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/synchronizer.hpp"
45 #include "runtime/thread.inline.hpp"
46 #include "runtime/threadSMR.inline.hpp"
47 #include "runtime/vmOperations.hpp"
48 #include "services/threadService.hpp"
49
50 #define VM_OP_NAME_INITIALIZE(name) #name,
51
52 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \
53 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) };
54
55 void VM_Operation::set_calling_thread(Thread* thread) {
56 _calling_thread = thread;
57 }
58
59 void VM_Operation::evaluate() {
60 ResourceMark rm;
61 LogTarget(Debug, vmoperation) lt;
62 if (lt.is_enabled()) {
63 LogStream ls(lt);
64 ls.print("begin ");
65 print_on_error(&ls);
66 ls.cr();
67 }
68 doit();
69 if (lt.is_enabled()) {
70 LogStream ls(lt);
71 ls.print("end ");
72 print_on_error(&ls);
73 ls.cr();
74 }
75 }
76
77 const char* VM_Operation::mode_to_string(Mode mode) {
78 switch(mode) {
79 case _safepoint : return "safepoint";
80 case _no_safepoint : return "no safepoint";
81 case _concurrent : return "concurrent";
82 case _async_safepoint: return "async safepoint";
83 default : return "unknown";
84 }
85 }
86 // Called by fatal error handler.
87 void VM_Operation::print_on_error(outputStream* st) const {
88 st->print("VM_Operation (" PTR_FORMAT "): ", p2i(this));
89 st->print("%s", name());
90
91 const char* mode = mode_to_string(evaluation_mode());
92 st->print(", mode: %s", mode);
93
94 if (calling_thread()) {
95 st->print(", requested by thread " PTR_FORMAT, p2i(calling_thread()));
96 }
97 }
98
99 void VM_ThreadStop::doit() {
100 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
101 ThreadsListHandle tlh;
102 JavaThread* target = java_lang_Thread::thread(target_thread());
103 // Note that this now allows multiple ThreadDeath exceptions to be
104 // thrown at a thread.
105 if (target != NULL && (!EnableThreadSMRExtraValidityChecks || tlh.includes(target))) {
106 // The target thread has run and has not exited yet.
107 target->send_thread_stop(throwable());
108 }
109 }
110
111 void VM_ClearICs::doit() {
112 if (_preserve_static_stubs) {
113 CodeCache::cleanup_inline_caches();
114 } else {
115 CodeCache::clear_inline_caches();
116 }
117 }
118
119 void VM_Deoptimize::doit() {
120 // We do not want any GCs to happen while we are in the middle of this VM operation
121 ResourceMark rm;
122 DeoptimizationMarker dm;
123
124 // Deoptimize all activations depending on marked nmethods
125 Deoptimization::deoptimize_dependents();
126
127 // Make the dependent methods not entrant
128 CodeCache::make_marked_nmethods_not_entrant();
129 }
130
131 void VM_MarkActiveNMethods::doit() {
132 NMethodSweeper::mark_active_nmethods();
133 }
134
135 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id, int reason) {
136 _thread = thread;
137 _id = id;
138 _reason = reason;
139 }
140
141
142 void VM_DeoptimizeFrame::doit() {
143 assert(_reason > Deoptimization::Reason_none && _reason < Deoptimization::Reason_LIMIT, "invalid deopt reason");
144 Deoptimization::deoptimize_frame_internal(_thread, _id, (Deoptimization::DeoptReason)_reason);
145 }
146
147
148 #ifndef PRODUCT
149
150 void VM_DeoptimizeAll::doit() {
151 DeoptimizationMarker dm;
152 JavaThreadIteratorWithHandle jtiwh;
153 // deoptimize all java threads in the system
154 if (DeoptimizeALot) {
155 for (; JavaThread *thread = jtiwh.next(); ) {
156 if (thread->has_last_Java_frame()) {
157 thread->deoptimize();
158 }
159 }
160 } else if (DeoptimizeRandom) {
161
162 // Deoptimize some selected threads and frames
163 int tnum = os::random() & 0x3;
164 int fnum = os::random() & 0x3;
165 int tcount = 0;
166 for (; JavaThread *thread = jtiwh.next(); ) {
167 if (thread->has_last_Java_frame()) {
168 if (tcount++ == tnum) {
169 tcount = 0;
170 int fcount = 0;
171 // Deoptimize some selected frames.
172 // Biased llocking wants a updated register map
173 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) {
174 if (fst.current()->can_be_deoptimized()) {
175 if (fcount++ == fnum) {
176 fcount = 0;
177 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map());
178 }
179 }
180 }
181 }
182 }
183 }
184 }
185 }
186
187
188 void VM_ZombieAll::doit() {
189 JavaThread *thread = (JavaThread *)calling_thread();
190 assert(thread->is_Java_thread(), "must be a Java thread");
191 thread->make_zombies();
192 }
193
194 #endif // !PRODUCT
195
196 void VM_Verify::doit() {
197 Universe::heap()->prepare_for_verify();
198 Universe::verify();
199 }
200
201 bool VM_PrintThreads::doit_prologue() {
202 // Get Heap_lock if concurrent locks will be dumped
203 if (_print_concurrent_locks) {
204 Heap_lock->lock();
205 }
206 return true;
207 }
208
209 void VM_PrintThreads::doit() {
210 Threads::print_on(_out, true, false, _print_concurrent_locks, _print_extended_info);
211 }
212
213 void VM_PrintThreads::doit_epilogue() {
214 if (_print_concurrent_locks) {
215 // Release Heap_lock
216 Heap_lock->unlock();
217 }
218 }
219
220 void VM_PrintJNI::doit() {
221 JNIHandles::print_on(_out);
222 }
223
224 void VM_PrintMetadata::doit() {
225 MetaspaceUtils::print_report(_out, _scale, _flags);
226 }
227
228 VM_FindDeadlocks::~VM_FindDeadlocks() {
229 if (_deadlocks != NULL) {
230 DeadlockCycle* cycle = _deadlocks;
231 while (cycle != NULL) {
232 DeadlockCycle* d = cycle;
233 cycle = cycle->next();
234 delete d;
235 }
236 }
237 }
238
239 void VM_FindDeadlocks::doit() {
240 // Update the hazard ptr in the originating thread to the current
241 // list of threads. This VM operation needs the current list of
242 // threads for proper deadlock detection and those are the
243 // JavaThreads we need to be protected when we return info to the
244 // originating thread.
245 _setter.set();
246
247 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_setter.list(), _concurrent_locks);
248 if (_out != NULL) {
249 int num_deadlocks = 0;
250 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) {
251 num_deadlocks++;
252 cycle->print_on_with(_setter.list(), _out);
253 }
254
255 if (num_deadlocks == 1) {
256 _out->print_cr("\nFound 1 deadlock.\n");
257 _out->flush();
258 } else if (num_deadlocks > 1) {
259 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks);
260 _out->flush();
261 }
262 }
263 }
264
265 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
266 int max_depth,
267 bool with_locked_monitors,
268 bool with_locked_synchronizers) {
269 _result = result;
270 _num_threads = 0; // 0 indicates all threads
271 _threads = NULL;
272 _result = result;
273 _max_depth = max_depth;
274 _with_locked_monitors = with_locked_monitors;
275 _with_locked_synchronizers = with_locked_synchronizers;
276 }
277
278 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
279 GrowableArray<instanceHandle>* threads,
280 int num_threads,
281 int max_depth,
282 bool with_locked_monitors,
283 bool with_locked_synchronizers) {
284 _result = result;
285 _num_threads = num_threads;
286 _threads = threads;
287 _result = result;
288 _max_depth = max_depth;
289 _with_locked_monitors = with_locked_monitors;
290 _with_locked_synchronizers = with_locked_synchronizers;
291 }
292
293 bool VM_ThreadDump::doit_prologue() {
294 if (_with_locked_synchronizers) {
295 // Acquire Heap_lock to dump concurrent locks
296 Heap_lock->lock();
297 }
298
299 return true;
300 }
301
302 void VM_ThreadDump::doit_epilogue() {
303 if (_with_locked_synchronizers) {
304 // Release Heap_lock
305 Heap_lock->unlock();
306 }
307 }
308
309 void VM_ThreadDump::doit() {
310 ResourceMark rm;
311
312 // Set the hazard ptr in the originating thread to protect the
313 // current list of threads. This VM operation needs the current list
314 // of threads for a proper dump and those are the JavaThreads we need
315 // to be protected when we return info to the originating thread.
316 _result->set_t_list();
317
318 ConcurrentLocksDump concurrent_locks(true);
319 if (_with_locked_synchronizers) {
320 concurrent_locks.dump_at_safepoint();
321 }
322
323 if (_num_threads == 0) {
324 // Snapshot all live threads
325
326 for (uint i = 0; i < _result->t_list()->length(); i++) {
327 JavaThread* jt = _result->t_list()->thread_at(i);
328 if (jt->is_exiting() ||
329 jt->is_hidden_from_external_view()) {
330 // skip terminating threads and hidden threads
331 continue;
332 }
333 ThreadConcurrentLocks* tcl = NULL;
334 if (_with_locked_synchronizers) {
335 tcl = concurrent_locks.thread_concurrent_locks(jt);
336 }
337 snapshot_thread(jt, tcl);
338 }
339 } else {
340 // Snapshot threads in the given _threads array
341 // A dummy snapshot is created if a thread doesn't exist
342
343 for (int i = 0; i < _num_threads; i++) {
344 instanceHandle th = _threads->at(i);
345 if (th() == NULL) {
346 // skip if the thread doesn't exist
347 // Add a dummy snapshot
348 _result->add_thread_snapshot();
349 continue;
350 }
351
352 // Dump thread stack only if the thread is alive and not exiting
353 // and not VM internal thread.
354 JavaThread* jt = java_lang_Thread::thread(th());
355 if (jt != NULL && !_result->t_list()->includes(jt)) {
356 // _threads[i] doesn't refer to a valid JavaThread; this check
357 // is primarily for JVM_DumpThreads() which doesn't have a good
358 // way to validate the _threads array.
359 jt = NULL;
360 }
361 if (jt == NULL || /* thread not alive */
362 jt->is_exiting() ||
363 jt->is_hidden_from_external_view()) {
364 // add a NULL snapshot if skipped
365 _result->add_thread_snapshot();
366 continue;
367 }
368 ThreadConcurrentLocks* tcl = NULL;
369 if (_with_locked_synchronizers) {
370 tcl = concurrent_locks.thread_concurrent_locks(jt);
371 }
372 snapshot_thread(jt, tcl);
373 }
374 }
375 }
376
377 void VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {
378 ThreadSnapshot* snapshot = _result->add_thread_snapshot(java_thread);
379 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);
380 snapshot->set_concurrent_locks(tcl);
381 }
382
383 volatile bool VM_Exit::_vm_exited = false;
384 Thread * volatile VM_Exit::_shutdown_thread = NULL;
385
386 int VM_Exit::set_vm_exited() {
387
388 Thread * thr_cur = Thread::current();
389
390 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
391
392 int num_active = 0;
393
394 _shutdown_thread = thr_cur;
395 _vm_exited = true; // global flag
396 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thr = jtiwh.next(); ) {
397 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
398 ++num_active;
399 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag
400 }
401 }
402
403 return num_active;
404 }
405
406 int VM_Exit::wait_for_threads_in_native_to_block() {
407 // VM exits at safepoint. This function must be called at the final safepoint
408 // to wait for threads in _thread_in_native state to be quiescent.
409 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
410
411 Thread * thr_cur = Thread::current();
412 Monitor timer(Mutex::leaf, "VM_Exit timer", true,
413 Monitor::_safepoint_check_never);
414
415 // Compiler threads need longer wait because they can access VM data directly
416 // while in native. If they are active and some structures being used are
417 // deleted by the shutdown sequence, they will crash. On the other hand, user
418 // threads must go through native=>Java/VM transitions first to access VM
419 // data, and they will be stopped during state transition. In theory, we
420 // don't have to wait for user threads to be quiescent, but it's always
421 // better to terminate VM when current thread is the only active thread, so
422 // wait for user threads too. Numbers are in 10 milliseconds.
423 int max_wait_user_thread = 30; // at least 300 milliseconds
424 int max_wait_compiler_thread = 1000; // at least 10 seconds
425
426 int max_wait = max_wait_compiler_thread;
427
428 int attempts = 0;
429 JavaThreadIteratorWithHandle jtiwh;
430 while (true) {
431 int num_active = 0;
432 int num_active_compiler_thread = 0;
433
434 jtiwh.rewind();
435 for (; JavaThread *thr = jtiwh.next(); ) {
436 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
437 num_active++;
438 if (thr->is_Compiler_thread()) {
439 #if INCLUDE_JVMCI
440 CompilerThread* ct = (CompilerThread*) thr;
441 if (ct->compiler() == NULL || !ct->compiler()->is_jvmci()) {
442 num_active_compiler_thread++;
443 } else {
444 // A JVMCI compiler thread never accesses VM data structures
445 // while in _thread_in_native state so there's no need to wait
446 // for it and potentially add a 300 millisecond delay to VM
447 // shutdown.
448 num_active--;
449 }
450 #else
451 num_active_compiler_thread++;
452 #endif
453 }
454 }
455 }
456
457 if (num_active == 0) {
458 return 0;
459 } else if (attempts > max_wait) {
460 return num_active;
461 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) {
462 return num_active;
463 }
464
465 attempts++;
466
467 MonitorLocker ml(&timer, Mutex::_no_safepoint_check_flag);
468 ml.wait(10);
469 }
470 }
471
472 bool VM_Exit::doit_prologue() {
473 if (AsyncDeflateIdleMonitors && log_is_enabled(Info, monitorinflation)) {
474 // AsyncDeflateIdleMonitors does a special deflation at the VM_Exit
475 // safepoint in order to reduce the in-use monitor population that
476 // is reported by ObjectSynchronizer::log_in_use_monitor_details()
477 // at VM exit.
478 ObjectSynchronizer::set_is_special_deflation_requested(true);
479 }
480 return true;
481 }
482
483 void VM_Exit::doit() {
484
485 if (VerifyBeforeExit) {
486 HandleMark hm(VMThread::vm_thread());
487 // Among other things, this ensures that Eden top is correct.
488 Universe::heap()->prepare_for_verify();
489 // Silent verification so as not to pollute normal output,
490 // unless we really asked for it.
491 Universe::verify();
492 }
493
494 CompileBroker::set_should_block();
495
496 // Wait for a short period for threads in native to block. Any thread
497 // still executing native code after the wait will be stopped at
498 // native==>Java/VM barriers.
499 // Among 16276 JCK tests, 94% of them come here without any threads still
500 // running in native; the other 6% are quiescent within 250ms (Ultra 80).
501 wait_for_threads_in_native_to_block();
502
503 set_vm_exited();
504
505 // We'd like to call IdealGraphPrinter::clean_up() to finalize the
506 // XML logging, but we can't safely do that here. The logic to make
507 // XML termination logging safe is tied to the termination of the
508 // VMThread, and it doesn't terminate on this exit path. See 8222534.
509
510 // cleanup globals resources before exiting. exit_globals() currently
511 // cleans up outputStream resources and PerfMemory resources.
512 exit_globals();
513
514 LogConfiguration::finalize();
515
516 // Check for exit hook
517 exit_hook_t exit_hook = Arguments::exit_hook();
518 if (exit_hook != NULL) {
519 // exit hook should exit.
520 exit_hook(_exit_code);
521 // ... but if it didn't, we must do it here
522 vm_direct_exit(_exit_code);
523 } else {
524 vm_direct_exit(_exit_code);
525 }
526 }
527
528
529 void VM_Exit::wait_if_vm_exited() {
530 if (_vm_exited &&
531 Thread::current_or_null() != _shutdown_thread) {
532 // _vm_exited is set at safepoint, and the Threads_lock is never released
533 // we will block here until the process dies
534 Threads_lock->lock();
535 ShouldNotReachHere();
536 }
537 }
538
539 void VM_PrintCompileQueue::doit() {
540 CompileBroker::print_compile_queues(_out);
541 }
542
543 #if INCLUDE_SERVICES
544 void VM_PrintClassHierarchy::doit() {
545 KlassHierarchy::print_class_hierarchy(_out, _print_interfaces, _print_subclasses, _classname);
546 }
547 #endif