1 /* 2 * Copyright (c) 1997, 2019, 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/collectedHeap.hpp" 31 #include "gc/shared/isGCActiveMark.hpp" 32 #include "logging/log.hpp" 33 #include "logging/logStream.hpp" 34 #include "logging/logConfiguration.hpp" 35 #include "memory/heapInspection.hpp" 36 #include "memory/resourceArea.hpp" 37 #include "memory/universe.hpp" 38 #include "oops/symbol.hpp" 39 #include "runtime/arguments.hpp" 40 #include "runtime/deoptimization.hpp" 41 #include "runtime/frame.inline.hpp" 42 #include "runtime/interfaceSupport.inline.hpp" 43 #include "runtime/sweeper.hpp" 44 #include "runtime/thread.inline.hpp" 45 #include "runtime/threadSMR.inline.hpp" 46 #include "runtime/vmOperations.hpp" 47 #include "services/threadService.hpp" 48 49 #define VM_OP_NAME_INITIALIZE(name) #name, 50 51 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \ 52 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) }; 53 54 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) { 55 _calling_thread = thread; 56 assert(MinPriority <= priority && priority <= MaxPriority, "sanity check"); 57 _priority = priority; 58 } 59 60 61 void VM_Operation::evaluate() { 62 ResourceMark rm; 63 LogTarget(Debug, vmoperation) lt; 64 if (lt.is_enabled()) { 65 LogStream ls(lt); 66 ls.print("begin "); 67 print_on_error(&ls); 68 ls.cr(); 69 } 70 doit(); 71 if (lt.is_enabled()) { 72 LogStream ls(lt); 73 ls.print("end "); 74 print_on_error(&ls); 75 ls.cr(); 76 } 77 } 78 79 const char* VM_Operation::mode_to_string(Mode mode) { 80 switch(mode) { 81 case _safepoint : return "safepoint"; 82 case _no_safepoint : return "no safepoint"; 83 case _concurrent : return "concurrent"; 84 case _async_safepoint: return "async safepoint"; 85 default : return "unknown"; 86 } 87 } 88 // Called by fatal error handler. 89 void VM_Operation::print_on_error(outputStream* st) const { 90 st->print("VM_Operation (" PTR_FORMAT "): ", p2i(this)); 91 st->print("%s", name()); 92 93 const char* mode = mode_to_string(evaluation_mode()); 94 st->print(", mode: %s", mode); 95 96 if (calling_thread()) { 97 st->print(", requested by thread " PTR_FORMAT, p2i(calling_thread())); 98 } 99 } 100 101 void VM_ThreadStop::doit() { 102 assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint"); 103 ThreadsListHandle tlh; 104 JavaThread* target = java_lang_Thread::thread(target_thread()); 105 // Note that this now allows multiple ThreadDeath exceptions to be 106 // thrown at a thread. 107 if (target != NULL && (!EnableThreadSMRExtraValidityChecks || tlh.includes(target))) { 108 // The target thread has run and has not exited yet. 109 target->send_thread_stop(throwable()); 110 } 111 } 112 113 void VM_ClearICs::doit() { 114 if (_preserve_static_stubs) { 115 CodeCache::cleanup_inline_caches(); 116 } else { 117 CodeCache::clear_inline_caches(); 118 } 119 } 120 121 void VM_Deoptimize::doit() { 122 // We do not want any GCs to happen while we are in the middle of this VM operation 123 ResourceMark rm; 124 DeoptimizationMarker dm; 125 126 // Deoptimize all activations depending on marked nmethods 127 Deoptimization::deoptimize_dependents(); 128 129 // Make the dependent methods not entrant 130 CodeCache::make_marked_nmethods_not_entrant(); 131 } 132 133 void VM_MarkActiveNMethods::doit() { 134 NMethodSweeper::mark_active_nmethods(); 135 } 136 137 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id, int reason) { 138 _thread = thread; 139 _id = id; 140 _reason = reason; 141 } 142 143 144 void VM_DeoptimizeFrame::doit() { 145 assert(_reason > Deoptimization::Reason_none && _reason < Deoptimization::Reason_LIMIT, "invalid deopt reason"); 146 Deoptimization::deoptimize_frame_internal(_thread, _id, (Deoptimization::DeoptReason)_reason); 147 } 148 149 150 #ifndef PRODUCT 151 152 void VM_DeoptimizeAll::doit() { 153 DeoptimizationMarker dm; 154 JavaThreadIteratorWithHandle jtiwh; 155 // deoptimize all java threads in the system 156 if (DeoptimizeALot) { 157 for (; JavaThread *thread = jtiwh.next(); ) { 158 if (thread->has_last_Java_frame()) { 159 thread->deoptimize(); 160 } 161 } 162 } else if (DeoptimizeRandom) { 163 164 // Deoptimize some selected threads and frames 165 int tnum = os::random() & 0x3; 166 int fnum = os::random() & 0x3; 167 int tcount = 0; 168 for (; JavaThread *thread = jtiwh.next(); ) { 169 if (thread->has_last_Java_frame()) { 170 if (tcount++ == tnum) { 171 tcount = 0; 172 int fcount = 0; 173 // Deoptimize some selected frames. 174 // Biased llocking wants a updated register map 175 for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) { 176 if (fst.current()->can_be_deoptimized()) { 177 if (fcount++ == fnum) { 178 fcount = 0; 179 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map()); 180 } 181 } 182 } 183 } 184 } 185 } 186 } 187 } 188 189 190 void VM_ZombieAll::doit() { 191 JavaThread *thread = (JavaThread *)calling_thread(); 192 assert(thread->is_Java_thread(), "must be a Java thread"); 193 thread->make_zombies(); 194 } 195 196 #endif // !PRODUCT 197 198 void VM_Verify::doit() { 199 Universe::heap()->prepare_for_verify(); 200 Universe::verify(); 201 } 202 203 bool VM_PrintThreads::doit_prologue() { 204 // Get Heap_lock if concurrent locks will be dumped 205 if (_print_concurrent_locks) { 206 Heap_lock->lock(); 207 } 208 return true; 209 } 210 211 void VM_PrintThreads::doit() { 212 Threads::print_on(_out, true, false, _print_concurrent_locks, _print_extended_info); 213 } 214 215 void VM_PrintThreads::doit_epilogue() { 216 if (_print_concurrent_locks) { 217 // Release Heap_lock 218 Heap_lock->unlock(); 219 } 220 } 221 222 void VM_PrintJNI::doit() { 223 JNIHandles::print_on(_out); 224 } 225 226 void VM_PrintMetadata::doit() { 227 MetaspaceUtils::print_report(_out, _scale, _flags); 228 } 229 230 VM_FindDeadlocks::~VM_FindDeadlocks() { 231 if (_deadlocks != NULL) { 232 DeadlockCycle* cycle = _deadlocks; 233 while (cycle != NULL) { 234 DeadlockCycle* d = cycle; 235 cycle = cycle->next(); 236 delete d; 237 } 238 } 239 } 240 241 void VM_FindDeadlocks::doit() { 242 // Update the hazard ptr in the originating thread to the current 243 // list of threads. This VM operation needs the current list of 244 // threads for proper deadlock detection and those are the 245 // JavaThreads we need to be protected when we return info to the 246 // originating thread. 247 _setter.set(); 248 249 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_setter.list(), _concurrent_locks); 250 if (_out != NULL) { 251 int num_deadlocks = 0; 252 for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) { 253 num_deadlocks++; 254 cycle->print_on_with(_setter.list(), _out); 255 } 256 257 if (num_deadlocks == 1) { 258 _out->print_cr("\nFound 1 deadlock.\n"); 259 _out->flush(); 260 } else if (num_deadlocks > 1) { 261 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks); 262 _out->flush(); 263 } 264 } 265 } 266 267 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 268 int max_depth, 269 bool with_locked_monitors, 270 bool with_locked_synchronizers) { 271 _result = result; 272 _num_threads = 0; // 0 indicates all threads 273 _threads = NULL; 274 _result = result; 275 _max_depth = max_depth; 276 _with_locked_monitors = with_locked_monitors; 277 _with_locked_synchronizers = with_locked_synchronizers; 278 } 279 280 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 281 GrowableArray<instanceHandle>* threads, 282 int num_threads, 283 int max_depth, 284 bool with_locked_monitors, 285 bool with_locked_synchronizers) { 286 _result = result; 287 _num_threads = num_threads; 288 _threads = threads; 289 _result = result; 290 _max_depth = max_depth; 291 _with_locked_monitors = with_locked_monitors; 292 _with_locked_synchronizers = with_locked_synchronizers; 293 } 294 295 bool VM_ThreadDump::doit_prologue() { 296 if (_with_locked_synchronizers) { 297 // Acquire Heap_lock to dump concurrent locks 298 Heap_lock->lock(); 299 } 300 301 return true; 302 } 303 304 void VM_ThreadDump::doit_epilogue() { 305 if (_with_locked_synchronizers) { 306 // Release Heap_lock 307 Heap_lock->unlock(); 308 } 309 } 310 311 void VM_ThreadDump::doit() { 312 ResourceMark rm; 313 314 // Set the hazard ptr in the originating thread to protect the 315 // current list of threads. This VM operation needs the current list 316 // of threads for a proper dump and those are the JavaThreads we need 317 // to be protected when we return info to the originating thread. 318 _result->set_t_list(); 319 320 ConcurrentLocksDump concurrent_locks(true); 321 if (_with_locked_synchronizers) { 322 concurrent_locks.dump_at_safepoint(); 323 } 324 325 if (_num_threads == 0) { 326 // Snapshot all live threads 327 328 for (uint i = 0; i < _result->t_list()->length(); i++) { 329 JavaThread* jt = _result->t_list()->thread_at(i); 330 if (jt->is_exiting() || 331 jt->is_hidden_from_external_view()) { 332 // skip terminating threads and hidden threads 333 continue; 334 } 335 ThreadConcurrentLocks* tcl = NULL; 336 if (_with_locked_synchronizers) { 337 tcl = concurrent_locks.thread_concurrent_locks(jt); 338 } 339 snapshot_thread(jt, tcl); 340 } 341 } else { 342 // Snapshot threads in the given _threads array 343 // A dummy snapshot is created if a thread doesn't exist 344 345 for (int i = 0; i < _num_threads; i++) { 346 instanceHandle th = _threads->at(i); 347 if (th() == NULL) { 348 // skip if the thread doesn't exist 349 // Add a dummy snapshot 350 _result->add_thread_snapshot(); 351 continue; 352 } 353 354 // Dump thread stack only if the thread is alive and not exiting 355 // and not VM internal thread. 356 JavaThread* jt = java_lang_Thread::thread(th()); 357 if (jt != NULL && !_result->t_list()->includes(jt)) { 358 // _threads[i] doesn't refer to a valid JavaThread; this check 359 // is primarily for JVM_DumpThreads() which doesn't have a good 360 // way to validate the _threads array. 361 jt = NULL; 362 } 363 if (jt == NULL || /* thread not alive */ 364 jt->is_exiting() || 365 jt->is_hidden_from_external_view()) { 366 // add a NULL snapshot if skipped 367 _result->add_thread_snapshot(); 368 continue; 369 } 370 ThreadConcurrentLocks* tcl = NULL; 371 if (_with_locked_synchronizers) { 372 tcl = concurrent_locks.thread_concurrent_locks(jt); 373 } 374 snapshot_thread(jt, tcl); 375 } 376 } 377 } 378 379 void VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) { 380 ThreadSnapshot* snapshot = _result->add_thread_snapshot(java_thread); 381 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors); 382 snapshot->set_concurrent_locks(tcl); 383 } 384 385 volatile bool VM_Exit::_vm_exited = false; 386 Thread * volatile VM_Exit::_shutdown_thread = NULL; 387 388 int VM_Exit::set_vm_exited() { 389 390 Thread * thr_cur = Thread::current(); 391 392 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 393 394 int num_active = 0; 395 396 _shutdown_thread = thr_cur; 397 _vm_exited = true; // global flag 398 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thr = jtiwh.next(); ) { 399 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 400 ++num_active; 401 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag 402 } 403 } 404 405 return num_active; 406 } 407 408 int VM_Exit::wait_for_threads_in_native_to_block() { 409 // VM exits at safepoint. This function must be called at the final safepoint 410 // to wait for threads in _thread_in_native state to be quiescent. 411 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 412 413 Thread * thr_cur = Thread::current(); 414 Monitor timer(Mutex::leaf, "VM_Exit timer", true, 415 Monitor::_safepoint_check_never); 416 417 // Compiler threads need longer wait because they can access VM data directly 418 // while in native. If they are active and some structures being used are 419 // deleted by the shutdown sequence, they will crash. On the other hand, user 420 // threads must go through native=>Java/VM transitions first to access VM 421 // data, and they will be stopped during state transition. In theory, we 422 // don't have to wait for user threads to be quiescent, but it's always 423 // better to terminate VM when current thread is the only active thread, so 424 // wait for user threads too. Numbers are in 10 milliseconds. 425 int max_wait_user_thread = 30; // at least 300 milliseconds 426 int max_wait_compiler_thread = 1000; // at least 10 seconds 427 428 int max_wait = max_wait_compiler_thread; 429 430 int attempts = 0; 431 JavaThreadIteratorWithHandle jtiwh; 432 while (true) { 433 int num_active = 0; 434 int num_active_compiler_thread = 0; 435 436 jtiwh.rewind(); 437 for (; JavaThread *thr = jtiwh.next(); ) { 438 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 439 num_active++; 440 if (thr->is_Compiler_thread()) { 441 #if INCLUDE_JVMCI 442 CompilerThread* ct = (CompilerThread*) thr; 443 if (ct->compiler() == NULL || !ct->compiler()->is_jvmci()) { 444 num_active_compiler_thread++; 445 } else { 446 // A JVMCI compiler thread never accesses VM data structures 447 // while in _thread_in_native state so there's no need to wait 448 // for it and potentially add a 300 millisecond delay to VM 449 // shutdown. 450 num_active--; 451 } 452 #else 453 num_active_compiler_thread++; 454 #endif 455 } 456 } 457 } 458 459 if (num_active == 0) { 460 return 0; 461 } else if (attempts > max_wait) { 462 return num_active; 463 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) { 464 return num_active; 465 } 466 467 attempts++; 468 469 MonitorLocker ml(&timer, Mutex::_no_safepoint_check_flag); 470 ml.wait(10); 471 } 472 } 473 474 void VM_Exit::doit() { 475 476 if (VerifyBeforeExit) { 477 HandleMark hm(VMThread::vm_thread()); 478 // Among other things, this ensures that Eden top is correct. 479 Universe::heap()->prepare_for_verify(); 480 // Silent verification so as not to pollute normal output, 481 // unless we really asked for it. 482 Universe::verify(); 483 } 484 485 CompileBroker::set_should_block(); 486 487 // Wait for a short period for threads in native to block. Any thread 488 // still executing native code after the wait will be stopped at 489 // native==>Java/VM barriers. 490 // Among 16276 JCK tests, 94% of them come here without any threads still 491 // running in native; the other 6% are quiescent within 250ms (Ultra 80). 492 wait_for_threads_in_native_to_block(); 493 494 set_vm_exited(); 495 496 // We'd like to call IdealGraphPrinter::clean_up() to finalize the 497 // XML logging, but we can't safely do that here. The logic to make 498 // XML termination logging safe is tied to the termination of the 499 // VMThread, and it doesn't terminate on this exit path. See 8222534. 500 501 // cleanup globals resources before exiting. exit_globals() currently 502 // cleans up outputStream resources and PerfMemory resources. 503 exit_globals(); 504 505 LogConfiguration::finalize(); 506 507 // Check for exit hook 508 exit_hook_t exit_hook = Arguments::exit_hook(); 509 if (exit_hook != NULL) { 510 // exit hook should exit. 511 exit_hook(_exit_code); 512 // ... but if it didn't, we must do it here 513 vm_direct_exit(_exit_code); 514 } else { 515 vm_direct_exit(_exit_code); 516 } 517 } 518 519 520 void VM_Exit::wait_if_vm_exited() { 521 if (_vm_exited && 522 Thread::current_or_null() != _shutdown_thread) { 523 // _vm_exited is set at safepoint, and the Threads_lock is never released 524 // we will block here until the process dies 525 Threads_lock->lock_without_safepoint_check(); 526 ShouldNotReachHere(); 527 } 528 } 529 530 void VM_PrintCompileQueue::doit() { 531 CompileBroker::print_compile_queues(_out); 532 } 533 534 #if INCLUDE_SERVICES 535 void VM_PrintClassHierarchy::doit() { 536 KlassHierarchy::print_class_hierarchy(_out, _print_interfaces, _print_subclasses, _classname); 537 } 538 #endif