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 "compiler/compileBroker.hpp" 30 #include "compiler/compilerOracle.hpp" 31 #include "gc_implementation/shared/isGCActiveMark.hpp" 32 #include "memory/heapInspection.hpp" 33 #include "memory/resourceArea.hpp" 34 #include "oops/symbol.hpp" 35 #include "runtime/arguments.hpp" 36 #include "runtime/deoptimization.hpp" 37 #include "runtime/interfaceSupport.hpp" 38 #include "runtime/sweeper.hpp" 39 #include "runtime/thread.inline.hpp" 40 #include "runtime/vm_operations.hpp" 41 #include "services/threadService.hpp" 42 #include "trace/tracing.hpp" 43 44 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC 45 46 #define VM_OP_NAME_INITIALIZE(name) #name, 47 48 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \ 49 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) }; 50 51 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) { 52 _calling_thread = thread; 53 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); 54 _priority = priority; 55 } 56 57 58 void VM_Operation::evaluate() { 59 ResourceMark rm; 60 if (TraceVMOperation) { 61 tty->print("["); 62 NOT_PRODUCT(print();) 63 } 64 doit(); 65 if (TraceVMOperation) { 66 tty->print_cr("]"); 67 } 68 } 69 70 const char* VM_Operation::mode_to_string(Mode mode) { 71 switch(mode) { 72 case _safepoint : return "safepoint"; 73 case _no_safepoint : return "no safepoint"; 74 case _concurrent : return "concurrent"; 75 case _async_safepoint: return "async safepoint"; 76 default : return "unknown"; 77 } 78 } 79 // Called by fatal error handler. 80 void VM_Operation::print_on_error(outputStream* st) const { 81 st->print("VM_Operation (" PTR_FORMAT "): ", this); 82 st->print("%s", name()); 83 84 const char* mode = mode_to_string(evaluation_mode()); 85 st->print(", mode: %s", mode); 86 87 if (calling_thread()) { 88 st->print(", requested by thread " PTR_FORMAT, calling_thread()); 89 } 90 } 91 92 void VM_ThreadStop::doit() { 93 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint"); 94 JavaThread* target = java_lang_Thread::thread(target_thread()); 95 // Note that this now allows multiple ThreadDeath exceptions to be 96 // thrown at a thread. 97 if (target != NULL) { 98 // the thread has run and is not already in the process of exiting 99 target->send_thread_stop(throwable()); 100 } 101 } 102 103 void VM_Deoptimize::doit() { 104 // We do not want any GCs to happen while we are in the middle of this VM operation 105 ResourceMark rm; 106 DeoptimizationMarker dm; 107 108 // Deoptimize all activations depending on marked nmethods 109 Deoptimization::deoptimize_dependents(); 110 111 // Make the dependent methods zombies 112 CodeCache::make_marked_nmethods_zombies(); 113 } 114 115 void VM_MarkActiveNMethods::doit() { 116 NMethodSweeper::mark_active_nmethods(); 117 } 118 119 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id) { 120 _thread = thread; 121 _id = id; 122 } 123 124 125 void VM_DeoptimizeFrame::doit() { 126 Deoptimization::deoptimize_frame_internal(_thread, _id); 127 } 128 129 130 #ifndef PRODUCT 131 132 void VM_DeoptimizeAll::doit() { 133 DeoptimizationMarker dm; 134 // deoptimize all java threads in the system 135 if (DeoptimizeALot) { 136 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) { 137 if (thread->has_last_Java_frame()) { 138 thread->deoptimize(); 139 } 140 } 141 } else if (DeoptimizeRandom) { 142 143 // Deoptimize some selected threads and frames 144 int tnum = os::random() & 0x3; 145 int fnum = os::random() & 0x3; 146 int tcount = 0; 147 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) { 148 if (thread->has_last_Java_frame()) { 149 if (tcount++ == tnum) { 150 tcount = 0; 151 int fcount = 0; 152 // Deoptimize some selected frames. 153 // Biased llocking wants a updated register map 154 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) { 155 if (fst.current()->can_be_deoptimized()) { 156 if (fcount++ == fnum) { 157 fcount = 0; 158 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map()); 159 } 160 } 161 } 162 } 163 } 164 } 165 } 166 } 167 168 169 void VM_ZombieAll::doit() { 170 JavaThread *thread = (JavaThread *)calling_thread(); 171 assert(thread->is_Java_thread(), "must be a Java thread"); 172 thread->make_zombies(); 173 } 174 175 #endif // !PRODUCT 176 177 void VM_UnlinkSymbols::doit() { 178 JavaThread *thread = (JavaThread *)calling_thread(); 179 assert(thread->is_Java_thread(), "must be a Java thread"); 180 SymbolTable::unlink(); 181 } 182 183 void VM_Verify::doit() { 184 Universe::heap()->prepare_for_verify(); 185 Universe::verify(_silent); 186 } 187 188 bool VM_PrintThreads::doit_prologue() { 189 assert(Thread::current()->is_Java_thread(), "just checking"); 190 191 // Make sure AbstractOwnableSynchronizer is loaded 192 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 193 194 // Get Heap_lock if concurrent locks will be dumped 195 if (_print_concurrent_locks) { 196 Heap_lock->lock(); 197 } 198 return true; 199 } 200 201 void VM_PrintThreads::doit() { 202 Threads::print_on(_out, true, false, _print_concurrent_locks); 203 } 204 205 void VM_PrintThreads::doit_epilogue() { 206 if (_print_concurrent_locks) { 207 // Release Heap_lock 208 Heap_lock->unlock(); 209 } 210 } 211 212 void VM_PrintJNI::doit() { 213 JNIHandles::print_on(_out); 214 } 215 216 VM_FindDeadlocks::~VM_FindDeadlocks() { 217 if (_deadlocks != NULL) { 218 DeadlockCycle* cycle = _deadlocks; 219 while (cycle != NULL) { 220 DeadlockCycle* d = cycle; 221 cycle = cycle->next(); 222 delete d; 223 } 224 } 225 } 226 227 bool VM_FindDeadlocks::doit_prologue() { 228 assert(Thread::current()->is_Java_thread(), "just checking"); 229 230 // Load AbstractOwnableSynchronizer class 231 if (_concurrent_locks) { 232 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 233 } 234 235 return true; 236 } 237 238 void VM_FindDeadlocks::doit() { 239 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks); 240 if (_out != NULL) { 241 int num_deadlocks = 0; 242 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) { 243 num_deadlocks++; 244 cycle->print_on(_out); 245 } 246 247 if (num_deadlocks == 1) { 248 _out->print_cr("\nFound 1 deadlock.\n"); 249 _out->flush(); 250 } else if (num_deadlocks > 1) { 251 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks); 252 _out->flush(); 253 } 254 } 255 } 256 257 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 258 int max_depth, 259 bool with_locked_monitors, 260 bool with_locked_synchronizers) { 261 _result = result; 262 _num_threads = 0; // 0 indicates all threads 263 _threads = NULL; 264 _result = result; 265 _max_depth = max_depth; 266 _with_locked_monitors = with_locked_monitors; 267 _with_locked_synchronizers = with_locked_synchronizers; 268 } 269 270 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 271 GrowableArray<instanceHandle>* threads, 272 int num_threads, 273 int max_depth, 274 bool with_locked_monitors, 275 bool with_locked_synchronizers) { 276 _result = result; 277 _num_threads = num_threads; 278 _threads = threads; 279 _result = result; 280 _max_depth = max_depth; 281 _with_locked_monitors = with_locked_monitors; 282 _with_locked_synchronizers = with_locked_synchronizers; 283 } 284 285 bool VM_ThreadDump::doit_prologue() { 286 assert(Thread::current()->is_Java_thread(), "just checking"); 287 288 // Load AbstractOwnableSynchronizer class before taking thread snapshots 289 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 290 291 if (_with_locked_synchronizers) { 292 // Acquire Heap_lock to dump concurrent locks 293 Heap_lock->lock(); 294 } 295 296 return true; 297 } 298 299 void VM_ThreadDump::doit_epilogue() { 300 if (_with_locked_synchronizers) { 301 // Release Heap_lock 302 Heap_lock->unlock(); 303 } 304 } 305 306 void VM_ThreadDump::doit() { 307 ResourceMark rm; 308 309 ConcurrentLocksDump concurrent_locks(true); 310 if (_with_locked_synchronizers) { 311 concurrent_locks.dump_at_safepoint(); 312 } 313 314 if (_num_threads == 0) { 315 // Snapshot all live threads 316 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) { 317 if (jt->is_exiting() || 318 jt->is_hidden_from_external_view()) { 319 // skip terminating threads and hidden threads 320 continue; 321 } 322 ThreadConcurrentLocks* tcl = NULL; 323 if (_with_locked_synchronizers) { 324 tcl = concurrent_locks.thread_concurrent_locks(jt); 325 } 326 ThreadSnapshot* ts = snapshot_thread(jt, tcl); 327 _result->add_thread_snapshot(ts); 328 } 329 } else { 330 // Snapshot threads in the given _threads array 331 // A dummy snapshot is created if a thread doesn't exist 332 for (int i = 0; i < _num_threads; i++) { 333 instanceHandle th = _threads->at(i); 334 if (th() == NULL) { 335 // skip if the thread doesn't exist 336 // Add a dummy snapshot 337 _result->add_thread_snapshot(new ThreadSnapshot()); 338 continue; 339 } 340 341 // Dump thread stack only if the thread is alive and not exiting 342 // and not VM internal thread. 343 JavaThread* jt = java_lang_Thread::thread(th()); 344 if (jt == NULL || /* thread not alive */ 345 jt->is_exiting() || 346 jt->is_hidden_from_external_view()) { 347 // add a NULL snapshot if skipped 348 _result->add_thread_snapshot(new ThreadSnapshot()); 349 continue; 350 } 351 ThreadConcurrentLocks* tcl = NULL; 352 if (_with_locked_synchronizers) { 353 tcl = concurrent_locks.thread_concurrent_locks(jt); 354 } 355 ThreadSnapshot* ts = snapshot_thread(jt, tcl); 356 _result->add_thread_snapshot(ts); 357 } 358 } 359 } 360 361 ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) { 362 ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread); 363 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors); 364 snapshot->set_concurrent_locks(tcl); 365 return snapshot; 366 } 367 368 volatile bool VM_Exit::_vm_exited = false; 369 Thread * VM_Exit::_shutdown_thread = NULL; 370 371 int VM_Exit::set_vm_exited() { 372 Thread * thr_cur = ThreadLocalStorage::get_thread_slow(); 373 374 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 375 376 int num_active = 0; 377 378 _shutdown_thread = thr_cur; 379 _vm_exited = true; // global flag 380 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) 381 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 382 ++num_active; 383 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag 384 } 385 386 return num_active; 387 } 388 389 int VM_Exit::wait_for_threads_in_native_to_block() { 390 // VM exits at safepoint. This function must be called at the final safepoint 391 // to wait for threads in _thread_in_native state to be quiescent. 392 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 393 394 Thread * thr_cur = ThreadLocalStorage::get_thread_slow(); 395 Monitor timer(Mutex::leaf, "VM_Exit timer", true, 396 Monitor::_safepoint_check_never); 397 398 // Compiler threads need longer wait because they can access VM data directly 399 // while in native. If they are active and some structures being used are 400 // deleted by the shutdown sequence, they will crash. On the other hand, user 401 // threads must go through native=>Java/VM transitions first to access VM 402 // data, and they will be stopped during state transition. In theory, we 403 // don't have to wait for user threads to be quiescent, but it's always 404 // better to terminate VM when current thread is the only active thread, so 405 // wait for user threads too. Numbers are in 10 milliseconds. 406 int max_wait_user_thread = 30; // at least 300 milliseconds 407 int max_wait_compiler_thread = 1000; // at least 10 seconds 408 409 int max_wait = max_wait_compiler_thread; 410 411 int attempts = 0; 412 while (true) { 413 int num_active = 0; 414 int num_active_compiler_thread = 0; 415 416 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) { 417 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 418 num_active++; 419 if (thr->is_Compiler_thread()) { 420 num_active_compiler_thread++; 421 } 422 } 423 } 424 425 if (num_active == 0) { 426 return 0; 427 } else if (attempts > max_wait) { 428 return num_active; 429 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) { 430 return num_active; 431 } 432 433 attempts++; 434 435 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag); 436 timer.wait(Mutex::_no_safepoint_check_flag, 10); 437 } 438 } 439 440 void VM_Exit::doit() { 441 CompileBroker::set_should_block(); 442 443 // Wait for a short period for threads in native to block. Any thread 444 // still executing native code after the wait will be stopped at 445 // native==>Java/VM barriers. 446 // Among 16276 JCK tests, 94% of them come here without any threads still 447 // running in native; the other 6% are quiescent within 250ms (Ultra 80). 448 wait_for_threads_in_native_to_block(); 449 450 set_vm_exited(); 451 452 // cleanup globals resources before exiting. exit_globals() currently 453 // cleans up outputStream resources and PerfMemory resources. 454 exit_globals(); 455 456 // Check for exit hook 457 exit_hook_t exit_hook = Arguments::exit_hook(); 458 if (exit_hook != NULL) { 459 // exit hook should exit. 460 exit_hook(_exit_code); 461 // ... but if it didn't, we must do it here 462 vm_direct_exit(_exit_code); 463 } else { 464 vm_direct_exit(_exit_code); 465 } 466 } 467 468 469 void VM_Exit::wait_if_vm_exited() { 470 if (_vm_exited && 471 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) { 472 // _vm_exited is set at safepoint, and the Threads_lock is never released 473 // we will block here until the process dies 474 Threads_lock->lock_without_safepoint_check(); 475 ShouldNotReachHere(); 476 } 477 } 478 479 void VM_PrintCompileQueue::doit() { 480 CompileBroker::print_compile_queues(_out); 481 } 482 483 void VM_PrintCodeList::doit() { 484 CodeCache::print_codelist(_out); 485 } 486 487 void VM_PrintCodeCache::doit() { 488 CodeCache::print_layout(_out); 489 } 490 491 #if INCLUDE_SERVICES 492 void VM_PrintClassHierarchy::doit() { 493 KlassHierarchy::print_class_hierarchy(_out, _print_interfaces, _print_subclasses, _classname); 494 } 495 #endif