Mercurial > hg > graal-jvmci-8
annotate src/share/vm/runtime/os.cpp @ 350:d28aa69f0959
6618726: Introduce -XX:+UnlockExperimentalVMOptions flag
Summary: experimental() flags will protect features of an experimental nature that are not supported in the regular product build. Made UseG1GC an experimental flag.
Reviewed-by: jmasa, kamg, coleenp
author | ysr |
---|---|
date | Mon, 30 Jun 2008 17:04:59 -0700 |
parents | 5a76ab815e34 |
children | d1605aabd0a1 |
rev | line source |
---|---|
0 | 1 /* |
2 * Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 # include "incls/_precompiled.incl" | |
26 # include "incls/_os.cpp.incl" | |
27 | |
28 # include <signal.h> | |
29 | |
30 OSThread* os::_starting_thread = NULL; | |
31 address os::_polling_page = NULL; | |
32 volatile int32_t* os::_mem_serialize_page = NULL; | |
33 uintptr_t os::_serialize_page_mask = 0; | |
34 long os::_rand_seed = 1; | |
35 int os::_processor_count = 0; | |
36 size_t os::_page_sizes[os::page_sizes_max]; | |
37 | |
38 #ifndef PRODUCT | |
39 int os::num_mallocs = 0; // # of calls to malloc/realloc | |
40 size_t os::alloc_bytes = 0; // # of bytes allocated | |
41 int os::num_frees = 0; // # of calls to free | |
42 #endif | |
43 | |
44 // Fill in buffer with current local time as an ISO-8601 string. | |
45 // E.g., yyyy-mm-ddThh:mm:ss-zzzz. | |
46 // Returns buffer, or NULL if it failed. | |
47 // This would mostly be a call to | |
48 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....) | |
49 // except that on Windows the %z behaves badly, so we do it ourselves. | |
50 // Also, people wanted milliseconds on there, | |
51 // and strftime doesn't do milliseconds. | |
52 char* os::iso8601_time(char* buffer, size_t buffer_length) { | |
53 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0" | |
54 // 1 2 | |
55 // 12345678901234567890123456789 | |
56 static const char* iso8601_format = | |
57 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"; | |
58 static const size_t needed_buffer = 29; | |
59 | |
60 // Sanity check the arguments | |
61 if (buffer == NULL) { | |
62 assert(false, "NULL buffer"); | |
63 return NULL; | |
64 } | |
65 if (buffer_length < needed_buffer) { | |
66 assert(false, "buffer_length too small"); | |
67 return NULL; | |
68 } | |
69 // Get the current time | |
61 | 70 jlong milliseconds_since_19700101 = javaTimeMillis(); |
0 | 71 const int milliseconds_per_microsecond = 1000; |
72 const time_t seconds_since_19700101 = | |
73 milliseconds_since_19700101 / milliseconds_per_microsecond; | |
74 const int milliseconds_after_second = | |
75 milliseconds_since_19700101 % milliseconds_per_microsecond; | |
76 // Convert the time value to a tm and timezone variable | |
77 const struct tm *time_struct_temp = localtime(&seconds_since_19700101); | |
78 if (time_struct_temp == NULL) { | |
79 assert(false, "Failed localtime"); | |
80 return NULL; | |
81 } | |
82 // Save the results of localtime | |
83 const struct tm time_struct = *time_struct_temp; | |
84 const time_t zone = timezone; | |
85 | |
86 // If daylight savings time is in effect, | |
87 // we are 1 hour East of our time zone | |
88 const time_t seconds_per_minute = 60; | |
89 const time_t minutes_per_hour = 60; | |
90 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour; | |
91 time_t UTC_to_local = zone; | |
92 if (time_struct.tm_isdst > 0) { | |
93 UTC_to_local = UTC_to_local - seconds_per_hour; | |
94 } | |
95 // Compute the time zone offset. | |
96 // localtime(3C) sets timezone to the difference (in seconds) | |
97 // between UTC and and local time. | |
98 // ISO 8601 says we need the difference between local time and UTC, | |
99 // we change the sign of the localtime(3C) result. | |
100 const time_t local_to_UTC = -(UTC_to_local); | |
101 // Then we have to figure out if if we are ahead (+) or behind (-) UTC. | |
102 char sign_local_to_UTC = '+'; | |
103 time_t abs_local_to_UTC = local_to_UTC; | |
104 if (local_to_UTC < 0) { | |
105 sign_local_to_UTC = '-'; | |
106 abs_local_to_UTC = -(abs_local_to_UTC); | |
107 } | |
108 // Convert time zone offset seconds to hours and minutes. | |
109 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour); | |
110 const time_t zone_min = | |
111 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute); | |
112 | |
113 // Print an ISO 8601 date and time stamp into the buffer | |
114 const int year = 1900 + time_struct.tm_year; | |
115 const int month = 1 + time_struct.tm_mon; | |
116 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format, | |
117 year, | |
118 month, | |
119 time_struct.tm_mday, | |
120 time_struct.tm_hour, | |
121 time_struct.tm_min, | |
122 time_struct.tm_sec, | |
123 milliseconds_after_second, | |
124 sign_local_to_UTC, | |
125 zone_hours, | |
126 zone_min); | |
127 if (printed == 0) { | |
128 assert(false, "Failed jio_printf"); | |
129 return NULL; | |
130 } | |
131 return buffer; | |
132 } | |
133 | |
134 OSReturn os::set_priority(Thread* thread, ThreadPriority p) { | |
135 #ifdef ASSERT | |
136 if (!(!thread->is_Java_thread() || | |
137 Thread::current() == thread || | |
138 Threads_lock->owned_by_self() | |
139 || thread->is_Compiler_thread() | |
140 )) { | |
141 assert(false, "possibility of dangling Thread pointer"); | |
142 } | |
143 #endif | |
144 | |
145 if (p >= MinPriority && p <= MaxPriority) { | |
146 int priority = java_to_os_priority[p]; | |
147 return set_native_priority(thread, priority); | |
148 } else { | |
149 assert(false, "Should not happen"); | |
150 return OS_ERR; | |
151 } | |
152 } | |
153 | |
154 | |
155 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) { | |
156 int p; | |
157 int os_prio; | |
158 OSReturn ret = get_native_priority(thread, &os_prio); | |
159 if (ret != OS_OK) return ret; | |
160 | |
161 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ; | |
162 priority = (ThreadPriority)p; | |
163 return OS_OK; | |
164 } | |
165 | |
166 | |
167 // --------------------- sun.misc.Signal (optional) --------------------- | |
168 | |
169 | |
170 // SIGBREAK is sent by the keyboard to query the VM state | |
171 #ifndef SIGBREAK | |
172 #define SIGBREAK SIGQUIT | |
173 #endif | |
174 | |
175 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread. | |
176 | |
177 | |
178 static void signal_thread_entry(JavaThread* thread, TRAPS) { | |
179 os::set_priority(thread, NearMaxPriority); | |
180 while (true) { | |
181 int sig; | |
182 { | |
183 // FIXME : Currently we have not decieded what should be the status | |
184 // for this java thread blocked here. Once we decide about | |
185 // that we should fix this. | |
186 sig = os::signal_wait(); | |
187 } | |
188 if (sig == os::sigexitnum_pd()) { | |
189 // Terminate the signal thread | |
190 return; | |
191 } | |
192 | |
193 switch (sig) { | |
194 case SIGBREAK: { | |
195 // Check if the signal is a trigger to start the Attach Listener - in that | |
196 // case don't print stack traces. | |
197 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) { | |
198 continue; | |
199 } | |
200 // Print stack traces | |
201 // Any SIGBREAK operations added here should make sure to flush | |
202 // the output stream (e.g. tty->flush()) after output. See 4803766. | |
203 // Each module also prints an extra carriage return after its output. | |
204 VM_PrintThreads op; | |
205 VMThread::execute(&op); | |
206 VM_PrintJNI jni_op; | |
207 VMThread::execute(&jni_op); | |
208 VM_FindDeadlocks op1(tty); | |
209 VMThread::execute(&op1); | |
210 Universe::print_heap_at_SIGBREAK(); | |
211 if (PrintClassHistogram) { | |
212 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */); | |
213 VMThread::execute(&op1); | |
214 } | |
215 if (JvmtiExport::should_post_data_dump()) { | |
216 JvmtiExport::post_data_dump(); | |
217 } | |
218 break; | |
219 } | |
220 default: { | |
221 // Dispatch the signal to java | |
222 HandleMark hm(THREAD); | |
223 klassOop k = SystemDictionary::resolve_or_null(vmSymbolHandles::sun_misc_Signal(), THREAD); | |
224 KlassHandle klass (THREAD, k); | |
225 if (klass.not_null()) { | |
226 JavaValue result(T_VOID); | |
227 JavaCallArguments args; | |
228 args.push_int(sig); | |
229 JavaCalls::call_static( | |
230 &result, | |
231 klass, | |
232 vmSymbolHandles::dispatch_name(), | |
233 vmSymbolHandles::int_void_signature(), | |
234 &args, | |
235 THREAD | |
236 ); | |
237 } | |
238 if (HAS_PENDING_EXCEPTION) { | |
239 // tty is initialized early so we don't expect it to be null, but | |
240 // if it is we can't risk doing an initialization that might | |
241 // trigger additional out-of-memory conditions | |
242 if (tty != NULL) { | |
243 char klass_name[256]; | |
244 char tmp_sig_name[16]; | |
245 const char* sig_name = "UNKNOWN"; | |
246 instanceKlass::cast(PENDING_EXCEPTION->klass())-> | |
247 name()->as_klass_external_name(klass_name, 256); | |
248 if (os::exception_name(sig, tmp_sig_name, 16) != NULL) | |
249 sig_name = tmp_sig_name; | |
250 warning("Exception %s occurred dispatching signal %s to handler" | |
251 "- the VM may need to be forcibly terminated", | |
252 klass_name, sig_name ); | |
253 } | |
254 CLEAR_PENDING_EXCEPTION; | |
255 } | |
256 } | |
257 } | |
258 } | |
259 } | |
260 | |
261 | |
262 void os::signal_init() { | |
263 if (!ReduceSignalUsage) { | |
264 // Setup JavaThread for processing signals | |
265 EXCEPTION_MARK; | |
266 klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK); | |
267 instanceKlassHandle klass (THREAD, k); | |
268 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); | |
269 | |
270 const char thread_name[] = "Signal Dispatcher"; | |
271 Handle string = java_lang_String::create_from_str(thread_name, CHECK); | |
272 | |
273 // Initialize thread_oop to put it into the system threadGroup | |
274 Handle thread_group (THREAD, Universe::system_thread_group()); | |
275 JavaValue result(T_VOID); | |
276 JavaCalls::call_special(&result, thread_oop, | |
277 klass, | |
278 vmSymbolHandles::object_initializer_name(), | |
279 vmSymbolHandles::threadgroup_string_void_signature(), | |
280 thread_group, | |
281 string, | |
282 CHECK); | |
283 | |
284 KlassHandle group(THREAD, SystemDictionary::threadGroup_klass()); | |
285 JavaCalls::call_special(&result, | |
286 thread_group, | |
287 group, | |
288 vmSymbolHandles::add_method_name(), | |
289 vmSymbolHandles::thread_void_signature(), | |
290 thread_oop, // ARG 1 | |
291 CHECK); | |
292 | |
293 os::signal_init_pd(); | |
294 | |
295 { MutexLocker mu(Threads_lock); | |
296 JavaThread* signal_thread = new JavaThread(&signal_thread_entry); | |
297 | |
298 // At this point it may be possible that no osthread was created for the | |
299 // JavaThread due to lack of memory. We would have to throw an exception | |
300 // in that case. However, since this must work and we do not allow | |
301 // exceptions anyway, check and abort if this fails. | |
302 if (signal_thread == NULL || signal_thread->osthread() == NULL) { | |
303 vm_exit_during_initialization("java.lang.OutOfMemoryError", | |
304 "unable to create new native thread"); | |
305 } | |
306 | |
307 java_lang_Thread::set_thread(thread_oop(), signal_thread); | |
308 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority); | |
309 java_lang_Thread::set_daemon(thread_oop()); | |
310 | |
311 signal_thread->set_threadObj(thread_oop()); | |
312 Threads::add(signal_thread); | |
313 Thread::start(signal_thread); | |
314 } | |
315 // Handle ^BREAK | |
316 os::signal(SIGBREAK, os::user_handler()); | |
317 } | |
318 } | |
319 | |
320 | |
321 void os::terminate_signal_thread() { | |
322 if (!ReduceSignalUsage) | |
323 signal_notify(sigexitnum_pd()); | |
324 } | |
325 | |
326 | |
327 // --------------------- loading libraries --------------------- | |
328 | |
329 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *); | |
330 extern struct JavaVM_ main_vm; | |
331 | |
332 static void* _native_java_library = NULL; | |
333 | |
334 void* os::native_java_library() { | |
335 if (_native_java_library == NULL) { | |
336 char buffer[JVM_MAXPATHLEN]; | |
337 char ebuf[1024]; | |
338 | |
339 // Try to load verify dll first. In 1.3 java dll depends on it and is not always | |
340 // able to find it when the loading executable is outside the JDK. | |
341 // In order to keep working with 1.2 we ignore any loading errors. | |
342 hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify"); | |
343 hpi::dll_load(buffer, ebuf, sizeof(ebuf)); | |
344 | |
345 // Load java dll | |
346 hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "java"); | |
347 _native_java_library = hpi::dll_load(buffer, ebuf, sizeof(ebuf)); | |
348 if (_native_java_library == NULL) { | |
349 vm_exit_during_initialization("Unable to load native library", ebuf); | |
350 } | |
351 // The JNI_OnLoad handling is normally done by method load in java.lang.ClassLoader$NativeLibrary, | |
352 // but the VM loads the base library explicitly so we have to check for JNI_OnLoad as well | |
353 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS; | |
354 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(JNI_OnLoad_t, hpi::dll_lookup(_native_java_library, onLoadSymbols[0])); | |
355 if (JNI_OnLoad != NULL) { | |
356 JavaThread* thread = JavaThread::current(); | |
357 ThreadToNativeFromVM ttn(thread); | |
358 HandleMark hm(thread); | |
359 jint ver = (*JNI_OnLoad)(&main_vm, NULL); | |
360 if (!Threads::is_supported_jni_version_including_1_1(ver)) { | |
361 vm_exit_during_initialization("Unsupported JNI version"); | |
362 } | |
363 } | |
364 } | |
365 return _native_java_library; | |
366 } | |
367 | |
368 // --------------------- heap allocation utilities --------------------- | |
369 | |
370 char *os::strdup(const char *str) { | |
371 size_t size = strlen(str); | |
372 char *dup_str = (char *)malloc(size + 1); | |
373 if (dup_str == NULL) return NULL; | |
374 strcpy(dup_str, str); | |
375 return dup_str; | |
376 } | |
377 | |
378 | |
379 | |
380 #ifdef ASSERT | |
381 #define space_before (MallocCushion + sizeof(double)) | |
382 #define space_after MallocCushion | |
383 #define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t)) | |
384 #define size_addr_from_obj(p) ((size_t*)p - 1) | |
385 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly | |
386 // NB: cannot be debug variable, because these aren't set from the command line until | |
387 // *after* the first few allocs already happened | |
388 #define MallocCushion 16 | |
389 #else | |
390 #define space_before 0 | |
391 #define space_after 0 | |
392 #define size_addr_from_base(p) should not use w/o ASSERT | |
393 #define size_addr_from_obj(p) should not use w/o ASSERT | |
394 #define MallocCushion 0 | |
395 #endif | |
396 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */ | |
397 | |
398 #ifdef ASSERT | |
399 inline size_t get_size(void* obj) { | |
400 size_t size = *size_addr_from_obj(obj); | |
401 if (size < 0 ) | |
402 fatal2("free: size field of object #%p was overwritten (%lu)", obj, size); | |
403 return size; | |
404 } | |
405 | |
406 u_char* find_cushion_backwards(u_char* start) { | |
407 u_char* p = start; | |
408 while (p[ 0] != badResourceValue || p[-1] != badResourceValue || | |
409 p[-2] != badResourceValue || p[-3] != badResourceValue) p--; | |
410 // ok, we have four consecutive marker bytes; find start | |
411 u_char* q = p - 4; | |
412 while (*q == badResourceValue) q--; | |
413 return q + 1; | |
414 } | |
415 | |
416 u_char* find_cushion_forwards(u_char* start) { | |
417 u_char* p = start; | |
418 while (p[0] != badResourceValue || p[1] != badResourceValue || | |
419 p[2] != badResourceValue || p[3] != badResourceValue) p++; | |
420 // ok, we have four consecutive marker bytes; find end of cushion | |
421 u_char* q = p + 4; | |
422 while (*q == badResourceValue) q++; | |
423 return q - MallocCushion; | |
424 } | |
425 | |
426 void print_neighbor_blocks(void* ptr) { | |
427 // find block allocated before ptr (not entirely crash-proof) | |
428 if (MallocCushion < 4) { | |
429 tty->print_cr("### cannot find previous block (MallocCushion < 4)"); | |
430 return; | |
431 } | |
432 u_char* start_of_this_block = (u_char*)ptr - space_before; | |
433 u_char* end_of_prev_block_data = start_of_this_block - space_after -1; | |
434 // look for cushion in front of prev. block | |
435 u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data); | |
436 ptrdiff_t size = *size_addr_from_base(start_of_prev_block); | |
437 u_char* obj = start_of_prev_block + space_before; | |
438 if (size <= 0 ) { | |
439 // start is bad; mayhave been confused by OS data inbetween objects | |
440 // search one more backwards | |
441 start_of_prev_block = find_cushion_backwards(start_of_prev_block); | |
442 size = *size_addr_from_base(start_of_prev_block); | |
443 obj = start_of_prev_block + space_before; | |
444 } | |
445 | |
446 if (start_of_prev_block + space_before + size + space_after == start_of_this_block) { | |
447 tty->print_cr("### previous object: %p (%ld bytes)", obj, size); | |
448 } else { | |
449 tty->print_cr("### previous object (not sure if correct): %p (%ld bytes)", obj, size); | |
450 } | |
451 | |
452 // now find successor block | |
453 u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after; | |
454 start_of_next_block = find_cushion_forwards(start_of_next_block); | |
455 u_char* next_obj = start_of_next_block + space_before; | |
456 ptrdiff_t next_size = *size_addr_from_base(start_of_next_block); | |
457 if (start_of_next_block[0] == badResourceValue && | |
458 start_of_next_block[1] == badResourceValue && | |
459 start_of_next_block[2] == badResourceValue && | |
460 start_of_next_block[3] == badResourceValue) { | |
461 tty->print_cr("### next object: %p (%ld bytes)", next_obj, next_size); | |
462 } else { | |
463 tty->print_cr("### next object (not sure if correct): %p (%ld bytes)", next_obj, next_size); | |
464 } | |
465 } | |
466 | |
467 | |
468 void report_heap_error(void* memblock, void* bad, const char* where) { | |
469 tty->print_cr("## nof_mallocs = %d, nof_frees = %d", os::num_mallocs, os::num_frees); | |
470 tty->print_cr("## memory stomp: byte at %p %s object %p", bad, where, memblock); | |
471 print_neighbor_blocks(memblock); | |
472 fatal("memory stomping error"); | |
473 } | |
474 | |
475 void verify_block(void* memblock) { | |
476 size_t size = get_size(memblock); | |
477 if (MallocCushion) { | |
478 u_char* ptr = (u_char*)memblock - space_before; | |
479 for (int i = 0; i < MallocCushion; i++) { | |
480 if (ptr[i] != badResourceValue) { | |
481 report_heap_error(memblock, ptr+i, "in front of"); | |
482 } | |
483 } | |
484 u_char* end = (u_char*)memblock + size + space_after; | |
485 for (int j = -MallocCushion; j < 0; j++) { | |
486 if (end[j] != badResourceValue) { | |
487 report_heap_error(memblock, end+j, "after"); | |
488 } | |
489 } | |
490 } | |
491 } | |
492 #endif | |
493 | |
494 void* os::malloc(size_t size) { | |
495 NOT_PRODUCT(num_mallocs++); | |
496 NOT_PRODUCT(alloc_bytes += size); | |
497 | |
498 if (size == 0) { | |
499 // return a valid pointer if size is zero | |
500 // if NULL is returned the calling functions assume out of memory. | |
501 size = 1; | |
502 } | |
503 | |
504 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); | |
505 u_char* ptr = (u_char*)::malloc(size + space_before + space_after); | |
506 #ifdef ASSERT | |
507 if (ptr == NULL) return NULL; | |
508 if (MallocCushion) { | |
509 for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue; | |
510 u_char* end = ptr + space_before + size; | |
511 for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad; | |
512 for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue; | |
513 } | |
514 // put size just before data | |
515 *size_addr_from_base(ptr) = size; | |
516 #endif | |
517 u_char* memblock = ptr + space_before; | |
518 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { | |
519 tty->print_cr("os::malloc caught, %lu bytes --> %p", size, memblock); | |
520 breakpoint(); | |
521 } | |
522 debug_only(if (paranoid) verify_block(memblock)); | |
523 if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc %lu bytes --> %p", size, memblock); | |
524 return memblock; | |
525 } | |
526 | |
527 | |
528 void* os::realloc(void *memblock, size_t size) { | |
529 NOT_PRODUCT(num_mallocs++); | |
530 NOT_PRODUCT(alloc_bytes += size); | |
531 #ifndef ASSERT | |
532 return ::realloc(memblock, size); | |
533 #else | |
534 if (memblock == NULL) { | |
535 return os::malloc(size); | |
536 } | |
537 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { | |
538 tty->print_cr("os::realloc caught %p", memblock); | |
539 breakpoint(); | |
540 } | |
541 verify_block(memblock); | |
542 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); | |
543 if (size == 0) return NULL; | |
544 // always move the block | |
545 void* ptr = malloc(size); | |
546 if (PrintMalloc) tty->print_cr("os::remalloc %lu bytes, %p --> %p", size, memblock, ptr); | |
547 // Copy to new memory if malloc didn't fail | |
548 if ( ptr != NULL ) { | |
549 memcpy(ptr, memblock, MIN2(size, get_size(memblock))); | |
550 if (paranoid) verify_block(ptr); | |
551 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) { | |
552 tty->print_cr("os::realloc caught, %lu bytes --> %p", size, ptr); | |
553 breakpoint(); | |
554 } | |
555 free(memblock); | |
556 } | |
557 return ptr; | |
558 #endif | |
559 } | |
560 | |
561 | |
562 void os::free(void *memblock) { | |
563 NOT_PRODUCT(num_frees++); | |
564 #ifdef ASSERT | |
565 if (memblock == NULL) return; | |
566 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) { | |
567 if (tty != NULL) tty->print_cr("os::free caught %p", memblock); | |
568 breakpoint(); | |
569 } | |
570 verify_block(memblock); | |
571 if (PrintMalloc && tty != NULL) | |
572 // tty->print_cr("os::free %p", memblock); | |
573 fprintf(stderr, "os::free %p\n", memblock); | |
574 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap()); | |
575 // Added by detlefs. | |
576 if (MallocCushion) { | |
577 u_char* ptr = (u_char*)memblock - space_before; | |
578 for (u_char* p = ptr; p < ptr + MallocCushion; p++) { | |
579 guarantee(*p == badResourceValue, | |
580 "Thing freed should be malloc result."); | |
581 *p = (u_char)freeBlockPad; | |
582 } | |
583 size_t size = get_size(memblock); | |
584 u_char* end = ptr + space_before + size; | |
585 for (u_char* q = end; q < end + MallocCushion; q++) { | |
586 guarantee(*q == badResourceValue, | |
587 "Thing freed should be malloc result."); | |
588 *q = (u_char)freeBlockPad; | |
589 } | |
590 } | |
591 #endif | |
592 ::free((char*)memblock - space_before); | |
593 } | |
594 | |
595 void os::init_random(long initval) { | |
596 _rand_seed = initval; | |
597 } | |
598 | |
599 | |
600 long os::random() { | |
601 /* standard, well-known linear congruential random generator with | |
602 * next_rand = (16807*seed) mod (2**31-1) | |
603 * see | |
604 * (1) "Random Number Generators: Good Ones Are Hard to Find", | |
605 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988), | |
606 * (2) "Two Fast Implementations of the 'Minimal Standard' Random | |
607 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88. | |
608 */ | |
609 const long a = 16807; | |
610 const unsigned long m = 2147483647; | |
611 const long q = m / a; assert(q == 127773, "weird math"); | |
612 const long r = m % a; assert(r == 2836, "weird math"); | |
613 | |
614 // compute az=2^31p+q | |
615 unsigned long lo = a * (long)(_rand_seed & 0xFFFF); | |
616 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16); | |
617 lo += (hi & 0x7FFF) << 16; | |
618 | |
619 // if q overflowed, ignore the overflow and increment q | |
620 if (lo > m) { | |
621 lo &= m; | |
622 ++lo; | |
623 } | |
624 lo += hi >> 15; | |
625 | |
626 // if (p+q) overflowed, ignore the overflow and increment (p+q) | |
627 if (lo > m) { | |
628 lo &= m; | |
629 ++lo; | |
630 } | |
631 return (_rand_seed = lo); | |
632 } | |
633 | |
634 // The INITIALIZED state is distinguished from the SUSPENDED state because the | |
635 // conditions in which a thread is first started are different from those in which | |
636 // a suspension is resumed. These differences make it hard for us to apply the | |
637 // tougher checks when starting threads that we want to do when resuming them. | |
638 // However, when start_thread is called as a result of Thread.start, on a Java | |
639 // thread, the operation is synchronized on the Java Thread object. So there | |
640 // cannot be a race to start the thread and hence for the thread to exit while | |
641 // we are working on it. Non-Java threads that start Java threads either have | |
642 // to do so in a context in which races are impossible, or should do appropriate | |
643 // locking. | |
644 | |
645 void os::start_thread(Thread* thread) { | |
646 // guard suspend/resume | |
647 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag); | |
648 OSThread* osthread = thread->osthread(); | |
649 osthread->set_state(RUNNABLE); | |
650 pd_start_thread(thread); | |
651 } | |
652 | |
653 //--------------------------------------------------------------------------- | |
654 // Helper functions for fatal error handler | |
655 | |
656 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) { | |
657 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking"); | |
658 | |
659 int cols = 0; | |
660 int cols_per_line = 0; | |
661 switch (unitsize) { | |
662 case 1: cols_per_line = 16; break; | |
663 case 2: cols_per_line = 8; break; | |
664 case 4: cols_per_line = 4; break; | |
665 case 8: cols_per_line = 2; break; | |
666 default: return; | |
667 } | |
668 | |
669 address p = start; | |
670 st->print(PTR_FORMAT ": ", start); | |
671 while (p < end) { | |
672 switch (unitsize) { | |
673 case 1: st->print("%02x", *(u1*)p); break; | |
674 case 2: st->print("%04x", *(u2*)p); break; | |
675 case 4: st->print("%08x", *(u4*)p); break; | |
676 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break; | |
677 } | |
678 p += unitsize; | |
679 cols++; | |
680 if (cols >= cols_per_line && p < end) { | |
681 cols = 0; | |
682 st->cr(); | |
683 st->print(PTR_FORMAT ": ", p); | |
684 } else { | |
685 st->print(" "); | |
686 } | |
687 } | |
688 st->cr(); | |
689 } | |
690 | |
691 void os::print_environment_variables(outputStream* st, const char** env_list, | |
692 char* buffer, int len) { | |
693 if (env_list) { | |
694 st->print_cr("Environment Variables:"); | |
695 | |
696 for (int i = 0; env_list[i] != NULL; i++) { | |
697 if (getenv(env_list[i], buffer, len)) { | |
698 st->print(env_list[i]); | |
699 st->print("="); | |
700 st->print_cr(buffer); | |
701 } | |
702 } | |
703 } | |
704 } | |
705 | |
706 void os::print_cpu_info(outputStream* st) { | |
707 // cpu | |
708 st->print("CPU:"); | |
709 st->print("total %d", os::processor_count()); | |
710 // It's not safe to query number of active processors after crash | |
711 // st->print("(active %d)", os::active_processor_count()); | |
712 st->print(" %s", VM_Version::cpu_features()); | |
713 st->cr(); | |
714 } | |
715 | |
716 void os::print_date_and_time(outputStream *st) { | |
717 time_t tloc; | |
718 (void)time(&tloc); | |
719 st->print("time: %s", ctime(&tloc)); // ctime adds newline. | |
720 | |
721 double t = os::elapsedTime(); | |
722 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in | |
723 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int | |
724 // before printf. We lost some precision, but who cares? | |
725 st->print_cr("elapsed time: %d seconds", (int)t); | |
726 } | |
727 | |
728 | |
729 // Looks like all platforms except IA64 can use the same function to check | |
730 // if C stack is walkable beyond current frame. The check for fp() is not | |
731 // necessary on Sparc, but it's harmless. | |
732 bool os::is_first_C_frame(frame* fr) { | |
733 #ifdef IA64 | |
734 // In order to walk native frames on Itanium, we need to access the unwind | |
735 // table, which is inside ELF. We don't want to parse ELF after fatal error, | |
736 // so return true for IA64. If we need to support C stack walking on IA64, | |
737 // this function needs to be moved to CPU specific files, as fp() on IA64 | |
738 // is register stack, which grows towards higher memory address. | |
739 return true; | |
740 #endif | |
741 | |
742 // Load up sp, fp, sender sp and sender fp, check for reasonable values. | |
743 // Check usp first, because if that's bad the other accessors may fault | |
744 // on some architectures. Ditto ufp second, etc. | |
745 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1); | |
746 // sp on amd can be 32 bit aligned. | |
747 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1); | |
748 | |
749 uintptr_t usp = (uintptr_t)fr->sp(); | |
750 if ((usp & sp_align_mask) != 0) return true; | |
751 | |
752 uintptr_t ufp = (uintptr_t)fr->fp(); | |
753 if ((ufp & fp_align_mask) != 0) return true; | |
754 | |
755 uintptr_t old_sp = (uintptr_t)fr->sender_sp(); | |
756 if ((old_sp & sp_align_mask) != 0) return true; | |
757 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true; | |
758 | |
759 uintptr_t old_fp = (uintptr_t)fr->link(); | |
760 if ((old_fp & fp_align_mask) != 0) return true; | |
761 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true; | |
762 | |
763 // stack grows downwards; if old_fp is below current fp or if the stack | |
764 // frame is too large, either the stack is corrupted or fp is not saved | |
765 // on stack (i.e. on x86, ebp may be used as general register). The stack | |
766 // is not walkable beyond current frame. | |
767 if (old_fp < ufp) return true; | |
768 if (old_fp - ufp > 64 * K) return true; | |
769 | |
770 return false; | |
771 } | |
772 | |
773 #ifdef ASSERT | |
774 extern "C" void test_random() { | |
775 const double m = 2147483647; | |
776 double mean = 0.0, variance = 0.0, t; | |
777 long reps = 10000; | |
778 unsigned long seed = 1; | |
779 | |
780 tty->print_cr("seed %ld for %ld repeats...", seed, reps); | |
781 os::init_random(seed); | |
782 long num; | |
783 for (int k = 0; k < reps; k++) { | |
784 num = os::random(); | |
785 double u = (double)num / m; | |
786 assert(u >= 0.0 && u <= 1.0, "bad random number!"); | |
787 | |
788 // calculate mean and variance of the random sequence | |
789 mean += u; | |
790 variance += (u*u); | |
791 } | |
792 mean /= reps; | |
793 variance /= (reps - 1); | |
794 | |
795 assert(num == 1043618065, "bad seed"); | |
796 tty->print_cr("mean of the 1st 10000 numbers: %f", mean); | |
797 tty->print_cr("variance of the 1st 10000 numbers: %f", variance); | |
798 const double eps = 0.0001; | |
799 t = fabsd(mean - 0.5018); | |
800 assert(t < eps, "bad mean"); | |
801 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355; | |
802 assert(t < eps, "bad variance"); | |
803 } | |
804 #endif | |
805 | |
806 | |
807 // Set up the boot classpath. | |
808 | |
809 char* os::format_boot_path(const char* format_string, | |
810 const char* home, | |
811 int home_len, | |
812 char fileSep, | |
813 char pathSep) { | |
814 assert((fileSep == '/' && pathSep == ':') || | |
815 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars"); | |
816 | |
817 // Scan the format string to determine the length of the actual | |
818 // boot classpath, and handle platform dependencies as well. | |
819 int formatted_path_len = 0; | |
820 const char* p; | |
821 for (p = format_string; *p != 0; ++p) { | |
822 if (*p == '%') formatted_path_len += home_len - 1; | |
823 ++formatted_path_len; | |
824 } | |
825 | |
826 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1); | |
827 if (formatted_path == NULL) { | |
828 return NULL; | |
829 } | |
830 | |
831 // Create boot classpath from format, substituting separator chars and | |
832 // java home directory. | |
833 char* q = formatted_path; | |
834 for (p = format_string; *p != 0; ++p) { | |
835 switch (*p) { | |
836 case '%': | |
837 strcpy(q, home); | |
838 q += home_len; | |
839 break; | |
840 case '/': | |
841 *q++ = fileSep; | |
842 break; | |
843 case ':': | |
844 *q++ = pathSep; | |
845 break; | |
846 default: | |
847 *q++ = *p; | |
848 } | |
849 } | |
850 *q = '\0'; | |
851 | |
852 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched"); | |
853 return formatted_path; | |
854 } | |
855 | |
856 | |
857 bool os::set_boot_path(char fileSep, char pathSep) { | |
858 | |
859 const char* home = Arguments::get_java_home(); | |
860 int home_len = (int)strlen(home); | |
861 | |
862 static const char* meta_index_dir_format = "%/lib/"; | |
863 static const char* meta_index_format = "%/lib/meta-index"; | |
864 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep); | |
865 if (meta_index == NULL) return false; | |
866 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep); | |
867 if (meta_index_dir == NULL) return false; | |
868 Arguments::set_meta_index_path(meta_index, meta_index_dir); | |
869 | |
870 // Any modification to the JAR-file list, for the boot classpath must be | |
871 // aligned with install/install/make/common/Pack.gmk. Note: boot class | |
872 // path class JARs, are stripped for StackMapTable to reduce download size. | |
873 static const char classpath_format[] = | |
874 "%/lib/resources.jar:" | |
875 "%/lib/rt.jar:" | |
876 "%/lib/sunrsasign.jar:" | |
877 "%/lib/jsse.jar:" | |
878 "%/lib/jce.jar:" | |
879 "%/lib/charsets.jar:" | |
880 "%/classes"; | |
881 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep); | |
882 if (sysclasspath == NULL) return false; | |
883 Arguments::set_sysclasspath(sysclasspath); | |
884 | |
885 return true; | |
886 } | |
887 | |
888 void os::set_memory_serialize_page(address page) { | |
889 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64); | |
890 _mem_serialize_page = (volatile int32_t *)page; | |
891 // We initialize the serialization page shift count here | |
892 // We assume a cache line size of 64 bytes | |
893 assert(SerializePageShiftCount == count, | |
894 "thread size changed, fix SerializePageShiftCount constant"); | |
895 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t))); | |
896 } | |
897 | |
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898 static volatile intptr_t SerializePageLock = 0; |
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899 |
0 | 900 // This method is called from signal handler when SIGSEGV occurs while the current |
901 // thread tries to store to the "read-only" memory serialize page during state | |
902 // transition. | |
903 void os::block_on_serialize_page_trap() { | |
904 if (TraceSafepoint) { | |
905 tty->print_cr("Block until the serialize page permission restored"); | |
906 } | |
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907 // When VMThread is holding the SerializePageLock during modifying the |
0 | 908 // access permission of the memory serialize page, the following call |
909 // will block until the permission of that page is restored to rw. | |
910 // Generally, it is unsafe to manipulate locks in signal handlers, but in | |
911 // this case, it's OK as the signal is synchronous and we know precisely when | |
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912 // it can occur. |
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913 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page"); |
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914 Thread::muxRelease(&SerializePageLock); |
0 | 915 } |
916 | |
917 // Serialize all thread state variables | |
918 void os::serialize_thread_states() { | |
919 // On some platforms such as Solaris & Linux, the time duration of the page | |
920 // permission restoration is observed to be much longer than expected due to | |
921 // scheduler starvation problem etc. To avoid the long synchronization | |
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922 // time and expensive page trap spinning, 'SerializePageLock' is used to block |
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923 // the mutator thread if such case is encountered. See bug 6546278 for details. |
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924 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states"); |
0 | 925 os::protect_memory( (char *)os::get_memory_serialize_page(), os::vm_page_size() ); |
926 os::unguard_memory( (char *)os::get_memory_serialize_page(), os::vm_page_size() ); | |
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927 Thread::muxRelease(&SerializePageLock); |
0 | 928 } |
929 | |
930 // Returns true if the current stack pointer is above the stack shadow | |
931 // pages, false otherwise. | |
932 | |
933 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) { | |
934 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check"); | |
935 address sp = current_stack_pointer(); | |
936 // Check if we have StackShadowPages above the yellow zone. This parameter | |
937 // is dependant on the depth of the maximum VM call stack possible from | |
938 // the handler for stack overflow. 'instanceof' in the stack overflow | |
939 // handler or a println uses at least 8k stack of VM and native code | |
940 // respectively. | |
941 const int framesize_in_bytes = | |
942 Interpreter::size_top_interpreter_activation(method()) * wordSize; | |
943 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages) | |
944 * vm_page_size()) + framesize_in_bytes; | |
945 // The very lower end of the stack | |
946 address stack_limit = thread->stack_base() - thread->stack_size(); | |
947 return (sp > (stack_limit + reserved_area)); | |
948 } | |
949 | |
950 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size, | |
951 uint min_pages) | |
952 { | |
953 assert(min_pages > 0, "sanity"); | |
954 if (UseLargePages) { | |
955 const size_t max_page_size = region_max_size / min_pages; | |
956 | |
957 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) { | |
958 const size_t sz = _page_sizes[i]; | |
959 const size_t mask = sz - 1; | |
960 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) { | |
961 // The largest page size with no fragmentation. | |
962 return sz; | |
963 } | |
964 | |
965 if (sz <= max_page_size) { | |
966 // The largest page size that satisfies the min_pages requirement. | |
967 return sz; | |
968 } | |
969 } | |
970 } | |
971 | |
972 return vm_page_size(); | |
973 } | |
974 | |
975 #ifndef PRODUCT | |
976 void os::trace_page_sizes(const char* str, const size_t region_min_size, | |
977 const size_t region_max_size, const size_t page_size, | |
978 const char* base, const size_t size) | |
979 { | |
980 if (TracePageSizes) { | |
981 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT | |
982 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT | |
983 " size=" SIZE_FORMAT, | |
984 str, region_min_size, region_max_size, | |
985 page_size, base, size); | |
986 } | |
987 } | |
988 #endif // #ifndef PRODUCT | |
989 | |
990 // This is the working definition of a server class machine: | |
991 // >= 2 physical CPU's and >=2GB of memory, with some fuzz | |
992 // because the graphics memory (?) sometimes masks physical memory. | |
993 // If you want to change the definition of a server class machine | |
994 // on some OS or platform, e.g., >=4GB on Windohs platforms, | |
995 // then you'll have to parameterize this method based on that state, | |
996 // as was done for logical processors here, or replicate and | |
997 // specialize this method for each platform. (Or fix os to have | |
998 // some inheritance structure and use subclassing. Sigh.) | |
999 // If you want some platform to always or never behave as a server | |
1000 // class machine, change the setting of AlwaysActAsServerClassMachine | |
1001 // and NeverActAsServerClassMachine in globals*.hpp. | |
1002 bool os::is_server_class_machine() { | |
1003 // First check for the early returns | |
1004 if (NeverActAsServerClassMachine) { | |
1005 return false; | |
1006 } | |
1007 if (AlwaysActAsServerClassMachine) { | |
1008 return true; | |
1009 } | |
1010 // Then actually look at the machine | |
1011 bool result = false; | |
1012 const unsigned int server_processors = 2; | |
1013 const julong server_memory = 2UL * G; | |
1014 // We seem not to get our full complement of memory. | |
1015 // We allow some part (1/8?) of the memory to be "missing", | |
1016 // based on the sizes of DIMMs, and maybe graphics cards. | |
1017 const julong missing_memory = 256UL * M; | |
1018 | |
1019 /* Is this a server class machine? */ | |
1020 if ((os::active_processor_count() >= (int)server_processors) && | |
1021 (os::physical_memory() >= (server_memory - missing_memory))) { | |
1022 const unsigned int logical_processors = | |
1023 VM_Version::logical_processors_per_package(); | |
1024 if (logical_processors > 1) { | |
1025 const unsigned int physical_packages = | |
1026 os::active_processor_count() / logical_processors; | |
1027 if (physical_packages > server_processors) { | |
1028 result = true; | |
1029 } | |
1030 } else { | |
1031 result = true; | |
1032 } | |
1033 } | |
1034 return result; | |
1035 } |