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