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 #elif defined(_WIN32) && _MSC_VER > 1800
128 const time_t zone = _timezone;
129 #else
130 const time_t zone = timezone;
131 #endif
132
133 // If daylight savings time is in effect,
134 // we are 1 hour East of our time zone
135 const time_t seconds_per_minute = 60;
136 const time_t minutes_per_hour = 60;
137 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
138 time_t UTC_to_local = zone;
139 if (time_struct.tm_isdst > 0) {
140 UTC_to_local = UTC_to_local - seconds_per_hour;
141 }
142 // Compute the time zone offset.
143 // localtime_pd() sets timezone to the difference (in seconds)
144 // between UTC and and local time.
145 // ISO 8601 says we need the difference between local time and UTC,
146 // we change the sign of the localtime_pd() result.
147 const time_t local_to_UTC = -(UTC_to_local);
148 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
149 char sign_local_to_UTC = '+';
150 time_t abs_local_to_UTC = local_to_UTC;
151 if (local_to_UTC < 0) {
152 sign_local_to_UTC = '-';
153 abs_local_to_UTC = -(abs_local_to_UTC);
154 }
155 // Convert time zone offset seconds to hours and minutes.
156 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
157 const time_t zone_min =
158 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
159
160 // Print an ISO 8601 date and time stamp into the buffer
161 const int year = 1900 + time_struct.tm_year;
162 const int month = 1 + time_struct.tm_mon;
163 const int printed = jio_snprintf(buffer, buffer_length,
164 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d",
165 year,
166 month,
167 time_struct.tm_mday,
168 time_struct.tm_hour,
169 time_struct.tm_min,
170 time_struct.tm_sec,
171 milliseconds_after_second,
172 sign_local_to_UTC,
173 zone_hours,
174 zone_min);
175 if (printed == 0) {
176 assert(false, "Failed jio_printf");
177 return NULL;
178 }
179 return buffer;
180 }
181
182 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
183 #ifdef ASSERT
184 if (!(!thread->is_Java_thread() ||
185 Thread::current() == thread ||
186 Threads_lock->owned_by_self()
187 || thread->is_Compiler_thread()
188 )) {
189 assert(false, "possibility of dangling Thread pointer");
190 }
191 #endif
192
193 if (p >= MinPriority && p <= MaxPriority) {
194 int priority = java_to_os_priority[p];
195 return set_native_priority(thread, priority);
196 } else {
197 assert(false, "Should not happen");
198 return OS_ERR;
199 }
200 }
201
202 // The mapping from OS priority back to Java priority may be inexact because
203 // Java priorities can map M:1 with native priorities. If you want the definite
204 // Java priority then use JavaThread::java_priority()
205 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
206 int p;
207 int os_prio;
208 OSReturn ret = get_native_priority(thread, &os_prio);
209 if (ret != OS_OK) return ret;
210
211 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
212 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
213 } else {
214 // niceness values are in reverse order
215 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
216 }
217 priority = (ThreadPriority)p;
218 return OS_OK;
219 }
220
221
222 // --------------------- sun.misc.Signal (optional) ---------------------
223
224
225 // SIGBREAK is sent by the keyboard to query the VM state
226 #ifndef SIGBREAK
227 #define SIGBREAK SIGQUIT
228 #endif
229
230 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
231
232
233 static void signal_thread_entry(JavaThread* thread, TRAPS) {
234 os::set_priority(thread, NearMaxPriority);
235 while (true) {
236 int sig;
237 {
238 // FIXME : Currently we have not decided what should be the status
239 // for this java thread blocked here. Once we decide about
240 // that we should fix this.
241 sig = os::signal_wait();
242 }
243 if (sig == os::sigexitnum_pd()) {
244 // Terminate the signal thread
245 return;
246 }
247
248 switch (sig) {
249 case SIGBREAK: {
250 // Check if the signal is a trigger to start the Attach Listener - in that
251 // case don't print stack traces.
252 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
253 continue;
254 }
255 // Print stack traces
256 // Any SIGBREAK operations added here should make sure to flush
257 // the output stream (e.g. tty->flush()) after output. See 4803766.
258 // Each module also prints an extra carriage return after its output.
259 VM_PrintThreads op;
260 VMThread::execute(&op);
261 VM_PrintJNI jni_op;
262 VMThread::execute(&jni_op);
263 VM_FindDeadlocks op1(tty);
264 VMThread::execute(&op1);
265 Universe::print_heap_at_SIGBREAK();
266 if (PrintClassHistogram) {
267 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
268 VMThread::execute(&op1);
269 }
270 if (JvmtiExport::should_post_data_dump()) {
271 JvmtiExport::post_data_dump();
272 }
273 break;
274 }
275 default: {
276 // Dispatch the signal to java
277 HandleMark hm(THREAD);
278 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
279 KlassHandle klass (THREAD, k);
280 if (klass.not_null()) {
281 JavaValue result(T_VOID);
282 JavaCallArguments args;
283 args.push_int(sig);
284 JavaCalls::call_static(
285 &result,
286 klass,
287 vmSymbols::dispatch_name(),
288 vmSymbols::int_void_signature(),
289 &args,
290 THREAD
291 );
292 }
293 if (HAS_PENDING_EXCEPTION) {
294 // tty is initialized early so we don't expect it to be null, but
295 // if it is we can't risk doing an initialization that might
296 // trigger additional out-of-memory conditions
297 if (tty != NULL) {
298 char klass_name[256];
299 char tmp_sig_name[16];
300 const char* sig_name = "UNKNOWN";
301 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
302 name()->as_klass_external_name(klass_name, 256);
303 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
304 sig_name = tmp_sig_name;
305 warning("Exception %s occurred dispatching signal %s to handler"
306 "- the VM may need to be forcibly terminated",
307 klass_name, sig_name );
308 }
309 CLEAR_PENDING_EXCEPTION;
310 }
311 }
312 }
313 }
314 }
315
316 void os::init_before_ergo() {
317 // We need to initialize large page support here because ergonomics takes some
318 // decisions depending on large page support and the calculated large page size.
319 large_page_init();
320 }
321
322 void os::signal_init() {
323 if (!ReduceSignalUsage) {
324 // Setup JavaThread for processing signals
325 EXCEPTION_MARK;
326 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
327 instanceKlassHandle klass (THREAD, k);
328 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
329
330 const char thread_name[] = "Signal Dispatcher";
331 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
332
333 // Initialize thread_oop to put it into the system threadGroup
334 Handle thread_group (THREAD, Universe::system_thread_group());
335 JavaValue result(T_VOID);
336 JavaCalls::call_special(&result, thread_oop,
337 klass,
338 vmSymbols::object_initializer_name(),
339 vmSymbols::threadgroup_string_void_signature(),
340 thread_group,
341 string,
342 CHECK);
343
344 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
345 JavaCalls::call_special(&result,
346 thread_group,
347 group,
348 vmSymbols::add_method_name(),
349 vmSymbols::thread_void_signature(),
350 thread_oop, // ARG 1
351 CHECK);
352
353 os::signal_init_pd();
354
355 { MutexLocker mu(Threads_lock);
356 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
357
358 // At this point it may be possible that no osthread was created for the
359 // JavaThread due to lack of memory. We would have to throw an exception
360 // in that case. However, since this must work and we do not allow
361 // exceptions anyway, check and abort if this fails.
362 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
363 vm_exit_during_initialization("java.lang.OutOfMemoryError",
364 os::native_thread_creation_failed_msg());
365 }
366
367 java_lang_Thread::set_thread(thread_oop(), signal_thread);
368 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
369 java_lang_Thread::set_daemon(thread_oop());
370
371 signal_thread->set_threadObj(thread_oop());
372 Threads::add(signal_thread);
373 Thread::start(signal_thread);
374 }
375 // Handle ^BREAK
376 os::signal(SIGBREAK, os::user_handler());
377 }
378 }
379
380
381 void os::terminate_signal_thread() {
382 if (!ReduceSignalUsage)
383 signal_notify(sigexitnum_pd());
384 }
385
386
387 // --------------------- loading libraries ---------------------
388
389 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
390 extern struct JavaVM_ main_vm;
391
392 static void* _native_java_library = NULL;
393
394 void* os::native_java_library() {
395 if (_native_java_library == NULL) {
396 char buffer[JVM_MAXPATHLEN];
397 char ebuf[1024];
398
399 // Try to load verify dll first. In 1.3 java dll depends on it and is not
400 // always able to find it when the loading executable is outside the JDK.
401 // In order to keep working with 1.2 we ignore any loading errors.
402 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
403 "verify")) {
404 dll_load(buffer, ebuf, sizeof(ebuf));
405 }
406
407 // Load java dll
408 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
409 "java")) {
410 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
411 }
412 if (_native_java_library == NULL) {
413 vm_exit_during_initialization("Unable to load native library", ebuf);
414 }
415
416 #if defined(__OpenBSD__)
417 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
418 // ignore errors
419 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
420 "net")) {
421 dll_load(buffer, ebuf, sizeof(ebuf));
422 }
423 #endif
424 }
425 static jboolean onLoaded = JNI_FALSE;
426 if (onLoaded) {
427 // We may have to wait to fire OnLoad until TLS is initialized.
428 if (ThreadLocalStorage::is_initialized()) {
429 // The JNI_OnLoad handling is normally done by method load in
430 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
431 // explicitly so we have to check for JNI_OnLoad as well
432 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
433 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
434 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
435 if (JNI_OnLoad != NULL) {
436 JavaThread* thread = JavaThread::current();
437 ThreadToNativeFromVM ttn(thread);
438 HandleMark hm(thread);
439 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
440 onLoaded = JNI_TRUE;
441 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
442 vm_exit_during_initialization("Unsupported JNI version");
443 }
444 }
445 }
446 }
447 return _native_java_library;
448 }
449
450 /*
451 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
452 * If check_lib == true then we are looking for an
453 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
454 * this library is statically linked into the image.
455 * If check_lib == false then we will look for the appropriate symbol in the
456 * executable if agent_lib->is_static_lib() == true or in the shared library
457 * referenced by 'handle'.
458 */
459 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
460 const char *syms[], size_t syms_len) {
461 assert(agent_lib != NULL, "sanity check");
462 const char *lib_name;
463 void *handle = agent_lib->os_lib();
464 void *entryName = NULL;
465 char *agent_function_name;
466 size_t i;
467
468 // If checking then use the agent name otherwise test is_static_lib() to
469 // see how to process this lookup
470 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
471 for (i = 0; i < syms_len; i++) {
472 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
473 if (agent_function_name == NULL) {
474 break;
475 }
476 entryName = dll_lookup(handle, agent_function_name);
477 FREE_C_HEAP_ARRAY(char, agent_function_name);
478 if (entryName != NULL) {
479 break;
480 }
481 }
482 return entryName;
483 }
484
485 // See if the passed in agent is statically linked into the VM image.
486 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
487 size_t syms_len) {
488 void *ret;
489 void *proc_handle;
490 void *save_handle;
491
492 assert(agent_lib != NULL, "sanity check");
493 if (agent_lib->name() == NULL) {
494 return false;
495 }
496 proc_handle = get_default_process_handle();
497 // Check for Agent_OnLoad/Attach_lib_name function
498 save_handle = agent_lib->os_lib();
499 // We want to look in this process' symbol table.
500 agent_lib->set_os_lib(proc_handle);
501 ret = find_agent_function(agent_lib, true, syms, syms_len);
502 if (ret != NULL) {
503 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
504 agent_lib->set_valid();
505 agent_lib->set_static_lib(true);
506 return true;
507 }
508 agent_lib->set_os_lib(save_handle);
509 return false;
510 }
511
512 // --------------------- heap allocation utilities ---------------------
513
514 char *os::strdup(const char *str, MEMFLAGS flags) {
515 size_t size = strlen(str);
516 char *dup_str = (char *)malloc(size + 1, flags);
517 if (dup_str == NULL) return NULL;
518 strcpy(dup_str, str);
519 return dup_str;
520 }
521
522 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
523 char* p = os::strdup(str, flags);
524 if (p == NULL) {
525 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
526 }
527 return p;
528 }
529
530
531 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
532
533 #ifdef ASSERT
534
535 static void verify_memory(void* ptr) {
536 GuardedMemory guarded(ptr);
537 if (!guarded.verify_guards()) {
538 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
539 tty->print_cr("## memory stomp:");
540 guarded.print_on(tty);
541 fatal("memory stomping error");
542 }
543 }
544
545 #endif
546
547 //
548 // This function supports testing of the malloc out of memory
549 // condition without really running the system out of memory.
550 //
551 static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
552 if (MallocMaxTestWords > 0) {
553 jint words = (jint)(alloc_size / BytesPerWord);
554
555 if ((cur_malloc_words + words) > MallocMaxTestWords) {
556 return true;
557 }
558 Atomic::add(words, (volatile jint *)&cur_malloc_words);
559 }
560 return false;
561 }
562
563 void* os::malloc(size_t size, MEMFLAGS flags) {
564 return os::malloc(size, flags, CALLER_PC);
565 }
566
567 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
568 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
569 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
570
571 #ifdef ASSERT
572 // checking for the WatcherThread and crash_protection first
573 // since os::malloc can be called when the libjvm.{dll,so} is
574 // first loaded and we don't have a thread yet.
575 // try to find the thread after we see that the watcher thread
576 // exists and has crash protection.
577 WatcherThread *wt = WatcherThread::watcher_thread();
578 if (wt != NULL && wt->has_crash_protection()) {
579 Thread* thread = ThreadLocalStorage::get_thread_slow();
580 if (thread == wt) {
581 assert(!wt->has_crash_protection(),
582 "Can't malloc with crash protection from WatcherThread");
583 }
584 }
585 #endif
586
587 if (size == 0) {
588 // return a valid pointer if size is zero
589 // if NULL is returned the calling functions assume out of memory.
590 size = 1;
591 }
592
593 // NMT support
594 NMT_TrackingLevel level = MemTracker::tracking_level();
595 size_t nmt_header_size = MemTracker::malloc_header_size(level);
596
597 #ifndef ASSERT
598 const size_t alloc_size = size + nmt_header_size;
599 #else
600 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
601 if (size + nmt_header_size > alloc_size) { // Check for rollover.
602 return NULL;
603 }
604 #endif
605
606 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
607
608 // For the test flag -XX:MallocMaxTestWords
609 if (has_reached_max_malloc_test_peak(size)) {
610 return NULL;
611 }
612
613 u_char* ptr;
614 ptr = (u_char*)::malloc(alloc_size);
615
616 #ifdef ASSERT
617 if (ptr == NULL) {
618 return NULL;
619 }
620 // Wrap memory with guard
621 GuardedMemory guarded(ptr, size + nmt_header_size);
622 ptr = guarded.get_user_ptr();
623 #endif
624 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
625 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
626 breakpoint();
627 }
628 debug_only(if (paranoid) verify_memory(ptr));
629 if (PrintMalloc && tty != NULL) {
630 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
631 }
632
633 // we do not track guard memory
634 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
635 }
636
637 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
638 return os::realloc(memblock, size, flags, CALLER_PC);
639 }
640
641 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
642
643 // For the test flag -XX:MallocMaxTestWords
644 if (has_reached_max_malloc_test_peak(size)) {
645 return NULL;
646 }
647
648 #ifndef ASSERT
649 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
650 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
651 // NMT support
652 void* membase = MemTracker::record_free(memblock);
653 NMT_TrackingLevel level = MemTracker::tracking_level();
654 size_t nmt_header_size = MemTracker::malloc_header_size(level);
655 void* ptr = ::realloc(membase, size + nmt_header_size);
656 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
657 #else
658 if (memblock == NULL) {
659 return os::malloc(size, memflags, stack);
660 }
661 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
662 tty->print_cr("os::realloc caught " PTR_FORMAT, p2i(memblock));
663 breakpoint();
664 }
665 // NMT support
666 void* membase = MemTracker::malloc_base(memblock);
667 verify_memory(membase);
668 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
669 if (size == 0) {
670 return NULL;
671 }
672 // always move the block
673 void* ptr = os::malloc(size, memflags, stack);
674 if (PrintMalloc && tty != NULL) {
675 tty->print_cr("os::realloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, p2i(memblock), p2i(ptr));
676 }
677 // Copy to new memory if malloc didn't fail
678 if ( ptr != NULL ) {
679 GuardedMemory guarded(MemTracker::malloc_base(memblock));
680 // Guard's user data contains NMT header
681 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
682 memcpy(ptr, memblock, MIN2(size, memblock_size));
683 if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
684 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
685 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
686 breakpoint();
687 }
688 os::free(memblock);
689 }
690 return ptr;
691 #endif
692 }
693
694
695 void os::free(void *memblock) {
696 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
697 #ifdef ASSERT
698 if (memblock == NULL) return;
699 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
700 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, p2i(memblock));
701 breakpoint();
702 }
703 void* membase = MemTracker::record_free(memblock);
704 verify_memory(membase);
705 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
706
707 GuardedMemory guarded(membase);
708 size_t size = guarded.get_user_size();
709 inc_stat_counter(&free_bytes, size);
710 membase = guarded.release_for_freeing();
711 if (PrintMalloc && tty != NULL) {
712 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
713 }
714 ::free(membase);
715 #else
716 void* membase = MemTracker::record_free(memblock);
717 ::free(membase);
718 #endif
719 }
720
721 void os::init_random(long initval) {
722 _rand_seed = initval;
723 }
724
725
726 long os::random() {
727 /* standard, well-known linear congruential random generator with
728 * next_rand = (16807*seed) mod (2**31-1)
729 * see
730 * (1) "Random Number Generators: Good Ones Are Hard to Find",
731 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
732 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
733 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
734 */
735 const long a = 16807;
736 const unsigned long m = 2147483647;
737 const long q = m / a; assert(q == 127773, "weird math");
738 const long r = m % a; assert(r == 2836, "weird math");
739
740 // compute az=2^31p+q
741 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
742 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
743 lo += (hi & 0x7FFF) << 16;
744
745 // if q overflowed, ignore the overflow and increment q
746 if (lo > m) {
747 lo &= m;
748 ++lo;
749 }
750 lo += hi >> 15;
751
752 // if (p+q) overflowed, ignore the overflow and increment (p+q)
753 if (lo > m) {
754 lo &= m;
755 ++lo;
756 }
757 return (_rand_seed = lo);
758 }
759
760 // The INITIALIZED state is distinguished from the SUSPENDED state because the
761 // conditions in which a thread is first started are different from those in which
762 // a suspension is resumed. These differences make it hard for us to apply the
763 // tougher checks when starting threads that we want to do when resuming them.
764 // However, when start_thread is called as a result of Thread.start, on a Java
765 // thread, the operation is synchronized on the Java Thread object. So there
766 // cannot be a race to start the thread and hence for the thread to exit while
767 // we are working on it. Non-Java threads that start Java threads either have
768 // to do so in a context in which races are impossible, or should do appropriate
769 // locking.
770
771 void os::start_thread(Thread* thread) {
772 // guard suspend/resume
773 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
774 OSThread* osthread = thread->osthread();
775 osthread->set_state(RUNNABLE);
776 pd_start_thread(thread);
777 }
778
779 void os::abort(bool dump_core) {
780 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
781 }
782
783 //---------------------------------------------------------------------------
784 // Helper functions for fatal error handler
785
786 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
787 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
788
789 int cols = 0;
790 int cols_per_line = 0;
791 switch (unitsize) {
792 case 1: cols_per_line = 16; break;
793 case 2: cols_per_line = 8; break;
794 case 4: cols_per_line = 4; break;
795 case 8: cols_per_line = 2; break;
796 default: return;
797 }
798
799 address p = start;
800 st->print(PTR_FORMAT ": ", p2i(start));
801 while (p < end) {
802 switch (unitsize) {
803 case 1: st->print("%02x", *(u1*)p); break;
804 case 2: st->print("%04x", *(u2*)p); break;
805 case 4: st->print("%08x", *(u4*)p); break;
806 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
807 }
808 p += unitsize;
809 cols++;
810 if (cols >= cols_per_line && p < end) {
811 cols = 0;
812 st->cr();
813 st->print(PTR_FORMAT ": ", p2i(p));
814 } else {
815 st->print(" ");
816 }
817 }
818 st->cr();
819 }
820
821 void os::print_environment_variables(outputStream* st, const char** env_list) {
822 if (env_list) {
823 st->print_cr("Environment Variables:");
824
825 for (int i = 0; env_list[i] != NULL; i++) {
826 char *envvar = ::getenv(env_list[i]);
827 if (envvar != NULL) {
828 st->print("%s", env_list[i]);
829 st->print("=");
830 st->print_cr("%s", envvar);
831 }
832 }
833 }
834 }
835
836 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
837 // cpu
838 st->print("CPU:");
839 st->print("total %d", os::processor_count());
840 // It's not safe to query number of active processors after crash
841 // st->print("(active %d)", os::active_processor_count());
842 st->print(" %s", VM_Version::cpu_features());
843 st->cr();
844 pd_print_cpu_info(st, buf, buflen);
845 }
846
847 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version
848 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
849 st->print("Host: ");
850 #ifndef PRODUCT
851 if (get_host_name(buf, buflen)) {
852 st->print("%s, ", buf);
853 }
854 #endif // PRODUCT
855 get_summary_cpu_info(buf, buflen);
856 st->print("%s, ", buf);
857 size_t mem = physical_memory()/G;
858 if (mem == 0) { // for low memory systems
859 mem = physical_memory()/M;
860 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
861 } else {
862 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
863 }
864 get_summary_os_info(buf, buflen);
865 st->print_raw(buf);
866 st->cr();
867 }
868
869 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
870 const int secs_per_day = 86400;
871 const int secs_per_hour = 3600;
872 const int secs_per_min = 60;
873
874 time_t tloc;
875 (void)time(&tloc);
876 char* timestring = ctime(&tloc); // ctime adds newline.
877 // edit out the newline
878 char* nl = strchr(timestring, '\n');
879 if (nl != NULL) {
880 *nl = '\0';
881 }
882
883 struct tm tz;
884 if (localtime_pd(&tloc, &tz) != NULL) {
885 ::strftime(buf, buflen, "%Z", &tz);
886 st->print("Time: %s %s", timestring, buf);
887 } else {
888 st->print("Time: %s", timestring);
889 }
890
891 double t = os::elapsedTime();
892 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
893 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
894 // before printf. We lost some precision, but who cares?
895 int eltime = (int)t; // elapsed time in seconds
896
897 // print elapsed time in a human-readable format:
898 int eldays = eltime / secs_per_day;
899 int day_secs = eldays * secs_per_day;
900 int elhours = (eltime - day_secs) / secs_per_hour;
901 int hour_secs = elhours * secs_per_hour;
902 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
903 int minute_secs = elmins * secs_per_min;
904 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
905 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
906 }
907
908 // moved from debug.cpp (used to be find()) but still called from there
909 // The verbose parameter is only set by the debug code in one case
910 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
911 address addr = (address)x;
912 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
913 if (b != NULL) {
914 if (b->is_buffer_blob()) {
915 // the interpreter is generated into a buffer blob
916 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
917 if (i != NULL) {
918 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", p2i(addr), (int)(addr - i->code_begin()));
919 i->print_on(st);
920 return;
921 }
922 if (Interpreter::contains(addr)) {
923 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
924 " (not bytecode specific)", p2i(addr));
925 return;
926 }
927 //
928 if (AdapterHandlerLibrary::contains(b)) {
929 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", p2i(addr), (int)(addr - b->code_begin()));
930 AdapterHandlerLibrary::print_handler_on(st, b);
931 }
932 // the stubroutines are generated into a buffer blob
933 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
934 if (d != NULL) {
935 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", p2i(addr), (int)(addr - d->begin()));
936 d->print_on(st);
937 st->cr();
938 return;
939 }
940 if (StubRoutines::contains(addr)) {
941 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) stub routine", p2i(addr));
942 return;
943 }
944 // the InlineCacheBuffer is using stubs generated into a buffer blob
945 if (InlineCacheBuffer::contains(addr)) {
946 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", p2i(addr));
947 return;
948 }
949 VtableStub* v = VtableStubs::stub_containing(addr);
950 if (v != NULL) {
951 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", p2i(addr), (int)(addr - v->entry_point()));
952 v->print_on(st);
953 st->cr();
954 return;
955 }
956 }
957 nmethod* nm = b->as_nmethod_or_null();
958 if (nm != NULL) {
959 ResourceMark rm;
960 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
961 p2i(addr), (int)(addr - nm->entry_point()), p2i(nm));
962 if (verbose) {
963 st->print(" for ");
964 nm->method()->print_value_on(st);
965 }
966 st->cr();
967 nm->print_nmethod(verbose);
968 return;
969 }
970 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", p2i(addr), (int)(addr - b->code_begin()));
971 b->print_on(st);
972 return;
973 }
974
975 if (Universe::heap()->is_in(addr)) {
976 HeapWord* p = Universe::heap()->block_start(addr);
977 bool print = false;
978 // If we couldn't find it it just may mean that heap wasn't parsable
979 // See if we were just given an oop directly
980 if (p != NULL && Universe::heap()->block_is_obj(p)) {
981 print = true;
982 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
983 p = (HeapWord*) addr;
984 print = true;
985 }
986 if (print) {
987 if (p == (HeapWord*) addr) {
988 st->print_cr(INTPTR_FORMAT " is an oop", p2i(addr));
989 } else {
990 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, p2i(addr), p2i(p));
991 }
992 oop(p)->print_on(st);
993 return;
994 }
995 } else {
996 if (Universe::heap()->is_in_reserved(addr)) {
997 st->print_cr(INTPTR_FORMAT " is an unallocated location "
998 "in the heap", p2i(addr));
999 return;
1000 }
1001 }
1002 if (JNIHandles::is_global_handle((jobject) addr)) {
1003 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
1004 return;
1005 }
1006 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1007 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
1008 return;
1009 }
1010 #ifndef PRODUCT
1011 // we don't keep the block list in product mode
1012 if (JNIHandleBlock::any_contains((jobject) addr)) {
1013 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
1014 return;
1015 }
1016 #endif
1017
1018 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
1019 // Check for privilege stack
1020 if (thread->privileged_stack_top() != NULL &&
1021 thread->privileged_stack_top()->contains(addr)) {
1022 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
1023 "for thread: " INTPTR_FORMAT, p2i(addr), p2i(thread));
1024 if (verbose) thread->print_on(st);
1025 return;
1026 }
1027 // If the addr is a java thread print information about that.
1028 if (addr == (address)thread) {
1029 if (verbose) {
1030 thread->print_on(st);
1031 } else {
1032 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
1033 }
1034 return;
1035 }
1036 // If the addr is in the stack region for this thread then report that
1037 // and print thread info
1038 if (thread->stack_base() >= addr &&
1039 addr > (thread->stack_base() - thread->stack_size())) {
1040 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1041 INTPTR_FORMAT, p2i(addr), p2i(thread));
1042 if (verbose) thread->print_on(st);
1043 return;
1044 }
1045
1046 }
1047
1048 // Check if in metaspace and print types that have vptrs (only method now)
1049 if (Metaspace::contains(addr)) {
1050 if (Method::has_method_vptr((const void*)addr)) {
1051 ((Method*)addr)->print_value_on(st);
1052 st->cr();
1053 } else {
1054 // Use addr->print() from the debugger instead (not here)
1055 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
1056 }
1057 return;
1058 }
1059
1060 // Try an OS specific find
1061 if (os::find(addr, st)) {
1062 return;
1063 }
1064
1065 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
1066 }
1067
1068 // Looks like all platforms except IA64 can use the same function to check
1069 // if C stack is walkable beyond current frame. The check for fp() is not
1070 // necessary on Sparc, but it's harmless.
1071 bool os::is_first_C_frame(frame* fr) {
1072 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1073 // On IA64 we have to check if the callers bsp is still valid
1074 // (i.e. within the register stack bounds).
1075 // Notice: this only works for threads created by the VM and only if
1076 // we walk the current stack!!! If we want to be able to walk
1077 // arbitrary other threads, we'll have to somehow store the thread
1078 // object in the frame.
1079 Thread *thread = Thread::current();
1080 if ((address)fr->fp() <=
1081 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1082 // This check is a little hacky, because on Linux the first C
1083 // frame's ('start_thread') register stack frame starts at
1084 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1085 // ('__pthread_bound_body') register stack frame seems to really
1086 // start at "register_stack_base".
1087 return true;
1088 } else {
1089 return false;
1090 }
1091 #elif defined(IA64) && defined(_WIN32)
1092 return true;
1093 #else
1094 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1095 // Check usp first, because if that's bad the other accessors may fault
1096 // on some architectures. Ditto ufp second, etc.
1097 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1098 // sp on amd can be 32 bit aligned.
1099 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1100
1101 uintptr_t usp = (uintptr_t)fr->sp();
1102 if ((usp & sp_align_mask) != 0) return true;
1103
1104 uintptr_t ufp = (uintptr_t)fr->fp();
1105 if ((ufp & fp_align_mask) != 0) return true;
1106
1107 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1108 if ((old_sp & sp_align_mask) != 0) return true;
1109 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1110
1111 uintptr_t old_fp = (uintptr_t)fr->link();
1112 if ((old_fp & fp_align_mask) != 0) return true;
1113 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1114
1115 // stack grows downwards; if old_fp is below current fp or if the stack
1116 // frame is too large, either the stack is corrupted or fp is not saved
1117 // on stack (i.e. on x86, ebp may be used as general register). The stack
1118 // is not walkable beyond current frame.
1119 if (old_fp < ufp) return true;
1120 if (old_fp - ufp > 64 * K) return true;
1121
1122 return false;
1123 #endif
1124 }
1125
1126 #ifdef ASSERT
1127 extern "C" void test_random() {
1128 const double m = 2147483647;
1129 double mean = 0.0, variance = 0.0, t;
1130 long reps = 10000;
1131 unsigned long seed = 1;
1132
1133 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1134 os::init_random(seed);
1135 long num;
1136 for (int k = 0; k < reps; k++) {
1137 num = os::random();
1138 double u = (double)num / m;
1139 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1140
1141 // calculate mean and variance of the random sequence
1142 mean += u;
1143 variance += (u*u);
1144 }
1145 mean /= reps;
1146 variance /= (reps - 1);
1147
1148 assert(num == 1043618065, "bad seed");
1149 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1150 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1151 const double eps = 0.0001;
1152 t = fabsd(mean - 0.5018);
1153 assert(t < eps, "bad mean");
1154 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1155 assert(t < eps, "bad variance");
1156 }
1157 #endif
1158
1159
1160 // Set up the boot classpath.
1161
1162 char* os::format_boot_path(const char* format_string,
1163 const char* home,
1164 int home_len,
1165 char fileSep,
1166 char pathSep) {
1167 assert((fileSep == '/' && pathSep == ':') ||
1168 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1169
1170 // Scan the format string to determine the length of the actual
1171 // boot classpath, and handle platform dependencies as well.
1172 int formatted_path_len = 0;
1173 const char* p;
1174 for (p = format_string; *p != 0; ++p) {
1175 if (*p == '%') formatted_path_len += home_len - 1;
1176 ++formatted_path_len;
1177 }
1178
1179 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1180 if (formatted_path == NULL) {
1181 return NULL;
1182 }
1183
1184 // Create boot classpath from format, substituting separator chars and
1185 // java home directory.
1186 char* q = formatted_path;
1187 for (p = format_string; *p != 0; ++p) {
1188 switch (*p) {
1189 case '%':
1190 strcpy(q, home);
1191 q += home_len;
1192 break;
1193 case '/':
1194 *q++ = fileSep;
1195 break;
1196 case ':':
1197 *q++ = pathSep;
1198 break;
1199 default:
1200 *q++ = *p;
1201 }
1202 }
1203 *q = '\0';
1204
1205 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1206 return formatted_path;
1207 }
1208
1209 // returns a PATH of all entries in the given directory that do not start with a '.'
1210 static char* expand_entries_to_path(char* directory, char fileSep, char pathSep) {
1211 DIR* dir = os::opendir(directory);
1212 if (dir == NULL) return NULL;
1213
1214 char* path = NULL;
1215 size_t path_len = 0; // path length including \0 terminator
1216
1217 size_t directory_len = strlen(directory);
1218 struct dirent *entry;
1219 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(directory), mtInternal);
1220 while ((entry = os::readdir(dir, (dirent *) dbuf)) != NULL) {
1221 const char* name = entry->d_name;
1222 if (name[0] == '.') continue;
1223
1224 size_t name_len = strlen(name);
1225 size_t needed = directory_len + name_len + 2;
1226 size_t new_len = path_len + needed;
1227 if (path == NULL) {
1228 path = NEW_C_HEAP_ARRAY(char, new_len, mtInternal);
1229 } else {
1230 path = REALLOC_C_HEAP_ARRAY(char, path, new_len, mtInternal);
1231 }
1232 if (path == NULL)
1233 break;
1234
1235 // append <pathSep>directory<fileSep>name
1236 char* p = path;
1237 if (path_len > 0) {
1238 p += (path_len -1);
1239 *p = pathSep;
1240 p++;
1241 }
1242
1243 strcpy(p, directory);
1244 p += directory_len;
1245
1246 *p = fileSep;
1247 p++;
1248
1249 strcpy(p, name);
1250 p += name_len;
1251
1252 path_len = new_len;
1253 }
1254
1255 FREE_C_HEAP_ARRAY(char, dbuf);
1256 os::closedir(dir);
1257
1258 return path;
1259 }
1260
1261 bool os::set_boot_path(char fileSep, char pathSep) {
1262 const char* home = Arguments::get_java_home();
1263 int home_len = (int)strlen(home);
1264
1265 char* sysclasspath = NULL;
1266 struct stat st;
1267
1268 // modular image if bootmodules.jimage exists
1269 char* jimage = format_boot_path("%/lib/modules/" BOOT_IMAGE_NAME, home, home_len, fileSep, pathSep);
1270 if (jimage == NULL) return false;
1271 bool has_jimage = (os::stat(jimage, &st) == 0);
1272 if (has_jimage) {
1273 Arguments::set_sysclasspath(jimage);
1274 FREE_C_HEAP_ARRAY(char, jimage);
1275 return true;
1276 }
1277 FREE_C_HEAP_ARRAY(char, jimage);
1278
1279 // check if developer build with exploded modules
1280 char* modules_dir = format_boot_path("%/modules", home, home_len, fileSep, pathSep);
1281 if (os::stat(modules_dir, &st) == 0) {
1282 if ((st.st_mode & S_IFDIR) == S_IFDIR) {
1283 sysclasspath = expand_entries_to_path(modules_dir, fileSep, pathSep);
1284 }
1285 }
1286 FREE_C_HEAP_ARRAY(char, modules_dir);
1287
1288 // fallback to classes
1289 if (sysclasspath == NULL)
1290 sysclasspath = format_boot_path("%/classes", home, home_len, fileSep, pathSep);
1291
1292 if (sysclasspath == NULL) return false;
1293 Arguments::set_sysclasspath(sysclasspath);
1294 FREE_C_HEAP_ARRAY(char, sysclasspath);
1295
1296 return true;
1297 }
1298
1299 /*
1300 * Splits a path, based on its separator, the number of
1301 * elements is returned back in n.
1302 * It is the callers responsibility to:
1303 * a> check the value of n, and n may be 0.
1304 * b> ignore any empty path elements
1305 * c> free up the data.
1306 */
1307 char** os::split_path(const char* path, int* n) {
1308 *n = 0;
1309 if (path == NULL || strlen(path) == 0) {
1310 return NULL;
1311 }
1312 const char psepchar = *os::path_separator();
1313 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1314 if (inpath == NULL) {
1315 return NULL;
1316 }
1317 strcpy(inpath, path);
1318 int count = 1;
1319 char* p = strchr(inpath, psepchar);
1320 // Get a count of elements to allocate memory
1321 while (p != NULL) {
1322 count++;
1323 p++;
1324 p = strchr(p, psepchar);
1325 }
1326 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1327 if (opath == NULL) {
1328 return NULL;
1329 }
1330
1331 // do the actual splitting
1332 p = inpath;
1333 for (int i = 0 ; i < count ; i++) {
1334 size_t len = strcspn(p, os::path_separator());
1335 if (len > JVM_MAXPATHLEN) {
1336 return NULL;
1337 }
1338 // allocate the string and add terminator storage
1339 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1340 if (s == NULL) {
1341 return NULL;
1342 }
1343 strncpy(s, p, len);
1344 s[len] = '\0';
1345 opath[i] = s;
1346 p += len + 1;
1347 }
1348 FREE_C_HEAP_ARRAY(char, inpath);
1349 *n = count;
1350 return opath;
1351 }
1352
1353 void os::set_memory_serialize_page(address page) {
1354 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1355 _mem_serialize_page = (volatile int32_t *)page;
1356 // We initialize the serialization page shift count here
1357 // We assume a cache line size of 64 bytes
1358 assert(SerializePageShiftCount == count,
1359 "thread size changed, fix SerializePageShiftCount constant");
1360 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1361 }
1362
1363 static volatile intptr_t SerializePageLock = 0;
1364
1365 // This method is called from signal handler when SIGSEGV occurs while the current
1366 // thread tries to store to the "read-only" memory serialize page during state
1367 // transition.
1368 void os::block_on_serialize_page_trap() {
1369 log_debug(safepoint)("Block until the serialize page permission restored");
1370
1371 // When VMThread is holding the SerializePageLock during modifying the
1372 // access permission of the memory serialize page, the following call
1373 // will block until the permission of that page is restored to rw.
1374 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1375 // this case, it's OK as the signal is synchronous and we know precisely when
1376 // it can occur.
1377 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1378 Thread::muxRelease(&SerializePageLock);
1379 }
1380
1381 // Serialize all thread state variables
1382 void os::serialize_thread_states() {
1383 // On some platforms such as Solaris & Linux, the time duration of the page
1384 // permission restoration is observed to be much longer than expected due to
1385 // scheduler starvation problem etc. To avoid the long synchronization
1386 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1387 // the mutator thread if such case is encountered. See bug 6546278 for details.
1388 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1389 os::protect_memory((char *)os::get_memory_serialize_page(),
1390 os::vm_page_size(), MEM_PROT_READ);
1391 os::protect_memory((char *)os::get_memory_serialize_page(),
1392 os::vm_page_size(), MEM_PROT_RW);
1393 Thread::muxRelease(&SerializePageLock);
1394 }
1395
1396 // Returns true if the current stack pointer is above the stack shadow
1397 // pages, false otherwise.
1398
1399 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method) {
1400 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1401 address sp = current_stack_pointer();
1402 // Check if we have StackShadowPages above the yellow zone. This parameter
1403 // is dependent on the depth of the maximum VM call stack possible from
1404 // the handler for stack overflow. 'instanceof' in the stack overflow
1405 // handler or a println uses at least 8k stack of VM and native code
1406 // respectively.
1407 const int framesize_in_bytes =
1408 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1409 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1410 * vm_page_size()) + framesize_in_bytes;
1411 // The very lower end of the stack
1412 address stack_limit = thread->stack_base() - thread->stack_size();
1413 return (sp > (stack_limit + reserved_area));
1414 }
1415
1416 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1417 assert(min_pages > 0, "sanity");
1418 if (UseLargePages) {
1419 const size_t max_page_size = region_size / min_pages;
1420
1421 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1422 const size_t page_size = _page_sizes[i];
1423 if (page_size <= max_page_size) {
1424 if (!must_be_aligned || is_size_aligned(region_size, page_size)) {
1425 return page_size;
1426 }
1427 }
1428 }
1429 }
1430
1431 return vm_page_size();
1432 }
1433
1434 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1435 return page_size_for_region(region_size, min_pages, true);
1436 }
1437
1438 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1439 return page_size_for_region(region_size, min_pages, false);
1440 }
1441
1442 #ifndef PRODUCT
1443 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1444 {
1445 if (TracePageSizes) {
1446 tty->print("%s: ", str);
1447 for (int i = 0; i < count; ++i) {
1448 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1449 }
1450 tty->cr();
1451 }
1452 }
1453
1454 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1455 const size_t region_max_size, const size_t page_size,
1456 const char* base, const size_t size)
1457 {
1458 if (TracePageSizes) {
1459 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1460 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1461 " size=" SIZE_FORMAT,
1462 str, region_min_size, region_max_size,
1463 page_size, p2i(base), size);
1464 }
1465 }
1466 #endif // #ifndef PRODUCT
1467
1468 // This is the working definition of a server class machine:
1469 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1470 // because the graphics memory (?) sometimes masks physical memory.
1471 // If you want to change the definition of a server class machine
1472 // on some OS or platform, e.g., >=4GB on Windows platforms,
1473 // then you'll have to parameterize this method based on that state,
1474 // as was done for logical processors here, or replicate and
1475 // specialize this method for each platform. (Or fix os to have
1476 // some inheritance structure and use subclassing. Sigh.)
1477 // If you want some platform to always or never behave as a server
1478 // class machine, change the setting of AlwaysActAsServerClassMachine
1479 // and NeverActAsServerClassMachine in globals*.hpp.
1480 bool os::is_server_class_machine() {
1481 // First check for the early returns
1482 if (NeverActAsServerClassMachine) {
1483 return false;
1484 }
1485 if (AlwaysActAsServerClassMachine) {
1486 return true;
1487 }
1488 // Then actually look at the machine
1489 bool result = false;
1490 const unsigned int server_processors = 2;
1491 const julong server_memory = 2UL * G;
1492 // We seem not to get our full complement of memory.
1493 // We allow some part (1/8?) of the memory to be "missing",
1494 // based on the sizes of DIMMs, and maybe graphics cards.
1495 const julong missing_memory = 256UL * M;
1496
1497 /* Is this a server class machine? */
1498 if ((os::active_processor_count() >= (int)server_processors) &&
1499 (os::physical_memory() >= (server_memory - missing_memory))) {
1500 const unsigned int logical_processors =
1501 VM_Version::logical_processors_per_package();
1502 if (logical_processors > 1) {
1503 const unsigned int physical_packages =
1504 os::active_processor_count() / logical_processors;
1505 if (physical_packages > server_processors) {
1506 result = true;
1507 }
1508 } else {
1509 result = true;
1510 }
1511 }
1512 return result;
1513 }
1514
1515 void os::SuspendedThreadTask::run() {
1516 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1517 internal_do_task();
1518 _done = true;
1519 }
1520
1521 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1522 return os::pd_create_stack_guard_pages(addr, bytes);
1523 }
1524
1525 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1526 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1527 if (result != NULL) {
1528 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1529 }
1530
1531 return result;
1532 }
1533
1534 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1535 MEMFLAGS flags) {
1536 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1537 if (result != NULL) {
1538 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1539 MemTracker::record_virtual_memory_type((address)result, flags);
1540 }
1541
1542 return result;
1543 }
1544
1545 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1546 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1547 if (result != NULL) {
1548 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1549 }
1550 return result;
1551 }
1552
1553 void os::split_reserved_memory(char *base, size_t size,
1554 size_t split, bool realloc) {
1555 pd_split_reserved_memory(base, size, split, realloc);
1556 }
1557
1558 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1559 bool res = pd_commit_memory(addr, bytes, executable);
1560 if (res) {
1561 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1562 }
1563 return res;
1564 }
1565
1566 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1567 bool executable) {
1568 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1569 if (res) {
1570 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1571 }
1572 return res;
1573 }
1574
1575 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1576 const char* mesg) {
1577 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1578 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1579 }
1580
1581 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1582 bool executable, const char* mesg) {
1583 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1584 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1585 }
1586
1587 bool os::uncommit_memory(char* addr, size_t bytes) {
1588 bool res;
1589 if (MemTracker::tracking_level() > NMT_minimal) {
1590 Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1591 res = pd_uncommit_memory(addr, bytes);
1592 if (res) {
1593 tkr.record((address)addr, bytes);
1594 }
1595 } else {
1596 res = pd_uncommit_memory(addr, bytes);
1597 }
1598 return res;
1599 }
1600
1601 bool os::release_memory(char* addr, size_t bytes) {
1602 bool res;
1603 if (MemTracker::tracking_level() > NMT_minimal) {
1604 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1605 res = pd_release_memory(addr, bytes);
1606 if (res) {
1607 tkr.record((address)addr, bytes);
1608 }
1609 } else {
1610 res = pd_release_memory(addr, bytes);
1611 }
1612 return res;
1613 }
1614
1615 void os::pretouch_memory(char* start, char* end) {
1616 for (volatile char *p = start; p < end; p += os::vm_page_size()) {
1617 *p = 0;
1618 }
1619 }
1620
1621 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1622 char *addr, size_t bytes, bool read_only,
1623 bool allow_exec) {
1624 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1625 if (result != NULL) {
1626 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1627 }
1628 return result;
1629 }
1630
1631 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1632 char *addr, size_t bytes, bool read_only,
1633 bool allow_exec) {
1634 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1635 read_only, allow_exec);
1636 }
1637
1638 bool os::unmap_memory(char *addr, size_t bytes) {
1639 bool result;
1640 if (MemTracker::tracking_level() > NMT_minimal) {
1641 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1642 result = pd_unmap_memory(addr, bytes);
1643 if (result) {
1644 tkr.record((address)addr, bytes);
1645 }
1646 } else {
1647 result = pd_unmap_memory(addr, bytes);
1648 }
1649 return result;
1650 }
1651
1652 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1653 pd_free_memory(addr, bytes, alignment_hint);
1654 }
1655
1656 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1657 pd_realign_memory(addr, bytes, alignment_hint);
1658 }
1659
1660 #ifndef TARGET_OS_FAMILY_windows
1661 /* try to switch state from state "from" to state "to"
1662 * returns the state set after the method is complete
1663 */
1664 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1665 os::SuspendResume::State to)
1666 {
1667 os::SuspendResume::State result =
1668 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1669 if (result == from) {
1670 // success
1671 return to;
1672 }
1673 return result;
1674 }
1675 #endif
1676
1677 /////////////// Unit tests ///////////////
1678
1679 #ifndef PRODUCT
1680
1681 #define assert_eq(a,b) assert(a == b, SIZE_FORMAT " != " SIZE_FORMAT, a, b)
1682
1683 class TestOS : AllStatic {
1684 static size_t small_page_size() {
1685 return os::vm_page_size();
1686 }
1687
1688 static size_t large_page_size() {
1689 const size_t large_page_size_example = 4 * M;
1690 return os::page_size_for_region_aligned(large_page_size_example, 1);
1691 }
1692
1693 static void test_page_size_for_region_aligned() {
1694 if (UseLargePages) {
1695 const size_t small_page = small_page_size();
1696 const size_t large_page = large_page_size();
1697
1698 if (large_page > small_page) {
1699 size_t num_small_pages_in_large = large_page / small_page;
1700 size_t page = os::page_size_for_region_aligned(large_page, num_small_pages_in_large);
1701
1702 assert_eq(page, small_page);
1703 }
1704 }
1705 }
1706
1707 static void test_page_size_for_region_alignment() {
1708 if (UseLargePages) {
1709 const size_t small_page = small_page_size();
1710 const size_t large_page = large_page_size();
1711 if (large_page > small_page) {
1712 const size_t unaligned_region = large_page + 17;
1713 size_t page = os::page_size_for_region_aligned(unaligned_region, 1);
1714 assert_eq(page, small_page);
1715
1716 const size_t num_pages = 5;
1717 const size_t aligned_region = large_page * num_pages;
1718 page = os::page_size_for_region_aligned(aligned_region, num_pages);
1719 assert_eq(page, large_page);
1720 }
1721 }
1722 }
1723
1724 static void test_page_size_for_region_unaligned() {
1725 if (UseLargePages) {
1726 // Given exact page size, should return that page size.
1727 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1728 size_t expected = os::_page_sizes[i];
1729 size_t actual = os::page_size_for_region_unaligned(expected, 1);
1730 assert_eq(expected, actual);
1731 }
1732
1733 // Given slightly larger size than a page size, return the page size.
1734 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1735 size_t expected = os::_page_sizes[i];
1736 size_t actual = os::page_size_for_region_unaligned(expected + 17, 1);
1737 assert_eq(expected, actual);
1738 }
1739
1740 // Given a slightly smaller size than a page size,
1741 // return the next smaller page size.
1742 if (os::_page_sizes[1] > os::_page_sizes[0]) {
1743 size_t expected = os::_page_sizes[0];
1744 size_t actual = os::page_size_for_region_unaligned(os::_page_sizes[1] - 17, 1);
1745 assert_eq(actual, expected);
1746 }
1747
1748 // Return small page size for values less than a small page.
1749 size_t small_page = small_page_size();
1750 size_t actual = os::page_size_for_region_unaligned(small_page - 17, 1);
1751 assert_eq(small_page, actual);
1752 }
1753 }
1754
1755 public:
1756 static void run_tests() {
1757 test_page_size_for_region_aligned();
1758 test_page_size_for_region_alignment();
1759 test_page_size_for_region_unaligned();
1760 }
1761 };
1762
1763 void TestOS_test() {
1764 TestOS::run_tests();
1765 }
1766
1767 #endif // PRODUCT