1 /* 2 * Copyright (c) 1997, 2023, 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/classLoaderDataGraph.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/metaspace/metaspaceReporter.hpp" 37 #include "memory/resourceArea.hpp" 38 #include "memory/universe.hpp" 39 #include "oops/symbol.hpp" 40 #include "runtime/arguments.hpp" 41 #include "runtime/deoptimization.hpp" 42 #include "runtime/frame.inline.hpp" 43 #include "runtime/interfaceSupport.inline.hpp" 44 #include "runtime/javaThread.inline.hpp" 45 #include "runtime/jniHandles.hpp" 46 #include "runtime/stackFrameStream.inline.hpp" 47 #include "runtime/synchronizer.hpp" 48 #include "runtime/threads.hpp" 49 #include "runtime/threadSMR.inline.hpp" 50 #include "runtime/vmOperations.hpp" 51 #include "services/threadService.hpp" 52 53 #define VM_OP_NAME_INITIALIZE(name) #name, 54 55 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \ 56 { VM_OPS_DO(VM_OP_NAME_INITIALIZE) }; 57 58 void VM_Operation::set_calling_thread(Thread* thread) { 59 _calling_thread = thread; 60 } 61 62 void VM_Operation::evaluate() { 63 ResourceMark rm; 64 LogTarget(Debug, vmoperation) lt; 65 if (lt.is_enabled()) { 66 LogStream ls(lt); 67 ls.print("begin "); 68 print_on_error(&ls); 69 ls.cr(); 70 } 71 doit(); 72 if (lt.is_enabled()) { 73 LogStream ls(lt); 74 ls.print("end "); 75 print_on_error(&ls); 76 ls.cr(); 77 } 78 } 79 80 // Called by fatal error handler. 81 void VM_Operation::print_on_error(outputStream* st) const { 82 st->print("VM_Operation (" PTR_FORMAT "): ", p2i(this)); 83 st->print("%s", name()); 84 85 st->print(", mode: %s", evaluate_at_safepoint() ? "safepoint" : "no safepoint"); 86 87 if (calling_thread()) { 88 st->print(", requested by thread " PTR_FORMAT, p2i(calling_thread())); 89 } 90 } 91 92 void VM_ClearICs::doit() { 93 if (_preserve_static_stubs) { 94 CodeCache::cleanup_inline_caches_whitebox(); 95 } else { 96 CodeCache::clear_inline_caches(); 97 } 98 } 99 100 void VM_CleanClassLoaderDataMetaspaces::doit() { 101 ClassLoaderDataGraph::walk_metadata_and_clean_metaspaces(); 102 } 103 104 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id, int reason) { 105 _thread = thread; 106 _id = id; 107 _reason = reason; 108 } 109 110 111 void VM_DeoptimizeFrame::doit() { 112 assert(_reason > Deoptimization::Reason_none && _reason < Deoptimization::Reason_LIMIT, "invalid deopt reason"); 113 Deoptimization::deoptimize_frame_internal(_thread, _id, (Deoptimization::DeoptReason)_reason); 114 } 115 116 117 #ifndef PRODUCT 118 119 void VM_DeoptimizeAll::doit() { 120 JavaThreadIteratorWithHandle jtiwh; 121 // deoptimize all java threads in the system 122 if (DeoptimizeALot) { 123 for (; JavaThread *thread = jtiwh.next(); ) { 124 if (thread->has_last_Java_frame()) { 125 thread->deoptimize(); 126 } 127 } 128 } else if (DeoptimizeRandom) { 129 130 // Deoptimize some selected threads and frames 131 int tnum = os::random() & 0x3; 132 int fnum = os::random() & 0x3; 133 int tcount = 0; 134 for (; JavaThread *thread = jtiwh.next(); ) { 135 if (thread->has_last_Java_frame()) { 136 if (tcount++ == tnum) { 137 tcount = 0; 138 int fcount = 0; 139 // Deoptimize some selected frames. 140 for(StackFrameStream fst(thread, false /* update */, true /* process_frames */); !fst.is_done(); fst.next()) { 141 if (fst.current()->can_be_deoptimized()) { 142 if (fcount++ == fnum) { 143 fcount = 0; 144 Deoptimization::deoptimize(thread, *fst.current()); 145 } 146 } 147 } 148 } 149 } 150 } 151 } 152 } 153 154 155 void VM_ZombieAll::doit() { 156 JavaThread::cast(calling_thread())->make_zombies(); 157 } 158 159 #endif // !PRODUCT 160 161 bool VM_PrintThreads::doit_prologue() { 162 // Get Heap_lock if concurrent locks will be dumped 163 if (_print_concurrent_locks) { 164 Heap_lock->lock(); 165 } 166 return true; 167 } 168 169 void VM_PrintThreads::doit() { 170 Threads::print_on(_out, true, false, _print_concurrent_locks, _print_extended_info); 171 if (_print_jni_handle_info) { 172 JNIHandles::print_on(_out); 173 } 174 } 175 176 void VM_PrintThreads::doit_epilogue() { 177 if (_print_concurrent_locks) { 178 // Release Heap_lock 179 Heap_lock->unlock(); 180 } 181 } 182 183 void VM_PrintMetadata::doit() { 184 metaspace::MetaspaceReporter::print_report(_out, _scale, _flags); 185 } 186 187 VM_FindDeadlocks::~VM_FindDeadlocks() { 188 if (_deadlocks != nullptr) { 189 DeadlockCycle* cycle = _deadlocks; 190 while (cycle != nullptr) { 191 DeadlockCycle* d = cycle; 192 cycle = cycle->next(); 193 delete d; 194 } 195 } 196 } 197 198 void VM_FindDeadlocks::doit() { 199 // Update the hazard ptr in the originating thread to the current 200 // list of threads. This VM operation needs the current list of 201 // threads for proper deadlock detection and those are the 202 // JavaThreads we need to be protected when we return info to the 203 // originating thread. 204 _setter.set(); 205 206 _deadlocks = ThreadService::find_deadlocks_at_safepoint(_setter.list(), _concurrent_locks); 207 if (_out != nullptr) { 208 int num_deadlocks = 0; 209 for (DeadlockCycle* cycle = _deadlocks; cycle != nullptr; cycle = cycle->next()) { 210 num_deadlocks++; 211 cycle->print_on_with(_setter.list(), _out); 212 } 213 214 if (num_deadlocks == 1) { 215 _out->print_cr("\nFound 1 deadlock.\n"); 216 _out->flush(); 217 } else if (num_deadlocks > 1) { 218 _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks); 219 _out->flush(); 220 } 221 } 222 } 223 224 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 225 int max_depth, 226 bool with_locked_monitors, 227 bool with_locked_synchronizers) { 228 _result = result; 229 _num_threads = 0; // 0 indicates all threads 230 _threads = nullptr; 231 _result = result; 232 _max_depth = max_depth; 233 _with_locked_monitors = with_locked_monitors; 234 _with_locked_synchronizers = with_locked_synchronizers; 235 } 236 237 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result, 238 GrowableArray<instanceHandle>* threads, 239 int num_threads, 240 int max_depth, 241 bool with_locked_monitors, 242 bool with_locked_synchronizers) { 243 _result = result; 244 _num_threads = num_threads; 245 _threads = threads; 246 _result = result; 247 _max_depth = max_depth; 248 _with_locked_monitors = with_locked_monitors; 249 _with_locked_synchronizers = with_locked_synchronizers; 250 } 251 252 bool VM_ThreadDump::doit_prologue() { 253 if (_with_locked_synchronizers) { 254 // Acquire Heap_lock to dump concurrent locks 255 Heap_lock->lock(); 256 } 257 258 return true; 259 } 260 261 void VM_ThreadDump::doit_epilogue() { 262 if (_with_locked_synchronizers) { 263 // Release Heap_lock 264 Heap_lock->unlock(); 265 } 266 } 267 268 void VM_ThreadDump::doit() { 269 ResourceMark rm; 270 271 // Set the hazard ptr in the originating thread to protect the 272 // current list of threads. This VM operation needs the current list 273 // of threads for a proper dump and those are the JavaThreads we need 274 // to be protected when we return info to the originating thread. 275 _result->set_t_list(); 276 277 ConcurrentLocksDump concurrent_locks(true); 278 if (_with_locked_synchronizers) { 279 concurrent_locks.dump_at_safepoint(); 280 } 281 282 ObjectMonitorsHashtable table; 283 ObjectMonitorsHashtable* tablep = nullptr; 284 if (_with_locked_monitors) { 285 // The caller wants locked monitor information and that's expensive to gather 286 // when there are a lot of inflated monitors. So we deflate idle monitors and 287 // gather information about owned monitors at the same time. 288 tablep = &table; 289 while (ObjectSynchronizer::deflate_idle_monitors(tablep) > 0) { 290 ; /* empty */ 291 } 292 } 293 294 if (_num_threads == 0) { 295 // Snapshot all live threads 296 297 for (uint i = 0; i < _result->t_list()->length(); i++) { 298 JavaThread* jt = _result->t_list()->thread_at(i); 299 if (jt->is_exiting() || 300 jt->is_hidden_from_external_view()) { 301 // skip terminating threads and hidden threads 302 continue; 303 } 304 ThreadConcurrentLocks* tcl = nullptr; 305 if (_with_locked_synchronizers) { 306 tcl = concurrent_locks.thread_concurrent_locks(jt); 307 } 308 snapshot_thread(jt, tcl, tablep); 309 } 310 } else { 311 // Snapshot threads in the given _threads array 312 // A dummy snapshot is created if a thread doesn't exist 313 314 for (int i = 0; i < _num_threads; i++) { 315 instanceHandle th = _threads->at(i); 316 if (th() == nullptr) { 317 // skip if the thread doesn't exist 318 // Add a dummy snapshot 319 _result->add_thread_snapshot(); 320 continue; 321 } 322 323 // Dump thread stack only if the thread is alive and not exiting 324 // and not VM internal thread. 325 JavaThread* jt = java_lang_Thread::thread(th()); 326 if (jt != nullptr && !_result->t_list()->includes(jt)) { 327 // _threads[i] doesn't refer to a valid JavaThread; this check 328 // is primarily for JVM_DumpThreads() which doesn't have a good 329 // way to validate the _threads array. 330 jt = nullptr; 331 } 332 if (jt == nullptr || /* thread not alive */ 333 jt->is_exiting() || 334 jt->is_hidden_from_external_view()) { 335 // add a nullptr snapshot if skipped 336 _result->add_thread_snapshot(); 337 continue; 338 } 339 ThreadConcurrentLocks* tcl = nullptr; 340 if (_with_locked_synchronizers) { 341 tcl = concurrent_locks.thread_concurrent_locks(jt); 342 } 343 snapshot_thread(jt, tcl, tablep); 344 } 345 } 346 } 347 348 void VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl, 349 ObjectMonitorsHashtable* table) { 350 ThreadSnapshot* snapshot = _result->add_thread_snapshot(java_thread); 351 snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors, table, false); 352 snapshot->set_concurrent_locks(tcl); 353 } 354 355 volatile bool VM_Exit::_vm_exited = false; 356 Thread * volatile VM_Exit::_shutdown_thread = nullptr; 357 358 int VM_Exit::set_vm_exited() { 359 360 Thread * thr_cur = Thread::current(); 361 362 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 363 364 int num_active = 0; 365 366 _shutdown_thread = thr_cur; 367 _vm_exited = true; // global flag 368 for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thr = jtiwh.next(); ) { 369 if (thr != thr_cur && thr->thread_state() == _thread_in_native) { 370 ++num_active; 371 thr->set_terminated(JavaThread::_vm_exited); // per-thread flag 372 } 373 } 374 375 return num_active; 376 } 377 378 int VM_Exit::wait_for_threads_in_native_to_block() { 379 // VM exits at safepoint. This function must be called at the final safepoint 380 // to wait for threads in _thread_in_native state to be quiescent. 381 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already"); 382 383 Thread * thr_cur = Thread::current(); 384 Monitor timer(Mutex::nosafepoint, "VM_ExitTimer_lock"); 385 386 // Compiler threads need longer wait because they can access VM data directly 387 // while in native. If they are active and some structures being used are 388 // deleted by the shutdown sequence, they will crash. On the other hand, user 389 // threads must go through native=>Java/VM transitions first to access VM 390 // data, and they will be stopped during state transition. In theory, we 391 // don't have to wait for user threads to be quiescent, but it's always 392 // better to terminate VM when current thread is the only active thread, so 393 // wait for user threads too. Numbers are in 10 milliseconds. 394 int max_wait_user_thread = 30; // at least 300 milliseconds 395 int max_wait_compiler_thread = 1000; // at least 10 seconds 396 397 int max_wait = max_wait_compiler_thread; 398 399 int attempts = 0; 400 JavaThreadIteratorWithHandle jtiwh; 401 while (true) { 402 int num_active = 0; 403 int num_active_compiler_thread = 0; 404 405 jtiwh.rewind(); 406 for (; JavaThread *thr = jtiwh.next(); ) { 407 if (thr!=thr_cur && thr->thread_state() == _thread_in_native) { 408 num_active++; 409 if (thr->is_Compiler_thread()) { 410 #if INCLUDE_JVMCI 411 CompilerThread* ct = (CompilerThread*) thr; 412 if (ct->compiler() == nullptr || !ct->compiler()->is_jvmci()) { 413 num_active_compiler_thread++; 414 } else { 415 // A JVMCI compiler thread never accesses VM data structures 416 // while in _thread_in_native state so there's no need to wait 417 // for it and potentially add a 300 millisecond delay to VM 418 // shutdown. 419 num_active--; 420 } 421 #else 422 num_active_compiler_thread++; 423 #endif 424 } 425 } 426 } 427 428 if (num_active == 0) { 429 return 0; 430 } else if (attempts > max_wait) { 431 return num_active; 432 } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) { 433 return num_active; 434 } 435 436 attempts++; 437 438 MonitorLocker ml(&timer, Mutex::_no_safepoint_check_flag); 439 ml.wait(10); 440 } 441 } 442 443 void VM_Exit::doit() { 444 445 if (VerifyBeforeExit) { 446 HandleMark hm(VMThread::vm_thread()); 447 // Among other things, this ensures that Eden top is correct. 448 Universe::heap()->prepare_for_verify(); 449 // Silent verification so as not to pollute normal output, 450 // unless we really asked for it. 451 Universe::verify(); 452 } 453 454 CompileBroker::set_should_block(); 455 456 // Wait for a short period for threads in native to block. Any thread 457 // still executing native code after the wait will be stopped at 458 // native==>Java/VM barriers. 459 // Among 16276 JCK tests, 94% of them come here without any threads still 460 // running in native; the other 6% are quiescent within 250ms (Ultra 80). 461 wait_for_threads_in_native_to_block(); 462 463 set_vm_exited(); 464 465 // The ObjectMonitor subsystem uses perf counters so do this before 466 // we call exit_globals() so we don't run afoul of perfMemory_exit(). 467 ObjectSynchronizer::do_final_audit_and_print_stats(); 468 469 // We'd like to call IdealGraphPrinter::clean_up() to finalize the 470 // XML logging, but we can't safely do that here. The logic to make 471 // XML termination logging safe is tied to the termination of the 472 // VMThread, and it doesn't terminate on this exit path. See 8222534. 473 474 // cleanup globals resources before exiting. exit_globals() currently 475 // cleans up outputStream resources and PerfMemory resources. 476 exit_globals(); 477 478 LogConfiguration::finalize(); 479 480 // Check for exit hook 481 exit_hook_t exit_hook = Arguments::exit_hook(); 482 if (exit_hook != nullptr) { 483 // exit hook should exit. 484 exit_hook(_exit_code); 485 // ... but if it didn't, we must do it here 486 vm_direct_exit(_exit_code); 487 } else { 488 vm_direct_exit(_exit_code); 489 } 490 } 491 492 493 void VM_Exit::wait_if_vm_exited() { 494 if (_vm_exited && 495 Thread::current_or_null() != _shutdown_thread) { 496 // _vm_exited is set at safepoint, and the Threads_lock is never released 497 // so we will block here until the process dies. 498 Threads_lock->lock(); 499 ShouldNotReachHere(); 500 } 501 } 502 503 void VM_PrintCompileQueue::doit() { 504 CompileBroker::print_compile_queues(_out); 505 } 506 507 #if INCLUDE_SERVICES 508 void VM_PrintClassHierarchy::doit() { 509 KlassHierarchy::print_class_hierarchy(_out, _print_interfaces, _print_subclasses, _classname); 510 } 511 512 void VM_PrintClassLayout::doit() { 513 PrintClassLayout::print_class_layout(_out, _class_name); 514 } 515 #endif