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 bool os::_nvdimm_present = false;
80 int os::_nvdimm_fd = -1;
81 address os::_dram_heap_base = NULL;
82 address os::_nvdimm_heap_base = NULL;
83 uint os::_nvdimm_region_length = 0;
84 int os::_initial_active_processor_count = 0;
85 size_t os::_page_sizes[os::page_sizes_max];
86
87 #ifndef PRODUCT
88 julong os::num_mallocs = 0; // # of calls to malloc/realloc
89 julong os::alloc_bytes = 0; // # of bytes allocated
90 julong os::num_frees = 0; // # of calls to free
91 julong os::free_bytes = 0; // # of bytes freed
92 #endif
93
94 static size_t cur_malloc_words = 0; // current size for MallocMaxTestWords
95
96 void os_init_globals() {
97 // Called from init_globals().
98 // See Threads::create_vm() in thread.cpp, and init.cpp.
99 os::init_globals();
100 }
101
102 static time_t get_timezone(const struct tm* time_struct) {
103 #if defined(_ALLBSD_SOURCE)
104 return time_struct->tm_gmtoff;
105 #elif defined(_WINDOWS)
106 long zone;
107 _get_timezone(&zone);
108 return static_cast<time_t>(zone);
109 #else
110 return timezone;
111 #endif
112 }
113
114 int os::snprintf(char* buf, size_t len, const char* fmt, ...) {
115 va_list args;
116 va_start(args, fmt);
117 int result = os::vsnprintf(buf, len, fmt, args);
118 va_end(args);
119 return result;
120 }
121
122 // Fill in buffer with current local time as an ISO-8601 string.
123 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
124 // Returns buffer, or NULL if it failed.
125 // This would mostly be a call to
126 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
127 // except that on Windows the %z behaves badly, so we do it ourselves.
128 // Also, people wanted milliseconds on there,
129 // and strftime doesn't do milliseconds.
130 char* os::iso8601_time(char* buffer, size_t buffer_length, bool utc) {
131 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
132 // 1 2
133 // 12345678901234567890123456789
134 // format string: "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"
135 static const size_t needed_buffer = 29;
136
137 // Sanity check the arguments
138 if (buffer == NULL) {
139 assert(false, "NULL buffer");
140 return NULL;
141 }
142 if (buffer_length < needed_buffer) {
143 assert(false, "buffer_length too small");
144 return NULL;
145 }
146 // Get the current time
147 jlong milliseconds_since_19700101 = javaTimeMillis();
148 const int milliseconds_per_microsecond = 1000;
149 const time_t seconds_since_19700101 =
150 milliseconds_since_19700101 / milliseconds_per_microsecond;
151 const int milliseconds_after_second =
152 milliseconds_since_19700101 % milliseconds_per_microsecond;
153 // Convert the time value to a tm and timezone variable
154 struct tm time_struct;
155 if (utc) {
156 if (gmtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
157 assert(false, "Failed gmtime_pd");
158 return NULL;
159 }
160 } else {
161 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
162 assert(false, "Failed localtime_pd");
163 return NULL;
164 }
165 }
166 const time_t zone = get_timezone(&time_struct);
167
168 // If daylight savings time is in effect,
169 // we are 1 hour East of our time zone
170 const time_t seconds_per_minute = 60;
171 const time_t minutes_per_hour = 60;
172 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
173 time_t UTC_to_local = zone;
174 if (time_struct.tm_isdst > 0) {
175 UTC_to_local = UTC_to_local - seconds_per_hour;
176 }
177
178 // No offset when dealing with UTC
179 if (utc) {
180 UTC_to_local = 0;
181 }
182
183 // Compute the time zone offset.
184 // localtime_pd() sets timezone to the difference (in seconds)
185 // between UTC and and local time.
186 // ISO 8601 says we need the difference between local time and UTC,
187 // we change the sign of the localtime_pd() result.
188 const time_t local_to_UTC = -(UTC_to_local);
189 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
190 char sign_local_to_UTC = '+';
191 time_t abs_local_to_UTC = local_to_UTC;
192 if (local_to_UTC < 0) {
193 sign_local_to_UTC = '-';
194 abs_local_to_UTC = -(abs_local_to_UTC);
195 }
196 // Convert time zone offset seconds to hours and minutes.
197 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
198 const time_t zone_min =
199 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
200
201 // Print an ISO 8601 date and time stamp into the buffer
202 const int year = 1900 + time_struct.tm_year;
203 const int month = 1 + time_struct.tm_mon;
204 const int printed = jio_snprintf(buffer, buffer_length,
205 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d",
206 year,
207 month,
208 time_struct.tm_mday,
209 time_struct.tm_hour,
210 time_struct.tm_min,
211 time_struct.tm_sec,
212 milliseconds_after_second,
213 sign_local_to_UTC,
214 zone_hours,
215 zone_min);
216 if (printed == 0) {
217 assert(false, "Failed jio_printf");
218 return NULL;
219 }
220 return buffer;
221 }
222
223 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
224 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
225
226 if (p >= MinPriority && p <= MaxPriority) {
227 int priority = java_to_os_priority[p];
228 return set_native_priority(thread, priority);
229 } else {
230 assert(false, "Should not happen");
231 return OS_ERR;
232 }
233 }
234
235 // The mapping from OS priority back to Java priority may be inexact because
236 // Java priorities can map M:1 with native priorities. If you want the definite
237 // Java priority then use JavaThread::java_priority()
238 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
239 int p;
240 int os_prio;
241 OSReturn ret = get_native_priority(thread, &os_prio);
242 if (ret != OS_OK) return ret;
243
244 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
245 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
246 } else {
247 // niceness values are in reverse order
248 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
249 }
250 priority = (ThreadPriority)p;
251 return OS_OK;
252 }
253
254 bool os::dll_build_name(char* buffer, size_t size, const char* fname) {
255 int n = jio_snprintf(buffer, size, "%s%s%s", JNI_LIB_PREFIX, fname, JNI_LIB_SUFFIX);
256 return (n != -1);
257 }
258
259 #if !defined(LINUX) && !defined(_WINDOWS)
260 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
261 committed_start = start;
262 committed_size = size;
263 return true;
264 }
265 #endif
266
267 // Helper for dll_locate_lib.
268 // Pass buffer and printbuffer as we already printed the path to buffer
269 // when we called get_current_directory. This way we avoid another buffer
270 // of size MAX_PATH.
271 static bool conc_path_file_and_check(char *buffer, char *printbuffer, size_t printbuflen,
272 const char* pname, char lastchar, const char* fname) {
273
274 // Concatenate path and file name, but don't print double path separators.
275 const char *filesep = (WINDOWS_ONLY(lastchar == ':' ||) lastchar == os::file_separator()[0]) ?
276 "" : os::file_separator();
277 int ret = jio_snprintf(printbuffer, printbuflen, "%s%s%s", pname, filesep, fname);
278 // Check whether file exists.
279 if (ret != -1) {
280 struct stat statbuf;
281 return os::stat(buffer, &statbuf) == 0;
282 }
283 return false;
284 }
285
286 bool os::dll_locate_lib(char *buffer, size_t buflen,
287 const char* pname, const char* fname) {
288 bool retval = false;
289
290 size_t fullfnamelen = strlen(JNI_LIB_PREFIX) + strlen(fname) + strlen(JNI_LIB_SUFFIX);
291 char* fullfname = (char*)NEW_C_HEAP_ARRAY(char, fullfnamelen + 1, mtInternal);
292 if (dll_build_name(fullfname, fullfnamelen + 1, fname)) {
293 const size_t pnamelen = pname ? strlen(pname) : 0;
294
295 if (pnamelen == 0) {
296 // If no path given, use current working directory.
297 const char* p = get_current_directory(buffer, buflen);
298 if (p != NULL) {
299 const size_t plen = strlen(buffer);
300 const char lastchar = buffer[plen - 1];
301 retval = conc_path_file_and_check(buffer, &buffer[plen], buflen - plen,
302 "", lastchar, fullfname);
303 }
304 } else if (strchr(pname, *os::path_separator()) != NULL) {
305 // A list of paths. Search for the path that contains the library.
306 int n;
307 char** pelements = split_path(pname, &n);
308 if (pelements != NULL) {
309 for (int i = 0; i < n; i++) {
310 char* path = pelements[i];
311 // Really shouldn't be NULL, but check can't hurt.
312 size_t plen = (path == NULL) ? 0 : strlen(path);
313 if (plen == 0) {
314 continue; // Skip the empty path values.
315 }
316 const char lastchar = path[plen - 1];
317 retval = conc_path_file_and_check(buffer, buffer, buflen, path, lastchar, fullfname);
318 if (retval) break;
319 }
320 // Release the storage allocated by split_path.
321 for (int i = 0; i < n; i++) {
322 if (pelements[i] != NULL) {
323 FREE_C_HEAP_ARRAY(char, pelements[i]);
324 }
325 }
326 FREE_C_HEAP_ARRAY(char*, pelements);
327 }
328 } else {
329 // A definite path.
330 const char lastchar = pname[pnamelen-1];
331 retval = conc_path_file_and_check(buffer, buffer, buflen, pname, lastchar, fullfname);
332 }
333 }
334
335 FREE_C_HEAP_ARRAY(char*, fullfname);
336 return retval;
337 }
338
339 // --------------------- sun.misc.Signal (optional) ---------------------
340
341
342 // SIGBREAK is sent by the keyboard to query the VM state
343 #ifndef SIGBREAK
344 #define SIGBREAK SIGQUIT
345 #endif
346
347 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
348
349
350 static void signal_thread_entry(JavaThread* thread, TRAPS) {
351 os::set_priority(thread, NearMaxPriority);
352 while (true) {
353 int sig;
354 {
355 // FIXME : Currently we have not decided what should be the status
356 // for this java thread blocked here. Once we decide about
357 // that we should fix this.
358 sig = os::signal_wait();
359 }
360 if (sig == os::sigexitnum_pd()) {
361 // Terminate the signal thread
362 return;
363 }
364
365 switch (sig) {
366 case SIGBREAK: {
367 // Check if the signal is a trigger to start the Attach Listener - in that
368 // case don't print stack traces.
369 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
370 continue;
371 }
372 // Print stack traces
373 // Any SIGBREAK operations added here should make sure to flush
374 // the output stream (e.g. tty->flush()) after output. See 4803766.
375 // Each module also prints an extra carriage return after its output.
376 VM_PrintThreads op;
377 VMThread::execute(&op);
378 VM_PrintJNI jni_op;
379 VMThread::execute(&jni_op);
380 VM_FindDeadlocks op1(tty);
381 VMThread::execute(&op1);
382 Universe::print_heap_at_SIGBREAK();
383 if (PrintClassHistogram) {
384 VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */);
385 VMThread::execute(&op1);
386 }
387 if (JvmtiExport::should_post_data_dump()) {
388 JvmtiExport::post_data_dump();
389 }
390 break;
391 }
392 default: {
393 // Dispatch the signal to java
394 HandleMark hm(THREAD);
395 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD);
396 if (klass != NULL) {
397 JavaValue result(T_VOID);
398 JavaCallArguments args;
399 args.push_int(sig);
400 JavaCalls::call_static(
401 &result,
402 klass,
403 vmSymbols::dispatch_name(),
404 vmSymbols::int_void_signature(),
405 &args,
406 THREAD
407 );
408 }
409 if (HAS_PENDING_EXCEPTION) {
410 // tty is initialized early so we don't expect it to be null, but
411 // if it is we can't risk doing an initialization that might
412 // trigger additional out-of-memory conditions
413 if (tty != NULL) {
414 char klass_name[256];
415 char tmp_sig_name[16];
416 const char* sig_name = "UNKNOWN";
417 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
418 name()->as_klass_external_name(klass_name, 256);
419 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
420 sig_name = tmp_sig_name;
421 warning("Exception %s occurred dispatching signal %s to handler"
422 "- the VM may need to be forcibly terminated",
423 klass_name, sig_name );
424 }
425 CLEAR_PENDING_EXCEPTION;
426 }
427 }
428 }
429 }
430 }
431
432 void os::init_before_ergo() {
433 initialize_initial_active_processor_count();
434 // We need to initialize large page support here because ergonomics takes some
435 // decisions depending on large page support and the calculated large page size.
436 large_page_init();
437
438 // We need to adapt the configured number of stack protection pages given
439 // in 4K pages to the actual os page size. We must do this before setting
440 // up minimal stack sizes etc. in os::init_2().
441 JavaThread::set_stack_red_zone_size (align_up(StackRedPages * 4 * K, vm_page_size()));
442 JavaThread::set_stack_yellow_zone_size (align_up(StackYellowPages * 4 * K, vm_page_size()));
443 JavaThread::set_stack_reserved_zone_size(align_up(StackReservedPages * 4 * K, vm_page_size()));
444 JavaThread::set_stack_shadow_zone_size (align_up(StackShadowPages * 4 * K, vm_page_size()));
445
446 // VM version initialization identifies some characteristics of the
447 // platform that are used during ergonomic decisions.
448 VM_Version::init_before_ergo();
449 }
450
451 void os::initialize_jdk_signal_support(TRAPS) {
452 if (!ReduceSignalUsage) {
453 // Setup JavaThread for processing signals
454 const char thread_name[] = "Signal Dispatcher";
455 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
456
457 // Initialize thread_oop to put it into the system threadGroup
458 Handle thread_group (THREAD, Universe::system_thread_group());
459 Handle thread_oop = JavaCalls::construct_new_instance(SystemDictionary::Thread_klass(),
460 vmSymbols::threadgroup_string_void_signature(),
461 thread_group,
462 string,
463 CHECK);
464
465 Klass* group = SystemDictionary::ThreadGroup_klass();
466 JavaValue result(T_VOID);
467 JavaCalls::call_special(&result,
468 thread_group,
469 group,
470 vmSymbols::add_method_name(),
471 vmSymbols::thread_void_signature(),
472 thread_oop,
473 CHECK);
474
475 { MutexLocker mu(Threads_lock);
476 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
477
478 // At this point it may be possible that no osthread was created for the
479 // JavaThread due to lack of memory. We would have to throw an exception
480 // in that case. However, since this must work and we do not allow
481 // exceptions anyway, check and abort if this fails.
482 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
483 vm_exit_during_initialization("java.lang.OutOfMemoryError",
484 os::native_thread_creation_failed_msg());
485 }
486
487 java_lang_Thread::set_thread(thread_oop(), signal_thread);
488 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
489 java_lang_Thread::set_daemon(thread_oop());
490
491 signal_thread->set_threadObj(thread_oop());
492 Threads::add(signal_thread);
493 Thread::start(signal_thread);
494 }
495 // Handle ^BREAK
496 os::signal(SIGBREAK, os::user_handler());
497 }
498 }
499
500
501 void os::terminate_signal_thread() {
502 if (!ReduceSignalUsage)
503 signal_notify(sigexitnum_pd());
504 }
505
506
507 // --------------------- loading libraries ---------------------
508
509 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
510 extern struct JavaVM_ main_vm;
511
512 static void* _native_java_library = NULL;
513
514 void* os::native_java_library() {
515 if (_native_java_library == NULL) {
516 char buffer[JVM_MAXPATHLEN];
517 char ebuf[1024];
518
519 // Try to load verify dll first. In 1.3 java dll depends on it and is not
520 // always able to find it when the loading executable is outside the JDK.
521 // In order to keep working with 1.2 we ignore any loading errors.
522 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
523 "verify")) {
524 dll_load(buffer, ebuf, sizeof(ebuf));
525 }
526
527 // Load java dll
528 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
529 "java")) {
530 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
531 }
532 if (_native_java_library == NULL) {
533 vm_exit_during_initialization("Unable to load native library", ebuf);
534 }
535
536 #if defined(__OpenBSD__)
537 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
538 // ignore errors
539 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
540 "net")) {
541 dll_load(buffer, ebuf, sizeof(ebuf));
542 }
543 #endif
544 }
545 return _native_java_library;
546 }
547
548 /*
549 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
550 * If check_lib == true then we are looking for an
551 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
552 * this library is statically linked into the image.
553 * If check_lib == false then we will look for the appropriate symbol in the
554 * executable if agent_lib->is_static_lib() == true or in the shared library
555 * referenced by 'handle'.
556 */
557 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
558 const char *syms[], size_t syms_len) {
559 assert(agent_lib != NULL, "sanity check");
560 const char *lib_name;
561 void *handle = agent_lib->os_lib();
562 void *entryName = NULL;
563 char *agent_function_name;
564 size_t i;
565
566 // If checking then use the agent name otherwise test is_static_lib() to
567 // see how to process this lookup
568 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
569 for (i = 0; i < syms_len; i++) {
570 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
571 if (agent_function_name == NULL) {
572 break;
573 }
574 entryName = dll_lookup(handle, agent_function_name);
575 FREE_C_HEAP_ARRAY(char, agent_function_name);
576 if (entryName != NULL) {
577 break;
578 }
579 }
580 return entryName;
581 }
582
583 // See if the passed in agent is statically linked into the VM image.
584 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
585 size_t syms_len) {
586 void *ret;
587 void *proc_handle;
588 void *save_handle;
589
590 assert(agent_lib != NULL, "sanity check");
591 if (agent_lib->name() == NULL) {
592 return false;
593 }
594 proc_handle = get_default_process_handle();
595 // Check for Agent_OnLoad/Attach_lib_name function
596 save_handle = agent_lib->os_lib();
597 // We want to look in this process' symbol table.
598 agent_lib->set_os_lib(proc_handle);
599 ret = find_agent_function(agent_lib, true, syms, syms_len);
600 if (ret != NULL) {
601 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
602 agent_lib->set_valid();
603 agent_lib->set_static_lib(true);
604 return true;
605 }
606 agent_lib->set_os_lib(save_handle);
607 return false;
608 }
609
610 // --------------------- heap allocation utilities ---------------------
611
612 char *os::strdup(const char *str, MEMFLAGS flags) {
613 size_t size = strlen(str);
614 char *dup_str = (char *)malloc(size + 1, flags);
615 if (dup_str == NULL) return NULL;
616 strcpy(dup_str, str);
617 return dup_str;
618 }
619
620 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
621 char* p = os::strdup(str, flags);
622 if (p == NULL) {
623 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
624 }
625 return p;
626 }
627
628
629 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
630
631 #ifdef ASSERT
632
633 static void verify_memory(void* ptr) {
634 GuardedMemory guarded(ptr);
635 if (!guarded.verify_guards()) {
636 LogTarget(Warning, malloc, free) lt;
637 ResourceMark rm;
638 LogStream ls(lt);
639 ls.print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
640 ls.print_cr("## memory stomp:");
641 guarded.print_on(&ls);
642 fatal("memory stomping error");
643 }
644 }
645
646 #endif
647
648 //
649 // This function supports testing of the malloc out of memory
650 // condition without really running the system out of memory.
651 //
652 static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
653 if (MallocMaxTestWords > 0) {
654 size_t words = (alloc_size / BytesPerWord);
655
656 if ((cur_malloc_words + words) > MallocMaxTestWords) {
657 return true;
658 }
659 Atomic::add(words, &cur_malloc_words);
660 }
661 return false;
662 }
663
664 void* os::malloc(size_t size, MEMFLAGS flags) {
665 return os::malloc(size, flags, CALLER_PC);
666 }
667
668 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
669 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
670 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
671
672 // Since os::malloc can be called when the libjvm.{dll,so} is
673 // first loaded and we don't have a thread yet we must accept NULL also here.
674 assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()),
675 "malloc() not allowed when crash protection is set");
676
677 if (size == 0) {
678 // return a valid pointer if size is zero
679 // if NULL is returned the calling functions assume out of memory.
680 size = 1;
681 }
682
683 // NMT support
684 NMT_TrackingLevel level = MemTracker::tracking_level();
685 size_t nmt_header_size = MemTracker::malloc_header_size(level);
686
687 #ifndef ASSERT
688 const size_t alloc_size = size + nmt_header_size;
689 #else
690 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
691 if (size + nmt_header_size > alloc_size) { // Check for rollover.
692 return NULL;
693 }
694 #endif
695
696 // For the test flag -XX:MallocMaxTestWords
697 if (has_reached_max_malloc_test_peak(size)) {
698 return NULL;
699 }
700
701 u_char* ptr;
702 ptr = (u_char*)::malloc(alloc_size);
703
704 #ifdef ASSERT
705 if (ptr == NULL) {
706 return NULL;
707 }
708 // Wrap memory with guard
709 GuardedMemory guarded(ptr, size + nmt_header_size);
710 ptr = guarded.get_user_ptr();
711 #endif
712 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
713 log_warning(malloc, free)("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
714 breakpoint();
715 }
716 debug_only(if (paranoid) verify_memory(ptr));
717
718 // we do not track guard memory
719 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
720 }
721
722 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
723 return os::realloc(memblock, size, flags, CALLER_PC);
724 }
725
726 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
727
728 // For the test flag -XX:MallocMaxTestWords
729 if (has_reached_max_malloc_test_peak(size)) {
730 return NULL;
731 }
732
733 if (size == 0) {
734 // return a valid pointer if size is zero
735 // if NULL is returned the calling functions assume out of memory.
736 size = 1;
737 }
738
739 #ifndef ASSERT
740 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
741 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
742 // NMT support
743 void* membase = MemTracker::record_free(memblock);
744 NMT_TrackingLevel level = MemTracker::tracking_level();
745 size_t nmt_header_size = MemTracker::malloc_header_size(level);
746 void* ptr = ::realloc(membase, size + nmt_header_size);
747 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
748 #else
749 if (memblock == NULL) {
750 return os::malloc(size, memflags, stack);
751 }
752 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
753 log_warning(malloc, free)("os::realloc caught " PTR_FORMAT, p2i(memblock));
754 breakpoint();
755 }
756 // NMT support
757 void* membase = MemTracker::malloc_base(memblock);
758 verify_memory(membase);
759 // always move the block
760 void* ptr = os::malloc(size, memflags, stack);
761 // Copy to new memory if malloc didn't fail
762 if (ptr != NULL ) {
763 GuardedMemory guarded(MemTracker::malloc_base(memblock));
764 // Guard's user data contains NMT header
765 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
766 memcpy(ptr, memblock, MIN2(size, memblock_size));
767 if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
768 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
769 log_warning(malloc, free)("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
770 breakpoint();
771 }
772 os::free(memblock);
773 }
774 return ptr;
775 #endif
776 }
777
778
779 void os::free(void *memblock) {
780 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
781 #ifdef ASSERT
782 if (memblock == NULL) return;
783 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
784 log_warning(malloc, free)("os::free caught " PTR_FORMAT, p2i(memblock));
785 breakpoint();
786 }
787 void* membase = MemTracker::record_free(memblock);
788 verify_memory(membase);
789
790 GuardedMemory guarded(membase);
791 size_t size = guarded.get_user_size();
792 inc_stat_counter(&free_bytes, size);
793 membase = guarded.release_for_freeing();
794 ::free(membase);
795 #else
796 void* membase = MemTracker::record_free(memblock);
797 ::free(membase);
798 #endif
799 }
800
801 void os::init_random(unsigned int initval) {
802 _rand_seed = initval;
803 }
804
805
806 static int random_helper(unsigned int rand_seed) {
807 /* standard, well-known linear congruential random generator with
808 * next_rand = (16807*seed) mod (2**31-1)
809 * see
810 * (1) "Random Number Generators: Good Ones Are Hard to Find",
811 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
812 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
813 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
814 */
815 const unsigned int a = 16807;
816 const unsigned int m = 2147483647;
817 const int q = m / a; assert(q == 127773, "weird math");
818 const int r = m % a; assert(r == 2836, "weird math");
819
820 // compute az=2^31p+q
821 unsigned int lo = a * (rand_seed & 0xFFFF);
822 unsigned int hi = a * (rand_seed >> 16);
823 lo += (hi & 0x7FFF) << 16;
824
825 // if q overflowed, ignore the overflow and increment q
826 if (lo > m) {
827 lo &= m;
828 ++lo;
829 }
830 lo += hi >> 15;
831
832 // if (p+q) overflowed, ignore the overflow and increment (p+q)
833 if (lo > m) {
834 lo &= m;
835 ++lo;
836 }
837 return lo;
838 }
839
840 int os::random() {
841 // Make updating the random seed thread safe.
842 while (true) {
843 unsigned int seed = _rand_seed;
844 unsigned int rand = random_helper(seed);
845 if (Atomic::cmpxchg(rand, &_rand_seed, seed) == seed) {
846 return static_cast<int>(rand);
847 }
848 }
849 }
850
851 // The INITIALIZED state is distinguished from the SUSPENDED state because the
852 // conditions in which a thread is first started are different from those in which
853 // a suspension is resumed. These differences make it hard for us to apply the
854 // tougher checks when starting threads that we want to do when resuming them.
855 // However, when start_thread is called as a result of Thread.start, on a Java
856 // thread, the operation is synchronized on the Java Thread object. So there
857 // cannot be a race to start the thread and hence for the thread to exit while
858 // we are working on it. Non-Java threads that start Java threads either have
859 // to do so in a context in which races are impossible, or should do appropriate
860 // locking.
861
862 void os::start_thread(Thread* thread) {
863 // guard suspend/resume
864 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
865 OSThread* osthread = thread->osthread();
866 osthread->set_state(RUNNABLE);
867 pd_start_thread(thread);
868 }
869
870 void os::abort(bool dump_core) {
871 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
872 }
873
874 //---------------------------------------------------------------------------
875 // Helper functions for fatal error handler
876
877 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
878 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
879
880 int cols = 0;
881 int cols_per_line = 0;
882 switch (unitsize) {
883 case 1: cols_per_line = 16; break;
884 case 2: cols_per_line = 8; break;
885 case 4: cols_per_line = 4; break;
886 case 8: cols_per_line = 2; break;
887 default: return;
888 }
889
890 address p = start;
891 st->print(PTR_FORMAT ": ", p2i(start));
892 while (p < end) {
893 switch (unitsize) {
894 case 1: st->print("%02x", *(u1*)p); break;
895 case 2: st->print("%04x", *(u2*)p); break;
896 case 4: st->print("%08x", *(u4*)p); break;
897 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
898 }
899 p += unitsize;
900 cols++;
901 if (cols >= cols_per_line && p < end) {
902 cols = 0;
903 st->cr();
904 st->print(PTR_FORMAT ": ", p2i(p));
905 } else {
906 st->print(" ");
907 }
908 }
909 st->cr();
910 }
911
912 void os::print_environment_variables(outputStream* st, const char** env_list) {
913 if (env_list) {
914 st->print_cr("Environment Variables:");
915
916 for (int i = 0; env_list[i] != NULL; i++) {
917 char *envvar = ::getenv(env_list[i]);
918 if (envvar != NULL) {
919 st->print("%s", env_list[i]);
920 st->print("=");
921 st->print_cr("%s", envvar);
922 }
923 }
924 }
925 }
926
927 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
928 // cpu
929 st->print("CPU:");
930 st->print("total %d", os::processor_count());
931 // It's not safe to query number of active processors after crash
932 // st->print("(active %d)", os::active_processor_count()); but we can
933 // print the initial number of active processors.
934 // We access the raw value here because the assert in the accessor will
935 // fail if the crash occurs before initialization of this value.
936 st->print(" (initial active %d)", _initial_active_processor_count);
937 st->print(" %s", VM_Version::features_string());
938 st->cr();
939 pd_print_cpu_info(st, buf, buflen);
940 }
941
942 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version
943 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
944 st->print("Host: ");
945 #ifndef PRODUCT
946 if (get_host_name(buf, buflen)) {
947 st->print("%s, ", buf);
948 }
949 #endif // PRODUCT
950 get_summary_cpu_info(buf, buflen);
951 st->print("%s, ", buf);
952 size_t mem = physical_memory()/G;
953 if (mem == 0) { // for low memory systems
954 mem = physical_memory()/M;
955 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
956 } else {
957 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
958 }
959 get_summary_os_info(buf, buflen);
960 st->print_raw(buf);
961 st->cr();
962 }
963
964 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
965 const int secs_per_day = 86400;
966 const int secs_per_hour = 3600;
967 const int secs_per_min = 60;
968
969 time_t tloc;
970 (void)time(&tloc);
971 char* timestring = ctime(&tloc); // ctime adds newline.
972 // edit out the newline
973 char* nl = strchr(timestring, '\n');
974 if (nl != NULL) {
975 *nl = '\0';
976 }
977
978 struct tm tz;
979 if (localtime_pd(&tloc, &tz) != NULL) {
980 ::strftime(buf, buflen, "%Z", &tz);
981 st->print("Time: %s %s", timestring, buf);
982 } else {
983 st->print("Time: %s", timestring);
984 }
985
986 double t = os::elapsedTime();
987 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
988 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
989 // before printf. We lost some precision, but who cares?
990 int eltime = (int)t; // elapsed time in seconds
991
992 // print elapsed time in a human-readable format:
993 int eldays = eltime / secs_per_day;
994 int day_secs = eldays * secs_per_day;
995 int elhours = (eltime - day_secs) / secs_per_hour;
996 int hour_secs = elhours * secs_per_hour;
997 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
998 int minute_secs = elmins * secs_per_min;
999 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
1000 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
1001 }
1002
1003 // moved from debug.cpp (used to be find()) but still called from there
1004 // The verbose parameter is only set by the debug code in one case
1005 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
1006 address addr = (address)x;
1007 // Handle NULL first, so later checks don't need to protect against it.
1008 if (addr == NULL) {
1009 st->print_cr("0x0 is NULL");
1010 return;
1011 }
1012 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
1013 if (b != NULL) {
1014 if (b->is_buffer_blob()) {
1015 // the interpreter is generated into a buffer blob
1016 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
1017 if (i != NULL) {
1018 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", p2i(addr), (int)(addr - i->code_begin()));
1019 i->print_on(st);
1020 return;
1021 }
1022 if (Interpreter::contains(addr)) {
1023 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
1024 " (not bytecode specific)", p2i(addr));
1025 return;
1026 }
1027 //
1028 if (AdapterHandlerLibrary::contains(b)) {
1029 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", p2i(addr), (int)(addr - b->code_begin()));
1030 AdapterHandlerLibrary::print_handler_on(st, b);
1031 }
1032 // the stubroutines are generated into a buffer blob
1033 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
1034 if (d != NULL) {
1035 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", p2i(addr), (int)(addr - d->begin()));
1036 d->print_on(st);
1037 st->cr();
1038 return;
1039 }
1040 if (StubRoutines::contains(addr)) {
1041 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) stub routine", p2i(addr));
1042 return;
1043 }
1044 // the InlineCacheBuffer is using stubs generated into a buffer blob
1045 if (InlineCacheBuffer::contains(addr)) {
1046 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", p2i(addr));
1047 return;
1048 }
1049 VtableStub* v = VtableStubs::stub_containing(addr);
1050 if (v != NULL) {
1051 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", p2i(addr), (int)(addr - v->entry_point()));
1052 v->print_on(st);
1053 st->cr();
1054 return;
1055 }
1056 }
1057 nmethod* nm = b->as_nmethod_or_null();
1058 if (nm != NULL) {
1059 ResourceMark rm;
1060 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
1061 p2i(addr), (int)(addr - nm->entry_point()), p2i(nm));
1062 if (verbose) {
1063 st->print(" for ");
1064 nm->method()->print_value_on(st);
1065 }
1066 st->cr();
1067 nm->print_nmethod(verbose);
1068 return;
1069 }
1070 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", p2i(addr), (int)(addr - b->code_begin()));
1071 b->print_on(st);
1072 return;
1073 }
1074
1075 if (Universe::heap()->is_in(addr)) {
1076 HeapWord* p = Universe::heap()->block_start(addr);
1077 bool print = false;
1078 // If we couldn't find it it just may mean that heap wasn't parsable
1079 // See if we were just given an oop directly
1080 if (p != NULL && Universe::heap()->block_is_obj(p)) {
1081 print = true;
1082 } else if (p == NULL && oopDesc::is_oop(oop(addr))) {
1083 p = (HeapWord*) addr;
1084 print = true;
1085 }
1086 if (print) {
1087 if (p == (HeapWord*) addr) {
1088 st->print_cr(INTPTR_FORMAT " is an oop", p2i(addr));
1089 } else {
1090 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, p2i(addr), p2i(p));
1091 }
1092 oop(p)->print_on(st);
1093 return;
1094 }
1095 } else {
1096 if (Universe::heap()->is_in_reserved(addr)) {
1097 st->print_cr(INTPTR_FORMAT " is an unallocated location "
1098 "in the heap", p2i(addr));
1099 return;
1100 }
1101 }
1102 if (JNIHandles::is_global_handle((jobject) addr)) {
1103 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
1104 return;
1105 }
1106 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1107 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
1108 return;
1109 }
1110 #ifndef PRODUCT
1111 // we don't keep the block list in product mode
1112 if (JNIHandles::is_local_handle((jobject) addr)) {
1113 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
1114 return;
1115 }
1116 #endif
1117
1118 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
1119 // Check for privilege stack
1120 if (thread->privileged_stack_top() != NULL &&
1121 thread->privileged_stack_top()->contains(addr)) {
1122 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
1123 "for thread: " INTPTR_FORMAT, p2i(addr), p2i(thread));
1124 if (verbose) thread->print_on(st);
1125 return;
1126 }
1127 // If the addr is a java thread print information about that.
1128 if (addr == (address)thread) {
1129 if (verbose) {
1130 thread->print_on(st);
1131 } else {
1132 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
1133 }
1134 return;
1135 }
1136 // If the addr is in the stack region for this thread then report that
1137 // and print thread info
1138 if (thread->on_local_stack(addr)) {
1139 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1140 INTPTR_FORMAT, p2i(addr), p2i(thread));
1141 if (verbose) thread->print_on(st);
1142 return;
1143 }
1144 }
1145
1146 // Check if in metaspace and print types that have vptrs (only method now)
1147 if (Metaspace::contains(addr)) {
1148 if (Method::has_method_vptr((const void*)addr)) {
1149 ((Method*)addr)->print_value_on(st);
1150 st->cr();
1151 } else {
1152 // Use addr->print() from the debugger instead (not here)
1153 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
1154 }
1155 return;
1156 }
1157
1158 // Try an OS specific find
1159 if (os::find(addr, st)) {
1160 return;
1161 }
1162
1163 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
1164 }
1165
1166 // Looks like all platforms can use the same function to check if C
1167 // stack is walkable beyond current frame. The check for fp() is not
1168 // necessary on Sparc, but it's harmless.
1169 bool os::is_first_C_frame(frame* fr) {
1170 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1171 // Check usp first, because if that's bad the other accessors may fault
1172 // on some architectures. Ditto ufp second, etc.
1173 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1174 // sp on amd can be 32 bit aligned.
1175 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1176
1177 uintptr_t usp = (uintptr_t)fr->sp();
1178 if ((usp & sp_align_mask) != 0) return true;
1179
1180 uintptr_t ufp = (uintptr_t)fr->fp();
1181 if ((ufp & fp_align_mask) != 0) return true;
1182
1183 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1184 if ((old_sp & sp_align_mask) != 0) return true;
1185 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1186
1187 uintptr_t old_fp = (uintptr_t)fr->link();
1188 if ((old_fp & fp_align_mask) != 0) return true;
1189 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1190
1191 // stack grows downwards; if old_fp is below current fp or if the stack
1192 // frame is too large, either the stack is corrupted or fp is not saved
1193 // on stack (i.e. on x86, ebp may be used as general register). The stack
1194 // is not walkable beyond current frame.
1195 if (old_fp < ufp) return true;
1196 if (old_fp - ufp > 64 * K) return true;
1197
1198 return false;
1199 }
1200
1201
1202 // Set up the boot classpath.
1203
1204 char* os::format_boot_path(const char* format_string,
1205 const char* home,
1206 int home_len,
1207 char fileSep,
1208 char pathSep) {
1209 assert((fileSep == '/' && pathSep == ':') ||
1210 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1211
1212 // Scan the format string to determine the length of the actual
1213 // boot classpath, and handle platform dependencies as well.
1214 int formatted_path_len = 0;
1215 const char* p;
1216 for (p = format_string; *p != 0; ++p) {
1217 if (*p == '%') formatted_path_len += home_len - 1;
1218 ++formatted_path_len;
1219 }
1220
1221 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1222 if (formatted_path == NULL) {
1223 return NULL;
1224 }
1225
1226 // Create boot classpath from format, substituting separator chars and
1227 // java home directory.
1228 char* q = formatted_path;
1229 for (p = format_string; *p != 0; ++p) {
1230 switch (*p) {
1231 case '%':
1232 strcpy(q, home);
1233 q += home_len;
1234 break;
1235 case '/':
1236 *q++ = fileSep;
1237 break;
1238 case ':':
1239 *q++ = pathSep;
1240 break;
1241 default:
1242 *q++ = *p;
1243 }
1244 }
1245 *q = '\0';
1246
1247 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1248 return formatted_path;
1249 }
1250
1251 // This function is a proxy to fopen, it tries to add a non standard flag ('e' or 'N')
1252 // that ensures automatic closing of the file on exec. If it can not find support in
1253 // the underlying c library, it will make an extra system call (fcntl) to ensure automatic
1254 // closing of the file on exec.
1255 FILE* os::fopen(const char* path, const char* mode) {
1256 char modified_mode[20];
1257 assert(strlen(mode) + 1 < sizeof(modified_mode), "mode chars plus one extra must fit in buffer");
1258 sprintf(modified_mode, "%s" LINUX_ONLY("e") BSD_ONLY("e") WINDOWS_ONLY("N"), mode);
1259 FILE* file = ::fopen(path, modified_mode);
1260
1261 #if !(defined LINUX || defined BSD || defined _WINDOWS)
1262 // assume fcntl FD_CLOEXEC support as a backup solution when 'e' or 'N'
1263 // is not supported as mode in fopen
1264 if (file != NULL) {
1265 int fd = fileno(file);
1266 if (fd != -1) {
1267 int fd_flags = fcntl(fd, F_GETFD);
1268 if (fd_flags != -1) {
1269 fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC);
1270 }
1271 }
1272 }
1273 #endif
1274
1275 return file;
1276 }
1277
1278 bool os::set_boot_path(char fileSep, char pathSep) {
1279 const char* home = Arguments::get_java_home();
1280 int home_len = (int)strlen(home);
1281
1282 struct stat st;
1283
1284 // modular image if "modules" jimage exists
1285 char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep);
1286 if (jimage == NULL) return false;
1287 bool has_jimage = (os::stat(jimage, &st) == 0);
1288 if (has_jimage) {
1289 Arguments::set_sysclasspath(jimage, true);
1290 FREE_C_HEAP_ARRAY(char, jimage);
1291 return true;
1292 }
1293 FREE_C_HEAP_ARRAY(char, jimage);
1294
1295 // check if developer build with exploded modules
1296 char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep);
1297 if (base_classes == NULL) return false;
1298 if (os::stat(base_classes, &st) == 0) {
1299 Arguments::set_sysclasspath(base_classes, false);
1300 FREE_C_HEAP_ARRAY(char, base_classes);
1301 return true;
1302 }
1303 FREE_C_HEAP_ARRAY(char, base_classes);
1304
1305 return false;
1306 }
1307
1308 /*
1309 * Splits a path, based on its separator, the number of
1310 * elements is returned back in n.
1311 * It is the callers responsibility to:
1312 * a> check the value of n, and n may be 0.
1313 * b> ignore any empty path elements
1314 * c> free up the data.
1315 */
1316 char** os::split_path(const char* path, int* n) {
1317 *n = 0;
1318 if (path == NULL || strlen(path) == 0) {
1319 return NULL;
1320 }
1321 const char psepchar = *os::path_separator();
1322 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1323 if (inpath == NULL) {
1324 return NULL;
1325 }
1326 strcpy(inpath, path);
1327 int count = 1;
1328 char* p = strchr(inpath, psepchar);
1329 // Get a count of elements to allocate memory
1330 while (p != NULL) {
1331 count++;
1332 p++;
1333 p = strchr(p, psepchar);
1334 }
1335 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1336 if (opath == NULL) {
1337 return NULL;
1338 }
1339
1340 // do the actual splitting
1341 p = inpath;
1342 for (int i = 0 ; i < count ; i++) {
1343 size_t len = strcspn(p, os::path_separator());
1344 if (len > JVM_MAXPATHLEN) {
1345 return NULL;
1346 }
1347 // allocate the string and add terminator storage
1348 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1349 if (s == NULL) {
1350 return NULL;
1351 }
1352 strncpy(s, p, len);
1353 s[len] = '\0';
1354 opath[i] = s;
1355 p += len + 1;
1356 }
1357 FREE_C_HEAP_ARRAY(char, inpath);
1358 *n = count;
1359 return opath;
1360 }
1361
1362 void os::set_memory_serialize_page(address page) {
1363 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1364 _mem_serialize_page = (volatile int32_t *)page;
1365 // We initialize the serialization page shift count here
1366 // We assume a cache line size of 64 bytes
1367 assert(SerializePageShiftCount == count, "JavaThread size changed; "
1368 "SerializePageShiftCount constant should be %d", count);
1369 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1370 }
1371
1372 static volatile intptr_t SerializePageLock = 0;
1373
1374 // This method is called from signal handler when SIGSEGV occurs while the current
1375 // thread tries to store to the "read-only" memory serialize page during state
1376 // transition.
1377 void os::block_on_serialize_page_trap() {
1378 log_debug(safepoint)("Block until the serialize page permission restored");
1379
1380 // When VMThread is holding the SerializePageLock during modifying the
1381 // access permission of the memory serialize page, the following call
1382 // will block until the permission of that page is restored to rw.
1383 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1384 // this case, it's OK as the signal is synchronous and we know precisely when
1385 // it can occur.
1386 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1387 Thread::muxRelease(&SerializePageLock);
1388 }
1389
1390 // Serialize all thread state variables
1391 void os::serialize_thread_states() {
1392 // On some platforms such as Solaris & Linux, the time duration of the page
1393 // permission restoration is observed to be much longer than expected due to
1394 // scheduler starvation problem etc. To avoid the long synchronization
1395 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1396 // the mutator thread if such case is encountered. See bug 6546278 for details.
1397 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1398 os::protect_memory((char *)os::get_memory_serialize_page(),
1399 os::vm_page_size(), MEM_PROT_READ);
1400 os::protect_memory((char *)os::get_memory_serialize_page(),
1401 os::vm_page_size(), MEM_PROT_RW);
1402 Thread::muxRelease(&SerializePageLock);
1403 }
1404
1405 // Returns true if the current stack pointer is above the stack shadow
1406 // pages, false otherwise.
1407 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) {
1408 if (!thread->is_Java_thread()) return false;
1409 // Check if we have StackShadowPages above the yellow zone. This parameter
1410 // is dependent on the depth of the maximum VM call stack possible from
1411 // the handler for stack overflow. 'instanceof' in the stack overflow
1412 // handler or a println uses at least 8k stack of VM and native code
1413 // respectively.
1414 const int framesize_in_bytes =
1415 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1416
1417 address limit = ((JavaThread*)thread)->stack_end() +
1418 (JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size());
1419
1420 return sp > (limit + framesize_in_bytes);
1421 }
1422
1423 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1424 assert(min_pages > 0, "sanity");
1425 if (UseLargePages) {
1426 const size_t max_page_size = region_size / min_pages;
1427
1428 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1429 const size_t page_size = _page_sizes[i];
1430 if (page_size <= max_page_size) {
1431 if (!must_be_aligned || is_aligned(region_size, page_size)) {
1432 return page_size;
1433 }
1434 }
1435 }
1436 }
1437
1438 return vm_page_size();
1439 }
1440
1441 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1442 return page_size_for_region(region_size, min_pages, true);
1443 }
1444
1445 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1446 return page_size_for_region(region_size, min_pages, false);
1447 }
1448
1449 static const char* errno_to_string (int e, bool short_text) {
1450 #define ALL_SHARED_ENUMS(X) \
1451 X(E2BIG, "Argument list too long") \
1452 X(EACCES, "Permission denied") \
1453 X(EADDRINUSE, "Address in use") \
1454 X(EADDRNOTAVAIL, "Address not available") \
1455 X(EAFNOSUPPORT, "Address family not supported") \
1456 X(EAGAIN, "Resource unavailable, try again") \
1457 X(EALREADY, "Connection already in progress") \
1458 X(EBADF, "Bad file descriptor") \
1459 X(EBADMSG, "Bad message") \
1460 X(EBUSY, "Device or resource busy") \
1461 X(ECANCELED, "Operation canceled") \
1462 X(ECHILD, "No child processes") \
1463 X(ECONNABORTED, "Connection aborted") \
1464 X(ECONNREFUSED, "Connection refused") \
1465 X(ECONNRESET, "Connection reset") \
1466 X(EDEADLK, "Resource deadlock would occur") \
1467 X(EDESTADDRREQ, "Destination address required") \
1468 X(EDOM, "Mathematics argument out of domain of function") \
1469 X(EEXIST, "File exists") \
1470 X(EFAULT, "Bad address") \
1471 X(EFBIG, "File too large") \
1472 X(EHOSTUNREACH, "Host is unreachable") \
1473 X(EIDRM, "Identifier removed") \
1474 X(EILSEQ, "Illegal byte sequence") \
1475 X(EINPROGRESS, "Operation in progress") \
1476 X(EINTR, "Interrupted function") \
1477 X(EINVAL, "Invalid argument") \
1478 X(EIO, "I/O error") \
1479 X(EISCONN, "Socket is connected") \
1480 X(EISDIR, "Is a directory") \
1481 X(ELOOP, "Too many levels of symbolic links") \
1482 X(EMFILE, "Too many open files") \
1483 X(EMLINK, "Too many links") \
1484 X(EMSGSIZE, "Message too large") \
1485 X(ENAMETOOLONG, "Filename too long") \
1486 X(ENETDOWN, "Network is down") \
1487 X(ENETRESET, "Connection aborted by network") \
1488 X(ENETUNREACH, "Network unreachable") \
1489 X(ENFILE, "Too many files open in system") \
1490 X(ENOBUFS, "No buffer space available") \
1491 X(ENODATA, "No message is available on the STREAM head read queue") \
1492 X(ENODEV, "No such device") \
1493 X(ENOENT, "No such file or directory") \
1494 X(ENOEXEC, "Executable file format error") \
1495 X(ENOLCK, "No locks available") \
1496 X(ENOLINK, "Reserved") \
1497 X(ENOMEM, "Not enough space") \
1498 X(ENOMSG, "No message of the desired type") \
1499 X(ENOPROTOOPT, "Protocol not available") \
1500 X(ENOSPC, "No space left on device") \
1501 X(ENOSR, "No STREAM resources") \
1502 X(ENOSTR, "Not a STREAM") \
1503 X(ENOSYS, "Function not supported") \
1504 X(ENOTCONN, "The socket is not connected") \
1505 X(ENOTDIR, "Not a directory") \
1506 X(ENOTEMPTY, "Directory not empty") \
1507 X(ENOTSOCK, "Not a socket") \
1508 X(ENOTSUP, "Not supported") \
1509 X(ENOTTY, "Inappropriate I/O control operation") \
1510 X(ENXIO, "No such device or address") \
1511 X(EOPNOTSUPP, "Operation not supported on socket") \
1512 X(EOVERFLOW, "Value too large to be stored in data type") \
1513 X(EPERM, "Operation not permitted") \
1514 X(EPIPE, "Broken pipe") \
1515 X(EPROTO, "Protocol error") \
1516 X(EPROTONOSUPPORT, "Protocol not supported") \
1517 X(EPROTOTYPE, "Protocol wrong type for socket") \
1518 X(ERANGE, "Result too large") \
1519 X(EROFS, "Read-only file system") \
1520 X(ESPIPE, "Invalid seek") \
1521 X(ESRCH, "No such process") \
1522 X(ETIME, "Stream ioctl() timeout") \
1523 X(ETIMEDOUT, "Connection timed out") \
1524 X(ETXTBSY, "Text file busy") \
1525 X(EWOULDBLOCK, "Operation would block") \
1526 X(EXDEV, "Cross-device link")
1527
1528 #define DEFINE_ENTRY(e, text) { e, #e, text },
1529
1530 static const struct {
1531 int v;
1532 const char* short_text;
1533 const char* long_text;
1534 } table [] = {
1535
1536 ALL_SHARED_ENUMS(DEFINE_ENTRY)
1537
1538 // The following enums are not defined on all platforms.
1539 #ifdef ESTALE
1540 DEFINE_ENTRY(ESTALE, "Reserved")
1541 #endif
1542 #ifdef EDQUOT
1543 DEFINE_ENTRY(EDQUOT, "Reserved")
1544 #endif
1545 #ifdef EMULTIHOP
1546 DEFINE_ENTRY(EMULTIHOP, "Reserved")
1547 #endif
1548
1549 // End marker.
1550 { -1, "Unknown errno", "Unknown error" }
1551
1552 };
1553
1554 #undef DEFINE_ENTRY
1555 #undef ALL_FLAGS
1556
1557 int i = 0;
1558 while (table[i].v != -1 && table[i].v != e) {
1559 i ++;
1560 }
1561
1562 return short_text ? table[i].short_text : table[i].long_text;
1563
1564 }
1565
1566 const char* os::strerror(int e) {
1567 return errno_to_string(e, false);
1568 }
1569
1570 const char* os::errno_name(int e) {
1571 return errno_to_string(e, true);
1572 }
1573
1574 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) {
1575 LogTarget(Info, pagesize) log;
1576 if (log.is_enabled()) {
1577 LogStream out(log);
1578
1579 out.print("%s: ", str);
1580 for (int i = 0; i < count; ++i) {
1581 out.print(" " SIZE_FORMAT, page_sizes[i]);
1582 }
1583 out.cr();
1584 }
1585 }
1586
1587 #define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size)
1588
1589 void os::trace_page_sizes(const char* str,
1590 const size_t region_min_size,
1591 const size_t region_max_size,
1592 const size_t page_size,
1593 const char* base,
1594 const size_t size) {
1595
1596 log_info(pagesize)("%s: "
1597 " min=" SIZE_FORMAT "%s"
1598 " max=" SIZE_FORMAT "%s"
1599 " base=" PTR_FORMAT
1600 " page_size=" SIZE_FORMAT "%s"
1601 " size=" SIZE_FORMAT "%s",
1602 str,
1603 trace_page_size_params(region_min_size),
1604 trace_page_size_params(region_max_size),
1605 p2i(base),
1606 trace_page_size_params(page_size),
1607 trace_page_size_params(size));
1608 }
1609
1610 void os::trace_page_sizes_for_requested_size(const char* str,
1611 const size_t requested_size,
1612 const size_t page_size,
1613 const size_t alignment,
1614 const char* base,
1615 const size_t size) {
1616
1617 log_info(pagesize)("%s:"
1618 " req_size=" SIZE_FORMAT "%s"
1619 " base=" PTR_FORMAT
1620 " page_size=" SIZE_FORMAT "%s"
1621 " alignment=" SIZE_FORMAT "%s"
1622 " size=" SIZE_FORMAT "%s",
1623 str,
1624 trace_page_size_params(requested_size),
1625 p2i(base),
1626 trace_page_size_params(page_size),
1627 trace_page_size_params(alignment),
1628 trace_page_size_params(size));
1629 }
1630
1631
1632 // This is the working definition of a server class machine:
1633 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1634 // because the graphics memory (?) sometimes masks physical memory.
1635 // If you want to change the definition of a server class machine
1636 // on some OS or platform, e.g., >=4GB on Windows platforms,
1637 // then you'll have to parameterize this method based on that state,
1638 // as was done for logical processors here, or replicate and
1639 // specialize this method for each platform. (Or fix os to have
1640 // some inheritance structure and use subclassing. Sigh.)
1641 // If you want some platform to always or never behave as a server
1642 // class machine, change the setting of AlwaysActAsServerClassMachine
1643 // and NeverActAsServerClassMachine in globals*.hpp.
1644 bool os::is_server_class_machine() {
1645 // First check for the early returns
1646 if (NeverActAsServerClassMachine) {
1647 return false;
1648 }
1649 if (AlwaysActAsServerClassMachine) {
1650 return true;
1651 }
1652 // Then actually look at the machine
1653 bool result = false;
1654 const unsigned int server_processors = 2;
1655 const julong server_memory = 2UL * G;
1656 // We seem not to get our full complement of memory.
1657 // We allow some part (1/8?) of the memory to be "missing",
1658 // based on the sizes of DIMMs, and maybe graphics cards.
1659 const julong missing_memory = 256UL * M;
1660
1661 /* Is this a server class machine? */
1662 if ((os::active_processor_count() >= (int)server_processors) &&
1663 (os::physical_memory() >= (server_memory - missing_memory))) {
1664 const unsigned int logical_processors =
1665 VM_Version::logical_processors_per_package();
1666 if (logical_processors > 1) {
1667 const unsigned int physical_packages =
1668 os::active_processor_count() / logical_processors;
1669 if (physical_packages >= server_processors) {
1670 result = true;
1671 }
1672 } else {
1673 result = true;
1674 }
1675 }
1676 return result;
1677 }
1678
1679 void os::initialize_initial_active_processor_count() {
1680 assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
1681 _initial_active_processor_count = active_processor_count();
1682 log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count);
1683 }
1684
1685 void os::SuspendedThreadTask::run() {
1686 internal_do_task();
1687 _done = true;
1688 }
1689
1690 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1691 return os::pd_create_stack_guard_pages(addr, bytes);
1692 }
1693
1694 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, int file_desc) {
1695 char* result = NULL;
1696
1697 if (file_desc != -1) {
1698 // Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(),
1699 // but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file.
1700 result = os::map_memory_to_file(addr, bytes, file_desc);
1701 if (result != NULL) {
1702 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1703 }
1704 } else {
1705 result = pd_reserve_memory(bytes, addr, alignment_hint);
1706 if (result != NULL) {
1707 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1708 }
1709 }
1710
1711 return result;
1712 }
1713
1714 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1715 MEMFLAGS flags) {
1716 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1717 if (result != NULL) {
1718 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1719 MemTracker::record_virtual_memory_type((address)result, flags);
1720 }
1721
1722 return result;
1723 }
1724
1725 char* os::attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc) {
1726 char* result = NULL;
1727 if (file_desc != -1) {
1728 result = pd_attempt_reserve_memory_at(bytes, addr, file_desc);
1729 if (result != NULL) {
1730 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1731 }
1732 } else {
1733 result = pd_attempt_reserve_memory_at(bytes, addr);
1734 if (result != NULL) {
1735 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1736 }
1737 }
1738 return result;
1739 }
1740
1741 void os::split_reserved_memory(char *base, size_t size,
1742 size_t split, bool realloc) {
1743 pd_split_reserved_memory(base, size, split, realloc);
1744 }
1745
1746 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1747 bool res = pd_commit_memory(addr, bytes, executable);
1748 if (res) {
1749 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1750 }
1751 return res;
1752 }
1753
1754 bool os::commit_memory(char* addr, size_t size, bool executable, int file_desc, size_t offset) {
1755
1756 bool res = false;
1757
1758 if (os::map_memory_to_file(addr, size, file_desc, offset, executable, false) != NULL) {
1759 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1760 return true;
1761 }
1762 return false;
1763 }
1764
1765 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1766 bool executable) {
1767 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1768 if (res) {
1769 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1770 }
1771 return res;
1772 }
1773
1774 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1775 bool executable, int file_desc, size_t offset) {
1776
1777 // ignoring alignemnt hint.
1778 bool res = false;
1779 if (os::map_memory_to_file(addr, size, file_desc, offset, executable, false) != NULL) {
1780 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1781 return true;
1782 }
1783 return false;
1784 }
1785
1786 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1787 const char* mesg) {
1788 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1789 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1790 }
1791
1792 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1793 bool executable, const char* mesg) {
1794 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1795 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1796 }
1797
1798 bool os::uncommit_memory(char* addr, size_t bytes) {
1799 bool res;
1800 if (MemTracker::tracking_level() > NMT_minimal) {
1801 Tracker tkr(Tracker::uncommit);
1802 res = pd_uncommit_memory(addr, bytes);
1803 if (res) {
1804 tkr.record((address)addr, bytes);
1805 }
1806 } else {
1807 res = pd_uncommit_memory(addr, bytes);
1808 }
1809 return res;
1810 }
1811
1812 bool os::release_memory(char* addr, size_t bytes) {
1813 bool res;
1814 if (MemTracker::tracking_level() > NMT_minimal) {
1815 Tracker tkr(Tracker::release);
1816 res = pd_release_memory(addr, bytes);
1817 if (res) {
1818 tkr.record((address)addr, bytes);
1819 }
1820 } else {
1821 res = pd_release_memory(addr, bytes);
1822 }
1823 return res;
1824 }
1825
1826 void os::pretouch_memory(void* start, void* end, size_t page_size) {
1827 for (volatile char *p = (char*)start; p < (char*)end; p += page_size) {
1828 *p = 0;
1829 }
1830 }
1831
1832 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1833 char *addr, size_t bytes, bool read_only,
1834 bool allow_exec) {
1835 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1836 if (result != NULL) {
1837 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1838 }
1839 return result;
1840 }
1841
1842 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1843 char *addr, size_t bytes, bool read_only,
1844 bool allow_exec) {
1845 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1846 read_only, allow_exec);
1847 }
1848
1849 bool os::unmap_memory(char *addr, size_t bytes) {
1850 bool result;
1851 if (MemTracker::tracking_level() > NMT_minimal) {
1852 Tracker tkr(Tracker::release);
1853 result = pd_unmap_memory(addr, bytes);
1854 if (result) {
1855 tkr.record((address)addr, bytes);
1856 }
1857 } else {
1858 result = pd_unmap_memory(addr, bytes);
1859 }
1860 return result;
1861 }
1862
1863 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1864 pd_free_memory(addr, bytes, alignment_hint);
1865 }
1866
1867 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1868 pd_realign_memory(addr, bytes, alignment_hint);
1869 }
1870
1871 #ifndef _WINDOWS
1872 /* try to switch state from state "from" to state "to"
1873 * returns the state set after the method is complete
1874 */
1875 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1876 os::SuspendResume::State to)
1877 {
1878 os::SuspendResume::State result = Atomic::cmpxchg(to, &_state, from);
1879 if (result == from) {
1880 // success
1881 return to;
1882 }
1883 return result;
1884 }
1885 #endif