1 /*
2 * Copyright (c) 1997, 2020, 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/metaspace/msReport.hpp"
37 #include "memory/resourceArea.hpp"
38 #include "memory/universe.hpp"
39 #include "oops/symbol.hpp"
40 #include "runtime/arguments.hpp"
41 #include "runtime/deoptimization.hpp"
42 #include "runtime/frame.inline.hpp"
43 #include "runtime/interfaceSupport.inline.hpp"
44 #include "runtime/sweeper.hpp"
45 #include "runtime/synchronizer.hpp"
46 #include "runtime/thread.inline.hpp"
47 #include "runtime/threadSMR.inline.hpp"
48 #include "runtime/vmOperations.hpp"
49 #include "services/threadService.hpp"
50
51 #define VM_OP_NAME_INITIALIZE(name) #name,
52
53 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \
54 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) };
55
56 void VM_Operation::set_calling_thread(Thread* thread) {
57 _calling_thread = thread;
58 }
59
60 void VM_Operation::evaluate() {
61 ResourceMark rm;
62 LogTarget(Debug, vmoperation) lt;
63 if (lt.is_enabled()) {
64 LogStream ls(lt);
65 ls.print("begin ");
66 print_on_error(&ls);
67 ls.cr();
68 }
69 doit();
70 if (lt.is_enabled()) {
71 LogStream ls(lt);
72 ls.print("end ");
73 print_on_error(&ls);
74 ls.cr();
75 }
76 }
77
78 // Called by fatal error handler.
79 void VM_Operation::print_on_error(outputStream* st) const {
80 st->print("VM_Operation (" PTR_FORMAT "): ", p2i(this));
81 st->print("%s", name());
82
83 st->print(", mode: %s", evaluate_at_safepoint() ? "safepoint" : "no safepoint");
84
85 if (calling_thread()) {
86 st->print(", requested by thread " PTR_FORMAT, p2i(calling_thread()));
87 }
88 }
89
90 void VM_ClearICs::doit() {
91 if (_preserve_static_stubs) {
92 CodeCache::cleanup_inline_caches();
93 } else {
94 CodeCache::clear_inline_caches();
95 }
96 }
97
98 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id, int reason) {
99 _thread = thread;
100 _id = id;
101 _reason = reason;
102 }
103
104
105 void VM_DeoptimizeFrame::doit() {
106 assert(_reason > Deoptimization::Reason_none && _reason < Deoptimization::Reason_LIMIT, "invalid deopt reason");
107 Deoptimization::deoptimize_frame_internal(_thread, _id, (Deoptimization::DeoptReason)_reason);
108 }
109
110
111 #ifndef PRODUCT
112
113 void VM_DeoptimizeAll::doit() {
114 DeoptimizationMarker dm;
115 JavaThreadIteratorWithHandle jtiwh;
116 // deoptimize all java threads in the system
117 if (DeoptimizeALot) {
118 for (; JavaThread *thread = jtiwh.next(); ) {
119 if (thread->has_last_Java_frame()) {
120 thread->deoptimize();
121 }
122 }
123 } else if (DeoptimizeRandom) {
124
125 // Deoptimize some selected threads and frames
126 int tnum = os::random() & 0x3;
127 int fnum = os::random() & 0x3;
128 int tcount = 0;
129 for (; JavaThread *thread = jtiwh.next(); ) {
130 if (thread->has_last_Java_frame()) {
131 if (tcount++ == tnum) {
132 tcount = 0;
133 int fcount = 0;
134 // Deoptimize some selected frames.
135 for(StackFrameStream fst(thread, false); !fst.is_done(); fst.next()) {
136 if (fst.current()->can_be_deoptimized()) {
137 if (fcount++ == fnum) {
138 fcount = 0;
139 Deoptimization::deoptimize(thread, *fst.current());
140 }
141 }
142 }
143 }
144 }
145 }
146 }
147 }
148
149
150 void VM_ZombieAll::doit() {
151 JavaThread *thread = (JavaThread *)calling_thread();
152 assert(thread->is_Java_thread(), "must be a Java thread");
153 thread->make_zombies();
154 }
155
156 #endif // !PRODUCT
157
158 void VM_Verify::doit() {
159 Universe::heap()->prepare_for_verify();
160 Universe::verify();
161 }
162
163 bool VM_PrintThreads::doit_prologue() {
164 // Get Heap_lock if concurrent locks will be dumped
165 if (_print_concurrent_locks) {
166 Heap_lock->lock();
167 }
168 return true;
169 }
170
171 void VM_PrintThreads::doit() {
172 Threads::print_on(_out, true, false, _print_concurrent_locks, _print_extended_info);
173 }
174
175 void VM_PrintThreads::doit_epilogue() {
176 if (_print_concurrent_locks) {
177 // Release Heap_lock
178 Heap_lock->unlock();
179 }
180 }
181
182 void VM_PrintJNI::doit() {
183 JNIHandles::print_on(_out);
184 }
185
186 void VM_PrintMetadata::doit() {
187 metaspace::MetaspaceReporter::print_report(_out, _scale, _flags);
188 }
189
190 VM_FindDeadlocks::~VM_FindDeadlocks() {
191 if (_deadlocks != NULL) {
192 DeadlockCycle* cycle = _deadlocks;
193 while (cycle != NULL) {
194 DeadlockCycle* d = cycle;
195 cycle = cycle->next();
196 delete d;
197 }
198 }
199 }
200
201 void VM_FindDeadlocks::doit() {
202 // Update the hazard ptr in the originating thread to the current
203 // list of threads. This VM operation needs the current list of
204 // threads for proper deadlock detection and those are the
205 // JavaThreads we need to be protected when we return info to the
206 // originating thread.
207 _setter.set();
208
209 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_setter.list(), _concurrent_locks);
210 if (_out != NULL) {
211 int num_deadlocks = 0;
212 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) {
213 num_deadlocks++;
214 cycle->print_on_with(_setter.list(), _out);
215 }
216
217 if (num_deadlocks == 1) {
218 _out->print_cr("\nFound 1 deadlock.\n");
219 _out->flush();
220 } else if (num_deadlocks > 1) {
221 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks);
222 _out->flush();
223 }
224 }
225 }
226
227 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
228 int max_depth,
229 bool with_locked_monitors,
230 bool with_locked_synchronizers) {
231 _result = result;
232 _num_threads = 0; // 0 indicates all threads
233 _threads = NULL;
234 _result = result;
235 _max_depth = max_depth;
236 _with_locked_monitors = with_locked_monitors;
237 _with_locked_synchronizers = with_locked_synchronizers;
238 }
239
240 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
241 GrowableArray<instanceHandle>* threads,
242 int num_threads,
243 int max_depth,
244 bool with_locked_monitors,
245 bool with_locked_synchronizers) {
246 _result = result;
247 _num_threads = num_threads;
248 _threads = threads;
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 bool VM_ThreadDump::doit_prologue() {
256 if (_with_locked_synchronizers) {
257 // Acquire Heap_lock to dump concurrent locks
258 Heap_lock->lock();
259 }
260
261 return true;
262 }
263
264 void VM_ThreadDump::doit_epilogue() {
265 if (_with_locked_synchronizers) {
266 // Release Heap_lock
267 Heap_lock->unlock();
268 }
269 }
270
271 void VM_ThreadDump::doit() {
272 ResourceMark rm;
273
274 // Set the hazard ptr in the originating thread to protect the
275 // current list of threads. This VM operation needs the current list
276 // of threads for a proper dump and those are the JavaThreads we need
277 // to be protected when we return info to the originating thread.
278 _result->set_t_list();
279
280 ConcurrentLocksDump concurrent_locks(true);
281 if (_with_locked_synchronizers) {
282 concurrent_locks.dump_at_safepoint();
283 }
284
285 if (_num_threads == 0) {
286 // Snapshot all live threads
287
288 for (uint i = 0; i < _result->t_list()->length(); i++) {
289 JavaThread* jt = _result->t_list()->thread_at(i);
290 if (jt->is_exiting() ||
291 jt->is_hidden_from_external_view()) {
292 // skip terminating threads and hidden threads
293 continue;
294 }
295 ThreadConcurrentLocks* tcl = NULL;
296 if (_with_locked_synchronizers) {
297 tcl = concurrent_locks.thread_concurrent_locks(jt);
298 }
299 snapshot_thread(jt, tcl);
300 }
301 } else {
302 // Snapshot threads in the given _threads array
303 // A dummy snapshot is created if a thread doesn't exist
304
305 for (int i = 0; i < _num_threads; i++) {
306 instanceHandle th = _threads->at(i);
307 if (th() == NULL) {
308 // skip if the thread doesn't exist
309 // Add a dummy snapshot
310 _result->add_thread_snapshot();
311 continue;
312 }
313
314 // Dump thread stack only if the thread is alive and not exiting
315 // and not VM internal thread.
316 JavaThread* jt = java_lang_Thread::thread(th());
317 if (jt != NULL && !_result->t_list()->includes(jt)) {
318 // _threads[i] doesn't refer to a valid JavaThread; this check
319 // is primarily for JVM_DumpThreads() which doesn't have a good
320 // way to validate the _threads array.
321 jt = NULL;
322 }
323 if (jt == NULL || /* thread not alive */
324 jt->is_exiting() ||
325 jt->is_hidden_from_external_view()) {
326 // add a NULL snapshot if skipped
327 _result->add_thread_snapshot();
328 continue;
329 }
330 ThreadConcurrentLocks* tcl = NULL;
331 if (_with_locked_synchronizers) {
332 tcl = concurrent_locks.thread_concurrent_locks(jt);
333 }
334 snapshot_thread(jt, tcl);
335 }
336 }
337 }
338
339 void VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {
340 ThreadSnapshot* snapshot = _result->add_thread_snapshot(java_thread);
341 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);
342 snapshot->set_concurrent_locks(tcl);
343 }
344
345 volatile bool VM_Exit::_vm_exited = false;
346 Thread * volatile VM_Exit::_shutdown_thread = NULL;
347
348 int VM_Exit::set_vm_exited() {
349
350 Thread * thr_cur = Thread::current();
351
352 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
353
354 int num_active = 0;
355
356 _shutdown_thread = thr_cur;
357 _vm_exited = true; // global flag
358 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thr = jtiwh.next(); ) {
359 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
360 ++num_active;
361 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag
362 }
363 }
364
365 return num_active;
366 }
367
368 int VM_Exit::wait_for_threads_in_native_to_block() {
369 // VM exits at safepoint. This function must be called at the final safepoint
370 // to wait for threads in _thread_in_native state to be quiescent.
371 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
372
373 Thread * thr_cur = Thread::current();
374 Monitor timer(Mutex::leaf, "VM_Exit timer", true,
375 Monitor::_safepoint_check_never);
376
377 // Compiler threads need longer wait because they can access VM data directly
378 // while in native. If they are active and some structures being used are
379 // deleted by the shutdown sequence, they will crash. On the other hand, user
380 // threads must go through native=>Java/VM transitions first to access VM
381 // data, and they will be stopped during state transition. In theory, we
382 // don't have to wait for user threads to be quiescent, but it's always
383 // better to terminate VM when current thread is the only active thread, so
384 // wait for user threads too. Numbers are in 10 milliseconds.
385 int max_wait_user_thread = 30; // at least 300 milliseconds
386 int max_wait_compiler_thread = 1000; // at least 10 seconds
387
388 int max_wait = max_wait_compiler_thread;
389
390 int attempts = 0;
391 JavaThreadIteratorWithHandle jtiwh;
392 while (true) {
393 int num_active = 0;
394 int num_active_compiler_thread = 0;
395
396 jtiwh.rewind();
397 for (; JavaThread *thr = jtiwh.next(); ) {
398 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
399 num_active++;
400 if (thr->is_Compiler_thread()) {
401 #if INCLUDE_JVMCI
402 CompilerThread* ct = (CompilerThread*) thr;
403 if (ct->compiler() == NULL || !ct->compiler()->is_jvmci()) {
404 num_active_compiler_thread++;
405 } else {
406 // A JVMCI compiler thread never accesses VM data structures
407 // while in _thread_in_native state so there's no need to wait
408 // for it and potentially add a 300 millisecond delay to VM
409 // shutdown.
410 num_active--;
411 }
412 #else
413 num_active_compiler_thread++;
414 #endif
415 }
416 }
417 }
418
419 if (num_active == 0) {
420 return 0;
421 } else if (attempts > max_wait) {
422 return num_active;
423 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) {
424 return num_active;
425 }
426
427 attempts++;
428
429 MonitorLocker ml(&timer, Mutex::_no_safepoint_check_flag);
430 ml.wait(10);
431 }
432 }
433
434 bool VM_Exit::doit_prologue() {
435 if (log_is_enabled(Info, monitorinflation)) {
436 // Do a deflation in order to reduce the in-use monitor population
437 // that is reported by ObjectSynchronizer::log_in_use_monitor_details()
438 // at VM exit.
439 ObjectSynchronizer::request_deflate_idle_monitors();
440 }
441 return true;
442 }
443
444 void VM_Exit::doit() {
445
446 if (VerifyBeforeExit) {
447 HandleMark hm(VMThread::vm_thread());
448 // Among other things, this ensures that Eden top is correct.
449 Universe::heap()->prepare_for_verify();
450 // Silent verification so as not to pollute normal output,
451 // unless we really asked for it.
452 Universe::verify();
453 }
454
455 CompileBroker::set_should_block();
456
457 // Wait for a short period for threads in native to block. Any thread
458 // still executing native code after the wait will be stopped at
459 // native==>Java/VM barriers.
460 // Among 16276 JCK tests, 94% of them come here without any threads still
461 // running in native; the other 6% are quiescent within 250ms (Ultra 80).
462 wait_for_threads_in_native_to_block();
463
464 set_vm_exited();
465
466 // We'd like to call IdealGraphPrinter::clean_up() to finalize the
467 // XML logging, but we can't safely do that here. The logic to make
468 // XML termination logging safe is tied to the termination of the
469 // VMThread, and it doesn't terminate on this exit path. See 8222534.
470
471 // cleanup globals resources before exiting. exit_globals() currently
472 // cleans up outputStream resources and PerfMemory resources.
473 exit_globals();
474
475 LogConfiguration::finalize();
476
477 // Check for exit hook
478 exit_hook_t exit_hook = Arguments::exit_hook();
479 if (exit_hook != NULL) {
480 // exit hook should exit.
481 exit_hook(_exit_code);
482 // ... but if it didn't, we must do it here
483 vm_direct_exit(_exit_code);
484 } else {
485 vm_direct_exit(_exit_code);
486 }
487 }
488
489
490 void VM_Exit::wait_if_vm_exited() {
491 if (_vm_exited &&
492 Thread::current_or_null() != _shutdown_thread) {
493 // _vm_exited is set at safepoint, and the Threads_lock is never released
494 // we will block here until the process dies
495 Threads_lock->lock();
496 ShouldNotReachHere();
497 }
498 }
499
500 void VM_PrintCompileQueue::doit() {
501 CompileBroker::print_compile_queues(_out);
502 }
503
504 #if INCLUDE_SERVICES
505 void VM_PrintClassHierarchy::doit() {
506 KlassHierarchy::print_class_hierarchy(_out, _print_interfaces, _print_subclasses, _classname);
507 }
508 #endif