1 /* 2 * Copyright (c) 1997, 2015, 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 "code/codeCacheExtensions.hpp" 30 #include "compiler/compileBroker.hpp" 31 #include "compiler/compilerOracle.hpp" 32 #include "gc/shared/isGCActiveMark.hpp" 33 #include "memory/heapInspection.hpp" 34 #include "memory/resourceArea.hpp" 35 #include "oops/symbol.hpp" 36 #include "runtime/arguments.hpp" 37 #include "runtime/deoptimization.hpp" 38 #include "runtime/interfaceSupport.hpp" 39 #include "runtime/sweeper.hpp" 40 #include "runtime/thread.inline.hpp" 41 #include "runtime/vm_operations.hpp" 42 #include "services/threadService.hpp" 43 #include "trace/tracing.hpp" 44 45 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 46 47 #define VM_OP_NAME_INITIALIZE(name) #name, 48 49 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \ 50 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) }; 51 52 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) { 53 _calling_thread = thread; 54 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); 55 _priority = priority; 56 } 57 58 59 void VM_Operation::evaluate() { 60 ResourceMark rm; 61 if (TraceVMOperation) { 62 tty->print("["); 63 NOT_PRODUCT(print();) 64 } 65 doit(); 66 if (TraceVMOperation) { 67 tty->print_cr("]"); 68 } 69 } 70 71 const char* VM_Operation::mode_to_string(Mode mode) { 72 switch(mode) { 73 case _safepoint : return "safepoint"; 74 case _no_safepoint : return "no safepoint"; 75 case _concurrent : return "concurrent"; 76 case _async_safepoint: return "async safepoint"; 77 default : return "unknown"; 78 } 79 } 80 // Called by fatal error handler. 81 void VM_Operation::print_on_error(outputStream* st) const { 82 st->print("VM_Operation (" PTR_FORMAT "): ", this); 83 st->print("%s", name()); 84 85 const char* mode = mode_to_string(evaluation_mode()); 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 void VM_MarkActiveNMethods::doit() { 117 NMethodSweeper::mark_active_nmethods(); 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_Verify::doit() { 185 Universe::heap()->prepare_for_verify(); 186 Universe::verify(_silent); 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 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 194 195 // Get Heap_lock if concurrent locks will be dumped 196 if (_print_concurrent_locks) { 197 Heap_lock->lock(); 198 } 199 return true; 200 } 201 202 void VM_PrintThreads::doit() { 203 Threads::print_on(_out, true, false, _print_concurrent_locks); 204 } 205 206 void VM_PrintThreads::doit_epilogue() { 207 if (_print_concurrent_locks) { 208 // Release Heap_lock 209 Heap_lock->unlock(); 210 } 211 } 212 213 void VM_PrintJNI::doit() { 214 JNIHandles::print_on(_out); 215 } 216 217 VM_FindDeadlocks::~VM_FindDeadlocks() { 218 if (_deadlocks != NULL) { 219 DeadlockCycle* cycle = _deadlocks; 220 while (cycle != NULL) { 221 DeadlockCycle* d = cycle; 222 cycle = cycle->next(); 223 delete d; 224 } 225 } 226 } 227 228 bool VM_FindDeadlocks::doit_prologue() { 229 assert(Thread::current()->is_Java_thread(), "just checking"); 230 231 // Load AbstractOwnableSynchronizer class 232 if (_concurrent_locks) { 233 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 234 } 235 236 return true; 237 } 238 239 void VM_FindDeadlocks::doit() { 240 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks); 241 if (_out != NULL) { 242 int num_deadlocks = 0; 243 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) { 244 num_deadlocks++; 245 cycle->print_on(_out); 246 } 247 248 if (num_deadlocks == 1) { 249 _out->print_cr("\nFound 1 deadlock.\n"); 250 _out->flush(); 251 } else if (num_deadlocks > 1) { 252 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks); 253 _out->flush(); 254 } 255 } 256 } 257 258 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 259 int max_depth, 260 bool with_locked_monitors, 261 bool with_locked_synchronizers) { 262 _result = result; 263 _num_threads = 0; // 0 indicates all threads 264 _threads = NULL; 265 _result = result; 266 _max_depth = max_depth; 267 _with_locked_monitors = with_locked_monitors; 268 _with_locked_synchronizers = with_locked_synchronizers; 269 } 270 271 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 272 GrowableArray<instanceHandle>* threads, 273 int num_threads, 274 int max_depth, 275 bool with_locked_monitors, 276 bool with_locked_synchronizers) { 277 _result = result; 278 _num_threads = num_threads; 279 _threads = threads; 280 _result = result; 281 _max_depth = max_depth; 282 _with_locked_monitors = with_locked_monitors; 283 _with_locked_synchronizers = with_locked_synchronizers; 284 } 285 286 bool VM_ThreadDump::doit_prologue() { 287 assert(Thread::current()->is_Java_thread(), "just checking"); 288 289 // Load AbstractOwnableSynchronizer class before taking thread snapshots 290 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 291 292 if (_with_locked_synchronizers) { 293 // Acquire Heap_lock to dump concurrent locks 294 Heap_lock->lock(); 295 } 296 297 return true; 298 } 299 300 void VM_ThreadDump::doit_epilogue() { 301 if (_with_locked_synchronizers) { 302 // Release Heap_lock 303 Heap_lock->unlock(); 304 } 305 } 306 307 void VM_ThreadDump::doit() { 308 ResourceMark rm; 309 310 ConcurrentLocksDump concurrent_locks(true); 311 if (_with_locked_synchronizers) { 312 concurrent_locks.dump_at_safepoint(); 313 } 314 315 if (_num_threads == 0) { 316 // Snapshot all live threads 317 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) { 318 if (jt->is_exiting() || 319 jt->is_hidden_from_external_view()) { 320 // skip terminating threads and hidden threads 321 continue; 322 } 323 ThreadConcurrentLocks* tcl = NULL; 324 if (_with_locked_synchronizers) { 325 tcl = concurrent_locks.thread_concurrent_locks(jt); 326 } 327 ThreadSnapshot* ts = snapshot_thread(jt, tcl); 328 _result->add_thread_snapshot(ts); 329 } 330 } else { 331 // Snapshot threads in the given _threads array 332 // A dummy snapshot is created if a thread doesn't exist 333 for (int i = 0; i < _num_threads; i++) { 334 instanceHandle th = _threads->at(i); 335 if (th() == NULL) { 336 // skip if the thread doesn't exist 337 // Add a dummy snapshot 338 _result->add_thread_snapshot(new ThreadSnapshot()); 339 continue; 340 } 341 342 // Dump thread stack only if the thread is alive and not exiting 343 // and not VM internal thread. 344 JavaThread* jt = java_lang_Thread::thread(th()); 345 if (jt == NULL || /* thread not alive */ 346 jt->is_exiting() || 347 jt->is_hidden_from_external_view()) { 348 // add a NULL snapshot if skipped 349 _result->add_thread_snapshot(new ThreadSnapshot()); 350 continue; 351 } 352 ThreadConcurrentLocks* tcl = NULL; 353 if (_with_locked_synchronizers) { 354 tcl = concurrent_locks.thread_concurrent_locks(jt); 355 } 356 ThreadSnapshot* ts = snapshot_thread(jt, tcl); 357 _result->add_thread_snapshot(ts); 358 } 359 } 360 } 361 362 ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) { 363 ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread); 364 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors); 365 snapshot->set_concurrent_locks(tcl); 366 return snapshot; 367 } 368 369 volatile bool VM_Exit::_vm_exited = false; 370 Thread * VM_Exit::_shutdown_thread = NULL; 371 372 int VM_Exit::set_vm_exited() { 373 CodeCacheExtensions::complete_step(CodeCacheExtensionsSteps::LastStep); 374 375 Thread * thr_cur = ThreadLocalStorage::get_thread_slow(); 376 377 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 378 379 int num_active = 0; 380 381 _shutdown_thread = thr_cur; 382 _vm_exited = true; // global flag 383 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) 384 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 385 ++num_active; 386 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag 387 } 388 389 return num_active; 390 } 391 392 int VM_Exit::wait_for_threads_in_native_to_block() { 393 // VM exits at safepoint. This function must be called at the final safepoint 394 // to wait for threads in _thread_in_native state to be quiescent. 395 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 396 397 Thread * thr_cur = ThreadLocalStorage::get_thread_slow(); 398 Monitor timer(Mutex::leaf, "VM_Exit timer", true, 399 Monitor::_safepoint_check_never); 400 401 // Compiler threads need longer wait because they can access VM data directly 402 // while in native. If they are active and some structures being used are 403 // deleted by the shutdown sequence, they will crash. On the other hand, user 404 // threads must go through native=>Java/VM transitions first to access VM 405 // data, and they will be stopped during state transition. In theory, we 406 // don't have to wait for user threads to be quiescent, but it's always 407 // better to terminate VM when current thread is the only active thread, so 408 // wait for user threads too. Numbers are in 10 milliseconds. 409 int max_wait_user_thread = 30; // at least 300 milliseconds 410 int max_wait_compiler_thread = 1000; // at least 10 seconds 411 412 int max_wait = max_wait_compiler_thread; 413 414 int attempts = 0; 415 while (true) { 416 int num_active = 0; 417 int num_active_compiler_thread = 0; 418 419 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) { 420 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 421 num_active++; 422 if (thr->is_Compiler_thread()) { 423 num_active_compiler_thread++; 424 } 425 } 426 } 427 428 if (num_active == 0) { 429 return 0; 430 } else if (attempts > max_wait) { 431 return num_active; 432 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) { 433 return num_active; 434 } 435 436 attempts++; 437 438 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag); 439 timer.wait(Mutex::_no_safepoint_check_flag, 10); 440 } 441 } 442 443 void VM_Exit::doit() { 444 CompileBroker::set_should_block(); 445 446 // Wait for a short period for threads in native to block. Any thread 447 // still executing native code after the wait will be stopped at 448 // native==>Java/VM barriers. 449 // Among 16276 JCK tests, 94% of them come here without any threads still 450 // running in native; the other 6% are quiescent within 250ms (Ultra 80). 451 wait_for_threads_in_native_to_block(); 452 453 set_vm_exited(); 454 455 // cleanup globals resources before exiting. exit_globals() currently 456 // cleans up outputStream resources and PerfMemory resources. 457 exit_globals(); 458 459 // Check for exit hook 460 exit_hook_t exit_hook = Arguments::exit_hook(); 461 if (exit_hook != NULL) { 462 // exit hook should exit. 463 exit_hook(_exit_code); 464 // ... but if it didn't, we must do it here 465 vm_direct_exit(_exit_code); 466 } else { 467 vm_direct_exit(_exit_code); 468 } 469 } 470 471 472 void VM_Exit::wait_if_vm_exited() { 473 if (_vm_exited && 474 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) { 475 // _vm_exited is set at safepoint, and the Threads_lock is never released 476 // we will block here until the process dies 477 Threads_lock->lock_without_safepoint_check(); 478 ShouldNotReachHere(); 479 } 480 } 481 482 void VM_PrintCompileQueue::doit() { 483 CompileBroker::print_compile_queues(_out); 484 } 485 486 void VM_PrintCodeList::doit() { 487 CodeCache::print_codelist(_out); 488 } 489 490 void VM_PrintCodeCache::doit() { 491 CodeCache::print_layout(_out); 492 } 493 494 #if INCLUDE_SERVICES 495 void VM_PrintClassHierarchy::doit() { 496 KlassHierarchy::print_class_hierarchy(_out, _print_interfaces, _print_subclasses, _classname); 497 } 498 #endif