jdk8-mips64-public/hotspot: comparison src/share/vm/utilities/workgroup.hpp

--1:000000000000
+:f90c822e73f8
+/*
+* Copyright (c) 2002, 2013, 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_UTILITIES_WORKGROUP_HPP
+#define SHARE_VM_UTILITIES_WORKGROUP_HPP
+#include "runtime/thread.inline.hpp"
+#include "utilities/taskqueue.hpp"
+// Task class hierarchy:
+//   AbstractGangTask
+//     AbstractGangTaskWOopQueues
+//
+// Gang/Group class hierarchy:
+//   AbstractWorkGang
+//     WorkGang
+//       FlexibleWorkGang
+//         YieldingFlexibleWorkGang (defined in another file)
+//
+// Worker class hierarchy:
+//   GangWorker (subclass of WorkerThread)
+//     YieldingFlexibleGangWorker   (defined in another file)
+// Forward declarations of classes defined here
+class WorkGang;
+class GangWorker;
+class YieldingFlexibleGangWorker;
+class YieldingFlexibleGangTask;
+class WorkData;
+class AbstractWorkGang;
+// An abstract task to be worked on by a gang.
+// You subclass this to supply your own work() method
+class AbstractGangTask VALUE_OBJ_CLASS_SPEC {
+public:
+// The abstract work method.
+// The argument tells you which member of the gang you are.
+virtual void work(uint worker_id) = 0;
+// This method configures the task for proper termination.
+// Some tasks do not have any requirements on termination
+// and may inherit this method that does nothing.  Some
+// tasks do some coordination on termination and override
+// this method to implement that coordination.
+virtual void set_for_termination(int active_workers) {};
+// 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;
+}
+~AbstractGangTask() { }
+public:
+};
+class AbstractGangTaskWOopQueues : public AbstractGangTask {
+OopTaskQueueSet*       _queues;
+ParallelTaskTerminator _terminator;
+public:
+AbstractGangTaskWOopQueues(const char* name, OopTaskQueueSet* queues) :
+AbstractGangTask(name), _queues(queues), _terminator(0, _queues) {}
+ParallelTaskTerminator* terminator() { return &_terminator; }
+virtual void set_for_termination(int active_workers) {
+terminator()->reset_for_reuse(active_workers);
+}
+OopTaskQueueSet* queues() { return _queues; }
+};
+// Class AbstractWorkGang:
+// An abstract class representing a gang of workers.
+// You subclass this to supply an implementation of run_task().
+class AbstractWorkGang: public CHeapObj<mtInternal> {
+// Here's the public interface to this class.
+public:
+// Constructor and destructor.
+AbstractWorkGang(const char* name, bool are_GC_task_threads,
+bool are_ConcurrentGC_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();
+// Return true if more workers should be applied to the task.
+virtual bool needs_more_workers() const { return true; }
+public:
+// Debugging.
+const char* name() const;
+protected:
+// Initialize only instance data.
+const bool _are_GC_task_threads;
+const bool _are_ConcurrentGC_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.
+uint _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.
+uint _started_workers;
+// The number of finished workers.
+uint _finished_workers;
+public:
+// Accessors for fields
+Monitor* monitor() const {
+return _monitor;
+}
+uint total_workers() const {
+return _total_workers;
+}
+virtual uint active_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;
+}
+uint started_workers() const {
+return _started_workers;
+}
+uint finished_workers() const {
+return _finished_workers;
+}
+bool are_GC_task_threads() const {
+return _are_GC_task_threads;
+}
+bool are_ConcurrentGC_threads() const {
+return _are_ConcurrentGC_threads;
+}
+// Predicates.
+bool is_idle() const {
+return (task() == NULL);
+}
+// Return the Ith gang worker.
+GangWorker* gang_worker(uint 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, uint workers,
+bool are_GC_task_threads, bool are_ConcurrentGC_threads);
+// Run a task, returns when the task is done (or terminated).
+virtual void run_task(AbstractGangTask* task);
+void run_task(AbstractGangTask* task, uint no_of_parallel_workers);
+// Allocate a worker and return a pointer to it.
+virtual GangWorker* allocate_worker(uint which);
+// Initialize workers in the gang.  Return true if initialization
+// succeeded. The type of the worker can be overridden in a derived
+// class with the appropriate implementation of allocate_worker().
+bool initialize_workers();
+};
+// 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;
+virtual bool is_ConcurrentGC_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; }
+};
+// Dynamic number of worker threads
+//
+// This type of work gang is used to run different numbers of
+// worker threads at different times.  The
+// number of workers run for a task is "_active_workers"
+// instead of "_total_workers" in a WorkGang.  The method
+// "needs_more_workers()" returns true until "_active_workers"
+// have been started and returns false afterwards.  The
+// implementation of "needs_more_workers()" in WorkGang always
+// returns true so that all workers are started.  The method
+// "loop()" in GangWorker was modified to ask "needs_more_workers()"
+// in its loop to decide if it should start working on a task.
+// A worker in "loop()" waits for notification on the WorkGang
+// monitor and execution of each worker as it checks for work
+// is serialized via the same monitor.  The "needs_more_workers()"
+// call is serialized and additionally the calculation for the
+// "part" (effectively the worker id for executing the task) is
+// serialized to give each worker a unique "part".  Workers that
+// are not needed for this tasks (i.e., "_active_workers" have
+// been started before it, continue to wait for work.
+class FlexibleWorkGang: public WorkGang {
+// The currently active workers in this gang.
+// This is a number that is dynamically adjusted
+// and checked in the run_task() method at each invocation.
+// As described above _active_workers determines the number
+// of threads started on a task.  It must also be used to
+// determine completion.
+protected:
+uint _active_workers;
+public:
+// Constructor and destructor.
+// Initialize active_workers to a minimum value.  Setting it to
+// the parameter "workers" will initialize it to a maximum
+// value which is not desirable.
+FlexibleWorkGang(const char* name, uint workers,
+bool are_GC_task_threads,
+bool  are_ConcurrentGC_threads) :
+WorkGang(name, workers, are_GC_task_threads, are_ConcurrentGC_threads),
+_active_workers(UseDynamicNumberOfGCThreads ? 1U : ParallelGCThreads) {}
+// Accessors for fields
+virtual uint active_workers() const { return _active_workers; }
+void set_active_workers(uint v) {
+assert(v <= _total_workers,
+"Trying to set more workers active than there are");
+_active_workers = MIN2(v, _total_workers);
+assert(v != 0, "Trying to set active workers to 0");
+_active_workers = MAX2(1U, _active_workers);
+assert(UseDynamicNumberOfGCThreads || _active_workers == _total_workers,
+"Unless dynamic should use total workers");
+}
+virtual void run_task(AbstractGangTask* task);
+virtual bool needs_more_workers() const {
+return _started_workers < _active_workers;
+}
+};
+// Work gangs in garbage collectors: 2009-06-10
+//
+// SharedHeap - work gang for stop-the-world parallel collection.
+//   Used by
+//     ParNewGeneration
+//     CMSParRemarkTask
+//     CMSRefProcTaskExecutor
+//     G1CollectedHeap
+//     G1ParFinalCountTask
+// ConcurrentMark
+// CMSCollector
+// 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;
+uint    _n_workers;
+uint    _n_completed;
+bool    _should_reset;
+bool    _aborted;
+Monitor* monitor()        { return &_monitor; }
+uint     n_workers()      { return _n_workers; }
+uint     n_completed()    { return _n_completed; }
+bool     should_reset()   { return _should_reset; }
+bool     aborted()        { return _aborted; }
+void     zero_completed() { _n_completed = 0; }
+void     inc_completed()  { _n_completed++; }
+void     set_aborted()    { _aborted = true; }
+void     set_should_reset(bool v) { _should_reset = v; }
+public:
+WorkGangBarrierSync();
+WorkGangBarrierSync(uint 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(uint 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 or the barrier is aborted.
+// Returns false if the barrier was aborted.
+bool enter();
+// Aborts the barrier and wakes up any threads waiting for
+// the barrier to complete. The barrier will remain in the
+// aborted state until the next call to set_n_workers().
+void abort();
+};
+// 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<mtInternal> {
+uint* _tasks;
+uint _n_tasks;
+// _n_threads is used to determine when a sub task is done.
+// It does not control how many threads will execute the subtask
+// but must be initialized to the number that do execute the task
+// in order to correctly decide when the subtask is done (all the
+// threads working on the task have finished).
+uint _n_threads;
+uint _threads_completed;
+#ifdef ASSERT
+volatile uint _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(uint n);
+// True iff the object is in a valid state.
+bool valid();
+// Get/set the number of parallel threads doing the tasks to "t".  Can only
+// be called before tasks start or after they are complete.
+uint n_threads() { return _n_threads; }
+void set_n_threads(uint 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(uint 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:
+uint _n_tasks;     // Total number of tasks available.
+uint _n_claimed;   // Number of tasks claimed.
+// _n_threads is used to determine when a sub task is done.
+// See comments on SubTasksDone::_n_threads
+uint _n_threads;   // Total number of parallel threads.
+uint _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
+uint n_tasks() const { return _n_tasks; }
+// Get/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.
+uint n_threads() { return _n_threads; }
+void set_n_threads(uint 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(uint 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(uint& 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();
+};
+// Represents a set of free small integer ids.
+class FreeIdSet : public CHeapObj<mtInternal> {
+enum {
+end_of_list = -1,
+claimed = -2
+};
+int _sz;
+Monitor* _mon;
+int* _ids;
+int _hd;
+int _waiters;
+int _claimed;
+static bool _safepoint;
+typedef FreeIdSet* FreeIdSetPtr;
+static const int NSets = 10;
+static FreeIdSetPtr _sets[NSets];
+static bool _stat_init;
+int _index;
+public:
+FreeIdSet(int sz, Monitor* mon);
+~FreeIdSet();
+static void set_safepoint(bool b);
+// Attempt to claim the given id permanently.  Returns "true" iff
+// successful.
+bool claim_perm_id(int i);
+// Returns an unclaimed parallel id (waiting for one to be released if
+// necessary).  Returns "-1" if a GC wakes up a wait for an id.
+int claim_par_id();
+void release_par_id(int id);
+};
+#endif // SHARE_VM_UTILITIES_WORKGROUP_HPP

Mercurial > jdk8-mips64-public > hotspot / file comparison

comparison: src/share/vm/utilities/workgroup.hpp

src/share/vm/utilities/workgroup.hpp