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