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 // Frees all memory allocated on the heap for the
283 // supplied array of arrays of chars (a), where n
284 // is the number of elements in the array.
285 static void free_array_of_char_arrays(char** a, size_t n) {
286 while (n > 0) {
287 n--;
288 if (a[n] != NULL) {
289 FREE_C_HEAP_ARRAY(char, a[n]);
290 }
291 }
292 FREE_C_HEAP_ARRAY(char*, a);
293 }
294
295 bool os::dll_locate_lib(char *buffer, size_t buflen,
296 const char* pname, const char* fname) {
297 bool retval = false;
298
299 size_t fullfnamelen = strlen(JNI_LIB_PREFIX) + strlen(fname) + strlen(JNI_LIB_SUFFIX);
300 char* fullfname = (char*)NEW_C_HEAP_ARRAY(char, fullfnamelen + 1, mtInternal);
301 if (dll_build_name(fullfname, fullfnamelen + 1, fname)) {
302 const size_t pnamelen = pname ? strlen(pname) : 0;
303
304 if (pnamelen == 0) {
305 // If no path given, use current working directory.
306 const char* p = get_current_directory(buffer, buflen);
307 if (p != NULL) {
308 const size_t plen = strlen(buffer);
309 const char lastchar = buffer[plen - 1];
310 retval = conc_path_file_and_check(buffer, &buffer[plen], buflen - plen,
311 "", lastchar, fullfname);
312 }
313 } else if (strchr(pname, *os::path_separator()) != NULL) {
314 // A list of paths. Search for the path that contains the library.
315 size_t n;
316 char** pelements = split_path(pname, &n, fullfnamelen);
317 if (pelements != NULL) {
318 for (size_t i = 0; i < n; i++) {
319 char* path = pelements[i];
320 // Really shouldn't be NULL, but check can't hurt.
321 size_t plen = (path == NULL) ? 0 : strlen(path);
322 if (plen == 0) {
323 continue; // Skip the empty path values.
324 }
325 const char lastchar = path[plen - 1];
326 retval = conc_path_file_and_check(buffer, buffer, buflen, path, lastchar, fullfname);
327 if (retval) break;
328 }
329 // Release the storage allocated by split_path.
330 free_array_of_char_arrays(pelements, n);
331 }
332 } else {
333 // A definite path.
334 const char lastchar = pname[pnamelen-1];
335 retval = conc_path_file_and_check(buffer, buffer, buflen, pname, lastchar, fullfname);
336 }
337 }
338
339 FREE_C_HEAP_ARRAY(char*, fullfname);
340 return retval;
341 }
342
343 // --------------------- sun.misc.Signal (optional) ---------------------
344
345
346 // SIGBREAK is sent by the keyboard to query the VM state
347 #ifndef SIGBREAK
348 #define SIGBREAK SIGQUIT
349 #endif
350
351 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
352
353
354 static void signal_thread_entry(JavaThread* thread, TRAPS) {
355 os::set_priority(thread, NearMaxPriority);
356 while (true) {
357 int sig;
358 {
359 // FIXME : Currently we have not decided what should be the status
360 // for this java thread blocked here. Once we decide about
361 // that we should fix this.
362 sig = os::signal_wait();
363 }
364 if (sig == os::sigexitnum_pd()) {
365 // Terminate the signal thread
366 return;
367 }
368
369 switch (sig) {
370 case SIGBREAK: {
371 #if INCLUDE_SERVICES
372 // Check if the signal is a trigger to start the Attach Listener - in that
373 // case don't print stack traces.
374 if (!DisableAttachMechanism) {
375 // Attempt to transit state to AL_INITIALIZING.
376 AttachListenerState cur_state = AttachListener::transit_state(AL_INITIALIZING, AL_NOT_INITIALIZED);
377 if (cur_state == AL_INITIALIZING) {
378 // Attach Listener has been started to initialize. Ignore this signal.
379 continue;
380 } else if (cur_state == AL_NOT_INITIALIZED) {
381 // Start to initialize.
382 if (AttachListener::is_init_trigger()) {
383 // Attach Listener has been initialized.
384 // Accept subsequent request.
385 continue;
386 } else {
387 // Attach Listener could not be started.
388 // So we need to transit the state to AL_NOT_INITIALIZED.
389 AttachListener::set_state(AL_NOT_INITIALIZED);
390 }
391 } else if (AttachListener::check_socket_file()) {
392 // Attach Listener has been started, but unix domain socket file
393 // does not exist. So restart Attach Listener.
394 continue;
395 }
396 }
397 #endif
398 // Print stack traces
399 // Any SIGBREAK operations added here should make sure to flush
400 // the output stream (e.g. tty->flush()) after output. See 4803766.
401 // Each module also prints an extra carriage return after its output.
402 VM_PrintThreads op;
403 VMThread::execute(&op);
404 VM_PrintJNI jni_op;
405 VMThread::execute(&jni_op);
406 VM_FindDeadlocks op1(tty);
407 VMThread::execute(&op1);
408 Universe::print_heap_at_SIGBREAK();
409 if (PrintClassHistogram) {
410 VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */);
411 VMThread::execute(&op1);
412 }
413 if (JvmtiExport::should_post_data_dump()) {
414 JvmtiExport::post_data_dump();
415 }
416 break;
417 }
418 default: {
419 // Dispatch the signal to java
420 HandleMark hm(THREAD);
421 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD);
422 if (klass != NULL) {
423 JavaValue result(T_VOID);
424 JavaCallArguments args;
425 args.push_int(sig);
426 JavaCalls::call_static(
427 &result,
428 klass,
429 vmSymbols::dispatch_name(),
430 vmSymbols::int_void_signature(),
431 &args,
432 THREAD
433 );
434 }
435 if (HAS_PENDING_EXCEPTION) {
436 // tty is initialized early so we don't expect it to be null, but
437 // if it is we can't risk doing an initialization that might
438 // trigger additional out-of-memory conditions
439 if (tty != NULL) {
440 char klass_name[256];
441 char tmp_sig_name[16];
442 const char* sig_name = "UNKNOWN";
443 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
444 name()->as_klass_external_name(klass_name, 256);
445 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
446 sig_name = tmp_sig_name;
447 warning("Exception %s occurred dispatching signal %s to handler"
448 "- the VM may need to be forcibly terminated",
449 klass_name, sig_name );
450 }
451 CLEAR_PENDING_EXCEPTION;
452 }
453 }
454 }
455 }
456 }
457
458 void os::init_before_ergo() {
459 initialize_initial_active_processor_count();
460 // We need to initialize large page support here because ergonomics takes some
461 // decisions depending on large page support and the calculated large page size.
462 large_page_init();
463
464 // We need to adapt the configured number of stack protection pages given
465 // in 4K pages to the actual os page size. We must do this before setting
466 // up minimal stack sizes etc. in os::init_2().
467 JavaThread::set_stack_red_zone_size (align_up(StackRedPages * 4 * K, vm_page_size()));
468 JavaThread::set_stack_yellow_zone_size (align_up(StackYellowPages * 4 * K, vm_page_size()));
469 JavaThread::set_stack_reserved_zone_size(align_up(StackReservedPages * 4 * K, vm_page_size()));
470 JavaThread::set_stack_shadow_zone_size (align_up(StackShadowPages * 4 * K, vm_page_size()));
471
472 // VM version initialization identifies some characteristics of the
473 // platform that are used during ergonomic decisions.
474 VM_Version::init_before_ergo();
475 }
476
477 void os::initialize_jdk_signal_support(TRAPS) {
478 if (!ReduceSignalUsage) {
479 // Setup JavaThread for processing signals
480 const char thread_name[] = "Signal Dispatcher";
481 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
482
483 // Initialize thread_oop to put it into the system threadGroup
484 Handle thread_group (THREAD, Universe::system_thread_group());
485 Handle thread_oop = JavaCalls::construct_new_instance(SystemDictionary::Thread_klass(),
486 vmSymbols::threadgroup_string_void_signature(),
487 thread_group,
488 string,
489 CHECK);
490
491 Klass* group = SystemDictionary::ThreadGroup_klass();
492 JavaValue result(T_VOID);
493 JavaCalls::call_special(&result,
494 thread_group,
495 group,
496 vmSymbols::add_method_name(),
497 vmSymbols::thread_void_signature(),
498 thread_oop,
499 CHECK);
500
501 { MutexLocker mu(Threads_lock);
502 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
503
504 // At this point it may be possible that no osthread was created for the
505 // JavaThread due to lack of memory. We would have to throw an exception
506 // in that case. However, since this must work and we do not allow
507 // exceptions anyway, check and abort if this fails.
508 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
509 vm_exit_during_initialization("java.lang.OutOfMemoryError",
510 os::native_thread_creation_failed_msg());
511 }
512
513 java_lang_Thread::set_thread(thread_oop(), signal_thread);
514 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
515 java_lang_Thread::set_daemon(thread_oop());
516
517 signal_thread->set_threadObj(thread_oop());
518 Threads::add(signal_thread);
519 Thread::start(signal_thread);
520 }
521 // Handle ^BREAK
522 os::signal(SIGBREAK, os::user_handler());
523 }
524 }
525
526
527 void os::terminate_signal_thread() {
528 if (!ReduceSignalUsage)
529 signal_notify(sigexitnum_pd());
530 }
531
532
533 // --------------------- loading libraries ---------------------
534
535 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
536 extern struct JavaVM_ main_vm;
537
538 static void* _native_java_library = NULL;
539
540 void* os::native_java_library() {
541 if (_native_java_library == NULL) {
542 char buffer[JVM_MAXPATHLEN];
543 char ebuf[1024];
544
545 // Try to load verify dll first. In 1.3 java dll depends on it and is not
546 // always able to find it when the loading executable is outside the JDK.
547 // In order to keep working with 1.2 we ignore any loading errors.
548 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
549 "verify")) {
550 dll_load(buffer, ebuf, sizeof(ebuf));
551 }
552
553 // Load java dll
554 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
555 "java")) {
556 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
557 }
558 if (_native_java_library == NULL) {
559 vm_exit_during_initialization("Unable to load native library", ebuf);
560 }
561
562 #if defined(__OpenBSD__)
563 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
564 // ignore errors
565 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
566 "net")) {
567 dll_load(buffer, ebuf, sizeof(ebuf));
568 }
569 #endif
570 }
571 return _native_java_library;
572 }
573
574 /*
575 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
576 * If check_lib == true then we are looking for an
577 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
578 * this library is statically linked into the image.
579 * If check_lib == false then we will look for the appropriate symbol in the
580 * executable if agent_lib->is_static_lib() == true or in the shared library
581 * referenced by 'handle'.
582 */
583 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
584 const char *syms[], size_t syms_len) {
585 assert(agent_lib != NULL, "sanity check");
586 const char *lib_name;
587 void *handle = agent_lib->os_lib();
588 void *entryName = NULL;
589 char *agent_function_name;
590 size_t i;
591
592 // If checking then use the agent name otherwise test is_static_lib() to
593 // see how to process this lookup
594 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
595 for (i = 0; i < syms_len; i++) {
596 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
597 if (agent_function_name == NULL) {
598 break;
599 }
600 entryName = dll_lookup(handle, agent_function_name);
601 FREE_C_HEAP_ARRAY(char, agent_function_name);
602 if (entryName != NULL) {
603 break;
604 }
605 }
606 return entryName;
607 }
608
609 // See if the passed in agent is statically linked into the VM image.
610 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
611 size_t syms_len) {
612 void *ret;
613 void *proc_handle;
614 void *save_handle;
615
616 assert(agent_lib != NULL, "sanity check");
617 if (agent_lib->name() == NULL) {
618 return false;
619 }
620 proc_handle = get_default_process_handle();
621 // Check for Agent_OnLoad/Attach_lib_name function
622 save_handle = agent_lib->os_lib();
623 // We want to look in this process' symbol table.
624 agent_lib->set_os_lib(proc_handle);
625 ret = find_agent_function(agent_lib, true, syms, syms_len);
626 if (ret != NULL) {
627 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
628 agent_lib->set_valid();
629 agent_lib->set_static_lib(true);
630 return true;
631 }
632 agent_lib->set_os_lib(save_handle);
633 return false;
634 }
635
636 // --------------------- heap allocation utilities ---------------------
637
638 char *os::strdup(const char *str, MEMFLAGS flags) {
639 size_t size = strlen(str);
640 char *dup_str = (char *)malloc(size + 1, flags);
641 if (dup_str == NULL) return NULL;
642 strcpy(dup_str, str);
643 return dup_str;
644 }
645
646 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
647 char* p = os::strdup(str, flags);
648 if (p == NULL) {
649 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
650 }
651 return p;
652 }
653
654
655 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
656
657 #ifdef ASSERT
658
659 static void verify_memory(void* ptr) {
660 GuardedMemory guarded(ptr);
661 if (!guarded.verify_guards()) {
662 LogTarget(Warning, malloc, free) lt;
663 ResourceMark rm;
664 LogStream ls(lt);
665 ls.print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
666 ls.print_cr("## memory stomp:");
667 guarded.print_on(&ls);
668 fatal("memory stomping error");
669 }
670 }
671
672 #endif
673
674 //
675 // This function supports testing of the malloc out of memory
676 // condition without really running the system out of memory.
677 //
678 static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
679 if (MallocMaxTestWords > 0) {
680 size_t words = (alloc_size / BytesPerWord);
681
682 if ((cur_malloc_words + words) > MallocMaxTestWords) {
683 return true;
684 }
685 Atomic::add(words, &cur_malloc_words);
686 }
687 return false;
688 }
689
690 void* os::malloc(size_t size, MEMFLAGS flags) {
691 return os::malloc(size, flags, CALLER_PC);
692 }
693
694 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
695 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
696 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
697
698 // Since os::malloc can be called when the libjvm.{dll,so} is
699 // first loaded and we don't have a thread yet we must accept NULL also here.
700 assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()),
701 "malloc() not allowed when crash protection is set");
702
703 if (size == 0) {
704 // return a valid pointer if size is zero
705 // if NULL is returned the calling functions assume out of memory.
706 size = 1;
707 }
708
709 // NMT support
710 NMT_TrackingLevel level = MemTracker::tracking_level();
711 size_t nmt_header_size = MemTracker::malloc_header_size(level);
712
713 #ifndef ASSERT
714 const size_t alloc_size = size + nmt_header_size;
715 #else
716 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
717 if (size + nmt_header_size > alloc_size) { // Check for rollover.
718 return NULL;
719 }
720 #endif
721
722 // For the test flag -XX:MallocMaxTestWords
723 if (has_reached_max_malloc_test_peak(size)) {
724 return NULL;
725 }
726
727 u_char* ptr;
728 ptr = (u_char*)::malloc(alloc_size);
729
730 #ifdef ASSERT
731 if (ptr == NULL) {
732 return NULL;
733 }
734 // Wrap memory with guard
735 GuardedMemory guarded(ptr, size + nmt_header_size);
736 ptr = guarded.get_user_ptr();
737
738 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
739 log_warning(malloc, free)("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
740 breakpoint();
741 }
742 if (paranoid) {
743 verify_memory(ptr);
744 }
745 #endif
746
747 // we do not track guard memory
748 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
749 }
750
751 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
752 return os::realloc(memblock, size, flags, CALLER_PC);
753 }
754
755 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
756
757 // For the test flag -XX:MallocMaxTestWords
758 if (has_reached_max_malloc_test_peak(size)) {
759 return NULL;
760 }
761
762 if (size == 0) {
763 // return a valid pointer if size is zero
764 // if NULL is returned the calling functions assume out of memory.
765 size = 1;
766 }
767
768 #ifndef ASSERT
769 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
770 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
771 // NMT support
772 void* membase = MemTracker::record_free(memblock);
773 NMT_TrackingLevel level = MemTracker::tracking_level();
774 size_t nmt_header_size = MemTracker::malloc_header_size(level);
775 void* ptr = ::realloc(membase, size + nmt_header_size);
776 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
777 #else
778 if (memblock == NULL) {
779 return os::malloc(size, memflags, stack);
780 }
781 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
782 log_warning(malloc, free)("os::realloc caught " PTR_FORMAT, p2i(memblock));
783 breakpoint();
784 }
785 // NMT support
786 void* membase = MemTracker::malloc_base(memblock);
787 verify_memory(membase);
788 // always move the block
789 void* ptr = os::malloc(size, memflags, stack);
790 // Copy to new memory if malloc didn't fail
791 if (ptr != NULL ) {
792 GuardedMemory guarded(MemTracker::malloc_base(memblock));
793 // Guard's user data contains NMT header
794 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
795 memcpy(ptr, memblock, MIN2(size, memblock_size));
796 if (paranoid) {
797 verify_memory(MemTracker::malloc_base(ptr));
798 }
799 os::free(memblock);
800 }
801 return ptr;
802 #endif
803 }
804
805
806 void os::free(void *memblock) {
807 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
808 #ifdef ASSERT
809 if (memblock == NULL) return;
810 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
811 log_warning(malloc, free)("os::free caught " PTR_FORMAT, p2i(memblock));
812 breakpoint();
813 }
814 void* membase = MemTracker::record_free(memblock);
815 verify_memory(membase);
816
817 GuardedMemory guarded(membase);
818 size_t size = guarded.get_user_size();
819 inc_stat_counter(&free_bytes, size);
820 membase = guarded.release_for_freeing();
821 ::free(membase);
822 #else
823 void* membase = MemTracker::record_free(memblock);
824 ::free(membase);
825 #endif
826 }
827
828 void os::init_random(unsigned int initval) {
829 _rand_seed = initval;
830 }
831
832
833 static int random_helper(unsigned int rand_seed) {
834 /* standard, well-known linear congruential random generator with
835 * next_rand = (16807*seed) mod (2**31-1)
836 * see
837 * (1) "Random Number Generators: Good Ones Are Hard to Find",
838 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
839 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
840 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
841 */
842 const unsigned int a = 16807;
843 const unsigned int m = 2147483647;
844 const int q = m / a; assert(q == 127773, "weird math");
845 const int r = m % a; assert(r == 2836, "weird math");
846
847 // compute az=2^31p+q
848 unsigned int lo = a * (rand_seed & 0xFFFF);
849 unsigned int hi = a * (rand_seed >> 16);
850 lo += (hi & 0x7FFF) << 16;
851
852 // if q overflowed, ignore the overflow and increment q
853 if (lo > m) {
854 lo &= m;
855 ++lo;
856 }
857 lo += hi >> 15;
858
859 // if (p+q) overflowed, ignore the overflow and increment (p+q)
860 if (lo > m) {
861 lo &= m;
862 ++lo;
863 }
864 return lo;
865 }
866
867 int os::random() {
868 // Make updating the random seed thread safe.
869 while (true) {
870 unsigned int seed = _rand_seed;
871 unsigned int rand = random_helper(seed);
872 if (Atomic::cmpxchg(rand, &_rand_seed, seed) == seed) {
873 return static_cast<int>(rand);
874 }
875 }
876 }
877
878 // The INITIALIZED state is distinguished from the SUSPENDED state because the
879 // conditions in which a thread is first started are different from those in which
880 // a suspension is resumed. These differences make it hard for us to apply the
881 // tougher checks when starting threads that we want to do when resuming them.
882 // However, when start_thread is called as a result of Thread.start, on a Java
883 // thread, the operation is synchronized on the Java Thread object. So there
884 // cannot be a race to start the thread and hence for the thread to exit while
885 // we are working on it. Non-Java threads that start Java threads either have
886 // to do so in a context in which races are impossible, or should do appropriate
887 // locking.
888
889 void os::start_thread(Thread* thread) {
890 // guard suspend/resume
891 MutexLocker ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
892 OSThread* osthread = thread->osthread();
893 osthread->set_state(RUNNABLE);
894 pd_start_thread(thread);
895 }
896
897 void os::abort(bool dump_core) {
898 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
899 }
900
901 //---------------------------------------------------------------------------
902 // Helper functions for fatal error handler
903
904 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
905 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
906
907 start = align_down(start, unitsize);
908
909 int cols = 0;
910 int cols_per_line = 0;
911 switch (unitsize) {
912 case 1: cols_per_line = 16; break;
913 case 2: cols_per_line = 8; break;
914 case 4: cols_per_line = 4; break;
915 case 8: cols_per_line = 2; break;
916 default: return;
917 }
918
919 address p = start;
920 st->print(PTR_FORMAT ": ", p2i(start));
921 while (p < end) {
922 if (is_readable_pointer(p)) {
923 switch (unitsize) {
924 case 1: st->print("%02x", *(u1*)p); break;
925 case 2: st->print("%04x", *(u2*)p); break;
926 case 4: st->print("%08x", *(u4*)p); break;
927 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
928 }
929 } else {
930 st->print("%*.*s", 2*unitsize, 2*unitsize, "????????????????");
931 }
932 p += unitsize;
933 cols++;
934 if (cols >= cols_per_line && p < end) {
935 cols = 0;
936 st->cr();
937 st->print(PTR_FORMAT ": ", p2i(p));
938 } else {
939 st->print(" ");
940 }
941 }
942 st->cr();
943 }
944
945 void os::print_instructions(outputStream* st, address pc, int unitsize) {
946 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
947 print_hex_dump(st, pc - 256, pc + 256, unitsize);
948 }
949
950 void os::print_environment_variables(outputStream* st, const char** env_list) {
951 if (env_list) {
952 st->print_cr("Environment Variables:");
953
954 for (int i = 0; env_list[i] != NULL; i++) {
955 char *envvar = ::getenv(env_list[i]);
956 if (envvar != NULL) {
957 st->print("%s", env_list[i]);
958 st->print("=");
959 st->print_cr("%s", envvar);
960 }
961 }
962 }
963 }
964
965 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
966 // cpu
967 st->print("CPU:");
968 st->print("total %d", os::processor_count());
969 // It's not safe to query number of active processors after crash
970 // st->print("(active %d)", os::active_processor_count()); but we can
971 // print the initial number of active processors.
972 // We access the raw value here because the assert in the accessor will
973 // fail if the crash occurs before initialization of this value.
974 st->print(" (initial active %d)", _initial_active_processor_count);
975 st->print(" %s", VM_Version::features_string());
976 st->cr();
977 pd_print_cpu_info(st, buf, buflen);
978 }
979
980 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version
981 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
982 st->print("Host: ");
983 #ifndef PRODUCT
984 if (get_host_name(buf, buflen)) {
985 st->print("%s, ", buf);
986 }
987 #endif // PRODUCT
988 get_summary_cpu_info(buf, buflen);
989 st->print("%s, ", buf);
990 size_t mem = physical_memory()/G;
991 if (mem == 0) { // for low memory systems
992 mem = physical_memory()/M;
993 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
994 } else {
995 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
996 }
997 get_summary_os_info(buf, buflen);
998 st->print_raw(buf);
999 st->cr();
1000 }
1001
1002 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
1003 const int secs_per_day = 86400;
1004 const int secs_per_hour = 3600;
1005 const int secs_per_min = 60;
1006
1007 time_t tloc;
1008 (void)time(&tloc);
1009 char* timestring = ctime(&tloc); // ctime adds newline.
1010 // edit out the newline
1011 char* nl = strchr(timestring, '\n');
1012 if (nl != NULL) {
1013 *nl = '\0';
1014 }
1015
1016 struct tm tz;
1017 if (localtime_pd(&tloc, &tz) != NULL) {
1018 ::strftime(buf, buflen, "%Z", &tz);
1019 st->print("Time: %s %s", timestring, buf);
1020 } else {
1021 st->print("Time: %s", timestring);
1022 }
1023
1024 double t = os::elapsedTime();
1025 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
1026 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
1027 // before printf. We lost some precision, but who cares?
1028 int eltime = (int)t; // elapsed time in seconds
1029
1030 // print elapsed time in a human-readable format:
1031 int eldays = eltime / secs_per_day;
1032 int day_secs = eldays * secs_per_day;
1033 int elhours = (eltime - day_secs) / secs_per_hour;
1034 int hour_secs = elhours * secs_per_hour;
1035 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
1036 int minute_secs = elmins * secs_per_min;
1037 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
1038 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
1039 }
1040
1041
1042 // Check if pointer can be read from (4-byte read access).
1043 // Helps to prove validity of a not-NULL pointer.
1044 // Returns true in very early stages of VM life when stub is not yet generated.
1045 #define SAFEFETCH_DEFAULT true
1046 bool os::is_readable_pointer(const void* p) {
1047 if (!CanUseSafeFetch32()) {
1048 return SAFEFETCH_DEFAULT;
1049 }
1050 int* const aligned = (int*) align_down((intptr_t)p, 4);
1051 int cafebabe = 0xcafebabe; // tester value 1
1052 int deadbeef = 0xdeadbeef; // tester value 2
1053 return (SafeFetch32(aligned, cafebabe) != cafebabe) || (SafeFetch32(aligned, deadbeef) != deadbeef);
1054 }
1055
1056 bool os::is_readable_range(const void* from, const void* to) {
1057 if ((uintptr_t)from >= (uintptr_t)to) return false;
1058 for (uintptr_t p = align_down((uintptr_t)from, min_page_size()); p < (uintptr_t)to; p += min_page_size()) {
1059 if (!is_readable_pointer((const void*)p)) {
1060 return false;
1061 }
1062 }
1063 return true;
1064 }
1065
1066
1067 // moved from debug.cpp (used to be find()) but still called from there
1068 // The verbose parameter is only set by the debug code in one case
1069 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
1070 address addr = (address)x;
1071 // Handle NULL first, so later checks don't need to protect against it.
1072 if (addr == NULL) {
1073 st->print_cr("0x0 is NULL");
1074 return;
1075 }
1076
1077 // Check if addr points into a code blob.
1078 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
1079 if (b != NULL) {
1080 b->dump_for_addr(addr, st, verbose);
1081 return;
1082 }
1083
1084 // Check if addr points into Java heap.
1085 if (Universe::heap()->print_location(st, addr)) {
1086 return;
1087 }
1088
1089 bool accessible = is_readable_pointer(addr);
1090
1091 // Check if addr is a JNI handle.
1092 if (align_down((intptr_t)addr, sizeof(intptr_t)) != 0 && accessible) {
1093 if (JNIHandles::is_global_handle((jobject) addr)) {
1094 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
1095 return;
1096 }
1097 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1098 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
1099 return;
1100 }
1101 #ifndef PRODUCT
1102 // we don't keep the block list in product mode
1103 if (JNIHandles::is_local_handle((jobject) addr)) {
1104 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
1105 return;
1106 }
1107 #endif
1108 }
1109
1110 // Check if addr belongs to a Java thread.
1111 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
1112 // If the addr is a java thread print information about that.
1113 if (addr == (address)thread) {
1114 if (verbose) {
1115 thread->print_on(st);
1116 } else {
1117 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
1118 }
1119 return;
1120 }
1121 // If the addr is in the stack region for this thread then report that
1122 // and print thread info
1123 if (thread->on_local_stack(addr)) {
1124 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1125 INTPTR_FORMAT, p2i(addr), p2i(thread));
1126 if (verbose) thread->print_on(st);
1127 return;
1128 }
1129 }
1130
1131 // Check if in metaspace and print types that have vptrs
1132 if (Metaspace::contains(addr)) {
1133 if (Klass::is_valid((Klass*)addr)) {
1134 st->print_cr(INTPTR_FORMAT " is a pointer to class: ", p2i(addr));
1135 ((Klass*)addr)->print_on(st);
1136 } else if (Method::is_valid_method((const Method*)addr)) {
1137 ((Method*)addr)->print_value_on(st);
1138 st->cr();
1139 } else {
1140 // Use addr->print() from the debugger instead (not here)
1141 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
1142 }
1143 return;
1144 }
1145
1146 // Compressed klass needs to be decoded first.
1147 #ifdef _LP64
1148 if (UseCompressedClassPointers && ((uintptr_t)addr &~ (uintptr_t)max_juint) == 0) {
1149 narrowKlass narrow_klass = (narrowKlass)(uintptr_t)addr;
1150 Klass* k = CompressedKlassPointers::decode_raw(narrow_klass);
1151
1152 if (Klass::is_valid(k)) {
1153 st->print_cr(UINT32_FORMAT " is a compressed pointer to class: " INTPTR_FORMAT, narrow_klass, p2i((HeapWord*)k));
1154 k->print_on(st);
1155 return;
1156 }
1157 }
1158 #endif
1159
1160 // Try an OS specific find
1161 if (os::find(addr, st)) {
1162 return;
1163 }
1164
1165 if (accessible) {
1166 st->print(INTPTR_FORMAT " points into unknown readable memory:", p2i(addr));
1167 for (address p = addr; p < align_up(addr + 1, sizeof(intptr_t)); ++p) {
1168 st->print(" %02x", *(u1*)p);
1169 }
1170 st->cr();
1171 return;
1172 }
1173
1174 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
1175 }
1176
1177 // Looks like all platforms can use the same function to check if C
1178 // stack is walkable beyond current frame. The check for fp() is not
1179 // necessary on Sparc, but it's harmless.
1180 bool os::is_first_C_frame(frame* fr) {
1181 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1182 // Check usp first, because if that's bad the other accessors may fault
1183 // on some architectures. Ditto ufp second, etc.
1184 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1185 // sp on amd can be 32 bit aligned.
1186 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1187
1188 uintptr_t usp = (uintptr_t)fr->sp();
1189 if ((usp & sp_align_mask) != 0) return true;
1190
1191 uintptr_t ufp = (uintptr_t)fr->fp();
1192 if ((ufp & fp_align_mask) != 0) return true;
1193
1194 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1195 if ((old_sp & sp_align_mask) != 0) return true;
1196 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1197
1198 uintptr_t old_fp = (uintptr_t)fr->link();
1199 if ((old_fp & fp_align_mask) != 0) return true;
1200 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1201
1202 // stack grows downwards; if old_fp is below current fp or if the stack
1203 // frame is too large, either the stack is corrupted or fp is not saved
1204 // on stack (i.e. on x86, ebp may be used as general register). The stack
1205 // is not walkable beyond current frame.
1206 if (old_fp < ufp) return true;
1207 if (old_fp - ufp > 64 * K) return true;
1208
1209 return false;
1210 }
1211
1212
1213 // Set up the boot classpath.
1214
1215 char* os::format_boot_path(const char* format_string,
1216 const char* home,
1217 int home_len,
1218 char fileSep,
1219 char pathSep) {
1220 assert((fileSep == '/' && pathSep == ':') ||
1221 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1222
1223 // Scan the format string to determine the length of the actual
1224 // boot classpath, and handle platform dependencies as well.
1225 int formatted_path_len = 0;
1226 const char* p;
1227 for (p = format_string; *p != 0; ++p) {
1228 if (*p == '%') formatted_path_len += home_len - 1;
1229 ++formatted_path_len;
1230 }
1231
1232 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1233 if (formatted_path == NULL) {
1234 return NULL;
1235 }
1236
1237 // Create boot classpath from format, substituting separator chars and
1238 // java home directory.
1239 char* q = formatted_path;
1240 for (p = format_string; *p != 0; ++p) {
1241 switch (*p) {
1242 case '%':
1243 strcpy(q, home);
1244 q += home_len;
1245 break;
1246 case '/':
1247 *q++ = fileSep;
1248 break;
1249 case ':':
1250 *q++ = pathSep;
1251 break;
1252 default:
1253 *q++ = *p;
1254 }
1255 }
1256 *q = '\0';
1257
1258 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1259 return formatted_path;
1260 }
1261
1262 // This function is a proxy to fopen, it tries to add a non standard flag ('e' or 'N')
1263 // that ensures automatic closing of the file on exec. If it can not find support in
1264 // the underlying c library, it will make an extra system call (fcntl) to ensure automatic
1265 // closing of the file on exec.
1266 FILE* os::fopen(const char* path, const char* mode) {
1267 char modified_mode[20];
1268 assert(strlen(mode) + 1 < sizeof(modified_mode), "mode chars plus one extra must fit in buffer");
1269 sprintf(modified_mode, "%s" LINUX_ONLY("e") BSD_ONLY("e") WINDOWS_ONLY("N"), mode);
1270 FILE* file = ::fopen(path, modified_mode);
1271
1272 #if !(defined LINUX || defined BSD || defined _WINDOWS)
1273 // assume fcntl FD_CLOEXEC support as a backup solution when 'e' or 'N'
1274 // is not supported as mode in fopen
1275 if (file != NULL) {
1276 int fd = fileno(file);
1277 if (fd != -1) {
1278 int fd_flags = fcntl(fd, F_GETFD);
1279 if (fd_flags != -1) {
1280 fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC);
1281 }
1282 }
1283 }
1284 #endif
1285
1286 return file;
1287 }
1288
1289 bool os::set_boot_path(char fileSep, char pathSep) {
1290 const char* home = Arguments::get_java_home();
1291 int home_len = (int)strlen(home);
1292
1293 struct stat st;
1294
1295 // modular image if "modules" jimage exists
1296 char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep);
1297 if (jimage == NULL) return false;
1298 bool has_jimage = (os::stat(jimage, &st) == 0);
1299 if (has_jimage) {
1300 Arguments::set_sysclasspath(jimage, true);
1301 FREE_C_HEAP_ARRAY(char, jimage);
1302 return true;
1303 }
1304 FREE_C_HEAP_ARRAY(char, jimage);
1305
1306 // check if developer build with exploded modules
1307 char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep);
1308 if (base_classes == NULL) return false;
1309 if (os::stat(base_classes, &st) == 0) {
1310 Arguments::set_sysclasspath(base_classes, false);
1311 FREE_C_HEAP_ARRAY(char, base_classes);
1312 return true;
1313 }
1314 FREE_C_HEAP_ARRAY(char, base_classes);
1315
1316 return false;
1317 }
1318
1319 // Splits a path, based on its separator, the number of
1320 // elements is returned back in "elements".
1321 // file_name_length is used as a modifier for each path's
1322 // length when compared to JVM_MAXPATHLEN. So if you know
1323 // each returned path will have something appended when
1324 // in use, you can pass the length of that in
1325 // file_name_length, to ensure we detect if any path
1326 // exceeds the maximum path length once prepended onto
1327 // the sub-path/file name.
1328 // It is the callers responsibility to:
1329 // a> check the value of "elements", which may be 0.
1330 // b> ignore any empty path elements
1331 // c> free up the data.
1332 char** os::split_path(const char* path, size_t* elements, size_t file_name_length) {
1333 *elements = (size_t)0;
1334 if (path == NULL || strlen(path) == 0 || file_name_length == (size_t)NULL) {
1335 return NULL;
1336 }
1337 const char psepchar = *os::path_separator();
1338 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1339 if (inpath == NULL) {
1340 return NULL;
1341 }
1342 strcpy(inpath, path);
1343 size_t count = 1;
1344 char* p = strchr(inpath, psepchar);
1345 // Get a count of elements to allocate memory
1346 while (p != NULL) {
1347 count++;
1348 p++;
1349 p = strchr(p, psepchar);
1350 }
1351 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1352
1353 // do the actual splitting
1354 p = inpath;
1355 for (size_t i = 0 ; i < count ; i++) {
1356 size_t len = strcspn(p, os::path_separator());
1357 if (len + file_name_length > JVM_MAXPATHLEN) {
1358 // release allocated storage before exiting the vm
1359 free_array_of_char_arrays(opath, i++);
1360 vm_exit_during_initialization("The VM tried to use a path that exceeds the maximum path length for "
1361 "this system. Review path-containing parameters and properties, such as "
1362 "sun.boot.library.path, to identify potential sources for this path.");
1363 }
1364 // allocate the string and add terminator storage
1365 char* s = (char*)NEW_C_HEAP_ARRAY_RETURN_NULL(char, len + 1, mtInternal);
1366 if (s == NULL) {
1367 // release allocated storage before returning null
1368 free_array_of_char_arrays(opath, i++);
1369 return NULL;
1370 }
1371 strncpy(s, p, len);
1372 s[len] = '\0';
1373 opath[i] = s;
1374 p += len + 1;
1375 }
1376 FREE_C_HEAP_ARRAY(char, inpath);
1377 *elements = count;
1378 return opath;
1379 }
1380
1381 // Returns true if the current stack pointer is above the stack shadow
1382 // pages, false otherwise.
1383 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) {
1384 if (!thread->is_Java_thread()) return false;
1385 // Check if we have StackShadowPages above the yellow zone. This parameter
1386 // is dependent on the depth of the maximum VM call stack possible from
1387 // the handler for stack overflow. 'instanceof' in the stack overflow
1388 // handler or a println uses at least 8k stack of VM and native code
1389 // respectively.
1390 const int framesize_in_bytes =
1391 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1392
1393 address limit = ((JavaThread*)thread)->stack_end() +
1394 (JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size());
1395
1396 return sp > (limit + framesize_in_bytes);
1397 }
1398
1399 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1400 assert(min_pages > 0, "sanity");
1401 if (UseLargePages) {
1402 const size_t max_page_size = region_size / min_pages;
1403
1404 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1405 const size_t page_size = _page_sizes[i];
1406 if (page_size <= max_page_size) {
1407 if (!must_be_aligned || is_aligned(region_size, page_size)) {
1408 return page_size;
1409 }
1410 }
1411 }
1412 }
1413
1414 return vm_page_size();
1415 }
1416
1417 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1418 return page_size_for_region(region_size, min_pages, true);
1419 }
1420
1421 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1422 return page_size_for_region(region_size, min_pages, false);
1423 }
1424
1425 static const char* errno_to_string (int e, bool short_text) {
1426 #define ALL_SHARED_ENUMS(X) \
1427 X(E2BIG, "Argument list too long") \
1428 X(EACCES, "Permission denied") \
1429 X(EADDRINUSE, "Address in use") \
1430 X(EADDRNOTAVAIL, "Address not available") \
1431 X(EAFNOSUPPORT, "Address family not supported") \
1432 X(EAGAIN, "Resource unavailable, try again") \
1433 X(EALREADY, "Connection already in progress") \
1434 X(EBADF, "Bad file descriptor") \
1435 X(EBADMSG, "Bad message") \
1436 X(EBUSY, "Device or resource busy") \
1437 X(ECANCELED, "Operation canceled") \
1438 X(ECHILD, "No child processes") \
1439 X(ECONNABORTED, "Connection aborted") \
1440 X(ECONNREFUSED, "Connection refused") \
1441 X(ECONNRESET, "Connection reset") \
1442 X(EDEADLK, "Resource deadlock would occur") \
1443 X(EDESTADDRREQ, "Destination address required") \
1444 X(EDOM, "Mathematics argument out of domain of function") \
1445 X(EEXIST, "File exists") \
1446 X(EFAULT, "Bad address") \
1447 X(EFBIG, "File too large") \
1448 X(EHOSTUNREACH, "Host is unreachable") \
1449 X(EIDRM, "Identifier removed") \
1450 X(EILSEQ, "Illegal byte sequence") \
1451 X(EINPROGRESS, "Operation in progress") \
1452 X(EINTR, "Interrupted function") \
1453 X(EINVAL, "Invalid argument") \
1454 X(EIO, "I/O error") \
1455 X(EISCONN, "Socket is connected") \
1456 X(EISDIR, "Is a directory") \
1457 X(ELOOP, "Too many levels of symbolic links") \
1458 X(EMFILE, "Too many open files") \
1459 X(EMLINK, "Too many links") \
1460 X(EMSGSIZE, "Message too large") \
1461 X(ENAMETOOLONG, "Filename too long") \
1462 X(ENETDOWN, "Network is down") \
1463 X(ENETRESET, "Connection aborted by network") \
1464 X(ENETUNREACH, "Network unreachable") \
1465 X(ENFILE, "Too many files open in system") \
1466 X(ENOBUFS, "No buffer space available") \
1467 X(ENODATA, "No message is available on the STREAM head read queue") \
1468 X(ENODEV, "No such device") \
1469 X(ENOENT, "No such file or directory") \
1470 X(ENOEXEC, "Executable file format error") \
1471 X(ENOLCK, "No locks available") \
1472 X(ENOLINK, "Reserved") \
1473 X(ENOMEM, "Not enough space") \
1474 X(ENOMSG, "No message of the desired type") \
1475 X(ENOPROTOOPT, "Protocol not available") \
1476 X(ENOSPC, "No space left on device") \
1477 X(ENOSR, "No STREAM resources") \
1478 X(ENOSTR, "Not a STREAM") \
1479 X(ENOSYS, "Function not supported") \
1480 X(ENOTCONN, "The socket is not connected") \
1481 X(ENOTDIR, "Not a directory") \
1482 X(ENOTEMPTY, "Directory not empty") \
1483 X(ENOTSOCK, "Not a socket") \
1484 X(ENOTSUP, "Not supported") \
1485 X(ENOTTY, "Inappropriate I/O control operation") \
1486 X(ENXIO, "No such device or address") \
1487 X(EOPNOTSUPP, "Operation not supported on socket") \
1488 X(EOVERFLOW, "Value too large to be stored in data type") \
1489 X(EPERM, "Operation not permitted") \
1490 X(EPIPE, "Broken pipe") \
1491 X(EPROTO, "Protocol error") \
1492 X(EPROTONOSUPPORT, "Protocol not supported") \
1493 X(EPROTOTYPE, "Protocol wrong type for socket") \
1494 X(ERANGE, "Result too large") \
1495 X(EROFS, "Read-only file system") \
1496 X(ESPIPE, "Invalid seek") \
1497 X(ESRCH, "No such process") \
1498 X(ETIME, "Stream ioctl() timeout") \
1499 X(ETIMEDOUT, "Connection timed out") \
1500 X(ETXTBSY, "Text file busy") \
1501 X(EWOULDBLOCK, "Operation would block") \
1502 X(EXDEV, "Cross-device link")
1503
1504 #define DEFINE_ENTRY(e, text) { e, #e, text },
1505
1506 static const struct {
1507 int v;
1508 const char* short_text;
1509 const char* long_text;
1510 } table [] = {
1511
1512 ALL_SHARED_ENUMS(DEFINE_ENTRY)
1513
1514 // The following enums are not defined on all platforms.
1515 #ifdef ESTALE
1516 DEFINE_ENTRY(ESTALE, "Reserved")
1517 #endif
1518 #ifdef EDQUOT
1519 DEFINE_ENTRY(EDQUOT, "Reserved")
1520 #endif
1521 #ifdef EMULTIHOP
1522 DEFINE_ENTRY(EMULTIHOP, "Reserved")
1523 #endif
1524
1525 // End marker.
1526 { -1, "Unknown errno", "Unknown error" }
1527
1528 };
1529
1530 #undef DEFINE_ENTRY
1531 #undef ALL_FLAGS
1532
1533 int i = 0;
1534 while (table[i].v != -1 && table[i].v != e) {
1535 i ++;
1536 }
1537
1538 return short_text ? table[i].short_text : table[i].long_text;
1539
1540 }
1541
1542 const char* os::strerror(int e) {
1543 return errno_to_string(e, false);
1544 }
1545
1546 const char* os::errno_name(int e) {
1547 return errno_to_string(e, true);
1548 }
1549
1550 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) {
1551 LogTarget(Info, pagesize) log;
1552 if (log.is_enabled()) {
1553 LogStream out(log);
1554
1555 out.print("%s: ", str);
1556 for (int i = 0; i < count; ++i) {
1557 out.print(" " SIZE_FORMAT, page_sizes[i]);
1558 }
1559 out.cr();
1560 }
1561 }
1562
1563 #define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size)
1564
1565 void os::trace_page_sizes(const char* str,
1566 const size_t region_min_size,
1567 const size_t region_max_size,
1568 const size_t page_size,
1569 const char* base,
1570 const size_t size) {
1571
1572 log_info(pagesize)("%s: "
1573 " min=" SIZE_FORMAT "%s"
1574 " max=" SIZE_FORMAT "%s"
1575 " base=" PTR_FORMAT
1576 " page_size=" SIZE_FORMAT "%s"
1577 " size=" SIZE_FORMAT "%s",
1578 str,
1579 trace_page_size_params(region_min_size),
1580 trace_page_size_params(region_max_size),
1581 p2i(base),
1582 trace_page_size_params(page_size),
1583 trace_page_size_params(size));
1584 }
1585
1586 void os::trace_page_sizes_for_requested_size(const char* str,
1587 const size_t requested_size,
1588 const size_t page_size,
1589 const size_t alignment,
1590 const char* base,
1591 const size_t size) {
1592
1593 log_info(pagesize)("%s:"
1594 " req_size=" SIZE_FORMAT "%s"
1595 " base=" PTR_FORMAT
1596 " page_size=" SIZE_FORMAT "%s"
1597 " alignment=" SIZE_FORMAT "%s"
1598 " size=" SIZE_FORMAT "%s",
1599 str,
1600 trace_page_size_params(requested_size),
1601 p2i(base),
1602 trace_page_size_params(page_size),
1603 trace_page_size_params(alignment),
1604 trace_page_size_params(size));
1605 }
1606
1607
1608 // This is the working definition of a server class machine:
1609 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1610 // because the graphics memory (?) sometimes masks physical memory.
1611 // If you want to change the definition of a server class machine
1612 // on some OS or platform, e.g., >=4GB on Windows platforms,
1613 // then you'll have to parameterize this method based on that state,
1614 // as was done for logical processors here, or replicate and
1615 // specialize this method for each platform. (Or fix os to have
1616 // some inheritance structure and use subclassing. Sigh.)
1617 // If you want some platform to always or never behave as a server
1618 // class machine, change the setting of AlwaysActAsServerClassMachine
1619 // and NeverActAsServerClassMachine in globals*.hpp.
1620 bool os::is_server_class_machine() {
1621 // First check for the early returns
1622 if (NeverActAsServerClassMachine) {
1623 return false;
1624 }
1625 if (AlwaysActAsServerClassMachine) {
1626 return true;
1627 }
1628 // Then actually look at the machine
1629 bool result = false;
1630 const unsigned int server_processors = 2;
1631 const julong server_memory = 2UL * G;
1632 // We seem not to get our full complement of memory.
1633 // We allow some part (1/8?) of the memory to be "missing",
1634 // based on the sizes of DIMMs, and maybe graphics cards.
1635 const julong missing_memory = 256UL * M;
1636
1637 /* Is this a server class machine? */
1638 if ((os::active_processor_count() >= (int)server_processors) &&
1639 (os::physical_memory() >= (server_memory - missing_memory))) {
1640 const unsigned int logical_processors =
1641 VM_Version::logical_processors_per_package();
1642 if (logical_processors > 1) {
1643 const unsigned int physical_packages =
1644 os::active_processor_count() / logical_processors;
1645 if (physical_packages >= server_processors) {
1646 result = true;
1647 }
1648 } else {
1649 result = true;
1650 }
1651 }
1652 return result;
1653 }
1654
1655 void os::initialize_initial_active_processor_count() {
1656 assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
1657 _initial_active_processor_count = active_processor_count();
1658 log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count);
1659 }
1660
1661 void os::SuspendedThreadTask::run() {
1662 internal_do_task();
1663 _done = true;
1664 }
1665
1666 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1667 return os::pd_create_stack_guard_pages(addr, bytes);
1668 }
1669
1670 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, int file_desc) {
1671 char* result = NULL;
1672
1673 if (file_desc != -1) {
1674 // Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(),
1675 // but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file.
1676 result = os::map_memory_to_file(addr, bytes, file_desc);
1677 if (result != NULL) {
1678 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1679 }
1680 } else {
1681 result = pd_reserve_memory(bytes, addr, alignment_hint);
1682 if (result != NULL) {
1683 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1684 }
1685 }
1686
1687 return result;
1688 }
1689
1690 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1691 MEMFLAGS flags) {
1692 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1693 if (result != NULL) {
1694 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1695 MemTracker::record_virtual_memory_type((address)result, flags);
1696 }
1697
1698 return result;
1699 }
1700
1701 char* os::attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc) {
1702 char* result = NULL;
1703 if (file_desc != -1) {
1704 result = pd_attempt_reserve_memory_at(bytes, addr, file_desc);
1705 if (result != NULL) {
1706 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1707 }
1708 } else {
1709 result = pd_attempt_reserve_memory_at(bytes, addr);
1710 if (result != NULL) {
1711 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1712 }
1713 }
1714 return result;
1715 }
1716
1717 void os::split_reserved_memory(char *base, size_t size,
1718 size_t split, bool realloc) {
1719 pd_split_reserved_memory(base, size, split, realloc);
1720 }
1721
1722 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1723 bool res = pd_commit_memory(addr, bytes, executable);
1724 if (res) {
1725 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1726 }
1727 return res;
1728 }
1729
1730 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1731 bool executable) {
1732 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1733 if (res) {
1734 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1735 }
1736 return res;
1737 }
1738
1739 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1740 const char* mesg) {
1741 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1742 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1743 }
1744
1745 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1746 bool executable, const char* mesg) {
1747 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1748 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1749 }
1750
1751 bool os::uncommit_memory(char* addr, size_t bytes) {
1752 bool res;
1753 if (MemTracker::tracking_level() > NMT_minimal) {
1754 Tracker tkr(Tracker::uncommit);
1755 res = pd_uncommit_memory(addr, bytes);
1756 if (res) {
1757 tkr.record((address)addr, bytes);
1758 }
1759 } else {
1760 res = pd_uncommit_memory(addr, bytes);
1761 }
1762 return res;
1763 }
1764
1765 bool os::release_memory(char* addr, size_t bytes) {
1766 bool res;
1767 if (MemTracker::tracking_level() > NMT_minimal) {
1768 Tracker tkr(Tracker::release);
1769 res = pd_release_memory(addr, bytes);
1770 if (res) {
1771 tkr.record((address)addr, bytes);
1772 }
1773 } else {
1774 res = pd_release_memory(addr, bytes);
1775 }
1776 return res;
1777 }
1778
1779 void os::pretouch_memory(void* start, void* end, size_t page_size) {
1780 for (volatile char *p = (char*)start; p < (char*)end; p += page_size) {
1781 *p = 0;
1782 }
1783 }
1784
1785 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1786 char *addr, size_t bytes, bool read_only,
1787 bool allow_exec) {
1788 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1789 if (result != NULL) {
1790 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1791 }
1792 return result;
1793 }
1794
1795 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1796 char *addr, size_t bytes, bool read_only,
1797 bool allow_exec) {
1798 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1799 read_only, allow_exec);
1800 }
1801
1802 bool os::unmap_memory(char *addr, size_t bytes) {
1803 bool result;
1804 if (MemTracker::tracking_level() > NMT_minimal) {
1805 Tracker tkr(Tracker::release);
1806 result = pd_unmap_memory(addr, bytes);
1807 if (result) {
1808 tkr.record((address)addr, bytes);
1809 }
1810 } else {
1811 result = pd_unmap_memory(addr, bytes);
1812 }
1813 return result;
1814 }
1815
1816 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1817 pd_free_memory(addr, bytes, alignment_hint);
1818 }
1819
1820 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1821 pd_realign_memory(addr, bytes, alignment_hint);
1822 }
1823
1824 #ifndef _WINDOWS
1825 /* try to switch state from state "from" to state "to"
1826 * returns the state set after the method is complete
1827 */
1828 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1829 os::SuspendResume::State to)
1830 {
1831 os::SuspendResume::State result = Atomic::cmpxchg(to, &_state, from);
1832 if (result == from) {
1833 // success
1834 return to;
1835 }
1836 return result;
1837 }
1838 #endif