1 /*
2 * Copyright (c) 1997, 2011, 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/threadService.hpp"
49 #include "utilities/defaultStream.hpp"
50 #include "utilities/events.hpp"
51 #ifdef TARGET_OS_FAMILY_linux
52 # include "os_linux.inline.hpp"
53 # include "thread_linux.inline.hpp"
54 #endif
55 #ifdef TARGET_OS_FAMILY_solaris
56 # include "os_solaris.inline.hpp"
57 # include "thread_solaris.inline.hpp"
58 #endif
59 #ifdef TARGET_OS_FAMILY_windows
60 # include "os_windows.inline.hpp"
61 # include "thread_windows.inline.hpp"
62 #endif
63 #ifdef TARGET_OS_FAMILY_bsd
64 # include "os_bsd.inline.hpp"
65 # include "thread_bsd.inline.hpp"
66 #endif
67
68 # include <signal.h>
69
70 OSThread* os::_starting_thread = NULL;
71 address os::_polling_page = NULL;
72 volatile int32_t* os::_mem_serialize_page = NULL;
73 uintptr_t os::_serialize_page_mask = 0;
74 long os::_rand_seed = 1;
75 int os::_processor_count = 0;
76 size_t os::_page_sizes[os::page_sizes_max];
77
78 #ifndef PRODUCT
79 julong os::num_mallocs = 0; // # of calls to malloc/realloc
80 julong os::alloc_bytes = 0; // # of bytes allocated
81 julong os::num_frees = 0; // # of calls to free
82 julong os::free_bytes = 0; // # of bytes freed
83 #endif
84
85 // Fill in buffer with current local time as an ISO-8601 string.
86 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
87 // Returns buffer, or NULL if it failed.
88 // This would mostly be a call to
89 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
90 // except that on Windows the %z behaves badly, so we do it ourselves.
91 // Also, people wanted milliseconds on there,
92 // and strftime doesn't do milliseconds.
93 char* os::iso8601_time(char* buffer, size_t buffer_length) {
94 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
95 // 1 2
96 // 12345678901234567890123456789
97 static const char* iso8601_format =
98 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
99 static const size_t needed_buffer = 29;
100
101 // Sanity check the arguments
102 if (buffer == NULL) {
103 assert(false, "NULL buffer");
104 return NULL;
105 }
106 if (buffer_length < needed_buffer) {
107 assert(false, "buffer_length too small");
108 return NULL;
109 }
110 // Get the current time
111 jlong milliseconds_since_19700101 = javaTimeMillis();
112 const int milliseconds_per_microsecond = 1000;
113 const time_t seconds_since_19700101 =
114 milliseconds_since_19700101 / milliseconds_per_microsecond;
115 const int milliseconds_after_second =
116 milliseconds_since_19700101 % milliseconds_per_microsecond;
117 // Convert the time value to a tm and timezone variable
118 struct tm time_struct;
119 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
120 assert(false, "Failed localtime_pd");
121 return NULL;
122 }
123 #if defined(_ALLBSD_SOURCE)
124 const time_t zone = (time_t) time_struct.tm_gmtoff;
125 #else
126 const time_t zone = timezone;
127 #endif
128
129 // If daylight savings time is in effect,
130 // we are 1 hour East of our time zone
131 const time_t seconds_per_minute = 60;
132 const time_t minutes_per_hour = 60;
133 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
134 time_t UTC_to_local = zone;
135 if (time_struct.tm_isdst > 0) {
136 UTC_to_local = UTC_to_local - seconds_per_hour;
137 }
138 // Compute the time zone offset.
139 // localtime_pd() sets timezone to the difference (in seconds)
140 // between UTC and and local time.
141 // ISO 8601 says we need the difference between local time and UTC,
142 // we change the sign of the localtime_pd() result.
143 const time_t local_to_UTC = -(UTC_to_local);
144 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
145 char sign_local_to_UTC = '+';
146 time_t abs_local_to_UTC = local_to_UTC;
147 if (local_to_UTC < 0) {
148 sign_local_to_UTC = '-';
149 abs_local_to_UTC = -(abs_local_to_UTC);
150 }
151 // Convert time zone offset seconds to hours and minutes.
152 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
153 const time_t zone_min =
154 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
155
156 // Print an ISO 8601 date and time stamp into the buffer
157 const int year = 1900 + time_struct.tm_year;
158 const int month = 1 + time_struct.tm_mon;
159 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
160 year,
161 month,
162 time_struct.tm_mday,
163 time_struct.tm_hour,
164 time_struct.tm_min,
165 time_struct.tm_sec,
166 milliseconds_after_second,
167 sign_local_to_UTC,
168 zone_hours,
169 zone_min);
170 if (printed == 0) {
171 assert(false, "Failed jio_printf");
172 return NULL;
173 }
174 return buffer;
175 }
176
177 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
178 #ifdef ASSERT
179 if (!(!thread->is_Java_thread() ||
180 Thread::current() == thread ||
181 Threads_lock->owned_by_self()
182 || thread->is_Compiler_thread()
183 )) {
184 assert(false, "possibility of dangling Thread pointer");
185 }
186 #endif
187
188 if (p >= MinPriority && p <= MaxPriority) {
189 int priority = java_to_os_priority[p];
190 return set_native_priority(thread, priority);
191 } else {
192 assert(false, "Should not happen");
193 return OS_ERR;
194 }
195 }
196
197
198 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
199 int p;
200 int os_prio;
201 OSReturn ret = get_native_priority(thread, &os_prio);
202 if (ret != OS_OK) return ret;
203
204 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
205 priority = (ThreadPriority)p;
206 return OS_OK;
207 }
208
209
210 // --------------------- sun.misc.Signal (optional) ---------------------
211
212
213 // SIGBREAK is sent by the keyboard to query the VM state
214 #ifndef SIGBREAK
215 #define SIGBREAK SIGQUIT
216 #endif
217
218 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
219
220
221 static void signal_thread_entry(JavaThread* thread, TRAPS) {
222 os::set_priority(thread, NearMaxPriority);
223 while (true) {
224 int sig;
225 {
226 // FIXME : Currently we have not decieded what should be the status
227 // for this java thread blocked here. Once we decide about
228 // that we should fix this.
229 sig = os::signal_wait();
230 }
231 if (sig == os::sigexitnum_pd()) {
232 // Terminate the signal thread
233 return;
234 }
235
236 switch (sig) {
237 case SIGBREAK: {
238 // Check if the signal is a trigger to start the Attach Listener - in that
239 // case don't print stack traces.
240 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
241 continue;
242 }
243 // Print stack traces
244 // Any SIGBREAK operations added here should make sure to flush
245 // the output stream (e.g. tty->flush()) after output. See 4803766.
246 // Each module also prints an extra carriage return after its output.
247 VM_PrintThreads op;
248 VMThread::execute(&op);
249 VM_PrintJNI jni_op;
250 VMThread::execute(&jni_op);
251 VM_FindDeadlocks op1(tty);
252 VMThread::execute(&op1);
253 Universe::print_heap_at_SIGBREAK();
254 if (PrintClassHistogram) {
255 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */,
256 true /* need_prologue */);
257 VMThread::execute(&op1);
258 }
259 if (JvmtiExport::should_post_data_dump()) {
260 JvmtiExport::post_data_dump();
261 }
262 break;
263 }
264 default: {
265 // Dispatch the signal to java
266 HandleMark hm(THREAD);
267 klassOop k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
268 KlassHandle klass (THREAD, k);
269 if (klass.not_null()) {
270 JavaValue result(T_VOID);
271 JavaCallArguments args;
272 args.push_int(sig);
273 JavaCalls::call_static(
274 &result,
275 klass,
276 vmSymbols::dispatch_name(),
277 vmSymbols::int_void_signature(),
278 &args,
279 THREAD
280 );
281 }
282 if (HAS_PENDING_EXCEPTION) {
283 // tty is initialized early so we don't expect it to be null, but
284 // if it is we can't risk doing an initialization that might
285 // trigger additional out-of-memory conditions
286 if (tty != NULL) {
287 char klass_name[256];
288 char tmp_sig_name[16];
289 const char* sig_name = "UNKNOWN";
290 instanceKlass::cast(PENDING_EXCEPTION->klass())->
291 name()->as_klass_external_name(klass_name, 256);
292 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
293 sig_name = tmp_sig_name;
294 warning("Exception %s occurred dispatching signal %s to handler"
295 "- the VM may need to be forcibly terminated",
296 klass_name, sig_name );
297 }
298 CLEAR_PENDING_EXCEPTION;
299 }
300 }
301 }
302 }
303 }
304
305
306 void os::signal_init() {
307 if (!ReduceSignalUsage) {
308 // Setup JavaThread for processing signals
309 EXCEPTION_MARK;
310 klassOop k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
311 instanceKlassHandle klass (THREAD, k);
312 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
313
314 const char thread_name[] = "Signal Dispatcher";
315 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
316
317 // Initialize thread_oop to put it into the system threadGroup
318 Handle thread_group (THREAD, Universe::system_thread_group());
319 JavaValue result(T_VOID);
320 JavaCalls::call_special(&result, thread_oop,
321 klass,
322 vmSymbols::object_initializer_name(),
323 vmSymbols::threadgroup_string_void_signature(),
324 thread_group,
325 string,
326 CHECK);
327
328 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
329 JavaCalls::call_special(&result,
330 thread_group,
331 group,
332 vmSymbols::add_method_name(),
333 vmSymbols::thread_void_signature(),
334 thread_oop, // ARG 1
335 CHECK);
336
337 os::signal_init_pd();
338
339 { MutexLocker mu(Threads_lock);
340 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
341
342 // At this point it may be possible that no osthread was created for the
343 // JavaThread due to lack of memory. We would have to throw an exception
344 // in that case. However, since this must work and we do not allow
345 // exceptions anyway, check and abort if this fails.
346 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
347 vm_exit_during_initialization("java.lang.OutOfMemoryError",
348 "unable to create new native thread");
349 }
350
351 java_lang_Thread::set_thread(thread_oop(), signal_thread);
352 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
353 java_lang_Thread::set_daemon(thread_oop());
354
355 signal_thread->set_threadObj(thread_oop());
356 Threads::add(signal_thread);
357 Thread::start(signal_thread);
358 }
359 // Handle ^BREAK
360 os::signal(SIGBREAK, os::user_handler());
361 }
362 }
363
364
365 void os::terminate_signal_thread() {
366 if (!ReduceSignalUsage)
367 signal_notify(sigexitnum_pd());
368 }
369
370
371 // --------------------- loading libraries ---------------------
372
373 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
374 extern struct JavaVM_ main_vm;
375
376 static void* _native_java_library = NULL;
377
378 void* os::native_java_library() {
379 if (_native_java_library == NULL) {
380 char buffer[JVM_MAXPATHLEN];
381 char ebuf[1024];
382
383 // Try to load verify dll first. In 1.3 java dll depends on it and is not
384 // always able to find it when the loading executable is outside the JDK.
385 // In order to keep working with 1.2 we ignore any loading errors.
386 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify");
387 dll_load(buffer, ebuf, sizeof(ebuf));
388
389 // Load java dll
390 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "java");
391 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
392 if (_native_java_library == NULL) {
393 vm_exit_during_initialization("Unable to load native library", ebuf);
394 }
395
396 #if defined(__OpenBSD__)
397 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
398 // ignore errors
399 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "net");
400 dll_load(buffer, ebuf, sizeof(ebuf));
401 #endif
402 }
403 static jboolean onLoaded = JNI_FALSE;
404 if (onLoaded) {
405 // We may have to wait to fire OnLoad until TLS is initialized.
406 if (ThreadLocalStorage::is_initialized()) {
407 // The JNI_OnLoad handling is normally done by method load in
408 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
409 // explicitly so we have to check for JNI_OnLoad as well
410 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
411 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
412 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
413 if (JNI_OnLoad != NULL) {
414 JavaThread* thread = JavaThread::current();
415 ThreadToNativeFromVM ttn(thread);
416 HandleMark hm(thread);
417 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
418 onLoaded = JNI_TRUE;
419 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
420 vm_exit_during_initialization("Unsupported JNI version");
421 }
422 }
423 }
424 }
425 return _native_java_library;
426 }
427
428 // --------------------- heap allocation utilities ---------------------
429
430 char *os::strdup(const char *str) {
431 size_t size = strlen(str);
432 char *dup_str = (char *)malloc(size + 1);
433 if (dup_str == NULL) return NULL;
434 strcpy(dup_str, str);
435 return dup_str;
436 }
437
438
439
440 #ifdef ASSERT
441 #define space_before (MallocCushion + sizeof(double))
442 #define space_after MallocCushion
443 #define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t))
444 #define size_addr_from_obj(p) ((size_t*)p - 1)
445 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
446 // NB: cannot be debug variable, because these aren't set from the command line until
447 // *after* the first few allocs already happened
448 #define MallocCushion 16
449 #else
450 #define space_before 0
451 #define space_after 0
452 #define size_addr_from_base(p) should not use w/o ASSERT
453 #define size_addr_from_obj(p) should not use w/o ASSERT
454 #define MallocCushion 0
455 #endif
456 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
457
458 #ifdef ASSERT
459 inline size_t get_size(void* obj) {
460 size_t size = *size_addr_from_obj(obj);
461 if (size < 0) {
462 fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten ("
463 SIZE_FORMAT ")", obj, size));
464 }
465 return size;
466 }
467
468 u_char* find_cushion_backwards(u_char* start) {
469 u_char* p = start;
470 while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
471 p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
472 // ok, we have four consecutive marker bytes; find start
473 u_char* q = p - 4;
474 while (*q == badResourceValue) q--;
475 return q + 1;
476 }
477
478 u_char* find_cushion_forwards(u_char* start) {
479 u_char* p = start;
480 while (p[0] != badResourceValue || p[1] != badResourceValue ||
481 p[2] != badResourceValue || p[3] != badResourceValue) p++;
482 // ok, we have four consecutive marker bytes; find end of cushion
483 u_char* q = p + 4;
484 while (*q == badResourceValue) q++;
485 return q - MallocCushion;
486 }
487
488 void print_neighbor_blocks(void* ptr) {
489 // find block allocated before ptr (not entirely crash-proof)
490 if (MallocCushion < 4) {
491 tty->print_cr("### cannot find previous block (MallocCushion < 4)");
492 return;
493 }
494 u_char* start_of_this_block = (u_char*)ptr - space_before;
495 u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
496 // look for cushion in front of prev. block
497 u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
498 ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
499 u_char* obj = start_of_prev_block + space_before;
500 if (size <= 0 ) {
501 // start is bad; mayhave been confused by OS data inbetween objects
502 // search one more backwards
503 start_of_prev_block = find_cushion_backwards(start_of_prev_block);
504 size = *size_addr_from_base(start_of_prev_block);
505 obj = start_of_prev_block + space_before;
506 }
507
508 if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
509 tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
510 } else {
511 tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
512 }
513
514 // now find successor block
515 u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
516 start_of_next_block = find_cushion_forwards(start_of_next_block);
517 u_char* next_obj = start_of_next_block + space_before;
518 ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
519 if (start_of_next_block[0] == badResourceValue &&
520 start_of_next_block[1] == badResourceValue &&
521 start_of_next_block[2] == badResourceValue &&
522 start_of_next_block[3] == badResourceValue) {
523 tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
524 } else {
525 tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
526 }
527 }
528
529
530 void report_heap_error(void* memblock, void* bad, const char* where) {
531 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
532 tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock);
533 print_neighbor_blocks(memblock);
534 fatal("memory stomping error");
535 }
536
537 void verify_block(void* memblock) {
538 size_t size = get_size(memblock);
539 if (MallocCushion) {
540 u_char* ptr = (u_char*)memblock - space_before;
541 for (int i = 0; i < MallocCushion; i++) {
542 if (ptr[i] != badResourceValue) {
543 report_heap_error(memblock, ptr+i, "in front of");
544 }
545 }
546 u_char* end = (u_char*)memblock + size + space_after;
547 for (int j = -MallocCushion; j < 0; j++) {
548 if (end[j] != badResourceValue) {
549 report_heap_error(memblock, end+j, "after");
550 }
551 }
552 }
553 }
554 #endif
555
556 void* os::malloc(size_t size) {
557 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
558 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
559
560 if (size == 0) {
561 // return a valid pointer if size is zero
562 // if NULL is returned the calling functions assume out of memory.
563 size = 1;
564 }
565
566 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
567 u_char* ptr = (u_char*)::malloc(size + space_before + space_after);
568 #ifdef ASSERT
569 if (ptr == NULL) return NULL;
570 if (MallocCushion) {
571 for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
572 u_char* end = ptr + space_before + size;
573 for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
574 for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
575 }
576 // put size just before data
577 *size_addr_from_base(ptr) = size;
578 #endif
579 u_char* memblock = ptr + space_before;
580 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
581 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
582 breakpoint();
583 }
584 debug_only(if (paranoid) verify_block(memblock));
585 if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
586 return memblock;
587 }
588
589
590 void* os::realloc(void *memblock, size_t size) {
591 #ifndef ASSERT
592 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
593 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
594 return ::realloc(memblock, size);
595 #else
596 if (memblock == NULL) {
597 return malloc(size);
598 }
599 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
600 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
601 breakpoint();
602 }
603 verify_block(memblock);
604 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
605 if (size == 0) return NULL;
606 // always move the block
607 void* ptr = malloc(size);
608 if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
609 // Copy to new memory if malloc didn't fail
610 if ( ptr != NULL ) {
611 memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
612 if (paranoid) verify_block(ptr);
613 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
614 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
615 breakpoint();
616 }
617 free(memblock);
618 }
619 return ptr;
620 #endif
621 }
622
623
624 void os::free(void *memblock) {
625 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
626 #ifdef ASSERT
627 if (memblock == NULL) return;
628 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
629 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
630 breakpoint();
631 }
632 verify_block(memblock);
633 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
634 // Added by detlefs.
635 if (MallocCushion) {
636 u_char* ptr = (u_char*)memblock - space_before;
637 for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
638 guarantee(*p == badResourceValue,
639 "Thing freed should be malloc result.");
640 *p = (u_char)freeBlockPad;
641 }
642 size_t size = get_size(memblock);
643 inc_stat_counter(&free_bytes, size);
644 u_char* end = ptr + space_before + size;
645 for (u_char* q = end; q < end + MallocCushion; q++) {
646 guarantee(*q == badResourceValue,
647 "Thing freed should be malloc result.");
648 *q = (u_char)freeBlockPad;
649 }
650 if (PrintMalloc && tty != NULL)
651 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
652 } else if (PrintMalloc && tty != NULL) {
653 // tty->print_cr("os::free %p", memblock);
654 fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock);
655 }
656 #endif
657 ::free((char*)memblock - space_before);
658 }
659
660 void os::init_random(long initval) {
661 _rand_seed = initval;
662 }
663
664
665 long os::random() {
666 /* standard, well-known linear congruential random generator with
667 * next_rand = (16807*seed) mod (2**31-1)
668 * see
669 * (1) "Random Number Generators: Good Ones Are Hard to Find",
670 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
671 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
672 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
673 */
674 const long a = 16807;
675 const unsigned long m = 2147483647;
676 const long q = m / a; assert(q == 127773, "weird math");
677 const long r = m % a; assert(r == 2836, "weird math");
678
679 // compute az=2^31p+q
680 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
681 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
682 lo += (hi & 0x7FFF) << 16;
683
684 // if q overflowed, ignore the overflow and increment q
685 if (lo > m) {
686 lo &= m;
687 ++lo;
688 }
689 lo += hi >> 15;
690
691 // if (p+q) overflowed, ignore the overflow and increment (p+q)
692 if (lo > m) {
693 lo &= m;
694 ++lo;
695 }
696 return (_rand_seed = lo);
697 }
698
699 // The INITIALIZED state is distinguished from the SUSPENDED state because the
700 // conditions in which a thread is first started are different from those in which
701 // a suspension is resumed. These differences make it hard for us to apply the
702 // tougher checks when starting threads that we want to do when resuming them.
703 // However, when start_thread is called as a result of Thread.start, on a Java
704 // thread, the operation is synchronized on the Java Thread object. So there
705 // cannot be a race to start the thread and hence for the thread to exit while
706 // we are working on it. Non-Java threads that start Java threads either have
707 // to do so in a context in which races are impossible, or should do appropriate
708 // locking.
709
710 void os::start_thread(Thread* thread) {
711 // guard suspend/resume
712 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
713 OSThread* osthread = thread->osthread();
714 osthread->set_state(RUNNABLE);
715 pd_start_thread(thread);
716 }
717
718 //---------------------------------------------------------------------------
719 // Helper functions for fatal error handler
720
721 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
722 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
723
724 int cols = 0;
725 int cols_per_line = 0;
726 switch (unitsize) {
727 case 1: cols_per_line = 16; break;
728 case 2: cols_per_line = 8; break;
729 case 4: cols_per_line = 4; break;
730 case 8: cols_per_line = 2; break;
731 default: return;
732 }
733
734 address p = start;
735 st->print(PTR_FORMAT ": ", start);
736 while (p < end) {
737 switch (unitsize) {
738 case 1: st->print("%02x", *(u1*)p); break;
739 case 2: st->print("%04x", *(u2*)p); break;
740 case 4: st->print("%08x", *(u4*)p); break;
741 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
742 }
743 p += unitsize;
744 cols++;
745 if (cols >= cols_per_line && p < end) {
746 cols = 0;
747 st->cr();
748 st->print(PTR_FORMAT ": ", p);
749 } else {
750 st->print(" ");
751 }
752 }
753 st->cr();
754 }
755
756 void os::print_environment_variables(outputStream* st, const char** env_list,
757 char* buffer, int len) {
758 if (env_list) {
759 st->print_cr("Environment Variables:");
760
761 for (int i = 0; env_list[i] != NULL; i++) {
762 if (getenv(env_list[i], buffer, len)) {
763 st->print(env_list[i]);
764 st->print("=");
765 st->print_cr(buffer);
766 }
767 }
768 }
769 }
770
771 void os::print_cpu_info(outputStream* st) {
772 // cpu
773 st->print("CPU:");
774 st->print("total %d", os::processor_count());
775 // It's not safe to query number of active processors after crash
776 // st->print("(active %d)", os::active_processor_count());
777 st->print(" %s", VM_Version::cpu_features());
778 st->cr();
779 pd_print_cpu_info(st);
780 }
781
782 void os::print_date_and_time(outputStream *st) {
783 time_t tloc;
784 (void)time(&tloc);
785 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
786
787 double t = os::elapsedTime();
788 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
789 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
790 // before printf. We lost some precision, but who cares?
791 st->print_cr("elapsed time: %d seconds", (int)t);
792 }
793
794 // moved from debug.cpp (used to be find()) but still called from there
795 // The verbose parameter is only set by the debug code in one case
796 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
797 address addr = (address)x;
798 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
799 if (b != NULL) {
800 if (b->is_buffer_blob()) {
801 // the interpreter is generated into a buffer blob
802 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
803 if (i != NULL) {
804 st->print_cr(INTPTR_FORMAT " is an Interpreter codelet", addr);
805 i->print_on(st);
806 return;
807 }
808 if (Interpreter::contains(addr)) {
809 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
810 " (not bytecode specific)", addr);
811 return;
812 }
813 //
814 if (AdapterHandlerLibrary::contains(b)) {
815 st->print_cr(INTPTR_FORMAT " is an AdapterHandler", addr);
816 AdapterHandlerLibrary::print_handler_on(st, b);
817 }
818 // the stubroutines are generated into a buffer blob
819 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
820 if (d != NULL) {
821 d->print_on(st);
822 if (verbose) st->cr();
823 return;
824 }
825 if (StubRoutines::contains(addr)) {
826 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
827 "stub routine", addr);
828 return;
829 }
830 // the InlineCacheBuffer is using stubs generated into a buffer blob
831 if (InlineCacheBuffer::contains(addr)) {
832 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
833 return;
834 }
835 VtableStub* v = VtableStubs::stub_containing(addr);
836 if (v != NULL) {
837 v->print_on(st);
838 return;
839 }
840 }
841 if (verbose && b->is_nmethod()) {
842 ResourceMark rm;
843 st->print("%#p: Compiled ", addr);
844 ((nmethod*)b)->method()->print_value_on(st);
845 st->print(" = (CodeBlob*)" INTPTR_FORMAT, b);
846 st->cr();
847 return;
848 }
849 st->print(INTPTR_FORMAT " ", b);
850 if ( b->is_nmethod()) {
851 if (b->is_zombie()) {
852 st->print_cr("is zombie nmethod");
853 } else if (b->is_not_entrant()) {
854 st->print_cr("is non-entrant nmethod");
855 }
856 }
857 b->print_on(st);
858 return;
859 }
860
861 if (Universe::heap()->is_in(addr)) {
862 HeapWord* p = Universe::heap()->block_start(addr);
863 bool print = false;
864 // If we couldn't find it it just may mean that heap wasn't parseable
865 // See if we were just given an oop directly
866 if (p != NULL && Universe::heap()->block_is_obj(p)) {
867 print = true;
868 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
869 p = (HeapWord*) addr;
870 print = true;
871 }
872 if (print) {
873 st->print_cr(INTPTR_FORMAT " is an oop", addr);
874 oop(p)->print_on(st);
875 if (p != (HeapWord*)x && oop(p)->is_constMethod() &&
876 constMethodOop(p)->contains(addr)) {
877 Thread *thread = Thread::current();
878 HandleMark hm(thread);
879 methodHandle mh (thread, constMethodOop(p)->method());
880 if (!mh->is_native()) {
881 st->print_cr("bci_from(%p) = %d; print_codes():",
882 addr, mh->bci_from(address(x)));
883 mh->print_codes_on(st);
884 }
885 }
886 return;
887 }
888 } else {
889 if (Universe::heap()->is_in_reserved(addr)) {
890 st->print_cr(INTPTR_FORMAT " is an unallocated location "
891 "in the heap", addr);
892 return;
893 }
894 }
895 if (JNIHandles::is_global_handle((jobject) addr)) {
896 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
897 return;
898 }
899 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
900 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
901 return;
902 }
903 #ifndef PRODUCT
904 // we don't keep the block list in product mode
905 if (JNIHandleBlock::any_contains((jobject) addr)) {
906 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
907 return;
908 }
909 #endif
910
911 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
912 // Check for privilege stack
913 if (thread->privileged_stack_top() != NULL &&
914 thread->privileged_stack_top()->contains(addr)) {
915 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
916 "for thread: " INTPTR_FORMAT, addr, thread);
917 if (verbose) thread->print_on(st);
918 return;
919 }
920 // If the addr is a java thread print information about that.
921 if (addr == (address)thread) {
922 if (verbose) {
923 thread->print_on(st);
924 } else {
925 st->print_cr(INTPTR_FORMAT " is a thread", addr);
926 }
927 return;
928 }
929 // If the addr is in the stack region for this thread then report that
930 // and print thread info
931 if (thread->stack_base() >= addr &&
932 addr > (thread->stack_base() - thread->stack_size())) {
933 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
934 INTPTR_FORMAT, addr, thread);
935 if (verbose) thread->print_on(st);
936 return;
937 }
938
939 }
940 // Try an OS specific find
941 if (os::find(addr, st)) {
942 return;
943 }
944
945 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
946 }
947
948 // Looks like all platforms except IA64 can use the same function to check
949 // if C stack is walkable beyond current frame. The check for fp() is not
950 // necessary on Sparc, but it's harmless.
951 bool os::is_first_C_frame(frame* fr) {
952 #ifdef IA64
953 // In order to walk native frames on Itanium, we need to access the unwind
954 // table, which is inside ELF. We don't want to parse ELF after fatal error,
955 // so return true for IA64. If we need to support C stack walking on IA64,
956 // this function needs to be moved to CPU specific files, as fp() on IA64
957 // is register stack, which grows towards higher memory address.
958 return true;
959 #endif
960
961 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
962 // Check usp first, because if that's bad the other accessors may fault
963 // on some architectures. Ditto ufp second, etc.
964 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
965 // sp on amd can be 32 bit aligned.
966 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
967
968 uintptr_t usp = (uintptr_t)fr->sp();
969 if ((usp & sp_align_mask) != 0) return true;
970
971 uintptr_t ufp = (uintptr_t)fr->fp();
972 if ((ufp & fp_align_mask) != 0) return true;
973
974 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
975 if ((old_sp & sp_align_mask) != 0) return true;
976 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
977
978 uintptr_t old_fp = (uintptr_t)fr->link();
979 if ((old_fp & fp_align_mask) != 0) return true;
980 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
981
982 // stack grows downwards; if old_fp is below current fp or if the stack
983 // frame is too large, either the stack is corrupted or fp is not saved
984 // on stack (i.e. on x86, ebp may be used as general register). The stack
985 // is not walkable beyond current frame.
986 if (old_fp < ufp) return true;
987 if (old_fp - ufp > 64 * K) return true;
988
989 return false;
990 }
991
992 #ifdef ASSERT
993 extern "C" void test_random() {
994 const double m = 2147483647;
995 double mean = 0.0, variance = 0.0, t;
996 long reps = 10000;
997 unsigned long seed = 1;
998
999 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1000 os::init_random(seed);
1001 long num;
1002 for (int k = 0; k < reps; k++) {
1003 num = os::random();
1004 double u = (double)num / m;
1005 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1006
1007 // calculate mean and variance of the random sequence
1008 mean += u;
1009 variance += (u*u);
1010 }
1011 mean /= reps;
1012 variance /= (reps - 1);
1013
1014 assert(num == 1043618065, "bad seed");
1015 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1016 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1017 const double eps = 0.0001;
1018 t = fabsd(mean - 0.5018);
1019 assert(t < eps, "bad mean");
1020 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1021 assert(t < eps, "bad variance");
1022 }
1023 #endif
1024
1025
1026 // Set up the boot classpath.
1027
1028 char* os::format_boot_path(const char* format_string,
1029 const char* home,
1030 int home_len,
1031 char fileSep,
1032 char pathSep) {
1033 assert((fileSep == '/' && pathSep == ':') ||
1034 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1035
1036 // Scan the format string to determine the length of the actual
1037 // boot classpath, and handle platform dependencies as well.
1038 int formatted_path_len = 0;
1039 const char* p;
1040 for (p = format_string; *p != 0; ++p) {
1041 if (*p == '%') formatted_path_len += home_len - 1;
1042 ++formatted_path_len;
1043 }
1044
1045 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1);
1046 if (formatted_path == NULL) {
1047 return NULL;
1048 }
1049
1050 // Create boot classpath from format, substituting separator chars and
1051 // java home directory.
1052 char* q = formatted_path;
1053 for (p = format_string; *p != 0; ++p) {
1054 switch (*p) {
1055 case '%':
1056 strcpy(q, home);
1057 q += home_len;
1058 break;
1059 case '/':
1060 *q++ = fileSep;
1061 break;
1062 case ':':
1063 *q++ = pathSep;
1064 break;
1065 default:
1066 *q++ = *p;
1067 }
1068 }
1069 *q = '\0';
1070
1071 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1072 return formatted_path;
1073 }
1074
1075
1076 bool os::set_boot_path(char fileSep, char pathSep) {
1077 const char* home = Arguments::get_java_home();
1078 int home_len = (int)strlen(home);
1079
1080 static const char* meta_index_dir_format = "%/lib/";
1081 static const char* meta_index_format = "%/lib/meta-index";
1082 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1083 if (meta_index == NULL) return false;
1084 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1085 if (meta_index_dir == NULL) return false;
1086 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1087
1088 // Any modification to the JAR-file list, for the boot classpath must be
1089 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1090 // path class JARs, are stripped for StackMapTable to reduce download size.
1091 static const char classpath_format[] =
1092 "%/lib/resources.jar:"
1093 "%/lib/rt.jar:"
1094 "%/lib/sunrsasign.jar:"
1095 "%/lib/jsse.jar:"
1096 "%/lib/jce.jar:"
1097 "%/lib/charsets.jar:"
1098 "%/classes";
1099 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1100 if (sysclasspath == NULL) return false;
1101 Arguments::set_sysclasspath(sysclasspath);
1102
1103 return true;
1104 }
1105
1106 /*
1107 * Splits a path, based on its separator, the number of
1108 * elements is returned back in n.
1109 * It is the callers responsibility to:
1110 * a> check the value of n, and n may be 0.
1111 * b> ignore any empty path elements
1112 * c> free up the data.
1113 */
1114 char** os::split_path(const char* path, int* n) {
1115 *n = 0;
1116 if (path == NULL || strlen(path) == 0) {
1117 return NULL;
1118 }
1119 const char psepchar = *os::path_separator();
1120 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1);
1121 if (inpath == NULL) {
1122 return NULL;
1123 }
1124 strncpy(inpath, path, strlen(path));
1125 int count = 1;
1126 char* p = strchr(inpath, psepchar);
1127 // Get a count of elements to allocate memory
1128 while (p != NULL) {
1129 count++;
1130 p++;
1131 p = strchr(p, psepchar);
1132 }
1133 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count);
1134 if (opath == NULL) {
1135 return NULL;
1136 }
1137
1138 // do the actual splitting
1139 p = inpath;
1140 for (int i = 0 ; i < count ; i++) {
1141 size_t len = strcspn(p, os::path_separator());
1142 if (len > JVM_MAXPATHLEN) {
1143 return NULL;
1144 }
1145 // allocate the string and add terminator storage
1146 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1);
1147 if (s == NULL) {
1148 return NULL;
1149 }
1150 strncpy(s, p, len);
1151 s[len] = '\0';
1152 opath[i] = s;
1153 p += len + 1;
1154 }
1155 FREE_C_HEAP_ARRAY(char, inpath);
1156 *n = count;
1157 return opath;
1158 }
1159
1160 void os::set_memory_serialize_page(address page) {
1161 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1162 _mem_serialize_page = (volatile int32_t *)page;
1163 // We initialize the serialization page shift count here
1164 // We assume a cache line size of 64 bytes
1165 assert(SerializePageShiftCount == count,
1166 "thread size changed, fix SerializePageShiftCount constant");
1167 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1168 }
1169
1170 static volatile intptr_t SerializePageLock = 0;
1171
1172 // This method is called from signal handler when SIGSEGV occurs while the current
1173 // thread tries to store to the "read-only" memory serialize page during state
1174 // transition.
1175 void os::block_on_serialize_page_trap() {
1176 if (TraceSafepoint) {
1177 tty->print_cr("Block until the serialize page permission restored");
1178 }
1179 // When VMThread is holding the SerializePageLock during modifying the
1180 // access permission of the memory serialize page, the following call
1181 // will block until the permission of that page is restored to rw.
1182 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1183 // this case, it's OK as the signal is synchronous and we know precisely when
1184 // it can occur.
1185 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1186 Thread::muxRelease(&SerializePageLock);
1187 }
1188
1189 // Serialize all thread state variables
1190 void os::serialize_thread_states() {
1191 // On some platforms such as Solaris & Linux, the time duration of the page
1192 // permission restoration is observed to be much longer than expected due to
1193 // scheduler starvation problem etc. To avoid the long synchronization
1194 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1195 // the mutator thread if such case is encountered. See bug 6546278 for details.
1196 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1197 os::protect_memory((char *)os::get_memory_serialize_page(),
1198 os::vm_page_size(), MEM_PROT_READ);
1199 os::protect_memory((char *)os::get_memory_serialize_page(),
1200 os::vm_page_size(), MEM_PROT_RW);
1201 Thread::muxRelease(&SerializePageLock);
1202 }
1203
1204 // Returns true if the current stack pointer is above the stack shadow
1205 // pages, false otherwise.
1206
1207 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1208 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1209 address sp = current_stack_pointer();
1210 // Check if we have StackShadowPages above the yellow zone. This parameter
1211 // is dependent on the depth of the maximum VM call stack possible from
1212 // the handler for stack overflow. 'instanceof' in the stack overflow
1213 // handler or a println uses at least 8k stack of VM and native code
1214 // respectively.
1215 const int framesize_in_bytes =
1216 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1217 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1218 * vm_page_size()) + framesize_in_bytes;
1219 // The very lower end of the stack
1220 address stack_limit = thread->stack_base() - thread->stack_size();
1221 return (sp > (stack_limit + reserved_area));
1222 }
1223
1224 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1225 uint min_pages)
1226 {
1227 assert(min_pages > 0, "sanity");
1228 if (UseLargePages) {
1229 const size_t max_page_size = region_max_size / min_pages;
1230
1231 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1232 const size_t sz = _page_sizes[i];
1233 const size_t mask = sz - 1;
1234 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1235 // The largest page size with no fragmentation.
1236 return sz;
1237 }
1238
1239 if (sz <= max_page_size) {
1240 // The largest page size that satisfies the min_pages requirement.
1241 return sz;
1242 }
1243 }
1244 }
1245
1246 return vm_page_size();
1247 }
1248
1249 #ifndef PRODUCT
1250 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1251 {
1252 if (TracePageSizes) {
1253 tty->print("%s: ", str);
1254 for (int i = 0; i < count; ++i) {
1255 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1256 }
1257 tty->cr();
1258 }
1259 }
1260
1261 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1262 const size_t region_max_size, const size_t page_size,
1263 const char* base, const size_t size)
1264 {
1265 if (TracePageSizes) {
1266 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1267 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1268 " size=" SIZE_FORMAT,
1269 str, region_min_size, region_max_size,
1270 page_size, base, size);
1271 }
1272 }
1273 #endif // #ifndef PRODUCT
1274
1275 // This is the working definition of a server class machine:
1276 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1277 // because the graphics memory (?) sometimes masks physical memory.
1278 // If you want to change the definition of a server class machine
1279 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1280 // then you'll have to parameterize this method based on that state,
1281 // as was done for logical processors here, or replicate and
1282 // specialize this method for each platform. (Or fix os to have
1283 // some inheritance structure and use subclassing. Sigh.)
1284 // If you want some platform to always or never behave as a server
1285 // class machine, change the setting of AlwaysActAsServerClassMachine
1286 // and NeverActAsServerClassMachine in globals*.hpp.
1287 bool os::is_server_class_machine() {
1288 // First check for the early returns
1289 if (NeverActAsServerClassMachine) {
1290 return false;
1291 }
1292 if (AlwaysActAsServerClassMachine) {
1293 return true;
1294 }
1295 // Then actually look at the machine
1296 bool result = false;
1297 const unsigned int server_processors = 2;
1298 const julong server_memory = 2UL * G;
1299 // We seem not to get our full complement of memory.
1300 // We allow some part (1/8?) of the memory to be "missing",
1301 // based on the sizes of DIMMs, and maybe graphics cards.
1302 const julong missing_memory = 256UL * M;
1303
1304 /* Is this a server class machine? */
1305 if ((os::active_processor_count() >= (int)server_processors) &&
1306 (os::physical_memory() >= (server_memory - missing_memory))) {
1307 const unsigned int logical_processors =
1308 VM_Version::logical_processors_per_package();
1309 if (logical_processors > 1) {
1310 const unsigned int physical_packages =
1311 os::active_processor_count() / logical_processors;
1312 if (physical_packages > server_processors) {
1313 result = true;
1314 }
1315 } else {
1316 result = true;
1317 }
1318 }
1319 return result;
1320 }
1321
1322 // Read file line by line, if line is longer than bsize,
1323 // skip rest of line.
1324 int os::get_line_chars(int fd, char* buf, const size_t bsize){
1325 size_t sz, i = 0;
1326
1327 // read until EOF, EOL or buf is full
1328 while ((sz = (int) read(fd, &buf[i], 1)) == 1 && i < (bsize-2) && buf[i] != '\n') {
1329 ++i;
1330 }
1331
1332 if (buf[i] == '\n') {
1333 // EOL reached so ignore EOL character and return
1334
1335 buf[i] = 0;
1336 return (int) i;
1337 }
1338
1339 buf[i+1] = 0;
1340
1341 if (sz != 1) {
1342 // EOF reached. if we read chars before EOF return them and
1343 // return EOF on next call otherwise return EOF
1344
1345 return (i == 0) ? -1 : (int) i;
1346 }
1347
1348 // line is longer than size of buf, skip to EOL
1349 char ch;
1350 while (read(fd, &ch, 1) == 1 && ch != '\n') {
1351 // Do nothing
1352 }
1353
1354 // return initial part of line that fits in buf.
1355 // If we reached EOF, it will be returned on next call.
1356
1357 return (int) i;
1358 }