duke@435: /*
ysr@2651:  * Copyright (c) 2002, 2011, Oracle and/or its affiliates. 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:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #ifndef SHARE_VM_UTILITIES_WORKGROUP_HPP
stefank@2314: #define SHARE_VM_UTILITIES_WORKGROUP_HPP
stefank@2314: 
stefank@2314: #include "utilities/taskqueue.hpp"
stefank@2314: #ifdef TARGET_OS_FAMILY_linux
stefank@2314: # include "thread_linux.inline.hpp"
stefank@2314: #endif
stefank@2314: #ifdef TARGET_OS_FAMILY_solaris
stefank@2314: # include "thread_solaris.inline.hpp"
stefank@2314: #endif
stefank@2314: #ifdef TARGET_OS_FAMILY_windows
stefank@2314: # include "thread_windows.inline.hpp"
stefank@2314: #endif
stefank@2314: 
ysr@2651: // Task class hierarchy:
ysr@2651: //   AbstractGangTask
ysr@2651: //     AbstractGangTaskWOopQueues
ysr@2651: //
ysr@2651: // Gang/Group class hierarchy:
ysr@2651: //   AbstractWorkGang
ysr@2651: //     WorkGang
ysr@2651: //       FlexibleWorkGang
ysr@2651: //         YieldingFlexibleWorkGang (defined in another file)
ysr@2651: //
ysr@2651: // Worker class hierarchy:
ysr@2651: //   GangWorker (subclass of WorkerThread)
ysr@2651: //     YieldingFlexibleGangWorker   (defined in another file)
ysr@2651: 
duke@435: // Forward declarations of classes defined here
duke@435: 
duke@435: class WorkGang;
duke@435: class GangWorker;
duke@435: class YieldingFlexibleGangWorker;
duke@435: class YieldingFlexibleGangTask;
duke@435: class WorkData;
jmasa@2188: class AbstractWorkGang;
duke@435: 
duke@435: // An abstract task to be worked on by a gang.
duke@435: // You subclass this to supply your own work() method
apetrusenko@984: class AbstractGangTask VALUE_OBJ_CLASS_SPEC {
duke@435: public:
duke@435:   // The abstract work method.
duke@435:   // The argument tells you which member of the gang you are.
duke@435:   virtual void work(int i) = 0;
duke@435: 
jmasa@2188:   // This method configures the task for proper termination.
jmasa@2188:   // Some tasks do not have any requirements on termination
jmasa@2188:   // and may inherit this method that does nothing.  Some
jmasa@2188:   // tasks do some coordination on termination and override
jmasa@2188:   // this method to implement that coordination.
jmasa@2188:   virtual void set_for_termination(int active_workers) {};
jmasa@2188: 
duke@435:   // Debugging accessor for the name.
duke@435:   const char* name() const PRODUCT_RETURN_(return NULL;);
duke@435:   int counter() { return _counter; }
duke@435:   void set_counter(int value) { _counter = value; }
duke@435:   int *address_of_counter() { return &_counter; }
duke@435: 
duke@435:   // RTTI
duke@435:   NOT_PRODUCT(virtual bool is_YieldingFlexibleGang_task() const {
duke@435:     return false;
duke@435:   })
duke@435: 
duke@435: private:
duke@435:   NOT_PRODUCT(const char* _name;)
duke@435:   // ??? Should a task have a priority associated with it?
duke@435:   // ??? Or can the run method adjust priority as needed?
duke@435:   int _counter;
duke@435: 
duke@435: protected:
duke@435:   // Constructor and desctructor: only construct subclasses.
duke@435:   AbstractGangTask(const char* name) {
duke@435:     NOT_PRODUCT(_name = name);
duke@435:     _counter = 0;
duke@435:   }
duke@435:   virtual ~AbstractGangTask() { }
duke@435: };
duke@435: 
jmasa@2188: class AbstractGangTaskWOopQueues : public AbstractGangTask {
jmasa@2188:   OopTaskQueueSet*       _queues;
jmasa@2188:   ParallelTaskTerminator _terminator;
jmasa@2188:  public:
jmasa@2188:   AbstractGangTaskWOopQueues(const char* name, OopTaskQueueSet* queues) :
jmasa@2188:     AbstractGangTask(name), _queues(queues), _terminator(0, _queues) {}
jmasa@2188:   ParallelTaskTerminator* terminator() { return &_terminator; }
jmasa@2188:   virtual void set_for_termination(int active_workers) {
jmasa@2188:     terminator()->reset_for_reuse(active_workers);
jmasa@2188:   }
jmasa@2188:   OopTaskQueueSet* queues() { return _queues; }
jmasa@2188: };
duke@435: 
duke@435: // Class AbstractWorkGang:
duke@435: // An abstract class representing a gang of workers.
duke@435: // You subclass this to supply an implementation of run_task().
duke@435: class AbstractWorkGang: public CHeapObj {
duke@435:   // Here's the public interface to this class.
duke@435: public:
duke@435:   // Constructor and destructor.
ysr@777:   AbstractWorkGang(const char* name, bool are_GC_task_threads,
ysr@777:                    bool are_ConcurrentGC_threads);
duke@435:   ~AbstractWorkGang();
duke@435:   // Run a task, returns when the task is done (or terminated).
duke@435:   virtual void run_task(AbstractGangTask* task) = 0;
duke@435:   // Stop and terminate all workers.
duke@435:   virtual void stop();
duke@435: public:
duke@435:   // Debugging.
duke@435:   const char* name() const;
duke@435: protected:
duke@435:   // Initialize only instance data.
ysr@777:   const bool _are_GC_task_threads;
ysr@777:   const bool _are_ConcurrentGC_threads;
duke@435:   // Printing support.
duke@435:   const char* _name;
duke@435:   // The monitor which protects these data,
duke@435:   // and notifies of changes in it.
duke@435:   Monitor*  _monitor;
duke@435:   // The count of the number of workers in the gang.
duke@435:   int _total_workers;
duke@435:   // Whether the workers should terminate.
duke@435:   bool _terminate;
duke@435:   // The array of worker threads for this gang.
duke@435:   // This is only needed for cleaning up.
duke@435:   GangWorker** _gang_workers;
duke@435:   // The task for this gang.
duke@435:   AbstractGangTask* _task;
duke@435:   // A sequence number for the current task.
duke@435:   int _sequence_number;
duke@435:   // The number of started workers.
duke@435:   int _started_workers;
duke@435:   // The number of finished workers.
duke@435:   int _finished_workers;
duke@435: public:
duke@435:   // Accessors for fields
duke@435:   Monitor* monitor() const {
duke@435:     return _monitor;
duke@435:   }
duke@435:   int total_workers() const {
duke@435:     return _total_workers;
duke@435:   }
jmasa@2188:   virtual int active_workers() const {
jmasa@2188:     return _total_workers;
jmasa@2188:   }
duke@435:   bool terminate() const {
duke@435:     return _terminate;
duke@435:   }
duke@435:   GangWorker** gang_workers() const {
duke@435:     return _gang_workers;
duke@435:   }
duke@435:   AbstractGangTask* task() const {
duke@435:     return _task;
duke@435:   }
duke@435:   int sequence_number() const {
duke@435:     return _sequence_number;
duke@435:   }
duke@435:   int started_workers() const {
duke@435:     return _started_workers;
duke@435:   }
duke@435:   int finished_workers() const {
duke@435:     return _finished_workers;
duke@435:   }
ysr@777:   bool are_GC_task_threads() const {
ysr@777:     return _are_GC_task_threads;
ysr@777:   }
ysr@777:   bool are_ConcurrentGC_threads() const {
ysr@777:     return _are_ConcurrentGC_threads;
duke@435:   }
duke@435:   // Predicates.
duke@435:   bool is_idle() const {
duke@435:     return (task() == NULL);
duke@435:   }
duke@435:   // Return the Ith gang worker.
duke@435:   GangWorker* gang_worker(int i) const;
duke@435: 
duke@435:   void threads_do(ThreadClosure* tc) const;
duke@435: 
duke@435:   // Printing
duke@435:   void print_worker_threads_on(outputStream *st) const;
duke@435:   void print_worker_threads() const {
duke@435:     print_worker_threads_on(tty);
duke@435:   }
duke@435: 
duke@435: protected:
duke@435:   friend class GangWorker;
duke@435:   friend class YieldingFlexibleGangWorker;
duke@435:   // Note activation and deactivation of workers.
duke@435:   // These methods should only be called with the mutex held.
duke@435:   void internal_worker_poll(WorkData* data) const;
duke@435:   void internal_note_start();
duke@435:   void internal_note_finish();
duke@435: };
duke@435: 
duke@435: class WorkData: public StackObj {
duke@435:   // This would be a struct, but I want accessor methods.
duke@435: private:
duke@435:   bool              _terminate;
duke@435:   AbstractGangTask* _task;
duke@435:   int               _sequence_number;
duke@435: public:
duke@435:   // Constructor and destructor
duke@435:   WorkData() {
duke@435:     _terminate       = false;
duke@435:     _task            = NULL;
duke@435:     _sequence_number = 0;
duke@435:   }
duke@435:   ~WorkData() {
duke@435:   }
duke@435:   // Accessors and modifiers
duke@435:   bool terminate()                       const { return _terminate;  }
duke@435:   void set_terminate(bool value)               { _terminate = value; }
duke@435:   AbstractGangTask* task()               const { return _task; }
duke@435:   void set_task(AbstractGangTask* value)       { _task = value; }
duke@435:   int sequence_number()                  const { return _sequence_number; }
duke@435:   void set_sequence_number(int value)          { _sequence_number = value; }
duke@435: 
duke@435:   YieldingFlexibleGangTask* yf_task()    const {
duke@435:     return (YieldingFlexibleGangTask*)_task;
duke@435:   }
duke@435: };
duke@435: 
duke@435: // Class WorkGang:
duke@435: class WorkGang: public AbstractWorkGang {
duke@435: public:
duke@435:   // Constructor
ysr@777:   WorkGang(const char* name, int workers,
ysr@777:            bool are_GC_task_threads, bool are_ConcurrentGC_threads);
duke@435:   // Run a task, returns when the task is done (or terminated).
duke@435:   virtual void run_task(AbstractGangTask* task);
jmasa@2188:   void run_task(AbstractGangTask* task, uint no_of_parallel_workers);
jmasa@2188:   // Allocate a worker and return a pointer to it.
jmasa@2188:   virtual GangWorker* allocate_worker(int which);
jmasa@2188:   // Initialize workers in the gang.  Return true if initialization
jmasa@2188:   // succeeded. The type of the worker can be overridden in a derived
jmasa@2188:   // class with the appropriate implementation of allocate_worker().
jmasa@2188:   bool initialize_workers();
duke@435: };
duke@435: 
duke@435: // Class GangWorker:
duke@435: //   Several instances of this class run in parallel as workers for a gang.
duke@435: class GangWorker: public WorkerThread {
duke@435: public:
duke@435:   // Constructors and destructor.
duke@435:   GangWorker(AbstractWorkGang* gang, uint id);
duke@435: 
duke@435:   // The only real method: run a task for the gang.
duke@435:   virtual void run();
duke@435:   // Predicate for Thread
duke@435:   virtual bool is_GC_task_thread() const;
ysr@777:   virtual bool is_ConcurrentGC_thread() const;
duke@435:   // Printing
duke@435:   void print_on(outputStream* st) const;
duke@435:   virtual void print() const { print_on(tty); }
duke@435: protected:
duke@435:   AbstractWorkGang* _gang;
duke@435: 
duke@435:   virtual void initialize();
duke@435:   virtual void loop();
duke@435: 
duke@435: public:
duke@435:   AbstractWorkGang* gang() const { return _gang; }
duke@435: };
duke@435: 
jmasa@2188: class FlexibleWorkGang: public WorkGang {
jmasa@2188:  protected:
jmasa@2188:   int _active_workers;
jmasa@2188:  public:
jmasa@2188:   // Constructor and destructor.
jmasa@2188:   FlexibleWorkGang(const char* name, int workers,
jmasa@2188:                    bool are_GC_task_threads,
jmasa@2188:                    bool  are_ConcurrentGC_threads) :
jmasa@2188:     WorkGang(name, workers, are_GC_task_threads, are_ConcurrentGC_threads) {
jmasa@2188:     _active_workers = ParallelGCThreads;
jmasa@2188:   };
jmasa@2188:   // Accessors for fields
jmasa@2188:   virtual int active_workers() const { return _active_workers; }
jmasa@2188:   void set_active_workers(int v) { _active_workers = v; }
jmasa@2188: };
jmasa@2188: 
jmasa@2188: // Work gangs in garbage collectors: 2009-06-10
jmasa@2188: //
jmasa@2188: // SharedHeap - work gang for stop-the-world parallel collection.
jmasa@2188: //   Used by
jmasa@2188: //     ParNewGeneration
jmasa@2188: //     CMSParRemarkTask
jmasa@2188: //     CMSRefProcTaskExecutor
jmasa@2188: //     G1CollectedHeap
jmasa@2188: //     G1ParFinalCountTask
jmasa@2188: // ConcurrentMark
jmasa@2188: // CMSCollector
jmasa@2188: 
duke@435: // A class that acts as a synchronisation barrier. Workers enter
duke@435: // the barrier and must wait until all other workers have entered
duke@435: // before any of them may leave.
duke@435: 
duke@435: class WorkGangBarrierSync : public StackObj {
duke@435: protected:
duke@435:   Monitor _monitor;
duke@435:   int     _n_workers;
duke@435:   int     _n_completed;
ysr@777:   bool    _should_reset;
duke@435: 
ysr@777:   Monitor* monitor()        { return &_monitor; }
ysr@777:   int      n_workers()      { return _n_workers; }
ysr@777:   int      n_completed()    { return _n_completed; }
ysr@777:   bool     should_reset()   { return _should_reset; }
duke@435: 
ysr@777:   void     zero_completed() { _n_completed = 0; }
ysr@777:   void     inc_completed()  { _n_completed++; }
ysr@777: 
ysr@777:   void     set_should_reset(bool v) { _should_reset = v; }
duke@435: 
duke@435: public:
duke@435:   WorkGangBarrierSync();
duke@435:   WorkGangBarrierSync(int n_workers, const char* name);
duke@435: 
duke@435:   // Set the number of workers that will use the barrier.
duke@435:   // Must be called before any of the workers start running.
duke@435:   void set_n_workers(int n_workers);
duke@435: 
duke@435:   // Enter the barrier. A worker that enters the barrier will
duke@435:   // not be allowed to leave until all other threads have
duke@435:   // also entered the barrier.
duke@435:   void enter();
duke@435: };
duke@435: 
duke@435: // A class to manage claiming of subtasks within a group of tasks.  The
duke@435: // subtasks will be identified by integer indices, usually elements of an
duke@435: // enumeration type.
duke@435: 
duke@435: class SubTasksDone: public CHeapObj {
duke@435:   jint* _tasks;
duke@435:   int _n_tasks;
duke@435:   int _n_threads;
duke@435:   jint _threads_completed;
duke@435: #ifdef ASSERT
jmasa@2188:   volatile jint _claimed;
duke@435: #endif
duke@435: 
duke@435:   // Set all tasks to unclaimed.
duke@435:   void clear();
duke@435: 
duke@435: public:
duke@435:   // Initializes "this" to a state in which there are "n" tasks to be
duke@435:   // processed, none of the which are originally claimed.  The number of
duke@435:   // threads doing the tasks is initialized 1.
duke@435:   SubTasksDone(int n);
duke@435: 
duke@435:   // True iff the object is in a valid state.
duke@435:   bool valid();
duke@435: 
jmasa@2188:   // Get/set the number of parallel threads doing the tasks to "t".  Can only
duke@435:   // be called before tasks start or after they are complete.
jmasa@2188:   int n_threads() { return _n_threads; }
jmasa@2188:   void set_n_threads(int t);
duke@435: 
duke@435:   // Returns "false" if the task "t" is unclaimed, and ensures that task is
duke@435:   // claimed.  The task "t" is required to be within the range of "this".
duke@435:   bool is_task_claimed(int t);
duke@435: 
duke@435:   // The calling thread asserts that it has attempted to claim all the
duke@435:   // tasks that it will try to claim.  Every thread in the parallel task
duke@435:   // must execute this.  (When the last thread does so, the task array is
duke@435:   // cleared.)
duke@435:   void all_tasks_completed();
duke@435: 
duke@435:   // Destructor.
duke@435:   ~SubTasksDone();
duke@435: };
duke@435: 
duke@435: // As above, but for sequential tasks, i.e. instead of claiming
duke@435: // sub-tasks from a set (possibly an enumeration), claim sub-tasks
duke@435: // in sequential order. This is ideal for claiming dynamically
duke@435: // partitioned tasks (like striding in the parallel remembered
duke@435: // set scanning). Note that unlike the above class this is
duke@435: // a stack object - is there any reason for it not to be?
duke@435: 
duke@435: class SequentialSubTasksDone : public StackObj {
duke@435: protected:
duke@435:   jint _n_tasks;     // Total number of tasks available.
duke@435:   jint _n_claimed;   // Number of tasks claimed.
jmasa@2188:   // _n_threads is used to determine when a sub task is done.
jmasa@2188:   // See comments on SubTasksDone::_n_threads
duke@435:   jint _n_threads;   // Total number of parallel threads.
duke@435:   jint _n_completed; // Number of completed threads.
duke@435: 
duke@435:   void clear();
duke@435: 
duke@435: public:
jmasa@2188:   SequentialSubTasksDone() {
jmasa@2188:     clear();
jmasa@2188:   }
duke@435:   ~SequentialSubTasksDone() {}
duke@435: 
duke@435:   // True iff the object is in a valid state.
duke@435:   bool valid();
duke@435: 
duke@435:   // number of tasks
duke@435:   jint n_tasks() const { return _n_tasks; }
duke@435: 
jmasa@2188:   // Get/set the number of parallel threads doing the tasks to t.
duke@435:   // Should be called before the task starts but it is safe
duke@435:   // to call this once a task is running provided that all
duke@435:   // threads agree on the number of threads.
jmasa@2188:   int n_threads() { return _n_threads; }
jmasa@2188:   void set_n_threads(int t) { _n_threads = t; }
duke@435: 
duke@435:   // Set the number of tasks to be claimed to t. As above,
duke@435:   // should be called before the tasks start but it is safe
duke@435:   // to call this once a task is running provided all threads
duke@435:   // agree on the number of tasks.
duke@435:   void set_n_tasks(int t) { _n_tasks = t; }
duke@435: 
duke@435:   // Returns false if the next task in the sequence is unclaimed,
duke@435:   // and ensures that it is claimed. Will set t to be the index
duke@435:   // of the claimed task in the sequence. Will return true if
duke@435:   // the task cannot be claimed and there are none left to claim.
duke@435:   bool is_task_claimed(int& t);
duke@435: 
duke@435:   // The calling thread asserts that it has attempted to claim
duke@435:   // all the tasks it possibly can in the sequence. Every thread
duke@435:   // claiming tasks must promise call this. Returns true if this
duke@435:   // is the last thread to complete so that the thread can perform
duke@435:   // cleanup if necessary.
duke@435:   bool all_tasks_completed();
duke@435: };
ysr@777: 
ysr@777: // Represents a set of free small integer ids.
ysr@777: class FreeIdSet {
ysr@777:   enum {
ysr@777:     end_of_list = -1,
ysr@777:     claimed = -2
ysr@777:   };
ysr@777: 
ysr@777:   int _sz;
ysr@777:   Monitor* _mon;
ysr@777: 
ysr@777:   int* _ids;
ysr@777:   int _hd;
ysr@777:   int _waiters;
ysr@777:   int _claimed;
ysr@777: 
ysr@777:   static bool _safepoint;
ysr@777:   typedef FreeIdSet* FreeIdSetPtr;
ysr@777:   static const int NSets = 10;
ysr@777:   static FreeIdSetPtr _sets[NSets];
ysr@777:   static bool _stat_init;
ysr@777:   int _index;
ysr@777: 
ysr@777: public:
ysr@777:   FreeIdSet(int sz, Monitor* mon);
ysr@777:   ~FreeIdSet();
ysr@777: 
ysr@777:   static void set_safepoint(bool b);
ysr@777: 
ysr@777:   // Attempt to claim the given id permanently.  Returns "true" iff
ysr@777:   // successful.
ysr@777:   bool claim_perm_id(int i);
ysr@777: 
ysr@777:   // Returns an unclaimed parallel id (waiting for one to be released if
ysr@777:   // necessary).  Returns "-1" if a GC wakes up a wait for an id.
ysr@777:   int claim_par_id();
ysr@777: 
ysr@777:   void release_par_id(int id);
ysr@777: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_UTILITIES_WORKGROUP_HPP