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 Monitor::_safepoint_check_never); 396 397 // Compiler threads need longer wait because they can access VM data directly 398 // while in native. If they are active and some structures being used are 399 // deleted by the shutdown sequence, they will crash. On the other hand, user 400 // threads must go through native=>Java/VM transitions first to access VM 401 // data, and they will be stopped during state transition. In theory, we 402 // don't have to wait for user threads to be quiescent, but it's always 403 // better to terminate VM when current thread is the only active thread, so 404 // wait for user threads too. Numbers are in 10 milliseconds. 405 int max_wait_user_thread = 30; // at least 300 milliseconds 406 int max_wait_compiler_thread = 1000; // at least 10 seconds 407 408 int max_wait = max_wait_compiler_thread; 409 410 int attempts = 0; 411 while (true) { 412 int num_active = 0; 413 int num_active_compiler_thread = 0; 414 415 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) { 416 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 417 num_active++; 418 if (thr->is_Compiler_thread()) { 419 num_active_compiler_thread++; 420 } 421 } 422 } 423 424 if (num_active == 0) { 425 return 0; 426 } else if (attempts > max_wait) { 427 return num_active; 428 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) { 429 return num_active; 430 } 431 432 attempts++; 433 434 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag); 435 timer.wait(Mutex::_no_safepoint_check_flag, 10); 436 } 437 } 438 439 void VM_Exit::doit() { 440 CompileBroker::set_should_block(); 441 442 // Wait for a short period for threads in native to block. Any thread 443 // still executing native code after the wait will be stopped at 444 // native==>Java/VM barriers. 445 // Among 16276 JCK tests, 94% of them come here without any threads still 446 // running in native; the other 6% are quiescent within 250ms (Ultra 80). 447 wait_for_threads_in_native_to_block(); 448 449 set_vm_exited(); 450 451 // cleanup globals resources before exiting. exit_globals() currently 452 // cleans up outputStream resources and PerfMemory resources. 453 exit_globals(); 454 455 // Check for exit hook 456 exit_hook_t exit_hook = Arguments::exit_hook(); 457 if (exit_hook != NULL) { 458 // exit hook should exit. 459 exit_hook(_exit_code); 460 // ... but if it didn't, we must do it here 461 vm_direct_exit(_exit_code); 462 } else { 463 vm_direct_exit(_exit_code); 464 } 465 } 466 467 468 void VM_Exit::wait_if_vm_exited() { 469 if (_vm_exited && 470 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) { 471 // _vm_exited is set at safepoint, and the Threads_lock is never released 472 // we will block here until the process dies 473 Threads_lock->lock_without_safepoint_check(); 474 ShouldNotReachHere(); 475 } 476 } 477 478 void VM_PrintCompileQueue::doit() { 479 CompileBroker::print_compile_queues(_out); 480 } 481 482 void VM_PrintCodeList::doit() { 483 CodeCache::print_codelist(_out); 484 } 485 486 void VM_PrintCodeCache::doit() { 487 CodeCache::print_layout(_out); 488 }