1 /*
   2  * Copyright 1997-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 # include "incls/_precompiled.incl"
  26 # include "incls/_vm_operations.cpp.incl"
  27 
  28 #define VM_OP_NAME_INITIALIZE(name) #name,
  29 
  30 const char* VM_Operation::_names[VM_Operation::VMOp_Terminating] = \
  31   { VM_OPS_DO(VM_OP_NAME_INITIALIZE) };
  32 
  33 void VM_Operation::set_calling_thread(Thread* thread, ThreadPriority priority) {
  34   _calling_thread = thread;
  35   assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
  36   _priority = priority;
  37 }
  38 
  39 
  40 void VM_Operation::evaluate() {
  41   ResourceMark rm;
  42   if (TraceVMOperation) {
  43     tty->print("[");
  44     NOT_PRODUCT(print();)
  45   }
  46   doit();
  47   if (TraceVMOperation) {
  48     tty->print_cr("]");
  49   }
  50 }
  51 
  52 // Called by fatal error handler.
  53 void VM_Operation::print_on_error(outputStream* st) const {
  54   st->print("VM_Operation (" PTR_FORMAT "): ", this);
  55   st->print("%s", name());
  56 
  57   const char* mode;
  58   switch(evaluation_mode()) {
  59     case _safepoint      : mode = "safepoint";       break;
  60     case _no_safepoint   : mode = "no safepoint";    break;
  61     case _concurrent     : mode = "concurrent";      break;
  62     case _async_safepoint: mode = "async safepoint"; break;
  63     default              : mode = "unknown";         break;
  64   }
  65   st->print(", mode: %s", mode);
  66 
  67   if (calling_thread()) {
  68     st->print(", requested by thread " PTR_FORMAT, calling_thread());
  69   }
  70 }
  71 
  72 void VM_ThreadStop::doit() {
  73   assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
  74   JavaThread* target = java_lang_Thread::thread(target_thread());
  75   // Note that this now allows multiple ThreadDeath exceptions to be
  76   // thrown at a thread.
  77   if (target != NULL) {
  78     // the thread has run and is not already in the process of exiting
  79     target->send_thread_stop(throwable());
  80   }
  81 }
  82 
  83 void VM_Deoptimize::doit() {
  84   // We do not want any GCs to happen while we are in the middle of this VM operation
  85   ResourceMark rm;
  86   DeoptimizationMarker dm;
  87 
  88   // Deoptimize all activations depending on marked nmethods
  89   Deoptimization::deoptimize_dependents();
  90 
  91   // Make the dependent methods zombies
  92   CodeCache::make_marked_nmethods_zombies();
  93 }
  94 
  95 
  96 VM_DeoptimizeFrame::VM_DeoptimizeFrame(JavaThread* thread, intptr_t* id) {
  97   _thread = thread;
  98   _id     = id;
  99 }
 100 
 101 
 102 void VM_DeoptimizeFrame::doit() {
 103   Deoptimization::deoptimize_frame(_thread, _id);
 104 }
 105 
 106 
 107 #ifndef PRODUCT
 108 
 109 void VM_DeoptimizeAll::doit() {
 110   DeoptimizationMarker dm;
 111   // deoptimize all java threads in the system
 112   if (DeoptimizeALot) {
 113     for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
 114       if (thread->has_last_Java_frame()) {
 115         thread->deoptimize();
 116       }
 117     }
 118   } else if (DeoptimizeRandom) {
 119 
 120     // Deoptimize some selected threads and frames
 121     int tnum = os::random() & 0x3;
 122     int fnum =  os::random() & 0x3;
 123     int tcount = 0;
 124     for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
 125       if (thread->has_last_Java_frame()) {
 126         if (tcount++ == tnum)  {
 127         tcount = 0;
 128           int fcount = 0;
 129           // Deoptimize some selected frames.
 130           // Biased llocking wants a updated register map
 131           for(StackFrameStream fst(thread, UseBiasedLocking); !fst.is_done(); fst.next()) {
 132             if (fst.current()->can_be_deoptimized()) {
 133               if (fcount++ == fnum) {
 134                 fcount = 0;
 135                 Deoptimization::deoptimize(thread, *fst.current(), fst.register_map());
 136               }
 137             }
 138           }
 139         }
 140       }
 141     }
 142   }
 143 }
 144 
 145 
 146 void VM_ZombieAll::doit() {
 147   JavaThread *thread = (JavaThread *)calling_thread();
 148   assert(thread->is_Java_thread(), "must be a Java thread");
 149   thread->make_zombies();
 150 }
 151 
 152 #endif // !PRODUCT
 153 
 154 void VM_Verify::doit() {
 155   Universe::verify();
 156 }
 157 
 158 bool VM_PrintThreads::doit_prologue() {
 159   assert(Thread::current()->is_Java_thread(), "just checking");
 160 
 161   // Make sure AbstractOwnableSynchronizer is loaded
 162   if (JDK_Version::is_gte_jdk16x_version()) {
 163     java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
 164   }
 165 
 166   // Get Heap_lock if concurrent locks will be dumped
 167   if (_print_concurrent_locks) {
 168     Heap_lock->lock();
 169   }
 170   return true;
 171 }
 172 
 173 void VM_PrintThreads::doit() {
 174   Threads::print_on(_out, true, false, _print_concurrent_locks);
 175 }
 176 
 177 void VM_PrintThreads::doit_epilogue() {
 178   if (_print_concurrent_locks) {
 179     // Release Heap_lock
 180     Heap_lock->unlock();
 181   }
 182 }
 183 
 184 void VM_PrintJNI::doit() {
 185   JNIHandles::print_on(_out);
 186 }
 187 
 188 VM_FindDeadlocks::~VM_FindDeadlocks() {
 189   if (_deadlocks != NULL) {
 190     DeadlockCycle* cycle = _deadlocks;
 191     while (cycle != NULL) {
 192       DeadlockCycle* d = cycle;
 193       cycle = cycle->next();
 194       delete d;
 195     }
 196   }
 197 }
 198 
 199 bool VM_FindDeadlocks::doit_prologue() {
 200   assert(Thread::current()->is_Java_thread(), "just checking");
 201 
 202   // Load AbstractOwnableSynchronizer class
 203   if (_concurrent_locks && JDK_Version::is_gte_jdk16x_version()) {
 204     java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
 205   }
 206 
 207   return true;
 208 }
 209 
 210 void VM_FindDeadlocks::doit() {
 211   _deadlocks = ThreadService::find_deadlocks_at_safepoint(_concurrent_locks);
 212   if (_out != NULL) {
 213     int num_deadlocks = 0;
 214     for (DeadlockCycle* cycle = _deadlocks; cycle != NULL; cycle = cycle->next()) {
 215       num_deadlocks++;
 216       cycle->print_on(_out);
 217     }
 218 
 219     if (num_deadlocks == 1) {
 220       _out->print_cr("\nFound 1 deadlock.\n");
 221       _out->flush();
 222     } else if (num_deadlocks > 1) {
 223       _out->print_cr("\nFound %d deadlocks.\n", num_deadlocks);
 224       _out->flush();
 225     }
 226   }
 227 }
 228 
 229 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
 230                              int max_depth,
 231                              bool with_locked_monitors,
 232                              bool with_locked_synchronizers) {
 233   _result = result;
 234   _num_threads = 0; // 0 indicates all threads
 235   _threads = NULL;
 236   _result = result;
 237   _max_depth = max_depth;
 238   _with_locked_monitors = with_locked_monitors;
 239   _with_locked_synchronizers = with_locked_synchronizers;
 240 }
 241 
 242 VM_ThreadDump::VM_ThreadDump(ThreadDumpResult* result,
 243                              GrowableArray<instanceHandle>* threads,
 244                              int num_threads,
 245                              int max_depth,
 246                              bool with_locked_monitors,
 247                              bool with_locked_synchronizers) {
 248   _result = result;
 249   _num_threads = num_threads;
 250   _threads = threads;
 251   _result = result;
 252   _max_depth = max_depth;
 253   _with_locked_monitors = with_locked_monitors;
 254   _with_locked_synchronizers = with_locked_synchronizers;
 255 }
 256 
 257 bool VM_ThreadDump::doit_prologue() {
 258   assert(Thread::current()->is_Java_thread(), "just checking");
 259 
 260   // Load AbstractOwnableSynchronizer class before taking thread snapshots
 261   if (JDK_Version::is_gte_jdk16x_version()) {
 262     java_util_concurrent_locks_AbstractOwnableSynchronizer::initialize(JavaThread::current());
 263   }
 264 
 265   if (_with_locked_synchronizers) {
 266     // Acquire Heap_lock to dump concurrent locks
 267     Heap_lock->lock();
 268   }
 269 
 270   return true;
 271 }
 272 
 273 void VM_ThreadDump::doit_epilogue() {
 274   if (_with_locked_synchronizers) {
 275     // Release Heap_lock
 276     Heap_lock->unlock();
 277   }
 278 }
 279 
 280 void VM_ThreadDump::doit() {
 281   ResourceMark rm;
 282 
 283   ConcurrentLocksDump concurrent_locks(true);
 284   if (_with_locked_synchronizers) {
 285     concurrent_locks.dump_at_safepoint();
 286   }
 287 
 288   if (_num_threads == 0) {
 289     // Snapshot all live threads
 290     for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
 291       if (jt->is_exiting() ||
 292           jt->is_hidden_from_external_view())  {
 293         // skip terminating threads and hidden threads
 294         continue;
 295       }
 296       ThreadConcurrentLocks* tcl = NULL;
 297       if (_with_locked_synchronizers) {
 298         tcl = concurrent_locks.thread_concurrent_locks(jt);
 299       }
 300       ThreadSnapshot* ts = snapshot_thread(jt, tcl);
 301       _result->add_thread_snapshot(ts);
 302     }
 303   } else {
 304     // Snapshot threads in the given _threads array
 305     // A dummy snapshot is created if a thread doesn't exist
 306     for (int i = 0; i < _num_threads; i++) {
 307       instanceHandle th = _threads->at(i);
 308       if (th() == NULL) {
 309         // skip if the thread doesn't exist
 310         // Add a dummy snapshot
 311         _result->add_thread_snapshot(new ThreadSnapshot());
 312         continue;
 313       }
 314 
 315       // Dump thread stack only if the thread is alive and not exiting
 316       // and not VM internal thread.
 317       JavaThread* jt = java_lang_Thread::thread(th());
 318       if (jt == NULL || /* thread not alive */
 319           jt->is_exiting() ||
 320           jt->is_hidden_from_external_view())  {
 321         // add a NULL snapshot if skipped
 322         _result->add_thread_snapshot(new ThreadSnapshot());
 323         continue;
 324       }
 325       ThreadConcurrentLocks* tcl = NULL;
 326       if (_with_locked_synchronizers) {
 327         tcl = concurrent_locks.thread_concurrent_locks(jt);
 328       }
 329       ThreadSnapshot* ts = snapshot_thread(jt, tcl);
 330       _result->add_thread_snapshot(ts);
 331     }
 332   }
 333 }
 334 
 335 ThreadSnapshot* VM_ThreadDump::snapshot_thread(JavaThread* java_thread, ThreadConcurrentLocks* tcl) {
 336   ThreadSnapshot* snapshot = new ThreadSnapshot(java_thread);
 337   snapshot->dump_stack_at_safepoint(_max_depth, _with_locked_monitors);
 338   snapshot->set_concurrent_locks(tcl);
 339   return snapshot;
 340 }
 341 
 342 volatile bool VM_Exit::_vm_exited = false;
 343 Thread * VM_Exit::_shutdown_thread = NULL;
 344 
 345 int VM_Exit::set_vm_exited() {
 346   Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
 347 
 348   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
 349 
 350   int num_active = 0;
 351 
 352   _shutdown_thread = thr_cur;
 353   _vm_exited = true;                                // global flag
 354   for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next())
 355     if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
 356       ++num_active;
 357       thr->set_terminated(JavaThread::_vm_exited);  // per-thread flag
 358     }
 359 
 360   return num_active;
 361 }
 362 
 363 int VM_Exit::wait_for_threads_in_native_to_block() {
 364   // VM exits at safepoint. This function must be called at the final safepoint
 365   // to wait for threads in _thread_in_native state to be quiescent.
 366   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
 367 
 368   Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
 369   Monitor timer(Mutex::leaf, "VM_Exit timer", true);
 370 
 371   // Compiler threads need longer wait because they can access VM data directly
 372   // while in native. If they are active and some structures being used are
 373   // deleted by the shutdown sequence, they will crash. On the other hand, user
 374   // threads must go through native=>Java/VM transitions first to access VM
 375   // data, and they will be stopped during state transition. In theory, we
 376   // don't have to wait for user threads to be quiescent, but it's always
 377   // better to terminate VM when current thread is the only active thread, so
 378   // wait for user threads too. Numbers are in 10 milliseconds.
 379   int max_wait_user_thread = 30;                  // at least 300 milliseconds
 380   int max_wait_compiler_thread = 1000;            // at least 10 seconds
 381 
 382   int max_wait = max_wait_compiler_thread;
 383 
 384   int attempts = 0;
 385   while (true) {
 386     int num_active = 0;
 387     int num_active_compiler_thread = 0;
 388 
 389     for(JavaThread *thr = Threads::first(); thr != NULL; thr = thr->next()) {
 390       if (thr!=thr_cur && thr->thread_state() == _thread_in_native) {
 391         num_active++;
 392         if (thr->is_Compiler_thread()) {
 393           num_active_compiler_thread++;
 394         }
 395       }
 396     }
 397 
 398     if (num_active == 0) {
 399        return 0;
 400     } else if (attempts > max_wait) {
 401        return num_active;
 402     } else if (num_active_compiler_thread == 0 && attempts > max_wait_user_thread) {
 403        return num_active;
 404     }
 405 
 406     attempts++;
 407 
 408     MutexLockerEx ml(&timer, Mutex::_no_safepoint_check_flag);
 409     timer.wait(Mutex::_no_safepoint_check_flag, 10);
 410   }
 411 }
 412 
 413 void VM_Exit::doit() {
 414   CompileBroker::set_should_block();
 415 
 416   // Wait for a short period for threads in native to block. Any thread
 417   // still executing native code after the wait will be stopped at
 418   // native==>Java/VM barriers.
 419   // Among 16276 JCK tests, 94% of them come here without any threads still
 420   // running in native; the other 6% are quiescent within 250ms (Ultra 80).
 421   wait_for_threads_in_native_to_block();
 422 
 423   set_vm_exited();
 424 
 425   // cleanup globals resources before exiting. exit_globals() currently
 426   // cleans up outputStream resources and PerfMemory resources.
 427   exit_globals();
 428 
 429   // Check for exit hook
 430   exit_hook_t exit_hook = Arguments::exit_hook();
 431   if (exit_hook != NULL) {
 432     // exit hook should exit.
 433     exit_hook(_exit_code);
 434     // ... but if it didn't, we must do it here
 435     vm_direct_exit(_exit_code);
 436   } else {
 437     vm_direct_exit(_exit_code);
 438   }
 439 }
 440 
 441 
 442 void VM_Exit::wait_if_vm_exited() {
 443   if (_vm_exited &&
 444       ThreadLocalStorage::get_thread_slow() != _shutdown_thread) {
 445     // _vm_exited is set at safepoint, and the Threads_lock is never released
 446     // we will block here until the process dies
 447     Threads_lock->lock_without_safepoint_check();
 448     ShouldNotReachHere();
 449   }
 450 }