vm_operations.cpp revision 1472:c18cbe5936b8
1/* 2 * Copyright (c) 1997, 2007, 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 "incls/_precompiled.incl" 26# include "incls/_vm_operations.cpp.incl" 27 28#define VM_OP_NAME_INITIALIZE(name) #name, 29 30const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \ 31 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) }; 32 33void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) { 34 _calling_thread = thread; 35 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); 36 _priority = priority; 37} 38 39 40void VM_Operation::evaluate() { 41 ResourceMark rm; 42 if (TraceVMOperation) { 43 tty->print("["); 44 NOT_PRODUCT(print();) 45 } 46 doit(); 47 if (TraceVMOperation) { 48 tty->print_cr("]"); 49 } 50} 51 52// Called by fatal error handler. 53void VM_Operation::print_on_error(outputStream* st) const { 54 st->print("VM_Operation (" PTR_FORMAT "): ", this); 55 st->print("%s", name()); 56 57 const char* mode; 58 switch(evaluation_mode()) { 59 case _safepoint : mode = "safepoint"; break; 60 case _no_safepoint : mode = "no safepoint"; break; 61 case _concurrent : mode = "concurrent"; break; 62 case _async_safepoint: mode = "async safepoint"; break; 63 default : mode = "unknown"; break; 64 } 65 st->print(", mode: %s", mode); 66 67 if (calling_thread()) { 68 st->print(", requested by thread " PTR_FORMAT, calling_thread()); 69 } 70} 71 72void VM_ThreadStop::doit() { 73 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint"); 74 JavaThread* target = java_lang_Thread::thread(target_thread()); 75 // Note that this now allows multiple ThreadDeath exceptions to be 76 // thrown at a thread. 77 if (target != NULL) { 78 // the thread has run and is not already in the process of exiting 79 target->send_thread_stop(throwable()); 80 } 81} 82 83void VM_Deoptimize::doit() { 84 // We do not want any GCs to happen while we are in the middle of this VM operation 85 ResourceMark rm; 86 DeoptimizationMarker dm; 87 88 // Deoptimize all activations depending on marked nmethods 89 Deoptimization::deoptimize_dependents(); 90 91 // Make the dependent methods zombies 92 CodeCache::make_marked_nmethods_zombies(); 93} 94 95 96VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id) { 97 _thread = thread; 98 _id = id; 99} 100 101 102void VM_DeoptimizeFrame::doit() { 103 Deoptimization::deoptimize_frame(_thread, _id); 104} 105 106 107#ifndef PRODUCT 108 109void VM_DeoptimizeAll::doit() { 110 DeoptimizationMarker dm; 111 // deoptimize all java threads in the system 112 if (DeoptimizeALot) { 113 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) { 114 if (thread->has_last_Java_frame()) { 115 thread->deoptimize(); 116 } 117 } 118 } else if (DeoptimizeRandom) { 119 120 // Deoptimize some selected threads and frames 121 int tnum = os::random() & 0x3; 122 int fnum = os::random() & 0x3; 123 int tcount = 0; 124 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) { 125 if (thread->has_last_Java_frame()) { 126 if (tcount++ == tnum) { 127 tcount = 0; 128 int fcount = 0; 129 // Deoptimize some selected frames. 130 // Biased llocking wants a updated register map 131 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) { 132 if (fst.current()->can_be_deoptimized()) { 133 if (fcount++ == fnum) { 134 fcount = 0; 135 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map()); 136 } 137 } 138 } 139 } 140 } 141 } 142 } 143} 144 145 146void VM_ZombieAll::doit() { 147 JavaThread *thread = (JavaThread *)calling_thread(); 148 assert(thread->is_Java_thread(), "must be a Java thread"); 149 thread->make_zombies(); 150} 151 152#endif // !PRODUCT 153 154void VM_HandleFullCodeCache::doit() { 155 NMethodSweeper::speculative_disconnect_nmethods(_is_full); 156} 157 158void VM_Verify::doit() { 159 Universe::verify(); 160} 161 162bool VM_PrintThreads::doit_prologue() { 163 assert(Thread::current()->is_Java_thread(), "just checking"); 164 165 // Make sure AbstractOwnableSynchronizer is loaded 166 if (JDK_Version::is_gte_jdk16x_version()) { 167 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 168 } 169 170 // Get Heap_lock if concurrent locks will be dumped 171 if (_print_concurrent_locks) { 172 Heap_lock->lock(); 173 } 174 return true; 175} 176 177void VM_PrintThreads::doit() { 178 Threads::print_on(_out, true, false, _print_concurrent_locks); 179} 180 181void VM_PrintThreads::doit_epilogue() { 182 if (_print_concurrent_locks) { 183 // Release Heap_lock 184 Heap_lock->unlock(); 185 } 186} 187 188void VM_PrintJNI::doit() { 189 JNIHandles::print_on(_out); 190} 191 192VM_FindDeadlocks::~VM_FindDeadlocks() { 193 if (_deadlocks != NULL) { 194 DeadlockCycle* cycle = _deadlocks; 195 while (cycle != NULL) { 196 DeadlockCycle* d = cycle; 197 cycle = cycle->next(); 198 delete d; 199 } 200 } 201} 202 203bool VM_FindDeadlocks::doit_prologue() { 204 assert(Thread::current()->is_Java_thread(), "just checking"); 205 206 // Load AbstractOwnableSynchronizer class 207 if (_concurrent_locks && JDK_Version::is_gte_jdk16x_version()) { 208 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 209 } 210 211 return true; 212} 213 214void VM_FindDeadlocks::doit() { 215 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks); 216 if (_out != NULL) { 217 int num_deadlocks = 0; 218 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) { 219 num_deadlocks++; 220 cycle->print_on(_out); 221 } 222 223 if (num_deadlocks == 1) { 224 _out->print_cr("\nFound 1 deadlock.\n"); 225 _out->flush(); 226 } else if (num_deadlocks > 1) { 227 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks); 228 _out->flush(); 229 } 230 } 231} 232 233VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 234 int max_depth, 235 bool with_locked_monitors, 236 bool with_locked_synchronizers) { 237 _result = result; 238 _num_threads = 0; // 0 indicates all threads 239 _threads = NULL; 240 _result = result; 241 _max_depth = max_depth; 242 _with_locked_monitors = with_locked_monitors; 243 _with_locked_synchronizers = with_locked_synchronizers; 244} 245 246VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 247 GrowableArray<instanceHandle>* threads, 248 int num_threads, 249 int max_depth, 250 bool with_locked_monitors, 251 bool with_locked_synchronizers) { 252 _result = result; 253 _num_threads = num_threads; 254 _threads = threads; 255 _result = result; 256 _max_depth = max_depth; 257 _with_locked_monitors = with_locked_monitors; 258 _with_locked_synchronizers = with_locked_synchronizers; 259} 260 261bool VM_ThreadDump::doit_prologue() { 262 assert(Thread::current()->is_Java_thread(), "just checking"); 263 264 // Load AbstractOwnableSynchronizer class before taking thread snapshots 265 if (JDK_Version::is_gte_jdk16x_version()) { 266 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 267 } 268 269 if (_with_locked_synchronizers) { 270 // Acquire Heap_lock to dump concurrent locks 271 Heap_lock->lock(); 272 } 273 274 return true; 275} 276 277void VM_ThreadDump::doit_epilogue() { 278 if (_with_locked_synchronizers) { 279 // Release Heap_lock 280 Heap_lock->unlock(); 281 } 282} 283 284void VM_ThreadDump::doit() { 285 ResourceMark rm; 286 287 ConcurrentLocksDump concurrent_locks(true); 288 if (_with_locked_synchronizers) { 289 concurrent_locks.dump_at_safepoint(); 290 } 291 292 if (_num_threads == 0) { 293 // Snapshot all live threads 294 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) { 295 if (jt->is_exiting() || 296 jt->is_hidden_from_external_view()) { 297 // skip terminating threads and hidden threads 298 continue; 299 } 300 ThreadConcurrentLocks* tcl = NULL; 301 if (_with_locked_synchronizers) { 302 tcl = concurrent_locks.thread_concurrent_locks(jt); 303 } 304 ThreadSnapshot* ts = snapshot_thread(jt, tcl); 305 _result->add_thread_snapshot(ts); 306 } 307 } else { 308 // Snapshot threads in the given _threads array 309 // A dummy snapshot is created if a thread doesn't exist 310 for (int i = 0; i < _num_threads; i++) { 311 instanceHandle th = _threads->at(i); 312 if (th() == NULL) { 313 // skip if the thread doesn't exist 314 // Add a dummy snapshot 315 _result->add_thread_snapshot(new ThreadSnapshot()); 316 continue; 317 } 318 319 // Dump thread stack only if the thread is alive and not exiting 320 // and not VM internal thread. 321 JavaThread* jt = java_lang_Thread::thread(th()); 322 if (jt == NULL || /* thread not alive */ 323 jt->is_exiting() || 324 jt->is_hidden_from_external_view()) { 325 // add a NULL snapshot if skipped 326 _result->add_thread_snapshot(new ThreadSnapshot()); 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 } 337} 338 339ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) { 340 ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread); 341 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors); 342 snapshot->set_concurrent_locks(tcl); 343 return snapshot; 344} 345 346volatile bool VM_Exit::_vm_exited = false; 347Thread * VM_Exit::_shutdown_thread = NULL; 348 349int VM_Exit::set_vm_exited() { 350 Thread * thr_cur = ThreadLocalStorage::get_thread_slow(); 351 352 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 353 354 int num_active = 0; 355 356 _shutdown_thread = thr_cur; 357 _vm_exited = true; // global flag 358 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) 359 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 360 ++num_active; 361 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag 362 } 363 364 return num_active; 365} 366 367int VM_Exit::wait_for_threads_in_native_to_block() { 368 // VM exits at safepoint. This function must be called at the final safepoint 369 // to wait for threads in _thread_in_native state to be quiescent. 370 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 371 372 Thread * thr_cur = ThreadLocalStorage::get_thread_slow(); 373 Monitor timer(Mutex::leaf, "VM_Exit timer", true); 374 375 // Compiler threads need longer wait because they can access VM data directly 376 // while in native. If they are active and some structures being used are 377 // deleted by the shutdown sequence, they will crash. On the other hand, user 378 // threads must go through native=>Java/VM transitions first to access VM 379 // data, and they will be stopped during state transition. In theory, we 380 // don't have to wait for user threads to be quiescent, but it's always 381 // better to terminate VM when current thread is the only active thread, so 382 // wait for user threads too. Numbers are in 10 milliseconds. 383 int max_wait_user_thread = 30; // at least 300 milliseconds 384 int max_wait_compiler_thread = 1000; // at least 10 seconds 385 386 int max_wait = max_wait_compiler_thread; 387 388 int attempts = 0; 389 while (true) { 390 int num_active = 0; 391 int num_active_compiler_thread = 0; 392 393 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) { 394 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 395 num_active++; 396 if (thr->is_Compiler_thread()) { 397 num_active_compiler_thread++; 398 } 399 } 400 } 401 402 if (num_active == 0) { 403 return 0; 404 } else if (attempts > max_wait) { 405 return num_active; 406 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) { 407 return num_active; 408 } 409 410 attempts++; 411 412 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag); 413 timer.wait(Mutex::_no_safepoint_check_flag, 10); 414 } 415} 416 417void VM_Exit::doit() { 418 CompileBroker::set_should_block(); 419 420 // Wait for a short period for threads in native to block. Any thread 421 // still executing native code after the wait will be stopped at 422 // native==>Java/VM barriers. 423 // Among 16276 JCK tests, 94% of them come here without any threads still 424 // running in native; the other 6% are quiescent within 250ms (Ultra 80). 425 wait_for_threads_in_native_to_block(); 426 427 set_vm_exited(); 428 429 // cleanup globals resources before exiting. exit_globals() currently 430 // cleans up outputStream resources and PerfMemory resources. 431 exit_globals(); 432 433 // Check for exit hook 434 exit_hook_t exit_hook = Arguments::exit_hook(); 435 if (exit_hook != NULL) { 436 // exit hook should exit. 437 exit_hook(_exit_code); 438 // ... but if it didn't, we must do it here 439 vm_direct_exit(_exit_code); 440 } else { 441 vm_direct_exit(_exit_code); 442 } 443} 444 445 446void VM_Exit::wait_if_vm_exited() { 447 if (_vm_exited && 448 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) { 449 // _vm_exited is set at safepoint, and the Threads_lock is never released 450 // we will block here until the process dies 451 Threads_lock->lock_without_safepoint_check(); 452 ShouldNotReachHere(); 453 } 454} 455