vm_operations.cpp revision 4802:f2110083203d
1/* 2 * Copyright (c) 1997, 2013, 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 "compiler/compileBroker.hpp" 29#include "compiler/compilerOracle.hpp" 30#include "gc_implementation/shared/isGCActiveMark.hpp" 31#include "memory/resourceArea.hpp" 32#include "oops/symbol.hpp" 33#include "runtime/arguments.hpp" 34#include "runtime/deoptimization.hpp" 35#include "runtime/interfaceSupport.hpp" 36#include "runtime/sweeper.hpp" 37#include "runtime/thread.inline.hpp" 38#include "runtime/vm_operations.hpp" 39#include "services/threadService.hpp" 40#include "trace/tracing.hpp" 41 42#define VM_OP_NAME_INITIALIZE(name) #name, 43 44const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \ 45 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) }; 46 47void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) { 48 _calling_thread = thread; 49 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); 50 _priority = priority; 51} 52 53 54void VM_Operation::evaluate() { 55 ResourceMark rm; 56 if (TraceVMOperation) { 57 tty->print("["); 58 NOT_PRODUCT(print();) 59 } 60 doit(); 61 if (TraceVMOperation) { 62 tty->print_cr("]"); 63 } 64} 65 66const char* VM_Operation::mode_to_string(Mode mode) { 67 switch(mode) { 68 case _safepoint : return "safepoint"; 69 case _no_safepoint : return "no safepoint"; 70 case _concurrent : return "concurrent"; 71 case _async_safepoint: return "async safepoint"; 72 default : return "unknown"; 73 } 74} 75// Called by fatal error handler. 76void VM_Operation::print_on_error(outputStream* st) const { 77 st->print("VM_Operation (" PTR_FORMAT "): ", this); 78 st->print("%s", name()); 79 80 const char* mode = mode_to_string(evaluation_mode()); 81 st->print(", mode: %s", mode); 82 83 if (calling_thread()) { 84 st->print(", requested by thread " PTR_FORMAT, calling_thread()); 85 } 86} 87 88void VM_ThreadStop::doit() { 89 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint"); 90 JavaThread* target = java_lang_Thread::thread(target_thread()); 91 // Note that this now allows multiple ThreadDeath exceptions to be 92 // thrown at a thread. 93 if (target != NULL) { 94 // the thread has run and is not already in the process of exiting 95 target->send_thread_stop(throwable()); 96 } 97} 98 99void VM_Deoptimize::doit() { 100 // We do not want any GCs to happen while we are in the middle of this VM operation 101 ResourceMark rm; 102 DeoptimizationMarker dm; 103 104 // Deoptimize all activations depending on marked nmethods 105 Deoptimization::deoptimize_dependents(); 106 107 // Make the dependent methods zombies 108 CodeCache::make_marked_nmethods_zombies(); 109} 110 111 112VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id) { 113 _thread = thread; 114 _id = id; 115} 116 117 118void VM_DeoptimizeFrame::doit() { 119 Deoptimization::deoptimize_frame_internal(_thread, _id); 120} 121 122 123#ifndef PRODUCT 124 125void VM_DeoptimizeAll::doit() { 126 DeoptimizationMarker dm; 127 // deoptimize all java threads in the system 128 if (DeoptimizeALot) { 129 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) { 130 if (thread->has_last_Java_frame()) { 131 thread->deoptimize(); 132 } 133 } 134 } else if (DeoptimizeRandom) { 135 136 // Deoptimize some selected threads and frames 137 int tnum = os::random() & 0x3; 138 int fnum = os::random() & 0x3; 139 int tcount = 0; 140 for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) { 141 if (thread->has_last_Java_frame()) { 142 if (tcount++ == tnum) { 143 tcount = 0; 144 int fcount = 0; 145 // Deoptimize some selected frames. 146 // Biased llocking wants a updated register map 147 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) { 148 if (fst.current()->can_be_deoptimized()) { 149 if (fcount++ == fnum) { 150 fcount = 0; 151 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map()); 152 } 153 } 154 } 155 } 156 } 157 } 158 } 159} 160 161 162void VM_ZombieAll::doit() { 163 JavaThread *thread = (JavaThread *)calling_thread(); 164 assert(thread->is_Java_thread(), "must be a Java thread"); 165 thread->make_zombies(); 166} 167 168#endif // !PRODUCT 169 170void VM_UnlinkSymbols::doit() { 171 JavaThread *thread = (JavaThread *)calling_thread(); 172 assert(thread->is_Java_thread(), "must be a Java thread"); 173 SymbolTable::unlink(); 174} 175 176void VM_HandleFullCodeCache::doit() { 177 NMethodSweeper::speculative_disconnect_nmethods(_is_full); 178} 179 180void VM_Verify::doit() { 181 Universe::heap()->prepare_for_verify(); 182 Universe::verify(_silent); 183} 184 185bool VM_PrintThreads::doit_prologue() { 186 assert(Thread::current()->is_Java_thread(), "just checking"); 187 188 // Make sure AbstractOwnableSynchronizer is loaded 189 if (JDK_Version::is_gte_jdk16x_version()) { 190 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 191 } 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 200void VM_PrintThreads::doit() { 201 Threads::print_on(_out, true, false, _print_concurrent_locks); 202} 203 204void VM_PrintThreads::doit_epilogue() { 205 if (_print_concurrent_locks) { 206 // Release Heap_lock 207 Heap_lock->unlock(); 208 } 209} 210 211void VM_PrintJNI::doit() { 212 JNIHandles::print_on(_out); 213} 214 215VM_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 226bool VM_FindDeadlocks::doit_prologue() { 227 assert(Thread::current()->is_Java_thread(), "just checking"); 228 229 // Load AbstractOwnableSynchronizer class 230 if (_concurrent_locks && JDK_Version::is_gte_jdk16x_version()) { 231 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 232 } 233 234 return true; 235} 236 237void 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 256VM_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 269VM_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 284bool VM_ThreadDump::doit_prologue() { 285 assert(Thread::current()->is_Java_thread(), "just checking"); 286 287 // Load AbstractOwnableSynchronizer class before taking thread snapshots 288 if (JDK_Version::is_gte_jdk16x_version()) { 289 java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current()); 290 } 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 300void VM_ThreadDump::doit_epilogue() { 301 if (_with_locked_synchronizers) { 302 // Release Heap_lock 303 Heap_lock->unlock(); 304 } 305} 306 307void 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 362ThreadSnapshot* 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 369volatile bool VM_Exit::_vm_exited = false; 370Thread * VM_Exit::_shutdown_thread = NULL; 371 372int VM_Exit::set_vm_exited() { 373 Thread * thr_cur = ThreadLocalStorage::get_thread_slow(); 374 375 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 376 377 int num_active = 0; 378 379 _shutdown_thread = thr_cur; 380 _vm_exited = true; // global flag 381 for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) 382 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 383 ++num_active; 384 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag 385 } 386 387 return num_active; 388} 389 390int VM_Exit::wait_for_threads_in_native_to_block() { 391 // VM exits at safepoint. This function must be called at the final safepoint 392 // to wait for threads in _thread_in_native state to be quiescent. 393 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 394 395 Thread * thr_cur = ThreadLocalStorage::get_thread_slow(); 396 Monitor timer(Mutex::leaf, "VM_Exit timer", true); 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 440void 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 469void 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