1 /*
2 * Copyright (c) 1997, 2018, 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 #include "precompiled.hpp"
26 #include "jvm.h"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/javaClasses.hpp"
29 #include "classfile/moduleEntry.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "code/codeCache.hpp"
33 #include "code/icBuffer.hpp"
34 #include "code/vtableStubs.hpp"
35 #include "gc/shared/vmGCOperations.hpp"
36 #include "logging/log.hpp"
37 #include "interpreter/interpreter.hpp"
38 #include "logging/log.hpp"
39 #include "logging/logStream.hpp"
40 #include "memory/allocation.inline.hpp"
41 #ifdef ASSERT
42 #include "memory/guardedMemory.hpp"
43 #endif
44 #include "memory/resourceArea.hpp"
45 #include "oops/oop.inline.hpp"
46 #include "prims/jvm_misc.hpp"
47 #include "prims/privilegedStack.hpp"
48 #include "runtime/arguments.hpp"
49 #include "runtime/atomic.hpp"
50 #include "runtime/frame.inline.hpp"
51 #include "runtime/interfaceSupport.inline.hpp"
52 #include "runtime/java.hpp"
53 #include "runtime/javaCalls.hpp"
54 #include "runtime/mutexLocker.hpp"
55 #include "runtime/os.inline.hpp"
56 #include "runtime/sharedRuntime.hpp"
57 #include "runtime/stubRoutines.hpp"
58 #include "runtime/thread.inline.hpp"
59 #include "runtime/threadSMR.hpp"
60 #include "runtime/vm_version.hpp"
61 #include "services/attachListener.hpp"
62 #include "services/mallocTracker.hpp"
63 #include "services/memTracker.hpp"
64 #include "services/nmtCommon.hpp"
65 #include "services/threadService.hpp"
66 #include "utilities/align.hpp"
67 #include "utilities/defaultStream.hpp"
68 #include "utilities/events.hpp"
69
70 # include <signal.h>
71 # include <errno.h>
72
73 OSThread* os::_starting_thread = NULL;
74 address os::_polling_page = NULL;
75 volatile int32_t* os::_mem_serialize_page = NULL;
76 uintptr_t os::_serialize_page_mask = 0;
77 volatile unsigned int os::_rand_seed = 1;
78 int os::_processor_count = 0;
79 int os::_initial_active_processor_count = 0;
80 size_t os::_page_sizes[os::page_sizes_max];
81
82 #ifndef PRODUCT
83 julong os::num_mallocs = 0; // # of calls to malloc/realloc
84 julong os::alloc_bytes = 0; // # of bytes allocated
85 julong os::num_frees = 0; // # of calls to free
86 julong os::free_bytes = 0; // # of bytes freed
87 #endif
88
89 static size_t cur_malloc_words = 0; // current size for MallocMaxTestWords
90
91 void os_init_globals() {
92 // Called from init_globals().
93 // See Threads::create_vm() in thread.cpp, and init.cpp.
94 os::init_globals();
95 }
96
97 static time_t get_timezone(const struct tm* time_struct) {
98 #if defined(_ALLBSD_SOURCE)
99 return time_struct->tm_gmtoff;
100 #elif defined(_WINDOWS)
101 long zone;
102 _get_timezone(&zone);
103 return static_cast<time_t>(zone);
104 #else
105 return timezone;
106 #endif
107 }
108
109 int os::snprintf(char* buf, size_t len, const char* fmt, ...) {
110 va_list args;
111 va_start(args, fmt);
112 int result = os::vsnprintf(buf, len, fmt, args);
113 va_end(args);
114 return result;
115 }
116
117 // Fill in buffer with current local time as an ISO-8601 string.
118 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
119 // Returns buffer, or NULL if it failed.
120 // This would mostly be a call to
121 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
122 // except that on Windows the %z behaves badly, so we do it ourselves.
123 // Also, people wanted milliseconds on there,
124 // and strftime doesn't do milliseconds.
125 char* os::iso8601_time(char* buffer, size_t buffer_length, bool utc) {
126 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
127 // 1 2
128 // 12345678901234567890123456789
129 // format string: "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"
130 static const size_t needed_buffer = 29;
131
132 // Sanity check the arguments
133 if (buffer == NULL) {
134 assert(false, "NULL buffer");
135 return NULL;
136 }
137 if (buffer_length < needed_buffer) {
138 assert(false, "buffer_length too small");
139 return NULL;
140 }
141 // Get the current time
142 jlong milliseconds_since_19700101 = javaTimeMillis();
143 const int milliseconds_per_microsecond = 1000;
144 const time_t seconds_since_19700101 =
145 milliseconds_since_19700101 / milliseconds_per_microsecond;
146 const int milliseconds_after_second =
147 milliseconds_since_19700101 % milliseconds_per_microsecond;
148 // Convert the time value to a tm and timezone variable
149 struct tm time_struct;
150 if (utc) {
151 if (gmtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
152 assert(false, "Failed gmtime_pd");
153 return NULL;
154 }
155 } else {
156 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
157 assert(false, "Failed localtime_pd");
158 return NULL;
159 }
160 }
161 const time_t zone = get_timezone(&time_struct);
162
163 // If daylight savings time is in effect,
164 // we are 1 hour East of our time zone
165 const time_t seconds_per_minute = 60;
166 const time_t minutes_per_hour = 60;
167 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
168 time_t UTC_to_local = zone;
169 if (time_struct.tm_isdst > 0) {
170 UTC_to_local = UTC_to_local - seconds_per_hour;
171 }
172
173 // No offset when dealing with UTC
174 if (utc) {
175 UTC_to_local = 0;
176 }
177
178 // Compute the time zone offset.
179 // localtime_pd() sets timezone to the difference (in seconds)
180 // between UTC and and local time.
181 // ISO 8601 says we need the difference between local time and UTC,
182 // we change the sign of the localtime_pd() result.
183 const time_t local_to_UTC = -(UTC_to_local);
184 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
185 char sign_local_to_UTC = '+';
186 time_t abs_local_to_UTC = local_to_UTC;
187 if (local_to_UTC < 0) {
188 sign_local_to_UTC = '-';
189 abs_local_to_UTC = -(abs_local_to_UTC);
190 }
191 // Convert time zone offset seconds to hours and minutes.
192 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
193 const time_t zone_min =
194 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
195
196 // Print an ISO 8601 date and time stamp into the buffer
197 const int year = 1900 + time_struct.tm_year;
198 const int month = 1 + time_struct.tm_mon;
199 const int printed = jio_snprintf(buffer, buffer_length,
200 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d",
201 year,
202 month,
203 time_struct.tm_mday,
204 time_struct.tm_hour,
205 time_struct.tm_min,
206 time_struct.tm_sec,
207 milliseconds_after_second,
208 sign_local_to_UTC,
209 zone_hours,
210 zone_min);
211 if (printed == 0) {
212 assert(false, "Failed jio_printf");
213 return NULL;
214 }
215 return buffer;
216 }
217
218 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
219 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
220
221 if (p >= MinPriority && p <= MaxPriority) {
222 int priority = java_to_os_priority[p];
223 return set_native_priority(thread, priority);
224 } else {
225 assert(false, "Should not happen");
226 return OS_ERR;
227 }
228 }
229
230 // The mapping from OS priority back to Java priority may be inexact because
231 // Java priorities can map M:1 with native priorities. If you want the definite
232 // Java priority then use JavaThread::java_priority()
233 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
234 int p;
235 int os_prio;
236 OSReturn ret = get_native_priority(thread, &os_prio);
237 if (ret != OS_OK) return ret;
238
239 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
240 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
241 } else {
242 // niceness values are in reverse order
243 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
244 }
245 priority = (ThreadPriority)p;
246 return OS_OK;
247 }
248
249 bool os::dll_build_name(char* buffer, size_t size, const char* fname) {
250 int n = jio_snprintf(buffer, size, "%s%s%s", JNI_LIB_PREFIX, fname, JNI_LIB_SUFFIX);
251 return (n != -1);
252 }
253
254 #if !defined(LINUX) && !defined(_WINDOWS)
255 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
256 committed_start = start;
257 committed_size = size;
258 return true;
259 }
260 #endif
261
262 // Helper for dll_locate_lib.
263 // Pass buffer and printbuffer as we already printed the path to buffer
264 // when we called get_current_directory. This way we avoid another buffer
265 // of size MAX_PATH.
266 static bool conc_path_file_and_check(char *buffer, char *printbuffer, size_t printbuflen,
267 const char* pname, char lastchar, const char* fname) {
268
269 // Concatenate path and file name, but don't print double path separators.
270 const char *filesep = (WINDOWS_ONLY(lastchar == ':' ||) lastchar == os::file_separator()[0]) ?
271 "" : os::file_separator();
272 int ret = jio_snprintf(printbuffer, printbuflen, "%s%s%s", pname, filesep, fname);
273 // Check whether file exists.
274 if (ret != -1) {
275 struct stat statbuf;
276 return os::stat(buffer, &statbuf) == 0;
277 }
278 return false;
279 }
280
281 bool os::dll_locate_lib(char *buffer, size_t buflen,
282 const char* pname, const char* fname) {
283 bool retval = false;
284
285 size_t fullfnamelen = strlen(JNI_LIB_PREFIX) + strlen(fname) + strlen(JNI_LIB_SUFFIX);
286 char* fullfname = (char*)NEW_C_HEAP_ARRAY(char, fullfnamelen + 1, mtInternal);
287 if (dll_build_name(fullfname, fullfnamelen + 1, fname)) {
288 const size_t pnamelen = pname ? strlen(pname) : 0;
289
290 if (pnamelen == 0) {
291 // If no path given, use current working directory.
292 const char* p = get_current_directory(buffer, buflen);
293 if (p != NULL) {
294 const size_t plen = strlen(buffer);
295 const char lastchar = buffer[plen - 1];
296 retval = conc_path_file_and_check(buffer, &buffer[plen], buflen - plen,
297 "", lastchar, fullfname);
298 }
299 } else if (strchr(pname, *os::path_separator()) != NULL) {
300 // A list of paths. Search for the path that contains the library.
301 int n;
302 char** pelements = split_path(pname, &n);
303 if (pelements != NULL) {
304 for (int i = 0; i < n; i++) {
305 char* path = pelements[i];
306 // Really shouldn't be NULL, but check can't hurt.
307 size_t plen = (path == NULL) ? 0 : strlen(path);
308 if (plen == 0) {
309 continue; // Skip the empty path values.
310 }
311 const char lastchar = path[plen - 1];
312 retval = conc_path_file_and_check(buffer, buffer, buflen, path, lastchar, fullfname);
313 if (retval) break;
314 }
315 // Release the storage allocated by split_path.
316 for (int i = 0; i < n; i++) {
317 if (pelements[i] != NULL) {
318 FREE_C_HEAP_ARRAY(char, pelements[i]);
319 }
320 }
321 FREE_C_HEAP_ARRAY(char*, pelements);
322 }
323 } else {
324 // A definite path.
325 const char lastchar = pname[pnamelen-1];
326 retval = conc_path_file_and_check(buffer, buffer, buflen, pname, lastchar, fullfname);
327 }
328 }
329
330 FREE_C_HEAP_ARRAY(char*, fullfname);
331 return retval;
332 }
333
334 // --------------------- sun.misc.Signal (optional) ---------------------
335
336
337 // SIGBREAK is sent by the keyboard to query the VM state
338 #ifndef SIGBREAK
339 #define SIGBREAK SIGQUIT
340 #endif
341
342 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
343
344
345 static void signal_thread_entry(JavaThread* thread, TRAPS) {
346 os::set_priority(thread, NearMaxPriority);
347 while (true) {
348 int sig;
349 {
350 // FIXME : Currently we have not decided what should be the status
351 // for this java thread blocked here. Once we decide about
352 // that we should fix this.
353 sig = os::signal_wait();
354 }
355 if (sig == os::sigexitnum_pd()) {
356 // Terminate the signal thread
357 return;
358 }
359
360 switch (sig) {
361 case SIGBREAK: {
362 // Check if the signal is a trigger to start the Attach Listener - in that
363 // case don't print stack traces.
364 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
365 continue;
366 }
367 // Print stack traces
368 // Any SIGBREAK operations added here should make sure to flush
369 // the output stream (e.g. tty->flush()) after output. See 4803766.
370 // Each module also prints an extra carriage return after its output.
371 VM_PrintThreads op;
372 VMThread::execute(&op);
373 VM_PrintJNI jni_op;
374 VMThread::execute(&jni_op);
375 VM_FindDeadlocks op1(tty);
376 VMThread::execute(&op1);
377 Universe::print_heap_at_SIGBREAK();
378 if (PrintClassHistogram) {
379 VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */);
380 VMThread::execute(&op1);
381 }
382 if (JvmtiExport::should_post_data_dump()) {
383 JvmtiExport::post_data_dump();
384 }
385 break;
386 }
387 default: {
388 // Dispatch the signal to java
389 HandleMark hm(THREAD);
390 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD);
391 if (klass != NULL) {
392 JavaValue result(T_VOID);
393 JavaCallArguments args;
394 args.push_int(sig);
395 JavaCalls::call_static(
396 &result,
397 klass,
398 vmSymbols::dispatch_name(),
399 vmSymbols::int_void_signature(),
400 &args,
401 THREAD
402 );
403 }
404 if (HAS_PENDING_EXCEPTION) {
405 // tty is initialized early so we don't expect it to be null, but
406 // if it is we can't risk doing an initialization that might
407 // trigger additional out-of-memory conditions
408 if (tty != NULL) {
409 char klass_name[256];
410 char tmp_sig_name[16];
411 const char* sig_name = "UNKNOWN";
412 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
413 name()->as_klass_external_name(klass_name, 256);
414 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
415 sig_name = tmp_sig_name;
416 warning("Exception %s occurred dispatching signal %s to handler"
417 "- the VM may need to be forcibly terminated",
418 klass_name, sig_name );
419 }
420 CLEAR_PENDING_EXCEPTION;
421 }
422 }
423 }
424 }
425 }
426
427 void os::init_before_ergo() {
428 initialize_initial_active_processor_count();
429 // We need to initialize large page support here because ergonomics takes some
430 // decisions depending on large page support and the calculated large page size.
431 large_page_init();
432
433 // We need to adapt the configured number of stack protection pages given
434 // in 4K pages to the actual os page size. We must do this before setting
435 // up minimal stack sizes etc. in os::init_2().
436 JavaThread::set_stack_red_zone_size (align_up(StackRedPages * 4 * K, vm_page_size()));
437 JavaThread::set_stack_yellow_zone_size (align_up(StackYellowPages * 4 * K, vm_page_size()));
438 JavaThread::set_stack_reserved_zone_size(align_up(StackReservedPages * 4 * K, vm_page_size()));
439 JavaThread::set_stack_shadow_zone_size (align_up(StackShadowPages * 4 * K, vm_page_size()));
440
441 // VM version initialization identifies some characteristics of the
442 // platform that are used during ergonomic decisions.
443 VM_Version::init_before_ergo();
444 }
445
446 void os::signal_init(TRAPS) {
447 if (!ReduceSignalUsage) {
448 // Setup JavaThread for processing signals
449 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
450 InstanceKlass* ik = InstanceKlass::cast(k);
451 instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
452
453 const char thread_name[] = "Signal Dispatcher";
454 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
455
456 // Initialize thread_oop to put it into the system threadGroup
457 Handle thread_group (THREAD, Universe::system_thread_group());
458 JavaValue result(T_VOID);
459 JavaCalls::call_special(&result, thread_oop,
460 ik,
461 vmSymbols::object_initializer_name(),
462 vmSymbols::threadgroup_string_void_signature(),
463 thread_group,
464 string,
465 CHECK);
466
467 Klass* group = SystemDictionary::ThreadGroup_klass();
468 JavaCalls::call_special(&result,
469 thread_group,
470 group,
471 vmSymbols::add_method_name(),
472 vmSymbols::thread_void_signature(),
473 thread_oop, // ARG 1
474 CHECK);
475
476 os::signal_init_pd();
477
478 { MutexLocker mu(Threads_lock);
479 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
480
481 // At this point it may be possible that no osthread was created for the
482 // JavaThread due to lack of memory. We would have to throw an exception
483 // in that case. However, since this must work and we do not allow
484 // exceptions anyway, check and abort if this fails.
485 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
486 vm_exit_during_initialization("java.lang.OutOfMemoryError",
487 os::native_thread_creation_failed_msg());
488 }
489
490 java_lang_Thread::set_thread(thread_oop(), signal_thread);
491 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
492 java_lang_Thread::set_daemon(thread_oop());
493
494 signal_thread->set_threadObj(thread_oop());
495 Threads::add(signal_thread);
496 Thread::start(signal_thread);
497 }
498 // Handle ^BREAK
499 os::signal(SIGBREAK, os::user_handler());
500 }
501 }
502
503
504 void os::terminate_signal_thread() {
505 if (!ReduceSignalUsage)
506 signal_notify(sigexitnum_pd());
507 }
508
509
510 // --------------------- loading libraries ---------------------
511
512 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
513 extern struct JavaVM_ main_vm;
514
515 static void* _native_java_library = NULL;
516
517 void* os::native_java_library() {
518 if (_native_java_library == NULL) {
519 char buffer[JVM_MAXPATHLEN];
520 char ebuf[1024];
521
522 // Try to load verify dll first. In 1.3 java dll depends on it and is not
523 // always able to find it when the loading executable is outside the JDK.
524 // In order to keep working with 1.2 we ignore any loading errors.
525 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
526 "verify")) {
527 dll_load(buffer, ebuf, sizeof(ebuf));
528 }
529
530 // Load java dll
531 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
532 "java")) {
533 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
534 }
535 if (_native_java_library == NULL) {
536 vm_exit_during_initialization("Unable to load native library", ebuf);
537 }
538
539 #if defined(__OpenBSD__)
540 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
541 // ignore errors
542 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
543 "net")) {
544 dll_load(buffer, ebuf, sizeof(ebuf));
545 }
546 #endif
547 }
548 return _native_java_library;
549 }
550
551 /*
552 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
553 * If check_lib == true then we are looking for an
554 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
555 * this library is statically linked into the image.
556 * If check_lib == false then we will look for the appropriate symbol in the
557 * executable if agent_lib->is_static_lib() == true or in the shared library
558 * referenced by 'handle'.
559 */
560 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
561 const char *syms[], size_t syms_len) {
562 assert(agent_lib != NULL, "sanity check");
563 const char *lib_name;
564 void *handle = agent_lib->os_lib();
565 void *entryName = NULL;
566 char *agent_function_name;
567 size_t i;
568
569 // If checking then use the agent name otherwise test is_static_lib() to
570 // see how to process this lookup
571 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
572 for (i = 0; i < syms_len; i++) {
573 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
574 if (agent_function_name == NULL) {
575 break;
576 }
577 entryName = dll_lookup(handle, agent_function_name);
578 FREE_C_HEAP_ARRAY(char, agent_function_name);
579 if (entryName != NULL) {
580 break;
581 }
582 }
583 return entryName;
584 }
585
586 // See if the passed in agent is statically linked into the VM image.
587 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
588 size_t syms_len) {
589 void *ret;
590 void *proc_handle;
591 void *save_handle;
592
593 assert(agent_lib != NULL, "sanity check");
594 if (agent_lib->name() == NULL) {
595 return false;
596 }
597 proc_handle = get_default_process_handle();
598 // Check for Agent_OnLoad/Attach_lib_name function
599 save_handle = agent_lib->os_lib();
600 // We want to look in this process' symbol table.
601 agent_lib->set_os_lib(proc_handle);
602 ret = find_agent_function(agent_lib, true, syms, syms_len);
603 if (ret != NULL) {
604 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
605 agent_lib->set_valid();
606 agent_lib->set_static_lib(true);
607 return true;
608 }
609 agent_lib->set_os_lib(save_handle);
610 return false;
611 }
612
613 // --------------------- heap allocation utilities ---------------------
614
615 char *os::strdup(const char *str, MEMFLAGS flags) {
616 size_t size = strlen(str);
617 char *dup_str = (char *)malloc(size + 1, flags);
618 if (dup_str == NULL) return NULL;
619 strcpy(dup_str, str);
620 return dup_str;
621 }
622
623 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
624 char* p = os::strdup(str, flags);
625 if (p == NULL) {
626 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
627 }
628 return p;
629 }
630
631
632 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
633
634 #ifdef ASSERT
635
636 static void verify_memory(void* ptr) {
637 GuardedMemory guarded(ptr);
638 if (!guarded.verify_guards()) {
639 LogTarget(Warning, malloc, free) lt;
640 ResourceMark rm;
641 LogStream ls(lt);
642 ls.print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
643 ls.print_cr("## memory stomp:");
644 guarded.print_on(&ls);
645 fatal("memory stomping error");
646 }
647 }
648
649 #endif
650
651 //
652 // This function supports testing of the malloc out of memory
653 // condition without really running the system out of memory.
654 //
655 static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
656 if (MallocMaxTestWords > 0) {
657 size_t words = (alloc_size / BytesPerWord);
658
659 if ((cur_malloc_words + words) > MallocMaxTestWords) {
660 return true;
661 }
662 Atomic::add(words, &cur_malloc_words);
663 }
664 return false;
665 }
666
667 void* os::malloc(size_t size, MEMFLAGS flags) {
668 return os::malloc(size, flags, CALLER_PC);
669 }
670
671 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
672 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
673 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
674
675 // Since os::malloc can be called when the libjvm.{dll,so} is
676 // first loaded and we don't have a thread yet we must accept NULL also here.
677 assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()),
678 "malloc() not allowed when crash protection is set");
679
680 if (size == 0) {
681 // return a valid pointer if size is zero
682 // if NULL is returned the calling functions assume out of memory.
683 size = 1;
684 }
685
686 // NMT support
687 NMT_TrackingLevel level = MemTracker::tracking_level();
688 size_t nmt_header_size = MemTracker::malloc_header_size(level);
689
690 #ifndef ASSERT
691 const size_t alloc_size = size + nmt_header_size;
692 #else
693 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
694 if (size + nmt_header_size > alloc_size) { // Check for rollover.
695 return NULL;
696 }
697 #endif
698
699 // For the test flag -XX:MallocMaxTestWords
700 if (has_reached_max_malloc_test_peak(size)) {
701 return NULL;
702 }
703
704 u_char* ptr;
705 ptr = (u_char*)::malloc(alloc_size);
706
707 #ifdef ASSERT
708 if (ptr == NULL) {
709 return NULL;
710 }
711 // Wrap memory with guard
712 GuardedMemory guarded(ptr, size + nmt_header_size);
713 ptr = guarded.get_user_ptr();
714 #endif
715 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
716 log_warning(malloc, free)("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
717 breakpoint();
718 }
719 debug_only(if (paranoid) verify_memory(ptr));
720
721 // we do not track guard memory
722 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
723 }
724
725 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
726 return os::realloc(memblock, size, flags, CALLER_PC);
727 }
728
729 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
730
731 // For the test flag -XX:MallocMaxTestWords
732 if (has_reached_max_malloc_test_peak(size)) {
733 return NULL;
734 }
735
736 if (size == 0) {
737 // return a valid pointer if size is zero
738 // if NULL is returned the calling functions assume out of memory.
739 size = 1;
740 }
741
742 #ifndef ASSERT
743 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
744 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
745 // NMT support
746 void* membase = MemTracker::record_free(memblock);
747 NMT_TrackingLevel level = MemTracker::tracking_level();
748 size_t nmt_header_size = MemTracker::malloc_header_size(level);
749 void* ptr = ::realloc(membase, size + nmt_header_size);
750 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
751 #else
752 if (memblock == NULL) {
753 return os::malloc(size, memflags, stack);
754 }
755 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
756 log_warning(malloc, free)("os::realloc caught " PTR_FORMAT, p2i(memblock));
757 breakpoint();
758 }
759 // NMT support
760 void* membase = MemTracker::malloc_base(memblock);
761 verify_memory(membase);
762 // always move the block
763 void* ptr = os::malloc(size, memflags, stack);
764 // Copy to new memory if malloc didn't fail
765 if (ptr != NULL ) {
766 GuardedMemory guarded(MemTracker::malloc_base(memblock));
767 // Guard's user data contains NMT header
768 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
769 memcpy(ptr, memblock, MIN2(size, memblock_size));
770 if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
771 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
772 log_warning(malloc, free)("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
773 breakpoint();
774 }
775 os::free(memblock);
776 }
777 return ptr;
778 #endif
779 }
780
781
782 void os::free(void *memblock) {
783 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
784 #ifdef ASSERT
785 if (memblock == NULL) return;
786 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
787 log_warning(malloc, free)("os::free caught " PTR_FORMAT, p2i(memblock));
788 breakpoint();
789 }
790 void* membase = MemTracker::record_free(memblock);
791 verify_memory(membase);
792
793 GuardedMemory guarded(membase);
794 size_t size = guarded.get_user_size();
795 inc_stat_counter(&free_bytes, size);
796 membase = guarded.release_for_freeing();
797 ::free(membase);
798 #else
799 void* membase = MemTracker::record_free(memblock);
800 ::free(membase);
801 #endif
802 }
803
804 void os::init_random(unsigned int initval) {
805 _rand_seed = initval;
806 }
807
808
809 static int random_helper(unsigned int rand_seed) {
810 /* standard, well-known linear congruential random generator with
811 * next_rand = (16807*seed) mod (2**31-1)
812 * see
813 * (1) "Random Number Generators: Good Ones Are Hard to Find",
814 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
815 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
816 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
817 */
818 const unsigned int a = 16807;
819 const unsigned int m = 2147483647;
820 const int q = m / a; assert(q == 127773, "weird math");
821 const int r = m % a; assert(r == 2836, "weird math");
822
823 // compute az=2^31p+q
824 unsigned int lo = a * (rand_seed & 0xFFFF);
825 unsigned int hi = a * (rand_seed >> 16);
826 lo += (hi & 0x7FFF) << 16;
827
828 // if q overflowed, ignore the overflow and increment q
829 if (lo > m) {
830 lo &= m;
831 ++lo;
832 }
833 lo += hi >> 15;
834
835 // if (p+q) overflowed, ignore the overflow and increment (p+q)
836 if (lo > m) {
837 lo &= m;
838 ++lo;
839 }
840 return lo;
841 }
842
843 int os::random() {
844 // Make updating the random seed thread safe.
845 while (true) {
846 unsigned int seed = _rand_seed;
847 unsigned int rand = random_helper(seed);
848 if (Atomic::cmpxchg(rand, &_rand_seed, seed) == seed) {
849 return static_cast<int>(rand);
850 }
851 }
852 }
853
854 // The INITIALIZED state is distinguished from the SUSPENDED state because the
855 // conditions in which a thread is first started are different from those in which
856 // a suspension is resumed. These differences make it hard for us to apply the
857 // tougher checks when starting threads that we want to do when resuming them.
858 // However, when start_thread is called as a result of Thread.start, on a Java
859 // thread, the operation is synchronized on the Java Thread object. So there
860 // cannot be a race to start the thread and hence for the thread to exit while
861 // we are working on it. Non-Java threads that start Java threads either have
862 // to do so in a context in which races are impossible, or should do appropriate
863 // locking.
864
865 void os::start_thread(Thread* thread) {
866 // guard suspend/resume
867 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
868 OSThread* osthread = thread->osthread();
869 osthread->set_state(RUNNABLE);
870 pd_start_thread(thread);
871 }
872
873 void os::abort(bool dump_core) {
874 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
875 }
876
877 //---------------------------------------------------------------------------
878 // Helper functions for fatal error handler
879
880 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
881 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
882
883 int cols = 0;
884 int cols_per_line = 0;
885 switch (unitsize) {
886 case 1: cols_per_line = 16; break;
887 case 2: cols_per_line = 8; break;
888 case 4: cols_per_line = 4; break;
889 case 8: cols_per_line = 2; break;
890 default: return;
891 }
892
893 address p = start;
894 st->print(PTR_FORMAT ": ", p2i(start));
895 while (p < end) {
896 switch (unitsize) {
897 case 1: st->print("%02x", *(u1*)p); break;
898 case 2: st->print("%04x", *(u2*)p); break;
899 case 4: st->print("%08x", *(u4*)p); break;
900 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
901 }
902 p += unitsize;
903 cols++;
904 if (cols >= cols_per_line && p < end) {
905 cols = 0;
906 st->cr();
907 st->print(PTR_FORMAT ": ", p2i(p));
908 } else {
909 st->print(" ");
910 }
911 }
912 st->cr();
913 }
914
915 void os::print_environment_variables(outputStream* st, const char** env_list) {
916 if (env_list) {
917 st->print_cr("Environment Variables:");
918
919 for (int i = 0; env_list[i] != NULL; i++) {
920 char *envvar = ::getenv(env_list[i]);
921 if (envvar != NULL) {
922 st->print("%s", env_list[i]);
923 st->print("=");
924 st->print_cr("%s", envvar);
925 }
926 }
927 }
928 }
929
930 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
931 // cpu
932 st->print("CPU:");
933 st->print("total %d", os::processor_count());
934 // It's not safe to query number of active processors after crash
935 // st->print("(active %d)", os::active_processor_count()); but we can
936 // print the initial number of active processors.
937 // We access the raw value here because the assert in the accessor will
938 // fail if the crash occurs before initialization of this value.
939 st->print(" (initial active %d)", _initial_active_processor_count);
940 st->print(" %s", VM_Version::features_string());
941 st->cr();
942 pd_print_cpu_info(st, buf, buflen);
943 }
944
945 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version
946 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
947 st->print("Host: ");
948 #ifndef PRODUCT
949 if (get_host_name(buf, buflen)) {
950 st->print("%s, ", buf);
951 }
952 #endif // PRODUCT
953 get_summary_cpu_info(buf, buflen);
954 st->print("%s, ", buf);
955 size_t mem = physical_memory()/G;
956 if (mem == 0) { // for low memory systems
957 mem = physical_memory()/M;
958 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
959 } else {
960 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
961 }
962 get_summary_os_info(buf, buflen);
963 st->print_raw(buf);
964 st->cr();
965 }
966
967 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
968 const int secs_per_day = 86400;
969 const int secs_per_hour = 3600;
970 const int secs_per_min = 60;
971
972 time_t tloc;
973 (void)time(&tloc);
974 char* timestring = ctime(&tloc); // ctime adds newline.
975 // edit out the newline
976 char* nl = strchr(timestring, '\n');
977 if (nl != NULL) {
978 *nl = '\0';
979 }
980
981 struct tm tz;
982 if (localtime_pd(&tloc, &tz) != NULL) {
983 ::strftime(buf, buflen, "%Z", &tz);
984 st->print("Time: %s %s", timestring, buf);
985 } else {
986 st->print("Time: %s", timestring);
987 }
988
989 double t = os::elapsedTime();
990 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
991 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
992 // before printf. We lost some precision, but who cares?
993 int eltime = (int)t; // elapsed time in seconds
994
995 // print elapsed time in a human-readable format:
996 int eldays = eltime / secs_per_day;
997 int day_secs = eldays * secs_per_day;
998 int elhours = (eltime - day_secs) / secs_per_hour;
999 int hour_secs = elhours * secs_per_hour;
1000 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
1001 int minute_secs = elmins * secs_per_min;
1002 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
1003 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
1004 }
1005
1006 // moved from debug.cpp (used to be find()) but still called from there
1007 // The verbose parameter is only set by the debug code in one case
1008 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
1009 address addr = (address)x;
1010 // Handle NULL first, so later checks don't need to protect against it.
1011 if (addr == NULL) {
1012 st->print_cr("0x0 is NULL");
1013 return;
1014 }
1015 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
1016 if (b != NULL) {
1017 if (b->is_buffer_blob()) {
1018 // the interpreter is generated into a buffer blob
1019 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
1020 if (i != NULL) {
1021 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", p2i(addr), (int)(addr - i->code_begin()));
1022 i->print_on(st);
1023 return;
1024 }
1025 if (Interpreter::contains(addr)) {
1026 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
1027 " (not bytecode specific)", p2i(addr));
1028 return;
1029 }
1030 //
1031 if (AdapterHandlerLibrary::contains(b)) {
1032 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", p2i(addr), (int)(addr - b->code_begin()));
1033 AdapterHandlerLibrary::print_handler_on(st, b);
1034 }
1035 // the stubroutines are generated into a buffer blob
1036 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
1037 if (d != NULL) {
1038 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", p2i(addr), (int)(addr - d->begin()));
1039 d->print_on(st);
1040 st->cr();
1041 return;
1042 }
1043 if (StubRoutines::contains(addr)) {
1044 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) stub routine", p2i(addr));
1045 return;
1046 }
1047 // the InlineCacheBuffer is using stubs generated into a buffer blob
1048 if (InlineCacheBuffer::contains(addr)) {
1049 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", p2i(addr));
1050 return;
1051 }
1052 VtableStub* v = VtableStubs::stub_containing(addr);
1053 if (v != NULL) {
1054 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", p2i(addr), (int)(addr - v->entry_point()));
1055 v->print_on(st);
1056 st->cr();
1057 return;
1058 }
1059 }
1060 nmethod* nm = b->as_nmethod_or_null();
1061 if (nm != NULL) {
1062 ResourceMark rm;
1063 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
1064 p2i(addr), (int)(addr - nm->entry_point()), p2i(nm));
1065 if (verbose) {
1066 st->print(" for ");
1067 nm->method()->print_value_on(st);
1068 }
1069 st->cr();
1070 nm->print_nmethod(verbose);
1071 return;
1072 }
1073 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", p2i(addr), (int)(addr - b->code_begin()));
1074 b->print_on(st);
1075 return;
1076 }
1077
1078 if (Universe::heap()->is_in(addr)) {
1079 HeapWord* p = Universe::heap()->block_start(addr);
1080 bool print = false;
1081 // If we couldn't find it it just may mean that heap wasn't parsable
1082 // See if we were just given an oop directly
1083 if (p != NULL && Universe::heap()->block_is_obj(p)) {
1084 print = true;
1085 } else if (p == NULL && oopDesc::is_oop(oop(addr))) {
1086 p = (HeapWord*) addr;
1087 print = true;
1088 }
1089 if (print) {
1090 if (p == (HeapWord*) addr) {
1091 st->print_cr(INTPTR_FORMAT " is an oop", p2i(addr));
1092 } else {
1093 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, p2i(addr), p2i(p));
1094 }
1095 oop(p)->print_on(st);
1096 return;
1097 }
1098 } else {
1099 if (Universe::heap()->is_in_reserved(addr)) {
1100 st->print_cr(INTPTR_FORMAT " is an unallocated location "
1101 "in the heap", p2i(addr));
1102 return;
1103 }
1104 }
1105 if (JNIHandles::is_global_handle((jobject) addr)) {
1106 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
1107 return;
1108 }
1109 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1110 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
1111 return;
1112 }
1113 #ifndef PRODUCT
1114 // we don't keep the block list in product mode
1115 if (JNIHandles::is_local_handle((jobject) addr)) {
1116 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
1117 return;
1118 }
1119 #endif
1120
1121 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
1122 // Check for privilege stack
1123 if (thread->privileged_stack_top() != NULL &&
1124 thread->privileged_stack_top()->contains(addr)) {
1125 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
1126 "for thread: " INTPTR_FORMAT, p2i(addr), p2i(thread));
1127 if (verbose) thread->print_on(st);
1128 return;
1129 }
1130 // If the addr is a java thread print information about that.
1131 if (addr == (address)thread) {
1132 if (verbose) {
1133 thread->print_on(st);
1134 } else {
1135 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
1136 }
1137 return;
1138 }
1139 // If the addr is in the stack region for this thread then report that
1140 // and print thread info
1141 if (thread->on_local_stack(addr)) {
1142 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1143 INTPTR_FORMAT, p2i(addr), p2i(thread));
1144 if (verbose) thread->print_on(st);
1145 return;
1146 }
1147 }
1148
1149 // Check if in metaspace and print types that have vptrs (only method now)
1150 if (Metaspace::contains(addr)) {
1151 if (Method::has_method_vptr((const void*)addr)) {
1152 ((Method*)addr)->print_value_on(st);
1153 st->cr();
1154 } else {
1155 // Use addr->print() from the debugger instead (not here)
1156 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
1157 }
1158 return;
1159 }
1160
1161 // Try an OS specific find
1162 if (os::find(addr, st)) {
1163 return;
1164 }
1165
1166 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
1167 }
1168
1169 // Looks like all platforms can use the same function to check if C
1170 // stack is walkable beyond current frame. The check for fp() is not
1171 // necessary on Sparc, but it's harmless.
1172 bool os::is_first_C_frame(frame* fr) {
1173 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1174 // Check usp first, because if that's bad the other accessors may fault
1175 // on some architectures. Ditto ufp second, etc.
1176 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1177 // sp on amd can be 32 bit aligned.
1178 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1179
1180 uintptr_t usp = (uintptr_t)fr->sp();
1181 if ((usp & sp_align_mask) != 0) return true;
1182
1183 uintptr_t ufp = (uintptr_t)fr->fp();
1184 if ((ufp & fp_align_mask) != 0) return true;
1185
1186 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1187 if ((old_sp & sp_align_mask) != 0) return true;
1188 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1189
1190 uintptr_t old_fp = (uintptr_t)fr->link();
1191 if ((old_fp & fp_align_mask) != 0) return true;
1192 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1193
1194 // stack grows downwards; if old_fp is below current fp or if the stack
1195 // frame is too large, either the stack is corrupted or fp is not saved
1196 // on stack (i.e. on x86, ebp may be used as general register). The stack
1197 // is not walkable beyond current frame.
1198 if (old_fp < ufp) return true;
1199 if (old_fp - ufp > 64 * K) return true;
1200
1201 return false;
1202 }
1203
1204
1205 // Set up the boot classpath.
1206
1207 char* os::format_boot_path(const char* format_string,
1208 const char* home,
1209 int home_len,
1210 char fileSep,
1211 char pathSep) {
1212 assert((fileSep == '/' && pathSep == ':') ||
1213 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1214
1215 // Scan the format string to determine the length of the actual
1216 // boot classpath, and handle platform dependencies as well.
1217 int formatted_path_len = 0;
1218 const char* p;
1219 for (p = format_string; *p != 0; ++p) {
1220 if (*p == '%') formatted_path_len += home_len - 1;
1221 ++formatted_path_len;
1222 }
1223
1224 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1225 if (formatted_path == NULL) {
1226 return NULL;
1227 }
1228
1229 // Create boot classpath from format, substituting separator chars and
1230 // java home directory.
1231 char* q = formatted_path;
1232 for (p = format_string; *p != 0; ++p) {
1233 switch (*p) {
1234 case '%':
1235 strcpy(q, home);
1236 q += home_len;
1237 break;
1238 case '/':
1239 *q++ = fileSep;
1240 break;
1241 case ':':
1242 *q++ = pathSep;
1243 break;
1244 default:
1245 *q++ = *p;
1246 }
1247 }
1248 *q = '\0';
1249
1250 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1251 return formatted_path;
1252 }
1253
1254 // This function is a proxy to fopen, it tries to add a non standard flag ('e' or 'N')
1255 // that ensures automatic closing of the file on exec. If it can not find support in
1256 // the underlying c library, it will make an extra system call (fcntl) to ensure automatic
1257 // closing of the file on exec.
1258 FILE* os::fopen(const char* path, const char* mode) {
1259 char modified_mode[20];
1260 assert(strlen(mode) + 1 < sizeof(modified_mode), "mode chars plus one extra must fit in buffer");
1261 sprintf(modified_mode, "%s" LINUX_ONLY("e") BSD_ONLY("e") WINDOWS_ONLY("N"), mode);
1262 FILE* file = ::fopen(path, modified_mode);
1263
1264 #if !(defined LINUX || defined BSD || defined _WINDOWS)
1265 // assume fcntl FD_CLOEXEC support as a backup solution when 'e' or 'N'
1266 // is not supported as mode in fopen
1267 if (file != NULL) {
1268 int fd = fileno(file);
1269 if (fd != -1) {
1270 int fd_flags = fcntl(fd, F_GETFD);
1271 if (fd_flags != -1) {
1272 fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC);
1273 }
1274 }
1275 }
1276 #endif
1277
1278 return file;
1279 }
1280
1281 bool os::set_boot_path(char fileSep, char pathSep) {
1282 const char* home = Arguments::get_java_home();
1283 int home_len = (int)strlen(home);
1284
1285 struct stat st;
1286
1287 // modular image if "modules" jimage exists
1288 char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep);
1289 if (jimage == NULL) return false;
1290 bool has_jimage = (os::stat(jimage, &st) == 0);
1291 if (has_jimage) {
1292 Arguments::set_sysclasspath(jimage, true);
1293 FREE_C_HEAP_ARRAY(char, jimage);
1294 return true;
1295 }
1296 FREE_C_HEAP_ARRAY(char, jimage);
1297
1298 // check if developer build with exploded modules
1299 char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep);
1300 if (base_classes == NULL) return false;
1301 if (os::stat(base_classes, &st) == 0) {
1302 Arguments::set_sysclasspath(base_classes, false);
1303 FREE_C_HEAP_ARRAY(char, base_classes);
1304 return true;
1305 }
1306 FREE_C_HEAP_ARRAY(char, base_classes);
1307
1308 return false;
1309 }
1310
1311 /*
1312 * Splits a path, based on its separator, the number of
1313 * elements is returned back in n.
1314 * It is the callers responsibility to:
1315 * a> check the value of n, and n may be 0.
1316 * b> ignore any empty path elements
1317 * c> free up the data.
1318 */
1319 char** os::split_path(const char* path, int* n) {
1320 *n = 0;
1321 if (path == NULL || strlen(path) == 0) {
1322 return NULL;
1323 }
1324 const char psepchar = *os::path_separator();
1325 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1326 if (inpath == NULL) {
1327 return NULL;
1328 }
1329 strcpy(inpath, path);
1330 int count = 1;
1331 char* p = strchr(inpath, psepchar);
1332 // Get a count of elements to allocate memory
1333 while (p != NULL) {
1334 count++;
1335 p++;
1336 p = strchr(p, psepchar);
1337 }
1338 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1339 if (opath == NULL) {
1340 return NULL;
1341 }
1342
1343 // do the actual splitting
1344 p = inpath;
1345 for (int i = 0 ; i < count ; i++) {
1346 size_t len = strcspn(p, os::path_separator());
1347 if (len > JVM_MAXPATHLEN) {
1348 return NULL;
1349 }
1350 // allocate the string and add terminator storage
1351 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1352 if (s == NULL) {
1353 return NULL;
1354 }
1355 strncpy(s, p, len);
1356 s[len] = '\0';
1357 opath[i] = s;
1358 p += len + 1;
1359 }
1360 FREE_C_HEAP_ARRAY(char, inpath);
1361 *n = count;
1362 return opath;
1363 }
1364
1365 void os::set_memory_serialize_page(address page) {
1366 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1367 _mem_serialize_page = (volatile int32_t *)page;
1368 // We initialize the serialization page shift count here
1369 // We assume a cache line size of 64 bytes
1370 assert(SerializePageShiftCount == count, "JavaThread size changed; "
1371 "SerializePageShiftCount constant should be %d", count);
1372 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1373 }
1374
1375 static volatile intptr_t SerializePageLock = 0;
1376
1377 // This method is called from signal handler when SIGSEGV occurs while the current
1378 // thread tries to store to the "read-only" memory serialize page during state
1379 // transition.
1380 void os::block_on_serialize_page_trap() {
1381 log_debug(safepoint)("Block until the serialize page permission restored");
1382
1383 // When VMThread is holding the SerializePageLock during modifying the
1384 // access permission of the memory serialize page, the following call
1385 // will block until the permission of that page is restored to rw.
1386 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1387 // this case, it's OK as the signal is synchronous and we know precisely when
1388 // it can occur.
1389 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1390 Thread::muxRelease(&SerializePageLock);
1391 }
1392
1393 // Serialize all thread state variables
1394 void os::serialize_thread_states() {
1395 // On some platforms such as Solaris & Linux, the time duration of the page
1396 // permission restoration is observed to be much longer than expected due to
1397 // scheduler starvation problem etc. To avoid the long synchronization
1398 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1399 // the mutator thread if such case is encountered. See bug 6546278 for details.
1400 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1401 os::protect_memory((char *)os::get_memory_serialize_page(),
1402 os::vm_page_size(), MEM_PROT_READ);
1403 os::protect_memory((char *)os::get_memory_serialize_page(),
1404 os::vm_page_size(), MEM_PROT_RW);
1405 Thread::muxRelease(&SerializePageLock);
1406 }
1407
1408 // Returns true if the current stack pointer is above the stack shadow
1409 // pages, false otherwise.
1410 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) {
1411 if (!thread->is_Java_thread()) return false;
1412 // Check if we have StackShadowPages above the yellow zone. This parameter
1413 // is dependent on the depth of the maximum VM call stack possible from
1414 // the handler for stack overflow. 'instanceof' in the stack overflow
1415 // handler or a println uses at least 8k stack of VM and native code
1416 // respectively.
1417 const int framesize_in_bytes =
1418 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1419
1420 address limit = ((JavaThread*)thread)->stack_end() +
1421 (JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size());
1422
1423 return sp > (limit + framesize_in_bytes);
1424 }
1425
1426 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1427 assert(min_pages > 0, "sanity");
1428 if (UseLargePages) {
1429 const size_t max_page_size = region_size / min_pages;
1430
1431 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1432 const size_t page_size = _page_sizes[i];
1433 if (page_size <= max_page_size) {
1434 if (!must_be_aligned || is_aligned(region_size, page_size)) {
1435 return page_size;
1436 }
1437 }
1438 }
1439 }
1440
1441 return vm_page_size();
1442 }
1443
1444 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1445 return page_size_for_region(region_size, min_pages, true);
1446 }
1447
1448 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1449 return page_size_for_region(region_size, min_pages, false);
1450 }
1451
1452 static const char* errno_to_string (int e, bool short_text) {
1453 #define ALL_SHARED_ENUMS(X) \
1454 X(E2BIG, "Argument list too long") \
1455 X(EACCES, "Permission denied") \
1456 X(EADDRINUSE, "Address in use") \
1457 X(EADDRNOTAVAIL, "Address not available") \
1458 X(EAFNOSUPPORT, "Address family not supported") \
1459 X(EAGAIN, "Resource unavailable, try again") \
1460 X(EALREADY, "Connection already in progress") \
1461 X(EBADF, "Bad file descriptor") \
1462 X(EBADMSG, "Bad message") \
1463 X(EBUSY, "Device or resource busy") \
1464 X(ECANCELED, "Operation canceled") \
1465 X(ECHILD, "No child processes") \
1466 X(ECONNABORTED, "Connection aborted") \
1467 X(ECONNREFUSED, "Connection refused") \
1468 X(ECONNRESET, "Connection reset") \
1469 X(EDEADLK, "Resource deadlock would occur") \
1470 X(EDESTADDRREQ, "Destination address required") \
1471 X(EDOM, "Mathematics argument out of domain of function") \
1472 X(EEXIST, "File exists") \
1473 X(EFAULT, "Bad address") \
1474 X(EFBIG, "File too large") \
1475 X(EHOSTUNREACH, "Host is unreachable") \
1476 X(EIDRM, "Identifier removed") \
1477 X(EILSEQ, "Illegal byte sequence") \
1478 X(EINPROGRESS, "Operation in progress") \
1479 X(EINTR, "Interrupted function") \
1480 X(EINVAL, "Invalid argument") \
1481 X(EIO, "I/O error") \
1482 X(EISCONN, "Socket is connected") \
1483 X(EISDIR, "Is a directory") \
1484 X(ELOOP, "Too many levels of symbolic links") \
1485 X(EMFILE, "Too many open files") \
1486 X(EMLINK, "Too many links") \
1487 X(EMSGSIZE, "Message too large") \
1488 X(ENAMETOOLONG, "Filename too long") \
1489 X(ENETDOWN, "Network is down") \
1490 X(ENETRESET, "Connection aborted by network") \
1491 X(ENETUNREACH, "Network unreachable") \
1492 X(ENFILE, "Too many files open in system") \
1493 X(ENOBUFS, "No buffer space available") \
1494 X(ENODATA, "No message is available on the STREAM head read queue") \
1495 X(ENODEV, "No such device") \
1496 X(ENOENT, "No such file or directory") \
1497 X(ENOEXEC, "Executable file format error") \
1498 X(ENOLCK, "No locks available") \
1499 X(ENOLINK, "Reserved") \
1500 X(ENOMEM, "Not enough space") \
1501 X(ENOMSG, "No message of the desired type") \
1502 X(ENOPROTOOPT, "Protocol not available") \
1503 X(ENOSPC, "No space left on device") \
1504 X(ENOSR, "No STREAM resources") \
1505 X(ENOSTR, "Not a STREAM") \
1506 X(ENOSYS, "Function not supported") \
1507 X(ENOTCONN, "The socket is not connected") \
1508 X(ENOTDIR, "Not a directory") \
1509 X(ENOTEMPTY, "Directory not empty") \
1510 X(ENOTSOCK, "Not a socket") \
1511 X(ENOTSUP, "Not supported") \
1512 X(ENOTTY, "Inappropriate I/O control operation") \
1513 X(ENXIO, "No such device or address") \
1514 X(EOPNOTSUPP, "Operation not supported on socket") \
1515 X(EOVERFLOW, "Value too large to be stored in data type") \
1516 X(EPERM, "Operation not permitted") \
1517 X(EPIPE, "Broken pipe") \
1518 X(EPROTO, "Protocol error") \
1519 X(EPROTONOSUPPORT, "Protocol not supported") \
1520 X(EPROTOTYPE, "Protocol wrong type for socket") \
1521 X(ERANGE, "Result too large") \
1522 X(EROFS, "Read-only file system") \
1523 X(ESPIPE, "Invalid seek") \
1524 X(ESRCH, "No such process") \
1525 X(ETIME, "Stream ioctl() timeout") \
1526 X(ETIMEDOUT, "Connection timed out") \
1527 X(ETXTBSY, "Text file busy") \
1528 X(EWOULDBLOCK, "Operation would block") \
1529 X(EXDEV, "Cross-device link")
1530
1531 #define DEFINE_ENTRY(e, text) { e, #e, text },
1532
1533 static const struct {
1534 int v;
1535 const char* short_text;
1536 const char* long_text;
1537 } table [] = {
1538
1539 ALL_SHARED_ENUMS(DEFINE_ENTRY)
1540
1541 // The following enums are not defined on all platforms.
1542 #ifdef ESTALE
1543 DEFINE_ENTRY(ESTALE, "Reserved")
1544 #endif
1545 #ifdef EDQUOT
1546 DEFINE_ENTRY(EDQUOT, "Reserved")
1547 #endif
1548 #ifdef EMULTIHOP
1549 DEFINE_ENTRY(EMULTIHOP, "Reserved")
1550 #endif
1551
1552 // End marker.
1553 { -1, "Unknown errno", "Unknown error" }
1554
1555 };
1556
1557 #undef DEFINE_ENTRY
1558 #undef ALL_FLAGS
1559
1560 int i = 0;
1561 while (table[i].v != -1 && table[i].v != e) {
1562 i ++;
1563 }
1564
1565 return short_text ? table[i].short_text : table[i].long_text;
1566
1567 }
1568
1569 const char* os::strerror(int e) {
1570 return errno_to_string(e, false);
1571 }
1572
1573 const char* os::errno_name(int e) {
1574 return errno_to_string(e, true);
1575 }
1576
1577 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) {
1578 LogTarget(Info, pagesize) log;
1579 if (log.is_enabled()) {
1580 LogStream out(log);
1581
1582 out.print("%s: ", str);
1583 for (int i = 0; i < count; ++i) {
1584 out.print(" " SIZE_FORMAT, page_sizes[i]);
1585 }
1586 out.cr();
1587 }
1588 }
1589
1590 #define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size)
1591
1592 void os::trace_page_sizes(const char* str,
1593 const size_t region_min_size,
1594 const size_t region_max_size,
1595 const size_t page_size,
1596 const char* base,
1597 const size_t size) {
1598
1599 log_info(pagesize)("%s: "
1600 " min=" SIZE_FORMAT "%s"
1601 " max=" SIZE_FORMAT "%s"
1602 " base=" PTR_FORMAT
1603 " page_size=" SIZE_FORMAT "%s"
1604 " size=" SIZE_FORMAT "%s",
1605 str,
1606 trace_page_size_params(region_min_size),
1607 trace_page_size_params(region_max_size),
1608 p2i(base),
1609 trace_page_size_params(page_size),
1610 trace_page_size_params(size));
1611 }
1612
1613 void os::trace_page_sizes_for_requested_size(const char* str,
1614 const size_t requested_size,
1615 const size_t page_size,
1616 const size_t alignment,
1617 const char* base,
1618 const size_t size) {
1619
1620 log_info(pagesize)("%s:"
1621 " req_size=" SIZE_FORMAT "%s"
1622 " base=" PTR_FORMAT
1623 " page_size=" SIZE_FORMAT "%s"
1624 " alignment=" SIZE_FORMAT "%s"
1625 " size=" SIZE_FORMAT "%s",
1626 str,
1627 trace_page_size_params(requested_size),
1628 p2i(base),
1629 trace_page_size_params(page_size),
1630 trace_page_size_params(alignment),
1631 trace_page_size_params(size));
1632 }
1633
1634
1635 // This is the working definition of a server class machine:
1636 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1637 // because the graphics memory (?) sometimes masks physical memory.
1638 // If you want to change the definition of a server class machine
1639 // on some OS or platform, e.g., >=4GB on Windows platforms,
1640 // then you'll have to parameterize this method based on that state,
1641 // as was done for logical processors here, or replicate and
1642 // specialize this method for each platform. (Or fix os to have
1643 // some inheritance structure and use subclassing. Sigh.)
1644 // If you want some platform to always or never behave as a server
1645 // class machine, change the setting of AlwaysActAsServerClassMachine
1646 // and NeverActAsServerClassMachine in globals*.hpp.
1647 bool os::is_server_class_machine() {
1648 // First check for the early returns
1649 if (NeverActAsServerClassMachine) {
1650 return false;
1651 }
1652 if (AlwaysActAsServerClassMachine) {
1653 return true;
1654 }
1655 // Then actually look at the machine
1656 bool result = false;
1657 const unsigned int server_processors = 2;
1658 const julong server_memory = 2UL * G;
1659 // We seem not to get our full complement of memory.
1660 // We allow some part (1/8?) of the memory to be "missing",
1661 // based on the sizes of DIMMs, and maybe graphics cards.
1662 const julong missing_memory = 256UL * M;
1663
1664 /* Is this a server class machine? */
1665 if ((os::active_processor_count() >= (int)server_processors) &&
1666 (os::physical_memory() >= (server_memory - missing_memory))) {
1667 const unsigned int logical_processors =
1668 VM_Version::logical_processors_per_package();
1669 if (logical_processors > 1) {
1670 const unsigned int physical_packages =
1671 os::active_processor_count() / logical_processors;
1672 if (physical_packages >= server_processors) {
1673 result = true;
1674 }
1675 } else {
1676 result = true;
1677 }
1678 }
1679 return result;
1680 }
1681
1682 void os::initialize_initial_active_processor_count() {
1683 assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
1684 _initial_active_processor_count = active_processor_count();
1685 log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count);
1686 }
1687
1688 void os::SuspendedThreadTask::run() {
1689 internal_do_task();
1690 _done = true;
1691 }
1692
1693 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1694 return os::pd_create_stack_guard_pages(addr, bytes);
1695 }
1696
1697 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, int file_desc) {
1698 char* result = NULL;
1699
1700 if (file_desc != -1) {
1701 // Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(),
1702 // but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file.
1703 result = os::map_memory_to_file(addr, bytes, file_desc);
1704 if (result != NULL) {
1705 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1706 }
1707 } else {
1708 result = pd_reserve_memory(bytes, addr, alignment_hint);
1709 if (result != NULL) {
1710 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1711 }
1712 }
1713
1714 return result;
1715 }
1716
1717 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1718 MEMFLAGS flags) {
1719 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1720 if (result != NULL) {
1721 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1722 MemTracker::record_virtual_memory_type((address)result, flags);
1723 }
1724
1725 return result;
1726 }
1727
1728 char* os::attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc) {
1729 char* result = NULL;
1730 if (file_desc != -1) {
1731 result = pd_attempt_reserve_memory_at(bytes, addr, file_desc);
1732 if (result != NULL) {
1733 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1734 }
1735 } else {
1736 result = pd_attempt_reserve_memory_at(bytes, addr);
1737 if (result != NULL) {
1738 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1739 }
1740 }
1741 return result;
1742 }
1743
1744 void os::split_reserved_memory(char *base, size_t size,
1745 size_t split, bool realloc) {
1746 pd_split_reserved_memory(base, size, split, realloc);
1747 }
1748
1749 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1750 bool res = pd_commit_memory(addr, bytes, executable);
1751 if (res) {
1752 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1753 }
1754 return res;
1755 }
1756
1757 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1758 bool executable) {
1759 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1760 if (res) {
1761 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1762 }
1763 return res;
1764 }
1765
1766 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1767 const char* mesg) {
1768 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1769 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1770 }
1771
1772 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1773 bool executable, const char* mesg) {
1774 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1775 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1776 }
1777
1778 bool os::uncommit_memory(char* addr, size_t bytes) {
1779 bool res;
1780 if (MemTracker::tracking_level() > NMT_minimal) {
1781 Tracker tkr(Tracker::uncommit);
1782 res = pd_uncommit_memory(addr, bytes);
1783 if (res) {
1784 tkr.record((address)addr, bytes);
1785 }
1786 } else {
1787 res = pd_uncommit_memory(addr, bytes);
1788 }
1789 return res;
1790 }
1791
1792 bool os::release_memory(char* addr, size_t bytes) {
1793 bool res;
1794 if (MemTracker::tracking_level() > NMT_minimal) {
1795 Tracker tkr(Tracker::release);
1796 res = pd_release_memory(addr, bytes);
1797 if (res) {
1798 tkr.record((address)addr, bytes);
1799 }
1800 } else {
1801 res = pd_release_memory(addr, bytes);
1802 }
1803 return res;
1804 }
1805
1806 void os::pretouch_memory(void* start, void* end, size_t page_size) {
1807 for (volatile char *p = (char*)start; p < (char*)end; p += page_size) {
1808 *p = 0;
1809 }
1810 }
1811
1812 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1813 char *addr, size_t bytes, bool read_only,
1814 bool allow_exec) {
1815 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1816 if (result != NULL) {
1817 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1818 }
1819 return result;
1820 }
1821
1822 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1823 char *addr, size_t bytes, bool read_only,
1824 bool allow_exec) {
1825 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1826 read_only, allow_exec);
1827 }
1828
1829 bool os::unmap_memory(char *addr, size_t bytes) {
1830 bool result;
1831 if (MemTracker::tracking_level() > NMT_minimal) {
1832 Tracker tkr(Tracker::release);
1833 result = pd_unmap_memory(addr, bytes);
1834 if (result) {
1835 tkr.record((address)addr, bytes);
1836 }
1837 } else {
1838 result = pd_unmap_memory(addr, bytes);
1839 }
1840 return result;
1841 }
1842
1843 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1844 pd_free_memory(addr, bytes, alignment_hint);
1845 }
1846
1847 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1848 pd_realign_memory(addr, bytes, alignment_hint);
1849 }
1850
1851 #ifndef _WINDOWS
1852 /* try to switch state from state "from" to state "to"
1853 * returns the state set after the method is complete
1854 */
1855 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1856 os::SuspendResume::State to)
1857 {
1858 os::SuspendResume::State result = Atomic::cmpxchg(to, &_state, from);
1859 if (result == from) {
1860 // success
1861 return to;
1862 }
1863 return result;
1864 }
1865 #endif