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