1 /*
2 * Copyright (c) 1997, 2016, 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/frame.inline.hpp"
44 #include "runtime/interfaceSupport.hpp"
45 #include "runtime/java.hpp"
46 #include "runtime/javaCalls.hpp"
47 #include "runtime/mutexLocker.hpp"
48 #include "runtime/os.hpp"
49 #include "runtime/stubRoutines.hpp"
50 #include "runtime/thread.inline.hpp"
51 #include "services/attachListener.hpp"
52 #include "services/nmtCommon.hpp"
53 #include "services/mallocTracker.hpp"
54 #include "services/memTracker.hpp"
55 #include "services/threadService.hpp"
56 #include "utilities/defaultStream.hpp"
57 #include "utilities/events.hpp"
58 #ifdef TARGET_OS_FAMILY_linux
59 # include "os_linux.inline.hpp"
60 #endif
61 #ifdef TARGET_OS_FAMILY_solaris
62 # include "os_solaris.inline.hpp"
63 #endif
64 #ifdef TARGET_OS_FAMILY_windows
65 # include "os_windows.inline.hpp"
66 #endif
67 #ifdef TARGET_OS_FAMILY_bsd
68 # include "os_bsd.inline.hpp"
69 #endif
70
71 # include <signal.h>
72
73 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
74
75 OSThread* os::_starting_thread = NULL;
76 address os::_polling_page = NULL;
77 volatile int32_t* os::_mem_serialize_page = NULL;
78 uintptr_t os::_serialize_page_mask = 0;
79 long os::_rand_seed = 1;
80 int os::_processor_count = 0;
81 int os::_initial_active_processor_count = 0;
82 size_t os::_page_sizes[os::page_sizes_max];
83
84 #ifndef PRODUCT
85 julong os::num_mallocs = 0; // # of calls to malloc/realloc
86 julong os::alloc_bytes = 0; // # of bytes allocated
87 julong os::num_frees = 0; // # of calls to free
88 julong os::free_bytes = 0; // # of bytes freed
89 #endif
90
91 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
92
93 void os_init_globals() {
94 // Called from init_globals().
95 // See Threads::create_vm() in thread.cpp, and init.cpp.
96 os::init_globals();
97 }
98
99 // Fill in buffer with current local time as an ISO-8601 string.
100 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
101 // Returns buffer, or NULL if it failed.
102 // This would mostly be a call to
103 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
104 // except that on Windows the %z behaves badly, so we do it ourselves.
105 // Also, people wanted milliseconds on there,
106 // and strftime doesn't do milliseconds.
107 char* os::iso8601_time(char* buffer, size_t buffer_length) {
108 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
109 // 1 2
110 // 12345678901234567890123456789
111 static const char* iso8601_format =
112 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
113 static const size_t needed_buffer = 29;
114
115 // Sanity check the arguments
116 if (buffer == NULL) {
117 assert(false, "NULL buffer");
118 return NULL;
119 }
120 if (buffer_length < needed_buffer) {
121 assert(false, "buffer_length too small");
122 return NULL;
123 }
124 // Get the current time
125 jlong milliseconds_since_19700101 = javaTimeMillis();
126 const int milliseconds_per_microsecond = 1000;
127 const time_t seconds_since_19700101 =
128 milliseconds_since_19700101 / milliseconds_per_microsecond;
129 const int milliseconds_after_second =
130 milliseconds_since_19700101 % milliseconds_per_microsecond;
131 // Convert the time value to a tm and timezone variable
132 struct tm time_struct;
133 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
134 assert(false, "Failed localtime_pd");
135 return NULL;
136 }
137 #if defined(_ALLBSD_SOURCE)
138 const time_t zone = (time_t) time_struct.tm_gmtoff;
139 #else
140 const time_t zone = timezone;
141 #endif
142
143 // If daylight savings time is in effect,
144 // we are 1 hour East of our time zone
145 const time_t seconds_per_minute = 60;
146 const time_t minutes_per_hour = 60;
147 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
148 time_t UTC_to_local = zone;
149 if (time_struct.tm_isdst > 0) {
150 UTC_to_local = UTC_to_local - seconds_per_hour;
151 }
152 // Compute the time zone offset.
153 // localtime_pd() sets timezone to the difference (in seconds)
154 // between UTC and and local time.
155 // ISO 8601 says we need the difference between local time and UTC,
156 // we change the sign of the localtime_pd() result.
157 const time_t local_to_UTC = -(UTC_to_local);
158 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
159 char sign_local_to_UTC = '+';
160 time_t abs_local_to_UTC = local_to_UTC;
161 if (local_to_UTC < 0) {
162 sign_local_to_UTC = '-';
163 abs_local_to_UTC = -(abs_local_to_UTC);
164 }
165 // Convert time zone offset seconds to hours and minutes.
166 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
167 const time_t zone_min =
168 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
169
170 // Print an ISO 8601 date and time stamp into the buffer
171 const int year = 1900 + time_struct.tm_year;
172 const int month = 1 + time_struct.tm_mon;
173 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
174 year,
175 month,
176 time_struct.tm_mday,
177 time_struct.tm_hour,
178 time_struct.tm_min,
179 time_struct.tm_sec,
180 milliseconds_after_second,
181 sign_local_to_UTC,
182 zone_hours,
183 zone_min);
184 if (printed == 0) {
185 assert(false, "Failed jio_printf");
186 return NULL;
187 }
188 return buffer;
189 }
190
191 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
192 #ifdef ASSERT
193 if (!(!thread->is_Java_thread() ||
194 Thread::current() == thread ||
195 Threads_lock->owned_by_self()
196 || thread->is_Compiler_thread()
197 )) {
198 assert(false, "possibility of dangling Thread pointer");
199 }
200 #endif
201
202 if (p >= MinPriority && p <= MaxPriority) {
203 int priority = java_to_os_priority[p];
204 return set_native_priority(thread, priority);
205 } else {
206 assert(false, "Should not happen");
207 return OS_ERR;
208 }
209 }
210
211 // The mapping from OS priority back to Java priority may be inexact because
212 // Java priorities can map M:1 with native priorities. If you want the definite
213 // Java priority then use JavaThread::java_priority()
214 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
215 int p;
216 int os_prio;
217 OSReturn ret = get_native_priority(thread, &os_prio);
218 if (ret != OS_OK) return ret;
219
220 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
221 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
222 } else {
223 // niceness values are in reverse order
224 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
225 }
226 priority = (ThreadPriority)p;
227 return OS_OK;
228 }
229
230
231 // --------------------- sun.misc.Signal (optional) ---------------------
232
233
234 // SIGBREAK is sent by the keyboard to query the VM state
235 #ifndef SIGBREAK
236 #define SIGBREAK SIGQUIT
237 #endif
238
239 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
240
241
242 static void signal_thread_entry(JavaThread* thread, TRAPS) {
243 os::set_priority(thread, NearMaxPriority);
244 while (true) {
245 int sig;
246 {
247 // FIXME : Currently we have not decieded what should be the status
248 // for this java thread blocked here. Once we decide about
249 // that we should fix this.
250 sig = os::signal_wait();
251 }
252 if (sig == os::sigexitnum_pd()) {
253 // Terminate the signal thread
254 return;
255 }
256
257 switch (sig) {
258 case SIGBREAK: {
259 // Check if the signal is a trigger to start the Attach Listener - in that
260 // case don't print stack traces.
261 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
262 continue;
263 }
264 // Print stack traces
265 // Any SIGBREAK operations added here should make sure to flush
266 // the output stream (e.g. tty->flush()) after output. See 4803766.
267 // Each module also prints an extra carriage return after its output.
268 VM_PrintThreads op;
269 VMThread::execute(&op);
270 VM_PrintJNI jni_op;
271 VMThread::execute(&jni_op);
272 VM_FindDeadlocks op1(tty);
273 VMThread::execute(&op1);
274 Universe::print_heap_at_SIGBREAK();
275 if (PrintClassHistogram) {
276 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
277 VMThread::execute(&op1);
278 }
279 if (JvmtiExport::should_post_data_dump()) {
280 JvmtiExport::post_data_dump();
281 }
282 break;
283 }
284 default: {
285 // Dispatch the signal to java
286 HandleMark hm(THREAD);
287 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
288 KlassHandle klass (THREAD, k);
289 if (klass.not_null()) {
290 JavaValue result(T_VOID);
291 JavaCallArguments args;
292 args.push_int(sig);
293 JavaCalls::call_static(
294 &result,
295 klass,
296 vmSymbols::dispatch_name(),
297 vmSymbols::int_void_signature(),
298 &args,
299 THREAD
300 );
301 }
302 if (HAS_PENDING_EXCEPTION) {
303 // tty is initialized early so we don't expect it to be null, but
304 // if it is we can't risk doing an initialization that might
305 // trigger additional out-of-memory conditions
306 if (tty != NULL) {
307 char klass_name[256];
308 char tmp_sig_name[16];
309 const char* sig_name = "UNKNOWN";
310 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
311 name()->as_klass_external_name(klass_name, 256);
312 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
313 sig_name = tmp_sig_name;
314 warning("Exception %s occurred dispatching signal %s to handler"
315 "- the VM may need to be forcibly terminated",
316 klass_name, sig_name );
317 }
318 CLEAR_PENDING_EXCEPTION;
319 }
320 }
321 }
322 }
323 }
324
325 void os::init_before_ergo() {
326 initialize_initial_active_processor_count();
327 // We need to initialize large page support here because ergonomics takes some
328 // decisions depending on large page support and the calculated large page size.
329 large_page_init();
330
331 // VM version initialization identifies some characteristics of the
332 // the platform that are used during ergonomic decisions.
333 VM_Version::init_before_ergo();
334 }
335
336 void os::signal_init() {
337 if (!ReduceSignalUsage) {
338 // Setup JavaThread for processing signals
339 EXCEPTION_MARK;
340 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
341 instanceKlassHandle klass (THREAD, k);
342 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
343
344 const char thread_name[] = "Signal Dispatcher";
345 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
346
347 // Initialize thread_oop to put it into the system threadGroup
348 Handle thread_group (THREAD, Universe::system_thread_group());
349 JavaValue result(T_VOID);
350 JavaCalls::call_special(&result, thread_oop,
351 klass,
352 vmSymbols::object_initializer_name(),
353 vmSymbols::threadgroup_string_void_signature(),
354 thread_group,
355 string,
356 CHECK);
357
358 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
359 JavaCalls::call_special(&result,
360 thread_group,
361 group,
362 vmSymbols::add_method_name(),
363 vmSymbols::thread_void_signature(),
364 thread_oop, // ARG 1
365 CHECK);
366
367 os::signal_init_pd();
368
369 { MutexLocker mu(Threads_lock);
370 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
371
372 // At this point it may be possible that no osthread was created for the
373 // JavaThread due to lack of memory. We would have to throw an exception
374 // in that case. However, since this must work and we do not allow
375 // exceptions anyway, check and abort if this fails.
376 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
377 vm_exit_during_initialization("java.lang.OutOfMemoryError",
378 "unable to create new native thread");
379 }
380
381 java_lang_Thread::set_thread(thread_oop(), signal_thread);
382 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
383 java_lang_Thread::set_daemon(thread_oop());
384
385 signal_thread->set_threadObj(thread_oop());
386 Threads::add(signal_thread);
387 Thread::start(signal_thread);
388 }
389 // Handle ^BREAK
390 os::signal(SIGBREAK, os::user_handler());
391 }
392 }
393
394
395 void os::terminate_signal_thread() {
396 if (!ReduceSignalUsage)
397 signal_notify(sigexitnum_pd());
398 }
399
400
401 // --------------------- loading libraries ---------------------
402
403 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
404 extern struct JavaVM_ main_vm;
405
406 static void* _native_java_library = NULL;
407
408 void* os::native_java_library() {
409 if (_native_java_library == NULL) {
410 char buffer[JVM_MAXPATHLEN];
411 char ebuf[1024];
412
413 // Try to load verify dll first. In 1.3 java dll depends on it and is not
414 // always able to find it when the loading executable is outside the JDK.
415 // In order to keep working with 1.2 we ignore any loading errors.
416 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
417 "verify")) {
418 dll_load(buffer, ebuf, sizeof(ebuf));
419 }
420
421 // Load java dll
422 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
423 "java")) {
424 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
425 }
426 if (_native_java_library == NULL) {
427 vm_exit_during_initialization("Unable to load native library", ebuf);
428 }
429
430 #if defined(__OpenBSD__)
431 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
432 // ignore errors
433 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
434 "net")) {
435 dll_load(buffer, ebuf, sizeof(ebuf));
436 }
437 #endif
438 }
439 static jboolean onLoaded = JNI_FALSE;
440 if (onLoaded) {
441 // We may have to wait to fire OnLoad until TLS is initialized.
442 if (ThreadLocalStorage::is_initialized()) {
443 // The JNI_OnLoad handling is normally done by method load in
444 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
445 // explicitly so we have to check for JNI_OnLoad as well
446 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
447 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
448 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
449 if (JNI_OnLoad != NULL) {
450 JavaThread* thread = JavaThread::current();
451 ThreadToNativeFromVM ttn(thread);
452 HandleMark hm(thread);
453 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
454 onLoaded = JNI_TRUE;
455 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
456 vm_exit_during_initialization("Unsupported JNI version");
457 }
458 }
459 }
460 }
461 return _native_java_library;
462 }
463
464 /*
465 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
466 * If check_lib == true then we are looking for an
467 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
468 * this library is statically linked into the image.
469 * If check_lib == false then we will look for the appropriate symbol in the
470 * executable if agent_lib->is_static_lib() == true or in the shared library
471 * referenced by 'handle'.
472 */
473 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
474 const char *syms[], size_t syms_len) {
475 assert(agent_lib != NULL, "sanity check");
476 const char *lib_name;
477 void *handle = agent_lib->os_lib();
478 void *entryName = NULL;
479 char *agent_function_name;
480 size_t i;
481
482 // If checking then use the agent name otherwise test is_static_lib() to
483 // see how to process this lookup
484 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
485 for (i = 0; i < syms_len; i++) {
486 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
487 if (agent_function_name == NULL) {
488 break;
489 }
490 entryName = dll_lookup(handle, agent_function_name);
491 FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread);
492 if (entryName != NULL) {
493 break;
494 }
495 }
496 return entryName;
497 }
498
499 // See if the passed in agent is statically linked into the VM image.
500 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
501 size_t syms_len) {
502 void *ret;
503 void *proc_handle;
504 void *save_handle;
505
506 assert(agent_lib != NULL, "sanity check");
507 if (agent_lib->name() == NULL) {
508 return false;
509 }
510 proc_handle = get_default_process_handle();
511 // Check for Agent_OnLoad/Attach_lib_name function
512 save_handle = agent_lib->os_lib();
513 // We want to look in this process' symbol table.
514 agent_lib->set_os_lib(proc_handle);
515 ret = find_agent_function(agent_lib, true, syms, syms_len);
516 if (ret != NULL) {
517 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
518 agent_lib->set_valid();
519 agent_lib->set_static_lib(true);
520 return true;
521 }
522 agent_lib->set_os_lib(save_handle);
523 return false;
524 }
525
526 // --------------------- heap allocation utilities ---------------------
527
528 char *os::strdup(const char *str, MEMFLAGS flags) {
529 size_t size = strlen(str);
530 char *dup_str = (char *)malloc(size + 1, flags);
531 if (dup_str == NULL) return NULL;
532 strcpy(dup_str, str);
533 return dup_str;
534 }
535
536
537
538 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
539
540 #ifdef ASSERT
541 static void verify_memory(void* ptr) {
542 GuardedMemory guarded(ptr);
543 if (!guarded.verify_guards()) {
544 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
545 tty->print_cr("## memory stomp:");
546 guarded.print_on(tty);
547 fatal("memory stomping error");
548 }
549 }
550 #endif
551
552 //
553 // This function supports testing of the malloc out of memory
554 // condition without really running the system out of memory.
555 //
556 static u_char* testMalloc(size_t alloc_size) {
557 assert(MallocMaxTestWords > 0, "sanity check");
558
559 if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
560 return NULL;
561 }
562
563 u_char* ptr = (u_char*)::malloc(alloc_size);
564
565 if (ptr != NULL) {
566 Atomic::add(((jint) (alloc_size / BytesPerWord)),
567 (volatile jint *) &cur_malloc_words);
568 }
569 return ptr;
570 }
571
572 void* os::malloc(size_t size, MEMFLAGS flags) {
573 return os::malloc(size, flags, CALLER_PC);
574 }
575
576 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
577 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
578 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
579
580 #ifdef ASSERT
581 // checking for the WatcherThread and crash_protection first
582 // since os::malloc can be called when the libjvm.{dll,so} is
583 // first loaded and we don't have a thread yet.
584 // try to find the thread after we see that the watcher thread
585 // exists and has crash protection.
586 WatcherThread *wt = WatcherThread::watcher_thread();
587 if (wt != NULL && wt->has_crash_protection()) {
588 Thread* thread = ThreadLocalStorage::get_thread_slow();
589 if (thread == wt) {
590 assert(!wt->has_crash_protection(),
591 "Can't malloc with crash protection from WatcherThread");
592 }
593 }
594 #endif
595
596 if (size == 0) {
597 // return a valid pointer if size is zero
598 // if NULL is returned the calling functions assume out of memory.
599 size = 1;
600 }
601
602 // NMT support
603 NMT_TrackingLevel level = MemTracker::tracking_level();
604 size_t nmt_header_size = MemTracker::malloc_header_size(level);
605
606 #ifndef ASSERT
607 const size_t alloc_size = size + nmt_header_size;
608 #else
609 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
610 if (size + nmt_header_size > alloc_size) { // Check for rollover.
611 return NULL;
612 }
613 #endif
614
615 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
616
617 u_char* ptr;
618 if (MallocMaxTestWords > 0) {
619 ptr = testMalloc(alloc_size);
620 } else {
621 ptr = (u_char*)::malloc(alloc_size);
622 }
623
624 #ifdef ASSERT
625 if (ptr == NULL) {
626 return NULL;
627 }
628 // Wrap memory with guard
629 GuardedMemory guarded(ptr, size + nmt_header_size);
630 ptr = guarded.get_user_ptr();
631 #endif
632 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
633 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
634 breakpoint();
635 }
636 debug_only(if (paranoid) verify_memory(ptr));
637 if (PrintMalloc && tty != NULL) {
638 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
639 }
640
641 // we do not track guard memory
642 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
643 }
644
645 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
646 return os::realloc(memblock, size, flags, CALLER_PC);
647 }
648
649 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
650
651 #ifndef ASSERT
652 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
653 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
654 // NMT support
655 void* membase = MemTracker::record_free(memblock);
656 NMT_TrackingLevel level = MemTracker::tracking_level();
657 size_t nmt_header_size = MemTracker::malloc_header_size(level);
658 void* ptr = ::realloc(membase, size + nmt_header_size);
659 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
660 #else
661 if (memblock == NULL) {
662 return os::malloc(size, memflags, stack);
663 }
664 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
665 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
666 breakpoint();
667 }
668 // NMT support
669 void* membase = MemTracker::malloc_base(memblock);
670 verify_memory(membase);
671 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
672 if (size == 0) {
673 return NULL;
674 }
675 // always move the block
676 void* ptr = os::malloc(size, memflags, stack);
677 if (PrintMalloc) {
678 tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
679 }
680 // Copy to new memory if malloc didn't fail
681 if ( ptr != NULL ) {
682 GuardedMemory guarded(MemTracker::malloc_base(memblock));
683 // Guard's user data contains NMT header
684 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
685 memcpy(ptr, memblock, MIN2(size, memblock_size));
686 if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
687 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
688 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
689 breakpoint();
690 }
691 os::free(memblock);
692 }
693 return ptr;
694 #endif
695 }
696
697
698 void os::free(void *memblock, MEMFLAGS memflags) {
699 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
700 #ifdef ASSERT
701 if (memblock == NULL) return;
702 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
703 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
704 breakpoint();
705 }
706 void* membase = MemTracker::record_free(memblock);
707 verify_memory(membase);
708 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
709
710 GuardedMemory guarded(membase);
711 size_t size = guarded.get_user_size();
712 inc_stat_counter(&free_bytes, size);
713 membase = guarded.release_for_freeing();
714 if (PrintMalloc && tty != NULL) {
715 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
716 }
717 ::free(membase);
718 #else
719 void* membase = MemTracker::record_free(memblock);
720 ::free(membase);
721 #endif
722 }
723
724 void os::init_random(long initval) {
725 _rand_seed = initval;
726 }
727
728
729 long os::random() {
730 /* standard, well-known linear congruential random generator with
731 * next_rand = (16807*seed) mod (2**31-1)
732 * see
733 * (1) "Random Number Generators: Good Ones Are Hard to Find",
734 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
735 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
736 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
737 */
738 const long a = 16807;
739 const unsigned long m = 2147483647;
740 const long q = m / a; assert(q == 127773, "weird math");
741 const long r = m % a; assert(r == 2836, "weird math");
742
743 // compute az=2^31p+q
744 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
745 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
746 lo += (hi & 0x7FFF) << 16;
747
748 // if q overflowed, ignore the overflow and increment q
749 if (lo > m) {
750 lo &= m;
751 ++lo;
752 }
753 lo += hi >> 15;
754
755 // if (p+q) overflowed, ignore the overflow and increment (p+q)
756 if (lo > m) {
757 lo &= m;
758 ++lo;
759 }
760 return (_rand_seed = lo);
761 }
762
763 // The INITIALIZED state is distinguished from the SUSPENDED state because the
764 // conditions in which a thread is first started are different from those in which
765 // a suspension is resumed. These differences make it hard for us to apply the
766 // tougher checks when starting threads that we want to do when resuming them.
767 // However, when start_thread is called as a result of Thread.start, on a Java
768 // thread, the operation is synchronized on the Java Thread object. So there
769 // cannot be a race to start the thread and hence for the thread to exit while
770 // we are working on it. Non-Java threads that start Java threads either have
771 // to do so in a context in which races are impossible, or should do appropriate
772 // locking.
773
774 void os::start_thread(Thread* thread) {
775 // guard suspend/resume
776 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
777 OSThread* osthread = thread->osthread();
778 osthread->set_state(RUNNABLE);
779 pd_start_thread(thread);
780 }
781
782 //---------------------------------------------------------------------------
783 // Helper functions for fatal error handler
784
785 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
786 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
787
788 int cols = 0;
789 int cols_per_line = 0;
790 switch (unitsize) {
791 case 1: cols_per_line = 16; break;
792 case 2: cols_per_line = 8; break;
793 case 4: cols_per_line = 4; break;
794 case 8: cols_per_line = 2; break;
795 default: return;
796 }
797
798 address p = start;
799 st->print(PTR_FORMAT ": ", start);
800 while (p < end) {
801 switch (unitsize) {
802 case 1: st->print("%02x", *(u1*)p); break;
803 case 2: st->print("%04x", *(u2*)p); break;
804 case 4: st->print("%08x", *(u4*)p); break;
805 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
806 }
807 p += unitsize;
808 cols++;
809 if (cols >= cols_per_line && p < end) {
810 cols = 0;
811 st->cr();
812 st->print(PTR_FORMAT ": ", p);
813 } else {
814 st->print(" ");
815 }
816 }
817 st->cr();
818 }
819
820 void os::print_environment_variables(outputStream* st, const char** env_list,
821 char* buffer, int len) {
822 if (env_list) {
823 st->print_cr("Environment Variables:");
824
825 for (int i = 0; env_list[i] != NULL; i++) {
826 if (getenv(env_list[i], buffer, len)) {
827 st->print("%s", env_list[i]);
828 st->print("=");
829 st->print_cr("%s", buffer);
830 }
831 }
832 }
833 }
834
835 void os::print_cpu_info(outputStream* st) {
836 // cpu
837 st->print("CPU:");
838 st->print("total %d", os::processor_count());
839 // It's not safe to query number of active processors after crash
840 // st->print("(active %d)", os::active_processor_count()); but we can
841 // print the initial number of active processors.
842 // We access the raw value here because the assert in the accessor will
843 // fail if the crash occurs before initialization of this value.
844 st->print(" (initial active %d)", _initial_active_processor_count);
845 st->print(" %s", VM_Version::cpu_features());
846 st->cr();
847 pd_print_cpu_info(st);
848 }
849
850 void os::print_date_and_time(outputStream *st) {
851 const int secs_per_day = 86400;
852 const int secs_per_hour = 3600;
853 const int secs_per_min = 60;
854
855 time_t tloc;
856 (void)time(&tloc);
857 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
858
859 double t = os::elapsedTime();
860 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
861 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
862 // before printf. We lost some precision, but who cares?
863 int eltime = (int)t; // elapsed time in seconds
864
865 // print elapsed time in a human-readable format:
866 int eldays = eltime / secs_per_day;
867 int day_secs = eldays * secs_per_day;
868 int elhours = (eltime - day_secs) / secs_per_hour;
869 int hour_secs = elhours * secs_per_hour;
870 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
871 int minute_secs = elmins * secs_per_min;
872 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
873 st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
874 }
875
876 // moved from debug.cpp (used to be find()) but still called from there
877 // The verbose parameter is only set by the debug code in one case
878 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
879 address addr = (address)x;
880 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
881 if (b != NULL) {
882 if (b->is_buffer_blob()) {
883 // the interpreter is generated into a buffer blob
884 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
885 if (i != NULL) {
886 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
887 i->print_on(st);
888 return;
889 }
890 if (Interpreter::contains(addr)) {
891 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
892 " (not bytecode specific)", addr);
893 return;
894 }
895 //
896 if (AdapterHandlerLibrary::contains(b)) {
897 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
898 AdapterHandlerLibrary::print_handler_on(st, b);
899 }
900 // the stubroutines are generated into a buffer blob
901 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
902 if (d != NULL) {
903 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
904 d->print_on(st);
905 st->cr();
906 return;
907 }
908 if (StubRoutines::contains(addr)) {
909 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
910 "stub routine", addr);
911 return;
912 }
913 // the InlineCacheBuffer is using stubs generated into a buffer blob
914 if (InlineCacheBuffer::contains(addr)) {
915 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
916 return;
917 }
918 VtableStub* v = VtableStubs::stub_containing(addr);
919 if (v != NULL) {
920 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
921 v->print_on(st);
922 st->cr();
923 return;
924 }
925 }
926 nmethod* nm = b->as_nmethod_or_null();
927 if (nm != NULL) {
928 ResourceMark rm;
929 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
930 addr, (int)(addr - nm->entry_point()), nm);
931 if (verbose) {
932 st->print(" for ");
933 nm->method()->print_value_on(st);
934 }
935 st->cr();
936 nm->print_nmethod(verbose);
937 return;
938 }
939 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
940 b->print_on(st);
941 return;
942 }
943
944 if (Universe::heap()->is_in(addr)) {
945 HeapWord* p = Universe::heap()->block_start(addr);
946 bool print = false;
947 // If we couldn't find it it just may mean that heap wasn't parseable
948 // See if we were just given an oop directly
949 if (p != NULL && Universe::heap()->block_is_obj(p)) {
950 print = true;
951 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
952 p = (HeapWord*) addr;
953 print = true;
954 }
955 if (print) {
956 if (p == (HeapWord*) addr) {
957 st->print_cr(INTPTR_FORMAT " is an oop", addr);
958 } else {
959 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
960 }
961 oop(p)->print_on(st);
962 return;
963 }
964 } else {
965 if (Universe::heap()->is_in_reserved(addr)) {
966 st->print_cr(INTPTR_FORMAT " is an unallocated location "
967 "in the heap", addr);
968 return;
969 }
970 }
971 if (JNIHandles::is_global_handle((jobject) addr)) {
972 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
973 return;
974 }
975 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
976 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
977 return;
978 }
979 #ifndef PRODUCT
980 // we don't keep the block list in product mode
981 if (JNIHandleBlock::any_contains((jobject) addr)) {
982 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
983 return;
984 }
985 #endif
986
987 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
988 // Check for privilege stack
989 if (thread->privileged_stack_top() != NULL &&
990 thread->privileged_stack_top()->contains(addr)) {
991 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
992 "for thread: " INTPTR_FORMAT, addr, thread);
993 if (verbose) thread->print_on(st);
994 return;
995 }
996 // If the addr is a java thread print information about that.
997 if (addr == (address)thread) {
998 if (verbose) {
999 thread->print_on(st);
1000 } else {
1001 st->print_cr(INTPTR_FORMAT " is a thread", addr);
1002 }
1003 return;
1004 }
1005 // If the addr is in the stack region for this thread then report that
1006 // and print thread info
1007 if (thread->stack_base() >= addr &&
1008 addr > (thread->stack_base() - thread->stack_size())) {
1009 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1010 INTPTR_FORMAT, addr, thread);
1011 if (verbose) thread->print_on(st);
1012 return;
1013 }
1014
1015 }
1016
1017 // Check if in metaspace and print types that have vptrs (only method now)
1018 if (Metaspace::contains(addr)) {
1019 if (Method::has_method_vptr((const void*)addr)) {
1020 ((Method*)addr)->print_value_on(st);
1021 st->cr();
1022 } else {
1023 // Use addr->print() from the debugger instead (not here)
1024 st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr);
1025 }
1026 return;
1027 }
1028
1029 // Try an OS specific find
1030 if (os::find(addr, st)) {
1031 return;
1032 }
1033
1034 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1035 }
1036
1037 // Looks like all platforms except IA64 can use the same function to check
1038 // if C stack is walkable beyond current frame. The check for fp() is not
1039 // necessary on Sparc, but it's harmless.
1040 bool os::is_first_C_frame(frame* fr) {
1041 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1042 // On IA64 we have to check if the callers bsp is still valid
1043 // (i.e. within the register stack bounds).
1044 // Notice: this only works for threads created by the VM and only if
1045 // we walk the current stack!!! If we want to be able to walk
1046 // arbitrary other threads, we'll have to somehow store the thread
1047 // object in the frame.
1048 Thread *thread = Thread::current();
1049 if ((address)fr->fp() <=
1050 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1051 // This check is a little hacky, because on Linux the first C
1052 // frame's ('start_thread') register stack frame starts at
1053 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1054 // ('__pthread_bound_body') register stack frame seems to really
1055 // start at "register_stack_base".
1056 return true;
1057 } else {
1058 return false;
1059 }
1060 #elif defined(IA64) && defined(_WIN32)
1061 return true;
1062 #else
1063 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1064 // Check usp first, because if that's bad the other accessors may fault
1065 // on some architectures. Ditto ufp second, etc.
1066 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1067 // sp on amd can be 32 bit aligned.
1068 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1069
1070 uintptr_t usp = (uintptr_t)fr->sp();
1071 if ((usp & sp_align_mask) != 0) return true;
1072
1073 uintptr_t ufp = (uintptr_t)fr->fp();
1074 if ((ufp & fp_align_mask) != 0) return true;
1075
1076 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1077 if ((old_sp & sp_align_mask) != 0) return true;
1078 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1079
1080 uintptr_t old_fp = (uintptr_t)fr->link();
1081 if ((old_fp & fp_align_mask) != 0) return true;
1082 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1083
1084 // stack grows downwards; if old_fp is below current fp or if the stack
1085 // frame is too large, either the stack is corrupted or fp is not saved
1086 // on stack (i.e. on x86, ebp may be used as general register). The stack
1087 // is not walkable beyond current frame.
1088 if (old_fp < ufp) return true;
1089 if (old_fp - ufp > 64 * K) return true;
1090
1091 return false;
1092 #endif
1093 }
1094
1095 #ifdef ASSERT
1096 extern "C" void test_random() {
1097 const double m = 2147483647;
1098 double mean = 0.0, variance = 0.0, t;
1099 long reps = 10000;
1100 unsigned long seed = 1;
1101
1102 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1103 os::init_random(seed);
1104 long num;
1105 for (int k = 0; k < reps; k++) {
1106 num = os::random();
1107 double u = (double)num / m;
1108 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1109
1110 // calculate mean and variance of the random sequence
1111 mean += u;
1112 variance += (u*u);
1113 }
1114 mean /= reps;
1115 variance /= (reps - 1);
1116
1117 assert(num == 1043618065, "bad seed");
1118 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1119 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1120 const double eps = 0.0001;
1121 t = fabsd(mean - 0.5018);
1122 assert(t < eps, "bad mean");
1123 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1124 assert(t < eps, "bad variance");
1125 }
1126 #endif
1127
1128
1129 // Set up the boot classpath.
1130
1131 char* os::format_boot_path(const char* format_string,
1132 const char* home,
1133 int home_len,
1134 char fileSep,
1135 char pathSep) {
1136 assert((fileSep == '/' && pathSep == ':') ||
1137 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1138
1139 // Scan the format string to determine the length of the actual
1140 // boot classpath, and handle platform dependencies as well.
1141 int formatted_path_len = 0;
1142 const char* p;
1143 for (p = format_string; *p != 0; ++p) {
1144 if (*p == '%') formatted_path_len += home_len - 1;
1145 ++formatted_path_len;
1146 }
1147
1148 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1149 if (formatted_path == NULL) {
1150 return NULL;
1151 }
1152
1153 // Create boot classpath from format, substituting separator chars and
1154 // java home directory.
1155 char* q = formatted_path;
1156 for (p = format_string; *p != 0; ++p) {
1157 switch (*p) {
1158 case '%':
1159 strcpy(q, home);
1160 q += home_len;
1161 break;
1162 case '/':
1163 *q++ = fileSep;
1164 break;
1165 case ':':
1166 *q++ = pathSep;
1167 break;
1168 default:
1169 *q++ = *p;
1170 }
1171 }
1172 *q = '\0';
1173
1174 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1175 return formatted_path;
1176 }
1177
1178
1179 bool os::set_boot_path(char fileSep, char pathSep) {
1180 const char* home = Arguments::get_java_home();
1181 int home_len = (int)strlen(home);
1182
1183 static const char* meta_index_dir_format = "%/lib/";
1184 static const char* meta_index_format = "%/lib/meta-index";
1185 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1186 if (meta_index == NULL) return false;
1187 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1188 if (meta_index_dir == NULL) return false;
1189 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1190
1191 // Any modification to the JAR-file list, for the boot classpath must be
1192 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1193 // path class JARs, are stripped for StackMapTable to reduce download size.
1194 static const char classpath_format[] =
1195 "%/lib/resources.jar:"
1196 "%/lib/rt.jar:"
1197 "%/lib/sunrsasign.jar:"
1198 "%/lib/jsse.jar:"
1199 "%/lib/jce.jar:"
1200 "%/lib/charsets.jar:"
1201 "%/lib/jfr.jar:"
1202 "%/classes";
1203 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1204 if (sysclasspath == NULL) return false;
1205 Arguments::set_sysclasspath(sysclasspath);
1206
1207 return true;
1208 }
1209
1210 /*
1211 * Splits a path, based on its separator, the number of
1212 * elements is returned back in n.
1213 * It is the callers responsibility to:
1214 * a> check the value of n, and n may be 0.
1215 * b> ignore any empty path elements
1216 * c> free up the data.
1217 */
1218 char** os::split_path(const char* path, int* n) {
1219 *n = 0;
1220 if (path == NULL || strlen(path) == 0) {
1221 return NULL;
1222 }
1223 const char psepchar = *os::path_separator();
1224 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1225 if (inpath == NULL) {
1226 return NULL;
1227 }
1228 strcpy(inpath, path);
1229 int count = 1;
1230 char* p = strchr(inpath, psepchar);
1231 // Get a count of elements to allocate memory
1232 while (p != NULL) {
1233 count++;
1234 p++;
1235 p = strchr(p, psepchar);
1236 }
1237 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1238 if (opath == NULL) {
1239 return NULL;
1240 }
1241
1242 // do the actual splitting
1243 p = inpath;
1244 for (int i = 0 ; i < count ; i++) {
1245 size_t len = strcspn(p, os::path_separator());
1246 if (len > JVM_MAXPATHLEN) {
1247 return NULL;
1248 }
1249 // allocate the string and add terminator storage
1250 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1251 if (s == NULL) {
1252 return NULL;
1253 }
1254 strncpy(s, p, len);
1255 s[len] = '\0';
1256 opath[i] = s;
1257 p += len + 1;
1258 }
1259 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1260 *n = count;
1261 return opath;
1262 }
1263
1264 void os::set_memory_serialize_page(address page) {
1265 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1266 _mem_serialize_page = (volatile int32_t *)page;
1267 // We initialize the serialization page shift count here
1268 // We assume a cache line size of 64 bytes
1269 assert(SerializePageShiftCount == count,
1270 "thread size changed, fix SerializePageShiftCount constant");
1271 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1272 }
1273
1274 static volatile intptr_t SerializePageLock = 0;
1275
1276 // This method is called from signal handler when SIGSEGV occurs while the current
1277 // thread tries to store to the "read-only" memory serialize page during state
1278 // transition.
1279 void os::block_on_serialize_page_trap() {
1280 if (TraceSafepoint) {
1281 tty->print_cr("Block until the serialize page permission restored");
1282 }
1283 // When VMThread is holding the SerializePageLock during modifying the
1284 // access permission of the memory serialize page, the following call
1285 // will block until the permission of that page is restored to rw.
1286 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1287 // this case, it's OK as the signal is synchronous and we know precisely when
1288 // it can occur.
1289 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1290 Thread::muxRelease(&SerializePageLock);
1291 }
1292
1293 // Serialize all thread state variables
1294 void os::serialize_thread_states() {
1295 // On some platforms such as Solaris & Linux, the time duration of the page
1296 // permission restoration is observed to be much longer than expected due to
1297 // scheduler starvation problem etc. To avoid the long synchronization
1298 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1299 // the mutator thread if such case is encountered. See bug 6546278 for details.
1300 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1301 os::protect_memory((char *)os::get_memory_serialize_page(),
1302 os::vm_page_size(), MEM_PROT_READ);
1303 os::protect_memory((char *)os::get_memory_serialize_page(),
1304 os::vm_page_size(), MEM_PROT_RW);
1305 Thread::muxRelease(&SerializePageLock);
1306 }
1307
1308 // Returns true if the current stack pointer is above the stack shadow
1309 // pages, false otherwise.
1310
1311 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1312 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1313 address sp = current_stack_pointer();
1314 // Check if we have StackShadowPages above the yellow zone. This parameter
1315 // is dependent on the depth of the maximum VM call stack possible from
1316 // the handler for stack overflow. 'instanceof' in the stack overflow
1317 // handler or a println uses at least 8k stack of VM and native code
1318 // respectively.
1319 const int framesize_in_bytes =
1320 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1321 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1322 * vm_page_size()) + framesize_in_bytes;
1323 // The very lower end of the stack
1324 address stack_limit = thread->stack_base() - thread->stack_size();
1325 return (sp > (stack_limit + reserved_area));
1326 }
1327
1328 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1329 assert(min_pages > 0, "sanity");
1330 if (UseLargePages) {
1331 const size_t max_page_size = region_size / min_pages;
1332
1333 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1334 const size_t page_size = _page_sizes[i];
1335 if (page_size <= max_page_size) {
1336 if (!must_be_aligned || is_size_aligned(region_size, page_size)) {
1337 return page_size;
1338 }
1339 }
1340 }
1341 }
1342
1343 return vm_page_size();
1344 }
1345
1346 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1347 return page_size_for_region(region_size, min_pages, true);
1348 }
1349
1350 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1351 return page_size_for_region(region_size, min_pages, false);
1352 }
1353
1354 #ifndef PRODUCT
1355 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1356 {
1357 if (TracePageSizes) {
1358 tty->print("%s: ", str);
1359 for (int i = 0; i < count; ++i) {
1360 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1361 }
1362 tty->cr();
1363 }
1364 }
1365
1366 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1367 const size_t region_max_size, const size_t page_size,
1368 const char* base, const size_t size)
1369 {
1370 if (TracePageSizes) {
1371 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1372 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1373 " size=" SIZE_FORMAT,
1374 str, region_min_size, region_max_size,
1375 page_size, base, size);
1376 }
1377 }
1378 #endif // #ifndef PRODUCT
1379
1380 // This is the working definition of a server class machine:
1381 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1382 // because the graphics memory (?) sometimes masks physical memory.
1383 // If you want to change the definition of a server class machine
1384 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1385 // then you'll have to parameterize this method based on that state,
1386 // as was done for logical processors here, or replicate and
1387 // specialize this method for each platform. (Or fix os to have
1388 // some inheritance structure and use subclassing. Sigh.)
1389 // If you want some platform to always or never behave as a server
1390 // class machine, change the setting of AlwaysActAsServerClassMachine
1391 // and NeverActAsServerClassMachine in globals*.hpp.
1392 bool os::is_server_class_machine() {
1393 // First check for the early returns
1394 if (NeverActAsServerClassMachine) {
1395 return false;
1396 }
1397 if (AlwaysActAsServerClassMachine) {
1398 return true;
1399 }
1400 // Then actually look at the machine
1401 bool result = false;
1402 const unsigned int server_processors = 2;
1403 const julong server_memory = 2UL * G;
1404 // We seem not to get our full complement of memory.
1405 // We allow some part (1/8?) of the memory to be "missing",
1406 // based on the sizes of DIMMs, and maybe graphics cards.
1407 const julong missing_memory = 256UL * M;
1408
1409 /* Is this a server class machine? */
1410 if ((os::active_processor_count() >= (int)server_processors) &&
1411 (os::physical_memory() >= (server_memory - missing_memory))) {
1412 const unsigned int logical_processors =
1413 VM_Version::logical_processors_per_package();
1414 if (logical_processors > 1) {
1415 const unsigned int physical_packages =
1416 os::active_processor_count() / logical_processors;
1417 if (physical_packages > server_processors) {
1418 result = true;
1419 }
1420 } else {
1421 result = true;
1422 }
1423 }
1424 return result;
1425 }
1426
1427 void os::initialize_initial_active_processor_count() {
1428 assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
1429 _initial_active_processor_count = active_processor_count();
1430 }
1431
1432 void os::SuspendedThreadTask::run() {
1433 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1434 internal_do_task();
1435 _done = true;
1436 }
1437
1438 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1439 return os::pd_create_stack_guard_pages(addr, bytes);
1440 }
1441
1442 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1443 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1444 if (result != NULL) {
1445 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1446 }
1447
1448 return result;
1449 }
1450
1451 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1452 MEMFLAGS flags) {
1453 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1454 if (result != NULL) {
1455 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1456 MemTracker::record_virtual_memory_type((address)result, flags);
1457 }
1458
1459 return result;
1460 }
1461
1462 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1463 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1464 if (result != NULL) {
1465 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1466 }
1467 return result;
1468 }
1469
1470 void os::split_reserved_memory(char *base, size_t size,
1471 size_t split, bool realloc) {
1472 pd_split_reserved_memory(base, size, split, realloc);
1473 }
1474
1475 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1476 bool res = pd_commit_memory(addr, bytes, executable);
1477 if (res) {
1478 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1479 }
1480 return res;
1481 }
1482
1483 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1484 bool executable) {
1485 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1486 if (res) {
1487 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1488 }
1489 return res;
1490 }
1491
1492 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1493 const char* mesg) {
1494 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1495 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1496 }
1497
1498 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1499 bool executable, const char* mesg) {
1500 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1501 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1502 }
1503
1504 bool os::uncommit_memory(char* addr, size_t bytes) {
1505 bool res;
1506 if (MemTracker::tracking_level() > NMT_minimal) {
1507 Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1508 res = pd_uncommit_memory(addr, bytes);
1509 if (res) {
1510 tkr.record((address)addr, bytes);
1511 }
1512 } else {
1513 res = pd_uncommit_memory(addr, bytes);
1514 }
1515 return res;
1516 }
1517
1518 bool os::release_memory(char* addr, size_t bytes) {
1519 bool res;
1520 if (MemTracker::tracking_level() > NMT_minimal) {
1521 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1522 res = pd_release_memory(addr, bytes);
1523 if (res) {
1524 tkr.record((address)addr, bytes);
1525 }
1526 } else {
1527 res = pd_release_memory(addr, bytes);
1528 }
1529 return res;
1530 }
1531
1532 void os::pretouch_memory(char* start, char* end) {
1533 for (volatile char *p = start; p < end; p += os::vm_page_size()) {
1534 *p = 0;
1535 }
1536 }
1537
1538 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1539 char *addr, size_t bytes, bool read_only,
1540 bool allow_exec) {
1541 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1542 if (result != NULL) {
1543 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1544 }
1545 return result;
1546 }
1547
1548 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1549 char *addr, size_t bytes, bool read_only,
1550 bool allow_exec) {
1551 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1552 read_only, allow_exec);
1553 }
1554
1555 bool os::unmap_memory(char *addr, size_t bytes) {
1556 bool result;
1557 if (MemTracker::tracking_level() > NMT_minimal) {
1558 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1559 result = pd_unmap_memory(addr, bytes);
1560 if (result) {
1561 tkr.record((address)addr, bytes);
1562 }
1563 } else {
1564 result = pd_unmap_memory(addr, bytes);
1565 }
1566 return result;
1567 }
1568
1569 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1570 pd_free_memory(addr, bytes, alignment_hint);
1571 }
1572
1573 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1574 pd_realign_memory(addr, bytes, alignment_hint);
1575 }
1576
1577 #ifndef TARGET_OS_FAMILY_windows
1578 /* try to switch state from state "from" to state "to"
1579 * returns the state set after the method is complete
1580 */
1581 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1582 os::SuspendResume::State to)
1583 {
1584 os::SuspendResume::State result =
1585 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1586 if (result == from) {
1587 // success
1588 return to;
1589 }
1590 return result;
1591 }
1592 #endif
1593
1594 /////////////// Unit tests ///////////////
1595
1596 #ifndef PRODUCT
1597
1598 #define assert_eq(a,b) assert(a == b, err_msg(SIZE_FORMAT " != " SIZE_FORMAT, a, b))
1599
1600 class TestOS : AllStatic {
1601 static size_t small_page_size() {
1602 return os::vm_page_size();
1603 }
1604
1605 static size_t large_page_size() {
1606 const size_t large_page_size_example = 4 * M;
1607 return os::page_size_for_region_aligned(large_page_size_example, 1);
1608 }
1609
1610 static void test_page_size_for_region_aligned() {
1611 if (UseLargePages) {
1612 const size_t small_page = small_page_size();
1613 const size_t large_page = large_page_size();
1614
1615 if (large_page > small_page) {
1616 size_t num_small_pages_in_large = large_page / small_page;
1617 size_t page = os::page_size_for_region_aligned(large_page, num_small_pages_in_large);
1618
1619 assert_eq(page, small_page);
1620 }
1621 }
1622 }
1623
1624 static void test_page_size_for_region_alignment() {
1625 if (UseLargePages) {
1626 const size_t small_page = small_page_size();
1627 const size_t large_page = large_page_size();
1628 if (large_page > small_page) {
1629 const size_t unaligned_region = large_page + 17;
1630 size_t page = os::page_size_for_region_aligned(unaligned_region, 1);
1631 assert_eq(page, small_page);
1632
1633 const size_t num_pages = 5;
1634 const size_t aligned_region = large_page * num_pages;
1635 page = os::page_size_for_region_aligned(aligned_region, num_pages);
1636 assert_eq(page, large_page);
1637 }
1638 }
1639 }
1640
1641 static void test_page_size_for_region_unaligned() {
1642 if (UseLargePages) {
1643 // Given exact page size, should return that page size.
1644 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1645 size_t expected = os::_page_sizes[i];
1646 size_t actual = os::page_size_for_region_unaligned(expected, 1);
1647 assert_eq(expected, actual);
1648 }
1649
1650 // Given slightly larger size than a page size, return the page size.
1651 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1652 size_t expected = os::_page_sizes[i];
1653 size_t actual = os::page_size_for_region_unaligned(expected + 17, 1);
1654 assert_eq(expected, actual);
1655 }
1656
1657 // Given a slightly smaller size than a page size,
1658 // return the next smaller page size.
1659 if (os::_page_sizes[1] > os::_page_sizes[0]) {
1660 size_t expected = os::_page_sizes[0];
1661 size_t actual = os::page_size_for_region_unaligned(os::_page_sizes[1] - 17, 1);
1662 assert_eq(actual, expected);
1663 }
1664
1665 // Return small page size for values less than a small page.
1666 size_t small_page = small_page_size();
1667 size_t actual = os::page_size_for_region_unaligned(small_page - 17, 1);
1668 assert_eq(small_page, actual);
1669 }
1670 }
1671
1672 public:
1673 static void run_tests() {
1674 test_page_size_for_region_aligned();
1675 test_page_size_for_region_alignment();
1676 test_page_size_for_region_unaligned();
1677 }
1678 };
1679
1680 void TestOS_test() {
1681 TestOS::run_tests();
1682 }
1683
1684 #endif // PRODUCT