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 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classLoader.hpp"
27 #include "classfile/javaClasses.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "code/icBuffer.hpp"
31 #include "code/vtableStubs.hpp"
32 #include "gc_implementation/shared/vmGCOperations.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "memory/allocation.inline.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "prims/jvm.h"
37 #include "prims/jvm_misc.hpp"
38 #include "prims/privilegedStack.hpp"
39 #include "runtime/arguments.hpp"
40 #include "runtime/frame.inline.hpp"
41 #include "runtime/interfaceSupport.hpp"
42 #include "runtime/java.hpp"
43 #include "runtime/javaCalls.hpp"
44 #include "runtime/mutexLocker.hpp"
45 #include "runtime/os.hpp"
46 #include "runtime/stubRoutines.hpp"
47 #include "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
68
69 # include <signal.h>
70
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];
78
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
85
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 }
91
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;
107
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
135
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);
162
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 }
183
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
194
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 }
203
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;
212
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 }
222
223
224 // --------------------- sun.misc.Signal (optional) ---------------------
225
226
227 // SIGBREAK is sent by the keyboard to query the VM state
228 #ifndef SIGBREAK
229 #define SIGBREAK SIGQUIT
230 #endif
231
232 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
233
234
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 }
249
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 }
318
319
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);
327
328 const char thread_name[] = "Signal Dispatcher";
329 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
330
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);
341
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);
350
351 os::signal_init_pd();
352
353 { MutexLocker mu(Threads_lock);
354 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
355
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 }
364
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());
368
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 }
377
378
379 void os::terminate_signal_thread() {
380 if (!ReduceSignalUsage)
381 signal_notify(sigexitnum_pd());
382 }
383
384
385 // --------------------- loading libraries ---------------------
386
387 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
388 extern struct JavaVM_ main_vm;
389
390 static void* _native_java_library = NULL;
391
392 void* os::native_java_library() {
393 if (_native_java_library == NULL) {
394 char buffer[JVM_MAXPATHLEN];
395 char ebuf[1024];
396
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 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify");
401 dll_load(buffer, ebuf, sizeof(ebuf));
402
403 // Load java dll
404 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "java");
405 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
406 if (_native_java_library == NULL) {
407 vm_exit_during_initialization("Unable to load native library", ebuf);
408 }
409
410 #if defined(__OpenBSD__)
411 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
412 // ignore errors
413 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "net");
414 dll_load(buffer, ebuf, sizeof(ebuf));
415 #endif
416 }
417 static jboolean onLoaded = JNI_FALSE;
418 if (onLoaded) {
419 // We may have to wait to fire OnLoad until TLS is initialized.
420 if (ThreadLocalStorage::is_initialized()) {
421 // The JNI_OnLoad handling is normally done by method load in
422 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
423 // explicitly so we have to check for JNI_OnLoad as well
424 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
425 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
426 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
427 if (JNI_OnLoad != NULL) {
428 JavaThread* thread = JavaThread::current();
429 ThreadToNativeFromVM ttn(thread);
430 HandleMark hm(thread);
431 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
432 onLoaded = JNI_TRUE;
433 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
434 vm_exit_during_initialization("Unsupported JNI version");
435 }
436 }
437 }
438 }
439 return _native_java_library;
440 }
441
442 // --------------------- heap allocation utilities ---------------------
443
444 char *os::strdup(const char *str, MEMFLAGS flags) {
445 size_t size = strlen(str);
446 char *dup_str = (char *)malloc(size + 1, flags);
447 if (dup_str == NULL) return NULL;
448 strcpy(dup_str, str);
449 return dup_str;
450 }
451
452
453
454 #ifdef ASSERT
455 #define space_before (MallocCushion + sizeof(double))
456 #define space_after MallocCushion
457 #define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t))
458 #define size_addr_from_obj(p) ((size_t*)p - 1)
459 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
460 // NB: cannot be debug variable, because these aren't set from the command line until
461 // *after* the first few allocs already happened
462 #define MallocCushion 16
463 #else
464 #define space_before 0
465 #define space_after 0
466 #define size_addr_from_base(p) should not use w/o ASSERT
467 #define size_addr_from_obj(p) should not use w/o ASSERT
468 #define MallocCushion 0
469 #endif
470 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
471
472 #ifdef ASSERT
473 inline size_t get_size(void* obj) {
474 size_t size = *size_addr_from_obj(obj);
475 if (size < 0) {
476 fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten ("
477 SIZE_FORMAT ")", obj, size));
478 }
479 return size;
480 }
481
482 u_char* find_cushion_backwards(u_char* start) {
483 u_char* p = start;
484 while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
485 p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
486 // ok, we have four consecutive marker bytes; find start
487 u_char* q = p - 4;
488 while (*q == badResourceValue) q--;
489 return q + 1;
490 }
491
492 u_char* find_cushion_forwards(u_char* start) {
493 u_char* p = start;
494 while (p[0] != badResourceValue || p[1] != badResourceValue ||
495 p[2] != badResourceValue || p[3] != badResourceValue) p++;
496 // ok, we have four consecutive marker bytes; find end of cushion
497 u_char* q = p + 4;
498 while (*q == badResourceValue) q++;
499 return q - MallocCushion;
500 }
501
502 void print_neighbor_blocks(void* ptr) {
503 // find block allocated before ptr (not entirely crash-proof)
504 if (MallocCushion < 4) {
505 tty->print_cr("### cannot find previous block (MallocCushion < 4)");
506 return;
507 }
508 u_char* start_of_this_block = (u_char*)ptr - space_before;
509 u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
510 // look for cushion in front of prev. block
511 u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
512 ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
513 u_char* obj = start_of_prev_block + space_before;
514 if (size <= 0 ) {
515 // start is bad; mayhave been confused by OS data inbetween objects
516 // search one more backwards
517 start_of_prev_block = find_cushion_backwards(start_of_prev_block);
518 size = *size_addr_from_base(start_of_prev_block);
519 obj = start_of_prev_block + space_before;
520 }
521
522 if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
523 tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
524 } else {
525 tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
526 }
527
528 // now find successor block
529 u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
530 start_of_next_block = find_cushion_forwards(start_of_next_block);
531 u_char* next_obj = start_of_next_block + space_before;
532 ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
533 if (start_of_next_block[0] == badResourceValue &&
534 start_of_next_block[1] == badResourceValue &&
535 start_of_next_block[2] == badResourceValue &&
536 start_of_next_block[3] == badResourceValue) {
537 tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
538 } else {
539 tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
540 }
541 }
542
543
544 void report_heap_error(void* memblock, void* bad, const char* where) {
545 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
546 tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock);
547 print_neighbor_blocks(memblock);
548 fatal("memory stomping error");
549 }
550
551 void verify_block(void* memblock) {
552 size_t size = get_size(memblock);
553 if (MallocCushion) {
554 u_char* ptr = (u_char*)memblock - space_before;
555 for (int i = 0; i < MallocCushion; i++) {
556 if (ptr[i] != badResourceValue) {
557 report_heap_error(memblock, ptr+i, "in front of");
558 }
559 }
560 u_char* end = (u_char*)memblock + size + space_after;
561 for (int j = -MallocCushion; j < 0; j++) {
562 if (end[j] != badResourceValue) {
563 report_heap_error(memblock, end+j, "after");
564 }
565 }
566 }
567 }
568 #endif
569
570 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
571 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
572 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
573
574 if (size == 0) {
575 // return a valid pointer if size is zero
576 // if NULL is returned the calling functions assume out of memory.
577 size = 1;
578 }
579
580 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
581 u_char* ptr = (u_char*)::malloc(size + space_before + space_after);
582
583 #ifdef ASSERT
584 if (ptr == NULL) return NULL;
585 if (MallocCushion) {
586 for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
587 u_char* end = ptr + space_before + size;
588 for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
589 for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
590 }
591 // put size just before data
592 *size_addr_from_base(ptr) = size;
593 #endif
594 u_char* memblock = ptr + space_before;
595 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
596 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
597 breakpoint();
598 }
599 debug_only(if (paranoid) verify_block(memblock));
600 if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
601
602 // we do not track MallocCushion memory
603 if (MemTracker::is_on()) {
604 MemTracker::record_malloc((address)memblock, size, memflags, caller == 0 ? CALLER_PC : caller);
605 }
606
607 return memblock;
608 }
609
610
611 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
612 #ifndef ASSERT
613 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
614 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
615 void* ptr = ::realloc(memblock, size);
616 if (ptr != NULL && MemTracker::is_on()) {
617 MemTracker::record_realloc((address)memblock, (address)ptr, size, memflags,
618 caller == 0 ? CALLER_PC : caller);
619 }
620 return ptr;
621 #else
622 if (memblock == NULL) {
623 return malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
624 }
625 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
626 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
627 breakpoint();
628 }
629 verify_block(memblock);
630 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
631 if (size == 0) return NULL;
632 // always move the block
633 void* ptr = malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
634 if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
635 // Copy to new memory if malloc didn't fail
636 if ( ptr != NULL ) {
637 memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
638 if (paranoid) verify_block(ptr);
639 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
640 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
641 breakpoint();
642 }
643 free(memblock);
644 }
645 return ptr;
646 #endif
647 }
648
649
650 void os::free(void *memblock, MEMFLAGS memflags) {
651 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
652 #ifdef ASSERT
653 if (memblock == NULL) return;
654 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
655 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
656 breakpoint();
657 }
658 verify_block(memblock);
659 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
660 // Added by detlefs.
661 if (MallocCushion) {
662 u_char* ptr = (u_char*)memblock - space_before;
663 for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
664 guarantee(*p == badResourceValue,
665 "Thing freed should be malloc result.");
666 *p = (u_char)freeBlockPad;
667 }
668 size_t size = get_size(memblock);
669 inc_stat_counter(&free_bytes, size);
670 u_char* end = ptr + space_before + size;
671 for (u_char* q = end; q < end + MallocCushion; q++) {
672 guarantee(*q == badResourceValue,
673 "Thing freed should be malloc result.");
674 *q = (u_char)freeBlockPad;
675 }
676 if (PrintMalloc && tty != NULL)
677 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
678 } else if (PrintMalloc && tty != NULL) {
679 // tty->print_cr("os::free %p", memblock);
680 fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock);
681 }
682 #endif
683 MemTracker::record_free((address)memblock, memflags);
684
685 ::free((char*)memblock - space_before);
686 }
687
688 void os::init_random(long initval) {
689 _rand_seed = initval;
690 }
691
692
693 long os::random() {
694 /* standard, well-known linear congruential random generator with
695 * next_rand = (16807*seed) mod (2**31-1)
696 * see
697 * (1) "Random Number Generators: Good Ones Are Hard to Find",
698 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
699 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
700 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
701 */
702 const long a = 16807;
703 const unsigned long m = 2147483647;
704 const long q = m / a; assert(q == 127773, "weird math");
705 const long r = m % a; assert(r == 2836, "weird math");
706
707 // compute az=2^31p+q
708 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
709 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
710 lo += (hi & 0x7FFF) << 16;
711
712 // if q overflowed, ignore the overflow and increment q
713 if (lo > m) {
714 lo &= m;
715 ++lo;
716 }
717 lo += hi >> 15;
718
719 // if (p+q) overflowed, ignore the overflow and increment (p+q)
720 if (lo > m) {
721 lo &= m;
722 ++lo;
723 }
724 return (_rand_seed = lo);
725 }
726
727 // The INITIALIZED state is distinguished from the SUSPENDED state because the
728 // conditions in which a thread is first started are different from those in which
729 // a suspension is resumed. These differences make it hard for us to apply the
730 // tougher checks when starting threads that we want to do when resuming them.
731 // However, when start_thread is called as a result of Thread.start, on a Java
732 // thread, the operation is synchronized on the Java Thread object. So there
733 // cannot be a race to start the thread and hence for the thread to exit while
734 // we are working on it. Non-Java threads that start Java threads either have
735 // to do so in a context in which races are impossible, or should do appropriate
736 // locking.
737
738 void os::start_thread(Thread* thread) {
739 // guard suspend/resume
740 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
741 OSThread* osthread = thread->osthread();
742 osthread->set_state(RUNNABLE);
743 pd_start_thread(thread);
744 }
745
746 //---------------------------------------------------------------------------
747 // Helper functions for fatal error handler
748
749 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
750 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
751
752 int cols = 0;
753 int cols_per_line = 0;
754 switch (unitsize) {
755 case 1: cols_per_line = 16; break;
756 case 2: cols_per_line = 8; break;
757 case 4: cols_per_line = 4; break;
758 case 8: cols_per_line = 2; break;
759 default: return;
760 }
761
762 address p = start;
763 st->print(PTR_FORMAT ": ", start);
764 while (p < end) {
765 switch (unitsize) {
766 case 1: st->print("%02x", *(u1*)p); break;
767 case 2: st->print("%04x", *(u2*)p); break;
768 case 4: st->print("%08x", *(u4*)p); break;
769 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
770 }
771 p += unitsize;
772 cols++;
773 if (cols >= cols_per_line && p < end) {
774 cols = 0;
775 st->cr();
776 st->print(PTR_FORMAT ": ", p);
777 } else {
778 st->print(" ");
779 }
780 }
781 st->cr();
782 }
783
784 void os::print_environment_variables(outputStream* st, const char** env_list,
785 char* buffer, int len) {
786 if (env_list) {
787 st->print_cr("Environment Variables:");
788
789 for (int i = 0; env_list[i] != NULL; i++) {
790 if (getenv(env_list[i], buffer, len)) {
791 st->print(env_list[i]);
792 st->print("=");
793 st->print_cr(buffer);
794 }
795 }
796 }
797 }
798
799 void os::print_cpu_info(outputStream* st) {
800 // cpu
801 st->print("CPU:");
802 st->print("total %d", os::processor_count());
803 // It's not safe to query number of active processors after crash
804 // st->print("(active %d)", os::active_processor_count());
805 st->print(" %s", VM_Version::cpu_features());
806 st->cr();
807 pd_print_cpu_info(st);
808 }
809
810 void os::print_date_and_time(outputStream *st) {
811 time_t tloc;
812 (void)time(&tloc);
813 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
814
815 double t = os::elapsedTime();
816 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
817 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
818 // before printf. We lost some precision, but who cares?
819 st->print_cr("elapsed time: %d seconds", (int)t);
820 }
821
822 // moved from debug.cpp (used to be find()) but still called from there
823 // The verbose parameter is only set by the debug code in one case
824 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
825 address addr = (address)x;
826 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
827 if (b != NULL) {
828 if (b->is_buffer_blob()) {
829 // the interpreter is generated into a buffer blob
830 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
831 if (i != NULL) {
832 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
833 i->print_on(st);
834 return;
835 }
836 if (Interpreter::contains(addr)) {
837 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
838 " (not bytecode specific)", addr);
839 return;
840 }
841 //
842 if (AdapterHandlerLibrary::contains(b)) {
843 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
844 AdapterHandlerLibrary::print_handler_on(st, b);
845 }
846 // the stubroutines are generated into a buffer blob
847 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
848 if (d != NULL) {
849 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
850 d->print_on(st);
851 st->cr();
852 return;
853 }
854 if (StubRoutines::contains(addr)) {
855 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
856 "stub routine", addr);
857 return;
858 }
859 // the InlineCacheBuffer is using stubs generated into a buffer blob
860 if (InlineCacheBuffer::contains(addr)) {
861 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
862 return;
863 }
864 VtableStub* v = VtableStubs::stub_containing(addr);
865 if (v != NULL) {
866 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
867 v->print_on(st);
868 st->cr();
869 return;
870 }
871 }
872 nmethod* nm = b->as_nmethod_or_null();
873 if (nm != NULL) {
874 ResourceMark rm;
875 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
876 addr, (int)(addr - nm->entry_point()), nm);
877 if (verbose) {
878 st->print(" for ");
879 nm->method()->print_value_on(st);
880 }
881 st->cr();
882 nm->print_nmethod(verbose);
883 return;
884 }
885 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
886 b->print_on(st);
887 return;
888 }
889
890 if (Universe::heap()->is_in(addr)) {
891 HeapWord* p = Universe::heap()->block_start(addr);
892 bool print = false;
893 // If we couldn't find it it just may mean that heap wasn't parseable
894 // See if we were just given an oop directly
895 if (p != NULL && Universe::heap()->block_is_obj(p)) {
896 print = true;
897 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
898 p = (HeapWord*) addr;
899 print = true;
900 }
901 if (print) {
902 if (p == (HeapWord*) addr) {
903 st->print_cr(INTPTR_FORMAT " is an oop", addr);
904 } else {
905 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
906 }
907 oop(p)->print_on(st);
908 return;
909 }
910 } else {
911 if (Universe::heap()->is_in_reserved(addr)) {
912 st->print_cr(INTPTR_FORMAT " is an unallocated location "
913 "in the heap", addr);
914 return;
915 }
916 }
917 if (JNIHandles::is_global_handle((jobject) addr)) {
918 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
919 return;
920 }
921 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
922 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
923 return;
924 }
925 #ifndef PRODUCT
926 // we don't keep the block list in product mode
927 if (JNIHandleBlock::any_contains((jobject) addr)) {
928 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
929 return;
930 }
931 #endif
932
933 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
934 // Check for privilege stack
935 if (thread->privileged_stack_top() != NULL &&
936 thread->privileged_stack_top()->contains(addr)) {
937 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
938 "for thread: " INTPTR_FORMAT, addr, thread);
939 if (verbose) thread->print_on(st);
940 return;
941 }
942 // If the addr is a java thread print information about that.
943 if (addr == (address)thread) {
944 if (verbose) {
945 thread->print_on(st);
946 } else {
947 st->print_cr(INTPTR_FORMAT " is a thread", addr);
948 }
949 return;
950 }
951 // If the addr is in the stack region for this thread then report that
952 // and print thread info
953 if (thread->stack_base() >= addr &&
954 addr > (thread->stack_base() - thread->stack_size())) {
955 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
956 INTPTR_FORMAT, addr, thread);
957 if (verbose) thread->print_on(st);
958 return;
959 }
960
961 }
962
963 #ifndef PRODUCT
964 // Check if in metaspace.
965 if (ClassLoaderDataGraph::contains((address)addr)) {
966 // Use addr->print() from the debugger instead (not here)
967 st->print_cr(INTPTR_FORMAT
968 " is pointing into metadata", addr);
969 return;
970 }
971 #endif
972
973 // Try an OS specific find
974 if (os::find(addr, st)) {
975 return;
976 }
977
978 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
979 }
980
981 // Looks like all platforms except IA64 can use the same function to check
982 // if C stack is walkable beyond current frame. The check for fp() is not
983 // necessary on Sparc, but it's harmless.
984 bool os::is_first_C_frame(frame* fr) {
985 #ifdef IA64
986 // In order to walk native frames on Itanium, we need to access the unwind
987 // table, which is inside ELF. We don't want to parse ELF after fatal error,
988 // so return true for IA64. If we need to support C stack walking on IA64,
989 // this function needs to be moved to CPU specific files, as fp() on IA64
990 // is register stack, which grows towards higher memory address.
991 return true;
992 #endif
993
994 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
995 // Check usp first, because if that's bad the other accessors may fault
996 // on some architectures. Ditto ufp second, etc.
997 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
998 // sp on amd can be 32 bit aligned.
999 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1000
1001 uintptr_t usp = (uintptr_t)fr->sp();
1002 if ((usp & sp_align_mask) != 0) return true;
1003
1004 uintptr_t ufp = (uintptr_t)fr->fp();
1005 if ((ufp & fp_align_mask) != 0) return true;
1006
1007 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1008 if ((old_sp & sp_align_mask) != 0) return true;
1009 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1010
1011 uintptr_t old_fp = (uintptr_t)fr->link();
1012 if ((old_fp & fp_align_mask) != 0) return true;
1013 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1014
1015 // stack grows downwards; if old_fp is below current fp or if the stack
1016 // frame is too large, either the stack is corrupted or fp is not saved
1017 // on stack (i.e. on x86, ebp may be used as general register). The stack
1018 // is not walkable beyond current frame.
1019 if (old_fp < ufp) return true;
1020 if (old_fp - ufp > 64 * K) return true;
1021
1022 return false;
1023 }
1024
1025 #ifdef ASSERT
1026 extern "C" void test_random() {
1027 const double m = 2147483647;
1028 double mean = 0.0, variance = 0.0, t;
1029 long reps = 10000;
1030 unsigned long seed = 1;
1031
1032 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1033 os::init_random(seed);
1034 long num;
1035 for (int k = 0; k < reps; k++) {
1036 num = os::random();
1037 double u = (double)num / m;
1038 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1039
1040 // calculate mean and variance of the random sequence
1041 mean += u;
1042 variance += (u*u);
1043 }
1044 mean /= reps;
1045 variance /= (reps - 1);
1046
1047 assert(num == 1043618065, "bad seed");
1048 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1049 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1050 const double eps = 0.0001;
1051 t = fabsd(mean - 0.5018);
1052 assert(t < eps, "bad mean");
1053 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1054 assert(t < eps, "bad variance");
1055 }
1056 #endif
1057
1058
1059 // Set up the boot classpath.
1060
1061 char* os::format_boot_path(const char* format_string,
1062 const char* home,
1063 int home_len,
1064 char fileSep,
1065 char pathSep) {
1066 assert((fileSep == '/' && pathSep == ':') ||
1067 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1068
1069 // Scan the format string to determine the length of the actual
1070 // boot classpath, and handle platform dependencies as well.
1071 int formatted_path_len = 0;
1072 const char* p;
1073 for (p = format_string; *p != 0; ++p) {
1074 if (*p == '%') formatted_path_len += home_len - 1;
1075 ++formatted_path_len;
1076 }
1077
1078 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1079 if (formatted_path == NULL) {
1080 return NULL;
1081 }
1082
1083 // Create boot classpath from format, substituting separator chars and
1084 // java home directory.
1085 char* q = formatted_path;
1086 for (p = format_string; *p != 0; ++p) {
1087 switch (*p) {
1088 case '%':
1089 strcpy(q, home);
1090 q += home_len;
1091 break;
1092 case '/':
1093 *q++ = fileSep;
1094 break;
1095 case ':':
1096 *q++ = pathSep;
1097 break;
1098 default:
1099 *q++ = *p;
1100 }
1101 }
1102 *q = '\0';
1103
1104 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1105 return formatted_path;
1106 }
1107
1108
1109 bool os::set_boot_path(char fileSep, char pathSep) {
1110 const char* home = Arguments::get_java_home();
1111 int home_len = (int)strlen(home);
1112
1113 static const char* meta_index_dir_format = "%/lib/";
1114 static const char* meta_index_format = "%/lib/meta-index";
1115 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1116 if (meta_index == NULL) return false;
1117 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1118 if (meta_index_dir == NULL) return false;
1119 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1120
1121 // Any modification to the JAR-file list, for the boot classpath must be
1122 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1123 // path class JARs, are stripped for StackMapTable to reduce download size.
1124 static const char classpath_format[] =
1125 "%/lib/resources.jar:"
1126 "%/lib/rt.jar:"
1127 "%/lib/sunrsasign.jar:"
1128 "%/lib/jsse.jar:"
1129 "%/lib/jce.jar:"
1130 "%/lib/charsets.jar:"
1131 "%/lib/jfr.jar:"
1132 #ifdef __APPLE__
1133 "%/lib/JObjC.jar:"
1134 #endif
1135 "%/classes";
1136 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1137 if (sysclasspath == NULL) return false;
1138 Arguments::set_sysclasspath(sysclasspath);
1139
1140 return true;
1141 }
1142
1143 /*
1144 * Splits a path, based on its separator, the number of
1145 * elements is returned back in n.
1146 * It is the callers responsibility to:
1147 * a> check the value of n, and n may be 0.
1148 * b> ignore any empty path elements
1149 * c> free up the data.
1150 */
1151 char** os::split_path(const char* path, int* n) {
1152 *n = 0;
1153 if (path == NULL || strlen(path) == 0) {
1154 return NULL;
1155 }
1156 const char psepchar = *os::path_separator();
1157 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1158 if (inpath == NULL) {
1159 return NULL;
1160 }
1161 strncpy(inpath, path, strlen(path));
1162 int count = 1;
1163 char* p = strchr(inpath, psepchar);
1164 // Get a count of elements to allocate memory
1165 while (p != NULL) {
1166 count++;
1167 p++;
1168 p = strchr(p, psepchar);
1169 }
1170 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1171 if (opath == NULL) {
1172 return NULL;
1173 }
1174
1175 // do the actual splitting
1176 p = inpath;
1177 for (int i = 0 ; i < count ; i++) {
1178 size_t len = strcspn(p, os::path_separator());
1179 if (len > JVM_MAXPATHLEN) {
1180 return NULL;
1181 }
1182 // allocate the string and add terminator storage
1183 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1184 if (s == NULL) {
1185 return NULL;
1186 }
1187 strncpy(s, p, len);
1188 s[len] = '\0';
1189 opath[i] = s;
1190 p += len + 1;
1191 }
1192 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1193 *n = count;
1194 return opath;
1195 }
1196
1197 void os::set_memory_serialize_page(address page) {
1198 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1199 _mem_serialize_page = (volatile int32_t *)page;
1200 // We initialize the serialization page shift count here
1201 // We assume a cache line size of 64 bytes
1202 assert(SerializePageShiftCount == count,
1203 "thread size changed, fix SerializePageShiftCount constant");
1204 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1205 }
1206
1207 static volatile intptr_t SerializePageLock = 0;
1208
1209 // This method is called from signal handler when SIGSEGV occurs while the current
1210 // thread tries to store to the "read-only" memory serialize page during state
1211 // transition.
1212 void os::block_on_serialize_page_trap() {
1213 if (TraceSafepoint) {
1214 tty->print_cr("Block until the serialize page permission restored");
1215 }
1216 // When VMThread is holding the SerializePageLock during modifying the
1217 // access permission of the memory serialize page, the following call
1218 // will block until the permission of that page is restored to rw.
1219 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1220 // this case, it's OK as the signal is synchronous and we know precisely when
1221 // it can occur.
1222 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1223 Thread::muxRelease(&SerializePageLock);
1224 }
1225
1226 // Serialize all thread state variables
1227 void os::serialize_thread_states() {
1228 // On some platforms such as Solaris & Linux, the time duration of the page
1229 // permission restoration is observed to be much longer than expected due to
1230 // scheduler starvation problem etc. To avoid the long synchronization
1231 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1232 // the mutator thread if such case is encountered. See bug 6546278 for details.
1233 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1234 os::protect_memory((char *)os::get_memory_serialize_page(),
1235 os::vm_page_size(), MEM_PROT_READ);
1236 os::protect_memory((char *)os::get_memory_serialize_page(),
1237 os::vm_page_size(), MEM_PROT_RW);
1238 Thread::muxRelease(&SerializePageLock);
1239 }
1240
1241 // Returns true if the current stack pointer is above the stack shadow
1242 // pages, false otherwise.
1243
1244 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1245 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1246 address sp = current_stack_pointer();
1247 // Check if we have StackShadowPages above the yellow zone. This parameter
1248 // is dependent on the depth of the maximum VM call stack possible from
1249 // the handler for stack overflow. 'instanceof' in the stack overflow
1250 // handler or a println uses at least 8k stack of VM and native code
1251 // respectively.
1252 const int framesize_in_bytes =
1253 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1254 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1255 * vm_page_size()) + framesize_in_bytes;
1256 // The very lower end of the stack
1257 address stack_limit = thread->stack_base() - thread->stack_size();
1258 return (sp > (stack_limit + reserved_area));
1259 }
1260
1261 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1262 uint min_pages)
1263 {
1264 assert(min_pages > 0, "sanity");
1265 if (UseLargePages) {
1266 const size_t max_page_size = region_max_size / min_pages;
1267
1268 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1269 const size_t sz = _page_sizes[i];
1270 const size_t mask = sz - 1;
1271 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1272 // The largest page size with no fragmentation.
1273 return sz;
1274 }
1275
1276 if (sz <= max_page_size) {
1277 // The largest page size that satisfies the min_pages requirement.
1278 return sz;
1279 }
1280 }
1281 }
1282
1283 return vm_page_size();
1284 }
1285
1286 #ifndef PRODUCT
1287 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1288 {
1289 if (TracePageSizes) {
1290 tty->print("%s: ", str);
1291 for (int i = 0; i < count; ++i) {
1292 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1293 }
1294 tty->cr();
1295 }
1296 }
1297
1298 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1299 const size_t region_max_size, const size_t page_size,
1300 const char* base, const size_t size)
1301 {
1302 if (TracePageSizes) {
1303 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1304 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1305 " size=" SIZE_FORMAT,
1306 str, region_min_size, region_max_size,
1307 page_size, base, size);
1308 }
1309 }
1310 #endif // #ifndef PRODUCT
1311
1312 // This is the working definition of a server class machine:
1313 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1314 // because the graphics memory (?) sometimes masks physical memory.
1315 // If you want to change the definition of a server class machine
1316 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1317 // then you'll have to parameterize this method based on that state,
1318 // as was done for logical processors here, or replicate and
1319 // specialize this method for each platform. (Or fix os to have
1320 // some inheritance structure and use subclassing. Sigh.)
1321 // If you want some platform to always or never behave as a server
1322 // class machine, change the setting of AlwaysActAsServerClassMachine
1323 // and NeverActAsServerClassMachine in globals*.hpp.
1324 bool os::is_server_class_machine() {
1325 // First check for the early returns
1326 if (NeverActAsServerClassMachine) {
1327 return false;
1328 }
1329 if (AlwaysActAsServerClassMachine) {
1330 return true;
1331 }
1332 // Then actually look at the machine
1333 bool result = false;
1334 const unsigned int server_processors = 2;
1335 const julong server_memory = 2UL * G;
1336 // We seem not to get our full complement of memory.
1337 // We allow some part (1/8?) of the memory to be "missing",
1338 // based on the sizes of DIMMs, and maybe graphics cards.
1339 const julong missing_memory = 256UL * M;
1340
1341 /* Is this a server class machine? */
1342 if ((os::active_processor_count() >= (int)server_processors) &&
1343 (os::physical_memory() >= (server_memory - missing_memory))) {
1344 const unsigned int logical_processors =
1345 VM_Version::logical_processors_per_package();
1346 if (logical_processors > 1) {
1347 const unsigned int physical_packages =
1348 os::active_processor_count() / logical_processors;
1349 if (physical_packages > server_processors) {
1350 result = true;
1351 }
1352 } else {
1353 result = true;
1354 }
1355 }
1356 return result;
1357 }
1358
1359 // Read file line by line, if line is longer than bsize,
1360 // skip rest of line.
1361 int os::get_line_chars(int fd, char* buf, const size_t bsize){
1362 size_t sz, i = 0;
1363
1364 // read until EOF, EOL or buf is full
1365 while ((sz = (int) read(fd, &buf[i], 1)) == 1 && i < (bsize-2) && buf[i] != '\n') {
1366 ++i;
1367 }
1368
1369 if (buf[i] == '\n') {
1370 // EOL reached so ignore EOL character and return
1371
1372 buf[i] = 0;
1373 return (int) i;
1374 }
1375
1376 buf[i+1] = 0;
1377
1378 if (sz != 1) {
1379 // EOF reached. if we read chars before EOF return them and
1380 // return EOF on next call otherwise return EOF
1381
1382 return (i == 0) ? -1 : (int) i;
1383 }
1384
1385 // line is longer than size of buf, skip to EOL
1386 char ch;
1387 while (read(fd, &ch, 1) == 1 && ch != '\n') {
1388 // Do nothing
1389 }
1390
1391 // return initial part of line that fits in buf.
1392 // If we reached EOF, it will be returned on next call.
1393
1394 return (int) i;
1395 }
1396
1397 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1398 return os::pd_create_stack_guard_pages(addr, bytes);
1399 }
1400
1401
1402 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1403 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1404 if (result != NULL && MemTracker::is_on()) {
1405 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1406 }
1407
1408 return result;
1409 }
1410 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1411 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1412 if (result != NULL && MemTracker::is_on()) {
1413 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1414 }
1415 return result;
1416 }
1417
1418 void os::split_reserved_memory(char *base, size_t size,
1419 size_t split, bool realloc) {
1420 pd_split_reserved_memory(base, size, split, realloc);
1421 }
1422
1423 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1424 bool res = pd_commit_memory(addr, bytes, executable);
1425 if (res && MemTracker::is_on()) {
1426 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1427 }
1428 return res;
1429 }
1430
1431 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1432 bool executable) {
1433 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1434 if (res && MemTracker::is_on()) {
1435 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1436 }
1437 return res;
1438 }
1439
1440 bool os::uncommit_memory(char* addr, size_t bytes) {
1441 bool res = pd_uncommit_memory(addr, bytes);
1442 if (res) {
1443 MemTracker::record_virtual_memory_uncommit((address)addr, bytes);
1444 }
1445 return res;
1446 }
1447
1448 bool os::release_memory(char* addr, size_t bytes) {
1449 bool res = pd_release_memory(addr, bytes);
1450 if (res) {
1451 MemTracker::record_virtual_memory_release((address)addr, bytes);
1452 }
1453 return res;
1454 }
1455
1456
1457 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1458 char *addr, size_t bytes, bool read_only,
1459 bool allow_exec) {
1460 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1461 if (result != NULL && MemTracker::is_on()) {
1462 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1463 }
1464 return result;
1465 }
1466
1467 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1468 char *addr, size_t bytes, bool read_only,
1469 bool allow_exec) {
1470 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1471 read_only, allow_exec);
1472 }
1473
1474 bool os::unmap_memory(char *addr, size_t bytes) {
1475 bool result = pd_unmap_memory(addr, bytes);
1476 if (result) {
1477 MemTracker::record_virtual_memory_release((address)addr, bytes);
1478 }
1479 return result;
1480 }
1481
1482 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1483 pd_free_memory(addr, bytes, alignment_hint);
1484 }
1485
1486 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1487 pd_realign_memory(addr, bytes, alignment_hint);
1488 }
1489