Mercurial > hg > graal-compiler
diff src/share/vm/memory/metachunk.hpp @ 12902:bdfbb1fb19ca
8026391: The Metachunk header wastes memory
Reviewed-by: coleenp, jmasa
author | stefank |
---|---|
date | Tue, 15 Oct 2013 14:28:51 +0200 |
parents | c23dbf0e8ab7 |
children | 28df60a5badf |
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--- a/src/share/vm/memory/metachunk.hpp Tue Oct 15 07:10:09 2013 -0700 +++ b/src/share/vm/memory/metachunk.hpp Tue Oct 15 14:28:51 2013 +0200 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. + * 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 @@ -24,89 +24,44 @@ #ifndef SHARE_VM_MEMORY_METACHUNK_HPP #define SHARE_VM_MEMORY_METACHUNK_HPP -// 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 | -// | | | | -// | | | | capacity -// | | | | -// | | <- top --+ | -// | | ---+ | -// | | | used | -// | | | | -// | | | | -// +--------------+ <- bottom ---+ ---+ +#include "memory/allocation.hpp" +#include "utilities/debug.hpp" +#include "utilities/globalDefinitions.hpp" class VirtualSpaceNode; -class Metachunk VALUE_OBJ_CLASS_SPEC { - // link to support lists of chunks - Metachunk* _next; - Metachunk* _prev; - VirtualSpaceNode* _container; - - MetaWord* _bottom; - MetaWord* _end; - MetaWord* _top; +// 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; - // Used in a guarantee() so included in the Product builds - // even through it is only for debugging. - bool _is_free; + T* _next; + T* _prev; - // 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. - static size_t _overhead; + protected: + Metabase(size_t word_size) : _word_size(word_size), _next(NULL), _prev(NULL) {} public: - Metachunk(size_t word_size , VirtualSpaceNode* container); - - // Used to add a Metachunk to a list of Metachunks - void set_next(Metachunk* v) { _next = v; assert(v != this, "Boom");} - void set_prev(Metachunk* v) { _prev = v; assert(v != this, "Boom");} - void set_container(VirtualSpaceNode* v) { _container = v; } - - MetaWord* allocate(size_t word_size); + 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); } - // Accessors - Metachunk* next() const { return _next; } - Metachunk* prev() const { return _prev; } - VirtualSpaceNode* container() const { return _container; } - MetaWord* bottom() const { return _bottom; } - MetaWord* end() const { return _end; } - MetaWord* top() const { return _top; } - size_t word_size() const { return _word_size; } size_t size() const volatile { return _word_size; } void set_size(size_t v) { _word_size = v; } - bool is_free() { return _is_free; } - void set_is_free(bool v) { _is_free = v; } - static size_t overhead() { return _overhead; } - void clear_next() { set_next(NULL); } - void link_prev(Metachunk* ptr) { set_prev(ptr); } - uintptr_t* end() { return ((uintptr_t*) this) + size(); } - bool cantCoalesce() const { return false; } - void link_next(Metachunk* ptr) { set_next(ptr); } - void link_after(Metachunk* ptr){ + + 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(this); + if (ptr != NULL) ptr->link_prev((T*)this); } - // Reset top to bottom so chunk can be reused. - void reset_empty() { _top = (_bottom + _overhead); _next = NULL; _prev = NULL; } - bool is_empty() { return _top == (_bottom + _overhead); } + uintptr_t* end() const { return ((uintptr_t*) this) + size(); } - // used (has been allocated) - // free (available for future allocations) - // capacity (total size of chunk) - size_t used_word_size() const; - size_t free_word_size() const; - size_t capacity_word_size()const; + bool cantCoalesce() const { return false; } // Debug support #ifdef ASSERT @@ -114,14 +69,98 @@ void* next_addr() const { return (void*)&_next; } void* size_addr() const { return (void*)&_word_size; } #endif - bool verify_chunk_in_free_list(Metachunk* tc) const { return true; } + 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 "\*/} - NOT_PRODUCT(void mangle();) + 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 + void mangle(); + bool is_tagged_free() { return _is_tagged_free; } + void set_is_tagged_free(bool v) { _is_tagged_free = v; } +#endif 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