1 /*
2 * Copyright (c) 1997, 2013, 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 "runtime/thread.inline.hpp"
48 #include "services/attachListener.hpp"
49 #include "services/memTracker.hpp"
50 #include "services/threadService.hpp"
51 #include "utilities/defaultStream.hpp"
52 #include "utilities/events.hpp"
53 #ifdef TARGET_OS_FAMILY_linux
54 # include "os_linux.inline.hpp"
55 #endif
56 #ifdef TARGET_OS_FAMILY_solaris
57 # include "os_solaris.inline.hpp"
58 #endif
59 #ifdef TARGET_OS_FAMILY_windows
60 # include "os_windows.inline.hpp"
61 #endif
62 #ifdef TARGET_OS_FAMILY_bsd
63 # include "os_bsd.inline.hpp"
64 #endif
65
66 # include <signal.h>
67
68 OSThread* os::_starting_thread = NULL;
69 address os::_polling_page = NULL;
70 volatile int32_t* os::_mem_serialize_page = NULL;
71 uintptr_t os::_serialize_page_mask = 0;
72 long os::_rand_seed = 1;
73 int os::_processor_count = 0;
74 size_t os::_page_sizes[os::page_sizes_max];
75
76 #ifndef PRODUCT
77 julong os::num_mallocs = 0; // # of calls to malloc/realloc
78 julong os::alloc_bytes = 0; // # of bytes allocated
79 julong os::num_frees = 0; // # of calls to free
80 julong os::free_bytes = 0; // # of bytes freed
81 #endif
82
83 static juint cur_malloc_words = 0; // current size for MallocMaxTestWords
84
85 void os_init_globals() {
86 // Called from init_globals().
87 // See Threads::create_vm() in thread.cpp, and init.cpp.
88 os::init_globals();
89 }
90
91 // Fill in buffer with current local time as an ISO-8601 string.
92 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
93 // Returns buffer, or NULL if it failed.
94 // This would mostly be a call to
95 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
96 // except that on Windows the %z behaves badly, so we do it ourselves.
97 // Also, people wanted milliseconds on there,
98 // and strftime doesn't do milliseconds.
99 char* os::iso8601_time(char* buffer, size_t buffer_length) {
100 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
101 // 1 2
102 // 12345678901234567890123456789
103 static const char* iso8601_format =
104 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d";
105 static const size_t needed_buffer = 29;
106
107 // Sanity check the arguments
108 if (buffer == NULL) {
109 assert(false, "NULL buffer");
110 return NULL;
111 }
112 if (buffer_length < needed_buffer) {
113 assert(false, "buffer_length too small");
114 return NULL;
115 }
116 // Get the current time
117 jlong milliseconds_since_19700101 = javaTimeMillis();
118 const int milliseconds_per_microsecond = 1000;
119 const time_t seconds_since_19700101 =
120 milliseconds_since_19700101 / milliseconds_per_microsecond;
121 const int milliseconds_after_second =
122 milliseconds_since_19700101 % milliseconds_per_microsecond;
123 // Convert the time value to a tm and timezone variable
124 struct tm time_struct;
125 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
126 assert(false, "Failed localtime_pd");
127 return NULL;
128 }
129 #if defined(_ALLBSD_SOURCE)
130 const time_t zone = (time_t) time_struct.tm_gmtoff;
131 #else
132 const time_t zone = timezone;
133 #endif
134
135 // If daylight savings time is in effect,
136 // we are 1 hour East of our time zone
137 const time_t seconds_per_minute = 60;
138 const time_t minutes_per_hour = 60;
139 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
140 time_t UTC_to_local = zone;
141 if (time_struct.tm_isdst > 0) {
142 UTC_to_local = UTC_to_local - seconds_per_hour;
143 }
144 // Compute the time zone offset.
145 // localtime_pd() sets timezone to the difference (in seconds)
146 // between UTC and and local time.
147 // ISO 8601 says we need the difference between local time and UTC,
148 // we change the sign of the localtime_pd() result.
149 const time_t local_to_UTC = -(UTC_to_local);
150 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
151 char sign_local_to_UTC = '+';
152 time_t abs_local_to_UTC = local_to_UTC;
153 if (local_to_UTC < 0) {
154 sign_local_to_UTC = '-';
155 abs_local_to_UTC = -(abs_local_to_UTC);
156 }
157 // Convert time zone offset seconds to hours and minutes.
158 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
159 const time_t zone_min =
160 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
161
162 // Print an ISO 8601 date and time stamp into the buffer
163 const int year = 1900 + time_struct.tm_year;
164 const int month = 1 + time_struct.tm_mon;
165 const int printed = jio_snprintf(buffer, buffer_length, iso8601_format,
166 year,
167 month,
168 time_struct.tm_mday,
169 time_struct.tm_hour,
170 time_struct.tm_min,
171 time_struct.tm_sec,
172 milliseconds_after_second,
173 sign_local_to_UTC,
174 zone_hours,
175 zone_min);
176 if (printed == 0) {
177 assert(false, "Failed jio_printf");
178 return NULL;
179 }
180 return buffer;
181 }
182
183 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
184 #ifdef ASSERT
185 if (!(!thread->is_Java_thread() ||
186 Thread::current() == thread ||
187 Threads_lock->owned_by_self()
188 || thread->is_Compiler_thread()
189 )) {
190 assert(false, "possibility of dangling Thread pointer");
191 }
192 #endif
193
194 if (p >= MinPriority && p <= MaxPriority) {
195 int priority = java_to_os_priority[p];
196 return set_native_priority(thread, priority);
197 } else {
198 assert(false, "Should not happen");
199 return OS_ERR;
200 }
201 }
202
203 // The mapping from OS priority back to Java priority may be inexact because
204 // Java priorities can map M:1 with native priorities. If you want the definite
205 // Java priority then use JavaThread::java_priority()
206 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
207 int p;
208 int os_prio;
209 OSReturn ret = get_native_priority(thread, &os_prio);
210 if (ret != OS_OK) return ret;
211
212 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
213 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
214 } else {
215 // niceness values are in reverse order
216 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
217 }
218 priority = (ThreadPriority)p;
219 return OS_OK;
220 }
221
222
223 // --------------------- sun.misc.Signal (optional) ---------------------
224
225
226 // SIGBREAK is sent by the keyboard to query the VM state
227 #ifndef SIGBREAK
228 #define SIGBREAK SIGQUIT
229 #endif
230
231 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
232
233
234 static void signal_thread_entry(JavaThread* thread, TRAPS) {
235 os::set_priority(thread, NearMaxPriority);
236 while (true) {
237 int sig;
238 {
239 // FIXME : Currently we have not decided what should be the status
240 // for this java thread blocked here. Once we decide about
241 // that we should fix this.
242 sig = os::signal_wait();
243 }
244 if (sig == os::sigexitnum_pd()) {
245 // Terminate the signal thread
246 return;
247 }
248
249 switch (sig) {
250 case SIGBREAK: {
251 // Check if the signal is a trigger to start the Attach Listener - in that
252 // case don't print stack traces.
253 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
254 continue;
255 }
256 // Print stack traces
257 // Any SIGBREAK operations added here should make sure to flush
258 // the output stream (e.g. tty->flush()) after output. See 4803766.
259 // Each module also prints an extra carriage return after its output.
260 VM_PrintThreads op;
261 VMThread::execute(&op);
262 VM_PrintJNI jni_op;
263 VMThread::execute(&jni_op);
264 VM_FindDeadlocks op1(tty);
265 VMThread::execute(&op1);
266 Universe::print_heap_at_SIGBREAK();
267 if (PrintClassHistogram) {
268 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */);
269 VMThread::execute(&op1);
270 }
271 if (JvmtiExport::should_post_data_dump()) {
272 JvmtiExport::post_data_dump();
273 }
274 break;
275 }
276 default: {
277 // Dispatch the signal to java
278 HandleMark hm(THREAD);
279 Klass* k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
280 KlassHandle klass (THREAD, k);
281 if (klass.not_null()) {
282 JavaValue result(T_VOID);
283 JavaCallArguments args;
284 args.push_int(sig);
285 JavaCalls::call_static(
286 &result,
287 klass,
288 vmSymbols::dispatch_name(),
289 vmSymbols::int_void_signature(),
290 &args,
291 THREAD
292 );
293 }
294 if (HAS_PENDING_EXCEPTION) {
295 // tty is initialized early so we don't expect it to be null, but
296 // if it is we can't risk doing an initialization that might
297 // trigger additional out-of-memory conditions
298 if (tty != NULL) {
299 char klass_name[256];
300 char tmp_sig_name[16];
301 const char* sig_name = "UNKNOWN";
302 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
303 name()->as_klass_external_name(klass_name, 256);
304 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
305 sig_name = tmp_sig_name;
306 warning("Exception %s occurred dispatching signal %s to handler"
307 "- the VM may need to be forcibly terminated",
308 klass_name, sig_name );
309 }
310 CLEAR_PENDING_EXCEPTION;
311 }
312 }
313 }
314 }
315 }
316
317 void os::init_before_ergo() {
318 // We need to initialize large page support here because ergonomics takes some
319 // decisions depending on large page support and the calculated large page size.
320 large_page_init();
321 }
322
323 void os::signal_init() {
324 if (!ReduceSignalUsage) {
325 // Setup JavaThread for processing signals
326 EXCEPTION_MARK;
327 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
328 instanceKlassHandle klass (THREAD, k);
329 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
330
331 const char thread_name[] = "Signal Dispatcher";
332 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
333
334 // Initialize thread_oop to put it into the system threadGroup
335 Handle thread_group (THREAD, Universe::system_thread_group());
336 JavaValue result(T_VOID);
337 JavaCalls::call_special(&result, thread_oop,
338 klass,
339 vmSymbols::object_initializer_name(),
340 vmSymbols::threadgroup_string_void_signature(),
341 thread_group,
342 string,
343 CHECK);
344
345 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
346 JavaCalls::call_special(&result,
347 thread_group,
348 group,
349 vmSymbols::add_method_name(),
350 vmSymbols::thread_void_signature(),
351 thread_oop, // ARG 1
352 CHECK);
353
354 os::signal_init_pd();
355
356 { MutexLocker mu(Threads_lock);
357 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
358
359 // At this point it may be possible that no osthread was created for the
360 // JavaThread due to lack of memory. We would have to throw an exception
361 // in that case. However, since this must work and we do not allow
362 // exceptions anyway, check and abort if this fails.
363 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
364 vm_exit_during_initialization("java.lang.OutOfMemoryError",
365 os::native_thread_creation_failed_msg());
366 }
367
368 java_lang_Thread::set_thread(thread_oop(), signal_thread);
369 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
370 java_lang_Thread::set_daemon(thread_oop());
371
372 signal_thread->set_threadObj(thread_oop());
373 Threads::add(signal_thread);
374 Thread::start(signal_thread);
375 }
376 // Handle ^BREAK
377 os::signal(SIGBREAK, os::user_handler());
378 }
379 }
380
381
382 void os::terminate_signal_thread() {
383 if (!ReduceSignalUsage)
384 signal_notify(sigexitnum_pd());
385 }
386
387
388 // --------------------- loading libraries ---------------------
389
390 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
391 extern struct JavaVM_ main_vm;
392
393 static void* _native_java_library = NULL;
394
395 void* os::native_java_library() {
396 if (_native_java_library == NULL) {
397 char buffer[JVM_MAXPATHLEN];
398 char ebuf[1024];
399
400 // Try to load verify dll first. In 1.3 java dll depends on it and is not
401 // always able to find it when the loading executable is outside the JDK.
402 // In order to keep working with 1.2 we ignore any loading errors.
403 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
404 "verify")) {
405 dll_load(buffer, ebuf, sizeof(ebuf));
406 }
407
408 // Load java dll
409 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
410 "java")) {
411 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
412 }
413 if (_native_java_library == NULL) {
414 vm_exit_during_initialization("Unable to load native library", ebuf);
415 }
416
417 #if defined(__OpenBSD__)
418 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
419 // ignore errors
420 if (dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(),
421 "net")) {
422 dll_load(buffer, ebuf, sizeof(ebuf));
423 }
424 #endif
425 }
426 static jboolean onLoaded = JNI_FALSE;
427 if (onLoaded) {
428 // We may have to wait to fire OnLoad until TLS is initialized.
429 if (ThreadLocalStorage::is_initialized()) {
430 // The JNI_OnLoad handling is normally done by method load in
431 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
432 // explicitly so we have to check for JNI_OnLoad as well
433 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
434 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
435 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
436 if (JNI_OnLoad != NULL) {
437 JavaThread* thread = JavaThread::current();
438 ThreadToNativeFromVM ttn(thread);
439 HandleMark hm(thread);
440 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
441 onLoaded = JNI_TRUE;
442 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
443 vm_exit_during_initialization("Unsupported JNI version");
444 }
445 }
446 }
447 }
448 return _native_java_library;
449 }
450
451 /*
452 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
453 * If check_lib == true then we are looking for an
454 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
455 * this library is statically linked into the image.
456 * If check_lib == false then we will look for the appropriate symbol in the
457 * executable if agent_lib->is_static_lib() == true or in the shared library
458 * referenced by 'handle'.
459 */
460 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
461 const char *syms[], size_t syms_len) {
462 assert(agent_lib != NULL, "sanity check");
463 const char *lib_name;
464 void *handle = agent_lib->os_lib();
465 void *entryName = NULL;
466 char *agent_function_name;
467 size_t i;
468
469 // If checking then use the agent name otherwise test is_static_lib() to
470 // see how to process this lookup
471 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
472 for (i = 0; i < syms_len; i++) {
473 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
474 if (agent_function_name == NULL) {
475 break;
476 }
477 entryName = dll_lookup(handle, agent_function_name);
478 FREE_C_HEAP_ARRAY(char, agent_function_name, mtThread);
479 if (entryName != NULL) {
480 break;
481 }
482 }
483 return entryName;
484 }
485
486 // See if the passed in agent is statically linked into the VM image.
487 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
488 size_t syms_len) {
489 void *ret;
490 void *proc_handle;
491 void *save_handle;
492
493 assert(agent_lib != NULL, "sanity check");
494 if (agent_lib->name() == NULL) {
495 return false;
496 }
497 proc_handle = get_default_process_handle();
498 // Check for Agent_OnLoad/Attach_lib_name function
499 save_handle = agent_lib->os_lib();
500 // We want to look in this process' symbol table.
501 agent_lib->set_os_lib(proc_handle);
502 ret = find_agent_function(agent_lib, true, syms, syms_len);
503 if (ret != NULL) {
504 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
505 agent_lib->set_valid();
506 agent_lib->set_static_lib(true);
507 return true;
508 }
509 agent_lib->set_os_lib(save_handle);
510 return false;
511 }
512
513 // --------------------- heap allocation utilities ---------------------
514
515 char *os::strdup(const char *str, MEMFLAGS flags) {
516 size_t size = strlen(str);
517 char *dup_str = (char *)malloc(size + 1, flags);
518 if (dup_str == NULL) return NULL;
519 strcpy(dup_str, str);
520 return dup_str;
521 }
522
523
524
525 #ifdef ASSERT
526 #define space_before (MallocCushion + sizeof(double))
527 #define space_after MallocCushion
528 #define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t))
529 #define size_addr_from_obj(p) ((size_t*)p - 1)
530 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
531 // NB: cannot be debug variable, because these aren't set from the command line until
532 // *after* the first few allocs already happened
533 #define MallocCushion 16
534 #else
535 #define space_before 0
536 #define space_after 0
537 #define size_addr_from_base(p) should not use w/o ASSERT
538 #define size_addr_from_obj(p) should not use w/o ASSERT
539 #define MallocCushion 0
540 #endif
541 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
542
543 #ifdef ASSERT
544 inline size_t get_size(void* obj) {
545 size_t size = *size_addr_from_obj(obj);
546 if (size < 0) {
547 fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten ("
548 SIZE_FORMAT ")", obj, size));
549 }
550 return size;
551 }
552
553 u_char* find_cushion_backwards(u_char* start) {
554 u_char* p = start;
555 while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
556 p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
557 // ok, we have four consecutive marker bytes; find start
558 u_char* q = p - 4;
559 while (*q == badResourceValue) q--;
560 return q + 1;
561 }
562
563 u_char* find_cushion_forwards(u_char* start) {
564 u_char* p = start;
565 while (p[0] != badResourceValue || p[1] != badResourceValue ||
566 p[2] != badResourceValue || p[3] != badResourceValue) p++;
567 // ok, we have four consecutive marker bytes; find end of cushion
568 u_char* q = p + 4;
569 while (*q == badResourceValue) q++;
570 return q - MallocCushion;
571 }
572
573 void print_neighbor_blocks(void* ptr) {
574 // find block allocated before ptr (not entirely crash-proof)
575 if (MallocCushion < 4) {
576 tty->print_cr("### cannot find previous block (MallocCushion < 4)");
577 return;
578 }
579 u_char* start_of_this_block = (u_char*)ptr - space_before;
580 u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
581 // look for cushion in front of prev. block
582 u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
583 ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
584 u_char* obj = start_of_prev_block + space_before;
585 if (size <= 0 ) {
586 // start is bad; may have been confused by OS data in between objects
587 // search one more backwards
588 start_of_prev_block = find_cushion_backwards(start_of_prev_block);
589 size = *size_addr_from_base(start_of_prev_block);
590 obj = start_of_prev_block + space_before;
591 }
592
593 if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
594 tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
595 } else {
596 tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
597 }
598
599 // now find successor block
600 u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
601 start_of_next_block = find_cushion_forwards(start_of_next_block);
602 u_char* next_obj = start_of_next_block + space_before;
603 ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
604 if (start_of_next_block[0] == badResourceValue &&
605 start_of_next_block[1] == badResourceValue &&
606 start_of_next_block[2] == badResourceValue &&
607 start_of_next_block[3] == badResourceValue) {
608 tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
609 } else {
610 tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
611 }
612 }
613
614
615 void report_heap_error(void* memblock, void* bad, const char* where) {
616 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
617 tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock);
618 print_neighbor_blocks(memblock);
619 fatal("memory stomping error");
620 }
621
622 void verify_block(void* memblock) {
623 size_t size = get_size(memblock);
624 if (MallocCushion) {
625 u_char* ptr = (u_char*)memblock - space_before;
626 for (int i = 0; i < MallocCushion; i++) {
627 if (ptr[i] != badResourceValue) {
628 report_heap_error(memblock, ptr+i, "in front of");
629 }
630 }
631 u_char* end = (u_char*)memblock + size + space_after;
632 for (int j = -MallocCushion; j < 0; j++) {
633 if (end[j] != badResourceValue) {
634 report_heap_error(memblock, end+j, "after");
635 }
636 }
637 }
638 }
639 #endif
640
641 //
642 // This function supports testing of the malloc out of memory
643 // condition without really running the system out of memory.
644 //
645 static u_char* testMalloc(size_t alloc_size) {
646 assert(MallocMaxTestWords > 0, "sanity check");
647
648 if ((cur_malloc_words + (alloc_size / BytesPerWord)) > MallocMaxTestWords) {
649 return NULL;
650 }
651
652 u_char* ptr = (u_char*)::malloc(alloc_size);
653
654 if (ptr != NULL) {
655 Atomic::add(((jint) (alloc_size / BytesPerWord)),
656 (volatile jint *) &cur_malloc_words);
657 }
658 return ptr;
659 }
660
661 void* os::malloc(size_t size, MEMFLAGS memflags, address caller) {
662 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
663 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
664
665 #ifdef ASSERT
666 // checking for the WatcherThread and crash_protection first
667 // since os::malloc can be called when the libjvm.{dll,so} is
668 // first loaded and we don't have a thread yet.
669 // try to find the thread after we see that the watcher thread
670 // exists and has crash protection.
671 WatcherThread *wt = WatcherThread::watcher_thread();
672 if (wt != NULL && wt->has_crash_protection()) {
673 Thread* thread = ThreadLocalStorage::get_thread_slow();
674 if (thread == wt) {
675 assert(!wt->has_crash_protection(),
676 "Can't malloc with crash protection from WatcherThread");
677 }
678 }
679 #endif
680
681 if (size == 0) {
682 // return a valid pointer if size is zero
683 // if NULL is returned the calling functions assume out of memory.
684 size = 1;
685 }
686
687 const size_t alloc_size = size + space_before + space_after;
688
689 if (size > alloc_size) { // Check for rollover.
690 return NULL;
691 }
692
693 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
694
695 u_char* ptr;
696
697 if (MallocMaxTestWords > 0) {
698 ptr = testMalloc(alloc_size);
699 } else {
700 ptr = (u_char*)::malloc(alloc_size);
701 }
702
703 #ifdef ASSERT
704 if (ptr == NULL) return NULL;
705 if (MallocCushion) {
706 for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
707 u_char* end = ptr + space_before + size;
708 for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
709 for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
710 }
711 // put size just before data
712 *size_addr_from_base(ptr) = size;
713 #endif
714 u_char* memblock = ptr + space_before;
715 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
716 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
717 breakpoint();
718 }
719 debug_only(if (paranoid) verify_block(memblock));
720 if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
721
722 // we do not track MallocCushion memory
723 MemTracker::record_malloc((address)memblock, size, memflags, caller == 0 ? CALLER_PC : caller);
724
725 return memblock;
726 }
727
728
729 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, address caller) {
730 #ifndef ASSERT
731 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
732 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
733 MemTracker::Tracker tkr = MemTracker::get_realloc_tracker();
734 void* ptr = ::realloc(memblock, size);
735 if (ptr != NULL) {
736 tkr.record((address)memblock, (address)ptr, size, memflags,
737 caller == 0 ? CALLER_PC : caller);
738 } else {
739 tkr.discard();
740 }
741 return ptr;
742 #else
743 if (memblock == NULL) {
744 return malloc(size, memflags, (caller == 0 ? CALLER_PC : caller));
745 }
746 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
747 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
748 breakpoint();
749 }
750 verify_block(memblock);
751 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
752 if (size == 0) return NULL;
753 // always move the block
754 void* ptr = malloc(size, memflags, caller == 0 ? CALLER_PC : caller);
755 if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
756 // Copy to new memory if malloc didn't fail
757 if ( ptr != NULL ) {
758 memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
759 if (paranoid) verify_block(ptr);
760 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
761 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
762 breakpoint();
763 }
764 free(memblock);
765 }
766 return ptr;
767 #endif
768 }
769
770
771 void os::free(void *memblock, MEMFLAGS memflags) {
772 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
773 #ifdef ASSERT
774 if (memblock == NULL) return;
775 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
776 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
777 breakpoint();
778 }
779 verify_block(memblock);
780 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
781 // Added by detlefs.
782 if (MallocCushion) {
783 u_char* ptr = (u_char*)memblock - space_before;
784 for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
785 guarantee(*p == badResourceValue,
786 "Thing freed should be malloc result.");
787 *p = (u_char)freeBlockPad;
788 }
789 size_t size = get_size(memblock);
790 inc_stat_counter(&free_bytes, size);
791 u_char* end = ptr + space_before + size;
792 for (u_char* q = end; q < end + MallocCushion; q++) {
793 guarantee(*q == badResourceValue,
794 "Thing freed should be malloc result.");
795 *q = (u_char)freeBlockPad;
796 }
797 if (PrintMalloc && tty != NULL)
798 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
799 } else if (PrintMalloc && tty != NULL) {
800 // tty->print_cr("os::free %p", memblock);
801 fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock);
802 }
803 #endif
804 MemTracker::record_free((address)memblock, memflags);
805
806 ::free((char*)memblock - space_before);
807 }
808
809 void os::init_random(long initval) {
810 _rand_seed = initval;
811 }
812
813
814 long os::random() {
815 /* standard, well-known linear congruential random generator with
816 * next_rand = (16807*seed) mod (2**31-1)
817 * see
818 * (1) "Random Number Generators: Good Ones Are Hard to Find",
819 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
820 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
821 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
822 */
823 const long a = 16807;
824 const unsigned long m = 2147483647;
825 const long q = m / a; assert(q == 127773, "weird math");
826 const long r = m % a; assert(r == 2836, "weird math");
827
828 // compute az=2^31p+q
829 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
830 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
831 lo += (hi & 0x7FFF) << 16;
832
833 // if q overflowed, ignore the overflow and increment q
834 if (lo > m) {
835 lo &= m;
836 ++lo;
837 }
838 lo += hi >> 15;
839
840 // if (p+q) overflowed, ignore the overflow and increment (p+q)
841 if (lo > m) {
842 lo &= m;
843 ++lo;
844 }
845 return (_rand_seed = lo);
846 }
847
848 // The INITIALIZED state is distinguished from the SUSPENDED state because the
849 // conditions in which a thread is first started are different from those in which
850 // a suspension is resumed. These differences make it hard for us to apply the
851 // tougher checks when starting threads that we want to do when resuming them.
852 // However, when start_thread is called as a result of Thread.start, on a Java
853 // thread, the operation is synchronized on the Java Thread object. So there
854 // cannot be a race to start the thread and hence for the thread to exit while
855 // we are working on it. Non-Java threads that start Java threads either have
856 // to do so in a context in which races are impossible, or should do appropriate
857 // locking.
858
859 void os::start_thread(Thread* thread) {
860 // guard suspend/resume
861 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
862 OSThread* osthread = thread->osthread();
863 osthread->set_state(RUNNABLE);
864 pd_start_thread(thread);
865 }
866
867 //---------------------------------------------------------------------------
868 // Helper functions for fatal error handler
869
870 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
871 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
872
873 int cols = 0;
874 int cols_per_line = 0;
875 switch (unitsize) {
876 case 1: cols_per_line = 16; break;
877 case 2: cols_per_line = 8; break;
878 case 4: cols_per_line = 4; break;
879 case 8: cols_per_line = 2; break;
880 default: return;
881 }
882
883 address p = start;
884 st->print(PTR_FORMAT ": ", start);
885 while (p < end) {
886 switch (unitsize) {
887 case 1: st->print("%02x", *(u1*)p); break;
888 case 2: st->print("%04x", *(u2*)p); break;
889 case 4: st->print("%08x", *(u4*)p); break;
890 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
891 }
892 p += unitsize;
893 cols++;
894 if (cols >= cols_per_line && p < end) {
895 cols = 0;
896 st->cr();
897 st->print(PTR_FORMAT ": ", p);
898 } else {
899 st->print(" ");
900 }
901 }
902 st->cr();
903 }
904
905 void os::print_environment_variables(outputStream* st, const char** env_list,
906 char* buffer, int len) {
907 if (env_list) {
908 st->print_cr("Environment Variables:");
909
910 for (int i = 0; env_list[i] != NULL; i++) {
911 if (getenv(env_list[i], buffer, len)) {
912 st->print(env_list[i]);
913 st->print("=");
914 st->print_cr(buffer);
915 }
916 }
917 }
918 }
919
920 void os::print_cpu_info(outputStream* st) {
921 // cpu
922 st->print("CPU:");
923 st->print("total %d", os::processor_count());
924 // It's not safe to query number of active processors after crash
925 // st->print("(active %d)", os::active_processor_count());
926 st->print(" %s", VM_Version::cpu_features());
927 st->cr();
928 pd_print_cpu_info(st);
929 }
930
931 void os::print_date_and_time(outputStream *st) {
932 const int secs_per_day = 86400;
933 const int secs_per_hour = 3600;
934 const int secs_per_min = 60;
935
936 time_t tloc;
937 (void)time(&tloc);
938 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
939
940 double t = os::elapsedTime();
941 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
942 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
943 // before printf. We lost some precision, but who cares?
944 int eltime = (int)t; // elapsed time in seconds
945
946 // print elapsed time in a human-readable format:
947 int eldays = eltime / secs_per_day;
948 int day_secs = eldays * secs_per_day;
949 int elhours = (eltime - day_secs) / secs_per_hour;
950 int hour_secs = elhours * secs_per_hour;
951 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
952 int minute_secs = elmins * secs_per_min;
953 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
954 st->print_cr("elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
955 }
956
957 // moved from debug.cpp (used to be find()) but still called from there
958 // The verbose parameter is only set by the debug code in one case
959 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
960 address addr = (address)x;
961 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
962 if (b != NULL) {
963 if (b->is_buffer_blob()) {
964 // the interpreter is generated into a buffer blob
965 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
966 if (i != NULL) {
967 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an Interpreter codelet", addr, (int)(addr - i->code_begin()));
968 i->print_on(st);
969 return;
970 }
971 if (Interpreter::contains(addr)) {
972 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
973 " (not bytecode specific)", addr);
974 return;
975 }
976 //
977 if (AdapterHandlerLibrary::contains(b)) {
978 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in an AdapterHandler", addr, (int)(addr - b->code_begin()));
979 AdapterHandlerLibrary::print_handler_on(st, b);
980 }
981 // the stubroutines are generated into a buffer blob
982 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
983 if (d != NULL) {
984 st->print_cr(INTPTR_FORMAT " is at begin+%d in a stub", addr, (int)(addr - d->begin()));
985 d->print_on(st);
986 st->cr();
987 return;
988 }
989 if (StubRoutines::contains(addr)) {
990 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
991 "stub routine", addr);
992 return;
993 }
994 // the InlineCacheBuffer is using stubs generated into a buffer blob
995 if (InlineCacheBuffer::contains(addr)) {
996 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
997 return;
998 }
999 VtableStub* v = VtableStubs::stub_containing(addr);
1000 if (v != NULL) {
1001 st->print_cr(INTPTR_FORMAT " is at entry_point+%d in a vtable stub", addr, (int)(addr - v->entry_point()));
1002 v->print_on(st);
1003 st->cr();
1004 return;
1005 }
1006 }
1007 nmethod* nm = b->as_nmethod_or_null();
1008 if (nm != NULL) {
1009 ResourceMark rm;
1010 st->print(INTPTR_FORMAT " is at entry_point+%d in (nmethod*)" INTPTR_FORMAT,
1011 addr, (int)(addr - nm->entry_point()), nm);
1012 if (verbose) {
1013 st->print(" for ");
1014 nm->method()->print_value_on(st);
1015 }
1016 st->cr();
1017 nm->print_nmethod(verbose);
1018 return;
1019 }
1020 st->print_cr(INTPTR_FORMAT " is at code_begin+%d in ", addr, (int)(addr - b->code_begin()));
1021 b->print_on(st);
1022 return;
1023 }
1024
1025 if (Universe::heap()->is_in(addr)) {
1026 HeapWord* p = Universe::heap()->block_start(addr);
1027 bool print = false;
1028 // If we couldn't find it it just may mean that heap wasn't parsable
1029 // See if we were just given an oop directly
1030 if (p != NULL && Universe::heap()->block_is_obj(p)) {
1031 print = true;
1032 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
1033 p = (HeapWord*) addr;
1034 print = true;
1035 }
1036 if (print) {
1037 if (p == (HeapWord*) addr) {
1038 st->print_cr(INTPTR_FORMAT " is an oop", addr);
1039 } else {
1040 st->print_cr(INTPTR_FORMAT " is pointing into object: " INTPTR_FORMAT, addr, p);
1041 }
1042 oop(p)->print_on(st);
1043 return;
1044 }
1045 } else {
1046 if (Universe::heap()->is_in_reserved(addr)) {
1047 st->print_cr(INTPTR_FORMAT " is an unallocated location "
1048 "in the heap", addr);
1049 return;
1050 }
1051 }
1052 if (JNIHandles::is_global_handle((jobject) addr)) {
1053 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
1054 return;
1055 }
1056 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1057 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
1058 return;
1059 }
1060 #ifndef PRODUCT
1061 // we don't keep the block list in product mode
1062 if (JNIHandleBlock::any_contains((jobject) addr)) {
1063 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
1064 return;
1065 }
1066 #endif
1067
1068 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
1069 // Check for privilege stack
1070 if (thread->privileged_stack_top() != NULL &&
1071 thread->privileged_stack_top()->contains(addr)) {
1072 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
1073 "for thread: " INTPTR_FORMAT, addr, thread);
1074 if (verbose) thread->print_on(st);
1075 return;
1076 }
1077 // If the addr is a java thread print information about that.
1078 if (addr == (address)thread) {
1079 if (verbose) {
1080 thread->print_on(st);
1081 } else {
1082 st->print_cr(INTPTR_FORMAT " is a thread", addr);
1083 }
1084 return;
1085 }
1086 // If the addr is in the stack region for this thread then report that
1087 // and print thread info
1088 if (thread->stack_base() >= addr &&
1089 addr > (thread->stack_base() - thread->stack_size())) {
1090 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1091 INTPTR_FORMAT, addr, thread);
1092 if (verbose) thread->print_on(st);
1093 return;
1094 }
1095
1096 }
1097
1098 // Check if in metaspace.
1099 if (ClassLoaderDataGraph::contains((address)addr)) {
1100 // Use addr->print() from the debugger instead (not here)
1101 st->print_cr(INTPTR_FORMAT
1102 " is pointing into metadata", addr);
1103 return;
1104 }
1105
1106 // Try an OS specific find
1107 if (os::find(addr, st)) {
1108 return;
1109 }
1110
1111 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
1112 }
1113
1114 // Looks like all platforms except IA64 can use the same function to check
1115 // if C stack is walkable beyond current frame. The check for fp() is not
1116 // necessary on Sparc, but it's harmless.
1117 bool os::is_first_C_frame(frame* fr) {
1118 #if (defined(IA64) && !defined(AIX)) && !defined(_WIN32)
1119 // On IA64 we have to check if the callers bsp is still valid
1120 // (i.e. within the register stack bounds).
1121 // Notice: this only works for threads created by the VM and only if
1122 // we walk the current stack!!! If we want to be able to walk
1123 // arbitrary other threads, we'll have to somehow store the thread
1124 // object in the frame.
1125 Thread *thread = Thread::current();
1126 if ((address)fr->fp() <=
1127 thread->register_stack_base() HPUX_ONLY(+ 0x0) LINUX_ONLY(+ 0x50)) {
1128 // This check is a little hacky, because on Linux the first C
1129 // frame's ('start_thread') register stack frame starts at
1130 // "register_stack_base + 0x48" while on HPUX, the first C frame's
1131 // ('__pthread_bound_body') register stack frame seems to really
1132 // start at "register_stack_base".
1133 return true;
1134 } else {
1135 return false;
1136 }
1137 #elif defined(IA64) && defined(_WIN32)
1138 return true;
1139 #else
1140 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1141 // Check usp first, because if that's bad the other accessors may fault
1142 // on some architectures. Ditto ufp second, etc.
1143 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1144 // sp on amd can be 32 bit aligned.
1145 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1146
1147 uintptr_t usp = (uintptr_t)fr->sp();
1148 if ((usp & sp_align_mask) != 0) return true;
1149
1150 uintptr_t ufp = (uintptr_t)fr->fp();
1151 if ((ufp & fp_align_mask) != 0) return true;
1152
1153 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1154 if ((old_sp & sp_align_mask) != 0) return true;
1155 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1156
1157 uintptr_t old_fp = (uintptr_t)fr->link();
1158 if ((old_fp & fp_align_mask) != 0) return true;
1159 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1160
1161 // stack grows downwards; if old_fp is below current fp or if the stack
1162 // frame is too large, either the stack is corrupted or fp is not saved
1163 // on stack (i.e. on x86, ebp may be used as general register). The stack
1164 // is not walkable beyond current frame.
1165 if (old_fp < ufp) return true;
1166 if (old_fp - ufp > 64 * K) return true;
1167
1168 return false;
1169 #endif
1170 }
1171
1172 #ifdef ASSERT
1173 extern "C" void test_random() {
1174 const double m = 2147483647;
1175 double mean = 0.0, variance = 0.0, t;
1176 long reps = 10000;
1177 unsigned long seed = 1;
1178
1179 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1180 os::init_random(seed);
1181 long num;
1182 for (int k = 0; k < reps; k++) {
1183 num = os::random();
1184 double u = (double)num / m;
1185 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1186
1187 // calculate mean and variance of the random sequence
1188 mean += u;
1189 variance += (u*u);
1190 }
1191 mean /= reps;
1192 variance /= (reps - 1);
1193
1194 assert(num == 1043618065, "bad seed");
1195 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1196 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1197 const double eps = 0.0001;
1198 t = fabsd(mean - 0.5018);
1199 assert(t < eps, "bad mean");
1200 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1201 assert(t < eps, "bad variance");
1202 }
1203 #endif
1204
1205
1206 // Set up the boot classpath.
1207
1208 char* os::format_boot_path(const char* format_string,
1209 const char* home,
1210 int home_len,
1211 char fileSep,
1212 char pathSep) {
1213 assert((fileSep == '/' && pathSep == ':') ||
1214 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1215
1216 // Scan the format string to determine the length of the actual
1217 // boot classpath, and handle platform dependencies as well.
1218 int formatted_path_len = 0;
1219 const char* p;
1220 for (p = format_string; *p != 0; ++p) {
1221 if (*p == '%') formatted_path_len += home_len - 1;
1222 ++formatted_path_len;
1223 }
1224
1225 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1226 if (formatted_path == NULL) {
1227 return NULL;
1228 }
1229
1230 // Create boot classpath from format, substituting separator chars and
1231 // java home directory.
1232 char* q = formatted_path;
1233 for (p = format_string; *p != 0; ++p) {
1234 switch (*p) {
1235 case '%':
1236 strcpy(q, home);
1237 q += home_len;
1238 break;
1239 case '/':
1240 *q++ = fileSep;
1241 break;
1242 case ':':
1243 *q++ = pathSep;
1244 break;
1245 default:
1246 *q++ = *p;
1247 }
1248 }
1249 *q = '\0';
1250
1251 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1252 return formatted_path;
1253 }
1254
1255
1256 bool os::set_boot_path(char fileSep, char pathSep) {
1257 const char* home = Arguments::get_java_home();
1258 int home_len = (int)strlen(home);
1259
1260 static const char* meta_index_dir_format = "%/lib/";
1261 static const char* meta_index_format = "%/lib/meta-index";
1262 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1263 if (meta_index == NULL) return false;
1264 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1265 if (meta_index_dir == NULL) return false;
1266 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1267
1268 // Any modification to the JAR-file list, for the boot classpath must be
1269 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1270 // path class JARs, are stripped for StackMapTable to reduce download size.
1271 static const char classpath_format[] =
1272 "%/lib/resources.jar:"
1273 "%/lib/rt.jar:"
1274 "%/lib/sunrsasign.jar:"
1275 "%/lib/jsse.jar:"
1276 "%/lib/jce.jar:"
1277 "%/lib/charsets.jar:"
1278 "%/lib/jfr.jar:"
1279 "%/classes";
1280 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1281 if (sysclasspath == NULL) return false;
1282 Arguments::set_sysclasspath(sysclasspath);
1283
1284 return true;
1285 }
1286
1287 /*
1288 * Splits a path, based on its separator, the number of
1289 * elements is returned back in n.
1290 * It is the callers responsibility to:
1291 * a> check the value of n, and n may be 0.
1292 * b> ignore any empty path elements
1293 * c> free up the data.
1294 */
1295 char** os::split_path(const char* path, int* n) {
1296 *n = 0;
1297 if (path == NULL || strlen(path) == 0) {
1298 return NULL;
1299 }
1300 const char psepchar = *os::path_separator();
1301 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1302 if (inpath == NULL) {
1303 return NULL;
1304 }
1305 strcpy(inpath, path);
1306 int count = 1;
1307 char* p = strchr(inpath, psepchar);
1308 // Get a count of elements to allocate memory
1309 while (p != NULL) {
1310 count++;
1311 p++;
1312 p = strchr(p, psepchar);
1313 }
1314 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1315 if (opath == NULL) {
1316 return NULL;
1317 }
1318
1319 // do the actual splitting
1320 p = inpath;
1321 for (int i = 0 ; i < count ; i++) {
1322 size_t len = strcspn(p, os::path_separator());
1323 if (len > JVM_MAXPATHLEN) {
1324 return NULL;
1325 }
1326 // allocate the string and add terminator storage
1327 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1328 if (s == NULL) {
1329 return NULL;
1330 }
1331 strncpy(s, p, len);
1332 s[len] = '\0';
1333 opath[i] = s;
1334 p += len + 1;
1335 }
1336 FREE_C_HEAP_ARRAY(char, inpath, mtInternal);
1337 *n = count;
1338 return opath;
1339 }
1340
1341 void os::set_memory_serialize_page(address page) {
1342 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1343 _mem_serialize_page = (volatile int32_t *)page;
1344 // We initialize the serialization page shift count here
1345 // We assume a cache line size of 64 bytes
1346 assert(SerializePageShiftCount == count,
1347 "thread size changed, fix SerializePageShiftCount constant");
1348 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1349 }
1350
1351 static volatile intptr_t SerializePageLock = 0;
1352
1353 // This method is called from signal handler when SIGSEGV occurs while the current
1354 // thread tries to store to the "read-only" memory serialize page during state
1355 // transition.
1356 void os::block_on_serialize_page_trap() {
1357 if (TraceSafepoint) {
1358 tty->print_cr("Block until the serialize page permission restored");
1359 }
1360 // When VMThread is holding the SerializePageLock during modifying the
1361 // access permission of the memory serialize page, the following call
1362 // will block until the permission of that page is restored to rw.
1363 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1364 // this case, it's OK as the signal is synchronous and we know precisely when
1365 // it can occur.
1366 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1367 Thread::muxRelease(&SerializePageLock);
1368 }
1369
1370 // Serialize all thread state variables
1371 void os::serialize_thread_states() {
1372 // On some platforms such as Solaris & Linux, the time duration of the page
1373 // permission restoration is observed to be much longer than expected due to
1374 // scheduler starvation problem etc. To avoid the long synchronization
1375 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1376 // the mutator thread if such case is encountered. See bug 6546278 for details.
1377 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1378 os::protect_memory((char *)os::get_memory_serialize_page(),
1379 os::vm_page_size(), MEM_PROT_READ);
1380 os::protect_memory((char *)os::get_memory_serialize_page(),
1381 os::vm_page_size(), MEM_PROT_RW);
1382 Thread::muxRelease(&SerializePageLock);
1383 }
1384
1385 // Returns true if the current stack pointer is above the stack shadow
1386 // pages, false otherwise.
1387
1388 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1389 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1390 address sp = current_stack_pointer();
1391 // Check if we have StackShadowPages above the yellow zone. This parameter
1392 // is dependent on the depth of the maximum VM call stack possible from
1393 // the handler for stack overflow. 'instanceof' in the stack overflow
1394 // handler or a println uses at least 8k stack of VM and native code
1395 // respectively.
1396 const int framesize_in_bytes =
1397 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1398 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1399 * vm_page_size()) + framesize_in_bytes;
1400 // The very lower end of the stack
1401 address stack_limit = thread->stack_base() - thread->stack_size();
1402 return (sp > (stack_limit + reserved_area));
1403 }
1404
1405 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1406 uint min_pages)
1407 {
1408 assert(min_pages > 0, "sanity");
1409 if (UseLargePages) {
1410 const size_t max_page_size = region_max_size / min_pages;
1411
1412 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1413 const size_t sz = _page_sizes[i];
1414 const size_t mask = sz - 1;
1415 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1416 // The largest page size with no fragmentation.
1417 return sz;
1418 }
1419
1420 if (sz <= max_page_size) {
1421 // The largest page size that satisfies the min_pages requirement.
1422 return sz;
1423 }
1424 }
1425 }
1426
1427 return vm_page_size();
1428 }
1429
1430 #ifndef PRODUCT
1431 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1432 {
1433 if (TracePageSizes) {
1434 tty->print("%s: ", str);
1435 for (int i = 0; i < count; ++i) {
1436 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1437 }
1438 tty->cr();
1439 }
1440 }
1441
1442 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1443 const size_t region_max_size, const size_t page_size,
1444 const char* base, const size_t size)
1445 {
1446 if (TracePageSizes) {
1447 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1448 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1449 " size=" SIZE_FORMAT,
1450 str, region_min_size, region_max_size,
1451 page_size, base, size);
1452 }
1453 }
1454 #endif // #ifndef PRODUCT
1455
1456 // This is the working definition of a server class machine:
1457 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1458 // because the graphics memory (?) sometimes masks physical memory.
1459 // If you want to change the definition of a server class machine
1460 // on some OS or platform, e.g., >=4GB on Windows platforms,
1461 // then you'll have to parameterize this method based on that state,
1462 // as was done for logical processors here, or replicate and
1463 // specialize this method for each platform. (Or fix os to have
1464 // some inheritance structure and use subclassing. Sigh.)
1465 // If you want some platform to always or never behave as a server
1466 // class machine, change the setting of AlwaysActAsServerClassMachine
1467 // and NeverActAsServerClassMachine in globals*.hpp.
1468 bool os::is_server_class_machine() {
1469 // First check for the early returns
1470 if (NeverActAsServerClassMachine) {
1471 return false;
1472 }
1473 if (AlwaysActAsServerClassMachine) {
1474 return true;
1475 }
1476 // Then actually look at the machine
1477 bool result = false;
1478 const unsigned int server_processors = 2;
1479 const julong server_memory = 2UL * G;
1480 // We seem not to get our full complement of memory.
1481 // We allow some part (1/8?) of the memory to be "missing",
1482 // based on the sizes of DIMMs, and maybe graphics cards.
1483 const julong missing_memory = 256UL * M;
1484
1485 /* Is this a server class machine? */
1486 if ((os::active_processor_count() >= (int)server_processors) &&
1487 (os::physical_memory() >= (server_memory - missing_memory))) {
1488 const unsigned int logical_processors =
1489 VM_Version::logical_processors_per_package();
1490 if (logical_processors > 1) {
1491 const unsigned int physical_packages =
1492 os::active_processor_count() / logical_processors;
1493 if (physical_packages > server_processors) {
1494 result = true;
1495 }
1496 } else {
1497 result = true;
1498 }
1499 }
1500 return result;
1501 }
1502
1503 void os::SuspendedThreadTask::run() {
1504 assert(Threads_lock->owned_by_self() || (_thread == VMThread::vm_thread()), "must have threads lock to call this");
1505 internal_do_task();
1506 _done = true;
1507 }
1508
1509 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1510 return os::pd_create_stack_guard_pages(addr, bytes);
1511 }
1512
1513 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint) {
1514 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1515 if (result != NULL) {
1516 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1517 }
1518
1519 return result;
1520 }
1521
1522 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1523 MEMFLAGS flags) {
1524 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1525 if (result != NULL) {
1526 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1527 MemTracker::record_virtual_memory_type((address)result, flags);
1528 }
1529
1530 return result;
1531 }
1532
1533 char* os::attempt_reserve_memory_at(size_t bytes, char* addr) {
1534 char* result = pd_attempt_reserve_memory_at(bytes, addr);
1535 if (result != NULL) {
1536 MemTracker::record_virtual_memory_reserve((address)result, bytes, mtNone, CALLER_PC);
1537 }
1538 return result;
1539 }
1540
1541 void os::split_reserved_memory(char *base, size_t size,
1542 size_t split, bool realloc) {
1543 pd_split_reserved_memory(base, size, split, realloc);
1544 }
1545
1546 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1547 bool res = pd_commit_memory(addr, bytes, executable);
1548 if (res) {
1549 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1550 }
1551 return res;
1552 }
1553
1554 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1555 bool executable) {
1556 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1557 if (res) {
1558 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1559 }
1560 return res;
1561 }
1562
1563 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1564 const char* mesg) {
1565 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1566 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1567 }
1568
1569 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1570 bool executable, const char* mesg) {
1571 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1572 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1573 }
1574
1575 bool os::uncommit_memory(char* addr, size_t bytes) {
1576 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_uncommit_tracker();
1577 bool res = pd_uncommit_memory(addr, bytes);
1578 if (res) {
1579 tkr.record((address)addr, bytes);
1580 } else {
1581 tkr.discard();
1582 }
1583 return res;
1584 }
1585
1586 bool os::release_memory(char* addr, size_t bytes) {
1587 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1588 bool res = pd_release_memory(addr, bytes);
1589 if (res) {
1590 tkr.record((address)addr, bytes);
1591 } else {
1592 tkr.discard();
1593 }
1594 return res;
1595 }
1596
1597
1598 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1599 char *addr, size_t bytes, bool read_only,
1600 bool allow_exec) {
1601 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1602 if (result != NULL) {
1603 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, mtNone, CALLER_PC);
1604 }
1605 return result;
1606 }
1607
1608 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1609 char *addr, size_t bytes, bool read_only,
1610 bool allow_exec) {
1611 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1612 read_only, allow_exec);
1613 }
1614
1615 bool os::unmap_memory(char *addr, size_t bytes) {
1616 MemTracker::Tracker tkr = MemTracker::get_virtual_memory_release_tracker();
1617 bool result = pd_unmap_memory(addr, bytes);
1618 if (result) {
1619 tkr.record((address)addr, bytes);
1620 } else {
1621 tkr.discard();
1622 }
1623 return result;
1624 }
1625
1626 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1627 pd_free_memory(addr, bytes, alignment_hint);
1628 }
1629
1630 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1631 pd_realign_memory(addr, bytes, alignment_hint);
1632 }
1633
1634 #ifndef TARGET_OS_FAMILY_windows
1635 /* try to switch state from state "from" to state "to"
1636 * returns the state set after the method is complete
1637 */
1638 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1639 os::SuspendResume::State to)
1640 {
1641 os::SuspendResume::State result =
1642 (os::SuspendResume::State) Atomic::cmpxchg((jint) to, (jint *) &_state, (jint) from);
1643 if (result == from) {
1644 // success
1645 return to;
1646 }
1647 return result;
1648 }
1649 #endif