1 /*
2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/codeCache.hpp"
31 #include "code/icBuffer.hpp"
32 #include "code/vtableStubs.hpp"
33 #include "gc/shared/vmGCOperations.hpp"
34 #include "interpreter/interpreter.hpp"
35 #include "memory/allocation.inline.hpp"
36 #ifdef ASSERT
37 #include "memory/guardedMemory.hpp"
38 #endif
39 #include "oops/oop.inline.hpp"
40 #include "prims/jvm.h"
41 #include "prims/jvm_misc.hpp"
42 #include "prims/privilegedStack.hpp"
43 #include "runtime/arguments.hpp"
44 #include "runtime/atomic.inline.hpp"
45 #include "runtime/frame.inline.hpp"
46 #include "runtime/interfaceSupport.hpp"
47 #include "runtime/java.hpp"
48 #include "runtime/javaCalls.hpp"
49 #include "runtime/mutexLocker.hpp"
50 #include "runtime/os.inline.hpp"
51 #include "runtime/stubRoutines.hpp"
52 #include "runtime/thread.inline.hpp"
53 #include "runtime/vm_version.hpp"
54 #include "services/attachListener.hpp"
55 #include "services/mallocTracker.hpp"
56 #include "services/memTracker.hpp"
57 #include "services/nmtCommon.hpp"
58 #include "services/threadService.hpp"
59 #include "utilities/defaultStream.hpp"
60 #include "utilities/events.hpp"
61
62 # include <signal.h>
63
64 OSThread* os::_starting_thread = NULL;
65 address os::_polling_page = NULL;
66 volatile int32_t* os::_mem_serialize_page = NULL;
67 uintptr_t os::_serialize_page_mask = 0;
68 long os::_rand_seed = 1;
69 int os::_processor_count = 0;
70 size_t os::_page_sizes[os::page_sizes_max];
71
72 #ifndef PRODUCT
73 julong os::num_mallocs = 0; // # of calls to malloc/realloc
74 julong os::alloc_bytes = 0; // # of bytes allocated
75 julong os::num_frees = 0; // # of calls to free
76 julong os::free_bytes = 0; // # of bytes freed
77 #endif
78
79 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
80
81 void os_init_globals() {
82 // Called from init_globals().
83 // See Threads::create_vm() in thread.cpp, and init.cpp.
84 os::init_globals();
85 }
86
87 // Fill in buffer with current local time as an ISO-8601 string.
88 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
89 // Returns buffer, or NULL if it failed.
90 // This would mostly be a call to
91 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
92 // except that on Windows the %z behaves badly, so we do it ourselves.
93 // Also, people wanted milliseconds on there,
94 // and strftime doesn't do milliseconds.
95 char* os::iso8601_time(char* buffer, size_t buffer_length) {
96 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
97 // 1 2
98 // 12345678901234567890123456789
99 // format string: "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"
100 static const size_t needed_buffer = 29;
101
102 // Sanity check the arguments
103 if (buffer == NULL) {
104 assert(false, "NULL buffer");
105 return NULL;
106 }
107 if (buffer_length < needed_buffer) {
108 assert(false, "buffer_length too small");
109 return NULL;
110 }
111 // Get the current time
112 jlong milliseconds_since_19700101 = javaTimeMillis();
113 const int milliseconds_per_microsecond = 1000;
114 const time_t seconds_since_19700101 =
115 milliseconds_since_19700101 / milliseconds_per_microsecond;
116 const int milliseconds_after_second =
117 milliseconds_since_19700101 % milliseconds_per_microsecond;
118 // Convert the time value to a tm and timezone variable
119 struct tm time_struct;
120 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
121 assert(false, "Failed localtime_pd");
122 return NULL;
123 }
124 #if defined(_ALLBSD_SOURCE)
125 const time_t zone = (time_t) time_struct.tm_gmtoff;
126 #else
127 const time_t zone = timezone;
128 #endif
129
130 // If daylight savings time is in effect,
131 // we are 1 hour East of our time zone
132 const time_t seconds_per_minute = 60;
133 const time_t minutes_per_hour = 60;
134 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
135 time_t UTC_to_local = zone;
136 if (time_struct.tm_isdst > 0) {
137 UTC_to_local = UTC_to_local - seconds_per_hour;
138 }
139 // Compute the time zone offset.
140 // localtime_pd() sets timezone to the difference (in seconds)
141 // between UTC and and local time.
142 // ISO 8601 says we need the difference between local time and UTC,
143 // we change the sign of the localtime_pd() result.
144 const time_t local_to_UTC = -(UTC_to_local);
145 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
146 char sign_local_to_UTC = '+';
147 time_t abs_local_to_UTC = local_to_UTC;
148 if (local_to_UTC < 0) {
149 sign_local_to_UTC = '-';
150 abs_local_to_UTC = -(abs_local_to_UTC);
151 }
152 // Convert time zone offset seconds to hours and minutes.
153 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
154 const time_t zone_min =
155 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
156
157 // Print an ISO 8601 date and time stamp into the buffer
158 const int year = 1900 + time_struct.tm_year;
159 const int month = 1 + time_struct.tm_mon;
160 const int printed = jio_snprintf(buffer, buffer_length,
161 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d",
162 year,
163 month,
164 time_struct.tm_mday,
165 time_struct.tm_hour,
166 time_struct.tm_min,
167 time_struct.tm_sec,
168 milliseconds_after_second,
169 sign_local_to_UTC,
170 zone_hours,
171 zone_min);
172 if (printed == 0) {
173 assert(false, "Failed jio_printf");
174 return NULL;
175 }
176 return buffer;
177 }
178
179 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
180 #ifdef ASSERT
181 if (!(!thread->is_Java_thread() ||
182 Thread::current() == thread ||
183 Threads_lock->owned_by_self()
184 || thread->is_Compiler_thread()
185 )) {
186 assert(false, "possibility of dangling Thread pointer");
187 }
188 #endif
189
190 if (p >= MinPriority && p <= MaxPriority) {
191 int priority = java_to_os_priority[p];
192 return set_native_priority(thread, priority);
193 } else {
194 assert(false, "Should not happen");
195 return OS_ERR;
196 }
197 }
198
199 // The mapping from OS priority back to Java priority may be inexact because
200 // Java priorities can map M:1 with native priorities. If you want the definite
201 // Java priority then use JavaThread::java_priority()
202 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
203 int p;
204 int os_prio;
205 OSReturn ret = get_native_priority(thread, &os_prio);
206 if (ret != OS_OK) return ret;
207
208 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
209 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
210 } else {
211 // niceness values are in reverse order
212 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
213 }
214 priority = (ThreadPriority)p;
215 return OS_OK;
216 }
217
218
219 // --------------------- sun.misc.Signal (optional) ---------------------
220
221
222 // SIGBREAK is sent by the keyboard to query the VM state
223 #ifndef SIGBREAK
224 #define SIGBREAK SIGQUIT
225 #endif
226
227 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
228
229
230 static void signal_thread_entry(JavaThread* thread, TRAPS) {
231 os::set_priority(thread, NearMaxPriority);
232 while (true) {
233 int sig;
234 {
235 // FIXME : Currently we have not decided what should be the status
236 // for this java thread blocked here. Once we decide about
237 // that we should fix this.
238 sig = os::signal_wait();
239 }
240 if (sig == os::sigexitnum_pd()) {
241 // Terminate the signal thread
242 return;
243 }
244
245 switch (sig) {
246 case SIGBREAK: {
247 // Check if the signal is a trigger to start the Attach Listener - in that
248 // case don't print stack traces.
249 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
250 continue;
251 }
252 // Print stack traces
253 // Any SIGBREAK operations added here should make sure to flush
254 // the output stream (e.g. tty->flush()) after output. See 4803766.
255 // Each module also prints an extra carriage return after its output.
256 VM_PrintThreads op;
257 VMThread::execute(&op);
258 VM_PrintJNI jni_op;
259 VMThread::execute(&jni_op);
260 VM_FindDeadlocks op1(tty);
261 VMThread::execute(&op1);
262 Universe::print_heap_at_SIGBREAK();
263 if (PrintClassHistogram) {
264 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
265 VMThread::execute(&op1);
266 }
267 if (JvmtiExport::should_post_data_dump()) {
268 JvmtiExport::post_data_dump();
269 }
270 break;
271 }
272 default: {
273 // Dispatch the signal to java
274 HandleMark hm(THREAD);
275 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
276 KlassHandle klass (THREAD, k);
277 if (klass.not_null()) {
278 JavaValue result(T_VOID);
279 JavaCallArguments args;
280 args.push_int(sig);
281 JavaCalls::call_static(
282 &result,
283 klass,
284 vmSymbols::dispatch_name(),
285 vmSymbols::int_void_signature(),
286 &args,
287 THREAD
288 );
289 }
290 if (HAS_PENDING_EXCEPTION) {
291 // tty is initialized early so we don't expect it to be null, but
292 // if it is we can't risk doing an initialization that might
293 // trigger additional out-of-memory conditions
294 if (tty != NULL) {
295 char klass_name[256];
296 char tmp_sig_name[16];
297 const char* sig_name = "UNKNOWN";
298 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
299 name()->as_klass_external_name(klass_name, 256);
300 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
301 sig_name = tmp_sig_name;
302 warning("Exception %s occurred dispatching signal %s to handler"
303 "- the VM may need to be forcibly terminated",
304 klass_name, sig_name );
305 }
306 CLEAR_PENDING_EXCEPTION;
307 }
308 }
309 }
310 }
311 }
312
313 void os::init_before_ergo() {
314 // We need to initialize large page support here because ergonomics takes some
315 // decisions depending on large page support and the calculated large page size.
316 large_page_init();
317 }
318
319 void os::signal_init() {
320 if (!ReduceSignalUsage) {
321 // Setup JavaThread for processing signals
322 EXCEPTION_MARK;
323 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
324 instanceKlassHandle klass (THREAD, k);
325 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
326
327 const char thread_name[] = "Signal Dispatcher";
328 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
329
330 // Initialize thread_oop to put it into the system threadGroup
331 Handle thread_group (THREAD, Universe::system_thread_group());
332 JavaValue result(T_VOID);
333 JavaCalls::call_special(&result, thread_oop,
334 klass,
335 vmSymbols::object_initializer_name(),
336 vmSymbols::threadgroup_string_void_signature(),
337 thread_group,
338 string,
339 CHECK);
340
341 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
342 JavaCalls::call_special(&result,
343 thread_group,
344 group,
345 vmSymbols::add_method_name(),
346 vmSymbols::thread_void_signature(),
347 thread_oop, // ARG 1
348 CHECK);
349
350 os::signal_init_pd();
351
352 { MutexLocker mu(Threads_lock);
353 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
354
355 // At this point it may be possible that no osthread was created for the
356 // JavaThread due to lack of memory. We would have to throw an exception
357 // in that case. However, since this must work and we do not allow
358 // exceptions anyway, check and abort if this fails.
359 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
360 vm_exit_during_initialization("java.lang.OutOfMemoryError",
361 os::native_thread_creation_failed_msg());
362 }
363
364 java_lang_Thread::set_thread(thread_oop(), signal_thread);
365 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
366 java_lang_Thread::set_daemon(thread_oop());
367
368 signal_thread->set_threadObj(thread_oop());
369 Threads::add(signal_thread);
370 Thread::start(signal_thread);
371 }
372 // Handle ^BREAK
373 os::signal(SIGBREAK, os::user_handler());
374 }
375 }
376
377
378 void os::terminate_signal_thread() {
379 if (!ReduceSignalUsage)
380 signal_notify(sigexitnum_pd());
381 }
382
383
384 // --------------------- loading libraries ---------------------
385
386 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
387 extern struct JavaVM_ main_vm;
388
389 static void* _native_java_library = NULL;
390
391 void* os::native_java_library() {
392 if (_native_java_library == NULL) {
393 char buffer[JVM_MAXPATHLEN];
394 char ebuf[1024];
395
396 // Try to load verify dll first. In 1.3 java dll depends on it and is not
397 // always able to find it when the loading executable is outside the JDK.
398 // In order to keep working with 1.2 we ignore any loading errors.
399 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
400 "verify")) {
401 dll_load(buffer, ebuf, sizeof(ebuf));
402 }
403
404 // Load java dll
405 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
406 "java")) {
407 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
408 }
409 if (_native_java_library == NULL) {
410 vm_exit_during_initialization("Unable to load native library", ebuf);
411 }
412
413 #if defined(__OpenBSD__)
414 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
415 // ignore errors
416 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
417 "net")) {
418 dll_load(buffer, ebuf, sizeof(ebuf));
419 }
420 #endif
421 }
422 static jboolean onLoaded = JNI_FALSE;
423 if (onLoaded) {
424 // We may have to wait to fire OnLoad until TLS is initialized.
425 if (ThreadLocalStorage::is_initialized()) {
426 // The JNI_OnLoad handling is normally done by method load in
427 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
428 // explicitly so we have to check for JNI_OnLoad as well
429 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
430 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
431 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
432 if (JNI_OnLoad != NULL) {
433 JavaThread* thread = JavaThread::current();
434 ThreadToNativeFromVM ttn(thread);
435 HandleMark hm(thread);
436 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
437 onLoaded = JNI_TRUE;
438 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
439 vm_exit_during_initialization("Unsupported JNI version");
440 }
441 }
442 }
443 }
444 return _native_java_library;
445 }
446
447 /*
448 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
449 * If check_lib == true then we are looking for an
450 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
451 * this library is statically linked into the image.
452 * If check_lib == false then we will look for the appropriate symbol in the
453 * executable if agent_lib->is_static_lib() == true or in the shared library
454 * referenced by 'handle'.
455 */
456 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
457 const char *syms[], size_t syms_len) {
458 assert(agent_lib != NULL, "sanity check");
459 const char *lib_name;
460 void *handle = agent_lib->os_lib();
461 void *entryName = NULL;
462 char *agent_function_name;
463 size_t i;
464
465 // If checking then use the agent name otherwise test is_static_lib() to
466 // see how to process this lookup
467 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
468 for (i = 0; i < syms_len; i++) {
469 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
470 if (agent_function_name == NULL) {
471 break;
472 }
473 entryName = dll_lookup(handle, agent_function_name);
474 FREE_C_HEAP_ARRAY(char, agent_function_name);
475 if (entryName != NULL) {
476 break;
477 }
478 }
479 return entryName;
480 }
481
482 // See if the passed in agent is statically linked into the VM image.
483 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
484 size_t syms_len) {
485 void *ret;
486 void *proc_handle;
487 void *save_handle;
488
489 assert(agent_lib != NULL, "sanity check");
490 if (agent_lib->name() == NULL) {
491 return false;
492 }
493 proc_handle = get_default_process_handle();
494 // Check for Agent_OnLoad/Attach_lib_name function
495 save_handle = agent_lib->os_lib();
496 // We want to look in this process' symbol table.
497 agent_lib->set_os_lib(proc_handle);
498 ret = find_agent_function(agent_lib, true, syms, syms_len);
499 if (ret != NULL) {
500 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
501 agent_lib->set_valid();
502 agent_lib->set_static_lib(true);
503 return true;
504 }
505 agent_lib->set_os_lib(save_handle);
506 return false;
507 }
508
509 // --------------------- heap allocation utilities ---------------------
510
511 char *os::strdup(const char *str, MEMFLAGS flags) {
512 size_t size = strlen(str);
513 char *dup_str = (char *)malloc(size + 1, flags);
514 if (dup_str == NULL) return NULL;
515 strcpy(dup_str, str);
516 return dup_str;
517 }
518
519 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
520 char* p = os::strdup(str, flags);
521 if (p == NULL) {
522 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
523 }
524 return p;
525 }
526
527
528 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
529
530 #ifdef ASSERT
531
532 static void verify_memory(void* ptr) {
533 GuardedMemory guarded(ptr);
534 if (!guarded.verify_guards()) {
535 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
536 tty->print_cr("## memory stomp:");
537 guarded.print_on(tty);
538 fatal("memory stomping error");
539 }
540 }
541
542 #endif
543
544 //
545 // This function supports testing of the malloc out of memory
546 // condition without really running the system out of memory.
547 //
548 static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
549 if (MallocMaxTestWords > 0) {
550 jint words = (jint)(alloc_size / BytesPerWord);
551
552 if ((cur_malloc_words + words) > MallocMaxTestWords) {
553 return true;
554 }
555 Atomic::add(words, (volatile jint *)&cur_malloc_words);
556 }
557 return false;
558 }
559
560 void* os::malloc(size_t size, MEMFLAGS flags) {
561 return os::malloc(size, flags, CALLER_PC);
562 }
563
564 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
565 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
566 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
567
568 #ifdef ASSERT
569 // checking for the WatcherThread and crash_protection first
570 // since os::malloc can be called when the libjvm.{dll,so} is
571 // first loaded and we don't have a thread yet.
572 // try to find the thread after we see that the watcher thread
573 // exists and has crash protection.
574 WatcherThread *wt = WatcherThread::watcher_thread();
575 if (wt != NULL && wt->has_crash_protection()) {
576 Thread* thread = ThreadLocalStorage::get_thread_slow();
577 if (thread == wt) {
578 assert(!wt->has_crash_protection(),
579 "Can't malloc with crash protection from WatcherThread");
580 }
581 }
582 #endif
583
584 if (size == 0) {
585 // return a valid pointer if size is zero
586 // if NULL is returned the calling functions assume out of memory.
587 size = 1;
588 }
589
590 // NMT support
591 NMT_TrackingLevel level = MemTracker::tracking_level();
592 size_t nmt_header_size = MemTracker::malloc_header_size(level);
593
594 #ifndef ASSERT
595 const size_t alloc_size = size + nmt_header_size;
596 #else
597 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
598 if (size + nmt_header_size > alloc_size) { // Check for rollover.
599 return NULL;
600 }
601 #endif
602
603 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
604
605 // For the test flag -XX:MallocMaxTestWords
606 if (has_reached_max_malloc_test_peak(size)) {
607 return NULL;
608 }
609
610 u_char* ptr;
611 ptr = (u_char*)::malloc(alloc_size);
612
613 #ifdef ASSERT
614 if (ptr == NULL) {
615 return NULL;
616 }
617 // Wrap memory with guard
618 GuardedMemory guarded(ptr, size + nmt_header_size);
619 ptr = guarded.get_user_ptr();
620 #endif
621 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
622 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
623 breakpoint();
624 }
625 debug_only(if (paranoid) verify_memory(ptr));
626 if (PrintMalloc && tty != NULL) {
627 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
628 }
629
630 // we do not track guard memory
631 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
632 }
633
634 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
635 return os::realloc(memblock, size, flags, CALLER_PC);
636 }
637
638 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
639
640 // For the test flag -XX:MallocMaxTestWords
641 if (has_reached_max_malloc_test_peak(size)) {
642 return NULL;
643 }
644
645 #ifndef ASSERT
646 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
647 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
648 // NMT support
649 void* membase = MemTracker::record_free(memblock);
650 NMT_TrackingLevel level = MemTracker::tracking_level();
651 size_t nmt_header_size = MemTracker::malloc_header_size(level);
652 void* ptr = ::realloc(membase, size + nmt_header_size);
653 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
654 #else
655 if (memblock == NULL) {
656 return os::malloc(size, memflags, stack);
657 }
658 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
659 tty->print_cr("os::realloc caught " PTR_FORMAT, p2i(memblock));
660 breakpoint();
661 }
662 // NMT support
663 void* membase = MemTracker::malloc_base(memblock);
664 verify_memory(membase);
665 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
666 if (size == 0) {
667 return NULL;
668 }
669 // always move the block
670 void* ptr = os::malloc(size, memflags, stack);
671 if (PrintMalloc && tty != NULL) {
672 tty->print_cr("os::realloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, p2i(memblock), p2i(ptr));
673 }
674 // Copy to new memory if malloc didn't fail
675 if ( ptr != NULL ) {
676 GuardedMemory guarded(MemTracker::malloc_base(memblock));
677 // Guard's user data contains NMT header
678 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
679 memcpy(ptr, memblock, MIN2(size, memblock_size));
680 if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
681 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
682 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
683 breakpoint();
684 }
685 os::free(memblock);
686 }
687 return ptr;
688 #endif
689 }
690
691
692 void os::free(void *memblock) {
693 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
694 #ifdef ASSERT
695 if (memblock == NULL) return;
696 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
697 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, p2i(memblock));
698 breakpoint();
699 }
700 void* membase = MemTracker::record_free(memblock);
701 verify_memory(membase);
702 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
703
704 GuardedMemory guarded(membase);
705 size_t size = guarded.get_user_size();
706 inc_stat_counter(&free_bytes, size);
707 membase = guarded.release_for_freeing();
708 if (PrintMalloc && tty != NULL) {
709 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
710 }
711 ::free(membase);
712 #else
713 void* membase = MemTracker::record_free(memblock);
714 ::free(membase);
715 #endif
716 }
717
718 void os::init_random(long initval) {
719 _rand_seed = initval;
720 }
721
722
723 long os::random() {
724 /* standard, well-known linear congruential random generator with
725 * next_rand = (16807*seed) mod (2**31-1)
726 * see
727 * (1) "Random Number Generators: Good Ones Are Hard to Find",
728 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
729 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
730 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
731 */
732 const long a = 16807;
733 const unsigned long m = 2147483647;
734 const long q = m / a; assert(q == 127773, "weird math");
735 const long r = m % a; assert(r == 2836, "weird math");
736
737 // compute az=2^31p+q
738 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
739 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
740 lo += (hi & 0x7FFF) << 16;
741
742 // if q overflowed, ignore the overflow and increment q
743 if (lo > m) {
744 lo &= m;
745 ++lo;
746 }
747 lo += hi >> 15;
748
749 // if (p+q) overflowed, ignore the overflow and increment (p+q)
750 if (lo > m) {
751 lo &= m;
752 ++lo;
753 }
754 return (_rand_seed = lo);
755 }
756
757 // The INITIALIZED state is distinguished from the SUSPENDED state because the
758 // conditions in which a thread is first started are different from those in which
759 // a suspension is resumed. These differences make it hard for us to apply the
760 // tougher checks when starting threads that we want to do when resuming them.
761 // However, when start_thread is called as a result of Thread.start, on a Java
762 // thread, the operation is synchronized on the Java Thread object. So there
763 // cannot be a race to start the thread and hence for the thread to exit while
764 // we are working on it. Non-Java threads that start Java threads either have
765 // to do so in a context in which races are impossible, or should do appropriate
766 // locking.
767
768 void os::start_thread(Thread* thread) {
769 // guard suspend/resume
770 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
771 OSThread* osthread = thread->osthread();
772 osthread->set_state(RUNNABLE);
773 pd_start_thread(thread);
774 }
775
776 void os::abort(bool dump_core) {
777 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
778 }
779
780 //---------------------------------------------------------------------------
781 // Helper functions for fatal error handler
782
783 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
784 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
785
786 int cols = 0;
787 int cols_per_line = 0;
788 switch (unitsize) {
789 case 1: cols_per_line = 16; break;
790 case 2: cols_per_line = 8; break;
791 case 4: cols_per_line = 4; break;
792 case 8: cols_per_line = 2; break;
793 default: return;
794 }
795
796 address p = start;
797 st->print(PTR_FORMAT ": ", p2i(start));
798 while (p < end) {
799 switch (unitsize) {
800 case 1: st->print("%02x", *(u1*)p); break;
801 case 2: st->print("%04x", *(u2*)p); break;
802 case 4: st->print("%08x", *(u4*)p); break;
803 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
804 }
805 p += unitsize;
806 cols++;
807 if (cols >= cols_per_line && p < end) {
808 cols = 0;
809 st->cr();
810 st->print(PTR_FORMAT ": ", p2i(p));
811 } else {
812 st->print(" ");
813 }
814 }
815 st->cr();
816 }
817
818 void os::print_environment_variables(outputStream* st, const char** env_list) {
819 if (env_list) {
820 st->print_cr("Environment Variables:");
821
822 for (int i = 0; env_list[i] != NULL; i++) {
823 char *envvar = ::getenv(env_list[i]);
824 if (envvar != NULL) {
825 st->print("%s", env_list[i]);
826 st->print("=");
827 st->print_cr("%s", envvar);
828 }
829 }
830 }
831 }
832
833 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
834 // cpu
835 st->print("CPU:");
836 st->print("total %d", os::processor_count());
837 // It's not safe to query number of active processors after crash
838 // st->print("(active %d)", os::active_processor_count());
839 st->print(" %s", VM_Version::cpu_features());
840 st->cr();
841 pd_print_cpu_info(st, buf, buflen);
842 }
843
844 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version
845 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
846 st->print("Host: ");
847 #ifndef PRODUCT
848 if (get_host_name(buf, buflen)) {
849 st->print("%s, ", buf);
850 }
851 #endif // PRODUCT
852 get_summary_cpu_info(buf, buflen);
853 st->print("%s, ", buf);
854 size_t mem = physical_memory()/G;
855 if (mem == 0) { // for low memory systems
856 mem = physical_memory()/M;
857 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
858 } else {
859 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
860 }
861 get_summary_os_info(buf, buflen);
862 st->print_raw(buf);
863 st->cr();
864 }
865
866 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
867 const int secs_per_day = 86400;
868 const int secs_per_hour = 3600;
869 const int secs_per_min = 60;
870
871 time_t tloc;
872 (void)time(&tloc);
873 char* timestring = ctime(&tloc); // ctime adds newline.
874 // edit out the newline
875 char* nl = strchr(timestring, '\n');
876 if (nl != NULL) {
877 *nl = '\0';
878 }
879
880 struct tm tz;
881 if (localtime_pd(&tloc, &tz) != NULL) {
882 ::strftime(buf, buflen, "%Z", &tz);
883 st->print("Time: %s %s", timestring, buf);
884 } else {
885 st->print("Time: %s", timestring);
886 }
887
888 double t = os::elapsedTime();
889 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
890 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
891 // before printf. We lost some precision, but who cares?
892 int eltime = (int)t; // elapsed time in seconds
893
894 // print elapsed time in a human-readable format:
895 int eldays = eltime / secs_per_day;
896 int day_secs = eldays * secs_per_day;
897 int elhours = (eltime - day_secs) / secs_per_hour;
898 int hour_secs = elhours * secs_per_hour;
899 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
900 int minute_secs = elmins * secs_per_min;
901 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
902 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
903 }
904
905 // moved from debug.cpp (used to be find()) but still called from there
906 // The verbose parameter is only set by the debug code in one case
907 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
908 address addr = (address)x;
909 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
910 if (b != NULL) {
911 if (b->is_buffer_blob()) {
912 // the interpreter is generated into a buffer blob
913 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
914 if (i != NULL) {
915 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", p2i(addr), (int)(addr - i->code_begin()));
916 i->print_on(st);
917 return;
918 }
919 if (Interpreter::contains(addr)) {
920 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
921 " (not bytecode specific)", p2i(addr));
922 return;
923 }
924 //
925 if (AdapterHandlerLibrary::contains(b)) {
926 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", p2i(addr), (int)(addr - b->code_begin()));
927 AdapterHandlerLibrary::print_handler_on(st, b);
928 }
929 // the stubroutines are generated into a buffer blob
930 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
931 if (d != NULL) {
932 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", p2i(addr), (int)(addr - d->begin()));
933 d->print_on(st);
934 st->cr();
935 return;
936 }
937 if (StubRoutines::contains(addr)) {
938 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) stub routine", p2i(addr));
939 return;
940 }
941 // the InlineCacheBuffer is using stubs generated into a buffer blob
942 if (InlineCacheBuffer::contains(addr)) {
943 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", p2i(addr));
944 return;
945 }
946 VtableStub* v = VtableStubs::stub_containing(addr);
947 if (v != NULL) {
948 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", p2i(addr), (int)(addr - v->entry_point()));
949 v->print_on(st);
950 st->cr();
951 return;
952 }
953 }
954 nmethod* nm = b->as_nmethod_or_null();
955 if (nm != NULL) {
956 ResourceMark rm;
957 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
958 p2i(addr), (int)(addr - nm->entry_point()), p2i(nm));
959 if (verbose) {
960 st->print(" for ");
961 nm->method()->print_value_on(st);
962 }
963 st->cr();
964 nm->print_nmethod(verbose);
965 return;
966 }
967 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", p2i(addr), (int)(addr - b->code_begin()));
968 b->print_on(st);
969 return;
970 }
971
972 if (Universe::heap()->is_in(addr)) {
973 HeapWord* p = Universe::heap()->block_start(addr);
974 bool print = false;
975 // If we couldn't find it it just may mean that heap wasn't parsable
976 // See if we were just given an oop directly
977 if (p != NULL && Universe::heap()->block_is_obj(p)) {
978 print = true;
979 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
980 p = (HeapWord*) addr;
981 print = true;
982 }
983 if (print) {
984 if (p == (HeapWord*) addr) {
985 st->print_cr(INTPTR_FORMAT " is an oop", p2i(addr));
986 } else {
987 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, p2i(addr), p2i(p));
988 }
989 oop(p)->print_on(st);
990 return;
991 }
992 } else {
993 if (Universe::heap()->is_in_reserved(addr)) {
994 st->print_cr(INTPTR_FORMAT " is an unallocated location "
995 "in the heap", p2i(addr));
996 return;
997 }
998 }
999 if (JNIHandles::is_global_handle((jobject) addr)) {
1000 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
1001 return;
1002 }
1003 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1004 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
1005 return;
1006 }
1007 #ifndef PRODUCT
1008 // we don't keep the block list in product mode
1009 if (JNIHandleBlock::any_contains((jobject) addr)) {
1010 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
1011 return;
1012 }
1013 #endif
1014
1015 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
1016 // Check for privilege stack
1017 if (thread->privileged_stack_top() != NULL &&
1018 thread->privileged_stack_top()->contains(addr)) {
1019 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
1020 "for thread: " INTPTR_FORMAT, p2i(addr), p2i(thread));
1021 if (verbose) thread->print_on(st);
1022 return;
1023 }
1024 // If the addr is a java thread print information about that.
1025 if (addr == (address)thread) {
1026 if (verbose) {
1027 thread->print_on(st);
1028 } else {
1029 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
1030 }
1031 return;
1032 }
1033 // If the addr is in the stack region for this thread then report that
1034 // and print thread info
1035 if (thread->stack_base() >= addr &&
1036 addr > (thread->stack_base() - thread->stack_size())) {
1037 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1038 INTPTR_FORMAT, p2i(addr), p2i(thread));
1039 if (verbose) thread->print_on(st);
1040 return;
1041 }
1042
1043 }
1044
1045 // Check if in metaspace and print types that have vptrs (only method now)
1046 if (Metaspace::contains(addr)) {
1047 if (Method::has_method_vptr((const void*)addr)) {
1048 ((Method*)addr)->print_value_on(st);
1049 st->cr();
1050 } else {
1051 // Use addr->print() from the debugger instead (not here)
1052 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
1053 }
1054 return;
1055 }
1056
1057 // Try an OS specific find
1058 if (os::find(addr, st)) {
1059 return;
1060 }
1061
1062 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
1063 }
1064
1065 // Looks like all platforms except IA64 can use the same function to check
1066 // if C stack is walkable beyond current frame. The check for fp() is not
1067 // necessary on Sparc, but it's harmless.
1068 bool os::is_first_C_frame(frame* fr) {
1069 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1070 // On IA64 we have to check if the callers bsp is still valid
1071 // (i.e. within the register stack bounds).
1072 // Notice: this only works for threads created by the VM and only if
1073 // we walk the current stack!!! If we want to be able to walk
1074 // arbitrary other threads, we'll have to somehow store the thread
1075 // object in the frame.
1076 Thread *thread = Thread::current();
1077 if ((address)fr->fp() <=
1078 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1079 // This check is a little hacky, because on Linux the first C
1080 // frame's ('start_thread') register stack frame starts at
1081 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1082 // ('__pthread_bound_body') register stack frame seems to really
1083 // start at "register_stack_base".
1084 return true;
1085 } else {
1086 return false;
1087 }
1088 #elif defined(IA64) && defined(_WIN32)
1089 return true;
1090 #else
1091 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1092 // Check usp first, because if that's bad the other accessors may fault
1093 // on some architectures. Ditto ufp second, etc.
1094 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1095 // sp on amd can be 32 bit aligned.
1096 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1097
1098 uintptr_t usp = (uintptr_t)fr->sp();
1099 if ((usp & sp_align_mask) != 0) return true;
1100
1101 uintptr_t ufp = (uintptr_t)fr->fp();
1102 if ((ufp & fp_align_mask) != 0) return true;
1103
1104 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1105 if ((old_sp & sp_align_mask) != 0) return true;
1106 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1107
1108 uintptr_t old_fp = (uintptr_t)fr->link();
1109 if ((old_fp & fp_align_mask) != 0) return true;
1110 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1111
1112 // stack grows downwards; if old_fp is below current fp or if the stack
1113 // frame is too large, either the stack is corrupted or fp is not saved
1114 // on stack (i.e. on x86, ebp may be used as general register). The stack
1115 // is not walkable beyond current frame.
1116 if (old_fp < ufp) return true;
1117 if (old_fp - ufp > 64 * K) return true;
1118
1119 return false;
1120 #endif
1121 }
1122
1123 #ifdef ASSERT
1124 extern "C" void test_random() {
1125 const double m = 2147483647;
1126 double mean = 0.0, variance = 0.0, t;
1127 long reps = 10000;
1128 unsigned long seed = 1;
1129
1130 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1131 os::init_random(seed);
1132 long num;
1133 for (int k = 0; k < reps; k++) {
1134 num = os::random();
1135 double u = (double)num / m;
1136 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1137
1138 // calculate mean and variance of the random sequence
1139 mean += u;
1140 variance += (u*u);
1141 }
1142 mean /= reps;
1143 variance /= (reps - 1);
1144
1145 assert(num == 1043618065, "bad seed");
1146 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1147 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1148 const double eps = 0.0001;
1149 t = fabsd(mean - 0.5018);
1150 assert(t < eps, "bad mean");
1151 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1152 assert(t < eps, "bad variance");
1153 }
1154 #endif
1155
1156
1157 // Set up the boot classpath.
1158
1159 char* os::format_boot_path(const char* format_string,
1160 const char* home,
1161 int home_len,
1162 char fileSep,
1163 char pathSep) {
1164 assert((fileSep == '/' && pathSep == ':') ||
1165 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1166
1167 // Scan the format string to determine the length of the actual
1168 // boot classpath, and handle platform dependencies as well.
1169 int formatted_path_len = 0;
1170 const char* p;
1171 for (p = format_string; *p != 0; ++p) {
1172 if (*p == '%') formatted_path_len += home_len - 1;
1173 ++formatted_path_len;
1174 }
1175
1176 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1177 if (formatted_path == NULL) {
1178 return NULL;
1179 }
1180
1181 // Create boot classpath from format, substituting separator chars and
1182 // java home directory.
1183 char* q = formatted_path;
1184 for (p = format_string; *p != 0; ++p) {
1185 switch (*p) {
1186 case '%':
1187 strcpy(q, home);
1188 q += home_len;
1189 break;
1190 case '/':
1191 *q++ = fileSep;
1192 break;
1193 case ':':
1194 *q++ = pathSep;
1195 break;
1196 default:
1197 *q++ = *p;
1198 }
1199 }
1200 *q = '\0';
1201
1202 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1203 return formatted_path;
1204 }
1205
1206 // returns a PATH of all entries in the given directory that do not start with a '.'
1207 static char* expand_entries_to_path(char* directory, char fileSep, char pathSep) {
1208 DIR* dir = os::opendir(directory);
1209 if (dir == NULL) return NULL;
1210
1211 char* path = NULL;
1212 size_t path_len = 0; // path length including \0 terminator
1213
1214 size_t directory_len = strlen(directory);
1215 struct dirent *entry;
1216 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(directory), mtInternal);
1217 while ((entry = os::readdir(dir, (dirent *) dbuf)) != NULL) {
1218 const char* name = entry->d_name;
1219 if (name[0] == '.') continue;
1220
1221 size_t name_len = strlen(name);
1222 size_t needed = directory_len + name_len + 2;
1223 size_t new_len = path_len + needed;
1224 if (path == NULL) {
1225 path = NEW_C_HEAP_ARRAY(char, new_len, mtInternal);
1226 } else {
1227 path = REALLOC_C_HEAP_ARRAY(char, path, new_len, mtInternal);
1228 }
1229 if (path == NULL)
1230 break;
1231
1232 // append <pathSep>directory<fileSep>name
1233 char* p = path;
1234 if (path_len > 0) {
1235 p += (path_len -1);
1236 *p = pathSep;
1237 p++;
1238 }
1239
1240 strcpy(p, directory);
1241 p += directory_len;
1242
1243 *p = fileSep;
1244 p++;
1245
1246 strcpy(p, name);
1247 p += name_len;
1248
1249 path_len = new_len;
1250 }
1251
1252 FREE_C_HEAP_ARRAY(char, dbuf);
1253 os::closedir(dir);
1254
1255 return path;
1256 }
1257
1258 bool os::set_boot_path(char fileSep, char pathSep) {
1259 const char* home = Arguments::get_java_home();
1260 int home_len = (int)strlen(home);
1261
1262 char* sysclasspath = NULL;
1263 struct stat st;
1264
1265 // modular image if bootmodules.jimage exists
1266 char* jimage = format_boot_path("%/lib/modules/" BOOT_IMAGE_NAME, home, home_len, fileSep, pathSep);
1267 if (jimage == NULL) return false;
1268 bool has_jimage = (os::stat(jimage, &st) == 0);
1269 if (has_jimage) {
1270 Arguments::set_sysclasspath(jimage);
1271 FREE_C_HEAP_ARRAY(char, jimage);
1272 return true;
1273 }
1274 FREE_C_HEAP_ARRAY(char, jimage);
1275
1276 // check if developer build with exploded modules
1277 char* modules_dir = format_boot_path("%/modules", home, home_len, fileSep, pathSep);
1278 if (os::stat(modules_dir, &st) == 0) {
1279 if ((st.st_mode & S_IFDIR) == S_IFDIR) {
1280 sysclasspath = expand_entries_to_path(modules_dir, fileSep, pathSep);
1281 }
1282 }
1283 FREE_C_HEAP_ARRAY(char, modules_dir);
1284
1285 // fallback to classes
1286 if (sysclasspath == NULL)
1287 sysclasspath = format_boot_path("%/classes", home, home_len, fileSep, pathSep);
1288
1289 if (sysclasspath == NULL) return false;
1290 Arguments::set_sysclasspath(sysclasspath);
1291 FREE_C_HEAP_ARRAY(char, sysclasspath);
1292
1293 return true;
1294 }
1295
1296 /*
1297 * Splits a path, based on its separator, the number of
1298 * elements is returned back in n.
1299 * It is the callers responsibility to:
1300 * a> check the value of n, and n may be 0.
1301 * b> ignore any empty path elements
1302 * c> free up the data.
1303 */
1304 char** os::split_path(const char* path, int* n) {
1305 *n = 0;
1306 if (path == NULL || strlen(path) == 0) {
1307 return NULL;
1308 }
1309 const char psepchar = *os::path_separator();
1310 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1311 if (inpath == NULL) {
1312 return NULL;
1313 }
1314 strcpy(inpath, path);
1315 int count = 1;
1316 char* p = strchr(inpath, psepchar);
1317 // Get a count of elements to allocate memory
1318 while (p != NULL) {
1319 count++;
1320 p++;
1321 p = strchr(p, psepchar);
1322 }
1323 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1324 if (opath == NULL) {
1325 return NULL;
1326 }
1327
1328 // do the actual splitting
1329 p = inpath;
1330 for (int i = 0 ; i < count ; i++) {
1331 size_t len = strcspn(p, os::path_separator());
1332 if (len > JVM_MAXPATHLEN) {
1333 return NULL;
1334 }
1335 // allocate the string and add terminator storage
1336 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1337 if (s == NULL) {
1338 return NULL;
1339 }
1340 strncpy(s, p, len);
1341 s[len] = '\0';
1342 opath[i] = s;
1343 p += len + 1;
1344 }
1345 FREE_C_HEAP_ARRAY(char, inpath);
1346 *n = count;
1347 return opath;
1348 }
1349
1350 void os::set_memory_serialize_page(address page) {
1351 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1352 _mem_serialize_page = (volatile int32_t *)page;
1353 // We initialize the serialization page shift count here
1354 // We assume a cache line size of 64 bytes
1355 assert(SerializePageShiftCount == count,
1356 "thread size changed, fix SerializePageShiftCount constant");
1357 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1358 }
1359
1360 static volatile intptr_t SerializePageLock = 0;
1361
1362 // This method is called from signal handler when SIGSEGV occurs while the current
1363 // thread tries to store to the "read-only" memory serialize page during state
1364 // transition.
1365 void os::block_on_serialize_page_trap() {
1366 if (TraceSafepoint) {
1367 tty->print_cr("Block until the serialize page permission restored");
1368 }
1369 // When VMThread is holding the SerializePageLock during modifying the
1370 // access permission of the memory serialize page, the following call
1371 // will block until the permission of that page is restored to rw.
1372 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1373 // this case, it's OK as the signal is synchronous and we know precisely when
1374 // it can occur.
1375 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1376 Thread::muxRelease(&SerializePageLock);
1377 }
1378
1379 // Serialize all thread state variables
1380 void os::serialize_thread_states() {
1381 // On some platforms such as Solaris & Linux, the time duration of the page
1382 // permission restoration is observed to be much longer than expected due to
1383 // scheduler starvation problem etc. To avoid the long synchronization
1384 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1385 // the mutator thread if such case is encountered. See bug 6546278 for details.
1386 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1387 os::protect_memory((char *)os::get_memory_serialize_page(),
1388 os::vm_page_size(), MEM_PROT_READ);
1389 os::protect_memory((char *)os::get_memory_serialize_page(),
1390 os::vm_page_size(), MEM_PROT_RW);
1391 Thread::muxRelease(&SerializePageLock);
1392 }
1393
1394 // Returns true if the current stack pointer is above the stack shadow
1395 // pages, false otherwise.
1396
1397 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method) {
1398 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1399 address sp = current_stack_pointer();
1400 // Check if we have StackShadowPages above the yellow zone. This parameter
1401 // is dependent on the depth of the maximum VM call stack possible from
1402 // the handler for stack overflow. 'instanceof' in the stack overflow
1403 // handler or a println uses at least 8k stack of VM and native code
1404 // respectively.
1405 const int framesize_in_bytes =
1406 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1407 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1408 * vm_page_size()) + framesize_in_bytes;
1409 // The very lower end of the stack
1410 address stack_limit = thread->stack_base() - thread->stack_size();
1411 return (sp > (stack_limit + reserved_area));
1412 }
1413
1414 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1415 assert(min_pages > 0, "sanity");
1416 if (UseLargePages) {
1417 const size_t max_page_size = region_size / min_pages;
1418
1419 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1420 const size_t page_size = _page_sizes[i];
1421 if (page_size <= max_page_size) {
1422 if (!must_be_aligned || is_size_aligned(region_size, page_size)) {
1423 return page_size;
1424 }
1425 }
1426 }
1427 }
1428
1429 return vm_page_size();
1430 }
1431
1432 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1433 return page_size_for_region(region_size, min_pages, true);
1434 }
1435
1436 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1437 return page_size_for_region(region_size, min_pages, false);
1438 }
1439
1440 #ifndef PRODUCT
1441 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1442 {
1443 if (TracePageSizes) {
1444 tty->print("%s: ", str);
1445 for (int i = 0; i < count; ++i) {
1446 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1447 }
1448 tty->cr();
1449 }
1450 }
1451
1452 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1453 const size_t region_max_size, const size_t page_size,
1454 const char* base, const size_t size)
1455 {
1456 if (TracePageSizes) {
1457 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1458 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1459 " size=" SIZE_FORMAT,
1460 str, region_min_size, region_max_size,
1461 page_size, p2i(base), size);
1462 }
1463 }
1464 #endif // #ifndef PRODUCT
1465
1466 // This is the working definition of a server class machine:
1467 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1468 // because the graphics memory (?) sometimes masks physical memory.
1469 // If you want to change the definition of a server class machine
1470 // on some OS or platform, e.g., >=4GB on Windows platforms,
1471 // then you'll have to parameterize this method based on that state,
1472 // as was done for logical processors here, or replicate and
1473 // specialize this method for each platform. (Or fix os to have
1474 // some inheritance structure and use subclassing. Sigh.)
1475 // If you want some platform to always or never behave as a server
1476 // class machine, change the setting of AlwaysActAsServerClassMachine
1477 // and NeverActAsServerClassMachine in globals*.hpp.
1478 bool os::is_server_class_machine() {
1479 // First check for the early returns
1480 if (NeverActAsServerClassMachine) {
1481 return false;
1482 }
1483 if (AlwaysActAsServerClassMachine) {
1484 return true;
1485 }
1486 // Then actually look at the machine
1487 bool result = false;
1488 const unsigned int server_processors = 2;
1489 const julong server_memory = 2UL * G;
1490 // We seem not to get our full complement of memory.
1491 // We allow some part (1/8?) of the memory to be "missing",
1492 // based on the sizes of DIMMs, and maybe graphics cards.
1493 const julong missing_memory = 256UL * M;
1494
1495 /* Is this a server class machine? */
1496 if ((os::active_processor_count() >= (int)server_processors) &&
1497 (os::physical_memory() >= (server_memory - missing_memory))) {
1498 const unsigned int logical_processors =
1499 VM_Version::logical_processors_per_package();
1500 if (logical_processors > 1) {
1501 const unsigned int physical_packages =
1502 os::active_processor_count() / logical_processors;
1503 if (physical_packages > server_processors) {
1504 result = true;
1505 }
1506 } else {
1507 result = true;
1508 }
1509 }
1510 return result;
1511 }
1512
1513 void os::SuspendedThreadTask::run() {
1514 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1515 internal_do_task();
1516 _done = true;
1517 }
1518
1519 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1520 return os::pd_create_stack_guard_pages(addr, bytes);
1521 }
1522
1523 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1524 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1525 if (result != NULL) {
1526 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1527 }
1528
1529 return result;
1530 }
1531
1532 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1533 MEMFLAGS flags) {
1534 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1535 if (result != NULL) {
1536 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1537 MemTracker::record_virtual_memory_type((address)result, flags);
1538 }
1539
1540 return result;
1541 }
1542
1543 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1544 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1545 if (result != NULL) {
1546 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1547 }
1548 return result;
1549 }
1550
1551 void os::split_reserved_memory(char *base, size_t size,
1552 size_t split, bool realloc) {
1553 pd_split_reserved_memory(base, size, split, realloc);
1554 }
1555
1556 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1557 bool res = pd_commit_memory(addr, bytes, executable);
1558 if (res) {
1559 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1560 }
1561 return res;
1562 }
1563
1564 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1565 bool executable) {
1566 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1567 if (res) {
1568 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1569 }
1570 return res;
1571 }
1572
1573 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1574 const char* mesg) {
1575 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1576 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1577 }
1578
1579 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1580 bool executable, const char* mesg) {
1581 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1582 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1583 }
1584
1585 bool os::uncommit_memory(char* addr, size_t bytes) {
1586 bool res;
1587 if (MemTracker::tracking_level() > NMT_minimal) {
1588 Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1589 res = pd_uncommit_memory(addr, bytes);
1590 if (res) {
1591 tkr.record((address)addr, bytes);
1592 }
1593 } else {
1594 res = pd_uncommit_memory(addr, bytes);
1595 }
1596 return res;
1597 }
1598
1599 bool os::release_memory(char* addr, size_t bytes) {
1600 bool res;
1601 if (MemTracker::tracking_level() > NMT_minimal) {
1602 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1603 res = pd_release_memory(addr, bytes);
1604 if (res) {
1605 tkr.record((address)addr, bytes);
1606 }
1607 } else {
1608 res = pd_release_memory(addr, bytes);
1609 }
1610 return res;
1611 }
1612
1613 void os::pretouch_memory(char* start, char* end) {
1614 for (volatile char *p = start; p < end; p += os::vm_page_size()) {
1615 *p = 0;
1616 }
1617 }
1618
1619 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1620 char *addr, size_t bytes, bool read_only,
1621 bool allow_exec) {
1622 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1623 if (result != NULL) {
1624 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1625 }
1626 return result;
1627 }
1628
1629 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1630 char *addr, size_t bytes, bool read_only,
1631 bool allow_exec) {
1632 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1633 read_only, allow_exec);
1634 }
1635
1636 bool os::unmap_memory(char *addr, size_t bytes) {
1637 bool result;
1638 if (MemTracker::tracking_level() > NMT_minimal) {
1639 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1640 result = pd_unmap_memory(addr, bytes);
1641 if (result) {
1642 tkr.record((address)addr, bytes);
1643 }
1644 } else {
1645 result = pd_unmap_memory(addr, bytes);
1646 }
1647 return result;
1648 }
1649
1650 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1651 pd_free_memory(addr, bytes, alignment_hint);
1652 }
1653
1654 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1655 pd_realign_memory(addr, bytes, alignment_hint);
1656 }
1657
1658 #ifndef TARGET_OS_FAMILY_windows
1659 /* try to switch state from state "from" to state "to"
1660 * returns the state set after the method is complete
1661 */
1662 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1663 os::SuspendResume::State to)
1664 {
1665 os::SuspendResume::State result =
1666 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1667 if (result == from) {
1668 // success
1669 return to;
1670 }
1671 return result;
1672 }
1673 #endif
1674
1675 /////////////// Unit tests ///////////////
1676
1677 #ifndef PRODUCT
1678
1679 #define assert_eq(a,b) assert(a == b, SIZE_FORMAT " != " SIZE_FORMAT, a, b)
1680
1681 class TestOS : AllStatic {
1682 static size_t small_page_size() {
1683 return os::vm_page_size();
1684 }
1685
1686 static size_t large_page_size() {
1687 const size_t large_page_size_example = 4 * M;
1688 return os::page_size_for_region_aligned(large_page_size_example, 1);
1689 }
1690
1691 static void test_page_size_for_region_aligned() {
1692 if (UseLargePages) {
1693 const size_t small_page = small_page_size();
1694 const size_t large_page = large_page_size();
1695
1696 if (large_page > small_page) {
1697 size_t num_small_pages_in_large = large_page / small_page;
1698 size_t page = os::page_size_for_region_aligned(large_page, num_small_pages_in_large);
1699
1700 assert_eq(page, small_page);
1701 }
1702 }
1703 }
1704
1705 static void test_page_size_for_region_alignment() {
1706 if (UseLargePages) {
1707 const size_t small_page = small_page_size();
1708 const size_t large_page = large_page_size();
1709 if (large_page > small_page) {
1710 const size_t unaligned_region = large_page + 17;
1711 size_t page = os::page_size_for_region_aligned(unaligned_region, 1);
1712 assert_eq(page, small_page);
1713
1714 const size_t num_pages = 5;
1715 const size_t aligned_region = large_page * num_pages;
1716 page = os::page_size_for_region_aligned(aligned_region, num_pages);
1717 assert_eq(page, large_page);
1718 }
1719 }
1720 }
1721
1722 static void test_page_size_for_region_unaligned() {
1723 if (UseLargePages) {
1724 // Given exact page size, should return that page size.
1725 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1726 size_t expected = os::_page_sizes[i];
1727 size_t actual = os::page_size_for_region_unaligned(expected, 1);
1728 assert_eq(expected, actual);
1729 }
1730
1731 // Given slightly larger size than a page size, return the page size.
1732 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1733 size_t expected = os::_page_sizes[i];
1734 size_t actual = os::page_size_for_region_unaligned(expected + 17, 1);
1735 assert_eq(expected, actual);
1736 }
1737
1738 // Given a slightly smaller size than a page size,
1739 // return the next smaller page size.
1740 if (os::_page_sizes[1] > os::_page_sizes[0]) {
1741 size_t expected = os::_page_sizes[0];
1742 size_t actual = os::page_size_for_region_unaligned(os::_page_sizes[1] - 17, 1);
1743 assert_eq(actual, expected);
1744 }
1745
1746 // Return small page size for values less than a small page.
1747 size_t small_page = small_page_size();
1748 size_t actual = os::page_size_for_region_unaligned(small_page - 17, 1);
1749 assert_eq(small_page, actual);
1750 }
1751 }
1752
1753 public:
1754 static void run_tests() {
1755 test_page_size_for_region_aligned();
1756 test_page_size_for_region_alignment();
1757 test_page_size_for_region_unaligned();
1758 }
1759 };
1760
1761 void TestOS_test() {
1762 TestOS::run_tests();
1763 }
1764
1765 #endif // PRODUCT