1 /*
2 * Copyright (c) 1997, 2011, 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 "compiler/compileBroker.hpp"
29 #include "compiler/compilerOracle.hpp"
30 #include "gc_implementation/shared/isGCActiveMark.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/symbol.hpp"
33 #include "runtime/arguments.hpp"
34 #include "runtime/deoptimization.hpp"
35 #include "runtime/interfaceSupport.hpp"
36 #include "runtime/sweeper.hpp"
37 #include "runtime/thread.inline.hpp"
38 #include "runtime/vm_operations.hpp"
39 #include "services/threadService.hpp"
40
41 #define VM_OP_NAME_INITIALIZE(name) #name,
42
43 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \
44 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) };
45
46 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) {
47 _calling_thread = thread;
48 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
49 _priority = priority;
50 }
51
52
53 void VM_Operation::evaluate() {
54 ResourceMark rm;
55 if (TraceVMOperation) {
56 tty->print("[");
57 NOT_PRODUCT(print();)
58 }
59 doit();
60 if (TraceVMOperation) {
61 tty->print_cr("]");
62 }
63 }
64
65 // Called by fatal error handler.
66 void VM_Operation::print_on_error(outputStream* st) const {
67 st->print("VM_Operation (" PTR_FORMAT "): ", this);
68 st->print("%s", name());
69
70 const char* mode;
71 switch(evaluation_mode()) {
72 case _safepoint : mode = "safepoint"; break;
73 case _no_safepoint : mode = "no safepoint"; break;
74 case _concurrent : mode = "concurrent"; break;
75 case _async_safepoint: mode = "async safepoint"; break;
76 default : mode = "unknown"; break;
77 }
78 st->print(", mode: %s", mode);
79
80 if (calling_thread()) {
81 st->print(", requested by thread " PTR_FORMAT, calling_thread());
82 }
83 }
84
85 void VM_ThreadStop::doit() {
86 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
87 JavaThread* target = java_lang_Thread::thread(target_thread());
88 // Note that this now allows multiple ThreadDeath exceptions to be
89 // thrown at a thread.
90 if (target != NULL) {
91 // the thread has run and is not already in the process of exiting
92 target->send_thread_stop(throwable());
93 }
94 }
95
96 void VM_Deoptimize::doit() {
97 // We do not want any GCs to happen while we are in the middle of this VM operation
98 ResourceMark rm;
99 DeoptimizationMarker dm;
100
101 // Deoptimize all activations depending on marked nmethods
102 Deoptimization::deoptimize_dependents();
103
104 // Make the dependent methods zombies
105 CodeCache::make_marked_nmethods_zombies();
106 }
107
108
109 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id) {
110 _thread = thread;
111 _id = id;
112 }
113
114
115 void VM_DeoptimizeFrame::doit() {
116 Deoptimization::deoptimize_frame_internal(_thread, _id);
117 }
118
119
120 #ifndef PRODUCT
121
122 void VM_DeoptimizeAll::doit() {
123 DeoptimizationMarker dm;
124 // deoptimize all java threads in the system
125 if (DeoptimizeALot) {
126 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
127 if (thread->has_last_Java_frame()) {
128 thread->deoptimize();
129 }
130 }
131 } else if (DeoptimizeRandom) {
132
133 // Deoptimize some selected threads and frames
134 int tnum = os::random() & 0x3;
135 int fnum = os::random() & 0x3;
136 int tcount = 0;
137 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
138 if (thread->has_last_Java_frame()) {
139 if (tcount++ == tnum) {
140 tcount = 0;
141 int fcount = 0;
142 // Deoptimize some selected frames.
143 // Biased llocking wants a updated register map
144 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) {
145 if (fst.current()->can_be_deoptimized()) {
146 if (fcount++ == fnum) {
147 fcount = 0;
148 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map());
149 }
150 }
151 }
152 }
153 }
154 }
155 }
156 }
157
158
159 void VM_ZombieAll::doit() {
160 JavaThread *thread = (JavaThread *)calling_thread();
161 assert(thread->is_Java_thread(), "must be a Java thread");
162 thread->make_zombies();
163 }
164
165 #endif // !PRODUCT
166
167 void VM_UnlinkSymbols::doit() {
168 JavaThread *thread = (JavaThread *)calling_thread();
169 assert(thread->is_Java_thread(), "must be a Java thread");
170 SymbolTable::unlink();
171 }
172
173 void VM_HandleFullCodeCache::doit() {
174 NMethodSweeper::speculative_disconnect_nmethods(_is_full);
175 }
176
177 void VM_Verify::doit() {
178 Universe::verify();
179 }
180
181 bool VM_PrintThreads::doit_prologue() {
182 assert(Thread::current()->is_Java_thread(), "just checking");
183
184 // Make sure AbstractOwnableSynchronizer is loaded
185 if (JDK_Version::is_gte_jdk16x_version()) {
186 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
187 }
188
189 // Get Heap_lock if concurrent locks will be dumped
190 if (_print_concurrent_locks) {
191 Heap_lock->lock();
192 }
193 return true;
194 }
195
196 void VM_PrintThreads::doit() {
197 Threads::print_on(_out, true, false, _print_concurrent_locks);
198 }
199
200 void VM_PrintThreads::doit_epilogue() {
201 if (_print_concurrent_locks) {
202 // Release Heap_lock
203 Heap_lock->unlock();
204 }
205 }
206
207 void VM_PrintJNI::doit() {
208 JNIHandles::print_on(_out);
209 }
210
211 VM_FindDeadlocks::~VM_FindDeadlocks() {
212 if (_deadlocks != NULL) {
213 DeadlockCycle* cycle = _deadlocks;
214 while (cycle != NULL) {
215 DeadlockCycle* d = cycle;
216 cycle = cycle->next();
217 delete d;
218 }
219 }
220 }
221
222 bool VM_FindDeadlocks::doit_prologue() {
223 assert(Thread::current()->is_Java_thread(), "just checking");
224
225 // Load AbstractOwnableSynchronizer class
226 if (_concurrent_locks && JDK_Version::is_gte_jdk16x_version()) {
227 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
228 }
229
230 return true;
231 }
232
233 void VM_FindDeadlocks::doit() {
234 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks);
235 if (_out != NULL) {
236 int num_deadlocks = 0;
237 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) {
238 num_deadlocks++;
239 cycle->print_on(_out);
240 }
241
242 if (num_deadlocks == 1) {
243 _out->print_cr("\nFound 1 deadlock.\n");
244 _out->flush();
245 } else if (num_deadlocks > 1) {
246 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks);
247 _out->flush();
248 }
249 }
250 }
251
252 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
253 int max_depth,
254 bool with_locked_monitors,
255 bool with_locked_synchronizers) {
256 _result = result;
257 _num_threads = 0; // 0 indicates all threads
258 _threads = NULL;
259 _result = result;
260 _max_depth = max_depth;
261 _with_locked_monitors = with_locked_monitors;
262 _with_locked_synchronizers = with_locked_synchronizers;
263 }
264
265 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
266 GrowableArray<instanceHandle>* threads,
267 int num_threads,
268 int max_depth,
269 bool with_locked_monitors,
270 bool with_locked_synchronizers) {
271 _result = result;
272 _num_threads = num_threads;
273 _threads = threads;
274 _result = result;
275 _max_depth = max_depth;
276 _with_locked_monitors = with_locked_monitors;
277 _with_locked_synchronizers = with_locked_synchronizers;
278 }
279
280 bool VM_ThreadDump::doit_prologue() {
281 assert(Thread::current()->is_Java_thread(), "just checking");
282
283 // Load AbstractOwnableSynchronizer class before taking thread snapshots
284 if (JDK_Version::is_gte_jdk16x_version()) {
285 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
286 }
287
288 if (_with_locked_synchronizers) {
289 // Acquire Heap_lock to dump concurrent locks
290 Heap_lock->lock();
291 }
292
293 return true;
294 }
295
296 void VM_ThreadDump::doit_epilogue() {
297 if (_with_locked_synchronizers) {
298 // Release Heap_lock
299 Heap_lock->unlock();
300 }
301 }
302
303 void VM_ThreadDump::doit() {
304 ResourceMark rm;
305
306 ConcurrentLocksDump concurrent_locks(true);
307 if (_with_locked_synchronizers) {
308 concurrent_locks.dump_at_safepoint();
309 }
310
311 if (_num_threads == 0) {
312 // Snapshot all live threads
313 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
314 if (jt->is_exiting() ||
315 jt->is_hidden_from_external_view()) {
316 // skip terminating threads and hidden threads
317 continue;
318 }
319 ThreadConcurrentLocks* tcl = NULL;
320 if (_with_locked_synchronizers) {
321 tcl = concurrent_locks.thread_concurrent_locks(jt);
322 }
323 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
324 _result->add_thread_snapshot(ts);
325 }
326 } else {
327 // Snapshot threads in the given _threads array
328 // A dummy snapshot is created if a thread doesn't exist
329 for (int i = 0; i < _num_threads; i++) {
330 instanceHandle th = _threads->at(i);
331 if (th() == NULL) {
332 // skip if the thread doesn't exist
333 // Add a dummy snapshot
334 _result->add_thread_snapshot(new ThreadSnapshot());
335 continue;
336 }
337
338 // Dump thread stack only if the thread is alive and not exiting
339 // and not VM internal thread.
340 JavaThread* jt = java_lang_Thread::thread(th());
341 if (jt == NULL || /* thread not alive */
342 jt->is_exiting() ||
343 jt->is_hidden_from_external_view()) {
344 // add a NULL snapshot if skipped
345 _result->add_thread_snapshot(new ThreadSnapshot());
346 continue;
347 }
348 ThreadConcurrentLocks* tcl = NULL;
349 if (_with_locked_synchronizers) {
350 tcl = concurrent_locks.thread_concurrent_locks(jt);
351 }
352 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
353 _result->add_thread_snapshot(ts);
354 }
355 }
356 }
357
358 ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {
359 ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread);
360 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);
361 snapshot->set_concurrent_locks(tcl);
362 return snapshot;
363 }
364
365 volatile bool VM_Exit::_vm_exited = false;
366 Thread * VM_Exit::_shutdown_thread = NULL;
367
368 int VM_Exit::set_vm_exited() {
369 Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
370
371 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
372
373 int num_active = 0;
374
375 _shutdown_thread = thr_cur;
376 _vm_exited = true; // global flag
377 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next())
378 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
379 ++num_active;
380 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag
381 }
382
383 return num_active;
384 }
385
386 int VM_Exit::wait_for_threads_in_native_to_block() {
387 // VM exits at safepoint. This function must be called at the final safepoint
388 // to wait for threads in _thread_in_native state to be quiescent.
389 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
390
391 Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
392 Monitor timer(Mutex::leaf, "VM_Exit timer", true);
393
394 // Compiler threads need longer wait because they can access VM data directly
395 // while in native. If they are active and some structures being used are
396 // deleted by the shutdown sequence, they will crash. On the other hand, user
397 // threads must go through native=>Java/VM transitions first to access VM
398 // data, and they will be stopped during state transition. In theory, we
399 // don't have to wait for user threads to be quiescent, but it's always
400 // better to terminate VM when current thread is the only active thread, so
401 // wait for user threads too. Numbers are in 10 milliseconds.
402 int max_wait_user_thread = 30; // at least 300 milliseconds
403 int max_wait_compiler_thread = 1000; // at least 10 seconds
404
405 int max_wait = max_wait_compiler_thread;
406
407 int attempts = 0;
408 while (true) {
409 int num_active = 0;
410 int num_active_compiler_thread = 0;
411
412 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) {
413 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
414 num_active++;
415 if (thr->is_Compiler_thread()) {
416 num_active_compiler_thread++;
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 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag);
432 timer.wait(Mutex::_no_safepoint_check_flag, 10);
433 }
434 }
435
436 void VM_Exit::doit() {
437 CompileBroker::set_should_block();
438
439 // Wait for a short period for threads in native to block. Any thread
440 // still executing native code after the wait will be stopped at
441 // native==>Java/VM barriers.
442 // Among 16276 JCK tests, 94% of them come here without any threads still
443 // running in native; the other 6% are quiescent within 250ms (Ultra 80).
444 wait_for_threads_in_native_to_block();
445
446 set_vm_exited();
447
448 // cleanup globals resources before exiting. exit_globals() currently
449 // cleans up outputStream resources and PerfMemory resources.
450 exit_globals();
451
452 // Check for exit hook
453 exit_hook_t exit_hook = Arguments::exit_hook();
454 if (exit_hook != NULL) {
455 // exit hook should exit.
456 exit_hook(_exit_code);
457 // ... but if it didn't, we must do it here
458 vm_direct_exit(_exit_code);
459 } else {
460 vm_direct_exit(_exit_code);
461 }
462 }
463
464
465 void VM_Exit::wait_if_vm_exited() {
466 if (_vm_exited &&
467 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) {
468 // _vm_exited is set at safepoint, and the Threads_lock is never released
469 // we will block here until the process dies
470 Threads_lock->lock_without_safepoint_check();
471 ShouldNotReachHere();
472 }
473 }