Wed, 11 Jan 2012 17:34:02 -0500
7115199: Add event tracing hooks and Java Flight Recorder infrastructure
Summary: Added a nop tracing infrastructure, JFR makefile changes and other infrastructure used only by JFR.
Reviewed-by: acorn, sspitsyn
Contributed-by: markus.gronlund@oracle.com
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 */
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
68 # include <signal.h>
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];
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
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 }
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;
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
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);
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 }
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
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 }
204 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
205 int p;
206 int os_prio;
207 OSReturn ret = get_native_priority(thread, &os_prio);
208 if (ret != OS_OK) return ret;
210 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
211 priority = (ThreadPriority)p;
212 return OS_OK;
213 }
216 // --------------------- sun.misc.Signal (optional) ---------------------
219 // SIGBREAK is sent by the keyboard to query the VM state
220 #ifndef SIGBREAK
221 #define SIGBREAK SIGQUIT
222 #endif
224 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
227 static void signal_thread_entry(JavaThread* thread, TRAPS) {
228 os::set_priority(thread, NearMaxPriority);
229 while (true) {
230 int sig;
231 {
232 // FIXME : Currently we have not decieded what should be the status
233 // for this java thread blocked here. Once we decide about
234 // that we should fix this.
235 sig = os::signal_wait();
236 }
237 if (sig == os::sigexitnum_pd()) {
238 // Terminate the signal thread
239 return;
240 }
242 switch (sig) {
243 case SIGBREAK: {
244 // Check if the signal is a trigger to start the Attach Listener - in that
245 // case don't print stack traces.
246 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
247 continue;
248 }
249 // Print stack traces
250 // Any SIGBREAK operations added here should make sure to flush
251 // the output stream (e.g. tty->flush()) after output. See 4803766.
252 // Each module also prints an extra carriage return after its output.
253 VM_PrintThreads op;
254 VMThread::execute(&op);
255 VM_PrintJNI jni_op;
256 VMThread::execute(&jni_op);
257 VM_FindDeadlocks op1(tty);
258 VMThread::execute(&op1);
259 Universe::print_heap_at_SIGBREAK();
260 if (PrintClassHistogram) {
261 VM_GC_HeapInspection op1(gclog_or_tty, true /* force full GC before heap inspection */,
262 true /* need_prologue */);
263 VMThread::execute(&op1);
264 }
265 if (JvmtiExport::should_post_data_dump()) {
266 JvmtiExport::post_data_dump();
267 }
268 break;
269 }
270 default: {
271 // Dispatch the signal to java
272 HandleMark hm(THREAD);
273 klassOop k = SystemDictionary::resolve_or_null(vmSymbols::sun_misc_Signal(), THREAD);
274 KlassHandle klass (THREAD, k);
275 if (klass.not_null()) {
276 JavaValue result(T_VOID);
277 JavaCallArguments args;
278 args.push_int(sig);
279 JavaCalls::call_static(
280 &result,
281 klass,
282 vmSymbols::dispatch_name(),
283 vmSymbols::int_void_signature(),
284 &args,
285 THREAD
286 );
287 }
288 if (HAS_PENDING_EXCEPTION) {
289 // tty is initialized early so we don't expect it to be null, but
290 // if it is we can't risk doing an initialization that might
291 // trigger additional out-of-memory conditions
292 if (tty != NULL) {
293 char klass_name[256];
294 char tmp_sig_name[16];
295 const char* sig_name = "UNKNOWN";
296 instanceKlass::cast(PENDING_EXCEPTION->klass())->
297 name()->as_klass_external_name(klass_name, 256);
298 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
299 sig_name = tmp_sig_name;
300 warning("Exception %s occurred dispatching signal %s to handler"
301 "- the VM may need to be forcibly terminated",
302 klass_name, sig_name );
303 }
304 CLEAR_PENDING_EXCEPTION;
305 }
306 }
307 }
308 }
309 }
312 void os::signal_init() {
313 if (!ReduceSignalUsage) {
314 // Setup JavaThread for processing signals
315 EXCEPTION_MARK;
316 klassOop k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
317 instanceKlassHandle klass (THREAD, k);
318 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
320 const char thread_name[] = "Signal Dispatcher";
321 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
323 // Initialize thread_oop to put it into the system threadGroup
324 Handle thread_group (THREAD, Universe::system_thread_group());
325 JavaValue result(T_VOID);
326 JavaCalls::call_special(&result, thread_oop,
327 klass,
328 vmSymbols::object_initializer_name(),
329 vmSymbols::threadgroup_string_void_signature(),
330 thread_group,
331 string,
332 CHECK);
334 KlassHandle group(THREAD, SystemDictionary::ThreadGroup_klass());
335 JavaCalls::call_special(&result,
336 thread_group,
337 group,
338 vmSymbols::add_method_name(),
339 vmSymbols::thread_void_signature(),
340 thread_oop, // ARG 1
341 CHECK);
343 os::signal_init_pd();
345 { MutexLocker mu(Threads_lock);
346 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
348 // At this point it may be possible that no osthread was created for the
349 // JavaThread due to lack of memory. We would have to throw an exception
350 // in that case. However, since this must work and we do not allow
351 // exceptions anyway, check and abort if this fails.
352 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
353 vm_exit_during_initialization("java.lang.OutOfMemoryError",
354 "unable to create new native thread");
355 }
357 java_lang_Thread::set_thread(thread_oop(), signal_thread);
358 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
359 java_lang_Thread::set_daemon(thread_oop());
361 signal_thread->set_threadObj(thread_oop());
362 Threads::add(signal_thread);
363 Thread::start(signal_thread);
364 }
365 // Handle ^BREAK
366 os::signal(SIGBREAK, os::user_handler());
367 }
368 }
371 void os::terminate_signal_thread() {
372 if (!ReduceSignalUsage)
373 signal_notify(sigexitnum_pd());
374 }
377 // --------------------- loading libraries ---------------------
379 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
380 extern struct JavaVM_ main_vm;
382 static void* _native_java_library = NULL;
384 void* os::native_java_library() {
385 if (_native_java_library == NULL) {
386 char buffer[JVM_MAXPATHLEN];
387 char ebuf[1024];
389 // Try to load verify dll first. In 1.3 java dll depends on it and is not
390 // always able to find it when the loading executable is outside the JDK.
391 // In order to keep working with 1.2 we ignore any loading errors.
392 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "verify");
393 dll_load(buffer, ebuf, sizeof(ebuf));
395 // Load java dll
396 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "java");
397 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
398 if (_native_java_library == NULL) {
399 vm_exit_during_initialization("Unable to load native library", ebuf);
400 }
402 #if defined(__OpenBSD__)
403 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
404 // ignore errors
405 dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), "net");
406 dll_load(buffer, ebuf, sizeof(ebuf));
407 #endif
408 }
409 static jboolean onLoaded = JNI_FALSE;
410 if (onLoaded) {
411 // We may have to wait to fire OnLoad until TLS is initialized.
412 if (ThreadLocalStorage::is_initialized()) {
413 // The JNI_OnLoad handling is normally done by method load in
414 // java.lang.ClassLoader$NativeLibrary, but the VM loads the base library
415 // explicitly so we have to check for JNI_OnLoad as well
416 const char *onLoadSymbols[] = JNI_ONLOAD_SYMBOLS;
417 JNI_OnLoad_t JNI_OnLoad = CAST_TO_FN_PTR(
418 JNI_OnLoad_t, dll_lookup(_native_java_library, onLoadSymbols[0]));
419 if (JNI_OnLoad != NULL) {
420 JavaThread* thread = JavaThread::current();
421 ThreadToNativeFromVM ttn(thread);
422 HandleMark hm(thread);
423 jint ver = (*JNI_OnLoad)(&main_vm, NULL);
424 onLoaded = JNI_TRUE;
425 if (!Threads::is_supported_jni_version_including_1_1(ver)) {
426 vm_exit_during_initialization("Unsupported JNI version");
427 }
428 }
429 }
430 }
431 return _native_java_library;
432 }
434 // --------------------- heap allocation utilities ---------------------
436 char *os::strdup(const char *str) {
437 size_t size = strlen(str);
438 char *dup_str = (char *)malloc(size + 1);
439 if (dup_str == NULL) return NULL;
440 strcpy(dup_str, str);
441 return dup_str;
442 }
446 #ifdef ASSERT
447 #define space_before (MallocCushion + sizeof(double))
448 #define space_after MallocCushion
449 #define size_addr_from_base(p) (size_t*)(p + space_before - sizeof(size_t))
450 #define size_addr_from_obj(p) ((size_t*)p - 1)
451 // MallocCushion: size of extra cushion allocated around objects with +UseMallocOnly
452 // NB: cannot be debug variable, because these aren't set from the command line until
453 // *after* the first few allocs already happened
454 #define MallocCushion 16
455 #else
456 #define space_before 0
457 #define space_after 0
458 #define size_addr_from_base(p) should not use w/o ASSERT
459 #define size_addr_from_obj(p) should not use w/o ASSERT
460 #define MallocCushion 0
461 #endif
462 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
464 #ifdef ASSERT
465 inline size_t get_size(void* obj) {
466 size_t size = *size_addr_from_obj(obj);
467 if (size < 0) {
468 fatal(err_msg("free: size field of object #" PTR_FORMAT " was overwritten ("
469 SIZE_FORMAT ")", obj, size));
470 }
471 return size;
472 }
474 u_char* find_cushion_backwards(u_char* start) {
475 u_char* p = start;
476 while (p[ 0] != badResourceValue || p[-1] != badResourceValue ||
477 p[-2] != badResourceValue || p[-3] != badResourceValue) p--;
478 // ok, we have four consecutive marker bytes; find start
479 u_char* q = p - 4;
480 while (*q == badResourceValue) q--;
481 return q + 1;
482 }
484 u_char* find_cushion_forwards(u_char* start) {
485 u_char* p = start;
486 while (p[0] != badResourceValue || p[1] != badResourceValue ||
487 p[2] != badResourceValue || p[3] != badResourceValue) p++;
488 // ok, we have four consecutive marker bytes; find end of cushion
489 u_char* q = p + 4;
490 while (*q == badResourceValue) q++;
491 return q - MallocCushion;
492 }
494 void print_neighbor_blocks(void* ptr) {
495 // find block allocated before ptr (not entirely crash-proof)
496 if (MallocCushion < 4) {
497 tty->print_cr("### cannot find previous block (MallocCushion < 4)");
498 return;
499 }
500 u_char* start_of_this_block = (u_char*)ptr - space_before;
501 u_char* end_of_prev_block_data = start_of_this_block - space_after -1;
502 // look for cushion in front of prev. block
503 u_char* start_of_prev_block = find_cushion_backwards(end_of_prev_block_data);
504 ptrdiff_t size = *size_addr_from_base(start_of_prev_block);
505 u_char* obj = start_of_prev_block + space_before;
506 if (size <= 0 ) {
507 // start is bad; mayhave been confused by OS data inbetween objects
508 // search one more backwards
509 start_of_prev_block = find_cushion_backwards(start_of_prev_block);
510 size = *size_addr_from_base(start_of_prev_block);
511 obj = start_of_prev_block + space_before;
512 }
514 if (start_of_prev_block + space_before + size + space_after == start_of_this_block) {
515 tty->print_cr("### previous object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
516 } else {
517 tty->print_cr("### previous object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", obj, size);
518 }
520 // now find successor block
521 u_char* start_of_next_block = (u_char*)ptr + *size_addr_from_obj(ptr) + space_after;
522 start_of_next_block = find_cushion_forwards(start_of_next_block);
523 u_char* next_obj = start_of_next_block + space_before;
524 ptrdiff_t next_size = *size_addr_from_base(start_of_next_block);
525 if (start_of_next_block[0] == badResourceValue &&
526 start_of_next_block[1] == badResourceValue &&
527 start_of_next_block[2] == badResourceValue &&
528 start_of_next_block[3] == badResourceValue) {
529 tty->print_cr("### next object: " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
530 } else {
531 tty->print_cr("### next object (not sure if correct): " PTR_FORMAT " (" SSIZE_FORMAT " bytes)", next_obj, next_size);
532 }
533 }
536 void report_heap_error(void* memblock, void* bad, const char* where) {
537 tty->print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
538 tty->print_cr("## memory stomp: byte at " PTR_FORMAT " %s object " PTR_FORMAT, bad, where, memblock);
539 print_neighbor_blocks(memblock);
540 fatal("memory stomping error");
541 }
543 void verify_block(void* memblock) {
544 size_t size = get_size(memblock);
545 if (MallocCushion) {
546 u_char* ptr = (u_char*)memblock - space_before;
547 for (int i = 0; i < MallocCushion; i++) {
548 if (ptr[i] != badResourceValue) {
549 report_heap_error(memblock, ptr+i, "in front of");
550 }
551 }
552 u_char* end = (u_char*)memblock + size + space_after;
553 for (int j = -MallocCushion; j < 0; j++) {
554 if (end[j] != badResourceValue) {
555 report_heap_error(memblock, end+j, "after");
556 }
557 }
558 }
559 }
560 #endif
562 void* os::malloc(size_t size) {
563 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
564 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
566 if (size == 0) {
567 // return a valid pointer if size is zero
568 // if NULL is returned the calling functions assume out of memory.
569 size = 1;
570 }
572 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
573 u_char* ptr = (u_char*)::malloc(size + space_before + space_after);
574 #ifdef ASSERT
575 if (ptr == NULL) return NULL;
576 if (MallocCushion) {
577 for (u_char* p = ptr; p < ptr + MallocCushion; p++) *p = (u_char)badResourceValue;
578 u_char* end = ptr + space_before + size;
579 for (u_char* pq = ptr+MallocCushion; pq < end; pq++) *pq = (u_char)uninitBlockPad;
580 for (u_char* q = end; q < end + MallocCushion; q++) *q = (u_char)badResourceValue;
581 }
582 // put size just before data
583 *size_addr_from_base(ptr) = size;
584 #endif
585 u_char* memblock = ptr + space_before;
586 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
587 tty->print_cr("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
588 breakpoint();
589 }
590 debug_only(if (paranoid) verify_block(memblock));
591 if (PrintMalloc && tty != NULL) tty->print_cr("os::malloc " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, memblock);
592 return memblock;
593 }
596 void* os::realloc(void *memblock, size_t size) {
597 #ifndef ASSERT
598 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
599 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
600 return ::realloc(memblock, size);
601 #else
602 if (memblock == NULL) {
603 return malloc(size);
604 }
605 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
606 tty->print_cr("os::realloc caught " PTR_FORMAT, memblock);
607 breakpoint();
608 }
609 verify_block(memblock);
610 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
611 if (size == 0) return NULL;
612 // always move the block
613 void* ptr = malloc(size);
614 if (PrintMalloc) tty->print_cr("os::remalloc " SIZE_FORMAT " bytes, " PTR_FORMAT " --> " PTR_FORMAT, size, memblock, ptr);
615 // Copy to new memory if malloc didn't fail
616 if ( ptr != NULL ) {
617 memcpy(ptr, memblock, MIN2(size, get_size(memblock)));
618 if (paranoid) verify_block(ptr);
619 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
620 tty->print_cr("os::realloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, ptr);
621 breakpoint();
622 }
623 free(memblock);
624 }
625 return ptr;
626 #endif
627 }
630 void os::free(void *memblock) {
631 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
632 #ifdef ASSERT
633 if (memblock == NULL) return;
634 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
635 if (tty != NULL) tty->print_cr("os::free caught " PTR_FORMAT, memblock);
636 breakpoint();
637 }
638 verify_block(memblock);
639 NOT_PRODUCT(if (MallocVerifyInterval > 0) check_heap());
640 // Added by detlefs.
641 if (MallocCushion) {
642 u_char* ptr = (u_char*)memblock - space_before;
643 for (u_char* p = ptr; p < ptr + MallocCushion; p++) {
644 guarantee(*p == badResourceValue,
645 "Thing freed should be malloc result.");
646 *p = (u_char)freeBlockPad;
647 }
648 size_t size = get_size(memblock);
649 inc_stat_counter(&free_bytes, size);
650 u_char* end = ptr + space_before + size;
651 for (u_char* q = end; q < end + MallocCushion; q++) {
652 guarantee(*q == badResourceValue,
653 "Thing freed should be malloc result.");
654 *q = (u_char)freeBlockPad;
655 }
656 if (PrintMalloc && tty != NULL)
657 fprintf(stderr, "os::free " SIZE_FORMAT " bytes --> " PTR_FORMAT "\n", size, (uintptr_t)memblock);
658 } else if (PrintMalloc && tty != NULL) {
659 // tty->print_cr("os::free %p", memblock);
660 fprintf(stderr, "os::free " PTR_FORMAT "\n", (uintptr_t)memblock);
661 }
662 #endif
663 ::free((char*)memblock - space_before);
664 }
666 void os::init_random(long initval) {
667 _rand_seed = initval;
668 }
671 long os::random() {
672 /* standard, well-known linear congruential random generator with
673 * next_rand = (16807*seed) mod (2**31-1)
674 * see
675 * (1) "Random Number Generators: Good Ones Are Hard to Find",
676 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
677 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
678 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
679 */
680 const long a = 16807;
681 const unsigned long m = 2147483647;
682 const long q = m / a; assert(q == 127773, "weird math");
683 const long r = m % a; assert(r == 2836, "weird math");
685 // compute az=2^31p+q
686 unsigned long lo = a * (long)(_rand_seed & 0xFFFF);
687 unsigned long hi = a * (long)((unsigned long)_rand_seed >> 16);
688 lo += (hi & 0x7FFF) << 16;
690 // if q overflowed, ignore the overflow and increment q
691 if (lo > m) {
692 lo &= m;
693 ++lo;
694 }
695 lo += hi >> 15;
697 // if (p+q) overflowed, ignore the overflow and increment (p+q)
698 if (lo > m) {
699 lo &= m;
700 ++lo;
701 }
702 return (_rand_seed = lo);
703 }
705 // The INITIALIZED state is distinguished from the SUSPENDED state because the
706 // conditions in which a thread is first started are different from those in which
707 // a suspension is resumed. These differences make it hard for us to apply the
708 // tougher checks when starting threads that we want to do when resuming them.
709 // However, when start_thread is called as a result of Thread.start, on a Java
710 // thread, the operation is synchronized on the Java Thread object. So there
711 // cannot be a race to start the thread and hence for the thread to exit while
712 // we are working on it. Non-Java threads that start Java threads either have
713 // to do so in a context in which races are impossible, or should do appropriate
714 // locking.
716 void os::start_thread(Thread* thread) {
717 // guard suspend/resume
718 MutexLockerEx ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
719 OSThread* osthread = thread->osthread();
720 osthread->set_state(RUNNABLE);
721 pd_start_thread(thread);
722 }
724 //---------------------------------------------------------------------------
725 // Helper functions for fatal error handler
727 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
728 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
730 int cols = 0;
731 int cols_per_line = 0;
732 switch (unitsize) {
733 case 1: cols_per_line = 16; break;
734 case 2: cols_per_line = 8; break;
735 case 4: cols_per_line = 4; break;
736 case 8: cols_per_line = 2; break;
737 default: return;
738 }
740 address p = start;
741 st->print(PTR_FORMAT ": ", start);
742 while (p < end) {
743 switch (unitsize) {
744 case 1: st->print("%02x", *(u1*)p); break;
745 case 2: st->print("%04x", *(u2*)p); break;
746 case 4: st->print("%08x", *(u4*)p); break;
747 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
748 }
749 p += unitsize;
750 cols++;
751 if (cols >= cols_per_line && p < end) {
752 cols = 0;
753 st->cr();
754 st->print(PTR_FORMAT ": ", p);
755 } else {
756 st->print(" ");
757 }
758 }
759 st->cr();
760 }
762 void os::print_environment_variables(outputStream* st, const char** env_list,
763 char* buffer, int len) {
764 if (env_list) {
765 st->print_cr("Environment Variables:");
767 for (int i = 0; env_list[i] != NULL; i++) {
768 if (getenv(env_list[i], buffer, len)) {
769 st->print(env_list[i]);
770 st->print("=");
771 st->print_cr(buffer);
772 }
773 }
774 }
775 }
777 void os::print_cpu_info(outputStream* st) {
778 // cpu
779 st->print("CPU:");
780 st->print("total %d", os::processor_count());
781 // It's not safe to query number of active processors after crash
782 // st->print("(active %d)", os::active_processor_count());
783 st->print(" %s", VM_Version::cpu_features());
784 st->cr();
785 pd_print_cpu_info(st);
786 }
788 void os::print_date_and_time(outputStream *st) {
789 time_t tloc;
790 (void)time(&tloc);
791 st->print("time: %s", ctime(&tloc)); // ctime adds newline.
793 double t = os::elapsedTime();
794 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
795 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
796 // before printf. We lost some precision, but who cares?
797 st->print_cr("elapsed time: %d seconds", (int)t);
798 }
800 // moved from debug.cpp (used to be find()) but still called from there
801 // The verbose parameter is only set by the debug code in one case
802 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
803 address addr = (address)x;
804 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
805 if (b != NULL) {
806 if (b->is_buffer_blob()) {
807 // the interpreter is generated into a buffer blob
808 InterpreterCodelet* i = Interpreter::codelet_containing(addr);
809 if (i != NULL) {
810 st->print_cr(INTPTR_FORMAT " is an Interpreter codelet", addr);
811 i->print_on(st);
812 return;
813 }
814 if (Interpreter::contains(addr)) {
815 st->print_cr(INTPTR_FORMAT " is pointing into interpreter code"
816 " (not bytecode specific)", addr);
817 return;
818 }
819 //
820 if (AdapterHandlerLibrary::contains(b)) {
821 st->print_cr(INTPTR_FORMAT " is an AdapterHandler", addr);
822 AdapterHandlerLibrary::print_handler_on(st, b);
823 }
824 // the stubroutines are generated into a buffer blob
825 StubCodeDesc* d = StubCodeDesc::desc_for(addr);
826 if (d != NULL) {
827 d->print_on(st);
828 if (verbose) st->cr();
829 return;
830 }
831 if (StubRoutines::contains(addr)) {
832 st->print_cr(INTPTR_FORMAT " is pointing to an (unnamed) "
833 "stub routine", addr);
834 return;
835 }
836 // the InlineCacheBuffer is using stubs generated into a buffer blob
837 if (InlineCacheBuffer::contains(addr)) {
838 st->print_cr(INTPTR_FORMAT " is pointing into InlineCacheBuffer", addr);
839 return;
840 }
841 VtableStub* v = VtableStubs::stub_containing(addr);
842 if (v != NULL) {
843 v->print_on(st);
844 return;
845 }
846 }
847 if (verbose && b->is_nmethod()) {
848 ResourceMark rm;
849 st->print("%#p: Compiled ", addr);
850 ((nmethod*)b)->method()->print_value_on(st);
851 st->print(" = (CodeBlob*)" INTPTR_FORMAT, b);
852 st->cr();
853 return;
854 }
855 st->print(INTPTR_FORMAT " ", b);
856 if ( b->is_nmethod()) {
857 if (b->is_zombie()) {
858 st->print_cr("is zombie nmethod");
859 } else if (b->is_not_entrant()) {
860 st->print_cr("is non-entrant nmethod");
861 }
862 }
863 b->print_on(st);
864 return;
865 }
867 if (Universe::heap()->is_in(addr)) {
868 HeapWord* p = Universe::heap()->block_start(addr);
869 bool print = false;
870 // If we couldn't find it it just may mean that heap wasn't parseable
871 // See if we were just given an oop directly
872 if (p != NULL && Universe::heap()->block_is_obj(p)) {
873 print = true;
874 } else if (p == NULL && ((oopDesc*)addr)->is_oop()) {
875 p = (HeapWord*) addr;
876 print = true;
877 }
878 if (print) {
879 st->print_cr(INTPTR_FORMAT " is an oop", addr);
880 oop(p)->print_on(st);
881 if (p != (HeapWord*)x && oop(p)->is_constMethod() &&
882 constMethodOop(p)->contains(addr)) {
883 Thread *thread = Thread::current();
884 HandleMark hm(thread);
885 methodHandle mh (thread, constMethodOop(p)->method());
886 if (!mh->is_native()) {
887 st->print_cr("bci_from(%p) = %d; print_codes():",
888 addr, mh->bci_from(address(x)));
889 mh->print_codes_on(st);
890 }
891 }
892 return;
893 }
894 } else {
895 if (Universe::heap()->is_in_reserved(addr)) {
896 st->print_cr(INTPTR_FORMAT " is an unallocated location "
897 "in the heap", addr);
898 return;
899 }
900 }
901 if (JNIHandles::is_global_handle((jobject) addr)) {
902 st->print_cr(INTPTR_FORMAT " is a global jni handle", addr);
903 return;
904 }
905 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
906 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", addr);
907 return;
908 }
909 #ifndef PRODUCT
910 // we don't keep the block list in product mode
911 if (JNIHandleBlock::any_contains((jobject) addr)) {
912 st->print_cr(INTPTR_FORMAT " is a local jni handle", addr);
913 return;
914 }
915 #endif
917 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
918 // Check for privilege stack
919 if (thread->privileged_stack_top() != NULL &&
920 thread->privileged_stack_top()->contains(addr)) {
921 st->print_cr(INTPTR_FORMAT " is pointing into the privilege stack "
922 "for thread: " INTPTR_FORMAT, addr, thread);
923 if (verbose) thread->print_on(st);
924 return;
925 }
926 // If the addr is a java thread print information about that.
927 if (addr == (address)thread) {
928 if (verbose) {
929 thread->print_on(st);
930 } else {
931 st->print_cr(INTPTR_FORMAT " is a thread", addr);
932 }
933 return;
934 }
935 // If the addr is in the stack region for this thread then report that
936 // and print thread info
937 if (thread->stack_base() >= addr &&
938 addr > (thread->stack_base() - thread->stack_size())) {
939 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
940 INTPTR_FORMAT, addr, thread);
941 if (verbose) thread->print_on(st);
942 return;
943 }
945 }
946 // Try an OS specific find
947 if (os::find(addr, st)) {
948 return;
949 }
951 st->print_cr(INTPTR_FORMAT " is an unknown value", addr);
952 }
954 // Looks like all platforms except IA64 can use the same function to check
955 // if C stack is walkable beyond current frame. The check for fp() is not
956 // necessary on Sparc, but it's harmless.
957 bool os::is_first_C_frame(frame* fr) {
958 #ifdef IA64
959 // In order to walk native frames on Itanium, we need to access the unwind
960 // table, which is inside ELF. We don't want to parse ELF after fatal error,
961 // so return true for IA64. If we need to support C stack walking on IA64,
962 // this function needs to be moved to CPU specific files, as fp() on IA64
963 // is register stack, which grows towards higher memory address.
964 return true;
965 #endif
967 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
968 // Check usp first, because if that's bad the other accessors may fault
969 // on some architectures. Ditto ufp second, etc.
970 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
971 // sp on amd can be 32 bit aligned.
972 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
974 uintptr_t usp = (uintptr_t)fr->sp();
975 if ((usp & sp_align_mask) != 0) return true;
977 uintptr_t ufp = (uintptr_t)fr->fp();
978 if ((ufp & fp_align_mask) != 0) return true;
980 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
981 if ((old_sp & sp_align_mask) != 0) return true;
982 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
984 uintptr_t old_fp = (uintptr_t)fr->link();
985 if ((old_fp & fp_align_mask) != 0) return true;
986 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
988 // stack grows downwards; if old_fp is below current fp or if the stack
989 // frame is too large, either the stack is corrupted or fp is not saved
990 // on stack (i.e. on x86, ebp may be used as general register). The stack
991 // is not walkable beyond current frame.
992 if (old_fp < ufp) return true;
993 if (old_fp - ufp > 64 * K) return true;
995 return false;
996 }
998 #ifdef ASSERT
999 extern "C" void test_random() {
1000 const double m = 2147483647;
1001 double mean = 0.0, variance = 0.0, t;
1002 long reps = 10000;
1003 unsigned long seed = 1;
1005 tty->print_cr("seed %ld for %ld repeats...", seed, reps);
1006 os::init_random(seed);
1007 long num;
1008 for (int k = 0; k < reps; k++) {
1009 num = os::random();
1010 double u = (double)num / m;
1011 assert(u >= 0.0 && u <= 1.0, "bad random number!");
1013 // calculate mean and variance of the random sequence
1014 mean += u;
1015 variance += (u*u);
1016 }
1017 mean /= reps;
1018 variance /= (reps - 1);
1020 assert(num == 1043618065, "bad seed");
1021 tty->print_cr("mean of the 1st 10000 numbers: %f", mean);
1022 tty->print_cr("variance of the 1st 10000 numbers: %f", variance);
1023 const double eps = 0.0001;
1024 t = fabsd(mean - 0.5018);
1025 assert(t < eps, "bad mean");
1026 t = (variance - 0.3355) < 0.0 ? -(variance - 0.3355) : variance - 0.3355;
1027 assert(t < eps, "bad variance");
1028 }
1029 #endif
1032 // Set up the boot classpath.
1034 char* os::format_boot_path(const char* format_string,
1035 const char* home,
1036 int home_len,
1037 char fileSep,
1038 char pathSep) {
1039 assert((fileSep == '/' && pathSep == ':') ||
1040 (fileSep == '\\' && pathSep == ';'), "unexpected seperator chars");
1042 // Scan the format string to determine the length of the actual
1043 // boot classpath, and handle platform dependencies as well.
1044 int formatted_path_len = 0;
1045 const char* p;
1046 for (p = format_string; *p != 0; ++p) {
1047 if (*p == '%') formatted_path_len += home_len - 1;
1048 ++formatted_path_len;
1049 }
1051 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1);
1052 if (formatted_path == NULL) {
1053 return NULL;
1054 }
1056 // Create boot classpath from format, substituting separator chars and
1057 // java home directory.
1058 char* q = formatted_path;
1059 for (p = format_string; *p != 0; ++p) {
1060 switch (*p) {
1061 case '%':
1062 strcpy(q, home);
1063 q += home_len;
1064 break;
1065 case '/':
1066 *q++ = fileSep;
1067 break;
1068 case ':':
1069 *q++ = pathSep;
1070 break;
1071 default:
1072 *q++ = *p;
1073 }
1074 }
1075 *q = '\0';
1077 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1078 return formatted_path;
1079 }
1082 bool os::set_boot_path(char fileSep, char pathSep) {
1083 const char* home = Arguments::get_java_home();
1084 int home_len = (int)strlen(home);
1086 static const char* meta_index_dir_format = "%/lib/";
1087 static const char* meta_index_format = "%/lib/meta-index";
1088 char* meta_index = format_boot_path(meta_index_format, home, home_len, fileSep, pathSep);
1089 if (meta_index == NULL) return false;
1090 char* meta_index_dir = format_boot_path(meta_index_dir_format, home, home_len, fileSep, pathSep);
1091 if (meta_index_dir == NULL) return false;
1092 Arguments::set_meta_index_path(meta_index, meta_index_dir);
1094 // Any modification to the JAR-file list, for the boot classpath must be
1095 // aligned with install/install/make/common/Pack.gmk. Note: boot class
1096 // path class JARs, are stripped for StackMapTable to reduce download size.
1097 static const char classpath_format[] =
1098 "%/lib/resources.jar:"
1099 "%/lib/rt.jar:"
1100 "%/lib/sunrsasign.jar:"
1101 "%/lib/jsse.jar:"
1102 "%/lib/jce.jar:"
1103 "%/lib/charsets.jar:"
1104 "%/lib/jfr.jar:"
1105 #ifdef __APPLE__
1106 "%/lib/JObjC.jar:"
1107 #endif
1108 "%/classes";
1109 char* sysclasspath = format_boot_path(classpath_format, home, home_len, fileSep, pathSep);
1110 if (sysclasspath == NULL) return false;
1111 Arguments::set_sysclasspath(sysclasspath);
1113 return true;
1114 }
1116 /*
1117 * Splits a path, based on its separator, the number of
1118 * elements is returned back in n.
1119 * It is the callers responsibility to:
1120 * a> check the value of n, and n may be 0.
1121 * b> ignore any empty path elements
1122 * c> free up the data.
1123 */
1124 char** os::split_path(const char* path, int* n) {
1125 *n = 0;
1126 if (path == NULL || strlen(path) == 0) {
1127 return NULL;
1128 }
1129 const char psepchar = *os::path_separator();
1130 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1);
1131 if (inpath == NULL) {
1132 return NULL;
1133 }
1134 strncpy(inpath, path, strlen(path));
1135 int count = 1;
1136 char* p = strchr(inpath, psepchar);
1137 // Get a count of elements to allocate memory
1138 while (p != NULL) {
1139 count++;
1140 p++;
1141 p = strchr(p, psepchar);
1142 }
1143 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count);
1144 if (opath == NULL) {
1145 return NULL;
1146 }
1148 // do the actual splitting
1149 p = inpath;
1150 for (int i = 0 ; i < count ; i++) {
1151 size_t len = strcspn(p, os::path_separator());
1152 if (len > JVM_MAXPATHLEN) {
1153 return NULL;
1154 }
1155 // allocate the string and add terminator storage
1156 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1);
1157 if (s == NULL) {
1158 return NULL;
1159 }
1160 strncpy(s, p, len);
1161 s[len] = '\0';
1162 opath[i] = s;
1163 p += len + 1;
1164 }
1165 FREE_C_HEAP_ARRAY(char, inpath);
1166 *n = count;
1167 return opath;
1168 }
1170 void os::set_memory_serialize_page(address page) {
1171 int count = log2_intptr(sizeof(class JavaThread)) - log2_intptr(64);
1172 _mem_serialize_page = (volatile int32_t *)page;
1173 // We initialize the serialization page shift count here
1174 // We assume a cache line size of 64 bytes
1175 assert(SerializePageShiftCount == count,
1176 "thread size changed, fix SerializePageShiftCount constant");
1177 set_serialize_page_mask((uintptr_t)(vm_page_size() - sizeof(int32_t)));
1178 }
1180 static volatile intptr_t SerializePageLock = 0;
1182 // This method is called from signal handler when SIGSEGV occurs while the current
1183 // thread tries to store to the "read-only" memory serialize page during state
1184 // transition.
1185 void os::block_on_serialize_page_trap() {
1186 if (TraceSafepoint) {
1187 tty->print_cr("Block until the serialize page permission restored");
1188 }
1189 // When VMThread is holding the SerializePageLock during modifying the
1190 // access permission of the memory serialize page, the following call
1191 // will block until the permission of that page is restored to rw.
1192 // Generally, it is unsafe to manipulate locks in signal handlers, but in
1193 // this case, it's OK as the signal is synchronous and we know precisely when
1194 // it can occur.
1195 Thread::muxAcquire(&SerializePageLock, "set_memory_serialize_page");
1196 Thread::muxRelease(&SerializePageLock);
1197 }
1199 // Serialize all thread state variables
1200 void os::serialize_thread_states() {
1201 // On some platforms such as Solaris & Linux, the time duration of the page
1202 // permission restoration is observed to be much longer than expected due to
1203 // scheduler starvation problem etc. To avoid the long synchronization
1204 // time and expensive page trap spinning, 'SerializePageLock' is used to block
1205 // the mutator thread if such case is encountered. See bug 6546278 for details.
1206 Thread::muxAcquire(&SerializePageLock, "serialize_thread_states");
1207 os::protect_memory((char *)os::get_memory_serialize_page(),
1208 os::vm_page_size(), MEM_PROT_READ);
1209 os::protect_memory((char *)os::get_memory_serialize_page(),
1210 os::vm_page_size(), MEM_PROT_RW);
1211 Thread::muxRelease(&SerializePageLock);
1212 }
1214 // Returns true if the current stack pointer is above the stack shadow
1215 // pages, false otherwise.
1217 bool os::stack_shadow_pages_available(Thread *thread, methodHandle method) {
1218 assert(StackRedPages > 0 && StackYellowPages > 0,"Sanity check");
1219 address sp = current_stack_pointer();
1220 // Check if we have StackShadowPages above the yellow zone. This parameter
1221 // is dependent on the depth of the maximum VM call stack possible from
1222 // the handler for stack overflow. 'instanceof' in the stack overflow
1223 // handler or a println uses at least 8k stack of VM and native code
1224 // respectively.
1225 const int framesize_in_bytes =
1226 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1227 int reserved_area = ((StackShadowPages + StackRedPages + StackYellowPages)
1228 * vm_page_size()) + framesize_in_bytes;
1229 // The very lower end of the stack
1230 address stack_limit = thread->stack_base() - thread->stack_size();
1231 return (sp > (stack_limit + reserved_area));
1232 }
1234 size_t os::page_size_for_region(size_t region_min_size, size_t region_max_size,
1235 uint min_pages)
1236 {
1237 assert(min_pages > 0, "sanity");
1238 if (UseLargePages) {
1239 const size_t max_page_size = region_max_size / min_pages;
1241 for (unsigned int i = 0; _page_sizes[i] != 0; ++i) {
1242 const size_t sz = _page_sizes[i];
1243 const size_t mask = sz - 1;
1244 if ((region_min_size & mask) == 0 && (region_max_size & mask) == 0) {
1245 // The largest page size with no fragmentation.
1246 return sz;
1247 }
1249 if (sz <= max_page_size) {
1250 // The largest page size that satisfies the min_pages requirement.
1251 return sz;
1252 }
1253 }
1254 }
1256 return vm_page_size();
1257 }
1259 #ifndef PRODUCT
1260 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count)
1261 {
1262 if (TracePageSizes) {
1263 tty->print("%s: ", str);
1264 for (int i = 0; i < count; ++i) {
1265 tty->print(" " SIZE_FORMAT, page_sizes[i]);
1266 }
1267 tty->cr();
1268 }
1269 }
1271 void os::trace_page_sizes(const char* str, const size_t region_min_size,
1272 const size_t region_max_size, const size_t page_size,
1273 const char* base, const size_t size)
1274 {
1275 if (TracePageSizes) {
1276 tty->print_cr("%s: min=" SIZE_FORMAT " max=" SIZE_FORMAT
1277 " pg_sz=" SIZE_FORMAT " base=" PTR_FORMAT
1278 " size=" SIZE_FORMAT,
1279 str, region_min_size, region_max_size,
1280 page_size, base, size);
1281 }
1282 }
1283 #endif // #ifndef PRODUCT
1285 // This is the working definition of a server class machine:
1286 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1287 // because the graphics memory (?) sometimes masks physical memory.
1288 // If you want to change the definition of a server class machine
1289 // on some OS or platform, e.g., >=4GB on Windohs platforms,
1290 // then you'll have to parameterize this method based on that state,
1291 // as was done for logical processors here, or replicate and
1292 // specialize this method for each platform. (Or fix os to have
1293 // some inheritance structure and use subclassing. Sigh.)
1294 // If you want some platform to always or never behave as a server
1295 // class machine, change the setting of AlwaysActAsServerClassMachine
1296 // and NeverActAsServerClassMachine in globals*.hpp.
1297 bool os::is_server_class_machine() {
1298 // First check for the early returns
1299 if (NeverActAsServerClassMachine) {
1300 return false;
1301 }
1302 if (AlwaysActAsServerClassMachine) {
1303 return true;
1304 }
1305 // Then actually look at the machine
1306 bool result = false;
1307 const unsigned int server_processors = 2;
1308 const julong server_memory = 2UL * G;
1309 // We seem not to get our full complement of memory.
1310 // We allow some part (1/8?) of the memory to be "missing",
1311 // based on the sizes of DIMMs, and maybe graphics cards.
1312 const julong missing_memory = 256UL * M;
1314 /* Is this a server class machine? */
1315 if ((os::active_processor_count() >= (int)server_processors) &&
1316 (os::physical_memory() >= (server_memory - missing_memory))) {
1317 const unsigned int logical_processors =
1318 VM_Version::logical_processors_per_package();
1319 if (logical_processors > 1) {
1320 const unsigned int physical_packages =
1321 os::active_processor_count() / logical_processors;
1322 if (physical_packages > server_processors) {
1323 result = true;
1324 }
1325 } else {
1326 result = true;
1327 }
1328 }
1329 return result;
1330 }
1332 // Read file line by line, if line is longer than bsize,
1333 // skip rest of line.
1334 int os::get_line_chars(int fd, char* buf, const size_t bsize){
1335 size_t sz, i = 0;
1337 // read until EOF, EOL or buf is full
1338 while ((sz = (int) read(fd, &buf[i], 1)) == 1 && i < (bsize-2) && buf[i] != '\n') {
1339 ++i;
1340 }
1342 if (buf[i] == '\n') {
1343 // EOL reached so ignore EOL character and return
1345 buf[i] = 0;
1346 return (int) i;
1347 }
1349 buf[i+1] = 0;
1351 if (sz != 1) {
1352 // EOF reached. if we read chars before EOF return them and
1353 // return EOF on next call otherwise return EOF
1355 return (i == 0) ? -1 : (int) i;
1356 }
1358 // line is longer than size of buf, skip to EOL
1359 char ch;
1360 while (read(fd, &ch, 1) == 1 && ch != '\n') {
1361 // Do nothing
1362 }
1364 // return initial part of line that fits in buf.
1365 // If we reached EOF, it will be returned on next call.
1367 return (int) i;
1368 }