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