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 // Check if the signal is a trigger to start the Attach Listener - in that
372 // case don't print stack traces.
373 if (!DisableAttachMechanism && AttachListener::is_init_trigger()) {
374 continue;
375 }
376 // Print stack traces
377 // Any SIGBREAK operations added here should make sure to flush
378 // the output stream (e.g. tty->flush()) after output. See 4803766.
379 // Each module also prints an extra carriage return after its output.
380 VM_PrintThreads op;
381 VMThread::execute(&op);
382 VM_PrintJNI jni_op;
383 VMThread::execute(&jni_op);
384 VM_FindDeadlocks op1(tty);
385 VMThread::execute(&op1);
386 Universe::print_heap_at_SIGBREAK();
387 if (PrintClassHistogram) {
388 VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */);
389 VMThread::execute(&op1);
390 }
391 if (JvmtiExport::should_post_data_dump()) {
392 JvmtiExport::post_data_dump();
393 }
394 break;
395 }
396 default: {
397 // Dispatch the signal to java
398 HandleMark hm(THREAD);
399 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD);
400 if (klass != NULL) {
401 JavaValue result(T_VOID);
402 JavaCallArguments args;
403 args.push_int(sig);
404 JavaCalls::call_static(
405 &result,
406 klass,
407 vmSymbols::dispatch_name(),
408 vmSymbols::int_void_signature(),
409 &args,
410 THREAD
411 );
412 }
413 if (HAS_PENDING_EXCEPTION) {
414 // tty is initialized early so we don't expect it to be null, but
415 // if it is we can't risk doing an initialization that might
416 // trigger additional out-of-memory conditions
417 if (tty != NULL) {
418 char klass_name[256];
419 char tmp_sig_name[16];
420 const char* sig_name = "UNKNOWN";
421 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
422 name()->as_klass_external_name(klass_name, 256);
423 if (os::exception_name(sig, tmp_sig_name, 16) != NULL)
424 sig_name = tmp_sig_name;
425 warning("Exception %s occurred dispatching signal %s to handler"
426 "- the VM may need to be forcibly terminated",
427 klass_name, sig_name );
428 }
429 CLEAR_PENDING_EXCEPTION;
430 }
431 }
432 }
433 }
434 }
435
436 void os::init_before_ergo() {
437 initialize_initial_active_processor_count();
438 // We need to initialize large page support here because ergonomics takes some
439 // decisions depending on large page support and the calculated large page size.
440 large_page_init();
441
442 // We need to adapt the configured number of stack protection pages given
443 // in 4K pages to the actual os page size. We must do this before setting
444 // up minimal stack sizes etc. in os::init_2().
445 JavaThread::set_stack_red_zone_size (align_up(StackRedPages * 4 * K, vm_page_size()));
446 JavaThread::set_stack_yellow_zone_size (align_up(StackYellowPages * 4 * K, vm_page_size()));
447 JavaThread::set_stack_reserved_zone_size(align_up(StackReservedPages * 4 * K, vm_page_size()));
448 JavaThread::set_stack_shadow_zone_size (align_up(StackShadowPages * 4 * K, vm_page_size()));
449
450 // VM version initialization identifies some characteristics of the
451 // platform that are used during ergonomic decisions.
452 VM_Version::init_before_ergo();
453 }
454
455 void os::initialize_jdk_signal_support(TRAPS) {
456 if (!ReduceSignalUsage) {
457 // Setup JavaThread for processing signals
458 const char thread_name[] = "Signal Dispatcher";
459 Handle string = java_lang_String::create_from_str(thread_name, CHECK);
460
461 // Initialize thread_oop to put it into the system threadGroup
462 Handle thread_group (THREAD, Universe::system_thread_group());
463 Handle thread_oop = JavaCalls::construct_new_instance(SystemDictionary::Thread_klass(),
464 vmSymbols::threadgroup_string_void_signature(),
465 thread_group,
466 string,
467 CHECK);
468
469 Klass* group = SystemDictionary::ThreadGroup_klass();
470 JavaValue result(T_VOID);
471 JavaCalls::call_special(&result,
472 thread_group,
473 group,
474 vmSymbols::add_method_name(),
475 vmSymbols::thread_void_signature(),
476 thread_oop,
477 CHECK);
478
479 { MutexLocker mu(Threads_lock);
480 JavaThread* signal_thread = new JavaThread(&signal_thread_entry);
481
482 // At this point it may be possible that no osthread was created for the
483 // JavaThread due to lack of memory. We would have to throw an exception
484 // in that case. However, since this must work and we do not allow
485 // exceptions anyway, check and abort if this fails.
486 if (signal_thread == NULL || signal_thread->osthread() == NULL) {
487 vm_exit_during_initialization("java.lang.OutOfMemoryError",
488 os::native_thread_creation_failed_msg());
489 }
490
491 java_lang_Thread::set_thread(thread_oop(), signal_thread);
492 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
493 java_lang_Thread::set_daemon(thread_oop());
494
495 signal_thread->set_threadObj(thread_oop());
496 Threads::add(signal_thread);
497 Thread::start(signal_thread);
498 }
499 // Handle ^BREAK
500 os::signal(SIGBREAK, os::user_handler());
501 }
502 }
503
504
505 void os::terminate_signal_thread() {
506 if (!ReduceSignalUsage)
507 signal_notify(sigexitnum_pd());
508 }
509
510
511 // --------------------- loading libraries ---------------------
512
513 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
514 extern struct JavaVM_ main_vm;
515
516 static void* _native_java_library = NULL;
517
518 void* os::native_java_library() {
519 if (_native_java_library == NULL) {
520 char buffer[JVM_MAXPATHLEN];
521 char ebuf[1024];
522
523 // Try to load verify dll first. In 1.3 java dll depends on it and is not
524 // always able to find it when the loading executable is outside the JDK.
525 // In order to keep working with 1.2 we ignore any loading errors.
526 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
527 "verify")) {
528 dll_load(buffer, ebuf, sizeof(ebuf));
529 }
530
531 // Load java dll
532 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
533 "java")) {
534 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
535 }
536 if (_native_java_library == NULL) {
537 vm_exit_during_initialization("Unable to load native library", ebuf);
538 }
539
540 #if defined(__OpenBSD__)
541 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
542 // ignore errors
543 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
544 "net")) {
545 dll_load(buffer, ebuf, sizeof(ebuf));
546 }
547 #endif
548 }
549 return _native_java_library;
550 }
551
552 /*
553 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
554 * If check_lib == true then we are looking for an
555 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
556 * this library is statically linked into the image.
557 * If check_lib == false then we will look for the appropriate symbol in the
558 * executable if agent_lib->is_static_lib() == true or in the shared library
559 * referenced by 'handle'.
560 */
561 void* os::find_agent_function(AgentLibrary *agent_lib, bool check_lib,
562 const char *syms[], size_t syms_len) {
563 assert(agent_lib != NULL, "sanity check");
564 const char *lib_name;
565 void *handle = agent_lib->os_lib();
566 void *entryName = NULL;
567 char *agent_function_name;
568 size_t i;
569
570 // If checking then use the agent name otherwise test is_static_lib() to
571 // see how to process this lookup
572 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : NULL);
573 for (i = 0; i < syms_len; i++) {
574 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
575 if (agent_function_name == NULL) {
576 break;
577 }
578 entryName = dll_lookup(handle, agent_function_name);
579 FREE_C_HEAP_ARRAY(char, agent_function_name);
580 if (entryName != NULL) {
581 break;
582 }
583 }
584 return entryName;
585 }
586
587 // See if the passed in agent is statically linked into the VM image.
588 bool os::find_builtin_agent(AgentLibrary *agent_lib, const char *syms[],
589 size_t syms_len) {
590 void *ret;
591 void *proc_handle;
592 void *save_handle;
593
594 assert(agent_lib != NULL, "sanity check");
595 if (agent_lib->name() == NULL) {
596 return false;
597 }
598 proc_handle = get_default_process_handle();
599 // Check for Agent_OnLoad/Attach_lib_name function
600 save_handle = agent_lib->os_lib();
601 // We want to look in this process' symbol table.
602 agent_lib->set_os_lib(proc_handle);
603 ret = find_agent_function(agent_lib, true, syms, syms_len);
604 if (ret != NULL) {
605 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
606 agent_lib->set_valid();
607 agent_lib->set_static_lib(true);
608 return true;
609 }
610 agent_lib->set_os_lib(save_handle);
611 return false;
612 }
613
614 // --------------------- heap allocation utilities ---------------------
615
616 char *os::strdup(const char *str, MEMFLAGS flags) {
617 size_t size = strlen(str);
618 char *dup_str = (char *)malloc(size + 1, flags);
619 if (dup_str == NULL) return NULL;
620 strcpy(dup_str, str);
621 return dup_str;
622 }
623
624 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
625 char* p = os::strdup(str, flags);
626 if (p == NULL) {
627 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
628 }
629 return p;
630 }
631
632
633 #define paranoid 0 /* only set to 1 if you suspect checking code has bug */
634
635 #ifdef ASSERT
636
637 static void verify_memory(void* ptr) {
638 GuardedMemory guarded(ptr);
639 if (!guarded.verify_guards()) {
640 LogTarget(Warning, malloc, free) lt;
641 ResourceMark rm;
642 LogStream ls(lt);
643 ls.print_cr("## nof_mallocs = " UINT64_FORMAT ", nof_frees = " UINT64_FORMAT, os::num_mallocs, os::num_frees);
644 ls.print_cr("## memory stomp:");
645 guarded.print_on(&ls);
646 fatal("memory stomping error");
647 }
648 }
649
650 #endif
651
652 //
653 // This function supports testing of the malloc out of memory
654 // condition without really running the system out of memory.
655 //
656 static bool has_reached_max_malloc_test_peak(size_t alloc_size) {
657 if (MallocMaxTestWords > 0) {
658 size_t words = (alloc_size / BytesPerWord);
659
660 if ((cur_malloc_words + words) > MallocMaxTestWords) {
661 return true;
662 }
663 Atomic::add(words, &cur_malloc_words);
664 }
665 return false;
666 }
667
668 void* os::malloc(size_t size, MEMFLAGS flags) {
669 return os::malloc(size, flags, CALLER_PC);
670 }
671
672 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
673 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
674 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
675
676 // Since os::malloc can be called when the libjvm.{dll,so} is
677 // first loaded and we don't have a thread yet we must accept NULL also here.
678 assert(!os::ThreadCrashProtection::is_crash_protected(Thread::current_or_null()),
679 "malloc() not allowed when crash protection is set");
680
681 if (size == 0) {
682 // return a valid pointer if size is zero
683 // if NULL is returned the calling functions assume out of memory.
684 size = 1;
685 }
686
687 // NMT support
688 NMT_TrackingLevel level = MemTracker::tracking_level();
689 size_t nmt_header_size = MemTracker::malloc_header_size(level);
690
691 #ifndef ASSERT
692 const size_t alloc_size = size + nmt_header_size;
693 #else
694 const size_t alloc_size = GuardedMemory::get_total_size(size + nmt_header_size);
695 if (size + nmt_header_size > alloc_size) { // Check for rollover.
696 return NULL;
697 }
698 #endif
699
700 // For the test flag -XX:MallocMaxTestWords
701 if (has_reached_max_malloc_test_peak(size)) {
702 return NULL;
703 }
704
705 u_char* ptr;
706 ptr = (u_char*)::malloc(alloc_size);
707
708 #ifdef ASSERT
709 if (ptr == NULL) {
710 return NULL;
711 }
712 // Wrap memory with guard
713 GuardedMemory guarded(ptr, size + nmt_header_size);
714 ptr = guarded.get_user_ptr();
715
716 if ((intptr_t)ptr == (intptr_t)MallocCatchPtr) {
717 log_warning(malloc, free)("os::malloc caught, " SIZE_FORMAT " bytes --> " PTR_FORMAT, size, p2i(ptr));
718 breakpoint();
719 }
720 if (paranoid) {
721 verify_memory(ptr);
722 }
723 #endif
724
725 // we do not track guard memory
726 return MemTracker::record_malloc((address)ptr, size, memflags, stack, level);
727 }
728
729 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
730 return os::realloc(memblock, size, flags, CALLER_PC);
731 }
732
733 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
734
735 // For the test flag -XX:MallocMaxTestWords
736 if (has_reached_max_malloc_test_peak(size)) {
737 return NULL;
738 }
739
740 if (size == 0) {
741 // return a valid pointer if size is zero
742 // if NULL is returned the calling functions assume out of memory.
743 size = 1;
744 }
745
746 #ifndef ASSERT
747 NOT_PRODUCT(inc_stat_counter(&num_mallocs, 1));
748 NOT_PRODUCT(inc_stat_counter(&alloc_bytes, size));
749 // NMT support
750 void* membase = MemTracker::record_free(memblock);
751 NMT_TrackingLevel level = MemTracker::tracking_level();
752 size_t nmt_header_size = MemTracker::malloc_header_size(level);
753 void* ptr = ::realloc(membase, size + nmt_header_size);
754 return MemTracker::record_malloc(ptr, size, memflags, stack, level);
755 #else
756 if (memblock == NULL) {
757 return os::malloc(size, memflags, stack);
758 }
759 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
760 log_warning(malloc, free)("os::realloc caught " PTR_FORMAT, p2i(memblock));
761 breakpoint();
762 }
763 // NMT support
764 void* membase = MemTracker::malloc_base(memblock);
765 verify_memory(membase);
766 // always move the block
767 void* ptr = os::malloc(size, memflags, stack);
768 // Copy to new memory if malloc didn't fail
769 if (ptr != NULL ) {
770 GuardedMemory guarded(MemTracker::malloc_base(memblock));
771 // Guard's user data contains NMT header
772 size_t memblock_size = guarded.get_user_size() - MemTracker::malloc_header_size(memblock);
773 memcpy(ptr, memblock, MIN2(size, memblock_size));
774 if (paranoid) {
775 verify_memory(MemTracker::malloc_base(ptr));
776 }
777 os::free(memblock);
778 }
779 return ptr;
780 #endif
781 }
782
783
784 void os::free(void *memblock) {
785 NOT_PRODUCT(inc_stat_counter(&num_frees, 1));
786 #ifdef ASSERT
787 if (memblock == NULL) return;
788 if ((intptr_t)memblock == (intptr_t)MallocCatchPtr) {
789 log_warning(malloc, free)("os::free caught " PTR_FORMAT, p2i(memblock));
790 breakpoint();
791 }
792 void* membase = MemTracker::record_free(memblock);
793 verify_memory(membase);
794
795 GuardedMemory guarded(membase);
796 size_t size = guarded.get_user_size();
797 inc_stat_counter(&free_bytes, size);
798 membase = guarded.release_for_freeing();
799 ::free(membase);
800 #else
801 void* membase = MemTracker::record_free(memblock);
802 ::free(membase);
803 #endif
804 }
805
806 void os::init_random(unsigned int initval) {
807 _rand_seed = initval;
808 }
809
810
811 static int random_helper(unsigned int rand_seed) {
812 /* standard, well-known linear congruential random generator with
813 * next_rand = (16807*seed) mod (2**31-1)
814 * see
815 * (1) "Random Number Generators: Good Ones Are Hard to Find",
816 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
817 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
818 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
819 */
820 const unsigned int a = 16807;
821 const unsigned int m = 2147483647;
822 const int q = m / a; assert(q == 127773, "weird math");
823 const int r = m % a; assert(r == 2836, "weird math");
824
825 // compute az=2^31p+q
826 unsigned int lo = a * (rand_seed & 0xFFFF);
827 unsigned int hi = a * (rand_seed >> 16);
828 lo += (hi & 0x7FFF) << 16;
829
830 // if q overflowed, ignore the overflow and increment q
831 if (lo > m) {
832 lo &= m;
833 ++lo;
834 }
835 lo += hi >> 15;
836
837 // if (p+q) overflowed, ignore the overflow and increment (p+q)
838 if (lo > m) {
839 lo &= m;
840 ++lo;
841 }
842 return lo;
843 }
844
845 int os::random() {
846 // Make updating the random seed thread safe.
847 while (true) {
848 unsigned int seed = _rand_seed;
849 unsigned int rand = random_helper(seed);
850 if (Atomic::cmpxchg(rand, &_rand_seed, seed) == seed) {
851 return static_cast<int>(rand);
852 }
853 }
854 }
855
856 // The INITIALIZED state is distinguished from the SUSPENDED state because the
857 // conditions in which a thread is first started are different from those in which
858 // a suspension is resumed. These differences make it hard for us to apply the
859 // tougher checks when starting threads that we want to do when resuming them.
860 // However, when start_thread is called as a result of Thread.start, on a Java
861 // thread, the operation is synchronized on the Java Thread object. So there
862 // cannot be a race to start the thread and hence for the thread to exit while
863 // we are working on it. Non-Java threads that start Java threads either have
864 // to do so in a context in which races are impossible, or should do appropriate
865 // locking.
866
867 void os::start_thread(Thread* thread) {
868 // guard suspend/resume
869 MutexLocker ml(thread->SR_lock(), Mutex::_no_safepoint_check_flag);
870 OSThread* osthread = thread->osthread();
871 osthread->set_state(RUNNABLE);
872 pd_start_thread(thread);
873 }
874
875 void os::abort(bool dump_core) {
876 abort(dump_core && CreateCoredumpOnCrash, NULL, NULL);
877 }
878
879 //---------------------------------------------------------------------------
880 // Helper functions for fatal error handler
881
882 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize) {
883 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
884
885 start = align_down(start, unitsize);
886
887 int cols = 0;
888 int cols_per_line = 0;
889 switch (unitsize) {
890 case 1: cols_per_line = 16; break;
891 case 2: cols_per_line = 8; break;
892 case 4: cols_per_line = 4; break;
893 case 8: cols_per_line = 2; break;
894 default: return;
895 }
896
897 address p = start;
898 st->print(PTR_FORMAT ": ", p2i(start));
899 while (p < end) {
900 if (is_readable_pointer(p)) {
901 switch (unitsize) {
902 case 1: st->print("%02x", *(u1*)p); break;
903 case 2: st->print("%04x", *(u2*)p); break;
904 case 4: st->print("%08x", *(u4*)p); break;
905 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
906 }
907 } else {
908 st->print("%*.*s", 2*unitsize, 2*unitsize, "????????????????");
909 }
910 p += unitsize;
911 cols++;
912 if (cols >= cols_per_line && p < end) {
913 cols = 0;
914 st->cr();
915 st->print(PTR_FORMAT ": ", p2i(p));
916 } else {
917 st->print(" ");
918 }
919 }
920 st->cr();
921 }
922
923 void os::print_instructions(outputStream* st, address pc, int unitsize) {
924 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
925 print_hex_dump(st, pc - 256, pc + 256, unitsize);
926 }
927
928 void os::print_environment_variables(outputStream* st, const char** env_list) {
929 if (env_list) {
930 st->print_cr("Environment Variables:");
931
932 for (int i = 0; env_list[i] != NULL; i++) {
933 char *envvar = ::getenv(env_list[i]);
934 if (envvar != NULL) {
935 st->print("%s", env_list[i]);
936 st->print("=");
937 st->print_cr("%s", envvar);
938 }
939 }
940 }
941 }
942
943 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
944 // cpu
945 st->print("CPU:");
946 st->print("total %d", os::processor_count());
947 // It's not safe to query number of active processors after crash
948 // st->print("(active %d)", os::active_processor_count()); but we can
949 // print the initial number of active processors.
950 // We access the raw value here because the assert in the accessor will
951 // fail if the crash occurs before initialization of this value.
952 st->print(" (initial active %d)", _initial_active_processor_count);
953 st->print(" %s", VM_Version::features_string());
954 st->cr();
955 pd_print_cpu_info(st, buf, buflen);
956 }
957
958 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version
959 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
960 st->print("Host: ");
961 #ifndef PRODUCT
962 if (get_host_name(buf, buflen)) {
963 st->print("%s, ", buf);
964 }
965 #endif // PRODUCT
966 get_summary_cpu_info(buf, buflen);
967 st->print("%s, ", buf);
968 size_t mem = physical_memory()/G;
969 if (mem == 0) { // for low memory systems
970 mem = physical_memory()/M;
971 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
972 } else {
973 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
974 }
975 get_summary_os_info(buf, buflen);
976 st->print_raw(buf);
977 st->cr();
978 }
979
980 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
981 const int secs_per_day = 86400;
982 const int secs_per_hour = 3600;
983 const int secs_per_min = 60;
984
985 time_t tloc;
986 (void)time(&tloc);
987 char* timestring = ctime(&tloc); // ctime adds newline.
988 // edit out the newline
989 char* nl = strchr(timestring, '\n');
990 if (nl != NULL) {
991 *nl = '\0';
992 }
993
994 struct tm tz;
995 if (localtime_pd(&tloc, &tz) != NULL) {
996 ::strftime(buf, buflen, "%Z", &tz);
997 st->print("Time: %s %s", timestring, buf);
998 } else {
999 st->print("Time: %s", timestring);
1000 }
1001
1002 double t = os::elapsedTime();
1003 // NOTE: It tends to crash after a SEGV if we want to printf("%f",...) in
1004 // Linux. Must be a bug in glibc ? Workaround is to round "t" to int
1005 // before printf. We lost some precision, but who cares?
1006 int eltime = (int)t; // elapsed time in seconds
1007
1008 // print elapsed time in a human-readable format:
1009 int eldays = eltime / secs_per_day;
1010 int day_secs = eldays * secs_per_day;
1011 int elhours = (eltime - day_secs) / secs_per_hour;
1012 int hour_secs = elhours * secs_per_hour;
1013 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
1014 int minute_secs = elmins * secs_per_min;
1015 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
1016 st->print_cr(" elapsed time: %d seconds (%dd %dh %dm %ds)", eltime, eldays, elhours, elmins, elsecs);
1017 }
1018
1019
1020 // Check if pointer can be read from (4-byte read access).
1021 // Helps to prove validity of a not-NULL pointer.
1022 // Returns true in very early stages of VM life when stub is not yet generated.
1023 #define SAFEFETCH_DEFAULT true
1024 bool os::is_readable_pointer(const void* p) {
1025 if (!CanUseSafeFetch32()) {
1026 return SAFEFETCH_DEFAULT;
1027 }
1028 int* const aligned = (int*) align_down((intptr_t)p, 4);
1029 int cafebabe = 0xcafebabe; // tester value 1
1030 int deadbeef = 0xdeadbeef; // tester value 2
1031 return (SafeFetch32(aligned, cafebabe) != cafebabe) || (SafeFetch32(aligned, deadbeef) != deadbeef);
1032 }
1033
1034 bool os::is_readable_range(const void* from, const void* to) {
1035 if ((uintptr_t)from >= (uintptr_t)to) return false;
1036 for (uintptr_t p = align_down((uintptr_t)from, min_page_size()); p < (uintptr_t)to; p += min_page_size()) {
1037 if (!is_readable_pointer((const void*)p)) {
1038 return false;
1039 }
1040 }
1041 return true;
1042 }
1043
1044
1045 // moved from debug.cpp (used to be find()) but still called from there
1046 // The verbose parameter is only set by the debug code in one case
1047 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
1048 address addr = (address)x;
1049 // Handle NULL first, so later checks don't need to protect against it.
1050 if (addr == NULL) {
1051 st->print_cr("0x0 is NULL");
1052 return;
1053 }
1054
1055 // Check if addr points into a code blob.
1056 CodeBlob* b = CodeCache::find_blob_unsafe(addr);
1057 if (b != NULL) {
1058 b->dump_for_addr(addr, st, verbose);
1059 return;
1060 }
1061
1062 // Check if addr points into Java heap.
1063 if (Universe::heap()->is_in(addr)) {
1064 oop o = oopDesc::oop_or_null(addr);
1065 if (o != NULL) {
1066 if ((HeapWord*)o == (HeapWord*)addr) {
1067 st->print(INTPTR_FORMAT " is an oop: ", p2i(addr));
1068 } else {
1069 st->print(INTPTR_FORMAT " is pointing into object: " , p2i(addr));
1070 }
1071 o->print_on(st);
1072 return;
1073 }
1074 } else if (Universe::heap()->is_in_reserved(addr)) {
1075 st->print_cr(INTPTR_FORMAT " is an unallocated location in the heap", p2i(addr));
1076 return;
1077 }
1078
1079 // Compressed oop needs to be decoded first.
1080 #ifdef _LP64
1081 if (UseCompressedOops && ((uintptr_t)addr &~ (uintptr_t)max_juint) == 0) {
1082 narrowOop narrow_oop = (narrowOop)(uintptr_t)addr;
1083 oop o = CompressedOops::decode_raw(narrow_oop);
1084
1085 if (oopDesc::is_valid(o)) {
1086 st->print(UINT32_FORMAT " is a compressed pointer to object: ", narrow_oop);
1087 o->print_on(st);
1088 return;
1089 }
1090 }
1091 #endif
1092
1093 bool accessible = is_readable_pointer(addr);
1094
1095 // Check if addr is a JNI handle.
1096 if (align_down((intptr_t)addr, sizeof(intptr_t)) != 0 && accessible) {
1097 if (JNIHandles::is_global_handle((jobject) addr)) {
1098 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
1099 return;
1100 }
1101 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1102 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
1103 return;
1104 }
1105 #ifndef PRODUCT
1106 // we don't keep the block list in product mode
1107 if (JNIHandles::is_local_handle((jobject) addr)) {
1108 st->print_cr(INTPTR_FORMAT " is a local jni handle", p2i(addr));
1109 return;
1110 }
1111 #endif
1112 }
1113
1114 // Check if addr belongs to a Java thread.
1115 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
1116 // If the addr is a java thread print information about that.
1117 if (addr == (address)thread) {
1118 if (verbose) {
1119 thread->print_on(st);
1120 } else {
1121 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
1122 }
1123 return;
1124 }
1125 // If the addr is in the stack region for this thread then report that
1126 // and print thread info
1127 if (thread->on_local_stack(addr)) {
1128 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1129 INTPTR_FORMAT, p2i(addr), p2i(thread));
1130 if (verbose) thread->print_on(st);
1131 return;
1132 }
1133 }
1134
1135 // Check if in metaspace and print types that have vptrs
1136 if (Metaspace::contains(addr)) {
1137 if (Klass::is_valid((Klass*)addr)) {
1138 st->print_cr(INTPTR_FORMAT " is a pointer to class: ", p2i(addr));
1139 ((Klass*)addr)->print_on(st);
1140 } else if (Method::is_valid_method((const Method*)addr)) {
1141 ((Method*)addr)->print_value_on(st);
1142 st->cr();
1143 } else {
1144 // Use addr->print() from the debugger instead (not here)
1145 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
1146 }
1147 return;
1148 }
1149
1150 // Compressed klass needs to be decoded first.
1151 #ifdef _LP64
1152 if (UseCompressedClassPointers && ((uintptr_t)addr &~ (uintptr_t)max_juint) == 0) {
1153 narrowKlass narrow_klass = (narrowKlass)(uintptr_t)addr;
1154 Klass* k = CompressedKlassPointers::decode_raw(narrow_klass);
1155
1156 if (Klass::is_valid(k)) {
1157 st->print_cr(UINT32_FORMAT " is a compressed pointer to class: " INTPTR_FORMAT, narrow_klass, p2i((HeapWord*)k));
1158 k->print_on(st);
1159 return;
1160 }
1161 }
1162 #endif
1163
1164 // Try an OS specific find
1165 if (os::find(addr, st)) {
1166 return;
1167 }
1168
1169 if (accessible) {
1170 st->print(INTPTR_FORMAT " points into unknown readable memory:", p2i(addr));
1171 for (address p = addr; p < align_up(addr + 1, sizeof(intptr_t)); ++p) {
1172 st->print(" %02x", *(u1*)p);
1173 }
1174 st->cr();
1175 return;
1176 }
1177
1178 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
1179 }
1180
1181 // Looks like all platforms can use the same function to check if C
1182 // stack is walkable beyond current frame. The check for fp() is not
1183 // necessary on Sparc, but it's harmless.
1184 bool os::is_first_C_frame(frame* fr) {
1185 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1186 // Check usp first, because if that's bad the other accessors may fault
1187 // on some architectures. Ditto ufp second, etc.
1188 uintptr_t fp_align_mask = (uintptr_t)(sizeof(address)-1);
1189 // sp on amd can be 32 bit aligned.
1190 uintptr_t sp_align_mask = (uintptr_t)(sizeof(int)-1);
1191
1192 uintptr_t usp = (uintptr_t)fr->sp();
1193 if ((usp & sp_align_mask) != 0) return true;
1194
1195 uintptr_t ufp = (uintptr_t)fr->fp();
1196 if ((ufp & fp_align_mask) != 0) return true;
1197
1198 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1199 if ((old_sp & sp_align_mask) != 0) return true;
1200 if (old_sp == 0 || old_sp == (uintptr_t)-1) return true;
1201
1202 uintptr_t old_fp = (uintptr_t)fr->link();
1203 if ((old_fp & fp_align_mask) != 0) return true;
1204 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp) return true;
1205
1206 // stack grows downwards; if old_fp is below current fp or if the stack
1207 // frame is too large, either the stack is corrupted or fp is not saved
1208 // on stack (i.e. on x86, ebp may be used as general register). The stack
1209 // is not walkable beyond current frame.
1210 if (old_fp < ufp) return true;
1211 if (old_fp - ufp > 64 * K) return true;
1212
1213 return false;
1214 }
1215
1216
1217 // Set up the boot classpath.
1218
1219 char* os::format_boot_path(const char* format_string,
1220 const char* home,
1221 int home_len,
1222 char fileSep,
1223 char pathSep) {
1224 assert((fileSep == '/' && pathSep == ':') ||
1225 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1226
1227 // Scan the format string to determine the length of the actual
1228 // boot classpath, and handle platform dependencies as well.
1229 int formatted_path_len = 0;
1230 const char* p;
1231 for (p = format_string; *p != 0; ++p) {
1232 if (*p == '%') formatted_path_len += home_len - 1;
1233 ++formatted_path_len;
1234 }
1235
1236 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1237 if (formatted_path == NULL) {
1238 return NULL;
1239 }
1240
1241 // Create boot classpath from format, substituting separator chars and
1242 // java home directory.
1243 char* q = formatted_path;
1244 for (p = format_string; *p != 0; ++p) {
1245 switch (*p) {
1246 case '%':
1247 strcpy(q, home);
1248 q += home_len;
1249 break;
1250 case '/':
1251 *q++ = fileSep;
1252 break;
1253 case ':':
1254 *q++ = pathSep;
1255 break;
1256 default:
1257 *q++ = *p;
1258 }
1259 }
1260 *q = '\0';
1261
1262 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1263 return formatted_path;
1264 }
1265
1266 // This function is a proxy to fopen, it tries to add a non standard flag ('e' or 'N')
1267 // that ensures automatic closing of the file on exec. If it can not find support in
1268 // the underlying c library, it will make an extra system call (fcntl) to ensure automatic
1269 // closing of the file on exec.
1270 FILE* os::fopen(const char* path, const char* mode) {
1271 char modified_mode[20];
1272 assert(strlen(mode) + 1 < sizeof(modified_mode), "mode chars plus one extra must fit in buffer");
1273 sprintf(modified_mode, "%s" LINUX_ONLY("e") BSD_ONLY("e") WINDOWS_ONLY("N"), mode);
1274 FILE* file = ::fopen(path, modified_mode);
1275
1276 #if !(defined LINUX || defined BSD || defined _WINDOWS)
1277 // assume fcntl FD_CLOEXEC support as a backup solution when 'e' or 'N'
1278 // is not supported as mode in fopen
1279 if (file != NULL) {
1280 int fd = fileno(file);
1281 if (fd != -1) {
1282 int fd_flags = fcntl(fd, F_GETFD);
1283 if (fd_flags != -1) {
1284 fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC);
1285 }
1286 }
1287 }
1288 #endif
1289
1290 return file;
1291 }
1292
1293 bool os::set_boot_path(char fileSep, char pathSep) {
1294 const char* home = Arguments::get_java_home();
1295 int home_len = (int)strlen(home);
1296
1297 struct stat st;
1298
1299 // modular image if "modules" jimage exists
1300 char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep);
1301 if (jimage == NULL) return false;
1302 bool has_jimage = (os::stat(jimage, &st) == 0);
1303 if (has_jimage) {
1304 Arguments::set_sysclasspath(jimage, true);
1305 FREE_C_HEAP_ARRAY(char, jimage);
1306 return true;
1307 }
1308 FREE_C_HEAP_ARRAY(char, jimage);
1309
1310 // check if developer build with exploded modules
1311 char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep);
1312 if (base_classes == NULL) return false;
1313 if (os::stat(base_classes, &st) == 0) {
1314 Arguments::set_sysclasspath(base_classes, false);
1315 FREE_C_HEAP_ARRAY(char, base_classes);
1316 return true;
1317 }
1318 FREE_C_HEAP_ARRAY(char, base_classes);
1319
1320 return false;
1321 }
1322
1323 // Splits a path, based on its separator, the number of
1324 // elements is returned back in "elements".
1325 // file_name_length is used as a modifier for each path's
1326 // length when compared to JVM_MAXPATHLEN. So if you know
1327 // each returned path will have something appended when
1328 // in use, you can pass the length of that in
1329 // file_name_length, to ensure we detect if any path
1330 // exceeds the maximum path length once prepended onto
1331 // the sub-path/file name.
1332 // It is the callers responsibility to:
1333 // a> check the value of "elements", which may be 0.
1334 // b> ignore any empty path elements
1335 // c> free up the data.
1336 char** os::split_path(const char* path, size_t* elements, size_t file_name_length) {
1337 *elements = (size_t)0;
1338 if (path == NULL || strlen(path) == 0 || file_name_length == (size_t)NULL) {
1339 return NULL;
1340 }
1341 const char psepchar = *os::path_separator();
1342 char* inpath = (char*)NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1343 if (inpath == NULL) {
1344 return NULL;
1345 }
1346 strcpy(inpath, path);
1347 size_t count = 1;
1348 char* p = strchr(inpath, psepchar);
1349 // Get a count of elements to allocate memory
1350 while (p != NULL) {
1351 count++;
1352 p++;
1353 p = strchr(p, psepchar);
1354 }
1355 char** opath = (char**) NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1356
1357 // do the actual splitting
1358 p = inpath;
1359 for (size_t i = 0 ; i < count ; i++) {
1360 size_t len = strcspn(p, os::path_separator());
1361 if (len + file_name_length > JVM_MAXPATHLEN) {
1362 // release allocated storage before exiting the vm
1363 free_array_of_char_arrays(opath, i++);
1364 vm_exit_during_initialization("The VM tried to use a path that exceeds the maximum path length for "
1365 "this system. Review path-containing parameters and properties, such as "
1366 "sun.boot.library.path, to identify potential sources for this path.");
1367 }
1368 // allocate the string and add terminator storage
1369 char* s = (char*)NEW_C_HEAP_ARRAY_RETURN_NULL(char, len + 1, mtInternal);
1370 if (s == NULL) {
1371 // release allocated storage before returning null
1372 free_array_of_char_arrays(opath, i++);
1373 return NULL;
1374 }
1375 strncpy(s, p, len);
1376 s[len] = '\0';
1377 opath[i] = s;
1378 p += len + 1;
1379 }
1380 FREE_C_HEAP_ARRAY(char, inpath);
1381 *elements = count;
1382 return opath;
1383 }
1384
1385 // Returns true if the current stack pointer is above the stack shadow
1386 // pages, false otherwise.
1387 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) {
1388 if (!thread->is_Java_thread()) return false;
1389 // Check if we have StackShadowPages above the yellow zone. This parameter
1390 // is dependent on the depth of the maximum VM call stack possible from
1391 // the handler for stack overflow. 'instanceof' in the stack overflow
1392 // handler or a println uses at least 8k stack of VM and native code
1393 // respectively.
1394 const int framesize_in_bytes =
1395 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1396
1397 address limit = ((JavaThread*)thread)->stack_end() +
1398 (JavaThread::stack_guard_zone_size() + JavaThread::stack_shadow_zone_size());
1399
1400 return sp > (limit + framesize_in_bytes);
1401 }
1402
1403 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1404 assert(min_pages > 0, "sanity");
1405 if (UseLargePages) {
1406 const size_t max_page_size = region_size / min_pages;
1407
1408 for (size_t i = 0; _page_sizes[i] != 0; ++i) {
1409 const size_t page_size = _page_sizes[i];
1410 if (page_size <= max_page_size) {
1411 if (!must_be_aligned || is_aligned(region_size, page_size)) {
1412 return page_size;
1413 }
1414 }
1415 }
1416 }
1417
1418 return vm_page_size();
1419 }
1420
1421 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1422 return page_size_for_region(region_size, min_pages, true);
1423 }
1424
1425 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1426 return page_size_for_region(region_size, min_pages, false);
1427 }
1428
1429 static const char* errno_to_string (int e, bool short_text) {
1430 #define ALL_SHARED_ENUMS(X) \
1431 X(E2BIG, "Argument list too long") \
1432 X(EACCES, "Permission denied") \
1433 X(EADDRINUSE, "Address in use") \
1434 X(EADDRNOTAVAIL, "Address not available") \
1435 X(EAFNOSUPPORT, "Address family not supported") \
1436 X(EAGAIN, "Resource unavailable, try again") \
1437 X(EALREADY, "Connection already in progress") \
1438 X(EBADF, "Bad file descriptor") \
1439 X(EBADMSG, "Bad message") \
1440 X(EBUSY, "Device or resource busy") \
1441 X(ECANCELED, "Operation canceled") \
1442 X(ECHILD, "No child processes") \
1443 X(ECONNABORTED, "Connection aborted") \
1444 X(ECONNREFUSED, "Connection refused") \
1445 X(ECONNRESET, "Connection reset") \
1446 X(EDEADLK, "Resource deadlock would occur") \
1447 X(EDESTADDRREQ, "Destination address required") \
1448 X(EDOM, "Mathematics argument out of domain of function") \
1449 X(EEXIST, "File exists") \
1450 X(EFAULT, "Bad address") \
1451 X(EFBIG, "File too large") \
1452 X(EHOSTUNREACH, "Host is unreachable") \
1453 X(EIDRM, "Identifier removed") \
1454 X(EILSEQ, "Illegal byte sequence") \
1455 X(EINPROGRESS, "Operation in progress") \
1456 X(EINTR, "Interrupted function") \
1457 X(EINVAL, "Invalid argument") \
1458 X(EIO, "I/O error") \
1459 X(EISCONN, "Socket is connected") \
1460 X(EISDIR, "Is a directory") \
1461 X(ELOOP, "Too many levels of symbolic links") \
1462 X(EMFILE, "Too many open files") \
1463 X(EMLINK, "Too many links") \
1464 X(EMSGSIZE, "Message too large") \
1465 X(ENAMETOOLONG, "Filename too long") \
1466 X(ENETDOWN, "Network is down") \
1467 X(ENETRESET, "Connection aborted by network") \
1468 X(ENETUNREACH, "Network unreachable") \
1469 X(ENFILE, "Too many files open in system") \
1470 X(ENOBUFS, "No buffer space available") \
1471 X(ENODATA, "No message is available on the STREAM head read queue") \
1472 X(ENODEV, "No such device") \
1473 X(ENOENT, "No such file or directory") \
1474 X(ENOEXEC, "Executable file format error") \
1475 X(ENOLCK, "No locks available") \
1476 X(ENOLINK, "Reserved") \
1477 X(ENOMEM, "Not enough space") \
1478 X(ENOMSG, "No message of the desired type") \
1479 X(ENOPROTOOPT, "Protocol not available") \
1480 X(ENOSPC, "No space left on device") \
1481 X(ENOSR, "No STREAM resources") \
1482 X(ENOSTR, "Not a STREAM") \
1483 X(ENOSYS, "Function not supported") \
1484 X(ENOTCONN, "The socket is not connected") \
1485 X(ENOTDIR, "Not a directory") \
1486 X(ENOTEMPTY, "Directory not empty") \
1487 X(ENOTSOCK, "Not a socket") \
1488 X(ENOTSUP, "Not supported") \
1489 X(ENOTTY, "Inappropriate I/O control operation") \
1490 X(ENXIO, "No such device or address") \
1491 X(EOPNOTSUPP, "Operation not supported on socket") \
1492 X(EOVERFLOW, "Value too large to be stored in data type") \
1493 X(EPERM, "Operation not permitted") \
1494 X(EPIPE, "Broken pipe") \
1495 X(EPROTO, "Protocol error") \
1496 X(EPROTONOSUPPORT, "Protocol not supported") \
1497 X(EPROTOTYPE, "Protocol wrong type for socket") \
1498 X(ERANGE, "Result too large") \
1499 X(EROFS, "Read-only file system") \
1500 X(ESPIPE, "Invalid seek") \
1501 X(ESRCH, "No such process") \
1502 X(ETIME, "Stream ioctl() timeout") \
1503 X(ETIMEDOUT, "Connection timed out") \
1504 X(ETXTBSY, "Text file busy") \
1505 X(EWOULDBLOCK, "Operation would block") \
1506 X(EXDEV, "Cross-device link")
1507
1508 #define DEFINE_ENTRY(e, text) { e, #e, text },
1509
1510 static const struct {
1511 int v;
1512 const char* short_text;
1513 const char* long_text;
1514 } table [] = {
1515
1516 ALL_SHARED_ENUMS(DEFINE_ENTRY)
1517
1518 // The following enums are not defined on all platforms.
1519 #ifdef ESTALE
1520 DEFINE_ENTRY(ESTALE, "Reserved")
1521 #endif
1522 #ifdef EDQUOT
1523 DEFINE_ENTRY(EDQUOT, "Reserved")
1524 #endif
1525 #ifdef EMULTIHOP
1526 DEFINE_ENTRY(EMULTIHOP, "Reserved")
1527 #endif
1528
1529 // End marker.
1530 { -1, "Unknown errno", "Unknown error" }
1531
1532 };
1533
1534 #undef DEFINE_ENTRY
1535 #undef ALL_FLAGS
1536
1537 int i = 0;
1538 while (table[i].v != -1 && table[i].v != e) {
1539 i ++;
1540 }
1541
1542 return short_text ? table[i].short_text : table[i].long_text;
1543
1544 }
1545
1546 const char* os::strerror(int e) {
1547 return errno_to_string(e, false);
1548 }
1549
1550 const char* os::errno_name(int e) {
1551 return errno_to_string(e, true);
1552 }
1553
1554 void os::trace_page_sizes(const char* str, const size_t* page_sizes, int count) {
1555 LogTarget(Info, pagesize) log;
1556 if (log.is_enabled()) {
1557 LogStream out(log);
1558
1559 out.print("%s: ", str);
1560 for (int i = 0; i < count; ++i) {
1561 out.print(" " SIZE_FORMAT, page_sizes[i]);
1562 }
1563 out.cr();
1564 }
1565 }
1566
1567 #define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size)
1568
1569 void os::trace_page_sizes(const char* str,
1570 const size_t region_min_size,
1571 const size_t region_max_size,
1572 const size_t page_size,
1573 const char* base,
1574 const size_t size) {
1575
1576 log_info(pagesize)("%s: "
1577 " min=" SIZE_FORMAT "%s"
1578 " max=" SIZE_FORMAT "%s"
1579 " base=" PTR_FORMAT
1580 " page_size=" SIZE_FORMAT "%s"
1581 " size=" SIZE_FORMAT "%s",
1582 str,
1583 trace_page_size_params(region_min_size),
1584 trace_page_size_params(region_max_size),
1585 p2i(base),
1586 trace_page_size_params(page_size),
1587 trace_page_size_params(size));
1588 }
1589
1590 void os::trace_page_sizes_for_requested_size(const char* str,
1591 const size_t requested_size,
1592 const size_t page_size,
1593 const size_t alignment,
1594 const char* base,
1595 const size_t size) {
1596
1597 log_info(pagesize)("%s:"
1598 " req_size=" SIZE_FORMAT "%s"
1599 " base=" PTR_FORMAT
1600 " page_size=" SIZE_FORMAT "%s"
1601 " alignment=" SIZE_FORMAT "%s"
1602 " size=" SIZE_FORMAT "%s",
1603 str,
1604 trace_page_size_params(requested_size),
1605 p2i(base),
1606 trace_page_size_params(page_size),
1607 trace_page_size_params(alignment),
1608 trace_page_size_params(size));
1609 }
1610
1611
1612 // This is the working definition of a server class machine:
1613 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1614 // because the graphics memory (?) sometimes masks physical memory.
1615 // If you want to change the definition of a server class machine
1616 // on some OS or platform, e.g., >=4GB on Windows platforms,
1617 // then you'll have to parameterize this method based on that state,
1618 // as was done for logical processors here, or replicate and
1619 // specialize this method for each platform. (Or fix os to have
1620 // some inheritance structure and use subclassing. Sigh.)
1621 // If you want some platform to always or never behave as a server
1622 // class machine, change the setting of AlwaysActAsServerClassMachine
1623 // and NeverActAsServerClassMachine in globals*.hpp.
1624 bool os::is_server_class_machine() {
1625 // First check for the early returns
1626 if (NeverActAsServerClassMachine) {
1627 return false;
1628 }
1629 if (AlwaysActAsServerClassMachine) {
1630 return true;
1631 }
1632 // Then actually look at the machine
1633 bool result = false;
1634 const unsigned int server_processors = 2;
1635 const julong server_memory = 2UL * G;
1636 // We seem not to get our full complement of memory.
1637 // We allow some part (1/8?) of the memory to be "missing",
1638 // based on the sizes of DIMMs, and maybe graphics cards.
1639 const julong missing_memory = 256UL * M;
1640
1641 /* Is this a server class machine? */
1642 if ((os::active_processor_count() >= (int)server_processors) &&
1643 (os::physical_memory() >= (server_memory - missing_memory))) {
1644 const unsigned int logical_processors =
1645 VM_Version::logical_processors_per_package();
1646 if (logical_processors > 1) {
1647 const unsigned int physical_packages =
1648 os::active_processor_count() / logical_processors;
1649 if (physical_packages >= server_processors) {
1650 result = true;
1651 }
1652 } else {
1653 result = true;
1654 }
1655 }
1656 return result;
1657 }
1658
1659 void os::initialize_initial_active_processor_count() {
1660 assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
1661 _initial_active_processor_count = active_processor_count();
1662 log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count);
1663 }
1664
1665 void os::SuspendedThreadTask::run() {
1666 internal_do_task();
1667 _done = true;
1668 }
1669
1670 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1671 return os::pd_create_stack_guard_pages(addr, bytes);
1672 }
1673
1674 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint, int file_desc) {
1675 char* result = NULL;
1676
1677 if (file_desc != -1) {
1678 // Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(),
1679 // but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file.
1680 result = os::map_memory_to_file(addr, bytes, file_desc);
1681 if (result != NULL) {
1682 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1683 }
1684 } else {
1685 result = pd_reserve_memory(bytes, addr, alignment_hint);
1686 if (result != NULL) {
1687 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1688 }
1689 }
1690
1691 return result;
1692 }
1693
1694 char* os::reserve_memory(size_t bytes, char* addr, size_t alignment_hint,
1695 MEMFLAGS flags) {
1696 char* result = pd_reserve_memory(bytes, addr, alignment_hint);
1697 if (result != NULL) {
1698 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1699 MemTracker::record_virtual_memory_type((address)result, flags);
1700 }
1701
1702 return result;
1703 }
1704
1705 char* os::attempt_reserve_memory_at(size_t bytes, char* addr, int file_desc) {
1706 char* result = NULL;
1707 if (file_desc != -1) {
1708 result = pd_attempt_reserve_memory_at(bytes, addr, file_desc);
1709 if (result != NULL) {
1710 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1711 }
1712 } else {
1713 result = pd_attempt_reserve_memory_at(bytes, addr);
1714 if (result != NULL) {
1715 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1716 }
1717 }
1718 return result;
1719 }
1720
1721 void os::split_reserved_memory(char *base, size_t size,
1722 size_t split, bool realloc) {
1723 pd_split_reserved_memory(base, size, split, realloc);
1724 }
1725
1726 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1727 bool res = pd_commit_memory(addr, bytes, executable);
1728 if (res) {
1729 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1730 }
1731 return res;
1732 }
1733
1734 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1735 bool executable) {
1736 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1737 if (res) {
1738 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1739 }
1740 return res;
1741 }
1742
1743 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1744 const char* mesg) {
1745 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1746 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1747 }
1748
1749 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1750 bool executable, const char* mesg) {
1751 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1752 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1753 }
1754
1755 bool os::uncommit_memory(char* addr, size_t bytes) {
1756 bool res;
1757 if (MemTracker::tracking_level() > NMT_minimal) {
1758 Tracker tkr(Tracker::uncommit);
1759 res = pd_uncommit_memory(addr, bytes);
1760 if (res) {
1761 tkr.record((address)addr, bytes);
1762 }
1763 } else {
1764 res = pd_uncommit_memory(addr, bytes);
1765 }
1766 return res;
1767 }
1768
1769 bool os::release_memory(char* addr, size_t bytes) {
1770 bool res;
1771 if (MemTracker::tracking_level() > NMT_minimal) {
1772 Tracker tkr(Tracker::release);
1773 res = pd_release_memory(addr, bytes);
1774 if (res) {
1775 tkr.record((address)addr, bytes);
1776 }
1777 } else {
1778 res = pd_release_memory(addr, bytes);
1779 }
1780 return res;
1781 }
1782
1783 void os::pretouch_memory(void* start, void* end, size_t page_size) {
1784 for (volatile char *p = (char*)start; p < (char*)end; p += page_size) {
1785 *p = 0;
1786 }
1787 }
1788
1789 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1790 char *addr, size_t bytes, bool read_only,
1791 bool allow_exec) {
1792 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1793 if (result != NULL) {
1794 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1795 }
1796 return result;
1797 }
1798
1799 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1800 char *addr, size_t bytes, bool read_only,
1801 bool allow_exec) {
1802 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1803 read_only, allow_exec);
1804 }
1805
1806 bool os::unmap_memory(char *addr, size_t bytes) {
1807 bool result;
1808 if (MemTracker::tracking_level() > NMT_minimal) {
1809 Tracker tkr(Tracker::release);
1810 result = pd_unmap_memory(addr, bytes);
1811 if (result) {
1812 tkr.record((address)addr, bytes);
1813 }
1814 } else {
1815 result = pd_unmap_memory(addr, bytes);
1816 }
1817 return result;
1818 }
1819
1820 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1821 pd_free_memory(addr, bytes, alignment_hint);
1822 }
1823
1824 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1825 pd_realign_memory(addr, bytes, alignment_hint);
1826 }
1827
1828 #ifndef _WINDOWS
1829 /* try to switch state from state "from" to state "to"
1830 * returns the state set after the method is complete
1831 */
1832 os::SuspendResume::State os::SuspendResume::switch_state(os::SuspendResume::State from,
1833 os::SuspendResume::State to)
1834 {
1835 os::SuspendResume::State result = Atomic::cmpxchg(to, &_state, from);
1836 if (result == from) {
1837 // success
1838 return to;
1839 }
1840 return result;
1841 }
1842 #endif