1 /*
2 * Copyright (c) 1997, 2014, 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 "compiler/compilerOracle.hpp"
31 #include "gc_implementation/shared/isGCActiveMark.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "oops/symbol.hpp"
34 #include "runtime/arguments.hpp"
35 #include "runtime/deoptimization.hpp"
36 #include "runtime/interfaceSupport.hpp"
37 #include "runtime/sweeper.hpp"
38 #include "runtime/thread.inline.hpp"
39 #include "runtime/vm_operations.hpp"
40 #include "services/threadService.hpp"
41 #include "trace/tracing.hpp"
42
43 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
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 if (TraceVMOperation) {
60 tty->print("[");
61 NOT_PRODUCT(print();)
62 }
63 doit();
64 if (TraceVMOperation) {
65 tty->print_cr("]");
66 }
67 }
68
69 const char* VM_Operation::mode_to_string(Mode mode) {
70 switch(mode) {
71 case _safepoint : return "safepoint";
72 case _no_safepoint : return "no safepoint";
73 case _concurrent : return "concurrent";
74 case _async_safepoint: return "async safepoint";
75 default : return "unknown";
76 }
77 }
78 // Called by fatal error handler.
79 void VM_Operation::print_on_error(outputStream* st) const {
80 st->print("VM_Operation (" PTR_FORMAT "): ", this);
81 st->print("%s", name());
82
83 const char* mode = mode_to_string(evaluation_mode());
84 st->print(", mode: %s", mode);
85
86 if (calling_thread()) {
87 st->print(", requested by thread " PTR_FORMAT, calling_thread());
88 }
89 }
90
91 void VM_ThreadStop::doit() {
92 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
93 JavaThread* target = java_lang_Thread::thread(target_thread());
94 // Note that this now allows multiple ThreadDeath exceptions to be
95 // thrown at a thread.
96 if (target != NULL) {
97 // the thread has run and is not already in the process of exiting
98 target->send_thread_stop(throwable());
99 }
100 }
101
102 void VM_Deoptimize::doit() {
103 // We do not want any GCs to happen while we are in the middle of this VM operation
104 ResourceMark rm;
105 DeoptimizationMarker dm;
106
107 // Deoptimize all activations depending on marked nmethods
108 Deoptimization::deoptimize_dependents();
109
110 // Make the dependent methods zombies
111 CodeCache::make_marked_nmethods_zombies();
112 }
113
114 void VM_MarkActiveNMethods::doit() {
115 NMethodSweeper::mark_active_nmethods();
116 }
117
118 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id) {
119 _thread = thread;
120 _id = id;
121 }
122
123
124 void VM_DeoptimizeFrame::doit() {
125 Deoptimization::deoptimize_frame_internal(_thread, _id);
126 }
127
128
129 #ifndef PRODUCT
130
131 void VM_DeoptimizeAll::doit() {
132 DeoptimizationMarker dm;
133 // deoptimize all java threads in the system
134 if (DeoptimizeALot) {
135 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
136 if (thread->has_last_Java_frame()) {
137 thread->deoptimize();
138 }
139 }
140 } else if (DeoptimizeRandom) {
141
142 // Deoptimize some selected threads and frames
143 int tnum = os::random() & 0x3;
144 int fnum = os::random() & 0x3;
145 int tcount = 0;
146 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
147 if (thread->has_last_Java_frame()) {
148 if (tcount++ == tnum) {
149 tcount = 0;
150 int fcount = 0;
151 // Deoptimize some selected frames.
152 // Biased llocking wants a updated register map
153 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) {
154 if (fst.current()->can_be_deoptimized()) {
155 if (fcount++ == fnum) {
156 fcount = 0;
157 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map());
158 }
159 }
160 }
161 }
162 }
163 }
164 }
165 }
166
167
168 void VM_ZombieAll::doit() {
169 JavaThread *thread = (JavaThread *)calling_thread();
170 assert(thread->is_Java_thread(), "must be a Java thread");
171 thread->make_zombies();
172 }
173
174 #endif // !PRODUCT
175
176 void VM_UnlinkSymbols::doit() {
177 JavaThread *thread = (JavaThread *)calling_thread();
178 assert(thread->is_Java_thread(), "must be a Java thread");
179 SymbolTable::unlink();
180 }
181
182 void VM_Verify::doit() {
183 Universe::heap()->prepare_for_verify();
184 Universe::verify(_silent);
185 }
186
187 bool VM_PrintThreads::doit_prologue() {
188 assert(Thread::current()->is_Java_thread(), "just checking");
189
190 // Make sure AbstractOwnableSynchronizer is loaded
191 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
192
193 // Get Heap_lock if concurrent locks will be dumped
194 if (_print_concurrent_locks) {
195 Heap_lock->lock();
196 }
197 return true;
198 }
199
200 void VM_PrintThreads::doit() {
201 Threads::print_on(_out, true, false, _print_concurrent_locks);
202 }
203
204 void VM_PrintThreads::doit_epilogue() {
205 if (_print_concurrent_locks) {
206 // Release Heap_lock
207 Heap_lock->unlock();
208 }
209 }
210
211 void VM_PrintJNI::doit() {
212 JNIHandles::print_on(_out);
213 }
214
215 VM_FindDeadlocks::~VM_FindDeadlocks() {
216 if (_deadlocks != NULL) {
217 DeadlockCycle* cycle = _deadlocks;
218 while (cycle != NULL) {
219 DeadlockCycle* d = cycle;
220 cycle = cycle->next();
221 delete d;
222 }
223 }
224 }
225
226 bool VM_FindDeadlocks::doit_prologue() {
227 assert(Thread::current()->is_Java_thread(), "just checking");
228
229 // Load AbstractOwnableSynchronizer class
230 if (_concurrent_locks) {
231 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
232 }
233
234 return true;
235 }
236
237 void VM_FindDeadlocks::doit() {
238 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks);
239 if (_out != NULL) {
240 int num_deadlocks = 0;
241 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) {
242 num_deadlocks++;
243 cycle->print_on(_out);
244 }
245
246 if (num_deadlocks == 1) {
247 _out->print_cr("\nFound 1 deadlock.\n");
248 _out->flush();
249 } else if (num_deadlocks > 1) {
250 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks);
251 _out->flush();
252 }
253 }
254 }
255
256 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
257 int max_depth,
258 bool with_locked_monitors,
259 bool with_locked_synchronizers) {
260 _result = result;
261 _num_threads = 0; // 0 indicates all threads
262 _threads = NULL;
263 _result = result;
264 _max_depth = max_depth;
265 _with_locked_monitors = with_locked_monitors;
266 _with_locked_synchronizers = with_locked_synchronizers;
267 }
268
269 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
270 GrowableArray<instanceHandle>* threads,
271 int num_threads,
272 int max_depth,
273 bool with_locked_monitors,
274 bool with_locked_synchronizers) {
275 _result = result;
276 _num_threads = num_threads;
277 _threads = threads;
278 _result = result;
279 _max_depth = max_depth;
280 _with_locked_monitors = with_locked_monitors;
281 _with_locked_synchronizers = with_locked_synchronizers;
282 }
283
284 bool VM_ThreadDump::doit_prologue() {
285 assert(Thread::current()->is_Java_thread(), "just checking");
286
287 // Load AbstractOwnableSynchronizer class before taking thread snapshots
288 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
289
290 if (_with_locked_synchronizers) {
291 // Acquire Heap_lock to dump concurrent locks
292 Heap_lock->lock();
293 }
294
295 return true;
296 }
297
298 void VM_ThreadDump::doit_epilogue() {
299 if (_with_locked_synchronizers) {
300 // Release Heap_lock
301 Heap_lock->unlock();
302 }
303 }
304
305 void VM_ThreadDump::doit() {
306 ResourceMark rm;
307
308 ConcurrentLocksDump concurrent_locks(true);
309 if (_with_locked_synchronizers) {
310 concurrent_locks.dump_at_safepoint();
311 }
312
313 if (_num_threads == 0) {
314 // Snapshot all live threads
315 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
316 if (jt->is_exiting() ||
317 jt->is_hidden_from_external_view()) {
318 // skip terminating threads and hidden threads
319 continue;
320 }
321 ThreadConcurrentLocks* tcl = NULL;
322 if (_with_locked_synchronizers) {
323 tcl = concurrent_locks.thread_concurrent_locks(jt);
324 }
325 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
326 _result->add_thread_snapshot(ts);
327 }
328 } else {
329 // Snapshot threads in the given _threads array
330 // A dummy snapshot is created if a thread doesn't exist
331 for (int i = 0; i < _num_threads; i++) {
332 instanceHandle th = _threads->at(i);
333 if (th() == NULL) {
334 // skip if the thread doesn't exist
335 // Add a dummy snapshot
336 _result->add_thread_snapshot(new ThreadSnapshot());
337 continue;
338 }
339
340 // Dump thread stack only if the thread is alive and not exiting
341 // and not VM internal thread.
342 JavaThread* jt = java_lang_Thread::thread(th());
343 if (jt == NULL || /* thread not alive */
344 jt->is_exiting() ||
345 jt->is_hidden_from_external_view()) {
346 // add a NULL snapshot if skipped
347 _result->add_thread_snapshot(new ThreadSnapshot());
348 continue;
349 }
350 ThreadConcurrentLocks* tcl = NULL;
351 if (_with_locked_synchronizers) {
352 tcl = concurrent_locks.thread_concurrent_locks(jt);
353 }
354 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
355 _result->add_thread_snapshot(ts);
356 }
357 }
358 }
359
360 ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {
361 ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread);
362 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);
363 snapshot->set_concurrent_locks(tcl);
364 return snapshot;
365 }
366
367 volatile bool VM_Exit::_vm_exited = false;
368 Thread * VM_Exit::_shutdown_thread = NULL;
369
370 int VM_Exit::set_vm_exited() {
371 Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
372
373 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
374
375 int num_active = 0;
376
377 _shutdown_thread = thr_cur;
378 _vm_exited = true; // global flag
379 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next())
380 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
381 ++num_active;
382 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag
383 }
384
385 return num_active;
386 }
387
388 int VM_Exit::wait_for_threads_in_native_to_block() {
389 // VM exits at safepoint. This function must be called at the final safepoint
390 // to wait for threads in _thread_in_native state to be quiescent.
391 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
392
393 Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
394 Monitor timer(Mutex::leaf, "VM_Exit timer", true);
395
396 // Compiler threads need longer wait because they can access VM data directly
397 // while in native. If they are active and some structures being used are
398 // deleted by the shutdown sequence, they will crash. On the other hand, user
399 // threads must go through native=>Java/VM transitions first to access VM
400 // data, and they will be stopped during state transition. In theory, we
401 // don't have to wait for user threads to be quiescent, but it's always
402 // better to terminate VM when current thread is the only active thread, so
403 // wait for user threads too. Numbers are in 10 milliseconds.
404 int max_wait_user_thread = 30; // at least 300 milliseconds
405 int max_wait_compiler_thread = 1000; // at least 10 seconds
406
407 int max_wait = max_wait_compiler_thread;
408
409 int attempts = 0;
410 while (true) {
411 int num_active = 0;
412 int num_active_compiler_thread = 0;
413
414 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) {
415 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
416 num_active++;
417 if (thr->is_Compiler_thread()) {
418 num_active_compiler_thread++;
419 }
420 }
421 }
422
423 if (num_active == 0) {
424 return 0;
425 } else if (attempts > max_wait) {
426 return num_active;
427 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) {
428 return num_active;
429 }
430
431 attempts++;
432
433 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag);
434 timer.wait(Mutex::_no_safepoint_check_flag, 10);
435 }
436 }
437
438 void VM_Exit::doit() {
439 CompileBroker::set_should_block();
440
441 // Wait for a short period for threads in native to block. Any thread
442 // still executing native code after the wait will be stopped at
443 // native==>Java/VM barriers.
444 // Among 16276 JCK tests, 94% of them come here without any threads still
445 // running in native; the other 6% are quiescent within 250ms (Ultra 80).
446 wait_for_threads_in_native_to_block();
447
448 set_vm_exited();
449
450 // cleanup globals resources before exiting. exit_globals() currently
451 // cleans up outputStream resources and PerfMemory resources.
452 exit_globals();
453
454 // Check for exit hook
455 exit_hook_t exit_hook = Arguments::exit_hook();
456 if (exit_hook != NULL) {
457 // exit hook should exit.
458 exit_hook(_exit_code);
459 // ... but if it didn't, we must do it here
460 vm_direct_exit(_exit_code);
461 } else {
462 vm_direct_exit(_exit_code);
463 }
464 }
465
466
467 void VM_Exit::wait_if_vm_exited() {
468 if (_vm_exited &&
469 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) {
470 // _vm_exited is set at safepoint, and the Threads_lock is never released
471 // we will block here until the process dies
472 Threads_lock->lock_without_safepoint_check();
473 ShouldNotReachHere();
474 }
475 }
476
477 void VM_PrintCompileQueue::doit() {
478 CompileBroker::print_compile_queues(_out);
479 }
480
481 void VM_PrintCodeList::doit() {
482 CodeCache::print_codelist(_out);
483 }
484
485 void VM_PrintCodeCache::doit() {
486 CodeCache::print_layout(_out);
487 }