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
205 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
206 int p;
207 int os_prio;
208 OSReturn ret = get_native_priority(thread, &os_prio);
209 if (ret != OS_OK) return ret;
210
211 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
212 priority = (ThreadPriority)p;
213 return OS_OK;
214 }
215
216
217 // --------------------- sun.misc.Signal (optional) ---------------------
218
219
220 // SIGBREAK is sent by the keyboard to query the VM state
221 #ifndef SIGBREAK
222 #define SIGBREAK SIGQUIT
223 #endif
224
225 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
226
227
228 static void signal_thread_entry(JavaThread* thread, TRAPS) {
229 os::set_priority(thread, NearMaxPriority);
230 while (true) {
231 int sig;
232 {
233 // FIXME : Currently we have not decieded what should be the status
234 // for this java thread blocked here. Once we decide about
235 // that we should fix this.
236 sig = os::signal_wait();
237 }
238 if (sig == os::sigexitnum_pd()) {
239 // Terminate the signal thread
240 return;
241 }
242
243 switch (sig) {
244 case SIGBREAK: {
245 // Check if the signal is a trigger to start the Attach Listener - in that
246 // case don't print stack traces.
247 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
248 continue;
249 }
250 // Print stack traces
251 // Any SIGBREAK operations added here should make sure to flush
252 // the output stream (e.g. tty->flush()) after output. See 4803766.
253 // Each module also prints an extra carriage return after its output.
254 VM_PrintThreads op;
255 VMThread::execute(&op);
256 VM_PrintJNI jni_op;
257 VMThread::execute(&jni_op);
258 VM_FindDeadlocks op1(tty);
259 VMThread::execute(&op1);
260 Universe::print_heap_at_SIGBREAK();
261 if (PrintClassHistogram) {
262 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */,
263 true /* need_prologue */);
264 VMThread::execute(&op1);
265 }
266 if (JvmtiExport::should_post_data_dump()) {
267 JvmtiExport::post_data_dump();
268 }
269 break;
270 }
271 default: {
272 // Dispatch the signal to java
273 HandleMark hm(THREAD);
274 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
275 KlassHandle klass (THREAD, k);
276 if (klass.not_null()) {
277 JavaValue result(T_VOID);
278 JavaCallArguments args;
279 args.push_int(sig);
280 JavaCalls::call_static(
281 &result,
282 klass,
283 vmSymbols::dispatch_name(),
284 vmSymbols::int_void_signature(),
285 &args,
286 THREAD
287 );
288 }
289 if (HAS_PENDING_EXCEPTION) {
290 // tty is initialized early so we don't expect it to be null, but
291 // if it is we can't risk doing an initialization that might
292 // trigger additional out-of-memory conditions
293 if (tty != NULL) {
294 char klass_name[256];
295 char tmp_sig_name[16];
296 const char* sig_name = "UNKNOWN";
297 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
298 name()->as_klass_external_name(klass_name, 256);
299 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
300 sig_name = tmp_sig_name;
301 warning("Exception %s occurred dispatching signal %s to handler"
302 "- the VM may need to be forcibly terminated",
303 klass_name, sig_name );
304 }
305 CLEAR_PENDING_EXCEPTION;
306 }
307 }
308 }
309 }
310 }
311
312
313 void os::signal_init() {
314 if (!ReduceSignalUsage) {
315 // Setup JavaThread for processing signals
316 EXCEPTION_MARK;
317 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
318 instanceKlassHandle klass (THREAD, k);
319 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
320
321 const char thread_name[] = "Signal Dispatcher";
322 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
323
324 // Initialize thread_oop to put it into the system threadGroup
325 Handle thread_group (THREAD, Universe::system_thread_group());
326 JavaValue result(T_VOID);
327 JavaCalls::call_special(&result, thread_oop,
328 klass,
329 vmSymbols::object_initializer_name(),
330 vmSymbols::threadgroup_string_void_signature(),
331 thread_group,
332 string,
333 CHECK);
334
335 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
336 JavaCalls::call_special(&result,
337 thread_group,
338 group,
339 vmSymbols::add_method_name(),
340 vmSymbols::thread_void_signature(),
341 thread_oop, // ARG 1
342 CHECK);
343
344 os::signal_init_pd();
345
346 { MutexLocker mu(Threads_lock);
347 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
348
349 // At this point it may be possible that no osthread was created for the
350 // JavaThread due to lack of memory. We would have to throw an exception
351 // in that case. However, since this must work and we do not allow
352 // exceptions anyway, check and abort if this fails.
353 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
354 vm_exit_during_initialization("java.lang.OutOfMemoryError",
355 "unable to create new native thread");
356 }
357
358 java_lang_Thread::set_thread(thread_oop(), signal_thread);
359 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
360 java_lang_Thread::set_daemon(thread_oop());
361
362 signal_thread->set_threadObj(thread_oop());
363 Threads::add(signal_thread);
364 Thread::start(signal_thread);
365 }
366 // Handle ^BREAK
367 os::signal(SIGBREAK, os::user_handler());
368 }
369 }
370
371
372 void os::terminate_signal_thread() {
373 if (!ReduceSignalUsage)
374 signal_notify(sigexitnum_pd());
375 }
376
377
378 // --------------------- loading libraries ---------------------
379
380 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
381 extern struct JavaVM_ main_vm;
382
383 static void* _native_java_library = NULL;
384
385 void* os::native_java_library() {
386 if (_native_java_library == NULL) {
387 char buffer[JVM_MAXPATHLEN];
388 char ebuf[1024];
389
390 // Try to load verify dll first. In 1.3 java dll depends on it and is not
391 // always able to find it when the loading executable is outside the JDK.
392 // In order to keep working with 1.2 we ignore any loading errors.
393 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify");
394 dll_load(buffer, ebuf, sizeof(ebuf));
395
396 // Load java dll
397 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "java");
398 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
399 if (_native_java_library == NULL) {
400 vm_exit_during_initialization("Unable to load native library", ebuf);
401 }
402
403 #if defined(__OpenBSD__)
404 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
405 // ignore errors
406 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "net");
407 dll_load(buffer, ebuf, sizeof(ebuf));
408 #endif
409 }
410 static jboolean onLoaded = JNI_FALSE;
411 if (onLoaded) {
412 // We may have to wait to fire OnLoad until TLS is initialized.
413 if (ThreadLocalStorage::is_initialized()) {
414 // The JNI_OnLoad handling is normally done by method load in
415 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
416 // explicitly so we have to check for JNI_OnLoad as well
417 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
418 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
419 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
420 if (JNI_OnLoad != NULL) {
421 JavaThread* thread = JavaThread::current();
422 ThreadToNativeFromVM ttn(thread);
423 HandleMark hm(thread);
424 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
425 onLoaded = JNI_TRUE;
426 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
427 vm_exit_during_initialization("Unsupported JNI version");
428 }
429 }
430 }
431 }
432 return _native_java_library;
433 }
434
435 // --------------------- heap allocation utilities ---------------------
436
437 char *os::strdup(const char *str, MEMFLAGS flags) {
438 size_t size = strlen(str);
439 char *dup_str = (char *)malloc(size + 1, flags);
440 if (dup_str == NULL) return NULL;
441 strcpy(dup_str, str);
442 return dup_str;
443 }
444
445
446
447 #ifdef ASSERT
448 #define space_before (MallocCushion + sizeof(double))
449 #define space_after MallocCushion
450 #define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t))
451 #define size_addr_from_obj(p) ((size_t*)p - 1)
452 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
453 // NB: cannot be debug variable, because these aren't set from the command line until
454 // *after* the first few allocs already happened
455 #define MallocCushion 16
456 #else
457 #define space_before 0
458 #define space_after 0
459 #define size_addr_from_base(p) should not use w/o ASSERT
460 #define size_addr_from_obj(p) should not use w/o ASSERT
461 #define MallocCushion 0
462 #endif
463 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
464
465 #ifdef ASSERT
466 inline size_t get_size(void* obj) {
467 size_t size = *size_addr_from_obj(obj);
468 if (size < 0) {
469 fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten ("
470 SIZE_FORMAT ")", obj, size));
471 }
472 return size;
473 }
474
475 u_char* find_cushion_backwards(u_char* start) {
476 u_char* p = start;
477 while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
478 p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
479 // ok, we have four consecutive marker bytes; find start
480 u_char* q = p - 4;
481 while (*q == badResourceValue) q--;
482 return q + 1;
483 }
484
485 u_char* find_cushion_forwards(u_char* start) {
486 u_char* p = start;
487 while (p[0] != badResourceValue || p[1] != badResourceValue ||
488 p[2] != badResourceValue || p[3] != badResourceValue) p++;
489 // ok, we have four consecutive marker bytes; find end of cushion
490 u_char* q = p + 4;
491 while (*q == badResourceValue) q++;
492 return q - MallocCushion;
493 }
494
495 void print_neighbor_blocks(void* ptr) {
496 // find block allocated before ptr (not entirely crash-proof)
497 if (MallocCushion < 4) {
498 tty->print_cr("### cannot find previous block (MallocCushion < 4)");
499 return;
500 }
501 u_char* start_of_this_block = (u_char*)ptr - space_before;
502 u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
503 // look for cushion in front of prev. block
504 u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
505 ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
506 u_char* obj = start_of_prev_block + space_before;
507 if (size <= 0 ) {
508 // start is bad; mayhave been confused by OS data inbetween objects
509 // search one more backwards
510 start_of_prev_block = find_cushion_backwards(start_of_prev_block);
511 size = *size_addr_from_base(start_of_prev_block);
512 obj = start_of_prev_block + space_before;
513 }
514
515 if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
516 tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
517 } else {
518 tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
519 }
520
521 // now find successor block
522 u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
523 start_of_next_block = find_cushion_forwards(start_of_next_block);
524 u_char* next_obj = start_of_next_block + space_before;
525 ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
526 if (start_of_next_block[0] == badResourceValue &&
527 start_of_next_block[1] == badResourceValue &&
528 start_of_next_block[2] == badResourceValue &&
529 start_of_next_block[3] == badResourceValue) {
530 tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
531 } else {
532 tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
533 }
534 }
535
536
537 void report_heap_error(void* memblock, void* bad, const char* where) {
538 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
539 tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock);
540 print_neighbor_blocks(memblock);
541 fatal("memory stomping error");
542 }
543
544 void verify_block(void* memblock) {
545 size_t size = get_size(memblock);
546 if (MallocCushion) {
547 u_char* ptr = (u_char*)memblock - space_before;
548 for (int i = 0; i < MallocCushion; i++) {
549 if (ptr[i] != badResourceValue) {
550 report_heap_error(memblock, ptr+i, "in front of");
551 }
552 }
553 u_char* end = (u_char*)memblock + size + space_after;
554 for (int j = -MallocCushion; j < 0; j++) {
555 if (end[j] != badResourceValue) {
556 report_heap_error(memblock, end+j, "after");
557 }
558 }
559 }
560 }
561 #endif
562
563 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
564 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
565 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
566
567 if (size == 0) {
568 // return a valid pointer if size is zero
569 // if NULL is returned the calling functions assume out of memory.
570 size = 1;
571 }
572
573 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
574 u_char* ptr = (u_char*)::malloc(size + space_before + space_after);
575
576 #ifdef ASSERT
577 if (ptr == NULL) return NULL;
578 if (MallocCushion) {
579 for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
580 u_char* end = ptr + space_before + size;
581 for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
582 for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
583 }
584 // put size just before data
585 *size_addr_from_base(ptr) = size;
586 #endif
587 u_char* memblock = ptr + space_before;
588 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
589 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
590 breakpoint();
591 }
592 debug_only(if (paranoid) verify_block(memblock));
593 if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
594
595 // we do not track MallocCushion memory
596 if (MemTracker::is_on()) {
597 MemTracker::record_malloc((address)memblock, size, memflags, caller == 0 ? CALLER_PC : caller);
598 }
599
600 return memblock;
601 }
602
603
604 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
605 #ifndef ASSERT
606 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
607 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
608 void* ptr = ::realloc(memblock, size);
609 if (ptr != NULL && MemTracker::is_on()) {
610 MemTracker::record_realloc((address)memblock, (address)ptr, size, memflags,
611 caller == 0 ? CALLER_PC : caller);
612 }
613 return ptr;
614 #else
615 if (memblock == NULL) {
616 return malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
617 }
618 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
619 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
620 breakpoint();
621 }
622 verify_block(memblock);
623 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
624 if (size == 0) return NULL;
625 // always move the block
626 void* ptr = malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
627 if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
628 // Copy to new memory if malloc didn't fail
629 if ( ptr != NULL ) {
630 memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
631 if (paranoid) verify_block(ptr);
632 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
633 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
634 breakpoint();
635 }
636 free(memblock);
637 }
638 return ptr;
639 #endif
640 }
641
642
643 void os::free(void *memblock, MEMFLAGS memflags) {
644 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
645 #ifdef ASSERT
646 if (memblock == NULL) return;
647 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
648 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
649 breakpoint();
650 }
651 verify_block(memblock);
652 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
653 // Added by detlefs.
654 if (MallocCushion) {
655 u_char* ptr = (u_char*)memblock - space_before;
656 for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
657 guarantee(*p == badResourceValue,
658 "Thing freed should be malloc result.");
659 *p = (u_char)freeBlockPad;
660 }
661 size_t size = get_size(memblock);
662 inc_stat_counter(&free_bytes, size);
663 u_char* end = ptr + space_before + size;
664 for (u_char* q = end; q < end + MallocCushion; q++) {
665 guarantee(*q == badResourceValue,
666 "Thing freed should be malloc result.");
667 *q = (u_char)freeBlockPad;
668 }
669 if (PrintMalloc && tty != NULL)
670 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
671 } else if (PrintMalloc && tty != NULL) {
672 // tty->print_cr("os::free %p", memblock);
673 fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock);
674 }
675 #endif
676 MemTracker::record_free((address)memblock, memflags);
677
678 ::free((char*)memblock - space_before);
679 }
680
681 void os::init_random(long initval) {
682 _rand_seed = initval;
683 }
684
685
686 long os::random() {
687 /* standard, well-known linear congruential random generator with
688 * next_rand = (16807*seed) mod (2**31-1)
689 * see
690 * (1) "Random Number Generators: Good Ones Are Hard to Find",
691 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
692 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
693 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
694 */
695 const long a = 16807;
696 const unsigned long m = 2147483647;
697 const long q = m / a; assert(q == 127773, "weird math");
698 const long r = m % a; assert(r == 2836, "weird math");
699
700 // compute az=2^31p+q
701 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
702 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
703 lo += (hi & 0x7FFF) << 16;
704
705 // if q overflowed, ignore the overflow and increment q
706 if (lo > m) {
707 lo &= m;
708 ++lo;
709 }
710 lo += hi >> 15;
711
712 // if (p+q) overflowed, ignore the overflow and increment (p+q)
713 if (lo > m) {
714 lo &= m;
715 ++lo;
716 }
717 return (_rand_seed = lo);
718 }
719
720 // The INITIALIZED state is distinguished from the SUSPENDED state because the
721 // conditions in which a thread is first started are different from those in which
722 // a suspension is resumed. These differences make it hard for us to apply the
723 // tougher checks when starting threads that we want to do when resuming them.
724 // However, when start_thread is called as a result of Thread.start, on a Java
725 // thread, the operation is synchronized on the Java Thread object. So there
726 // cannot be a race to start the thread and hence for the thread to exit while
727 // we are working on it. Non-Java threads that start Java threads either have
728 // to do so in a context in which races are impossible, or should do appropriate
729 // locking.
730
731 void os::start_thread(Thread* thread) {
732 // guard suspend/resume
733 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
734 OSThread* osthread = thread->osthread();
735 osthread->set_state(RUNNABLE);
736 pd_start_thread(thread);
737 }
738
739 //---------------------------------------------------------------------------
740 // Helper functions for fatal error handler
741
742 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
743 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
744
745 int cols = 0;
746 int cols_per_line = 0;
747 switch (unitsize) {
748 case 1: cols_per_line = 16; break;
749 case 2: cols_per_line = 8; break;
750 case 4: cols_per_line = 4; break;
751 case 8: cols_per_line = 2; break;
752 default: return;
753 }
754
755 address p = start;
756 st->print(PTR_FORMAT ": ", start);
757 while (p < end) {
758 switch (unitsize) {
759 case 1: st->print("%02x", *(u1*)p); break;
760 case 2: st->print("%04x", *(u2*)p); break;
761 case 4: st->print("%08x", *(u4*)p); break;
762 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
763 }
764 p += unitsize;
765 cols++;
766 if (cols >= cols_per_line && p < end) {
767 cols = 0;
768 st->cr();
769 st->print(PTR_FORMAT ": ", p);
770 } else {
771 st->print(" ");
772 }
773 }
774 st->cr();
775 }
776
777 void os::print_environment_variables(outputStream* st, const char** env_list,
778 char* buffer, int len) {
779 if (env_list) {
780 st->print_cr("Environment Variables:");
781
782 for (int i = 0; env_list[i] != NULL; i++) {
783 if (getenv(env_list[i], buffer, len)) {
784 st->print(env_list[i]);
785 st->print("=");
786 st->print_cr(buffer);
787 }
788 }
789 }
790 }
791
792 void os::print_cpu_info(outputStream* st) {
793 // cpu
794 st->print("CPU:");
795 st->print("total %d", os::processor_count());
796 // It's not safe to query number of active processors after crash
797 // st->print("(active %d)", os::active_processor_count());
798 st->print(" %s", VM_Version::cpu_features());
799 st->cr();
800 pd_print_cpu_info(st);
801 }
802
803 void os::print_date_and_time(outputStream *st) {
804 time_t tloc;
805 (void)time(&tloc);
806 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
807
808 double t = os::elapsedTime();
809 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
810 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
811 // before printf. We lost some precision, but who cares?
812 st->print_cr("elapsed time: %d seconds", (int)t);
813 }
814
815 // moved from debug.cpp (used to be find()) but still called from there
816 // The verbose parameter is only set by the debug code in one case
817 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
818 address addr = (address)x;
819 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
820 if (b != NULL) {
821 if (b->is_buffer_blob()) {
822 // the interpreter is generated into a buffer blob
823 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
824 if (i != NULL) {
825 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
826 i->print_on(st);
827 return;
828 }
829 if (Interpreter::contains(addr)) {
830 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
831 " (not bytecode specific)", addr);
832 return;
833 }
834 //
835 if (AdapterHandlerLibrary::contains(b)) {
836 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
837 AdapterHandlerLibrary::print_handler_on(st, b);
838 }
839 // the stubroutines are generated into a buffer blob
840 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
841 if (d != NULL) {
842 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
843 d->print_on(st);
844 st->cr();
845 return;
846 }
847 if (StubRoutines::contains(addr)) {
848 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
849 "stub routine", addr);
850 return;
851 }
852 // the InlineCacheBuffer is using stubs generated into a buffer blob
853 if (InlineCacheBuffer::contains(addr)) {
854 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
855 return;
856 }
857 VtableStub* v = VtableStubs::stub_containing(addr);
858 if (v != NULL) {
859 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
860 v->print_on(st);
861 st->cr();
862 return;
863 }
864 }
865 nmethod* nm = b->as_nmethod_or_null();
866 if (nm != NULL) {
867 ResourceMark rm;
868 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
869 addr, (int)(addr - nm->entry_point()), nm);
870 if (verbose) {
871 st->print(" for ");
872 nm->method()->print_value_on(st);
873 }
874 nm->print_nmethod(verbose);
875 return;
876 }
877 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
878 b->print_on(st);
879 return;
880 }
881
882 if (Universe::heap()->is_in(addr)) {
883 HeapWord* p = Universe::heap()->block_start(addr);
884 bool print = false;
885 // If we couldn't find it it just may mean that heap wasn't parseable
886 // See if we were just given an oop directly
887 if (p != NULL && Universe::heap()->block_is_obj(p)) {
888 print = true;
889 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
890 p = (HeapWord*) addr;
891 print = true;
892 }
893 if (print) {
894 if (p == (HeapWord*) addr) {
895 st->print_cr(INTPTR_FORMAT " is an oop", addr);
896 } else {
897 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
898 }
899 oop(p)->print_on(st);
900 return;
901 }
902 } else {
903 if (Universe::heap()->is_in_reserved(addr)) {
904 st->print_cr(INTPTR_FORMAT " is an unallocated location "
905 "in the heap", addr);
906 return;
907 }
908 }
909 if (JNIHandles::is_global_handle((jobject) addr)) {
910 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
911 return;
912 }
913 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
914 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
915 return;
916 }
917 #ifndef PRODUCT
918 // we don't keep the block list in product mode
919 if (JNIHandleBlock::any_contains((jobject) addr)) {
920 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
921 return;
922 }
923 #endif
924
925 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
926 // Check for privilege stack
927 if (thread->privileged_stack_top() != NULL &&
928 thread->privileged_stack_top()->contains(addr)) {
929 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
930 "for thread: " INTPTR_FORMAT, addr, thread);
931 if (verbose) thread->print_on(st);
932 return;
933 }
934 // If the addr is a java thread print information about that.
935 if (addr == (address)thread) {
936 if (verbose) {
937 thread->print_on(st);
938 } else {
939 st->print_cr(INTPTR_FORMAT " is a thread", addr);
940 }
941 return;
942 }
943 // If the addr is in the stack region for this thread then report that
944 // and print thread info
945 if (thread->stack_base() >= addr &&
946 addr > (thread->stack_base() - thread->stack_size())) {
947 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
948 INTPTR_FORMAT, addr, thread);
949 if (verbose) thread->print_on(st);
950 return;
951 }
952
953 }
954
955 #ifndef PRODUCT
956 // Check if in metaspace.
957 if (ClassLoaderDataGraph::contains((address)addr)) {
958 // Use addr->print() from the debugger instead (not here)
959 st->print_cr(INTPTR_FORMAT
960 " is pointing into metadata", addr);
961 return;
962 }
963 #endif
964
965 // Try an OS specific find
966 if (os::find(addr, st)) {
967 return;
968 }
969
970 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
971 }
972
973 // Looks like all platforms except IA64 can use the same function to check
974 // if C stack is walkable beyond current frame. The check for fp() is not
975 // necessary on Sparc, but it's harmless.
976 bool os::is_first_C_frame(frame* fr) {
977 #ifdef IA64
978 // In order to walk native frames on Itanium, we need to access the unwind
979 // table, which is inside ELF. We don't want to parse ELF after fatal error,
980 // so return true for IA64. If we need to support C stack walking on IA64,
981 // this function needs to be moved to CPU specific files, as fp() on IA64
982 // is register stack, which grows towards higher memory address.
983 return true;
984 #endif
985
986 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
987 // Check usp first, because if that's bad the other accessors may fault
988 // on some architectures. Ditto ufp second, etc.
989 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
990 // sp on amd can be 32 bit aligned.
991 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
992
993 uintptr_t usp = (uintptr_t)fr->sp();
994 if ((usp & sp_align_mask) != 0) return true;
995
996 uintptr_t ufp = (uintptr_t)fr->fp();
997 if ((ufp & fp_align_mask) != 0) return true;
998
999 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1000 if ((old_sp & sp_align_mask) != 0) return true;
1001 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1002
1003 uintptr_t old_fp = (uintptr_t)fr->link();
1004 if ((old_fp & fp_align_mask) != 0) return true;
1005 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1006
1007 // stack grows downwards; if old_fp is below current fp or if the stack
1008 // frame is too large, either the stack is corrupted or fp is not saved
1009 // on stack (i.e. on x86, ebp may be used as general register). The stack
1010 // is not walkable beyond current frame.
1011 if (old_fp < ufp) return true;
1012 if (old_fp - ufp > 64 * K) return true;
1013
1014 return false;
1015 }
1016
1017 #ifdef ASSERT
1018 extern "C" void test_random() {
1019 const double m = 2147483647;
1020 double mean = 0.0, variance = 0.0, t;
1021 long reps = 10000;
1022 unsigned long seed = 1;
1023
1024 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1025 os::init_random(seed);
1026 long num;
1027 for (int k = 0; k < reps; k++) {
1028 num = os::random();
1029 double u = (double)num / m;
1030 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1031
1032 // calculate mean and variance of the random sequence
1033 mean += u;
1034 variance += (u*u);
1035 }
1036 mean /= reps;
1037 variance /= (reps - 1);
1038
1039 assert(num == 1043618065, "bad seed");
1040 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1041 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1042 const double eps = 0.0001;
1043 t = fabsd(mean - 0.5018);
1044 assert(t < eps, "bad mean");
1045 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1046 assert(t < eps, "bad variance");
1047 }
1048 #endif
1049
1050
1051 // Set up the boot classpath.
1052
1053 char* os::format_boot_path(const char* format_string,
1054 const char* home,
1055 int home_len,
1056 char fileSep,
1057 char pathSep) {
1058 assert((fileSep == '/' && pathSep == ':') ||
1059 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1060
1061 // Scan the format string to determine the length of the actual
1062 // boot classpath, and handle platform dependencies as well.
1063 int formatted_path_len = 0;
1064 const char* p;
1065 for (p = format_string; *p != 0; ++p) {
1066 if (*p == '%') formatted_path_len += home_len - 1;
1067 ++formatted_path_len;
1068 }
1069
1070 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1071 if (formatted_path == NULL) {
1072 return NULL;
1073 }
1074
1075 // Create boot classpath from format, substituting separator chars and
1076 // java home directory.
1077 char* q = formatted_path;
1078 for (p = format_string; *p != 0; ++p) {
1079 switch (*p) {
1080 case '%':
1081 strcpy(q, home);
1082 q += home_len;
1083 break;
1084 case '/':
1085 *q++ = fileSep;
1086 break;
1087 case ':':
1088 *q++ = pathSep;
1089 break;
1090 default:
1091 *q++ = *p;
1092 }
1093 }
1094 *q = '\0';
1095
1096 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1097 return formatted_path;
1098 }
1099
1100
1101 bool os::set_boot_path(char fileSep, char pathSep) {
1102 const char* home = Arguments::get_java_home();
1103 int home_len = (int)strlen(home);
1104
1105 static const char* meta_index_dir_format = "%/lib/";
1106 static const char* meta_index_format = "%/lib/meta-index";
1107 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1108 if (meta_index == NULL) return false;
1109 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1110 if (meta_index_dir == NULL) return false;
1111 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1112
1113 // Any modification to the JAR-file list, for the boot classpath must be
1114 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1115 // path class JARs, are stripped for StackMapTable to reduce download size.
1116 static const char classpath_format[] =
1117 "%/lib/resources.jar:"
1118 "%/lib/rt.jar:"
1119 "%/lib/sunrsasign.jar:"
1120 "%/lib/jsse.jar:"
1121 "%/lib/jce.jar:"
1122 "%/lib/charsets.jar:"
1123 "%/lib/jfr.jar:"
1124 #ifdef __APPLE__
1125 "%/lib/JObjC.jar:"
1126 #endif
1127 "%/classes";
1128 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1129 if (sysclasspath == NULL) return false;
1130 Arguments::set_sysclasspath(sysclasspath);
1131
1132 return true;
1133 }
1134
1135 /*
1136 * Splits a path, based on its separator, the number of
1137 * elements is returned back in n.
1138 * It is the callers responsibility to:
1139 * a> check the value of n, and n may be 0.
1140 * b> ignore any empty path elements
1141 * c> free up the data.
1142 */
1143 char** os::split_path(const char* path, int* n) {
1144 *n = 0;
1145 if (path == NULL || strlen(path) == 0) {
1146 return NULL;
1147 }
1148 const char psepchar = *os::path_separator();
1149 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1150 if (inpath == NULL) {
1151 return NULL;
1152 }
1153 strncpy(inpath, path, strlen(path));
1154 int count = 1;
1155 char* p = strchr(inpath, psepchar);
1156 // Get a count of elements to allocate memory
1157 while (p != NULL) {
1158 count++;
1159 p++;
1160 p = strchr(p, psepchar);
1161 }
1162 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1163 if (opath == NULL) {
1164 return NULL;
1165 }
1166
1167 // do the actual splitting
1168 p = inpath;
1169 for (int i = 0 ; i < count ; i++) {
1170 size_t len = strcspn(p, os::path_separator());
1171 if (len > JVM_MAXPATHLEN) {
1172 return NULL;
1173 }
1174 // allocate the string and add terminator storage
1175 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1176 if (s == NULL) {
1177 return NULL;
1178 }
1179 strncpy(s, p, len);
1180 s[len] = '\0';
1181 opath[i] = s;
1182 p += len + 1;
1183 }
1184 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1185 *n = count;
1186 return opath;
1187 }
1188
1189 void os::set_memory_serialize_page(address page) {
1190 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1191 _mem_serialize_page = (volatile int32_t *)page;
1192 // We initialize the serialization page shift count here
1193 // We assume a cache line size of 64 bytes
1194 assert(SerializePageShiftCount == count,
1195 "thread size changed, fix SerializePageShiftCount constant");
1196 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1197 }
1198
1199 static volatile intptr_t SerializePageLock = 0;
1200
1201 // This method is called from signal handler when SIGSEGV occurs while the current
1202 // thread tries to store to the "read-only" memory serialize page during state
1203 // transition.
1204 void os::block_on_serialize_page_trap() {
1205 if (TraceSafepoint) {
1206 tty->print_cr("Block until the serialize page permission restored");
1207 }
1208 // When VMThread is holding the SerializePageLock during modifying the
1209 // access permission of the memory serialize page, the following call
1210 // will block until the permission of that page is restored to rw.
1211 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1212 // this case, it's OK as the signal is synchronous and we know precisely when
1213 // it can occur.
1214 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1215 Thread::muxRelease(&SerializePageLock);
1216 }
1217
1218 // Serialize all thread state variables
1219 void os::serialize_thread_states() {
1220 // On some platforms such as Solaris & Linux, the time duration of the page
1221 // permission restoration is observed to be much longer than expected due to
1222 // scheduler starvation problem etc. To avoid the long synchronization
1223 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1224 // the mutator thread if such case is encountered. See bug 6546278 for details.
1225 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1226 os::protect_memory((char *)os::get_memory_serialize_page(),
1227 os::vm_page_size(), MEM_PROT_READ);
1228 os::protect_memory((char *)os::get_memory_serialize_page(),
1229 os::vm_page_size(), MEM_PROT_RW);
1230 Thread::muxRelease(&SerializePageLock);
1231 }
1232
1233 // Returns true if the current stack pointer is above the stack shadow
1234 // pages, false otherwise.
1235
1236 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1237 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1238 address sp = current_stack_pointer();
1239 // Check if we have StackShadowPages above the yellow zone. This parameter
1240 // is dependent on the depth of the maximum VM call stack possible from
1241 // the handler for stack overflow. 'instanceof' in the stack overflow
1242 // handler or a println uses at least 8k stack of VM and native code
1243 // respectively.
1244 const int framesize_in_bytes =
1245 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1246 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1247 * vm_page_size()) + framesize_in_bytes;
1248 // The very lower end of the stack
1249 address stack_limit = thread->stack_base() - thread->stack_size();
1250 return (sp > (stack_limit + reserved_area));
1251 }
1252
1253 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1254 uint min_pages)
1255 {
1256 assert(min_pages > 0, "sanity");
1257 if (UseLargePages) {
1258 const size_t max_page_size = region_max_size / min_pages;
1259
1260 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1261 const size_t sz = _page_sizes[i];
1262 const size_t mask = sz - 1;
1263 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1264 // The largest page size with no fragmentation.
1265 return sz;
1266 }
1267
1268 if (sz <= max_page_size) {
1269 // The largest page size that satisfies the min_pages requirement.
1270 return sz;
1271 }
1272 }
1273 }
1274
1275 return vm_page_size();
1276 }
1277
1278 #ifndef PRODUCT
1279 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1280 {
1281 if (TracePageSizes) {
1282 tty->print("%s: ", str);
1283 for (int i = 0; i < count; ++i) {
1284 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1285 }
1286 tty->cr();
1287 }
1288 }
1289
1290 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1291 const size_t region_max_size, const size_t page_size,
1292 const char* base, const size_t size)
1293 {
1294 if (TracePageSizes) {
1295 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1296 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1297 " size=" SIZE_FORMAT,
1298 str, region_min_size, region_max_size,
1299 page_size, base, size);
1300 }
1301 }
1302 #endif // #ifndef PRODUCT
1303
1304 // This is the working definition of a server class machine:
1305 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1306 // because the graphics memory (?) sometimes masks physical memory.
1307 // If you want to change the definition of a server class machine
1308 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1309 // then you'll have to parameterize this method based on that state,
1310 // as was done for logical processors here, or replicate and
1311 // specialize this method for each platform. (Or fix os to have
1312 // some inheritance structure and use subclassing. Sigh.)
1313 // If you want some platform to always or never behave as a server
1314 // class machine, change the setting of AlwaysActAsServerClassMachine
1315 // and NeverActAsServerClassMachine in globals*.hpp.
1316 bool os::is_server_class_machine() {
1317 // First check for the early returns
1318 if (NeverActAsServerClassMachine) {
1319 return false;
1320 }
1321 if (AlwaysActAsServerClassMachine) {
1322 return true;
1323 }
1324 // Then actually look at the machine
1325 bool result = false;
1326 const unsigned int server_processors = 2;
1327 const julong server_memory = 2UL * G;
1328 // We seem not to get our full complement of memory.
1329 // We allow some part (1/8?) of the memory to be "missing",
1330 // based on the sizes of DIMMs, and maybe graphics cards.
1331 const julong missing_memory = 256UL * M;
1332
1333 /* Is this a server class machine? */
1334 if ((os::active_processor_count() >= (int)server_processors) &&
1335 (os::physical_memory() >= (server_memory - missing_memory))) {
1336 const unsigned int logical_processors =
1337 VM_Version::logical_processors_per_package();
1338 if (logical_processors > 1) {
1339 const unsigned int physical_packages =
1340 os::active_processor_count() / logical_processors;
1341 if (physical_packages > server_processors) {
1342 result = true;
1343 }
1344 } else {
1345 result = true;
1346 }
1347 }
1348 return result;
1349 }
1350
1351 // Read file line by line, if line is longer than bsize,
1352 // skip rest of line.
1353 int os::get_line_chars(int fd, char* buf, const size_t bsize){
1354 size_t sz, i = 0;
1355
1356 // read until EOF, EOL or buf is full
1357 while ((sz = (int) read(fd, &buf[i], 1)) == 1 && i < (bsize-2) && buf[i] != '\n') {
1358 ++i;
1359 }
1360
1361 if (buf[i] == '\n') {
1362 // EOL reached so ignore EOL character and return
1363
1364 buf[i] = 0;
1365 return (int) i;
1366 }
1367
1368 buf[i+1] = 0;
1369
1370 if (sz != 1) {
1371 // EOF reached. if we read chars before EOF return them and
1372 // return EOF on next call otherwise return EOF
1373
1374 return (i == 0) ? -1 : (int) i;
1375 }
1376
1377 // line is longer than size of buf, skip to EOL
1378 char ch;
1379 while (read(fd, &ch, 1) == 1 && ch != '\n') {
1380 // Do nothing
1381 }
1382
1383 // return initial part of line that fits in buf.
1384 // If we reached EOF, it will be returned on next call.
1385
1386 return (int) i;
1387 }
1388
1389 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1390 return os::pd_create_stack_guard_pages(addr, bytes);
1391 }
1392
1393
1394 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1395 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1396 if (result != NULL && MemTracker::is_on()) {
1397 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1398 }
1399
1400 return result;
1401 }
1402 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1403 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1404 if (result != NULL && MemTracker::is_on()) {
1405 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1406 }
1407 return result;
1408 }
1409
1410 void os::split_reserved_memory(char *base, size_t size,
1411 size_t split, bool realloc) {
1412 pd_split_reserved_memory(base, size, split, realloc);
1413 }
1414
1415 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1416 bool res = pd_commit_memory(addr, bytes, executable);
1417 if (res && MemTracker::is_on()) {
1418 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1419 }
1420 return res;
1421 }
1422
1423 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1424 bool executable) {
1425 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1426 if (res && MemTracker::is_on()) {
1427 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1428 }
1429 return res;
1430 }
1431
1432 bool os::uncommit_memory(char* addr, size_t bytes) {
1433 bool res = pd_uncommit_memory(addr, bytes);
1434 if (res) {
1435 MemTracker::record_virtual_memory_uncommit((address)addr, bytes);
1436 }
1437 return res;
1438 }
1439
1440 bool os::release_memory(char* addr, size_t bytes) {
1441 bool res = pd_release_memory(addr, bytes);
1442 if (res) {
1443 MemTracker::record_virtual_memory_release((address)addr, bytes);
1444 }
1445 return res;
1446 }
1447
1448
1449 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1450 char *addr, size_t bytes, bool read_only,
1451 bool allow_exec) {
1452 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1453 if (result != NULL && MemTracker::is_on()) {
1454 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1455 }
1456 return result;
1457 }
1458
1459 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1460 char *addr, size_t bytes, bool read_only,
1461 bool allow_exec) {
1462 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1463 read_only, allow_exec);
1464 }
1465
1466 bool os::unmap_memory(char *addr, size_t bytes) {
1467 bool result = pd_unmap_memory(addr, bytes);
1468 if (result) {
1469 MemTracker::record_virtual_memory_release((address)addr, bytes);
1470 }
1471 return result;
1472 }
1473
1474 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1475 pd_free_memory(addr, bytes, alignment_hint);
1476 }
1477
1478 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1479 pd_realign_memory(addr, bytes, alignment_hint);
1480 }
1481