1 /*
2 * Copyright (c) 1997, 2019, 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 "jvm.h"
27 #include "classfile/classLoader.hpp"
28 #include "classfile/javaClasses.hpp"
29 #include "classfile/moduleEntry.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "code/codeCache.hpp"
33 #include "code/icBuffer.hpp"
34 #include "code/vtableStubs.hpp"
35 #include "gc/shared/gcVMOperations.hpp"
36 #include "logging/log.hpp"
37 #include "interpreter/interpreter.hpp"
38 #include "logging/log.hpp"
39 #include "logging/logStream.hpp"
40 #include "memory/allocation.inline.hpp"
41 #include "memory/guardedMemory.hpp"
42 #include "memory/resourceArea.hpp"
43 #include "memory/universe.hpp"
44 #include "oops/compressedOops.inline.hpp"
45 #include "oops/oop.inline.hpp"
46 #include "prims/jvm_misc.hpp"
47 #include "runtime/arguments.hpp"
48 #include "runtime/atomic.hpp"
49 #include "runtime/frame.inline.hpp"
50 #include "runtime/handles.inline.hpp"
51 #include "runtime/interfaceSupport.inline.hpp"
52 #include "runtime/java.hpp"
53 #include "runtime/javaCalls.hpp"
54 #include "runtime/mutexLocker.hpp"
55 #include "runtime/os.inline.hpp"
56 #include "runtime/sharedRuntime.hpp"
57 #include "runtime/stubRoutines.hpp"
58 #include "runtime/thread.inline.hpp"
59 #include "runtime/threadSMR.hpp"
60 #include "runtime/vm_version.hpp"
61 #include "services/attachListener.hpp"
62 #include "services/mallocTracker.hpp"
63 #include "services/memTracker.hpp"
64 #include "services/nmtCommon.hpp"
65 #include "services/threadService.hpp"
66 #include "utilities/align.hpp"
67 #include "utilities/defaultStream.hpp"
68 #include "utilities/events.hpp"
69
70 # include <signal.h>
71 # include <errno.h>
72
73 OSThread* os::_starting_thread = NULL;
74 address os::_polling_page = NULL;
75 volatile unsigned int os::_rand_seed = 1;
76 int os::_processor_count = 0;
77 int os::_initial_active_processor_count = 0;
78 size_t os::_page_sizes[os::page_sizes_max];
79
80 #ifndef PRODUCT
81 julong os::num_mallocs = 0; // # of calls to malloc/realloc
82 julong os::alloc_bytes = 0; // # of bytes allocated
83 julong os::num_frees = 0; // # of calls to free
84 julong os::free_bytes = 0; // # of bytes freed
85 #endif
86
87 static size_t cur_malloc_words = 0; // current size for MallocMaxTestWords
88
89 DEBUG_ONLY(bool os::_mutex_init_done = false;)
90
91 void os_init_globals() {
92 // Called from init_globals().
93 // See Threads::create_vm() in thread.cpp, and init.cpp.
94 os::init_globals();
95 }
96
97 static time_t get_timezone(const struct tm* time_struct) {
98 #if defined(_ALLBSD_SOURCE)
99 return time_struct->tm_gmtoff;
100 #elif defined(_WINDOWS)
101 long zone;
102 _get_timezone(&zone);
103 return static_cast<time_t>(zone);
104 #else
105 return timezone;
106 #endif
107 }
108
109 int os::snprintf(char* buf, size_t len, const char* fmt, ...) {
110 va_list args;
111 va_start(args, fmt);
112 int result = os::vsnprintf(buf, len, fmt, args);
113 va_end(args);
114 return result;
115 }
116
117 // Fill in buffer with current local time as an ISO-8601 string.
118 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
119 // Returns buffer, or NULL if it failed.
120 // This would mostly be a call to
121 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
122 // except that on Windows the %z behaves badly, so we do it ourselves.
123 // Also, people wanted milliseconds on there,
124 // and strftime doesn't do milliseconds.
125 char* os::iso8601_time(char* buffer, size_t buffer_length, bool utc) {
126 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
127 // 1 2
128 // 12345678901234567890123456789
129 // format string: "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d"
130 static const size_t needed_buffer = 29;
131
132 // Sanity check the arguments
133 if (buffer == NULL) {
134 assert(false, "NULL buffer");
135 return NULL;
136 }
137 if (buffer_length < needed_buffer) {
138 assert(false, "buffer_length too small");
139 return NULL;
140 }
141 // Get the current time
142 jlong milliseconds_since_19700101 = javaTimeMillis();
143 const int milliseconds_per_microsecond = 1000;
144 const time_t seconds_since_19700101 =
145 milliseconds_since_19700101 / milliseconds_per_microsecond;
146 const int milliseconds_after_second =
147 milliseconds_since_19700101 % milliseconds_per_microsecond;
148 // Convert the time value to a tm and timezone variable
149 struct tm time_struct;
150 if (utc) {
151 if (gmtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
152 assert(false, "Failed gmtime_pd");
153 return NULL;
154 }
155 } else {
156 if (localtime_pd(&seconds_since_19700101, &time_struct) == NULL) {
157 assert(false, "Failed localtime_pd");
158 return NULL;
159 }
160 }
161 const time_t zone = get_timezone(&time_struct);
162
163 // If daylight savings time is in effect,
164 // we are 1 hour East of our time zone
165 const time_t seconds_per_minute = 60;
166 const time_t minutes_per_hour = 60;
167 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
168 time_t UTC_to_local = zone;
169 if (time_struct.tm_isdst > 0) {
170 UTC_to_local = UTC_to_local - seconds_per_hour;
171 }
172
173 // No offset when dealing with UTC
174 if (utc) {
175 UTC_to_local = 0;
176 }
177
178 // Compute the time zone offset.
179 // localtime_pd() sets timezone to the difference (in seconds)
180 // between UTC and and local time.
181 // ISO 8601 says we need the difference between local time and UTC,
182 // we change the sign of the localtime_pd() result.
183 const time_t local_to_UTC = -(UTC_to_local);
184 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
185 char sign_local_to_UTC = '+';
186 time_t abs_local_to_UTC = local_to_UTC;
187 if (local_to_UTC < 0) {
188 sign_local_to_UTC = '-';
189 abs_local_to_UTC = -(abs_local_to_UTC);
190 }
191 // Convert time zone offset seconds to hours and minutes.
192 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
193 const time_t zone_min =
194 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
195
196 // Print an ISO 8601 date and time stamp into the buffer
197 const int year = 1900 + time_struct.tm_year;
198 const int month = 1 + time_struct.tm_mon;
199 const int printed = jio_snprintf(buffer, buffer_length,
200 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d",
201 year,
202 month,
203 time_struct.tm_mday,
204 time_struct.tm_hour,
205 time_struct.tm_min,
206 time_struct.tm_sec,
207 milliseconds_after_second,
208 sign_local_to_UTC,
209 zone_hours,
210 zone_min);
211 if (printed == 0) {
212 assert(false, "Failed jio_printf");
213 return NULL;
214 }
215 return buffer;
216 }
217
218 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
219 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
220
221 if ((p >= MinPriority && p <= MaxPriority) ||
222 (p == CriticalPriority && thread->is_ConcurrentGC_thread())) {
223 int priority = java_to_os_priority[p];
224 return set_native_priority(thread, priority);
225 } else {
226 assert(false, "Should not happen");
227 return OS_ERR;
228 }
229 }
230
231 // The mapping from OS priority back to Java priority may be inexact because
232 // Java priorities can map M:1 with native priorities. If you want the definite
233 // Java priority then use JavaThread::java_priority()
234 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
235 int p;
236 int os_prio;
237 OSReturn ret = get_native_priority(thread, &os_prio);
238 if (ret != OS_OK) return ret;
239
240 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
241 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
242 } else {
243 // niceness values are in reverse order
244 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
245 }
246 priority = (ThreadPriority)p;
247 return OS_OK;
248 }
249
250 bool os::dll_build_name(char* buffer, size_t size, const char* fname) {
251 int n = jio_snprintf(buffer, size, "%s%s%s", JNI_LIB_PREFIX, fname, JNI_LIB_SUFFIX);
252 return (n != -1);
253 }
254
255 #if !defined(LINUX) && !defined(_WINDOWS)
256 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
257 committed_start = start;
258 committed_size = size;
259 return true;
260 }
261 #endif
262
263 // Helper for dll_locate_lib.
264 // Pass buffer and printbuffer as we already printed the path to buffer
265 // when we called get_current_directory. This way we avoid another buffer
266 // of size MAX_PATH.
267 static bool conc_path_file_and_check(char *buffer, char *printbuffer, size_t printbuflen,
268 const char* pname, char lastchar, const char* fname) {
269
270 // Concatenate path and file name, but don't print double path separators.
271 const char *filesep = (WINDOWS_ONLY(lastchar == ':' ||) lastchar == os::file_separator()[0]) ?
272 "" : os::file_separator();
273 int ret = jio_snprintf(printbuffer, printbuflen, "%s%s%s", pname, filesep, fname);
274 // Check whether file exists.
275 if (ret != -1) {
276 struct stat statbuf;
277 return os::stat(buffer, &statbuf) == 0;
278 }
279 return false;
280 }
281
282 bool os::dll_locate_lib(char *buffer, size_t buflen,
283 const char* pname, const char* fname) {
284 bool retval = false;
285
286 size_t fullfnamelen = strlen(JNI_LIB_PREFIX) + strlen(fname) + strlen(JNI_LIB_SUFFIX);
287 char* fullfname = (char*)NEW_C_HEAP_ARRAY(char, fullfnamelen + 1, mtInternal);
288 if (dll_build_name(fullfname, fullfnamelen + 1, fname)) {
289 const size_t pnamelen = pname ? strlen(pname) : 0;
290
291 if (pnamelen == 0) {
292 // If no path given, use current working directory.
293 const char* p = get_current_directory(buffer, buflen);
294 if (p != NULL) {
295 const size_t plen = strlen(buffer);
296 const char lastchar = buffer[plen - 1];
297 retval = conc_path_file_and_check(buffer, &buffer[plen], buflen - plen,
298 "", lastchar, fullfname);
299 }
300 } else if (strchr(pname, *os::path_separator()) != NULL) {
301 // A list of paths. Search for the path that contains the library.
302 int n;
303 char** pelements = split_path(pname, &n);
304 if (pelements != NULL) {
305 for (int i = 0; i < n; i++) {
306 char* path = pelements[i];
307 // Really shouldn't be NULL, but check can't hurt.
308 size_t plen = (path == NULL) ? 0 : strlen(path);
309 if (plen == 0) {
310 continue; // Skip the empty path values.
311 }
312 const char lastchar = path[plen - 1];
313 retval = conc_path_file_and_check(buffer, buffer, buflen, path, lastchar, fullfname);
314 if (retval) break;
315 }
316 // Release the storage allocated by split_path.
317 for (int i = 0; i < n; i++) {
318 if (pelements[i] != NULL) {
319 FREE_C_HEAP_ARRAY(char, pelements[i]);
320 }
321 }
322 FREE_C_HEAP_ARRAY(char*, pelements);
323 }
324 } else {
325 // A definite path.
326 const char lastchar = pname[pnamelen-1];
327 retval = conc_path_file_and_check(buffer, buffer, buflen, pname, lastchar, fullfname);
328 }
329 }
330
331 FREE_C_HEAP_ARRAY(char*, fullfname);
332 return retval;
333 }
334
335 // --------------------- sun.misc.Signal (optional) ---------------------
336
337
338 // SIGBREAK is sent by the keyboard to query the VM state
339 #ifndef SIGBREAK
340 #define SIGBREAK SIGQUIT
341 #endif
342
343 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
344
345
346 static void signal_thread_entry(JavaThread* thread, TRAPS) {
347 os::set_priority(thread, NearMaxPriority);
348 while (true) {
349 int sig;
350 {
351 // FIXME : Currently we have not decided what should be the status
352 // for this java thread blocked here. Once we decide about
353 // that we should fix this.
354 sig = os::signal_wait();
355 }
356 if (sig == os::sigexitnum_pd()) {
357 // Terminate the signal thread
358 return;
359 }
360
361 switch (sig) {
362 case SIGBREAK: {
363 // Check if the signal is a trigger to start the Attach Listener - in that
364 // case don't print stack traces.
365 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
366 continue;
367 }
368 // Print stack traces
369 // Any SIGBREAK operations added here should make sure to flush
370 // the output stream (e.g. tty->flush()) after output. See 4803766.
371 // Each module also prints an extra carriage return after its output.
372 VM_PrintThreads op;
373 VMThread::execute(&op);
374 VM_PrintJNI jni_op;
375 VMThread::execute(&jni_op);
376 VM_FindDeadlocks op1(tty);
377 VMThread::execute(&op1);
378 Universe::print_heap_at_SIGBREAK();
379 if (PrintClassHistogram) {
380 VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */);
381 VMThread::execute(&op1);
382 }
383 if (JvmtiExport::should_post_data_dump()) {
384 JvmtiExport::post_data_dump();
385 }
386 break;
387 }
388 default: {
389 // Dispatch the signal to java
390 HandleMark hm(THREAD);
391 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD);
392 if (klass != NULL) {
393 JavaValue result(T_VOID);
394 JavaCallArguments args;
395 args.push_int(sig);
396 JavaCalls::call_static(
397 &result,
398 klass,
399 vmSymbols::dispatch_name(),
400 vmSymbols::int_void_signature(),
401 &args,
402 THREAD
403 );
404 }
405 if (HAS_PENDING_EXCEPTION) {
406 // tty is initialized early so we don't expect it to be null, but
407 // if it is we can't risk doing an initialization that might
408 // trigger additional out-of-memory conditions
409 if (tty != NULL) {
410 char klass_name[256];
411 char tmp_sig_name[16];
412 const char* sig_name = "UNKNOWN";
413 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
414 name()->as_klass_external_name(klass_name, 256);
415 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
416 sig_name = tmp_sig_name;
417 warning("Exception %s occurred dispatching signal %s to handler"
418 "- the VM may need to be forcibly terminated",
419 klass_name, sig_name );
420 }
421 CLEAR_PENDING_EXCEPTION;
422 }
423 }
424 }
425 }
426 }
427
428 void os::init_before_ergo() {
429 initialize_initial_active_processor_count();
430 // We need to initialize large page support here because ergonomics takes some
431 // decisions depending on large page support and the calculated large page size.
432 large_page_init();
433
434 // We need to adapt the configured number of stack protection pages given
435 // in 4K pages to the actual os page size. We must do this before setting
436 // up minimal stack sizes etc. in os::init_2().
437 JavaThread::set_stack_red_zone_size (align_up(StackRedPages * 4 * K, vm_page_size()));
438 JavaThread::set_stack_yellow_zone_size (align_up(StackYellowPages * 4 * K, vm_page_size()));
439 JavaThread::set_stack_reserved_zone_size(align_up(StackReservedPages * 4 * K, vm_page_size()));
440 JavaThread::set_stack_shadow_zone_size (align_up(StackShadowPages * 4 * K, vm_page_size()));
441
442 // VM version initialization identifies some characteristics of the
443 // platform that are used during ergonomic decisions.
444 VM_Version::init_before_ergo();
445 }
446
447 void os::initialize_jdk_signal_support(TRAPS) {
448 if (!ReduceSignalUsage) {
449 // Setup JavaThread for processing signals
450 const char thread_name[] = "Signal Dispatcher";
451 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
452
453 // Initialize thread_oop to put it into the system threadGroup
454 Handle thread_group (THREAD, Universe::system_thread_group());
455 Handle thread_oop = JavaCalls::construct_new_instance(SystemDictionary::Thread_klass(),
456 vmSymbols::threadgroup_string_void_signature(),
457 thread_group,
458 string,
459 CHECK);
460
461 Klass* group = SystemDictionary::ThreadGroup_klass();
462 JavaValue result(T_VOID);
463 JavaCalls::call_special(&result,
464 thread_group,
465 group,
466 vmSymbols::add_method_name(),
467 vmSymbols::thread_void_signature(),
468 thread_oop,
469 CHECK);
470
471 { MutexLocker mu(Threads_lock);
472 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
473
474 // At this point it may be possible that no osthread was created for the
475 // JavaThread due to lack of memory. We would have to throw an exception
476 // in that case. However, since this must work and we do not allow
477 // exceptions anyway, check and abort if this fails.
478 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
479 vm_exit_during_initialization("java.lang.OutOfMemoryError",
480 os::native_thread_creation_failed_msg());
481 }
482
483 java_lang_Thread::set_thread(thread_oop(), signal_thread);
484 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
485 java_lang_Thread::set_daemon(thread_oop());
486
487 signal_thread->set_threadObj(thread_oop());
488 Threads::add(signal_thread);
489 Thread::start(signal_thread);
490 }
491 // Handle ^BREAK
492 os::signal(SIGBREAK, os::user_handler());
493 }
494 }
495
496
497 void os::terminate_signal_thread() {
498 if (!ReduceSignalUsage)
499 signal_notify(sigexitnum_pd());
500 }
501
502
503 // --------------------- loading libraries ---------------------
504
505 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
506 extern struct JavaVM_ main_vm;
507
508 static void* _native_java_library = NULL;
509
510 void* os::native_java_library() {
511 if (_native_java_library == NULL) {
512 char buffer[JVM_MAXPATHLEN];
513 char ebuf[1024];
514
515 // Try to load verify dll first. In 1.3 java dll depends on it and is not
516 // always able to find it when the loading executable is outside the JDK.
517 // In order to keep working with 1.2 we ignore any loading errors.
518 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
519 "verify")) {
520 dll_load(buffer, ebuf, sizeof(ebuf));
521 }
522
523 // Load java dll
524 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
525 "java")) {
526 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
527 }
528 if (_native_java_library == NULL) {
529 vm_exit_during_initialization("Unable to load native library", ebuf);
530 }
531
532 #if defined(__OpenBSD__)
533 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
534 // ignore errors
535 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
536 "net")) {
537 dll_load(buffer, ebuf, sizeof(ebuf));
538 }
539 #endif
540 }
541 return _native_java_library;
542 }
543
544 /*
545 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
546 * If check_lib == true then we are looking for an
547 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
548 * this library is statically linked into the image.
549 * If check_lib == false then we will look for the appropriate symbol in the
550 * executable if agent_lib->is_static_lib() == true or in the shared library
551 * referenced by 'handle'.
552 */
553 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
554 const char *syms[], size_t syms_len) {
555 assert(agent_lib != NULL, "sanity check");
556 const char *lib_name;
557 void *handle = agent_lib->os_lib();
558 void *entryName = NULL;
559 char *agent_function_name;
560 size_t i;
561
562 // If checking then use the agent name otherwise test is_static_lib() to
563 // see how to process this lookup
564 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
565 for (i = 0; i < syms_len; i++) {
566 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
567 if (agent_function_name == NULL) {
568 break;
569 }
570 entryName = dll_lookup(handle, agent_function_name);
571 FREE_C_HEAP_ARRAY(char, agent_function_name);
572 if (entryName != NULL) {
573 break;
574 }
575 }
576 return entryName;
577 }
578
579 // See if the passed in agent is statically linked into the VM image.
580 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
581 size_t syms_len) {
582 void *ret;
583 void *proc_handle;
584 void *save_handle;
585
586 assert(agent_lib != NULL, "sanity check");
587 if (agent_lib->name() == NULL) {
588 return false;
589 }
590 proc_handle = get_default_process_handle();
591 // Check for Agent_OnLoad/Attach_lib_name function
592 save_handle = agent_lib->os_lib();
593 // We want to look in this process' symbol table.
594 agent_lib->set_os_lib(proc_handle);
595 ret = find_agent_function(agent_lib, true, syms, syms_len);
596 if (ret != NULL) {
597 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
598 agent_lib->set_valid();
599 agent_lib->set_static_lib(true);
600 return true;
601 }
602 agent_lib->set_os_lib(save_handle);
603 return false;
604 }
605
606 // --------------------- heap allocation utilities ---------------------
607
608 char *os::strdup(const char *str, MEMFLAGS flags) {
609 size_t size = strlen(str);
610 char *dup_str = (char *)malloc(size + 1, flags);
611 if (dup_str == NULL) return NULL;
612 strcpy(dup_str, str);
613 return dup_str;
614 }
615
616 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
617 char* p = os::strdup(str, flags);
618 if (p == NULL) {
619 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
620 }
621 return p;
622 }
623
624
625 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
626
627 #ifdef ASSERT
628
629 static void verify_memory(void* ptr) {
630 GuardedMemory guarded(ptr);
631 if (!guarded.verify_guards()) {
632 LogTarget(Warning, malloc, free) lt;
633 ResourceMark rm;
634 LogStream ls(lt);
635 ls.print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
636 ls.print_cr("## memory stomp:");
637 guarded.print_on(&ls);
638 fatal("memory stomping error");
639 }
640 }
641
642 #endif
643
644 //
645 // This function supports testing of the malloc out of memory
646 // condition without really running the system out of memory.
647 //
648 static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
649 if (MallocMaxTestWords > 0) {
650 size_t words = (alloc_size / BytesPerWord);
651
652 if ((cur_malloc_words + words) > MallocMaxTestWords) {
653 return true;
654 }
655 Atomic::add(words, &cur_malloc_words);
656 }
657 return false;
658 }
659
660 void* os::malloc(size_t size, MEMFLAGS flags) {
661 return os::malloc(size, flags, CALLER_PC);
662 }
663
664 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
665 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
666 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
667
668 // Since os::malloc can be called when the libjvm.{dll,so} is
669 // first loaded and we don't have a thread yet we must accept NULL also here.
670 assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()),
671 "malloc() not allowed when crash protection is set");
672
673 if (size == 0) {
674 // return a valid pointer if size is zero
675 // if NULL is returned the calling functions assume out of memory.
676 size = 1;
677 }
678
679 // NMT support
680 NMT_TrackingLevel level = MemTracker::tracking_level();
681 size_t nmt_header_size = MemTracker::malloc_header_size(level);
682
683 #ifndef ASSERT
684 const size_t alloc_size = size + nmt_header_size;
685 #else
686 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
687 if (size + nmt_header_size > alloc_size) { // Check for rollover.
688 return NULL;
689 }
690 #endif
691
692 // For the test flag -XX:MallocMaxTestWords
693 if (has_reached_max_malloc_test_peak(size)) {
694 return NULL;
695 }
696
697 u_char* ptr;
698 ptr = (u_char*)::malloc(alloc_size);
699
700 #ifdef ASSERT
701 if (ptr == NULL) {
702 return NULL;
703 }
704 // Wrap memory with guard
705 GuardedMemory guarded(ptr, size + nmt_header_size);
706 ptr = guarded.get_user_ptr();
707
708 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
709 log_warning(malloc, free)("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
710 breakpoint();
711 }
712 if (paranoid) {
713 verify_memory(ptr);
714 }
715 #endif
716
717 // we do not track guard memory
718 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
719 }
720
721 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
722 return os::realloc(memblock, size, flags, CALLER_PC);
723 }
724
725 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
726
727 // For the test flag -XX:MallocMaxTestWords
728 if (has_reached_max_malloc_test_peak(size)) {
729 return NULL;
730 }
731
732 if (size == 0) {
733 // return a valid pointer if size is zero
734 // if NULL is returned the calling functions assume out of memory.
735 size = 1;
736 }
737
738 #ifndef ASSERT
739 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
740 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
741 // NMT support
742 void* membase = MemTracker::record_free(memblock);
743 NMT_TrackingLevel level = MemTracker::tracking_level();
744 size_t nmt_header_size = MemTracker::malloc_header_size(level);
745 void* ptr = ::realloc(membase, size + nmt_header_size);
746 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
747 #else
748 if (memblock == NULL) {
749 return os::malloc(size, memflags, stack);
750 }
751 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
752 log_warning(malloc, free)("os::realloc caught " PTR_FORMAT, p2i(memblock));
753 breakpoint();
754 }
755 // NMT support
756 void* membase = MemTracker::malloc_base(memblock);
757 verify_memory(membase);
758 // always move the block
759 void* ptr = os::malloc(size, memflags, stack);
760 // Copy to new memory if malloc didn't fail
761 if (ptr != NULL ) {
762 GuardedMemory guarded(MemTracker::malloc_base(memblock));
763 // Guard's user data contains NMT header
764 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
765 memcpy(ptr, memblock, MIN2(size, memblock_size));
766 if (paranoid) {
767 verify_memory(MemTracker::malloc_base(ptr));
768 }
769 os::free(memblock);
770 }
771 return ptr;
772 #endif
773 }
774
775
776 void os::free(void *memblock) {
777 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
778 #ifdef ASSERT
779 if (memblock == NULL) return;
780 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
781 log_warning(malloc, free)("os::free caught " PTR_FORMAT, p2i(memblock));
782 breakpoint();
783 }
784 void* membase = MemTracker::record_free(memblock);
785 verify_memory(membase);
786
787 GuardedMemory guarded(membase);
788 size_t size = guarded.get_user_size();
789 inc_stat_counter(&free_bytes, size);
790 membase = guarded.release_for_freeing();
791 ::free(membase);
792 #else
793 void* membase = MemTracker::record_free(memblock);
794 ::free(membase);
795 #endif
796 }
797
798 void os::init_random(unsigned int initval) {
799 _rand_seed = initval;
800 }
801
802
803 static int random_helper(unsigned int rand_seed) {
804 /* standard, well-known linear congruential random generator with
805 * next_rand = (16807*seed) mod (2**31-1)
806 * see
807 * (1) "Random Number Generators: Good Ones Are Hard to Find",
808 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
809 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
810 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
811 */
812 const unsigned int a = 16807;
813 const unsigned int m = 2147483647;
814 const int q = m / a; assert(q == 127773, "weird math");
815 const int r = m % a; assert(r == 2836, "weird math");
816
817 // compute az=2^31p+q
818 unsigned int lo = a * (rand_seed & 0xFFFF);
819 unsigned int hi = a * (rand_seed >> 16);
820 lo += (hi & 0x7FFF) << 16;
821
822 // if q overflowed, ignore the overflow and increment q
823 if (lo > m) {
824 lo &= m;
825 ++lo;
826 }
827 lo += hi >> 15;
828
829 // if (p+q) overflowed, ignore the overflow and increment (p+q)
830 if (lo > m) {
831 lo &= m;
832 ++lo;
833 }
834 return lo;
835 }
836
837 int os::random() {
838 // Make updating the random seed thread safe.
839 while (true) {
840 unsigned int seed = _rand_seed;
841 unsigned int rand = random_helper(seed);
842 if (Atomic::cmpxchg(rand, &_rand_seed, seed) == seed) {
843 return static_cast<int>(rand);
844 }
845 }
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 MutexLocker 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 void os::abort(bool dump_core) {
868 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
869 }
870
871 //---------------------------------------------------------------------------
872 // Helper functions for fatal error handler
873
874 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
875 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
876
877 start = align_down(start, unitsize);
878
879 int cols = 0;
880 int cols_per_line = 0;
881 switch (unitsize) {
882 case 1: cols_per_line = 16; break;
883 case 2: cols_per_line = 8; break;
884 case 4: cols_per_line = 4; break;
885 case 8: cols_per_line = 2; break;
886 default: return;
887 }
888
889 address p = start;
890 st->print(PTR_FORMAT ": ", p2i(start));
891 while (p < end) {
892 if (is_readable_pointer(p)) {
893 switch (unitsize) {
894 case 1: st->print("%02x", *(u1*)p); break;
895 case 2: st->print("%04x", *(u2*)p); break;
896 case 4: st->print("%08x", *(u4*)p); break;
897 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
898 }
899 } else {
900 st->print("%*.*s", 2*unitsize, 2*unitsize, "????????????????");
901 }
902 p += unitsize;
903 cols++;
904 if (cols >= cols_per_line && p < end) {
905 cols = 0;
906 st->cr();
907 st->print(PTR_FORMAT ": ", p2i(p));
908 } else {
909 st->print(" ");
910 }
911 }
912 st->cr();
913 }
914
915 void os::print_instructions(outputStream* st, address pc, int unitsize) {
916 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
917 print_hex_dump(st, pc - 256, pc + 256, unitsize);
918 }
919
920 void os::print_environment_variables(outputStream* st, const char** env_list) {
921 if (env_list) {
922 st->print_cr("Environment Variables:");
923
924 for (int i = 0; env_list[i] != NULL; i++) {
925 char *envvar = ::getenv(env_list[i]);
926 if (envvar != NULL) {
927 st->print("%s", env_list[i]);
928 st->print("=");
929 st->print_cr("%s", envvar);
930 }
931 }
932 }
933 }
934
935 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
936 // cpu
937 st->print("CPU:");
938 st->print("total %d", os::processor_count());
939 // It's not safe to query number of active processors after crash
940 // st->print("(active %d)", os::active_processor_count()); but we can
941 // print the initial number of active processors.
942 // We access the raw value here because the assert in the accessor will
943 // fail if the crash occurs before initialization of this value.
944 st->print(" (initial active %d)", _initial_active_processor_count);
945 st->print(" %s", VM_Version::features_string());
946 st->cr();
947 pd_print_cpu_info(st, buf, buflen);
948 }
949
950 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version
951 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
952 st->print("Host: ");
953 #ifndef PRODUCT
954 if (get_host_name(buf, buflen)) {
955 st->print("%s, ", buf);
956 }
957 #endif // PRODUCT
958 get_summary_cpu_info(buf, buflen);
959 st->print("%s, ", buf);
960 size_t mem = physical_memory()/G;
961 if (mem == 0) { // for low memory systems
962 mem = physical_memory()/M;
963 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
964 } else {
965 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
966 }
967 get_summary_os_info(buf, buflen);
968 st->print_raw(buf);
969 st->cr();
970 }
971
972 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
973 const int secs_per_day = 86400;
974 const int secs_per_hour = 3600;
975 const int secs_per_min = 60;
976
977 time_t tloc;
978 (void)time(&tloc);
979 char* timestring = ctime(&tloc); // ctime adds newline.
980 // edit out the newline
981 char* nl = strchr(timestring, '\n');
982 if (nl != NULL) {
983 *nl = '\0';
984 }
985
986 struct tm tz;
987 if (localtime_pd(&tloc, &tz) != NULL) {
988 ::strftime(buf, buflen, "%Z", &tz);
989 st->print("Time: %s %s", timestring, buf);
990 } else {
991 st->print("Time: %s", timestring);
992 }
993
994 double t = os::elapsedTime();
995 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
996 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
997 // before printf. We lost some precision, but who cares?
998 int eltime = (int)t; // elapsed time in seconds
999
1000 // print elapsed time in a human-readable format:
1001 int eldays = eltime / secs_per_day;
1002 int day_secs = eldays * secs_per_day;
1003 int elhours = (eltime - day_secs) / secs_per_hour;
1004 int hour_secs = elhours * secs_per_hour;
1005 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
1006 int minute_secs = elmins * secs_per_min;
1007 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
1008 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
1009 }
1010
1011
1012 // Check if pointer can be read from (4-byte read access).
1013 // Helps to prove validity of a not-NULL pointer.
1014 // Returns true in very early stages of VM life when stub is not yet generated.
1015 #define SAFEFETCH_DEFAULT true
1016 bool os::is_readable_pointer(const void* p) {
1017 if (!CanUseSafeFetch32()) {
1018 return SAFEFETCH_DEFAULT;
1019 }
1020 int* const aligned = (int*) align_down((intptr_t)p, 4);
1021 int cafebabe = 0xcafebabe; // tester value 1
1022 int deadbeef = 0xdeadbeef; // tester value 2
1023 return (SafeFetch32(aligned, cafebabe) != cafebabe) || (SafeFetch32(aligned, deadbeef) != deadbeef);
1024 }
1025
1026 bool os::is_readable_range(const void* from, const void* to) {
1027 if ((uintptr_t)from >= (uintptr_t)to) return false;
1028 for (uintptr_t p = align_down((uintptr_t)from, min_page_size()); p < (uintptr_t)to; p += min_page_size()) {
1029 if (!is_readable_pointer((const void*)p)) {
1030 return false;
1031 }
1032 }
1033 return true;
1034 }
1035
1036
1037 // moved from debug.cpp (used to be find()) but still called from there
1038 // The verbose parameter is only set by the debug code in one case
1039 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
1040 address addr = (address)x;
1041 // Handle NULL first, so later checks don't need to protect against it.
1042 if (addr == NULL) {
1043 st->print_cr("0x0 is NULL");
1044 return;
1045 }
1046
1047 // Check if addr points into a code blob.
1048 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
1049 if (b != NULL) {
1050 b->dump_for_addr(addr, st, verbose);
1051 return;
1052 }
1053
1054 // Check if addr points into Java heap.
1055 if (Universe::heap()->is_in(addr)) {
1056 oop o = oopDesc::oop_or_null(addr);
1057 if (o != NULL) {
1058 if ((HeapWord*)o == (HeapWord*)addr) {
1059 st->print(INTPTR_FORMAT " is an oop: ", p2i(addr));
1060 } else {
1061 st->print(INTPTR_FORMAT " is pointing into object: " , p2i(addr));
1062 }
1063 o->print_on(st);
1064 return;
1065 }
1066 } else if (Universe::heap()->is_in_reserved(addr)) {
1067 st->print_cr(INTPTR_FORMAT " is an unallocated location in the heap", p2i(addr));
1068 return;
1069 }
1070
1071 // Compressed oop needs to be decoded first.
1072 #ifdef _LP64
1073 if (UseCompressedOops && ((uintptr_t)addr &~ (uintptr_t)max_juint) == 0) {
1074 narrowOop narrow_oop = (narrowOop)(uintptr_t)addr;
1075 oop o = CompressedOops::decode_raw(narrow_oop);
1076
1077 if (oopDesc::is_valid(o)) {
1078 st->print(UINT32_FORMAT " is a compressed pointer to object: ", narrow_oop);
1079 o->print_on(st);
1080 return;
1081 }
1082 }
1083 #endif
1084
1085 bool accessible = is_readable_pointer(addr);
1086
1087 // Check if addr is a JNI handle.
1088 if (align_down((intptr_t)addr, sizeof(intptr_t)) != 0 && accessible) {
1089 if (JNIHandles::is_global_handle((jobject) addr)) {
1090 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
1091 return;
1092 }
1093 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1094 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
1095 return;
1096 }
1097 #ifndef PRODUCT
1098 // we don't keep the block list in product mode
1099 if (JNIHandles::is_local_handle((jobject) addr)) {
1100 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
1101 return;
1102 }
1103 #endif
1104 }
1105
1106 // Check if addr belongs to a Java thread.
1107 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
1108 // If the addr is a java thread print information about that.
1109 if (addr == (address)thread) {
1110 if (verbose) {
1111 thread->print_on(st);
1112 } else {
1113 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
1114 }
1115 return;
1116 }
1117 // If the addr is in the stack region for this thread then report that
1118 // and print thread info
1119 if (thread->on_local_stack(addr)) {
1120 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1121 INTPTR_FORMAT, p2i(addr), p2i(thread));
1122 if (verbose) thread->print_on(st);
1123 return;
1124 }
1125 }
1126
1127 // Check if in metaspace and print types that have vptrs
1128 if (Metaspace::contains(addr)) {
1129 if (Klass::is_valid((Klass*)addr)) {
1130 st->print_cr(INTPTR_FORMAT " is a pointer to class: ", p2i(addr));
1131 ((Klass*)addr)->print_on(st);
1132 } else if (Method::is_valid_method((const Method*)addr)) {
1133 ((Method*)addr)->print_value_on(st);
1134 st->cr();
1135 } else {
1136 // Use addr->print() from the debugger instead (not here)
1137 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
1138 }
1139 return;
1140 }
1141
1142 // Compressed klass needs to be decoded first.
1143 #ifdef _LP64
1144 if (UseCompressedClassPointers && ((uintptr_t)addr &~ (uintptr_t)max_juint) == 0) {
1145 narrowKlass narrow_klass = (narrowKlass)(uintptr_t)addr;
1146 Klass* k = CompressedKlassPointers::decode_raw(narrow_klass);
1147
1148 if (Klass::is_valid(k)) {
1149 st->print_cr(UINT32_FORMAT " is a compressed pointer to class: " INTPTR_FORMAT, narrow_klass, p2i((HeapWord*)k));
1150 k->print_on(st);
1151 return;
1152 }
1153 }
1154 #endif
1155
1156 // Try an OS specific find
1157 if (os::find(addr, st)) {
1158 return;
1159 }
1160
1161 if (accessible) {
1162 st->print(INTPTR_FORMAT " points into unknown readable memory:", p2i(addr));
1163 for (address p = addr; p < align_up(addr + 1, sizeof(intptr_t)); ++p) {
1164 st->print(" %02x", *(u1*)p);
1165 }
1166 st->cr();
1167 return;
1168 }
1169
1170 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
1171 }
1172
1173 // Looks like all platforms can use the same function to check if C
1174 // stack is walkable beyond current frame. The check for fp() is not
1175 // necessary on Sparc, but it's harmless.
1176 bool os::is_first_C_frame(frame* fr) {
1177 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1178 // Check usp first, because if that's bad the other accessors may fault
1179 // on some architectures. Ditto ufp second, etc.
1180 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1181 // sp on amd can be 32 bit aligned.
1182 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1183
1184 uintptr_t usp = (uintptr_t)fr->sp();
1185 if ((usp & sp_align_mask) != 0) return true;
1186
1187 uintptr_t ufp = (uintptr_t)fr->fp();
1188 if ((ufp & fp_align_mask) != 0) return true;
1189
1190 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1191 if ((old_sp & sp_align_mask) != 0) return true;
1192 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1193
1194 uintptr_t old_fp = (uintptr_t)fr->link();
1195 if ((old_fp & fp_align_mask) != 0) return true;
1196 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1197
1198 // stack grows downwards; if old_fp is below current fp or if the stack
1199 // frame is too large, either the stack is corrupted or fp is not saved
1200 // on stack (i.e. on x86, ebp may be used as general register). The stack
1201 // is not walkable beyond current frame.
1202 if (old_fp < ufp) return true;
1203 if (old_fp - ufp > 64 * K) return true;
1204
1205 return false;
1206 }
1207
1208
1209 // Set up the boot classpath.
1210
1211 char* os::format_boot_path(const char* format_string,
1212 const char* home,
1213 int home_len,
1214 char fileSep,
1215 char pathSep) {
1216 assert((fileSep == '/' && pathSep == ':') ||
1217 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1218
1219 // Scan the format string to determine the length of the actual
1220 // boot classpath, and handle platform dependencies as well.
1221 int formatted_path_len = 0;
1222 const char* p;
1223 for (p = format_string; *p != 0; ++p) {
1224 if (*p == '%') formatted_path_len += home_len - 1;
1225 ++formatted_path_len;
1226 }
1227
1228 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1229 if (formatted_path == NULL) {
1230 return NULL;
1231 }
1232
1233 // Create boot classpath from format, substituting separator chars and
1234 // java home directory.
1235 char* q = formatted_path;
1236 for (p = format_string; *p != 0; ++p) {
1237 switch (*p) {
1238 case '%':
1239 strcpy(q, home);
1240 q += home_len;
1241 break;
1242 case '/':
1243 *q++ = fileSep;
1244 break;
1245 case ':':
1246 *q++ = pathSep;
1247 break;
1248 default:
1249 *q++ = *p;
1250 }
1251 }
1252 *q = '\0';
1253
1254 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1255 return formatted_path;
1256 }
1257
1258 // This function is a proxy to fopen, it tries to add a non standard flag ('e' or 'N')
1259 // that ensures automatic closing of the file on exec. If it can not find support in
1260 // the underlying c library, it will make an extra system call (fcntl) to ensure automatic
1261 // closing of the file on exec.
1262 FILE* os::fopen(const char* path, const char* mode) {
1263 char modified_mode[20];
1264 assert(strlen(mode) + 1 < sizeof(modified_mode), "mode chars plus one extra must fit in buffer");
1265 sprintf(modified_mode, "%s" LINUX_ONLY("e") BSD_ONLY("e") WINDOWS_ONLY("N"), mode);
1266 FILE* file = ::fopen(path, modified_mode);
1267
1268 #if !(defined LINUX || defined BSD || defined _WINDOWS)
1269 // assume fcntl FD_CLOEXEC support as a backup solution when 'e' or 'N'
1270 // is not supported as mode in fopen
1271 if (file != NULL) {
1272 int fd = fileno(file);
1273 if (fd != -1) {
1274 int fd_flags = fcntl(fd, F_GETFD);
1275 if (fd_flags != -1) {
1276 fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC);
1277 }
1278 }
1279 }
1280 #endif
1281
1282 return file;
1283 }
1284
1285 bool os::set_boot_path(char fileSep, char pathSep) {
1286 const char* home = Arguments::get_java_home();
1287 int home_len = (int)strlen(home);
1288
1289 struct stat st;
1290
1291 // modular image if "modules" jimage exists
1292 char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep);
1293 if (jimage == NULL) return false;
1294 bool has_jimage = (os::stat(jimage, &st) == 0);
1295 if (has_jimage) {
1296 Arguments::set_sysclasspath(jimage, true);
1297 FREE_C_HEAP_ARRAY(char, jimage);
1298 return true;
1299 }
1300 FREE_C_HEAP_ARRAY(char, jimage);
1301
1302 // check if developer build with exploded modules
1303 char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep);
1304 if (base_classes == NULL) return false;
1305 if (os::stat(base_classes, &st) == 0) {
1306 Arguments::set_sysclasspath(base_classes, false);
1307 FREE_C_HEAP_ARRAY(char, base_classes);
1308 return true;
1309 }
1310 FREE_C_HEAP_ARRAY(char, base_classes);
1311
1312 return false;
1313 }
1314
1315 /*
1316 * Splits a path, based on its separator, the number of
1317 * elements is returned back in n.
1318 * It is the callers responsibility to:
1319 * a> check the value of n, and n may be 0.
1320 * b> ignore any empty path elements
1321 * c> free up the data.
1322 */
1323 char** os::split_path(const char* path, int* n) {
1324 *n = 0;
1325 if (path == NULL || strlen(path) == 0) {
1326 return NULL;
1327 }
1328 const char psepchar = *os::path_separator();
1329 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1330 if (inpath == NULL) {
1331 return NULL;
1332 }
1333 strcpy(inpath, path);
1334 int count = 1;
1335 char* p = strchr(inpath, psepchar);
1336 // Get a count of elements to allocate memory
1337 while (p != NULL) {
1338 count++;
1339 p++;
1340 p = strchr(p, psepchar);
1341 }
1342 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1343 if (opath == NULL) {
1344 return NULL;
1345 }
1346
1347 // do the actual splitting
1348 p = inpath;
1349 for (int i = 0 ; i < count ; i++) {
1350 size_t len = strcspn(p, os::path_separator());
1351 if (len > JVM_MAXPATHLEN) {
1352 return NULL;
1353 }
1354 // allocate the string and add terminator storage
1355 char* s = (char*)NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1356 if (s == NULL) {
1357 return NULL;
1358 }
1359 strncpy(s, p, len);
1360 s[len] = '\0';
1361 opath[i] = s;
1362 p += len + 1;
1363 }
1364 FREE_C_HEAP_ARRAY(char, inpath);
1365 *n = count;
1366 return opath;
1367 }
1368
1369 // Returns true if the current stack pointer is above the stack shadow
1370 // pages, false otherwise.
1371 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) {
1372 if (!thread->is_Java_thread()) return false;
1373 // Check if we have StackShadowPages above the yellow zone. This parameter
1374 // is dependent on the depth of the maximum VM call stack possible from
1375 // the handler for stack overflow. 'instanceof' in the stack overflow
1376 // handler or a println uses at least 8k stack of VM and native code
1377 // respectively.
1378 const int framesize_in_bytes =
1379 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1380
1381 address limit = ((JavaThread*)thread)->stack_end() +
1382 (JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size());
1383
1384 return sp > (limit + framesize_in_bytes);
1385 }
1386
1387 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1388 assert(min_pages > 0, "sanity");
1389 if (UseLargePages) {
1390 const size_t max_page_size = region_size / min_pages;
1391
1392 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1393 const size_t page_size = _page_sizes[i];
1394 if (page_size <= max_page_size) {
1395 if (!must_be_aligned || is_aligned(region_size, page_size)) {
1396 return page_size;
1397 }
1398 }
1399 }
1400 }
1401
1402 return vm_page_size();
1403 }
1404
1405 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1406 return page_size_for_region(region_size, min_pages, true);
1407 }
1408
1409 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1410 return page_size_for_region(region_size, min_pages, false);
1411 }
1412
1413 static const char* errno_to_string (int e, bool short_text) {
1414 #define ALL_SHARED_ENUMS(X) \
1415 X(E2BIG, "Argument list too long") \
1416 X(EACCES, "Permission denied") \
1417 X(EADDRINUSE, "Address in use") \
1418 X(EADDRNOTAVAIL, "Address not available") \
1419 X(EAFNOSUPPORT, "Address family not supported") \
1420 X(EAGAIN, "Resource unavailable, try again") \
1421 X(EALREADY, "Connection already in progress") \
1422 X(EBADF, "Bad file descriptor") \
1423 X(EBADMSG, "Bad message") \
1424 X(EBUSY, "Device or resource busy") \
1425 X(ECANCELED, "Operation canceled") \
1426 X(ECHILD, "No child processes") \
1427 X(ECONNABORTED, "Connection aborted") \
1428 X(ECONNREFUSED, "Connection refused") \
1429 X(ECONNRESET, "Connection reset") \
1430 X(EDEADLK, "Resource deadlock would occur") \
1431 X(EDESTADDRREQ, "Destination address required") \
1432 X(EDOM, "Mathematics argument out of domain of function") \
1433 X(EEXIST, "File exists") \
1434 X(EFAULT, "Bad address") \
1435 X(EFBIG, "File too large") \
1436 X(EHOSTUNREACH, "Host is unreachable") \
1437 X(EIDRM, "Identifier removed") \
1438 X(EILSEQ, "Illegal byte sequence") \
1439 X(EINPROGRESS, "Operation in progress") \
1440 X(EINTR, "Interrupted function") \
1441 X(EINVAL, "Invalid argument") \
1442 X(EIO, "I/O error") \
1443 X(EISCONN, "Socket is connected") \
1444 X(EISDIR, "Is a directory") \
1445 X(ELOOP, "Too many levels of symbolic links") \
1446 X(EMFILE, "Too many open files") \
1447 X(EMLINK, "Too many links") \
1448 X(EMSGSIZE, "Message too large") \
1449 X(ENAMETOOLONG, "Filename too long") \
1450 X(ENETDOWN, "Network is down") \
1451 X(ENETRESET, "Connection aborted by network") \
1452 X(ENETUNREACH, "Network unreachable") \
1453 X(ENFILE, "Too many files open in system") \
1454 X(ENOBUFS, "No buffer space available") \
1455 X(ENODATA, "No message is available on the STREAM head read queue") \
1456 X(ENODEV, "No such device") \
1457 X(ENOENT, "No such file or directory") \
1458 X(ENOEXEC, "Executable file format error") \
1459 X(ENOLCK, "No locks available") \
1460 X(ENOLINK, "Reserved") \
1461 X(ENOMEM, "Not enough space") \
1462 X(ENOMSG, "No message of the desired type") \
1463 X(ENOPROTOOPT, "Protocol not available") \
1464 X(ENOSPC, "No space left on device") \
1465 X(ENOSR, "No STREAM resources") \
1466 X(ENOSTR, "Not a STREAM") \
1467 X(ENOSYS, "Function not supported") \
1468 X(ENOTCONN, "The socket is not connected") \
1469 X(ENOTDIR, "Not a directory") \
1470 X(ENOTEMPTY, "Directory not empty") \
1471 X(ENOTSOCK, "Not a socket") \
1472 X(ENOTSUP, "Not supported") \
1473 X(ENOTTY, "Inappropriate I/O control operation") \
1474 X(ENXIO, "No such device or address") \
1475 X(EOPNOTSUPP, "Operation not supported on socket") \
1476 X(EOVERFLOW, "Value too large to be stored in data type") \
1477 X(EPERM, "Operation not permitted") \
1478 X(EPIPE, "Broken pipe") \
1479 X(EPROTO, "Protocol error") \
1480 X(EPROTONOSUPPORT, "Protocol not supported") \
1481 X(EPROTOTYPE, "Protocol wrong type for socket") \
1482 X(ERANGE, "Result too large") \
1483 X(EROFS, "Read-only file system") \
1484 X(ESPIPE, "Invalid seek") \
1485 X(ESRCH, "No such process") \
1486 X(ETIME, "Stream ioctl() timeout") \
1487 X(ETIMEDOUT, "Connection timed out") \
1488 X(ETXTBSY, "Text file busy") \
1489 X(EWOULDBLOCK, "Operation would block") \
1490 X(EXDEV, "Cross-device link")
1491
1492 #define DEFINE_ENTRY(e, text) { e, #e, text },
1493
1494 static const struct {
1495 int v;
1496 const char* short_text;
1497 const char* long_text;
1498 } table [] = {
1499
1500 ALL_SHARED_ENUMS(DEFINE_ENTRY)
1501
1502 // The following enums are not defined on all platforms.
1503 #ifdef ESTALE
1504 DEFINE_ENTRY(ESTALE, "Reserved")
1505 #endif
1506 #ifdef EDQUOT
1507 DEFINE_ENTRY(EDQUOT, "Reserved")
1508 #endif
1509 #ifdef EMULTIHOP
1510 DEFINE_ENTRY(EMULTIHOP, "Reserved")
1511 #endif
1512
1513 // End marker.
1514 { -1, "Unknown errno", "Unknown error" }
1515
1516 };
1517
1518 #undef DEFINE_ENTRY
1519 #undef ALL_FLAGS
1520
1521 int i = 0;
1522 while (table[i].v != -1 && table[i].v != e) {
1523 i ++;
1524 }
1525
1526 return short_text ? table[i].short_text : table[i].long_text;
1527
1528 }
1529
1530 const char* os::strerror(int e) {
1531 return errno_to_string(e, false);
1532 }
1533
1534 const char* os::errno_name(int e) {
1535 return errno_to_string(e, true);
1536 }
1537
1538 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) {
1539 LogTarget(Info, pagesize) log;
1540 if (log.is_enabled()) {
1541 LogStream out(log);
1542
1543 out.print("%s: ", str);
1544 for (int i = 0; i < count; ++i) {
1545 out.print(" " SIZE_FORMAT, page_sizes[i]);
1546 }
1547 out.cr();
1548 }
1549 }
1550
1551 #define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size)
1552
1553 void os::trace_page_sizes(const char* str,
1554 const size_t region_min_size,
1555 const size_t region_max_size,
1556 const size_t page_size,
1557 const char* base,
1558 const size_t size) {
1559
1560 log_info(pagesize)("%s: "
1561 " min=" SIZE_FORMAT "%s"
1562 " max=" SIZE_FORMAT "%s"
1563 " base=" PTR_FORMAT
1564 " page_size=" SIZE_FORMAT "%s"
1565 " size=" SIZE_FORMAT "%s",
1566 str,
1567 trace_page_size_params(region_min_size),
1568 trace_page_size_params(region_max_size),
1569 p2i(base),
1570 trace_page_size_params(page_size),
1571 trace_page_size_params(size));
1572 }
1573
1574 void os::trace_page_sizes_for_requested_size(const char* str,
1575 const size_t requested_size,
1576 const size_t page_size,
1577 const size_t alignment,
1578 const char* base,
1579 const size_t size) {
1580
1581 log_info(pagesize)("%s:"
1582 " req_size=" SIZE_FORMAT "%s"
1583 " base=" PTR_FORMAT
1584 " page_size=" SIZE_FORMAT "%s"
1585 " alignment=" SIZE_FORMAT "%s"
1586 " size=" SIZE_FORMAT "%s",
1587 str,
1588 trace_page_size_params(requested_size),
1589 p2i(base),
1590 trace_page_size_params(page_size),
1591 trace_page_size_params(alignment),
1592 trace_page_size_params(size));
1593 }
1594
1595
1596 // This is the working definition of a server class machine:
1597 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1598 // because the graphics memory (?) sometimes masks physical memory.
1599 // If you want to change the definition of a server class machine
1600 // on some OS or platform, e.g., >=4GB on Windows platforms,
1601 // then you'll have to parameterize this method based on that state,
1602 // as was done for logical processors here, or replicate and
1603 // specialize this method for each platform. (Or fix os to have
1604 // some inheritance structure and use subclassing. Sigh.)
1605 // If you want some platform to always or never behave as a server
1606 // class machine, change the setting of AlwaysActAsServerClassMachine
1607 // and NeverActAsServerClassMachine in globals*.hpp.
1608 bool os::is_server_class_machine() {
1609 // First check for the early returns
1610 if (NeverActAsServerClassMachine) {
1611 return false;
1612 }
1613 if (AlwaysActAsServerClassMachine) {
1614 return true;
1615 }
1616 // Then actually look at the machine
1617 bool result = false;
1618 const unsigned int server_processors = 2;
1619 const julong server_memory = 2UL * G;
1620 // We seem not to get our full complement of memory.
1621 // We allow some part (1/8?) of the memory to be "missing",
1622 // based on the sizes of DIMMs, and maybe graphics cards.
1623 const julong missing_memory = 256UL * M;
1624
1625 /* Is this a server class machine? */
1626 if ((os::active_processor_count() >= (int)server_processors) &&
1627 (os::physical_memory() >= (server_memory - missing_memory))) {
1628 const unsigned int logical_processors =
1629 VM_Version::logical_processors_per_package();
1630 if (logical_processors > 1) {
1631 const unsigned int physical_packages =
1632 os::active_processor_count() / logical_processors;
1633 if (physical_packages >= server_processors) {
1634 result = true;
1635 }
1636 } else {
1637 result = true;
1638 }
1639 }
1640 return result;
1641 }
1642
1643 void os::initialize_initial_active_processor_count() {
1644 assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
1645 _initial_active_processor_count = active_processor_count();
1646 log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count);
1647 }
1648
1649 void os::SuspendedThreadTask::run() {
1650 internal_do_task();
1651 _done = true;
1652 }
1653
1654 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1655 return os::pd_create_stack_guard_pages(addr, bytes);
1656 }
1657
1658 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, int file_desc) {
1659 char* result = NULL;
1660
1661 if (file_desc != -1) {
1662 // Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(),
1663 // but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file.
1664 result = os::map_memory_to_file(addr, bytes, file_desc);
1665 if (result != NULL) {
1666 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1667 }
1668 } else {
1669 result = pd_reserve_memory(bytes, addr, alignment_hint);
1670 if (result != NULL) {
1671 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1672 }
1673 }
1674
1675 return result;
1676 }
1677
1678 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1679 MEMFLAGS flags) {
1680 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1681 if (result != NULL) {
1682 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1683 MemTracker::record_virtual_memory_type((address)result, flags);
1684 }
1685
1686 return result;
1687 }
1688
1689 char* os::attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc) {
1690 char* result = NULL;
1691 if (file_desc != -1) {
1692 result = pd_attempt_reserve_memory_at(bytes, addr, file_desc);
1693 if (result != NULL) {
1694 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1695 }
1696 } else {
1697 result = pd_attempt_reserve_memory_at(bytes, addr);
1698 if (result != NULL) {
1699 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1700 }
1701 }
1702 return result;
1703 }
1704
1705 void os::split_reserved_memory(char *base, size_t size,
1706 size_t split, bool realloc) {
1707 pd_split_reserved_memory(base, size, split, realloc);
1708 }
1709
1710 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1711 bool res = pd_commit_memory(addr, bytes, executable);
1712 if (res) {
1713 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1714 }
1715 return res;
1716 }
1717
1718 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1719 bool executable) {
1720 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1721 if (res) {
1722 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1723 }
1724 return res;
1725 }
1726
1727 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1728 const char* mesg) {
1729 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1730 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1731 }
1732
1733 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1734 bool executable, const char* mesg) {
1735 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1736 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1737 }
1738
1739 bool os::uncommit_memory(char* addr, size_t bytes) {
1740 bool res;
1741 if (MemTracker::tracking_level() > NMT_minimal) {
1742 Tracker tkr(Tracker::uncommit);
1743 res = pd_uncommit_memory(addr, bytes);
1744 if (res) {
1745 tkr.record((address)addr, bytes);
1746 }
1747 } else {
1748 res = pd_uncommit_memory(addr, bytes);
1749 }
1750 return res;
1751 }
1752
1753 bool os::release_memory(char* addr, size_t bytes) {
1754 bool res;
1755 if (MemTracker::tracking_level() > NMT_minimal) {
1756 Tracker tkr(Tracker::release);
1757 res = pd_release_memory(addr, bytes);
1758 if (res) {
1759 tkr.record((address)addr, bytes);
1760 }
1761 } else {
1762 res = pd_release_memory(addr, bytes);
1763 }
1764 return res;
1765 }
1766
1767 void os::pretouch_memory(void* start, void* end, size_t page_size) {
1768 for (volatile char *p = (char*)start; p < (char*)end; p += page_size) {
1769 *p = 0;
1770 }
1771 }
1772
1773 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1774 char *addr, size_t bytes, bool read_only,
1775 bool allow_exec) {
1776 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1777 if (result != NULL) {
1778 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1779 }
1780 return result;
1781 }
1782
1783 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1784 char *addr, size_t bytes, bool read_only,
1785 bool allow_exec) {
1786 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1787 read_only, allow_exec);
1788 }
1789
1790 bool os::unmap_memory(char *addr, size_t bytes) {
1791 bool result;
1792 if (MemTracker::tracking_level() > NMT_minimal) {
1793 Tracker tkr(Tracker::release);
1794 result = pd_unmap_memory(addr, bytes);
1795 if (result) {
1796 tkr.record((address)addr, bytes);
1797 }
1798 } else {
1799 result = pd_unmap_memory(addr, bytes);
1800 }
1801 return result;
1802 }
1803
1804 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1805 pd_free_memory(addr, bytes, alignment_hint);
1806 }
1807
1808 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1809 pd_realign_memory(addr, bytes, alignment_hint);
1810 }
1811
1812 #ifndef _WINDOWS
1813 /* try to switch state from state "from" to state "to"
1814 * returns the state set after the method is complete
1815 */
1816 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1817 os::SuspendResume::State to)
1818 {
1819 os::SuspendResume::State result = Atomic::cmpxchg(to, &_state, from);
1820 if (result == from) {
1821 // success
1822 return to;
1823 }
1824 return result;
1825 }
1826 #endif