Mercurial > hg > graal-compiler
view src/share/vm/memory/metachunk.hpp @ 17699:54436d3b2a91 hs25.20-b05
Merge
author | amurillo |
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date | Fri, 28 Feb 2014 08:43:42 -0800 |
parents | 40353abd7984 |
children | 4ca6dc0799b6 |
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/* * Copyright (c) 2012, 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_MEMORY_METACHUNK_HPP #define SHARE_VM_MEMORY_METACHUNK_HPP #include "memory/allocation.hpp" #include "utilities/debug.hpp" #include "utilities/globalDefinitions.hpp" class VirtualSpaceNode; // Super class of Metablock and Metachunk to allow them to // be put on the FreeList and in the BinaryTreeDictionary. template <class T> class Metabase VALUE_OBJ_CLASS_SPEC { size_t _word_size; T* _next; T* _prev; protected: Metabase(size_t word_size) : _word_size(word_size), _next(NULL), _prev(NULL) {} public: T* next() const { return _next; } T* prev() const { return _prev; } void set_next(T* v) { _next = v; assert(v != this, "Boom");} void set_prev(T* v) { _prev = v; assert(v != this, "Boom");} void clear_next() { set_next(NULL); } void clear_prev() { set_prev(NULL); } size_t size() const volatile { return _word_size; } void set_size(size_t v) { _word_size = v; } void link_next(T* ptr) { set_next(ptr); } void link_prev(T* ptr) { set_prev(ptr); } void link_after(T* ptr) { link_next(ptr); if (ptr != NULL) ptr->link_prev((T*)this); } uintptr_t* end() const { return ((uintptr_t*) this) + size(); } bool cantCoalesce() const { return false; } // Debug support #ifdef ASSERT void* prev_addr() const { return (void*)&_prev; } void* next_addr() const { return (void*)&_next; } void* size_addr() const { return (void*)&_word_size; } #endif bool verify_chunk_in_free_list(T* tc) const { return true; } bool verify_par_locked() { return true; } void assert_is_mangled() const {/* Don't check "\*/} bool is_free() { return true; } }; // Metachunk - Quantum of allocation from a Virtualspace // Metachunks are reused (when freed are put on a global freelist) and // have no permanent association to a SpaceManager. // +--------------+ <- end --+ --+ // | | | | // | | | free | // | | | | // | | | | size | capacity // | | | | // | | <- top -- + | // | | | | // | | | used | // | | | | // | | | | // +--------------+ <- bottom --+ --+ class Metachunk : public Metabase<Metachunk> { friend class TestMetachunk; // The VirtualSpaceNode containing this chunk. VirtualSpaceNode* _container; // Current allocation top. MetaWord* _top; DEBUG_ONLY(bool _is_tagged_free;) MetaWord* initial_top() const { return (MetaWord*)this + overhead(); } MetaWord* top() const { return _top; } public: // Metachunks are allocated out of a MetadataVirtualSpace and // and use some of its space to describe itself (plus alignment // considerations). Metadata is allocated in the rest of the chunk. // This size is the overhead of maintaining the Metachunk within // the space. // Alignment of each allocation in the chunks. static size_t object_alignment(); // Size of the Metachunk header, including alignment. static size_t overhead(); Metachunk(size_t word_size , VirtualSpaceNode* container); MetaWord* allocate(size_t word_size); VirtualSpaceNode* container() const { return _container; } MetaWord* bottom() const { return (MetaWord*) this; } // Reset top to bottom so chunk can be reused. void reset_empty() { _top = initial_top(); clear_next(); clear_prev(); } bool is_empty() { return _top == initial_top(); } // used (has been allocated) // free (available for future allocations) size_t word_size() const { return size(); } size_t used_word_size() const; size_t free_word_size() const; #ifdef ASSERT bool is_tagged_free() { return _is_tagged_free; } void set_is_tagged_free(bool v) { _is_tagged_free = v; } #endif bool contains(const void* ptr) { return bottom() <= ptr && ptr < _top; } NOT_PRODUCT(void mangle();) void print_on(outputStream* st) const; void verify(); }; // Metablock is the unit of allocation from a Chunk. // // A Metablock may be reused by its SpaceManager but are never moved between // SpaceManagers. There is no explicit link to the Metachunk // from which it was allocated. Metablock may be deallocated and // put on a freelist but the space is never freed, rather // the Metachunk it is a part of will be deallocated when it's // associated class loader is collected. class Metablock : public Metabase<Metablock> { friend class VMStructs; public: Metablock(size_t word_size) : Metabase<Metablock>(word_size) {} }; #endif // SHARE_VM_MEMORY_METACHUNK_HPP