1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/psTasks.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,183 @@
1.4 +/*
1.5 + * Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSTASKS_HPP
1.29 +#define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSTASKS_HPP
1.30 +
1.31 +#include "memory/allocation.hpp"
1.32 +#include "utilities/growableArray.hpp"
1.33 +
1.34 +//
1.35 +// psTasks.hpp is a collection of GCTasks used by the
1.36 +// parallelScavenge collector.
1.37 +//
1.38 +
1.39 +class GCTask;
1.40 +class OopClosure;
1.41 +class OopStack;
1.42 +class ObjectStartArray;
1.43 +class ParallelTaskTerminator;
1.44 +class MutableSpace;
1.45 +class PSOldGen;
1.46 +class Thread;
1.47 +class VMThread;
1.48 +
1.49 +//
1.50 +// ScavengeRootsTask
1.51 +//
1.52 +// This task scans all the roots of a given type.
1.53 +//
1.54 +//
1.55 +
1.56 +class ScavengeRootsTask : public GCTask {
1.57 + public:
1.58 + enum RootType {
1.59 + universe = 1,
1.60 + jni_handles = 2,
1.61 + threads = 3,
1.62 + object_synchronizer = 4,
1.63 + flat_profiler = 5,
1.64 + system_dictionary = 6,
1.65 + class_loader_data = 7,
1.66 + management = 8,
1.67 + jvmti = 9,
1.68 + code_cache = 10
1.69 + };
1.70 + private:
1.71 + RootType _root_type;
1.72 + public:
1.73 + ScavengeRootsTask(RootType value) : _root_type(value) {}
1.74 +
1.75 + char* name() { return (char *)"scavenge-roots-task"; }
1.76 +
1.77 + virtual void do_it(GCTaskManager* manager, uint which);
1.78 +};
1.79 +
1.80 +//
1.81 +// ThreadRootsTask
1.82 +//
1.83 +// This task scans the roots of a single thread. This task
1.84 +// enables scanning of thread roots in parallel.
1.85 +//
1.86 +
1.87 +class ThreadRootsTask : public GCTask {
1.88 + private:
1.89 + JavaThread* _java_thread;
1.90 + VMThread* _vm_thread;
1.91 + public:
1.92 + ThreadRootsTask(JavaThread* root) : _java_thread(root), _vm_thread(NULL) {}
1.93 + ThreadRootsTask(VMThread* root) : _java_thread(NULL), _vm_thread(root) {}
1.94 +
1.95 + char* name() { return (char *)"thread-roots-task"; }
1.96 +
1.97 + virtual void do_it(GCTaskManager* manager, uint which);
1.98 +};
1.99 +
1.100 +//
1.101 +// StealTask
1.102 +//
1.103 +// This task is used to distribute work to idle threads.
1.104 +//
1.105 +
1.106 +class StealTask : public GCTask {
1.107 + private:
1.108 + ParallelTaskTerminator* const _terminator;
1.109 + public:
1.110 + char* name() { return (char *)"steal-task"; }
1.111 +
1.112 + StealTask(ParallelTaskTerminator* t);
1.113 +
1.114 + ParallelTaskTerminator* terminator() { return _terminator; }
1.115 +
1.116 + virtual void do_it(GCTaskManager* manager, uint which);
1.117 +};
1.118 +
1.119 +//
1.120 +// OldToYoungRootsTask
1.121 +//
1.122 +// This task is used to scan old to young roots in parallel
1.123 +//
1.124 +// A GC thread executing this tasks divides the generation (old gen)
1.125 +// into slices and takes a stripe in the slice as its part of the
1.126 +// work.
1.127 +//
1.128 +// +===============+ slice 0
1.129 +// | stripe 0 |
1.130 +// +---------------+
1.131 +// | stripe 1 |
1.132 +// +---------------+
1.133 +// | stripe 2 |
1.134 +// +---------------+
1.135 +// | stripe 3 |
1.136 +// +===============+ slice 1
1.137 +// | stripe 0 |
1.138 +// +---------------+
1.139 +// | stripe 1 |
1.140 +// +---------------+
1.141 +// | stripe 2 |
1.142 +// +---------------+
1.143 +// | stripe 3 |
1.144 +// +===============+ slice 2
1.145 +// ...
1.146 +//
1.147 +// A task is created for each stripe. In this case there are 4 tasks
1.148 +// created. A GC thread first works on its stripe within slice 0
1.149 +// and then moves to its stripe in the next slice until all stripes
1.150 +// exceed the top of the generation. Note that having fewer GC threads
1.151 +// than stripes works because all the tasks are executed so all stripes
1.152 +// will be covered. In this example if 4 tasks have been created to cover
1.153 +// all the stripes and there are only 3 threads, one of the threads will
1.154 +// get the tasks with the 4th stripe. However, there is a dependence in
1.155 +// CardTableExtension::scavenge_contents_parallel() on the number
1.156 +// of tasks created. In scavenge_contents_parallel the distance
1.157 +// to the next stripe is calculated based on the number of tasks.
1.158 +// If the stripe width is ssize, a task's next stripe is at
1.159 +// ssize * number_of_tasks (= slice_stride). In this case after
1.160 +// finishing stripe 0 in slice 0, the thread finds the stripe 0 in slice1
1.161 +// by adding slice_stride to the start of stripe 0 in slice 0 to get
1.162 +// to the start of stride 0 in slice 1.
1.163 +
1.164 +class OldToYoungRootsTask : public GCTask {
1.165 + private:
1.166 + PSOldGen* _gen;
1.167 + HeapWord* _gen_top;
1.168 + uint _stripe_number;
1.169 + uint _stripe_total;
1.170 +
1.171 + public:
1.172 + OldToYoungRootsTask(PSOldGen *gen,
1.173 + HeapWord* gen_top,
1.174 + uint stripe_number,
1.175 + uint stripe_total) :
1.176 + _gen(gen),
1.177 + _gen_top(gen_top),
1.178 + _stripe_number(stripe_number),
1.179 + _stripe_total(stripe_total) { }
1.180 +
1.181 + char* name() { return (char *)"old-to-young-roots-task"; }
1.182 +
1.183 + virtual void do_it(GCTaskManager* manager, uint which);
1.184 +};
1.185 +
1.186 +#endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSTASKS_HPP
