Fri, 16 Nov 2012 09:19:12 -0500
Merge
1 /*
2 * Copyright (c) 1997, 2012, 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 */
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 "services/attachListener.hpp"
48 #include "services/memTracker.hpp"
49 #include "services/threadService.hpp"
50 #include "utilities/defaultStream.hpp"
51 #include "utilities/events.hpp"
52 #ifdef TARGET_OS_FAMILY_linux
53 # include "os_linux.inline.hpp"
54 # include "thread_linux.inline.hpp"
55 #endif
56 #ifdef TARGET_OS_FAMILY_solaris
57 # include "os_solaris.inline.hpp"
58 # include "thread_solaris.inline.hpp"
59 #endif
60 #ifdef TARGET_OS_FAMILY_windows
61 # include "os_windows.inline.hpp"
62 # include "thread_windows.inline.hpp"
63 #endif
64 #ifdef TARGET_OS_FAMILY_bsd
65 # include "os_bsd.inline.hpp"
66 # include "thread_bsd.inline.hpp"
67 #endif
69 # include <signal.h>
71 OSThread* os::_starting_thread = NULL;
72 address os::_polling_page = NULL;
73 volatile int32_t* os::_mem_serialize_page = NULL;
74 uintptr_t os::_serialize_page_mask = 0;
75 long os::_rand_seed = 1;
76 int os::_processor_count = 0;
77 size_t os::_page_sizes[os::page_sizes_max];
79 #ifndef PRODUCT
80 julong os::num_mallocs = 0; // # of calls to malloc/realloc
81 julong os::alloc_bytes = 0; // # of bytes allocated
82 julong os::num_frees = 0; // # of calls to free
83 julong os::free_bytes = 0; // # of bytes freed
84 #endif
86 void os_init_globals() {
87 // Called from init_globals().
88 // See Threads::create_vm() in thread.cpp, and init.cpp.
89 os::init_globals();
90 }
92 // Fill in buffer with current local time as an ISO-8601 string.
93 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
94 // Returns buffer, or NULL if it failed.
95 // This would mostly be a call to
96 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
97 // except that on Windows the %z behaves badly, so we do it ourselves.
98 // Also, people wanted milliseconds on there,
99 // and strftime doesn't do milliseconds.
100 char* os::iso8601_time(char* buffer, size_t buffer_length) {
101 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
102 // 1 2
103 // 12345678901234567890123456789
104 static const char* iso8601_format =
105 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
106 static const size_t needed_buffer = 29;
108 // Sanity check the arguments
109 if (buffer == NULL) {
110 assert(false, "NULL buffer");
111 return NULL;
112 }
113 if (buffer_length < needed_buffer) {
114 assert(false, "buffer_length too small");
115 return NULL;
116 }
117 // Get the current time
118 jlong milliseconds_since_19700101 = javaTimeMillis();
119 const int milliseconds_per_microsecond = 1000;
120 const time_t seconds_since_19700101 =
121 milliseconds_since_19700101 / milliseconds_per_microsecond;
122 const int milliseconds_after_second =
123 milliseconds_since_19700101 % milliseconds_per_microsecond;
124 // Convert the time value to a tm and timezone variable
125 struct tm time_struct;
126 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
127 assert(false, "Failed localtime_pd");
128 return NULL;
129 }
130 #if defined(_ALLBSD_SOURCE)
131 const time_t zone = (time_t) time_struct.tm_gmtoff;
132 #else
133 const time_t zone = timezone;
134 #endif
136 // If daylight savings time is in effect,
137 // we are 1 hour East of our time zone
138 const time_t seconds_per_minute = 60;
139 const time_t minutes_per_hour = 60;
140 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
141 time_t UTC_to_local = zone;
142 if (time_struct.tm_isdst > 0) {
143 UTC_to_local = UTC_to_local - seconds_per_hour;
144 }
145 // Compute the time zone offset.
146 // localtime_pd() sets timezone to the difference (in seconds)
147 // between UTC and and local time.
148 // ISO 8601 says we need the difference between local time and UTC,
149 // we change the sign of the localtime_pd() result.
150 const time_t local_to_UTC = -(UTC_to_local);
151 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
152 char sign_local_to_UTC = '+';
153 time_t abs_local_to_UTC = local_to_UTC;
154 if (local_to_UTC < 0) {
155 sign_local_to_UTC = '-';
156 abs_local_to_UTC = -(abs_local_to_UTC);
157 }
158 // Convert time zone offset seconds to hours and minutes.
159 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
160 const time_t zone_min =
161 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
163 // Print an ISO 8601 date and time stamp into the buffer
164 const int year = 1900 + time_struct.tm_year;
165 const int month = 1 + time_struct.tm_mon;
166 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
167 year,
168 month,
169 time_struct.tm_mday,
170 time_struct.tm_hour,
171 time_struct.tm_min,
172 time_struct.tm_sec,
173 milliseconds_after_second,
174 sign_local_to_UTC,
175 zone_hours,
176 zone_min);
177 if (printed == 0) {
178 assert(false, "Failed jio_printf");
179 return NULL;
180 }
181 return buffer;
182 }
184 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
185 #ifdef ASSERT
186 if (!(!thread->is_Java_thread() ||
187 Thread::current() == thread ||
188 Threads_lock->owned_by_self()
189 || thread->is_Compiler_thread()
190 )) {
191 assert(false, "possibility of dangling Thread pointer");
192 }
193 #endif
195 if (p >= MinPriority && p <= MaxPriority) {
196 int priority = java_to_os_priority[p];
197 return set_native_priority(thread, priority);
198 } else {
199 assert(false, "Should not happen");
200 return OS_ERR;
201 }
202 }
204 // The mapping from OS priority back to Java priority may be inexact because
205 // Java priorities can map M:1 with native priorities. If you want the definite
206 // Java priority then use JavaThread::java_priority()
207 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
208 int p;
209 int os_prio;
210 OSReturn ret = get_native_priority(thread, &os_prio);
211 if (ret != OS_OK) return ret;
213 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
214 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
215 } else {
216 // niceness values are in reverse order
217 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
218 }
219 priority = (ThreadPriority)p;
220 return OS_OK;
221 }
224 // --------------------- sun.misc.Signal (optional) ---------------------
227 // SIGBREAK is sent by the keyboard to query the VM state
228 #ifndef SIGBREAK
229 #define SIGBREAK SIGQUIT
230 #endif
232 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
235 static void signal_thread_entry(JavaThread* thread, TRAPS) {
236 os::set_priority(thread, NearMaxPriority);
237 while (true) {
238 int sig;
239 {
240 // FIXME : Currently we have not decieded what should be the status
241 // for this java thread blocked here. Once we decide about
242 // that we should fix this.
243 sig = os::signal_wait();
244 }
245 if (sig == os::sigexitnum_pd()) {
246 // Terminate the signal thread
247 return;
248 }
250 switch (sig) {
251 case SIGBREAK: {
252 // Check if the signal is a trigger to start the Attach Listener - in that
253 // case don't print stack traces.
254 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
255 continue;
256 }
257 // Print stack traces
258 // Any SIGBREAK operations added here should make sure to flush
259 // the output stream (e.g. tty->flush()) after output. See 4803766.
260 // Each module also prints an extra carriage return after its output.
261 VM_PrintThreads op;
262 VMThread::execute(&op);
263 VM_PrintJNI jni_op;
264 VMThread::execute(&jni_op);
265 VM_FindDeadlocks op1(tty);
266 VMThread::execute(&op1);
267 Universe::print_heap_at_SIGBREAK();
268 if (PrintClassHistogram) {
269 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */,
270 true /* need_prologue */);
271 VMThread::execute(&op1);
272 }
273 if (JvmtiExport::should_post_data_dump()) {
274 JvmtiExport::post_data_dump();
275 }
276 break;
277 }
278 default: {
279 // Dispatch the signal to java
280 HandleMark hm(THREAD);
281 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
282 KlassHandle klass (THREAD, k);
283 if (klass.not_null()) {
284 JavaValue result(T_VOID);
285 JavaCallArguments args;
286 args.push_int(sig);
287 JavaCalls::call_static(
288 &result,
289 klass,
290 vmSymbols::dispatch_name(),
291 vmSymbols::int_void_signature(),
292 &args,
293 THREAD
294 );
295 }
296 if (HAS_PENDING_EXCEPTION) {
297 // tty is initialized early so we don't expect it to be null, but
298 // if it is we can't risk doing an initialization that might
299 // trigger additional out-of-memory conditions
300 if (tty != NULL) {
301 char klass_name[256];
302 char tmp_sig_name[16];
303 const char* sig_name = "UNKNOWN";
304 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
305 name()->as_klass_external_name(klass_name, 256);
306 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
307 sig_name = tmp_sig_name;
308 warning("Exception %s occurred dispatching signal %s to handler"
309 "- the VM may need to be forcibly terminated",
310 klass_name, sig_name );
311 }
312 CLEAR_PENDING_EXCEPTION;
313 }
314 }
315 }
316 }
317 }
320 void os::signal_init() {
321 if (!ReduceSignalUsage) {
322 // Setup JavaThread for processing signals
323 EXCEPTION_MARK;
324 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
325 instanceKlassHandle klass (THREAD, k);
326 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
328 const char thread_name[] = "Signal Dispatcher";
329 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
331 // Initialize thread_oop to put it into the system threadGroup
332 Handle thread_group (THREAD, Universe::system_thread_group());
333 JavaValue result(T_VOID);
334 JavaCalls::call_special(&result, thread_oop,
335 klass,
336 vmSymbols::object_initializer_name(),
337 vmSymbols::threadgroup_string_void_signature(),
338 thread_group,
339 string,
340 CHECK);
342 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
343 JavaCalls::call_special(&result,
344 thread_group,
345 group,
346 vmSymbols::add_method_name(),
347 vmSymbols::thread_void_signature(),
348 thread_oop, // ARG 1
349 CHECK);
351 os::signal_init_pd();
353 { MutexLocker mu(Threads_lock);
354 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
356 // At this point it may be possible that no osthread was created for the
357 // JavaThread due to lack of memory. We would have to throw an exception
358 // in that case. However, since this must work and we do not allow
359 // exceptions anyway, check and abort if this fails.
360 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
361 vm_exit_during_initialization("java.lang.OutOfMemoryError",
362 "unable to create new native thread");
363 }
365 java_lang_Thread::set_thread(thread_oop(), signal_thread);
366 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
367 java_lang_Thread::set_daemon(thread_oop());
369 signal_thread->set_threadObj(thread_oop());
370 Threads::add(signal_thread);
371 Thread::start(signal_thread);
372 }
373 // Handle ^BREAK
374 os::signal(SIGBREAK, os::user_handler());
375 }
376 }
379 void os::terminate_signal_thread() {
380 if (!ReduceSignalUsage)
381 signal_notify(sigexitnum_pd());
382 }
385 // --------------------- loading libraries ---------------------
387 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
388 extern struct JavaVM_ main_vm;
390 static void* _native_java_library = NULL;
392 void* os::native_java_library() {
393 if (_native_java_library == NULL) {
394 char buffer[JVM_MAXPATHLEN];
395 char ebuf[1024];
397 // Try to load verify dll first. In 1.3 java dll depends on it and is not
398 // always able to find it when the loading executable is outside the JDK.
399 // In order to keep working with 1.2 we ignore any loading errors.
400 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
401 "verify")) {
402 dll_load(buffer, ebuf, sizeof(ebuf));
403 }
405 // Load java dll
406 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
407 "java")) {
408 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
409 }
410 if (_native_java_library == NULL) {
411 vm_exit_during_initialization("Unable to load native library", ebuf);
412 }
414 #if defined(__OpenBSD__)
415 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
416 // ignore errors
417 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
418 "net")) {
419 dll_load(buffer, ebuf, sizeof(ebuf));
420 }
421 #endif
422 }
423 static jboolean onLoaded = JNI_FALSE;
424 if (onLoaded) {
425 // We may have to wait to fire OnLoad until TLS is initialized.
426 if (ThreadLocalStorage::is_initialized()) {
427 // The JNI_OnLoad handling is normally done by method load in
428 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
429 // explicitly so we have to check for JNI_OnLoad as well
430 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
431 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
432 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
433 if (JNI_OnLoad != NULL) {
434 JavaThread* thread = JavaThread::current();
435 ThreadToNativeFromVM ttn(thread);
436 HandleMark hm(thread);
437 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
438 onLoaded = JNI_TRUE;
439 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
440 vm_exit_during_initialization("Unsupported JNI version");
441 }
442 }
443 }
444 }
445 return _native_java_library;
446 }
448 // --------------------- heap allocation utilities ---------------------
450 char *os::strdup(const char *str, MEMFLAGS flags) {
451 size_t size = strlen(str);
452 char *dup_str = (char *)malloc(size + 1, flags);
453 if (dup_str == NULL) return NULL;
454 strcpy(dup_str, str);
455 return dup_str;
456 }
460 #ifdef ASSERT
461 #define space_before (MallocCushion + sizeof(double))
462 #define space_after MallocCushion
463 #define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t))
464 #define size_addr_from_obj(p) ((size_t*)p - 1)
465 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
466 // NB: cannot be debug variable, because these aren't set from the command line until
467 // *after* the first few allocs already happened
468 #define MallocCushion 16
469 #else
470 #define space_before 0
471 #define space_after 0
472 #define size_addr_from_base(p) should not use w/o ASSERT
473 #define size_addr_from_obj(p) should not use w/o ASSERT
474 #define MallocCushion 0
475 #endif
476 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
478 #ifdef ASSERT
479 inline size_t get_size(void* obj) {
480 size_t size = *size_addr_from_obj(obj);
481 if (size < 0) {
482 fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten ("
483 SIZE_FORMAT ")", obj, size));
484 }
485 return size;
486 }
488 u_char* find_cushion_backwards(u_char* start) {
489 u_char* p = start;
490 while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
491 p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
492 // ok, we have four consecutive marker bytes; find start
493 u_char* q = p - 4;
494 while (*q == badResourceValue) q--;
495 return q + 1;
496 }
498 u_char* find_cushion_forwards(u_char* start) {
499 u_char* p = start;
500 while (p[0] != badResourceValue || p[1] != badResourceValue ||
501 p[2] != badResourceValue || p[3] != badResourceValue) p++;
502 // ok, we have four consecutive marker bytes; find end of cushion
503 u_char* q = p + 4;
504 while (*q == badResourceValue) q++;
505 return q - MallocCushion;
506 }
508 void print_neighbor_blocks(void* ptr) {
509 // find block allocated before ptr (not entirely crash-proof)
510 if (MallocCushion < 4) {
511 tty->print_cr("### cannot find previous block (MallocCushion < 4)");
512 return;
513 }
514 u_char* start_of_this_block = (u_char*)ptr - space_before;
515 u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
516 // look for cushion in front of prev. block
517 u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
518 ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
519 u_char* obj = start_of_prev_block + space_before;
520 if (size <= 0 ) {
521 // start is bad; mayhave been confused by OS data inbetween objects
522 // search one more backwards
523 start_of_prev_block = find_cushion_backwards(start_of_prev_block);
524 size = *size_addr_from_base(start_of_prev_block);
525 obj = start_of_prev_block + space_before;
526 }
528 if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
529 tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
530 } else {
531 tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
532 }
534 // now find successor block
535 u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
536 start_of_next_block = find_cushion_forwards(start_of_next_block);
537 u_char* next_obj = start_of_next_block + space_before;
538 ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
539 if (start_of_next_block[0] == badResourceValue &&
540 start_of_next_block[1] == badResourceValue &&
541 start_of_next_block[2] == badResourceValue &&
542 start_of_next_block[3] == badResourceValue) {
543 tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
544 } else {
545 tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
546 }
547 }
550 void report_heap_error(void* memblock, void* bad, const char* where) {
551 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
552 tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock);
553 print_neighbor_blocks(memblock);
554 fatal("memory stomping error");
555 }
557 void verify_block(void* memblock) {
558 size_t size = get_size(memblock);
559 if (MallocCushion) {
560 u_char* ptr = (u_char*)memblock - space_before;
561 for (int i = 0; i < MallocCushion; i++) {
562 if (ptr[i] != badResourceValue) {
563 report_heap_error(memblock, ptr+i, "in front of");
564 }
565 }
566 u_char* end = (u_char*)memblock + size + space_after;
567 for (int j = -MallocCushion; j < 0; j++) {
568 if (end[j] != badResourceValue) {
569 report_heap_error(memblock, end+j, "after");
570 }
571 }
572 }
573 }
574 #endif
576 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
577 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
578 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
580 if (size == 0) {
581 // return a valid pointer if size is zero
582 // if NULL is returned the calling functions assume out of memory.
583 size = 1;
584 }
585 if (size > size + space_before + space_after) { // Check for rollover.
586 return NULL;
587 }
588 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
589 u_char* ptr = (u_char*)::malloc(size + space_before + space_after);
591 #ifdef ASSERT
592 if (ptr == NULL) return NULL;
593 if (MallocCushion) {
594 for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
595 u_char* end = ptr + space_before + size;
596 for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
597 for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
598 }
599 // put size just before data
600 *size_addr_from_base(ptr) = size;
601 #endif
602 u_char* memblock = ptr + space_before;
603 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
604 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
605 breakpoint();
606 }
607 debug_only(if (paranoid) verify_block(memblock));
608 if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
610 // we do not track MallocCushion memory
611 MemTracker::record_malloc((address)memblock, size, memflags, caller == 0 ? CALLER_PC : caller);
613 return memblock;
614 }
617 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
618 #ifndef ASSERT
619 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
620 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
621 void* ptr = ::realloc(memblock, size);
622 if (ptr != NULL) {
623 MemTracker::record_realloc((address)memblock, (address)ptr, size, memflags,
624 caller == 0 ? CALLER_PC : caller);
625 }
626 return ptr;
627 #else
628 if (memblock == NULL) {
629 return malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
630 }
631 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
632 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
633 breakpoint();
634 }
635 verify_block(memblock);
636 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
637 if (size == 0) return NULL;
638 // always move the block
639 void* ptr = malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
640 if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
641 // Copy to new memory if malloc didn't fail
642 if ( ptr != NULL ) {
643 memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
644 if (paranoid) verify_block(ptr);
645 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
646 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
647 breakpoint();
648 }
649 free(memblock);
650 }
651 return ptr;
652 #endif
653 }
656 void os::free(void *memblock, MEMFLAGS memflags) {
657 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
658 #ifdef ASSERT
659 if (memblock == NULL) return;
660 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
661 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
662 breakpoint();
663 }
664 verify_block(memblock);
665 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
666 // Added by detlefs.
667 if (MallocCushion) {
668 u_char* ptr = (u_char*)memblock - space_before;
669 for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
670 guarantee(*p == badResourceValue,
671 "Thing freed should be malloc result.");
672 *p = (u_char)freeBlockPad;
673 }
674 size_t size = get_size(memblock);
675 inc_stat_counter(&free_bytes, size);
676 u_char* end = ptr + space_before + size;
677 for (u_char* q = end; q < end + MallocCushion; q++) {
678 guarantee(*q == badResourceValue,
679 "Thing freed should be malloc result.");
680 *q = (u_char)freeBlockPad;
681 }
682 if (PrintMalloc && tty != NULL)
683 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
684 } else if (PrintMalloc && tty != NULL) {
685 // tty->print_cr("os::free %p", memblock);
686 fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock);
687 }
688 #endif
689 MemTracker::record_free((address)memblock, memflags);
691 ::free((char*)memblock - space_before);
692 }
694 void os::init_random(long initval) {
695 _rand_seed = initval;
696 }
699 long os::random() {
700 /* standard, well-known linear congruential random generator with
701 * next_rand = (16807*seed) mod (2**31-1)
702 * see
703 * (1) "Random Number Generators: Good Ones Are Hard to Find",
704 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
705 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
706 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
707 */
708 const long a = 16807;
709 const unsigned long m = 2147483647;
710 const long q = m / a; assert(q == 127773, "weird math");
711 const long r = m % a; assert(r == 2836, "weird math");
713 // compute az=2^31p+q
714 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
715 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
716 lo += (hi & 0x7FFF) << 16;
718 // if q overflowed, ignore the overflow and increment q
719 if (lo > m) {
720 lo &= m;
721 ++lo;
722 }
723 lo += hi >> 15;
725 // if (p+q) overflowed, ignore the overflow and increment (p+q)
726 if (lo > m) {
727 lo &= m;
728 ++lo;
729 }
730 return (_rand_seed = lo);
731 }
733 // The INITIALIZED state is distinguished from the SUSPENDED state because the
734 // conditions in which a thread is first started are different from those in which
735 // a suspension is resumed. These differences make it hard for us to apply the
736 // tougher checks when starting threads that we want to do when resuming them.
737 // However, when start_thread is called as a result of Thread.start, on a Java
738 // thread, the operation is synchronized on the Java Thread object. So there
739 // cannot be a race to start the thread and hence for the thread to exit while
740 // we are working on it. Non-Java threads that start Java threads either have
741 // to do so in a context in which races are impossible, or should do appropriate
742 // locking.
744 void os::start_thread(Thread* thread) {
745 // guard suspend/resume
746 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
747 OSThread* osthread = thread->osthread();
748 osthread->set_state(RUNNABLE);
749 pd_start_thread(thread);
750 }
752 //---------------------------------------------------------------------------
753 // Helper functions for fatal error handler
755 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
756 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
758 int cols = 0;
759 int cols_per_line = 0;
760 switch (unitsize) {
761 case 1: cols_per_line = 16; break;
762 case 2: cols_per_line = 8; break;
763 case 4: cols_per_line = 4; break;
764 case 8: cols_per_line = 2; break;
765 default: return;
766 }
768 address p = start;
769 st->print(PTR_FORMAT ": ", start);
770 while (p < end) {
771 switch (unitsize) {
772 case 1: st->print("%02x", *(u1*)p); break;
773 case 2: st->print("%04x", *(u2*)p); break;
774 case 4: st->print("%08x", *(u4*)p); break;
775 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
776 }
777 p += unitsize;
778 cols++;
779 if (cols >= cols_per_line && p < end) {
780 cols = 0;
781 st->cr();
782 st->print(PTR_FORMAT ": ", p);
783 } else {
784 st->print(" ");
785 }
786 }
787 st->cr();
788 }
790 void os::print_environment_variables(outputStream* st, const char** env_list,
791 char* buffer, int len) {
792 if (env_list) {
793 st->print_cr("Environment Variables:");
795 for (int i = 0; env_list[i] != NULL; i++) {
796 if (getenv(env_list[i], buffer, len)) {
797 st->print(env_list[i]);
798 st->print("=");
799 st->print_cr(buffer);
800 }
801 }
802 }
803 }
805 void os::print_cpu_info(outputStream* st) {
806 // cpu
807 st->print("CPU:");
808 st->print("total %d", os::processor_count());
809 // It's not safe to query number of active processors after crash
810 // st->print("(active %d)", os::active_processor_count());
811 st->print(" %s", VM_Version::cpu_features());
812 st->cr();
813 pd_print_cpu_info(st);
814 }
816 void os::print_date_and_time(outputStream *st) {
817 time_t tloc;
818 (void)time(&tloc);
819 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
821 double t = os::elapsedTime();
822 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
823 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
824 // before printf. We lost some precision, but who cares?
825 st->print_cr("elapsed time: %d seconds", (int)t);
826 }
828 // moved from debug.cpp (used to be find()) but still called from there
829 // The verbose parameter is only set by the debug code in one case
830 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
831 address addr = (address)x;
832 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
833 if (b != NULL) {
834 if (b->is_buffer_blob()) {
835 // the interpreter is generated into a buffer blob
836 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
837 if (i != NULL) {
838 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
839 i->print_on(st);
840 return;
841 }
842 if (Interpreter::contains(addr)) {
843 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
844 " (not bytecode specific)", addr);
845 return;
846 }
847 //
848 if (AdapterHandlerLibrary::contains(b)) {
849 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
850 AdapterHandlerLibrary::print_handler_on(st, b);
851 }
852 // the stubroutines are generated into a buffer blob
853 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
854 if (d != NULL) {
855 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
856 d->print_on(st);
857 st->cr();
858 return;
859 }
860 if (StubRoutines::contains(addr)) {
861 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
862 "stub routine", addr);
863 return;
864 }
865 // the InlineCacheBuffer is using stubs generated into a buffer blob
866 if (InlineCacheBuffer::contains(addr)) {
867 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
868 return;
869 }
870 VtableStub* v = VtableStubs::stub_containing(addr);
871 if (v != NULL) {
872 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
873 v->print_on(st);
874 st->cr();
875 return;
876 }
877 }
878 nmethod* nm = b->as_nmethod_or_null();
879 if (nm != NULL) {
880 ResourceMark rm;
881 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
882 addr, (int)(addr - nm->entry_point()), nm);
883 if (verbose) {
884 st->print(" for ");
885 nm->method()->print_value_on(st);
886 }
887 st->cr();
888 nm->print_nmethod(verbose);
889 return;
890 }
891 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
892 b->print_on(st);
893 return;
894 }
896 if (Universe::heap()->is_in(addr)) {
897 HeapWord* p = Universe::heap()->block_start(addr);
898 bool print = false;
899 // If we couldn't find it it just may mean that heap wasn't parseable
900 // See if we were just given an oop directly
901 if (p != NULL && Universe::heap()->block_is_obj(p)) {
902 print = true;
903 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
904 p = (HeapWord*) addr;
905 print = true;
906 }
907 if (print) {
908 if (p == (HeapWord*) addr) {
909 st->print_cr(INTPTR_FORMAT " is an oop", addr);
910 } else {
911 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
912 }
913 oop(p)->print_on(st);
914 return;
915 }
916 } else {
917 if (Universe::heap()->is_in_reserved(addr)) {
918 st->print_cr(INTPTR_FORMAT " is an unallocated location "
919 "in the heap", addr);
920 return;
921 }
922 }
923 if (JNIHandles::is_global_handle((jobject) addr)) {
924 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
925 return;
926 }
927 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
928 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
929 return;
930 }
931 #ifndef PRODUCT
932 // we don't keep the block list in product mode
933 if (JNIHandleBlock::any_contains((jobject) addr)) {
934 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
935 return;
936 }
937 #endif
939 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
940 // Check for privilege stack
941 if (thread->privileged_stack_top() != NULL &&
942 thread->privileged_stack_top()->contains(addr)) {
943 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
944 "for thread: " INTPTR_FORMAT, addr, thread);
945 if (verbose) thread->print_on(st);
946 return;
947 }
948 // If the addr is a java thread print information about that.
949 if (addr == (address)thread) {
950 if (verbose) {
951 thread->print_on(st);
952 } else {
953 st->print_cr(INTPTR_FORMAT " is a thread", addr);
954 }
955 return;
956 }
957 // If the addr is in the stack region for this thread then report that
958 // and print thread info
959 if (thread->stack_base() >= addr &&
960 addr > (thread->stack_base() - thread->stack_size())) {
961 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
962 INTPTR_FORMAT, addr, thread);
963 if (verbose) thread->print_on(st);
964 return;
965 }
967 }
969 #ifndef PRODUCT
970 // Check if in metaspace.
971 if (ClassLoaderDataGraph::contains((address)addr)) {
972 // Use addr->print() from the debugger instead (not here)
973 st->print_cr(INTPTR_FORMAT
974 " is pointing into metadata", addr);
975 return;
976 }
977 #endif
979 // Try an OS specific find
980 if (os::find(addr, st)) {
981 return;
982 }
984 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
985 }
987 // Looks like all platforms except IA64 can use the same function to check
988 // if C stack is walkable beyond current frame. The check for fp() is not
989 // necessary on Sparc, but it's harmless.
990 bool os::is_first_C_frame(frame* fr) {
991 #ifdef IA64
992 // In order to walk native frames on Itanium, we need to access the unwind
993 // table, which is inside ELF. We don't want to parse ELF after fatal error,
994 // so return true for IA64. If we need to support C stack walking on IA64,
995 // this function needs to be moved to CPU specific files, as fp() on IA64
996 // is register stack, which grows towards higher memory address.
997 return true;
998 #endif
1000 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1001 // Check usp first, because if that's bad the other accessors may fault
1002 // on some architectures. Ditto ufp second, etc.
1003 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1004 // sp on amd can be 32 bit aligned.
1005 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1007 uintptr_t usp = (uintptr_t)fr->sp();
1008 if ((usp & sp_align_mask) != 0) return true;
1010 uintptr_t ufp = (uintptr_t)fr->fp();
1011 if ((ufp & fp_align_mask) != 0) return true;
1013 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1014 if ((old_sp & sp_align_mask) != 0) return true;
1015 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1017 uintptr_t old_fp = (uintptr_t)fr->link();
1018 if ((old_fp & fp_align_mask) != 0) return true;
1019 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1021 // stack grows downwards; if old_fp is below current fp or if the stack
1022 // frame is too large, either the stack is corrupted or fp is not saved
1023 // on stack (i.e. on x86, ebp may be used as general register). The stack
1024 // is not walkable beyond current frame.
1025 if (old_fp < ufp) return true;
1026 if (old_fp - ufp > 64 * K) return true;
1028 return false;
1029 }
1031 #ifdef ASSERT
1032 extern "C" void test_random() {
1033 const double m = 2147483647;
1034 double mean = 0.0, variance = 0.0, t;
1035 long reps = 10000;
1036 unsigned long seed = 1;
1038 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1039 os::init_random(seed);
1040 long num;
1041 for (int k = 0; k < reps; k++) {
1042 num = os::random();
1043 double u = (double)num / m;
1044 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1046 // calculate mean and variance of the random sequence
1047 mean += u;
1048 variance += (u*u);
1049 }
1050 mean /= reps;
1051 variance /= (reps - 1);
1053 assert(num == 1043618065, "bad seed");
1054 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1055 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1056 const double eps = 0.0001;
1057 t = fabsd(mean - 0.5018);
1058 assert(t < eps, "bad mean");
1059 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1060 assert(t < eps, "bad variance");
1061 }
1062 #endif
1065 // Set up the boot classpath.
1067 char* os::format_boot_path(const char* format_string,
1068 const char* home,
1069 int home_len,
1070 char fileSep,
1071 char pathSep) {
1072 assert((fileSep == '/' && pathSep == ':') ||
1073 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1075 // Scan the format string to determine the length of the actual
1076 // boot classpath, and handle platform dependencies as well.
1077 int formatted_path_len = 0;
1078 const char* p;
1079 for (p = format_string; *p != 0; ++p) {
1080 if (*p == '%') formatted_path_len += home_len - 1;
1081 ++formatted_path_len;
1082 }
1084 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1085 if (formatted_path == NULL) {
1086 return NULL;
1087 }
1089 // Create boot classpath from format, substituting separator chars and
1090 // java home directory.
1091 char* q = formatted_path;
1092 for (p = format_string; *p != 0; ++p) {
1093 switch (*p) {
1094 case '%':
1095 strcpy(q, home);
1096 q += home_len;
1097 break;
1098 case '/':
1099 *q++ = fileSep;
1100 break;
1101 case ':':
1102 *q++ = pathSep;
1103 break;
1104 default:
1105 *q++ = *p;
1106 }
1107 }
1108 *q = '\0';
1110 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1111 return formatted_path;
1112 }
1115 bool os::set_boot_path(char fileSep, char pathSep) {
1116 const char* home = Arguments::get_java_home();
1117 int home_len = (int)strlen(home);
1119 static const char* meta_index_dir_format = "%/lib/";
1120 static const char* meta_index_format = "%/lib/meta-index";
1121 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1122 if (meta_index == NULL) return false;
1123 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1124 if (meta_index_dir == NULL) return false;
1125 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1127 // Any modification to the JAR-file list, for the boot classpath must be
1128 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1129 // path class JARs, are stripped for StackMapTable to reduce download size.
1130 static const char classpath_format[] =
1131 "%/lib/resources.jar:"
1132 "%/lib/rt.jar:"
1133 "%/lib/sunrsasign.jar:"
1134 "%/lib/jsse.jar:"
1135 "%/lib/jce.jar:"
1136 "%/lib/charsets.jar:"
1137 "%/lib/jfr.jar:"
1138 #ifdef __APPLE__
1139 "%/lib/JObjC.jar:"
1140 #endif
1141 "%/classes";
1142 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1143 if (sysclasspath == NULL) return false;
1144 Arguments::set_sysclasspath(sysclasspath);
1146 return true;
1147 }
1149 /*
1150 * Splits a path, based on its separator, the number of
1151 * elements is returned back in n.
1152 * It is the callers responsibility to:
1153 * a> check the value of n, and n may be 0.
1154 * b> ignore any empty path elements
1155 * c> free up the data.
1156 */
1157 char** os::split_path(const char* path, int* n) {
1158 *n = 0;
1159 if (path == NULL || strlen(path) == 0) {
1160 return NULL;
1161 }
1162 const char psepchar = *os::path_separator();
1163 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1164 if (inpath == NULL) {
1165 return NULL;
1166 }
1167 strcpy(inpath, path);
1168 int count = 1;
1169 char* p = strchr(inpath, psepchar);
1170 // Get a count of elements to allocate memory
1171 while (p != NULL) {
1172 count++;
1173 p++;
1174 p = strchr(p, psepchar);
1175 }
1176 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1177 if (opath == NULL) {
1178 return NULL;
1179 }
1181 // do the actual splitting
1182 p = inpath;
1183 for (int i = 0 ; i < count ; i++) {
1184 size_t len = strcspn(p, os::path_separator());
1185 if (len > JVM_MAXPATHLEN) {
1186 return NULL;
1187 }
1188 // allocate the string and add terminator storage
1189 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1190 if (s == NULL) {
1191 return NULL;
1192 }
1193 strncpy(s, p, len);
1194 s[len] = '\0';
1195 opath[i] = s;
1196 p += len + 1;
1197 }
1198 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1199 *n = count;
1200 return opath;
1201 }
1203 void os::set_memory_serialize_page(address page) {
1204 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1205 _mem_serialize_page = (volatile int32_t *)page;
1206 // We initialize the serialization page shift count here
1207 // We assume a cache line size of 64 bytes
1208 assert(SerializePageShiftCount == count,
1209 "thread size changed, fix SerializePageShiftCount constant");
1210 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1211 }
1213 static volatile intptr_t SerializePageLock = 0;
1215 // This method is called from signal handler when SIGSEGV occurs while the current
1216 // thread tries to store to the "read-only" memory serialize page during state
1217 // transition.
1218 void os::block_on_serialize_page_trap() {
1219 if (TraceSafepoint) {
1220 tty->print_cr("Block until the serialize page permission restored");
1221 }
1222 // When VMThread is holding the SerializePageLock during modifying the
1223 // access permission of the memory serialize page, the following call
1224 // will block until the permission of that page is restored to rw.
1225 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1226 // this case, it's OK as the signal is synchronous and we know precisely when
1227 // it can occur.
1228 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1229 Thread::muxRelease(&SerializePageLock);
1230 }
1232 // Serialize all thread state variables
1233 void os::serialize_thread_states() {
1234 // On some platforms such as Solaris & Linux, the time duration of the page
1235 // permission restoration is observed to be much longer than expected due to
1236 // scheduler starvation problem etc. To avoid the long synchronization
1237 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1238 // the mutator thread if such case is encountered. See bug 6546278 for details.
1239 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1240 os::protect_memory((char *)os::get_memory_serialize_page(),
1241 os::vm_page_size(), MEM_PROT_READ);
1242 os::protect_memory((char *)os::get_memory_serialize_page(),
1243 os::vm_page_size(), MEM_PROT_RW);
1244 Thread::muxRelease(&SerializePageLock);
1245 }
1247 // Returns true if the current stack pointer is above the stack shadow
1248 // pages, false otherwise.
1250 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1251 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1252 address sp = current_stack_pointer();
1253 // Check if we have StackShadowPages above the yellow zone. This parameter
1254 // is dependent on the depth of the maximum VM call stack possible from
1255 // the handler for stack overflow. 'instanceof' in the stack overflow
1256 // handler or a println uses at least 8k stack of VM and native code
1257 // respectively.
1258 const int framesize_in_bytes =
1259 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1260 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1261 * vm_page_size()) + framesize_in_bytes;
1262 // The very lower end of the stack
1263 address stack_limit = thread->stack_base() - thread->stack_size();
1264 return (sp > (stack_limit + reserved_area));
1265 }
1267 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1268 uint min_pages)
1269 {
1270 assert(min_pages > 0, "sanity");
1271 if (UseLargePages) {
1272 const size_t max_page_size = region_max_size / min_pages;
1274 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1275 const size_t sz = _page_sizes[i];
1276 const size_t mask = sz - 1;
1277 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1278 // The largest page size with no fragmentation.
1279 return sz;
1280 }
1282 if (sz <= max_page_size) {
1283 // The largest page size that satisfies the min_pages requirement.
1284 return sz;
1285 }
1286 }
1287 }
1289 return vm_page_size();
1290 }
1292 #ifndef PRODUCT
1293 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1294 {
1295 if (TracePageSizes) {
1296 tty->print("%s: ", str);
1297 for (int i = 0; i < count; ++i) {
1298 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1299 }
1300 tty->cr();
1301 }
1302 }
1304 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1305 const size_t region_max_size, const size_t page_size,
1306 const char* base, const size_t size)
1307 {
1308 if (TracePageSizes) {
1309 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1310 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1311 " size=" SIZE_FORMAT,
1312 str, region_min_size, region_max_size,
1313 page_size, base, size);
1314 }
1315 }
1316 #endif // #ifndef PRODUCT
1318 // This is the working definition of a server class machine:
1319 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1320 // because the graphics memory (?) sometimes masks physical memory.
1321 // If you want to change the definition of a server class machine
1322 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1323 // then you'll have to parameterize this method based on that state,
1324 // as was done for logical processors here, or replicate and
1325 // specialize this method for each platform. (Or fix os to have
1326 // some inheritance structure and use subclassing. Sigh.)
1327 // If you want some platform to always or never behave as a server
1328 // class machine, change the setting of AlwaysActAsServerClassMachine
1329 // and NeverActAsServerClassMachine in globals*.hpp.
1330 bool os::is_server_class_machine() {
1331 // First check for the early returns
1332 if (NeverActAsServerClassMachine) {
1333 return false;
1334 }
1335 if (AlwaysActAsServerClassMachine) {
1336 return true;
1337 }
1338 // Then actually look at the machine
1339 bool result = false;
1340 const unsigned int server_processors = 2;
1341 const julong server_memory = 2UL * G;
1342 // We seem not to get our full complement of memory.
1343 // We allow some part (1/8?) of the memory to be "missing",
1344 // based on the sizes of DIMMs, and maybe graphics cards.
1345 const julong missing_memory = 256UL * M;
1347 /* Is this a server class machine? */
1348 if ((os::active_processor_count() >= (int)server_processors) &&
1349 (os::physical_memory() >= (server_memory - missing_memory))) {
1350 const unsigned int logical_processors =
1351 VM_Version::logical_processors_per_package();
1352 if (logical_processors > 1) {
1353 const unsigned int physical_packages =
1354 os::active_processor_count() / logical_processors;
1355 if (physical_packages > server_processors) {
1356 result = true;
1357 }
1358 } else {
1359 result = true;
1360 }
1361 }
1362 return result;
1363 }
1365 // Read file line by line, if line is longer than bsize,
1366 // skip rest of line.
1367 int os::get_line_chars(int fd, char* buf, const size_t bsize){
1368 size_t sz, i = 0;
1370 // read until EOF, EOL or buf is full
1371 while ((sz = (int) read(fd, &buf[i], 1)) == 1 && i < (bsize-2) && buf[i] != '\n') {
1372 ++i;
1373 }
1375 if (buf[i] == '\n') {
1376 // EOL reached so ignore EOL character and return
1378 buf[i] = 0;
1379 return (int) i;
1380 }
1382 buf[i+1] = 0;
1384 if (sz != 1) {
1385 // EOF reached. if we read chars before EOF return them and
1386 // return EOF on next call otherwise return EOF
1388 return (i == 0) ? -1 : (int) i;
1389 }
1391 // line is longer than size of buf, skip to EOL
1392 char ch;
1393 while (read(fd, &ch, 1) == 1 && ch != '\n') {
1394 // Do nothing
1395 }
1397 // return initial part of line that fits in buf.
1398 // If we reached EOF, it will be returned on next call.
1400 return (int) i;
1401 }
1403 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1404 return os::pd_create_stack_guard_pages(addr, bytes);
1405 }
1408 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1409 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1410 if (result != NULL) {
1411 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1412 }
1414 return result;
1415 }
1416 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1417 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1418 if (result != NULL) {
1419 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1420 }
1421 return result;
1422 }
1424 void os::split_reserved_memory(char *base, size_t size,
1425 size_t split, bool realloc) {
1426 pd_split_reserved_memory(base, size, split, realloc);
1427 }
1429 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1430 bool res = pd_commit_memory(addr, bytes, executable);
1431 if (res) {
1432 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1433 }
1434 return res;
1435 }
1437 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1438 bool executable) {
1439 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1440 if (res) {
1441 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1442 }
1443 return res;
1444 }
1446 bool os::uncommit_memory(char* addr, size_t bytes) {
1447 bool res = pd_uncommit_memory(addr, bytes);
1448 if (res) {
1449 MemTracker::record_virtual_memory_uncommit((address)addr, bytes);
1450 }
1451 return res;
1452 }
1454 bool os::release_memory(char* addr, size_t bytes) {
1455 bool res = pd_release_memory(addr, bytes);
1456 if (res) {
1457 MemTracker::record_virtual_memory_release((address)addr, bytes);
1458 }
1459 return res;
1460 }
1463 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1464 char *addr, size_t bytes, bool read_only,
1465 bool allow_exec) {
1466 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1467 if (result != NULL) {
1468 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1469 MemTracker::record_virtual_memory_commit((address)result, bytes, CALLER_PC);
1470 }
1471 return result;
1472 }
1474 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1475 char *addr, size_t bytes, bool read_only,
1476 bool allow_exec) {
1477 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1478 read_only, allow_exec);
1479 }
1481 bool os::unmap_memory(char *addr, size_t bytes) {
1482 bool result = pd_unmap_memory(addr, bytes);
1483 if (result) {
1484 MemTracker::record_virtual_memory_uncommit((address)addr, bytes);
1485 MemTracker::record_virtual_memory_release((address)addr, bytes);
1486 }
1487 return result;
1488 }
1490 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1491 pd_free_memory(addr, bytes, alignment_hint);
1492 }
1494 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1495 pd_realign_memory(addr, bytes, alignment_hint);
1496 }