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