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/icBuffer.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "gc_implementation/shared/vmGCOperations.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "memory/allocation.inline.hpp"
35 #ifdef ASSERT
36 #include "memory/guardedMemory.hpp"
37 #endif
38 #include "oops/oop.inline.hpp"
39 #include "prims/jvm.h"
40 #include "prims/jvm_misc.hpp"
41 #include "prims/privilegedStack.hpp"
42 #include "runtime/arguments.hpp"
43 #include "runtime/atomic.inline.hpp"
44 #include "runtime/frame.inline.hpp"
45 #include "runtime/interfaceSupport.hpp"
46 #include "runtime/java.hpp"
47 #include "runtime/javaCalls.hpp"
48 #include "runtime/mutexLocker.hpp"
49 #include "runtime/os.hpp"
50 #include "runtime/stubRoutines.hpp"
51 #include "runtime/thread.inline.hpp"
52 #include "services/attachListener.hpp"
53 #include "services/memTracker.hpp"
54 #include "services/threadService.hpp"
55 #include "utilities/defaultStream.hpp"
56 #include "utilities/events.hpp"
57 #ifdef TARGET_OS_FAMILY_linux
58 # include "os_linux.inline.hpp"
59 #endif
60 #ifdef TARGET_OS_FAMILY_solaris
61 # include "os_solaris.inline.hpp"
62 #endif
63 #ifdef TARGET_OS_FAMILY_windows
64 # include "os_windows.inline.hpp"
65 #endif
66 #ifdef TARGET_OS_FAMILY_bsd
67 # include "os_bsd.inline.hpp"
68 #endif
69
70 # include <signal.h>
71
72 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
73
74 OSThread* os::_starting_thread = NULL;
75 address os::_polling_page = NULL;
76 volatile int32_t* os::_mem_serialize_page = NULL;
77 uintptr_t os::_serialize_page_mask = 0;
78 long os::_rand_seed = 1;
79 int os::_processor_count = 0;
80 size_t os::_page_sizes[os::page_sizes_max];
81
82 #ifndef PRODUCT
83 julong os::num_mallocs = 0; // # of calls to malloc/realloc
84 julong os::alloc_bytes = 0; // # of bytes allocated
85 julong os::num_frees = 0; // # of calls to free
86 julong os::free_bytes = 0; // # of bytes freed
87 #endif
88
89 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
90
91 void os_init_globals() {
92 // Called from init_globals().
93 // See Threads::create_vm() in thread.cpp, and init.cpp.
94 os::init_globals();
95 }
96
97 // Fill in buffer with current local time as an ISO-8601 string.
98 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
99 // Returns buffer, or NULL if it failed.
100 // This would mostly be a call to
101 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
102 // except that on Windows the %z behaves badly, so we do it ourselves.
103 // Also, people wanted milliseconds on there,
104 // and strftime doesn't do milliseconds.
105 char* os::iso8601_time(char* buffer, size_t buffer_length) {
106 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
107 // 1 2
108 // 12345678901234567890123456789
109 static const char* iso8601_format =
110 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
111 static const size_t needed_buffer = 29;
112
113 // Sanity check the arguments
114 if (buffer == NULL) {
115 assert(false, "NULL buffer");
116 return NULL;
117 }
118 if (buffer_length < needed_buffer) {
119 assert(false, "buffer_length too small");
120 return NULL;
121 }
122 // Get the current time
123 jlong milliseconds_since_19700101 = javaTimeMillis();
124 const int milliseconds_per_microsecond = 1000;
125 const time_t seconds_since_19700101 =
126 milliseconds_since_19700101 / milliseconds_per_microsecond;
127 const int milliseconds_after_second =
128 milliseconds_since_19700101 % milliseconds_per_microsecond;
129 // Convert the time value to a tm and timezone variable
130 struct tm time_struct;
131 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
132 assert(false, "Failed localtime_pd");
133 return NULL;
134 }
135 #if defined(_ALLBSD_SOURCE)
136 const time_t zone = (time_t) time_struct.tm_gmtoff;
137 #else
138 const time_t zone = timezone;
139 #endif
140
141 // If daylight savings time is in effect,
142 // we are 1 hour East of our time zone
143 const time_t seconds_per_minute = 60;
144 const time_t minutes_per_hour = 60;
145 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
146 time_t UTC_to_local = zone;
147 if (time_struct.tm_isdst > 0) {
148 UTC_to_local = UTC_to_local - seconds_per_hour;
149 }
150 // Compute the time zone offset.
151 // localtime_pd() sets timezone to the difference (in seconds)
152 // between UTC and and local time.
153 // ISO 8601 says we need the difference between local time and UTC,
154 // we change the sign of the localtime_pd() result.
155 const time_t local_to_UTC = -(UTC_to_local);
156 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
157 char sign_local_to_UTC = '+';
158 time_t abs_local_to_UTC = local_to_UTC;
159 if (local_to_UTC < 0) {
160 sign_local_to_UTC = '-';
161 abs_local_to_UTC = -(abs_local_to_UTC);
162 }
163 // Convert time zone offset seconds to hours and minutes.
164 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
165 const time_t zone_min =
166 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
167
168 // Print an ISO 8601 date and time stamp into the buffer
169 const int year = 1900 + time_struct.tm_year;
170 const int month = 1 + time_struct.tm_mon;
171 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
172 year,
173 month,
174 time_struct.tm_mday,
175 time_struct.tm_hour,
176 time_struct.tm_min,
177 time_struct.tm_sec,
178 milliseconds_after_second,
179 sign_local_to_UTC,
180 zone_hours,
181 zone_min);
182 if (printed == 0) {
183 assert(false, "Failed jio_printf");
184 return NULL;
185 }
186 return buffer;
187 }
188
189 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
190 #ifdef ASSERT
191 if (!(!thread->is_Java_thread() ||
192 Thread::current() == thread ||
193 Threads_lock->owned_by_self()
194 || thread->is_Compiler_thread()
195 )) {
196 assert(false, "possibility of dangling Thread pointer");
197 }
198 #endif
199
200 if (p >= MinPriority && p <= MaxPriority) {
201 int priority = java_to_os_priority[p];
202 return set_native_priority(thread, priority);
203 } else {
204 assert(false, "Should not happen");
205 return OS_ERR;
206 }
207 }
208
209 // The mapping from OS priority back to Java priority may be inexact because
210 // Java priorities can map M:1 with native priorities. If you want the definite
211 // Java priority then use JavaThread::java_priority()
212 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
213 int p;
214 int os_prio;
215 OSReturn ret = get_native_priority(thread, &os_prio);
216 if (ret != OS_OK) return ret;
217
218 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
219 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
220 } else {
221 // niceness values are in reverse order
222 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
223 }
224 priority = (ThreadPriority)p;
225 return OS_OK;
226 }
227
228
229 // --------------------- sun.misc.Signal (optional) ---------------------
230
231
232 // SIGBREAK is sent by the keyboard to query the VM state
233 #ifndef SIGBREAK
234 #define SIGBREAK SIGQUIT
235 #endif
236
237 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
238
239
240 static void signal_thread_entry(JavaThread* thread, TRAPS) {
241 os::set_priority(thread, NearMaxPriority);
242 while (true) {
243 int sig;
244 {
245 // FIXME : Currently we have not decided what should be the status
246 // for this java thread blocked here. Once we decide about
247 // that we should fix this.
248 sig = os::signal_wait();
249 }
250 if (sig == os::sigexitnum_pd()) {
251 // Terminate the signal thread
252 return;
253 }
254
255 switch (sig) {
256 case SIGBREAK: {
257 // Check if the signal is a trigger to start the Attach Listener - in that
258 // case don't print stack traces.
259 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
260 continue;
261 }
262 // Print stack traces
263 // Any SIGBREAK operations added here should make sure to flush
264 // the output stream (e.g. tty->flush()) after output. See 4803766.
265 // Each module also prints an extra carriage return after its output.
266 VM_PrintThreads op;
267 VMThread::execute(&op);
268 VM_PrintJNI jni_op;
269 VMThread::execute(&jni_op);
270 VM_FindDeadlocks op1(tty);
271 VMThread::execute(&op1);
272 Universe::print_heap_at_SIGBREAK();
273 if (PrintClassHistogram) {
274 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
275 VMThread::execute(&op1);
276 }
277 if (JvmtiExport::should_post_data_dump()) {
278 JvmtiExport::post_data_dump();
279 }
280 break;
281 }
282 default: {
283 // Dispatch the signal to java
284 HandleMark hm(THREAD);
285 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
286 KlassHandle klass (THREAD, k);
287 if (klass.not_null()) {
288 JavaValue result(T_VOID);
289 JavaCallArguments args;
290 args.push_int(sig);
291 JavaCalls::call_static(
292 &result,
293 klass,
294 vmSymbols::dispatch_name(),
295 vmSymbols::int_void_signature(),
296 &args,
297 THREAD
298 );
299 }
300 if (HAS_PENDING_EXCEPTION) {
301 // tty is initialized early so we don't expect it to be null, but
302 // if it is we can't risk doing an initialization that might
303 // trigger additional out-of-memory conditions
304 if (tty != NULL) {
305 char klass_name[256];
306 char tmp_sig_name[16];
307 const char* sig_name = "UNKNOWN";
308 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
309 name()->as_klass_external_name(klass_name, 256);
310 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
311 sig_name = tmp_sig_name;
312 warning("Exception %s occurred dispatching signal %s to handler"
313 "- the VM may need to be forcibly terminated",
314 klass_name, sig_name );
315 }
316 CLEAR_PENDING_EXCEPTION;
317 }
318 }
319 }
320 }
321 }
322
323 void os::init_before_ergo() {
324 // We need to initialize large page support here because ergonomics takes some
325 // decisions depending on large page support and the calculated large page size.
326 large_page_init();
327 }
328
329 void os::signal_init() {
330 if (!ReduceSignalUsage) {
331 // Setup JavaThread for processing signals
332 EXCEPTION_MARK;
333 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
334 instanceKlassHandle klass (THREAD, k);
335 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
336
337 const char thread_name[] = "Signal Dispatcher";
338 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
339
340 // Initialize thread_oop to put it into the system threadGroup
341 Handle thread_group (THREAD, Universe::system_thread_group());
342 JavaValue result(T_VOID);
343 JavaCalls::call_special(&result, thread_oop,
344 klass,
345 vmSymbols::object_initializer_name(),
346 vmSymbols::threadgroup_string_void_signature(),
347 thread_group,
348 string,
349 CHECK);
350
351 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
352 JavaCalls::call_special(&result,
353 thread_group,
354 group,
355 vmSymbols::add_method_name(),
356 vmSymbols::thread_void_signature(),
357 thread_oop, // ARG 1
358 CHECK);
359
360 os::signal_init_pd();
361
362 { MutexLocker mu(Threads_lock);
363 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
364
365 // At this point it may be possible that no osthread was created for the
366 // JavaThread due to lack of memory. We would have to throw an exception
367 // in that case. However, since this must work and we do not allow
368 // exceptions anyway, check and abort if this fails.
369 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
370 vm_exit_during_initialization("java.lang.OutOfMemoryError",
371 os::native_thread_creation_failed_msg());
372 }
373
374 java_lang_Thread::set_thread(thread_oop(), signal_thread);
375 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
376 java_lang_Thread::set_daemon(thread_oop());
377
378 signal_thread->set_threadObj(thread_oop());
379 Threads::add(signal_thread);
380 Thread::start(signal_thread);
381 }
382 // Handle ^BREAK
383 os::signal(SIGBREAK, os::user_handler());
384 }
385 }
386
387
388 void os::terminate_signal_thread() {
389 if (!ReduceSignalUsage)
390 signal_notify(sigexitnum_pd());
391 }
392
393
394 // --------------------- loading libraries ---------------------
395
396 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
397 extern struct JavaVM_ main_vm;
398
399 static void* _native_java_library = NULL;
400
401 void* os::native_java_library() {
402 if (_native_java_library == NULL) {
403 char buffer[JVM_MAXPATHLEN];
404 char ebuf[1024];
405
406 // Try to load verify dll first. In 1.3 java dll depends on it and is not
407 // always able to find it when the loading executable is outside the JDK.
408 // In order to keep working with 1.2 we ignore any loading errors.
409 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
410 "verify")) {
411 dll_load(buffer, ebuf, sizeof(ebuf));
412 }
413
414 // Load java dll
415 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
416 "java")) {
417 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
418 }
419 if (_native_java_library == NULL) {
420 vm_exit_during_initialization("Unable to load native library", ebuf);
421 }
422
423 #if defined(__OpenBSD__)
424 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
425 // ignore errors
426 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
427 "net")) {
428 dll_load(buffer, ebuf, sizeof(ebuf));
429 }
430 #endif
431 }
432 static jboolean onLoaded = JNI_FALSE;
433 if (onLoaded) {
434 // We may have to wait to fire OnLoad until TLS is initialized.
435 if (ThreadLocalStorage::is_initialized()) {
436 // The JNI_OnLoad handling is normally done by method load in
437 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
438 // explicitly so we have to check for JNI_OnLoad as well
439 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
440 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
441 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
442 if (JNI_OnLoad != NULL) {
443 JavaThread* thread = JavaThread::current();
444 ThreadToNativeFromVM ttn(thread);
445 HandleMark hm(thread);
446 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
447 onLoaded = JNI_TRUE;
448 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
449 vm_exit_during_initialization("Unsupported JNI version");
450 }
451 }
452 }
453 }
454 return _native_java_library;
455 }
456
457 /*
458 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
459 * If check_lib == true then we are looking for an
460 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
461 * this library is statically linked into the image.
462 * If check_lib == false then we will look for the appropriate symbol in the
463 * executable if agent_lib->is_static_lib() == true or in the shared library
464 * referenced by 'handle'.
465 */
466 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
467 const char *syms[], size_t syms_len) {
468 assert(agent_lib != NULL, "sanity check");
469 const char *lib_name;
470 void *handle = agent_lib->os_lib();
471 void *entryName = NULL;
472 char *agent_function_name;
473 size_t i;
474
475 // If checking then use the agent name otherwise test is_static_lib() to
476 // see how to process this lookup
477 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
478 for (i = 0; i < syms_len; i++) {
479 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
480 if (agent_function_name == NULL) {
481 break;
482 }
483 entryName = dll_lookup(handle, agent_function_name);
484 FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread);
485 if (entryName != NULL) {
486 break;
487 }
488 }
489 return entryName;
490 }
491
492 // See if the passed in agent is statically linked into the VM image.
493 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
494 size_t syms_len) {
495 void *ret;
496 void *proc_handle;
497 void *save_handle;
498
499 assert(agent_lib != NULL, "sanity check");
500 if (agent_lib->name() == NULL) {
501 return false;
502 }
503 proc_handle = get_default_process_handle();
504 // Check for Agent_OnLoad/Attach_lib_name function
505 save_handle = agent_lib->os_lib();
506 // We want to look in this process' symbol table.
507 agent_lib->set_os_lib(proc_handle);
508 ret = find_agent_function(agent_lib, true, syms, syms_len);
509 if (ret != NULL) {
510 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
511 agent_lib->set_valid();
512 agent_lib->set_static_lib(true);
513 return true;
514 }
515 agent_lib->set_os_lib(save_handle);
516 return false;
517 }
518
519 // --------------------- heap allocation utilities ---------------------
520
521 char *os::strdup(const char *str, MEMFLAGS flags) {
522 size_t size = strlen(str);
523 char *dup_str = (char *)malloc(size + 1, flags);
524 if (dup_str == NULL) return NULL;
525 strcpy(dup_str, str);
526 return dup_str;
527 }
528
529
530 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
531
532 #ifdef ASSERT
533
534 static void verify_memory(void* ptr) {
535 GuardedMemory guarded(ptr);
536 if (!guarded.verify_guards()) {
537 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
538 tty->print_cr("## memory stomp:");
539 guarded.print_on(tty);
540 fatal("memory stomping error");
541 }
542 }
543
544 #endif
545
546 //
547 // This function supports testing of the malloc out of memory
548 // condition without really running the system out of memory.
549 //
550 static u_char* testMalloc(size_t alloc_size) {
551 assert(MallocMaxTestWords > 0, "sanity check");
552
553 if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
554 return NULL;
555 }
556
557 u_char* ptr = (u_char*)::malloc(alloc_size);
558
559 if (ptr != NULL) {
560 Atomic::add(((jint) (alloc_size / BytesPerWord)),
561 (volatile jint *) &cur_malloc_words);
562 }
563 return ptr;
564 }
565
566 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
567 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
568 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
569
570 #ifdef ASSERT
571 // checking for the WatcherThread and crash_protection first
572 // since os::malloc can be called when the libjvm.{dll,so} is
573 // first loaded and we don't have a thread yet.
574 // try to find the thread after we see that the watcher thread
575 // exists and has crash protection.
576 WatcherThread *wt = WatcherThread::watcher_thread();
577 if (wt != NULL && wt->has_crash_protection()) {
578 Thread* thread = ThreadLocalStorage::get_thread_slow();
579 if (thread == wt) {
580 assert(!wt->has_crash_protection(),
581 "Can't malloc with crash protection from WatcherThread");
582 }
583 }
584 #endif
585
586 if (size == 0) {
587 // return a valid pointer if size is zero
588 // if NULL is returned the calling functions assume out of memory.
589 size = 1;
590 }
591
592 #ifndef ASSERT
593 const size_t alloc_size = size;
594 #else
595 const size_t alloc_size = GuardedMemory::get_total_size(size);
596 if (size > alloc_size) { // Check for rollover.
597 return NULL;
598 }
599 #endif
600
601 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
602
603 u_char* ptr;
604 if (MallocMaxTestWords > 0) {
605 ptr = testMalloc(alloc_size);
606 } else {
607 ptr = (u_char*)::malloc(alloc_size);
608 }
609
610 #ifdef ASSERT
611 if (ptr == NULL) {
612 return NULL;
613 }
614 // Wrap memory with guard
615 GuardedMemory guarded(ptr, size);
616 ptr = guarded.get_user_ptr();
617 #endif
618 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
619 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
620 breakpoint();
621 }
622 debug_only(if (paranoid) verify_memory(ptr));
623 if (PrintMalloc && tty != NULL) {
624 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
625 }
626
627 // we do not track guard memory
628 MemTracker::record_malloc((address)ptr, size, memflags, caller == 0 ? CALLER_PC : caller);
629
630 return ptr;
631 }
632
633
634 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
635 #ifndef ASSERT
636 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
637 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
638 MemTracker::Tracker tkr = MemTracker::get_realloc_tracker();
639 void* ptr = ::realloc(memblock, size);
640 if (ptr != NULL) {
641 tkr.record((address)memblock, (address)ptr, size, memflags,
642 caller == 0 ? CALLER_PC : caller);
643 } else {
644 tkr.discard();
645 }
646 return ptr;
647 #else
648 if (memblock == NULL) {
649 return os::malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
650 }
651 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
652 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
653 breakpoint();
654 }
655 verify_memory(memblock);
656 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
657 if (size == 0) {
658 return NULL;
659 }
660 // always move the block
661 void* ptr = os::malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
662 if (PrintMalloc) {
663 tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
664 }
665 // Copy to new memory if malloc didn't fail
666 if ( ptr != NULL ) {
667 GuardedMemory guarded(memblock);
668 memcpy(ptr, memblock, MIN2(size, guarded.get_user_size()));
669 if (paranoid) verify_memory(ptr);
670 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
671 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
672 breakpoint();
673 }
674 os::free(memblock);
675 }
676 return ptr;
677 #endif
678 }
679
680
681 void os::free(void *memblock, MEMFLAGS memflags) {
682 address trackp = (address) memblock;
683 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
684 #ifdef ASSERT
685 if (memblock == NULL) return;
686 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
687 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
688 breakpoint();
689 }
690 verify_memory(memblock);
691 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
692
693 GuardedMemory guarded(memblock);
694 size_t size = guarded.get_user_size();
695 inc_stat_counter(&free_bytes, size);
696 memblock = guarded.release_for_freeing();
697 if (PrintMalloc && tty != NULL) {
698 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
699 }
700 #endif
701 MemTracker::record_free(trackp, memflags);
702
703 ::free(memblock);
704 }
705
706 void os::init_random(long initval) {
707 _rand_seed = initval;
708 }
709
710
711 long os::random() {
712 /* standard, well-known linear congruential random generator with
713 * next_rand = (16807*seed) mod (2**31-1)
714 * see
715 * (1) "Random Number Generators: Good Ones Are Hard to Find",
716 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
717 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
718 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
719 */
720 const long a = 16807;
721 const unsigned long m = 2147483647;
722 const long q = m / a; assert(q == 127773, "weird math");
723 const long r = m % a; assert(r == 2836, "weird math");
724
725 // compute az=2^31p+q
726 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
727 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
728 lo += (hi & 0x7FFF) << 16;
729
730 // if q overflowed, ignore the overflow and increment q
731 if (lo > m) {
732 lo &= m;
733 ++lo;
734 }
735 lo += hi >> 15;
736
737 // if (p+q) overflowed, ignore the overflow and increment (p+q)
738 if (lo > m) {
739 lo &= m;
740 ++lo;
741 }
742 return (_rand_seed = lo);
743 }
744
745 // The INITIALIZED state is distinguished from the SUSPENDED state because the
746 // conditions in which a thread is first started are different from those in which
747 // a suspension is resumed. These differences make it hard for us to apply the
748 // tougher checks when starting threads that we want to do when resuming them.
749 // However, when start_thread is called as a result of Thread.start, on a Java
750 // thread, the operation is synchronized on the Java Thread object. So there
751 // cannot be a race to start the thread and hence for the thread to exit while
752 // we are working on it. Non-Java threads that start Java threads either have
753 // to do so in a context in which races are impossible, or should do appropriate
754 // locking.
755
756 void os::start_thread(Thread* thread) {
757 // guard suspend/resume
758 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
759 OSThread* osthread = thread->osthread();
760 osthread->set_state(RUNNABLE);
761 pd_start_thread(thread);
762 }
763
764 //---------------------------------------------------------------------------
765 // Helper functions for fatal error handler
766
767 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
768 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
769
770 int cols = 0;
771 int cols_per_line = 0;
772 switch (unitsize) {
773 case 1: cols_per_line = 16; break;
774 case 2: cols_per_line = 8; break;
775 case 4: cols_per_line = 4; break;
776 case 8: cols_per_line = 2; break;
777 default: return;
778 }
779
780 address p = start;
781 st->print(PTR_FORMAT ": ", start);
782 while (p < end) {
783 switch (unitsize) {
784 case 1: st->print("%02x", *(u1*)p); break;
785 case 2: st->print("%04x", *(u2*)p); break;
786 case 4: st->print("%08x", *(u4*)p); break;
787 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
788 }
789 p += unitsize;
790 cols++;
791 if (cols >= cols_per_line && p < end) {
792 cols = 0;
793 st->cr();
794 st->print(PTR_FORMAT ": ", p);
795 } else {
796 st->print(" ");
797 }
798 }
799 st->cr();
800 }
801
802 void os::print_environment_variables(outputStream* st, const char** env_list,
803 char* buffer, int len) {
804 if (env_list) {
805 st->print_cr("Environment Variables:");
806
807 for (int i = 0; env_list[i] != NULL; i++) {
808 if (getenv(env_list[i], buffer, len)) {
809 st->print("%s", env_list[i]);
810 st->print("=");
811 st->print_cr("%s", buffer);
812 }
813 }
814 }
815 }
816
817 void os::print_cpu_info(outputStream* st) {
818 // cpu
819 st->print("CPU:");
820 st->print("total %d", os::processor_count());
821 // It's not safe to query number of active processors after crash
822 // st->print("(active %d)", os::active_processor_count());
823 st->print(" %s", VM_Version::cpu_features());
824 st->cr();
825 pd_print_cpu_info(st);
826 }
827
828 void os::print_date_and_time(outputStream *st) {
829 const int secs_per_day = 86400;
830 const int secs_per_hour = 3600;
831 const int secs_per_min = 60;
832
833 time_t tloc;
834 (void)time(&tloc);
835 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
836
837 double t = os::elapsedTime();
838 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
839 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
840 // before printf. We lost some precision, but who cares?
841 int eltime = (int)t; // elapsed time in seconds
842
843 // print elapsed time in a human-readable format:
844 int eldays = eltime / secs_per_day;
845 int day_secs = eldays * secs_per_day;
846 int elhours = (eltime - day_secs) / secs_per_hour;
847 int hour_secs = elhours * secs_per_hour;
848 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
849 int minute_secs = elmins * secs_per_min;
850 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
851 st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
852 }
853
854 // moved from debug.cpp (used to be find()) but still called from there
855 // The verbose parameter is only set by the debug code in one case
856 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
857 address addr = (address)x;
858 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
859 if (b != NULL) {
860 if (b->is_buffer_blob()) {
861 // the interpreter is generated into a buffer blob
862 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
863 if (i != NULL) {
864 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
865 i->print_on(st);
866 return;
867 }
868 if (Interpreter::contains(addr)) {
869 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
870 " (not bytecode specific)", addr);
871 return;
872 }
873 //
874 if (AdapterHandlerLibrary::contains(b)) {
875 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
876 AdapterHandlerLibrary::print_handler_on(st, b);
877 }
878 // the stubroutines are generated into a buffer blob
879 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
880 if (d != NULL) {
881 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
882 d->print_on(st);
883 st->cr();
884 return;
885 }
886 if (StubRoutines::contains(addr)) {
887 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
888 "stub routine", addr);
889 return;
890 }
891 // the InlineCacheBuffer is using stubs generated into a buffer blob
892 if (InlineCacheBuffer::contains(addr)) {
893 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
894 return;
895 }
896 VtableStub* v = VtableStubs::stub_containing(addr);
897 if (v != NULL) {
898 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
899 v->print_on(st);
900 st->cr();
901 return;
902 }
903 }
904 nmethod* nm = b->as_nmethod_or_null();
905 if (nm != NULL) {
906 ResourceMark rm;
907 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
908 addr, (int)(addr - nm->entry_point()), nm);
909 if (verbose) {
910 st->print(" for ");
911 nm->method()->print_value_on(st);
912 }
913 st->cr();
914 nm->print_nmethod(verbose);
915 return;
916 }
917 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
918 b->print_on(st);
919 return;
920 }
921
922 if (Universe::heap()->is_in(addr)) {
923 HeapWord* p = Universe::heap()->block_start(addr);
924 bool print = false;
925 // If we couldn't find it it just may mean that heap wasn't parsable
926 // See if we were just given an oop directly
927 if (p != NULL && Universe::heap()->block_is_obj(p)) {
928 print = true;
929 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
930 p = (HeapWord*) addr;
931 print = true;
932 }
933 if (print) {
934 if (p == (HeapWord*) addr) {
935 st->print_cr(INTPTR_FORMAT " is an oop", addr);
936 } else {
937 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
938 }
939 oop(p)->print_on(st);
940 return;
941 }
942 } else {
943 if (Universe::heap()->is_in_reserved(addr)) {
944 st->print_cr(INTPTR_FORMAT " is an unallocated location "
945 "in the heap", addr);
946 return;
947 }
948 }
949 if (JNIHandles::is_global_handle((jobject) addr)) {
950 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
951 return;
952 }
953 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
954 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
955 return;
956 }
957 #ifndef PRODUCT
958 // we don't keep the block list in product mode
959 if (JNIHandleBlock::any_contains((jobject) addr)) {
960 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
961 return;
962 }
963 #endif
964
965 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
966 // Check for privilege stack
967 if (thread->privileged_stack_top() != NULL &&
968 thread->privileged_stack_top()->contains(addr)) {
969 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
970 "for thread: " INTPTR_FORMAT, addr, thread);
971 if (verbose) thread->print_on(st);
972 return;
973 }
974 // If the addr is a java thread print information about that.
975 if (addr == (address)thread) {
976 if (verbose) {
977 thread->print_on(st);
978 } else {
979 st->print_cr(INTPTR_FORMAT " is a thread", addr);
980 }
981 return;
982 }
983 // If the addr is in the stack region for this thread then report that
984 // and print thread info
985 if (thread->stack_base() >= addr &&
986 addr > (thread->stack_base() - thread->stack_size())) {
987 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
988 INTPTR_FORMAT, addr, thread);
989 if (verbose) thread->print_on(st);
990 return;
991 }
992
993 }
994
995 // Check if in metaspace and print types that have vptrs (only method now)
996 if (Metaspace::contains(addr)) {
997 if (Method::has_method_vptr((const void*)addr)) {
998 ((Method*)addr)->print_value_on(st);
999 st->cr();
1000 } else {
1001 // Use addr->print() from the debugger instead (not here)
1002 st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr);
1003 }
1004 return;
1005 }
1006
1007 // Try an OS specific find
1008 if (os::find(addr, st)) {
1009 return;
1010 }
1011
1012 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1013 }
1014
1015 // Looks like all platforms except IA64 can use the same function to check
1016 // if C stack is walkable beyond current frame. The check for fp() is not
1017 // necessary on Sparc, but it's harmless.
1018 bool os::is_first_C_frame(frame* fr) {
1019 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1020 // On IA64 we have to check if the callers bsp is still valid
1021 // (i.e. within the register stack bounds).
1022 // Notice: this only works for threads created by the VM and only if
1023 // we walk the current stack!!! If we want to be able to walk
1024 // arbitrary other threads, we'll have to somehow store the thread
1025 // object in the frame.
1026 Thread *thread = Thread::current();
1027 if ((address)fr->fp() <=
1028 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1029 // This check is a little hacky, because on Linux the first C
1030 // frame's ('start_thread') register stack frame starts at
1031 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1032 // ('__pthread_bound_body') register stack frame seems to really
1033 // start at "register_stack_base".
1034 return true;
1035 } else {
1036 return false;
1037 }
1038 #elif defined(IA64) && defined(_WIN32)
1039 return true;
1040 #else
1041 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1042 // Check usp first, because if that's bad the other accessors may fault
1043 // on some architectures. Ditto ufp second, etc.
1044 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1045 // sp on amd can be 32 bit aligned.
1046 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1047
1048 uintptr_t usp = (uintptr_t)fr->sp();
1049 if ((usp & sp_align_mask) != 0) return true;
1050
1051 uintptr_t ufp = (uintptr_t)fr->fp();
1052 if ((ufp & fp_align_mask) != 0) return true;
1053
1054 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1055 if ((old_sp & sp_align_mask) != 0) return true;
1056 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1057
1058 uintptr_t old_fp = (uintptr_t)fr->link();
1059 if ((old_fp & fp_align_mask) != 0) return true;
1060 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1061
1062 // stack grows downwards; if old_fp is below current fp or if the stack
1063 // frame is too large, either the stack is corrupted or fp is not saved
1064 // on stack (i.e. on x86, ebp may be used as general register). The stack
1065 // is not walkable beyond current frame.
1066 if (old_fp < ufp) return true;
1067 if (old_fp - ufp > 64 * K) return true;
1068
1069 return false;
1070 #endif
1071 }
1072
1073 #ifdef ASSERT
1074 extern "C" void test_random() {
1075 const double m = 2147483647;
1076 double mean = 0.0, variance = 0.0, t;
1077 long reps = 10000;
1078 unsigned long seed = 1;
1079
1080 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1081 os::init_random(seed);
1082 long num;
1083 for (int k = 0; k < reps; k++) {
1084 num = os::random();
1085 double u = (double)num / m;
1086 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1087
1088 // calculate mean and variance of the random sequence
1089 mean += u;
1090 variance += (u*u);
1091 }
1092 mean /= reps;
1093 variance /= (reps - 1);
1094
1095 assert(num == 1043618065, "bad seed");
1096 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1097 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1098 const double eps = 0.0001;
1099 t = fabsd(mean - 0.5018);
1100 assert(t < eps, "bad mean");
1101 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1102 assert(t < eps, "bad variance");
1103 }
1104 #endif
1105
1106
1107 // Set up the boot classpath.
1108
1109 char* os::format_boot_path(const char* format_string,
1110 const char* home,
1111 int home_len,
1112 char fileSep,
1113 char pathSep) {
1114 assert((fileSep == '/' && pathSep == ':') ||
1115 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1116
1117 // Scan the format string to determine the length of the actual
1118 // boot classpath, and handle platform dependencies as well.
1119 int formatted_path_len = 0;
1120 const char* p;
1121 for (p = format_string; *p != 0; ++p) {
1122 if (*p == '%') formatted_path_len += home_len - 1;
1123 ++formatted_path_len;
1124 }
1125
1126 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1127 if (formatted_path == NULL) {
1128 return NULL;
1129 }
1130
1131 // Create boot classpath from format, substituting separator chars and
1132 // java home directory.
1133 char* q = formatted_path;
1134 for (p = format_string; *p != 0; ++p) {
1135 switch (*p) {
1136 case '%':
1137 strcpy(q, home);
1138 q += home_len;
1139 break;
1140 case '/':
1141 *q++ = fileSep;
1142 break;
1143 case ':':
1144 *q++ = pathSep;
1145 break;
1146 default:
1147 *q++ = *p;
1148 }
1149 }
1150 *q = '\0';
1151
1152 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1153 return formatted_path;
1154 }
1155
1156
1157 bool os::set_boot_path(char fileSep, char pathSep) {
1158 const char* home = Arguments::get_java_home();
1159 int home_len = (int)strlen(home);
1160
1161 static const char* meta_index_dir_format = "%/lib/";
1162 static const char* meta_index_format = "%/lib/meta-index";
1163 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1164 if (meta_index == NULL) return false;
1165 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1166 if (meta_index_dir == NULL) return false;
1167 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1168
1169 // Any modification to the JAR-file list, for the boot classpath must be
1170 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1171 // path class JARs, are stripped for StackMapTable to reduce download size.
1172 static const char classpath_format[] =
1173 "%/lib/resources.jar:"
1174 "%/lib/rt.jar:"
1175 "%/lib/sunrsasign.jar:"
1176 "%/lib/jsse.jar:"
1177 "%/lib/jce.jar:"
1178 "%/lib/charsets.jar:"
1179 "%/lib/jfr.jar:"
1180 "%/classes";
1181 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1182 if (sysclasspath == NULL) return false;
1183 Arguments::set_sysclasspath(sysclasspath);
1184
1185 return true;
1186 }
1187
1188 /*
1189 * Splits a path, based on its separator, the number of
1190 * elements is returned back in n.
1191 * It is the callers responsibility to:
1192 * a> check the value of n, and n may be 0.
1193 * b> ignore any empty path elements
1194 * c> free up the data.
1195 */
1196 char** os::split_path(const char* path, int* n) {
1197 *n = 0;
1198 if (path == NULL || strlen(path) == 0) {
1199 return NULL;
1200 }
1201 const char psepchar = *os::path_separator();
1202 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1203 if (inpath == NULL) {
1204 return NULL;
1205 }
1206 strcpy(inpath, path);
1207 int count = 1;
1208 char* p = strchr(inpath, psepchar);
1209 // Get a count of elements to allocate memory
1210 while (p != NULL) {
1211 count++;
1212 p++;
1213 p = strchr(p, psepchar);
1214 }
1215 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1216 if (opath == NULL) {
1217 return NULL;
1218 }
1219
1220 // do the actual splitting
1221 p = inpath;
1222 for (int i = 0 ; i < count ; i++) {
1223 size_t len = strcspn(p, os::path_separator());
1224 if (len > JVM_MAXPATHLEN) {
1225 return NULL;
1226 }
1227 // allocate the string and add terminator storage
1228 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1229 if (s == NULL) {
1230 return NULL;
1231 }
1232 strncpy(s, p, len);
1233 s[len] = '\0';
1234 opath[i] = s;
1235 p += len + 1;
1236 }
1237 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1238 *n = count;
1239 return opath;
1240 }
1241
1242 void os::set_memory_serialize_page(address page) {
1243 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1244 _mem_serialize_page = (volatile int32_t *)page;
1245 // We initialize the serialization page shift count here
1246 // We assume a cache line size of 64 bytes
1247 assert(SerializePageShiftCount == count,
1248 "thread size changed, fix SerializePageShiftCount constant");
1249 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1250 }
1251
1252 static volatile intptr_t SerializePageLock = 0;
1253
1254 // This method is called from signal handler when SIGSEGV occurs while the current
1255 // thread tries to store to the "read-only" memory serialize page during state
1256 // transition.
1257 void os::block_on_serialize_page_trap() {
1258 if (TraceSafepoint) {
1259 tty->print_cr("Block until the serialize page permission restored");
1260 }
1261 // When VMThread is holding the SerializePageLock during modifying the
1262 // access permission of the memory serialize page, the following call
1263 // will block until the permission of that page is restored to rw.
1264 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1265 // this case, it's OK as the signal is synchronous and we know precisely when
1266 // it can occur.
1267 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1268 Thread::muxRelease(&SerializePageLock);
1269 }
1270
1271 // Serialize all thread state variables
1272 void os::serialize_thread_states() {
1273 // On some platforms such as Solaris & Linux, the time duration of the page
1274 // permission restoration is observed to be much longer than expected due to
1275 // scheduler starvation problem etc. To avoid the long synchronization
1276 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1277 // the mutator thread if such case is encountered. See bug 6546278 for details.
1278 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1279 os::protect_memory((char *)os::get_memory_serialize_page(),
1280 os::vm_page_size(), MEM_PROT_READ);
1281 os::protect_memory((char *)os::get_memory_serialize_page(),
1282 os::vm_page_size(), MEM_PROT_RW);
1283 Thread::muxRelease(&SerializePageLock);
1284 }
1285
1286 // Returns true if the current stack pointer is above the stack shadow
1287 // pages, false otherwise.
1288
1289 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1290 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1291 address sp = current_stack_pointer();
1292 // Check if we have StackShadowPages above the yellow zone. This parameter
1293 // is dependent on the depth of the maximum VM call stack possible from
1294 // the handler for stack overflow. 'instanceof' in the stack overflow
1295 // handler or a println uses at least 8k stack of VM and native code
1296 // respectively.
1297 const int framesize_in_bytes =
1298 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1299 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1300 * vm_page_size()) + framesize_in_bytes;
1301 // The very lower end of the stack
1302 address stack_limit = thread->stack_base() - thread->stack_size();
1303 return (sp > (stack_limit + reserved_area));
1304 }
1305
1306 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1307 uint min_pages)
1308 {
1309 assert(min_pages > 0, "sanity");
1310 if (UseLargePages) {
1311 const size_t max_page_size = region_max_size / min_pages;
1312
1313 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1314 const size_t sz = _page_sizes[i];
1315 const size_t mask = sz - 1;
1316 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1317 // The largest page size with no fragmentation.
1318 return sz;
1319 }
1320
1321 if (sz <= max_page_size) {
1322 // The largest page size that satisfies the min_pages requirement.
1323 return sz;
1324 }
1325 }
1326 }
1327
1328 return vm_page_size();
1329 }
1330
1331 #ifndef PRODUCT
1332 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1333 {
1334 if (TracePageSizes) {
1335 tty->print("%s: ", str);
1336 for (int i = 0; i < count; ++i) {
1337 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1338 }
1339 tty->cr();
1340 }
1341 }
1342
1343 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1344 const size_t region_max_size, const size_t page_size,
1345 const char* base, const size_t size)
1346 {
1347 if (TracePageSizes) {
1348 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1349 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1350 " size=" SIZE_FORMAT,
1351 str, region_min_size, region_max_size,
1352 page_size, base, size);
1353 }
1354 }
1355 #endif // #ifndef PRODUCT
1356
1357 // This is the working definition of a server class machine:
1358 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1359 // because the graphics memory (?) sometimes masks physical memory.
1360 // If you want to change the definition of a server class machine
1361 // on some OS or platform, e.g., >=4GB on Windows platforms,
1362 // then you'll have to parameterize this method based on that state,
1363 // as was done for logical processors here, or replicate and
1364 // specialize this method for each platform. (Or fix os to have
1365 // some inheritance structure and use subclassing. Sigh.)
1366 // If you want some platform to always or never behave as a server
1367 // class machine, change the setting of AlwaysActAsServerClassMachine
1368 // and NeverActAsServerClassMachine in globals*.hpp.
1369 bool os::is_server_class_machine() {
1370 // First check for the early returns
1371 if (NeverActAsServerClassMachine) {
1372 return false;
1373 }
1374 if (AlwaysActAsServerClassMachine) {
1375 return true;
1376 }
1377 // Then actually look at the machine
1378 bool result = false;
1379 const unsigned int server_processors = 2;
1380 const julong server_memory = 2UL * G;
1381 // We seem not to get our full complement of memory.
1382 // We allow some part (1/8?) of the memory to be "missing",
1383 // based on the sizes of DIMMs, and maybe graphics cards.
1384 const julong missing_memory = 256UL * M;
1385
1386 /* Is this a server class machine? */
1387 if ((os::active_processor_count() >= (int)server_processors) &&
1388 (os::physical_memory() >= (server_memory - missing_memory))) {
1389 const unsigned int logical_processors =
1390 VM_Version::logical_processors_per_package();
1391 if (logical_processors > 1) {
1392 const unsigned int physical_packages =
1393 os::active_processor_count() / logical_processors;
1394 if (physical_packages > server_processors) {
1395 result = true;
1396 }
1397 } else {
1398 result = true;
1399 }
1400 }
1401 return result;
1402 }
1403
1404 void os::SuspendedThreadTask::run() {
1405 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1406 internal_do_task();
1407 _done = true;
1408 }
1409
1410 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1411 return os::pd_create_stack_guard_pages(addr, bytes);
1412 }
1413
1414 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
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 }
1419
1420 return result;
1421 }
1422
1423 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1424 MEMFLAGS flags) {
1425 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1426 if (result != NULL) {
1427 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1428 MemTracker::record_virtual_memory_type((address)result, flags);
1429 }
1430
1431 return result;
1432 }
1433
1434 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1435 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1436 if (result != NULL) {
1437 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1438 }
1439 return result;
1440 }
1441
1442 void os::split_reserved_memory(char *base, size_t size,
1443 size_t split, bool realloc) {
1444 pd_split_reserved_memory(base, size, split, realloc);
1445 }
1446
1447 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1448 bool res = pd_commit_memory(addr, bytes, executable);
1449 if (res) {
1450 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1451 }
1452 return res;
1453 }
1454
1455 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1456 bool executable) {
1457 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1458 if (res) {
1459 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1460 }
1461 return res;
1462 }
1463
1464 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1465 const char* mesg) {
1466 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1467 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1468 }
1469
1470 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1471 bool executable, const char* mesg) {
1472 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1473 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1474 }
1475
1476 bool os::uncommit_memory(char* addr, size_t bytes) {
1477 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1478 bool res = pd_uncommit_memory(addr, bytes);
1479 if (res) {
1480 tkr.record((address)addr, bytes);
1481 } else {
1482 tkr.discard();
1483 }
1484 return res;
1485 }
1486
1487 bool os::release_memory(char* addr, size_t bytes) {
1488 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1489 bool res = pd_release_memory(addr, bytes);
1490 if (res) {
1491 tkr.record((address)addr, bytes);
1492 } else {
1493 tkr.discard();
1494 }
1495 return res;
1496 }
1497
1498
1499 char* os::map_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 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1503 if (result != NULL) {
1504 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, mtNone, CALLER_PC);
1505 }
1506 return result;
1507 }
1508
1509 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1510 char *addr, size_t bytes, bool read_only,
1511 bool allow_exec) {
1512 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1513 read_only, allow_exec);
1514 }
1515
1516 bool os::unmap_memory(char *addr, size_t bytes) {
1517 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1518 bool result = pd_unmap_memory(addr, bytes);
1519 if (result) {
1520 tkr.record((address)addr, bytes);
1521 } else {
1522 tkr.discard();
1523 }
1524 return result;
1525 }
1526
1527 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1528 pd_free_memory(addr, bytes, alignment_hint);
1529 }
1530
1531 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1532 pd_realign_memory(addr, bytes, alignment_hint);
1533 }
1534
1535 #ifndef TARGET_OS_FAMILY_windows
1536 /* try to switch state from state "from" to state "to"
1537 * returns the state set after the method is complete
1538 */
1539 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1540 os::SuspendResume::State to)
1541 {
1542 os::SuspendResume::State result =
1543 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1544 if (result == from) {
1545 // success
1546 return to;
1547 }
1548 return result;
1549 }
1550 #endif