1.1 --- a/src/share/vm/memory/metachunk.hpp Tue Oct 15 07:10:09 2013 -0700
1.2 +++ b/src/share/vm/memory/metachunk.hpp Tue Oct 15 14:28:51 2013 +0200
1.3 @@ -1,5 +1,5 @@
1.4 /*
1.5 - * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
1.6 + * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
1.7 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.8 *
1.9 * This code is free software; you can redistribute it and/or modify it
1.10 @@ -24,89 +24,44 @@
1.11 #ifndef SHARE_VM_MEMORY_METACHUNK_HPP
1.12 #define SHARE_VM_MEMORY_METACHUNK_HPP
1.13
1.14 -// Metachunk - Quantum of allocation from a Virtualspace
1.15 -// Metachunks are reused (when freed are put on a global freelist) and
1.16 -// have no permanent association to a SpaceManager.
1.17 -
1.18 -// +--------------+ <- end
1.19 -// | | --+ ---+
1.20 -// | | | free |
1.21 -// | | | |
1.22 -// | | | | capacity
1.23 -// | | | |
1.24 -// | | <- top --+ |
1.25 -// | | ---+ |
1.26 -// | | | used |
1.27 -// | | | |
1.28 -// | | | |
1.29 -// +--------------+ <- bottom ---+ ---+
1.30 +#include "memory/allocation.hpp"
1.31 +#include "utilities/debug.hpp"
1.32 +#include "utilities/globalDefinitions.hpp"
1.33
1.34 class VirtualSpaceNode;
1.35
1.36 -class Metachunk VALUE_OBJ_CLASS_SPEC {
1.37 - // link to support lists of chunks
1.38 - Metachunk* _next;
1.39 - Metachunk* _prev;
1.40 - VirtualSpaceNode* _container;
1.41 +// Super class of Metablock and Metachunk to allow them to
1.42 +// be put on the FreeList and in the BinaryTreeDictionary.
1.43 +template <class T>
1.44 +class Metabase VALUE_OBJ_CLASS_SPEC {
1.45 + size_t _word_size;
1.46 + T* _next;
1.47 + T* _prev;
1.48
1.49 - MetaWord* _bottom;
1.50 - MetaWord* _end;
1.51 - MetaWord* _top;
1.52 - size_t _word_size;
1.53 - // Used in a guarantee() so included in the Product builds
1.54 - // even through it is only for debugging.
1.55 - bool _is_free;
1.56 -
1.57 - // Metachunks are allocated out of a MetadataVirtualSpace and
1.58 - // and use some of its space to describe itself (plus alignment
1.59 - // considerations). Metadata is allocated in the rest of the chunk.
1.60 - // This size is the overhead of maintaining the Metachunk within
1.61 - // the space.
1.62 - static size_t _overhead;
1.63 + protected:
1.64 + Metabase(size_t word_size) : _word_size(word_size), _next(NULL), _prev(NULL) {}
1.65
1.66 public:
1.67 - Metachunk(size_t word_size , VirtualSpaceNode* container);
1.68 + T* next() const { return _next; }
1.69 + T* prev() const { return _prev; }
1.70 + void set_next(T* v) { _next = v; assert(v != this, "Boom");}
1.71 + void set_prev(T* v) { _prev = v; assert(v != this, "Boom");}
1.72 + void clear_next() { set_next(NULL); }
1.73 + void clear_prev() { set_prev(NULL); }
1.74
1.75 - // Used to add a Metachunk to a list of Metachunks
1.76 - void set_next(Metachunk* v) { _next = v; assert(v != this, "Boom");}
1.77 - void set_prev(Metachunk* v) { _prev = v; assert(v != this, "Boom");}
1.78 - void set_container(VirtualSpaceNode* v) { _container = v; }
1.79 -
1.80 - MetaWord* allocate(size_t word_size);
1.81 -
1.82 - // Accessors
1.83 - Metachunk* next() const { return _next; }
1.84 - Metachunk* prev() const { return _prev; }
1.85 - VirtualSpaceNode* container() const { return _container; }
1.86 - MetaWord* bottom() const { return _bottom; }
1.87 - MetaWord* end() const { return _end; }
1.88 - MetaWord* top() const { return _top; }
1.89 - size_t word_size() const { return _word_size; }
1.90 size_t size() const volatile { return _word_size; }
1.91 void set_size(size_t v) { _word_size = v; }
1.92 - bool is_free() { return _is_free; }
1.93 - void set_is_free(bool v) { _is_free = v; }
1.94 - static size_t overhead() { return _overhead; }
1.95 - void clear_next() { set_next(NULL); }
1.96 - void link_prev(Metachunk* ptr) { set_prev(ptr); }
1.97 - uintptr_t* end() { return ((uintptr_t*) this) + size(); }
1.98 - bool cantCoalesce() const { return false; }
1.99 - void link_next(Metachunk* ptr) { set_next(ptr); }
1.100 - void link_after(Metachunk* ptr){
1.101 +
1.102 + void link_next(T* ptr) { set_next(ptr); }
1.103 + void link_prev(T* ptr) { set_prev(ptr); }
1.104 + void link_after(T* ptr) {
1.105 link_next(ptr);
1.106 - if (ptr != NULL) ptr->link_prev(this);
1.107 + if (ptr != NULL) ptr->link_prev((T*)this);
1.108 }
1.109
1.110 - // Reset top to bottom so chunk can be reused.
1.111 - void reset_empty() { _top = (_bottom + _overhead); _next = NULL; _prev = NULL; }
1.112 - bool is_empty() { return _top == (_bottom + _overhead); }
1.113 + uintptr_t* end() const { return ((uintptr_t*) this) + size(); }
1.114
1.115 - // used (has been allocated)
1.116 - // free (available for future allocations)
1.117 - // capacity (total size of chunk)
1.118 - size_t used_word_size() const;
1.119 - size_t free_word_size() const;
1.120 - size_t capacity_word_size()const;
1.121 + bool cantCoalesce() const { return false; }
1.122
1.123 // Debug support
1.124 #ifdef ASSERT
1.125 @@ -114,14 +69,98 @@
1.126 void* next_addr() const { return (void*)&_next; }
1.127 void* size_addr() const { return (void*)&_word_size; }
1.128 #endif
1.129 - bool verify_chunk_in_free_list(Metachunk* tc) const { return true; }
1.130 + bool verify_chunk_in_free_list(T* tc) const { return true; }
1.131 bool verify_par_locked() { return true; }
1.132
1.133 void assert_is_mangled() const {/* Don't check "\*/}
1.134
1.135 - NOT_PRODUCT(void mangle();)
1.136 + bool is_free() { return true; }
1.137 +};
1.138 +
1.139 +// Metachunk - Quantum of allocation from a Virtualspace
1.140 +// Metachunks are reused (when freed are put on a global freelist) and
1.141 +// have no permanent association to a SpaceManager.
1.142 +
1.143 +// +--------------+ <- end --+ --+
1.144 +// | | | |
1.145 +// | | | free |
1.146 +// | | | |
1.147 +// | | | | size | capacity
1.148 +// | | | |
1.149 +// | | <- top -- + |
1.150 +// | | | |
1.151 +// | | | used |
1.152 +// | | | |
1.153 +// | | | |
1.154 +// +--------------+ <- bottom --+ --+
1.155 +
1.156 +class Metachunk : public Metabase<Metachunk> {
1.157 + friend class TestMetachunk;
1.158 + // The VirtualSpaceNode containing this chunk.
1.159 + VirtualSpaceNode* _container;
1.160 +
1.161 + // Current allocation top.
1.162 + MetaWord* _top;
1.163 +
1.164 + DEBUG_ONLY(bool _is_tagged_free;)
1.165 +
1.166 + MetaWord* initial_top() const { return (MetaWord*)this + overhead(); }
1.167 + MetaWord* top() const { return _top; }
1.168 +
1.169 + public:
1.170 + // Metachunks are allocated out of a MetadataVirtualSpace and
1.171 + // and use some of its space to describe itself (plus alignment
1.172 + // considerations). Metadata is allocated in the rest of the chunk.
1.173 + // This size is the overhead of maintaining the Metachunk within
1.174 + // the space.
1.175 +
1.176 + // Alignment of each allocation in the chunks.
1.177 + static size_t object_alignment();
1.178 +
1.179 + // Size of the Metachunk header, including alignment.
1.180 + static size_t overhead();
1.181 +
1.182 + Metachunk(size_t word_size , VirtualSpaceNode* container);
1.183 +
1.184 + MetaWord* allocate(size_t word_size);
1.185 +
1.186 + VirtualSpaceNode* container() const { return _container; }
1.187 +
1.188 + MetaWord* bottom() const { return (MetaWord*) this; }
1.189 +
1.190 + // Reset top to bottom so chunk can be reused.
1.191 + void reset_empty() { _top = initial_top(); clear_next(); clear_prev(); }
1.192 + bool is_empty() { return _top == initial_top(); }
1.193 +
1.194 + // used (has been allocated)
1.195 + // free (available for future allocations)
1.196 + size_t word_size() const { return size(); }
1.197 + size_t used_word_size() const;
1.198 + size_t free_word_size() const;
1.199 +
1.200 +#ifdef ASSERT
1.201 + void mangle();
1.202 + bool is_tagged_free() { return _is_tagged_free; }
1.203 + void set_is_tagged_free(bool v) { _is_tagged_free = v; }
1.204 +#endif
1.205
1.206 void print_on(outputStream* st) const;
1.207 void verify();
1.208 };
1.209 +
1.210 +// Metablock is the unit of allocation from a Chunk.
1.211 +//
1.212 +// A Metablock may be reused by its SpaceManager but are never moved between
1.213 +// SpaceManagers. There is no explicit link to the Metachunk
1.214 +// from which it was allocated. Metablock may be deallocated and
1.215 +// put on a freelist but the space is never freed, rather
1.216 +// the Metachunk it is a part of will be deallocated when it's
1.217 +// associated class loader is collected.
1.218 +
1.219 +class Metablock : public Metabase<Metablock> {
1.220 + friend class VMStructs;
1.221 + public:
1.222 + Metablock(size_t word_size) : Metabase<Metablock>(word_size) {}
1.223 +};
1.224 +
1.225 #endif // SHARE_VM_MEMORY_METACHUNK_HPP
