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