duke@435: /*
stefank@2314:  * Copyright (c) 2002, 2010, 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_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSTASKS_HPP
stefank@2314: #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSTASKS_HPP
stefank@2314: 
stefank@2314: #include "memory/allocation.hpp"
stefank@2314: #include "utilities/growableArray.hpp"
stefank@2314: 
duke@435: //
duke@435: // psTasks.hpp is a collection of GCTasks used by the
duke@435: // parallelScavenge collector.
duke@435: //
duke@435: 
duke@435: class GCTask;
duke@435: class OopClosure;
duke@435: class OopStack;
duke@435: class ObjectStartArray;
duke@435: class ParallelTaskTerminator;
duke@435: class MutableSpace;
duke@435: class PSOldGen;
duke@435: class Thread;
duke@435: class VMThread;
duke@435: 
duke@435: //
duke@435: // ScavengeRootsTask
duke@435: //
duke@435: // This task scans all the roots of a given type.
duke@435: //
duke@435: //
duke@435: 
duke@435: class ScavengeRootsTask : public GCTask {
duke@435:  public:
duke@435:   enum RootType {
duke@435:     universe              = 1,
duke@435:     jni_handles           = 2,
duke@435:     threads               = 3,
duke@435:     object_synchronizer   = 4,
duke@435:     flat_profiler         = 5,
duke@435:     system_dictionary     = 6,
stefank@5194:     class_loader_data     = 7,
stefank@5194:     management            = 8,
stefank@5194:     jvmti                 = 9,
stefank@5194:     code_cache            = 10
duke@435:   };
duke@435:  private:
duke@435:   RootType _root_type;
duke@435:  public:
duke@435:   ScavengeRootsTask(RootType value) : _root_type(value) {}
duke@435: 
duke@435:   char* name() { return (char *)"scavenge-roots-task"; }
duke@435: 
duke@435:   virtual void do_it(GCTaskManager* manager, uint which);
duke@435: };
duke@435: 
duke@435: //
duke@435: // ThreadRootsTask
duke@435: //
duke@435: // This task scans the roots of a single thread. This task
duke@435: // enables scanning of thread roots in parallel.
duke@435: //
duke@435: 
duke@435: class ThreadRootsTask : public GCTask {
duke@435:  private:
duke@435:   JavaThread* _java_thread;
duke@435:   VMThread* _vm_thread;
duke@435:  public:
duke@435:   ThreadRootsTask(JavaThread* root) : _java_thread(root), _vm_thread(NULL) {}
duke@435:   ThreadRootsTask(VMThread* root) : _java_thread(NULL), _vm_thread(root) {}
duke@435: 
duke@435:   char* name() { return (char *)"thread-roots-task"; }
duke@435: 
duke@435:   virtual void do_it(GCTaskManager* manager, uint which);
duke@435: };
duke@435: 
duke@435: //
duke@435: // StealTask
duke@435: //
duke@435: // This task is used to distribute work to idle threads.
duke@435: //
duke@435: 
duke@435: class StealTask : public GCTask {
duke@435:  private:
duke@435:    ParallelTaskTerminator* const _terminator;
duke@435:  public:
duke@435:   char* name() { return (char *)"steal-task"; }
duke@435: 
duke@435:   StealTask(ParallelTaskTerminator* t);
duke@435: 
duke@435:   ParallelTaskTerminator* terminator() { return _terminator; }
duke@435: 
duke@435:   virtual void do_it(GCTaskManager* manager, uint which);
duke@435: };
duke@435: 
duke@435: //
duke@435: // OldToYoungRootsTask
duke@435: //
duke@435: // This task is used to scan old to young roots in parallel
jmasa@3294: //
jmasa@3294: // A GC thread executing this tasks divides the generation (old gen)
jmasa@3294: // into slices and takes a stripe in the slice as its part of the
jmasa@3294: // work.
jmasa@3294: //
jmasa@3294: //      +===============+        slice 0
jmasa@3294: //      |  stripe 0     |
jmasa@3294: //      +---------------+
jmasa@3294: //      |  stripe 1     |
jmasa@3294: //      +---------------+
jmasa@3294: //      |  stripe 2     |
jmasa@3294: //      +---------------+
jmasa@3294: //      |  stripe 3     |
jmasa@3294: //      +===============+        slice 1
jmasa@3294: //      |  stripe 0     |
jmasa@3294: //      +---------------+
jmasa@3294: //      |  stripe 1     |
jmasa@3294: //      +---------------+
jmasa@3294: //      |  stripe 2     |
jmasa@3294: //      +---------------+
jmasa@3294: //      |  stripe 3     |
jmasa@3294: //      +===============+        slice 2
jmasa@3294: //      ...
jmasa@3294: //
jmasa@3294: // A task is created for each stripe.  In this case there are 4 tasks
jmasa@3294: // created.  A GC thread first works on its stripe within slice 0
jmasa@3294: // and then moves to its stripe in the next slice until all stripes
jmasa@3294: // exceed the top of the generation.  Note that having fewer GC threads
jmasa@3294: // than stripes works because all the tasks are executed so all stripes
jmasa@3294: // will be covered.  In this example if 4 tasks have been created to cover
jmasa@3294: // all the stripes and there are only 3 threads, one of the threads will
jmasa@3294: // get the tasks with the 4th stripe.  However, there is a dependence in
jmasa@3294: // CardTableExtension::scavenge_contents_parallel() on the number
jmasa@3294: // of tasks created.  In scavenge_contents_parallel the distance
jmasa@3294: // to the next stripe is calculated based on the number of tasks.
jmasa@3294: // If the stripe width is ssize, a task's next stripe is at
jmasa@3294: // ssize * number_of_tasks (= slice_stride).  In this case after
jmasa@3294: // finishing stripe 0 in slice 0, the thread finds the stripe 0 in slice1
jmasa@3294: // by adding slice_stride to the start of stripe 0 in slice 0 to get
jmasa@3294: // to the start of stride 0 in slice 1.
duke@435: 
duke@435: class OldToYoungRootsTask : public GCTask {
duke@435:  private:
duke@435:   PSOldGen* _gen;
duke@435:   HeapWord* _gen_top;
duke@435:   uint _stripe_number;
jmasa@3294:   uint _stripe_total;
duke@435: 
duke@435:  public:
jmasa@3294:   OldToYoungRootsTask(PSOldGen *gen,
jmasa@3294:                       HeapWord* gen_top,
jmasa@3294:                       uint stripe_number,
jmasa@3294:                       uint stripe_total) :
jmasa@3294:     _gen(gen),
jmasa@3294:     _gen_top(gen_top),
jmasa@3294:     _stripe_number(stripe_number),
jmasa@3294:     _stripe_total(stripe_total) { }
duke@435: 
duke@435:   char* name() { return (char *)"old-to-young-roots-task"; }
duke@435: 
duke@435:   virtual void do_it(GCTaskManager* manager, uint which);
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSTASKS_HPP