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 "logging/log.hpp"
36 #include "memory/allocation.inline.hpp"
37 #ifdef ASSERT
38 #include "memory/guardedMemory.hpp"
39 #endif
40 #include "oops/oop.inline.hpp"
41 #include "prims/jvm.h"
42 #include "prims/jvm_misc.hpp"
43 #include "prims/privilegedStack.hpp"
44 #include "runtime/arguments.hpp"
45 #include "runtime/atomic.inline.hpp"
46 #include "runtime/frame.inline.hpp"
47 #include "runtime/interfaceSupport.hpp"
48 #include "runtime/java.hpp"
49 #include "runtime/javaCalls.hpp"
50 #include "runtime/mutexLocker.hpp"
51 #include "runtime/os.inline.hpp"
52 #include "runtime/stubRoutines.hpp"
53 #include "runtime/thread.inline.hpp"
54 #include "runtime/vm_version.hpp"
55 #include "services/attachListener.hpp"
56 #include "services/mallocTracker.hpp"
57 #include "services/memTracker.hpp"
58 #include "services/nmtCommon.hpp"
59 #include "services/threadService.hpp"
60 #include "utilities/defaultStream.hpp"
61 #include "utilities/events.hpp"
62
63 # include <signal.h>
64
65 OSThread* os::_starting_thread = NULL;
66 address os::_polling_page = NULL;
67 volatile int32_t* os::_mem_serialize_page = NULL;
68 uintptr_t os::_serialize_page_mask = 0;
69 long os::_rand_seed = 1;
70 int os::_processor_count = 0;
71 size_t os::_page_sizes[os::page_sizes_max];
72
73 #ifndef PRODUCT
74 julong os::num_mallocs = 0; // # of calls to malloc/realloc
75 julong os::alloc_bytes = 0; // # of bytes allocated
76 julong os::num_frees = 0; // # of calls to free
77 julong os::free_bytes = 0; // # of bytes freed
78 #endif
79
80 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
81
82 void os_init_globals() {
83 // Called from init_globals().
84 // See Threads::create_vm() in thread.cpp, and init.cpp.
85 os::init_globals();
86 }
87
88 // Fill in buffer with current local time as an ISO-8601 string.
89 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
90 // Returns buffer, or NULL if it failed.
91 // This would mostly be a call to
92 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
93 // except that on Windows the %z behaves badly, so we do it ourselves.
94 // Also, people wanted milliseconds on there,
95 // and strftime doesn't do milliseconds.
96 char* os::iso8601_time(char* buffer, size_t buffer_length) {
97 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
98 // 1 2
99 // 12345678901234567890123456789
100 // format string: "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"
101 static const size_t needed_buffer = 29;
102
103 // Sanity check the arguments
104 if (buffer == NULL) {
105 assert(false, "NULL buffer");
106 return NULL;
107 }
108 if (buffer_length < needed_buffer) {
109 assert(false, "buffer_length too small");
110 return NULL;
111 }
112 // Get the current time
113 jlong milliseconds_since_19700101 = javaTimeMillis();
114 const int milliseconds_per_microsecond = 1000;
115 const time_t seconds_since_19700101 =
116 milliseconds_since_19700101 / milliseconds_per_microsecond;
117 const int milliseconds_after_second =
118 milliseconds_since_19700101 % milliseconds_per_microsecond;
119 // Convert the time value to a tm and timezone variable
120 struct tm time_struct;
121 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
122 assert(false, "Failed localtime_pd");
123 return NULL;
124 }
125 #if defined(_ALLBSD_SOURCE)
126 const time_t zone = (time_t) time_struct.tm_gmtoff;
127 #else
128 const time_t zone = timezone;
129 #endif
130
131 // If daylight savings time is in effect,
132 // we are 1 hour East of our time zone
133 const time_t seconds_per_minute = 60;
134 const time_t minutes_per_hour = 60;
135 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
136 time_t UTC_to_local = zone;
137 if (time_struct.tm_isdst > 0) {
138 UTC_to_local = UTC_to_local - seconds_per_hour;
139 }
140 // Compute the time zone offset.
141 // localtime_pd() sets timezone to the difference (in seconds)
142 // between UTC and and local time.
143 // ISO 8601 says we need the difference between local time and UTC,
144 // we change the sign of the localtime_pd() result.
145 const time_t local_to_UTC = -(UTC_to_local);
146 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
147 char sign_local_to_UTC = '+';
148 time_t abs_local_to_UTC = local_to_UTC;
149 if (local_to_UTC < 0) {
150 sign_local_to_UTC = '-';
151 abs_local_to_UTC = -(abs_local_to_UTC);
152 }
153 // Convert time zone offset seconds to hours and minutes.
154 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
155 const time_t zone_min =
156 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
157
158 // Print an ISO 8601 date and time stamp into the buffer
159 const int year = 1900 + time_struct.tm_year;
160 const int month = 1 + time_struct.tm_mon;
161 const int printed = jio_snprintf(buffer, buffer_length,
162 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d",
163 year,
164 month,
165 time_struct.tm_mday,
166 time_struct.tm_hour,
167 time_struct.tm_min,
168 time_struct.tm_sec,
169 milliseconds_after_second,
170 sign_local_to_UTC,
171 zone_hours,
172 zone_min);
173 if (printed == 0) {
174 assert(false, "Failed jio_printf");
175 return NULL;
176 }
177 return buffer;
178 }
179
180 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
181 #ifdef ASSERT
182 if (!(!thread->is_Java_thread() ||
183 Thread::current() == thread ||
184 Threads_lock->owned_by_self()
185 || thread->is_Compiler_thread()
186 )) {
187 assert(false, "possibility of dangling Thread pointer");
188 }
189 #endif
190
191 if (p >= MinPriority && p <= MaxPriority) {
192 int priority = java_to_os_priority[p];
193 return set_native_priority(thread, priority);
194 } else {
195 assert(false, "Should not happen");
196 return OS_ERR;
197 }
198 }
199
200 // The mapping from OS priority back to Java priority may be inexact because
201 // Java priorities can map M:1 with native priorities. If you want the definite
202 // Java priority then use JavaThread::java_priority()
203 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
204 int p;
205 int os_prio;
206 OSReturn ret = get_native_priority(thread, &os_prio);
207 if (ret != OS_OK) return ret;
208
209 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
210 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
211 } else {
212 // niceness values are in reverse order
213 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
214 }
215 priority = (ThreadPriority)p;
216 return OS_OK;
217 }
218
219
220 // --------------------- sun.misc.Signal (optional) ---------------------
221
222
223 // SIGBREAK is sent by the keyboard to query the VM state
224 #ifndef SIGBREAK
225 #define SIGBREAK SIGQUIT
226 #endif
227
228 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
229
230
231 static void signal_thread_entry(JavaThread* thread, TRAPS) {
232 os::set_priority(thread, NearMaxPriority);
233 while (true) {
234 int sig;
235 {
236 // FIXME : Currently we have not decided what should be the status
237 // for this java thread blocked here. Once we decide about
238 // that we should fix this.
239 sig = os::signal_wait();
240 }
241 if (sig == os::sigexitnum_pd()) {
242 // Terminate the signal thread
243 return;
244 }
245
246 switch (sig) {
247 case SIGBREAK: {
248 // Check if the signal is a trigger to start the Attach Listener - in that
249 // case don't print stack traces.
250 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
251 continue;
252 }
253 // Print stack traces
254 // Any SIGBREAK operations added here should make sure to flush
255 // the output stream (e.g. tty->flush()) after output. See 4803766.
256 // Each module also prints an extra carriage return after its output.
257 VM_PrintThreads op;
258 VMThread::execute(&op);
259 VM_PrintJNI jni_op;
260 VMThread::execute(&jni_op);
261 VM_FindDeadlocks op1(tty);
262 VMThread::execute(&op1);
263 Universe::print_heap_at_SIGBREAK();
264 if (PrintClassHistogram) {
265 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
266 VMThread::execute(&op1);
267 }
268 if (JvmtiExport::should_post_data_dump()) {
269 JvmtiExport::post_data_dump();
270 }
271 break;
272 }
273 default: {
274 // Dispatch the signal to java
275 HandleMark hm(THREAD);
276 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
277 KlassHandle klass (THREAD, k);
278 if (klass.not_null()) {
279 JavaValue result(T_VOID);
280 JavaCallArguments args;
281 args.push_int(sig);
282 JavaCalls::call_static(
283 &result,
284 klass,
285 vmSymbols::dispatch_name(),
286 vmSymbols::int_void_signature(),
287 &args,
288 THREAD
289 );
290 }
291 if (HAS_PENDING_EXCEPTION) {
292 // tty is initialized early so we don't expect it to be null, but
293 // if it is we can't risk doing an initialization that might
294 // trigger additional out-of-memory conditions
295 if (tty != NULL) {
296 char klass_name[256];
297 char tmp_sig_name[16];
298 const char* sig_name = "UNKNOWN";
299 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
300 name()->as_klass_external_name(klass_name, 256);
301 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
302 sig_name = tmp_sig_name;
303 warning("Exception %s occurred dispatching signal %s to handler"
304 "- the VM may need to be forcibly terminated",
305 klass_name, sig_name );
306 }
307 CLEAR_PENDING_EXCEPTION;
308 }
309 }
310 }
311 }
312 }
313
314 void os::init_before_ergo() {
315 // We need to initialize large page support here because ergonomics takes some
316 // decisions depending on large page support and the calculated large page size.
317 large_page_init();
318 }
319
320 void os::signal_init() {
321 if (!ReduceSignalUsage) {
322 // Setup JavaThread for processing signals
323 EXCEPTION_MARK;
324 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
325 instanceKlassHandle klass (THREAD, k);
326 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
327
328 const char thread_name[] = "Signal Dispatcher";
329 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
330
331 // Initialize thread_oop to put it into the system threadGroup
332 Handle thread_group (THREAD, Universe::system_thread_group());
333 JavaValue result(T_VOID);
334 JavaCalls::call_special(&result, thread_oop,
335 klass,
336 vmSymbols::object_initializer_name(),
337 vmSymbols::threadgroup_string_void_signature(),
338 thread_group,
339 string,
340 CHECK);
341
342 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
343 JavaCalls::call_special(&result,
344 thread_group,
345 group,
346 vmSymbols::add_method_name(),
347 vmSymbols::thread_void_signature(),
348 thread_oop, // ARG 1
349 CHECK);
350
351 os::signal_init_pd();
352
353 { MutexLocker mu(Threads_lock);
354 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
355
356 // At this point it may be possible that no osthread was created for the
357 // JavaThread due to lack of memory. We would have to throw an exception
358 // in that case. However, since this must work and we do not allow
359 // exceptions anyway, check and abort if this fails.
360 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
361 vm_exit_during_initialization("java.lang.OutOfMemoryError",
362 os::native_thread_creation_failed_msg());
363 }
364
365 java_lang_Thread::set_thread(thread_oop(), signal_thread);
366 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
367 java_lang_Thread::set_daemon(thread_oop());
368
369 signal_thread->set_threadObj(thread_oop());
370 Threads::add(signal_thread);
371 Thread::start(signal_thread);
372 }
373 // Handle ^BREAK
374 os::signal(SIGBREAK, os::user_handler());
375 }
376 }
377
378
379 void os::terminate_signal_thread() {
380 if (!ReduceSignalUsage)
381 signal_notify(sigexitnum_pd());
382 }
383
384
385 // --------------------- loading libraries ---------------------
386
387 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
388 extern struct JavaVM_ main_vm;
389
390 static void* _native_java_library = NULL;
391
392 void* os::native_java_library() {
393 if (_native_java_library == NULL) {
394 char buffer[JVM_MAXPATHLEN];
395 char ebuf[1024];
396
397 // Try to load verify dll first. In 1.3 java dll depends on it and is not
398 // always able to find it when the loading executable is outside the JDK.
399 // In order to keep working with 1.2 we ignore any loading errors.
400 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
401 "verify")) {
402 dll_load(buffer, ebuf, sizeof(ebuf));
403 }
404
405 // Load java dll
406 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
407 "java")) {
408 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
409 }
410 if (_native_java_library == NULL) {
411 vm_exit_during_initialization("Unable to load native library", ebuf);
412 }
413
414 #if defined(__OpenBSD__)
415 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
416 // ignore errors
417 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
418 "net")) {
419 dll_load(buffer, ebuf, sizeof(ebuf));
420 }
421 #endif
422 }
423 static jboolean onLoaded = JNI_FALSE;
424 if (onLoaded) {
425 // We may have to wait to fire OnLoad until TLS is initialized.
426 if (ThreadLocalStorage::is_initialized()) {
427 // The JNI_OnLoad handling is normally done by method load in
428 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
429 // explicitly so we have to check for JNI_OnLoad as well
430 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
431 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
432 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
433 if (JNI_OnLoad != NULL) {
434 JavaThread* thread = JavaThread::current();
435 ThreadToNativeFromVM ttn(thread);
436 HandleMark hm(thread);
437 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
438 onLoaded = JNI_TRUE;
439 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
440 vm_exit_during_initialization("Unsupported JNI version");
441 }
442 }
443 }
444 }
445 return _native_java_library;
446 }
447
448 /*
449 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
450 * If check_lib == true then we are looking for an
451 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
452 * this library is statically linked into the image.
453 * If check_lib == false then we will look for the appropriate symbol in the
454 * executable if agent_lib->is_static_lib() == true or in the shared library
455 * referenced by 'handle'.
456 */
457 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
458 const char *syms[], size_t syms_len) {
459 assert(agent_lib != NULL, "sanity check");
460 const char *lib_name;
461 void *handle = agent_lib->os_lib();
462 void *entryName = NULL;
463 char *agent_function_name;
464 size_t i;
465
466 // If checking then use the agent name otherwise test is_static_lib() to
467 // see how to process this lookup
468 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
469 for (i = 0; i < syms_len; i++) {
470 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
471 if (agent_function_name == NULL) {
472 break;
473 }
474 entryName = dll_lookup(handle, agent_function_name);
475 FREE_C_HEAP_ARRAY(char, agent_function_name);
476 if (entryName != NULL) {
477 break;
478 }
479 }
480 return entryName;
481 }
482
483 // See if the passed in agent is statically linked into the VM image.
484 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
485 size_t syms_len) {
486 void *ret;
487 void *proc_handle;
488 void *save_handle;
489
490 assert(agent_lib != NULL, "sanity check");
491 if (agent_lib->name() == NULL) {
492 return false;
493 }
494 proc_handle = get_default_process_handle();
495 // Check for Agent_OnLoad/Attach_lib_name function
496 save_handle = agent_lib->os_lib();
497 // We want to look in this process' symbol table.
498 agent_lib->set_os_lib(proc_handle);
499 ret = find_agent_function(agent_lib, true, syms, syms_len);
500 if (ret != NULL) {
501 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
502 agent_lib->set_valid();
503 agent_lib->set_static_lib(true);
504 return true;
505 }
506 agent_lib->set_os_lib(save_handle);
507 return false;
508 }
509
510 // --------------------- heap allocation utilities ---------------------
511
512 char *os::strdup(const char *str, MEMFLAGS flags) {
513 size_t size = strlen(str);
514 char *dup_str = (char *)malloc(size + 1, flags);
515 if (dup_str == NULL) return NULL;
516 strcpy(dup_str, str);
517 return dup_str;
518 }
519
520 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
521 char* p = os::strdup(str, flags);
522 if (p == NULL) {
523 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
524 }
525 return p;
526 }
527
528
529 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
530
531 #ifdef ASSERT
532
533 static void verify_memory(void* ptr) {
534 GuardedMemory guarded(ptr);
535 if (!guarded.verify_guards()) {
536 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
537 tty->print_cr("## memory stomp:");
538 guarded.print_on(tty);
539 fatal("memory stomping error");
540 }
541 }
542
543 #endif
544
545 //
546 // This function supports testing of the malloc out of memory
547 // condition without really running the system out of memory.
548 //
549 static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
550 if (MallocMaxTestWords > 0) {
551 jint words = (jint)(alloc_size / BytesPerWord);
552
553 if ((cur_malloc_words + words) > MallocMaxTestWords) {
554 return true;
555 }
556 Atomic::add(words, (volatile jint *)&cur_malloc_words);
557 }
558 return false;
559 }
560
561 void* os::malloc(size_t size, MEMFLAGS flags) {
562 return os::malloc(size, flags, CALLER_PC);
563 }
564
565 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
566 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
567 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
568
569 #ifdef ASSERT
570 // checking for the WatcherThread and crash_protection first
571 // since os::malloc can be called when the libjvm.{dll,so} is
572 // first loaded and we don't have a thread yet.
573 // try to find the thread after we see that the watcher thread
574 // exists and has crash protection.
575 WatcherThread *wt = WatcherThread::watcher_thread();
576 if (wt != NULL && wt->has_crash_protection()) {
577 Thread* thread = ThreadLocalStorage::get_thread_slow();
578 if (thread == wt) {
579 assert(!wt->has_crash_protection(),
580 "Can't malloc with crash protection from WatcherThread");
581 }
582 }
583 #endif
584
585 if (size == 0) {
586 // return a valid pointer if size is zero
587 // if NULL is returned the calling functions assume out of memory.
588 size = 1;
589 }
590
591 // NMT support
592 NMT_TrackingLevel level = MemTracker::tracking_level();
593 size_t nmt_header_size = MemTracker::malloc_header_size(level);
594
595 #ifndef ASSERT
596 const size_t alloc_size = size + nmt_header_size;
597 #else
598 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
599 if (size + nmt_header_size > alloc_size) { // Check for rollover.
600 return NULL;
601 }
602 #endif
603
604 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
605
606 // For the test flag -XX:MallocMaxTestWords
607 if (has_reached_max_malloc_test_peak(size)) {
608 return NULL;
609 }
610
611 u_char* ptr;
612 ptr = (u_char*)::malloc(alloc_size);
613
614 #ifdef ASSERT
615 if (ptr == NULL) {
616 return NULL;
617 }
618 // Wrap memory with guard
619 GuardedMemory guarded(ptr, size + nmt_header_size);
620 ptr = guarded.get_user_ptr();
621 #endif
622 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
623 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
624 breakpoint();
625 }
626 debug_only(if (paranoid) verify_memory(ptr));
627 if (PrintMalloc && tty != NULL) {
628 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
629 }
630
631 // we do not track guard memory
632 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
633 }
634
635 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
636 return os::realloc(memblock, size, flags, CALLER_PC);
637 }
638
639 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
640
641 // For the test flag -XX:MallocMaxTestWords
642 if (has_reached_max_malloc_test_peak(size)) {
643 return NULL;
644 }
645
646 #ifndef ASSERT
647 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
648 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
649 // NMT support
650 void* membase = MemTracker::record_free(memblock);
651 NMT_TrackingLevel level = MemTracker::tracking_level();
652 size_t nmt_header_size = MemTracker::malloc_header_size(level);
653 void* ptr = ::realloc(membase, size + nmt_header_size);
654 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
655 #else
656 if (memblock == NULL) {
657 return os::malloc(size, memflags, stack);
658 }
659 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
660 tty->print_cr("os::realloc caught " PTR_FORMAT, p2i(memblock));
661 breakpoint();
662 }
663 // NMT support
664 void* membase = MemTracker::malloc_base(memblock);
665 verify_memory(membase);
666 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
667 if (size == 0) {
668 return NULL;
669 }
670 // always move the block
671 void* ptr = os::malloc(size, memflags, stack);
672 if (PrintMalloc && tty != NULL) {
673 tty->print_cr("os::realloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, p2i(memblock), p2i(ptr));
674 }
675 // Copy to new memory if malloc didn't fail
676 if ( ptr != NULL ) {
677 GuardedMemory guarded(MemTracker::malloc_base(memblock));
678 // Guard's user data contains NMT header
679 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
680 memcpy(ptr, memblock, MIN2(size, memblock_size));
681 if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
682 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
683 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
684 breakpoint();
685 }
686 os::free(memblock);
687 }
688 return ptr;
689 #endif
690 }
691
692
693 void os::free(void *memblock) {
694 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
695 #ifdef ASSERT
696 if (memblock == NULL) return;
697 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
698 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, p2i(memblock));
699 breakpoint();
700 }
701 void* membase = MemTracker::record_free(memblock);
702 verify_memory(membase);
703 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
704
705 GuardedMemory guarded(membase);
706 size_t size = guarded.get_user_size();
707 inc_stat_counter(&free_bytes, size);
708 membase = guarded.release_for_freeing();
709 if (PrintMalloc && tty != NULL) {
710 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
711 }
712 ::free(membase);
713 #else
714 void* membase = MemTracker::record_free(memblock);
715 ::free(membase);
716 #endif
717 }
718
719 void os::init_random(long initval) {
720 _rand_seed = initval;
721 }
722
723
724 long os::random() {
725 /* standard, well-known linear congruential random generator with
726 * next_rand = (16807*seed) mod (2**31-1)
727 * see
728 * (1) "Random Number Generators: Good Ones Are Hard to Find",
729 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
730 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
731 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
732 */
733 const long a = 16807;
734 const unsigned long m = 2147483647;
735 const long q = m / a; assert(q == 127773, "weird math");
736 const long r = m % a; assert(r == 2836, "weird math");
737
738 // compute az=2^31p+q
739 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
740 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
741 lo += (hi & 0x7FFF) << 16;
742
743 // if q overflowed, ignore the overflow and increment q
744 if (lo > m) {
745 lo &= m;
746 ++lo;
747 }
748 lo += hi >> 15;
749
750 // if (p+q) overflowed, ignore the overflow and increment (p+q)
751 if (lo > m) {
752 lo &= m;
753 ++lo;
754 }
755 return (_rand_seed = lo);
756 }
757
758 // The INITIALIZED state is distinguished from the SUSPENDED state because the
759 // conditions in which a thread is first started are different from those in which
760 // a suspension is resumed. These differences make it hard for us to apply the
761 // tougher checks when starting threads that we want to do when resuming them.
762 // However, when start_thread is called as a result of Thread.start, on a Java
763 // thread, the operation is synchronized on the Java Thread object. So there
764 // cannot be a race to start the thread and hence for the thread to exit while
765 // we are working on it. Non-Java threads that start Java threads either have
766 // to do so in a context in which races are impossible, or should do appropriate
767 // locking.
768
769 void os::start_thread(Thread* thread) {
770 // guard suspend/resume
771 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
772 OSThread* osthread = thread->osthread();
773 osthread->set_state(RUNNABLE);
774 pd_start_thread(thread);
775 }
776
777 void os::abort(bool dump_core) {
778 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
779 }
780
781 //---------------------------------------------------------------------------
782 // Helper functions for fatal error handler
783
784 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
785 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
786
787 int cols = 0;
788 int cols_per_line = 0;
789 switch (unitsize) {
790 case 1: cols_per_line = 16; break;
791 case 2: cols_per_line = 8; break;
792 case 4: cols_per_line = 4; break;
793 case 8: cols_per_line = 2; break;
794 default: return;
795 }
796
797 address p = start;
798 st->print(PTR_FORMAT ": ", p2i(start));
799 while (p < end) {
800 switch (unitsize) {
801 case 1: st->print("%02x", *(u1*)p); break;
802 case 2: st->print("%04x", *(u2*)p); break;
803 case 4: st->print("%08x", *(u4*)p); break;
804 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
805 }
806 p += unitsize;
807 cols++;
808 if (cols >= cols_per_line && p < end) {
809 cols = 0;
810 st->cr();
811 st->print(PTR_FORMAT ": ", p2i(p));
812 } else {
813 st->print(" ");
814 }
815 }
816 st->cr();
817 }
818
819 void os::print_environment_variables(outputStream* st, const char** env_list) {
820 if (env_list) {
821 st->print_cr("Environment Variables:");
822
823 for (int i = 0; env_list[i] != NULL; i++) {
824 char *envvar = ::getenv(env_list[i]);
825 if (envvar != NULL) {
826 st->print("%s", env_list[i]);
827 st->print("=");
828 st->print_cr("%s", envvar);
829 }
830 }
831 }
832 }
833
834 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
835 // cpu
836 st->print("CPU:");
837 st->print("total %d", os::processor_count());
838 // It's not safe to query number of active processors after crash
839 // st->print("(active %d)", os::active_processor_count());
840 st->print(" %s", VM_Version::cpu_features());
841 st->cr();
842 pd_print_cpu_info(st, buf, buflen);
843 }
844
845 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version
846 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
847 st->print("Host: ");
848 #ifndef PRODUCT
849 if (get_host_name(buf, buflen)) {
850 st->print("%s, ", buf);
851 }
852 #endif // PRODUCT
853 get_summary_cpu_info(buf, buflen);
854 st->print("%s, ", buf);
855 size_t mem = physical_memory()/G;
856 if (mem == 0) { // for low memory systems
857 mem = physical_memory()/M;
858 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
859 } else {
860 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
861 }
862 get_summary_os_info(buf, buflen);
863 st->print_raw(buf);
864 st->cr();
865 }
866
867 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
868 const int secs_per_day = 86400;
869 const int secs_per_hour = 3600;
870 const int secs_per_min = 60;
871
872 time_t tloc;
873 (void)time(&tloc);
874 char* timestring = ctime(&tloc); // ctime adds newline.
875 // edit out the newline
876 char* nl = strchr(timestring, '\n');
877 if (nl != NULL) {
878 *nl = '\0';
879 }
880
881 struct tm tz;
882 if (localtime_pd(&tloc, &tz) != NULL) {
883 ::strftime(buf, buflen, "%Z", &tz);
884 st->print("Time: %s %s", timestring, buf);
885 } else {
886 st->print("Time: %s", timestring);
887 }
888
889 double t = os::elapsedTime();
890 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
891 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
892 // before printf. We lost some precision, but who cares?
893 int eltime = (int)t; // elapsed time in seconds
894
895 // print elapsed time in a human-readable format:
896 int eldays = eltime / secs_per_day;
897 int day_secs = eldays * secs_per_day;
898 int elhours = (eltime - day_secs) / secs_per_hour;
899 int hour_secs = elhours * secs_per_hour;
900 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
901 int minute_secs = elmins * secs_per_min;
902 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
903 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
904 }
905
906 // moved from debug.cpp (used to be find()) but still called from there
907 // The verbose parameter is only set by the debug code in one case
908 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
909 address addr = (address)x;
910 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
911 if (b != NULL) {
912 if (b->is_buffer_blob()) {
913 // the interpreter is generated into a buffer blob
914 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
915 if (i != NULL) {
916 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", p2i(addr), (int)(addr - i->code_begin()));
917 i->print_on(st);
918 return;
919 }
920 if (Interpreter::contains(addr)) {
921 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
922 " (not bytecode specific)", p2i(addr));
923 return;
924 }
925 //
926 if (AdapterHandlerLibrary::contains(b)) {
927 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", p2i(addr), (int)(addr - b->code_begin()));
928 AdapterHandlerLibrary::print_handler_on(st, b);
929 }
930 // the stubroutines are generated into a buffer blob
931 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
932 if (d != NULL) {
933 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", p2i(addr), (int)(addr - d->begin()));
934 d->print_on(st);
935 st->cr();
936 return;
937 }
938 if (StubRoutines::contains(addr)) {
939 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) stub routine", p2i(addr));
940 return;
941 }
942 // the InlineCacheBuffer is using stubs generated into a buffer blob
943 if (InlineCacheBuffer::contains(addr)) {
944 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", p2i(addr));
945 return;
946 }
947 VtableStub* v = VtableStubs::stub_containing(addr);
948 if (v != NULL) {
949 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", p2i(addr), (int)(addr - v->entry_point()));
950 v->print_on(st);
951 st->cr();
952 return;
953 }
954 }
955 nmethod* nm = b->as_nmethod_or_null();
956 if (nm != NULL) {
957 ResourceMark rm;
958 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
959 p2i(addr), (int)(addr - nm->entry_point()), p2i(nm));
960 if (verbose) {
961 st->print(" for ");
962 nm->method()->print_value_on(st);
963 }
964 st->cr();
965 nm->print_nmethod(verbose);
966 return;
967 }
968 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", p2i(addr), (int)(addr - b->code_begin()));
969 b->print_on(st);
970 return;
971 }
972
973 if (Universe::heap()->is_in(addr)) {
974 HeapWord* p = Universe::heap()->block_start(addr);
975 bool print = false;
976 // If we couldn't find it it just may mean that heap wasn't parsable
977 // See if we were just given an oop directly
978 if (p != NULL && Universe::heap()->block_is_obj(p)) {
979 print = true;
980 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
981 p = (HeapWord*) addr;
982 print = true;
983 }
984 if (print) {
985 if (p == (HeapWord*) addr) {
986 st->print_cr(INTPTR_FORMAT " is an oop", p2i(addr));
987 } else {
988 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, p2i(addr), p2i(p));
989 }
990 oop(p)->print_on(st);
991 return;
992 }
993 } else {
994 if (Universe::heap()->is_in_reserved(addr)) {
995 st->print_cr(INTPTR_FORMAT " is an unallocated location "
996 "in the heap", p2i(addr));
997 return;
998 }
999 }
1000 if (JNIHandles::is_global_handle((jobject) addr)) {
1001 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
1002 return;
1003 }
1004 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1005 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
1006 return;
1007 }
1008 #ifndef PRODUCT
1009 // we don't keep the block list in product mode
1010 if (JNIHandleBlock::any_contains((jobject) addr)) {
1011 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
1012 return;
1013 }
1014 #endif
1015
1016 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
1017 // Check for privilege stack
1018 if (thread->privileged_stack_top() != NULL &&
1019 thread->privileged_stack_top()->contains(addr)) {
1020 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
1021 "for thread: " INTPTR_FORMAT, p2i(addr), p2i(thread));
1022 if (verbose) thread->print_on(st);
1023 return;
1024 }
1025 // If the addr is a java thread print information about that.
1026 if (addr == (address)thread) {
1027 if (verbose) {
1028 thread->print_on(st);
1029 } else {
1030 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
1031 }
1032 return;
1033 }
1034 // If the addr is in the stack region for this thread then report that
1035 // and print thread info
1036 if (thread->stack_base() >= addr &&
1037 addr > (thread->stack_base() - thread->stack_size())) {
1038 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1039 INTPTR_FORMAT, p2i(addr), p2i(thread));
1040 if (verbose) thread->print_on(st);
1041 return;
1042 }
1043
1044 }
1045
1046 // Check if in metaspace and print types that have vptrs (only method now)
1047 if (Metaspace::contains(addr)) {
1048 if (Method::has_method_vptr((const void*)addr)) {
1049 ((Method*)addr)->print_value_on(st);
1050 st->cr();
1051 } else {
1052 // Use addr->print() from the debugger instead (not here)
1053 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
1054 }
1055 return;
1056 }
1057
1058 // Try an OS specific find
1059 if (os::find(addr, st)) {
1060 return;
1061 }
1062
1063 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
1064 }
1065
1066 // Looks like all platforms except IA64 can use the same function to check
1067 // if C stack is walkable beyond current frame. The check for fp() is not
1068 // necessary on Sparc, but it's harmless.
1069 bool os::is_first_C_frame(frame* fr) {
1070 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1071 // On IA64 we have to check if the callers bsp is still valid
1072 // (i.e. within the register stack bounds).
1073 // Notice: this only works for threads created by the VM and only if
1074 // we walk the current stack!!! If we want to be able to walk
1075 // arbitrary other threads, we'll have to somehow store the thread
1076 // object in the frame.
1077 Thread *thread = Thread::current();
1078 if ((address)fr->fp() <=
1079 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1080 // This check is a little hacky, because on Linux the first C
1081 // frame's ('start_thread') register stack frame starts at
1082 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1083 // ('__pthread_bound_body') register stack frame seems to really
1084 // start at "register_stack_base".
1085 return true;
1086 } else {
1087 return false;
1088 }
1089 #elif defined(IA64) && defined(_WIN32)
1090 return true;
1091 #else
1092 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1093 // Check usp first, because if that's bad the other accessors may fault
1094 // on some architectures. Ditto ufp second, etc.
1095 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1096 // sp on amd can be 32 bit aligned.
1097 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1098
1099 uintptr_t usp = (uintptr_t)fr->sp();
1100 if ((usp & sp_align_mask) != 0) return true;
1101
1102 uintptr_t ufp = (uintptr_t)fr->fp();
1103 if ((ufp & fp_align_mask) != 0) return true;
1104
1105 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1106 if ((old_sp & sp_align_mask) != 0) return true;
1107 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1108
1109 uintptr_t old_fp = (uintptr_t)fr->link();
1110 if ((old_fp & fp_align_mask) != 0) return true;
1111 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1112
1113 // stack grows downwards; if old_fp is below current fp or if the stack
1114 // frame is too large, either the stack is corrupted or fp is not saved
1115 // on stack (i.e. on x86, ebp may be used as general register). The stack
1116 // is not walkable beyond current frame.
1117 if (old_fp < ufp) return true;
1118 if (old_fp - ufp > 64 * K) return true;
1119
1120 return false;
1121 #endif
1122 }
1123
1124 #ifdef ASSERT
1125 extern "C" void test_random() {
1126 const double m = 2147483647;
1127 double mean = 0.0, variance = 0.0, t;
1128 long reps = 10000;
1129 unsigned long seed = 1;
1130
1131 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1132 os::init_random(seed);
1133 long num;
1134 for (int k = 0; k < reps; k++) {
1135 num = os::random();
1136 double u = (double)num / m;
1137 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1138
1139 // calculate mean and variance of the random sequence
1140 mean += u;
1141 variance += (u*u);
1142 }
1143 mean /= reps;
1144 variance /= (reps - 1);
1145
1146 assert(num == 1043618065, "bad seed");
1147 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1148 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1149 const double eps = 0.0001;
1150 t = fabsd(mean - 0.5018);
1151 assert(t < eps, "bad mean");
1152 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1153 assert(t < eps, "bad variance");
1154 }
1155 #endif
1156
1157
1158 // Set up the boot classpath.
1159
1160 char* os::format_boot_path(const char* format_string,
1161 const char* home,
1162 int home_len,
1163 char fileSep,
1164 char pathSep) {
1165 assert((fileSep == '/' && pathSep == ':') ||
1166 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1167
1168 // Scan the format string to determine the length of the actual
1169 // boot classpath, and handle platform dependencies as well.
1170 int formatted_path_len = 0;
1171 const char* p;
1172 for (p = format_string; *p != 0; ++p) {
1173 if (*p == '%') formatted_path_len += home_len - 1;
1174 ++formatted_path_len;
1175 }
1176
1177 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1178 if (formatted_path == NULL) {
1179 return NULL;
1180 }
1181
1182 // Create boot classpath from format, substituting separator chars and
1183 // java home directory.
1184 char* q = formatted_path;
1185 for (p = format_string; *p != 0; ++p) {
1186 switch (*p) {
1187 case '%':
1188 strcpy(q, home);
1189 q += home_len;
1190 break;
1191 case '/':
1192 *q++ = fileSep;
1193 break;
1194 case ':':
1195 *q++ = pathSep;
1196 break;
1197 default:
1198 *q++ = *p;
1199 }
1200 }
1201 *q = '\0';
1202
1203 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1204 return formatted_path;
1205 }
1206
1207 // returns a PATH of all entries in the given directory that do not start with a '.'
1208 static char* expand_entries_to_path(char* directory, char fileSep, char pathSep) {
1209 DIR* dir = os::opendir(directory);
1210 if (dir == NULL) return NULL;
1211
1212 char* path = NULL;
1213 size_t path_len = 0; // path length including \0 terminator
1214
1215 size_t directory_len = strlen(directory);
1216 struct dirent *entry;
1217 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(directory), mtInternal);
1218 while ((entry = os::readdir(dir, (dirent *) dbuf)) != NULL) {
1219 const char* name = entry->d_name;
1220 if (name[0] == '.') continue;
1221
1222 size_t name_len = strlen(name);
1223 size_t needed = directory_len + name_len + 2;
1224 size_t new_len = path_len + needed;
1225 if (path == NULL) {
1226 path = NEW_C_HEAP_ARRAY(char, new_len, mtInternal);
1227 } else {
1228 path = REALLOC_C_HEAP_ARRAY(char, path, new_len, mtInternal);
1229 }
1230 if (path == NULL)
1231 break;
1232
1233 // append <pathSep>directory<fileSep>name
1234 char* p = path;
1235 if (path_len > 0) {
1236 p += (path_len -1);
1237 *p = pathSep;
1238 p++;
1239 }
1240
1241 strcpy(p, directory);
1242 p += directory_len;
1243
1244 *p = fileSep;
1245 p++;
1246
1247 strcpy(p, name);
1248 p += name_len;
1249
1250 path_len = new_len;
1251 }
1252
1253 FREE_C_HEAP_ARRAY(char, dbuf);
1254 os::closedir(dir);
1255
1256 return path;
1257 }
1258
1259 bool os::set_boot_path(char fileSep, char pathSep) {
1260 const char* home = Arguments::get_java_home();
1261 int home_len = (int)strlen(home);
1262
1263 char* sysclasspath = NULL;
1264 struct stat st;
1265
1266 // modular image if bootmodules.jimage exists
1267 char* jimage = format_boot_path("%/lib/modules/" BOOT_IMAGE_NAME, home, home_len, fileSep, pathSep);
1268 if (jimage == NULL) return false;
1269 bool has_jimage = (os::stat(jimage, &st) == 0);
1270 if (has_jimage) {
1271 Arguments::set_sysclasspath(jimage);
1272 FREE_C_HEAP_ARRAY(char, jimage);
1273 return true;
1274 }
1275 FREE_C_HEAP_ARRAY(char, jimage);
1276
1277 // check if developer build with exploded modules
1278 char* modules_dir = format_boot_path("%/modules", home, home_len, fileSep, pathSep);
1279 if (os::stat(modules_dir, &st) == 0) {
1280 if ((st.st_mode & S_IFDIR) == S_IFDIR) {
1281 sysclasspath = expand_entries_to_path(modules_dir, fileSep, pathSep);
1282 }
1283 }
1284 FREE_C_HEAP_ARRAY(char, modules_dir);
1285
1286 // fallback to classes
1287 if (sysclasspath == NULL)
1288 sysclasspath = format_boot_path("%/classes", home, home_len, fileSep, pathSep);
1289
1290 if (sysclasspath == NULL) return false;
1291 Arguments::set_sysclasspath(sysclasspath);
1292 FREE_C_HEAP_ARRAY(char, sysclasspath);
1293
1294 return true;
1295 }
1296
1297 /*
1298 * Splits a path, based on its separator, the number of
1299 * elements is returned back in n.
1300 * It is the callers responsibility to:
1301 * a> check the value of n, and n may be 0.
1302 * b> ignore any empty path elements
1303 * c> free up the data.
1304 */
1305 char** os::split_path(const char* path, int* n) {
1306 *n = 0;
1307 if (path == NULL || strlen(path) == 0) {
1308 return NULL;
1309 }
1310 const char psepchar = *os::path_separator();
1311 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1312 if (inpath == NULL) {
1313 return NULL;
1314 }
1315 strcpy(inpath, path);
1316 int count = 1;
1317 char* p = strchr(inpath, psepchar);
1318 // Get a count of elements to allocate memory
1319 while (p != NULL) {
1320 count++;
1321 p++;
1322 p = strchr(p, psepchar);
1323 }
1324 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1325 if (opath == NULL) {
1326 return NULL;
1327 }
1328
1329 // do the actual splitting
1330 p = inpath;
1331 for (int i = 0 ; i < count ; i++) {
1332 size_t len = strcspn(p, os::path_separator());
1333 if (len > JVM_MAXPATHLEN) {
1334 return NULL;
1335 }
1336 // allocate the string and add terminator storage
1337 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1338 if (s == NULL) {
1339 return NULL;
1340 }
1341 strncpy(s, p, len);
1342 s[len] = '\0';
1343 opath[i] = s;
1344 p += len + 1;
1345 }
1346 FREE_C_HEAP_ARRAY(char, inpath);
1347 *n = count;
1348 return opath;
1349 }
1350
1351 void os::set_memory_serialize_page(address page) {
1352 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1353 _mem_serialize_page = (volatile int32_t *)page;
1354 // We initialize the serialization page shift count here
1355 // We assume a cache line size of 64 bytes
1356 assert(SerializePageShiftCount == count,
1357 "thread size changed, fix SerializePageShiftCount constant");
1358 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1359 }
1360
1361 static volatile intptr_t SerializePageLock = 0;
1362
1363 // This method is called from signal handler when SIGSEGV occurs while the current
1364 // thread tries to store to the "read-only" memory serialize page during state
1365 // transition.
1366 void os::block_on_serialize_page_trap() {
1367 log_debug(safepoint)("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