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