1 /*
   2  * Copyright (c) 2003, 2018, 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/systemDictionary.hpp"
  27 #include "memory/allocation.hpp"
  28 #include "memory/heapInspection.hpp"
  29 #include "memory/oopFactory.hpp"
  30 #include "memory/resourceArea.hpp"
  31 #include "oops/instanceKlass.hpp"
  32 #include "oops/objArrayOop.inline.hpp"
  33 #include "oops/oop.inline.hpp"
  34 #include "runtime/atomic.hpp"
  35 #include "runtime/handles.inline.hpp"
  36 #include "runtime/init.hpp"
  37 #include "runtime/objectMonitor.inline.hpp"
  38 #include "runtime/thread.inline.hpp"
  39 #include "runtime/threadSMR.inline.hpp"
  40 #include "runtime/vframe.hpp"
  41 #include "runtime/vmThread.hpp"
  42 #include "runtime/vm_operations.hpp"
  43 #include "services/threadService.hpp"
  44 
  45 // TODO: we need to define a naming convention for perf counters
  46 // to distinguish counters for:
  47 //   - standard JSR174 use
  48 //   - Hotspot extension (public and committed)
  49 //   - Hotspot extension (private/internal and uncommitted)
  50 
  51 // Default is disabled.
  52 bool ThreadService::_thread_monitoring_contention_enabled = false;
  53 bool ThreadService::_thread_cpu_time_enabled = false;
  54 bool ThreadService::_thread_allocated_memory_enabled = false;
  55 
  56 PerfCounter*  ThreadService::_total_threads_count = NULL;
  57 PerfVariable* ThreadService::_live_threads_count = NULL;
  58 PerfVariable* ThreadService::_peak_threads_count = NULL;
  59 PerfVariable* ThreadService::_daemon_threads_count = NULL;
  60 volatile int ThreadService::_exiting_threads_count = 0;
  61 volatile int ThreadService::_exiting_daemon_threads_count = 0;
  62 
  63 ThreadDumpResult* ThreadService::_threaddump_list = NULL;
  64 
  65 static const int INITIAL_ARRAY_SIZE = 10;
  66 
  67 void ThreadService::init() {
  68   EXCEPTION_MARK;
  69 
  70   // These counters are for java.lang.management API support.
  71   // They are created even if -XX:-UsePerfData is set and in
  72   // that case, they will be allocated on C heap.
  73 
  74   _total_threads_count =
  75                 PerfDataManager::create_counter(JAVA_THREADS, "started",
  76                                                 PerfData::U_Events, CHECK);
  77 
  78   _live_threads_count =
  79                 PerfDataManager::create_variable(JAVA_THREADS, "live",
  80                                                  PerfData::U_None, CHECK);
  81 
  82   _peak_threads_count =
  83                 PerfDataManager::create_variable(JAVA_THREADS, "livePeak",
  84                                                  PerfData::U_None, CHECK);
  85 
  86   _daemon_threads_count =
  87                 PerfDataManager::create_variable(JAVA_THREADS, "daemon",
  88                                                  PerfData::U_None, CHECK);
  89 
  90   if (os::is_thread_cpu_time_supported()) {
  91     _thread_cpu_time_enabled = true;
  92   }
  93 
  94   _thread_allocated_memory_enabled = true; // Always on, so enable it
  95 }
  96 
  97 void ThreadService::reset_peak_thread_count() {
  98   // Acquire the lock to update the peak thread count
  99   // to synchronize with thread addition and removal.
 100   MutexLockerEx mu(Threads_lock);
 101   _peak_threads_count->set_value(get_live_thread_count());
 102 }
 103 




 104 void ThreadService::add_thread(JavaThread* thread, bool daemon) {


 105   // Do not count VM internal or JVMTI agent threads
 106   if (thread->is_hidden_from_external_view() ||
 107       thread->is_jvmti_agent_thread()) {
 108     return;
 109   }
 110 
 111   _total_threads_count->inc();
 112   _live_threads_count->inc();


 113 
 114   if (_live_threads_count->get_value() > _peak_threads_count->get_value()) {
 115     _peak_threads_count->set_value(_live_threads_count->get_value());
 116   }
 117 
 118   if (daemon) {
 119     _daemon_threads_count->inc();

 120   }
 121 }
 122 
 123 void ThreadService::remove_thread(JavaThread* thread, bool daemon) {
 124   Atomic::dec(&_exiting_threads_count);
 125   if (daemon) {
 126     Atomic::dec(&_exiting_daemon_threads_count);


 127   }




 128 
 129   if (thread->is_hidden_from_external_view() ||
 130       thread->is_jvmti_agent_thread()) {
 131     return;
 132   }
 133 
 134   _live_threads_count->set_value(_live_threads_count->get_value() - 1);















 135   if (daemon) {
 136     _daemon_threads_count->set_value(_daemon_threads_count->get_value() - 1);
 137   }























 138 }
 139 
 140 void ThreadService::current_thread_exiting(JavaThread* jt) {





 141   assert(jt == JavaThread::current(), "Called by current thread");
 142   Atomic::inc(&_exiting_threads_count);
 143 
 144   oop threadObj = jt->threadObj();
 145   if (threadObj != NULL && java_lang_Thread::is_daemon(threadObj)) {
 146     Atomic::inc(&_exiting_daemon_threads_count);
 147   }
 148 }
 149 
 150 // FIXME: JVMTI should call this function
 151 Handle ThreadService::get_current_contended_monitor(JavaThread* thread) {
 152   assert(thread != NULL, "should be non-NULL");
 153   debug_only(Thread::check_for_dangling_thread_pointer(thread);)
 154 
 155   ObjectMonitor *wait_obj = thread->current_waiting_monitor();
 156 
 157   oop obj = NULL;
 158   if (wait_obj != NULL) {
 159     // thread is doing an Object.wait() call
 160     obj = (oop) wait_obj->object();
 161     assert(obj != NULL, "Object.wait() should have an object");
 162   } else {
 163     ObjectMonitor *enter_obj = thread->current_pending_monitor();
 164     if (enter_obj != NULL) {
 165       // thread is trying to enter() or raw_enter() an ObjectMonitor.
 166       obj = (oop) enter_obj->object();
 167     }
 168     // If obj == NULL, then ObjectMonitor is raw which doesn't count.
 169   }
 170 
 171   Handle h(Thread::current(), obj);
 172   return h;
 173 }
 174 
 175 bool ThreadService::set_thread_monitoring_contention(bool flag) {
 176   MutexLocker m(Management_lock);
 177 
 178   bool prev = _thread_monitoring_contention_enabled;
 179   _thread_monitoring_contention_enabled = flag;
 180 
 181   return prev;
 182 }
 183 
 184 bool ThreadService::set_thread_cpu_time_enabled(bool flag) {
 185   MutexLocker m(Management_lock);
 186 
 187   bool prev = _thread_cpu_time_enabled;
 188   _thread_cpu_time_enabled = flag;
 189 
 190   return prev;
 191 }
 192 
 193 bool ThreadService::set_thread_allocated_memory_enabled(bool flag) {
 194   MutexLocker m(Management_lock);
 195 
 196   bool prev = _thread_allocated_memory_enabled;
 197   _thread_allocated_memory_enabled = flag;
 198 
 199   return prev;
 200 }
 201 
 202 // GC support
 203 void ThreadService::oops_do(OopClosure* f) {
 204   for (ThreadDumpResult* dump = _threaddump_list; dump != NULL; dump = dump->next()) {
 205     dump->oops_do(f);
 206   }
 207 }
 208 
 209 void ThreadService::metadata_do(void f(Metadata*)) {
 210   for (ThreadDumpResult* dump = _threaddump_list; dump != NULL; dump = dump->next()) {
 211     dump->metadata_do(f);
 212   }
 213 }
 214 
 215 void ThreadService::add_thread_dump(ThreadDumpResult* dump) {
 216   MutexLocker ml(Management_lock);
 217   if (_threaddump_list == NULL) {
 218     _threaddump_list = dump;
 219   } else {
 220     dump->set_next(_threaddump_list);
 221     _threaddump_list = dump;
 222   }
 223 }
 224 
 225 void ThreadService::remove_thread_dump(ThreadDumpResult* dump) {
 226   MutexLocker ml(Management_lock);
 227 
 228   ThreadDumpResult* prev = NULL;
 229   bool found = false;
 230   for (ThreadDumpResult* d = _threaddump_list; d != NULL; prev = d, d = d->next()) {
 231     if (d == dump) {
 232       if (prev == NULL) {
 233         _threaddump_list = dump->next();
 234       } else {
 235         prev->set_next(dump->next());
 236       }
 237       found = true;
 238       break;
 239     }
 240   }
 241   assert(found, "The threaddump result to be removed must exist.");
 242 }
 243 
 244 // Dump stack trace of threads specified in the given threads array.
 245 // Returns StackTraceElement[][] each element is the stack trace of a thread in
 246 // the corresponding entry in the given threads array
 247 Handle ThreadService::dump_stack_traces(GrowableArray<instanceHandle>* threads,
 248                                         int num_threads,
 249                                         TRAPS) {
 250   assert(num_threads > 0, "just checking");
 251 
 252   ThreadDumpResult dump_result;
 253   VM_ThreadDump op(&dump_result,
 254                    threads,
 255                    num_threads,
 256                    -1,    /* entire stack */
 257                    false, /* with locked monitors */
 258                    false  /* with locked synchronizers */);
 259   VMThread::execute(&op);
 260 
 261   // Allocate the resulting StackTraceElement[][] object
 262 
 263   ResourceMark rm(THREAD);
 264   Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_StackTraceElement_array(), true, CHECK_NH);
 265   ObjArrayKlass* ik = ObjArrayKlass::cast(k);
 266   objArrayOop r = oopFactory::new_objArray(ik, num_threads, CHECK_NH);
 267   objArrayHandle result_obj(THREAD, r);
 268 
 269   int num_snapshots = dump_result.num_snapshots();
 270   assert(num_snapshots == num_threads, "Must have num_threads thread snapshots");
 271   assert(num_snapshots == 0 || dump_result.t_list_has_been_set(), "ThreadsList must have been set if we have a snapshot");
 272   int i = 0;
 273   for (ThreadSnapshot* ts = dump_result.snapshots(); ts != NULL; i++, ts = ts->next()) {
 274     ThreadStackTrace* stacktrace = ts->get_stack_trace();
 275     if (stacktrace == NULL) {
 276       // No stack trace
 277       result_obj->obj_at_put(i, NULL);
 278     } else {
 279       // Construct an array of java/lang/StackTraceElement object
 280       Handle backtrace_h = stacktrace->allocate_fill_stack_trace_element_array(CHECK_NH);
 281       result_obj->obj_at_put(i, backtrace_h());
 282     }
 283   }
 284 
 285   return result_obj;
 286 }
 287 
 288 void ThreadService::reset_contention_count_stat(JavaThread* thread) {
 289   ThreadStatistics* stat = thread->get_thread_stat();
 290   if (stat != NULL) {
 291     stat->reset_count_stat();
 292   }
 293 }
 294 
 295 void ThreadService::reset_contention_time_stat(JavaThread* thread) {
 296   ThreadStatistics* stat = thread->get_thread_stat();
 297   if (stat != NULL) {
 298     stat->reset_time_stat();
 299   }
 300 }
 301 
 302 // Find deadlocks involving object monitors and concurrent locks if concurrent_locks is true
 303 DeadlockCycle* ThreadService::find_deadlocks_at_safepoint(ThreadsList * t_list, bool concurrent_locks) {
 304   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
 305 
 306   // This code was modified from the original Threads::find_deadlocks code.
 307   int globalDfn = 0, thisDfn;
 308   ObjectMonitor* waitingToLockMonitor = NULL;
 309   oop waitingToLockBlocker = NULL;
 310   bool blocked_on_monitor = false;
 311   JavaThread *currentThread, *previousThread;
 312   int num_deadlocks = 0;
 313 
 314   // Initialize the depth-first-number for each JavaThread.
 315   JavaThreadIterator jti(t_list);
 316   for (JavaThread* jt = jti.first(); jt != NULL; jt = jti.next()) {
 317     jt->set_depth_first_number(-1);
 318   }
 319 
 320   DeadlockCycle* deadlocks = NULL;
 321   DeadlockCycle* last = NULL;
 322   DeadlockCycle* cycle = new DeadlockCycle();
 323   for (JavaThread* jt = jti.first(); jt != NULL; jt = jti.next()) {
 324     if (jt->depth_first_number() >= 0) {
 325       // this thread was already visited
 326       continue;
 327     }
 328 
 329     thisDfn = globalDfn;
 330     jt->set_depth_first_number(globalDfn++);
 331     previousThread = jt;
 332     currentThread = jt;
 333 
 334     cycle->reset();
 335 
 336     // When there is a deadlock, all the monitors involved in the dependency
 337     // cycle must be contended and heavyweight. So we only care about the
 338     // heavyweight monitor a thread is waiting to lock.
 339     waitingToLockMonitor = (ObjectMonitor*)jt->current_pending_monitor();
 340     if (concurrent_locks) {
 341       waitingToLockBlocker = jt->current_park_blocker();
 342     }
 343     while (waitingToLockMonitor != NULL || waitingToLockBlocker != NULL) {
 344       cycle->add_thread(currentThread);
 345       if (waitingToLockMonitor != NULL) {
 346         address currentOwner = (address)waitingToLockMonitor->owner();
 347         if (currentOwner != NULL) {
 348           currentThread = Threads::owning_thread_from_monitor_owner(t_list,
 349                                                                     currentOwner);
 350           if (currentThread == NULL) {
 351             // This function is called at a safepoint so the JavaThread
 352             // that owns waitingToLockMonitor should be findable, but
 353             // if it is not findable, then the previous currentThread is
 354             // blocked permanently. We record this as a deadlock.
 355             num_deadlocks++;
 356 
 357             cycle->set_deadlock(true);
 358 
 359             // add this cycle to the deadlocks list
 360             if (deadlocks == NULL) {
 361               deadlocks = cycle;
 362             } else {
 363               last->set_next(cycle);
 364             }
 365             last = cycle;
 366             cycle = new DeadlockCycle();
 367             break;
 368           }
 369         }
 370       } else {
 371         if (concurrent_locks) {
 372           if (waitingToLockBlocker->is_a(SystemDictionary::java_util_concurrent_locks_AbstractOwnableSynchronizer_klass())) {
 373             oop threadObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
 374             // This JavaThread (if there is one) is protected by the
 375             // ThreadsListSetter in VM_FindDeadlocks::doit().
 376             currentThread = threadObj != NULL ? java_lang_Thread::thread(threadObj) : NULL;
 377           } else {
 378             currentThread = NULL;
 379           }
 380         }
 381       }
 382 
 383       if (currentThread == NULL) {
 384         // No dependency on another thread
 385         break;
 386       }
 387       if (currentThread->depth_first_number() < 0) {
 388         // First visit to this thread
 389         currentThread->set_depth_first_number(globalDfn++);
 390       } else if (currentThread->depth_first_number() < thisDfn) {
 391         // Thread already visited, and not on a (new) cycle
 392         break;
 393       } else if (currentThread == previousThread) {
 394         // Self-loop, ignore
 395         break;
 396       } else {
 397         // We have a (new) cycle
 398         num_deadlocks++;
 399 
 400         cycle->set_deadlock(true);
 401 
 402         // add this cycle to the deadlocks list
 403         if (deadlocks == NULL) {
 404           deadlocks = cycle;
 405         } else {
 406           last->set_next(cycle);
 407         }
 408         last = cycle;
 409         cycle = new DeadlockCycle();
 410         break;
 411       }
 412       previousThread = currentThread;
 413       waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
 414       if (concurrent_locks) {
 415         waitingToLockBlocker = currentThread->current_park_blocker();
 416       }
 417     }
 418 
 419   }
 420   delete cycle;
 421   return deadlocks;
 422 }
 423 
 424 ThreadDumpResult::ThreadDumpResult() : _num_threads(0), _num_snapshots(0), _snapshots(NULL), _last(NULL), _next(NULL), _setter() {
 425 
 426   // Create a new ThreadDumpResult object and append to the list.
 427   // If GC happens before this function returns, Method*
 428   // in the stack trace will be visited.
 429   ThreadService::add_thread_dump(this);
 430 }
 431 
 432 ThreadDumpResult::ThreadDumpResult(int num_threads) : _num_threads(num_threads), _num_snapshots(0), _snapshots(NULL), _last(NULL), _next(NULL), _setter() {
 433   // Create a new ThreadDumpResult object and append to the list.
 434   // If GC happens before this function returns, oops
 435   // will be visited.
 436   ThreadService::add_thread_dump(this);
 437 }
 438 
 439 ThreadDumpResult::~ThreadDumpResult() {
 440   ThreadService::remove_thread_dump(this);
 441 
 442   // free all the ThreadSnapshot objects created during
 443   // the VM_ThreadDump operation
 444   ThreadSnapshot* ts = _snapshots;
 445   while (ts != NULL) {
 446     ThreadSnapshot* p = ts;
 447     ts = ts->next();
 448     delete p;
 449   }
 450 }
 451 
 452 
 453 void ThreadDumpResult::add_thread_snapshot(ThreadSnapshot* ts) {
 454   assert(_num_threads == 0 || _num_snapshots < _num_threads,
 455          "_num_snapshots must be less than _num_threads");
 456   _num_snapshots++;
 457   if (_snapshots == NULL) {
 458     _snapshots = ts;
 459   } else {
 460     _last->set_next(ts);
 461   }
 462   _last = ts;
 463 }
 464 
 465 void ThreadDumpResult::oops_do(OopClosure* f) {
 466   for (ThreadSnapshot* ts = _snapshots; ts != NULL; ts = ts->next()) {
 467     ts->oops_do(f);
 468   }
 469 }
 470 
 471 void ThreadDumpResult::metadata_do(void f(Metadata*)) {
 472   for (ThreadSnapshot* ts = _snapshots; ts != NULL; ts = ts->next()) {
 473     ts->metadata_do(f);
 474   }
 475 }
 476 
 477 ThreadsList* ThreadDumpResult::t_list() {
 478   return _setter.list();
 479 }
 480 
 481 StackFrameInfo::StackFrameInfo(javaVFrame* jvf, bool with_lock_info) {
 482   _method = jvf->method();
 483   _bci = jvf->bci();
 484   _class_holder = _method->method_holder()->klass_holder();
 485   _locked_monitors = NULL;
 486   if (with_lock_info) {
 487     ResourceMark rm;
 488     GrowableArray<MonitorInfo*>* list = jvf->locked_monitors();
 489     int length = list->length();
 490     if (length > 0) {
 491       _locked_monitors = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(length, true);
 492       for (int i = 0; i < length; i++) {
 493         MonitorInfo* monitor = list->at(i);
 494         assert(monitor->owner() != NULL, "This monitor must have an owning object");
 495         _locked_monitors->append(monitor->owner());
 496       }
 497     }
 498   }
 499 }
 500 
 501 void StackFrameInfo::oops_do(OopClosure* f) {
 502   if (_locked_monitors != NULL) {
 503     int length = _locked_monitors->length();
 504     for (int i = 0; i < length; i++) {
 505       f->do_oop((oop*) _locked_monitors->adr_at(i));
 506     }
 507   }
 508   f->do_oop(&_class_holder);
 509 }
 510 
 511 void StackFrameInfo::metadata_do(void f(Metadata*)) {
 512   f(_method);
 513 }
 514 
 515 void StackFrameInfo::print_on(outputStream* st) const {
 516   ResourceMark rm;
 517   java_lang_Throwable::print_stack_element(st, method(), bci());
 518   int len = (_locked_monitors != NULL ? _locked_monitors->length() : 0);
 519   for (int i = 0; i < len; i++) {
 520     oop o = _locked_monitors->at(i);
 521     st->print_cr("\t- locked <" INTPTR_FORMAT "> (a %s)", p2i(o), o->klass()->external_name());
 522   }
 523 
 524 }
 525 
 526 // Iterate through monitor cache to find JNI locked monitors
 527 class InflatedMonitorsClosure: public MonitorClosure {
 528 private:
 529   ThreadStackTrace* _stack_trace;
 530   Thread* _thread;
 531 public:
 532   InflatedMonitorsClosure(Thread* t, ThreadStackTrace* st) {
 533     _thread = t;
 534     _stack_trace = st;
 535   }
 536   void do_monitor(ObjectMonitor* mid) {
 537     if (mid->owner() == _thread) {
 538       oop object = (oop) mid->object();
 539       if (!_stack_trace->is_owned_monitor_on_stack(object)) {
 540         _stack_trace->add_jni_locked_monitor(object);
 541       }
 542     }
 543   }
 544 };
 545 
 546 ThreadStackTrace::ThreadStackTrace(JavaThread* t, bool with_locked_monitors) {
 547   _thread = t;
 548   _frames = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<StackFrameInfo*>(INITIAL_ARRAY_SIZE, true);
 549   _depth = 0;
 550   _with_locked_monitors = with_locked_monitors;
 551   if (_with_locked_monitors) {
 552     _jni_locked_monitors = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(INITIAL_ARRAY_SIZE, true);
 553   } else {
 554     _jni_locked_monitors = NULL;
 555   }
 556 }
 557 
 558 ThreadStackTrace::~ThreadStackTrace() {
 559   for (int i = 0; i < _frames->length(); i++) {
 560     delete _frames->at(i);
 561   }
 562   delete _frames;
 563   if (_jni_locked_monitors != NULL) {
 564     delete _jni_locked_monitors;
 565   }
 566 }
 567 
 568 void ThreadStackTrace::dump_stack_at_safepoint(int maxDepth) {
 569   assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
 570 
 571   if (_thread->has_last_Java_frame()) {
 572     RegisterMap reg_map(_thread);
 573     vframe* start_vf = _thread->last_java_vframe(&reg_map);
 574     int count = 0;
 575     for (vframe* f = start_vf; f; f = f->sender() ) {
 576       if (maxDepth >= 0 && count == maxDepth) {
 577         // Skip frames if more than maxDepth
 578         break;
 579       }
 580       if (f->is_java_frame()) {
 581         javaVFrame* jvf = javaVFrame::cast(f);
 582         add_stack_frame(jvf);
 583         count++;
 584       } else {
 585         // Ignore non-Java frames
 586       }
 587     }
 588   }
 589 
 590   if (_with_locked_monitors) {
 591     // Iterate inflated monitors and find monitors locked by this thread
 592     // not found in the stack
 593     InflatedMonitorsClosure imc(_thread, this);
 594     ObjectSynchronizer::monitors_iterate(&imc);
 595   }
 596 }
 597 
 598 
 599 bool ThreadStackTrace::is_owned_monitor_on_stack(oop object) {
 600   assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
 601 
 602   bool found = false;
 603   int num_frames = get_stack_depth();
 604   for (int depth = 0; depth < num_frames; depth++) {
 605     StackFrameInfo* frame = stack_frame_at(depth);
 606     int len = frame->num_locked_monitors();
 607     GrowableArray<oop>* locked_monitors = frame->locked_monitors();
 608     for (int j = 0; j < len; j++) {
 609       oop monitor = locked_monitors->at(j);
 610       assert(monitor != NULL, "must be a Java object");
 611       if (oopDesc::equals(monitor, object)) {
 612         found = true;
 613         break;
 614       }
 615     }
 616   }
 617   return found;
 618 }
 619 
 620 Handle ThreadStackTrace::allocate_fill_stack_trace_element_array(TRAPS) {
 621   InstanceKlass* ik = SystemDictionary::StackTraceElement_klass();
 622   assert(ik != NULL, "must be loaded in 1.4+");
 623 
 624   // Allocate an array of java/lang/StackTraceElement object
 625   objArrayOop ste = oopFactory::new_objArray(ik, _depth, CHECK_NH);
 626   objArrayHandle backtrace(THREAD, ste);
 627   for (int j = 0; j < _depth; j++) {
 628     StackFrameInfo* frame = _frames->at(j);
 629     methodHandle mh(THREAD, frame->method());
 630     oop element = java_lang_StackTraceElement::create(mh, frame->bci(), CHECK_NH);
 631     backtrace->obj_at_put(j, element);
 632   }
 633   return backtrace;
 634 }
 635 
 636 void ThreadStackTrace::add_stack_frame(javaVFrame* jvf) {
 637   StackFrameInfo* frame = new StackFrameInfo(jvf, _with_locked_monitors);
 638   _frames->append(frame);
 639   _depth++;
 640 }
 641 
 642 void ThreadStackTrace::oops_do(OopClosure* f) {
 643   int length = _frames->length();
 644   for (int i = 0; i < length; i++) {
 645     _frames->at(i)->oops_do(f);
 646   }
 647 
 648   length = (_jni_locked_monitors != NULL ? _jni_locked_monitors->length() : 0);
 649   for (int j = 0; j < length; j++) {
 650     f->do_oop((oop*) _jni_locked_monitors->adr_at(j));
 651   }
 652 }
 653 
 654 void ThreadStackTrace::metadata_do(void f(Metadata*)) {
 655   int length = _frames->length();
 656   for (int i = 0; i < length; i++) {
 657     _frames->at(i)->metadata_do(f);
 658   }
 659 }
 660 
 661 
 662 ConcurrentLocksDump::~ConcurrentLocksDump() {
 663   if (_retain_map_on_free) {
 664     return;
 665   }
 666 
 667   for (ThreadConcurrentLocks* t = _map; t != NULL;)  {
 668     ThreadConcurrentLocks* tcl = t;
 669     t = t->next();
 670     delete tcl;
 671   }
 672 }
 673 
 674 void ConcurrentLocksDump::dump_at_safepoint() {
 675   // dump all locked concurrent locks
 676   assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
 677 
 678   GrowableArray<oop>* aos_objects = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(INITIAL_ARRAY_SIZE, true /* C_heap */);
 679 
 680   // Find all instances of AbstractOwnableSynchronizer
 681   HeapInspection::find_instances_at_safepoint(SystemDictionary::java_util_concurrent_locks_AbstractOwnableSynchronizer_klass(),
 682                                               aos_objects);
 683   // Build a map of thread to its owned AQS locks
 684   build_map(aos_objects);
 685 
 686   delete aos_objects;
 687 }
 688 
 689 
 690 // build a map of JavaThread to all its owned AbstractOwnableSynchronizer
 691 void ConcurrentLocksDump::build_map(GrowableArray<oop>* aos_objects) {
 692   int length = aos_objects->length();
 693   for (int i = 0; i < length; i++) {
 694     oop o = aos_objects->at(i);
 695     oop owner_thread_obj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(o);
 696     if (owner_thread_obj != NULL) {
 697       // See comments in ThreadConcurrentLocks to see how this
 698       // JavaThread* is protected.
 699       JavaThread* thread = java_lang_Thread::thread(owner_thread_obj);
 700       assert(o->is_instance(), "Must be an instanceOop");
 701       add_lock(thread, (instanceOop) o);
 702     }
 703   }
 704 }
 705 
 706 void ConcurrentLocksDump::add_lock(JavaThread* thread, instanceOop o) {
 707   ThreadConcurrentLocks* tcl = thread_concurrent_locks(thread);
 708   if (tcl != NULL) {
 709     tcl->add_lock(o);
 710     return;
 711   }
 712 
 713   // First owned lock found for this thread
 714   tcl = new ThreadConcurrentLocks(thread);
 715   tcl->add_lock(o);
 716   if (_map == NULL) {
 717     _map = tcl;
 718   } else {
 719     _last->set_next(tcl);
 720   }
 721   _last = tcl;
 722 }
 723 
 724 ThreadConcurrentLocks* ConcurrentLocksDump::thread_concurrent_locks(JavaThread* thread) {
 725   for (ThreadConcurrentLocks* tcl = _map; tcl != NULL; tcl = tcl->next()) {
 726     if (tcl->java_thread() == thread) {
 727       return tcl;
 728     }
 729   }
 730   return NULL;
 731 }
 732 
 733 void ConcurrentLocksDump::print_locks_on(JavaThread* t, outputStream* st) {
 734   st->print_cr("   Locked ownable synchronizers:");
 735   ThreadConcurrentLocks* tcl = thread_concurrent_locks(t);
 736   GrowableArray<instanceOop>* locks = (tcl != NULL ? tcl->owned_locks() : NULL);
 737   if (locks == NULL || locks->is_empty()) {
 738     st->print_cr("\t- None");
 739     st->cr();
 740     return;
 741   }
 742 
 743   for (int i = 0; i < locks->length(); i++) {
 744     instanceOop obj = locks->at(i);
 745     st->print_cr("\t- <" INTPTR_FORMAT "> (a %s)", p2i(obj), obj->klass()->external_name());
 746   }
 747   st->cr();
 748 }
 749 
 750 ThreadConcurrentLocks::ThreadConcurrentLocks(JavaThread* thread) {
 751   _thread = thread;
 752   _owned_locks = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<instanceOop>(INITIAL_ARRAY_SIZE, true);
 753   _next = NULL;
 754 }
 755 
 756 ThreadConcurrentLocks::~ThreadConcurrentLocks() {
 757   delete _owned_locks;
 758 }
 759 
 760 void ThreadConcurrentLocks::add_lock(instanceOop o) {
 761   _owned_locks->append(o);
 762 }
 763 
 764 void ThreadConcurrentLocks::oops_do(OopClosure* f) {
 765   int length = _owned_locks->length();
 766   for (int i = 0; i < length; i++) {
 767     f->do_oop((oop*) _owned_locks->adr_at(i));
 768   }
 769 }
 770 
 771 ThreadStatistics::ThreadStatistics() {
 772   _contended_enter_count = 0;
 773   _monitor_wait_count = 0;
 774   _sleep_count = 0;
 775   _count_pending_reset = false;
 776   _timer_pending_reset = false;
 777   memset((void*) _perf_recursion_counts, 0, sizeof(_perf_recursion_counts));
 778 }
 779 
 780 ThreadSnapshot::ThreadSnapshot(ThreadsList * t_list, JavaThread* thread) {
 781   _thread = thread;
 782   _threadObj = thread->threadObj();
 783   _stack_trace = NULL;
 784   _concurrent_locks = NULL;
 785   _next = NULL;
 786 
 787   ThreadStatistics* stat = thread->get_thread_stat();
 788   _contended_enter_ticks = stat->contended_enter_ticks();
 789   _contended_enter_count = stat->contended_enter_count();
 790   _monitor_wait_ticks = stat->monitor_wait_ticks();
 791   _monitor_wait_count = stat->monitor_wait_count();
 792   _sleep_ticks = stat->sleep_ticks();
 793   _sleep_count = stat->sleep_count();
 794 
 795   _blocker_object = NULL;
 796   _blocker_object_owner = NULL;
 797 
 798   _thread_status = java_lang_Thread::get_thread_status(_threadObj);
 799   _is_ext_suspended = thread->is_being_ext_suspended();
 800   _is_in_native = (thread->thread_state() == _thread_in_native);
 801 
 802   if (_thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER ||
 803       _thread_status == java_lang_Thread::IN_OBJECT_WAIT ||
 804       _thread_status == java_lang_Thread::IN_OBJECT_WAIT_TIMED) {
 805 
 806     Handle obj = ThreadService::get_current_contended_monitor(thread);
 807     if (obj() == NULL) {
 808       // monitor no longer exists; thread is not blocked
 809       _thread_status = java_lang_Thread::RUNNABLE;
 810     } else {
 811       _blocker_object = obj();
 812       JavaThread* owner = ObjectSynchronizer::get_lock_owner(t_list, obj);
 813       if ((owner == NULL && _thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER)
 814           || (owner != NULL && owner->is_attaching_via_jni())) {
 815         // ownership information of the monitor is not available
 816         // (may no longer be owned or releasing to some other thread)
 817         // make this thread in RUNNABLE state.
 818         // And when the owner thread is in attaching state, the java thread
 819         // is not completely initialized. For example thread name and id
 820         // and may not be set, so hide the attaching thread.
 821         _thread_status = java_lang_Thread::RUNNABLE;
 822         _blocker_object = NULL;
 823       } else if (owner != NULL) {
 824         _blocker_object_owner = owner->threadObj();
 825       }
 826     }
 827   }
 828 
 829   // Support for JSR-166 locks
 830   if (JDK_Version::current().supports_thread_park_blocker() &&
 831         (_thread_status == java_lang_Thread::PARKED ||
 832          _thread_status == java_lang_Thread::PARKED_TIMED)) {
 833 
 834     _blocker_object = thread->current_park_blocker();
 835     if (_blocker_object != NULL && _blocker_object->is_a(SystemDictionary::java_util_concurrent_locks_AbstractOwnableSynchronizer_klass())) {
 836       _blocker_object_owner = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(_blocker_object);
 837     }
 838   }
 839 }
 840 
 841 ThreadSnapshot::~ThreadSnapshot() {
 842   delete _stack_trace;
 843   delete _concurrent_locks;
 844 }
 845 
 846 void ThreadSnapshot::dump_stack_at_safepoint(int max_depth, bool with_locked_monitors) {
 847   _stack_trace = new ThreadStackTrace(_thread, with_locked_monitors);
 848   _stack_trace->dump_stack_at_safepoint(max_depth);
 849 }
 850 
 851 
 852 void ThreadSnapshot::oops_do(OopClosure* f) {
 853   f->do_oop(&_threadObj);
 854   f->do_oop(&_blocker_object);
 855   f->do_oop(&_blocker_object_owner);
 856   if (_stack_trace != NULL) {
 857     _stack_trace->oops_do(f);
 858   }
 859   if (_concurrent_locks != NULL) {
 860     _concurrent_locks->oops_do(f);
 861   }
 862 }
 863 
 864 void ThreadSnapshot::metadata_do(void f(Metadata*)) {
 865   if (_stack_trace != NULL) {
 866     _stack_trace->metadata_do(f);
 867   }
 868 }
 869 
 870 
 871 DeadlockCycle::DeadlockCycle() {
 872   _is_deadlock = false;
 873   _threads = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<JavaThread*>(INITIAL_ARRAY_SIZE, true);
 874   _next = NULL;
 875 }
 876 
 877 DeadlockCycle::~DeadlockCycle() {
 878   delete _threads;
 879 }
 880 
 881 void DeadlockCycle::print_on_with(ThreadsList * t_list, outputStream* st) const {
 882   st->cr();
 883   st->print_cr("Found one Java-level deadlock:");
 884   st->print("=============================");
 885 
 886   JavaThread* currentThread;
 887   ObjectMonitor* waitingToLockMonitor;
 888   oop waitingToLockBlocker;
 889   int len = _threads->length();
 890   for (int i = 0; i < len; i++) {
 891     currentThread = _threads->at(i);
 892     waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
 893     waitingToLockBlocker = currentThread->current_park_blocker();
 894     st->cr();
 895     st->print_cr("\"%s\":", currentThread->get_thread_name());
 896     const char* owner_desc = ",\n  which is held by";
 897     if (waitingToLockMonitor != NULL) {
 898       st->print("  waiting to lock monitor " INTPTR_FORMAT, p2i(waitingToLockMonitor));
 899       oop obj = (oop)waitingToLockMonitor->object();
 900       if (obj != NULL) {
 901         st->print(" (object " INTPTR_FORMAT ", a %s)", p2i(obj),
 902                    obj->klass()->external_name());
 903 
 904         if (!currentThread->current_pending_monitor_is_from_java()) {
 905           owner_desc = "\n  in JNI, which is held by";
 906         }
 907       } else {
 908         // No Java object associated - a JVMTI raw monitor
 909         owner_desc = " (JVMTI raw monitor),\n  which is held by";
 910       }
 911       currentThread = Threads::owning_thread_from_monitor_owner(t_list,
 912                                                                 (address)waitingToLockMonitor->owner());
 913       if (currentThread == NULL) {
 914         // The deadlock was detected at a safepoint so the JavaThread
 915         // that owns waitingToLockMonitor should be findable, but
 916         // if it is not findable, then the previous currentThread is
 917         // blocked permanently.
 918         st->print("%s UNKNOWN_owner_addr=" PTR_FORMAT, owner_desc,
 919                   p2i(waitingToLockMonitor->owner()));
 920         continue;
 921       }
 922     } else {
 923       st->print("  waiting for ownable synchronizer " INTPTR_FORMAT ", (a %s)",
 924                 p2i(waitingToLockBlocker),
 925                 waitingToLockBlocker->klass()->external_name());
 926       assert(waitingToLockBlocker->is_a(SystemDictionary::java_util_concurrent_locks_AbstractOwnableSynchronizer_klass()),
 927              "Must be an AbstractOwnableSynchronizer");
 928       oop ownerObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
 929       currentThread = java_lang_Thread::thread(ownerObj);
 930       assert(currentThread != NULL, "AbstractOwnableSynchronizer owning thread is unexpectedly NULL");
 931     }
 932     st->print("%s \"%s\"", owner_desc, currentThread->get_thread_name());
 933   }
 934 
 935   st->cr();
 936   st->cr();
 937 
 938   // Print stack traces
 939   bool oldJavaMonitorsInStackTrace = JavaMonitorsInStackTrace;
 940   JavaMonitorsInStackTrace = true;
 941   st->print_cr("Java stack information for the threads listed above:");
 942   st->print_cr("===================================================");
 943   for (int j = 0; j < len; j++) {
 944     currentThread = _threads->at(j);
 945     st->print_cr("\"%s\":", currentThread->get_thread_name());
 946     currentThread->print_stack_on(st);
 947   }
 948   JavaMonitorsInStackTrace = oldJavaMonitorsInStackTrace;
 949 }
 950 
 951 ThreadsListEnumerator::ThreadsListEnumerator(Thread* cur_thread,
 952                                              bool include_jvmti_agent_threads,
 953                                              bool include_jni_attaching_threads) {
 954   assert(cur_thread == Thread::current(), "Check current thread");
 955 
 956   int init_size = ThreadService::get_live_thread_count();
 957   _threads_array = new GrowableArray<instanceHandle>(init_size);
 958 
 959   for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
 960     // skips JavaThreads in the process of exiting
 961     // and also skips VM internal JavaThreads
 962     // Threads in _thread_new or _thread_new_trans state are included.
 963     // i.e. threads have been started but not yet running.
 964     if (jt->threadObj() == NULL   ||
 965         jt->is_exiting() ||
 966         !java_lang_Thread::is_alive(jt->threadObj())   ||
 967         jt->is_hidden_from_external_view()) {
 968       continue;
 969     }
 970 
 971     // skip agent threads
 972     if (!include_jvmti_agent_threads && jt->is_jvmti_agent_thread()) {
 973       continue;
 974     }
 975 
 976     // skip jni threads in the process of attaching
 977     if (!include_jni_attaching_threads && jt->is_attaching_via_jni()) {
 978       continue;
 979     }
 980 
 981     instanceHandle h(cur_thread, (instanceOop) jt->threadObj());
 982     _threads_array->append(h);
 983   }
 984 }
--- EOF ---