1/* 2 * Copyright (c) 1997, 2016, 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 "gc/shared/isGCActiveMark.hpp" 31#include "logging/log.hpp" 32#include "logging/logStream.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#define VM_OP_NAME_INITIALIZE(name) #name, 46 47const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \ 48 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) }; 49 50void 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 57void VM_Operation::evaluate() { 58 ResourceMark rm; 59 LogTarget(Debug, vmoperation) lt; 60 if (lt.is_enabled()) { 61 LogStream ls(lt); 62 ls.print("begin "); 63 print_on_error(&ls); 64 ls.cr(); 65 } 66 doit(); 67 if (lt.is_enabled()) { 68 LogStream ls(lt); 69 ls.print("end "); 70 print_on_error(&ls); 71 ls.cr(); 72 } 73} 74 75const char* VM_Operation::mode_to_string(Mode mode) { 76 switch(mode) { 77 case _safepoint : return "safepoint"; 78 case _no_safepoint : return "no safepoint"; 79 case _concurrent : return "concurrent"; 80 case _async_safepoint: return "async safepoint"; 81 default : return "unknown"; 82 } 83} 84// Called by fatal error handler. 85void VM_Operation::print_on_error(outputStream* st) const { 86 st->print("VM_Operation (" PTR_FORMAT "): ", p2i(this)); 87 st->print("%s", name()); 88 89 const char* mode = mode_to_string(evaluation_mode()); 90 st->print(", mode: %s", mode); 91 92 if (calling_thread()) { 93 st->print(", requested by thread " PTR_FORMAT, p2i(calling_thread())); 94 } 95} 96 97void VM_ThreadStop::doit() { 98 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint"); 99 JavaThread* target = java_lang_Thread::thread(target_thread()); 100 // Note that this now allows multiple ThreadDeath exceptions to be 101 // thrown at a thread. 102 if (target != NULL) { 103 // the thread has run and is not already in the process of exiting 104 target->send_thread_stop(throwable()); 105 } 106} 107 108void VM_ClearICs::doit() { 109 if (_preserve_static_stubs) { 110 CodeCache::cleanup_inline_caches(); 111 } else { 112 CodeCache::clear_inline_caches(); 113 } 114} 115 116void VM_Deoptimize::doit() { 117 // We do not want any GCs to happen while we are in the middle of this VM operation 118 ResourceMark rm; 119 DeoptimizationMarker dm; 120 121 // Deoptimize all activations depending on marked nmethods 122 Deoptimization::deoptimize_dependents(); 123 124 // Make the dependent methods not entrant 125 CodeCache::make_marked_nmethods_not_entrant(); 126} 127 128void VM_MarkActiveNMethods::doit() { 129 NMethodSweeper::mark_active_nmethods(); 130} 131 132VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id, int reason) { 133 _thread = thread; 134 _id = id; 135 _reason = reason; 136} 137 138 139void VM_DeoptimizeFrame::doit() { 140 assert(_reason > Deoptimization::Reason_none && _reason < Deoptimization::Reason_LIMIT, "invalid deopt reason"); 141 Deoptimization::deoptimize_frame_internal(_thread, _id, (Deoptimization::DeoptReason)_reason); 142} 143 144 145#ifndef PRODUCT 146 147void VM_DeoptimizeAll::doit() { 148 DeoptimizationMarker dm; 149 // deoptimize all java threads in the system 150 if (DeoptimizeALot) { 151 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) { 152 if (thread->has_last_Java_frame()) { 153 thread->deoptimize(); 154 } 155 } 156 } else if (DeoptimizeRandom) { 157 158 // Deoptimize some selected threads and frames 159 int tnum = os::random() & 0x3; 160 int fnum = os::random() & 0x3; 161 int tcount = 0; 162 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) { 163 if (thread->has_last_Java_frame()) { 164 if (tcount++ == tnum) { 165 tcount = 0; 166 int fcount = 0; 167 // Deoptimize some selected frames. 168 // Biased llocking wants a updated register map 169 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) { 170 if (fst.current()->can_be_deoptimized()) { 171 if (fcount++ == fnum) { 172 fcount = 0; 173 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map()); 174 } 175 } 176 } 177 } 178 } 179 } 180 } 181} 182 183 184void VM_ZombieAll::doit() { 185 JavaThread *thread = (JavaThread *)calling_thread(); 186 assert(thread->is_Java_thread(), "must be a Java thread"); 187 thread->make_zombies(); 188} 189 190#endif // !PRODUCT 191 192void VM_UnlinkSymbols::doit() { 193 JavaThread *thread = (JavaThread *)calling_thread(); 194 assert(thread->is_Java_thread(), "must be a Java thread"); 195 SymbolTable::unlink(); 196} 197 198void VM_Verify::doit() { 199 Universe::heap()->prepare_for_verify(); 200 Universe::verify(); 201} 202 203bool VM_PrintThreads::doit_prologue() { 204 // Make sure AbstractOwnableSynchronizer is loaded 205 JavaThread* jt = JavaThread::current(); 206 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(jt); 207 if (jt->has_pending_exception()) { 208 return false; 209 } 210 211 // Get Heap_lock if concurrent locks will be dumped 212 if (_print_concurrent_locks) { 213 Heap_lock->lock(); 214 } 215 return true; 216} 217 218void VM_PrintThreads::doit() { 219 Threads::print_on(_out, true, false, _print_concurrent_locks); 220} 221 222void VM_PrintThreads::doit_epilogue() { 223 if (_print_concurrent_locks) { 224 // Release Heap_lock 225 Heap_lock->unlock(); 226 } 227} 228 229void VM_PrintJNI::doit() { 230 JNIHandles::print_on(_out); 231} 232 233VM_FindDeadlocks::~VM_FindDeadlocks() { 234 if (_deadlocks != NULL) { 235 DeadlockCycle* cycle = _deadlocks; 236 while (cycle != NULL) { 237 DeadlockCycle* d = cycle; 238 cycle = cycle->next(); 239 delete d; 240 } 241 } 242} 243 244bool VM_FindDeadlocks::doit_prologue() { 245 if (_concurrent_locks) { 246 // Make sure AbstractOwnableSynchronizer is loaded 247 JavaThread* jt = JavaThread::current(); 248 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(jt); 249 if (jt->has_pending_exception()) { 250 return false; 251 } 252 } 253 254 return true; 255} 256 257void VM_FindDeadlocks::doit() { 258 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks); 259 if (_out != NULL) { 260 int num_deadlocks = 0; 261 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) { 262 num_deadlocks++; 263 cycle->print_on(_out); 264 } 265 266 if (num_deadlocks == 1) { 267 _out->print_cr("\nFound 1 deadlock.\n"); 268 _out->flush(); 269 } else if (num_deadlocks > 1) { 270 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks); 271 _out->flush(); 272 } 273 } 274} 275 276VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 277 int max_depth, 278 bool with_locked_monitors, 279 bool with_locked_synchronizers) { 280 _result = result; 281 _num_threads = 0; // 0 indicates all threads 282 _threads = NULL; 283 _result = result; 284 _max_depth = max_depth; 285 _with_locked_monitors = with_locked_monitors; 286 _with_locked_synchronizers = with_locked_synchronizers; 287} 288 289VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 290 GrowableArray<instanceHandle>* threads, 291 int num_threads, 292 int max_depth, 293 bool with_locked_monitors, 294 bool with_locked_synchronizers) { 295 _result = result; 296 _num_threads = num_threads; 297 _threads = threads; 298 _result = result; 299 _max_depth = max_depth; 300 _with_locked_monitors = with_locked_monitors; 301 _with_locked_synchronizers = with_locked_synchronizers; 302} 303 304bool VM_ThreadDump::doit_prologue() { 305 // Make sure AbstractOwnableSynchronizer is loaded 306 JavaThread* jt = JavaThread::current(); 307 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(jt); 308 if (jt->has_pending_exception()) { 309 return false; 310 } 311 312 if (_with_locked_synchronizers) { 313 // Acquire Heap_lock to dump concurrent locks 314 Heap_lock->lock(); 315 } 316 317 return true; 318} 319 320void VM_ThreadDump::doit_epilogue() { 321 if (_with_locked_synchronizers) { 322 // Release Heap_lock 323 Heap_lock->unlock(); 324 } 325} 326 327void VM_ThreadDump::doit() { 328 ResourceMark rm; 329 330 ConcurrentLocksDump concurrent_locks(true); 331 if (_with_locked_synchronizers) { 332 concurrent_locks.dump_at_safepoint(); 333 } 334 335 if (_num_threads == 0) { 336 // Snapshot all live threads 337 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) { 338 if (jt->is_exiting() || 339 jt->is_hidden_from_external_view()) { 340 // skip terminating threads and hidden threads 341 continue; 342 } 343 ThreadConcurrentLocks* tcl = NULL; 344 if (_with_locked_synchronizers) { 345 tcl = concurrent_locks.thread_concurrent_locks(jt); 346 } 347 ThreadSnapshot* ts = snapshot_thread(jt, tcl); 348 _result->add_thread_snapshot(ts); 349 } 350 } else { 351 // Snapshot threads in the given _threads array 352 // A dummy snapshot is created if a thread doesn't exist 353 for (int i = 0; i < _num_threads; i++) { 354 instanceHandle th = _threads->at(i); 355 if (th() == NULL) { 356 // skip if the thread doesn't exist 357 // Add a dummy snapshot 358 _result->add_thread_snapshot(new ThreadSnapshot()); 359 continue; 360 } 361 362 // Dump thread stack only if the thread is alive and not exiting 363 // and not VM internal thread. 364 JavaThread* jt = java_lang_Thread::thread(th()); 365 if (jt == NULL || /* thread not alive */ 366 jt->is_exiting() || 367 jt->is_hidden_from_external_view()) { 368 // add a NULL snapshot if skipped 369 _result->add_thread_snapshot(new ThreadSnapshot()); 370 continue; 371 } 372 ThreadConcurrentLocks* tcl = NULL; 373 if (_with_locked_synchronizers) { 374 tcl = concurrent_locks.thread_concurrent_locks(jt); 375 } 376 ThreadSnapshot* ts = snapshot_thread(jt, tcl); 377 _result->add_thread_snapshot(ts); 378 } 379 } 380} 381 382ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) { 383 ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread); 384 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors); 385 snapshot->set_concurrent_locks(tcl); 386 return snapshot; 387} 388 389volatile bool VM_Exit::_vm_exited = false; 390Thread * VM_Exit::_shutdown_thread = NULL; 391 392int VM_Exit::set_vm_exited() { 393 394 Thread * thr_cur = Thread::current(); 395 396 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 397 398 int num_active = 0; 399 400 _shutdown_thread = thr_cur; 401 _vm_exited = true; // global flag 402 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) 403 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 404 ++num_active; 405 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag 406 } 407 408 return num_active; 409} 410 411int VM_Exit::wait_for_threads_in_native_to_block() { 412 // VM exits at safepoint. This function must be called at the final safepoint 413 // to wait for threads in _thread_in_native state to be quiescent. 414 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 415 416 Thread * thr_cur = Thread::current(); 417 Monitor timer(Mutex::leaf, "VM_Exit timer", true, 418 Monitor::_safepoint_check_never); 419 420 // Compiler threads need longer wait because they can access VM data directly 421 // while in native. If they are active and some structures being used are 422 // deleted by the shutdown sequence, they will crash. On the other hand, user 423 // threads must go through native=>Java/VM transitions first to access VM 424 // data, and they will be stopped during state transition. In theory, we 425 // don't have to wait for user threads to be quiescent, but it's always 426 // better to terminate VM when current thread is the only active thread, so 427 // wait for user threads too. Numbers are in 10 milliseconds. 428 int max_wait_user_thread = 30; // at least 300 milliseconds 429 int max_wait_compiler_thread = 1000; // at least 10 seconds 430 431 int max_wait = max_wait_compiler_thread; 432 433 int attempts = 0; 434 while (true) { 435 int num_active = 0; 436 int num_active_compiler_thread = 0; 437 438 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) { 439 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 440 num_active++; 441 if (thr->is_Compiler_thread()) { 442 num_active_compiler_thread++; 443 } 444 } 445 } 446 447 if (num_active == 0) { 448 return 0; 449 } else if (attempts > max_wait) { 450 return num_active; 451 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) { 452 return num_active; 453 } 454 455 attempts++; 456 457 MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag); 458 timer.wait(Mutex::_no_safepoint_check_flag, 10); 459 } 460} 461 462void VM_Exit::doit() { 463 CompileBroker::set_should_block(); 464 465 // Wait for a short period for threads in native to block. Any thread 466 // still executing native code after the wait will be stopped at 467 // native==>Java/VM barriers. 468 // Among 16276 JCK tests, 94% of them come here without any threads still 469 // running in native; the other 6% are quiescent within 250ms (Ultra 80). 470 wait_for_threads_in_native_to_block(); 471 472 set_vm_exited(); 473 474 // cleanup globals resources before exiting. exit_globals() currently 475 // cleans up outputStream resources and PerfMemory resources. 476 exit_globals(); 477 478 // Check for exit hook 479 exit_hook_t exit_hook = Arguments::exit_hook(); 480 if (exit_hook != NULL) { 481 // exit hook should exit. 482 exit_hook(_exit_code); 483 // ... but if it didn't, we must do it here 484 vm_direct_exit(_exit_code); 485 } else { 486 vm_direct_exit(_exit_code); 487 } 488} 489 490 491void VM_Exit::wait_if_vm_exited() { 492 if (_vm_exited && 493 Thread::current_or_null() != _shutdown_thread) { 494 // _vm_exited is set at safepoint, and the Threads_lock is never released 495 // we will block here until the process dies 496 Threads_lock->lock_without_safepoint_check(); 497 ShouldNotReachHere(); 498 } 499} 500 501void VM_PrintCompileQueue::doit() { 502 CompileBroker::print_compile_queues(_out); 503} 504 505#if INCLUDE_SERVICES 506void VM_PrintClassHierarchy::doit() { 507 KlassHierarchy::print_class_hierarchy(_out, _print_interfaces, _print_subclasses, _classname); 508} 509#endif 510