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 #ifdef TARGET_OS_FAMILY_bsd
49 # include "thread_bsd.inline.hpp"
50 #endif
51
52 #define VM_OP_NAME_INITIALIZE(name) #name,
53
54 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \
55 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) };
56
57 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) {
58 _calling_thread = thread;
59 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
60 _priority = priority;
61 }
62
63
64 void VM_Operation::evaluate() {
65 ResourceMark rm;
66 if (TraceVMOperation) {
67 tty->print("[");
68 NOT_PRODUCT(print();)
69 }
70 doit();
71 if (TraceVMOperation) {
72 tty->print_cr("]");
73 }
74 }
75
76 // Called by fatal error handler.
77 void VM_Operation::print_on_error(outputStream* st) const {
78 st->print("VM_Operation (" PTR_FORMAT "): ", this);
79 st->print("%s", name());
80
81 const char* mode;
82 switch(evaluation_mode()) {
83 case _safepoint : mode = "safepoint"; break;
84 case _no_safepoint : mode = "no safepoint"; break;
85 case _concurrent : mode = "concurrent"; break;
86 case _async_safepoint: mode = "async safepoint"; break;
87 default : mode = "unknown"; break;
88 }
89 st->print(", mode: %s", mode);
90
91 if (calling_thread()) {
92 st->print(", requested by thread " PTR_FORMAT, calling_thread());
93 }
94 }
95
96 void VM_ThreadStop::doit() {
97 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
98 JavaThread* target = java_lang_Thread::thread(target_thread());
99 // Note that this now allows multiple ThreadDeath exceptions to be
100 // thrown at a thread.
101 if (target != NULL) {
102 // the thread has run and is not already in the process of exiting
103 target->send_thread_stop(throwable());
104 }
105 }
106
107 void VM_Deoptimize::doit() {
108 // We do not want any GCs to happen while we are in the middle of this VM operation
109 ResourceMark rm;
110 DeoptimizationMarker dm;
111
112 // Deoptimize all activations depending on marked nmethods
113 Deoptimization::deoptimize_dependents();
114
115 // Make the dependent methods zombies
116 CodeCache::make_marked_nmethods_zombies();
117 }
118
119
120 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id) {
121 _thread = thread;
122 _id = id;
123 }
124
125
126 void VM_DeoptimizeFrame::doit() {
127 Deoptimization::deoptimize_frame_internal(_thread, _id);
128 }
129
130
131 #ifndef PRODUCT
132
133 void VM_DeoptimizeAll::doit() {
134 DeoptimizationMarker dm;
135 // deoptimize all java threads in the system
136 if (DeoptimizeALot) {
137 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
138 if (thread->has_last_Java_frame()) {
139 thread->deoptimize();
140 }
141 }
142 } else if (DeoptimizeRandom) {
143
144 // Deoptimize some selected threads and frames
145 int tnum = os::random() & 0x3;
146 int fnum = os::random() & 0x3;
147 int tcount = 0;
148 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
149 if (thread->has_last_Java_frame()) {
150 if (tcount++ == tnum) {
151 tcount = 0;
152 int fcount = 0;
153 // Deoptimize some selected frames.
154 // Biased llocking wants a updated register map
155 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) {
156 if (fst.current()->can_be_deoptimized()) {
157 if (fcount++ == fnum) {
158 fcount = 0;
159 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map());
160 }
161 }
162 }
163 }
164 }
165 }
166 }
167 }
168
169
170 void VM_ZombieAll::doit() {
171 JavaThread *thread = (JavaThread *)calling_thread();
172 assert(thread->is_Java_thread(), "must be a Java thread");
173 thread->make_zombies();
174 }
175
176 #endif // !PRODUCT
177
178 void VM_UnlinkSymbols::doit() {
179 JavaThread *thread = (JavaThread *)calling_thread();
180 assert(thread->is_Java_thread(), "must be a Java thread");
181 SymbolTable::unlink();
182 }
183
184 void VM_HandleFullCodeCache::doit() {
185 NMethodSweeper::speculative_disconnect_nmethods(_is_full);
186 }
187
188 void VM_Verify::doit() {
189 Universe::verify();
190 }
191
192 bool VM_PrintThreads::doit_prologue() {
193 assert(Thread::current()->is_Java_thread(), "just checking");
194
195 // Make sure AbstractOwnableSynchronizer is loaded
196 if (JDK_Version::is_gte_jdk16x_version()) {
197 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
198 }
199
200 // Get Heap_lock if concurrent locks will be dumped
201 if (_print_concurrent_locks) {
202 Heap_lock->lock();
203 }
204 return true;
205 }
206
207 void VM_PrintThreads::doit() {
208 Threads::print_on(_out, true, false, _print_concurrent_locks);
209 }
210
211 void VM_PrintThreads::doit_epilogue() {
212 if (_print_concurrent_locks) {
213 // Release Heap_lock
214 Heap_lock->unlock();
215 }
216 }
217
218 void VM_PrintJNI::doit() {
219 JNIHandles::print_on(_out);
220 }
221
222 VM_FindDeadlocks::~VM_FindDeadlocks() {
223 if (_deadlocks != NULL) {
224 DeadlockCycle* cycle = _deadlocks;
225 while (cycle != NULL) {
226 DeadlockCycle* d = cycle;
227 cycle = cycle->next();
228 delete d;
229 }
230 }
231 }
232
233 bool VM_FindDeadlocks::doit_prologue() {
234 assert(Thread::current()->is_Java_thread(), "just checking");
235
236 // Load AbstractOwnableSynchronizer class
237 if (_concurrent_locks && JDK_Version::is_gte_jdk16x_version()) {
238 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
239 }
240
241 return true;
242 }
243
244 void VM_FindDeadlocks::doit() {
245 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks);
246 if (_out != NULL) {
247 int num_deadlocks = 0;
248 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) {
249 num_deadlocks++;
250 cycle->print_on(_out);
251 }
252
253 if (num_deadlocks == 1) {
254 _out->print_cr("\nFound 1 deadlock.\n");
255 _out->flush();
256 } else if (num_deadlocks > 1) {
257 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks);
258 _out->flush();
259 }
260 }
261 }
262
263 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
264 int max_depth,
265 bool with_locked_monitors,
266 bool with_locked_synchronizers) {
267 _result = result;
268 _num_threads = 0; // 0 indicates all threads
269 _threads = NULL;
270 _result = result;
271 _max_depth = max_depth;
272 _with_locked_monitors = with_locked_monitors;
273 _with_locked_synchronizers = with_locked_synchronizers;
274 }
275
276 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
277 GrowableArray<instanceHandle>* threads,
278 int num_threads,
279 int max_depth,
280 bool with_locked_monitors,
281 bool with_locked_synchronizers) {
282 _result = result;
283 _num_threads = num_threads;
284 _threads = threads;
285 _result = result;
286 _max_depth = max_depth;
287 _with_locked_monitors = with_locked_monitors;
288 _with_locked_synchronizers = with_locked_synchronizers;
289 }
290
291 bool VM_ThreadDump::doit_prologue() {
292 assert(Thread::current()->is_Java_thread(), "just checking");
293
294 // Load AbstractOwnableSynchronizer class before taking thread snapshots
295 if (JDK_Version::is_gte_jdk16x_version()) {
296 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
297 }
298
299 if (_with_locked_synchronizers) {
300 // Acquire Heap_lock to dump concurrent locks
301 Heap_lock->lock();
302 }
303
304 return true;
305 }
306
307 void VM_ThreadDump::doit_epilogue() {
308 if (_with_locked_synchronizers) {
309 // Release Heap_lock
310 Heap_lock->unlock();
311 }
312 }
313
314 void VM_ThreadDump::doit() {
315 ResourceMark rm;
316
317 ConcurrentLocksDump concurrent_locks(true);
318 if (_with_locked_synchronizers) {
319 concurrent_locks.dump_at_safepoint();
320 }
321
322 if (_num_threads == 0) {
323 // Snapshot all live threads
324 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
325 if (jt->is_exiting() ||
326 jt->is_hidden_from_external_view()) {
327 // skip terminating threads and hidden threads
328 continue;
329 }
330 ThreadConcurrentLocks* tcl = NULL;
331 if (_with_locked_synchronizers) {
332 tcl = concurrent_locks.thread_concurrent_locks(jt);
333 }
334 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
335 _result->add_thread_snapshot(ts);
336 }
337 } else {
338 // Snapshot threads in the given _threads array
339 // A dummy snapshot is created if a thread doesn't exist
340 for (int i = 0; i < _num_threads; i++) {
341 instanceHandle th = _threads->at(i);
342 if (th() == NULL) {
343 // skip if the thread doesn't exist
344 // Add a dummy snapshot
345 _result->add_thread_snapshot(new ThreadSnapshot());
346 continue;
347 }
348
349 // Dump thread stack only if the thread is alive and not exiting
350 // and not VM internal thread.
351 JavaThread* jt = java_lang_Thread::thread(th());
352 if (jt == NULL || /* thread not alive */
353 jt->is_exiting() ||
354 jt->is_hidden_from_external_view()) {
355 // add a NULL snapshot if skipped
356 _result->add_thread_snapshot(new ThreadSnapshot());
357 continue;
358 }
359 ThreadConcurrentLocks* tcl = NULL;
360 if (_with_locked_synchronizers) {
361 tcl = concurrent_locks.thread_concurrent_locks(jt);
362 }
363 ThreadSnapshot* ts = snapshot_thread(jt, tcl);
364 _result->add_thread_snapshot(ts);
365 }
366 }
367 }
368
369 ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {
370 ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread);
371 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);
372 snapshot->set_concurrent_locks(tcl);
373 return snapshot;
374 }
375
376 volatile bool VM_Exit::_vm_exited = false;
377 Thread * VM_Exit::_shutdown_thread = NULL;
378
379 int VM_Exit::set_vm_exited() {
380 Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
381
382 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
383
384 int num_active = 0;
385
386 _shutdown_thread = thr_cur;
387 _vm_exited = true; // global flag
388 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next())
389 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
390 ++num_active;
391 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag
392 }
393
394 return num_active;
395 }
396
397 int VM_Exit::wait_for_threads_in_native_to_block() {
398 // VM exits at safepoint. This function must be called at the final safepoint
399 // to wait for threads in _thread_in_native state to be quiescent.
400 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
401
402 Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
403 Monitor timer(Mutex::leaf, "VM_Exit timer", true);
404
405 // Compiler threads need longer wait because they can access VM data directly
406 // while in native. If they are active and some structures being used are
407 // deleted by the shutdown sequence, they will crash. On the other hand, user
408 // threads must go through native=>Java/VM transitions first to access VM
409 // data, and they will be stopped during state transition. In theory, we
410 // don't have to wait for user threads to be quiescent, but it's always
411 // better to terminate VM when current thread is the only active thread, so
412 // wait for user threads too. Numbers are in 10 milliseconds.
413 int max_wait_user_thread = 30; // at least 300 milliseconds
414 int max_wait_compiler_thread = 1000; // at least 10 seconds
415
416 int max_wait = max_wait_compiler_thread;
417
418 int attempts = 0;
419 while (true) {
420 int num_active = 0;
421 int num_active_compiler_thread = 0;
422
423 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) {
424 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
425 num_active++;
426 if (thr->is_Compiler_thread()) {
427 num_active_compiler_thread++;
428 }
429 }
430 }
431
432 if (num_active == 0) {
433 return 0;
434 } else if (attempts > max_wait) {
435 return num_active;
436 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) {
437 return num_active;
438 }
439
440 attempts++;
441
442 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag);
443 timer.wait(Mutex::_no_safepoint_check_flag, 10);
444 }
445 }
446
447 void VM_Exit::doit() {
448 CompileBroker::set_should_block();
449
450 // Wait for a short period for threads in native to block. Any thread
451 // still executing native code after the wait will be stopped at
452 // native==>Java/VM barriers.
453 // Among 16276 JCK tests, 94% of them come here without any threads still
454 // running in native; the other 6% are quiescent within 250ms (Ultra 80).
455 wait_for_threads_in_native_to_block();
456
457 set_vm_exited();
458
459 // cleanup globals resources before exiting. exit_globals() currently
460 // cleans up outputStream resources and PerfMemory resources.
461 exit_globals();
462
463 // Check for exit hook
464 exit_hook_t exit_hook = Arguments::exit_hook();
465 if (exit_hook != NULL) {
466 // exit hook should exit.
467 exit_hook(_exit_code);
468 // ... but if it didn't, we must do it here
469 vm_direct_exit(_exit_code);
470 } else {
471 vm_direct_exit(_exit_code);
472 }
473 }
474
475
476 void VM_Exit::wait_if_vm_exited() {
477 if (_vm_exited &&
478 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) {
479 // _vm_exited is set at safepoint, and the Threads_lock is never released
480 // we will block here until the process dies
481 Threads_lock->lock_without_safepoint_check();
482 ShouldNotReachHere();
483 }
484 }