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/vm_operations.hpp"
38 #include "services/threadService.hpp"
39 #ifdef TARGET_OS_FAMILY_linux
40 # include "thread_linux.inline.hpp"
41 #endif
42 #ifdef TARGET_OS_FAMILY_solaris
43 # include "thread_solaris.inline.hpp"
44 #endif
45 #ifdef TARGET_OS_FAMILY_windows
46 # include "thread_windows.inline.hpp"
47 #endif
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, ThreadPriority priority) {
55 _calling_thread = thread;
56 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
57 _priority = priority;
58 }
59
60
61 void VM_Operation::evaluate() {
62 ResourceMark rm;
63 if (TraceVMOperation) {
64 tty->print("[");
65 NOT_PRODUCT(print();)
66 }
67 doit();
68 if (TraceVMOperation) {
69 tty->print_cr("]");
70 }
71 }
72
73 // Called by fatal error handler.
74 void VM_Operation::print_on_error(outputStream* st) const {
75 st->print("VM_Operation (" PTR_FORMAT "): ", this);
76 st->print("%s", name());
77
78 const char* mode;
79 switch(evaluation_mode()) {
80 case _safepoint : mode = "safepoint"; break;
81 case _no_safepoint : mode = "no safepoint"; break;
82 case _concurrent : mode = "concurrent"; break;
83 case _async_safepoint: mode = "async safepoint"; break;
84 default : mode = "unknown"; break;
85 }
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 zombies
113 CodeCache::make_marked_nmethods_zombies();
114 }
115
116
117 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id) {
118 _thread = thread;
119 _id = id;
120 }
121
122
123 void VM_DeoptimizeFrame::doit() {
124 Deoptimization::deoptimize_frame_internal(_thread, _id);
125 }
126
127
128 #ifndef PRODUCT
129
130 void VM_DeoptimizeAll::doit() {
131 DeoptimizationMarker dm;
132 // deoptimize all java threads in the system
133 if (DeoptimizeALot) {
134 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
135 if (thread->has_last_Java_frame()) {
136 thread->deoptimize();
137 }
138 }
139 } else if (DeoptimizeRandom) {
140
141 // Deoptimize some selected threads and frames
142 int tnum = os::random() & 0x3;
143 int fnum = os::random() & 0x3;
144 int tcount = 0;
145 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
146 if (thread->has_last_Java_frame()) {
147 if (tcount++ == tnum) {
148 tcount = 0;
149 int fcount = 0;
150 // Deoptimize some selected frames.
151 // Biased llocking wants a updated register map
152 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) {
153 if (fst.current()->can_be_deoptimized()) {
154 if (fcount++ == fnum) {
155 fcount = 0;
156 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map());
157 }
158 }
159 }
160 }
161 }
162 }
163 }
164 }
165
166
167 void VM_ZombieAll::doit() {
168 JavaThread *thread = (JavaThread *)calling_thread();
169 assert(thread->is_Java_thread(), "must be a Java thread");
170 thread->make_zombies();
171 }
172
173 #endif // !PRODUCT
174
175 void VM_UnlinkSymbols::doit() {
176 JavaThread *thread = (JavaThread *)calling_thread();
177 assert(thread->is_Java_thread(), "must be a Java thread");
178 SymbolTable::unlink();
179 }
180
181 void VM_HandleFullCodeCache::doit() {
182 NMethodSweeper::speculative_disconnect_nmethods(_is_full);
183 }
184
185 void VM_Verify::doit() {
186 Universe::verify();
187 }
188
189 bool VM_PrintThreads::doit_prologue() {
190 assert(Thread::current()->is_Java_thread(), "just checking");
191
192 // Make sure AbstractOwnableSynchronizer is loaded
193 if (JDK_Version::is_gte_jdk16x_version()) {
194 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
195 }
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 && JDK_Version::is_gte_jdk16x_version()) {
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 if (JDK_Version::is_gte_jdk16x_version()) {
293 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
294 }
295
296 if (_with_locked_synchronizers) {
297 // Acquire Heap_lock to dump concurrent locks
298 Heap_lock->lock();
299 }
300
301 return true;
302 }
303
304 void VM_ThreadDump::doit_epilogue() {
305 if (_with_locked_synchronizers) {
306 // Release Heap_lock
307 Heap_lock->unlock();
308 }
309 }
310
311 void VM_ThreadDump::doit() {
312 ResourceMark rm;
313
314 ConcurrentLocksDump concurrent_locks(true);
315 if (_with_locked_synchronizers) {
316 concurrent_locks.dump_at_safepoint();
317 }
318
319 if (_num_threads == 0) {
320 // Snapshot all live threads
321 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
322 if (jt->is_exiting() ||
323 jt->is_hidden_from_external_view()) {
324 // skip terminating threads and hidden threads
325 continue;
326 }
327 ThreadConcurrentLocks* tcl = NULL;
328 if (_with_locked_synchronizers) {
329 tcl = concurrent_locks.thread_concurrent_locks(jt);
330 }
331 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
332 _result->add_thread_snapshot(ts);
333 }
334 } else {
335 // Snapshot threads in the given _threads array
336 // A dummy snapshot is created if a thread doesn't exist
337 for (int i = 0; i < _num_threads; i++) {
338 instanceHandle th = _threads->at(i);
339 if (th() == NULL) {
340 // skip if the thread doesn't exist
341 // Add a dummy snapshot
342 _result->add_thread_snapshot(new ThreadSnapshot());
343 continue;
344 }
345
346 // Dump thread stack only if the thread is alive and not exiting
347 // and not VM internal thread.
348 JavaThread* jt = java_lang_Thread::thread(th());
349 if (jt == NULL || /* thread not alive */
350 jt->is_exiting() ||
351 jt->is_hidden_from_external_view()) {
352 // add a NULL snapshot if skipped
353 _result->add_thread_snapshot(new ThreadSnapshot());
354 continue;
355 }
356 ThreadConcurrentLocks* tcl = NULL;
357 if (_with_locked_synchronizers) {
358 tcl = concurrent_locks.thread_concurrent_locks(jt);
359 }
360 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
361 _result->add_thread_snapshot(ts);
362 }
363 }
364 }
365
366 ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {
367 ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread);
368 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);
369 snapshot->set_concurrent_locks(tcl);
370 return snapshot;
371 }
372
373 volatile bool VM_Exit::_vm_exited = false;
374 Thread * VM_Exit::_shutdown_thread = NULL;
375
376 int VM_Exit::set_vm_exited() {
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
402 // Compiler threads need longer wait because they can access VM data directly
403 // while in native. If they are active and some structures being used are
404 // deleted by the shutdown sequence, they will crash. On the other hand, user
405 // threads must go through native=>Java/VM transitions first to access VM
406 // data, and they will be stopped during state transition. In theory, we
407 // don't have to wait for user threads to be quiescent, but it's always
408 // better to terminate VM when current thread is the only active thread, so
409 // wait for user threads too. Numbers are in 10 milliseconds.
410 int max_wait_user_thread = 30; // at least 300 milliseconds
411 int max_wait_compiler_thread = 1000; // at least 10 seconds
412
413 int max_wait = max_wait_compiler_thread;
414
415 int attempts = 0;
416 while (true) {
417 int num_active = 0;
418 int num_active_compiler_thread = 0;
419
420 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) {
421 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
422 num_active++;
423 if (thr->is_Compiler_thread()) {
424 num_active_compiler_thread++;
425 }
426 }
427 }
428
429 if (num_active == 0) {
430 return 0;
431 } else if (attempts > max_wait) {
432 return num_active;
433 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) {
434 return num_active;
435 }
436
437 attempts++;
438
439 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag);
440 timer.wait(Mutex::_no_safepoint_check_flag, 10);
441 }
442 }
443
444 void VM_Exit::doit() {
445 CompileBroker::set_should_block();
446
447 // Wait for a short period for threads in native to block. Any thread
448 // still executing native code after the wait will be stopped at
449 // native==>Java/VM barriers.
450 // Among 16276 JCK tests, 94% of them come here without any threads still
451 // running in native; the other 6% are quiescent within 250ms (Ultra 80).
452 wait_for_threads_in_native_to_block();
453
454 set_vm_exited();
455
456 // cleanup globals resources before exiting. exit_globals() currently
457 // cleans up outputStream resources and PerfMemory resources.
458 exit_globals();
459
460 // Check for exit hook
461 exit_hook_t exit_hook = Arguments::exit_hook();
462 if (exit_hook != NULL) {
463 // exit hook should exit.
464 exit_hook(_exit_code);
465 // ... but if it didn't, we must do it here
466 vm_direct_exit(_exit_code);
467 } else {
468 vm_direct_exit(_exit_code);
469 }
470 }
471
472
473 void VM_Exit::wait_if_vm_exited() {
474 if (_vm_exited &&
475 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) {
476 // _vm_exited is set at safepoint, and the Threads_lock is never released
477 // we will block here until the process dies
478 Threads_lock->lock_without_safepoint_check();
479 ShouldNotReachHere();
480 }
481 }