Mercurial > hg > graal-compiler
diff src/share/vm/gc_implementation/g1/g1RegionToSpaceMapper.hpp @ 20337:1f1d373cd044
8038423: G1: Decommit memory within heap
Summary: Allow G1 to decommit memory of arbitrary regions within the heap and their associated auxiliary data structures card table, BOT, hot card cache, and mark bitmaps.
Reviewed-by: mgerdin, brutisso, jwilhelm
author | tschatzl |
---|---|
date | Thu, 21 Aug 2014 11:47:10 +0200 |
parents | |
children | 7b2fc3129653 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/g1/g1RegionToSpaceMapper.hpp Thu Aug 21 11:47:10 2014 +0200 @@ -0,0 +1,82 @@ +/* + * Copyright (c) 2014, 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_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP +#define SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP + +#include "gc_implementation/g1/g1PageBasedVirtualSpace.hpp" +#include "utilities/debug.hpp" + +class G1MappingChangedListener VALUE_OBJ_CLASS_SPEC { + public: + // Fired after commit of the memory, i.e. the memory this listener is registered + // for can be accessed. + virtual void on_commit(uint start_idx, size_t num_regions) = 0; +}; + +// Maps region based commit/uncommit requests to the underlying page sized virtual +// space. +class G1RegionToSpaceMapper : public CHeapObj<mtGC> { + private: + G1MappingChangedListener* _listener; + protected: + // Backing storage. + G1PageBasedVirtualSpace _storage; + size_t _commit_granularity; + size_t _region_granularity; + // Mapping management + BitMap _commit_map; + + G1RegionToSpaceMapper(ReservedSpace rs, size_t commit_granularity, size_t region_granularity, MemoryType type); + + void fire_on_commit(uint start_idx, size_t num_regions); + public: + MemRegion reserved() { return _storage.reserved(); } + + void set_mapping_changed_listener(G1MappingChangedListener* listener) { _listener = listener; } + + virtual ~G1RegionToSpaceMapper() { + _commit_map.resize(0, /* in_resource_area */ false); + } + + bool is_committed(uintptr_t idx) const { + return _commit_map.at(idx); + } + + virtual void commit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0; + virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0; + + // Creates an appropriate G1RegionToSpaceMapper for the given parameters. + // The byte_translation_factor defines how many bytes in a region correspond to + // a single byte in the data structure this mapper is for. + // Eg. in the card table, this value corresponds to the size a single card + // table entry corresponds to. + static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs, + size_t os_commit_granularity, + size_t region_granularity, + size_t byte_translation_factor, + MemoryType type); +}; + +#endif /* SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP */