jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/parallelScavenge/pcTasks.hpp@4dfb2df418f2 (annotated)

src/share/vm/gc_implementation/parallelScavenge/pcTasks.hpp@4dfb2df418f2 (annotated)

src/share/vm/gc_implementation/parallelScavenge/pcTasks.hpp

Thu, 22 Sep 2011 10:57:37 -0700

author: johnc
date: Thu, 22 Sep 2011 10:57:37 -0700
changeset 3175: 4dfb2df418f2
parent 3115: c2bf0120ee5d
child 5194: eda078b01c65
permissions: -rw-r--r--

6484982: G1: process references during evacuation pauses
Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp

 /*
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  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
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  * published by the Free Software Foundation.
  *
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  * 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.
  *
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 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PCTASKS_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PCTASKS_HPP
 #include "gc_implementation/parallelScavenge/gcTaskManager.hpp"
 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
 #include "gc_implementation/parallelScavenge/psTasks.hpp"
 // Tasks for parallel compaction of the old generation
 //
 // Tasks are created and enqueued on a task queue. The
 // tasks for parallel old collector for marking objects
 // are MarkFromRootsTask and ThreadRootsMarkingTask.
 //
 // MarkFromRootsTask's are created
 // with a root group (e.g., jni_handles) and when the do_it()
 // method of a MarkFromRootsTask is executed, it starts marking
 // form it's root group.
 //
 // ThreadRootsMarkingTask's are created for each Java thread.  When
 // the do_it() method of a ThreadRootsMarkingTask is executed, it
 // starts marking from the thread's roots.
 //
 // The enqueuing of the MarkFromRootsTask and ThreadRootsMarkingTask
 // do little more than create the task and put it on a queue.  The
 // queue is a GCTaskQueue and threads steal tasks from this GCTaskQueue.
 //
 // In addition to the MarkFromRootsTask and ThreadRootsMarkingTask
 // tasks there are StealMarkingTask tasks.  The StealMarkingTask's
 // steal a reference from the marking stack of another
 // thread and transitively marks the object of the reference
 // and internal references.  After successfully stealing a reference
 // and marking it, the StealMarkingTask drains its marking stack
 // stack before attempting another steal.
 //
 // ThreadRootsMarkingTask
 //
 // This task marks from the roots of a single thread. This task
 // enables marking of thread roots in parallel.
 //
 class ParallelTaskTerminator;
 class ThreadRootsMarkingTask : public GCTask {
  private:
   JavaThread* _java_thread;
   VMThread* _vm_thread;
  public:
   ThreadRootsMarkingTask(JavaThread* root) : _java_thread(root), _vm_thread(NULL) {}
   ThreadRootsMarkingTask(VMThread* root) : _java_thread(NULL), _vm_thread(root) {}
   char* name() { return (char *)"thread-roots-marking-task"; }
   virtual void do_it(GCTaskManager* manager, uint which);
 };
 //
 // MarkFromRootsTask
 //
 // This task marks from all the roots to all live
 // objects.
 //
 //
 class MarkFromRootsTask : public GCTask {
  public:
   enum RootType {
     universe              = 1,
     jni_handles           = 2,
     threads               = 3,
     object_synchronizer   = 4,
     flat_profiler         = 5,
     management            = 6,
     jvmti                 = 7,
     system_dictionary     = 8,
     code_cache            = 9
   };
  private:
   RootType _root_type;
  public:
   MarkFromRootsTask(RootType value) : _root_type(value) {}
   char* name() { return (char *)"mark-from-roots-task"; }
   virtual void do_it(GCTaskManager* manager, uint which);
 };
 //
 // RefProcTaskProxy
 //
 // This task is used as a proxy to parallel reference processing tasks .
 //
 class RefProcTaskProxy : public GCTask {
   typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask;
   ProcessTask & _rp_task;
   uint          _work_id;
 public:
   RefProcTaskProxy(ProcessTask & rp_task, uint work_id)
     : _rp_task(rp_task),
       _work_id(work_id)
   { }
 private:
   virtual char* name() { return (char *)"Process referents by policy in parallel"; }
   virtual void do_it(GCTaskManager* manager, uint which);
 };
 //
 // RefEnqueueTaskProxy
 //
 // This task is used as a proxy to parallel reference processing tasks .
 //
 class RefEnqueueTaskProxy: public GCTask {
   typedef AbstractRefProcTaskExecutor::EnqueueTask EnqueueTask;
   EnqueueTask& _enq_task;
   uint         _work_id;
 public:
   RefEnqueueTaskProxy(EnqueueTask& enq_task, uint work_id)
     : _enq_task(enq_task),
       _work_id(work_id)
   { }
   virtual char* name() { return (char *)"Enqueue reference objects in parallel"; }
   virtual void do_it(GCTaskManager* manager, uint which)
   {
     _enq_task.work(_work_id);
   }
 };
 //
 // RefProcTaskExecutor
 //
 // Task executor is an interface for the reference processor to run
 // tasks using GCTaskManager.
 //
 class RefProcTaskExecutor: public AbstractRefProcTaskExecutor {
   virtual void execute(ProcessTask& task);
   virtual void execute(EnqueueTask& task);
 };
 //
 // StealMarkingTask
 //
 // This task is used to distribute work to idle threads.
 //
 class StealMarkingTask : public GCTask {
  private:
    ParallelTaskTerminator* const _terminator;
  private:
  public:
   char* name() { return (char *)"steal-marking-task"; }
   StealMarkingTask(ParallelTaskTerminator* t);
   ParallelTaskTerminator* terminator() { return _terminator; }
   virtual void do_it(GCTaskManager* manager, uint which);
 };
 //
 // StealRegionCompactionTask
 //
 // This task is used to distribute work to idle threads.
 //
 class StealRegionCompactionTask : public GCTask {
  private:
    ParallelTaskTerminator* const _terminator;
  public:
   StealRegionCompactionTask(ParallelTaskTerminator* t);
   char* name() { return (char *)"steal-region-task"; }
   ParallelTaskTerminator* terminator() { return _terminator; }
   virtual void do_it(GCTaskManager* manager, uint which);
 };
 //
 // UpdateDensePrefixTask
 //
 // This task is used to update the dense prefix
 // of a space.
 //
 class UpdateDensePrefixTask : public GCTask {
  private:
   PSParallelCompact::SpaceId _space_id;
   size_t _region_index_start;
   size_t _region_index_end;
  public:
   char* name() { return (char *)"update-dense_prefix-task"; }
   UpdateDensePrefixTask(PSParallelCompact::SpaceId space_id,
                         size_t region_index_start,
                         size_t region_index_end);
   virtual void do_it(GCTaskManager* manager, uint which);
 };
 //
 // DrainStacksCompactionTask
 //
 // This task processes regions that have been added to the stacks of each
 // compaction manager.
 //
 // Trying to use one draining thread does not work because there are no
 // guarantees about which task will be picked up by which thread.  For example,
 // if thread A gets all the preloaded regions, thread A may not get a draining
 // task (they may all be done by other threads).
 //
 class DrainStacksCompactionTask : public GCTask {
  uint _stack_index;
  uint stack_index() { return _stack_index; }
  public:
   DrainStacksCompactionTask(uint stack_index) : GCTask(),
                                                 _stack_index(stack_index) {};
   char* name() { return (char *)"drain-region-task"; }
   virtual void do_it(GCTaskManager* manager, uint which);
 };
 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PCTASKS_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/parallelScavenge/pcTasks.hpp@4dfb2df418f2 (annotated)

src/share/vm/gc_implementation/parallelScavenge/pcTasks.hpp