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 "classfile/symbolTable.hpp"
27 #include "classfile/vmSymbols.hpp"
28 #include "code/codeCache.hpp"
29 #include "compiler/compileBroker.hpp"
30 #include "gc/shared/collectedHeap.hpp"
31 #include "gc/shared/isGCActiveMark.hpp"
32 #include "logging/log.hpp"
33 #include "logging/logStream.hpp"
34 #include "logging/logConfiguration.hpp"
35 #include "memory/heapInspection.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "memory/universe.hpp"
38 #include "oops/symbol.hpp"
39 #include "runtime/arguments.hpp"
40 #include "runtime/deoptimization.hpp"
41 #include "runtime/frame.inline.hpp"
42 #include "runtime/interfaceSupport.inline.hpp"
43 #include "runtime/sweeper.hpp"
44 #include "runtime/thread.inline.hpp"
45 #include "runtime/threadSMR.inline.hpp"
46 #include "runtime/vmOperations.hpp"
47 #include "services/threadService.hpp"
48
49 #define VM_OP_NAME_INITIALIZE(name) #name,
50
51 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \
52 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) };
53
54 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) {
55 _calling_thread = thread;
56 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
57 _priority = priority;
58 }
59
60
61 void VM_Operation::evaluate() {
62 ResourceMark rm;
63 LogTarget(Debug, vmoperation) lt;
64 if (lt.is_enabled()) {
65 LogStream ls(lt);
66 ls.print("begin ");
67 print_on_error(&ls);
68 ls.cr();
69 }
70 doit();
71 if (lt.is_enabled()) {
72 LogStream ls(lt);
73 ls.print("end ");
74 print_on_error(&ls);
75 ls.cr();
76 }
77 }
78
79 const char* VM_Operation::mode_to_string(Mode mode) {
80 switch(mode) {
81 case _safepoint : return "safepoint";
82 case _no_safepoint : return "no safepoint";
83 case _concurrent : return "concurrent";
84 case _async_safepoint: return "async safepoint";
85 default : return "unknown";
86 }
87 }
88 // Called by fatal error handler.
89 void VM_Operation::print_on_error(outputStream* st) const {
90 st->print("VM_Operation (" PTR_FORMAT "): ", p2i(this));
91 st->print("%s", name());
92
93 const char* mode = mode_to_string(evaluation_mode());
94 st->print(", mode: %s", mode);
95
96 if (calling_thread()) {
97 st->print(", requested by thread " PTR_FORMAT, p2i(calling_thread()));
98 }
99 }
100
101 void VM_ThreadStop::doit() {
102 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
103 ThreadsListHandle tlh;
104 JavaThread* target = java_lang_Thread::thread(target_thread());
105 // Note that this now allows multiple ThreadDeath exceptions to be
106 // thrown at a thread.
107 if (target != NULL && (!EnableThreadSMRExtraValidityChecks || tlh.includes(target))) {
108 // The target thread has run and has not exited yet.
109 target->send_thread_stop(throwable());
110 }
111 }
112
113 void VM_ClearICs::doit() {
114 if (_preserve_static_stubs) {
115 CodeCache::cleanup_inline_caches();
116 } else {
117 CodeCache::clear_inline_caches();
118 }
119 }
120
121 void VM_Deoptimize::doit() {
122 // We do not want any GCs to happen while we are in the middle of this VM operation
123 ResourceMark rm;
124 DeoptimizationMarker dm;
125
126 // Deoptimize all activations depending on marked nmethods
127 Deoptimization::deoptimize_dependents();
128
129 // Make the dependent methods not entrant
130 CodeCache::make_marked_nmethods_not_entrant();
131 }
132
133 void VM_MarkActiveNMethods::doit() {
134 NMethodSweeper::mark_active_nmethods();
135 }
136
137 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id, int reason) {
138 _thread = thread;
139 _id = id;
140 _reason = reason;
141 }
142
143
144 void VM_DeoptimizeFrame::doit() {
145 assert(_reason > Deoptimization::Reason_none && _reason < Deoptimization::Reason_LIMIT, "invalid deopt reason");
146 Deoptimization::deoptimize_frame_internal(_thread, _id, (Deoptimization::DeoptReason)_reason);
147 }
148
149
150 #ifndef PRODUCT
151
152 void VM_DeoptimizeAll::doit() {
153 DeoptimizationMarker dm;
154 JavaThreadIteratorWithHandle jtiwh;
155 // deoptimize all java threads in the system
156 if (DeoptimizeALot) {
157 for (; JavaThread *thread = jtiwh.next(); ) {
158 if (thread->has_last_Java_frame()) {
159 thread->deoptimize();
160 }
161 }
162 } else if (DeoptimizeRandom) {
163
164 // Deoptimize some selected threads and frames
165 int tnum = os::random() & 0x3;
166 int fnum = os::random() & 0x3;
167 int tcount = 0;
168 for (; JavaThread *thread = jtiwh.next(); ) {
169 if (thread->has_last_Java_frame()) {
170 if (tcount++ == tnum) {
171 tcount = 0;
172 int fcount = 0;
173 // Deoptimize some selected frames.
174 // Biased llocking wants a updated register map
175 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) {
176 if (fst.current()->can_be_deoptimized()) {
177 if (fcount++ == fnum) {
178 fcount = 0;
179 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map());
180 }
181 }
182 }
183 }
184 }
185 }
186 }
187 }
188
189
190 void VM_ZombieAll::doit() {
191 JavaThread *thread = (JavaThread *)calling_thread();
192 assert(thread->is_Java_thread(), "must be a Java thread");
193 thread->make_zombies();
194 }
195
196 #endif // !PRODUCT
197
198 void VM_Verify::doit() {
199 Universe::heap()->prepare_for_verify();
200 Universe::verify();
201 }
202
203 bool VM_PrintThreads::doit_prologue() {
204 // Get Heap_lock if concurrent locks will be dumped
205 if (_print_concurrent_locks) {
206 Heap_lock->lock();
207 }
208 return true;
209 }
210
211 void VM_PrintThreads::doit() {
212 Threads::print_on(_out, true, false, _print_concurrent_locks, _print_extended_info);
213 }
214
215 void VM_PrintThreads::doit_epilogue() {
216 if (_print_concurrent_locks) {
217 // Release Heap_lock
218 Heap_lock->unlock();
219 }
220 }
221
222 void VM_PrintJNI::doit() {
223 JNIHandles::print_on(_out);
224 }
225
226 void VM_PrintMetadata::doit() {
227 MetaspaceUtils::print_report(_out, _scale, _flags);
228 }
229
230 VM_FindDeadlocks::~VM_FindDeadlocks() {
231 if (_deadlocks != NULL) {
232 DeadlockCycle* cycle = _deadlocks;
233 while (cycle != NULL) {
234 DeadlockCycle* d = cycle;
235 cycle = cycle->next();
236 delete d;
237 }
238 }
239 }
240
241 void VM_FindDeadlocks::doit() {
242 // Update the hazard ptr in the originating thread to the current
243 // list of threads. This VM operation needs the current list of
244 // threads for proper deadlock detection and those are the
245 // JavaThreads we need to be protected when we return info to the
246 // originating thread.
247 _setter.set();
248
249 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_setter.list(), _concurrent_locks);
250 if (_out != NULL) {
251 int num_deadlocks = 0;
252 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) {
253 num_deadlocks++;
254 cycle->print_on_with(_setter.list(), _out);
255 }
256
257 if (num_deadlocks == 1) {
258 _out->print_cr("\nFound 1 deadlock.\n");
259 _out->flush();
260 } else if (num_deadlocks > 1) {
261 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks);
262 _out->flush();
263 }
264 }
265 }
266
267 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
268 int max_depth,
269 bool with_locked_monitors,
270 bool with_locked_synchronizers) {
271 _result = result;
272 _num_threads = 0; // 0 indicates all threads
273 _threads = NULL;
274 _result = result;
275 _max_depth = max_depth;
276 _with_locked_monitors = with_locked_monitors;
277 _with_locked_synchronizers = with_locked_synchronizers;
278 }
279
280 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
281 GrowableArray<instanceHandle>* threads,
282 int num_threads,
283 int max_depth,
284 bool with_locked_monitors,
285 bool with_locked_synchronizers) {
286 _result = result;
287 _num_threads = num_threads;
288 _threads = threads;
289 _result = result;
290 _max_depth = max_depth;
291 _with_locked_monitors = with_locked_monitors;
292 _with_locked_synchronizers = with_locked_synchronizers;
293 }
294
295 bool VM_ThreadDump::doit_prologue() {
296 if (_with_locked_synchronizers) {
297 // Acquire Heap_lock to dump concurrent locks
298 Heap_lock->lock();
299 }
300
301 return true;
302 }
303
304 void VM_ThreadDump::doit_epilogue() {
305 if (_with_locked_synchronizers) {
306 // Release Heap_lock
307 Heap_lock->unlock();
308 }
309 }
310
311 void VM_ThreadDump::doit() {
312 ResourceMark rm;
313
314 // Set the hazard ptr in the originating thread to protect the
315 // current list of threads. This VM operation needs the current list
316 // of threads for a proper dump and those are the JavaThreads we need
317 // to be protected when we return info to the originating thread.
318 _result->set_t_list();
319
320 ConcurrentLocksDump concurrent_locks(true);
321 if (_with_locked_synchronizers) {
322 concurrent_locks.dump_at_safepoint();
323 }
324
325 if (_num_threads == 0) {
326 // Snapshot all live threads
327
328 for (uint i = 0; i < _result->t_list()->length(); i++) {
329 JavaThread* jt = _result->t_list()->thread_at(i);
330 if (jt->is_exiting() ||
331 jt->is_hidden_from_external_view()) {
332 // skip terminating threads and hidden threads
333 continue;
334 }
335 ThreadConcurrentLocks* tcl = NULL;
336 if (_with_locked_synchronizers) {
337 tcl = concurrent_locks.thread_concurrent_locks(jt);
338 }
339 snapshot_thread(jt, tcl);
340 }
341 } else {
342 // Snapshot threads in the given _threads array
343 // A dummy snapshot is created if a thread doesn't exist
344
345 for (int i = 0; i < _num_threads; i++) {
346 instanceHandle th = _threads->at(i);
347 if (th() == NULL) {
348 // skip if the thread doesn't exist
349 // Add a dummy snapshot
350 _result->add_thread_snapshot();
351 continue;
352 }
353
354 // Dump thread stack only if the thread is alive and not exiting
355 // and not VM internal thread.
356 JavaThread* jt = java_lang_Thread::thread(th());
357 if (jt != NULL && !_result->t_list()->includes(jt)) {
358 // _threads[i] doesn't refer to a valid JavaThread; this check
359 // is primarily for JVM_DumpThreads() which doesn't have a good
360 // way to validate the _threads array.
361 jt = NULL;
362 }
363 if (jt == NULL || /* thread not alive */
364 jt->is_exiting() ||
365 jt->is_hidden_from_external_view()) {
366 // add a NULL snapshot if skipped
367 _result->add_thread_snapshot();
368 continue;
369 }
370 ThreadConcurrentLocks* tcl = NULL;
371 if (_with_locked_synchronizers) {
372 tcl = concurrent_locks.thread_concurrent_locks(jt);
373 }
374 snapshot_thread(jt, tcl);
375 }
376 }
377 }
378
379 void VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {
380 ThreadSnapshot* snapshot = _result->add_thread_snapshot(java_thread);
381 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);
382 snapshot->set_concurrent_locks(tcl);
383 }
384
385 volatile bool VM_Exit::_vm_exited = false;
386 Thread * volatile VM_Exit::_shutdown_thread = NULL;
387
388 int VM_Exit::set_vm_exited() {
389
390 Thread * thr_cur = Thread::current();
391
392 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
393
394 int num_active = 0;
395
396 _shutdown_thread = thr_cur;
397 _vm_exited = true; // global flag
398 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thr = jtiwh.next(); ) {
399 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
400 ++num_active;
401 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag
402 }
403 }
404
405 return num_active;
406 }
407
408 int VM_Exit::wait_for_threads_in_native_to_block() {
409 // VM exits at safepoint. This function must be called at the final safepoint
410 // to wait for threads in _thread_in_native state to be quiescent.
411 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
412
413 Thread * thr_cur = Thread::current();
414 Monitor timer(Mutex::leaf, "VM_Exit timer", true,
415 Monitor::_safepoint_check_never);
416
417 // Compiler threads need longer wait because they can access VM data directly
418 // while in native. If they are active and some structures being used are
419 // deleted by the shutdown sequence, they will crash. On the other hand, user
420 // threads must go through native=>Java/VM transitions first to access VM
421 // data, and they will be stopped during state transition. In theory, we
422 // don't have to wait for user threads to be quiescent, but it's always
423 // better to terminate VM when current thread is the only active thread, so
424 // wait for user threads too. Numbers are in 10 milliseconds.
425 int max_wait_user_thread = 30; // at least 300 milliseconds
426 int max_wait_compiler_thread = 1000; // at least 10 seconds
427
428 int max_wait = max_wait_compiler_thread;
429
430 int attempts = 0;
431 JavaThreadIteratorWithHandle jtiwh;
432 while (true) {
433 int num_active = 0;
434 int num_active_compiler_thread = 0;
435
436 jtiwh.rewind();
437 for (; JavaThread *thr = jtiwh.next(); ) {
438 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
439 num_active++;
440 if (thr->is_Compiler_thread()) {
441 #if INCLUDE_JVMCI
442 CompilerThread* ct = (CompilerThread*) thr;
443 if (ct->compiler() == NULL || !ct->compiler()->is_jvmci()) {
444 num_active_compiler_thread++;
445 } else {
446 // A JVMCI compiler thread never accesses VM data structures
447 // while in _thread_in_native state so there's no need to wait
448 // for it and potentially add a 300 millisecond delay to VM
449 // shutdown.
450 num_active--;
451 }
452 #else
453 num_active_compiler_thread++;
454 #endif
455 }
456 }
457 }
458
459 if (num_active == 0) {
460 return 0;
461 } else if (attempts > max_wait) {
462 return num_active;
463 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) {
464 return num_active;
465 }
466
467 attempts++;
468
469 MonitorLocker ml(&timer, Mutex::_no_safepoint_check_flag);
470 ml.wait(10);
471 }
472 }
473
474 void VM_Exit::doit() {
475
476 if (VerifyBeforeExit) {
477 HandleMark hm(VMThread::vm_thread());
478 // Among other things, this ensures that Eden top is correct.
479 Universe::heap()->prepare_for_verify();
480 // Silent verification so as not to pollute normal output,
481 // unless we really asked for it.
482 Universe::verify();
483 }
484
485 CompileBroker::set_should_block();
486
487 // Wait for a short period for threads in native to block. Any thread
488 // still executing native code after the wait will be stopped at
489 // native==>Java/VM barriers.
490 // Among 16276 JCK tests, 94% of them come here without any threads still
491 // running in native; the other 6% are quiescent within 250ms (Ultra 80).
492 wait_for_threads_in_native_to_block();
493
494 set_vm_exited();
495
496 // We'd like to call IdealGraphPrinter::clean_up() to finalize the
497 // XML logging, but we can't safely do that here. The logic to make
498 // XML termination logging safe is tied to the termination of the
499 // VMThread, and it doesn't terminate on this exit path. See 8222534.
500
501 // cleanup globals resources before exiting. exit_globals() currently
502 // cleans up outputStream resources and PerfMemory resources.
503 exit_globals();
504
505 LogConfiguration::finalize();
506
507 // Check for exit hook
508 exit_hook_t exit_hook = Arguments::exit_hook();
509 if (exit_hook != NULL) {
510 // exit hook should exit.
511 exit_hook(_exit_code);
512 // ... but if it didn't, we must do it here
513 vm_direct_exit(_exit_code);
514 } else {
515 vm_direct_exit(_exit_code);
516 }
517 }
518
519
520 void VM_Exit::wait_if_vm_exited() {
521 if (_vm_exited &&
522 Thread::current_or_null() != _shutdown_thread) {
523 // _vm_exited is set at safepoint, and the Threads_lock is never released
524 // we will block here until the process dies
525 Threads_lock->lock_without_safepoint_check();
526 ShouldNotReachHere();
527 }
528 }
529
530 void VM_PrintCompileQueue::doit() {
531 CompileBroker::print_compile_queues(_out);
532 }
533
534 #if INCLUDE_SERVICES
535 void VM_PrintClassHierarchy::doit() {
536 KlassHierarchy::print_class_hierarchy(_out, _print_interfaces, _print_subclasses, _classname);
537 }
538 #endif