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