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 // VM version initialization identifies some characteristics of the
320 // the platform that are used during ergonomic decisions.
321 VM_Version::init_before_ergo();
322 }
323
324 void os::signal_init() {
325 if (!ReduceSignalUsage) {
326 // Setup JavaThread for processing signals
327 EXCEPTION_MARK;
328 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
329 instanceKlassHandle klass (THREAD, k);
330 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
331
332 const char thread_name[] = "Signal Dispatcher";
333 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
334
335 // Initialize thread_oop to put it into the system threadGroup
336 Handle thread_group (THREAD, Universe::system_thread_group());
337 JavaValue result(T_VOID);
338 JavaCalls::call_special(&result, thread_oop,
339 klass,
340 vmSymbols::object_initializer_name(),
341 vmSymbols::threadgroup_string_void_signature(),
342 thread_group,
343 string,
344 CHECK);
345
346 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
347 JavaCalls::call_special(&result,
348 thread_group,
349 group,
350 vmSymbols::add_method_name(),
351 vmSymbols::thread_void_signature(),
352 thread_oop, // ARG 1
353 CHECK);
354
355 os::signal_init_pd();
356
357 { MutexLocker mu(Threads_lock);
358 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
359
360 // At this point it may be possible that no osthread was created for the
361 // JavaThread due to lack of memory. We would have to throw an exception
362 // in that case. However, since this must work and we do not allow
363 // exceptions anyway, check and abort if this fails.
364 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
365 vm_exit_during_initialization("java.lang.OutOfMemoryError",
366 os::native_thread_creation_failed_msg());
367 }
368
369 java_lang_Thread::set_thread(thread_oop(), signal_thread);
370 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
371 java_lang_Thread::set_daemon(thread_oop());
372
373 signal_thread->set_threadObj(thread_oop());
374 Threads::add(signal_thread);
375 Thread::start(signal_thread);
376 }
377 // Handle ^BREAK
378 os::signal(SIGBREAK, os::user_handler());
379 }
380 }
381
382
383 void os::terminate_signal_thread() {
384 if (!ReduceSignalUsage)
385 signal_notify(sigexitnum_pd());
386 }
387
388
389 // --------------------- loading libraries ---------------------
390
391 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
392 extern struct JavaVM_ main_vm;
393
394 static void* _native_java_library = NULL;
395
396 void* os::native_java_library() {
397 if (_native_java_library == NULL) {
398 char buffer[JVM_MAXPATHLEN];
399 char ebuf[1024];
400
401 // Try to load verify dll first. In 1.3 java dll depends on it and is not
402 // always able to find it when the loading executable is outside the JDK.
403 // In order to keep working with 1.2 we ignore any loading errors.
404 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
405 "verify")) {
406 dll_load(buffer, ebuf, sizeof(ebuf));
407 }
408
409 // Load java dll
410 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
411 "java")) {
412 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
413 }
414 if (_native_java_library == NULL) {
415 vm_exit_during_initialization("Unable to load native library", ebuf);
416 }
417
418 #if defined(__OpenBSD__)
419 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
420 // ignore errors
421 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
422 "net")) {
423 dll_load(buffer, ebuf, sizeof(ebuf));
424 }
425 #endif
426 }
427 static jboolean onLoaded = JNI_FALSE;
428 if (onLoaded) {
429 // We may have to wait to fire OnLoad until TLS is initialized.
430 if (ThreadLocalStorage::is_initialized()) {
431 // The JNI_OnLoad handling is normally done by method load in
432 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
433 // explicitly so we have to check for JNI_OnLoad as well
434 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
435 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
436 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
437 if (JNI_OnLoad != NULL) {
438 JavaThread* thread = JavaThread::current();
439 ThreadToNativeFromVM ttn(thread);
440 HandleMark hm(thread);
441 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
442 onLoaded = JNI_TRUE;
443 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
444 vm_exit_during_initialization("Unsupported JNI version");
445 }
446 }
447 }
448 }
449 return _native_java_library;
450 }
451
452 /*
453 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
454 * If check_lib == true then we are looking for an
455 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
456 * this library is statically linked into the image.
457 * If check_lib == false then we will look for the appropriate symbol in the
458 * executable if agent_lib->is_static_lib() == true or in the shared library
459 * referenced by 'handle'.
460 */
461 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
462 const char *syms[], size_t syms_len) {
463 assert(agent_lib != NULL, "sanity check");
464 const char *lib_name;
465 void *handle = agent_lib->os_lib();
466 void *entryName = NULL;
467 char *agent_function_name;
468 size_t i;
469
470 // If checking then use the agent name otherwise test is_static_lib() to
471 // see how to process this lookup
472 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
473 for (i = 0; i < syms_len; i++) {
474 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
475 if (agent_function_name == NULL) {
476 break;
477 }
478 entryName = dll_lookup(handle, agent_function_name);
479 FREE_C_HEAP_ARRAY(char, agent_function_name);
480 if (entryName != NULL) {
481 break;
482 }
483 }
484 return entryName;
485 }
486
487 // See if the passed in agent is statically linked into the VM image.
488 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
489 size_t syms_len) {
490 void *ret;
491 void *proc_handle;
492 void *save_handle;
493
494 assert(agent_lib != NULL, "sanity check");
495 if (agent_lib->name() == NULL) {
496 return false;
497 }
498 proc_handle = get_default_process_handle();
499 // Check for Agent_OnLoad/Attach_lib_name function
500 save_handle = agent_lib->os_lib();
501 // We want to look in this process' symbol table.
502 agent_lib->set_os_lib(proc_handle);
503 ret = find_agent_function(agent_lib, true, syms, syms_len);
504 if (ret != NULL) {
505 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
506 agent_lib->set_valid();
507 agent_lib->set_static_lib(true);
508 return true;
509 }
510 agent_lib->set_os_lib(save_handle);
511 return false;
512 }
513
514 // --------------------- heap allocation utilities ---------------------
515
516 char *os::strdup(const char *str, MEMFLAGS flags) {
517 size_t size = strlen(str);
518 char *dup_str = (char *)malloc(size + 1, flags);
519 if (dup_str == NULL) return NULL;
520 strcpy(dup_str, str);
521 return dup_str;
522 }
523
524 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
525 char* p = os::strdup(str, flags);
526 if (p == NULL) {
527 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
528 }
529 return p;
530 }
531
532
533 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
534
535 #ifdef ASSERT
536
537 static void verify_memory(void* ptr) {
538 GuardedMemory guarded(ptr);
539 if (!guarded.verify_guards()) {
540 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
541 tty->print_cr("## memory stomp:");
542 guarded.print_on(tty);
543 fatal("memory stomping error");
544 }
545 }
546
547 #endif
548
549 //
550 // This function supports testing of the malloc out of memory
551 // condition without really running the system out of memory.
552 //
553 static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
554 if (MallocMaxTestWords > 0) {
555 jint words = (jint)(alloc_size / BytesPerWord);
556
557 if ((cur_malloc_words + words) > MallocMaxTestWords) {
558 return true;
559 }
560 Atomic::add(words, (volatile jint *)&cur_malloc_words);
561 }
562 return false;
563 }
564
565 void* os::malloc(size_t size, MEMFLAGS flags) {
566 return os::malloc(size, flags, CALLER_PC);
567 }
568
569 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
570 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
571 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
572
573 #ifdef ASSERT
574 // checking for the WatcherThread and crash_protection first
575 // since os::malloc can be called when the libjvm.{dll,so} is
576 // first loaded and we don't have a thread yet.
577 // try to find the thread after we see that the watcher thread
578 // exists and has crash protection.
579 WatcherThread *wt = WatcherThread::watcher_thread();
580 if (wt != NULL && wt->has_crash_protection()) {
581 Thread* thread = ThreadLocalStorage::get_thread_slow();
582 if (thread == wt) {
583 assert(!wt->has_crash_protection(),
584 "Can't malloc with crash protection from WatcherThread");
585 }
586 }
587 #endif
588
589 if (size == 0) {
590 // return a valid pointer if size is zero
591 // if NULL is returned the calling functions assume out of memory.
592 size = 1;
593 }
594
595 // NMT support
596 NMT_TrackingLevel level = MemTracker::tracking_level();
597 size_t nmt_header_size = MemTracker::malloc_header_size(level);
598
599 #ifndef ASSERT
600 const size_t alloc_size = size + nmt_header_size;
601 #else
602 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
603 if (size + nmt_header_size > alloc_size) { // Check for rollover.
604 return NULL;
605 }
606 #endif
607
608 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
609
610 // For the test flag -XX:MallocMaxTestWords
611 if (has_reached_max_malloc_test_peak(size)) {
612 return NULL;
613 }
614
615 u_char* ptr;
616 ptr = (u_char*)::malloc(alloc_size);
617
618 #ifdef ASSERT
619 if (ptr == NULL) {
620 return NULL;
621 }
622 // Wrap memory with guard
623 GuardedMemory guarded(ptr, size + nmt_header_size);
624 ptr = guarded.get_user_ptr();
625 #endif
626 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
627 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
628 breakpoint();
629 }
630 debug_only(if (paranoid) verify_memory(ptr));
631 if (PrintMalloc && tty != NULL) {
632 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
633 }
634
635 // we do not track guard memory
636 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
637 }
638
639 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
640 return os::realloc(memblock, size, flags, CALLER_PC);
641 }
642
643 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
644
645 // For the test flag -XX:MallocMaxTestWords
646 if (has_reached_max_malloc_test_peak(size)) {
647 return NULL;
648 }
649
650 #ifndef ASSERT
651 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
652 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
653 // NMT support
654 void* membase = MemTracker::record_free(memblock);
655 NMT_TrackingLevel level = MemTracker::tracking_level();
656 size_t nmt_header_size = MemTracker::malloc_header_size(level);
657 void* ptr = ::realloc(membase, size + nmt_header_size);
658 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
659 #else
660 if (memblock == NULL) {
661 return os::malloc(size, memflags, stack);
662 }
663 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
664 tty->print_cr("os::realloc caught " PTR_FORMAT, p2i(memblock));
665 breakpoint();
666 }
667 // NMT support
668 void* membase = MemTracker::malloc_base(memblock);
669 verify_memory(membase);
670 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
671 if (size == 0) {
672 return NULL;
673 }
674 // always move the block
675 void* ptr = os::malloc(size, memflags, stack);
676 if (PrintMalloc && tty != NULL) {
677 tty->print_cr("os::realloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, p2i(memblock), p2i(ptr));
678 }
679 // Copy to new memory if malloc didn't fail
680 if ( ptr != NULL ) {
681 GuardedMemory guarded(MemTracker::malloc_base(memblock));
682 // Guard's user data contains NMT header
683 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
684 memcpy(ptr, memblock, MIN2(size, memblock_size));
685 if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
686 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
687 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
688 breakpoint();
689 }
690 os::free(memblock);
691 }
692 return ptr;
693 #endif
694 }
695
696
697 void os::free(void *memblock) {
698 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
699 #ifdef ASSERT
700 if (memblock == NULL) return;
701 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
702 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, p2i(memblock));
703 breakpoint();
704 }
705 void* membase = MemTracker::record_free(memblock);
706 verify_memory(membase);
707 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
708
709 GuardedMemory guarded(membase);
710 size_t size = guarded.get_user_size();
711 inc_stat_counter(&free_bytes, size);
712 membase = guarded.release_for_freeing();
713 if (PrintMalloc && tty != NULL) {
714 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
715 }
716 ::free(membase);
717 #else
718 void* membase = MemTracker::record_free(memblock);
719 ::free(membase);
720 #endif
721 }
722
723 void os::init_random(long initval) {
724 _rand_seed = initval;
725 }
726
727
728 long os::random() {
729 /* standard, well-known linear congruential random generator with
730 * next_rand = (16807*seed) mod (2**31-1)
731 * see
732 * (1) "Random Number Generators: Good Ones Are Hard to Find",
733 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
734 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
735 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
736 */
737 const long a = 16807;
738 const unsigned long m = 2147483647;
739 const long q = m / a; assert(q == 127773, "weird math");
740 const long r = m % a; assert(r == 2836, "weird math");
741
742 // compute az=2^31p+q
743 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
744 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
745 lo += (hi & 0x7FFF) << 16;
746
747 // if q overflowed, ignore the overflow and increment q
748 if (lo > m) {
749 lo &= m;
750 ++lo;
751 }
752 lo += hi >> 15;
753
754 // if (p+q) overflowed, ignore the overflow and increment (p+q)
755 if (lo > m) {
756 lo &= m;
757 ++lo;
758 }
759 return (_rand_seed = lo);
760 }
761
762 // The INITIALIZED state is distinguished from the SUSPENDED state because the
763 // conditions in which a thread is first started are different from those in which
764 // a suspension is resumed. These differences make it hard for us to apply the
765 // tougher checks when starting threads that we want to do when resuming them.
766 // However, when start_thread is called as a result of Thread.start, on a Java
767 // thread, the operation is synchronized on the Java Thread object. So there
768 // cannot be a race to start the thread and hence for the thread to exit while
769 // we are working on it. Non-Java threads that start Java threads either have
770 // to do so in a context in which races are impossible, or should do appropriate
771 // locking.
772
773 void os::start_thread(Thread* thread) {
774 // guard suspend/resume
775 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
776 OSThread* osthread = thread->osthread();
777 osthread->set_state(RUNNABLE);
778 pd_start_thread(thread);
779 }
780
781 void os::abort(bool dump_core) {
782 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
783 }
784
785 //---------------------------------------------------------------------------
786 // Helper functions for fatal error handler
787
788 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
789 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
790
791 int cols = 0;
792 int cols_per_line = 0;
793 switch (unitsize) {
794 case 1: cols_per_line = 16; break;
795 case 2: cols_per_line = 8; break;
796 case 4: cols_per_line = 4; break;
797 case 8: cols_per_line = 2; break;
798 default: return;
799 }
800
801 address p = start;
802 st->print(PTR_FORMAT ": ", p2i(start));
803 while (p < end) {
804 switch (unitsize) {
805 case 1: st->print("%02x", *(u1*)p); break;
806 case 2: st->print("%04x", *(u2*)p); break;
807 case 4: st->print("%08x", *(u4*)p); break;
808 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
809 }
810 p += unitsize;
811 cols++;
812 if (cols >= cols_per_line && p < end) {
813 cols = 0;
814 st->cr();
815 st->print(PTR_FORMAT ": ", p2i(p));
816 } else {
817 st->print(" ");
818 }
819 }
820 st->cr();
821 }
822
823 void os::print_environment_variables(outputStream* st, const char** env_list) {
824 if (env_list) {
825 st->print_cr("Environment Variables:");
826
827 for (int i = 0; env_list[i] != NULL; i++) {
828 char *envvar = ::getenv(env_list[i]);
829 if (envvar != NULL) {
830 st->print("%s", env_list[i]);
831 st->print("=");
832 st->print_cr("%s", envvar);
833 }
834 }
835 }
836 }
837
838 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
839 // cpu
840 st->print("CPU:");
841 st->print("total %d", os::processor_count());
842 // It's not safe to query number of active processors after crash
843 // st->print("(active %d)", os::active_processor_count());
844 st->print(" %s", VM_Version::cpu_features());
845 st->cr();
846 pd_print_cpu_info(st, buf, buflen);
847 }
848
849 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version
850 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
851 st->print("Host: ");
852 #ifndef PRODUCT
853 if (get_host_name(buf, buflen)) {
854 st->print("%s, ", buf);
855 }
856 #endif // PRODUCT
857 get_summary_cpu_info(buf, buflen);
858 st->print("%s, ", buf);
859 size_t mem = physical_memory()/G;
860 if (mem == 0) { // for low memory systems
861 mem = physical_memory()/M;
862 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
863 } else {
864 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
865 }
866 get_summary_os_info(buf, buflen);
867 st->print_raw(buf);
868 st->cr();
869 }
870
871 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
872 const int secs_per_day = 86400;
873 const int secs_per_hour = 3600;
874 const int secs_per_min = 60;
875
876 time_t tloc;
877 (void)time(&tloc);
878 char* timestring = ctime(&tloc); // ctime adds newline.
879 // edit out the newline
880 char* nl = strchr(timestring, '\n');
881 if (nl != NULL) {
882 *nl = '\0';
883 }
884
885 struct tm tz;
886 if (localtime_pd(&tloc, &tz) != NULL) {
887 ::strftime(buf, buflen, "%Z", &tz);
888 st->print("Time: %s %s", timestring, buf);
889 } else {
890 st->print("Time: %s", timestring);
891 }
892
893 double t = os::elapsedTime();
894 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
895 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
896 // before printf. We lost some precision, but who cares?
897 int eltime = (int)t; // elapsed time in seconds
898
899 // print elapsed time in a human-readable format:
900 int eldays = eltime / secs_per_day;
901 int day_secs = eldays * secs_per_day;
902 int elhours = (eltime - day_secs) / secs_per_hour;
903 int hour_secs = elhours * secs_per_hour;
904 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
905 int minute_secs = elmins * secs_per_min;
906 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
907 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
908 }
909
910 // moved from debug.cpp (used to be find()) but still called from there
911 // The verbose parameter is only set by the debug code in one case
912 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
913 address addr = (address)x;
914 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
915 if (b != NULL) {
916 if (b->is_buffer_blob()) {
917 // the interpreter is generated into a buffer blob
918 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
919 if (i != NULL) {
920 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", p2i(addr), (int)(addr - i->code_begin()));
921 i->print_on(st);
922 return;
923 }
924 if (Interpreter::contains(addr)) {
925 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
926 " (not bytecode specific)", p2i(addr));
927 return;
928 }
929 //
930 if (AdapterHandlerLibrary::contains(b)) {
931 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", p2i(addr), (int)(addr - b->code_begin()));
932 AdapterHandlerLibrary::print_handler_on(st, b);
933 }
934 // the stubroutines are generated into a buffer blob
935 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
936 if (d != NULL) {
937 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", p2i(addr), (int)(addr - d->begin()));
938 d->print_on(st);
939 st->cr();
940 return;
941 }
942 if (StubRoutines::contains(addr)) {
943 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) stub routine", p2i(addr));
944 return;
945 }
946 // the InlineCacheBuffer is using stubs generated into a buffer blob
947 if (InlineCacheBuffer::contains(addr)) {
948 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", p2i(addr));
949 return;
950 }
951 VtableStub* v = VtableStubs::stub_containing(addr);
952 if (v != NULL) {
953 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", p2i(addr), (int)(addr - v->entry_point()));
954 v->print_on(st);
955 st->cr();
956 return;
957 }
958 }
959 nmethod* nm = b->as_nmethod_or_null();
960 if (nm != NULL) {
961 ResourceMark rm;
962 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
963 p2i(addr), (int)(addr - nm->entry_point()), p2i(nm));
964 if (verbose) {
965 st->print(" for ");
966 nm->method()->print_value_on(st);
967 }
968 st->cr();
969 nm->print_nmethod(verbose);
970 return;
971 }
972 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", p2i(addr), (int)(addr - b->code_begin()));
973 b->print_on(st);
974 return;
975 }
976
977 if (Universe::heap()->is_in(addr)) {
978 HeapWord* p = Universe::heap()->block_start(addr);
979 bool print = false;
980 // If we couldn't find it it just may mean that heap wasn't parsable
981 // See if we were just given an oop directly
982 if (p != NULL && Universe::heap()->block_is_obj(p)) {
983 print = true;
984 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
985 p = (HeapWord*) addr;
986 print = true;
987 }
988 if (print) {
989 if (p == (HeapWord*) addr) {
990 st->print_cr(INTPTR_FORMAT " is an oop", p2i(addr));
991 } else {
992 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, p2i(addr), p2i(p));
993 }
994 oop(p)->print_on(st);
995 return;
996 }
997 } else {
998 if (Universe::heap()->is_in_reserved(addr)) {
999 st->print_cr(INTPTR_FORMAT " is an unallocated location "
1000 "in the heap", p2i(addr));
1001 return;
1002 }
1003 }
1004 if (JNIHandles::is_global_handle((jobject) addr)) {
1005 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
1006 return;
1007 }
1008 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1009 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
1010 return;
1011 }
1012 #ifndef PRODUCT
1013 // we don't keep the block list in product mode
1014 if (JNIHandleBlock::any_contains((jobject) addr)) {
1015 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
1016 return;
1017 }
1018 #endif
1019
1020 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
1021 // Check for privilege stack
1022 if (thread->privileged_stack_top() != NULL &&
1023 thread->privileged_stack_top()->contains(addr)) {
1024 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
1025 "for thread: " INTPTR_FORMAT, p2i(addr), p2i(thread));
1026 if (verbose) thread->print_on(st);
1027 return;
1028 }
1029 // If the addr is a java thread print information about that.
1030 if (addr == (address)thread) {
1031 if (verbose) {
1032 thread->print_on(st);
1033 } else {
1034 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
1035 }
1036 return;
1037 }
1038 // If the addr is in the stack region for this thread then report that
1039 // and print thread info
1040 if (thread->stack_base() >= addr &&
1041 addr > (thread->stack_base() - thread->stack_size())) {
1042 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1043 INTPTR_FORMAT, p2i(addr), p2i(thread));
1044 if (verbose) thread->print_on(st);
1045 return;
1046 }
1047
1048 }
1049
1050 // Check if in metaspace and print types that have vptrs (only method now)
1051 if (Metaspace::contains(addr)) {
1052 if (Method::has_method_vptr((const void*)addr)) {
1053 ((Method*)addr)->print_value_on(st);
1054 st->cr();
1055 } else {
1056 // Use addr->print() from the debugger instead (not here)
1057 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
1058 }
1059 return;
1060 }
1061
1062 // Try an OS specific find
1063 if (os::find(addr, st)) {
1064 return;
1065 }
1066
1067 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
1068 }
1069
1070 // Looks like all platforms except IA64 can use the same function to check
1071 // if C stack is walkable beyond current frame. The check for fp() is not
1072 // necessary on Sparc, but it's harmless.
1073 bool os::is_first_C_frame(frame* fr) {
1074 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1075 // On IA64 we have to check if the callers bsp is still valid
1076 // (i.e. within the register stack bounds).
1077 // Notice: this only works for threads created by the VM and only if
1078 // we walk the current stack!!! If we want to be able to walk
1079 // arbitrary other threads, we'll have to somehow store the thread
1080 // object in the frame.
1081 Thread *thread = Thread::current();
1082 if ((address)fr->fp() <=
1083 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1084 // This check is a little hacky, because on Linux the first C
1085 // frame's ('start_thread') register stack frame starts at
1086 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1087 // ('__pthread_bound_body') register stack frame seems to really
1088 // start at "register_stack_base".
1089 return true;
1090 } else {
1091 return false;
1092 }
1093 #elif defined(IA64) && defined(_WIN32)
1094 return true;
1095 #else
1096 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1097 // Check usp first, because if that's bad the other accessors may fault
1098 // on some architectures. Ditto ufp second, etc.
1099 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1100 // sp on amd can be 32 bit aligned.
1101 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1102
1103 uintptr_t usp = (uintptr_t)fr->sp();
1104 if ((usp & sp_align_mask) != 0) return true;
1105
1106 uintptr_t ufp = (uintptr_t)fr->fp();
1107 if ((ufp & fp_align_mask) != 0) return true;
1108
1109 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1110 if ((old_sp & sp_align_mask) != 0) return true;
1111 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1112
1113 uintptr_t old_fp = (uintptr_t)fr->link();
1114 if ((old_fp & fp_align_mask) != 0) return true;
1115 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1116
1117 // stack grows downwards; if old_fp is below current fp or if the stack
1118 // frame is too large, either the stack is corrupted or fp is not saved
1119 // on stack (i.e. on x86, ebp may be used as general register). The stack
1120 // is not walkable beyond current frame.
1121 if (old_fp < ufp) return true;
1122 if (old_fp - ufp > 64 * K) return true;
1123
1124 return false;
1125 #endif
1126 }
1127
1128 #ifdef ASSERT
1129 extern "C" void test_random() {
1130 const double m = 2147483647;
1131 double mean = 0.0, variance = 0.0, t;
1132 long reps = 10000;
1133 unsigned long seed = 1;
1134
1135 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1136 os::init_random(seed);
1137 long num;
1138 for (int k = 0; k < reps; k++) {
1139 num = os::random();
1140 double u = (double)num / m;
1141 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1142
1143 // calculate mean and variance of the random sequence
1144 mean += u;
1145 variance += (u*u);
1146 }
1147 mean /= reps;
1148 variance /= (reps - 1);
1149
1150 assert(num == 1043618065, "bad seed");
1151 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1152 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1153 const double eps = 0.0001;
1154 t = fabsd(mean - 0.5018);
1155 assert(t < eps, "bad mean");
1156 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1157 assert(t < eps, "bad variance");
1158 }
1159 #endif
1160
1161
1162 // Set up the boot classpath.
1163
1164 char* os::format_boot_path(const char* format_string,
1165 const char* home,
1166 int home_len,
1167 char fileSep,
1168 char pathSep) {
1169 assert((fileSep == '/' && pathSep == ':') ||
1170 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1171
1172 // Scan the format string to determine the length of the actual
1173 // boot classpath, and handle platform dependencies as well.
1174 int formatted_path_len = 0;
1175 const char* p;
1176 for (p = format_string; *p != 0; ++p) {
1177 if (*p == '%') formatted_path_len += home_len - 1;
1178 ++formatted_path_len;
1179 }
1180
1181 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1182 if (formatted_path == NULL) {
1183 return NULL;
1184 }
1185
1186 // Create boot classpath from format, substituting separator chars and
1187 // java home directory.
1188 char* q = formatted_path;
1189 for (p = format_string; *p != 0; ++p) {
1190 switch (*p) {
1191 case '%':
1192 strcpy(q, home);
1193 q += home_len;
1194 break;
1195 case '/':
1196 *q++ = fileSep;
1197 break;
1198 case ':':
1199 *q++ = pathSep;
1200 break;
1201 default:
1202 *q++ = *p;
1203 }
1204 }
1205 *q = '\0';
1206
1207 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1208 return formatted_path;
1209 }
1210
1211 // returns a PATH of all entries in the given directory that do not start with a '.'
1212 static char* expand_entries_to_path(char* directory, char fileSep, char pathSep) {
1213 DIR* dir = os::opendir(directory);
1214 if (dir == NULL) return NULL;
1215
1216 char* path = NULL;
1217 size_t path_len = 0; // path length including \0 terminator
1218
1219 size_t directory_len = strlen(directory);
1220 struct dirent *entry;
1221 char* dbuf = NEW_C_HEAP_ARRAY(char, os::readdir_buf_size(directory), mtInternal);
1222 while ((entry = os::readdir(dir, (dirent *) dbuf)) != NULL) {
1223 const char* name = entry->d_name;
1224 if (name[0] == '.') continue;
1225
1226 size_t name_len = strlen(name);
1227 size_t needed = directory_len + name_len + 2;
1228 size_t new_len = path_len + needed;
1229 if (path == NULL) {
1230 path = NEW_C_HEAP_ARRAY(char, new_len, mtInternal);
1231 } else {
1232 path = REALLOC_C_HEAP_ARRAY(char, path, new_len, mtInternal);
1233 }
1234 if (path == NULL)
1235 break;
1236
1237 // append <pathSep>directory<fileSep>name
1238 char* p = path;
1239 if (path_len > 0) {
1240 p += (path_len -1);
1241 *p = pathSep;
1242 p++;
1243 }
1244
1245 strcpy(p, directory);
1246 p += directory_len;
1247
1248 *p = fileSep;
1249 p++;
1250
1251 strcpy(p, name);
1252 p += name_len;
1253
1254 path_len = new_len;
1255 }
1256
1257 FREE_C_HEAP_ARRAY(char, dbuf);
1258 os::closedir(dir);
1259
1260 return path;
1261 }
1262
1263 bool os::set_boot_path(char fileSep, char pathSep) {
1264 const char* home = Arguments::get_java_home();
1265 int home_len = (int)strlen(home);
1266
1267 char* sysclasspath = NULL;
1268 struct stat st;
1269
1270 // modular image if bootmodules.jimage exists
1271 char* jimage = format_boot_path("%/lib/modules/" BOOT_IMAGE_NAME, home, home_len, fileSep, pathSep);
1272 if (jimage == NULL) return false;
1273 bool has_jimage = (os::stat(jimage, &st) == 0);
1274 if (has_jimage) {
1275 Arguments::set_sysclasspath(jimage);
1276 FREE_C_HEAP_ARRAY(char, jimage);
1277 return true;
1278 }
1279 FREE_C_HEAP_ARRAY(char, jimage);
1280
1281 // check if developer build with exploded modules
1282 char* modules_dir = format_boot_path("%/modules", home, home_len, fileSep, pathSep);
1283 if (os::stat(modules_dir, &st) == 0) {
1284 if ((st.st_mode & S_IFDIR) == S_IFDIR) {
1285 sysclasspath = expand_entries_to_path(modules_dir, fileSep, pathSep);
1286 }
1287 }
1288 FREE_C_HEAP_ARRAY(char, modules_dir);
1289
1290 // fallback to classes
1291 if (sysclasspath == NULL)
1292 sysclasspath = format_boot_path("%/classes", home, home_len, fileSep, pathSep);
1293
1294 if (sysclasspath == NULL) return false;
1295 Arguments::set_sysclasspath(sysclasspath);
1296 FREE_C_HEAP_ARRAY(char, sysclasspath);
1297
1298 return true;
1299 }
1300
1301 /*
1302 * Splits a path, based on its separator, the number of
1303 * elements is returned back in n.
1304 * It is the callers responsibility to:
1305 * a> check the value of n, and n may be 0.
1306 * b> ignore any empty path elements
1307 * c> free up the data.
1308 */
1309 char** os::split_path(const char* path, int* n) {
1310 *n = 0;
1311 if (path == NULL || strlen(path) == 0) {
1312 return NULL;
1313 }
1314 const char psepchar = *os::path_separator();
1315 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1316 if (inpath == NULL) {
1317 return NULL;
1318 }
1319 strcpy(inpath, path);
1320 int count = 1;
1321 char* p = strchr(inpath, psepchar);
1322 // Get a count of elements to allocate memory
1323 while (p != NULL) {
1324 count++;
1325 p++;
1326 p = strchr(p, psepchar);
1327 }
1328 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1329 if (opath == NULL) {
1330 return NULL;
1331 }
1332
1333 // do the actual splitting
1334 p = inpath;
1335 for (int i = 0 ; i < count ; i++) {
1336 size_t len = strcspn(p, os::path_separator());
1337 if (len > JVM_MAXPATHLEN) {
1338 return NULL;
1339 }
1340 // allocate the string and add terminator storage
1341 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1342 if (s == NULL) {
1343 return NULL;
1344 }
1345 strncpy(s, p, len);
1346 s[len] = '\0';
1347 opath[i] = s;
1348 p += len + 1;
1349 }
1350 FREE_C_HEAP_ARRAY(char, inpath);
1351 *n = count;
1352 return opath;
1353 }
1354
1355 void os::set_memory_serialize_page(address page) {
1356 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1357 _mem_serialize_page = (volatile int32_t *)page;
1358 // We initialize the serialization page shift count here
1359 // We assume a cache line size of 64 bytes
1360 assert(SerializePageShiftCount == count,
1361 "thread size changed, fix SerializePageShiftCount constant");
1362 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1363 }
1364
1365 static volatile intptr_t SerializePageLock = 0;
1366
1367 // This method is called from signal handler when SIGSEGV occurs while the current
1368 // thread tries to store to the "read-only" memory serialize page during state
1369 // transition.
1370 void os::block_on_serialize_page_trap() {
1371 log_debug(safepoint)("Block until the serialize page permission restored");
1372
1373 // When VMThread is holding the SerializePageLock during modifying the
1374 // access permission of the memory serialize page, the following call
1375 // will block until the permission of that page is restored to rw.
1376 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1377 // this case, it's OK as the signal is synchronous and we know precisely when
1378 // it can occur.
1379 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1380 Thread::muxRelease(&SerializePageLock);
1381 }
1382
1383 // Serialize all thread state variables
1384 void os::serialize_thread_states() {
1385 // On some platforms such as Solaris & Linux, the time duration of the page
1386 // permission restoration is observed to be much longer than expected due to
1387 // scheduler starvation problem etc. To avoid the long synchronization
1388 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1389 // the mutator thread if such case is encountered. See bug 6546278 for details.
1390 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1391 os::protect_memory((char *)os::get_memory_serialize_page(),
1392 os::vm_page_size(), MEM_PROT_READ);
1393 os::protect_memory((char *)os::get_memory_serialize_page(),
1394 os::vm_page_size(), MEM_PROT_RW);
1395 Thread::muxRelease(&SerializePageLock);
1396 }
1397
1398 // Returns true if the current stack pointer is above the stack shadow
1399 // pages, false otherwise.
1400
1401 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method) {
1402 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1403 address sp = current_stack_pointer();
1404 // Check if we have StackShadowPages above the yellow zone. This parameter
1405 // is dependent on the depth of the maximum VM call stack possible from
1406 // the handler for stack overflow. 'instanceof' in the stack overflow
1407 // handler or a println uses at least 8k stack of VM and native code
1408 // respectively.
1409 const int framesize_in_bytes =
1410 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1411 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1412 * vm_page_size()) + framesize_in_bytes;
1413 // The very lower end of the stack
1414 address stack_limit = thread->stack_base() - thread->stack_size();
1415 return (sp > (stack_limit + reserved_area));
1416 }
1417
1418 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1419 assert(min_pages > 0, "sanity");
1420 if (UseLargePages) {
1421 const size_t max_page_size = region_size / min_pages;
1422
1423 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1424 const size_t page_size = _page_sizes[i];
1425 if (page_size <= max_page_size) {
1426 if (!must_be_aligned || is_size_aligned(region_size, page_size)) {
1427 return page_size;
1428 }
1429 }
1430 }
1431 }
1432
1433 return vm_page_size();
1434 }
1435
1436 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1437 return page_size_for_region(region_size, min_pages, true);
1438 }
1439
1440 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1441 return page_size_for_region(region_size, min_pages, false);
1442 }
1443
1444 #ifndef PRODUCT
1445 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1446 {
1447 if (TracePageSizes) {
1448 tty->print("%s: ", str);
1449 for (int i = 0; i < count; ++i) {
1450 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1451 }
1452 tty->cr();
1453 }
1454 }
1455
1456 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1457 const size_t region_max_size, const size_t page_size,
1458 const char* base, const size_t size)
1459 {
1460 if (TracePageSizes) {
1461 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1462 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1463 " size=" SIZE_FORMAT,
1464 str, region_min_size, region_max_size,
1465 page_size, p2i(base), size);
1466 }
1467 }
1468 #endif // #ifndef PRODUCT
1469
1470 // This is the working definition of a server class machine:
1471 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1472 // because the graphics memory (?) sometimes masks physical memory.
1473 // If you want to change the definition of a server class machine
1474 // on some OS or platform, e.g., >=4GB on Windows platforms,
1475 // then you'll have to parameterize this method based on that state,
1476 // as was done for logical processors here, or replicate and
1477 // specialize this method for each platform. (Or fix os to have
1478 // some inheritance structure and use subclassing. Sigh.)
1479 // If you want some platform to always or never behave as a server
1480 // class machine, change the setting of AlwaysActAsServerClassMachine
1481 // and NeverActAsServerClassMachine in globals*.hpp.
1482 bool os::is_server_class_machine() {
1483 // First check for the early returns
1484 if (NeverActAsServerClassMachine) {
1485 return false;
1486 }
1487 if (AlwaysActAsServerClassMachine) {
1488 return true;
1489 }
1490 // Then actually look at the machine
1491 bool result = false;
1492 const unsigned int server_processors = 2;
1493 const julong server_memory = 2UL * G;
1494 // We seem not to get our full complement of memory.
1495 // We allow some part (1/8?) of the memory to be "missing",
1496 // based on the sizes of DIMMs, and maybe graphics cards.
1497 const julong missing_memory = 256UL * M;
1498
1499 /* Is this a server class machine? */
1500 if ((os::active_processor_count() >= (int)server_processors) &&
1501 (os::physical_memory() >= (server_memory - missing_memory))) {
1502 const unsigned int logical_processors =
1503 VM_Version::logical_processors_per_package();
1504 if (logical_processors > 1) {
1505 const unsigned int physical_packages =
1506 os::active_processor_count() / logical_processors;
1507 if (physical_packages > server_processors) {
1508 result = true;
1509 }
1510 } else {
1511 result = true;
1512 }
1513 }
1514 return result;
1515 }
1516
1517 void os::SuspendedThreadTask::run() {
1518 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1519 internal_do_task();
1520 _done = true;
1521 }
1522
1523 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1524 return os::pd_create_stack_guard_pages(addr, bytes);
1525 }
1526
1527 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1528 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1529 if (result != NULL) {
1530 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1531 }
1532
1533 return result;
1534 }
1535
1536 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1537 MEMFLAGS flags) {
1538 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1539 if (result != NULL) {
1540 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1541 MemTracker::record_virtual_memory_type((address)result, flags);
1542 }
1543
1544 return result;
1545 }
1546
1547 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1548 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1549 if (result != NULL) {
1550 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1551 }
1552 return result;
1553 }
1554
1555 void os::split_reserved_memory(char *base, size_t size,
1556 size_t split, bool realloc) {
1557 pd_split_reserved_memory(base, size, split, realloc);
1558 }
1559
1560 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1561 bool res = pd_commit_memory(addr, bytes, executable);
1562 if (res) {
1563 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1564 }
1565 return res;
1566 }
1567
1568 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1569 bool executable) {
1570 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1571 if (res) {
1572 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1573 }
1574 return res;
1575 }
1576
1577 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1578 const char* mesg) {
1579 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1580 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1581 }
1582
1583 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1584 bool executable, const char* mesg) {
1585 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1586 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1587 }
1588
1589 bool os::uncommit_memory(char* addr, size_t bytes) {
1590 bool res;
1591 if (MemTracker::tracking_level() > NMT_minimal) {
1592 Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1593 res = pd_uncommit_memory(addr, bytes);
1594 if (res) {
1595 tkr.record((address)addr, bytes);
1596 }
1597 } else {
1598 res = pd_uncommit_memory(addr, bytes);
1599 }
1600 return res;
1601 }
1602
1603 bool os::release_memory(char* addr, size_t bytes) {
1604 bool res;
1605 if (MemTracker::tracking_level() > NMT_minimal) {
1606 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1607 res = pd_release_memory(addr, bytes);
1608 if (res) {
1609 tkr.record((address)addr, bytes);
1610 }
1611 } else {
1612 res = pd_release_memory(addr, bytes);
1613 }
1614 return res;
1615 }
1616
1617 void os::pretouch_memory(char* start, char* end) {
1618 for (volatile char *p = start; p < end; p += os::vm_page_size()) {
1619 *p = 0;
1620 }
1621 }
1622
1623 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1624 char *addr, size_t bytes, bool read_only,
1625 bool allow_exec) {
1626 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1627 if (result != NULL) {
1628 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1629 }
1630 return result;
1631 }
1632
1633 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1634 char *addr, size_t bytes, bool read_only,
1635 bool allow_exec) {
1636 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1637 read_only, allow_exec);
1638 }
1639
1640 bool os::unmap_memory(char *addr, size_t bytes) {
1641 bool result;
1642 if (MemTracker::tracking_level() > NMT_minimal) {
1643 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1644 result = pd_unmap_memory(addr, bytes);
1645 if (result) {
1646 tkr.record((address)addr, bytes);
1647 }
1648 } else {
1649 result = pd_unmap_memory(addr, bytes);
1650 }
1651 return result;
1652 }
1653
1654 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1655 pd_free_memory(addr, bytes, alignment_hint);
1656 }
1657
1658 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1659 pd_realign_memory(addr, bytes, alignment_hint);
1660 }
1661
1662 #ifndef TARGET_OS_FAMILY_windows
1663 /* try to switch state from state "from" to state "to"
1664 * returns the state set after the method is complete
1665 */
1666 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1667 os::SuspendResume::State to)
1668 {
1669 os::SuspendResume::State result =
1670 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1671 if (result == from) {
1672 // success
1673 return to;
1674 }
1675 return result;
1676 }
1677 #endif
1678
1679 /////////////// Unit tests ///////////////
1680
1681 #ifndef PRODUCT
1682
1683 #define assert_eq(a,b) assert(a == b, SIZE_FORMAT " != " SIZE_FORMAT, a, b)
1684
1685 class TestOS : AllStatic {
1686 static size_t small_page_size() {
1687 return os::vm_page_size();
1688 }
1689
1690 static size_t large_page_size() {
1691 const size_t large_page_size_example = 4 * M;
1692 return os::page_size_for_region_aligned(large_page_size_example, 1);
1693 }
1694
1695 static void test_page_size_for_region_aligned() {
1696 if (UseLargePages) {
1697 const size_t small_page = small_page_size();
1698 const size_t large_page = large_page_size();
1699
1700 if (large_page > small_page) {
1701 size_t num_small_pages_in_large = large_page / small_page;
1702 size_t page = os::page_size_for_region_aligned(large_page, num_small_pages_in_large);
1703
1704 assert_eq(page, small_page);
1705 }
1706 }
1707 }
1708
1709 static void test_page_size_for_region_alignment() {
1710 if (UseLargePages) {
1711 const size_t small_page = small_page_size();
1712 const size_t large_page = large_page_size();
1713 if (large_page > small_page) {
1714 const size_t unaligned_region = large_page + 17;
1715 size_t page = os::page_size_for_region_aligned(unaligned_region, 1);
1716 assert_eq(page, small_page);
1717
1718 const size_t num_pages = 5;
1719 const size_t aligned_region = large_page * num_pages;
1720 page = os::page_size_for_region_aligned(aligned_region, num_pages);
1721 assert_eq(page, large_page);
1722 }
1723 }
1724 }
1725
1726 static void test_page_size_for_region_unaligned() {
1727 if (UseLargePages) {
1728 // Given exact page size, should return that page size.
1729 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1730 size_t expected = os::_page_sizes[i];
1731 size_t actual = os::page_size_for_region_unaligned(expected, 1);
1732 assert_eq(expected, actual);
1733 }
1734
1735 // Given slightly larger size than a page size, return the page size.
1736 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1737 size_t expected = os::_page_sizes[i];
1738 size_t actual = os::page_size_for_region_unaligned(expected + 17, 1);
1739 assert_eq(expected, actual);
1740 }
1741
1742 // Given a slightly smaller size than a page size,
1743 // return the next smaller page size.
1744 if (os::_page_sizes[1] > os::_page_sizes[0]) {
1745 size_t expected = os::_page_sizes[0];
1746 size_t actual = os::page_size_for_region_unaligned(os::_page_sizes[1] - 17, 1);
1747 assert_eq(actual, expected);
1748 }
1749
1750 // Return small page size for values less than a small page.
1751 size_t small_page = small_page_size();
1752 size_t actual = os::page_size_for_region_unaligned(small_page - 17, 1);
1753 assert_eq(small_page, actual);
1754 }
1755 }
1756
1757 public:
1758 static void run_tests() {
1759 test_page_size_for_region_aligned();
1760 test_page_size_for_region_alignment();
1761 test_page_size_for_region_unaligned();
1762 }
1763 };
1764
1765 void TestOS_test() {
1766 TestOS::run_tests();
1767 }
1768
1769 #endif // PRODUCT