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