--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.hpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,638 @@
+/*
+ * Copyright 2002-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+//
+// 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;
+// 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
+ };
+ 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;
+ }
+ 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");
+ 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;
+};
+
+// A GCTaskQueue that can be synchronized.
+// This "has-a" GCTaskQueue and a mutex to do the exclusion.
+class SynchronizedGCTaskQueue : public CHeapObj {
+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 {
+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.
+ }
+};
+
+class GCTaskManager : public CHeapObj {
+ friend class ParCompactionManager;
+ friend class PSParallelCompact;
+ friend class PSScavenge;
+ friend class PSRefProcTaskExecutor;
+ friend class RefProcTaskExecutor;
+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 _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.
+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;
+ }
+ // Pun between Monitor* and Mutex*
+ Monitor* monitor() const {
+ return _monitor;
+ }
+ Monitor * lock() const {
+ return _monitor;
+ }
+ // 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);
+ // 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;
+ }
+ 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;
+ }
+ // Other methods.
+ void initialize();
+};
+
+//
+// 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);
+ // 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();
+ // 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 {
+private:
+ // Instance state.
+ Monitor* _monitor; // Guard and notify changes.
+ 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();
+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;
+ }
+ void set_should_wait(bool value) {
+ _should_wait = value;
+ }
+ bool is_c_heap_obj() {
+ return _is_c_heap_obj;
+ }
+};
+
+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;
+ }
+};