3905 for (i = 0; i < 78; i++) err.print_raw("=");
3906 err.cr();
3908 char buf[16];
3909 // Prevent process from exiting upon "read error" without consuming all CPU
3910 while (::read(0, buf, sizeof(buf)) <= 0) { ::sleep(100); }
3912 return buf[0] == 'y' || buf[0] == 'Y';
3913 }
3915 int os::stat(const char *path, struct stat *sbuf) {
3916 char pathbuf[MAX_PATH];
3917 if (strlen(path) > MAX_PATH - 1) {
3918 errno = ENAMETOOLONG;
3919 return -1;
3920 }
3921 os::native_path(strcpy(pathbuf, path));
3922 return ::stat(pathbuf, sbuf);
3923 }
3925 bool os::check_heap(bool force) {
3926 return true;
3927 }
3929 ATTRIBUTE_PRINTF(3, 0)
3930 int local_vsnprintf(char* buf, size_t count, const char* format, va_list args) {
3931 return ::vsnprintf(buf, count, format, args);
3932 }
3934 // Is a (classpath) directory empty?
3935 bool os::dir_is_empty(const char* path) {
3936 DIR *dir = NULL;
3937 struct dirent *ptr;
3939 dir = opendir(path);
3940 if (dir == NULL) return true;
3942 /* Scan the directory */
3943 bool result = true;
3944 char buf[sizeof(struct dirent) + MAX_PATH];
3945 while (result && (ptr = ::readdir(dir)) != NULL) {
3946 if (strcmp(ptr->d_name, ".") != 0 && strcmp(ptr->d_name, "..") != 0) {
3947 result = false;
3948 }
3949 }
3950 closedir(dir);
3951 return result;
3952 }
3954 // This code originates from JDK's sysOpen and open64_w
3955 // from src/solaris/hpi/src/system_md.c
3957 #ifndef O_DELETE
3958 #define O_DELETE 0x10000
3959 #endif
3961 // Open a file. Unlink the file immediately after open returns
3962 // if the specified oflag has the O_DELETE flag set.
3963 // O_DELETE is used only in j2se/src/share/native/java/util/zip/ZipFile.c
3965 int os::open(const char *path, int oflag, int mode) {
3967 if (strlen(path) > MAX_PATH - 1) {
3968 errno = ENAMETOOLONG;
3969 return -1;
3970 }
3971 int fd;
3972 int o_delete = (oflag & O_DELETE);
3973 oflag = oflag & ~O_DELETE;
3975 fd = ::open(path, oflag, mode);
3976 if (fd == -1) return -1;
3978 //If the open succeeded, the file might still be a directory
3979 {
3980 struct stat buf;
3981 int ret = ::fstat(fd, &buf);
3982 int st_mode = buf.st_mode;
3984 if (ret != -1) {
3985 if ((st_mode & S_IFMT) == S_IFDIR) {
3986 errno = EISDIR;
3987 ::close(fd);
3988 return -1;
3989 }
3990 } else {
3991 ::close(fd);
3992 return -1;
3993 }
3994 }
3996 /*
3997 * All file descriptors that are opened in the JVM and not
3998 * specifically destined for a subprocess should have the
3999 * close-on-exec flag set. If we don't set it, then careless 3rd
4000 * party native code might fork and exec without closing all
4001 * appropriate file descriptors (e.g. as we do in closeDescriptors in
4002 * UNIXProcess.c), and this in turn might:
4003 *
4004 * - cause end-of-file to fail to be detected on some file
4005 * descriptors, resulting in mysterious hangs, or
4006 *
4007 * - might cause an fopen in the subprocess to fail on a system
4008 * suffering from bug 1085341.
4009 *
4010 * (Yes, the default setting of the close-on-exec flag is a Unix
4011 * design flaw)
4012 *
4013 * See:
4014 * 1085341: 32-bit stdio routines should support file descriptors >255
4015 * 4843136: (process) pipe file descriptor from Runtime.exec not being closed
4016 * 6339493: (process) Runtime.exec does not close all file descriptors on Solaris 9
4017 */
4018 #ifdef FD_CLOEXEC
4019 {
4020 int flags = ::fcntl(fd, F_GETFD);
4021 if (flags != -1)
4022 ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
4023 }
4024 #endif
4026 if (o_delete != 0) {
4027 ::unlink(path);
4028 }
4029 return fd;
4030 }
4033 // create binary file, rewriting existing file if required
4034 int os::create_binary_file(const char* path, bool rewrite_existing) {
4035 int oflags = O_WRONLY | O_CREAT;
4036 if (!rewrite_existing) {
4037 oflags |= O_EXCL;
4038 }
4039 return ::open(path, oflags, S_IREAD | S_IWRITE);
4040 }
4042 // return current position of file pointer
4043 jlong os::current_file_offset(int fd) {
4044 return (jlong)::lseek(fd, (off_t)0, SEEK_CUR);
4045 }
4047 // move file pointer to the specified offset
4048 jlong os::seek_to_file_offset(int fd, jlong offset) {
4049 return (jlong)::lseek(fd, (off_t)offset, SEEK_SET);
4050 }
4052 // This code originates from JDK's sysAvailable
4053 // from src/solaris/hpi/src/native_threads/src/sys_api_td.c
4055 int os::available(int fd, jlong *bytes) {
4056 jlong cur, end;
4057 int mode;
4058 struct stat buf;
4060 if (::fstat(fd, &buf) >= 0) {
4061 mode = buf.st_mode;
4062 if (S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode)) {
4063 /*
4064 * XXX: is the following call interruptible? If so, this might
4065 * need to go through the INTERRUPT_IO() wrapper as for other
4066 * blocking, interruptible calls in this file.
4067 */
4068 int n;
4069 if (::ioctl(fd, FIONREAD, &n) >= 0) {
4070 *bytes = n;
4071 return 1;
4072 }
4073 }
4074 }
4075 if ((cur = ::lseek(fd, 0L, SEEK_CUR)) == -1) {
4076 return 0;
4077 } else if ((end = ::lseek(fd, 0L, SEEK_END)) == -1) {
4078 return 0;
4079 } else if (::lseek(fd, cur, SEEK_SET) == -1) {
4080 return 0;
4081 }
4082 *bytes = end - cur;
4083 return 1;
4084 }
4086 int os::socket_available(int fd, jint *pbytes) {
4087 if (fd < 0)
4088 return OS_OK;
4090 int ret;
4092 RESTARTABLE(::ioctl(fd, FIONREAD, pbytes), ret);
4094 //%% note ioctl can return 0 when successful, JVM_SocketAvailable
4095 // is expected to return 0 on failure and 1 on success to the jdk.
4097 return (ret == OS_ERR) ? 0 : 1;
4098 }
4100 // Map a block of memory.
4101 char* os::pd_map_memory(int fd, const char* file_name, size_t file_offset,
4102 char *addr, size_t bytes, bool read_only,
4103 bool allow_exec) {
4104 int prot;
4105 int flags;
4107 if (read_only) {
4108 prot = PROT_READ;
4109 flags = MAP_SHARED;
4110 } else {
4111 prot = PROT_READ | PROT_WRITE;
4112 flags = MAP_PRIVATE;
4113 }
4115 if (allow_exec) {
4116 prot |= PROT_EXEC;
4117 }
4119 if (addr != NULL) {
4120 flags |= MAP_FIXED;
4121 }
4123 char* mapped_address = (char*)mmap(addr, (size_t)bytes, prot, flags,
4124 fd, file_offset);
4125 if (mapped_address == MAP_FAILED) {
4126 return NULL;
4127 }
4128 return mapped_address;
4129 }
4132 // Remap a block of memory.
4133 char* os::pd_remap_memory(int fd, const char* file_name, size_t file_offset,
4134 char *addr, size_t bytes, bool read_only,
4135 bool allow_exec) {
4136 // same as map_memory() on this OS
4137 return os::map_memory(fd, file_name, file_offset, addr, bytes, read_only,
4138 allow_exec);
4139 }
4142 // Unmap a block of memory.
4143 bool os::pd_unmap_memory(char* addr, size_t bytes) {
4144 return munmap(addr, bytes) == 0;
4145 }
4147 // current_thread_cpu_time(bool) and thread_cpu_time(Thread*, bool)
4148 // are used by JVM M&M and JVMTI to get user+sys or user CPU time
4149 // of a thread.
4150 //
4151 // current_thread_cpu_time() and thread_cpu_time(Thread*) returns
4152 // the fast estimate available on the platform.
4154 jlong os::current_thread_cpu_time() {
4155 #ifdef __APPLE__
4156 return os::thread_cpu_time(Thread::current(), true /* user + sys */);
4157 #else
4158 Unimplemented();
4159 return 0;
4160 #endif
4161 }
4163 jlong os::thread_cpu_time(Thread* thread) {
4164 #ifdef __APPLE__
4165 return os::thread_cpu_time(thread, true /* user + sys */);
4166 #else
4167 Unimplemented();
4168 return 0;
4169 #endif
4170 }
4172 jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
4173 #ifdef __APPLE__
4174 return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
4175 #else
4176 Unimplemented();
4177 return 0;
4178 #endif
4179 }
4181 jlong os::thread_cpu_time(Thread *thread, bool user_sys_cpu_time) {
4182 #ifdef __APPLE__
4183 struct thread_basic_info tinfo;
4184 mach_msg_type_number_t tcount = THREAD_INFO_MAX;
4185 kern_return_t kr;
4186 thread_t mach_thread;
4188 mach_thread = thread->osthread()->thread_id();
4189 kr = thread_info(mach_thread, THREAD_BASIC_INFO, (thread_info_t)&tinfo, &tcount);
4190 if (kr != KERN_SUCCESS)
4191 return -1;
4193 if (user_sys_cpu_time) {
4194 jlong nanos;
4195 nanos = ((jlong) tinfo.system_time.seconds + tinfo.user_time.seconds) * (jlong)1000000000;
4196 nanos += ((jlong) tinfo.system_time.microseconds + (jlong) tinfo.user_time.microseconds) * (jlong)1000;
4197 return nanos;
4198 } else {
4199 return ((jlong)tinfo.user_time.seconds * 1000000000) + ((jlong)tinfo.user_time.microseconds * (jlong)1000);
4200 }
4201 #else
4202 Unimplemented();
4203 return 0;
4204 #endif
4205 }
4208 void os::current_thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4209 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
4210 info_ptr->may_skip_backward = false; // elapsed time not wall time
4211 info_ptr->may_skip_forward = false; // elapsed time not wall time
4212 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
4213 }
4215 void os::thread_cpu_time_info(jvmtiTimerInfo *info_ptr) {
4216 info_ptr->max_value = ALL_64_BITS; // will not wrap in less than 64 bits
4217 info_ptr->may_skip_backward = false; // elapsed time not wall time
4218 info_ptr->may_skip_forward = false; // elapsed time not wall time
4219 info_ptr->kind = JVMTI_TIMER_TOTAL_CPU; // user+system time is returned
4220 }
4222 bool os::is_thread_cpu_time_supported() {
4223 #ifdef __APPLE__
4224 return true;
4225 #else
4226 return false;
4227 #endif
4228 }
4230 // System loadavg support. Returns -1 if load average cannot be obtained.
4231 // Bsd doesn't yet have a (official) notion of processor sets,
4232 // so just return the system wide load average.
4233 int os::loadavg(double loadavg[], int nelem) {
4234 return ::getloadavg(loadavg, nelem);
4235 }
4237 void os::pause() {
4238 char filename[MAX_PATH];
4239 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
4240 jio_snprintf(filename, MAX_PATH, PauseAtStartupFile);
4241 } else {
4242 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
4243 }
4245 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
4246 if (fd != -1) {
4247 struct stat buf;
4248 ::close(fd);
4249 while (::stat(filename, &buf) == 0) {
4250 (void)::poll(NULL, 0, 100);
4251 }
4252 } else {
4253 jio_fprintf(stderr,
4254 "Could not open pause file '%s', continuing immediately.\n", filename);
4255 }
4256 }
4259 // Refer to the comments in os_solaris.cpp park-unpark.
4260 //
4261 // Beware -- Some versions of NPTL embody a flaw where pthread_cond_timedwait() can
4262 // hang indefinitely. For instance NPTL 0.60 on 2.4.21-4ELsmp is vulnerable.
4263 // For specifics regarding the bug see GLIBC BUGID 261237 :
4264 // http://www.mail-archive.com/debian-glibc@lists.debian.org/msg10837.html.
4265 // Briefly, pthread_cond_timedwait() calls with an expiry time that's not in the future
4266 // will either hang or corrupt the condvar, resulting in subsequent hangs if the condvar
4267 // is used. (The simple C test-case provided in the GLIBC bug report manifests the
4268 // hang). The JVM is vulernable via sleep(), Object.wait(timo), LockSupport.parkNanos()
4269 // and monitorenter when we're using 1-0 locking. All those operations may result in
4270 // calls to pthread_cond_timedwait(). Using LD_ASSUME_KERNEL to use an older version
4271 // of libpthread avoids the problem, but isn't practical.
4272 //
4273 // Possible remedies:
4274 //
4275 // 1. Establish a minimum relative wait time. 50 to 100 msecs seems to work.
4276 // This is palliative and probabilistic, however. If the thread is preempted
4277 // between the call to compute_abstime() and pthread_cond_timedwait(), more
4278 // than the minimum period may have passed, and the abstime may be stale (in the
4279 // past) resultin in a hang. Using this technique reduces the odds of a hang
4280 // but the JVM is still vulnerable, particularly on heavily loaded systems.
4281 //
4282 // 2. Modify park-unpark to use per-thread (per ParkEvent) pipe-pairs instead
4283 // of the usual flag-condvar-mutex idiom. The write side of the pipe is set
4284 // NDELAY. unpark() reduces to write(), park() reduces to read() and park(timo)
4285 // reduces to poll()+read(). This works well, but consumes 2 FDs per extant
4286 // thread.
4287 //
4288 // 3. Embargo pthread_cond_timedwait() and implement a native "chron" thread
4289 // that manages timeouts. We'd emulate pthread_cond_timedwait() by enqueuing
4290 // a timeout request to the chron thread and then blocking via pthread_cond_wait().
4291 // This also works well. In fact it avoids kernel-level scalability impediments
4292 // on certain platforms that don't handle lots of active pthread_cond_timedwait()
4293 // timers in a graceful fashion.
4294 //
4295 // 4. When the abstime value is in the past it appears that control returns
4296 // correctly from pthread_cond_timedwait(), but the condvar is left corrupt.
4297 // Subsequent timedwait/wait calls may hang indefinitely. Given that, we
4298 // can avoid the problem by reinitializing the condvar -- by cond_destroy()
4299 // followed by cond_init() -- after all calls to pthread_cond_timedwait().
4300 // It may be possible to avoid reinitialization by checking the return
4301 // value from pthread_cond_timedwait(). In addition to reinitializing the
4302 // condvar we must establish the invariant that cond_signal() is only called
4303 // within critical sections protected by the adjunct mutex. This prevents
4304 // cond_signal() from "seeing" a condvar that's in the midst of being
4305 // reinitialized or that is corrupt. Sadly, this invariant obviates the
4306 // desirable signal-after-unlock optimization that avoids futile context switching.
4307 //
4308 // I'm also concerned that some versions of NTPL might allocate an auxilliary
4309 // structure when a condvar is used or initialized. cond_destroy() would
4310 // release the helper structure. Our reinitialize-after-timedwait fix
4311 // put excessive stress on malloc/free and locks protecting the c-heap.
4312 //
4313 // We currently use (4). See the WorkAroundNTPLTimedWaitHang flag.
4314 // It may be possible to refine (4) by checking the kernel and NTPL verisons
4315 // and only enabling the work-around for vulnerable environments.
4317 // utility to compute the abstime argument to timedwait:
4318 // millis is the relative timeout time
4319 // abstime will be the absolute timeout time
4320 // TODO: replace compute_abstime() with unpackTime()
4322 static struct timespec* compute_abstime(struct timespec* abstime, jlong millis) {
4323 if (millis < 0) millis = 0;
4324 struct timeval now;
4325 int status = gettimeofday(&now, NULL);
4326 assert(status == 0, "gettimeofday");
4327 jlong seconds = millis / 1000;
4328 millis %= 1000;
4329 if (seconds > 50000000) { // see man cond_timedwait(3T)
4330 seconds = 50000000;
4331 }
4332 abstime->tv_sec = now.tv_sec + seconds;
4333 long usec = now.tv_usec + millis * 1000;
4334 if (usec >= 1000000) {
4335 abstime->tv_sec += 1;
4336 usec -= 1000000;
4337 }
4338 abstime->tv_nsec = usec * 1000;
4339 return abstime;
4340 }
4343 // Test-and-clear _Event, always leaves _Event set to 0, returns immediately.
4344 // Conceptually TryPark() should be equivalent to park(0).
4346 int os::PlatformEvent::TryPark() {
4347 for (;;) {
4348 const int v = _Event ;
4349 guarantee ((v == 0) || (v == 1), "invariant") ;
4350 if (Atomic::cmpxchg (0, &_Event, v) == v) return v ;
4351 }
4352 }
4354 void os::PlatformEvent::park() { // AKA "down()"
4355 // Invariant: Only the thread associated with the Event/PlatformEvent
4356 // may call park().
4357 // TODO: assert that _Assoc != NULL or _Assoc == Self
4358 int v ;
4359 for (;;) {
4360 v = _Event ;
4361 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4362 }
4363 guarantee (v >= 0, "invariant") ;
4364 if (v == 0) {
4365 // Do this the hard way by blocking ...
4366 int status = pthread_mutex_lock(_mutex);
4367 assert_status(status == 0, status, "mutex_lock");
4368 guarantee (_nParked == 0, "invariant") ;
4369 ++ _nParked ;
4370 while (_Event < 0) {
4371 status = pthread_cond_wait(_cond, _mutex);
4372 // for some reason, under 2.7 lwp_cond_wait() may return ETIME ...
4373 // Treat this the same as if the wait was interrupted
4374 if (status == ETIMEDOUT) { status = EINTR; }
4375 assert_status(status == 0 || status == EINTR, status, "cond_wait");
4376 }
4377 -- _nParked ;
4379 _Event = 0 ;
4380 status = pthread_mutex_unlock(_mutex);
4381 assert_status(status == 0, status, "mutex_unlock");
4382 // Paranoia to ensure our locked and lock-free paths interact
4383 // correctly with each other.
4384 OrderAccess::fence();
4385 }
4386 guarantee (_Event >= 0, "invariant") ;
4387 }
4389 int os::PlatformEvent::park(jlong millis) {
4390 guarantee (_nParked == 0, "invariant") ;
4392 int v ;
4393 for (;;) {
4394 v = _Event ;
4395 if (Atomic::cmpxchg (v-1, &_Event, v) == v) break ;
4396 }
4397 guarantee (v >= 0, "invariant") ;
4398 if (v != 0) return OS_OK ;
4400 // We do this the hard way, by blocking the thread.
4401 // Consider enforcing a minimum timeout value.
4402 struct timespec abst;
4403 compute_abstime(&abst, millis);
4405 int ret = OS_TIMEOUT;
4406 int status = pthread_mutex_lock(_mutex);
4407 assert_status(status == 0, status, "mutex_lock");
4408 guarantee (_nParked == 0, "invariant") ;
4409 ++_nParked ;
4411 // Object.wait(timo) will return because of
4412 // (a) notification
4413 // (b) timeout
4414 // (c) thread.interrupt
4415 //
4416 // Thread.interrupt and object.notify{All} both call Event::set.
4417 // That is, we treat thread.interrupt as a special case of notification.
4418 // The underlying Solaris implementation, cond_timedwait, admits
4419 // spurious/premature wakeups, but the JLS/JVM spec prevents the
4420 // JVM from making those visible to Java code. As such, we must
4421 // filter out spurious wakeups. We assume all ETIME returns are valid.
4422 //
4423 // TODO: properly differentiate simultaneous notify+interrupt.
4424 // In that case, we should propagate the notify to another waiter.
4426 while (_Event < 0) {
4427 status = os::Bsd::safe_cond_timedwait(_cond, _mutex, &abst);
4428 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4429 pthread_cond_destroy (_cond);
4430 pthread_cond_init (_cond, NULL) ;
4431 }
4432 assert_status(status == 0 || status == EINTR ||
4433 status == ETIMEDOUT,
4434 status, "cond_timedwait");
4435 if (!FilterSpuriousWakeups) break ; // previous semantics
4436 if (status == ETIMEDOUT) break ;
4437 // We consume and ignore EINTR and spurious wakeups.
4438 }
4439 --_nParked ;
4440 if (_Event >= 0) {
4441 ret = OS_OK;
4442 }
4443 _Event = 0 ;
4444 status = pthread_mutex_unlock(_mutex);
4445 assert_status(status == 0, status, "mutex_unlock");
4446 assert (_nParked == 0, "invariant") ;
4447 // Paranoia to ensure our locked and lock-free paths interact
4448 // correctly with each other.
4449 OrderAccess::fence();
4450 return ret;
4451 }
4453 void os::PlatformEvent::unpark() {
4454 // Transitions for _Event:
4455 // 0 :=> 1
4456 // 1 :=> 1
4457 // -1 :=> either 0 or 1; must signal target thread
4458 // That is, we can safely transition _Event from -1 to either
4459 // 0 or 1. Forcing 1 is slightly more efficient for back-to-back
4460 // unpark() calls.
4461 // See also: "Semaphores in Plan 9" by Mullender & Cox
4462 //
4463 // Note: Forcing a transition from "-1" to "1" on an unpark() means
4464 // that it will take two back-to-back park() calls for the owning
4465 // thread to block. This has the benefit of forcing a spurious return
4466 // from the first park() call after an unpark() call which will help
4467 // shake out uses of park() and unpark() without condition variables.
4469 if (Atomic::xchg(1, &_Event) >= 0) return;
4471 // Wait for the thread associated with the event to vacate
4472 int status = pthread_mutex_lock(_mutex);
4473 assert_status(status == 0, status, "mutex_lock");
4474 int AnyWaiters = _nParked;
4475 assert(AnyWaiters == 0 || AnyWaiters == 1, "invariant");
4476 if (AnyWaiters != 0 && WorkAroundNPTLTimedWaitHang) {
4477 AnyWaiters = 0;
4478 pthread_cond_signal(_cond);
4479 }
4480 status = pthread_mutex_unlock(_mutex);
4481 assert_status(status == 0, status, "mutex_unlock");
4482 if (AnyWaiters != 0) {
4483 status = pthread_cond_signal(_cond);
4484 assert_status(status == 0, status, "cond_signal");
4485 }
4487 // Note that we signal() _after dropping the lock for "immortal" Events.
4488 // This is safe and avoids a common class of futile wakeups. In rare
4489 // circumstances this can cause a thread to return prematurely from
4490 // cond_{timed}wait() but the spurious wakeup is benign and the victim will
4491 // simply re-test the condition and re-park itself.
4492 }
4495 // JSR166
4496 // -------------------------------------------------------
4498 /*
4499 * The solaris and bsd implementations of park/unpark are fairly
4500 * conservative for now, but can be improved. They currently use a
4501 * mutex/condvar pair, plus a a count.
4502 * Park decrements count if > 0, else does a condvar wait. Unpark
4503 * sets count to 1 and signals condvar. Only one thread ever waits
4504 * on the condvar. Contention seen when trying to park implies that someone
4505 * is unparking you, so don't wait. And spurious returns are fine, so there
4506 * is no need to track notifications.
4507 */
4509 #define MAX_SECS 100000000
4510 /*
4511 * This code is common to bsd and solaris and will be moved to a
4512 * common place in dolphin.
4513 *
4514 * The passed in time value is either a relative time in nanoseconds
4515 * or an absolute time in milliseconds. Either way it has to be unpacked
4516 * into suitable seconds and nanoseconds components and stored in the
4517 * given timespec structure.
4518 * Given time is a 64-bit value and the time_t used in the timespec is only
4519 * a signed-32-bit value (except on 64-bit Bsd) we have to watch for
4520 * overflow if times way in the future are given. Further on Solaris versions
4521 * prior to 10 there is a restriction (see cond_timedwait) that the specified
4522 * number of seconds, in abstime, is less than current_time + 100,000,000.
4523 * As it will be 28 years before "now + 100000000" will overflow we can
4524 * ignore overflow and just impose a hard-limit on seconds using the value
4525 * of "now + 100,000,000". This places a limit on the timeout of about 3.17
4526 * years from "now".
4527 */
4529 static void unpackTime(struct timespec* absTime, bool isAbsolute, jlong time) {
4530 assert (time > 0, "convertTime");
4532 struct timeval now;
4533 int status = gettimeofday(&now, NULL);
4534 assert(status == 0, "gettimeofday");
4536 time_t max_secs = now.tv_sec + MAX_SECS;
4538 if (isAbsolute) {
4539 jlong secs = time / 1000;
4540 if (secs > max_secs) {
4541 absTime->tv_sec = max_secs;
4542 }
4543 else {
4544 absTime->tv_sec = secs;
4545 }
4546 absTime->tv_nsec = (time % 1000) * NANOSECS_PER_MILLISEC;
4547 }
4548 else {
4549 jlong secs = time / NANOSECS_PER_SEC;
4550 if (secs >= MAX_SECS) {
4551 absTime->tv_sec = max_secs;
4552 absTime->tv_nsec = 0;
4553 }
4554 else {
4555 absTime->tv_sec = now.tv_sec + secs;
4556 absTime->tv_nsec = (time % NANOSECS_PER_SEC) + now.tv_usec*1000;
4557 if (absTime->tv_nsec >= NANOSECS_PER_SEC) {
4558 absTime->tv_nsec -= NANOSECS_PER_SEC;
4559 ++absTime->tv_sec; // note: this must be <= max_secs
4560 }
4561 }
4562 }
4563 assert(absTime->tv_sec >= 0, "tv_sec < 0");
4564 assert(absTime->tv_sec <= max_secs, "tv_sec > max_secs");
4565 assert(absTime->tv_nsec >= 0, "tv_nsec < 0");
4566 assert(absTime->tv_nsec < NANOSECS_PER_SEC, "tv_nsec >= nanos_per_sec");
4567 }
4569 void Parker::park(bool isAbsolute, jlong time) {
4570 // Ideally we'd do something useful while spinning, such
4571 // as calling unpackTime().
4573 // Optional fast-path check:
4574 // Return immediately if a permit is available.
4575 // We depend on Atomic::xchg() having full barrier semantics
4576 // since we are doing a lock-free update to _counter.
4577 if (Atomic::xchg(0, &_counter) > 0) return;
4579 Thread* thread = Thread::current();
4580 assert(thread->is_Java_thread(), "Must be JavaThread");
4581 JavaThread *jt = (JavaThread *)thread;
4583 // Optional optimization -- avoid state transitions if there's an interrupt pending.
4584 // Check interrupt before trying to wait
4585 if (Thread::is_interrupted(thread, false)) {
4586 return;
4587 }
4589 // Next, demultiplex/decode time arguments
4590 struct timespec absTime;
4591 if (time < 0 || (isAbsolute && time == 0) ) { // don't wait at all
4592 return;
4593 }
4594 if (time > 0) {
4595 unpackTime(&absTime, isAbsolute, time);
4596 }
4599 // Enter safepoint region
4600 // Beware of deadlocks such as 6317397.
4601 // The per-thread Parker:: mutex is a classic leaf-lock.
4602 // In particular a thread must never block on the Threads_lock while
4603 // holding the Parker:: mutex. If safepoints are pending both the
4604 // the ThreadBlockInVM() CTOR and DTOR may grab Threads_lock.
4605 ThreadBlockInVM tbivm(jt);
4607 // Don't wait if cannot get lock since interference arises from
4608 // unblocking. Also. check interrupt before trying wait
4609 if (Thread::is_interrupted(thread, false) || pthread_mutex_trylock(_mutex) != 0) {
4610 return;
4611 }
4613 int status ;
4614 if (_counter > 0) { // no wait needed
4615 _counter = 0;
4616 status = pthread_mutex_unlock(_mutex);
4617 assert (status == 0, "invariant") ;
4618 // Paranoia to ensure our locked and lock-free paths interact
4619 // correctly with each other and Java-level accesses.
4620 OrderAccess::fence();
4621 return;
4622 }
4624 #ifdef ASSERT
4625 // Don't catch signals while blocked; let the running threads have the signals.
4626 // (This allows a debugger to break into the running thread.)
4627 sigset_t oldsigs;
4628 sigset_t* allowdebug_blocked = os::Bsd::allowdebug_blocked_signals();
4629 pthread_sigmask(SIG_BLOCK, allowdebug_blocked, &oldsigs);
4630 #endif
4632 OSThreadWaitState osts(thread->osthread(), false /* not Object.wait() */);
4633 jt->set_suspend_equivalent();
4634 // cleared by handle_special_suspend_equivalent_condition() or java_suspend_self()
4636 if (time == 0) {
4637 status = pthread_cond_wait (_cond, _mutex) ;
4638 } else {
4639 status = os::Bsd::safe_cond_timedwait (_cond, _mutex, &absTime) ;
4640 if (status != 0 && WorkAroundNPTLTimedWaitHang) {
4641 pthread_cond_destroy (_cond) ;
4642 pthread_cond_init (_cond, NULL);
4643 }
4644 }
4645 assert_status(status == 0 || status == EINTR ||
4646 status == ETIMEDOUT,
4647 status, "cond_timedwait");
4649 #ifdef ASSERT
4650 pthread_sigmask(SIG_SETMASK, &oldsigs, NULL);
4651 #endif
4653 _counter = 0 ;
4654 status = pthread_mutex_unlock(_mutex) ;
4655 assert_status(status == 0, status, "invariant") ;
4656 // Paranoia to ensure our locked and lock-free paths interact
4657 // correctly with each other and Java-level accesses.
4658 OrderAccess::fence();
4660 // If externally suspended while waiting, re-suspend
4661 if (jt->handle_special_suspend_equivalent_condition()) {
4662 jt->java_suspend_self();
4663 }
4664 }
4666 void Parker::unpark() {
4667 int s, status ;
4668 status = pthread_mutex_lock(_mutex);
4669 assert (status == 0, "invariant") ;
4670 s = _counter;
4671 _counter = 1;
4672 if (s < 1) {
4673 if (WorkAroundNPTLTimedWaitHang) {
4674 status = pthread_cond_signal (_cond) ;
4675 assert (status == 0, "invariant") ;
4676 status = pthread_mutex_unlock(_mutex);
4677 assert (status == 0, "invariant") ;
4678 } else {
4679 status = pthread_mutex_unlock(_mutex);
4680 assert (status == 0, "invariant") ;
4681 status = pthread_cond_signal (_cond) ;
4682 assert (status == 0, "invariant") ;
4683 }
4684 } else {
4685 pthread_mutex_unlock(_mutex);
4686 assert (status == 0, "invariant") ;
4687 }
4688 }
4691 /* Darwin has no "environ" in a dynamic library. */
4692 #ifdef __APPLE__
4693 #include <crt_externs.h>
4694 #define environ (*_NSGetEnviron())
4695 #else
4696 extern char** environ;
4697 #endif
4699 // Run the specified command in a separate process. Return its exit value,
4700 // or -1 on failure (e.g. can't fork a new process).
4701 // Unlike system(), this function can be called from signal handler. It
4702 // doesn't block SIGINT et al.
4703 int os::fork_and_exec(char* cmd) {
4704 const char * argv[4] = {"sh", "-c", cmd, NULL};
4706 // fork() in BsdThreads/NPTL is not async-safe. It needs to run
4707 // pthread_atfork handlers and reset pthread library. All we need is a
4708 // separate process to execve. Make a direct syscall to fork process.
4709 // On IA64 there's no fork syscall, we have to use fork() and hope for
4710 // the best...
4711 pid_t pid = fork();
4713 if (pid < 0) {
4714 // fork failed
4715 return -1;
4717 } else if (pid == 0) {
4718 // child process
4720 // execve() in BsdThreads will call pthread_kill_other_threads_np()
4721 // first to kill every thread on the thread list. Because this list is
4722 // not reset by fork() (see notes above), execve() will instead kill
4723 // every thread in the parent process. We know this is the only thread
4724 // in the new process, so make a system call directly.
4725 // IA64 should use normal execve() from glibc to match the glibc fork()
4726 // above.
4727 execve("/bin/sh", (char* const*)argv, environ);
4729 // execve failed
4730 _exit(-1);
4732 } else {
4733 // copied from J2SE ..._waitForProcessExit() in UNIXProcess_md.c; we don't
4734 // care about the actual exit code, for now.
4736 int status;
4738 // Wait for the child process to exit. This returns immediately if
4739 // the child has already exited. */
4740 while (waitpid(pid, &status, 0) < 0) {
4741 switch (errno) {
4742 case ECHILD: return 0;
4743 case EINTR: break;
4744 default: return -1;
4745 }
4746 }
4748 if (WIFEXITED(status)) {
4749 // The child exited normally; get its exit code.
4750 return WEXITSTATUS(status);
4751 } else if (WIFSIGNALED(status)) {
4752 // The child exited because of a signal
4753 // The best value to return is 0x80 + signal number,
4754 // because that is what all Unix shells do, and because
4755 // it allows callers to distinguish between process exit and
4756 // process death by signal.
4757 return 0x80 + WTERMSIG(status);
4758 } else {
4759 // Unknown exit code; pass it through
4760 return status;
4761 }
4762 }
4763 }
4765 // is_headless_jre()
4766 //
4767 // Test for the existence of xawt/libmawt.so or libawt_xawt.so
4768 // in order to report if we are running in a headless jre
4769 //
4770 // Since JDK8 xawt/libmawt.so was moved into the same directory
4771 // as libawt.so, and renamed libawt_xawt.so
4772 //
4773 bool os::is_headless_jre() {
4774 #ifdef __APPLE__
4775 // We no longer build headless-only on Mac OS X
4776 return false;
4777 #else
4778 struct stat statbuf;
4779 char buf[MAXPATHLEN];
4780 char libmawtpath[MAXPATHLEN];
4781 const char *xawtstr = "/xawt/libmawt" JNI_LIB_SUFFIX;
4782 const char *new_xawtstr = "/libawt_xawt" JNI_LIB_SUFFIX;
4783 char *p;
4785 // Get path to libjvm.so
4786 os::jvm_path(buf, sizeof(buf));
4788 // Get rid of libjvm.so
4789 p = strrchr(buf, '/');
4790 if (p == NULL) return false;
4791 else *p = '\0';
4793 // Get rid of client or server
4794 p = strrchr(buf, '/');
4795 if (p == NULL) return false;
4796 else *p = '\0';
4798 // check xawt/libmawt.so
4799 strcpy(libmawtpath, buf);
4800 strcat(libmawtpath, xawtstr);
4801 if (::stat(libmawtpath, &statbuf) == 0) return false;
4803 // check libawt_xawt.so
4804 strcpy(libmawtpath, buf);
4805 strcat(libmawtpath, new_xawtstr);
4806 if (::stat(libmawtpath, &statbuf) == 0) return false;
4808 return true;
4809 #endif
4810 }
4812 // Get the default path to the core file
4813 // Returns the length of the string
4814 int os::get_core_path(char* buffer, size_t bufferSize) {
4815 int n = jio_snprintf(buffer, bufferSize, "/cores");
4817 // Truncate if theoretical string was longer than bufferSize
4818 n = MIN2(n, (int)bufferSize);
4820 return n;
4821 }
4823 #ifndef PRODUCT
4824 void TestReserveMemorySpecial_test() {
4825 // No tests available for this platform
4826 }
4827 #endif