jdk8-mips64-public/hotspot: src/share/vm/utilities/yieldingWorkgroup.hpp@f90c822e73f8 (annotated)

src/share/vm/utilities/yieldingWorkgroup.hpp@f90c822e73f8 (annotated)

src/share/vm/utilities/yieldingWorkgroup.hpp

Wed, 27 Apr 2016 01:25:04 +0800

author: aoqi
date: Wed, 27 Apr 2016 01:25:04 +0800
changeset 0: f90c822e73f8
child 6876: 710a3c8b516e
permissions: -rw-r--r--

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http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

 /*
  * Copyright (c) 2005, 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_YIELDINGWORKGROUP_HPP
 #define SHARE_VM_UTILITIES_YIELDINGWORKGROUP_HPP
 #include "utilities/macros.hpp"
 #include "utilities/workgroup.hpp"
 // Forward declarations
 class YieldingFlexibleWorkGang;
 // Status of tasks
 enum Status {
     INACTIVE,
     ACTIVE,
     YIELDING,
     YIELDED,
     ABORTING,
     ABORTED,
     COMPLETING,
     COMPLETED
 };
 // Class YieldingFlexibleGangWorker:
 //   Several instances of this class run in parallel as workers for a gang.
 class YieldingFlexibleGangWorker: public GangWorker {
 public:
   // Ctor
   YieldingFlexibleGangWorker(AbstractWorkGang* gang, int id) :
     GangWorker(gang, id) { }
 public:
   YieldingFlexibleWorkGang* yf_gang() const
     { return (YieldingFlexibleWorkGang*)gang(); }
 protected: // Override from parent class
   virtual void loop();
 };
 class FlexibleGangTask: public AbstractGangTask {
   int _actual_size;                      // size of gang obtained
 protected:
   int _requested_size;                   // size of gang requested
 public:
  FlexibleGangTask(const char* name): AbstractGangTask(name),
     _requested_size(0) {}
   // The abstract work method.
   // The argument tells you which member of the gang you are.
   virtual void work(uint worker_id) = 0;
   int requested_size() const { return _requested_size; }
   int actual_size()    const { return _actual_size; }
   void set_requested_size(int sz) { _requested_size = sz; }
   void set_actual_size(int sz)    { _actual_size    = sz; }
 };
 // An abstract task to be worked on by a flexible work gang,
 // and where the workers will periodically yield, usually
 // in response to some condition that is signalled by means
 // that are specific to the task at hand.
 // You subclass this to supply your own work() method.
 // A second feature of this kind of work gang is that
 // it allows for the signalling of certain exceptional
 // conditions that may be encountered during the performance
 // of the task and that may require the task at hand to be
 // `aborted' forthwith. Finally, these gangs are `flexible'
 // in that they can operate at partial capacity with some
 // gang workers waiting on the bench; in other words, the
 // size of the active worker pool can flex (up to an apriori
 // maximum) in response to task requests at certain points.
 // The last part (the flexible part) has not yet been fully
 // fleshed out and is a work in progress.
 class YieldingFlexibleGangTask: public FlexibleGangTask {
   Status _status;
   YieldingFlexibleWorkGang* _gang;
 protected:
   // Constructor and desctructor: only construct subclasses.
   YieldingFlexibleGangTask(const char* name): FlexibleGangTask(name),
     _status(INACTIVE),
     _gang(NULL) { }
   ~YieldingFlexibleGangTask() { }
   friend class YieldingFlexibleWorkGang;
   friend class YieldingFlexibleGangWorker;
   NOT_PRODUCT(virtual bool is_YieldingFlexibleGang_task() const {
     return true;
   })
   void set_status(Status s) {
     _status = s;
   }
   YieldingFlexibleWorkGang* gang() {
     return _gang;
   }
   void set_gang(YieldingFlexibleWorkGang* gang) {
     assert(_gang == NULL || gang == NULL, "Clobber without intermediate reset?");
     _gang = gang;
   }
 public:
   // The abstract work method.
   // The argument tells you which member of the gang you are.
   virtual void work(uint worker_id) = 0;
   // Subclasses should call the parent's yield() method
   // after having done any work specific to the subclass.
   virtual void yield();
   // An abstract method supplied by
   // a concrete sub-class which is used by the coordinator
   // to do any "central yielding" work.
   virtual void coordinator_yield() = 0;
   // Subclasses should call the parent's abort() method
   // after having done any work specific to the sunbclass.
   virtual void abort();
   Status status()  const { return _status; }
   bool yielding()  const { return _status == YIELDING; }
   bool yielded()   const { return _status == YIELDED; }
   bool completed() const { return _status == COMPLETED; }
   bool aborted()   const { return _status == ABORTED; }
   bool active()    const { return _status == ACTIVE; }
 };
 // Class YieldingWorkGang: A subclass of WorkGang.
 // In particular, a YieldingWorkGang is made up of
 // YieldingGangWorkers, and provides infrastructure
 // supporting yielding to the "GangOverseer",
 // being the thread that orchestrates the WorkGang via run_task().
 class YieldingFlexibleWorkGang: public FlexibleWorkGang {
   // Here's the public interface to this class.
 public:
   // Constructor and destructor.
   YieldingFlexibleWorkGang(const char* name, uint workers,
                            bool are_GC_task_threads);
   YieldingFlexibleGangTask* yielding_task() const {
     assert(task() == NULL || task()->is_YieldingFlexibleGang_task(),
            "Incorrect cast");
     return (YieldingFlexibleGangTask*)task();
   }
   // Allocate a worker and return a pointer to it.
   GangWorker* allocate_worker(uint which);
   // Run a task; returns when the task is done, or the workers yield,
   // or the task is aborted, or the work gang is terminated via stop().
   // A task that has been yielded can be continued via this same interface
   // by using the same task repeatedly as the argument to the call.
   // It is expected that the YieldingFlexibleGangTask carries the appropriate
   // continuation information used by workers to continue the task
   // from its last yield point. Thus, a completed task will return
   // immediately with no actual work having been done by the workers.
   void run_task(AbstractGangTask* task) {
     guarantee(false, "Use start_task instead");
   }
   void start_task(YieldingFlexibleGangTask* new_task);
   void continue_task(YieldingFlexibleGangTask* gang_task);
   // Abort a currently running task, if any; returns when all the workers
   // have stopped working on the current task and have returned to their
   // waiting stations.
   void abort_task();
   // Yield: workers wait at their current working stations
   // until signalled to proceed by the overseer.
   void yield();
   // Abort: workers are expected to return to their waiting
   // stations, whence they are ready for the next task dispatched
   // by the overseer.
   void abort();
 private:
   uint _yielded_workers;
   void wait_for_gang();
 public:
   // Accessors for fields
   uint yielded_workers() const {
     return _yielded_workers;
   }
 private:
   friend class YieldingFlexibleGangWorker;
   void reset(); // NYI
 };
 #endif // SHARE_VM_UTILITIES_YIELDINGWORKGROUP_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/utilities/yieldingWorkgroup.hpp@f90c822e73f8 (annotated)

src/share/vm/utilities/yieldingWorkgroup.hpp