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 "gc/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 #define VM_OP_NAME_INITIALIZE(name) #name, 45 46 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \ 47 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) }; 48 49 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) { 50 _calling_thread = thread; 51 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); 52 _priority = priority; 53 } 54 55 56 void VM_Operation::evaluate() { 57 ResourceMark rm; 58 if (TraceVMOperation) { 59 tty->print("["); 60 NOT_PRODUCT(print();) 61 } 62 doit(); 63 if (TraceVMOperation) { 64 tty->print_cr("]"); 65 } 66 } 67 68 const char* VM_Operation::mode_to_string(Mode mode) { 69 switch(mode) { 70 case _safepoint : return "safepoint"; 71 case _no_safepoint : return "no safepoint"; 72 case _concurrent : return "concurrent"; 73 case _async_safepoint: return "async safepoint"; 74 default : return "unknown"; 75 } 76 } 77 // Called by fatal error handler. 78 void VM_Operation::print_on_error(outputStream* st) const { 79 st->print("VM_Operation (" PTR_FORMAT "): ", p2i(this)); 80 st->print("%s", name()); 81 82 const char* mode = mode_to_string(evaluation_mode()); 83 st->print(", mode: %s", mode); 84 85 if (calling_thread()) { 86 st->print(", requested by thread " PTR_FORMAT, p2i(calling_thread())); 87 } 88 } 89 90 void VM_ThreadStop::doit() { 91 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint"); 92 JavaThread* target = java_lang_Thread::thread(target_thread()); 93 // Note that this now allows multiple ThreadDeath exceptions to be 94 // thrown at a thread. 95 if (target != NULL) { 96 // the thread has run and is not already in the process of exiting 97 target->send_thread_stop(throwable()); 98 } 99 } 100 101 void VM_Deoptimize::doit() { 102 // We do not want any GCs to happen while we are in the middle of this VM operation 103 ResourceMark rm; 104 DeoptimizationMarker dm; 105 106 // Deoptimize all activations depending on marked nmethods 107 Deoptimization::deoptimize_dependents(); 108 109 // Make the dependent methods not entrant 110 CodeCache::make_marked_nmethods_not_entrant(); 111 } 112 113 void VM_MarkActiveNMethods::doit() { 114 NMethodSweeper::mark_active_nmethods(); 115 } 116 117 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id, int reason) { 118 _thread = thread; 119 _id = id; 120 _reason = reason; 121 } 122 123 124 void VM_DeoptimizeFrame::doit() { 125 assert(_reason > Deoptimization::Reason_none && _reason < Deoptimization::Reason_LIMIT, "invalid deopt reason"); 126 Deoptimization::deoptimize_frame_internal(_thread, _id, (Deoptimization::DeoptReason)_reason); 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 CodeCacheExtensions::complete_step(CodeCacheExtensionsSteps::LastStep); 373 374 Thread * thr_cur = ThreadLocalStorage::get_thread_slow(); 375 376 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 377 378 int num_active = 0; 379 380 _shutdown_thread = thr_cur; 381 _vm_exited = true; // global flag 382 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) 383 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 384 ++num_active; 385 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag 386 } 387 388 return num_active; 389 } 390 391 int VM_Exit::wait_for_threads_in_native_to_block() { 392 // VM exits at safepoint. This function must be called at the final safepoint 393 // to wait for threads in _thread_in_native state to be quiescent. 394 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 395 396 Thread * thr_cur = ThreadLocalStorage::get_thread_slow(); 397 Monitor timer(Mutex::leaf, "VM_Exit timer", true, 398 Monitor::_safepoint_check_never); 399 400 // Compiler threads need longer wait because they can access VM data directly 401 // while in native. If they are active and some structures being used are 402 // deleted by the shutdown sequence, they will crash. On the other hand, user 403 // threads must go through native=>Java/VM transitions first to access VM 404 // data, and they will be stopped during state transition. In theory, we 405 // don't have to wait for user threads to be quiescent, but it's always 406 // better to terminate VM when current thread is the only active thread, so 407 // wait for user threads too. Numbers are in 10 milliseconds. 408 int max_wait_user_thread = 30; // at least 300 milliseconds 409 int max_wait_compiler_thread = 1000; // at least 10 seconds 410 411 int max_wait = max_wait_compiler_thread; 412 413 int attempts = 0; 414 while (true) { 415 int num_active = 0; 416 int num_active_compiler_thread = 0; 417 418 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) { 419 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 420 num_active++; 421 if (thr->is_Compiler_thread()) { 422 num_active_compiler_thread++; 423 } 424 } 425 } 426 427 if (num_active == 0) { 428 return 0; 429 } else if (attempts > max_wait) { 430 return num_active; 431 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) { 432 return num_active; 433 } 434 435 attempts++; 436 437 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag); 438 timer.wait(Mutex::_no_safepoint_check_flag, 10); 439 } 440 } 441 442 void VM_Exit::doit() { 443 CompileBroker::set_should_block(); 444 445 // Wait for a short period for threads in native to block. Any thread 446 // still executing native code after the wait will be stopped at 447 // native==>Java/VM barriers. 448 // Among 16276 JCK tests, 94% of them come here without any threads still 449 // running in native; the other 6% are quiescent within 250ms (Ultra 80). 450 wait_for_threads_in_native_to_block(); 451 452 set_vm_exited(); 453 454 // cleanup globals resources before exiting. exit_globals() currently 455 // cleans up outputStream resources and PerfMemory resources. 456 exit_globals(); 457 458 // Check for exit hook 459 exit_hook_t exit_hook = Arguments::exit_hook(); 460 if (exit_hook != NULL) { 461 // exit hook should exit. 462 exit_hook(_exit_code); 463 // ... but if it didn't, we must do it here 464 vm_direct_exit(_exit_code); 465 } else { 466 vm_direct_exit(_exit_code); 467 } 468 } 469 470 471 void VM_Exit::wait_if_vm_exited() { 472 if (_vm_exited && 473 ThreadLocalStorage::get_thread_slow() != _shutdown_thread) { 474 // _vm_exited is set at safepoint, and the Threads_lock is never released 475 // we will block here until the process dies 476 Threads_lock->lock_without_safepoint_check(); 477 ShouldNotReachHere(); 478 } 479 } 480 481 void VM_PrintCompileQueue::doit() { 482 CompileBroker::print_compile_queues(_out); 483 } 484 485 void VM_PrintCodeList::doit() { 486 CodeCache::print_codelist(_out); 487 } 488 489 void VM_PrintCodeCache::doit() { 490 CodeCache::print_layout(_out); 491 } 492 493 #if INCLUDE_SERVICES 494 void VM_PrintClassHierarchy::doit() { 495 KlassHierarchy::print_class_hierarchy(_out, _print_interfaces, _print_subclasses, _classname); 496 } 497 #endif