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/sharedRuntime.hpp"
52 #include "runtime/stubRoutines.hpp"
53 #include "runtime/thread.inline.hpp"
54 #include "runtime/vm_version.hpp"
55 #include "services/attachListener.hpp"
56 #include "services/memTracker.hpp"
57 #include "services/threadService.hpp"
58 #include "utilities/defaultStream.hpp"
59 #include "utilities/events.hpp"
60
61 # include <signal.h>
62
63 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
64
65 OSThread* os::_starting_thread = NULL;
66 address os::_polling_page = NULL;
67 volatile int32_t* os::_mem_serialize_page = NULL;
68 uintptr_t os::_serialize_page_mask = 0;
69 long os::_rand_seed = 1;
70 int os::_processor_count = 0;
71 size_t os::_page_sizes[os::page_sizes_max];
72
73 #ifndef PRODUCT
74 julong os::num_mallocs = 0; // # of calls to malloc/realloc
75 julong os::alloc_bytes = 0; // # of bytes allocated
76 julong os::num_frees = 0; // # of calls to free
77 julong os::free_bytes = 0; // # of bytes freed
78 #endif
79
80 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
81
82 void os_init_globals() {
83 // Called from init_globals().
84 // See Threads::create_vm() in thread.cpp, and init.cpp.
85 os::init_globals();
86 }
87
88 // Fill in buffer with current local time as an ISO-8601 string.
89 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
90 // Returns buffer, or NULL if it failed.
91 // This would mostly be a call to
92 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
93 // except that on Windows the %z behaves badly, so we do it ourselves.
94 // Also, people wanted milliseconds on there,
95 // and strftime doesn't do milliseconds.
96 char* os::iso8601_time(char* buffer, size_t buffer_length) {
97 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
98 // 1 2
99 // 12345678901234567890123456789
100 static const char* iso8601_format =
101 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
102 static const size_t needed_buffer = 29;
103
104 // Sanity check the arguments
105 if (buffer == NULL) {
106 assert(false, "NULL buffer");
107 return NULL;
108 }
109 if (buffer_length < needed_buffer) {
110 assert(false, "buffer_length too small");
111 return NULL;
112 }
113 // Get the current time
114 jlong milliseconds_since_19700101 = javaTimeMillis();
115 const int milliseconds_per_microsecond = 1000;
116 const time_t seconds_since_19700101 =
117 milliseconds_since_19700101 / milliseconds_per_microsecond;
118 const int milliseconds_after_second =
119 milliseconds_since_19700101 % milliseconds_per_microsecond;
120 // Convert the time value to a tm and timezone variable
121 struct tm time_struct;
122 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
123 assert(false, "Failed localtime_pd");
124 return NULL;
125 }
126 #if defined(_ALLBSD_SOURCE)
127 const time_t zone = (time_t) time_struct.tm_gmtoff;
128 #else
129 const time_t zone = timezone;
130 #endif
131
132 // If daylight savings time is in effect,
133 // we are 1 hour East of our time zone
134 const time_t seconds_per_minute = 60;
135 const time_t minutes_per_hour = 60;
136 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
137 time_t UTC_to_local = zone;
138 if (time_struct.tm_isdst > 0) {
139 UTC_to_local = UTC_to_local - seconds_per_hour;
140 }
141 // Compute the time zone offset.
142 // localtime_pd() sets timezone to the difference (in seconds)
143 // between UTC and and local time.
144 // ISO 8601 says we need the difference between local time and UTC,
145 // we change the sign of the localtime_pd() result.
146 const time_t local_to_UTC = -(UTC_to_local);
147 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
148 char sign_local_to_UTC = '+';
149 time_t abs_local_to_UTC = local_to_UTC;
150 if (local_to_UTC < 0) {
151 sign_local_to_UTC = '-';
152 abs_local_to_UTC = -(abs_local_to_UTC);
153 }
154 // Convert time zone offset seconds to hours and minutes.
155 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
156 const time_t zone_min =
157 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
158
159 // Print an ISO 8601 date and time stamp into the buffer
160 const int year = 1900 + time_struct.tm_year;
161 const int month = 1 + time_struct.tm_mon;
162 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
163 year,
164 month,
165 time_struct.tm_mday,
166 time_struct.tm_hour,
167 time_struct.tm_min,
168 time_struct.tm_sec,
169 milliseconds_after_second,
170 sign_local_to_UTC,
171 zone_hours,
172 zone_min);
173 if (printed == 0) {
174 assert(false, "Failed jio_printf");
175 return NULL;
176 }
177 return buffer;
178 }
179
180 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
181 #ifdef ASSERT
182 if (!(!thread->is_Java_thread() ||
183 Thread::current() == thread ||
184 Threads_lock->owned_by_self()
185 || thread->is_Compiler_thread()
186 )) {
187 assert(false, "possibility of dangling Thread pointer");
188 }
189 #endif
190
191 if (p >= MinPriority && p <= MaxPriority) {
192 int priority = java_to_os_priority[p];
193 return set_native_priority(thread, priority);
194 } else {
195 assert(false, "Should not happen");
196 return OS_ERR;
197 }
198 }
199
200 // The mapping from OS priority back to Java priority may be inexact because
201 // Java priorities can map M:1 with native priorities. If you want the definite
202 // Java priority then use JavaThread::java_priority()
203 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
204 int p;
205 int os_prio;
206 OSReturn ret = get_native_priority(thread, &os_prio);
207 if (ret != OS_OK) return ret;
208
209 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
210 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
211 } else {
212 // niceness values are in reverse order
213 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
214 }
215 priority = (ThreadPriority)p;
216 return OS_OK;
217 }
218
219
220 // --------------------- sun.misc.Signal (optional) ---------------------
221
222
223 // SIGBREAK is sent by the keyboard to query the VM state
224 #ifndef SIGBREAK
225 #define SIGBREAK SIGQUIT
226 #endif
227
228 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
229
230
231 static void signal_thread_entry(JavaThread* thread, TRAPS) {
232 os::set_priority(thread, NearMaxPriority);
233 while (true) {
234 int sig;
235 {
236 // FIXME : Currently we have not decided what should be the status
237 // for this java thread blocked here. Once we decide about
238 // that we should fix this.
239 sig = os::signal_wait();
240 }
241 if (sig == os::sigexitnum_pd()) {
242 // Terminate the signal thread
243 return;
244 }
245
246 switch (sig) {
247 case SIGBREAK: {
248 // Check if the signal is a trigger to start the Attach Listener - in that
249 // case don't print stack traces.
250 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
251 continue;
252 }
253 // Print stack traces
254 // Any SIGBREAK operations added here should make sure to flush
255 // the output stream (e.g. tty->flush()) after output. See 4803766.
256 // Each module also prints an extra carriage return after its output.
257 VM_PrintThreads op;
258 VMThread::execute(&op);
259 VM_PrintJNI jni_op;
260 VMThread::execute(&jni_op);
261 VM_FindDeadlocks op1(tty);
262 VMThread::execute(&op1);
263 Universe::print_heap_at_SIGBREAK();
264 if (PrintClassHistogram) {
265 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
266 VMThread::execute(&op1);
267 }
268 if (JvmtiExport::should_post_data_dump()) {
269 JvmtiExport::post_data_dump();
270 }
271 break;
272 }
273 default: {
274 // Dispatch the signal to java
275 HandleMark hm(THREAD);
276 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
277 KlassHandle klass (THREAD, k);
278 if (klass.not_null()) {
279 JavaValue result(T_VOID);
280 JavaCallArguments args;
281 args.push_int(sig);
282 JavaCalls::call_static(
283 &result,
284 klass,
285 vmSymbols::dispatch_name(),
286 vmSymbols::int_void_signature(),
287 &args,
288 THREAD
289 );
290 }
291 if (HAS_PENDING_EXCEPTION) {
292 // tty is initialized early so we don't expect it to be null, but
293 // if it is we can't risk doing an initialization that might
294 // trigger additional out-of-memory conditions
295 if (tty != NULL) {
296 char klass_name[256];
297 char tmp_sig_name[16];
298 const char* sig_name = "UNKNOWN";
299 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
300 name()->as_klass_external_name(klass_name, 256);
301 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
302 sig_name = tmp_sig_name;
303 warning("Exception %s occurred dispatching signal %s to handler"
304 "- the VM may need to be forcibly terminated",
305 klass_name, sig_name );
306 }
307 CLEAR_PENDING_EXCEPTION;
308 }
309 }
310 }
311 }
312 }
313
314 void os::init_before_ergo() {
315 // We need to initialize large page support here because ergonomics takes some
316 // decisions depending on large page support and the calculated large page size.
317 large_page_init();
318 }
319
320 void os::signal_init() {
321 if (!ReduceSignalUsage) {
322 // Setup JavaThread for processing signals
323 EXCEPTION_MARK;
324 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
325 instanceKlassHandle klass (THREAD, k);
326 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
327
328 const char thread_name[] = "Signal Dispatcher";
329 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
330
331 // Initialize thread_oop to put it into the system threadGroup
332 Handle thread_group (THREAD, Universe::system_thread_group());
333 JavaValue result(T_VOID);
334 JavaCalls::call_special(&result, thread_oop,
335 klass,
336 vmSymbols::object_initializer_name(),
337 vmSymbols::threadgroup_string_void_signature(),
338 thread_group,
339 string,
340 CHECK);
341
342 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
343 JavaCalls::call_special(&result,
344 thread_group,
345 group,
346 vmSymbols::add_method_name(),
347 vmSymbols::thread_void_signature(),
348 thread_oop, // ARG 1
349 CHECK);
350
351 os::signal_init_pd();
352
353 { MutexLocker mu(Threads_lock);
354 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
355
356 // At this point it may be possible that no osthread was created for the
357 // JavaThread due to lack of memory. We would have to throw an exception
358 // in that case. However, since this must work and we do not allow
359 // exceptions anyway, check and abort if this fails.
360 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
361 vm_exit_during_initialization("java.lang.OutOfMemoryError",
362 os::native_thread_creation_failed_msg());
363 }
364
365 java_lang_Thread::set_thread(thread_oop(), signal_thread);
366 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
367 java_lang_Thread::set_daemon(thread_oop());
368
369 signal_thread->set_threadObj(thread_oop());
370 Threads::add(signal_thread);
371 Thread::start(signal_thread);
372 }
373 // Handle ^BREAK
374 os::signal(SIGBREAK, os::user_handler());
375 }
376 }
377
378
379 void os::terminate_signal_thread() {
380 if (!ReduceSignalUsage)
381 signal_notify(sigexitnum_pd());
382 }
383
384
385 // --------------------- loading libraries ---------------------
386
387 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
388 extern struct JavaVM_ main_vm;
389
390 static void* _native_java_library = NULL;
391
392 void* os::native_java_library() {
393 if (_native_java_library == NULL) {
394 char buffer[JVM_MAXPATHLEN];
395 char ebuf[1024];
396
397 // Try to load verify dll first. In 1.3 java dll depends on it and is not
398 // always able to find it when the loading executable is outside the JDK.
399 // In order to keep working with 1.2 we ignore any loading errors.
400 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
401 "verify")) {
402 dll_load(buffer, ebuf, sizeof(ebuf));
403 }
404
405 // Load java dll
406 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
407 "java")) {
408 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
409 }
410 if (_native_java_library == NULL) {
411 vm_exit_during_initialization("Unable to load native library", ebuf);
412 }
413
414 #if defined(__OpenBSD__)
415 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
416 // ignore errors
417 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
418 "net")) {
419 dll_load(buffer, ebuf, sizeof(ebuf));
420 }
421 #endif
422 }
423 static jboolean onLoaded = JNI_FALSE;
424 if (onLoaded) {
425 // We may have to wait to fire OnLoad until TLS is initialized.
426 if (ThreadLocalStorage::is_initialized()) {
427 // The JNI_OnLoad handling is normally done by method load in
428 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
429 // explicitly so we have to check for JNI_OnLoad as well
430 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
431 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
432 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
433 if (JNI_OnLoad != NULL) {
434 JavaThread* thread = JavaThread::current();
435 ThreadToNativeFromVM ttn(thread);
436 HandleMark hm(thread);
437 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
438 onLoaded = JNI_TRUE;
439 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
440 vm_exit_during_initialization("Unsupported JNI version");
441 }
442 }
443 }
444 }
445 return _native_java_library;
446 }
447
448 /*
449 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
450 * If check_lib == true then we are looking for an
451 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
452 * this library is statically linked into the image.
453 * If check_lib == false then we will look for the appropriate symbol in the
454 * executable if agent_lib->is_static_lib() == true or in the shared library
455 * referenced by 'handle'.
456 */
457 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
458 const char *syms[], size_t syms_len) {
459 assert(agent_lib != NULL, "sanity check");
460 const char *lib_name;
461 void *handle = agent_lib->os_lib();
462 void *entryName = NULL;
463 char *agent_function_name;
464 size_t i;
465
466 // If checking then use the agent name otherwise test is_static_lib() to
467 // see how to process this lookup
468 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
469 for (i = 0; i < syms_len; i++) {
470 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
471 if (agent_function_name == NULL) {
472 break;
473 }
474 entryName = dll_lookup(handle, agent_function_name);
475 FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread);
476 if (entryName != NULL) {
477 break;
478 }
479 }
480 return entryName;
481 }
482
483 // See if the passed in agent is statically linked into the VM image.
484 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
485 size_t syms_len) {
486 void *ret;
487 void *proc_handle;
488 void *save_handle;
489
490 assert(agent_lib != NULL, "sanity check");
491 if (agent_lib->name() == NULL) {
492 return false;
493 }
494 proc_handle = get_default_process_handle();
495 // Check for Agent_OnLoad/Attach_lib_name function
496 save_handle = agent_lib->os_lib();
497 // We want to look in this process' symbol table.
498 agent_lib->set_os_lib(proc_handle);
499 ret = find_agent_function(agent_lib, true, syms, syms_len);
500 if (ret != NULL) {
501 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
502 agent_lib->set_valid();
503 agent_lib->set_static_lib(true);
504 return true;
505 }
506 agent_lib->set_os_lib(save_handle);
507 return false;
508 }
509
510 // --------------------- heap allocation utilities ---------------------
511
512 char *os::strdup(const char *str, MEMFLAGS flags) {
513 size_t size = strlen(str);
514 char *dup_str = (char *)malloc(size + 1, flags);
515 if (dup_str == NULL) return NULL;
516 strcpy(dup_str, str);
517 return dup_str;
518 }
519
520
521 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
522
523 #ifdef ASSERT
524
525 static void verify_memory(void* ptr) {
526 GuardedMemory guarded(ptr);
527 if (!guarded.verify_guards()) {
528 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
529 tty->print_cr("## memory stomp:");
530 guarded.print_on(tty);
531 fatal("memory stomping error");
532 }
533 }
534
535 #endif
536
537 //
538 // This function supports testing of the malloc out of memory
539 // condition without really running the system out of memory.
540 //
541 static u_char* testMalloc(size_t alloc_size) {
542 assert(MallocMaxTestWords > 0, "sanity check");
543
544 if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
545 return NULL;
546 }
547
548 u_char* ptr = (u_char*)::malloc(alloc_size);
549
550 if (ptr != NULL) {
551 Atomic::add(((jint) (alloc_size / BytesPerWord)),
552 (volatile jint *) &cur_malloc_words);
553 }
554 return ptr;
555 }
556
557 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
558 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
559 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
560
561 #ifdef ASSERT
562 // checking for the WatcherThread and crash_protection first
563 // since os::malloc can be called when the libjvm.{dll,so} is
564 // first loaded and we don't have a thread yet.
565 // try to find the thread after we see that the watcher thread
566 // exists and has crash protection.
567 WatcherThread *wt = WatcherThread::watcher_thread();
568 if (wt != NULL && wt->has_crash_protection()) {
569 Thread* thread = ThreadLocalStorage::get_thread_slow();
570 if (thread == wt) {
571 assert(!wt->has_crash_protection(),
572 "Can't malloc with crash protection from WatcherThread");
573 }
574 }
575 #endif
576
577 if (size == 0) {
578 // return a valid pointer if size is zero
579 // if NULL is returned the calling functions assume out of memory.
580 size = 1;
581 }
582
583 #ifndef ASSERT
584 const size_t alloc_size = size;
585 #else
586 const size_t alloc_size = GuardedMemory::get_total_size(size);
587 if (size > alloc_size) { // Check for rollover.
588 return NULL;
589 }
590 #endif
591
592 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
593
594 u_char* ptr;
595 if (MallocMaxTestWords > 0) {
596 ptr = testMalloc(alloc_size);
597 } else {
598 ptr = (u_char*)::malloc(alloc_size);
599 }
600
601 #ifdef ASSERT
602 if (ptr == NULL) {
603 return NULL;
604 }
605 // Wrap memory with guard
606 GuardedMemory guarded(ptr, size);
607 ptr = guarded.get_user_ptr();
608 #endif
609 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
610 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
611 breakpoint();
612 }
613 debug_only(if (paranoid) verify_memory(ptr));
614 if (PrintMalloc && tty != NULL) {
615 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
616 }
617
618 // we do not track guard memory
619 MemTracker::record_malloc((address)ptr, size, memflags, caller == 0 ? CALLER_PC : caller);
620
621 return ptr;
622 }
623
624
625 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
626 #ifndef ASSERT
627 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
628 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
629 MemTracker::Tracker tkr = MemTracker::get_realloc_tracker();
630 void* ptr = ::realloc(memblock, size);
631 if (ptr != NULL) {
632 tkr.record((address)memblock, (address)ptr, size, memflags,
633 caller == 0 ? CALLER_PC : caller);
634 } else {
635 tkr.discard();
636 }
637 return ptr;
638 #else
639 if (memblock == NULL) {
640 return os::malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
641 }
642 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
643 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
644 breakpoint();
645 }
646 verify_memory(memblock);
647 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
648 if (size == 0) {
649 return NULL;
650 }
651 // always move the block
652 void* ptr = os::malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
653 if (PrintMalloc) {
654 tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
655 }
656 // Copy to new memory if malloc didn't fail
657 if ( ptr != NULL ) {
658 GuardedMemory guarded(memblock);
659 memcpy(ptr, memblock, MIN2(size, guarded.get_user_size()));
660 if (paranoid) verify_memory(ptr);
661 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
662 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
663 breakpoint();
664 }
665 os::free(memblock);
666 }
667 return ptr;
668 #endif
669 }
670
671
672 void os::free(void *memblock, MEMFLAGS memflags) {
673 address trackp = (address) memblock;
674 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
675 #ifdef ASSERT
676 if (memblock == NULL) return;
677 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
678 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
679 breakpoint();
680 }
681 verify_memory(memblock);
682 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
683
684 GuardedMemory guarded(memblock);
685 size_t size = guarded.get_user_size();
686 inc_stat_counter(&free_bytes, size);
687 memblock = guarded.release_for_freeing();
688 if (PrintMalloc && tty != NULL) {
689 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
690 }
691 #endif
692 MemTracker::record_free(trackp, memflags);
693
694 ::free(memblock);
695 }
696
697 void os::init_random(long initval) {
698 _rand_seed = initval;
699 }
700
701
702 long os::random() {
703 /* standard, well-known linear congruential random generator with
704 * next_rand = (16807*seed) mod (2**31-1)
705 * see
706 * (1) "Random Number Generators: Good Ones Are Hard to Find",
707 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
708 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
709 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
710 */
711 const long a = 16807;
712 const unsigned long m = 2147483647;
713 const long q = m / a; assert(q == 127773, "weird math");
714 const long r = m % a; assert(r == 2836, "weird math");
715
716 // compute az=2^31p+q
717 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
718 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
719 lo += (hi & 0x7FFF) << 16;
720
721 // if q overflowed, ignore the overflow and increment q
722 if (lo > m) {
723 lo &= m;
724 ++lo;
725 }
726 lo += hi >> 15;
727
728 // if (p+q) overflowed, ignore the overflow and increment (p+q)
729 if (lo > m) {
730 lo &= m;
731 ++lo;
732 }
733 return (_rand_seed = lo);
734 }
735
736 // The INITIALIZED state is distinguished from the SUSPENDED state because the
737 // conditions in which a thread is first started are different from those in which
738 // a suspension is resumed. These differences make it hard for us to apply the
739 // tougher checks when starting threads that we want to do when resuming them.
740 // However, when start_thread is called as a result of Thread.start, on a Java
741 // thread, the operation is synchronized on the Java Thread object. So there
742 // cannot be a race to start the thread and hence for the thread to exit while
743 // we are working on it. Non-Java threads that start Java threads either have
744 // to do so in a context in which races are impossible, or should do appropriate
745 // locking.
746
747 void os::start_thread(Thread* thread) {
748 // guard suspend/resume
749 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
750 OSThread* osthread = thread->osthread();
751 osthread->set_state(RUNNABLE);
752 pd_start_thread(thread);
753 }
754
755 //---------------------------------------------------------------------------
756 // Helper functions for fatal error handler
757
758 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
759 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
760
761 int cols = 0;
762 int cols_per_line = 0;
763 switch (unitsize) {
764 case 1: cols_per_line = 16; break;
765 case 2: cols_per_line = 8; break;
766 case 4: cols_per_line = 4; break;
767 case 8: cols_per_line = 2; break;
768 default: return;
769 }
770
771 address p = start;
772 st->print(PTR_FORMAT ": ", start);
773 while (p < end) {
774 switch (unitsize) {
775 case 1: st->print("%02x", *(u1*)p); break;
776 case 2: st->print("%04x", *(u2*)p); break;
777 case 4: st->print("%08x", *(u4*)p); break;
778 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
779 }
780 p += unitsize;
781 cols++;
782 if (cols >= cols_per_line && p < end) {
783 cols = 0;
784 st->cr();
785 st->print(PTR_FORMAT ": ", p);
786 } else {
787 st->print(" ");
788 }
789 }
790 st->cr();
791 }
792
793 void os::print_environment_variables(outputStream* st, const char** env_list,
794 char* buffer, int len) {
795 if (env_list) {
796 st->print_cr("Environment Variables:");
797
798 for (int i = 0; env_list[i] != NULL; i++) {
799 if (getenv(env_list[i], buffer, len)) {
800 st->print("%s", env_list[i]);
801 st->print("=");
802 st->print_cr("%s", buffer);
803 }
804 }
805 }
806 }
807
808 void os::print_cpu_info(outputStream* st) {
809 // cpu
810 st->print("CPU:");
811 st->print("total %d", os::processor_count());
812 // It's not safe to query number of active processors after crash
813 // st->print("(active %d)", os::active_processor_count());
814 st->print(" %s", VM_Version::cpu_features());
815 st->cr();
816 pd_print_cpu_info(st);
817 }
818
819 void os::print_date_and_time(outputStream *st) {
820 const int secs_per_day = 86400;
821 const int secs_per_hour = 3600;
822 const int secs_per_min = 60;
823
824 time_t tloc;
825 (void)time(&tloc);
826 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
827
828 double t = os::elapsedTime();
829 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
830 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
831 // before printf. We lost some precision, but who cares?
832 int eltime = (int)t; // elapsed time in seconds
833
834 // print elapsed time in a human-readable format:
835 int eldays = eltime / secs_per_day;
836 int day_secs = eldays * secs_per_day;
837 int elhours = (eltime - day_secs) / secs_per_hour;
838 int hour_secs = elhours * secs_per_hour;
839 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
840 int minute_secs = elmins * secs_per_min;
841 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
842 st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
843 }
844
845 // moved from debug.cpp (used to be find()) but still called from there
846 // The verbose parameter is only set by the debug code in one case
847 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
848 address addr = (address)x;
849 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
850 if (b != NULL) {
851 if (b->is_buffer_blob()) {
852 // the interpreter is generated into a buffer blob
853 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
854 if (i != NULL) {
855 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
856 i->print_on(st);
857 return;
858 }
859 if (Interpreter::contains(addr)) {
860 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
861 " (not bytecode specific)", addr);
862 return;
863 }
864 //
865 if (AdapterHandlerLibrary::contains(b)) {
866 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
867 AdapterHandlerLibrary::print_handler_on(st, b);
868 }
869 // the stubroutines are generated into a buffer blob
870 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
871 if (d != NULL) {
872 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
873 d->print_on(st);
874 st->cr();
875 return;
876 }
877 if (StubRoutines::contains(addr)) {
878 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
879 "stub routine", addr);
880 return;
881 }
882 // the InlineCacheBuffer is using stubs generated into a buffer blob
883 if (InlineCacheBuffer::contains(addr)) {
884 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
885 return;
886 }
887 VtableStub* v = VtableStubs::stub_containing(addr);
888 if (v != NULL) {
889 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
890 v->print_on(st);
891 st->cr();
892 return;
893 }
894 }
895 nmethod* nm = b->as_nmethod_or_null();
896 if (nm != NULL) {
897 ResourceMark rm;
898 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
899 addr, (int)(addr - nm->entry_point()), nm);
900 if (verbose) {
901 st->print(" for ");
902 nm->method()->print_value_on(st);
903 }
904 st->cr();
905 nm->print_nmethod(verbose);
906 return;
907 }
908 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
909 b->print_on(st);
910 return;
911 }
912
913 if (Universe::heap()->is_in(addr)) {
914 HeapWord* p = Universe::heap()->block_start(addr);
915 bool print = false;
916 // If we couldn't find it it just may mean that heap wasn't parsable
917 // See if we were just given an oop directly
918 if (p != NULL && Universe::heap()->block_is_obj(p)) {
919 print = true;
920 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
921 p = (HeapWord*) addr;
922 print = true;
923 }
924 if (print) {
925 if (p == (HeapWord*) addr) {
926 st->print_cr(INTPTR_FORMAT " is an oop", addr);
927 } else {
928 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
929 }
930 oop(p)->print_on(st);
931 return;
932 }
933 } else {
934 if (Universe::heap()->is_in_reserved(addr)) {
935 st->print_cr(INTPTR_FORMAT " is an unallocated location "
936 "in the heap", addr);
937 return;
938 }
939 }
940 if (JNIHandles::is_global_handle((jobject) addr)) {
941 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
942 return;
943 }
944 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
945 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
946 return;
947 }
948 #ifndef PRODUCT
949 // we don't keep the block list in product mode
950 if (JNIHandleBlock::any_contains((jobject) addr)) {
951 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
952 return;
953 }
954 #endif
955
956 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
957 // Check for privilege stack
958 if (thread->privileged_stack_top() != NULL &&
959 thread->privileged_stack_top()->contains(addr)) {
960 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
961 "for thread: " INTPTR_FORMAT, addr, thread);
962 if (verbose) thread->print_on(st);
963 return;
964 }
965 // If the addr is a java thread print information about that.
966 if (addr == (address)thread) {
967 if (verbose) {
968 thread->print_on(st);
969 } else {
970 st->print_cr(INTPTR_FORMAT " is a thread", addr);
971 }
972 return;
973 }
974 // If the addr is in the stack region for this thread then report that
975 // and print thread info
976 if (thread->stack_base() >= addr &&
977 addr > (thread->stack_base() - thread->stack_size())) {
978 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
979 INTPTR_FORMAT, addr, thread);
980 if (verbose) thread->print_on(st);
981 return;
982 }
983
984 }
985
986 // Check if in metaspace and print types that have vptrs (only method now)
987 if (Metaspace::contains(addr)) {
988 if (Method::has_method_vptr((const void*)addr)) {
989 ((Method*)addr)->print_value_on(st);
990 st->cr();
991 } else {
992 // Use addr->print() from the debugger instead (not here)
993 st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr);
994 }
995 return;
996 }
997
998 // Try an OS specific find
999 if (os::find(addr, st)) {
1000 return;
1001 }
1002
1003 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1004 }
1005
1006 // Looks like all platforms except IA64 can use the same function to check
1007 // if C stack is walkable beyond current frame. The check for fp() is not
1008 // necessary on Sparc, but it's harmless.
1009 bool os::is_first_C_frame(frame* fr) {
1010 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1011 // On IA64 we have to check if the callers bsp is still valid
1012 // (i.e. within the register stack bounds).
1013 // Notice: this only works for threads created by the VM and only if
1014 // we walk the current stack!!! If we want to be able to walk
1015 // arbitrary other threads, we'll have to somehow store the thread
1016 // object in the frame.
1017 Thread *thread = Thread::current();
1018 if ((address)fr->fp() <=
1019 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1020 // This check is a little hacky, because on Linux the first C
1021 // frame's ('start_thread') register stack frame starts at
1022 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1023 // ('__pthread_bound_body') register stack frame seems to really
1024 // start at "register_stack_base".
1025 return true;
1026 } else {
1027 return false;
1028 }
1029 #elif defined(IA64) && defined(_WIN32)
1030 return true;
1031 #else
1032 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1033 // Check usp first, because if that's bad the other accessors may fault
1034 // on some architectures. Ditto ufp second, etc.
1035 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1036 // sp on amd can be 32 bit aligned.
1037 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1038
1039 uintptr_t usp = (uintptr_t)fr->sp();
1040 if ((usp & sp_align_mask) != 0) return true;
1041
1042 uintptr_t ufp = (uintptr_t)fr->fp();
1043 if ((ufp & fp_align_mask) != 0) return true;
1044
1045 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1046 if ((old_sp & sp_align_mask) != 0) return true;
1047 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1048
1049 uintptr_t old_fp = (uintptr_t)fr->link();
1050 if ((old_fp & fp_align_mask) != 0) return true;
1051 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1052
1053 // stack grows downwards; if old_fp is below current fp or if the stack
1054 // frame is too large, either the stack is corrupted or fp is not saved
1055 // on stack (i.e. on x86, ebp may be used as general register). The stack
1056 // is not walkable beyond current frame.
1057 if (old_fp < ufp) return true;
1058 if (old_fp - ufp > 64 * K) return true;
1059
1060 return false;
1061 #endif
1062 }
1063
1064 #ifdef ASSERT
1065 extern "C" void test_random() {
1066 const double m = 2147483647;
1067 double mean = 0.0, variance = 0.0, t;
1068 long reps = 10000;
1069 unsigned long seed = 1;
1070
1071 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1072 os::init_random(seed);
1073 long num;
1074 for (int k = 0; k < reps; k++) {
1075 num = os::random();
1076 double u = (double)num / m;
1077 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1078
1079 // calculate mean and variance of the random sequence
1080 mean += u;
1081 variance += (u*u);
1082 }
1083 mean /= reps;
1084 variance /= (reps - 1);
1085
1086 assert(num == 1043618065, "bad seed");
1087 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1088 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1089 const double eps = 0.0001;
1090 t = fabsd(mean - 0.5018);
1091 assert(t < eps, "bad mean");
1092 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1093 assert(t < eps, "bad variance");
1094 }
1095 #endif
1096
1097
1098 // Set up the boot classpath.
1099
1100 char* os::format_boot_path(const char* format_string,
1101 const char* home,
1102 int home_len,
1103 char fileSep,
1104 char pathSep) {
1105 assert((fileSep == '/' && pathSep == ':') ||
1106 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1107
1108 // Scan the format string to determine the length of the actual
1109 // boot classpath, and handle platform dependencies as well.
1110 int formatted_path_len = 0;
1111 const char* p;
1112 for (p = format_string; *p != 0; ++p) {
1113 if (*p == '%') formatted_path_len += home_len - 1;
1114 ++formatted_path_len;
1115 }
1116
1117 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1118 if (formatted_path == NULL) {
1119 return NULL;
1120 }
1121
1122 // Create boot classpath from format, substituting separator chars and
1123 // java home directory.
1124 char* q = formatted_path;
1125 for (p = format_string; *p != 0; ++p) {
1126 switch (*p) {
1127 case '%':
1128 strcpy(q, home);
1129 q += home_len;
1130 break;
1131 case '/':
1132 *q++ = fileSep;
1133 break;
1134 case ':':
1135 *q++ = pathSep;
1136 break;
1137 default:
1138 *q++ = *p;
1139 }
1140 }
1141 *q = '\0';
1142
1143 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1144 return formatted_path;
1145 }
1146
1147
1148 bool os::set_boot_path(char fileSep, char pathSep) {
1149 const char* home = Arguments::get_java_home();
1150 int home_len = (int)strlen(home);
1151
1152 static const char* meta_index_dir_format = "%/lib/";
1153 static const char* meta_index_format = "%/lib/meta-index";
1154 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1155 if (meta_index == NULL) return false;
1156 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1157 if (meta_index_dir == NULL) return false;
1158 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1159
1160 // Any modification to the JAR-file list, for the boot classpath must be
1161 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1162 // path class JARs, are stripped for StackMapTable to reduce download size.
1163 static const char classpath_format[] =
1164 "%/lib/resources.jar:"
1165 "%/lib/rt.jar:"
1166 "%/lib/sunrsasign.jar:"
1167 "%/lib/jsse.jar:"
1168 "%/lib/jce.jar:"
1169 "%/lib/charsets.jar:"
1170 "%/lib/jfr.jar:"
1171 "%/classes";
1172 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1173 if (sysclasspath == NULL) return false;
1174 Arguments::set_sysclasspath(sysclasspath);
1175
1176 return true;
1177 }
1178
1179 /*
1180 * Splits a path, based on its separator, the number of
1181 * elements is returned back in n.
1182 * It is the callers responsibility to:
1183 * a> check the value of n, and n may be 0.
1184 * b> ignore any empty path elements
1185 * c> free up the data.
1186 */
1187 char** os::split_path(const char* path, int* n) {
1188 *n = 0;
1189 if (path == NULL || strlen(path) == 0) {
1190 return NULL;
1191 }
1192 const char psepchar = *os::path_separator();
1193 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1194 if (inpath == NULL) {
1195 return NULL;
1196 }
1197 strcpy(inpath, path);
1198 int count = 1;
1199 char* p = strchr(inpath, psepchar);
1200 // Get a count of elements to allocate memory
1201 while (p != NULL) {
1202 count++;
1203 p++;
1204 p = strchr(p, psepchar);
1205 }
1206 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1207 if (opath == NULL) {
1208 return NULL;
1209 }
1210
1211 // do the actual splitting
1212 p = inpath;
1213 for (int i = 0 ; i < count ; i++) {
1214 size_t len = strcspn(p, os::path_separator());
1215 if (len > JVM_MAXPATHLEN) {
1216 return NULL;
1217 }
1218 // allocate the string and add terminator storage
1219 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1220 if (s == NULL) {
1221 return NULL;
1222 }
1223 strncpy(s, p, len);
1224 s[len] = '\0';
1225 opath[i] = s;
1226 p += len + 1;
1227 }
1228 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1229 *n = count;
1230 return opath;
1231 }
1232
1233 void os::set_memory_serialize_page(address page) {
1234 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1235 _mem_serialize_page = (volatile int32_t *)page;
1236 // We initialize the serialization page shift count here
1237 // We assume a cache line size of 64 bytes
1238 assert(SerializePageShiftCount == count,
1239 "thread size changed, fix SerializePageShiftCount constant");
1240 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1241 }
1242
1243 static volatile intptr_t SerializePageLock = 0;
1244
1245 // This method is called from signal handler when SIGSEGV occurs while the current
1246 // thread tries to store to the "read-only" memory serialize page during state
1247 // transition.
1248 void os::block_on_serialize_page_trap() {
1249 if (TraceSafepoint) {
1250 tty->print_cr("Block until the serialize page permission restored");
1251 }
1252 // When VMThread is holding the SerializePageLock during modifying the
1253 // access permission of the memory serialize page, the following call
1254 // will block until the permission of that page is restored to rw.
1255 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1256 // this case, it's OK as the signal is synchronous and we know precisely when
1257 // it can occur.
1258 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1259 Thread::muxRelease(&SerializePageLock);
1260 }
1261
1262 // Serialize all thread state variables
1263 void os::serialize_thread_states() {
1264 // On some platforms such as Solaris & Linux, the time duration of the page
1265 // permission restoration is observed to be much longer than expected due to
1266 // scheduler starvation problem etc. To avoid the long synchronization
1267 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1268 // the mutator thread if such case is encountered. See bug 6546278 for details.
1269 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1270 os::protect_memory((char *)os::get_memory_serialize_page(),
1271 os::vm_page_size(), MEM_PROT_READ);
1272 os::protect_memory((char *)os::get_memory_serialize_page(),
1273 os::vm_page_size(), MEM_PROT_RW);
1274 Thread::muxRelease(&SerializePageLock);
1275 }
1276
1277 // Returns true if the current stack pointer is above the stack shadow
1278 // pages, false otherwise.
1279
1280 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1281 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1282 address sp = current_stack_pointer();
1283 // Check if we have StackShadowPages above the yellow zone. This parameter
1284 // is dependent on the depth of the maximum VM call stack possible from
1285 // the handler for stack overflow. 'instanceof' in the stack overflow
1286 // handler or a println uses at least 8k stack of VM and native code
1287 // respectively.
1288 const int framesize_in_bytes =
1289 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1290 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1291 * vm_page_size()) + framesize_in_bytes;
1292 // The very lower end of the stack
1293 address stack_limit = thread->stack_base() - thread->stack_size();
1294 return (sp > (stack_limit + reserved_area));
1295 }
1296
1297 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1298 uint min_pages)
1299 {
1300 assert(min_pages > 0, "sanity");
1301 if (UseLargePages) {
1302 const size_t max_page_size = region_max_size / min_pages;
1303
1304 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1305 const size_t sz = _page_sizes[i];
1306 const size_t mask = sz - 1;
1307 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1308 // The largest page size with no fragmentation.
1309 return sz;
1310 }
1311
1312 if (sz <= max_page_size) {
1313 // The largest page size that satisfies the min_pages requirement.
1314 return sz;
1315 }
1316 }
1317 }
1318
1319 return vm_page_size();
1320 }
1321
1322 #ifndef PRODUCT
1323 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1324 {
1325 if (TracePageSizes) {
1326 tty->print("%s: ", str);
1327 for (int i = 0; i < count; ++i) {
1328 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1329 }
1330 tty->cr();
1331 }
1332 }
1333
1334 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1335 const size_t region_max_size, const size_t page_size,
1336 const char* base, const size_t size)
1337 {
1338 if (TracePageSizes) {
1339 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1340 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1341 " size=" SIZE_FORMAT,
1342 str, region_min_size, region_max_size,
1343 page_size, base, size);
1344 }
1345 }
1346 #endif // #ifndef PRODUCT
1347
1348 // This is the working definition of a server class machine:
1349 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1350 // because the graphics memory (?) sometimes masks physical memory.
1351 // If you want to change the definition of a server class machine
1352 // on some OS or platform, e.g., >=4GB on Windows platforms,
1353 // then you'll have to parameterize this method based on that state,
1354 // as was done for logical processors here, or replicate and
1355 // specialize this method for each platform. (Or fix os to have
1356 // some inheritance structure and use subclassing. Sigh.)
1357 // If you want some platform to always or never behave as a server
1358 // class machine, change the setting of AlwaysActAsServerClassMachine
1359 // and NeverActAsServerClassMachine in globals*.hpp.
1360 bool os::is_server_class_machine() {
1361 // First check for the early returns
1362 if (NeverActAsServerClassMachine) {
1363 return false;
1364 }
1365 if (AlwaysActAsServerClassMachine) {
1366 return true;
1367 }
1368 // Then actually look at the machine
1369 bool result = false;
1370 const unsigned int server_processors = 2;
1371 const julong server_memory = 2UL * G;
1372 // We seem not to get our full complement of memory.
1373 // We allow some part (1/8?) of the memory to be "missing",
1374 // based on the sizes of DIMMs, and maybe graphics cards.
1375 const julong missing_memory = 256UL * M;
1376
1377 /* Is this a server class machine? */
1378 if ((os::active_processor_count() >= (int)server_processors) &&
1379 (os::physical_memory() >= (server_memory - missing_memory))) {
1380 const unsigned int logical_processors =
1381 VM_Version::logical_processors_per_package();
1382 if (logical_processors > 1) {
1383 const unsigned int physical_packages =
1384 os::active_processor_count() / logical_processors;
1385 if (physical_packages > server_processors) {
1386 result = true;
1387 }
1388 } else {
1389 result = true;
1390 }
1391 }
1392 return result;
1393 }
1394
1395 void os::SuspendedThreadTask::run() {
1396 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1397 internal_do_task();
1398 _done = true;
1399 }
1400
1401 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1402 return os::pd_create_stack_guard_pages(addr, bytes);
1403 }
1404
1405 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1406 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1407 if (result != NULL) {
1408 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1409 }
1410
1411 return result;
1412 }
1413
1414 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1415 MEMFLAGS flags) {
1416 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1417 if (result != NULL) {
1418 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1419 MemTracker::record_virtual_memory_type((address)result, flags);
1420 }
1421
1422 return result;
1423 }
1424
1425 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1426 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1427 if (result != NULL) {
1428 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1429 }
1430 return result;
1431 }
1432
1433 void os::split_reserved_memory(char *base, size_t size,
1434 size_t split, bool realloc) {
1435 pd_split_reserved_memory(base, size, split, realloc);
1436 }
1437
1438 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1439 bool res = pd_commit_memory(addr, bytes, executable);
1440 if (res) {
1441 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1442 }
1443 return res;
1444 }
1445
1446 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1447 bool executable) {
1448 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1449 if (res) {
1450 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1451 }
1452 return res;
1453 }
1454
1455 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1456 const char* mesg) {
1457 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1458 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1459 }
1460
1461 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1462 bool executable, const char* mesg) {
1463 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1464 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1465 }
1466
1467 bool os::uncommit_memory(char* addr, size_t bytes) {
1468 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1469 bool res = pd_uncommit_memory(addr, bytes);
1470 if (res) {
1471 tkr.record((address)addr, bytes);
1472 } else {
1473 tkr.discard();
1474 }
1475 return res;
1476 }
1477
1478 bool os::release_memory(char* addr, size_t bytes) {
1479 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1480 bool res = pd_release_memory(addr, bytes);
1481 if (res) {
1482 tkr.record((address)addr, bytes);
1483 } else {
1484 tkr.discard();
1485 }
1486 return res;
1487 }
1488
1489
1490 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1491 char *addr, size_t bytes, bool read_only,
1492 bool allow_exec) {
1493 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1494 if (result != NULL) {
1495 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, mtNone, CALLER_PC);
1496 }
1497 return result;
1498 }
1499
1500 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1501 char *addr, size_t bytes, bool read_only,
1502 bool allow_exec) {
1503 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1504 read_only, allow_exec);
1505 }
1506
1507 bool os::unmap_memory(char *addr, size_t bytes) {
1508 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1509 bool result = pd_unmap_memory(addr, bytes);
1510 if (result) {
1511 tkr.record((address)addr, bytes);
1512 } else {
1513 tkr.discard();
1514 }
1515 return result;
1516 }
1517
1518 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1519 pd_free_memory(addr, bytes, alignment_hint);
1520 }
1521
1522 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1523 pd_realign_memory(addr, bytes, alignment_hint);
1524 }
1525
1526 #ifndef TARGET_OS_FAMILY_windows
1527 /* try to switch state from state "from" to state "to"
1528 * returns the state set after the method is complete
1529 */
1530 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1531 os::SuspendResume::State to)
1532 {
1533 os::SuspendResume::State result =
1534 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1535 if (result == from) {
1536 // success
1537 return to;
1538 }
1539 return result;
1540 }
1541 #endif