Mercurial > hg > truffle
view src/share/vm/memory/heap.hpp @ 10127:b80cc96882f7
8012464: NMT: classes should not derive from _ValueObj, use VALUE_OBJ_CLASS_SPEC instead
Summary: NMT value objects should use VALUE_OBJ_CLASS_SPEC instead of deriving from _ValueObj
Reviewed-by: coleenp, hseigel, dholmes
author | zgu |
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date | Thu, 18 Apr 2013 10:04:44 -0400 |
parents | b9a9ed0f8eeb |
children | a7fb14888912 |
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/* * Copyright (c) 1997, 2012, 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_HEAP_HPP #define SHARE_VM_MEMORY_HEAP_HPP #include "memory/allocation.hpp" #include "runtime/virtualspace.hpp" // Blocks class HeapBlock VALUE_OBJ_CLASS_SPEC { friend class VMStructs; public: struct Header { size_t _length; // the length in segments bool _used; // Used bit }; protected: union { Header _header; int64_t _padding[ (sizeof(Header) + sizeof(int64_t)-1) / sizeof(int64_t) ]; // pad to 0 mod 8 }; public: // Initialization void initialize(size_t length) { _header._length = length; set_used(); } // Accessors void* allocated_space() const { return (void*)(this + 1); } size_t length() const { return _header._length; } // Used/free void set_used() { _header._used = true; } void set_free() { _header._used = false; } bool free() { return !_header._used; } }; class FreeBlock: public HeapBlock { friend class VMStructs; protected: FreeBlock* _link; public: // Initialization void initialize(size_t length) { HeapBlock::initialize(length); _link= NULL; } // Merging void set_length(size_t l) { _header._length = l; } // Accessors FreeBlock* link() const { return _link; } void set_link(FreeBlock* link) { _link = link; } }; class CodeHeap : public CHeapObj<mtCode> { friend class VMStructs; private: VirtualSpace _memory; // the memory holding the blocks VirtualSpace _segmap; // the memory holding the segment map size_t _number_of_committed_segments; size_t _number_of_reserved_segments; size_t _segment_size; int _log2_segment_size; size_t _next_segment; FreeBlock* _freelist; size_t _free_segments; // No. of segments in freelist // Helper functions size_t number_of_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; } size_t size(size_t number_of_segments) const { return number_of_segments << _log2_segment_size; } size_t segment_for(void* p) const { return ((char*)p - _memory.low()) >> _log2_segment_size; } HeapBlock* block_at(size_t i) const { return (HeapBlock*)(_memory.low() + (i << _log2_segment_size)); } void mark_segmap_as_free(size_t beg, size_t end); void mark_segmap_as_used(size_t beg, size_t end); // Freelist management helpers FreeBlock* following_block(FreeBlock *b); void insert_after(FreeBlock* a, FreeBlock* b); void merge_right (FreeBlock* a); // Toplevel freelist management void add_to_freelist(HeapBlock *b); FreeBlock* search_freelist(size_t length); // Iteration helpers void* next_free(HeapBlock* b) const; HeapBlock* first_block() const; HeapBlock* next_block(HeapBlock* b) const; HeapBlock* block_start(void* p) const; // to perform additional actions on creation of executable code void on_code_mapping(char* base, size_t size); public: CodeHeap(); // Heap extents bool reserve(size_t reserved_size, size_t committed_size, size_t segment_size); void release(); // releases all allocated memory bool expand_by(size_t size); // expands commited memory by size void shrink_by(size_t size); // shrinks commited memory by size void clear(); // clears all heap contents // Memory allocation void* allocate (size_t size); // allocates a block of size or returns NULL void deallocate(void* p); // deallocates a block // Attributes void* begin() const { return _memory.low (); } void* end() const { return _memory.high(); } bool contains(void* p) const { return begin() <= p && p < end(); } void* find_start(void* p) const; // returns the block containing p or NULL size_t alignment_unit() const; // alignment of any block size_t alignment_offset() const; // offset of first byte of any block, within the enclosing alignment unit static size_t header_size(); // returns the header size for each heap block // Returns reserved area high and low addresses char *low_boundary() const { return _memory.low_boundary (); } char *high() const { return _memory.high(); } char *high_boundary() const { return _memory.high_boundary(); } // Iteration // returns the first block or NULL void* first() const { return next_free(first_block()); } // returns the next block given a block p or NULL void* next(void* p) const { return next_free(next_block(block_start(p))); } // Statistics size_t capacity() const; size_t max_capacity() const; size_t allocated_capacity() const; size_t unallocated_capacity() const { return max_capacity() - allocated_capacity(); } size_t largest_free_block() const; // Debugging void verify(); void print() PRODUCT_RETURN; }; #endif // SHARE_VM_MEMORY_HEAP_HPP