duke@435: /*
duke@435:  * Copyright 2002-2007 Sun Microsystems, Inc.  All Rights Reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: //
duke@435: // The GCTaskManager is a queue of GCTasks, and accessors
duke@435: // to allow the queue to be accessed from many threads.
duke@435: //
duke@435: 
duke@435: // Forward declarations of types defined in this file.
duke@435: class GCTask;
duke@435: class GCTaskQueue;
duke@435: class SynchronizedGCTaskQueue;
duke@435: class GCTaskManager;
duke@435: class NotifyDoneClosure;
duke@435: // Some useful subclasses of GCTask.  You can also make up your own.
duke@435: class NoopGCTask;
duke@435: class BarrierGCTask;
duke@435: class ReleasingBarrierGCTask;
duke@435: class NotifyingBarrierGCTask;
duke@435: class WaitForBarrierGCTask;
duke@435: // A free list of Monitor*'s.
duke@435: class MonitorSupply;
duke@435: 
duke@435: // Forward declarations of classes referenced in this file via pointer.
duke@435: class GCTaskThread;
duke@435: class Mutex;
duke@435: class Monitor;
duke@435: class ThreadClosure;
duke@435: 
duke@435: // The abstract base GCTask.
duke@435: class GCTask : public ResourceObj {
duke@435: public:
duke@435:   // Known kinds of GCTasks, for predicates.
duke@435:   class Kind : AllStatic {
duke@435:   public:
duke@435:     enum kind {
duke@435:       unknown_task,
duke@435:       ordinary_task,
duke@435:       barrier_task,
duke@435:       noop_task
duke@435:     };
duke@435:     static const char* to_string(kind value);
duke@435:   };
duke@435: private:
duke@435:   // Instance state.
duke@435:   const Kind::kind _kind;               // For runtime type checking.
duke@435:   const uint       _affinity;           // Which worker should run task.
duke@435:   GCTask*          _newer;              // Tasks are on doubly-linked ...
duke@435:   GCTask*          _older;              // ... lists.
duke@435: public:
duke@435:   virtual char* name() { return (char *)"task"; }
duke@435: 
duke@435:   // Abstract do_it method
duke@435:   virtual void do_it(GCTaskManager* manager, uint which) = 0;
duke@435:   // Accessors
duke@435:   Kind::kind kind() const {
duke@435:     return _kind;
duke@435:   }
duke@435:   uint affinity() const {
duke@435:     return _affinity;
duke@435:   }
duke@435:   GCTask* newer() const {
duke@435:     return _newer;
duke@435:   }
duke@435:   void set_newer(GCTask* n) {
duke@435:     _newer = n;
duke@435:   }
duke@435:   GCTask* older() const {
duke@435:     return _older;
duke@435:   }
duke@435:   void set_older(GCTask* p) {
duke@435:     _older = p;
duke@435:   }
duke@435:   // Predicates.
duke@435:   bool is_ordinary_task() const {
duke@435:     return kind()==Kind::ordinary_task;
duke@435:   }
duke@435:   bool is_barrier_task() const {
duke@435:     return kind()==Kind::barrier_task;
duke@435:   }
duke@435:   bool is_noop_task() const {
duke@435:     return kind()==Kind::noop_task;
duke@435:   }
duke@435:   void print(const char* message) const PRODUCT_RETURN;
duke@435: protected:
duke@435:   // Constructors: Only create subclasses.
duke@435:   //     An ordinary GCTask.
duke@435:   GCTask();
duke@435:   //     A GCTask of a particular kind, usually barrier or noop.
duke@435:   GCTask(Kind::kind kind);
duke@435:   //     An ordinary GCTask with an affinity.
duke@435:   GCTask(uint affinity);
duke@435:   //     A GCTask of a particular kind, with and affinity.
duke@435:   GCTask(Kind::kind kind, uint affinity);
duke@435:   // We want a virtual destructor because virtual methods,
duke@435:   // but since ResourceObj's don't have their destructors
duke@435:   // called, we don't have one at all.  Instead we have
duke@435:   // this method, which gets called by subclasses to clean up.
duke@435:   virtual void destruct();
duke@435:   // Methods.
duke@435:   void initialize();
duke@435: };
duke@435: 
duke@435: // A doubly-linked list of GCTasks.
duke@435: // The list is not synchronized, because sometimes we want to
duke@435: // build up a list and then make it available to other threads.
duke@435: // See also: SynchronizedGCTaskQueue.
duke@435: class GCTaskQueue : public ResourceObj {
duke@435: private:
duke@435:   // Instance state.
duke@435:   GCTask*    _insert_end;               // Tasks are enqueued at this end.
duke@435:   GCTask*    _remove_end;               // Tasks are dequeued from this end.
duke@435:   uint       _length;                   // The current length of the queue.
duke@435:   const bool _is_c_heap_obj;            // Is this a CHeapObj?
duke@435: public:
duke@435:   // Factory create and destroy methods.
duke@435:   //     Create as ResourceObj.
duke@435:   static GCTaskQueue* create();
duke@435:   //     Create as CHeapObj.
duke@435:   static GCTaskQueue* create_on_c_heap();
duke@435:   //     Destroyer.
duke@435:   static void destroy(GCTaskQueue* that);
duke@435:   // Accessors.
duke@435:   //     These just examine the state of the queue.
duke@435:   bool is_empty() const {
duke@435:     assert(((insert_end() == NULL && remove_end() == NULL) ||
duke@435:             (insert_end() != NULL && remove_end() != NULL)),
duke@435:            "insert_end and remove_end don't match");
duke@435:     return insert_end() == NULL;
duke@435:   }
duke@435:   uint length() const {
duke@435:     return _length;
duke@435:   }
duke@435:   // Methods.
duke@435:   //     Enqueue one task.
duke@435:   void enqueue(GCTask* task);
duke@435:   //     Enqueue a list of tasks.  Empties the argument list.
duke@435:   void enqueue(GCTaskQueue* list);
duke@435:   //     Dequeue one task.
duke@435:   GCTask* dequeue();
duke@435:   //     Dequeue one task, preferring one with affinity.
duke@435:   GCTask* dequeue(uint affinity);
duke@435: protected:
duke@435:   // Constructor. Clients use factory, but there might be subclasses.
duke@435:   GCTaskQueue(bool on_c_heap);
duke@435:   // Destructor-like method.
duke@435:   // Because ResourceMark doesn't call destructors.
duke@435:   // This method cleans up like one.
duke@435:   virtual void destruct();
duke@435:   // Accessors.
duke@435:   GCTask* insert_end() const {
duke@435:     return _insert_end;
duke@435:   }
duke@435:   void set_insert_end(GCTask* value) {
duke@435:     _insert_end = value;
duke@435:   }
duke@435:   GCTask* remove_end() const {
duke@435:     return _remove_end;
duke@435:   }
duke@435:   void set_remove_end(GCTask* value) {
duke@435:     _remove_end = value;
duke@435:   }
duke@435:   void increment_length() {
duke@435:     _length += 1;
duke@435:   }
duke@435:   void decrement_length() {
duke@435:     _length -= 1;
duke@435:   }
duke@435:   void set_length(uint value) {
duke@435:     _length = value;
duke@435:   }
duke@435:   bool is_c_heap_obj() const {
duke@435:     return _is_c_heap_obj;
duke@435:   }
duke@435:   // Methods.
duke@435:   void initialize();
duke@435:   GCTask* remove();                     // Remove from remove end.
duke@435:   GCTask* remove(GCTask* task);         // Remove from the middle.
duke@435:   void print(const char* message) const PRODUCT_RETURN;
duke@435: };
duke@435: 
duke@435: // A GCTaskQueue that can be synchronized.
duke@435: // This "has-a" GCTaskQueue and a mutex to do the exclusion.
duke@435: class SynchronizedGCTaskQueue : public CHeapObj {
duke@435: private:
duke@435:   // Instance state.
duke@435:   GCTaskQueue* _unsynchronized_queue;   // Has-a unsynchronized queue.
duke@435:   Monitor *    _lock;                   // Lock to control access.
duke@435: public:
duke@435:   // Factory create and destroy methods.
duke@435:   static SynchronizedGCTaskQueue* create(GCTaskQueue* queue, Monitor * lock) {
duke@435:     return new SynchronizedGCTaskQueue(queue, lock);
duke@435:   }
duke@435:   static void destroy(SynchronizedGCTaskQueue* that) {
duke@435:     if (that != NULL) {
duke@435:       delete that;
duke@435:     }
duke@435:   }
duke@435:   // Accessors
duke@435:   GCTaskQueue* unsynchronized_queue() const {
duke@435:     return _unsynchronized_queue;
duke@435:   }
duke@435:   Monitor * lock() const {
duke@435:     return _lock;
duke@435:   }
duke@435:   // GCTaskQueue wrapper methods.
duke@435:   // These check that you hold the lock
duke@435:   // and then call the method on the queue.
duke@435:   bool is_empty() const {
duke@435:     guarantee(own_lock(), "don't own the lock");
duke@435:     return unsynchronized_queue()->is_empty();
duke@435:   }
duke@435:   void enqueue(GCTask* task) {
duke@435:     guarantee(own_lock(), "don't own the lock");
duke@435:     unsynchronized_queue()->enqueue(task);
duke@435:   }
duke@435:   void enqueue(GCTaskQueue* list) {
duke@435:     guarantee(own_lock(), "don't own the lock");
duke@435:     unsynchronized_queue()->enqueue(list);
duke@435:   }
duke@435:   GCTask* dequeue() {
duke@435:     guarantee(own_lock(), "don't own the lock");
duke@435:     return unsynchronized_queue()->dequeue();
duke@435:   }
duke@435:   GCTask* dequeue(uint affinity) {
duke@435:     guarantee(own_lock(), "don't own the lock");
duke@435:     return unsynchronized_queue()->dequeue(affinity);
duke@435:   }
duke@435:   uint length() const {
duke@435:     guarantee(own_lock(), "don't own the lock");
duke@435:     return unsynchronized_queue()->length();
duke@435:   }
duke@435:   // For guarantees.
duke@435:   bool own_lock() const {
duke@435:     return lock()->owned_by_self();
duke@435:   }
duke@435: protected:
duke@435:   // Constructor.  Clients use factory, but there might be subclasses.
duke@435:   SynchronizedGCTaskQueue(GCTaskQueue* queue, Monitor * lock);
duke@435:   // Destructor.  Not virtual because no virtuals.
duke@435:   ~SynchronizedGCTaskQueue();
duke@435: };
duke@435: 
duke@435: // This is an abstract base class for getting notifications
duke@435: // when a GCTaskManager is done.
duke@435: class NotifyDoneClosure : public CHeapObj {
duke@435: public:
duke@435:   // The notification callback method.
duke@435:   virtual void notify(GCTaskManager* manager) = 0;
duke@435: protected:
duke@435:   // Constructor.
duke@435:   NotifyDoneClosure() {
duke@435:     // Nothing to do.
duke@435:   }
duke@435:   // Virtual destructor because virtual methods.
duke@435:   virtual ~NotifyDoneClosure() {
duke@435:     // Nothing to do.
duke@435:   }
duke@435: };
duke@435: 
duke@435: class GCTaskManager : public CHeapObj {
duke@435:  friend class ParCompactionManager;
duke@435:  friend class PSParallelCompact;
duke@435:  friend class PSScavenge;
duke@435:  friend class PSRefProcTaskExecutor;
duke@435:  friend class RefProcTaskExecutor;
duke@435: private:
duke@435:   // Instance state.
duke@435:   NotifyDoneClosure*        _ndc;               // Notify on completion.
duke@435:   const uint                _workers;           // Number of workers.
duke@435:   Monitor*                  _monitor;           // Notification of changes.
duke@435:   SynchronizedGCTaskQueue*  _queue;             // Queue of tasks.
duke@435:   GCTaskThread**            _thread;            // Array of worker threads.
duke@435:   uint                      _busy_workers;      // Number of busy workers.
duke@435:   uint                      _blocking_worker;   // The worker that's blocking.
duke@435:   bool*                     _resource_flag;     // Array of flag per threads.
duke@435:   uint                      _delivered_tasks;   // Count of delivered tasks.
duke@435:   uint                      _completed_tasks;   // Count of completed tasks.
duke@435:   uint                      _barriers;          // Count of barrier tasks.
duke@435:   uint                      _emptied_queue;     // Times we emptied the queue.
duke@435:   NoopGCTask*               _noop_task;         // The NoopGCTask instance.
duke@435:   uint                      _noop_tasks;        // Count of noop tasks.
duke@435: public:
duke@435:   // Factory create and destroy methods.
duke@435:   static GCTaskManager* create(uint workers) {
duke@435:     return new GCTaskManager(workers);
duke@435:   }
duke@435:   static GCTaskManager* create(uint workers, NotifyDoneClosure* ndc) {
duke@435:     return new GCTaskManager(workers, ndc);
duke@435:   }
duke@435:   static void destroy(GCTaskManager* that) {
duke@435:     if (that != NULL) {
duke@435:       delete that;
duke@435:     }
duke@435:   }
duke@435:   // Accessors.
duke@435:   uint busy_workers() const {
duke@435:     return _busy_workers;
duke@435:   }
duke@435:   //     Pun between Monitor* and Mutex*
duke@435:   Monitor* monitor() const {
duke@435:     return _monitor;
duke@435:   }
duke@435:   Monitor * lock() const {
duke@435:     return _monitor;
duke@435:   }
duke@435:   // Methods.
duke@435:   //     Add the argument task to be run.
duke@435:   void add_task(GCTask* task);
duke@435:   //     Add a list of tasks.  Removes task from the argument list.
duke@435:   void add_list(GCTaskQueue* list);
duke@435:   //     Claim a task for argument worker.
duke@435:   GCTask* get_task(uint which);
duke@435:   //     Note the completion of a task by the argument worker.
duke@435:   void note_completion(uint which);
duke@435:   //     Is the queue blocked from handing out new tasks?
duke@435:   bool is_blocked() const {
duke@435:     return (blocking_worker() != sentinel_worker());
duke@435:   }
duke@435:   //     Request that all workers release their resources.
duke@435:   void release_all_resources();
duke@435:   //     Ask if a particular worker should release its resources.
duke@435:   bool should_release_resources(uint which); // Predicate.
duke@435:   //     Note the release of resources by the argument worker.
duke@435:   void note_release(uint which);
duke@435:   // Constants.
duke@435:   //     A sentinel worker identifier.
duke@435:   static uint sentinel_worker() {
duke@435:     return (uint) -1;                   // Why isn't there a max_uint?
duke@435:   }
duke@435: 
duke@435:   //     Execute the task queue and wait for the completion.
duke@435:   void execute_and_wait(GCTaskQueue* list);
duke@435: 
duke@435:   void print_task_time_stamps();
duke@435:   void print_threads_on(outputStream* st);
duke@435:   void threads_do(ThreadClosure* tc);
duke@435: 
duke@435: protected:
duke@435:   // Constructors.  Clients use factory, but there might be subclasses.
duke@435:   //     Create a GCTaskManager with the appropriate number of workers.
duke@435:   GCTaskManager(uint workers);
duke@435:   //     Create a GCTaskManager that calls back when there's no more work.
duke@435:   GCTaskManager(uint workers, NotifyDoneClosure* ndc);
duke@435:   //     Make virtual if necessary.
duke@435:   ~GCTaskManager();
duke@435:   // Accessors.
duke@435:   uint workers() const {
duke@435:     return _workers;
duke@435:   }
duke@435:   NotifyDoneClosure* notify_done_closure() const {
duke@435:     return _ndc;
duke@435:   }
duke@435:   SynchronizedGCTaskQueue* queue() const {
duke@435:     return _queue;
duke@435:   }
duke@435:   NoopGCTask* noop_task() const {
duke@435:     return _noop_task;
duke@435:   }
duke@435:   //     Bounds-checking per-thread data accessors.
duke@435:   GCTaskThread* thread(uint which);
duke@435:   void set_thread(uint which, GCTaskThread* value);
duke@435:   bool resource_flag(uint which);
duke@435:   void set_resource_flag(uint which, bool value);
duke@435:   // Modifier methods with some semantics.
duke@435:   //     Is any worker blocking handing out new tasks?
duke@435:   uint blocking_worker() const {
duke@435:     return _blocking_worker;
duke@435:   }
duke@435:   void set_blocking_worker(uint value) {
duke@435:     _blocking_worker = value;
duke@435:   }
duke@435:   void set_unblocked() {
duke@435:     set_blocking_worker(sentinel_worker());
duke@435:   }
duke@435:   //     Count of busy workers.
duke@435:   void reset_busy_workers() {
duke@435:     _busy_workers = 0;
duke@435:   }
duke@435:   uint increment_busy_workers();
duke@435:   uint decrement_busy_workers();
duke@435:   //     Count of tasks delivered to workers.
duke@435:   uint delivered_tasks() const {
duke@435:     return _delivered_tasks;
duke@435:   }
duke@435:   void increment_delivered_tasks() {
duke@435:     _delivered_tasks += 1;
duke@435:   }
duke@435:   void reset_delivered_tasks() {
duke@435:     _delivered_tasks = 0;
duke@435:   }
duke@435:   //     Count of tasks completed by workers.
duke@435:   uint completed_tasks() const {
duke@435:     return _completed_tasks;
duke@435:   }
duke@435:   void increment_completed_tasks() {
duke@435:     _completed_tasks += 1;
duke@435:   }
duke@435:   void reset_completed_tasks() {
duke@435:     _completed_tasks = 0;
duke@435:   }
duke@435:   //     Count of barrier tasks completed.
duke@435:   uint barriers() const {
duke@435:     return _barriers;
duke@435:   }
duke@435:   void increment_barriers() {
duke@435:     _barriers += 1;
duke@435:   }
duke@435:   void reset_barriers() {
duke@435:     _barriers = 0;
duke@435:   }
duke@435:   //     Count of how many times the queue has emptied.
duke@435:   uint emptied_queue() const {
duke@435:     return _emptied_queue;
duke@435:   }
duke@435:   void increment_emptied_queue() {
duke@435:     _emptied_queue += 1;
duke@435:   }
duke@435:   void reset_emptied_queue() {
duke@435:     _emptied_queue = 0;
duke@435:   }
duke@435:   //     Count of the number of noop tasks we've handed out,
duke@435:   //     e.g., to handle resource release requests.
duke@435:   uint noop_tasks() const {
duke@435:     return _noop_tasks;
duke@435:   }
duke@435:   void increment_noop_tasks() {
duke@435:     _noop_tasks += 1;
duke@435:   }
duke@435:   void reset_noop_tasks() {
duke@435:     _noop_tasks = 0;
duke@435:   }
duke@435:   // Other methods.
duke@435:   void initialize();
duke@435: };
duke@435: 
duke@435: //
duke@435: // Some exemplary GCTasks.
duke@435: //
duke@435: 
duke@435: // A noop task that does nothing,
duke@435: // except take us around the GCTaskThread loop.
duke@435: class NoopGCTask : public GCTask {
duke@435: private:
duke@435:   const bool _is_c_heap_obj;            // Is this a CHeapObj?
duke@435: public:
duke@435:   // Factory create and destroy methods.
duke@435:   static NoopGCTask* create();
duke@435:   static NoopGCTask* create_on_c_heap();
duke@435:   static void destroy(NoopGCTask* that);
duke@435:   // Methods from GCTask.
duke@435:   void do_it(GCTaskManager* manager, uint which) {
duke@435:     // Nothing to do.
duke@435:   }
duke@435: protected:
duke@435:   // Constructor.
duke@435:   NoopGCTask(bool on_c_heap) :
duke@435:     GCTask(GCTask::Kind::noop_task),
duke@435:     _is_c_heap_obj(on_c_heap) {
duke@435:     // Nothing to do.
duke@435:   }
duke@435:   // Destructor-like method.
duke@435:   void destruct();
duke@435:   // Accessors.
duke@435:   bool is_c_heap_obj() const {
duke@435:     return _is_c_heap_obj;
duke@435:   }
duke@435: };
duke@435: 
duke@435: // A BarrierGCTask blocks other tasks from starting,
duke@435: // and waits until it is the only task running.
duke@435: class BarrierGCTask : public GCTask {
duke@435: public:
duke@435:   // Factory create and destroy methods.
duke@435:   static BarrierGCTask* create() {
duke@435:     return new BarrierGCTask();
duke@435:   }
duke@435:   static void destroy(BarrierGCTask* that) {
duke@435:     if (that != NULL) {
duke@435:       that->destruct();
duke@435:       delete that;
duke@435:     }
duke@435:   }
duke@435:   // Methods from GCTask.
duke@435:   void do_it(GCTaskManager* manager, uint which);
duke@435: protected:
duke@435:   // Constructor.  Clients use factory, but there might be subclasses.
duke@435:   BarrierGCTask() :
duke@435:     GCTask(GCTask::Kind::barrier_task) {
duke@435:     // Nothing to do.
duke@435:   }
duke@435:   // Destructor-like method.
duke@435:   void destruct();
duke@435:   // Methods.
duke@435:   //     Wait for this to be the only task running.
duke@435:   void do_it_internal(GCTaskManager* manager, uint which);
duke@435: };
duke@435: 
duke@435: // A ReleasingBarrierGCTask is a BarrierGCTask
duke@435: // that tells all the tasks to release their resource areas.
duke@435: class ReleasingBarrierGCTask : public BarrierGCTask {
duke@435: public:
duke@435:   // Factory create and destroy methods.
duke@435:   static ReleasingBarrierGCTask* create() {
duke@435:     return new ReleasingBarrierGCTask();
duke@435:   }
duke@435:   static void destroy(ReleasingBarrierGCTask* that) {
duke@435:     if (that != NULL) {
duke@435:       that->destruct();
duke@435:       delete that;
duke@435:     }
duke@435:   }
duke@435:   // Methods from GCTask.
duke@435:   void do_it(GCTaskManager* manager, uint which);
duke@435: protected:
duke@435:   // Constructor.  Clients use factory, but there might be subclasses.
duke@435:   ReleasingBarrierGCTask() :
duke@435:     BarrierGCTask() {
duke@435:     // Nothing to do.
duke@435:   }
duke@435:   // Destructor-like method.
duke@435:   void destruct();
duke@435: };
duke@435: 
duke@435: // A NotifyingBarrierGCTask is a BarrierGCTask
duke@435: // that calls a notification method when it is the only task running.
duke@435: class NotifyingBarrierGCTask : public BarrierGCTask {
duke@435: private:
duke@435:   // Instance state.
duke@435:   NotifyDoneClosure* _ndc;              // The callback object.
duke@435: public:
duke@435:   // Factory create and destroy methods.
duke@435:   static NotifyingBarrierGCTask* create(NotifyDoneClosure* ndc) {
duke@435:     return new NotifyingBarrierGCTask(ndc);
duke@435:   }
duke@435:   static void destroy(NotifyingBarrierGCTask* that) {
duke@435:     if (that != NULL) {
duke@435:       that->destruct();
duke@435:       delete that;
duke@435:     }
duke@435:   }
duke@435:   // Methods from GCTask.
duke@435:   void do_it(GCTaskManager* manager, uint which);
duke@435: protected:
duke@435:   // Constructor.  Clients use factory, but there might be subclasses.
duke@435:   NotifyingBarrierGCTask(NotifyDoneClosure* ndc) :
duke@435:     BarrierGCTask(),
duke@435:     _ndc(ndc) {
duke@435:     assert(notify_done_closure() != NULL, "can't notify on NULL");
duke@435:   }
duke@435:   // Destructor-like method.
duke@435:   void destruct();
duke@435:   // Accessor.
duke@435:   NotifyDoneClosure* notify_done_closure() const { return _ndc; }
duke@435: };
duke@435: 
duke@435: // A WaitForBarrierGCTask is a BarrierGCTask
duke@435: // with a method you can call to wait until
duke@435: // the BarrierGCTask is done.
duke@435: // This may cover many of the uses of NotifyingBarrierGCTasks.
duke@435: class WaitForBarrierGCTask : public BarrierGCTask {
duke@435: private:
duke@435:   // Instance state.
duke@435:   Monitor*   _monitor;                  // Guard and notify changes.
duke@435:   bool       _should_wait;              // true=>wait, false=>proceed.
duke@435:   const bool _is_c_heap_obj;            // Was allocated on the heap.
duke@435: public:
duke@435:   virtual char* name() { return (char *) "waitfor-barrier-task"; }
duke@435: 
duke@435:   // Factory create and destroy methods.
duke@435:   static WaitForBarrierGCTask* create();
duke@435:   static WaitForBarrierGCTask* create_on_c_heap();
duke@435:   static void destroy(WaitForBarrierGCTask* that);
duke@435:   // Methods.
duke@435:   void     do_it(GCTaskManager* manager, uint which);
duke@435:   void     wait_for();
duke@435: protected:
duke@435:   // Constructor.  Clients use factory, but there might be subclasses.
duke@435:   WaitForBarrierGCTask(bool on_c_heap);
duke@435:   // Destructor-like method.
duke@435:   void destruct();
duke@435:   // Accessors.
duke@435:   Monitor* monitor() const {
duke@435:     return _monitor;
duke@435:   }
duke@435:   bool should_wait() const {
duke@435:     return _should_wait;
duke@435:   }
duke@435:   void set_should_wait(bool value) {
duke@435:     _should_wait = value;
duke@435:   }
duke@435:   bool is_c_heap_obj() {
duke@435:     return _is_c_heap_obj;
duke@435:   }
duke@435: };
duke@435: 
duke@435: class MonitorSupply : public AllStatic {
duke@435: private:
duke@435:   // State.
duke@435:   //     Control multi-threaded access.
duke@435:   static Mutex*                   _lock;
duke@435:   //     The list of available Monitor*'s.
duke@435:   static GrowableArray<Monitor*>* _freelist;
duke@435: public:
duke@435:   // Reserve a Monitor*.
duke@435:   static Monitor* reserve();
duke@435:   // Release a Monitor*.
duke@435:   static void release(Monitor* instance);
duke@435: private:
duke@435:   // Accessors.
duke@435:   static Mutex* lock() {
duke@435:     return _lock;
duke@435:   }
duke@435:   static GrowableArray<Monitor*>* freelist() {
duke@435:     return _freelist;
duke@435:   }
duke@435: };