1 /*
2 * Copyright (c) 1997, 2015, 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 "code/codeCacheExtensions.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "compiler/compilerOracle.hpp"
32 #include "gc/shared/isGCActiveMark.hpp"
33 #include "memory/heapInspection.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "oops/symbol.hpp"
36 #include "runtime/arguments.hpp"
37 #include "runtime/deoptimization.hpp"
38 #include "runtime/interfaceSupport.hpp"
39 #include "runtime/sweeper.hpp"
40 #include "runtime/thread.inline.hpp"
41 #include "runtime/vm_operations.hpp"
42 #include "services/threadService.hpp"
43 #include "trace/tracing.hpp"
44
45 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
46
47 #define VM_OP_NAME_INITIALIZE(name) #name,
48
49 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \
50 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) };
51
52 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) {
53 _calling_thread = thread;
54 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
55 _priority = priority;
56 }
57
58
59 void VM_Operation::evaluate() {
60 ResourceMark rm;
61 if (TraceVMOperation) {
62 tty->print("[");
63 NOT_PRODUCT(print();)
64 }
65 doit();
66 if (TraceVMOperation) {
67 tty->print_cr("]");
68 }
69 }
70
71 const char* VM_Operation::mode_to_string(Mode mode) {
72 switch(mode) {
73 case _safepoint : return "safepoint";
74 case _no_safepoint : return "no safepoint";
75 case _concurrent : return "concurrent";
76 case _async_safepoint: return "async safepoint";
77 default : return "unknown";
78 }
79 }
80 // Called by fatal error handler.
81 void VM_Operation::print_on_error(outputStream* st) const {
82 st->print("VM_Operation (" PTR_FORMAT "): ", this);
83 st->print("%s", name());
84
85 const char* mode = mode_to_string(evaluation_mode());
86 st->print(", mode: %s", mode);
87
88 if (calling_thread()) {
89 st->print(", requested by thread " PTR_FORMAT, calling_thread());
90 }
91 }
92
93 void VM_ThreadStop::doit() {
94 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
95 JavaThread* target = java_lang_Thread::thread(target_thread());
96 // Note that this now allows multiple ThreadDeath exceptions to be
97 // thrown at a thread.
98 if (target != NULL) {
99 // the thread has run and is not already in the process of exiting
100 target->send_thread_stop(throwable());
101 }
102 }
103
104 void VM_Deoptimize::doit() {
105 // We do not want any GCs to happen while we are in the middle of this VM operation
106 ResourceMark rm;
107 DeoptimizationMarker dm;
108
109 // Deoptimize all activations depending on marked nmethods
110 Deoptimization::deoptimize_dependents();
111
112 // Make the dependent methods not entrant
113 CodeCache::make_marked_nmethods_not_entrant();
114 }
115
116 void VM_MarkActiveNMethods::doit() {
117 NMethodSweeper::mark_active_nmethods();
118 }
119
120 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id, int reason) {
121 _thread = thread;
122 _id = id;
123 _reason = reason;
124 }
125
126
127 void VM_DeoptimizeFrame::doit() {
128 assert(_reason > Deoptimization::Reason_none && _reason < Deoptimization::Reason_LIMIT, "invalid deopt reason");
129 Deoptimization::deoptimize_frame_internal(_thread, _id, (Deoptimization::DeoptReason)_reason);
130 }
131
132
133 #ifndef PRODUCT
134
135 void VM_DeoptimizeAll::doit() {
136 DeoptimizationMarker dm;
137 // deoptimize all java threads in the system
138 if (DeoptimizeALot) {
139 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
140 if (thread->has_last_Java_frame()) {
141 thread->deoptimize();
142 }
143 }
144 } else if (DeoptimizeRandom) {
145
146 // Deoptimize some selected threads and frames
147 int tnum = os::random() & 0x3;
148 int fnum = os::random() & 0x3;
149 int tcount = 0;
150 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
151 if (thread->has_last_Java_frame()) {
152 if (tcount++ == tnum) {
153 tcount = 0;
154 int fcount = 0;
155 // Deoptimize some selected frames.
156 // Biased llocking wants a updated register map
157 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) {
158 if (fst.current()->can_be_deoptimized()) {
159 if (fcount++ == fnum) {
160 fcount = 0;
161 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map());
162 }
163 }
164 }
165 }
166 }
167 }
168 }
169 }
170
171
172 void VM_ZombieAll::doit() {
173 JavaThread *thread = (JavaThread *)calling_thread();
174 assert(thread->is_Java_thread(), "must be a Java thread");
175 thread->make_zombies();
176 }
177
178 #endif // !PRODUCT
179
180 void VM_UnlinkSymbols::doit() {
181 JavaThread *thread = (JavaThread *)calling_thread();
182 assert(thread->is_Java_thread(), "must be a Java thread");
183 SymbolTable::unlink();
184 }
185
186 void VM_Verify::doit() {
187 Universe::heap()->prepare_for_verify();
188 Universe::verify(_silent);
189 }
190
191 bool VM_PrintThreads::doit_prologue() {
192 assert(Thread::current()->is_Java_thread(), "just checking");
193
194 // Make sure AbstractOwnableSynchronizer is loaded
195 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
196
197 // Get Heap_lock if concurrent locks will be dumped
198 if (_print_concurrent_locks) {
199 Heap_lock->lock();
200 }
201 return true;
202 }
203
204 void VM_PrintThreads::doit() {
205 Threads::print_on(_out, true, false, _print_concurrent_locks);
206 }
207
208 void VM_PrintThreads::doit_epilogue() {
209 if (_print_concurrent_locks) {
210 // Release Heap_lock
211 Heap_lock->unlock();
212 }
213 }
214
215 void VM_PrintJNI::doit() {
216 JNIHandles::print_on(_out);
217 }
218
219 VM_FindDeadlocks::~VM_FindDeadlocks() {
220 if (_deadlocks != NULL) {
221 DeadlockCycle* cycle = _deadlocks;
222 while (cycle != NULL) {
223 DeadlockCycle* d = cycle;
224 cycle = cycle->next();
225 delete d;
226 }
227 }
228 }
229
230 bool VM_FindDeadlocks::doit_prologue() {
231 assert(Thread::current()->is_Java_thread(), "just checking");
232
233 // Load AbstractOwnableSynchronizer class
234 if (_concurrent_locks) {
235 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
236 }
237
238 return true;
239 }
240
241 void VM_FindDeadlocks::doit() {
242 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks);
243 if (_out != NULL) {
244 int num_deadlocks = 0;
245 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) {
246 num_deadlocks++;
247 cycle->print_on(_out);
248 }
249
250 if (num_deadlocks == 1) {
251 _out->print_cr("\nFound 1 deadlock.\n");
252 _out->flush();
253 } else if (num_deadlocks > 1) {
254 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks);
255 _out->flush();
256 }
257 }
258 }
259
260 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
261 int max_depth,
262 bool with_locked_monitors,
263 bool with_locked_synchronizers) {
264 _result = result;
265 _num_threads = 0; // 0 indicates all threads
266 _threads = NULL;
267 _result = result;
268 _max_depth = max_depth;
269 _with_locked_monitors = with_locked_monitors;
270 _with_locked_synchronizers = with_locked_synchronizers;
271 }
272
273 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
274 GrowableArray<instanceHandle>* threads,
275 int num_threads,
276 int max_depth,
277 bool with_locked_monitors,
278 bool with_locked_synchronizers) {
279 _result = result;
280 _num_threads = num_threads;
281 _threads = threads;
282 _result = result;
283 _max_depth = max_depth;
284 _with_locked_monitors = with_locked_monitors;
285 _with_locked_synchronizers = with_locked_synchronizers;
286 }
287
288 bool VM_ThreadDump::doit_prologue() {
289 assert(Thread::current()->is_Java_thread(), "just checking");
290
291 // Load AbstractOwnableSynchronizer class before taking thread snapshots
292 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
293
294 if (_with_locked_synchronizers) {
295 // Acquire Heap_lock to dump concurrent locks
296 Heap_lock->lock();
297 }
298
299 return true;
300 }
301
302 void VM_ThreadDump::doit_epilogue() {
303 if (_with_locked_synchronizers) {
304 // Release Heap_lock
305 Heap_lock->unlock();
306 }
307 }
308
309 void VM_ThreadDump::doit() {
310 ResourceMark rm;
311
312 ConcurrentLocksDump concurrent_locks(true);
313 if (_with_locked_synchronizers) {
314 concurrent_locks.dump_at_safepoint();
315 }
316
317 if (_num_threads == 0) {
318 // Snapshot all live threads
319 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
320 if (jt->is_exiting() ||
321 jt->is_hidden_from_external_view()) {
322 // skip terminating threads and hidden threads
323 continue;
324 }
325 ThreadConcurrentLocks* tcl = NULL;
326 if (_with_locked_synchronizers) {
327 tcl = concurrent_locks.thread_concurrent_locks(jt);
328 }
329 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
330 _result->add_thread_snapshot(ts);
331 }
332 } else {
333 // Snapshot threads in the given _threads array
334 // A dummy snapshot is created if a thread doesn't exist
335 for (int i = 0; i < _num_threads; i++) {
336 instanceHandle th = _threads->at(i);
337 if (th() == NULL) {
338 // skip if the thread doesn't exist
339 // Add a dummy snapshot
340 _result->add_thread_snapshot(new ThreadSnapshot());
341 continue;
342 }
343
344 // Dump thread stack only if the thread is alive and not exiting
345 // and not VM internal thread.
346 JavaThread* jt = java_lang_Thread::thread(th());
347 if (jt == NULL || /* thread not alive */
348 jt->is_exiting() ||
349 jt->is_hidden_from_external_view()) {
350 // add a NULL snapshot if skipped
351 _result->add_thread_snapshot(new ThreadSnapshot());
352 continue;
353 }
354 ThreadConcurrentLocks* tcl = NULL;
355 if (_with_locked_synchronizers) {
356 tcl = concurrent_locks.thread_concurrent_locks(jt);
357 }
358 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
359 _result->add_thread_snapshot(ts);
360 }
361 }
362 }
363
364 ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {
365 ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread);
366 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);
367 snapshot->set_concurrent_locks(tcl);
368 return snapshot;
369 }
370
371 volatile bool VM_Exit::_vm_exited = false;
372 Thread * VM_Exit::_shutdown_thread = NULL;
373
374 int VM_Exit::set_vm_exited() {
375 CodeCacheExtensions::complete_step(CodeCacheExtensionsSteps::LastStep);
376
377 Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
378
379 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
380
381 int num_active = 0;
382
383 _shutdown_thread = thr_cur;
384 _vm_exited = true; // global flag
385 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next())
386 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
387 ++num_active;
388 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag
389 }
390
391 return num_active;
392 }
393
394 int VM_Exit::wait_for_threads_in_native_to_block() {
395 // VM exits at safepoint. This function must be called at the final safepoint
396 // to wait for threads in _thread_in_native state to be quiescent.
397 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
398
399 Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
400 Monitor timer(Mutex::leaf, "VM_Exit timer", true,
401 Monitor::_safepoint_check_never);
402
403 // Compiler threads need longer wait because they can access VM data directly
404 // while in native. If they are active and some structures being used are
405 // deleted by the shutdown sequence, they will crash. On the other hand, user
406 // threads must go through native=>Java/VM transitions first to access VM
407 // data, and they will be stopped during state transition. In theory, we
408 // don't have to wait for user threads to be quiescent, but it's always
409 // better to terminate VM when current thread is the only active thread, so
410 // wait for user threads too. Numbers are in 10 milliseconds.
411 int max_wait_user_thread = 30; // at least 300 milliseconds
412 int max_wait_compiler_thread = 1000; // at least 10 seconds
413
414 int max_wait = max_wait_compiler_thread;
415
416 int attempts = 0;
417 while (true) {
418 int num_active = 0;
419 int num_active_compiler_thread = 0;
420
421 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) {
422 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
423 num_active++;
424 if (thr->is_Compiler_thread()) {
425 num_active_compiler_thread++;
426 }
427 }
428 }
429
430 if (num_active == 0) {
431 return 0;
432 } else if (attempts > max_wait) {
433 return num_active;
434 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) {
435 return num_active;
436 }
437
438 attempts++;
439
440 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag);
441 timer.wait(Mutex::_no_safepoint_check_flag, 10);
442 }
443 }
444
445 void VM_Exit::doit() {
446 CompileBroker::set_should_block();
447
448 // Wait for a short period for threads in native to block. Any thread
449 // still executing native code after the wait will be stopped at
450 // native==>Java/VM barriers.
451 // Among 16276 JCK tests, 94% of them come here without any threads still
452 // running in native; the other 6% are quiescent within 250ms (Ultra 80).
453 wait_for_threads_in_native_to_block();
454
455 set_vm_exited();
456
457 // cleanup globals resources before exiting. exit_globals() currently
458 // cleans up outputStream resources and PerfMemory resources.
459 exit_globals();
460
461 // Check for exit hook
462 exit_hook_t exit_hook = Arguments::exit_hook();
463 if (exit_hook != NULL) {
464 // exit hook should exit.
465 exit_hook(_exit_code);
466 // ... but if it didn't, we must do it here
467 vm_direct_exit(_exit_code);
468 } else {
469 vm_direct_exit(_exit_code);
470 }
471 }
472
473
474 void VM_Exit::wait_if_vm_exited() {
475 if (_vm_exited &&
476 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) {
477 // _vm_exited is set at safepoint, and the Threads_lock is never released
478 // we will block here until the process dies
479 Threads_lock->lock_without_safepoint_check();
480 ShouldNotReachHere();
481 }
482 }
483
484 void VM_PrintCompileQueue::doit() {
485 CompileBroker::print_compile_queues(_out);
486 }
487
488 void VM_PrintCodeList::doit() {
489 CodeCache::print_codelist(_out);
490 }
491
492 void VM_PrintCodeCache::doit() {
493 CodeCache::print_layout(_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