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.inline.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
58 # include <signal.h>
59
60 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
61
62 OSThread* os::_starting_thread = NULL;
63 address os::_polling_page = NULL;
64 volatile int32_t* os::_mem_serialize_page = NULL;
65 uintptr_t os::_serialize_page_mask = 0;
66 long os::_rand_seed = 1;
67 int os::_processor_count = 0;
68 size_t os::_page_sizes[os::page_sizes_max];
69
70 #ifndef PRODUCT
71 julong os::num_mallocs = 0; // # of calls to malloc/realloc
72 julong os::alloc_bytes = 0; // # of bytes allocated
73 julong os::num_frees = 0; // # of calls to free
74 julong os::free_bytes = 0; // # of bytes freed
75 #endif
76
77 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
78
79 void os_init_globals() {
80 // Called from init_globals().
81 // See Threads::create_vm() in thread.cpp, and init.cpp.
82 os::init_globals();
83 }
84
85 // Fill in buffer with current local time as an ISO-8601 string.
86 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
87 // Returns buffer, or NULL if it failed.
88 // This would mostly be a call to
89 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
90 // except that on Windows the %z behaves badly, so we do it ourselves.
91 // Also, people wanted milliseconds on there,
92 // and strftime doesn't do milliseconds.
93 char* os::iso8601_time(char* buffer, size_t buffer_length) {
94 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
95 // 1 2
96 // 12345678901234567890123456789
97 static const char* iso8601_format =
98 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
99 static const size_t needed_buffer = 29;
100
101 // Sanity check the arguments
102 if (buffer == NULL) {
103 assert(false, "NULL buffer");
104 return NULL;
105 }
106 if (buffer_length < needed_buffer) {
107 assert(false, "buffer_length too small");
108 return NULL;
109 }
110 // Get the current time
111 jlong milliseconds_since_19700101 = javaTimeMillis();
112 const int milliseconds_per_microsecond = 1000;
113 const time_t seconds_since_19700101 =
114 milliseconds_since_19700101 / milliseconds_per_microsecond;
115 const int milliseconds_after_second =
116 milliseconds_since_19700101 % milliseconds_per_microsecond;
117 // Convert the time value to a tm and timezone variable
118 struct tm time_struct;
119 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
120 assert(false, "Failed localtime_pd");
121 return NULL;
122 }
123 #if defined(_ALLBSD_SOURCE)
124 const time_t zone = (time_t) time_struct.tm_gmtoff;
125 #else
126 const time_t zone = timezone;
127 #endif
128
129 // If daylight savings time is in effect,
130 // we are 1 hour East of our time zone
131 const time_t seconds_per_minute = 60;
132 const time_t minutes_per_hour = 60;
133 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
134 time_t UTC_to_local = zone;
135 if (time_struct.tm_isdst > 0) {
136 UTC_to_local = UTC_to_local - seconds_per_hour;
137 }
138 // Compute the time zone offset.
139 // localtime_pd() sets timezone to the difference (in seconds)
140 // between UTC and and local time.
141 // ISO 8601 says we need the difference between local time and UTC,
142 // we change the sign of the localtime_pd() result.
143 const time_t local_to_UTC = -(UTC_to_local);
144 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
145 char sign_local_to_UTC = '+';
146 time_t abs_local_to_UTC = local_to_UTC;
147 if (local_to_UTC < 0) {
148 sign_local_to_UTC = '-';
149 abs_local_to_UTC = -(abs_local_to_UTC);
150 }
151 // Convert time zone offset seconds to hours and minutes.
152 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
153 const time_t zone_min =
154 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
155
156 // Print an ISO 8601 date and time stamp into the buffer
157 const int year = 1900 + time_struct.tm_year;
158 const int month = 1 + time_struct.tm_mon;
159 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
160 year,
161 month,
162 time_struct.tm_mday,
163 time_struct.tm_hour,
164 time_struct.tm_min,
165 time_struct.tm_sec,
166 milliseconds_after_second,
167 sign_local_to_UTC,
168 zone_hours,
169 zone_min);
170 if (printed == 0) {
171 assert(false, "Failed jio_printf");
172 return NULL;
173 }
174 return buffer;
175 }
176
177 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
178 #ifdef ASSERT
179 if (!(!thread->is_Java_thread() ||
180 Thread::current() == thread ||
181 Threads_lock->owned_by_self()
182 || thread->is_Compiler_thread()
183 )) {
184 assert(false, "possibility of dangling Thread pointer");
185 }
186 #endif
187
188 if (p >= MinPriority && p <= MaxPriority) {
189 int priority = java_to_os_priority[p];
190 return set_native_priority(thread, priority);
191 } else {
192 assert(false, "Should not happen");
193 return OS_ERR;
194 }
195 }
196
197 // The mapping from OS priority back to Java priority may be inexact because
198 // Java priorities can map M:1 with native priorities. If you want the definite
199 // Java priority then use JavaThread::java_priority()
200 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
201 int p;
202 int os_prio;
203 OSReturn ret = get_native_priority(thread, &os_prio);
204 if (ret != OS_OK) return ret;
205
206 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
207 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
208 } else {
209 // niceness values are in reverse order
210 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
211 }
212 priority = (ThreadPriority)p;
213 return OS_OK;
214 }
215
216
217 // --------------------- sun.misc.Signal (optional) ---------------------
218
219
220 // SIGBREAK is sent by the keyboard to query the VM state
221 #ifndef SIGBREAK
222 #define SIGBREAK SIGQUIT
223 #endif
224
225 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
226
227
228 static void signal_thread_entry(JavaThread* thread, TRAPS) {
229 os::set_priority(thread, NearMaxPriority);
230 while (true) {
231 int sig;
232 {
233 // FIXME : Currently we have not decided what should be the status
234 // for this java thread blocked here. Once we decide about
235 // that we should fix this.
236 sig = os::signal_wait();
237 }
238 if (sig == os::sigexitnum_pd()) {
239 // Terminate the signal thread
240 return;
241 }
242
243 switch (sig) {
244 case SIGBREAK: {
245 // Check if the signal is a trigger to start the Attach Listener - in that
246 // case don't print stack traces.
247 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
248 continue;
249 }
250 // Print stack traces
251 // Any SIGBREAK operations added here should make sure to flush
252 // the output stream (e.g. tty->flush()) after output. See 4803766.
253 // Each module also prints an extra carriage return after its output.
254 VM_PrintThreads op;
255 VMThread::execute(&op);
256 VM_PrintJNI jni_op;
257 VMThread::execute(&jni_op);
258 VM_FindDeadlocks op1(tty);
259 VMThread::execute(&op1);
260 Universe::print_heap_at_SIGBREAK();
261 if (PrintClassHistogram) {
262 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
263 VMThread::execute(&op1);
264 }
265 if (JvmtiExport::should_post_data_dump()) {
266 JvmtiExport::post_data_dump();
267 }
268 break;
269 }
270 default: {
271 // Dispatch the signal to java
272 HandleMark hm(THREAD);
273 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
274 KlassHandle klass (THREAD, k);
275 if (klass.not_null()) {
276 JavaValue result(T_VOID);
277 JavaCallArguments args;
278 args.push_int(sig);
279 JavaCalls::call_static(
280 &result,
281 klass,
282 vmSymbols::dispatch_name(),
283 vmSymbols::int_void_signature(),
284 &args,
285 THREAD
286 );
287 }
288 if (HAS_PENDING_EXCEPTION) {
289 // tty is initialized early so we don't expect it to be null, but
290 // if it is we can't risk doing an initialization that might
291 // trigger additional out-of-memory conditions
292 if (tty != NULL) {
293 char klass_name[256];
294 char tmp_sig_name[16];
295 const char* sig_name = "UNKNOWN";
296 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
297 name()->as_klass_external_name(klass_name, 256);
298 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
299 sig_name = tmp_sig_name;
300 warning("Exception %s occurred dispatching signal %s to handler"
301 "- the VM may need to be forcibly terminated",
302 klass_name, sig_name );
303 }
304 CLEAR_PENDING_EXCEPTION;
305 }
306 }
307 }
308 }
309 }
310
311 void os::init_before_ergo() {
312 // We need to initialize large page support here because ergonomics takes some
313 // decisions depending on large page support and the calculated large page size.
314 large_page_init();
315 }
316
317 void os::signal_init() {
318 if (!ReduceSignalUsage) {
319 // Setup JavaThread for processing signals
320 EXCEPTION_MARK;
321 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
322 instanceKlassHandle klass (THREAD, k);
323 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
324
325 const char thread_name[] = "Signal Dispatcher";
326 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
327
328 // Initialize thread_oop to put it into the system threadGroup
329 Handle thread_group (THREAD, Universe::system_thread_group());
330 JavaValue result(T_VOID);
331 JavaCalls::call_special(&result, thread_oop,
332 klass,
333 vmSymbols::object_initializer_name(),
334 vmSymbols::threadgroup_string_void_signature(),
335 thread_group,
336 string,
337 CHECK);
338
339 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
340 JavaCalls::call_special(&result,
341 thread_group,
342 group,
343 vmSymbols::add_method_name(),
344 vmSymbols::thread_void_signature(),
345 thread_oop, // ARG 1
346 CHECK);
347
348 os::signal_init_pd();
349
350 { MutexLocker mu(Threads_lock);
351 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
352
353 // At this point it may be possible that no osthread was created for the
354 // JavaThread due to lack of memory. We would have to throw an exception
355 // in that case. However, since this must work and we do not allow
356 // exceptions anyway, check and abort if this fails.
357 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
358 vm_exit_during_initialization("java.lang.OutOfMemoryError",
359 os::native_thread_creation_failed_msg());
360 }
361
362 java_lang_Thread::set_thread(thread_oop(), signal_thread);
363 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
364 java_lang_Thread::set_daemon(thread_oop());
365
366 signal_thread->set_threadObj(thread_oop());
367 Threads::add(signal_thread);
368 Thread::start(signal_thread);
369 }
370 // Handle ^BREAK
371 os::signal(SIGBREAK, os::user_handler());
372 }
373 }
374
375
376 void os::terminate_signal_thread() {
377 if (!ReduceSignalUsage)
378 signal_notify(sigexitnum_pd());
379 }
380
381
382 // --------------------- loading libraries ---------------------
383
384 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
385 extern struct JavaVM_ main_vm;
386
387 static void* _native_java_library = NULL;
388
389 void* os::native_java_library() {
390 if (_native_java_library == NULL) {
391 char buffer[JVM_MAXPATHLEN];
392 char ebuf[1024];
393
394 // Try to load verify dll first. In 1.3 java dll depends on it and is not
395 // always able to find it when the loading executable is outside the JDK.
396 // In order to keep working with 1.2 we ignore any loading errors.
397 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
398 "verify")) {
399 dll_load(buffer, ebuf, sizeof(ebuf));
400 }
401
402 // Load java dll
403 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
404 "java")) {
405 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
406 }
407 if (_native_java_library == NULL) {
408 vm_exit_during_initialization("Unable to load native library", ebuf);
409 }
410
411 #if defined(__OpenBSD__)
412 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
413 // ignore errors
414 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
415 "net")) {
416 dll_load(buffer, ebuf, sizeof(ebuf));
417 }
418 #endif
419 }
420 static jboolean onLoaded = JNI_FALSE;
421 if (onLoaded) {
422 // We may have to wait to fire OnLoad until TLS is initialized.
423 if (ThreadLocalStorage::is_initialized()) {
424 // The JNI_OnLoad handling is normally done by method load in
425 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
426 // explicitly so we have to check for JNI_OnLoad as well
427 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
428 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
429 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
430 if (JNI_OnLoad != NULL) {
431 JavaThread* thread = JavaThread::current();
432 ThreadToNativeFromVM ttn(thread);
433 HandleMark hm(thread);
434 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
435 onLoaded = JNI_TRUE;
436 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
437 vm_exit_during_initialization("Unsupported JNI version");
438 }
439 }
440 }
441 }
442 return _native_java_library;
443 }
444
445 /*
446 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
447 * If check_lib == true then we are looking for an
448 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
449 * this library is statically linked into the image.
450 * If check_lib == false then we will look for the appropriate symbol in the
451 * executable if agent_lib->is_static_lib() == true or in the shared library
452 * referenced by 'handle'.
453 */
454 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
455 const char *syms[], size_t syms_len) {
456 assert(agent_lib != NULL, "sanity check");
457 const char *lib_name;
458 void *handle = agent_lib->os_lib();
459 void *entryName = NULL;
460 char *agent_function_name;
461 size_t i;
462
463 // If checking then use the agent name otherwise test is_static_lib() to
464 // see how to process this lookup
465 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
466 for (i = 0; i < syms_len; i++) {
467 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
468 if (agent_function_name == NULL) {
469 break;
470 }
471 entryName = dll_lookup(handle, agent_function_name);
472 FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread);
473 if (entryName != NULL) {
474 break;
475 }
476 }
477 return entryName;
478 }
479
480 // See if the passed in agent is statically linked into the VM image.
481 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
482 size_t syms_len) {
483 void *ret;
484 void *proc_handle;
485 void *save_handle;
486
487 assert(agent_lib != NULL, "sanity check");
488 if (agent_lib->name() == NULL) {
489 return false;
490 }
491 proc_handle = get_default_process_handle();
492 // Check for Agent_OnLoad/Attach_lib_name function
493 save_handle = agent_lib->os_lib();
494 // We want to look in this process' symbol table.
495 agent_lib->set_os_lib(proc_handle);
496 ret = find_agent_function(agent_lib, true, syms, syms_len);
497 if (ret != NULL) {
498 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
499 agent_lib->set_valid();
500 agent_lib->set_static_lib(true);
501 return true;
502 }
503 agent_lib->set_os_lib(save_handle);
504 return false;
505 }
506
507 // --------------------- heap allocation utilities ---------------------
508
509 char *os::strdup(const char *str, MEMFLAGS flags) {
510 size_t size = strlen(str);
511 char *dup_str = (char *)malloc(size + 1, flags);
512 if (dup_str == NULL) return NULL;
513 strcpy(dup_str, str);
514 return dup_str;
515 }
516
517
518 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
519
520 #ifdef ASSERT
521
522 static void verify_memory(void* ptr) {
523 GuardedMemory guarded(ptr);
524 if (!guarded.verify_guards()) {
525 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
526 tty->print_cr("## memory stomp:");
527 guarded.print_on(tty);
528 fatal("memory stomping error");
529 }
530 }
531
532 #endif
533
534 //
535 // This function supports testing of the malloc out of memory
536 // condition without really running the system out of memory.
537 //
538 static u_char* testMalloc(size_t alloc_size) {
539 assert(MallocMaxTestWords > 0, "sanity check");
540
541 if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
542 return NULL;
543 }
544
545 u_char* ptr = (u_char*)::malloc(alloc_size);
546
547 if (ptr != NULL) {
548 Atomic::add(((jint) (alloc_size / BytesPerWord)),
549 (volatile jint *) &cur_malloc_words);
550 }
551 return ptr;
552 }
553
554 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
555 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
556 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
557
558 #ifdef ASSERT
559 // checking for the WatcherThread and crash_protection first
560 // since os::malloc can be called when the libjvm.{dll,so} is
561 // first loaded and we don't have a thread yet.
562 // try to find the thread after we see that the watcher thread
563 // exists and has crash protection.
564 WatcherThread *wt = WatcherThread::watcher_thread();
565 if (wt != NULL && wt->has_crash_protection()) {
566 Thread* thread = ThreadLocalStorage::get_thread_slow();
567 if (thread == wt) {
568 assert(!wt->has_crash_protection(),
569 "Can't malloc with crash protection from WatcherThread");
570 }
571 }
572 #endif
573
574 if (size == 0) {
575 // return a valid pointer if size is zero
576 // if NULL is returned the calling functions assume out of memory.
577 size = 1;
578 }
579
580 #ifndef ASSERT
581 const size_t alloc_size = size;
582 #else
583 const size_t alloc_size = GuardedMemory::get_total_size(size);
584 if (size > alloc_size) { // Check for rollover.
585 return NULL;
586 }
587 #endif
588
589 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
590
591 u_char* ptr;
592 if (MallocMaxTestWords > 0) {
593 ptr = testMalloc(alloc_size);
594 } else {
595 ptr = (u_char*)::malloc(alloc_size);
596 }
597
598 #ifdef ASSERT
599 if (ptr == NULL) {
600 return NULL;
601 }
602 // Wrap memory with guard
603 GuardedMemory guarded(ptr, size);
604 ptr = guarded.get_user_ptr();
605 #endif
606 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
607 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
608 breakpoint();
609 }
610 debug_only(if (paranoid) verify_memory(ptr));
611 if (PrintMalloc && tty != NULL) {
612 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
613 }
614
615 // we do not track guard memory
616 MemTracker::record_malloc((address)ptr, size, memflags, caller == 0 ? CALLER_PC : caller);
617
618 return ptr;
619 }
620
621
622 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
623 #ifndef ASSERT
624 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
625 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
626 MemTracker::Tracker tkr = MemTracker::get_realloc_tracker();
627 void* ptr = ::realloc(memblock, size);
628 if (ptr != NULL) {
629 tkr.record((address)memblock, (address)ptr, size, memflags,
630 caller == 0 ? CALLER_PC : caller);
631 } else {
632 tkr.discard();
633 }
634 return ptr;
635 #else
636 if (memblock == NULL) {
637 return os::malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
638 }
639 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
640 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
641 breakpoint();
642 }
643 verify_memory(memblock);
644 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
645 if (size == 0) {
646 return NULL;
647 }
648 // always move the block
649 void* ptr = os::malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
650 if (PrintMalloc) {
651 tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
652 }
653 // Copy to new memory if malloc didn't fail
654 if ( ptr != NULL ) {
655 GuardedMemory guarded(memblock);
656 memcpy(ptr, memblock, MIN2(size, guarded.get_user_size()));
657 if (paranoid) verify_memory(ptr);
658 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
659 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
660 breakpoint();
661 }
662 os::free(memblock);
663 }
664 return ptr;
665 #endif
666 }
667
668
669 void os::free(void *memblock, MEMFLAGS memflags) {
670 address trackp = (address) memblock;
671 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
672 #ifdef ASSERT
673 if (memblock == NULL) return;
674 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
675 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
676 breakpoint();
677 }
678 verify_memory(memblock);
679 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
680
681 GuardedMemory guarded(memblock);
682 size_t size = guarded.get_user_size();
683 inc_stat_counter(&free_bytes, size);
684 memblock = guarded.release_for_freeing();
685 if (PrintMalloc && tty != NULL) {
686 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
687 }
688 #endif
689 MemTracker::record_free(trackp, memflags);
690
691 ::free(memblock);
692 }
693
694 void os::init_random(long initval) {
695 _rand_seed = initval;
696 }
697
698
699 long os::random() {
700 /* standard, well-known linear congruential random generator with
701 * next_rand = (16807*seed) mod (2**31-1)
702 * see
703 * (1) "Random Number Generators: Good Ones Are Hard to Find",
704 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
705 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
706 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
707 */
708 const long a = 16807;
709 const unsigned long m = 2147483647;
710 const long q = m / a; assert(q == 127773, "weird math");
711 const long r = m % a; assert(r == 2836, "weird math");
712
713 // compute az=2^31p+q
714 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
715 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
716 lo += (hi & 0x7FFF) << 16;
717
718 // if q overflowed, ignore the overflow and increment q
719 if (lo > m) {
720 lo &= m;
721 ++lo;
722 }
723 lo += hi >> 15;
724
725 // if (p+q) overflowed, ignore the overflow and increment (p+q)
726 if (lo > m) {
727 lo &= m;
728 ++lo;
729 }
730 return (_rand_seed = lo);
731 }
732
733 // The INITIALIZED state is distinguished from the SUSPENDED state because the
734 // conditions in which a thread is first started are different from those in which
735 // a suspension is resumed. These differences make it hard for us to apply the
736 // tougher checks when starting threads that we want to do when resuming them.
737 // However, when start_thread is called as a result of Thread.start, on a Java
738 // thread, the operation is synchronized on the Java Thread object. So there
739 // cannot be a race to start the thread and hence for the thread to exit while
740 // we are working on it. Non-Java threads that start Java threads either have
741 // to do so in a context in which races are impossible, or should do appropriate
742 // locking.
743
744 void os::start_thread(Thread* thread) {
745 // guard suspend/resume
746 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
747 OSThread* osthread = thread->osthread();
748 osthread->set_state(RUNNABLE);
749 pd_start_thread(thread);
750 }
751
752 //---------------------------------------------------------------------------
753 // Helper functions for fatal error handler
754
755 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
756 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
757
758 int cols = 0;
759 int cols_per_line = 0;
760 switch (unitsize) {
761 case 1: cols_per_line = 16; break;
762 case 2: cols_per_line = 8; break;
763 case 4: cols_per_line = 4; break;
764 case 8: cols_per_line = 2; break;
765 default: return;
766 }
767
768 address p = start;
769 st->print(PTR_FORMAT ": ", start);
770 while (p < end) {
771 switch (unitsize) {
772 case 1: st->print("%02x", *(u1*)p); break;
773 case 2: st->print("%04x", *(u2*)p); break;
774 case 4: st->print("%08x", *(u4*)p); break;
775 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
776 }
777 p += unitsize;
778 cols++;
779 if (cols >= cols_per_line && p < end) {
780 cols = 0;
781 st->cr();
782 st->print(PTR_FORMAT ": ", p);
783 } else {
784 st->print(" ");
785 }
786 }
787 st->cr();
788 }
789
790 void os::print_environment_variables(outputStream* st, const char** env_list,
791 char* buffer, int len) {
792 if (env_list) {
793 st->print_cr("Environment Variables:");
794
795 for (int i = 0; env_list[i] != NULL; i++) {
796 if (getenv(env_list[i], buffer, len)) {
797 st->print("%s", env_list[i]);
798 st->print("=");
799 st->print_cr("%s", buffer);
800 }
801 }
802 }
803 }
804
805 void os::print_cpu_info(outputStream* st) {
806 // cpu
807 st->print("CPU:");
808 st->print("total %d", os::processor_count());
809 // It's not safe to query number of active processors after crash
810 // st->print("(active %d)", os::active_processor_count());
811 st->print(" %s", VM_Version::cpu_features());
812 st->cr();
813 pd_print_cpu_info(st);
814 }
815
816 void os::print_date_and_time(outputStream *st) {
817 const int secs_per_day = 86400;
818 const int secs_per_hour = 3600;
819 const int secs_per_min = 60;
820
821 time_t tloc;
822 (void)time(&tloc);
823 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
824
825 double t = os::elapsedTime();
826 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
827 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
828 // before printf. We lost some precision, but who cares?
829 int eltime = (int)t; // elapsed time in seconds
830
831 // print elapsed time in a human-readable format:
832 int eldays = eltime / secs_per_day;
833 int day_secs = eldays * secs_per_day;
834 int elhours = (eltime - day_secs) / secs_per_hour;
835 int hour_secs = elhours * secs_per_hour;
836 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
837 int minute_secs = elmins * secs_per_min;
838 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
839 st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
840 }
841
842 // moved from debug.cpp (used to be find()) but still called from there
843 // The verbose parameter is only set by the debug code in one case
844 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
845 address addr = (address)x;
846 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
847 if (b != NULL) {
848 if (b->is_buffer_blob()) {
849 // the interpreter is generated into a buffer blob
850 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
851 if (i != NULL) {
852 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
853 i->print_on(st);
854 return;
855 }
856 if (Interpreter::contains(addr)) {
857 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
858 " (not bytecode specific)", addr);
859 return;
860 }
861 //
862 if (AdapterHandlerLibrary::contains(b)) {
863 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
864 AdapterHandlerLibrary::print_handler_on(st, b);
865 }
866 // the stubroutines are generated into a buffer blob
867 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
868 if (d != NULL) {
869 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
870 d->print_on(st);
871 st->cr();
872 return;
873 }
874 if (StubRoutines::contains(addr)) {
875 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
876 "stub routine", addr);
877 return;
878 }
879 // the InlineCacheBuffer is using stubs generated into a buffer blob
880 if (InlineCacheBuffer::contains(addr)) {
881 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
882 return;
883 }
884 VtableStub* v = VtableStubs::stub_containing(addr);
885 if (v != NULL) {
886 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
887 v->print_on(st);
888 st->cr();
889 return;
890 }
891 }
892 nmethod* nm = b->as_nmethod_or_null();
893 if (nm != NULL) {
894 ResourceMark rm;
895 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
896 addr, (int)(addr - nm->entry_point()), nm);
897 if (verbose) {
898 st->print(" for ");
899 nm->method()->print_value_on(st);
900 }
901 st->cr();
902 nm->print_nmethod(verbose);
903 return;
904 }
905 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
906 b->print_on(st);
907 return;
908 }
909
910 if (Universe::heap()->is_in(addr)) {
911 HeapWord* p = Universe::heap()->block_start(addr);
912 bool print = false;
913 // If we couldn't find it it just may mean that heap wasn't parsable
914 // See if we were just given an oop directly
915 if (p != NULL && Universe::heap()->block_is_obj(p)) {
916 print = true;
917 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
918 p = (HeapWord*) addr;
919 print = true;
920 }
921 if (print) {
922 if (p == (HeapWord*) addr) {
923 st->print_cr(INTPTR_FORMAT " is an oop", addr);
924 } else {
925 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
926 }
927 oop(p)->print_on(st);
928 return;
929 }
930 } else {
931 if (Universe::heap()->is_in_reserved(addr)) {
932 st->print_cr(INTPTR_FORMAT " is an unallocated location "
933 "in the heap", addr);
934 return;
935 }
936 }
937 if (JNIHandles::is_global_handle((jobject) addr)) {
938 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
939 return;
940 }
941 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
942 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
943 return;
944 }
945 #ifndef PRODUCT
946 // we don't keep the block list in product mode
947 if (JNIHandleBlock::any_contains((jobject) addr)) {
948 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
949 return;
950 }
951 #endif
952
953 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
954 // Check for privilege stack
955 if (thread->privileged_stack_top() != NULL &&
956 thread->privileged_stack_top()->contains(addr)) {
957 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
958 "for thread: " INTPTR_FORMAT, addr, thread);
959 if (verbose) thread->print_on(st);
960 return;
961 }
962 // If the addr is a java thread print information about that.
963 if (addr == (address)thread) {
964 if (verbose) {
965 thread->print_on(st);
966 } else {
967 st->print_cr(INTPTR_FORMAT " is a thread", addr);
968 }
969 return;
970 }
971 // If the addr is in the stack region for this thread then report that
972 // and print thread info
973 if (thread->stack_base() >= addr &&
974 addr > (thread->stack_base() - thread->stack_size())) {
975 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
976 INTPTR_FORMAT, addr, thread);
977 if (verbose) thread->print_on(st);
978 return;
979 }
980
981 }
982
983 // Check if in metaspace and print types that have vptrs (only method now)
984 if (Metaspace::contains(addr)) {
985 if (Method::has_method_vptr((const void*)addr)) {
986 ((Method*)addr)->print_value_on(st);
987 st->cr();
988 } else {
989 // Use addr->print() from the debugger instead (not here)
990 st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr);
991 }
992 return;
993 }
994
995 // Try an OS specific find
996 if (os::find(addr, st)) {
997 return;
998 }
999
1000 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1001 }
1002
1003 // Looks like all platforms except IA64 can use the same function to check
1004 // if C stack is walkable beyond current frame. The check for fp() is not
1005 // necessary on Sparc, but it's harmless.
1006 bool os::is_first_C_frame(frame* fr) {
1007 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1008 // On IA64 we have to check if the callers bsp is still valid
1009 // (i.e. within the register stack bounds).
1010 // Notice: this only works for threads created by the VM and only if
1011 // we walk the current stack!!! If we want to be able to walk
1012 // arbitrary other threads, we'll have to somehow store the thread
1013 // object in the frame.
1014 Thread *thread = Thread::current();
1015 if ((address)fr->fp() <=
1016 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1017 // This check is a little hacky, because on Linux the first C
1018 // frame's ('start_thread') register stack frame starts at
1019 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1020 // ('__pthread_bound_body') register stack frame seems to really
1021 // start at "register_stack_base".
1022 return true;
1023 } else {
1024 return false;
1025 }
1026 #elif defined(IA64) && defined(_WIN32)
1027 return true;
1028 #else
1029 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1030 // Check usp first, because if that's bad the other accessors may fault
1031 // on some architectures. Ditto ufp second, etc.
1032 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1033 // sp on amd can be 32 bit aligned.
1034 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1035
1036 uintptr_t usp = (uintptr_t)fr->sp();
1037 if ((usp & sp_align_mask) != 0) return true;
1038
1039 uintptr_t ufp = (uintptr_t)fr->fp();
1040 if ((ufp & fp_align_mask) != 0) return true;
1041
1042 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1043 if ((old_sp & sp_align_mask) != 0) return true;
1044 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1045
1046 uintptr_t old_fp = (uintptr_t)fr->link();
1047 if ((old_fp & fp_align_mask) != 0) return true;
1048 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1049
1050 // stack grows downwards; if old_fp is below current fp or if the stack
1051 // frame is too large, either the stack is corrupted or fp is not saved
1052 // on stack (i.e. on x86, ebp may be used as general register). The stack
1053 // is not walkable beyond current frame.
1054 if (old_fp < ufp) return true;
1055 if (old_fp - ufp > 64 * K) return true;
1056
1057 return false;
1058 #endif
1059 }
1060
1061 #ifdef ASSERT
1062 extern "C" void test_random() {
1063 const double m = 2147483647;
1064 double mean = 0.0, variance = 0.0, t;
1065 long reps = 10000;
1066 unsigned long seed = 1;
1067
1068 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1069 os::init_random(seed);
1070 long num;
1071 for (int k = 0; k < reps; k++) {
1072 num = os::random();
1073 double u = (double)num / m;
1074 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1075
1076 // calculate mean and variance of the random sequence
1077 mean += u;
1078 variance += (u*u);
1079 }
1080 mean /= reps;
1081 variance /= (reps - 1);
1082
1083 assert(num == 1043618065, "bad seed");
1084 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1085 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1086 const double eps = 0.0001;
1087 t = fabsd(mean - 0.5018);
1088 assert(t < eps, "bad mean");
1089 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1090 assert(t < eps, "bad variance");
1091 }
1092 #endif
1093
1094
1095 // Set up the boot classpath.
1096
1097 char* os::format_boot_path(const char* format_string,
1098 const char* home,
1099 int home_len,
1100 char fileSep,
1101 char pathSep) {
1102 assert((fileSep == '/' && pathSep == ':') ||
1103 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1104
1105 // Scan the format string to determine the length of the actual
1106 // boot classpath, and handle platform dependencies as well.
1107 int formatted_path_len = 0;
1108 const char* p;
1109 for (p = format_string; *p != 0; ++p) {
1110 if (*p == '%') formatted_path_len += home_len - 1;
1111 ++formatted_path_len;
1112 }
1113
1114 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1115 if (formatted_path == NULL) {
1116 return NULL;
1117 }
1118
1119 // Create boot classpath from format, substituting separator chars and
1120 // java home directory.
1121 char* q = formatted_path;
1122 for (p = format_string; *p != 0; ++p) {
1123 switch (*p) {
1124 case '%':
1125 strcpy(q, home);
1126 q += home_len;
1127 break;
1128 case '/':
1129 *q++ = fileSep;
1130 break;
1131 case ':':
1132 *q++ = pathSep;
1133 break;
1134 default:
1135 *q++ = *p;
1136 }
1137 }
1138 *q = '\0';
1139
1140 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1141 return formatted_path;
1142 }
1143
1144
1145 bool os::set_boot_path(char fileSep, char pathSep) {
1146 const char* home = Arguments::get_java_home();
1147 int home_len = (int)strlen(home);
1148
1149 static const char* meta_index_dir_format = "%/lib/";
1150 static const char* meta_index_format = "%/lib/meta-index";
1151 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1152 if (meta_index == NULL) return false;
1153 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1154 if (meta_index_dir == NULL) return false;
1155 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1156
1157 // Any modification to the JAR-file list, for the boot classpath must be
1158 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1159 // path class JARs, are stripped for StackMapTable to reduce download size.
1160 static const char classpath_format[] =
1161 "%/lib/resources.jar:"
1162 "%/lib/rt.jar:"
1163 "%/lib/sunrsasign.jar:"
1164 "%/lib/jsse.jar:"
1165 "%/lib/jce.jar:"
1166 "%/lib/charsets.jar:"
1167 "%/lib/jfr.jar:"
1168 "%/classes";
1169 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1170 if (sysclasspath == NULL) return false;
1171 Arguments::set_sysclasspath(sysclasspath);
1172
1173 return true;
1174 }
1175
1176 /*
1177 * Splits a path, based on its separator, the number of
1178 * elements is returned back in n.
1179 * It is the callers responsibility to:
1180 * a> check the value of n, and n may be 0.
1181 * b> ignore any empty path elements
1182 * c> free up the data.
1183 */
1184 char** os::split_path(const char* path, int* n) {
1185 *n = 0;
1186 if (path == NULL || strlen(path) == 0) {
1187 return NULL;
1188 }
1189 const char psepchar = *os::path_separator();
1190 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1191 if (inpath == NULL) {
1192 return NULL;
1193 }
1194 strcpy(inpath, path);
1195 int count = 1;
1196 char* p = strchr(inpath, psepchar);
1197 // Get a count of elements to allocate memory
1198 while (p != NULL) {
1199 count++;
1200 p++;
1201 p = strchr(p, psepchar);
1202 }
1203 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1204 if (opath == NULL) {
1205 return NULL;
1206 }
1207
1208 // do the actual splitting
1209 p = inpath;
1210 for (int i = 0 ; i < count ; i++) {
1211 size_t len = strcspn(p, os::path_separator());
1212 if (len > JVM_MAXPATHLEN) {
1213 return NULL;
1214 }
1215 // allocate the string and add terminator storage
1216 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1217 if (s == NULL) {
1218 return NULL;
1219 }
1220 strncpy(s, p, len);
1221 s[len] = '\0';
1222 opath[i] = s;
1223 p += len + 1;
1224 }
1225 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1226 *n = count;
1227 return opath;
1228 }
1229
1230 void os::set_memory_serialize_page(address page) {
1231 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1232 _mem_serialize_page = (volatile int32_t *)page;
1233 // We initialize the serialization page shift count here
1234 // We assume a cache line size of 64 bytes
1235 assert(SerializePageShiftCount == count,
1236 "thread size changed, fix SerializePageShiftCount constant");
1237 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1238 }
1239
1240 static volatile intptr_t SerializePageLock = 0;
1241
1242 // This method is called from signal handler when SIGSEGV occurs while the current
1243 // thread tries to store to the "read-only" memory serialize page during state
1244 // transition.
1245 void os::block_on_serialize_page_trap() {
1246 if (TraceSafepoint) {
1247 tty->print_cr("Block until the serialize page permission restored");
1248 }
1249 // When VMThread is holding the SerializePageLock during modifying the
1250 // access permission of the memory serialize page, the following call
1251 // will block until the permission of that page is restored to rw.
1252 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1253 // this case, it's OK as the signal is synchronous and we know precisely when
1254 // it can occur.
1255 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1256 Thread::muxRelease(&SerializePageLock);
1257 }
1258
1259 // Serialize all thread state variables
1260 void os::serialize_thread_states() {
1261 // On some platforms such as Solaris & Linux, the time duration of the page
1262 // permission restoration is observed to be much longer than expected due to
1263 // scheduler starvation problem etc. To avoid the long synchronization
1264 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1265 // the mutator thread if such case is encountered. See bug 6546278 for details.
1266 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1267 os::protect_memory((char *)os::get_memory_serialize_page(),
1268 os::vm_page_size(), MEM_PROT_READ);
1269 os::protect_memory((char *)os::get_memory_serialize_page(),
1270 os::vm_page_size(), MEM_PROT_RW);
1271 Thread::muxRelease(&SerializePageLock);
1272 }
1273
1274 // Returns true if the current stack pointer is above the stack shadow
1275 // pages, false otherwise.
1276
1277 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1278 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1279 address sp = current_stack_pointer();
1280 // Check if we have StackShadowPages above the yellow zone. This parameter
1281 // is dependent on the depth of the maximum VM call stack possible from
1282 // the handler for stack overflow. 'instanceof' in the stack overflow
1283 // handler or a println uses at least 8k stack of VM and native code
1284 // respectively.
1285 const int framesize_in_bytes =
1286 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1287 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1288 * vm_page_size()) + framesize_in_bytes;
1289 // The very lower end of the stack
1290 address stack_limit = thread->stack_base() - thread->stack_size();
1291 return (sp > (stack_limit + reserved_area));
1292 }
1293
1294 size_t os::page_size_for_region(size_t region_size, size_t min_pages) {
1295 assert(min_pages > 0, "sanity");
1296 if (UseLargePages) {
1297 const size_t max_page_size = region_size / min_pages;
1298
1299 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1300 const size_t page_size = _page_sizes[i];
1301 if (page_size <= max_page_size && is_size_aligned(region_size, page_size)) {
1302 return page_size;
1303 }
1304 }
1305 }
1306
1307 return vm_page_size();
1308 }
1309
1310 #ifndef PRODUCT
1311 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1312 {
1313 if (TracePageSizes) {
1314 tty->print("%s: ", str);
1315 for (int i = 0; i < count; ++i) {
1316 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1317 }
1318 tty->cr();
1319 }
1320 }
1321
1322 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1323 const size_t region_max_size, const size_t page_size,
1324 const char* base, const size_t size)
1325 {
1326 if (TracePageSizes) {
1327 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1328 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1329 " size=" SIZE_FORMAT,
1330 str, region_min_size, region_max_size,
1331 page_size, base, size);
1332 }
1333 }
1334 #endif // #ifndef PRODUCT
1335
1336 // This is the working definition of a server class machine:
1337 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1338 // because the graphics memory (?) sometimes masks physical memory.
1339 // If you want to change the definition of a server class machine
1340 // on some OS or platform, e.g., >=4GB on Windows platforms,
1341 // then you'll have to parameterize this method based on that state,
1342 // as was done for logical processors here, or replicate and
1343 // specialize this method for each platform. (Or fix os to have
1344 // some inheritance structure and use subclassing. Sigh.)
1345 // If you want some platform to always or never behave as a server
1346 // class machine, change the setting of AlwaysActAsServerClassMachine
1347 // and NeverActAsServerClassMachine in globals*.hpp.
1348 bool os::is_server_class_machine() {
1349 // First check for the early returns
1350 if (NeverActAsServerClassMachine) {
1351 return false;
1352 }
1353 if (AlwaysActAsServerClassMachine) {
1354 return true;
1355 }
1356 // Then actually look at the machine
1357 bool result = false;
1358 const unsigned int server_processors = 2;
1359 const julong server_memory = 2UL * G;
1360 // We seem not to get our full complement of memory.
1361 // We allow some part (1/8?) of the memory to be "missing",
1362 // based on the sizes of DIMMs, and maybe graphics cards.
1363 const julong missing_memory = 256UL * M;
1364
1365 /* Is this a server class machine? */
1366 if ((os::active_processor_count() >= (int)server_processors) &&
1367 (os::physical_memory() >= (server_memory - missing_memory))) {
1368 const unsigned int logical_processors =
1369 VM_Version::logical_processors_per_package();
1370 if (logical_processors > 1) {
1371 const unsigned int physical_packages =
1372 os::active_processor_count() / logical_processors;
1373 if (physical_packages > server_processors) {
1374 result = true;
1375 }
1376 } else {
1377 result = true;
1378 }
1379 }
1380 return result;
1381 }
1382
1383 void os::SuspendedThreadTask::run() {
1384 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1385 internal_do_task();
1386 _done = true;
1387 }
1388
1389 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1390 return os::pd_create_stack_guard_pages(addr, bytes);
1391 }
1392
1393 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1394 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1395 if (result != NULL) {
1396 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1397 }
1398
1399 return result;
1400 }
1401
1402 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1403 MEMFLAGS flags) {
1404 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1405 if (result != NULL) {
1406 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1407 MemTracker::record_virtual_memory_type((address)result, flags);
1408 }
1409
1410 return result;
1411 }
1412
1413 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1414 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1415 if (result != NULL) {
1416 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1417 }
1418 return result;
1419 }
1420
1421 void os::split_reserved_memory(char *base, size_t size,
1422 size_t split, bool realloc) {
1423 pd_split_reserved_memory(base, size, split, realloc);
1424 }
1425
1426 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1427 bool res = pd_commit_memory(addr, bytes, executable);
1428 if (res) {
1429 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1430 }
1431 return res;
1432 }
1433
1434 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1435 bool executable) {
1436 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1437 if (res) {
1438 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1439 }
1440 return res;
1441 }
1442
1443 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1444 const char* mesg) {
1445 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1446 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1447 }
1448
1449 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1450 bool executable, const char* mesg) {
1451 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1452 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1453 }
1454
1455 bool os::uncommit_memory(char* addr, size_t bytes) {
1456 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1457 bool res = pd_uncommit_memory(addr, bytes);
1458 if (res) {
1459 tkr.record((address)addr, bytes);
1460 } else {
1461 tkr.discard();
1462 }
1463 return res;
1464 }
1465
1466 bool os::release_memory(char* addr, size_t bytes) {
1467 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1468 bool res = pd_release_memory(addr, bytes);
1469 if (res) {
1470 tkr.record((address)addr, bytes);
1471 } else {
1472 tkr.discard();
1473 }
1474 return res;
1475 }
1476
1477
1478 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1479 char *addr, size_t bytes, bool read_only,
1480 bool allow_exec) {
1481 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1482 if (result != NULL) {
1483 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, mtNone, CALLER_PC);
1484 }
1485 return result;
1486 }
1487
1488 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1489 char *addr, size_t bytes, bool read_only,
1490 bool allow_exec) {
1491 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1492 read_only, allow_exec);
1493 }
1494
1495 bool os::unmap_memory(char *addr, size_t bytes) {
1496 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1497 bool result = pd_unmap_memory(addr, bytes);
1498 if (result) {
1499 tkr.record((address)addr, bytes);
1500 } else {
1501 tkr.discard();
1502 }
1503 return result;
1504 }
1505
1506 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1507 pd_free_memory(addr, bytes, alignment_hint);
1508 }
1509
1510 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1511 pd_realign_memory(addr, bytes, alignment_hint);
1512 }
1513
1514 #ifndef TARGET_OS_FAMILY_windows
1515 /* try to switch state from state "from" to state "to"
1516 * returns the state set after the method is complete
1517 */
1518 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1519 os::SuspendResume::State to)
1520 {
1521 os::SuspendResume::State result =
1522 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1523 if (result == from) {
1524 // success
1525 return to;
1526 }
1527 return result;
1528 }
1529 #endif
1530
1531 /////////////// Unit tests ///////////////
1532
1533 #ifndef PRODUCT
1534
1535 #define assert_eq(a,b) assert(a == b, err_msg(SIZE_FORMAT " != " SIZE_FORMAT, a, b))
1536
1537 class TestOS : AllStatic {
1538 static size_t small_page_size() {
1539 return os::vm_page_size();
1540 }
1541
1542 static size_t large_page_size() {
1543 const size_t large_page_size_example = 4 * M;
1544 return os::page_size_for_region(large_page_size_example, 1);
1545 }
1546
1547 static void test_page_size_for_region() {
1548 if (UseLargePages) {
1549 const size_t small_page = small_page_size();
1550 const size_t large_page = large_page_size();
1551
1552 if (large_page > small_page) {
1553 size_t num_small_pages_in_large = large_page / small_page;
1554 size_t page = os::page_size_for_region(large_page, num_small_pages_in_large);
1555
1556 assert_eq(page, small_page);
1557 }
1558 }
1559 }
1560
1561 static void test_page_size_for_region_alignment() {
1562 if (UseLargePages) {
1563 const size_t small_page = small_page_size();
1564 const size_t large_page = large_page_size();
1565 if (large_page > small_page) {
1566 const size_t unaligned_region = large_page + 17;
1567 size_t page = os::page_size_for_region(unaligned_region, 1);
1568 assert_eq(page, small_page);
1569
1570 const size_t num_pages = 5;
1571 const size_t aligned_region = large_page * num_pages;
1572 page = os::page_size_for_region(aligned_region, num_pages);
1573 assert_eq(page, large_page);
1574 }
1575 }
1576 }
1577
1578 public:
1579 static void run_tests() {
1580 test_page_size_for_region();
1581 test_page_size_for_region_alignment();
1582 }
1583 };
1584
1585 void TestOS_test() {
1586 TestOS::run_tests();
1587 }
1588
1589 #endif // PRODUCT