1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/icBuffer.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "gc_implementation/shared/vmGCOperations.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "memory/allocation.inline.hpp"
35 #ifdef ASSERT
36 #include "memory/guardedMemory.hpp"
37 #endif
38 #include "oops/oop.inline.hpp"
39 #include "prims/jvm.h"
40 #include "prims/jvm_misc.hpp"
41 #include "prims/privilegedStack.hpp"
42 #include "runtime/arguments.hpp"
43 #include "runtime/frame.inline.hpp"
44 #include "runtime/interfaceSupport.hpp"
45 #include "runtime/java.hpp"
46 #include "runtime/javaCalls.hpp"
47 #include "runtime/mutexLocker.hpp"
48 #include "runtime/os.hpp"
49 #include "runtime/stubRoutines.hpp"
50 #include "runtime/thread.inline.hpp"
51 #include "services/attachListener.hpp"
52 #include "services/nmtCommon.hpp"
53 #include "services/mallocTracker.hpp"
54 #include "services/memTracker.hpp"
55 #include "services/threadService.hpp"
56 #include "utilities/defaultStream.hpp"
57 #include "utilities/events.hpp"
58 #ifdef TARGET_OS_FAMILY_linux
59 # include "os_linux.inline.hpp"
60 #endif
61 #ifdef TARGET_OS_FAMILY_solaris
62 # include "os_solaris.inline.hpp"
63 #endif
64 #ifdef TARGET_OS_FAMILY_windows
65 # include "os_windows.inline.hpp"
66 #endif
67 #ifdef TARGET_OS_FAMILY_bsd
68 # include "os_bsd.inline.hpp"
69 #endif
70
71 # include <signal.h>
72
73 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
74
75 OSThread* os::_starting_thread = NULL;
76 address os::_polling_page = NULL;
77 volatile int32_t* os::_mem_serialize_page = NULL;
78 uintptr_t os::_serialize_page_mask = 0;
79 long os::_rand_seed = 1;
80 int os::_processor_count = 0;
81 int os::_initial_active_processor_count = 0;
82 size_t os::_page_sizes[os::page_sizes_max];
83
84 #ifndef PRODUCT
85 julong os::num_mallocs = 0; // # of calls to malloc/realloc
86 julong os::alloc_bytes = 0; // # of bytes allocated
87 julong os::num_frees = 0; // # of calls to free
88 julong os::free_bytes = 0; // # of bytes freed
89 #endif
90
91 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
92
93 void os_init_globals() {
94 // Called from init_globals().
95 // See Threads::create_vm() in thread.cpp, and init.cpp.
96 os::init_globals();
97 }
98
99 static time_t get_timezone(const struct tm* time_struct) {
100 #if defined(_ALLBSD_SOURCE)
101 return time_struct->tm_gmtoff;
102 #elif defined(_WINDOWS)
103 long zone;
104 _get_timezone(&zone);
105 return static_cast<time_t>(zone);
106 #else
107 return timezone;
108 #endif
109 }
110
111 // Fill in buffer with current local time as an ISO-8601 string.
112 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
113 // Returns buffer, or NULL if it failed.
114 // This would mostly be a call to
115 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
116 // except that on Windows the %z behaves badly, so we do it ourselves.
117 // Also, people wanted milliseconds on there,
118 // and strftime doesn't do milliseconds.
119 char* os::iso8601_time(char* buffer, size_t buffer_length) {
120 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
121 // 1 2
122 // 12345678901234567890123456789
123 static const char* iso8601_format =
124 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
125 static const size_t needed_buffer = 29;
126
127 // Sanity check the arguments
128 if (buffer == NULL) {
129 assert(false, "NULL buffer");
130 return NULL;
131 }
132 if (buffer_length < needed_buffer) {
133 assert(false, "buffer_length too small");
134 return NULL;
135 }
136 // Get the current time
137 jlong milliseconds_since_19700101 = javaTimeMillis();
138 const int milliseconds_per_microsecond = 1000;
139 const time_t seconds_since_19700101 =
140 milliseconds_since_19700101 / milliseconds_per_microsecond;
141 const int milliseconds_after_second =
142 milliseconds_since_19700101 % milliseconds_per_microsecond;
143 // Convert the time value to a tm and timezone variable
144 struct tm time_struct;
145 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
146 assert(false, "Failed localtime_pd");
147 return NULL;
148 }
149 const time_t zone = get_timezone(&time_struct);
150
151 // If daylight savings time is in effect,
152 // we are 1 hour East of our time zone
153 const time_t seconds_per_minute = 60;
154 const time_t minutes_per_hour = 60;
155 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
156 time_t UTC_to_local = zone;
157 if (time_struct.tm_isdst > 0) {
158 UTC_to_local = UTC_to_local - seconds_per_hour;
159 }
160 // Compute the time zone offset.
161 // localtime_pd() sets timezone to the difference (in seconds)
162 // between UTC and and local time.
163 // ISO 8601 says we need the difference between local time and UTC,
164 // we change the sign of the localtime_pd() result.
165 const time_t local_to_UTC = -(UTC_to_local);
166 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
167 char sign_local_to_UTC = '+';
168 time_t abs_local_to_UTC = local_to_UTC;
169 if (local_to_UTC < 0) {
170 sign_local_to_UTC = '-';
171 abs_local_to_UTC = -(abs_local_to_UTC);
172 }
173 // Convert time zone offset seconds to hours and minutes.
174 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
175 const time_t zone_min =
176 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
177
178 // Print an ISO 8601 date and time stamp into the buffer
179 const int year = 1900 + time_struct.tm_year;
180 const int month = 1 + time_struct.tm_mon;
181 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
182 year,
183 month,
184 time_struct.tm_mday,
185 time_struct.tm_hour,
186 time_struct.tm_min,
187 time_struct.tm_sec,
188 milliseconds_after_second,
189 sign_local_to_UTC,
190 zone_hours,
191 zone_min);
192 if (printed == 0) {
193 assert(false, "Failed jio_printf");
194 return NULL;
195 }
196 return buffer;
197 }
198
199 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
200 #ifdef ASSERT
201 if (!(!thread->is_Java_thread() ||
202 Thread::current() == thread ||
203 Threads_lock->owned_by_self()
204 || thread->is_Compiler_thread()
205 )) {
206 assert(false, "possibility of dangling Thread pointer");
207 }
208 #endif
209
210 if (p >= MinPriority && p <= MaxPriority) {
211 int priority = java_to_os_priority[p];
212 return set_native_priority(thread, priority);
213 } else {
214 assert(false, "Should not happen");
215 return OS_ERR;
216 }
217 }
218
219 // The mapping from OS priority back to Java priority may be inexact because
220 // Java priorities can map M:1 with native priorities. If you want the definite
221 // Java priority then use JavaThread::java_priority()
222 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
223 int p;
224 int os_prio;
225 OSReturn ret = get_native_priority(thread, &os_prio);
226 if (ret != OS_OK) return ret;
227
228 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
229 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
230 } else {
231 // niceness values are in reverse order
232 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
233 }
234 priority = (ThreadPriority)p;
235 return OS_OK;
236 }
237
238
239 // --------------------- sun.misc.Signal (optional) ---------------------
240
241
242 // SIGBREAK is sent by the keyboard to query the VM state
243 #ifndef SIGBREAK
244 #define SIGBREAK SIGQUIT
245 #endif
246
247 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
248
249
250 static void signal_thread_entry(JavaThread* thread, TRAPS) {
251 os::set_priority(thread, NearMaxPriority);
252 while (true) {
253 int sig;
254 {
255 // FIXME : Currently we have not decieded what should be the status
256 // for this java thread blocked here. Once we decide about
257 // that we should fix this.
258 sig = os::signal_wait();
259 }
260 if (sig == os::sigexitnum_pd()) {
261 // Terminate the signal thread
262 return;
263 }
264
265 switch (sig) {
266 case SIGBREAK: {
267 // Check if the signal is a trigger to start the Attach Listener - in that
268 // case don't print stack traces.
269 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
270 continue;
271 }
272 // Print stack traces
273 // Any SIGBREAK operations added here should make sure to flush
274 // the output stream (e.g. tty->flush()) after output. See 4803766.
275 // Each module also prints an extra carriage return after its output.
276 VM_PrintThreads op;
277 VMThread::execute(&op);
278 VM_PrintJNI jni_op;
279 VMThread::execute(&jni_op);
280 VM_FindDeadlocks op1(tty);
281 VMThread::execute(&op1);
282 Universe::print_heap_at_SIGBREAK();
283 if (PrintClassHistogram) {
284 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
285 VMThread::execute(&op1);
286 }
287 if (JvmtiExport::should_post_data_dump()) {
288 JvmtiExport::post_data_dump();
289 }
290 break;
291 }
292 default: {
293 // Dispatch the signal to java
294 HandleMark hm(THREAD);
295 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
296 KlassHandle klass (THREAD, k);
297 if (klass.not_null()) {
298 JavaValue result(T_VOID);
299 JavaCallArguments args;
300 args.push_int(sig);
301 JavaCalls::call_static(
302 &result,
303 klass,
304 vmSymbols::dispatch_name(),
305 vmSymbols::int_void_signature(),
306 &args,
307 THREAD
308 );
309 }
310 if (HAS_PENDING_EXCEPTION) {
311 // tty is initialized early so we don't expect it to be null, but
312 // if it is we can't risk doing an initialization that might
313 // trigger additional out-of-memory conditions
314 if (tty != NULL) {
315 char klass_name[256];
316 char tmp_sig_name[16];
317 const char* sig_name = "UNKNOWN";
318 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
319 name()->as_klass_external_name(klass_name, 256);
320 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
321 sig_name = tmp_sig_name;
322 warning("Exception %s occurred dispatching signal %s to handler"
323 "- the VM may need to be forcibly terminated",
324 klass_name, sig_name );
325 }
326 CLEAR_PENDING_EXCEPTION;
327 }
328 }
329 }
330 }
331 }
332
333 void os::init_before_ergo() {
334 initialize_initial_active_processor_count();
335 // We need to initialize large page support here because ergonomics takes some
336 // decisions depending on large page support and the calculated large page size.
337 large_page_init();
338
339 // VM version initialization identifies some characteristics of the
340 // the platform that are used during ergonomic decisions.
341 VM_Version::init_before_ergo();
342 }
343
344 void os::signal_init() {
345 if (!ReduceSignalUsage) {
346 // Setup JavaThread for processing signals
347 EXCEPTION_MARK;
348 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
349 instanceKlassHandle klass (THREAD, k);
350 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
351
352 const char thread_name[] = "Signal Dispatcher";
353 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
354
355 // Initialize thread_oop to put it into the system threadGroup
356 Handle thread_group (THREAD, Universe::system_thread_group());
357 JavaValue result(T_VOID);
358 JavaCalls::call_special(&result, thread_oop,
359 klass,
360 vmSymbols::object_initializer_name(),
361 vmSymbols::threadgroup_string_void_signature(),
362 thread_group,
363 string,
364 CHECK);
365
366 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
367 JavaCalls::call_special(&result,
368 thread_group,
369 group,
370 vmSymbols::add_method_name(),
371 vmSymbols::thread_void_signature(),
372 thread_oop, // ARG 1
373 CHECK);
374
375 os::signal_init_pd();
376
377 { MutexLocker mu(Threads_lock);
378 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
379
380 // At this point it may be possible that no osthread was created for the
381 // JavaThread due to lack of memory. We would have to throw an exception
382 // in that case. However, since this must work and we do not allow
383 // exceptions anyway, check and abort if this fails.
384 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
385 vm_exit_during_initialization("java.lang.OutOfMemoryError",
386 "unable to create new native thread");
387 }
388
389 java_lang_Thread::set_thread(thread_oop(), signal_thread);
390 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
391 java_lang_Thread::set_daemon(thread_oop());
392
393 signal_thread->set_threadObj(thread_oop());
394 Threads::add(signal_thread);
395 Thread::start(signal_thread);
396 }
397 // Handle ^BREAK
398 os::signal(SIGBREAK, os::user_handler());
399 }
400 }
401
402
403 void os::terminate_signal_thread() {
404 if (!ReduceSignalUsage)
405 signal_notify(sigexitnum_pd());
406 }
407
408
409 // --------------------- loading libraries ---------------------
410
411 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
412 extern struct JavaVM_ main_vm;
413
414 static void* _native_java_library = NULL;
415
416 void* os::native_java_library() {
417 if (_native_java_library == NULL) {
418 char buffer[JVM_MAXPATHLEN];
419 char ebuf[1024];
420
421 // Try to load verify dll first. In 1.3 java dll depends on it and is not
422 // always able to find it when the loading executable is outside the JDK.
423 // In order to keep working with 1.2 we ignore any loading errors.
424 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
425 "verify")) {
426 dll_load(buffer, ebuf, sizeof(ebuf));
427 }
428
429 // Load java dll
430 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
431 "java")) {
432 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
433 }
434 if (_native_java_library == NULL) {
435 vm_exit_during_initialization("Unable to load native library", ebuf);
436 }
437
438 #if defined(__OpenBSD__)
439 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
440 // ignore errors
441 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
442 "net")) {
443 dll_load(buffer, ebuf, sizeof(ebuf));
444 }
445 #endif
446 }
447 static jboolean onLoaded = JNI_FALSE;
448 if (onLoaded) {
449 // We may have to wait to fire OnLoad until TLS is initialized.
450 if (ThreadLocalStorage::is_initialized()) {
451 // The JNI_OnLoad handling is normally done by method load in
452 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
453 // explicitly so we have to check for JNI_OnLoad as well
454 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
455 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
456 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
457 if (JNI_OnLoad != NULL) {
458 JavaThread* thread = JavaThread::current();
459 ThreadToNativeFromVM ttn(thread);
460 HandleMark hm(thread);
461 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
462 onLoaded = JNI_TRUE;
463 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
464 vm_exit_during_initialization("Unsupported JNI version");
465 }
466 }
467 }
468 }
469 return _native_java_library;
470 }
471
472 /*
473 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
474 * If check_lib == true then we are looking for an
475 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
476 * this library is statically linked into the image.
477 * If check_lib == false then we will look for the appropriate symbol in the
478 * executable if agent_lib->is_static_lib() == true or in the shared library
479 * referenced by 'handle'.
480 */
481 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
482 const char *syms[], size_t syms_len) {
483 assert(agent_lib != NULL, "sanity check");
484 const char *lib_name;
485 void *handle = agent_lib->os_lib();
486 void *entryName = NULL;
487 char *agent_function_name;
488 size_t i;
489
490 // If checking then use the agent name otherwise test is_static_lib() to
491 // see how to process this lookup
492 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
493 for (i = 0; i < syms_len; i++) {
494 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
495 if (agent_function_name == NULL) {
496 break;
497 }
498 entryName = dll_lookup(handle, agent_function_name);
499 FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread);
500 if (entryName != NULL) {
501 break;
502 }
503 }
504 return entryName;
505 }
506
507 // See if the passed in agent is statically linked into the VM image.
508 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
509 size_t syms_len) {
510 void *ret;
511 void *proc_handle;
512 void *save_handle;
513
514 assert(agent_lib != NULL, "sanity check");
515 if (agent_lib->name() == NULL) {
516 return false;
517 }
518 proc_handle = get_default_process_handle();
519 // Check for Agent_OnLoad/Attach_lib_name function
520 save_handle = agent_lib->os_lib();
521 // We want to look in this process' symbol table.
522 agent_lib->set_os_lib(proc_handle);
523 ret = find_agent_function(agent_lib, true, syms, syms_len);
524 if (ret != NULL) {
525 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
526 agent_lib->set_valid();
527 agent_lib->set_static_lib(true);
528 return true;
529 }
530 agent_lib->set_os_lib(save_handle);
531 return false;
532 }
533
534 // --------------------- heap allocation utilities ---------------------
535
536 char *os::strdup(const char *str, MEMFLAGS flags) {
537 size_t size = strlen(str);
538 char *dup_str = (char *)malloc(size + 1, flags);
539 if (dup_str == NULL) return NULL;
540 strcpy(dup_str, str);
541 return dup_str;
542 }
543
544
545
546 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
547
548 #ifdef ASSERT
549 static void verify_memory(void* ptr) {
550 GuardedMemory guarded(ptr);
551 if (!guarded.verify_guards()) {
552 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
553 tty->print_cr("## memory stomp:");
554 guarded.print_on(tty);
555 fatal("memory stomping error");
556 }
557 }
558 #endif
559
560 //
561 // This function supports testing of the malloc out of memory
562 // condition without really running the system out of memory.
563 //
564 static u_char* testMalloc(size_t alloc_size) {
565 assert(MallocMaxTestWords > 0, "sanity check");
566
567 if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
568 return NULL;
569 }
570
571 u_char* ptr = (u_char*)::malloc(alloc_size);
572
573 if (ptr != NULL) {
574 Atomic::add(((jint) (alloc_size / BytesPerWord)),
575 (volatile jint *) &cur_malloc_words);
576 }
577 return ptr;
578 }
579
580 void* os::malloc(size_t size, MEMFLAGS flags) {
581 return os::malloc(size, flags, CALLER_PC);
582 }
583
584 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
585 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
586 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
587
588 #ifdef ASSERT
589 // checking for the WatcherThread and crash_protection first
590 // since os::malloc can be called when the libjvm.{dll,so} is
591 // first loaded and we don't have a thread yet.
592 // try to find the thread after we see that the watcher thread
593 // exists and has crash protection.
594 WatcherThread *wt = WatcherThread::watcher_thread();
595 if (wt != NULL && wt->has_crash_protection()) {
596 Thread* thread = ThreadLocalStorage::get_thread_slow();
597 if (thread == wt) {
598 assert(!wt->has_crash_protection(),
599 "Can't malloc with crash protection from WatcherThread");
600 }
601 }
602 #endif
603
604 if (size == 0) {
605 // return a valid pointer if size is zero
606 // if NULL is returned the calling functions assume out of memory.
607 size = 1;
608 }
609
610 // NMT support
611 NMT_TrackingLevel level = MemTracker::tracking_level();
612 size_t nmt_header_size = MemTracker::malloc_header_size(level);
613
614 #ifndef ASSERT
615 const size_t alloc_size = size + nmt_header_size;
616 #else
617 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
618 if (size + nmt_header_size > alloc_size) { // Check for rollover.
619 return NULL;
620 }
621 #endif
622
623 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
624
625 u_char* ptr;
626 if (MallocMaxTestWords > 0) {
627 ptr = testMalloc(alloc_size);
628 } else {
629 ptr = (u_char*)::malloc(alloc_size);
630 }
631
632 #ifdef ASSERT
633 if (ptr == NULL) {
634 return NULL;
635 }
636 // Wrap memory with guard
637 GuardedMemory guarded(ptr, size + nmt_header_size);
638 ptr = guarded.get_user_ptr();
639 #endif
640 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
641 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
642 breakpoint();
643 }
644 debug_only(if (paranoid) verify_memory(ptr));
645 if (PrintMalloc && tty != NULL) {
646 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
647 }
648
649 // we do not track guard memory
650 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
651 }
652
653 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
654 return os::realloc(memblock, size, flags, CALLER_PC);
655 }
656
657 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
658
659 #ifndef ASSERT
660 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
661 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
662 // NMT support
663 void* membase = MemTracker::record_free(memblock);
664 NMT_TrackingLevel level = MemTracker::tracking_level();
665 size_t nmt_header_size = MemTracker::malloc_header_size(level);
666 void* ptr = ::realloc(membase, size + nmt_header_size);
667 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
668 #else
669 if (memblock == NULL) {
670 return os::malloc(size, memflags, stack);
671 }
672 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
673 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
674 breakpoint();
675 }
676 // NMT support
677 void* membase = MemTracker::malloc_base(memblock);
678 verify_memory(membase);
679 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
680 if (size == 0) {
681 return NULL;
682 }
683 // always move the block
684 void* ptr = os::malloc(size, memflags, stack);
685 if (PrintMalloc) {
686 tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
687 }
688 // Copy to new memory if malloc didn't fail
689 if ( ptr != NULL ) {
690 GuardedMemory guarded(MemTracker::malloc_base(memblock));
691 // Guard's user data contains NMT header
692 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
693 memcpy(ptr, memblock, MIN2(size, memblock_size));
694 if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
695 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
696 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
697 breakpoint();
698 }
699 os::free(memblock);
700 }
701 return ptr;
702 #endif
703 }
704
705
706 void os::free(void *memblock, MEMFLAGS memflags) {
707 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
708 #ifdef ASSERT
709 if (memblock == NULL) return;
710 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
711 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
712 breakpoint();
713 }
714 void* membase = MemTracker::record_free(memblock);
715 verify_memory(membase);
716 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
717
718 GuardedMemory guarded(membase);
719 size_t size = guarded.get_user_size();
720 inc_stat_counter(&free_bytes, size);
721 membase = guarded.release_for_freeing();
722 if (PrintMalloc && tty != NULL) {
723 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
724 }
725 ::free(membase);
726 #else
727 void* membase = MemTracker::record_free(memblock);
728 ::free(membase);
729 #endif
730 }
731
732 void os::init_random(long initval) {
733 _rand_seed = initval;
734 }
735
736
737 long os::random() {
738 /* standard, well-known linear congruential random generator with
739 * next_rand = (16807*seed) mod (2**31-1)
740 * see
741 * (1) "Random Number Generators: Good Ones Are Hard to Find",
742 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
743 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
744 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
745 */
746 const long a = 16807;
747 const unsigned long m = 2147483647;
748 const long q = m / a; assert(q == 127773, "weird math");
749 const long r = m % a; assert(r == 2836, "weird math");
750
751 // compute az=2^31p+q
752 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
753 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
754 lo += (hi & 0x7FFF) << 16;
755
756 // if q overflowed, ignore the overflow and increment q
757 if (lo > m) {
758 lo &= m;
759 ++lo;
760 }
761 lo += hi >> 15;
762
763 // if (p+q) overflowed, ignore the overflow and increment (p+q)
764 if (lo > m) {
765 lo &= m;
766 ++lo;
767 }
768 return (_rand_seed = lo);
769 }
770
771 // The INITIALIZED state is distinguished from the SUSPENDED state because the
772 // conditions in which a thread is first started are different from those in which
773 // a suspension is resumed. These differences make it hard for us to apply the
774 // tougher checks when starting threads that we want to do when resuming them.
775 // However, when start_thread is called as a result of Thread.start, on a Java
776 // thread, the operation is synchronized on the Java Thread object. So there
777 // cannot be a race to start the thread and hence for the thread to exit while
778 // we are working on it. Non-Java threads that start Java threads either have
779 // to do so in a context in which races are impossible, or should do appropriate
780 // locking.
781
782 void os::start_thread(Thread* thread) {
783 // guard suspend/resume
784 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
785 OSThread* osthread = thread->osthread();
786 osthread->set_state(RUNNABLE);
787 pd_start_thread(thread);
788 }
789
790 //---------------------------------------------------------------------------
791 // Helper functions for fatal error handler
792
793 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
794 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
795
796 int cols = 0;
797 int cols_per_line = 0;
798 switch (unitsize) {
799 case 1: cols_per_line = 16; break;
800 case 2: cols_per_line = 8; break;
801 case 4: cols_per_line = 4; break;
802 case 8: cols_per_line = 2; break;
803 default: return;
804 }
805
806 address p = start;
807 st->print(PTR_FORMAT ": ", start);
808 while (p < end) {
809 switch (unitsize) {
810 case 1: st->print("%02x", *(u1*)p); break;
811 case 2: st->print("%04x", *(u2*)p); break;
812 case 4: st->print("%08x", *(u4*)p); break;
813 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
814 }
815 p += unitsize;
816 cols++;
817 if (cols >= cols_per_line && p < end) {
818 cols = 0;
819 st->cr();
820 st->print(PTR_FORMAT ": ", p);
821 } else {
822 st->print(" ");
823 }
824 }
825 st->cr();
826 }
827
828 void os::print_environment_variables(outputStream* st, const char** env_list,
829 char* buffer, int len) {
830 if (env_list) {
831 st->print_cr("Environment Variables:");
832
833 for (int i = 0; env_list[i] != NULL; i++) {
834 if (getenv(env_list[i], buffer, len)) {
835 st->print("%s", env_list[i]);
836 st->print("=");
837 st->print_cr("%s", buffer);
838 }
839 }
840 }
841 }
842
843 void os::print_cpu_info(outputStream* st) {
844 // cpu
845 st->print("CPU:");
846 st->print("total %d", os::processor_count());
847 // It's not safe to query number of active processors after crash
848 // st->print("(active %d)", os::active_processor_count()); but we can
849 // print the initial number of active processors.
850 // We access the raw value here because the assert in the accessor will
851 // fail if the crash occurs before initialization of this value.
852 st->print(" (initial active %d)", _initial_active_processor_count);
853 st->print(" %s", VM_Version::cpu_features());
854 st->cr();
855 pd_print_cpu_info(st);
856 }
857
858 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
859 const int secs_per_day = 86400;
860 const int secs_per_hour = 3600;
861 const int secs_per_min = 60;
862
863 time_t tloc;
864 (void)time(&tloc);
865 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
866
867 struct tm tz;
868 if (localtime_pd(&tloc, &tz) != NULL) {
869 ::strftime(buf, buflen, "%Z", &tz);
870 st->print_cr("timezone: %s", buf);
871 }
872
873 double t = os::elapsedTime();
874 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
875 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
876 // before printf. We lost some precision, but who cares?
877 int eltime = (int)t; // elapsed time in seconds
878
879 // print elapsed time in a human-readable format:
880 int eldays = eltime / secs_per_day;
881 int day_secs = eldays * secs_per_day;
882 int elhours = (eltime - day_secs) / secs_per_hour;
883 int hour_secs = elhours * secs_per_hour;
884 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
885 int minute_secs = elmins * secs_per_min;
886 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
887 st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
888 }
889
890 // moved from debug.cpp (used to be find()) but still called from there
891 // The verbose parameter is only set by the debug code in one case
892 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
893 address addr = (address)x;
894 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
895 if (b != NULL) {
896 if (b->is_buffer_blob()) {
897 // the interpreter is generated into a buffer blob
898 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
899 if (i != NULL) {
900 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
901 i->print_on(st);
902 return;
903 }
904 if (Interpreter::contains(addr)) {
905 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
906 " (not bytecode specific)", addr);
907 return;
908 }
909 //
910 if (AdapterHandlerLibrary::contains(b)) {
911 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
912 AdapterHandlerLibrary::print_handler_on(st, b);
913 }
914 // the stubroutines are generated into a buffer blob
915 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
916 if (d != NULL) {
917 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
918 d->print_on(st);
919 st->cr();
920 return;
921 }
922 if (StubRoutines::contains(addr)) {
923 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
924 "stub routine", addr);
925 return;
926 }
927 // the InlineCacheBuffer is using stubs generated into a buffer blob
928 if (InlineCacheBuffer::contains(addr)) {
929 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
930 return;
931 }
932 VtableStub* v = VtableStubs::stub_containing(addr);
933 if (v != NULL) {
934 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
935 v->print_on(st);
936 st->cr();
937 return;
938 }
939 }
940 nmethod* nm = b->as_nmethod_or_null();
941 if (nm != NULL) {
942 ResourceMark rm;
943 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
944 addr, (int)(addr - nm->entry_point()), nm);
945 if (verbose) {
946 st->print(" for ");
947 nm->method()->print_value_on(st);
948 }
949 st->cr();
950 nm->print_nmethod(verbose);
951 return;
952 }
953 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
954 b->print_on(st);
955 return;
956 }
957
958 if (Universe::heap()->is_in(addr)) {
959 HeapWord* p = Universe::heap()->block_start(addr);
960 bool print = false;
961 // If we couldn't find it it just may mean that heap wasn't parseable
962 // See if we were just given an oop directly
963 if (p != NULL && Universe::heap()->block_is_obj(p)) {
964 print = true;
965 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
966 p = (HeapWord*) addr;
967 print = true;
968 }
969 if (print) {
970 if (p == (HeapWord*) addr) {
971 st->print_cr(INTPTR_FORMAT " is an oop", addr);
972 } else {
973 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
974 }
975 oop(p)->print_on(st);
976 return;
977 }
978 } else {
979 if (Universe::heap()->is_in_reserved(addr)) {
980 st->print_cr(INTPTR_FORMAT " is an unallocated location "
981 "in the heap", addr);
982 return;
983 }
984 }
985 if (JNIHandles::is_global_handle((jobject) addr)) {
986 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
987 return;
988 }
989 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
990 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
991 return;
992 }
993 #ifndef PRODUCT
994 // we don't keep the block list in product mode
995 if (JNIHandleBlock::any_contains((jobject) addr)) {
996 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
997 return;
998 }
999 #endif
1000
1001 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
1002 // Check for privilege stack
1003 if (thread->privileged_stack_top() != NULL &&
1004 thread->privileged_stack_top()->contains(addr)) {
1005 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
1006 "for thread: " INTPTR_FORMAT, addr, thread);
1007 if (verbose) thread->print_on(st);
1008 return;
1009 }
1010 // If the addr is a java thread print information about that.
1011 if (addr == (address)thread) {
1012 if (verbose) {
1013 thread->print_on(st);
1014 } else {
1015 st->print_cr(INTPTR_FORMAT " is a thread", addr);
1016 }
1017 return;
1018 }
1019 // If the addr is in the stack region for this thread then report that
1020 // and print thread info
1021 if (thread->stack_base() >= addr &&
1022 addr > (thread->stack_base() - thread->stack_size())) {
1023 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1024 INTPTR_FORMAT, addr, thread);
1025 if (verbose) thread->print_on(st);
1026 return;
1027 }
1028
1029 }
1030
1031 // Check if in metaspace and print types that have vptrs (only method now)
1032 if (Metaspace::contains(addr)) {
1033 if (Method::has_method_vptr((const void*)addr)) {
1034 ((Method*)addr)->print_value_on(st);
1035 st->cr();
1036 } else {
1037 // Use addr->print() from the debugger instead (not here)
1038 st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr);
1039 }
1040 return;
1041 }
1042
1043 // Try an OS specific find
1044 if (os::find(addr, st)) {
1045 return;
1046 }
1047
1048 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1049 }
1050
1051 // Looks like all platforms except IA64 can use the same function to check
1052 // if C stack is walkable beyond current frame. The check for fp() is not
1053 // necessary on Sparc, but it's harmless.
1054 bool os::is_first_C_frame(frame* fr) {
1055 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1056 // On IA64 we have to check if the callers bsp is still valid
1057 // (i.e. within the register stack bounds).
1058 // Notice: this only works for threads created by the VM and only if
1059 // we walk the current stack!!! If we want to be able to walk
1060 // arbitrary other threads, we'll have to somehow store the thread
1061 // object in the frame.
1062 Thread *thread = Thread::current();
1063 if ((address)fr->fp() <=
1064 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1065 // This check is a little hacky, because on Linux the first C
1066 // frame's ('start_thread') register stack frame starts at
1067 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1068 // ('__pthread_bound_body') register stack frame seems to really
1069 // start at "register_stack_base".
1070 return true;
1071 } else {
1072 return false;
1073 }
1074 #elif defined(IA64) && defined(_WIN32)
1075 return true;
1076 #else
1077 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1078 // Check usp first, because if that's bad the other accessors may fault
1079 // on some architectures. Ditto ufp second, etc.
1080 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1081 // sp on amd can be 32 bit aligned.
1082 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1083
1084 uintptr_t usp = (uintptr_t)fr->sp();
1085 if ((usp & sp_align_mask) != 0) return true;
1086
1087 uintptr_t ufp = (uintptr_t)fr->fp();
1088 if ((ufp & fp_align_mask) != 0) return true;
1089
1090 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1091 if ((old_sp & sp_align_mask) != 0) return true;
1092 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1093
1094 uintptr_t old_fp = (uintptr_t)fr->link();
1095 if ((old_fp & fp_align_mask) != 0) return true;
1096 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1097
1098 // stack grows downwards; if old_fp is below current fp or if the stack
1099 // frame is too large, either the stack is corrupted or fp is not saved
1100 // on stack (i.e. on x86, ebp may be used as general register). The stack
1101 // is not walkable beyond current frame.
1102 if (old_fp < ufp) return true;
1103 if (old_fp - ufp > 64 * K) return true;
1104
1105 return false;
1106 #endif
1107 }
1108
1109 #ifdef ASSERT
1110 extern "C" void test_random() {
1111 const double m = 2147483647;
1112 double mean = 0.0, variance = 0.0, t;
1113 long reps = 10000;
1114 unsigned long seed = 1;
1115
1116 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1117 os::init_random(seed);
1118 long num;
1119 for (int k = 0; k < reps; k++) {
1120 num = os::random();
1121 double u = (double)num / m;
1122 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1123
1124 // calculate mean and variance of the random sequence
1125 mean += u;
1126 variance += (u*u);
1127 }
1128 mean /= reps;
1129 variance /= (reps - 1);
1130
1131 assert(num == 1043618065, "bad seed");
1132 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1133 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1134 const double eps = 0.0001;
1135 t = fabsd(mean - 0.5018);
1136 assert(t < eps, "bad mean");
1137 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1138 assert(t < eps, "bad variance");
1139 }
1140 #endif
1141
1142
1143 // Set up the boot classpath.
1144
1145 char* os::format_boot_path(const char* format_string,
1146 const char* home,
1147 int home_len,
1148 char fileSep,
1149 char pathSep) {
1150 assert((fileSep == '/' && pathSep == ':') ||
1151 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1152
1153 // Scan the format string to determine the length of the actual
1154 // boot classpath, and handle platform dependencies as well.
1155 int formatted_path_len = 0;
1156 const char* p;
1157 for (p = format_string; *p != 0; ++p) {
1158 if (*p == '%') formatted_path_len += home_len - 1;
1159 ++formatted_path_len;
1160 }
1161
1162 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1163 if (formatted_path == NULL) {
1164 return NULL;
1165 }
1166
1167 // Create boot classpath from format, substituting separator chars and
1168 // java home directory.
1169 char* q = formatted_path;
1170 for (p = format_string; *p != 0; ++p) {
1171 switch (*p) {
1172 case '%':
1173 strcpy(q, home);
1174 q += home_len;
1175 break;
1176 case '/':
1177 *q++ = fileSep;
1178 break;
1179 case ':':
1180 *q++ = pathSep;
1181 break;
1182 default:
1183 *q++ = *p;
1184 }
1185 }
1186 *q = '\0';
1187
1188 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1189 return formatted_path;
1190 }
1191
1192
1193 bool os::set_boot_path(char fileSep, char pathSep) {
1194 const char* home = Arguments::get_java_home();
1195 int home_len = (int)strlen(home);
1196
1197 static const char* meta_index_dir_format = "%/lib/";
1198 static const char* meta_index_format = "%/lib/meta-index";
1199 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1200 if (meta_index == NULL) return false;
1201 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1202 if (meta_index_dir == NULL) return false;
1203 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1204
1205 // Any modification to the JAR-file list, for the boot classpath must be
1206 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1207 // path class JARs, are stripped for StackMapTable to reduce download size.
1208 static const char classpath_format[] =
1209 "%/lib/resources.jar:"
1210 "%/lib/rt.jar:"
1211 "%/lib/sunrsasign.jar:"
1212 "%/lib/jsse.jar:"
1213 "%/lib/jce.jar:"
1214 "%/lib/charsets.jar:"
1215 "%/lib/jfr.jar:"
1216 "%/classes";
1217 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1218 if (sysclasspath == NULL) return false;
1219 Arguments::set_sysclasspath(sysclasspath);
1220
1221 return true;
1222 }
1223
1224 /*
1225 * Splits a path, based on its separator, the number of
1226 * elements is returned back in n.
1227 * It is the callers responsibility to:
1228 * a> check the value of n, and n may be 0.
1229 * b> ignore any empty path elements
1230 * c> free up the data.
1231 */
1232 char** os::split_path(const char* path, int* n) {
1233 *n = 0;
1234 if (path == NULL || strlen(path) == 0) {
1235 return NULL;
1236 }
1237 const char psepchar = *os::path_separator();
1238 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1239 if (inpath == NULL) {
1240 return NULL;
1241 }
1242 strcpy(inpath, path);
1243 int count = 1;
1244 char* p = strchr(inpath, psepchar);
1245 // Get a count of elements to allocate memory
1246 while (p != NULL) {
1247 count++;
1248 p++;
1249 p = strchr(p, psepchar);
1250 }
1251 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1252 if (opath == NULL) {
1253 return NULL;
1254 }
1255
1256 // do the actual splitting
1257 p = inpath;
1258 for (int i = 0 ; i < count ; i++) {
1259 size_t len = strcspn(p, os::path_separator());
1260 if (len > JVM_MAXPATHLEN) {
1261 return NULL;
1262 }
1263 // allocate the string and add terminator storage
1264 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1265 if (s == NULL) {
1266 return NULL;
1267 }
1268 strncpy(s, p, len);
1269 s[len] = '\0';
1270 opath[i] = s;
1271 p += len + 1;
1272 }
1273 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1274 *n = count;
1275 return opath;
1276 }
1277
1278 void os::set_memory_serialize_page(address page) {
1279 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1280 _mem_serialize_page = (volatile int32_t *)page;
1281 // We initialize the serialization page shift count here
1282 // We assume a cache line size of 64 bytes
1283 assert(SerializePageShiftCount == count,
1284 "thread size changed, fix SerializePageShiftCount constant");
1285 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1286 }
1287
1288 static volatile intptr_t SerializePageLock = 0;
1289
1290 // This method is called from signal handler when SIGSEGV occurs while the current
1291 // thread tries to store to the "read-only" memory serialize page during state
1292 // transition.
1293 void os::block_on_serialize_page_trap() {
1294 if (TraceSafepoint) {
1295 tty->print_cr("Block until the serialize page permission restored");
1296 }
1297 // When VMThread is holding the SerializePageLock during modifying the
1298 // access permission of the memory serialize page, the following call
1299 // will block until the permission of that page is restored to rw.
1300 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1301 // this case, it's OK as the signal is synchronous and we know precisely when
1302 // it can occur.
1303 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1304 Thread::muxRelease(&SerializePageLock);
1305 }
1306
1307 // Serialize all thread state variables
1308 void os::serialize_thread_states() {
1309 // On some platforms such as Solaris & Linux, the time duration of the page
1310 // permission restoration is observed to be much longer than expected due to
1311 // scheduler starvation problem etc. To avoid the long synchronization
1312 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1313 // the mutator thread if such case is encountered. See bug 6546278 for details.
1314 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1315 os::protect_memory((char *)os::get_memory_serialize_page(),
1316 os::vm_page_size(), MEM_PROT_READ);
1317 os::protect_memory((char *)os::get_memory_serialize_page(),
1318 os::vm_page_size(), MEM_PROT_RW);
1319 Thread::muxRelease(&SerializePageLock);
1320 }
1321
1322 // Returns true if the current stack pointer is above the stack shadow
1323 // pages, false otherwise.
1324
1325 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1326 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1327 address sp = current_stack_pointer();
1328 // Check if we have StackShadowPages above the yellow zone. This parameter
1329 // is dependent on the depth of the maximum VM call stack possible from
1330 // the handler for stack overflow. 'instanceof' in the stack overflow
1331 // handler or a println uses at least 8k stack of VM and native code
1332 // respectively.
1333 const int framesize_in_bytes =
1334 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1335 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1336 * vm_page_size()) + framesize_in_bytes;
1337 // The very lower end of the stack
1338 address stack_limit = thread->stack_base() - thread->stack_size();
1339 return (sp > (stack_limit + reserved_area));
1340 }
1341
1342 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1343 assert(min_pages > 0, "sanity");
1344 if (UseLargePages) {
1345 const size_t max_page_size = region_size / min_pages;
1346
1347 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1348 const size_t page_size = _page_sizes[i];
1349 if (page_size <= max_page_size) {
1350 if (!must_be_aligned || is_size_aligned(region_size, page_size)) {
1351 return page_size;
1352 }
1353 }
1354 }
1355 }
1356
1357 return vm_page_size();
1358 }
1359
1360 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1361 return page_size_for_region(region_size, min_pages, true);
1362 }
1363
1364 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1365 return page_size_for_region(region_size, min_pages, false);
1366 }
1367
1368 #ifndef PRODUCT
1369 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1370 {
1371 if (TracePageSizes) {
1372 tty->print("%s: ", str);
1373 for (int i = 0; i < count; ++i) {
1374 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1375 }
1376 tty->cr();
1377 }
1378 }
1379
1380 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1381 const size_t region_max_size, const size_t page_size,
1382 const char* base, const size_t size)
1383 {
1384 if (TracePageSizes) {
1385 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1386 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1387 " size=" SIZE_FORMAT,
1388 str, region_min_size, region_max_size,
1389 page_size, base, size);
1390 }
1391 }
1392 #endif // #ifndef PRODUCT
1393
1394 // This is the working definition of a server class machine:
1395 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1396 // because the graphics memory (?) sometimes masks physical memory.
1397 // If you want to change the definition of a server class machine
1398 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1399 // then you'll have to parameterize this method based on that state,
1400 // as was done for logical processors here, or replicate and
1401 // specialize this method for each platform. (Or fix os to have
1402 // some inheritance structure and use subclassing. Sigh.)
1403 // If you want some platform to always or never behave as a server
1404 // class machine, change the setting of AlwaysActAsServerClassMachine
1405 // and NeverActAsServerClassMachine in globals*.hpp.
1406 bool os::is_server_class_machine() {
1407 // First check for the early returns
1408 if (NeverActAsServerClassMachine) {
1409 return false;
1410 }
1411 if (AlwaysActAsServerClassMachine) {
1412 return true;
1413 }
1414 // Then actually look at the machine
1415 bool result = false;
1416 const unsigned int server_processors = 2;
1417 const julong server_memory = 2UL * G;
1418 // We seem not to get our full complement of memory.
1419 // We allow some part (1/8?) of the memory to be "missing",
1420 // based on the sizes of DIMMs, and maybe graphics cards.
1421 const julong missing_memory = 256UL * M;
1422
1423 /* Is this a server class machine? */
1424 if ((os::active_processor_count() >= (int)server_processors) &&
1425 (os::physical_memory() >= (server_memory - missing_memory))) {
1426 const unsigned int logical_processors =
1427 VM_Version::logical_processors_per_package();
1428 if (logical_processors > 1) {
1429 const unsigned int physical_packages =
1430 os::active_processor_count() / logical_processors;
1431 if (physical_packages > server_processors) {
1432 result = true;
1433 }
1434 } else {
1435 result = true;
1436 }
1437 }
1438 return result;
1439 }
1440
1441 void os::initialize_initial_active_processor_count() {
1442 assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
1443 _initial_active_processor_count = active_processor_count();
1444 }
1445
1446 void os::SuspendedThreadTask::run() {
1447 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1448 internal_do_task();
1449 _done = true;
1450 }
1451
1452 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1453 return os::pd_create_stack_guard_pages(addr, bytes);
1454 }
1455
1456 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1457 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1458 if (result != NULL) {
1459 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1460 }
1461
1462 return result;
1463 }
1464
1465 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1466 MEMFLAGS flags) {
1467 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1468 if (result != NULL) {
1469 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1470 MemTracker::record_virtual_memory_type((address)result, flags);
1471 }
1472
1473 return result;
1474 }
1475
1476 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1477 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1478 if (result != NULL) {
1479 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1480 }
1481 return result;
1482 }
1483
1484 void os::split_reserved_memory(char *base, size_t size,
1485 size_t split, bool realloc) {
1486 pd_split_reserved_memory(base, size, split, realloc);
1487 }
1488
1489 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1490 bool res = pd_commit_memory(addr, bytes, executable);
1491 if (res) {
1492 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1493 }
1494 return res;
1495 }
1496
1497 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1498 bool executable) {
1499 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1500 if (res) {
1501 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1502 }
1503 return res;
1504 }
1505
1506 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1507 const char* mesg) {
1508 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1509 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1510 }
1511
1512 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1513 bool executable, const char* mesg) {
1514 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1515 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1516 }
1517
1518 bool os::uncommit_memory(char* addr, size_t bytes) {
1519 bool res;
1520 if (MemTracker::tracking_level() > NMT_minimal) {
1521 Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1522 res = pd_uncommit_memory(addr, bytes);
1523 if (res) {
1524 tkr.record((address)addr, bytes);
1525 }
1526 } else {
1527 res = pd_uncommit_memory(addr, bytes);
1528 }
1529 return res;
1530 }
1531
1532 bool os::release_memory(char* addr, size_t bytes) {
1533 bool res;
1534 if (MemTracker::tracking_level() > NMT_minimal) {
1535 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1536 res = pd_release_memory(addr, bytes);
1537 if (res) {
1538 tkr.record((address)addr, bytes);
1539 }
1540 } else {
1541 res = pd_release_memory(addr, bytes);
1542 }
1543 return res;
1544 }
1545
1546 void os::pretouch_memory(char* start, char* end) {
1547 for (volatile char *p = start; p < end; p += os::vm_page_size()) {
1548 *p = 0;
1549 }
1550 }
1551
1552 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1553 char *addr, size_t bytes, bool read_only,
1554 bool allow_exec) {
1555 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1556 if (result != NULL) {
1557 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1558 }
1559 return result;
1560 }
1561
1562 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1563 char *addr, size_t bytes, bool read_only,
1564 bool allow_exec) {
1565 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1566 read_only, allow_exec);
1567 }
1568
1569 bool os::unmap_memory(char *addr, size_t bytes) {
1570 bool result;
1571 if (MemTracker::tracking_level() > NMT_minimal) {
1572 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1573 result = pd_unmap_memory(addr, bytes);
1574 if (result) {
1575 tkr.record((address)addr, bytes);
1576 }
1577 } else {
1578 result = pd_unmap_memory(addr, bytes);
1579 }
1580 return result;
1581 }
1582
1583 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1584 pd_free_memory(addr, bytes, alignment_hint);
1585 }
1586
1587 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1588 pd_realign_memory(addr, bytes, alignment_hint);
1589 }
1590
1591 #ifndef TARGET_OS_FAMILY_windows
1592 /* try to switch state from state "from" to state "to"
1593 * returns the state set after the method is complete
1594 */
1595 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1596 os::SuspendResume::State to)
1597 {
1598 os::SuspendResume::State result =
1599 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1600 if (result == from) {
1601 // success
1602 return to;
1603 }
1604 return result;
1605 }
1606 #endif
1607
1608 /////////////// Unit tests ///////////////
1609
1610 #ifndef PRODUCT
1611
1612 #define assert_eq(a,b) assert(a == b, err_msg(SIZE_FORMAT " != " SIZE_FORMAT, a, b))
1613
1614 class TestOS : AllStatic {
1615 static size_t small_page_size() {
1616 return os::vm_page_size();
1617 }
1618
1619 static size_t large_page_size() {
1620 const size_t large_page_size_example = 4 * M;
1621 return os::page_size_for_region_aligned(large_page_size_example, 1);
1622 }
1623
1624 static void test_page_size_for_region_aligned() {
1625 if (UseLargePages) {
1626 const size_t small_page = small_page_size();
1627 const size_t large_page = large_page_size();
1628
1629 if (large_page > small_page) {
1630 size_t num_small_pages_in_large = large_page / small_page;
1631 size_t page = os::page_size_for_region_aligned(large_page, num_small_pages_in_large);
1632
1633 assert_eq(page, small_page);
1634 }
1635 }
1636 }
1637
1638 static void test_page_size_for_region_alignment() {
1639 if (UseLargePages) {
1640 const size_t small_page = small_page_size();
1641 const size_t large_page = large_page_size();
1642 if (large_page > small_page) {
1643 const size_t unaligned_region = large_page + 17;
1644 size_t page = os::page_size_for_region_aligned(unaligned_region, 1);
1645 assert_eq(page, small_page);
1646
1647 const size_t num_pages = 5;
1648 const size_t aligned_region = large_page * num_pages;
1649 page = os::page_size_for_region_aligned(aligned_region, num_pages);
1650 assert_eq(page, large_page);
1651 }
1652 }
1653 }
1654
1655 static void test_page_size_for_region_unaligned() {
1656 if (UseLargePages) {
1657 // Given exact page size, should return that page size.
1658 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1659 size_t expected = os::_page_sizes[i];
1660 size_t actual = os::page_size_for_region_unaligned(expected, 1);
1661 assert_eq(expected, actual);
1662 }
1663
1664 // Given slightly larger size than a page size, return the page size.
1665 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1666 size_t expected = os::_page_sizes[i];
1667 size_t actual = os::page_size_for_region_unaligned(expected + 17, 1);
1668 assert_eq(expected, actual);
1669 }
1670
1671 // Given a slightly smaller size than a page size,
1672 // return the next smaller page size.
1673 if (os::_page_sizes[1] > os::_page_sizes[0]) {
1674 size_t expected = os::_page_sizes[0];
1675 size_t actual = os::page_size_for_region_unaligned(os::_page_sizes[1] - 17, 1);
1676 assert_eq(actual, expected);
1677 }
1678
1679 // Return small page size for values less than a small page.
1680 size_t small_page = small_page_size();
1681 size_t actual = os::page_size_for_region_unaligned(small_page - 17, 1);
1682 assert_eq(small_page, actual);
1683 }
1684 }
1685
1686 public:
1687 static void run_tests() {
1688 test_page_size_for_region_aligned();
1689 test_page_size_for_region_alignment();
1690 test_page_size_for_region_unaligned();
1691 }
1692 };
1693
1694 void TestOS_test() {
1695 TestOS::run_tests();
1696 }
1697
1698 #endif // PRODUCT