1 /*
2 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/javaClasses.hpp"
27 #include "classfile/moduleEntry.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmClasses.hpp"
30 #include "classfile/vmSymbols.hpp"
31 #include "code/codeCache.hpp"
32 #include "code/icBuffer.hpp"
33 #include "code/vtableStubs.hpp"
34 #include "gc/shared/gcVMOperations.hpp"
35 #include "interpreter/interpreter.hpp"
36 #include "jvm.h"
37 #include "logging/log.hpp"
38 #include "logging/logStream.hpp"
39 #include "memory/allocation.inline.hpp"
40 #include "memory/resourceArea.hpp"
41 #include "memory/universe.hpp"
42 #include "oops/compressedOops.inline.hpp"
43 #include "oops/oop.inline.hpp"
44 #include "prims/jvmtiAgent.hpp"
45 #include "prims/jvm_misc.hpp"
46 #include "runtime/arguments.hpp"
47 #include "runtime/atomic.hpp"
48 #include "runtime/frame.inline.hpp"
49 #include "runtime/handles.inline.hpp"
50 #include "runtime/interfaceSupport.inline.hpp"
51 #include "runtime/java.hpp"
52 #include "runtime/javaCalls.hpp"
53 #include "runtime/javaThread.hpp"
54 #include "runtime/jniHandles.hpp"
55 #include "runtime/mutexLocker.hpp"
56 #include "runtime/os.inline.hpp"
57 #include "runtime/osThread.hpp"
58 #include "runtime/safefetch.hpp"
59 #include "runtime/sharedRuntime.hpp"
60 #include "runtime/threadCrashProtection.hpp"
61 #include "runtime/threadSMR.hpp"
62 #include "runtime/vmOperations.hpp"
63 #include "runtime/vm_version.hpp"
64 #include "sanitizers/address.hpp"
65 #include "services/attachListener.hpp"
66 #include "services/mallocTracker.hpp"
67 #include "services/mallocHeader.inline.hpp"
68 #include "services/memTracker.inline.hpp"
69 #include "services/nmtPreInit.hpp"
70 #include "services/nmtCommon.hpp"
71 #include "services/threadService.hpp"
72 #include "utilities/align.hpp"
73 #include "utilities/count_trailing_zeros.hpp"
74 #include "utilities/defaultStream.hpp"
75 #include "utilities/events.hpp"
76 #include "utilities/powerOfTwo.hpp"
77
78 #ifndef _WINDOWS
79 # include <poll.h>
80 #endif
81
82 # include <signal.h>
83 # include <errno.h>
84
85 OSThread* os::_starting_thread = nullptr;
86 volatile unsigned int os::_rand_seed = 1234567;
87 int os::_processor_count = 0;
88 int os::_initial_active_processor_count = 0;
89 os::PageSizes os::_page_sizes;
90
91 DEBUG_ONLY(bool os::_mutex_init_done = false;)
92
93 int os::snprintf(char* buf, size_t len, const char* fmt, ...) {
94 va_list args;
95 va_start(args, fmt);
96 int result = os::vsnprintf(buf, len, fmt, args);
97 va_end(args);
98 return result;
99 }
100
101 int os::snprintf_checked(char* buf, size_t len, const char* fmt, ...) {
102 va_list args;
103 va_start(args, fmt);
104 int result = os::vsnprintf(buf, len, fmt, args);
105 va_end(args);
106 assert(result >= 0, "os::snprintf error");
107 assert(static_cast<size_t>(result) < len, "os::snprintf truncated");
108 return result;
109 }
110
111 // Fill in buffer with current local time as an ISO-8601 string.
112 // E.g., YYYY-MM-DDThh:mm:ss.mmm+zzzz.
113 // Returns buffer, or null if it failed.
114 char* os::iso8601_time(char* buffer, size_t buffer_length, bool utc) {
115 const jlong now = javaTimeMillis();
116 return os::iso8601_time(now, buffer, buffer_length, utc);
117 }
118
119 // Fill in buffer with an ISO-8601 string corresponding to the given javaTimeMillis value
120 // E.g., yyyy-mm-ddThh:mm:ss-zzzz.
121 // Returns buffer, or null if it failed.
122 // This would mostly be a call to
123 // strftime(...., "%Y-%m-%d" "T" "%H:%M:%S" "%z", ....)
124 // except that on Windows the %z behaves badly, so we do it ourselves.
125 // Also, people wanted milliseconds on there,
126 // and strftime doesn't do milliseconds.
127 char* os::iso8601_time(jlong milliseconds_since_19700101, char* buffer, size_t buffer_length, bool utc) {
128 // Output will be of the form "YYYY-MM-DDThh:mm:ss.mmm+zzzz\0"
129
130 // Sanity check the arguments
131 if (buffer == nullptr) {
132 assert(false, "null buffer");
133 return nullptr;
134 }
135 if (buffer_length < os::iso8601_timestamp_size) {
136 assert(false, "buffer_length too small");
137 return nullptr;
138 }
139 const int milliseconds_per_microsecond = 1000;
140 const time_t seconds_since_19700101 =
141 milliseconds_since_19700101 / milliseconds_per_microsecond;
142 const int milliseconds_after_second =
143 milliseconds_since_19700101 % milliseconds_per_microsecond;
144 // Convert the time value to a tm and timezone variable
145 struct tm time_struct;
146 if (utc) {
147 if (gmtime_pd(&seconds_since_19700101, &time_struct) == nullptr) {
148 assert(false, "Failed gmtime_pd");
149 return nullptr;
150 }
151 } else {
152 if (localtime_pd(&seconds_since_19700101, &time_struct) == nullptr) {
153 assert(false, "Failed localtime_pd");
154 return nullptr;
155 }
156 }
157
158 const time_t seconds_per_minute = 60;
159 const time_t minutes_per_hour = 60;
160 const time_t seconds_per_hour = seconds_per_minute * minutes_per_hour;
161
162 // No offset when dealing with UTC
163 time_t UTC_to_local = 0;
164 if (!utc) {
165 #if defined(_ALLBSD_SOURCE) || defined(_GNU_SOURCE)
166 UTC_to_local = -(time_struct.tm_gmtoff);
167 #elif defined(_WINDOWS)
168 long zone;
169 _get_timezone(&zone);
170 UTC_to_local = static_cast<time_t>(zone);
171 #else
172 UTC_to_local = timezone;
173 #endif
174
175 // tm_gmtoff already includes adjustment for daylight saving
176 #if !defined(_ALLBSD_SOURCE) && !defined(_GNU_SOURCE)
177 // If daylight savings time is in effect,
178 // we are 1 hour East of our time zone
179 if (time_struct.tm_isdst > 0) {
180 UTC_to_local = UTC_to_local - seconds_per_hour;
181 }
182 #endif
183 }
184
185 // Compute the time zone offset.
186 // localtime_pd() sets timezone to the difference (in seconds)
187 // between UTC and local time.
188 // ISO 8601 says we need the difference between local time and UTC,
189 // we change the sign of the localtime_pd() result.
190 const time_t local_to_UTC = -(UTC_to_local);
191 // Then we have to figure out if if we are ahead (+) or behind (-) UTC.
192 char sign_local_to_UTC = '+';
193 time_t abs_local_to_UTC = local_to_UTC;
194 if (local_to_UTC < 0) {
195 sign_local_to_UTC = '-';
196 abs_local_to_UTC = -(abs_local_to_UTC);
197 }
198 // Convert time zone offset seconds to hours and minutes.
199 const time_t zone_hours = (abs_local_to_UTC / seconds_per_hour);
200 const time_t zone_min =
201 ((abs_local_to_UTC % seconds_per_hour) / seconds_per_minute);
202
203 // Print an ISO 8601 date and time stamp into the buffer
204 const int year = 1900 + time_struct.tm_year;
205 const int month = 1 + time_struct.tm_mon;
206 const int printed = jio_snprintf(buffer, buffer_length,
207 "%04d-%02d-%02dT%02d:%02d:%02d.%03d%c%02d%02d",
208 year,
209 month,
210 time_struct.tm_mday,
211 time_struct.tm_hour,
212 time_struct.tm_min,
213 time_struct.tm_sec,
214 milliseconds_after_second,
215 sign_local_to_UTC,
216 zone_hours,
217 zone_min);
218 if (printed == 0) {
219 assert(false, "Failed jio_printf");
220 return nullptr;
221 }
222 return buffer;
223 }
224
225 OSReturn os::set_priority(Thread* thread, ThreadPriority p) {
226 debug_only(Thread::check_for_dangling_thread_pointer(thread);)
227
228 if ((p >= MinPriority && p <= MaxPriority) ||
229 (p == CriticalPriority && thread->is_ConcurrentGC_thread())) {
230 int priority = java_to_os_priority[p];
231 return set_native_priority(thread, priority);
232 } else {
233 assert(false, "Should not happen");
234 return OS_ERR;
235 }
236 }
237
238 // The mapping from OS priority back to Java priority may be inexact because
239 // Java priorities can map M:1 with native priorities. If you want the definite
240 // Java priority then use JavaThread::java_priority()
241 OSReturn os::get_priority(const Thread* const thread, ThreadPriority& priority) {
242 int p;
243 int os_prio;
244 OSReturn ret = get_native_priority(thread, &os_prio);
245 if (ret != OS_OK) return ret;
246
247 if (java_to_os_priority[MaxPriority] > java_to_os_priority[MinPriority]) {
248 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] > os_prio; p--) ;
249 } else {
250 // niceness values are in reverse order
251 for (p = MaxPriority; p > MinPriority && java_to_os_priority[p] < os_prio; p--) ;
252 }
253 priority = (ThreadPriority)p;
254 return OS_OK;
255 }
256
257 bool os::dll_build_name(char* buffer, size_t size, const char* fname) {
258 int n = jio_snprintf(buffer, size, "%s%s%s", JNI_LIB_PREFIX, fname, JNI_LIB_SUFFIX);
259 return (n != -1);
260 }
261
262 #if !defined(LINUX) && !defined(_WINDOWS)
263 bool os::committed_in_range(address start, size_t size, address& committed_start, size_t& committed_size) {
264 committed_start = start;
265 committed_size = size;
266 return true;
267 }
268 #endif
269
270 // Helper for dll_locate_lib.
271 // Pass buffer and printbuffer as we already printed the path to buffer
272 // when we called get_current_directory. This way we avoid another buffer
273 // of size MAX_PATH.
274 static bool conc_path_file_and_check(char *buffer, char *printbuffer, size_t printbuflen,
275 const char* pname, char lastchar, const char* fname) {
276
277 // Concatenate path and file name, but don't print double path separators.
278 const char *filesep = (WINDOWS_ONLY(lastchar == ':' ||) lastchar == os::file_separator()[0]) ?
279 "" : os::file_separator();
280 int ret = jio_snprintf(printbuffer, printbuflen, "%s%s%s", pname, filesep, fname);
281 // Check whether file exists.
282 if (ret != -1) {
283 struct stat statbuf;
284 return os::stat(buffer, &statbuf) == 0;
285 }
286 return false;
287 }
288
289 // Frees all memory allocated on the heap for the
290 // supplied array of arrays of chars (a), where n
291 // is the number of elements in the array.
292 static void free_array_of_char_arrays(char** a, size_t n) {
293 while (n > 0) {
294 n--;
295 if (a[n] != nullptr) {
296 FREE_C_HEAP_ARRAY(char, a[n]);
297 }
298 }
299 FREE_C_HEAP_ARRAY(char*, a);
300 }
301
302 bool os::dll_locate_lib(char *buffer, size_t buflen,
303 const char* pname, const char* fname) {
304 bool retval = false;
305
306 size_t fullfnamelen = strlen(JNI_LIB_PREFIX) + strlen(fname) + strlen(JNI_LIB_SUFFIX);
307 char* fullfname = NEW_C_HEAP_ARRAY(char, fullfnamelen + 1, mtInternal);
308 if (dll_build_name(fullfname, fullfnamelen + 1, fname)) {
309 const size_t pnamelen = pname ? strlen(pname) : 0;
310
311 if (pnamelen == 0) {
312 // If no path given, use current working directory.
313 const char* p = get_current_directory(buffer, buflen);
314 if (p != nullptr) {
315 const size_t plen = strlen(buffer);
316 const char lastchar = buffer[plen - 1];
317 retval = conc_path_file_and_check(buffer, &buffer[plen], buflen - plen,
318 "", lastchar, fullfname);
319 }
320 } else if (strchr(pname, *os::path_separator()) != nullptr) {
321 // A list of paths. Search for the path that contains the library.
322 size_t n;
323 char** pelements = split_path(pname, &n, fullfnamelen);
324 if (pelements != nullptr) {
325 for (size_t i = 0; i < n; i++) {
326 char* path = pelements[i];
327 // Really shouldn't be null, but check can't hurt.
328 size_t plen = (path == nullptr) ? 0 : strlen(path);
329 if (plen == 0) {
330 continue; // Skip the empty path values.
331 }
332 const char lastchar = path[plen - 1];
333 retval = conc_path_file_and_check(buffer, buffer, buflen, path, lastchar, fullfname);
334 if (retval) break;
335 }
336 // Release the storage allocated by split_path.
337 free_array_of_char_arrays(pelements, n);
338 }
339 } else {
340 // A definite path.
341 const char lastchar = pname[pnamelen-1];
342 retval = conc_path_file_and_check(buffer, buffer, buflen, pname, lastchar, fullfname);
343 }
344 }
345
346 FREE_C_HEAP_ARRAY(char*, fullfname);
347 return retval;
348 }
349
350 // --------------------- sun.misc.Signal (optional) ---------------------
351
352
353 // SIGBREAK is sent by the keyboard to query the VM state
354 #ifndef SIGBREAK
355 #define SIGBREAK SIGQUIT
356 #endif
357
358 // sigexitnum_pd is a platform-specific special signal used for terminating the Signal thread.
359
360
361 static void signal_thread_entry(JavaThread* thread, TRAPS) {
362 os::set_priority(thread, NearMaxPriority);
363 while (true) {
364 int sig;
365 {
366 // FIXME : Currently we have not decided what should be the status
367 // for this java thread blocked here. Once we decide about
368 // that we should fix this.
369 sig = os::signal_wait();
370 }
371 if (sig == os::sigexitnum_pd()) {
372 // Terminate the signal thread
373 return;
374 }
375
376 switch (sig) {
377 case SIGBREAK: {
378 #if INCLUDE_SERVICES
379 // Check if the signal is a trigger to start the Attach Listener - in that
380 // case don't print stack traces.
381 if (!DisableAttachMechanism) {
382 // Attempt to transit state to AL_INITIALIZING.
383 AttachListenerState cur_state = AttachListener::transit_state(AL_INITIALIZING, AL_NOT_INITIALIZED);
384 if (cur_state == AL_INITIALIZING) {
385 // Attach Listener has been started to initialize. Ignore this signal.
386 continue;
387 } else if (cur_state == AL_NOT_INITIALIZED) {
388 // Start to initialize.
389 if (AttachListener::is_init_trigger()) {
390 // Attach Listener has been initialized.
391 // Accept subsequent request.
392 continue;
393 } else {
394 // Attach Listener could not be started.
395 // So we need to transit the state to AL_NOT_INITIALIZED.
396 AttachListener::set_state(AL_NOT_INITIALIZED);
397 }
398 } else if (AttachListener::check_socket_file()) {
399 // Attach Listener has been started, but unix domain socket file
400 // does not exist. So restart Attach Listener.
401 continue;
402 }
403 }
404 #endif
405 // Print stack traces
406 // Any SIGBREAK operations added here should make sure to flush
407 // the output stream (e.g. tty->flush()) after output. See 4803766.
408 // Each module also prints an extra carriage return after its output.
409 VM_PrintThreads op(tty, PrintConcurrentLocks, false /* no extended info */, true /* print JNI handle info */);
410 VMThread::execute(&op);
411 VM_FindDeadlocks op1(tty);
412 VMThread::execute(&op1);
413 Universe::print_heap_at_SIGBREAK();
414 if (PrintClassHistogram) {
415 VM_GC_HeapInspection op1(tty, true /* force full GC before heap inspection */);
416 VMThread::execute(&op1);
417 }
418 if (JvmtiExport::should_post_data_dump()) {
419 JvmtiExport::post_data_dump();
420 }
421 break;
422 }
423 default: {
424 // Dispatch the signal to java
425 HandleMark hm(THREAD);
426 Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_misc_Signal(), THREAD);
427 if (klass != nullptr) {
428 JavaValue result(T_VOID);
429 JavaCallArguments args;
430 args.push_int(sig);
431 JavaCalls::call_static(
432 &result,
433 klass,
434 vmSymbols::dispatch_name(),
435 vmSymbols::int_void_signature(),
436 &args,
437 THREAD
438 );
439 }
440 if (HAS_PENDING_EXCEPTION) {
441 // tty is initialized early so we don't expect it to be null, but
442 // if it is we can't risk doing an initialization that might
443 // trigger additional out-of-memory conditions
444 if (tty != nullptr) {
445 char klass_name[256];
446 char tmp_sig_name[16];
447 const char* sig_name = "UNKNOWN";
448 InstanceKlass::cast(PENDING_EXCEPTION->klass())->
449 name()->as_klass_external_name(klass_name, 256);
450 if (os::exception_name(sig, tmp_sig_name, 16) != nullptr)
451 sig_name = tmp_sig_name;
452 warning("Exception %s occurred dispatching signal %s to handler"
453 "- the VM may need to be forcibly terminated",
454 klass_name, sig_name );
455 }
456 CLEAR_PENDING_EXCEPTION;
457 }
458 }
459 }
460 }
461 }
462
463 void os::init_before_ergo() {
464 initialize_initial_active_processor_count();
465 // We need to initialize large page support here because ergonomics takes some
466 // decisions depending on large page support and the calculated large page size.
467 large_page_init();
468
469 StackOverflow::initialize_stack_zone_sizes();
470
471 // VM version initialization identifies some characteristics of the
472 // platform that are used during ergonomic decisions.
473 VM_Version::init_before_ergo();
474 }
475
476 void os::initialize_jdk_signal_support(TRAPS) {
477 if (!ReduceSignalUsage) {
478 // Setup JavaThread for processing signals
479 const char* name = "Signal Dispatcher";
480 Handle thread_oop = JavaThread::create_system_thread_object(name, CHECK);
481
482 JavaThread* thread = new JavaThread(&signal_thread_entry);
483 JavaThread::vm_exit_on_osthread_failure(thread);
484
485 JavaThread::start_internal_daemon(THREAD, thread, thread_oop, NearMaxPriority);
486 }
487 }
488
489
490 void os::terminate_signal_thread() {
491 if (!ReduceSignalUsage)
492 signal_notify(sigexitnum_pd());
493 }
494
495
496 // --------------------- loading libraries ---------------------
497
498 typedef jint (JNICALL *JNI_OnLoad_t)(JavaVM *, void *);
499 extern struct JavaVM_ main_vm;
500
501 static void* _native_java_library = nullptr;
502
503 void* os::native_java_library() {
504 if (_native_java_library == nullptr) {
505 char buffer[JVM_MAXPATHLEN];
506 char ebuf[1024];
507
508 // Load java dll
509 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
510 "java")) {
511 _native_java_library = dll_load(buffer, ebuf, sizeof(ebuf));
512 }
513 if (_native_java_library == nullptr) {
514 vm_exit_during_initialization("Unable to load native library", ebuf);
515 }
516
517 #if defined(__OpenBSD__)
518 // Work-around OpenBSD's lack of $ORIGIN support by pre-loading libnet.so
519 // ignore errors
520 if (dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
521 "net")) {
522 dll_load(buffer, ebuf, sizeof(ebuf));
523 }
524 #endif
525 }
526 return _native_java_library;
527 }
528
529 /*
530 * Support for finding Agent_On(Un)Load/Attach<_lib_name> if it exists.
531 * If check_lib == true then we are looking for an
532 * Agent_OnLoad_lib_name or Agent_OnAttach_lib_name function to determine if
533 * this library is statically linked into the image.
534 * If check_lib == false then we will look for the appropriate symbol in the
535 * executable if agent_lib->is_static_lib() == true or in the shared library
536 * referenced by 'handle'.
537 */
538 void* os::find_agent_function(JvmtiAgent *agent_lib, bool check_lib,
539 const char *syms[], size_t syms_len) {
540 assert(agent_lib != nullptr, "sanity check");
541 const char *lib_name;
542 void *handle = agent_lib->os_lib();
543 void *entryName = nullptr;
544 char *agent_function_name;
545 size_t i;
546
547 // If checking then use the agent name otherwise test is_static_lib() to
548 // see how to process this lookup
549 lib_name = ((check_lib || agent_lib->is_static_lib()) ? agent_lib->name() : nullptr);
550 for (i = 0; i < syms_len; i++) {
551 agent_function_name = build_agent_function_name(syms[i], lib_name, agent_lib->is_absolute_path());
552 if (agent_function_name == nullptr) {
553 break;
554 }
555 entryName = dll_lookup(handle, agent_function_name);
556 FREE_C_HEAP_ARRAY(char, agent_function_name);
557 if (entryName != nullptr) {
558 break;
559 }
560 }
561 return entryName;
562 }
563
564 // See if the passed in agent is statically linked into the VM image.
565 bool os::find_builtin_agent(JvmtiAgent* agent, const char *syms[],
566 size_t syms_len) {
567 void *ret;
568 void *proc_handle;
569 void *save_handle;
570
571 assert(agent != nullptr, "sanity check");
572 if (agent->name() == nullptr) {
573 return false;
574 }
575 proc_handle = get_default_process_handle();
576 // Check for Agent_OnLoad/Attach_lib_name function
577 save_handle = agent->os_lib();
578 // We want to look in this process' symbol table.
579 agent->set_os_lib(proc_handle);
580 ret = find_agent_function(agent, true, syms, syms_len);
581 if (ret != nullptr) {
582 // Found an entry point like Agent_OnLoad_lib_name so we have a static agent
583 agent->set_static_lib();
584 agent->set_loaded();
585 return true;
586 }
587 agent->set_os_lib(save_handle);
588 return false;
589 }
590
591 // --------------------- heap allocation utilities ---------------------
592
593 char *os::strdup(const char *str, MEMFLAGS flags) {
594 size_t size = strlen(str);
595 char *dup_str = (char *)malloc(size + 1, flags);
596 if (dup_str == nullptr) return nullptr;
597 strcpy(dup_str, str);
598 return dup_str;
599 }
600
601 char* os::strdup_check_oom(const char* str, MEMFLAGS flags) {
602 char* p = os::strdup(str, flags);
603 if (p == nullptr) {
604 vm_exit_out_of_memory(strlen(str) + 1, OOM_MALLOC_ERROR, "os::strdup_check_oom");
605 }
606 return p;
607 }
608
609 #ifdef ASSERT
610 static void check_crash_protection() {
611 assert(!ThreadCrashProtection::is_crash_protected(Thread::current_or_null()),
612 "not allowed when crash protection is set");
613 }
614 static void break_if_ptr_caught(void* ptr) {
615 if (p2i(ptr) == (intptr_t)MallocCatchPtr) {
616 log_warning(malloc, free)("ptr caught: " PTR_FORMAT, p2i(ptr));
617 breakpoint();
618 }
619 }
620 #endif // ASSERT
621
622 void* os::malloc(size_t size, MEMFLAGS flags) {
623 return os::malloc(size, flags, CALLER_PC);
624 }
625
626 void* os::malloc(size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
627
628 // Special handling for NMT preinit phase before arguments are parsed
629 void* rc = nullptr;
630 if (NMTPreInit::handle_malloc(&rc, size)) {
631 // No need to fill with 0 because DumpSharedSpaces doesn't use these
632 // early allocations.
633 return rc;
634 }
635
636 DEBUG_ONLY(check_crash_protection());
637
638 // On malloc(0), implementations of malloc(3) have the choice to return either
639 // null or a unique non-null pointer. To unify libc behavior across our platforms
640 // we chose the latter.
641 size = MAX2((size_t)1, size);
642
643 // Observe MallocLimit
644 if (MemTracker::check_exceeds_limit(size, memflags)) {
645 return nullptr;
646 }
647
648 const size_t outer_size = size + MemTracker::overhead_per_malloc();
649
650 // Check for overflow.
651 if (outer_size < size) {
652 return nullptr;
653 }
654
655 ALLOW_C_FUNCTION(::malloc, void* const outer_ptr = ::malloc(outer_size);)
656 if (outer_ptr == nullptr) {
657 return nullptr;
658 }
659
660 void* const inner_ptr = MemTracker::record_malloc((address)outer_ptr, size, memflags, stack);
661
662 if (DumpSharedSpaces) {
663 // Need to deterministically fill all the alignment gaps in C++ structures.
664 ::memset(inner_ptr, 0, size);
665 } else {
666 DEBUG_ONLY(::memset(inner_ptr, uninitBlockPad, size);)
667 }
668 DEBUG_ONLY(break_if_ptr_caught(inner_ptr);)
669 return inner_ptr;
670 }
671
672 void* os::realloc(void *memblock, size_t size, MEMFLAGS flags) {
673 return os::realloc(memblock, size, flags, CALLER_PC);
674 }
675
676 void* os::realloc(void *memblock, size_t size, MEMFLAGS memflags, const NativeCallStack& stack) {
677
678 // Special handling for NMT preinit phase before arguments are parsed
679 void* rc = nullptr;
680 if (NMTPreInit::handle_realloc(&rc, memblock, size, memflags)) {
681 return rc;
682 }
683
684 if (memblock == nullptr) {
685 return os::malloc(size, memflags, stack);
686 }
687
688 DEBUG_ONLY(check_crash_protection());
689
690 // On realloc(p, 0), implementers of realloc(3) have the choice to return either
691 // null or a unique non-null pointer. To unify libc behavior across our platforms
692 // we chose the latter.
693 size = MAX2((size_t)1, size);
694
695 if (MemTracker::enabled()) {
696 // NMT realloc handling
697
698 const size_t new_outer_size = size + MemTracker::overhead_per_malloc();
699
700 // Handle size overflow.
701 if (new_outer_size < size) {
702 return nullptr;
703 }
704
705 const size_t old_size = MallocTracker::malloc_header(memblock)->size();
706
707 // Observe MallocLimit
708 if ((size > old_size) && MemTracker::check_exceeds_limit(size - old_size, memflags)) {
709 return nullptr;
710 }
711
712 // Perform integrity checks on and mark the old block as dead *before* calling the real realloc(3) since it
713 // may invalidate the old block, including its header.
714 MallocHeader* header = MallocHeader::resolve_checked(memblock);
715 assert(memflags == header->flags(), "weird NMT flags mismatch (new:\"%s\" != old:\"%s\")\n",
716 NMTUtil::flag_to_name(memflags), NMTUtil::flag_to_name(header->flags()));
717 const MallocHeader::FreeInfo free_info = header->free_info();
718
719 header->mark_block_as_dead();
720
721 // the real realloc
722 ALLOW_C_FUNCTION(::realloc, void* const new_outer_ptr = ::realloc(header, new_outer_size);)
723
724 if (new_outer_ptr == nullptr) {
725 // realloc(3) failed and the block still exists.
726 // We have however marked it as dead, revert this change.
727 header->revive();
728 return nullptr;
729 }
730 // realloc(3) succeeded, variable header now points to invalid memory and we need to deaccount the old block.
731 MemTracker::deaccount(free_info);
732
733 // After a successful realloc(3), we account the resized block with its new size
734 // to NMT.
735 void* const new_inner_ptr = MemTracker::record_malloc(new_outer_ptr, size, memflags, stack);
736
737 #ifdef ASSERT
738 assert(old_size == free_info.size, "Sanity");
739 if (old_size < size) {
740 // We also zap the newly extended region.
741 ::memset((char*)new_inner_ptr + old_size, uninitBlockPad, size - old_size);
742 }
743 #endif
744
745 rc = new_inner_ptr;
746
747 } else {
748
749 // NMT disabled.
750 ALLOW_C_FUNCTION(::realloc, rc = ::realloc(memblock, size);)
751 if (rc == nullptr) {
752 return nullptr;
753 }
754
755 }
756
757 DEBUG_ONLY(break_if_ptr_caught(rc);)
758
759 return rc;
760 }
761
762 void os::free(void *memblock) {
763
764 // Special handling for NMT preinit phase before arguments are parsed
765 if (NMTPreInit::handle_free(memblock)) {
766 return;
767 }
768
769 if (memblock == nullptr) {
770 return;
771 }
772
773 DEBUG_ONLY(break_if_ptr_caught(memblock);)
774
775 // When NMT is enabled this checks for heap overwrites, then deaccounts the old block.
776 void* const old_outer_ptr = MemTracker::record_free(memblock);
777
778 ALLOW_C_FUNCTION(::free, ::free(old_outer_ptr);)
779 }
780
781 void os::init_random(unsigned int initval) {
782 _rand_seed = initval;
783 }
784
785
786 int os::next_random(unsigned int rand_seed) {
787 /* standard, well-known linear congruential random generator with
788 * next_rand = (16807*seed) mod (2**31-1)
789 * see
790 * (1) "Random Number Generators: Good Ones Are Hard to Find",
791 * S.K. Park and K.W. Miller, Communications of the ACM 31:10 (Oct 1988),
792 * (2) "Two Fast Implementations of the 'Minimal Standard' Random
793 * Number Generator", David G. Carta, Comm. ACM 33, 1 (Jan 1990), pp. 87-88.
794 */
795 const unsigned int a = 16807;
796 const unsigned int m = 2147483647;
797 const int q = m / a; assert(q == 127773, "weird math");
798 const int r = m % a; assert(r == 2836, "weird math");
799
800 // compute az=2^31p+q
801 unsigned int lo = a * (rand_seed & 0xFFFF);
802 unsigned int hi = a * (rand_seed >> 16);
803 lo += (hi & 0x7FFF) << 16;
804
805 // if q overflowed, ignore the overflow and increment q
806 if (lo > m) {
807 lo &= m;
808 ++lo;
809 }
810 lo += hi >> 15;
811
812 // if (p+q) overflowed, ignore the overflow and increment (p+q)
813 if (lo > m) {
814 lo &= m;
815 ++lo;
816 }
817 return lo;
818 }
819
820 int os::random() {
821 // Make updating the random seed thread safe.
822 while (true) {
823 unsigned int seed = _rand_seed;
824 unsigned int rand = next_random(seed);
825 if (Atomic::cmpxchg(&_rand_seed, seed, rand, memory_order_relaxed) == seed) {
826 return static_cast<int>(rand);
827 }
828 }
829 }
830
831 // The INITIALIZED state is distinguished from the SUSPENDED state because the
832 // conditions in which a thread is first started are different from those in which
833 // a suspension is resumed. These differences make it hard for us to apply the
834 // tougher checks when starting threads that we want to do when resuming them.
835 // However, when start_thread is called as a result of Thread.start, on a Java
836 // thread, the operation is synchronized on the Java Thread object. So there
837 // cannot be a race to start the thread and hence for the thread to exit while
838 // we are working on it. Non-Java threads that start Java threads either have
839 // to do so in a context in which races are impossible, or should do appropriate
840 // locking.
841
842 void os::start_thread(Thread* thread) {
843 OSThread* osthread = thread->osthread();
844 osthread->set_state(RUNNABLE);
845 pd_start_thread(thread);
846 }
847
848 void os::abort(bool dump_core) {
849 abort(dump_core && CreateCoredumpOnCrash, nullptr, nullptr);
850 }
851
852 //---------------------------------------------------------------------------
853 // Helper functions for fatal error handler
854
855 bool os::print_function_and_library_name(outputStream* st,
856 address addr,
857 char* buf, int buflen,
858 bool shorten_paths,
859 bool demangle,
860 bool strip_arguments) {
861 // If no scratch buffer given, allocate one here on stack.
862 // (used during error handling; its a coin toss, really, if on-stack allocation
863 // is worse than (raw) C-heap allocation in that case).
864 char* p = buf;
865 if (p == nullptr) {
866 p = (char*)::alloca(O_BUFLEN);
867 buflen = O_BUFLEN;
868 }
869 int offset = 0;
870 bool have_function_name = dll_address_to_function_name(addr, p, buflen,
871 &offset, demangle);
872 bool is_function_descriptor = false;
873 #ifdef HAVE_FUNCTION_DESCRIPTORS
874 // When we deal with a function descriptor instead of a real code pointer, try to
875 // resolve it. There is a small chance that a random pointer given to this function
876 // may just happen to look like a valid descriptor, but this is rare and worth the
877 // risk to see resolved function names. But we will print a little suffix to mark
878 // this as a function descriptor for the reader (see below).
879 if (!have_function_name && os::is_readable_pointer(addr)) {
880 address addr2 = (address)os::resolve_function_descriptor(addr);
881 if (have_function_name = is_function_descriptor =
882 dll_address_to_function_name(addr2, p, buflen, &offset, demangle)) {
883 addr = addr2;
884 }
885 }
886 #endif // HAVE_FUNCTION_DESCRIPTORS
887
888 if (have_function_name) {
889 // Print function name, optionally demangled
890 if (demangle && strip_arguments) {
891 char* args_start = strchr(p, '(');
892 if (args_start != nullptr) {
893 *args_start = '\0';
894 }
895 }
896 // Print offset. Omit printing if offset is zero, which makes the output
897 // more readable if we print function pointers.
898 if (offset == 0) {
899 st->print("%s", p);
900 } else {
901 st->print("%s+%d", p, offset);
902 }
903 } else {
904 st->print(PTR_FORMAT, p2i(addr));
905 }
906 offset = 0;
907
908 const bool have_library_name = dll_address_to_library_name(addr, p, buflen, &offset);
909 if (have_library_name) {
910 // Cut path parts
911 if (shorten_paths) {
912 char* p2 = strrchr(p, os::file_separator()[0]);
913 if (p2 != nullptr) {
914 p = p2 + 1;
915 }
916 }
917 st->print(" in %s", p);
918 if (!have_function_name) { // Omit offset if we already printed the function offset
919 st->print("+%d", offset);
920 }
921 }
922
923 // Write a trailing marker if this was a function descriptor
924 if (have_function_name && is_function_descriptor) {
925 st->print_raw(" (FD)");
926 }
927
928 return have_function_name || have_library_name;
929 }
930
931 ATTRIBUTE_NO_ASAN static void print_hex_readable_pointer(outputStream* st, address p,
932 int unitsize) {
933 switch (unitsize) {
934 case 1: st->print("%02x", *(u1*)p); break;
935 case 2: st->print("%04x", *(u2*)p); break;
936 case 4: st->print("%08x", *(u4*)p); break;
937 case 8: st->print("%016" FORMAT64_MODIFIER "x", *(u8*)p); break;
938 }
939 }
940
941 void os::print_hex_dump(outputStream* st, address start, address end, int unitsize,
942 int bytes_per_line, address logical_start) {
943 assert(unitsize == 1 || unitsize == 2 || unitsize == 4 || unitsize == 8, "just checking");
944
945 start = align_down(start, unitsize);
946 logical_start = align_down(logical_start, unitsize);
947 bytes_per_line = align_up(bytes_per_line, 8);
948
949 int cols = 0;
950 int cols_per_line = bytes_per_line / unitsize;
951
952 address p = start;
953 address logical_p = logical_start;
954
955 // Print out the addresses as if we were starting from logical_start.
956 st->print(PTR_FORMAT ": ", p2i(logical_p));
957 while (p < end) {
958 if (is_readable_pointer(p)) {
959 print_hex_readable_pointer(st, p, unitsize);
960 } else {
961 st->print("%*.*s", 2*unitsize, 2*unitsize, "????????????????");
962 }
963 p += unitsize;
964 logical_p += unitsize;
965 cols++;
966 if (cols >= cols_per_line && p < end) {
967 cols = 0;
968 st->cr();
969 st->print(PTR_FORMAT ": ", p2i(logical_p));
970 } else {
971 st->print(" ");
972 }
973 }
974 st->cr();
975 }
976
977 void os::print_dhm(outputStream* st, const char* startStr, long sec) {
978 long days = sec/86400;
979 long hours = (sec/3600) - (days * 24);
980 long minutes = (sec/60) - (days * 1440) - (hours * 60);
981 if (startStr == nullptr) startStr = "";
982 st->print_cr("%s %ld days %ld:%02ld hours", startStr, days, hours, minutes);
983 }
984
985 void os::print_tos(outputStream* st, address sp) {
986 st->print_cr("Top of Stack: (sp=" PTR_FORMAT ")", p2i(sp));
987 print_hex_dump(st, sp, sp + 512, sizeof(intptr_t));
988 }
989
990 void os::print_instructions(outputStream* st, address pc, int unitsize) {
991 st->print_cr("Instructions: (pc=" PTR_FORMAT ")", p2i(pc));
992 print_hex_dump(st, pc - 256, pc + 256, unitsize);
993 }
994
995 void os::print_environment_variables(outputStream* st, const char** env_list) {
996 if (env_list) {
997 st->print_cr("Environment Variables:");
998
999 for (int i = 0; env_list[i] != nullptr; i++) {
1000 char *envvar = ::getenv(env_list[i]);
1001 if (envvar != nullptr) {
1002 st->print("%s", env_list[i]);
1003 st->print("=");
1004 st->print("%s", envvar);
1005 // Use separate cr() printing to avoid unnecessary buffer operations that might cause truncation.
1006 st->cr();
1007 }
1008 }
1009 }
1010 }
1011
1012 void os::print_cpu_info(outputStream* st, char* buf, size_t buflen) {
1013 // cpu
1014 st->print("CPU:");
1015 #if defined(__APPLE__) && !defined(ZERO)
1016 if (VM_Version::is_cpu_emulated()) {
1017 st->print(" (EMULATED)");
1018 }
1019 #endif
1020 st->print(" total %d", os::processor_count());
1021 // It's not safe to query number of active processors after crash
1022 // st->print("(active %d)", os::active_processor_count()); but we can
1023 // print the initial number of active processors.
1024 // We access the raw value here because the assert in the accessor will
1025 // fail if the crash occurs before initialization of this value.
1026 st->print(" (initial active %d)", _initial_active_processor_count);
1027 st->print(" %s", VM_Version::features_string());
1028 st->cr();
1029 pd_print_cpu_info(st, buf, buflen);
1030 }
1031
1032 // Print a one line string summarizing the cpu, number of cores, memory, and operating system version
1033 void os::print_summary_info(outputStream* st, char* buf, size_t buflen) {
1034 st->print("Host: ");
1035 #ifndef PRODUCT
1036 if (get_host_name(buf, buflen)) {
1037 st->print("%s, ", buf);
1038 }
1039 #endif // PRODUCT
1040 get_summary_cpu_info(buf, buflen);
1041 st->print("%s, ", buf);
1042 size_t mem = physical_memory()/G;
1043 if (mem == 0) { // for low memory systems
1044 mem = physical_memory()/M;
1045 st->print("%d cores, " SIZE_FORMAT "M, ", processor_count(), mem);
1046 } else {
1047 st->print("%d cores, " SIZE_FORMAT "G, ", processor_count(), mem);
1048 }
1049 get_summary_os_info(buf, buflen);
1050 st->print_raw(buf);
1051 st->cr();
1052 }
1053
1054 void os::print_date_and_time(outputStream *st, char* buf, size_t buflen) {
1055 const int secs_per_day = 86400;
1056 const int secs_per_hour = 3600;
1057 const int secs_per_min = 60;
1058
1059 time_t tloc;
1060 (void)time(&tloc);
1061 char* timestring = ctime(&tloc); // ctime adds newline.
1062 // edit out the newline
1063 char* nl = strchr(timestring, '\n');
1064 if (nl != nullptr) {
1065 *nl = '\0';
1066 }
1067
1068 struct tm tz;
1069 if (localtime_pd(&tloc, &tz) != nullptr) {
1070 wchar_t w_buf[80];
1071 size_t n = ::wcsftime(w_buf, 80, L"%Z", &tz);
1072 if (n > 0) {
1073 ::wcstombs(buf, w_buf, buflen);
1074 st->print("Time: %s %s", timestring, buf);
1075 } else {
1076 st->print("Time: %s", timestring);
1077 }
1078 } else {
1079 st->print("Time: %s", timestring);
1080 }
1081
1082 double t = os::elapsedTime();
1083 // NOTE: a crash using printf("%f",...) on Linux was historically noted here.
1084 int eltime = (int)t; // elapsed time in seconds
1085 int eltimeFraction = (int) ((t - eltime) * 1000000);
1086
1087 // print elapsed time in a human-readable format:
1088 int eldays = eltime / secs_per_day;
1089 int day_secs = eldays * secs_per_day;
1090 int elhours = (eltime - day_secs) / secs_per_hour;
1091 int hour_secs = elhours * secs_per_hour;
1092 int elmins = (eltime - day_secs - hour_secs) / secs_per_min;
1093 int minute_secs = elmins * secs_per_min;
1094 int elsecs = (eltime - day_secs - hour_secs - minute_secs);
1095 st->print_cr(" elapsed time: %d.%06d seconds (%dd %dh %dm %ds)", eltime, eltimeFraction, eldays, elhours, elmins, elsecs);
1096 }
1097
1098
1099 // Check if pointer can be read from (4-byte read access).
1100 // Helps to prove validity of a non-null pointer.
1101 // Returns true in very early stages of VM life when stub is not yet generated.
1102 bool os::is_readable_pointer(const void* p) {
1103 int* const aligned = (int*) align_down((intptr_t)p, 4);
1104 int cafebabe = 0xcafebabe; // tester value 1
1105 int deadbeef = 0xdeadbeef; // tester value 2
1106 return (SafeFetch32(aligned, cafebabe) != cafebabe) || (SafeFetch32(aligned, deadbeef) != deadbeef);
1107 }
1108
1109 bool os::is_readable_range(const void* from, const void* to) {
1110 if ((uintptr_t)from >= (uintptr_t)to) return false;
1111 for (uintptr_t p = align_down((uintptr_t)from, min_page_size()); p < (uintptr_t)to; p += min_page_size()) {
1112 if (!is_readable_pointer((const void*)p)) {
1113 return false;
1114 }
1115 }
1116 return true;
1117 }
1118
1119
1120 // moved from debug.cpp (used to be find()) but still called from there
1121 // The verbose parameter is only set by the debug code in one case
1122 void os::print_location(outputStream* st, intptr_t x, bool verbose) {
1123 address addr = (address)x;
1124 // Handle null first, so later checks don't need to protect against it.
1125 if (addr == nullptr) {
1126 st->print_cr("0x0 is nullptr");
1127 return;
1128 }
1129
1130 // Check if addr points into a code blob.
1131 CodeBlob* b = CodeCache::find_blob(addr);
1132 if (b != nullptr) {
1133 b->dump_for_addr(addr, st, verbose);
1134 return;
1135 }
1136
1137 // Check if addr points into Java heap.
1138 if (Universe::heap()->print_location(st, addr)) {
1139 return;
1140 }
1141
1142 bool accessible = is_readable_pointer(addr);
1143
1144 // Check if addr is a JNI handle.
1145 if (align_down((intptr_t)addr, sizeof(intptr_t)) != 0 && accessible) {
1146 if (JNIHandles::is_global_handle((jobject) addr)) {
1147 st->print_cr(INTPTR_FORMAT " is a global jni handle", p2i(addr));
1148 return;
1149 }
1150 if (JNIHandles::is_weak_global_handle((jobject) addr)) {
1151 st->print_cr(INTPTR_FORMAT " is a weak global jni handle", p2i(addr));
1152 return;
1153 }
1154 }
1155
1156 // Check if addr belongs to a Java thread.
1157 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
1158 // If the addr is a java thread print information about that.
1159 if (addr == (address)thread) {
1160 if (verbose) {
1161 thread->print_on(st);
1162 } else {
1163 st->print_cr(INTPTR_FORMAT " is a thread", p2i(addr));
1164 }
1165 return;
1166 }
1167 // If the addr is in the stack region for this thread then report that
1168 // and print thread info
1169 if (thread->is_in_full_stack(addr)) {
1170 st->print_cr(INTPTR_FORMAT " is pointing into the stack for thread: "
1171 INTPTR_FORMAT, p2i(addr), p2i(thread));
1172 if (verbose) thread->print_on(st);
1173 return;
1174 }
1175 }
1176
1177 // Check if in metaspace and print types that have vptrs
1178 if (Metaspace::contains(addr)) {
1179 if (Klass::is_valid((Klass*)addr)) {
1180 st->print_cr(INTPTR_FORMAT " is a pointer to class: ", p2i(addr));
1181 ((Klass*)addr)->print_on(st);
1182 } else if (Method::is_valid_method((const Method*)addr)) {
1183 ((Method*)addr)->print_value_on(st);
1184 st->cr();
1185 } else {
1186 // Use addr->print() from the debugger instead (not here)
1187 st->print_cr(INTPTR_FORMAT " is pointing into metadata", p2i(addr));
1188 }
1189 return;
1190 }
1191
1192 // Compressed klass needs to be decoded first.
1193 #ifdef _LP64
1194 if (UseCompressedClassPointers && ((uintptr_t)addr &~ (uintptr_t)max_juint) == 0) {
1195 narrowKlass narrow_klass = (narrowKlass)(uintptr_t)addr;
1196 Klass* k = CompressedKlassPointers::decode_raw(narrow_klass);
1197
1198 if (Klass::is_valid(k)) {
1199 st->print_cr(UINT32_FORMAT " is a compressed pointer to class: " INTPTR_FORMAT, narrow_klass, p2i((HeapWord*)k));
1200 k->print_on(st);
1201 return;
1202 }
1203 }
1204 #endif
1205
1206 // Still nothing? If NMT is enabled, we can ask what it thinks...
1207 if (MemTracker::print_containing_region(addr, st)) {
1208 return;
1209 }
1210
1211 // Try an OS specific find
1212 if (os::find(addr, st)) {
1213 return;
1214 }
1215
1216 if (accessible) {
1217 st->print(INTPTR_FORMAT " points into unknown readable memory:", p2i(addr));
1218 if (is_aligned(addr, sizeof(intptr_t))) {
1219 st->print(" " PTR_FORMAT " |", *(intptr_t*)addr);
1220 }
1221 for (address p = addr; p < align_up(addr + 1, sizeof(intptr_t)); ++p) {
1222 st->print(" %02x", *(u1*)p);
1223 }
1224 st->cr();
1225 return;
1226 }
1227
1228 st->print_cr(INTPTR_FORMAT " is an unknown value", p2i(addr));
1229 }
1230
1231 bool is_pointer_bad(intptr_t* ptr) {
1232 return !is_aligned(ptr, sizeof(uintptr_t)) || !os::is_readable_pointer(ptr);
1233 }
1234
1235 // Looks like all platforms can use the same function to check if C
1236 // stack is walkable beyond current frame.
1237 // Returns true if this is not the case, i.e. the frame is possibly
1238 // the first C frame on the stack.
1239 bool os::is_first_C_frame(frame* fr) {
1240
1241 #ifdef _WINDOWS
1242 return true; // native stack isn't walkable on windows this way.
1243 #endif
1244 // Load up sp, fp, sender sp and sender fp, check for reasonable values.
1245 // Check usp first, because if that's bad the other accessors may fault
1246 // on some architectures. Ditto ufp second, etc.
1247
1248 if (is_pointer_bad(fr->sp())) return true;
1249
1250 uintptr_t ufp = (uintptr_t)fr->fp();
1251 if (is_pointer_bad(fr->fp())) return true;
1252
1253 uintptr_t old_sp = (uintptr_t)fr->sender_sp();
1254 if ((uintptr_t)fr->sender_sp() == (uintptr_t)-1 || is_pointer_bad(fr->sender_sp())) return true;
1255
1256 uintptr_t old_fp = (uintptr_t)fr->link_or_null();
1257 if (old_fp == 0 || old_fp == (uintptr_t)-1 || old_fp == ufp ||
1258 is_pointer_bad(fr->link_or_null())) return true;
1259
1260 // stack grows downwards; if old_fp is below current fp or if the stack
1261 // frame is too large, either the stack is corrupted or fp is not saved
1262 // on stack (i.e. on x86, ebp may be used as general register). The stack
1263 // is not walkable beyond current frame.
1264 if (old_fp < ufp) return true;
1265 if (old_fp - ufp > 64 * K) return true;
1266
1267 return false;
1268 }
1269
1270 // Set up the boot classpath.
1271
1272 char* os::format_boot_path(const char* format_string,
1273 const char* home,
1274 int home_len,
1275 char fileSep,
1276 char pathSep) {
1277 assert((fileSep == '/' && pathSep == ':') ||
1278 (fileSep == '\\' && pathSep == ';'), "unexpected separator chars");
1279
1280 // Scan the format string to determine the length of the actual
1281 // boot classpath, and handle platform dependencies as well.
1282 int formatted_path_len = 0;
1283 const char* p;
1284 for (p = format_string; *p != 0; ++p) {
1285 if (*p == '%') formatted_path_len += home_len - 1;
1286 ++formatted_path_len;
1287 }
1288
1289 char* formatted_path = NEW_C_HEAP_ARRAY(char, formatted_path_len + 1, mtInternal);
1290
1291 // Create boot classpath from format, substituting separator chars and
1292 // java home directory.
1293 char* q = formatted_path;
1294 for (p = format_string; *p != 0; ++p) {
1295 switch (*p) {
1296 case '%':
1297 strcpy(q, home);
1298 q += home_len;
1299 break;
1300 case '/':
1301 *q++ = fileSep;
1302 break;
1303 case ':':
1304 *q++ = pathSep;
1305 break;
1306 default:
1307 *q++ = *p;
1308 }
1309 }
1310 *q = '\0';
1311
1312 assert((q - formatted_path) == formatted_path_len, "formatted_path size botched");
1313 return formatted_path;
1314 }
1315
1316 // This function is a proxy to fopen, it tries to add a non standard flag ('e' or 'N')
1317 // that ensures automatic closing of the file on exec. If it can not find support in
1318 // the underlying c library, it will make an extra system call (fcntl) to ensure automatic
1319 // closing of the file on exec.
1320 FILE* os::fopen(const char* path, const char* mode) {
1321 char modified_mode[20];
1322 assert(strlen(mode) + 1 < sizeof(modified_mode), "mode chars plus one extra must fit in buffer");
1323 os::snprintf_checked(modified_mode, sizeof(modified_mode), "%s" LINUX_ONLY("e") BSD_ONLY("e") WINDOWS_ONLY("N"), mode);
1324 FILE* file = ::fopen(path, modified_mode);
1325
1326 #if !(defined LINUX || defined BSD || defined _WINDOWS)
1327 // assume fcntl FD_CLOEXEC support as a backup solution when 'e' or 'N'
1328 // is not supported as mode in fopen
1329 if (file != nullptr) {
1330 int fd = fileno(file);
1331 if (fd != -1) {
1332 int fd_flags = fcntl(fd, F_GETFD);
1333 if (fd_flags != -1) {
1334 fcntl(fd, F_SETFD, fd_flags | FD_CLOEXEC);
1335 }
1336 }
1337 }
1338 #endif
1339
1340 return file;
1341 }
1342
1343 bool os::set_boot_path(char fileSep, char pathSep) {
1344 const char* home = Arguments::get_java_home();
1345 int home_len = (int)strlen(home);
1346
1347 struct stat st;
1348
1349 // modular image if "modules" jimage exists
1350 char* jimage = format_boot_path("%/lib/" MODULES_IMAGE_NAME, home, home_len, fileSep, pathSep);
1351 if (jimage == nullptr) return false;
1352 bool has_jimage = (os::stat(jimage, &st) == 0);
1353 if (has_jimage) {
1354 Arguments::set_boot_class_path(jimage, true);
1355 FREE_C_HEAP_ARRAY(char, jimage);
1356 return true;
1357 }
1358 FREE_C_HEAP_ARRAY(char, jimage);
1359
1360 // check if developer build with exploded modules
1361 char* base_classes = format_boot_path("%/modules/" JAVA_BASE_NAME, home, home_len, fileSep, pathSep);
1362 if (base_classes == nullptr) return false;
1363 if (os::stat(base_classes, &st) == 0) {
1364 Arguments::set_boot_class_path(base_classes, false);
1365 FREE_C_HEAP_ARRAY(char, base_classes);
1366 return true;
1367 }
1368 FREE_C_HEAP_ARRAY(char, base_classes);
1369
1370 return false;
1371 }
1372
1373 bool os::file_exists(const char* filename) {
1374 struct stat statbuf;
1375 if (filename == nullptr || strlen(filename) == 0) {
1376 return false;
1377 }
1378 return os::stat(filename, &statbuf) == 0;
1379 }
1380
1381 // Splits a path, based on its separator, the number of
1382 // elements is returned back in "elements".
1383 // file_name_length is used as a modifier for each path's
1384 // length when compared to JVM_MAXPATHLEN. So if you know
1385 // each returned path will have something appended when
1386 // in use, you can pass the length of that in
1387 // file_name_length, to ensure we detect if any path
1388 // exceeds the maximum path length once prepended onto
1389 // the sub-path/file name.
1390 // It is the callers responsibility to:
1391 // a> check the value of "elements", which may be 0.
1392 // b> ignore any empty path elements
1393 // c> free up the data.
1394 char** os::split_path(const char* path, size_t* elements, size_t file_name_length) {
1395 *elements = (size_t)0;
1396 if (path == nullptr || strlen(path) == 0 || file_name_length == (size_t)nullptr) {
1397 return nullptr;
1398 }
1399 const char psepchar = *os::path_separator();
1400 char* inpath = NEW_C_HEAP_ARRAY(char, strlen(path) + 1, mtInternal);
1401 strcpy(inpath, path);
1402 size_t count = 1;
1403 char* p = strchr(inpath, psepchar);
1404 // Get a count of elements to allocate memory
1405 while (p != nullptr) {
1406 count++;
1407 p++;
1408 p = strchr(p, psepchar);
1409 }
1410
1411 char** opath = NEW_C_HEAP_ARRAY(char*, count, mtInternal);
1412
1413 // do the actual splitting
1414 p = inpath;
1415 for (size_t i = 0 ; i < count ; i++) {
1416 size_t len = strcspn(p, os::path_separator());
1417 if (len + file_name_length > JVM_MAXPATHLEN) {
1418 // release allocated storage before exiting the vm
1419 free_array_of_char_arrays(opath, i++);
1420 vm_exit_during_initialization("The VM tried to use a path that exceeds the maximum path length for "
1421 "this system. Review path-containing parameters and properties, such as "
1422 "sun.boot.library.path, to identify potential sources for this path.");
1423 }
1424 // allocate the string and add terminator storage
1425 char* s = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
1426 strncpy(s, p, len);
1427 s[len] = '\0';
1428 opath[i] = s;
1429 p += len + 1;
1430 }
1431 FREE_C_HEAP_ARRAY(char, inpath);
1432 *elements = count;
1433 return opath;
1434 }
1435
1436 // Returns true if the current stack pointer is above the stack shadow
1437 // pages, false otherwise.
1438 bool os::stack_shadow_pages_available(Thread *thread, const methodHandle& method, address sp) {
1439 if (!thread->is_Java_thread()) return false;
1440 // Check if we have StackShadowPages above the guard zone. This parameter
1441 // is dependent on the depth of the maximum VM call stack possible from
1442 // the handler for stack overflow. 'instanceof' in the stack overflow
1443 // handler or a println uses at least 8k stack of VM and native code
1444 // respectively.
1445 const int framesize_in_bytes =
1446 Interpreter::size_top_interpreter_activation(method()) * wordSize;
1447
1448 address limit = JavaThread::cast(thread)->stack_overflow_state()->shadow_zone_safe_limit();
1449 return sp > (limit + framesize_in_bytes);
1450 }
1451
1452 size_t os::page_size_for_region(size_t region_size, size_t min_pages, bool must_be_aligned) {
1453 assert(min_pages > 0, "sanity");
1454 if (UseLargePages) {
1455 const size_t max_page_size = region_size / min_pages;
1456
1457 for (size_t page_size = page_sizes().largest(); page_size != 0;
1458 page_size = page_sizes().next_smaller(page_size)) {
1459 if (page_size <= max_page_size) {
1460 if (!must_be_aligned || is_aligned(region_size, page_size)) {
1461 return page_size;
1462 }
1463 }
1464 }
1465 }
1466
1467 return vm_page_size();
1468 }
1469
1470 size_t os::page_size_for_region_aligned(size_t region_size, size_t min_pages) {
1471 return page_size_for_region(region_size, min_pages, true);
1472 }
1473
1474 size_t os::page_size_for_region_unaligned(size_t region_size, size_t min_pages) {
1475 return page_size_for_region(region_size, min_pages, false);
1476 }
1477
1478 #ifndef MAX_PATH
1479 #define MAX_PATH (2 * K)
1480 #endif
1481
1482 void os::pause() {
1483 char filename[MAX_PATH];
1484 if (PauseAtStartupFile && PauseAtStartupFile[0]) {
1485 jio_snprintf(filename, MAX_PATH, "%s", PauseAtStartupFile);
1486 } else {
1487 jio_snprintf(filename, MAX_PATH, "./vm.paused.%d", current_process_id());
1488 }
1489
1490 int fd = ::open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
1491 if (fd != -1) {
1492 struct stat buf;
1493 ::close(fd);
1494 while (::stat(filename, &buf) == 0) {
1495 #if defined(_WINDOWS)
1496 Sleep(100);
1497 #else
1498 (void)::poll(nullptr, 0, 100);
1499 #endif
1500 }
1501 } else {
1502 jio_fprintf(stderr,
1503 "Could not open pause file '%s', continuing immediately.\n", filename);
1504 }
1505 }
1506
1507 static const char* errno_to_string (int e, bool short_text) {
1508 #define ALL_SHARED_ENUMS(X) \
1509 X(E2BIG, "Argument list too long") \
1510 X(EACCES, "Permission denied") \
1511 X(EADDRINUSE, "Address in use") \
1512 X(EADDRNOTAVAIL, "Address not available") \
1513 X(EAFNOSUPPORT, "Address family not supported") \
1514 X(EAGAIN, "Resource unavailable, try again") \
1515 X(EALREADY, "Connection already in progress") \
1516 X(EBADF, "Bad file descriptor") \
1517 X(EBADMSG, "Bad message") \
1518 X(EBUSY, "Device or resource busy") \
1519 X(ECANCELED, "Operation canceled") \
1520 X(ECHILD, "No child processes") \
1521 X(ECONNABORTED, "Connection aborted") \
1522 X(ECONNREFUSED, "Connection refused") \
1523 X(ECONNRESET, "Connection reset") \
1524 X(EDEADLK, "Resource deadlock would occur") \
1525 X(EDESTADDRREQ, "Destination address required") \
1526 X(EDOM, "Mathematics argument out of domain of function") \
1527 X(EEXIST, "File exists") \
1528 X(EFAULT, "Bad address") \
1529 X(EFBIG, "File too large") \
1530 X(EHOSTUNREACH, "Host is unreachable") \
1531 X(EIDRM, "Identifier removed") \
1532 X(EILSEQ, "Illegal byte sequence") \
1533 X(EINPROGRESS, "Operation in progress") \
1534 X(EINTR, "Interrupted function") \
1535 X(EINVAL, "Invalid argument") \
1536 X(EIO, "I/O error") \
1537 X(EISCONN, "Socket is connected") \
1538 X(EISDIR, "Is a directory") \
1539 X(ELOOP, "Too many levels of symbolic links") \
1540 X(EMFILE, "Too many open files") \
1541 X(EMLINK, "Too many links") \
1542 X(EMSGSIZE, "Message too large") \
1543 X(ENAMETOOLONG, "Filename too long") \
1544 X(ENETDOWN, "Network is down") \
1545 X(ENETRESET, "Connection aborted by network") \
1546 X(ENETUNREACH, "Network unreachable") \
1547 X(ENFILE, "Too many files open in system") \
1548 X(ENOBUFS, "No buffer space available") \
1549 X(ENODATA, "No message is available on the STREAM head read queue") \
1550 X(ENODEV, "No such device") \
1551 X(ENOENT, "No such file or directory") \
1552 X(ENOEXEC, "Executable file format error") \
1553 X(ENOLCK, "No locks available") \
1554 X(ENOLINK, "Reserved") \
1555 X(ENOMEM, "Not enough space") \
1556 X(ENOMSG, "No message of the desired type") \
1557 X(ENOPROTOOPT, "Protocol not available") \
1558 X(ENOSPC, "No space left on device") \
1559 X(ENOSR, "No STREAM resources") \
1560 X(ENOSTR, "Not a STREAM") \
1561 X(ENOSYS, "Function not supported") \
1562 X(ENOTCONN, "The socket is not connected") \
1563 X(ENOTDIR, "Not a directory") \
1564 X(ENOTEMPTY, "Directory not empty") \
1565 X(ENOTSOCK, "Not a socket") \
1566 X(ENOTSUP, "Not supported") \
1567 X(ENOTTY, "Inappropriate I/O control operation") \
1568 X(ENXIO, "No such device or address") \
1569 X(EOPNOTSUPP, "Operation not supported on socket") \
1570 X(EOVERFLOW, "Value too large to be stored in data type") \
1571 X(EPERM, "Operation not permitted") \
1572 X(EPIPE, "Broken pipe") \
1573 X(EPROTO, "Protocol error") \
1574 X(EPROTONOSUPPORT, "Protocol not supported") \
1575 X(EPROTOTYPE, "Protocol wrong type for socket") \
1576 X(ERANGE, "Result too large") \
1577 X(EROFS, "Read-only file system") \
1578 X(ESPIPE, "Invalid seek") \
1579 X(ESRCH, "No such process") \
1580 X(ETIME, "Stream ioctl() timeout") \
1581 X(ETIMEDOUT, "Connection timed out") \
1582 X(ETXTBSY, "Text file busy") \
1583 X(EWOULDBLOCK, "Operation would block") \
1584 X(EXDEV, "Cross-device link")
1585
1586 #define DEFINE_ENTRY(e, text) { e, #e, text },
1587
1588 static const struct {
1589 int v;
1590 const char* short_text;
1591 const char* long_text;
1592 } table [] = {
1593
1594 ALL_SHARED_ENUMS(DEFINE_ENTRY)
1595
1596 // The following enums are not defined on all platforms.
1597 #ifdef ESTALE
1598 DEFINE_ENTRY(ESTALE, "Reserved")
1599 #endif
1600 #ifdef EDQUOT
1601 DEFINE_ENTRY(EDQUOT, "Reserved")
1602 #endif
1603 #ifdef EMULTIHOP
1604 DEFINE_ENTRY(EMULTIHOP, "Reserved")
1605 #endif
1606
1607 // End marker.
1608 { -1, "Unknown errno", "Unknown error" }
1609
1610 };
1611
1612 #undef DEFINE_ENTRY
1613 #undef ALL_FLAGS
1614
1615 int i = 0;
1616 while (table[i].v != -1 && table[i].v != e) {
1617 i ++;
1618 }
1619
1620 return short_text ? table[i].short_text : table[i].long_text;
1621
1622 }
1623
1624 const char* os::strerror(int e) {
1625 return errno_to_string(e, false);
1626 }
1627
1628 const char* os::errno_name(int e) {
1629 return errno_to_string(e, true);
1630 }
1631
1632 #define trace_page_size_params(size) byte_size_in_exact_unit(size), exact_unit_for_byte_size(size)
1633
1634 void os::trace_page_sizes(const char* str,
1635 const size_t region_min_size,
1636 const size_t region_max_size,
1637 const size_t page_size,
1638 const char* base,
1639 const size_t size) {
1640
1641 log_info(pagesize)("%s: "
1642 " min=" SIZE_FORMAT "%s"
1643 " max=" SIZE_FORMAT "%s"
1644 " base=" PTR_FORMAT
1645 " page_size=" SIZE_FORMAT "%s"
1646 " size=" SIZE_FORMAT "%s",
1647 str,
1648 trace_page_size_params(region_min_size),
1649 trace_page_size_params(region_max_size),
1650 p2i(base),
1651 trace_page_size_params(page_size),
1652 trace_page_size_params(size));
1653 }
1654
1655 void os::trace_page_sizes_for_requested_size(const char* str,
1656 const size_t requested_size,
1657 const size_t page_size,
1658 const size_t alignment,
1659 const char* base,
1660 const size_t size) {
1661
1662 log_info(pagesize)("%s:"
1663 " req_size=" SIZE_FORMAT "%s"
1664 " base=" PTR_FORMAT
1665 " page_size=" SIZE_FORMAT "%s"
1666 " alignment=" SIZE_FORMAT "%s"
1667 " size=" SIZE_FORMAT "%s",
1668 str,
1669 trace_page_size_params(requested_size),
1670 p2i(base),
1671 trace_page_size_params(page_size),
1672 trace_page_size_params(alignment),
1673 trace_page_size_params(size));
1674 }
1675
1676
1677 // This is the working definition of a server class machine:
1678 // >= 2 physical CPU's and >=2GB of memory, with some fuzz
1679 // because the graphics memory (?) sometimes masks physical memory.
1680 // If you want to change the definition of a server class machine
1681 // on some OS or platform, e.g., >=4GB on Windows platforms,
1682 // then you'll have to parameterize this method based on that state,
1683 // as was done for logical processors here, or replicate and
1684 // specialize this method for each platform. (Or fix os to have
1685 // some inheritance structure and use subclassing. Sigh.)
1686 // If you want some platform to always or never behave as a server
1687 // class machine, change the setting of AlwaysActAsServerClassMachine
1688 // and NeverActAsServerClassMachine in globals*.hpp.
1689 bool os::is_server_class_machine() {
1690 // First check for the early returns
1691 if (NeverActAsServerClassMachine) {
1692 return false;
1693 }
1694 if (AlwaysActAsServerClassMachine) {
1695 return true;
1696 }
1697 // Then actually look at the machine
1698 bool result = false;
1699 const unsigned int server_processors = 2;
1700 const julong server_memory = 2UL * G;
1701 // We seem not to get our full complement of memory.
1702 // We allow some part (1/8?) of the memory to be "missing",
1703 // based on the sizes of DIMMs, and maybe graphics cards.
1704 const julong missing_memory = 256UL * M;
1705
1706 /* Is this a server class machine? */
1707 if ((os::active_processor_count() >= (int)server_processors) &&
1708 (os::physical_memory() >= (server_memory - missing_memory))) {
1709 const unsigned int logical_processors =
1710 VM_Version::logical_processors_per_package();
1711 if (logical_processors > 1) {
1712 const unsigned int physical_packages =
1713 os::active_processor_count() / logical_processors;
1714 if (physical_packages >= server_processors) {
1715 result = true;
1716 }
1717 } else {
1718 result = true;
1719 }
1720 }
1721 return result;
1722 }
1723
1724 void os::initialize_initial_active_processor_count() {
1725 assert(_initial_active_processor_count == 0, "Initial active processor count already set.");
1726 _initial_active_processor_count = active_processor_count();
1727 log_debug(os)("Initial active processor count set to %d" , _initial_active_processor_count);
1728 }
1729
1730 bool os::create_stack_guard_pages(char* addr, size_t bytes) {
1731 return os::pd_create_stack_guard_pages(addr, bytes);
1732 }
1733
1734 char* os::reserve_memory(size_t bytes, bool executable, MEMFLAGS flags) {
1735 char* result = pd_reserve_memory(bytes, executable);
1736 if (result != nullptr) {
1737 MemTracker::record_virtual_memory_reserve(result, bytes, CALLER_PC, flags);
1738 }
1739 return result;
1740 }
1741
1742 char* os::attempt_reserve_memory_at(char* addr, size_t bytes, bool executable) {
1743 char* result = pd_attempt_reserve_memory_at(addr, bytes, executable);
1744 if (result != nullptr) {
1745 MemTracker::record_virtual_memory_reserve((address)result, bytes, CALLER_PC);
1746 } else {
1747 log_debug(os)("Attempt to reserve memory at " INTPTR_FORMAT " for "
1748 SIZE_FORMAT " bytes failed, errno %d", p2i(addr), bytes, get_last_error());
1749 }
1750 return result;
1751 }
1752
1753 static void assert_nonempty_range(const char* addr, size_t bytes) {
1754 assert(addr != nullptr && bytes > 0, "invalid range [" PTR_FORMAT ", " PTR_FORMAT ")",
1755 p2i(addr), p2i(addr) + bytes);
1756 }
1757
1758 bool os::commit_memory(char* addr, size_t bytes, bool executable) {
1759 assert_nonempty_range(addr, bytes);
1760 bool res = pd_commit_memory(addr, bytes, executable);
1761 if (res) {
1762 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1763 }
1764 return res;
1765 }
1766
1767 bool os::commit_memory(char* addr, size_t size, size_t alignment_hint,
1768 bool executable) {
1769 assert_nonempty_range(addr, size);
1770 bool res = os::pd_commit_memory(addr, size, alignment_hint, executable);
1771 if (res) {
1772 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1773 }
1774 return res;
1775 }
1776
1777 void os::commit_memory_or_exit(char* addr, size_t bytes, bool executable,
1778 const char* mesg) {
1779 assert_nonempty_range(addr, bytes);
1780 pd_commit_memory_or_exit(addr, bytes, executable, mesg);
1781 MemTracker::record_virtual_memory_commit((address)addr, bytes, CALLER_PC);
1782 }
1783
1784 void os::commit_memory_or_exit(char* addr, size_t size, size_t alignment_hint,
1785 bool executable, const char* mesg) {
1786 assert_nonempty_range(addr, size);
1787 os::pd_commit_memory_or_exit(addr, size, alignment_hint, executable, mesg);
1788 MemTracker::record_virtual_memory_commit((address)addr, size, CALLER_PC);
1789 }
1790
1791 bool os::uncommit_memory(char* addr, size_t bytes, bool executable) {
1792 assert_nonempty_range(addr, bytes);
1793 bool res;
1794 if (MemTracker::enabled()) {
1795 Tracker tkr(Tracker::uncommit);
1796 res = pd_uncommit_memory(addr, bytes, executable);
1797 if (res) {
1798 tkr.record((address)addr, bytes);
1799 }
1800 } else {
1801 res = pd_uncommit_memory(addr, bytes, executable);
1802 }
1803 return res;
1804 }
1805
1806 bool os::release_memory(char* addr, size_t bytes) {
1807 assert_nonempty_range(addr, bytes);
1808 bool res;
1809 if (MemTracker::enabled()) {
1810 // Note: Tracker contains a ThreadCritical.
1811 Tracker tkr(Tracker::release);
1812 res = pd_release_memory(addr, bytes);
1813 if (res) {
1814 tkr.record((address)addr, bytes);
1815 }
1816 } else {
1817 res = pd_release_memory(addr, bytes);
1818 }
1819 if (!res) {
1820 log_info(os)("os::release_memory failed (" PTR_FORMAT ", " SIZE_FORMAT ")", p2i(addr), bytes);
1821 }
1822 return res;
1823 }
1824
1825 // Prints all mappings
1826 void os::print_memory_mappings(outputStream* st) {
1827 os::print_memory_mappings(nullptr, SIZE_MAX, st);
1828 }
1829
1830 // Pretouching must use a store, not just a load. On many OSes loads from
1831 // fresh memory would be satisfied from a single mapped page containing all
1832 // zeros. We need to store something to each page to get them backed by
1833 // their own memory, which is the effect we want here. An atomic add of
1834 // zero is used instead of a simple store, allowing the memory to be used
1835 // while pretouch is in progress, rather than requiring users of the memory
1836 // to wait until the entire range has been touched. This is technically
1837 // a UB data race, but doesn't cause any problems for us.
1838 void os::pretouch_memory(void* start, void* end, size_t page_size) {
1839 assert(start <= end, "invalid range: " PTR_FORMAT " -> " PTR_FORMAT, p2i(start), p2i(end));
1840 assert(is_power_of_2(page_size), "page size misaligned: %zu", page_size);
1841 assert(page_size >= sizeof(int), "page size too small: %zu", page_size);
1842 if (start < end) {
1843 // We're doing concurrent-safe touch and memory state has page
1844 // granularity, so we can touch anywhere in a page. Touch at the
1845 // beginning of each page to simplify iteration.
1846 char* cur = static_cast<char*>(align_down(start, page_size));
1847 void* last = align_down(static_cast<char*>(end) - 1, page_size);
1848 assert(cur <= last, "invariant");
1849 // Iterate from first page through last (inclusive), being careful to
1850 // avoid overflow if the last page abuts the end of the address range.
1851 for ( ; true; cur += page_size) {
1852 Atomic::add(reinterpret_cast<int*>(cur), 0, memory_order_relaxed);
1853 if (cur >= last) break;
1854 }
1855 }
1856 }
1857
1858 char* os::map_memory_to_file(size_t bytes, int file_desc) {
1859 // Could have called pd_reserve_memory() followed by replace_existing_mapping_with_file_mapping(),
1860 // but AIX may use SHM in which case its more trouble to detach the segment and remap memory to the file.
1861 // On all current implementations null is interpreted as any available address.
1862 char* result = os::map_memory_to_file(nullptr /* addr */, bytes, file_desc);
1863 if (result != nullptr) {
1864 MemTracker::record_virtual_memory_reserve_and_commit(result, bytes, CALLER_PC);
1865 }
1866 return result;
1867 }
1868
1869 char* os::attempt_map_memory_to_file_at(char* addr, size_t bytes, int file_desc) {
1870 char* result = pd_attempt_map_memory_to_file_at(addr, bytes, file_desc);
1871 if (result != nullptr) {
1872 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC);
1873 }
1874 return result;
1875 }
1876
1877 char* os::map_memory(int fd, const char* file_name, size_t file_offset,
1878 char *addr, size_t bytes, bool read_only,
1879 bool allow_exec, MEMFLAGS flags) {
1880 char* result = pd_map_memory(fd, file_name, file_offset, addr, bytes, read_only, allow_exec);
1881 if (result != nullptr) {
1882 MemTracker::record_virtual_memory_reserve_and_commit((address)result, bytes, CALLER_PC, flags);
1883 }
1884 return result;
1885 }
1886
1887 char* os::remap_memory(int fd, const char* file_name, size_t file_offset,
1888 char *addr, size_t bytes, bool read_only,
1889 bool allow_exec) {
1890 return pd_remap_memory(fd, file_name, file_offset, addr, bytes,
1891 read_only, allow_exec);
1892 }
1893
1894 bool os::unmap_memory(char *addr, size_t bytes) {
1895 bool result;
1896 if (MemTracker::enabled()) {
1897 Tracker tkr(Tracker::release);
1898 result = pd_unmap_memory(addr, bytes);
1899 if (result) {
1900 tkr.record((address)addr, bytes);
1901 }
1902 } else {
1903 result = pd_unmap_memory(addr, bytes);
1904 }
1905 return result;
1906 }
1907
1908 void os::free_memory(char *addr, size_t bytes, size_t alignment_hint) {
1909 pd_free_memory(addr, bytes, alignment_hint);
1910 }
1911
1912 void os::realign_memory(char *addr, size_t bytes, size_t alignment_hint) {
1913 pd_realign_memory(addr, bytes, alignment_hint);
1914 }
1915
1916 char* os::reserve_memory_special(size_t size, size_t alignment, size_t page_size,
1917 char* addr, bool executable) {
1918
1919 assert(is_aligned(addr, alignment), "Unaligned request address");
1920
1921 char* result = pd_reserve_memory_special(size, alignment, page_size, addr, executable);
1922 if (result != nullptr) {
1923 // The memory is committed
1924 MemTracker::record_virtual_memory_reserve_and_commit((address)result, size, CALLER_PC);
1925 }
1926
1927 return result;
1928 }
1929
1930 bool os::release_memory_special(char* addr, size_t bytes) {
1931 bool res;
1932 if (MemTracker::enabled()) {
1933 // Note: Tracker contains a ThreadCritical.
1934 Tracker tkr(Tracker::release);
1935 res = pd_release_memory_special(addr, bytes);
1936 if (res) {
1937 tkr.record((address)addr, bytes);
1938 }
1939 } else {
1940 res = pd_release_memory_special(addr, bytes);
1941 }
1942 return res;
1943 }
1944
1945 // Convenience wrapper around naked_short_sleep to allow for longer sleep
1946 // times. Only for use by non-JavaThreads.
1947 void os::naked_sleep(jlong millis) {
1948 assert(!Thread::current()->is_Java_thread(), "not for use by JavaThreads");
1949 const jlong limit = 999;
1950 while (millis > limit) {
1951 naked_short_sleep(limit);
1952 millis -= limit;
1953 }
1954 naked_short_sleep(millis);
1955 }
1956
1957
1958 ////// Implementation of PageSizes
1959
1960 void os::PageSizes::add(size_t page_size) {
1961 assert(is_power_of_2(page_size), "page_size must be a power of 2: " SIZE_FORMAT_X, page_size);
1962 _v |= page_size;
1963 }
1964
1965 bool os::PageSizes::contains(size_t page_size) const {
1966 assert(is_power_of_2(page_size), "page_size must be a power of 2: " SIZE_FORMAT_X, page_size);
1967 return (_v & page_size) != 0;
1968 }
1969
1970 size_t os::PageSizes::next_smaller(size_t page_size) const {
1971 assert(is_power_of_2(page_size), "page_size must be a power of 2: " SIZE_FORMAT_X, page_size);
1972 size_t v2 = _v & (page_size - 1);
1973 if (v2 == 0) {
1974 return 0;
1975 }
1976 return round_down_power_of_2(v2);
1977 }
1978
1979 size_t os::PageSizes::next_larger(size_t page_size) const {
1980 assert(is_power_of_2(page_size), "page_size must be a power of 2: " SIZE_FORMAT_X, page_size);
1981 if (page_size == max_power_of_2<size_t>()) { // Shift by 32/64 would be UB
1982 return 0;
1983 }
1984 // Remove current and smaller page sizes
1985 size_t v2 = _v & ~(page_size + (page_size - 1));
1986 if (v2 == 0) {
1987 return 0;
1988 }
1989 return (size_t)1 << count_trailing_zeros(v2);
1990 }
1991
1992 size_t os::PageSizes::largest() const {
1993 const size_t max = max_power_of_2<size_t>();
1994 if (contains(max)) {
1995 return max;
1996 }
1997 return next_smaller(max);
1998 }
1999
2000 size_t os::PageSizes::smallest() const {
2001 // Strictly speaking the set should not contain sizes < os::vm_page_size().
2002 // But this is not enforced.
2003 return next_larger(1);
2004 }
2005
2006 void os::PageSizes::print_on(outputStream* st) const {
2007 bool first = true;
2008 for (size_t sz = smallest(); sz != 0; sz = next_larger(sz)) {
2009 if (first) {
2010 first = false;
2011 } else {
2012 st->print_raw(", ");
2013 }
2014 if (sz < M) {
2015 st->print(SIZE_FORMAT "k", sz / K);
2016 } else if (sz < G) {
2017 st->print(SIZE_FORMAT "M", sz / M);
2018 } else {
2019 st->print(SIZE_FORMAT "G", sz / G);
2020 }
2021 }
2022 if (first) {
2023 st->print("empty");
2024 }
2025 }
2026
2027 // Check minimum allowable stack sizes for thread creation and to initialize
2028 // the java system classes, including StackOverflowError - depends on page
2029 // size.
2030 // The space needed for frames during startup is platform dependent. It
2031 // depends on word size, platform calling conventions, C frame layout and
2032 // interpreter/C1/C2 design decisions. Therefore this is given in a
2033 // platform (os/cpu) dependent constant.
2034 // To this, space for guard mechanisms is added, which depends on the
2035 // page size which again depends on the concrete system the VM is running
2036 // on. Space for libc guard pages is not included in this size.
2037 jint os::set_minimum_stack_sizes() {
2038
2039 _java_thread_min_stack_allowed = _java_thread_min_stack_allowed +
2040 StackOverflow::stack_guard_zone_size() +
2041 StackOverflow::stack_shadow_zone_size();
2042
2043 _java_thread_min_stack_allowed = align_up(_java_thread_min_stack_allowed, vm_page_size());
2044 _java_thread_min_stack_allowed = MAX2(_java_thread_min_stack_allowed, _os_min_stack_allowed);
2045
2046 size_t stack_size_in_bytes = ThreadStackSize * K;
2047 if (stack_size_in_bytes != 0 &&
2048 stack_size_in_bytes < _java_thread_min_stack_allowed) {
2049 // The '-Xss' and '-XX:ThreadStackSize=N' options both set
2050 // ThreadStackSize so we go with "Java thread stack size" instead
2051 // of "ThreadStackSize" to be more friendly.
2052 tty->print_cr("\nThe Java thread stack size specified is too small. "
2053 "Specify at least " SIZE_FORMAT "k",
2054 _java_thread_min_stack_allowed / K);
2055 return JNI_ERR;
2056 }
2057
2058 // Make the stack size a multiple of the page size so that
2059 // the yellow/red zones can be guarded.
2060 JavaThread::set_stack_size_at_create(align_up(stack_size_in_bytes, vm_page_size()));
2061
2062 // Reminder: a compiler thread is a Java thread.
2063 _compiler_thread_min_stack_allowed = _compiler_thread_min_stack_allowed +
2064 StackOverflow::stack_guard_zone_size() +
2065 StackOverflow::stack_shadow_zone_size();
2066
2067 _compiler_thread_min_stack_allowed = align_up(_compiler_thread_min_stack_allowed, vm_page_size());
2068 _compiler_thread_min_stack_allowed = MAX2(_compiler_thread_min_stack_allowed, _os_min_stack_allowed);
2069
2070 stack_size_in_bytes = CompilerThreadStackSize * K;
2071 if (stack_size_in_bytes != 0 &&
2072 stack_size_in_bytes < _compiler_thread_min_stack_allowed) {
2073 tty->print_cr("\nThe CompilerThreadStackSize specified is too small. "
2074 "Specify at least " SIZE_FORMAT "k",
2075 _compiler_thread_min_stack_allowed / K);
2076 return JNI_ERR;
2077 }
2078
2079 _vm_internal_thread_min_stack_allowed = align_up(_vm_internal_thread_min_stack_allowed, vm_page_size());
2080 _vm_internal_thread_min_stack_allowed = MAX2(_vm_internal_thread_min_stack_allowed, _os_min_stack_allowed);
2081
2082 stack_size_in_bytes = VMThreadStackSize * K;
2083 if (stack_size_in_bytes != 0 &&
2084 stack_size_in_bytes < _vm_internal_thread_min_stack_allowed) {
2085 tty->print_cr("\nThe VMThreadStackSize specified is too small. "
2086 "Specify at least " SIZE_FORMAT "k",
2087 _vm_internal_thread_min_stack_allowed / K);
2088 return JNI_ERR;
2089 }
2090 return JNI_OK;
2091 }