--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/utilities/workgroup.hpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,345 @@
+/*
+ * 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.
+ *
+ */
+
+// Forward declarations of classes defined here
+
+class WorkGang;
+class GangWorker;
+class YieldingFlexibleGangWorker;
+class YieldingFlexibleGangTask;
+class WorkData;
+
+// An abstract task to be worked on by a gang.
+// You subclass this to supply your own work() method
+class AbstractGangTask: public CHeapObj {
+public:
+ // The abstract work method.
+ // The argument tells you which member of the gang you are.
+ virtual void work(int i) = 0;
+
+ // Debugging accessor for the name.
+ const char* name() const PRODUCT_RETURN_(return NULL;);
+ int counter() { return _counter; }
+ void set_counter(int value) { _counter = value; }
+ int *address_of_counter() { return &_counter; }
+
+ // RTTI
+ NOT_PRODUCT(virtual bool is_YieldingFlexibleGang_task() const {
+ return false;
+ })
+
+private:
+ NOT_PRODUCT(const char* _name;)
+ // ??? Should a task have a priority associated with it?
+ // ??? Or can the run method adjust priority as needed?
+ int _counter;
+
+protected:
+ // Constructor and desctructor: only construct subclasses.
+ AbstractGangTask(const char* name) {
+ NOT_PRODUCT(_name = name);
+ _counter = 0;
+ }
+ virtual ~AbstractGangTask() { }
+};
+
+
+// Class AbstractWorkGang:
+// An abstract class representing a gang of workers.
+// You subclass this to supply an implementation of run_task().
+class AbstractWorkGang: public CHeapObj {
+ // Here's the public interface to this class.
+public:
+ // Constructor and destructor.
+ AbstractWorkGang(const char* name, bool are_GC_threads);
+ ~AbstractWorkGang();
+ // Run a task, returns when the task is done (or terminated).
+ virtual void run_task(AbstractGangTask* task) = 0;
+ // Stop and terminate all workers.
+ virtual void stop();
+public:
+ // Debugging.
+ const char* name() const;
+protected:
+ // Initialize only instance data.
+ const bool _are_GC_threads;
+ // Printing support.
+ const char* _name;
+ // The monitor which protects these data,
+ // and notifies of changes in it.
+ Monitor* _monitor;
+ // The count of the number of workers in the gang.
+ int _total_workers;
+ // Whether the workers should terminate.
+ bool _terminate;
+ // The array of worker threads for this gang.
+ // This is only needed for cleaning up.
+ GangWorker** _gang_workers;
+ // The task for this gang.
+ AbstractGangTask* _task;
+ // A sequence number for the current task.
+ int _sequence_number;
+ // The number of started workers.
+ int _started_workers;
+ // The number of finished workers.
+ int _finished_workers;
+public:
+ // Accessors for fields
+ Monitor* monitor() const {
+ return _monitor;
+ }
+ int total_workers() const {
+ return _total_workers;
+ }
+ bool terminate() const {
+ return _terminate;
+ }
+ GangWorker** gang_workers() const {
+ return _gang_workers;
+ }
+ AbstractGangTask* task() const {
+ return _task;
+ }
+ int sequence_number() const {
+ return _sequence_number;
+ }
+ int started_workers() const {
+ return _started_workers;
+ }
+ int finished_workers() const {
+ return _finished_workers;
+ }
+ bool are_GC_threads() const {
+ return _are_GC_threads;
+ }
+ // Predicates.
+ bool is_idle() const {
+ return (task() == NULL);
+ }
+ // Return the Ith gang worker.
+ GangWorker* gang_worker(int i) const;
+
+ void threads_do(ThreadClosure* tc) const;
+
+ // Printing
+ void print_worker_threads_on(outputStream *st) const;
+ void print_worker_threads() const {
+ print_worker_threads_on(tty);
+ }
+
+protected:
+ friend class GangWorker;
+ friend class YieldingFlexibleGangWorker;
+ // Note activation and deactivation of workers.
+ // These methods should only be called with the mutex held.
+ void internal_worker_poll(WorkData* data) const;
+ void internal_note_start();
+ void internal_note_finish();
+};
+
+class WorkData: public StackObj {
+ // This would be a struct, but I want accessor methods.
+private:
+ bool _terminate;
+ AbstractGangTask* _task;
+ int _sequence_number;
+public:
+ // Constructor and destructor
+ WorkData() {
+ _terminate = false;
+ _task = NULL;
+ _sequence_number = 0;
+ }
+ ~WorkData() {
+ }
+ // Accessors and modifiers
+ bool terminate() const { return _terminate; }
+ void set_terminate(bool value) { _terminate = value; }
+ AbstractGangTask* task() const { return _task; }
+ void set_task(AbstractGangTask* value) { _task = value; }
+ int sequence_number() const { return _sequence_number; }
+ void set_sequence_number(int value) { _sequence_number = value; }
+
+ YieldingFlexibleGangTask* yf_task() const {
+ return (YieldingFlexibleGangTask*)_task;
+ }
+};
+
+// Class WorkGang:
+class WorkGang: public AbstractWorkGang {
+public:
+ // Constructor
+ WorkGang(const char* name, int workers, bool are_GC_threads);
+ // Run a task, returns when the task is done (or terminated).
+ virtual void run_task(AbstractGangTask* task);
+};
+
+// Class GangWorker:
+// Several instances of this class run in parallel as workers for a gang.
+class GangWorker: public WorkerThread {
+public:
+ // Constructors and destructor.
+ GangWorker(AbstractWorkGang* gang, uint id);
+
+ // The only real method: run a task for the gang.
+ virtual void run();
+ // Predicate for Thread
+ virtual bool is_GC_task_thread() const;
+ // Printing
+ void print_on(outputStream* st) const;
+ virtual void print() const { print_on(tty); }
+protected:
+ AbstractWorkGang* _gang;
+
+ virtual void initialize();
+ virtual void loop();
+
+public:
+ AbstractWorkGang* gang() const { return _gang; }
+};
+
+// A class that acts as a synchronisation barrier. Workers enter
+// the barrier and must wait until all other workers have entered
+// before any of them may leave.
+
+class WorkGangBarrierSync : public StackObj {
+protected:
+ Monitor _monitor;
+ int _n_workers;
+ int _n_completed;
+
+ Monitor* monitor() { return &_monitor; }
+ int n_workers() { return _n_workers; }
+ int n_completed() { return _n_completed; }
+
+ void inc_completed() { _n_completed++; }
+
+public:
+ WorkGangBarrierSync();
+ WorkGangBarrierSync(int n_workers, const char* name);
+
+ // Set the number of workers that will use the barrier.
+ // Must be called before any of the workers start running.
+ void set_n_workers(int n_workers);
+
+ // Enter the barrier. A worker that enters the barrier will
+ // not be allowed to leave until all other threads have
+ // also entered the barrier.
+ void enter();
+};
+
+// A class to manage claiming of subtasks within a group of tasks. The
+// subtasks will be identified by integer indices, usually elements of an
+// enumeration type.
+
+class SubTasksDone: public CHeapObj {
+ jint* _tasks;
+ int _n_tasks;
+ int _n_threads;
+ jint _threads_completed;
+#ifdef ASSERT
+ jint _claimed;
+#endif
+
+ // Set all tasks to unclaimed.
+ void clear();
+
+public:
+ // Initializes "this" to a state in which there are "n" tasks to be
+ // processed, none of the which are originally claimed. The number of
+ // threads doing the tasks is initialized 1.
+ SubTasksDone(int n);
+
+ // True iff the object is in a valid state.
+ bool valid();
+
+ // Set the number of parallel threads doing the tasks to "t". Can only
+ // be called before tasks start or after they are complete.
+ void set_par_threads(int t);
+
+ // Returns "false" if the task "t" is unclaimed, and ensures that task is
+ // claimed. The task "t" is required to be within the range of "this".
+ bool is_task_claimed(int t);
+
+ // The calling thread asserts that it has attempted to claim all the
+ // tasks that it will try to claim. Every thread in the parallel task
+ // must execute this. (When the last thread does so, the task array is
+ // cleared.)
+ void all_tasks_completed();
+
+ // Destructor.
+ ~SubTasksDone();
+};
+
+// As above, but for sequential tasks, i.e. instead of claiming
+// sub-tasks from a set (possibly an enumeration), claim sub-tasks
+// in sequential order. This is ideal for claiming dynamically
+// partitioned tasks (like striding in the parallel remembered
+// set scanning). Note that unlike the above class this is
+// a stack object - is there any reason for it not to be?
+
+class SequentialSubTasksDone : public StackObj {
+protected:
+ jint _n_tasks; // Total number of tasks available.
+ jint _n_claimed; // Number of tasks claimed.
+ jint _n_threads; // Total number of parallel threads.
+ jint _n_completed; // Number of completed threads.
+
+ void clear();
+
+public:
+ SequentialSubTasksDone() { clear(); }
+ ~SequentialSubTasksDone() {}
+
+ // True iff the object is in a valid state.
+ bool valid();
+
+ // number of tasks
+ jint n_tasks() const { return _n_tasks; }
+
+ // Set the number of parallel threads doing the tasks to t.
+ // Should be called before the task starts but it is safe
+ // to call this once a task is running provided that all
+ // threads agree on the number of threads.
+ void set_par_threads(int t) { _n_threads = t; }
+
+ // Set the number of tasks to be claimed to t. As above,
+ // should be called before the tasks start but it is safe
+ // to call this once a task is running provided all threads
+ // agree on the number of tasks.
+ void set_n_tasks(int t) { _n_tasks = t; }
+
+ // Returns false if the next task in the sequence is unclaimed,
+ // and ensures that it is claimed. Will set t to be the index
+ // of the claimed task in the sequence. Will return true if
+ // the task cannot be claimed and there are none left to claim.
+ bool is_task_claimed(int& t);
+
+ // The calling thread asserts that it has attempted to claim
+ // all the tasks it possibly can in the sequence. Every thread
+ // claiming tasks must promise call this. Returns true if this
+ // is the last thread to complete so that the thread can perform
+ // cleanup if necessary.
+ bool all_tasks_completed();
+};