1 /*
2 * Copyright (c) 1997, 2020, 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 int os::snprintf(char* buf, size_t len, const char* fmt, ...) {
100 va_list args;
101 va_start(args, fmt);
102 int result = os::vsnprintf(buf, len, fmt, args);
103 va_end(args);
104 return result;
105 }
106
107 // Fill in buffer with current local time as an ISO-8601 string.
108 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
109 // Returns buffer, or NULL if it failed.
110 // This would mostly be a call to
111 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
112 // except that on Windows the %z behaves badly, so we do it ourselves.
113 // Also, people wanted milliseconds on there,
114 // and strftime doesn't do milliseconds.
115 char* os::iso8601_time(char* buffer, size_t buffer_length) {
116 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
117 // 1 2
118 // 12345678901234567890123456789
119 static const char* iso8601_format =
120 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
121 static const size_t needed_buffer = 29;
122
123 // Sanity check the arguments
124 if (buffer == NULL) {
125 assert(false, "NULL buffer");
126 return NULL;
127 }
128 if (buffer_length < needed_buffer) {
129 assert(false, "buffer_length too small");
130 return NULL;
131 }
132 // Get the current time
133 jlong milliseconds_since_19700101 = javaTimeMillis();
134 const int milliseconds_per_microsecond = 1000;
135 const time_t seconds_since_19700101 =
136 milliseconds_since_19700101 / milliseconds_per_microsecond;
137 const int milliseconds_after_second =
138 milliseconds_since_19700101 % milliseconds_per_microsecond;
139 // Convert the time value to a tm and timezone variable
140 struct tm time_struct;
141 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
142 assert(false, "Failed localtime_pd");
143 return NULL;
144 }
145
146 const time_t seconds_per_minute = 60;
147 const time_t minutes_per_hour = 60;
148 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
149
150 time_t UTC_to_local = 0;
151 #if defined(_ALLBSD_SOURCE) || defined(_GNU_SOURCE)
152 UTC_to_local = -(time_struct.tm_gmtoff);
153 #elif defined(_WINDOWS)
154 long zone;
155 _get_timezone(&zone);
156 UTC_to_local = static_cast<time_t>(zone);
157 #else
158 UTC_to_local = timezone;
159 #endif
160
161 // tm_gmtoff already includes adjustment for daylight saving
162 #if !defined(_ALLBSD_SOURCE) && !defined(_GNU_SOURCE)
163 // If daylight savings time is in effect,
164 // we are 1 hour East of our time zone
165 if (time_struct.tm_isdst > 0) {
166 UTC_to_local = UTC_to_local - seconds_per_hour;
167 }
168 #endif
169
170 // Compute the time zone offset.
171 // localtime_pd() sets timezone to the difference (in seconds)
172 // between UTC and and local time.
173 // ISO 8601 says we need the difference between local time and UTC,
174 // we change the sign of the localtime_pd() result.
175 const time_t local_to_UTC = -(UTC_to_local);
176 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
177 char sign_local_to_UTC = '+';
178 time_t abs_local_to_UTC = local_to_UTC;
179 if (local_to_UTC < 0) {
180 sign_local_to_UTC = '-';
181 abs_local_to_UTC = -(abs_local_to_UTC);
182 }
183 // Convert time zone offset seconds to hours and minutes.
184 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
185 const time_t zone_min =
186 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
187
188 // Print an ISO 8601 date and time stamp into the buffer
189 const int year = 1900 + time_struct.tm_year;
190 const int month = 1 + time_struct.tm_mon;
191 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
192 year,
193 month,
194 time_struct.tm_mday,
195 time_struct.tm_hour,
196 time_struct.tm_min,
197 time_struct.tm_sec,
198 milliseconds_after_second,
199 sign_local_to_UTC,
200 zone_hours,
201 zone_min);
202 if (printed == 0) {
203 assert(false, "Failed jio_printf");
204 return NULL;
205 }
206 return buffer;
207 }
208
209 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
210 #ifdef ASSERT
211 if (!(!thread->is_Java_thread() ||
212 Thread::current() == thread ||
213 Threads_lock->owned_by_self()
214 || thread->is_Compiler_thread()
215 )) {
216 assert(false, "possibility of dangling Thread pointer");
217 }
218 #endif
219
220 if (p >= MinPriority && p <= MaxPriority) {
221 int priority = java_to_os_priority[p];
222 return set_native_priority(thread, priority);
223 } else {
224 assert(false, "Should not happen");
225 return OS_ERR;
226 }
227 }
228
229 // The mapping from OS priority back to Java priority may be inexact because
230 // Java priorities can map M:1 with native priorities. If you want the definite
231 // Java priority then use JavaThread::java_priority()
232 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
233 int p;
234 int os_prio;
235 OSReturn ret = get_native_priority(thread, &os_prio);
236 if (ret != OS_OK) return ret;
237
238 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
239 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
240 } else {
241 // niceness values are in reverse order
242 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
243 }
244 priority = (ThreadPriority)p;
245 return OS_OK;
246 }
247
248
249 // --------------------- sun.misc.Signal (optional) ---------------------
250
251
252 // SIGBREAK is sent by the keyboard to query the VM state
253 #ifndef SIGBREAK
254 #define SIGBREAK SIGQUIT
255 #endif
256
257 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
258
259
260 static void signal_thread_entry(JavaThread* thread, TRAPS) {
261 os::set_priority(thread, NearMaxPriority);
262 while (true) {
263 int sig;
264 {
265 // FIXME : Currently we have not decieded what should be the status
266 // for this java thread blocked here. Once we decide about
267 // that we should fix this.
268 sig = os::signal_wait();
269 }
270 if (sig == os::sigexitnum_pd()) {
271 // Terminate the signal thread
272 return;
273 }
274
275 switch (sig) {
276 case SIGBREAK: {
277 // Check if the signal is a trigger to start the Attach Listener - in that
278 // case don't print stack traces.
279 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
280 continue;
281 }
282 // Print stack traces
283 // Any SIGBREAK operations added here should make sure to flush
284 // the output stream (e.g. tty->flush()) after output. See 4803766.
285 // Each module also prints an extra carriage return after its output.
286 VM_PrintThreads op;
287 VMThread::execute(&op);
288 VM_PrintJNI jni_op;
289 VMThread::execute(&jni_op);
290 VM_FindDeadlocks op1(tty);
291 VMThread::execute(&op1);
292 Universe::print_heap_at_SIGBREAK();
293 if (PrintClassHistogram) {
294 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
295 VMThread::execute(&op1);
296 }
297 if (JvmtiExport::should_post_data_dump()) {
298 JvmtiExport::post_data_dump();
299 }
300 break;
301 }
302 default: {
303 // Dispatch the signal to java
304 HandleMark hm(THREAD);
305 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
306 KlassHandle klass (THREAD, k);
307 if (klass.not_null()) {
308 JavaValue result(T_VOID);
309 JavaCallArguments args;
310 args.push_int(sig);
311 JavaCalls::call_static(
312 &result,
313 klass,
314 vmSymbols::dispatch_name(),
315 vmSymbols::int_void_signature(),
316 &args,
317 THREAD
318 );
319 }
320 if (HAS_PENDING_EXCEPTION) {
321 // tty is initialized early so we don't expect it to be null, but
322 // if it is we can't risk doing an initialization that might
323 // trigger additional out-of-memory conditions
324 if (tty != NULL) {
325 char klass_name[256];
326 char tmp_sig_name[16];
327 const char* sig_name = "UNKNOWN";
328 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
329 name()->as_klass_external_name(klass_name, 256);
330 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
331 sig_name = tmp_sig_name;
332 warning("Exception %s occurred dispatching signal %s to handler"
333 "- the VM may need to be forcibly terminated",
334 klass_name, sig_name );
335 }
336 CLEAR_PENDING_EXCEPTION;
337 }
338 }
339 }
340 }
341 }
342
343 void os::init_before_ergo() {
344 initialize_initial_active_processor_count();
345 // We need to initialize large page support here because ergonomics takes some
346 // decisions depending on large page support and the calculated large page size.
347 large_page_init();
348
349 // VM version initialization identifies some characteristics of the
350 // the platform that are used during ergonomic decisions.
351 VM_Version::init_before_ergo();
352 }
353
354 void os::signal_init() {
355 if (!ReduceSignalUsage) {
356 // Setup JavaThread for processing signals
357 EXCEPTION_MARK;
358 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
359 instanceKlassHandle klass (THREAD, k);
360 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
361
362 const char thread_name[] = "Signal Dispatcher";
363 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
364
365 // Initialize thread_oop to put it into the system threadGroup
366 Handle thread_group (THREAD, Universe::system_thread_group());
367 JavaValue result(T_VOID);
368 JavaCalls::call_special(&result, thread_oop,
369 klass,
370 vmSymbols::object_initializer_name(),
371 vmSymbols::threadgroup_string_void_signature(),
372 thread_group,
373 string,
374 CHECK);
375
376 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
377 JavaCalls::call_special(&result,
378 thread_group,
379 group,
380 vmSymbols::add_method_name(),
381 vmSymbols::thread_void_signature(),
382 thread_oop, // ARG 1
383 CHECK);
384
385 os::signal_init_pd();
386
387 { MutexLocker mu(Threads_lock);
388 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
389
390 // At this point it may be possible that no osthread was created for the
391 // JavaThread due to lack of memory. We would have to throw an exception
392 // in that case. However, since this must work and we do not allow
393 // exceptions anyway, check and abort if this fails.
394 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
395 vm_exit_during_initialization("java.lang.OutOfMemoryError",
396 "unable to create new native thread");
397 }
398
399 java_lang_Thread::set_thread(thread_oop(), signal_thread);
400 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
401 java_lang_Thread::set_daemon(thread_oop());
402
403 signal_thread->set_threadObj(thread_oop());
404 Threads::add(signal_thread);
405 Thread::start(signal_thread);
406 }
407 // Handle ^BREAK
408 os::signal(SIGBREAK, os::user_handler());
409 }
410 }
411
412
413 void os::terminate_signal_thread() {
414 if (!ReduceSignalUsage)
415 signal_notify(sigexitnum_pd());
416 }
417
418
419 // --------------------- loading libraries ---------------------
420
421 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
422 extern struct JavaVM_ main_vm;
423
424 static void* _native_java_library = NULL;
425
426 void* os::native_java_library() {
427 if (_native_java_library == NULL) {
428 char buffer[JVM_MAXPATHLEN];
429 char ebuf[1024];
430
431 // Try to load verify dll first. In 1.3 java dll depends on it and is not
432 // always able to find it when the loading executable is outside the JDK.
433 // In order to keep working with 1.2 we ignore any loading errors.
434 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
435 "verify")) {
436 dll_load(buffer, ebuf, sizeof(ebuf));
437 }
438
439 // Load java dll
440 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
441 "java")) {
442 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
443 }
444 if (_native_java_library == NULL) {
445 vm_exit_during_initialization("Unable to load native library", ebuf);
446 }
447
448 #if defined(__OpenBSD__)
449 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
450 // ignore errors
451 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
452 "net")) {
453 dll_load(buffer, ebuf, sizeof(ebuf));
454 }
455 #endif
456 }
457 static jboolean onLoaded = JNI_FALSE;
458 if (onLoaded) {
459 // We may have to wait to fire OnLoad until TLS is initialized.
460 if (ThreadLocalStorage::is_initialized()) {
461 // The JNI_OnLoad handling is normally done by method load in
462 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
463 // explicitly so we have to check for JNI_OnLoad as well
464 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
465 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
466 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
467 if (JNI_OnLoad != NULL) {
468 JavaThread* thread = JavaThread::current();
469 ThreadToNativeFromVM ttn(thread);
470 HandleMark hm(thread);
471 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
472 onLoaded = JNI_TRUE;
473 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
474 vm_exit_during_initialization("Unsupported JNI version");
475 }
476 }
477 }
478 }
479 return _native_java_library;
480 }
481
482 /*
483 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
484 * If check_lib == true then we are looking for an
485 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
486 * this library is statically linked into the image.
487 * If check_lib == false then we will look for the appropriate symbol in the
488 * executable if agent_lib->is_static_lib() == true or in the shared library
489 * referenced by 'handle'.
490 */
491 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
492 const char *syms[], size_t syms_len) {
493 assert(agent_lib != NULL, "sanity check");
494 const char *lib_name;
495 void *handle = agent_lib->os_lib();
496 void *entryName = NULL;
497 char *agent_function_name;
498 size_t i;
499
500 // If checking then use the agent name otherwise test is_static_lib() to
501 // see how to process this lookup
502 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
503 for (i = 0; i < syms_len; i++) {
504 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
505 if (agent_function_name == NULL) {
506 break;
507 }
508 entryName = dll_lookup(handle, agent_function_name);
509 FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread);
510 if (entryName != NULL) {
511 break;
512 }
513 }
514 return entryName;
515 }
516
517 // See if the passed in agent is statically linked into the VM image.
518 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
519 size_t syms_len) {
520 void *ret;
521 void *proc_handle;
522 void *save_handle;
523
524 assert(agent_lib != NULL, "sanity check");
525 if (agent_lib->name() == NULL) {
526 return false;
527 }
528 proc_handle = get_default_process_handle();
529 // Check for Agent_OnLoad/Attach_lib_name function
530 save_handle = agent_lib->os_lib();
531 // We want to look in this process' symbol table.
532 agent_lib->set_os_lib(proc_handle);
533 ret = find_agent_function(agent_lib, true, syms, syms_len);
534 if (ret != NULL) {
535 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
536 agent_lib->set_valid();
537 agent_lib->set_static_lib(true);
538 return true;
539 }
540 agent_lib->set_os_lib(save_handle);
541 return false;
542 }
543
544 // --------------------- heap allocation utilities ---------------------
545
546 char *os::strdup(const char *str, MEMFLAGS flags) {
547 size_t size = strlen(str);
548 char *dup_str = (char *)malloc(size + 1, flags);
549 if (dup_str == NULL) return NULL;
550 strcpy(dup_str, str);
551 return dup_str;
552 }
553
554
555
556 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
557
558 #ifdef ASSERT
559 static void verify_memory(void* ptr) {
560 GuardedMemory guarded(ptr);
561 if (!guarded.verify_guards()) {
562 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
563 tty->print_cr("## memory stomp:");
564 guarded.print_on(tty);
565 fatal("memory stomping error");
566 }
567 }
568 #endif
569
570 //
571 // This function supports testing of the malloc out of memory
572 // condition without really running the system out of memory.
573 //
574 static u_char* testMalloc(size_t alloc_size) {
575 assert(MallocMaxTestWords > 0, "sanity check");
576
577 if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
578 return NULL;
579 }
580
581 u_char* ptr = (u_char*)::malloc(alloc_size);
582
583 if (ptr != NULL) {
584 Atomic::add(((jint) (alloc_size / BytesPerWord)),
585 (volatile jint *) &cur_malloc_words);
586 }
587 return ptr;
588 }
589
590 void* os::malloc(size_t size, MEMFLAGS flags) {
591 return os::malloc(size, flags, CALLER_PC);
592 }
593
594 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
595 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
596 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
597
598 // Since os::malloc can be called when the libjvm.{dll,so} is
599 // first loaded and we don't have a thread yet we must accept NULL also here.
600 assert(!os::ThreadCrashProtection::is_crash_protected(ThreadLocalStorage::thread()),
601 "malloc() not allowed when crash protection is set");
602
603 if (size == 0) {
604 // return a valid pointer if size is zero
605 // if NULL is returned the calling functions assume out of memory.
606 size = 1;
607 }
608
609 // NMT support
610 NMT_TrackingLevel level = MemTracker::tracking_level();
611 size_t nmt_header_size = MemTracker::malloc_header_size(level);
612
613 #ifndef ASSERT
614 const size_t alloc_size = size + nmt_header_size;
615 #else
616 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
617 if (size + nmt_header_size > alloc_size) { // Check for rollover.
618 return NULL;
619 }
620 #endif
621
622 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
623
624 u_char* ptr;
625 if (MallocMaxTestWords > 0) {
626 ptr = testMalloc(alloc_size);
627 } else {
628 ptr = (u_char*)::malloc(alloc_size);
629 }
630
631 #ifdef ASSERT
632 if (ptr == NULL) {
633 return NULL;
634 }
635 // Wrap memory with guard
636 GuardedMemory guarded(ptr, size + nmt_header_size);
637 ptr = guarded.get_user_ptr();
638 #endif
639 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
640 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
641 breakpoint();
642 }
643 debug_only(if (paranoid) verify_memory(ptr));
644 if (PrintMalloc && tty != NULL) {
645 tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
646 }
647
648 // we do not track guard memory
649 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
650 }
651
652 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
653 return os::realloc(memblock, size, flags, CALLER_PC);
654 }
655
656 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
657
658 #ifndef ASSERT
659 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
660 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
661 // NMT support
662 void* membase = MemTracker::record_free(memblock);
663 NMT_TrackingLevel level = MemTracker::tracking_level();
664 size_t nmt_header_size = MemTracker::malloc_header_size(level);
665 void* ptr = ::realloc(membase, size + nmt_header_size);
666 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
667 #else
668 if (memblock == NULL) {
669 return os::malloc(size, memflags, stack);
670 }
671 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
672 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
673 breakpoint();
674 }
675 // NMT support
676 void* membase = MemTracker::malloc_base(memblock);
677 verify_memory(membase);
678 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
679 if (size == 0) {
680 return NULL;
681 }
682 // always move the block
683 void* ptr = os::malloc(size, memflags, stack);
684 if (PrintMalloc) {
685 tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
686 }
687 // Copy to new memory if malloc didn't fail
688 if ( ptr != NULL ) {
689 GuardedMemory guarded(MemTracker::malloc_base(memblock));
690 // Guard's user data contains NMT header
691 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
692 memcpy(ptr, memblock, MIN2(size, memblock_size));
693 if (paranoid) verify_memory(MemTracker::malloc_base(ptr));
694 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
695 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
696 breakpoint();
697 }
698 os::free(memblock);
699 }
700 return ptr;
701 #endif
702 }
703
704
705 void os::free(void *memblock, MEMFLAGS memflags) {
706 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
707 #ifdef ASSERT
708 if (memblock == NULL) return;
709 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
710 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
711 breakpoint();
712 }
713 void* membase = MemTracker::record_free(memblock);
714 verify_memory(membase);
715 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
716
717 GuardedMemory guarded(membase);
718 size_t size = guarded.get_user_size();
719 inc_stat_counter(&free_bytes, size);
720 membase = guarded.release_for_freeing();
721 if (PrintMalloc && tty != NULL) {
722 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)membase);
723 }
724 ::free(membase);
725 #else
726 void* membase = MemTracker::record_free(memblock);
727 ::free(membase);
728 #endif
729 }
730
731 void os::init_random(long initval) {
732 _rand_seed = initval;
733 }
734
735
736 long os::random() {
737 /* standard, well-known linear congruential random generator with
738 * next_rand = (16807*seed) mod (2**31-1)
739 * see
740 * (1) "Random Number Generators: Good Ones Are Hard to Find",
741 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
742 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
743 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
744 */
745 const long a = 16807;
746 const unsigned long m = 2147483647;
747 const long q = m / a; assert(q == 127773, "weird math");
748 const long r = m % a; assert(r == 2836, "weird math");
749
750 // compute az=2^31p+q
751 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
752 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
753 lo += (hi & 0x7FFF) << 16;
754
755 // if q overflowed, ignore the overflow and increment q
756 if (lo > m) {
757 lo &= m;
758 ++lo;
759 }
760 lo += hi >> 15;
761
762 // if (p+q) overflowed, ignore the overflow and increment (p+q)
763 if (lo > m) {
764 lo &= m;
765 ++lo;
766 }
767 return (_rand_seed = lo);
768 }
769
770 // The INITIALIZED state is distinguished from the SUSPENDED state because the
771 // conditions in which a thread is first started are different from those in which
772 // a suspension is resumed. These differences make it hard for us to apply the
773 // tougher checks when starting threads that we want to do when resuming them.
774 // However, when start_thread is called as a result of Thread.start, on a Java
775 // thread, the operation is synchronized on the Java Thread object. So there
776 // cannot be a race to start the thread and hence for the thread to exit while
777 // we are working on it. Non-Java threads that start Java threads either have
778 // to do so in a context in which races are impossible, or should do appropriate
779 // locking.
780
781 void os::start_thread(Thread* thread) {
782 // guard suspend/resume
783 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
784 OSThread* osthread = thread->osthread();
785 osthread->set_state(RUNNABLE);
786 pd_start_thread(thread);
787 }
788
789 //---------------------------------------------------------------------------
790 // Helper functions for fatal error handler
791
792 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
793 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
794
795 int cols = 0;
796 int cols_per_line = 0;
797 switch (unitsize) {
798 case 1: cols_per_line = 16; break;
799 case 2: cols_per_line = 8; break;
800 case 4: cols_per_line = 4; break;
801 case 8: cols_per_line = 2; break;
802 default: return;
803 }
804
805 address p = start;
806 st->print(PTR_FORMAT ": ", start);
807 while (p < end) {
808 switch (unitsize) {
809 case 1: st->print("%02x", *(u1*)p); break;
810 case 2: st->print("%04x", *(u2*)p); break;
811 case 4: st->print("%08x", *(u4*)p); break;
812 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
813 }
814 p += unitsize;
815 cols++;
816 if (cols >= cols_per_line && p < end) {
817 cols = 0;
818 st->cr();
819 st->print(PTR_FORMAT ": ", p);
820 } else {
821 st->print(" ");
822 }
823 }
824 st->cr();
825 }
826
827 void os::print_environment_variables(outputStream* st, const char** env_list,
828 char* buffer, int len) {
829 if (env_list) {
830 st->print_cr("Environment Variables:");
831
832 for (int i = 0; env_list[i] != NULL; i++) {
833 if (getenv(env_list[i], buffer, len)) {
834 st->print("%s", env_list[i]);
835 st->print("=");
836 st->print_cr("%s", buffer);
837 }
838 }
839 }
840 }
841
842 void os::print_cpu_info(outputStream* st) {
843 // cpu
844 st->print("CPU:");
845 st->print("total %d", os::processor_count());
846 // It's not safe to query number of active processors after crash
847 // st->print("(active %d)", os::active_processor_count()); but we can
848 // print the initial number of active processors.
849 // We access the raw value here because the assert in the accessor will
850 // fail if the crash occurs before initialization of this value.
851 st->print(" (initial active %d)", _initial_active_processor_count);
852 st->print(" %s", VM_Version::cpu_features());
853 st->cr();
854 pd_print_cpu_info(st);
855 }
856
857 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
858 const int secs_per_day = 86400;
859 const int secs_per_hour = 3600;
860 const int secs_per_min = 60;
861
862 time_t tloc;
863 (void)time(&tloc);
864 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
865
866 struct tm tz;
867 if (localtime_pd(&tloc, &tz) != NULL) {
868 ::strftime(buf, buflen, "%Z", &tz);
869 st->print_cr("timezone: %s", buf);
870 }
871
872 double t = os::elapsedTime();
873 // NOTE: a crash using printf("%f",...) on Linux was historically noted here.
874 int eltime = (int)t; // elapsed time in seconds
875 int eltimeFraction = (int) ((t - eltime) * 1000000);
876
877 // print elapsed time in a human-readable format:
878 int eldays = eltime / secs_per_day;
879 int day_secs = eldays * secs_per_day;
880 int elhours = (eltime - day_secs) / secs_per_hour;
881 int hour_secs = elhours * secs_per_hour;
882 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
883 int minute_secs = elmins * secs_per_min;
884 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
885 st->print_cr("elapsed time: %d.%06d seconds (%dd %dh %dm %ds)", eltime, eltimeFraction, eldays, elhours, elmins, elsecs);
886 }
887
888 // moved from debug.cpp (used to be find()) but still called from there
889 // The verbose parameter is only set by the debug code in one case
890 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
891 address addr = (address)x;
892 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
893 if (b != NULL) {
894 if (b->is_buffer_blob()) {
895 // the interpreter is generated into a buffer blob
896 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
897 if (i != NULL) {
898 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
899 i->print_on(st);
900 return;
901 }
902 if (Interpreter::contains(addr)) {
903 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
904 " (not bytecode specific)", addr);
905 return;
906 }
907 //
908 if (AdapterHandlerLibrary::contains(b)) {
909 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
910 AdapterHandlerLibrary::print_handler_on(st, b);
911 }
912 // the stubroutines are generated into a buffer blob
913 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
914 if (d != NULL) {
915 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
916 d->print_on(st);
917 st->cr();
918 return;
919 }
920 if (StubRoutines::contains(addr)) {
921 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
922 "stub routine", addr);
923 return;
924 }
925 // the InlineCacheBuffer is using stubs generated into a buffer blob
926 if (InlineCacheBuffer::contains(addr)) {
927 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
928 return;
929 }
930 VtableStub* v = VtableStubs::stub_containing(addr);
931 if (v != NULL) {
932 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
933 v->print_on(st);
934 st->cr();
935 return;
936 }
937 }
938 nmethod* nm = b->as_nmethod_or_null();
939 if (nm != NULL) {
940 ResourceMark rm;
941 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
942 addr, (int)(addr - nm->entry_point()), nm);
943 if (verbose) {
944 st->print(" for ");
945 nm->method()->print_value_on(st);
946 }
947 st->cr();
948 nm->print_nmethod(verbose);
949 return;
950 }
951 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
952 b->print_on(st);
953 return;
954 }
955
956 if (Universe::heap()->is_in(addr)) {
957 HeapWord* p = Universe::heap()->block_start(addr);
958 bool print = false;
959 // If we couldn't find it it just may mean that heap wasn't parseable
960 // See if we were just given an oop directly
961 if (p != NULL && Universe::heap()->block_is_obj(p)) {
962 print = true;
963 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
964 p = (HeapWord*) addr;
965 print = true;
966 }
967 if (print) {
968 if (p == (HeapWord*) addr) {
969 st->print_cr(INTPTR_FORMAT " is an oop", addr);
970 } else {
971 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
972 }
973 oop(p)->print_on(st);
974 return;
975 }
976 } else {
977 if (Universe::heap()->is_in_reserved(addr)) {
978 st->print_cr(INTPTR_FORMAT " is an unallocated location "
979 "in the heap", addr);
980 return;
981 }
982 }
983 if (JNIHandles::is_global_handle((jobject) addr)) {
984 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
985 return;
986 }
987 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
988 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
989 return;
990 }
991 #ifndef PRODUCT
992 // we don't keep the block list in product mode
993 if (JNIHandleBlock::any_contains((jobject) addr)) {
994 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
995 return;
996 }
997 #endif
998
999 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
1000 // Check for privilege stack
1001 if (thread->privileged_stack_top() != NULL &&
1002 thread->privileged_stack_top()->contains(addr)) {
1003 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
1004 "for thread: " INTPTR_FORMAT, addr, thread);
1005 if (verbose) thread->print_on(st);
1006 return;
1007 }
1008 // If the addr is a java thread print information about that.
1009 if (addr == (address)thread) {
1010 if (verbose) {
1011 thread->print_on(st);
1012 } else {
1013 st->print_cr(INTPTR_FORMAT " is a thread", addr);
1014 }
1015 return;
1016 }
1017 // If the addr is in the stack region for this thread then report that
1018 // and print thread info
1019 if (thread->stack_base() >= addr &&
1020 addr > (thread->stack_base() - thread->stack_size())) {
1021 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1022 INTPTR_FORMAT, addr, thread);
1023 if (verbose) thread->print_on(st);
1024 return;
1025 }
1026
1027 }
1028
1029 // Check if in metaspace and print types that have vptrs (only method now)
1030 if (Metaspace::contains(addr)) {
1031 if (Method::has_method_vptr((const void*)addr)) {
1032 ((Method*)addr)->print_value_on(st);
1033 st->cr();
1034 } else {
1035 // Use addr->print() from the debugger instead (not here)
1036 st->print_cr(INTPTR_FORMAT " is pointing into metadata", addr);
1037 }
1038 return;
1039 }
1040
1041 // Try an OS specific find
1042 if (os::find(addr, st)) {
1043 return;
1044 }
1045
1046 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1047 }
1048
1049 // Looks like all platforms except IA64 can use the same function to check
1050 // if C stack is walkable beyond current frame. The check for fp() is not
1051 // necessary on Sparc, but it's harmless.
1052 bool os::is_first_C_frame(frame* fr) {
1053 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1054 // On IA64 we have to check if the callers bsp is still valid
1055 // (i.e. within the register stack bounds).
1056 // Notice: this only works for threads created by the VM and only if
1057 // we walk the current stack!!! If we want to be able to walk
1058 // arbitrary other threads, we'll have to somehow store the thread
1059 // object in the frame.
1060 Thread *thread = Thread::current();
1061 if ((address)fr->fp() <=
1062 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1063 // This check is a little hacky, because on Linux the first C
1064 // frame's ('start_thread') register stack frame starts at
1065 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1066 // ('__pthread_bound_body') register stack frame seems to really
1067 // start at "register_stack_base".
1068 return true;
1069 } else {
1070 return false;
1071 }
1072 #elif defined(IA64) && defined(_WIN32)
1073 return true;
1074 #else
1075 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1076 // Check usp first, because if that's bad the other accessors may fault
1077 // on some architectures. Ditto ufp second, etc.
1078 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1079 // sp on amd can be 32 bit aligned.
1080 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1081
1082 uintptr_t usp = (uintptr_t)fr->sp();
1083 if ((usp & sp_align_mask) != 0) return true;
1084
1085 uintptr_t ufp = (uintptr_t)fr->fp();
1086 if ((ufp & fp_align_mask) != 0) return true;
1087
1088 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1089 if ((old_sp & sp_align_mask) != 0) return true;
1090 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1091
1092 uintptr_t old_fp = (uintptr_t)fr->link();
1093 if ((old_fp & fp_align_mask) != 0) return true;
1094 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1095
1096 // stack grows downwards; if old_fp is below current fp or if the stack
1097 // frame is too large, either the stack is corrupted or fp is not saved
1098 // on stack (i.e. on x86, ebp may be used as general register). The stack
1099 // is not walkable beyond current frame.
1100 if (old_fp < ufp) return true;
1101 if (old_fp - ufp > 64 * K) return true;
1102
1103 return false;
1104 #endif
1105 }
1106
1107 #ifdef ASSERT
1108 extern "C" void test_random() {
1109 const double m = 2147483647;
1110 double mean = 0.0, variance = 0.0, t;
1111 long reps = 10000;
1112 unsigned long seed = 1;
1113
1114 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1115 os::init_random(seed);
1116 long num;
1117 for (int k = 0; k < reps; k++) {
1118 num = os::random();
1119 double u = (double)num / m;
1120 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1121
1122 // calculate mean and variance of the random sequence
1123 mean += u;
1124 variance += (u*u);
1125 }
1126 mean /= reps;
1127 variance /= (reps - 1);
1128
1129 assert(num == 1043618065, "bad seed");
1130 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1131 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1132 const double eps = 0.0001;
1133 t = fabsd(mean - 0.5018);
1134 assert(t < eps, "bad mean");
1135 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1136 assert(t < eps, "bad variance");
1137 }
1138 #endif
1139
1140
1141 // Set up the boot classpath.
1142
1143 char* os::format_boot_path(const char* format_string,
1144 const char* home,
1145 int home_len,
1146 char fileSep,
1147 char pathSep) {
1148 assert((fileSep == '/' && pathSep == ':') ||
1149 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1150
1151 // Scan the format string to determine the length of the actual
1152 // boot classpath, and handle platform dependencies as well.
1153 int formatted_path_len = 0;
1154 const char* p;
1155 for (p = format_string; *p != 0; ++p) {
1156 if (*p == '%') formatted_path_len += home_len - 1;
1157 ++formatted_path_len;
1158 }
1159
1160 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1161 if (formatted_path == NULL) {
1162 return NULL;
1163 }
1164
1165 // Create boot classpath from format, substituting separator chars and
1166 // java home directory.
1167 char* q = formatted_path;
1168 for (p = format_string; *p != 0; ++p) {
1169 switch (*p) {
1170 case '%':
1171 strcpy(q, home);
1172 q += home_len;
1173 break;
1174 case '/':
1175 *q++ = fileSep;
1176 break;
1177 case ':':
1178 *q++ = pathSep;
1179 break;
1180 default:
1181 *q++ = *p;
1182 }
1183 }
1184 *q = '\0';
1185
1186 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1187 return formatted_path;
1188 }
1189
1190
1191 bool os::set_boot_path(char fileSep, char pathSep) {
1192 const char* home = Arguments::get_java_home();
1193 int home_len = (int)strlen(home);
1194
1195 static const char* meta_index_dir_format = "%/lib/";
1196 static const char* meta_index_format = "%/lib/meta-index";
1197 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1198 if (meta_index == NULL) return false;
1199 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1200 if (meta_index_dir == NULL) return false;
1201 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1202
1203 // Any modification to the JAR-file list, for the boot classpath must be
1204 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1205 // path class JARs, are stripped for StackMapTable to reduce download size.
1206 static const char classpath_format[] =
1207 "%/lib/resources.jar:"
1208 "%/lib/rt.jar:"
1209 "%/lib/sunrsasign.jar:"
1210 "%/lib/jsse.jar:"
1211 "%/lib/jce.jar:"
1212 "%/lib/charsets.jar:"
1213 "%/lib/jfr.jar:"
1214 "%/classes";
1215 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1216 if (sysclasspath == NULL) return false;
1217 Arguments::set_sysclasspath(sysclasspath);
1218
1219 return true;
1220 }
1221
1222 /*
1223 * Splits a path, based on its separator, the number of
1224 * elements is returned back in n.
1225 * It is the callers responsibility to:
1226 * a> check the value of n, and n may be 0.
1227 * b> ignore any empty path elements
1228 * c> free up the data.
1229 */
1230 char** os::split_path(const char* path, int* n) {
1231 *n = 0;
1232 if (path == NULL || strlen(path) == 0) {
1233 return NULL;
1234 }
1235 const char psepchar = *os::path_separator();
1236 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1237 if (inpath == NULL) {
1238 return NULL;
1239 }
1240 strcpy(inpath, path);
1241 int count = 1;
1242 char* p = strchr(inpath, psepchar);
1243 // Get a count of elements to allocate memory
1244 while (p != NULL) {
1245 count++;
1246 p++;
1247 p = strchr(p, psepchar);
1248 }
1249 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1250 if (opath == NULL) {
1251 return NULL;
1252 }
1253
1254 // do the actual splitting
1255 p = inpath;
1256 for (int i = 0 ; i < count ; i++) {
1257 size_t len = strcspn(p, os::path_separator());
1258 if (len > JVM_MAXPATHLEN) {
1259 return NULL;
1260 }
1261 // allocate the string and add terminator storage
1262 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1263 if (s == NULL) {
1264 return NULL;
1265 }
1266 strncpy(s, p, len);
1267 s[len] = '\0';
1268 opath[i] = s;
1269 p += len + 1;
1270 }
1271 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1272 *n = count;
1273 return opath;
1274 }
1275
1276 void os::set_memory_serialize_page(address page) {
1277 int count = log2_intptr(sizeof(class JavaThread)) - log2_int(64);
1278 _mem_serialize_page = (volatile int32_t *)page;
1279 // We initialize the serialization page shift count here
1280 // We assume a cache line size of 64 bytes
1281 assert(SerializePageShiftCount == count,
1282 "thread size changed, fix SerializePageShiftCount constant");
1283 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1284 }
1285
1286 static volatile intptr_t SerializePageLock = 0;
1287
1288 // This method is called from signal handler when SIGSEGV occurs while the current
1289 // thread tries to store to the "read-only" memory serialize page during state
1290 // transition.
1291 void os::block_on_serialize_page_trap() {
1292 if (TraceSafepoint) {
1293 tty->print_cr("Block until the serialize page permission restored");
1294 }
1295 // When VMThread is holding the SerializePageLock during modifying the
1296 // access permission of the memory serialize page, the following call
1297 // will block until the permission of that page is restored to rw.
1298 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1299 // this case, it's OK as the signal is synchronous and we know precisely when
1300 // it can occur.
1301 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1302 Thread::muxRelease(&SerializePageLock);
1303 }
1304
1305 // Serialize all thread state variables
1306 void os::serialize_thread_states() {
1307 // On some platforms such as Solaris & Linux, the time duration of the page
1308 // permission restoration is observed to be much longer than expected due to
1309 // scheduler starvation problem etc. To avoid the long synchronization
1310 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1311 // the mutator thread if such case is encountered. See bug 6546278 for details.
1312 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1313 os::protect_memory((char *)os::get_memory_serialize_page(),
1314 os::vm_page_size(), MEM_PROT_READ);
1315 os::protect_memory((char *)os::get_memory_serialize_page(),
1316 os::vm_page_size(), MEM_PROT_RW);
1317 Thread::muxRelease(&SerializePageLock);
1318 }
1319
1320 // Returns true if the current stack pointer is above the stack shadow
1321 // pages, false otherwise.
1322
1323 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1324 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1325 address sp = current_stack_pointer();
1326 // Check if we have StackShadowPages above the yellow zone. This parameter
1327 // is dependent on the depth of the maximum VM call stack possible from
1328 // the handler for stack overflow. 'instanceof' in the stack overflow
1329 // handler or a println uses at least 8k stack of VM and native code
1330 // respectively.
1331 const int framesize_in_bytes =
1332 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1333 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1334 * vm_page_size()) + framesize_in_bytes;
1335 // The very lower end of the stack
1336 address stack_limit = thread->stack_base() - thread->stack_size();
1337 return (sp > (stack_limit + reserved_area));
1338 }
1339
1340 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1341 assert(min_pages > 0, "sanity");
1342 if (UseLargePages) {
1343 const size_t max_page_size = region_size / min_pages;
1344
1345 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1346 const size_t page_size = _page_sizes[i];
1347 if (page_size <= max_page_size) {
1348 if (!must_be_aligned || is_size_aligned(region_size, page_size)) {
1349 return page_size;
1350 }
1351 }
1352 }
1353 }
1354
1355 return vm_page_size();
1356 }
1357
1358 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1359 return page_size_for_region(region_size, min_pages, true);
1360 }
1361
1362 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1363 return page_size_for_region(region_size, min_pages, false);
1364 }
1365
1366 #ifndef PRODUCT
1367 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1368 {
1369 if (TracePageSizes) {
1370 tty->print("%s: ", str);
1371 for (int i = 0; i < count; ++i) {
1372 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1373 }
1374 tty->cr();
1375 }
1376 }
1377
1378 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1379 const size_t region_max_size, const size_t page_size,
1380 const char* base, const size_t size)
1381 {
1382 if (TracePageSizes) {
1383 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1384 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1385 " size=" SIZE_FORMAT,
1386 str, region_min_size, region_max_size,
1387 page_size, base, size);
1388 }
1389 }
1390 #endif // #ifndef PRODUCT
1391
1392 // This is the working definition of a server class machine:
1393 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1394 // because the graphics memory (?) sometimes masks physical memory.
1395 // If you want to change the definition of a server class machine
1396 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1397 // then you'll have to parameterize this method based on that state,
1398 // as was done for logical processors here, or replicate and
1399 // specialize this method for each platform. (Or fix os to have
1400 // some inheritance structure and use subclassing. Sigh.)
1401 // If you want some platform to always or never behave as a server
1402 // class machine, change the setting of AlwaysActAsServerClassMachine
1403 // and NeverActAsServerClassMachine in globals*.hpp.
1404 bool os::is_server_class_machine() {
1405 // First check for the early returns
1406 if (NeverActAsServerClassMachine) {
1407 return false;
1408 }
1409 if (AlwaysActAsServerClassMachine) {
1410 return true;
1411 }
1412 // Then actually look at the machine
1413 bool result = false;
1414 const unsigned int server_processors = 2;
1415 const julong server_memory = 2UL * G;
1416 // We seem not to get our full complement of memory.
1417 // We allow some part (1/8?) of the memory to be "missing",
1418 // based on the sizes of DIMMs, and maybe graphics cards.
1419 const julong missing_memory = 256UL * M;
1420
1421 /* Is this a server class machine? */
1422 if ((os::active_processor_count() >= (int)server_processors) &&
1423 (os::physical_memory() >= (server_memory - missing_memory))) {
1424 const unsigned int logical_processors =
1425 VM_Version::logical_processors_per_package();
1426 if (logical_processors > 1) {
1427 const unsigned int physical_packages =
1428 os::active_processor_count() / logical_processors;
1429 if (physical_packages > server_processors) {
1430 result = true;
1431 }
1432 } else {
1433 result = true;
1434 }
1435 }
1436 return result;
1437 }
1438
1439 void os::initialize_initial_active_processor_count() {
1440 assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
1441 _initial_active_processor_count = active_processor_count();
1442 }
1443
1444 void os::SuspendedThreadTask::run() {
1445 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1446 internal_do_task();
1447 _done = true;
1448 }
1449
1450 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1451 return os::pd_create_stack_guard_pages(addr, bytes);
1452 }
1453
1454 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1455 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1456 if (result != NULL) {
1457 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1458 }
1459
1460 return result;
1461 }
1462
1463 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1464 MEMFLAGS flags) {
1465 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1466 if (result != NULL) {
1467 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1468 MemTracker::record_virtual_memory_type((address)result, flags);
1469 }
1470
1471 return result;
1472 }
1473
1474 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1475 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1476 if (result != NULL) {
1477 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1478 }
1479 return result;
1480 }
1481
1482 void os::split_reserved_memory(char *base, size_t size,
1483 size_t split, bool realloc) {
1484 pd_split_reserved_memory(base, size, split, realloc);
1485 }
1486
1487 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1488 bool res = pd_commit_memory(addr, bytes, executable);
1489 if (res) {
1490 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1491 }
1492 return res;
1493 }
1494
1495 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1496 bool executable) {
1497 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1498 if (res) {
1499 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1500 }
1501 return res;
1502 }
1503
1504 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1505 const char* mesg) {
1506 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1507 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1508 }
1509
1510 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1511 bool executable, const char* mesg) {
1512 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1513 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1514 }
1515
1516 bool os::uncommit_memory(char* addr, size_t bytes) {
1517 bool res;
1518 if (MemTracker::tracking_level() > NMT_minimal) {
1519 Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1520 res = pd_uncommit_memory(addr, bytes);
1521 if (res) {
1522 tkr.record((address)addr, bytes);
1523 }
1524 } else {
1525 res = pd_uncommit_memory(addr, bytes);
1526 }
1527 return res;
1528 }
1529
1530 bool os::release_memory(char* addr, size_t bytes) {
1531 bool res;
1532 if (MemTracker::tracking_level() > NMT_minimal) {
1533 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1534 res = pd_release_memory(addr, bytes);
1535 if (res) {
1536 tkr.record((address)addr, bytes);
1537 }
1538 } else {
1539 res = pd_release_memory(addr, bytes);
1540 }
1541 return res;
1542 }
1543
1544 void os::pretouch_memory(char* start, char* end) {
1545 for (volatile char *p = start; p < end; p += os::vm_page_size()) {
1546 *p = 0;
1547 }
1548 }
1549
1550 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1551 char *addr, size_t bytes, bool read_only,
1552 bool allow_exec) {
1553 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1554 if (result != NULL) {
1555 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1556 }
1557 return result;
1558 }
1559
1560 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1561 char *addr, size_t bytes, bool read_only,
1562 bool allow_exec) {
1563 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1564 read_only, allow_exec);
1565 }
1566
1567 bool os::unmap_memory(char *addr, size_t bytes) {
1568 bool result;
1569 if (MemTracker::tracking_level() > NMT_minimal) {
1570 Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1571 result = pd_unmap_memory(addr, bytes);
1572 if (result) {
1573 tkr.record((address)addr, bytes);
1574 }
1575 } else {
1576 result = pd_unmap_memory(addr, bytes);
1577 }
1578 return result;
1579 }
1580
1581 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1582 pd_free_memory(addr, bytes, alignment_hint);
1583 }
1584
1585 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1586 pd_realign_memory(addr, bytes, alignment_hint);
1587 }
1588
1589 #ifndef TARGET_OS_FAMILY_windows
1590 /* try to switch state from state "from" to state "to"
1591 * returns the state set after the method is complete
1592 */
1593 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1594 os::SuspendResume::State to)
1595 {
1596 os::SuspendResume::State result =
1597 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1598 if (result == from) {
1599 // success
1600 return to;
1601 }
1602 return result;
1603 }
1604 #endif
1605
1606 /////////////// Unit tests ///////////////
1607
1608 #ifndef PRODUCT
1609
1610 #define assert_eq(a,b) assert(a == b, err_msg(SIZE_FORMAT " != " SIZE_FORMAT, a, b))
1611
1612 class TestOS : AllStatic {
1613 static size_t small_page_size() {
1614 return os::vm_page_size();
1615 }
1616
1617 static size_t large_page_size() {
1618 const size_t large_page_size_example = 4 * M;
1619 return os::page_size_for_region_aligned(large_page_size_example, 1);
1620 }
1621
1622 static void test_page_size_for_region_aligned() {
1623 if (UseLargePages) {
1624 const size_t small_page = small_page_size();
1625 const size_t large_page = large_page_size();
1626
1627 if (large_page > small_page) {
1628 size_t num_small_pages_in_large = large_page / small_page;
1629 size_t page = os::page_size_for_region_aligned(large_page, num_small_pages_in_large);
1630
1631 assert_eq(page, small_page);
1632 }
1633 }
1634 }
1635
1636 static void test_page_size_for_region_alignment() {
1637 if (UseLargePages) {
1638 const size_t small_page = small_page_size();
1639 const size_t large_page = large_page_size();
1640 if (large_page > small_page) {
1641 const size_t unaligned_region = large_page + 17;
1642 size_t page = os::page_size_for_region_aligned(unaligned_region, 1);
1643 assert_eq(page, small_page);
1644
1645 const size_t num_pages = 5;
1646 const size_t aligned_region = large_page * num_pages;
1647 page = os::page_size_for_region_aligned(aligned_region, num_pages);
1648 assert_eq(page, large_page);
1649 }
1650 }
1651 }
1652
1653 static void test_page_size_for_region_unaligned() {
1654 if (UseLargePages) {
1655 // Given exact page size, should return that page size.
1656 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1657 size_t expected = os::_page_sizes[i];
1658 size_t actual = os::page_size_for_region_unaligned(expected, 1);
1659 assert_eq(expected, actual);
1660 }
1661
1662 // Given slightly larger size than a page size, return the page size.
1663 for (size_t i = 0; os::_page_sizes[i] != 0; i++) {
1664 size_t expected = os::_page_sizes[i];
1665 size_t actual = os::page_size_for_region_unaligned(expected + 17, 1);
1666 assert_eq(expected, actual);
1667 }
1668
1669 // Given a slightly smaller size than a page size,
1670 // return the next smaller page size.
1671 if (os::_page_sizes[1] > os::_page_sizes[0]) {
1672 size_t expected = os::_page_sizes[0];
1673 size_t actual = os::page_size_for_region_unaligned(os::_page_sizes[1] - 17, 1);
1674 assert_eq(actual, expected);
1675 }
1676
1677 // Return small page size for values less than a small page.
1678 size_t small_page = small_page_size();
1679 size_t actual = os::page_size_for_region_unaligned(small_page - 17, 1);
1680 assert_eq(small_page, actual);
1681 }
1682 }
1683
1684 public:
1685 static void run_tests() {
1686 test_page_size_for_region_aligned();
1687 test_page_size_for_region_alignment();
1688 test_page_size_for_region_unaligned();
1689 }
1690 };
1691
1692 void TestOS_test() {
1693 TestOS::run_tests();
1694 }
1695
1696 #endif // PRODUCT