1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/codeCache.hpp"
31 #include "code/icBuffer.hpp"
32 #include "code/vtableStubs.hpp"
33 #include "gc_implementation/shared/vmGCOperations.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "memory/allocation.inline.hpp"
36 #ifdef ASSERT
37 #include "memory/guardedMemory.hpp"
38 #endif
39 #include "oops/oop.inline.hpp"
40 #include "prims/jvm.h"
41 #include "prims/jvm_misc.hpp"
42 #include "prims/privilegedStack.hpp"
43 #include "runtime/arguments.hpp"
44 #include "runtime/atomic.inline.hpp"
45 #include "runtime/frame.inline.hpp"
46 #include "runtime/interfaceSupport.hpp"
47 #include "runtime/java.hpp"
48 #include "runtime/javaCalls.hpp"
49 #include "runtime/mutexLocker.hpp"
50 #include "runtime/os.inline.hpp"
51 #include "runtime/stubRoutines.hpp"
52 #include "runtime/thread.inline.hpp"
53 #include "runtime/vm_version.hpp"
54 #include "services/attachListener.hpp"
55 #include "services/memTracker.hpp"
56 #include "services/threadService.hpp"
57 #include "utilities/defaultStream.hpp"
58 #include "utilities/events.hpp"
59
60 # include <signal.h>
61
62 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
63
64 OSThread* os::_starting_thread = NULL;
65 address os::_polling_page = NULL;
66 volatile int32_t* os::_mem_serialize_page = NULL;
67 uintptr_t os::_serialize_page_mask = 0;
68 long os::_rand_seed = 1;
69 int os::_processor_count = 0;
70 size_t os::_page_sizes[os::page_sizes_max];
71
72 #ifndef PRODUCT
73 julong os::num_mallocs = 0; // # of calls to malloc/realloc
74 julong os::alloc_bytes = 0; // # of bytes allocated
75 julong os::num_frees = 0; // # of calls to free
76 julong os::free_bytes = 0; // # of bytes freed
77 #endif
78
79 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
80
81 void os_init_globals() {
82 // Called from init_globals().
83 // See Threads::create_vm() in thread.cpp, and init.cpp.
84 os::init_globals();
85 }
86
87 // Fill in buffer with current local time as an ISO-8601 string.
88 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
89 // Returns buffer, or NULL if it failed.
90 // This would mostly be a call to
91 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
92 // except that on Windows the %z behaves badly, so we do it ourselves.
93 // Also, people wanted milliseconds on there,
94 // and strftime doesn't do milliseconds.
95 char* os::iso8601_time(char* buffer, size_t buffer_length) {
96 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
97 // 1 2
98 // 12345678901234567890123456789
99 static const char* iso8601_format =
100 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
101 static const size_t needed_buffer = 29;
102
103 // Sanity check the arguments
104 if (buffer == NULL) {
105 assert(false, "NULL buffer");
106 return NULL;
107 }
108 if (buffer_length < needed_buffer) {
109 assert(false, "buffer_length too small");
110 return NULL;
111 }
112 // Get the current time
113 jlong milliseconds_since_19700101 = javaTimeMillis();
114 const int milliseconds_per_microsecond = 1000;
115 const time_t seconds_since_19700101 =
116 milliseconds_since_19700101 / milliseconds_per_microsecond;
117 const int milliseconds_after_second =
118 milliseconds_since_19700101 % milliseconds_per_microsecond;
119 // Convert the time value to a tm and timezone variable
120 struct tm time_struct;
121 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
122 assert(false, "Failed localtime_pd");
123 return NULL;
124 }
125 #if defined(_ALLBSD_SOURCE)
126 const time_t zone = (time_t) time_struct.tm_gmtoff;
127 #else
128 const time_t zone = timezone;
129 #endif
130
131 // If daylight savings time is in effect,
132 // we are 1 hour East of our time zone
133 const time_t seconds_per_minute = 60;
134 const time_t minutes_per_hour = 60;
135 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
136 time_t UTC_to_local = zone;
137 if (time_struct.tm_isdst > 0) {
138 UTC_to_local = UTC_to_local - seconds_per_hour;
139 }
140 // Compute the time zone offset.
141 // localtime_pd() sets timezone to the difference (in seconds)
142 // between UTC and and local time.
143 // ISO 8601 says we need the difference between local time and UTC,
144 // we change the sign of the localtime_pd() result.
145 const time_t local_to_UTC = -(UTC_to_local);
146 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
147 char sign_local_to_UTC = '+';
148 time_t abs_local_to_UTC = local_to_UTC;
149 if (local_to_UTC < 0) {
150 sign_local_to_UTC = '-';
151 abs_local_to_UTC = -(abs_local_to_UTC);
152 }
153 // Convert time zone offset seconds to hours and minutes.
154 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
155 const time_t zone_min =
156 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
157
158 // Print an ISO 8601 date and time stamp into the buffer
159 const int year = 1900 + time_struct.tm_year;
160 const int month = 1 + time_struct.tm_mon;
161 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
162 year,
163 month,
164 time_struct.tm_mday,
165 time_struct.tm_hour,
166 time_struct.tm_min,
167 time_struct.tm_sec,
168 milliseconds_after_second,
169 sign_local_to_UTC,
170 zone_hours,
171 zone_min);
172 if (printed == 0) {
173 assert(false, "Failed jio_printf");
174 return NULL;
175 }
176 return buffer;
177 }
178
179 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
180 #ifdef ASSERT
181 if (!(!thread->is_Java_thread() ||
182 Thread::current() == thread ||
183 Threads_lock->owned_by_self()
184 || thread->is_Compiler_thread()
185 )) {
186 assert(false, "possibility of dangling Thread pointer");
187 }
188 #endif
189
190 if (p >= MinPriority && p <= MaxPriority) {
191 int priority = java_to_os_priority[p];
192 return set_native_priority(thread, priority);
193 } else {
194 assert(false, "Should not happen");
195 return OS_ERR;
196 }
197 }
198
199 // The mapping from OS priority back to Java priority may be inexact because
200 // Java priorities can map M:1 with native priorities. If you want the definite
201 // Java priority then use JavaThread::java_priority()
202 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
203 int p;
204 int os_prio;
205 OSReturn ret = get_native_priority(thread, &os_prio);
206 if (ret != OS_OK) return ret;
207
208 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
209 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
210 } else {
211 // niceness values are in reverse order
212 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
213 }
214 priority = (ThreadPriority)p;
215 return OS_OK;
216 }
217
218
219 // --------------------- sun.misc.Signal (optional) ---------------------
220
221
222 // SIGBREAK is sent by the keyboard to query the VM state
223 #ifndef SIGBREAK
224 #define SIGBREAK SIGQUIT
225 #endif
226
227 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
228
229
230 static void signal_thread_entry(JavaThread* thread, TRAPS) {
231 os::set_priority(thread, NearMaxPriority);
232 while (true) {
233 int sig;
234 {
235 // FIXME : Currently we have not decided what should be the status
236 // for this java thread blocked here. Once we decide about
237 // that we should fix this.
238 sig = os::signal_wait();
239 }
240 if (sig == os::sigexitnum_pd()) {
241 // Terminate the signal thread
242 return;
243 }
244
245 switch (sig) {
246 case SIGBREAK: {
247 // Check if the signal is a trigger to start the Attach Listener - in that
248 // case don't print stack traces.
249 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
250 continue;
251 }
252 // Print stack traces
253 // Any SIGBREAK operations added here should make sure to flush
254 // the output stream (e.g. tty->flush()) after output. See 4803766.
255 // Each module also prints an extra carriage return after its output.
256 VM_PrintThreads op;
257 VMThread::execute(&op);
258 VM_PrintJNI jni_op;
259 VMThread::execute(&jni_op);
260 VM_FindDeadlocks op1(tty);
261 VMThread::execute(&op1);
262 Universe::print_heap_at_SIGBREAK();
263 if (PrintClassHistogram) {
264 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
265 VMThread::execute(&op1);
266 }
267 if (JvmtiExport::should_post_data_dump()) {
268 JvmtiExport::post_data_dump();
269 }
270 break;
271 }
272 default: {
273 // Dispatch the signal to java
274 HandleMark hm(THREAD);
275 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
276 KlassHandle klass (THREAD, k);
277 if (klass.not_null()) {
278 JavaValue result(T_VOID);
279 JavaCallArguments args;
280 args.push_int(sig);
281 JavaCalls::call_static(
282 &result,
283 klass,
284 vmSymbols::dispatch_name(),
285 vmSymbols::int_void_signature(),
286 &args,
287 THREAD
288 );
289 }
290 if (HAS_PENDING_EXCEPTION) {
291 // tty is initialized early so we don't expect it to be null, but
292 // if it is we can't risk doing an initialization that might
293 // trigger additional out-of-memory conditions
294 if (tty != NULL) {
295 char klass_name[256];
296 char tmp_sig_name[16];
297 const char* sig_name = "UNKNOWN";
298 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
299 name()->as_klass_external_name(klass_name, 256);
300 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
301 sig_name = tmp_sig_name;
302 warning("Exception %s occurred dispatching signal %s to handler"
303 "- the VM may need to be forcibly terminated",
304 klass_name, sig_name );
305 }
306 CLEAR_PENDING_EXCEPTION;
307 }
308 }
309 }
310 }
311 }
312
313 void os::init_before_ergo() {
314 // We need to initialize large page support here because ergonomics takes some
315 // decisions depending on large page support and the calculated large page size.
316 large_page_init();
317 }
318
319 void os::signal_init() {
320 if (!ReduceSignalUsage) {
321 // Setup JavaThread for processing signals
322 EXCEPTION_MARK;
323 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
324 instanceKlassHandle klass (THREAD, k);
325 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
326
327 const char thread_name[] = "Signal Dispatcher";
328 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
329
330 // Initialize thread_oop to put it into the system threadGroup
331 Handle thread_group (THREAD, Universe::system_thread_group());
332 JavaValue result(T_VOID);
333 JavaCalls::call_special(&result, thread_oop,
334 klass,
335 vmSymbols::object_initializer_name(),
336 vmSymbols::threadgroup_string_void_signature(),
337 thread_group,
338 string,
339 CHECK);
340
341 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
342 JavaCalls::call_special(&result,
343 thread_group,
344 group,
345 vmSymbols::add_method_name(),
346 vmSymbols::thread_void_signature(),
347 thread_oop, // ARG 1
348 CHECK);
349
350 os::signal_init_pd();
351
352 { MutexLocker mu(Threads_lock);
353 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
354
355 // At this point it may be possible that no osthread was created for the
356 // JavaThread due to lack of memory. We would have to throw an exception
357 // in that case. However, since this must work and we do not allow
358 // exceptions anyway, check and abort if this fails.
359 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
360 vm_exit_during_initialization("java.lang.OutOfMemoryError",
361 os::native_thread_creation_failed_msg());
362 }
363
364 java_lang_Thread::set_thread(thread_oop(), signal_thread);
365 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
366 java_lang_Thread::set_daemon(thread_oop());
367
368 signal_thread->set_threadObj(thread_oop());
369 Threads::add(signal_thread);
370 Thread::start(signal_thread);
371 }
372 // Handle ^BREAK
373 os::signal(SIGBREAK, os::user_handler());
374 }
375 }
376
377
378 void os::terminate_signal_thread() {
379 if (!ReduceSignalUsage)
380 signal_notify(sigexitnum_pd());
381 }
382
383
384 // --------------------- loading libraries ---------------------
385
386 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
387 extern struct JavaVM_ main_vm;
388
389 static void* _native_java_library = NULL;
390
391 void* os::native_java_library() {
392 if (_native_java_library == NULL) {
393 char buffer[JVM_MAXPATHLEN];
394 char ebuf[1024];
395
396 // Try to load verify dll first. In 1.3 java dll depends on it and is not
397 // always able to find it when the loading executable is outside the JDK.
398 // In order to keep working with 1.2 we ignore any loading errors.
399 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
400 "verify")) {
401 dll_load(buffer, ebuf, sizeof(ebuf));
402 }
403
404 // Load java dll
405 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
406 "java")) {
407 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
408 }
409 if (_native_java_library == NULL) {
410 vm_exit_during_initialization("Unable to load native library", ebuf);
411 }
412
413 #if defined(__OpenBSD__)
414 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
415 // ignore errors
416 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
417 "net")) {
418 dll_load(buffer, ebuf, sizeof(ebuf));
419 }
420 #endif
421 }
422 static jboolean onLoaded = JNI_FALSE;
423 if (onLoaded) {
424 // We may have to wait to fire OnLoad until TLS is initialized.
425 if (ThreadLocalStorage::is_initialized()) {
426 // The JNI_OnLoad handling is normally done by method load in
427 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
428 // explicitly so we have to check for JNI_OnLoad as well
429 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
430 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
431 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
432 if (JNI_OnLoad != NULL) {
433 JavaThread* thread = JavaThread::current();
434 ThreadToNativeFromVM ttn(thread);
435 HandleMark hm(thread);
436 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
437 onLoaded = JNI_TRUE;
438 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
439 vm_exit_during_initialization("Unsupported JNI version");
440 }
441 }
442 }
443 }
444 return _native_java_library;
445 }
446
447 /*
448 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
449 * If check_lib == true then we are looking for an
450 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
451 * this library is statically linked into the image.
452 * If check_lib == false then we will look for the appropriate symbol in the
453 * executable if agent_lib->is_static_lib() == true or in the shared library
454 * referenced by 'handle'.
455 */
456 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
457 const char *syms[], size_t syms_len) {
458 assert(agent_lib != NULL, "sanity check");
459 const char *lib_name;
460 void *handle = agent_lib->os_lib();
461 void *entryName = NULL;
462 char *agent_function_name;
463 size_t i;
464
465 // If checking then use the agent name otherwise test is_static_lib() to
466 // see how to process this lookup
467 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
468 for (i = 0; i < syms_len; i++) {
469 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
470 if (agent_function_name == NULL) {
471 break;
472 }
473 entryName = dll_lookup(handle, agent_function_name);
474 FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread);
475 if (entryName != NULL) {
476 break;
477 }
478 }
479 return entryName;
480 }
481
482 // See if the passed in agent is statically linked into the VM image.
483 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
484 size_t syms_len) {
485 void *ret;
486 void *proc_handle;
487 void *save_handle;
488
489 assert(agent_lib != NULL, "sanity check");
490 if (agent_lib->name() == NULL) {
491 return false;
492 }
493 proc_handle = get_default_process_handle();
494 // Check for Agent_OnLoad/Attach_lib_name function
495 save_handle = agent_lib->os_lib();
496 // We want to look in this process' symbol table.
497 agent_lib->set_os_lib(proc_handle);
498 ret = find_agent_function(agent_lib, true, syms, syms_len);
499 if (ret != NULL) {
500 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
501 agent_lib->set_valid();
502 agent_lib->set_static_lib(true);
503 return true;
504 }
505 agent_lib->set_os_lib(save_handle);
506 return false;
507 }
508
509 // --------------------- heap allocation utilities ---------------------
510
511 char *os::strdup(const char *str, MEMFLAGS flags) {
512 size_t size = strlen(str);
513 char *dup_str = (char *)malloc(size + 1, flags);
514 if (dup_str == NULL) return NULL;
515 strcpy(dup_str, str);
516 return dup_str;
517 }
518
519
520 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
521
522 #ifdef ASSERT
523
524 static void verify_memory(void* ptr) {
525 GuardedMemory guarded(ptr);
526 if (!guarded.verify_guards()) {
527 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
528 tty->print_cr("## memory stomp:");
529 guarded.print_on(tty);
530 fatal("memory stomping error");
531 }
532 }
533
534 #endif
535
536 //
537 // This function supports testing of the malloc out of memory
538 // condition without really running the system out of memory.
539 //
540 static u_char* testMalloc(size_t alloc_size) {
541 assert(MallocMaxTestWords > 0, "sanity check");
542
543 if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
544 return NULL;
545 }
546
547 u_char* ptr = (u_char*)::malloc(alloc_size);
548
549 if (ptr != NULL) {
550 Atomic::add(((jint) (alloc_size / BytesPerWord)),
551 (volatile jint *) &cur_malloc_words);
552 }
553 return ptr;
554 }
555
556 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
557 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
558 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
559
560 #ifdef ASSERT
561 // checking for the WatcherThread and crash_protection first
562 // since os::malloc can be called when the libjvm.{dll,so} is
563 // first loaded and we don't have a thread yet.
564 // try to find the thread after we see that the watcher thread
565 // exists and has crash protection.
566 WatcherThread *wt = WatcherThread::watcher_thread();
567 if (wt != NULL && wt->has_crash_protection()) {
568 Thread* thread = ThreadLocalStorage::get_thread_slow();
569 if (thread == wt) {
570 assert(!wt->has_crash_protection(),
571 "Can't malloc with crash protection from WatcherThread");
572 }
573 }
574 #endif
575
576 if (size == 0) {
577 // return a valid pointer if size is zero
578 // if NULL is returned the calling functions assume out of memory.
579 size = 1;
580 }
581
582 #ifndef ASSERT
583 const size_t alloc_size = size;
584 #else
585 const size_t alloc_size = GuardedMemory::get_total_size(size);
586 if (size > alloc_size) { // Check for rollover.
587 return NULL;
588 }
589 #endif
590
591 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
592
593 u_char* ptr;
594 if (MallocMaxTestWords > 0) {
595 ptr = testMalloc(alloc_size);
596 } else {
597 ptr = (u_char*)::malloc(alloc_size);
598 }
599
600 #ifdef ASSERT
601 if (ptr == NULL) {
602 return NULL;
603 }
604 // Wrap memory with guard
605 GuardedMemory guarded(ptr, size);
606 ptr = guarded.get_user_ptr();
607 #endif
608 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
609 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
610 breakpoint();
611 }
612 debug_only(if (paranoid) verify_memory(ptr));
613 if (PrintMalloc && tty != NULL) {
614 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
615 }
616
617 // we do not track guard memory
618 MemTracker::record_malloc((address)ptr, size, memflags, caller == 0 ? CALLER_PC : caller);
619
620 return ptr;
621 }
622
623
624 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
625 #ifndef ASSERT
626 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
627 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
628 MemTracker::Tracker tkr = MemTracker::get_realloc_tracker();
629 void* ptr = ::realloc(memblock, size);
630 if (ptr != NULL) {
631 tkr.record((address)memblock, (address)ptr, size, memflags,
632 caller == 0 ? CALLER_PC : caller);
633 } else {
634 tkr.discard();
635 }
636 return ptr;
637 #else
638 if (memblock == NULL) {
639 return os::malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
640 }
641 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
642 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
643 breakpoint();
644 }
645 verify_memory(memblock);
646 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
647 if (size == 0) {
648 return NULL;
649 }
650 // always move the block
651 void* ptr = os::malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
652 if (PrintMalloc) {
653 tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
654 }
655 // Copy to new memory if malloc didn't fail
656 if ( ptr != NULL ) {
657 GuardedMemory guarded(memblock);
658 memcpy(ptr, memblock, MIN2(size, guarded.get_user_size()));
659 if (paranoid) verify_memory(ptr);
660 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
661 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
662 breakpoint();
663 }
664 os::free(memblock);
665 }
666 return ptr;
667 #endif
668 }
669
670
671 void os::free(void *memblock, MEMFLAGS memflags) {
672 address trackp = (address) memblock;
673 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
674 #ifdef ASSERT
675 if (memblock == NULL) return;
676 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
677 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
678 breakpoint();
679 }
680 verify_memory(memblock);
681 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
682
683 GuardedMemory guarded(memblock);
684 size_t size = guarded.get_user_size();
685 inc_stat_counter(&free_bytes, size);
686 memblock = guarded.release_for_freeing();
687 if (PrintMalloc && tty != NULL) {
688 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
689 }
690 #endif
691 MemTracker::record_free(trackp, memflags);
692
693 ::free(memblock);
694 }
695
696 void os::init_random(long initval) {
697 _rand_seed = initval;
698 }
699
700
701 long os::random() {
702 /* standard, well-known linear congruential random generator with
703 * next_rand = (16807*seed) mod (2**31-1)
704 * see
705 * (1) "Random Number Generators: Good Ones Are Hard to Find",
706 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
707 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
708 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
709 */
710 const long a = 16807;
711 const unsigned long m = 2147483647;
712 const long q = m / a; assert(q == 127773, "weird math");
713 const long r = m % a; assert(r == 2836, "weird math");
714
715 // compute az=2^31p+q
716 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
717 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
718 lo += (hi & 0x7FFF) << 16;
719
720 // if q overflowed, ignore the overflow and increment q
721 if (lo > m) {
722 lo &= m;
723 ++lo;
724 }
725 lo += hi >> 15;
726
727 // if (p+q) overflowed, ignore the overflow and increment (p+q)
728 if (lo > m) {
729 lo &= m;
730 ++lo;
731 }
732 return (_rand_seed = lo);
733 }
734
735 // The INITIALIZED state is distinguished from the SUSPENDED state because the
736 // conditions in which a thread is first started are different from those in which
737 // a suspension is resumed. These differences make it hard for us to apply the
738 // tougher checks when starting threads that we want to do when resuming them.
739 // However, when start_thread is called as a result of Thread.start, on a Java
740 // thread, the operation is synchronized on the Java Thread object. So there
741 // cannot be a race to start the thread and hence for the thread to exit while
742 // we are working on it. Non-Java threads that start Java threads either have
743 // to do so in a context in which races are impossible, or should do appropriate
744 // locking.
745
746 void os::start_thread(Thread* thread) {
747 // guard suspend/resume
748 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
749 OSThread* osthread = thread->osthread();
750 osthread->set_state(RUNNABLE);
751 pd_start_thread(thread);
752 }
753
754 //---------------------------------------------------------------------------
755 // Helper functions for fatal error handler
756
757 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
758 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
759
760 int cols = 0;
761 int cols_per_line = 0;
762 switch (unitsize) {
763 case 1: cols_per_line = 16; break;
764 case 2: cols_per_line = 8; break;
765 case 4: cols_per_line = 4; break;
766 case 8: cols_per_line = 2; break;
767 default: return;
768 }
769
770 address p = start;
771 st->print(PTR_FORMAT ": ", start);
772 while (p < end) {
773 switch (unitsize) {
774 case 1: st->print("%02x", *(u1*)p); break;
775 case 2: st->print("%04x", *(u2*)p); break;
776 case 4: st->print("%08x", *(u4*)p); break;
777 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
778 }
779 p += unitsize;
780 cols++;
781 if (cols >= cols_per_line && p < end) {
782 cols = 0;
783 st->cr();
784 st->print(PTR_FORMAT ": ", p);
785 } else {
786 st->print(" ");
787 }
788 }
789 st->cr();
790 }
791
792 void os::print_environment_variables(outputStream* st, const char** env_list,
793 char* buffer, int len) {
794 if (env_list) {
795 st->print_cr("Environment Variables:");
796
797 for (int i = 0; env_list[i] != NULL; i++) {
798 if (getenv(env_list[i], buffer, len)) {
799 st->print("%s", env_list[i]);
800 st->print("=");
801 st->print_cr("%s", buffer);
802 }
803 }
804 }
805 }
806
807 void os::print_cpu_info(outputStream* st) {
808 // cpu
809 st->print("CPU:");
810 st->print("total %d", os::processor_count());
811 // It's not safe to query number of active processors after crash
812 // st->print("(active %d)", os::active_processor_count());
813 st->print(" %s", VM_Version::cpu_features());
814 st->cr();
815 pd_print_cpu_info(st);
816 }
817
818 void os::print_date_and_time(outputStream *st) {
819 const int secs_per_day = 86400;
820 const int secs_per_hour = 3600;
821 const int secs_per_min = 60;
822
823 time_t tloc;
824 (void)time(&tloc);
825 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
826
827 double t = os::elapsedTime();
828 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
829 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
830 // before printf. We lost some precision, but who cares?
831 int eltime = (int)t; // elapsed time in seconds
832
833 // print elapsed time in a human-readable format:
834 int eldays = eltime / secs_per_day;
835 int day_secs = eldays * secs_per_day;
836 int elhours = (eltime - day_secs) / secs_per_hour;
837 int hour_secs = elhours * secs_per_hour;
838 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
839 int minute_secs = elmins * secs_per_min;
840 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
841 st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
842 }
843
844 // moved from debug.cpp (used to be find()) but still called from there
845 // The verbose parameter is only set by the debug code in one case
846 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
847 address addr = (address)x;
848 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
849 if (b != NULL) {
850 if (b->is_buffer_blob()) {
851 // the interpreter is generated into a buffer blob
852 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
853 if (i != NULL) {
854 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
855 i->print_on(st);
856 return;
857 }
858 if (Interpreter::contains(addr)) {
859 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
860 " (not bytecode specific)", addr);
861 return;
862 }
863 //
864 if (AdapterHandlerLibrary::contains(b)) {
865 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
866 AdapterHandlerLibrary::print_handler_on(st, b);
867 }
868 // the stubroutines are generated into a buffer blob
869 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
870 if (d != NULL) {
871 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
872 d->print_on(st);
873 st->cr();
874 return;
875 }
876 if (StubRoutines::contains(addr)) {
877 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
878 "stub routine", addr);
879 return;
880 }
881 // the InlineCacheBuffer is using stubs generated into a buffer blob
882 if (InlineCacheBuffer::contains(addr)) {
883 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
884 return;
885 }
886 VtableStub* v = VtableStubs::stub_containing(addr);
887 if (v != NULL) {
888 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
889 v->print_on(st);
890 st->cr();
891 return;
892 }
893 }
894 nmethod* nm = b->as_nmethod_or_null();
895 if (nm != NULL) {
896 ResourceMark rm;
897 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
898 addr, (int)(addr - nm->entry_point()), nm);
899 if (verbose) {
900 st->print(" for ");
901 nm->method()->print_value_on(st);
902 }
903 st->cr();
904 nm->print_nmethod(verbose);
905 return;
906 }
907 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
908 b->print_on(st);
909 return;
910 }
911
912 if (Universe::heap()->is_in(addr)) {
913 HeapWord* p = Universe::heap()->block_start(addr);
914 bool print = false;
915 // If we couldn't find it it just may mean that heap wasn't parsable
916 // See if we were just given an oop directly
917 if (p != NULL && Universe::heap()->block_is_obj(p)) {
918 print = true;
919 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
920 p = (HeapWord*) addr;
921 print = true;
922 }
923 if (print) {
924 if (p == (HeapWord*) addr) {
925 st->print_cr(INTPTR_FORMAT " is an oop", addr);
926 } else {
927 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
928 }
929 oop(p)->print_on(st);
930 return;
931 }
932 } else {
933 if (Universe::heap()->is_in_reserved(addr)) {
934 st->print_cr(INTPTR_FORMAT " is an unallocated location "
935 "in the heap", addr);
936 return;
937 }
938 }
939 if (JNIHandles::is_global_handle((jobject) addr)) {
940 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
941 return;
942 }
943 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
944 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
945 return;
946 }
947 #ifndef PRODUCT
948 // we don't keep the block list in product mode
949 if (JNIHandleBlock::any_contains((jobject) addr)) {
950 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
951 return;
952 }
953 #endif
954
955 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
956 // Check for privilege stack
957 if (thread->privileged_stack_top() != NULL &&
958 thread->privileged_stack_top()->contains(addr)) {
959 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
960 "for thread: " INTPTR_FORMAT, addr, thread);
961 if (verbose) thread->print_on(st);
962 return;
963 }
964 // If the addr is a java thread print information about that.
965 if (addr == (address)thread) {
966 if (verbose) {
967 thread->print_on(st);
968 } else {
969 st->print_cr(INTPTR_FORMAT " is a thread", addr);
970 }
971 return;
972 }
973 // If the addr is in the stack region for this thread then report that
974 // and print thread info
975 if (thread->stack_base() >= addr &&
976 addr > (thread->stack_base() - thread->stack_size())) {
977 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
978 INTPTR_FORMAT, addr, thread);
979 if (verbose) thread->print_on(st);
980 return;
981 }
982
983 }
984
985 // Check if in metaspace and print types that have vptrs (only method now)
986 if (Metaspace::contains(addr)) {
987 if (Method::has_method_vptr((const void*)addr)) {
988 ((Method*)addr)->print_value_on(st);
989 st->cr();
990 } else {
991 // Use addr->print() from the debugger instead (not here)
992 st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr);
993 }
994 return;
995 }
996
997 // Try an OS specific find
998 if (os::find(addr, st)) {
999 return;
1000 }
1001
1002 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1003 }
1004
1005 // Looks like all platforms except IA64 can use the same function to check
1006 // if C stack is walkable beyond current frame. The check for fp() is not
1007 // necessary on Sparc, but it's harmless.
1008 bool os::is_first_C_frame(frame* fr) {
1009 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1010 // On IA64 we have to check if the callers bsp is still valid
1011 // (i.e. within the register stack bounds).
1012 // Notice: this only works for threads created by the VM and only if
1013 // we walk the current stack!!! If we want to be able to walk
1014 // arbitrary other threads, we'll have to somehow store the thread
1015 // object in the frame.
1016 Thread *thread = Thread::current();
1017 if ((address)fr->fp() <=
1018 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1019 // This check is a little hacky, because on Linux the first C
1020 // frame's ('start_thread') register stack frame starts at
1021 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1022 // ('__pthread_bound_body') register stack frame seems to really
1023 // start at "register_stack_base".
1024 return true;
1025 } else {
1026 return false;
1027 }
1028 #elif defined(IA64) && defined(_WIN32)
1029 return true;
1030 #else
1031 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1032 // Check usp first, because if that's bad the other accessors may fault
1033 // on some architectures. Ditto ufp second, etc.
1034 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1035 // sp on amd can be 32 bit aligned.
1036 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1037
1038 uintptr_t usp = (uintptr_t)fr->sp();
1039 if ((usp & sp_align_mask) != 0) return true;
1040
1041 uintptr_t ufp = (uintptr_t)fr->fp();
1042 if ((ufp & fp_align_mask) != 0) return true;
1043
1044 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1045 if ((old_sp & sp_align_mask) != 0) return true;
1046 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1047
1048 uintptr_t old_fp = (uintptr_t)fr->link();
1049 if ((old_fp & fp_align_mask) != 0) return true;
1050 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1051
1052 // stack grows downwards; if old_fp is below current fp or if the stack
1053 // frame is too large, either the stack is corrupted or fp is not saved
1054 // on stack (i.e. on x86, ebp may be used as general register). The stack
1055 // is not walkable beyond current frame.
1056 if (old_fp < ufp) return true;
1057 if (old_fp - ufp > 64 * K) return true;
1058
1059 return false;
1060 #endif
1061 }
1062
1063 #ifdef ASSERT
1064 extern "C" void test_random() {
1065 const double m = 2147483647;
1066 double mean = 0.0, variance = 0.0, t;
1067 long reps = 10000;
1068 unsigned long seed = 1;
1069
1070 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1071 os::init_random(seed);
1072 long num;
1073 for (int k = 0; k < reps; k++) {
1074 num = os::random();
1075 double u = (double)num / m;
1076 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1077
1078 // calculate mean and variance of the random sequence
1079 mean += u;
1080 variance += (u*u);
1081 }
1082 mean /= reps;
1083 variance /= (reps - 1);
1084
1085 assert(num == 1043618065, "bad seed");
1086 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1087 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1088 const double eps = 0.0001;
1089 t = fabsd(mean - 0.5018);
1090 assert(t < eps, "bad mean");
1091 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1092 assert(t < eps, "bad variance");
1093 }
1094 #endif
1095
1096
1097 // Set up the boot classpath.
1098
1099 char* os::format_boot_path(const char* format_string,
1100 const char* home,
1101 int home_len,
1102 char fileSep,
1103 char pathSep) {
1104 assert((fileSep == '/' && pathSep == ':') ||
1105 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1106
1107 // Scan the format string to determine the length of the actual
1108 // boot classpath, and handle platform dependencies as well.
1109 int formatted_path_len = 0;
1110 const char* p;
1111 for (p = format_string; *p != 0; ++p) {
1112 if (*p == '%') formatted_path_len += home_len - 1;
1113 ++formatted_path_len;
1114 }
1115
1116 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1117 if (formatted_path == NULL) {
1118 return NULL;
1119 }
1120
1121 // Create boot classpath from format, substituting separator chars and
1122 // java home directory.
1123 char* q = formatted_path;
1124 for (p = format_string; *p != 0; ++p) {
1125 switch (*p) {
1126 case '%':
1127 strcpy(q, home);
1128 q += home_len;
1129 break;
1130 case '/':
1131 *q++ = fileSep;
1132 break;
1133 case ':':
1134 *q++ = pathSep;
1135 break;
1136 default:
1137 *q++ = *p;
1138 }
1139 }
1140 *q = '\0';
1141
1142 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1143 return formatted_path;
1144 }
1145
1146
1147 bool os::set_boot_path(char fileSep, char pathSep) {
1148 const char* home = Arguments::get_java_home();
1149 int home_len = (int)strlen(home);
1150
1151 static const char* meta_index_dir_format = "%/lib/";
1152 static const char* meta_index_format = "%/lib/meta-index";
1153 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1154 if (meta_index == NULL) return false;
1155 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1156 if (meta_index_dir == NULL) return false;
1157 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1158
1159 // Any modification to the JAR-file list, for the boot classpath must be
1160 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1161 // path class JARs, are stripped for StackMapTable to reduce download size.
1162 static const char classpath_format[] =
1163 "%/lib/resources.jar:"
1164 "%/lib/rt.jar:"
1165 "%/lib/sunrsasign.jar:"
1166 "%/lib/jsse.jar:"
1167 "%/lib/jce.jar:"
1168 "%/lib/charsets.jar:"
1169 "%/lib/jfr.jar:"
1170 "%/classes";
1171 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1172 if (sysclasspath == NULL) return false;
1173 Arguments::set_sysclasspath(sysclasspath);
1174
1175 return true;
1176 }
1177
1178 /*
1179 * Splits a path, based on its separator, the number of
1180 * elements is returned back in n.
1181 * It is the callers responsibility to:
1182 * a> check the value of n, and n may be 0.
1183 * b> ignore any empty path elements
1184 * c> free up the data.
1185 */
1186 char** os::split_path(const char* path, int* n) {
1187 *n = 0;
1188 if (path == NULL || strlen(path) == 0) {
1189 return NULL;
1190 }
1191 const char psepchar = *os::path_separator();
1192 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1193 if (inpath == NULL) {
1194 return NULL;
1195 }
1196 strcpy(inpath, path);
1197 int count = 1;
1198 char* p = strchr(inpath, psepchar);
1199 // Get a count of elements to allocate memory
1200 while (p != NULL) {
1201 count++;
1202 p++;
1203 p = strchr(p, psepchar);
1204 }
1205 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1206 if (opath == NULL) {
1207 return NULL;
1208 }
1209
1210 // do the actual splitting
1211 p = inpath;
1212 for (int i = 0 ; i < count ; i++) {
1213 size_t len = strcspn(p, os::path_separator());
1214 if (len > JVM_MAXPATHLEN) {
1215 return NULL;
1216 }
1217 // allocate the string and add terminator storage
1218 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1219 if (s == NULL) {
1220 return NULL;
1221 }
1222 strncpy(s, p, len);
1223 s[len] = '\0';
1224 opath[i] = s;
1225 p += len + 1;
1226 }
1227 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1228 *n = count;
1229 return opath;
1230 }
1231
1232 void os::set_memory_serialize_page(address page) {
1233 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1234 _mem_serialize_page = (volatile int32_t *)page;
1235 // We initialize the serialization page shift count here
1236 // We assume a cache line size of 64 bytes
1237 assert(SerializePageShiftCount == count,
1238 "thread size changed, fix SerializePageShiftCount constant");
1239 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1240 }
1241
1242 static volatile intptr_t SerializePageLock = 0;
1243
1244 // This method is called from signal handler when SIGSEGV occurs while the current
1245 // thread tries to store to the "read-only" memory serialize page during state
1246 // transition.
1247 void os::block_on_serialize_page_trap() {
1248 if (TraceSafepoint) {
1249 tty->print_cr("Block until the serialize page permission restored");
1250 }
1251 // When VMThread is holding the SerializePageLock during modifying the
1252 // access permission of the memory serialize page, the following call
1253 // will block until the permission of that page is restored to rw.
1254 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1255 // this case, it's OK as the signal is synchronous and we know precisely when
1256 // it can occur.
1257 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1258 Thread::muxRelease(&SerializePageLock);
1259 }
1260
1261 // Serialize all thread state variables
1262 void os::serialize_thread_states() {
1263 // On some platforms such as Solaris & Linux, the time duration of the page
1264 // permission restoration is observed to be much longer than expected due to
1265 // scheduler starvation problem etc. To avoid the long synchronization
1266 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1267 // the mutator thread if such case is encountered. See bug 6546278 for details.
1268 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1269 os::protect_memory((char *)os::get_memory_serialize_page(),
1270 os::vm_page_size(), MEM_PROT_READ);
1271 os::protect_memory((char *)os::get_memory_serialize_page(),
1272 os::vm_page_size(), MEM_PROT_RW);
1273 Thread::muxRelease(&SerializePageLock);
1274 }
1275
1276 // Returns true if the current stack pointer is above the stack shadow
1277 // pages, false otherwise.
1278
1279 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1280 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1281 address sp = current_stack_pointer();
1282 // Check if we have StackShadowPages above the yellow zone. This parameter
1283 // is dependent on the depth of the maximum VM call stack possible from
1284 // the handler for stack overflow. 'instanceof' in the stack overflow
1285 // handler or a println uses at least 8k stack of VM and native code
1286 // respectively.
1287 const int framesize_in_bytes =
1288 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1289 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1290 * vm_page_size()) + framesize_in_bytes;
1291 // The very lower end of the stack
1292 address stack_limit = thread->stack_base() - thread->stack_size();
1293 return (sp > (stack_limit + reserved_area));
1294 }
1295
1296 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1297 uint min_pages)
1298 {
1299 assert(min_pages > 0, "sanity");
1300 if (UseLargePages) {
1301 const size_t max_page_size = region_max_size / min_pages;
1302
1303 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1304 const size_t sz = _page_sizes[i];
1305 const size_t mask = sz - 1;
1306 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1307 // The largest page size with no fragmentation.
1308 return sz;
1309 }
1310
1311 if (sz <= max_page_size) {
1312 // The largest page size that satisfies the min_pages requirement.
1313 return sz;
1314 }
1315 }
1316 }
1317
1318 return vm_page_size();
1319 }
1320
1321 #ifndef PRODUCT
1322 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1323 {
1324 if (TracePageSizes) {
1325 tty->print("%s: ", str);
1326 for (int i = 0; i < count; ++i) {
1327 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1328 }
1329 tty->cr();
1330 }
1331 }
1332
1333 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1334 const size_t region_max_size, const size_t page_size,
1335 const char* base, const size_t size)
1336 {
1337 if (TracePageSizes) {
1338 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1339 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1340 " size=" SIZE_FORMAT,
1341 str, region_min_size, region_max_size,
1342 page_size, base, size);
1343 }
1344 }
1345 #endif // #ifndef PRODUCT
1346
1347 // This is the working definition of a server class machine:
1348 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1349 // because the graphics memory (?) sometimes masks physical memory.
1350 // If you want to change the definition of a server class machine
1351 // on some OS or platform, e.g., >=4GB on Windows platforms,
1352 // then you'll have to parameterize this method based on that state,
1353 // as was done for logical processors here, or replicate and
1354 // specialize this method for each platform. (Or fix os to have
1355 // some inheritance structure and use subclassing. Sigh.)
1356 // If you want some platform to always or never behave as a server
1357 // class machine, change the setting of AlwaysActAsServerClassMachine
1358 // and NeverActAsServerClassMachine in globals*.hpp.
1359 bool os::is_server_class_machine() {
1360 // First check for the early returns
1361 if (NeverActAsServerClassMachine) {
1362 return false;
1363 }
1364 if (AlwaysActAsServerClassMachine) {
1365 return true;
1366 }
1367 // Then actually look at the machine
1368 bool result = false;
1369 const unsigned int server_processors = 2;
1370 const julong server_memory = 2UL * G;
1371 // We seem not to get our full complement of memory.
1372 // We allow some part (1/8?) of the memory to be "missing",
1373 // based on the sizes of DIMMs, and maybe graphics cards.
1374 const julong missing_memory = 256UL * M;
1375
1376 /* Is this a server class machine? */
1377 if ((os::active_processor_count() >= (int)server_processors) &&
1378 (os::physical_memory() >= (server_memory - missing_memory))) {
1379 const unsigned int logical_processors =
1380 VM_Version::logical_processors_per_package();
1381 if (logical_processors > 1) {
1382 const unsigned int physical_packages =
1383 os::active_processor_count() / logical_processors;
1384 if (physical_packages > server_processors) {
1385 result = true;
1386 }
1387 } else {
1388 result = true;
1389 }
1390 }
1391 return result;
1392 }
1393
1394 void os::SuspendedThreadTask::run() {
1395 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1396 internal_do_task();
1397 _done = true;
1398 }
1399
1400 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1401 return os::pd_create_stack_guard_pages(addr, bytes);
1402 }
1403
1404 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1405 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1406 if (result != NULL) {
1407 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1408 }
1409
1410 return result;
1411 }
1412
1413 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1414 MEMFLAGS flags) {
1415 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1416 if (result != NULL) {
1417 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1418 MemTracker::record_virtual_memory_type((address)result, flags);
1419 }
1420
1421 return result;
1422 }
1423
1424 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1425 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1426 if (result != NULL) {
1427 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1428 }
1429 return result;
1430 }
1431
1432 void os::split_reserved_memory(char *base, size_t size,
1433 size_t split, bool realloc) {
1434 pd_split_reserved_memory(base, size, split, realloc);
1435 }
1436
1437 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1438 bool res = pd_commit_memory(addr, bytes, executable);
1439 if (res) {
1440 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1441 }
1442 return res;
1443 }
1444
1445 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1446 bool executable) {
1447 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1448 if (res) {
1449 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1450 }
1451 return res;
1452 }
1453
1454 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1455 const char* mesg) {
1456 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1457 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1458 }
1459
1460 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1461 bool executable, const char* mesg) {
1462 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1463 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1464 }
1465
1466 bool os::uncommit_memory(char* addr, size_t bytes) {
1467 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1468 bool res = pd_uncommit_memory(addr, bytes);
1469 if (res) {
1470 tkr.record((address)addr, bytes);
1471 } else {
1472 tkr.discard();
1473 }
1474 return res;
1475 }
1476
1477 bool os::release_memory(char* addr, size_t bytes) {
1478 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1479 bool res = pd_release_memory(addr, bytes);
1480 if (res) {
1481 tkr.record((address)addr, bytes);
1482 } else {
1483 tkr.discard();
1484 }
1485 return res;
1486 }
1487
1488
1489 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1490 char *addr, size_t bytes, bool read_only,
1491 bool allow_exec) {
1492 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1493 if (result != NULL) {
1494 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, mtNone, CALLER_PC);
1495 }
1496 return result;
1497 }
1498
1499 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1500 char *addr, size_t bytes, bool read_only,
1501 bool allow_exec) {
1502 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1503 read_only, allow_exec);
1504 }
1505
1506 bool os::unmap_memory(char *addr, size_t bytes) {
1507 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1508 bool result = pd_unmap_memory(addr, bytes);
1509 if (result) {
1510 tkr.record((address)addr, bytes);
1511 } else {
1512 tkr.discard();
1513 }
1514 return result;
1515 }
1516
1517 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1518 pd_free_memory(addr, bytes, alignment_hint);
1519 }
1520
1521 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1522 pd_realign_memory(addr, bytes, alignment_hint);
1523 }
1524
1525 #ifndef TARGET_OS_FAMILY_windows
1526 /* try to switch state from state "from" to state "to"
1527 * returns the state set after the method is complete
1528 */
1529 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1530 os::SuspendResume::State to)
1531 {
1532 os::SuspendResume::State result =
1533 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1534 if (result == from) {
1535 // success
1536 return to;
1537 }
1538 return result;
1539 }
1540 #endif