1 /*
2 * Copyright (c) 1997, 2013, 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 #include "oops/oop.inline.hpp"
36 #include "prims/jvm.h"
37 #include "prims/jvm_misc.hpp"
38 #include "prims/privilegedStack.hpp"
39 #include "runtime/arguments.hpp"
40 #include "runtime/frame.inline.hpp"
41 #include "runtime/interfaceSupport.hpp"
42 #include "runtime/java.hpp"
43 #include "runtime/javaCalls.hpp"
44 #include "runtime/mutexLocker.hpp"
45 #include "runtime/os.hpp"
46 #include "runtime/stubRoutines.hpp"
47 #include "runtime/thread.inline.hpp"
48 #include "services/attachListener.hpp"
49 #include "services/memTracker.hpp"
50 #include "services/threadService.hpp"
51 #include "utilities/defaultStream.hpp"
52 #include "utilities/events.hpp"
53 #ifdef TARGET_OS_FAMILY_linux
54 # include "os_linux.inline.hpp"
55 #endif
56 #ifdef TARGET_OS_FAMILY_solaris
57 # include "os_solaris.inline.hpp"
58 #endif
59 #ifdef TARGET_OS_FAMILY_windows
60 # include "os_windows.inline.hpp"
61 #endif
62 #ifdef TARGET_OS_FAMILY_bsd
63 # include "os_bsd.inline.hpp"
64 #endif
65
66 # include <signal.h>
67
68 OSThread* os::_starting_thread = NULL;
69 address os::_polling_page = NULL;
70 volatile int32_t* os::_mem_serialize_page = NULL;
71 uintptr_t os::_serialize_page_mask = 0;
72 long os::_rand_seed = 1;
73 int os::_processor_count = 0;
74 size_t os::_page_sizes[os::page_sizes_max];
75
76 #ifndef PRODUCT
77 julong os::num_mallocs = 0; // # of calls to malloc/realloc
78 julong os::alloc_bytes = 0; // # of bytes allocated
79 julong os::num_frees = 0; // # of calls to free
80 julong os::free_bytes = 0; // # of bytes freed
81 #endif
82
83 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
84
85 void os_init_globals() {
86 // Called from init_globals().
87 // See Threads::create_vm() in thread.cpp, and init.cpp.
88 os::init_globals();
89 }
90
91 // Fill in buffer with current local time as an ISO-8601 string.
92 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
93 // Returns buffer, or NULL if it failed.
94 // This would mostly be a call to
95 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
96 // except that on Windows the %z behaves badly, so we do it ourselves.
97 // Also, people wanted milliseconds on there,
98 // and strftime doesn't do milliseconds.
99 char* os::iso8601_time(char* buffer, size_t buffer_length) {
100 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
101 // 1 2
102 // 12345678901234567890123456789
103 static const char* iso8601_format =
104 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
105 static const size_t needed_buffer = 29;
106
107 // Sanity check the arguments
108 if (buffer == NULL) {
109 assert(false, "NULL buffer");
110 return NULL;
111 }
112 if (buffer_length < needed_buffer) {
113 assert(false, "buffer_length too small");
114 return NULL;
115 }
116 // Get the current time
117 jlong milliseconds_since_19700101 = javaTimeMillis();
118 const int milliseconds_per_microsecond = 1000;
119 const time_t seconds_since_19700101 =
120 milliseconds_since_19700101 / milliseconds_per_microsecond;
121 const int milliseconds_after_second =
122 milliseconds_since_19700101 % milliseconds_per_microsecond;
123 // Convert the time value to a tm and timezone variable
124 struct tm time_struct;
125 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
126 assert(false, "Failed localtime_pd");
127 return NULL;
128 }
129 #if defined(_ALLBSD_SOURCE)
130 const time_t zone = (time_t) time_struct.tm_gmtoff;
131 #else
132 const time_t zone = timezone;
133 #endif
134
135 // If daylight savings time is in effect,
136 // we are 1 hour East of our time zone
137 const time_t seconds_per_minute = 60;
138 const time_t minutes_per_hour = 60;
139 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
140 time_t UTC_to_local = zone;
141 if (time_struct.tm_isdst > 0) {
142 UTC_to_local = UTC_to_local - seconds_per_hour;
143 }
144 // Compute the time zone offset.
145 // localtime_pd() sets timezone to the difference (in seconds)
146 // between UTC and and local time.
147 // ISO 8601 says we need the difference between local time and UTC,
148 // we change the sign of the localtime_pd() result.
149 const time_t local_to_UTC = -(UTC_to_local);
150 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
151 char sign_local_to_UTC = '+';
152 time_t abs_local_to_UTC = local_to_UTC;
153 if (local_to_UTC < 0) {
154 sign_local_to_UTC = '-';
155 abs_local_to_UTC = -(abs_local_to_UTC);
156 }
157 // Convert time zone offset seconds to hours and minutes.
158 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
159 const time_t zone_min =
160 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
161
162 // Print an ISO 8601 date and time stamp into the buffer
163 const int year = 1900 + time_struct.tm_year;
164 const int month = 1 + time_struct.tm_mon;
165 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
166 year,
167 month,
168 time_struct.tm_mday,
169 time_struct.tm_hour,
170 time_struct.tm_min,
171 time_struct.tm_sec,
172 milliseconds_after_second,
173 sign_local_to_UTC,
174 zone_hours,
175 zone_min);
176 if (printed == 0) {
177 assert(false, "Failed jio_printf");
178 return NULL;
179 }
180 return buffer;
181 }
182
183 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
184 #ifdef ASSERT
185 if (!(!thread->is_Java_thread() ||
186 Thread::current() == thread ||
187 Threads_lock->owned_by_self()
188 || thread->is_Compiler_thread()
189 )) {
190 assert(false, "possibility of dangling Thread pointer");
191 }
192 #endif
193
194 if (p >= MinPriority && p <= MaxPriority) {
195 int priority = java_to_os_priority[p];
196 return set_native_priority(thread, priority);
197 } else {
198 assert(false, "Should not happen");
199 return OS_ERR;
200 }
201 }
202
203 // The mapping from OS priority back to Java priority may be inexact because
204 // Java priorities can map M:1 with native priorities. If you want the definite
205 // Java priority then use JavaThread::java_priority()
206 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
207 int p;
208 int os_prio;
209 OSReturn ret = get_native_priority(thread, &os_prio);
210 if (ret != OS_OK) return ret;
211
212 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
213 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
214 } else {
215 // niceness values are in reverse order
216 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
217 }
218 priority = (ThreadPriority)p;
219 return OS_OK;
220 }
221
222
223 // --------------------- sun.misc.Signal (optional) ---------------------
224
225
226 // SIGBREAK is sent by the keyboard to query the VM state
227 #ifndef SIGBREAK
228 #define SIGBREAK SIGQUIT
229 #endif
230
231 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
232
233
234 static void signal_thread_entry(JavaThread* thread, TRAPS) {
235 os::set_priority(thread, NearMaxPriority);
236 while (true) {
237 int sig;
238 {
239 // FIXME : Currently we have not decieded what should be the status
240 // for this java thread blocked here. Once we decide about
241 // that we should fix this.
242 sig = os::signal_wait();
243 }
244 if (sig == os::sigexitnum_pd()) {
245 // Terminate the signal thread
246 return;
247 }
248
249 switch (sig) {
250 case SIGBREAK: {
251 // Check if the signal is a trigger to start the Attach Listener - in that
252 // case don't print stack traces.
253 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
254 continue;
255 }
256 // Print stack traces
257 // Any SIGBREAK operations added here should make sure to flush
258 // the output stream (e.g. tty->flush()) after output. See 4803766.
259 // Each module also prints an extra carriage return after its output.
260 VM_PrintThreads op;
261 VMThread::execute(&op);
262 VM_PrintJNI jni_op;
263 VMThread::execute(&jni_op);
264 VM_FindDeadlocks op1(tty);
265 VMThread::execute(&op1);
266 Universe::print_heap_at_SIGBREAK();
267 if (PrintClassHistogram) {
268 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */,
269 true /* need_prologue */);
270 VMThread::execute(&op1);
271 }
272 if (JvmtiExport::should_post_data_dump()) {
273 JvmtiExport::post_data_dump();
274 }
275 break;
276 }
277 default: {
278 // Dispatch the signal to java
279 HandleMark hm(THREAD);
280 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
281 KlassHandle klass (THREAD, k);
282 if (klass.not_null()) {
283 JavaValue result(T_VOID);
284 JavaCallArguments args;
285 args.push_int(sig);
286 JavaCalls::call_static(
287 &result,
288 klass,
289 vmSymbols::dispatch_name(),
290 vmSymbols::int_void_signature(),
291 &args,
292 THREAD
293 );
294 }
295 if (HAS_PENDING_EXCEPTION) {
296 // tty is initialized early so we don't expect it to be null, but
297 // if it is we can't risk doing an initialization that might
298 // trigger additional out-of-memory conditions
299 if (tty != NULL) {
300 char klass_name[256];
301 char tmp_sig_name[16];
302 const char* sig_name = "UNKNOWN";
303 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
304 name()->as_klass_external_name(klass_name, 256);
305 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
306 sig_name = tmp_sig_name;
307 warning("Exception %s occurred dispatching signal %s to handler"
308 "- the VM may need to be forcibly terminated",
309 klass_name, sig_name );
310 }
311 CLEAR_PENDING_EXCEPTION;
312 }
313 }
314 }
315 }
316 }
317
318
319 void os::signal_init() {
320 if (!ReduceSignalUsage) {
321 // Setup JavaThread for processing signals
322 EXCEPTION_MARK;
323 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
324 instanceKlassHandle klass (THREAD, k);
325 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
326
327 const char thread_name[] = "Signal Dispatcher";
328 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
329
330 // Initialize thread_oop to put it into the system threadGroup
331 Handle thread_group (THREAD, Universe::system_thread_group());
332 JavaValue result(T_VOID);
333 JavaCalls::call_special(&result, thread_oop,
334 klass,
335 vmSymbols::object_initializer_name(),
336 vmSymbols::threadgroup_string_void_signature(),
337 thread_group,
338 string,
339 CHECK);
340
341 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
342 JavaCalls::call_special(&result,
343 thread_group,
344 group,
345 vmSymbols::add_method_name(),
346 vmSymbols::thread_void_signature(),
347 thread_oop, // ARG 1
348 CHECK);
349
350 os::signal_init_pd();
351
352 { MutexLocker mu(Threads_lock);
353 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
354
355 // At this point it may be possible that no osthread was created for the
356 // JavaThread due to lack of memory. We would have to throw an exception
357 // in that case. However, since this must work and we do not allow
358 // exceptions anyway, check and abort if this fails.
359 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
360 vm_exit_during_initialization("java.lang.OutOfMemoryError",
361 "unable to create new native thread");
362 }
363
364 java_lang_Thread::set_thread(thread_oop(), signal_thread);
365 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
366 java_lang_Thread::set_daemon(thread_oop());
367
368 signal_thread->set_threadObj(thread_oop());
369 Threads::add(signal_thread);
370 Thread::start(signal_thread);
371 }
372 // Handle ^BREAK
373 os::signal(SIGBREAK, os::user_handler());
374 }
375 }
376
377
378 void os::terminate_signal_thread() {
379 if (!ReduceSignalUsage)
380 signal_notify(sigexitnum_pd());
381 }
382
383
384 // --------------------- loading libraries ---------------------
385
386 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
387 extern struct JavaVM_ main_vm;
388
389 static void* _native_java_library = NULL;
390
391 void* os::native_java_library() {
392 if (_native_java_library == NULL) {
393 char buffer[JVM_MAXPATHLEN];
394 char ebuf[1024];
395
396 // Try to load verify dll first. In 1.3 java dll depends on it and is not
397 // always able to find it when the loading executable is outside the JDK.
398 // In order to keep working with 1.2 we ignore any loading errors.
399 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
400 "verify")) {
401 dll_load(buffer, ebuf, sizeof(ebuf));
402 }
403
404 // Load java dll
405 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
406 "java")) {
407 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
408 }
409 if (_native_java_library == NULL) {
410 vm_exit_during_initialization("Unable to load native library", ebuf);
411 }
412
413 #if defined(__OpenBSD__)
414 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
415 // ignore errors
416 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
417 "net")) {
418 dll_load(buffer, ebuf, sizeof(ebuf));
419 }
420 #endif
421 }
422 static jboolean onLoaded = JNI_FALSE;
423 if (onLoaded) {
424 // We may have to wait to fire OnLoad until TLS is initialized.
425 if (ThreadLocalStorage::is_initialized()) {
426 // The JNI_OnLoad handling is normally done by method load in
427 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
428 // explicitly so we have to check for JNI_OnLoad as well
429 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
430 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
431 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
432 if (JNI_OnLoad != NULL) {
433 JavaThread* thread = JavaThread::current();
434 ThreadToNativeFromVM ttn(thread);
435 HandleMark hm(thread);
436 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
437 onLoaded = JNI_TRUE;
438 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
439 vm_exit_during_initialization("Unsupported JNI version");
440 }
441 }
442 }
443 }
444 return _native_java_library;
445 }
446
447 // --------------------- heap allocation utilities ---------------------
448
449 char *os::strdup(const char *str, MEMFLAGS flags) {
450 size_t size = strlen(str);
451 char *dup_str = (char *)malloc(size + 1, flags);
452 if (dup_str == NULL) return NULL;
453 strcpy(dup_str, str);
454 return dup_str;
455 }
456
457
458
459 #ifdef ASSERT
460 #define space_before (MallocCushion + sizeof(double))
461 #define space_after MallocCushion
462 #define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t))
463 #define size_addr_from_obj(p) ((size_t*)p - 1)
464 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
465 // NB: cannot be debug variable, because these aren't set from the command line until
466 // *after* the first few allocs already happened
467 #define MallocCushion 16
468 #else
469 #define space_before 0
470 #define space_after 0
471 #define size_addr_from_base(p) should not use w/o ASSERT
472 #define size_addr_from_obj(p) should not use w/o ASSERT
473 #define MallocCushion 0
474 #endif
475 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
476
477 #ifdef ASSERT
478 inline size_t get_size(void* obj) {
479 size_t size = *size_addr_from_obj(obj);
480 if (size < 0) {
481 fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten ("
482 SIZE_FORMAT ")", obj, size));
483 }
484 return size;
485 }
486
487 u_char* find_cushion_backwards(u_char* start) {
488 u_char* p = start;
489 while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
490 p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
491 // ok, we have four consecutive marker bytes; find start
492 u_char* q = p - 4;
493 while (*q == badResourceValue) q--;
494 return q + 1;
495 }
496
497 u_char* find_cushion_forwards(u_char* start) {
498 u_char* p = start;
499 while (p[0] != badResourceValue || p[1] != badResourceValue ||
500 p[2] != badResourceValue || p[3] != badResourceValue) p++;
501 // ok, we have four consecutive marker bytes; find end of cushion
502 u_char* q = p + 4;
503 while (*q == badResourceValue) q++;
504 return q - MallocCushion;
505 }
506
507 void print_neighbor_blocks(void* ptr) {
508 // find block allocated before ptr (not entirely crash-proof)
509 if (MallocCushion < 4) {
510 tty->print_cr("### cannot find previous block (MallocCushion < 4)");
511 return;
512 }
513 u_char* start_of_this_block = (u_char*)ptr - space_before;
514 u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
515 // look for cushion in front of prev. block
516 u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
517 ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
518 u_char* obj = start_of_prev_block + space_before;
519 if (size <= 0 ) {
520 // start is bad; mayhave been confused by OS data inbetween objects
521 // search one more backwards
522 start_of_prev_block = find_cushion_backwards(start_of_prev_block);
523 size = *size_addr_from_base(start_of_prev_block);
524 obj = start_of_prev_block + space_before;
525 }
526
527 if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
528 tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
529 } else {
530 tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
531 }
532
533 // now find successor block
534 u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
535 start_of_next_block = find_cushion_forwards(start_of_next_block);
536 u_char* next_obj = start_of_next_block + space_before;
537 ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
538 if (start_of_next_block[0] == badResourceValue &&
539 start_of_next_block[1] == badResourceValue &&
540 start_of_next_block[2] == badResourceValue &&
541 start_of_next_block[3] == badResourceValue) {
542 tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
543 } else {
544 tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
545 }
546 }
547
548
549 void report_heap_error(void* memblock, void* bad, const char* where) {
550 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
551 tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock);
552 print_neighbor_blocks(memblock);
553 fatal("memory stomping error");
554 }
555
556 void verify_block(void* memblock) {
557 size_t size = get_size(memblock);
558 if (MallocCushion) {
559 u_char* ptr = (u_char*)memblock - space_before;
560 for (int i = 0; i < MallocCushion; i++) {
561 if (ptr[i] != badResourceValue) {
562 report_heap_error(memblock, ptr+i, "in front of");
563 }
564 }
565 u_char* end = (u_char*)memblock + size + space_after;
566 for (int j = -MallocCushion; j < 0; j++) {
567 if (end[j] != badResourceValue) {
568 report_heap_error(memblock, end+j, "after");
569 }
570 }
571 }
572 }
573 #endif
574
575 //
576 // This function supports testing of the malloc out of memory
577 // condition without really running the system out of memory.
578 //
579 static u_char* testMalloc(size_t alloc_size) {
580 assert(MallocMaxTestWords > 0, "sanity check");
581
582 if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
583 return NULL;
584 }
585
586 u_char* ptr = (u_char*)::malloc(alloc_size);
587
588 if (ptr != NULL) {
589 Atomic::add(((jint) (alloc_size / BytesPerWord)),
590 (volatile jint *) &cur_malloc_words);
591 }
592 return ptr;
593 }
594
595 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
596 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
597 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
598
599 if (size == 0) {
600 // return a valid pointer if size is zero
601 // if NULL is returned the calling functions assume out of memory.
602 size = 1;
603 }
604
605 const size_t alloc_size = size + space_before + space_after;
606
607 if (size > alloc_size) { // Check for rollover.
608 return NULL;
609 }
610
611 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
612
613 u_char* ptr;
614
615 if (MallocMaxTestWords > 0) {
616 ptr = testMalloc(alloc_size);
617 } else {
618 ptr = (u_char*)::malloc(alloc_size);
619 }
620
621 #ifdef ASSERT
622 if (ptr == NULL) return NULL;
623 if (MallocCushion) {
624 for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
625 u_char* end = ptr + space_before + size;
626 for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
627 for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
628 }
629 // put size just before data
630 *size_addr_from_base(ptr) = size;
631 #endif
632 u_char* memblock = ptr + space_before;
633 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
634 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
635 breakpoint();
636 }
637 debug_only(if (paranoid) verify_block(memblock));
638 if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
639
640 // we do not track MallocCushion memory
641 MemTracker::record_malloc((address)memblock, size, memflags, caller == 0 ? CALLER_PC : caller);
642
643 return memblock;
644 }
645
646
647 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
648 #ifndef ASSERT
649 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
650 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
651 MemTracker::Tracker tkr = MemTracker::get_realloc_tracker();
652 void* ptr = ::realloc(memblock, size);
653 if (ptr != NULL) {
654 tkr.record((address)memblock, (address)ptr, size, memflags,
655 caller == 0 ? CALLER_PC : caller);
656 } else {
657 tkr.discard();
658 }
659 return ptr;
660 #else
661 if (memblock == NULL) {
662 return malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
663 }
664 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
665 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
666 breakpoint();
667 }
668 verify_block(memblock);
669 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
670 if (size == 0) return NULL;
671 // always move the block
672 void* ptr = malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
673 if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
674 // Copy to new memory if malloc didn't fail
675 if ( ptr != NULL ) {
676 memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
677 if (paranoid) verify_block(ptr);
678 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
679 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
680 breakpoint();
681 }
682 free(memblock);
683 }
684 return ptr;
685 #endif
686 }
687
688
689 void os::free(void *memblock, MEMFLAGS memflags) {
690 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
691 #ifdef ASSERT
692 if (memblock == NULL) return;
693 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
694 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
695 breakpoint();
696 }
697 verify_block(memblock);
698 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
699 // Added by detlefs.
700 if (MallocCushion) {
701 u_char* ptr = (u_char*)memblock - space_before;
702 for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
703 guarantee(*p == badResourceValue,
704 "Thing freed should be malloc result.");
705 *p = (u_char)freeBlockPad;
706 }
707 size_t size = get_size(memblock);
708 inc_stat_counter(&free_bytes, size);
709 u_char* end = ptr + space_before + size;
710 for (u_char* q = end; q < end + MallocCushion; q++) {
711 guarantee(*q == badResourceValue,
712 "Thing freed should be malloc result.");
713 *q = (u_char)freeBlockPad;
714 }
715 if (PrintMalloc && tty != NULL)
716 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
717 } else if (PrintMalloc && tty != NULL) {
718 // tty->print_cr("os::free %p", memblock);
719 fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock);
720 }
721 #endif
722 MemTracker::record_free((address)memblock, memflags);
723
724 ::free((char*)memblock - space_before);
725 }
726
727 void os::init_random(long initval) {
728 _rand_seed = initval;
729 }
730
731
732 long os::random() {
733 /* standard, well-known linear congruential random generator with
734 * next_rand = (16807*seed) mod (2**31-1)
735 * see
736 * (1) "Random Number Generators: Good Ones Are Hard to Find",
737 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
738 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
739 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
740 */
741 const long a = 16807;
742 const unsigned long m = 2147483647;
743 const long q = m / a; assert(q == 127773, "weird math");
744 const long r = m % a; assert(r == 2836, "weird math");
745
746 // compute az=2^31p+q
747 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
748 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
749 lo += (hi & 0x7FFF) << 16;
750
751 // if q overflowed, ignore the overflow and increment q
752 if (lo > m) {
753 lo &= m;
754 ++lo;
755 }
756 lo += hi >> 15;
757
758 // if (p+q) overflowed, ignore the overflow and increment (p+q)
759 if (lo > m) {
760 lo &= m;
761 ++lo;
762 }
763 return (_rand_seed = lo);
764 }
765
766 // The INITIALIZED state is distinguished from the SUSPENDED state because the
767 // conditions in which a thread is first started are different from those in which
768 // a suspension is resumed. These differences make it hard for us to apply the
769 // tougher checks when starting threads that we want to do when resuming them.
770 // However, when start_thread is called as a result of Thread.start, on a Java
771 // thread, the operation is synchronized on the Java Thread object. So there
772 // cannot be a race to start the thread and hence for the thread to exit while
773 // we are working on it. Non-Java threads that start Java threads either have
774 // to do so in a context in which races are impossible, or should do appropriate
775 // locking.
776
777 void os::start_thread(Thread* thread) {
778 // guard suspend/resume
779 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
780 OSThread* osthread = thread->osthread();
781 osthread->set_state(RUNNABLE);
782 pd_start_thread(thread);
783 }
784
785 //---------------------------------------------------------------------------
786 // Helper functions for fatal error handler
787
788 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
789 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
790
791 int cols = 0;
792 int cols_per_line = 0;
793 switch (unitsize) {
794 case 1: cols_per_line = 16; break;
795 case 2: cols_per_line = 8; break;
796 case 4: cols_per_line = 4; break;
797 case 8: cols_per_line = 2; break;
798 default: return;
799 }
800
801 address p = start;
802 st->print(PTR_FORMAT ": ", start);
803 while (p < end) {
804 switch (unitsize) {
805 case 1: st->print("%02x", *(u1*)p); break;
806 case 2: st->print("%04x", *(u2*)p); break;
807 case 4: st->print("%08x", *(u4*)p); break;
808 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
809 }
810 p += unitsize;
811 cols++;
812 if (cols >= cols_per_line && p < end) {
813 cols = 0;
814 st->cr();
815 st->print(PTR_FORMAT ": ", p);
816 } else {
817 st->print(" ");
818 }
819 }
820 st->cr();
821 }
822
823 void os::print_environment_variables(outputStream* st, const char** env_list,
824 char* buffer, int len) {
825 if (env_list) {
826 st->print_cr("Environment Variables:");
827
828 for (int i = 0; env_list[i] != NULL; i++) {
829 if (getenv(env_list[i], buffer, len)) {
830 st->print(env_list[i]);
831 st->print("=");
832 st->print_cr(buffer);
833 }
834 }
835 }
836 }
837
838 void os::print_cpu_info(outputStream* st) {
839 // cpu
840 st->print("CPU:");
841 st->print("total %d", os::processor_count());
842 // It's not safe to query number of active processors after crash
843 // st->print("(active %d)", os::active_processor_count());
844 st->print(" %s", VM_Version::cpu_features());
845 st->cr();
846 pd_print_cpu_info(st);
847 }
848
849 void os::print_date_and_time(outputStream *st) {
850 time_t tloc;
851 (void)time(&tloc);
852 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
853
854 double t = os::elapsedTime();
855 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
856 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
857 // before printf. We lost some precision, but who cares?
858 st->print_cr("elapsed time: %d seconds", (int)t);
859 }
860
861 // moved from debug.cpp (used to be find()) but still called from there
862 // The verbose parameter is only set by the debug code in one case
863 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
864 address addr = (address)x;
865 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
866 if (b != NULL) {
867 if (b->is_buffer_blob()) {
868 // the interpreter is generated into a buffer blob
869 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
870 if (i != NULL) {
871 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
872 i->print_on(st);
873 return;
874 }
875 if (Interpreter::contains(addr)) {
876 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
877 " (not bytecode specific)", addr);
878 return;
879 }
880 //
881 if (AdapterHandlerLibrary::contains(b)) {
882 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
883 AdapterHandlerLibrary::print_handler_on(st, b);
884 }
885 // the stubroutines are generated into a buffer blob
886 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
887 if (d != NULL) {
888 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
889 d->print_on(st);
890 st->cr();
891 return;
892 }
893 if (StubRoutines::contains(addr)) {
894 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
895 "stub routine", addr);
896 return;
897 }
898 // the InlineCacheBuffer is using stubs generated into a buffer blob
899 if (InlineCacheBuffer::contains(addr)) {
900 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
901 return;
902 }
903 VtableStub* v = VtableStubs::stub_containing(addr);
904 if (v != NULL) {
905 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
906 v->print_on(st);
907 st->cr();
908 return;
909 }
910 }
911 nmethod* nm = b->as_nmethod_or_null();
912 if (nm != NULL) {
913 ResourceMark rm;
914 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
915 addr, (int)(addr - nm->entry_point()), nm);
916 if (verbose) {
917 st->print(" for ");
918 nm->method()->print_value_on(st);
919 }
920 st->cr();
921 nm->print_nmethod(verbose);
922 return;
923 }
924 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
925 b->print_on(st);
926 return;
927 }
928
929 if (Universe::heap()->is_in(addr)) {
930 HeapWord* p = Universe::heap()->block_start(addr);
931 bool print = false;
932 // If we couldn't find it it just may mean that heap wasn't parseable
933 // See if we were just given an oop directly
934 if (p != NULL && Universe::heap()->block_is_obj(p)) {
935 print = true;
936 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
937 p = (HeapWord*) addr;
938 print = true;
939 }
940 if (print) {
941 if (p == (HeapWord*) addr) {
942 st->print_cr(INTPTR_FORMAT " is an oop", addr);
943 } else {
944 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
945 }
946 oop(p)->print_on(st);
947 return;
948 }
949 } else {
950 if (Universe::heap()->is_in_reserved(addr)) {
951 st->print_cr(INTPTR_FORMAT " is an unallocated location "
952 "in the heap", addr);
953 return;
954 }
955 }
956 if (JNIHandles::is_global_handle((jobject) addr)) {
957 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
958 return;
959 }
960 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
961 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
962 return;
963 }
964 #ifndef PRODUCT
965 // we don't keep the block list in product mode
966 if (JNIHandleBlock::any_contains((jobject) addr)) {
967 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
968 return;
969 }
970 #endif
971
972 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
973 // Check for privilege stack
974 if (thread->privileged_stack_top() != NULL &&
975 thread->privileged_stack_top()->contains(addr)) {
976 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
977 "for thread: " INTPTR_FORMAT, addr, thread);
978 if (verbose) thread->print_on(st);
979 return;
980 }
981 // If the addr is a java thread print information about that.
982 if (addr == (address)thread) {
983 if (verbose) {
984 thread->print_on(st);
985 } else {
986 st->print_cr(INTPTR_FORMAT " is a thread", addr);
987 }
988 return;
989 }
990 // If the addr is in the stack region for this thread then report that
991 // and print thread info
992 if (thread->stack_base() >= addr &&
993 addr > (thread->stack_base() - thread->stack_size())) {
994 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
995 INTPTR_FORMAT, addr, thread);
996 if (verbose) thread->print_on(st);
997 return;
998 }
999
1000 }
1001
1002 #ifndef PRODUCT
1003 // Check if in metaspace.
1004 if (ClassLoaderDataGraph::contains((address)addr)) {
1005 // Use addr->print() from the debugger instead (not here)
1006 st->print_cr(INTPTR_FORMAT
1007 " is pointing into metadata", addr);
1008 return;
1009 }
1010 #endif
1011
1012 // Try an OS specific find
1013 if (os::find(addr, st)) {
1014 return;
1015 }
1016
1017 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1018 }
1019
1020 // Looks like all platforms except IA64 can use the same function to check
1021 // if C stack is walkable beyond current frame. The check for fp() is not
1022 // necessary on Sparc, but it's harmless.
1023 bool os::is_first_C_frame(frame* fr) {
1024 #if defined(IA64) && !defined(_WIN32)
1025 // On IA64 we have to check if the callers bsp is still valid
1026 // (i.e. within the register stack bounds).
1027 // Notice: this only works for threads created by the VM and only if
1028 // we walk the current stack!!! If we want to be able to walk
1029 // arbitrary other threads, we'll have to somehow store the thread
1030 // object in the frame.
1031 Thread *thread = Thread::current();
1032 if ((address)fr->fp() <=
1033 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1034 // This check is a little hacky, because on Linux the first C
1035 // frame's ('start_thread') register stack frame starts at
1036 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1037 // ('__pthread_bound_body') register stack frame seems to really
1038 // start at "register_stack_base".
1039 return true;
1040 } else {
1041 return false;
1042 }
1043 #elif defined(IA64) && defined(_WIN32)
1044 return true;
1045 #else
1046 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1047 // Check usp first, because if that's bad the other accessors may fault
1048 // on some architectures. Ditto ufp second, etc.
1049 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1050 // sp on amd can be 32 bit aligned.
1051 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1052
1053 uintptr_t usp = (uintptr_t)fr->sp();
1054 if ((usp & sp_align_mask) != 0) return true;
1055
1056 uintptr_t ufp = (uintptr_t)fr->fp();
1057 if ((ufp & fp_align_mask) != 0) return true;
1058
1059 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1060 if ((old_sp & sp_align_mask) != 0) return true;
1061 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1062
1063 uintptr_t old_fp = (uintptr_t)fr->link();
1064 if ((old_fp & fp_align_mask) != 0) return true;
1065 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1066
1067 // stack grows downwards; if old_fp is below current fp or if the stack
1068 // frame is too large, either the stack is corrupted or fp is not saved
1069 // on stack (i.e. on x86, ebp may be used as general register). The stack
1070 // is not walkable beyond current frame.
1071 if (old_fp < ufp) return true;
1072 if (old_fp - ufp > 64 * K) return true;
1073
1074 return false;
1075 #endif
1076 }
1077
1078 #ifdef ASSERT
1079 extern "C" void test_random() {
1080 const double m = 2147483647;
1081 double mean = 0.0, variance = 0.0, t;
1082 long reps = 10000;
1083 unsigned long seed = 1;
1084
1085 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1086 os::init_random(seed);
1087 long num;
1088 for (int k = 0; k < reps; k++) {
1089 num = os::random();
1090 double u = (double)num / m;
1091 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1092
1093 // calculate mean and variance of the random sequence
1094 mean += u;
1095 variance += (u*u);
1096 }
1097 mean /= reps;
1098 variance /= (reps - 1);
1099
1100 assert(num == 1043618065, "bad seed");
1101 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1102 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1103 const double eps = 0.0001;
1104 t = fabsd(mean - 0.5018);
1105 assert(t < eps, "bad mean");
1106 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1107 assert(t < eps, "bad variance");
1108 }
1109 #endif
1110
1111
1112 // Set up the boot classpath.
1113
1114 char* os::format_boot_path(const char* format_string,
1115 const char* home,
1116 int home_len,
1117 char fileSep,
1118 char pathSep) {
1119 assert((fileSep == '/' && pathSep == ':') ||
1120 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1121
1122 // Scan the format string to determine the length of the actual
1123 // boot classpath, and handle platform dependencies as well.
1124 int formatted_path_len = 0;
1125 const char* p;
1126 for (p = format_string; *p != 0; ++p) {
1127 if (*p == '%') formatted_path_len += home_len - 1;
1128 ++formatted_path_len;
1129 }
1130
1131 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1132 if (formatted_path == NULL) {
1133 return NULL;
1134 }
1135
1136 // Create boot classpath from format, substituting separator chars and
1137 // java home directory.
1138 char* q = formatted_path;
1139 for (p = format_string; *p != 0; ++p) {
1140 switch (*p) {
1141 case '%':
1142 strcpy(q, home);
1143 q += home_len;
1144 break;
1145 case '/':
1146 *q++ = fileSep;
1147 break;
1148 case ':':
1149 *q++ = pathSep;
1150 break;
1151 default:
1152 *q++ = *p;
1153 }
1154 }
1155 *q = '\0';
1156
1157 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1158 return formatted_path;
1159 }
1160
1161
1162 bool os::set_boot_path(char fileSep, char pathSep) {
1163 const char* home = Arguments::get_java_home();
1164 int home_len = (int)strlen(home);
1165
1166 static const char* meta_index_dir_format = "%/lib/";
1167 static const char* meta_index_format = "%/lib/meta-index";
1168 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1169 if (meta_index == NULL) return false;
1170 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1171 if (meta_index_dir == NULL) return false;
1172 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1173
1174 // Any modification to the JAR-file list, for the boot classpath must be
1175 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1176 // path class JARs, are stripped for StackMapTable to reduce download size.
1177 static const char classpath_format[] =
1178 "%/lib/resources.jar:"
1179 "%/lib/rt.jar:"
1180 "%/lib/sunrsasign.jar:"
1181 "%/lib/jsse.jar:"
1182 "%/lib/jce.jar:"
1183 "%/lib/charsets.jar:"
1184 "%/lib/jfr.jar:"
1185 #ifdef __APPLE__
1186 "%/lib/JObjC.jar:"
1187 #endif
1188 "%/classes";
1189 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1190 if (sysclasspath == NULL) return false;
1191 Arguments::set_sysclasspath(sysclasspath);
1192
1193 return true;
1194 }
1195
1196 /*
1197 * Splits a path, based on its separator, the number of
1198 * elements is returned back in n.
1199 * It is the callers responsibility to:
1200 * a> check the value of n, and n may be 0.
1201 * b> ignore any empty path elements
1202 * c> free up the data.
1203 */
1204 char** os::split_path(const char* path, int* n) {
1205 *n = 0;
1206 if (path == NULL || strlen(path) == 0) {
1207 return NULL;
1208 }
1209 const char psepchar = *os::path_separator();
1210 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1211 if (inpath == NULL) {
1212 return NULL;
1213 }
1214 strcpy(inpath, path);
1215 int count = 1;
1216 char* p = strchr(inpath, psepchar);
1217 // Get a count of elements to allocate memory
1218 while (p != NULL) {
1219 count++;
1220 p++;
1221 p = strchr(p, psepchar);
1222 }
1223 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1224 if (opath == NULL) {
1225 return NULL;
1226 }
1227
1228 // do the actual splitting
1229 p = inpath;
1230 for (int i = 0 ; i < count ; i++) {
1231 size_t len = strcspn(p, os::path_separator());
1232 if (len > JVM_MAXPATHLEN) {
1233 return NULL;
1234 }
1235 // allocate the string and add terminator storage
1236 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1237 if (s == NULL) {
1238 return NULL;
1239 }
1240 strncpy(s, p, len);
1241 s[len] = '\0';
1242 opath[i] = s;
1243 p += len + 1;
1244 }
1245 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1246 *n = count;
1247 return opath;
1248 }
1249
1250 void os::set_memory_serialize_page(address page) {
1251 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1252 _mem_serialize_page = (volatile int32_t *)page;
1253 // We initialize the serialization page shift count here
1254 // We assume a cache line size of 64 bytes
1255 assert(SerializePageShiftCount == count,
1256 "thread size changed, fix SerializePageShiftCount constant");
1257 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1258 }
1259
1260 static volatile intptr_t SerializePageLock = 0;
1261
1262 // This method is called from signal handler when SIGSEGV occurs while the current
1263 // thread tries to store to the "read-only" memory serialize page during state
1264 // transition.
1265 void os::block_on_serialize_page_trap() {
1266 if (TraceSafepoint) {
1267 tty->print_cr("Block until the serialize page permission restored");
1268 }
1269 // When VMThread is holding the SerializePageLock during modifying the
1270 // access permission of the memory serialize page, the following call
1271 // will block until the permission of that page is restored to rw.
1272 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1273 // this case, it's OK as the signal is synchronous and we know precisely when
1274 // it can occur.
1275 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1276 Thread::muxRelease(&SerializePageLock);
1277 }
1278
1279 // Serialize all thread state variables
1280 void os::serialize_thread_states() {
1281 // On some platforms such as Solaris & Linux, the time duration of the page
1282 // permission restoration is observed to be much longer than expected due to
1283 // scheduler starvation problem etc. To avoid the long synchronization
1284 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1285 // the mutator thread if such case is encountered. See bug 6546278 for details.
1286 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1287 os::protect_memory((char *)os::get_memory_serialize_page(),
1288 os::vm_page_size(), MEM_PROT_READ);
1289 os::protect_memory((char *)os::get_memory_serialize_page(),
1290 os::vm_page_size(), MEM_PROT_RW);
1291 Thread::muxRelease(&SerializePageLock);
1292 }
1293
1294 // Returns true if the current stack pointer is above the stack shadow
1295 // pages, false otherwise.
1296
1297 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1298 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1299 address sp = current_stack_pointer();
1300 // Check if we have StackShadowPages above the yellow zone. This parameter
1301 // is dependent on the depth of the maximum VM call stack possible from
1302 // the handler for stack overflow. 'instanceof' in the stack overflow
1303 // handler or a println uses at least 8k stack of VM and native code
1304 // respectively.
1305 const int framesize_in_bytes =
1306 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1307 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1308 * vm_page_size()) + framesize_in_bytes;
1309 // The very lower end of the stack
1310 address stack_limit = thread->stack_base() - thread->stack_size();
1311 return (sp > (stack_limit + reserved_area));
1312 }
1313
1314 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1315 uint min_pages)
1316 {
1317 assert(min_pages > 0, "sanity");
1318 if (UseLargePages) {
1319 const size_t max_page_size = region_max_size / min_pages;
1320
1321 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1322 const size_t sz = _page_sizes[i];
1323 const size_t mask = sz - 1;
1324 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1325 // The largest page size with no fragmentation.
1326 return sz;
1327 }
1328
1329 if (sz <= max_page_size) {
1330 // The largest page size that satisfies the min_pages requirement.
1331 return sz;
1332 }
1333 }
1334 }
1335
1336 return vm_page_size();
1337 }
1338
1339 #ifndef PRODUCT
1340 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1341 {
1342 if (TracePageSizes) {
1343 tty->print("%s: ", str);
1344 for (int i = 0; i < count; ++i) {
1345 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1346 }
1347 tty->cr();
1348 }
1349 }
1350
1351 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1352 const size_t region_max_size, const size_t page_size,
1353 const char* base, const size_t size)
1354 {
1355 if (TracePageSizes) {
1356 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1357 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1358 " size=" SIZE_FORMAT,
1359 str, region_min_size, region_max_size,
1360 page_size, base, size);
1361 }
1362 }
1363 #endif // #ifndef PRODUCT
1364
1365 // This is the working definition of a server class machine:
1366 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1367 // because the graphics memory (?) sometimes masks physical memory.
1368 // If you want to change the definition of a server class machine
1369 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1370 // then you'll have to parameterize this method based on that state,
1371 // as was done for logical processors here, or replicate and
1372 // specialize this method for each platform. (Or fix os to have
1373 // some inheritance structure and use subclassing. Sigh.)
1374 // If you want some platform to always or never behave as a server
1375 // class machine, change the setting of AlwaysActAsServerClassMachine
1376 // and NeverActAsServerClassMachine in globals*.hpp.
1377 bool os::is_server_class_machine() {
1378 // First check for the early returns
1379 if (NeverActAsServerClassMachine) {
1380 return false;
1381 }
1382 if (AlwaysActAsServerClassMachine) {
1383 return true;
1384 }
1385 // Then actually look at the machine
1386 bool result = false;
1387 const unsigned int server_processors = 2;
1388 const julong server_memory = 2UL * G;
1389 // We seem not to get our full complement of memory.
1390 // We allow some part (1/8?) of the memory to be "missing",
1391 // based on the sizes of DIMMs, and maybe graphics cards.
1392 const julong missing_memory = 256UL * M;
1393
1394 /* Is this a server class machine? */
1395 if ((os::active_processor_count() >= (int)server_processors) &&
1396 (os::physical_memory() >= (server_memory - missing_memory))) {
1397 const unsigned int logical_processors =
1398 VM_Version::logical_processors_per_package();
1399 if (logical_processors > 1) {
1400 const unsigned int physical_packages =
1401 os::active_processor_count() / logical_processors;
1402 if (physical_packages > server_processors) {
1403 result = true;
1404 }
1405 } else {
1406 result = true;
1407 }
1408 }
1409 return result;
1410 }
1411
1412 // Read file line by line, if line is longer than bsize,
1413 // skip rest of line.
1414 int os::get_line_chars(int fd, char* buf, const size_t bsize){
1415 size_t sz, i = 0;
1416
1417 // read until EOF, EOL or buf is full
1418 while ((sz = (int) read(fd, &buf[i], 1)) == 1 && i < (bsize-2) && buf[i] != '\n') {
1419 ++i;
1420 }
1421
1422 if (buf[i] == '\n') {
1423 // EOL reached so ignore EOL character and return
1424
1425 buf[i] = 0;
1426 return (int) i;
1427 }
1428
1429 buf[i+1] = 0;
1430
1431 if (sz != 1) {
1432 // EOF reached. if we read chars before EOF return them and
1433 // return EOF on next call otherwise return EOF
1434
1435 return (i == 0) ? -1 : (int) i;
1436 }
1437
1438 // line is longer than size of buf, skip to EOL
1439 char ch;
1440 while (read(fd, &ch, 1) == 1 && ch != '\n') {
1441 // Do nothing
1442 }
1443
1444 // return initial part of line that fits in buf.
1445 // If we reached EOF, it will be returned on next call.
1446
1447 return (int) i;
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
1455 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1456 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1457 if (result != NULL) {
1458 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1459 }
1460
1461 return result;
1462 }
1463
1464 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1465 MEMFLAGS flags) {
1466 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1467 if (result != NULL) {
1468 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1469 MemTracker::record_virtual_memory_type((address)result, flags);
1470 }
1471
1472 return result;
1473 }
1474
1475 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1476 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1477 if (result != NULL) {
1478 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1479 }
1480 return result;
1481 }
1482
1483 void os::split_reserved_memory(char *base, size_t size,
1484 size_t split, bool realloc) {
1485 pd_split_reserved_memory(base, size, split, realloc);
1486 }
1487
1488 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1489 bool res = pd_commit_memory(addr, bytes, executable);
1490 if (res) {
1491 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1492 }
1493 return res;
1494 }
1495
1496 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1497 bool executable) {
1498 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1499 if (res) {
1500 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1501 }
1502 return res;
1503 }
1504
1505 bool os::uncommit_memory(char* addr, size_t bytes) {
1506 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1507 bool res = pd_uncommit_memory(addr, bytes);
1508 if (res) {
1509 tkr.record((address)addr, bytes);
1510 } else {
1511 tkr.discard();
1512 }
1513 return res;
1514 }
1515
1516 bool os::release_memory(char* addr, size_t bytes) {
1517 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1518 bool res = pd_release_memory(addr, bytes);
1519 if (res) {
1520 tkr.record((address)addr, bytes);
1521 } else {
1522 tkr.discard();
1523 }
1524 return res;
1525 }
1526
1527
1528 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1529 char *addr, size_t bytes, bool read_only,
1530 bool allow_exec) {
1531 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1532 if (result != NULL) {
1533 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, mtNone, CALLER_PC);
1534 }
1535 return result;
1536 }
1537
1538 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1539 char *addr, size_t bytes, bool read_only,
1540 bool allow_exec) {
1541 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1542 read_only, allow_exec);
1543 }
1544
1545 bool os::unmap_memory(char *addr, size_t bytes) {
1546 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1547 bool result = pd_unmap_memory(addr, bytes);
1548 if (result) {
1549 tkr.record((address)addr, bytes);
1550 } else {
1551 tkr.discard();
1552 }
1553 return result;
1554 }
1555
1556 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1557 pd_free_memory(addr, bytes, alignment_hint);
1558 }
1559
1560 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1561 pd_realign_memory(addr, bytes, alignment_hint);
1562 }
1563