jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.hpp@b06ac540229e (annotated)

src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.hpp@b06ac540229e (annotated)

src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.hpp

Wed, 24 Apr 2013 20:13:37 +0200

author: stefank
date: Wed, 24 Apr 2013 20:13:37 +0200
changeset 5018: b06ac540229e
parent 4153: b9a9ed0f8eeb
child 6876: 710a3c8b516e
permissions: -rw-r--r--

8013132: Add a flag to turn off the output of the verbose verification code
Reviewed-by: johnc, brutisso

 /*
  * Copyright (c) 2002, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GCTASKMANAGER_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GCTASKMANAGER_HPP
 #include "runtime/mutex.hpp"
 #include "utilities/growableArray.hpp"
 //
 // The GCTaskManager is a queue of GCTasks, and accessors
 // to allow the queue to be accessed from many threads.
 //
 // Forward declarations of types defined in this file.
 class GCTask;
 class GCTaskQueue;
 class SynchronizedGCTaskQueue;
 class GCTaskManager;
 class NotifyDoneClosure;
 // Some useful subclasses of GCTask.  You can also make up your own.
 class NoopGCTask;
 class BarrierGCTask;
 class ReleasingBarrierGCTask;
 class NotifyingBarrierGCTask;
 class WaitForBarrierGCTask;
 class IdleGCTask;
 // A free list of Monitor*'s.
 class MonitorSupply;
 // Forward declarations of classes referenced in this file via pointer.
 class GCTaskThread;
 class Mutex;
 class Monitor;
 class ThreadClosure;
 // The abstract base GCTask.
 class GCTask : public ResourceObj {
 public:
   // Known kinds of GCTasks, for predicates.
   class Kind : AllStatic {
   public:
     enum kind {
       unknown_task,
       ordinary_task,
       barrier_task,
       noop_task,
       idle_task
     };
     static const char* to_string(kind value);
   };
 private:
   // Instance state.
   const Kind::kind _kind;               // For runtime type checking.
   const uint       _affinity;           // Which worker should run task.
   GCTask*          _newer;              // Tasks are on doubly-linked ...
   GCTask*          _older;              // ... lists.
 public:
   virtual char* name() { return (char *)"task"; }
   // Abstract do_it method
   virtual void do_it(GCTaskManager* manager, uint which) = 0;
   // Accessors
   Kind::kind kind() const {
     return _kind;
   }
   uint affinity() const {
     return _affinity;
   }
   GCTask* newer() const {
     return _newer;
   }
   void set_newer(GCTask* n) {
     _newer = n;
   }
   GCTask* older() const {
     return _older;
   }
   void set_older(GCTask* p) {
     _older = p;
   }
   // Predicates.
   bool is_ordinary_task() const {
     return kind()==Kind::ordinary_task;
   }
   bool is_barrier_task() const {
     return kind()==Kind::barrier_task;
   }
   bool is_noop_task() const {
     return kind()==Kind::noop_task;
   }
   bool is_idle_task() const {
     return kind()==Kind::idle_task;
   }
   void print(const char* message) const PRODUCT_RETURN;
 protected:
   // Constructors: Only create subclasses.
   //     An ordinary GCTask.
   GCTask();
   //     A GCTask of a particular kind, usually barrier or noop.
   GCTask(Kind::kind kind);
   //     An ordinary GCTask with an affinity.
   GCTask(uint affinity);
   //     A GCTask of a particular kind, with and affinity.
   GCTask(Kind::kind kind, uint affinity);
   // We want a virtual destructor because virtual methods,
   // but since ResourceObj's don't have their destructors
   // called, we don't have one at all.  Instead we have
   // this method, which gets called by subclasses to clean up.
   virtual void destruct();
   // Methods.
   void initialize();
 };
 // A doubly-linked list of GCTasks.
 // The list is not synchronized, because sometimes we want to
 // build up a list and then make it available to other threads.
 // See also: SynchronizedGCTaskQueue.
 class GCTaskQueue : public ResourceObj {
 private:
   // Instance state.
   GCTask*    _insert_end;               // Tasks are enqueued at this end.
   GCTask*    _remove_end;               // Tasks are dequeued from this end.
   uint       _length;                   // The current length of the queue.
   const bool _is_c_heap_obj;            // Is this a CHeapObj?
 public:
   // Factory create and destroy methods.
   //     Create as ResourceObj.
   static GCTaskQueue* create();
   //     Create as CHeapObj.
   static GCTaskQueue* create_on_c_heap();
   //     Destroyer.
   static void destroy(GCTaskQueue* that);
   // Accessors.
   //     These just examine the state of the queue.
   bool is_empty() const {
     assert(((insert_end() == NULL && remove_end() == NULL) ||
             (insert_end() != NULL && remove_end() != NULL)),
            "insert_end and remove_end don't match");
     assert((insert_end() != NULL) || (_length == 0), "Not empty");
     return insert_end() == NULL;
   }
   uint length() const {
     return _length;
   }
   // Methods.
   //     Enqueue one task.
   void enqueue(GCTask* task);
   //     Enqueue a list of tasks.  Empties the argument list.
   void enqueue(GCTaskQueue* list);
   //     Dequeue one task.
   GCTask* dequeue();
   //     Dequeue one task, preferring one with affinity.
   GCTask* dequeue(uint affinity);
 protected:
   // Constructor. Clients use factory, but there might be subclasses.
   GCTaskQueue(bool on_c_heap);
   // Destructor-like method.
   // Because ResourceMark doesn't call destructors.
   // This method cleans up like one.
   virtual void destruct();
   // Accessors.
   GCTask* insert_end() const {
     return _insert_end;
   }
   void set_insert_end(GCTask* value) {
     _insert_end = value;
   }
   GCTask* remove_end() const {
     return _remove_end;
   }
   void set_remove_end(GCTask* value) {
     _remove_end = value;
   }
   void increment_length() {
     _length += 1;
   }
   void decrement_length() {
     _length -= 1;
   }
   void set_length(uint value) {
     _length = value;
   }
   bool is_c_heap_obj() const {
     return _is_c_heap_obj;
   }
   // Methods.
   void initialize();
   GCTask* remove();                     // Remove from remove end.
   GCTask* remove(GCTask* task);         // Remove from the middle.
   void print(const char* message) const PRODUCT_RETURN;
   // Debug support
   void verify_length() const PRODUCT_RETURN;
 };
 // A GCTaskQueue that can be synchronized.
 // This "has-a" GCTaskQueue and a mutex to do the exclusion.
 class SynchronizedGCTaskQueue : public CHeapObj<mtGC> {
 private:
   // Instance state.
   GCTaskQueue* _unsynchronized_queue;   // Has-a unsynchronized queue.
   Monitor *    _lock;                   // Lock to control access.
 public:
   // Factory create and destroy methods.
   static SynchronizedGCTaskQueue* create(GCTaskQueue* queue, Monitor * lock) {
     return new SynchronizedGCTaskQueue(queue, lock);
   }
   static void destroy(SynchronizedGCTaskQueue* that) {
     if (that != NULL) {
       delete that;
     }
   }
   // Accessors
   GCTaskQueue* unsynchronized_queue() const {
     return _unsynchronized_queue;
   }
   Monitor * lock() const {
     return _lock;
   }
   // GCTaskQueue wrapper methods.
   // These check that you hold the lock
   // and then call the method on the queue.
   bool is_empty() const {
     guarantee(own_lock(), "don't own the lock");
     return unsynchronized_queue()->is_empty();
   }
   void enqueue(GCTask* task) {
     guarantee(own_lock(), "don't own the lock");
     unsynchronized_queue()->enqueue(task);
   }
   void enqueue(GCTaskQueue* list) {
     guarantee(own_lock(), "don't own the lock");
     unsynchronized_queue()->enqueue(list);
   }
   GCTask* dequeue() {
     guarantee(own_lock(), "don't own the lock");
     return unsynchronized_queue()->dequeue();
   }
   GCTask* dequeue(uint affinity) {
     guarantee(own_lock(), "don't own the lock");
     return unsynchronized_queue()->dequeue(affinity);
   }
   uint length() const {
     guarantee(own_lock(), "don't own the lock");
     return unsynchronized_queue()->length();
   }
   // For guarantees.
   bool own_lock() const {
     return lock()->owned_by_self();
   }
 protected:
   // Constructor.  Clients use factory, but there might be subclasses.
   SynchronizedGCTaskQueue(GCTaskQueue* queue, Monitor * lock);
   // Destructor.  Not virtual because no virtuals.
   ~SynchronizedGCTaskQueue();
 };
 // This is an abstract base class for getting notifications
 // when a GCTaskManager is done.
 class NotifyDoneClosure : public CHeapObj<mtGC> {
 public:
   // The notification callback method.
   virtual void notify(GCTaskManager* manager) = 0;
 protected:
   // Constructor.
   NotifyDoneClosure() {
     // Nothing to do.
   }
   // Virtual destructor because virtual methods.
   virtual ~NotifyDoneClosure() {
     // Nothing to do.
   }
 };
 // Dynamic number of GC threads
 //
 //  GC threads wait in get_task() for work (i.e., a task) to perform.
 // When the number of GC threads was static, the number of tasks
 // created to do a job was equal to or greater than the maximum
 // number of GC threads (ParallelGCThreads).  The job might be divided
 // into a number of tasks greater than the number of GC threads for
 // load balancing (i.e., over partitioning).  The last task to be
 // executed by a GC thread in a job is a work stealing task.  A
 // GC  thread that gets a work stealing task continues to execute
 // that task until the job is done.  In the static number of GC theads
 // case, tasks are added to a queue (FIFO).  The work stealing tasks are
 // the last to be added.  Once the tasks are added, the GC threads grab
 // a task and go.  A single thread can do all the non-work stealing tasks
 // and then execute a work stealing and wait for all the other GC threads
 // to execute their work stealing task.
 //  In the dynamic number of GC threads implementation, idle-tasks are
 // created to occupy the non-participating or "inactive" threads.  An
 // idle-task makes the GC thread wait on a barrier that is part of the
 // GCTaskManager.  The GC threads that have been "idled" in a IdleGCTask
 // are released once all the active GC threads have finished their work
 // stealing tasks.  The GCTaskManager does not wait for all the "idled"
 // GC threads to resume execution. When those GC threads do resume
 // execution in the course of the thread scheduling, they call get_tasks()
 // as all the other GC threads do.  Because all the "idled" threads are
 // not required to execute in order to finish a job, it is possible for
 // a GC thread to still be "idled" when the next job is started.  Such
 // a thread stays "idled" for the next job.  This can result in a new
 // job not having all the expected active workers.  For example if on
 // job requests 4 active workers out of a total of 10 workers so the
 // remaining 6 are "idled", if the next job requests 6 active workers
 // but all 6 of the "idled" workers are still idle, then the next job
 // will only get 4 active workers.
 //  The implementation for the parallel old compaction phase has an
 // added complication.  In the static case parold partitions the chunks
 // ready to be filled into stacks, one for each GC thread.  A GC thread
 // executing a draining task (drains the stack of ready chunks)
 // claims a stack according to it's id (the unique ordinal value assigned
 // to each GC thread).  In the dynamic case not all GC threads will
 // actively participate so stacks with ready to fill chunks can only be
 // given to the active threads.  An initial implementation chose stacks
 // number 1-n to get the ready chunks and required that GC threads
 // 1-n be the active workers.  This was undesirable because it required
 // certain threads to participate.  In the final implementation a
 // list of stacks equal in number to the active workers are filled
 // with ready chunks.  GC threads that participate get a stack from
 // the task (DrainStacksCompactionTask), empty the stack, and then add it to a
 // recycling list at the end of the task.  If the same GC thread gets
 // a second task, it gets a second stack to drain and returns it.  The
 // stacks are added to a recycling list so that later stealing tasks
 // for this tasks can get a stack from the recycling list.  Stealing tasks
 // use the stacks in its work in a way similar to the draining tasks.
 // A thread is not guaranteed to get anything but a stealing task and
 // a thread that only gets a stealing task has to get a stack. A failed
 // implementation tried to have the GC threads keep the stack they used
 // during a draining task for later use in the stealing task but that didn't
 // work because as noted a thread is not guaranteed to get a draining task.
 //
 // For PSScavenge and ParCompactionManager the GC threads are
 // held in the GCTaskThread** _thread array in GCTaskManager.
 class GCTaskManager : public CHeapObj<mtGC> {
  friend class ParCompactionManager;
  friend class PSParallelCompact;
  friend class PSScavenge;
  friend class PSRefProcTaskExecutor;
  friend class RefProcTaskExecutor;
  friend class GCTaskThread;
  friend class IdleGCTask;
 private:
   // Instance state.
   NotifyDoneClosure*        _ndc;               // Notify on completion.
   const uint                _workers;           // Number of workers.
   Monitor*                  _monitor;           // Notification of changes.
   SynchronizedGCTaskQueue*  _queue;             // Queue of tasks.
   GCTaskThread**            _thread;            // Array of worker threads.
   uint                      _active_workers;    // Number of active workers.
   uint                      _busy_workers;      // Number of busy workers.
   uint                      _blocking_worker;   // The worker that's blocking.
   bool*                     _resource_flag;     // Array of flag per threads.
   uint                      _delivered_tasks;   // Count of delivered tasks.
   uint                      _completed_tasks;   // Count of completed tasks.
   uint                      _barriers;          // Count of barrier tasks.
   uint                      _emptied_queue;     // Times we emptied the queue.
   NoopGCTask*               _noop_task;         // The NoopGCTask instance.
   uint                      _noop_tasks;        // Count of noop tasks.
   WaitForBarrierGCTask*     _idle_inactive_task;// Task for inactive workers
   volatile uint             _idle_workers;      // Number of idled workers
 public:
   // Factory create and destroy methods.
   static GCTaskManager* create(uint workers) {
     return new GCTaskManager(workers);
   }
   static GCTaskManager* create(uint workers, NotifyDoneClosure* ndc) {
     return new GCTaskManager(workers, ndc);
   }
   static void destroy(GCTaskManager* that) {
     if (that != NULL) {
       delete that;
     }
   }
   // Accessors.
   uint busy_workers() const {
     return _busy_workers;
   }
   volatile uint idle_workers() const {
     return _idle_workers;
   }
   //     Pun between Monitor* and Mutex*
   Monitor* monitor() const {
     return _monitor;
   }
   Monitor * lock() const {
     return _monitor;
   }
   WaitForBarrierGCTask* idle_inactive_task() {
     return _idle_inactive_task;
   }
   // Methods.
   //     Add the argument task to be run.
   void add_task(GCTask* task);
   //     Add a list of tasks.  Removes task from the argument list.
   void add_list(GCTaskQueue* list);
   //     Claim a task for argument worker.
   GCTask* get_task(uint which);
   //     Note the completion of a task by the argument worker.
   void note_completion(uint which);
   //     Is the queue blocked from handing out new tasks?
   bool is_blocked() const {
     return (blocking_worker() != sentinel_worker());
   }
   //     Request that all workers release their resources.
   void release_all_resources();
   //     Ask if a particular worker should release its resources.
   bool should_release_resources(uint which); // Predicate.
   //     Note the release of resources by the argument worker.
   void note_release(uint which);
   //     Create IdleGCTasks for inactive workers and start workers
   void task_idle_workers();
   //     Release the workers in IdleGCTasks
   void release_idle_workers();
   // Constants.
   //     A sentinel worker identifier.
   static uint sentinel_worker() {
     return (uint) -1;                   // Why isn't there a max_uint?
   }
   //     Execute the task queue and wait for the completion.
   void execute_and_wait(GCTaskQueue* list);
   void print_task_time_stamps();
   void print_threads_on(outputStream* st);
   void threads_do(ThreadClosure* tc);
 protected:
   // Constructors.  Clients use factory, but there might be subclasses.
   //     Create a GCTaskManager with the appropriate number of workers.
   GCTaskManager(uint workers);
   //     Create a GCTaskManager that calls back when there's no more work.
   GCTaskManager(uint workers, NotifyDoneClosure* ndc);
   //     Make virtual if necessary.
   ~GCTaskManager();
   // Accessors.
   uint workers() const {
     return _workers;
   }
   void set_active_workers(uint v) {
     assert(v <= _workers, "Trying to set more workers active than there are");
     _active_workers = MIN2(v, _workers);
     assert(v != 0, "Trying to set active workers to 0");
     _active_workers = MAX2(1U, _active_workers);
   }
   // Sets the number of threads that will be used in a collection
   void set_active_gang();
   NotifyDoneClosure* notify_done_closure() const {
     return _ndc;
   }
   SynchronizedGCTaskQueue* queue() const {
     return _queue;
   }
   NoopGCTask* noop_task() const {
     return _noop_task;
   }
   //     Bounds-checking per-thread data accessors.
   GCTaskThread* thread(uint which);
   void set_thread(uint which, GCTaskThread* value);
   bool resource_flag(uint which);
   void set_resource_flag(uint which, bool value);
   // Modifier methods with some semantics.
   //     Is any worker blocking handing out new tasks?
   uint blocking_worker() const {
     return _blocking_worker;
   }
   void set_blocking_worker(uint value) {
     _blocking_worker = value;
   }
   void set_unblocked() {
     set_blocking_worker(sentinel_worker());
   }
   //     Count of busy workers.
   void reset_busy_workers() {
     _busy_workers = 0;
   }
   uint increment_busy_workers();
   uint decrement_busy_workers();
   //     Count of tasks delivered to workers.
   uint delivered_tasks() const {
     return _delivered_tasks;
   }
   void increment_delivered_tasks() {
     _delivered_tasks += 1;
   }
   void reset_delivered_tasks() {
     _delivered_tasks = 0;
   }
   //     Count of tasks completed by workers.
   uint completed_tasks() const {
     return _completed_tasks;
   }
   void increment_completed_tasks() {
     _completed_tasks += 1;
   }
   void reset_completed_tasks() {
     _completed_tasks = 0;
   }
   //     Count of barrier tasks completed.
   uint barriers() const {
     return _barriers;
   }
   void increment_barriers() {
     _barriers += 1;
   }
   void reset_barriers() {
     _barriers = 0;
   }
   //     Count of how many times the queue has emptied.
   uint emptied_queue() const {
     return _emptied_queue;
   }
   void increment_emptied_queue() {
     _emptied_queue += 1;
   }
   void reset_emptied_queue() {
     _emptied_queue = 0;
   }
   //     Count of the number of noop tasks we've handed out,
   //     e.g., to handle resource release requests.
   uint noop_tasks() const {
     return _noop_tasks;
   }
   void increment_noop_tasks() {
     _noop_tasks += 1;
   }
   void reset_noop_tasks() {
     _noop_tasks = 0;
   }
   void increment_idle_workers() {
     _idle_workers++;
   }
   void decrement_idle_workers() {
     _idle_workers--;
   }
   // Other methods.
   void initialize();
  public:
   // Return true if all workers are currently active.
   bool all_workers_active() { return workers() == active_workers(); }
   uint active_workers() const {
     return _active_workers;
   }
 };
 //
 // Some exemplary GCTasks.
 //
 // A noop task that does nothing,
 // except take us around the GCTaskThread loop.
 class NoopGCTask : public GCTask {
 private:
   const bool _is_c_heap_obj;            // Is this a CHeapObj?
 public:
   // Factory create and destroy methods.
   static NoopGCTask* create();
   static NoopGCTask* create_on_c_heap();
   static void destroy(NoopGCTask* that);
   virtual char* name() { return (char *)"noop task"; }
   // Methods from GCTask.
   void do_it(GCTaskManager* manager, uint which) {
     // Nothing to do.
   }
 protected:
   // Constructor.
   NoopGCTask(bool on_c_heap) :
     GCTask(GCTask::Kind::noop_task),
     _is_c_heap_obj(on_c_heap) {
     // Nothing to do.
   }
   // Destructor-like method.
   void destruct();
   // Accessors.
   bool is_c_heap_obj() const {
     return _is_c_heap_obj;
   }
 };
 // A BarrierGCTask blocks other tasks from starting,
 // and waits until it is the only task running.
 class BarrierGCTask : public GCTask {
 public:
   // Factory create and destroy methods.
   static BarrierGCTask* create() {
     return new BarrierGCTask();
   }
   static void destroy(BarrierGCTask* that) {
     if (that != NULL) {
       that->destruct();
       delete that;
     }
   }
   // Methods from GCTask.
   void do_it(GCTaskManager* manager, uint which);
 protected:
   // Constructor.  Clients use factory, but there might be subclasses.
   BarrierGCTask() :
     GCTask(GCTask::Kind::barrier_task) {
     // Nothing to do.
   }
   // Destructor-like method.
   void destruct();
   virtual char* name() { return (char *)"barrier task"; }
   // Methods.
   //     Wait for this to be the only task running.
   void do_it_internal(GCTaskManager* manager, uint which);
 };
 // A ReleasingBarrierGCTask is a BarrierGCTask
 // that tells all the tasks to release their resource areas.
 class ReleasingBarrierGCTask : public BarrierGCTask {
 public:
   // Factory create and destroy methods.
   static ReleasingBarrierGCTask* create() {
     return new ReleasingBarrierGCTask();
   }
   static void destroy(ReleasingBarrierGCTask* that) {
     if (that != NULL) {
       that->destruct();
       delete that;
     }
   }
   // Methods from GCTask.
   void do_it(GCTaskManager* manager, uint which);
 protected:
   // Constructor.  Clients use factory, but there might be subclasses.
   ReleasingBarrierGCTask() :
     BarrierGCTask() {
     // Nothing to do.
   }
   // Destructor-like method.
   void destruct();
 };
 // A NotifyingBarrierGCTask is a BarrierGCTask
 // that calls a notification method when it is the only task running.
 class NotifyingBarrierGCTask : public BarrierGCTask {
 private:
   // Instance state.
   NotifyDoneClosure* _ndc;              // The callback object.
 public:
   // Factory create and destroy methods.
   static NotifyingBarrierGCTask* create(NotifyDoneClosure* ndc) {
     return new NotifyingBarrierGCTask(ndc);
   }
   static void destroy(NotifyingBarrierGCTask* that) {
     if (that != NULL) {
       that->destruct();
       delete that;
     }
   }
   // Methods from GCTask.
   void do_it(GCTaskManager* manager, uint which);
 protected:
   // Constructor.  Clients use factory, but there might be subclasses.
   NotifyingBarrierGCTask(NotifyDoneClosure* ndc) :
     BarrierGCTask(),
     _ndc(ndc) {
     assert(notify_done_closure() != NULL, "can't notify on NULL");
   }
   // Destructor-like method.
   void destruct();
   // Accessor.
   NotifyDoneClosure* notify_done_closure() const { return _ndc; }
 };
 // A WaitForBarrierGCTask is a BarrierGCTask
 // with a method you can call to wait until
 // the BarrierGCTask is done.
 // This may cover many of the uses of NotifyingBarrierGCTasks.
 class WaitForBarrierGCTask : public BarrierGCTask {
   friend class GCTaskManager;
   friend class IdleGCTask;
 private:
   // Instance state.
   Monitor*      _monitor;                  // Guard and notify changes.
   volatile bool _should_wait;              // true=>wait, false=>proceed.
   const bool    _is_c_heap_obj;            // Was allocated on the heap.
 public:
   virtual char* name() { return (char *) "waitfor-barrier-task"; }
   // Factory create and destroy methods.
   static WaitForBarrierGCTask* create();
   static WaitForBarrierGCTask* create_on_c_heap();
   static void destroy(WaitForBarrierGCTask* that);
   // Methods.
   void     do_it(GCTaskManager* manager, uint which);
   void     wait_for(bool reset);
   void set_should_wait(bool value) {
     _should_wait = value;
   }
 protected:
   // Constructor.  Clients use factory, but there might be subclasses.
   WaitForBarrierGCTask(bool on_c_heap);
   // Destructor-like method.
   void destruct();
   // Accessors.
   Monitor* monitor() const {
     return _monitor;
   }
   bool should_wait() const {
     return _should_wait;
   }
   bool is_c_heap_obj() {
     return _is_c_heap_obj;
   }
 };
 // Task that is used to idle a GC task when fewer than
 // the maximum workers are wanted.
 class IdleGCTask : public GCTask {
   const bool    _is_c_heap_obj;            // Was allocated on the heap.
  public:
   bool is_c_heap_obj() {
     return _is_c_heap_obj;
   }
   // Factory create and destroy methods.
   static IdleGCTask* create();
   static IdleGCTask* create_on_c_heap();
   static void destroy(IdleGCTask* that);
   virtual char* name() { return (char *)"idle task"; }
   // Methods from GCTask.
   virtual void do_it(GCTaskManager* manager, uint which);
 protected:
   // Constructor.
   IdleGCTask(bool on_c_heap) :
     GCTask(GCTask::Kind::idle_task),
     _is_c_heap_obj(on_c_heap) {
     // Nothing to do.
   }
   // Destructor-like method.
   void destruct();
 };
 class MonitorSupply : public AllStatic {
 private:
   // State.
   //     Control multi-threaded access.
   static Mutex*                   _lock;
   //     The list of available Monitor*'s.
   static GrowableArray<Monitor*>* _freelist;
 public:
   // Reserve a Monitor*.
   static Monitor* reserve();
   // Release a Monitor*.
   static void release(Monitor* instance);
 private:
   // Accessors.
   static Mutex* lock() {
     return _lock;
   }
   static GrowableArray<Monitor*>* freelist() {
     return _freelist;
   }
 };
 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GCTASKMANAGER_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.hpp@b06ac540229e (annotated)

src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.hpp