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