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 "gc/shared/isGCActiveMark.hpp"
32 #include "logging/log.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 #define VM_OP_NAME_INITIALIZE(name) #name,
46
47 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \
48 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) };
49
50 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) {
51 _calling_thread = thread;
52 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
53 _priority = priority;
54 }
55
56
57 void VM_Operation::evaluate() {
58 ResourceMark rm;
59 outputStream* debugstream;
60 bool enabled = log_is_enabled(Debug, vmoperation);
61 if (enabled) {
62 debugstream = LogHandle(vmoperation)::debug_stream();
63 debugstream->print("begin ");
64 print_on_error(debugstream);
65 debugstream->cr();
66 }
67 doit();
68 if (enabled) {
69 debugstream->print("end ");
70 print_on_error(debugstream);
71 debugstream->cr();
72 }
73 }
74
75 const char* VM_Operation::mode_to_string(Mode mode) {
76 switch(mode) {
77 case _safepoint : return "safepoint";
78 case _no_safepoint : return "no safepoint";
79 case _concurrent : return "concurrent";
80 case _async_safepoint: return "async safepoint";
81 default : return "unknown";
82 }
83 }
84 // Called by fatal error handler.
85 void VM_Operation::print_on_error(outputStream* st) const {
86 st->print("VM_Operation (" PTR_FORMAT "): ", p2i(this));
87 st->print("%s", name());
88
89 const char* mode = mode_to_string(evaluation_mode());
90 st->print(", mode: %s", mode);
91
92 if (calling_thread()) {
93 st->print(", requested by thread " PTR_FORMAT, p2i(calling_thread()));
94 }
95 }
96
97 void VM_ThreadStop::doit() {
98 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
99 JavaThread* target = java_lang_Thread::thread(target_thread());
100 // Note that this now allows multiple ThreadDeath exceptions to be
101 // thrown at a thread.
102 if (target != NULL) {
103 // the thread has run and is not already in the process of exiting
104 target->send_thread_stop(throwable());
105 }
106 }
107
108 void VM_Deoptimize::doit() {
109 // We do not want any GCs to happen while we are in the middle of this VM operation
110 ResourceMark rm;
111 DeoptimizationMarker dm;
112
113 // Deoptimize all activations depending on marked nmethods
114 Deoptimization::deoptimize_dependents();
115
116 // Make the dependent methods not entrant
117 CodeCache::make_marked_nmethods_not_entrant();
118 }
119
120 void VM_MarkActiveNMethods::doit() {
121 NMethodSweeper::mark_active_nmethods();
122 }
123
124 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id, int reason) {
125 _thread = thread;
126 _id = id;
127 _reason = reason;
128 }
129
130
131 void VM_DeoptimizeFrame::doit() {
132 assert(_reason > Deoptimization::Reason_none && _reason < Deoptimization::Reason_LIMIT, "invalid deopt reason");
133 Deoptimization::deoptimize_frame_internal(_thread, _id, (Deoptimization::DeoptReason)_reason);
134 }
135
136
137 #ifndef PRODUCT
138
139 void VM_DeoptimizeAll::doit() {
140 DeoptimizationMarker dm;
141 // deoptimize all java threads in the system
142 if (DeoptimizeALot) {
143 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
144 if (thread->has_last_Java_frame()) {
145 thread->deoptimize();
146 }
147 }
148 } else if (DeoptimizeRandom) {
149
150 // Deoptimize some selected threads and frames
151 int tnum = os::random() & 0x3;
152 int fnum = os::random() & 0x3;
153 int tcount = 0;
154 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
155 if (thread->has_last_Java_frame()) {
156 if (tcount++ == tnum) {
157 tcount = 0;
158 int fcount = 0;
159 // Deoptimize some selected frames.
160 // Biased llocking wants a updated register map
161 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) {
162 if (fst.current()->can_be_deoptimized()) {
163 if (fcount++ == fnum) {
164 fcount = 0;
165 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map());
166 }
167 }
168 }
169 }
170 }
171 }
172 }
173 }
174
175
176 void VM_ZombieAll::doit() {
177 JavaThread *thread = (JavaThread *)calling_thread();
178 assert(thread->is_Java_thread(), "must be a Java thread");
179 thread->make_zombies();
180 }
181
182 #endif // !PRODUCT
183
184 void VM_UnlinkSymbols::doit() {
185 JavaThread *thread = (JavaThread *)calling_thread();
186 assert(thread->is_Java_thread(), "must be a Java thread");
187 SymbolTable::unlink();
188 }
189
190 void VM_Verify::doit() {
191 Universe::heap()->prepare_for_verify();
192 Universe::verify(_silent);
193 }
194
195 bool VM_PrintThreads::doit_prologue() {
196 assert(Thread::current()->is_Java_thread(), "just checking");
197
198 // Make sure AbstractOwnableSynchronizer is loaded
199 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
200
201 // Get Heap_lock if concurrent locks will be dumped
202 if (_print_concurrent_locks) {
203 Heap_lock->lock();
204 }
205 return true;
206 }
207
208 void VM_PrintThreads::doit() {
209 Threads::print_on(_out, true, false, _print_concurrent_locks);
210 }
211
212 void VM_PrintThreads::doit_epilogue() {
213 if (_print_concurrent_locks) {
214 // Release Heap_lock
215 Heap_lock->unlock();
216 }
217 }
218
219 void VM_PrintJNI::doit() {
220 JNIHandles::print_on(_out);
221 }
222
223 VM_FindDeadlocks::~VM_FindDeadlocks() {
224 if (_deadlocks != NULL) {
225 DeadlockCycle* cycle = _deadlocks;
226 while (cycle != NULL) {
227 DeadlockCycle* d = cycle;
228 cycle = cycle->next();
229 delete d;
230 }
231 }
232 }
233
234 bool VM_FindDeadlocks::doit_prologue() {
235 assert(Thread::current()->is_Java_thread(), "just checking");
236
237 // Load AbstractOwnableSynchronizer class
238 if (_concurrent_locks) {
239 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
240 }
241
242 return true;
243 }
244
245 void VM_FindDeadlocks::doit() {
246 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks);
247 if (_out != NULL) {
248 int num_deadlocks = 0;
249 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) {
250 num_deadlocks++;
251 cycle->print_on(_out);
252 }
253
254 if (num_deadlocks == 1) {
255 _out->print_cr("\nFound 1 deadlock.\n");
256 _out->flush();
257 } else if (num_deadlocks > 1) {
258 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks);
259 _out->flush();
260 }
261 }
262 }
263
264 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
265 int max_depth,
266 bool with_locked_monitors,
267 bool with_locked_synchronizers) {
268 _result = result;
269 _num_threads = 0; // 0 indicates all threads
270 _threads = NULL;
271 _result = result;
272 _max_depth = max_depth;
273 _with_locked_monitors = with_locked_monitors;
274 _with_locked_synchronizers = with_locked_synchronizers;
275 }
276
277 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
278 GrowableArray<instanceHandle>* threads,
279 int num_threads,
280 int max_depth,
281 bool with_locked_monitors,
282 bool with_locked_synchronizers) {
283 _result = result;
284 _num_threads = num_threads;
285 _threads = threads;
286 _result = result;
287 _max_depth = max_depth;
288 _with_locked_monitors = with_locked_monitors;
289 _with_locked_synchronizers = with_locked_synchronizers;
290 }
291
292 bool VM_ThreadDump::doit_prologue() {
293 assert(Thread::current()->is_Java_thread(), "just checking");
294
295 // Load AbstractOwnableSynchronizer class before taking thread snapshots
296 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
297
298 if (_with_locked_synchronizers) {
299 // Acquire Heap_lock to dump concurrent locks
300 Heap_lock->lock();
301 }
302
303 return true;
304 }
305
306 void VM_ThreadDump::doit_epilogue() {
307 if (_with_locked_synchronizers) {
308 // Release Heap_lock
309 Heap_lock->unlock();
310 }
311 }
312
313 void VM_ThreadDump::doit() {
314 ResourceMark rm;
315
316 ConcurrentLocksDump concurrent_locks(true);
317 if (_with_locked_synchronizers) {
318 concurrent_locks.dump_at_safepoint();
319 }
320
321 if (_num_threads == 0) {
322 // Snapshot all live threads
323 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
324 if (jt->is_exiting() ||
325 jt->is_hidden_from_external_view()) {
326 // skip terminating threads and hidden threads
327 continue;
328 }
329 ThreadConcurrentLocks* tcl = NULL;
330 if (_with_locked_synchronizers) {
331 tcl = concurrent_locks.thread_concurrent_locks(jt);
332 }
333 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
334 _result->add_thread_snapshot(ts);
335 }
336 } else {
337 // Snapshot threads in the given _threads array
338 // A dummy snapshot is created if a thread doesn't exist
339 for (int i = 0; i < _num_threads; i++) {
340 instanceHandle th = _threads->at(i);
341 if (th() == NULL) {
342 // skip if the thread doesn't exist
343 // Add a dummy snapshot
344 _result->add_thread_snapshot(new ThreadSnapshot());
345 continue;
346 }
347
348 // Dump thread stack only if the thread is alive and not exiting
349 // and not VM internal thread.
350 JavaThread* jt = java_lang_Thread::thread(th());
351 if (jt == NULL || /* thread not alive */
352 jt->is_exiting() ||
353 jt->is_hidden_from_external_view()) {
354 // add a NULL snapshot if skipped
355 _result->add_thread_snapshot(new ThreadSnapshot());
356 continue;
357 }
358 ThreadConcurrentLocks* tcl = NULL;
359 if (_with_locked_synchronizers) {
360 tcl = concurrent_locks.thread_concurrent_locks(jt);
361 }
362 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
363 _result->add_thread_snapshot(ts);
364 }
365 }
366 }
367
368 ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {
369 ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread);
370 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);
371 snapshot->set_concurrent_locks(tcl);
372 return snapshot;
373 }
374
375 volatile bool VM_Exit::_vm_exited = false;
376 Thread * VM_Exit::_shutdown_thread = NULL;
377
378 int VM_Exit::set_vm_exited() {
379 CodeCacheExtensions::complete_step(CodeCacheExtensionsSteps::LastStep);
380
381 Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
382
383 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
384
385 int num_active = 0;
386
387 _shutdown_thread = thr_cur;
388 _vm_exited = true; // global flag
389 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next())
390 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
391 ++num_active;
392 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag
393 }
394
395 return num_active;
396 }
397
398 int VM_Exit::wait_for_threads_in_native_to_block() {
399 // VM exits at safepoint. This function must be called at the final safepoint
400 // to wait for threads in _thread_in_native state to be quiescent.
401 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
402
403 Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
404 Monitor timer(Mutex::leaf, "VM_Exit timer", true,
405 Monitor::_safepoint_check_never);
406
407 // Compiler threads need longer wait because they can access VM data directly
408 // while in native. If they are active and some structures being used are
409 // deleted by the shutdown sequence, they will crash. On the other hand, user
410 // threads must go through native=>Java/VM transitions first to access VM
411 // data, and they will be stopped during state transition. In theory, we
412 // don't have to wait for user threads to be quiescent, but it's always
413 // better to terminate VM when current thread is the only active thread, so
414 // wait for user threads too. Numbers are in 10 milliseconds.
415 int max_wait_user_thread = 30; // at least 300 milliseconds
416 int max_wait_compiler_thread = 1000; // at least 10 seconds
417
418 int max_wait = max_wait_compiler_thread;
419
420 int attempts = 0;
421 while (true) {
422 int num_active = 0;
423 int num_active_compiler_thread = 0;
424
425 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) {
426 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
427 num_active++;
428 if (thr->is_Compiler_thread()) {
429 num_active_compiler_thread++;
430 }
431 }
432 }
433
434 if (num_active == 0) {
435 return 0;
436 } else if (attempts > max_wait) {
437 return num_active;
438 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) {
439 return num_active;
440 }
441
442 attempts++;
443
444 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag);
445 timer.wait(Mutex::_no_safepoint_check_flag, 10);
446 }
447 }
448
449 void VM_Exit::doit() {
450 CompileBroker::set_should_block();
451
452 // Wait for a short period for threads in native to block. Any thread
453 // still executing native code after the wait will be stopped at
454 // native==>Java/VM barriers.
455 // Among 16276 JCK tests, 94% of them come here without any threads still
456 // running in native; the other 6% are quiescent within 250ms (Ultra 80).
457 wait_for_threads_in_native_to_block();
458
459 set_vm_exited();
460
461 // cleanup globals resources before exiting. exit_globals() currently
462 // cleans up outputStream resources and PerfMemory resources.
463 exit_globals();
464
465 // Check for exit hook
466 exit_hook_t exit_hook = Arguments::exit_hook();
467 if (exit_hook != NULL) {
468 // exit hook should exit.
469 exit_hook(_exit_code);
470 // ... but if it didn't, we must do it here
471 vm_direct_exit(_exit_code);
472 } else {
473 vm_direct_exit(_exit_code);
474 }
475 }
476
477
478 void VM_Exit::wait_if_vm_exited() {
479 if (_vm_exited &&
480 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) {
481 // _vm_exited is set at safepoint, and the Threads_lock is never released
482 // we will block here until the process dies
483 Threads_lock->lock_without_safepoint_check();
484 ShouldNotReachHere();
485 }
486 }
487
488 void VM_PrintCompileQueue::doit() {
489 CompileBroker::print_compile_queues(_out);
490 }
491
492 void VM_PrintCodeList::doit() {
493 CodeCache::print_codelist(_out);
494 }
495
496 void VM_PrintCodeCache::doit() {
497 CodeCache::print_layout(_out);
498 }
499
500 #if INCLUDE_SERVICES
501 void VM_PrintClassHierarchy::doit() {
502 KlassHierarchy::print_class_hierarchy(_out, _print_interfaces, _print_subclasses, _classname);
503 }
504 #endif