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