Mon, 26 Jan 2009 12:47:21 -0800
6786503: Overflow list performance can be improved
Summary: Avoid overflow list walk in CMS & ParNew when it is unnecessary. Fix a couple of correctness issues, including a C-heap leak, in ParNew at the intersection of promotion failure, work queue overflow and object array chunking. Add stress testing option and related assertion checking.
Reviewed-by: jmasa
duke@435 | 1 | /* |
duke@435 | 2 | * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | // Blocks |
duke@435 | 26 | |
duke@435 | 27 | class HeapBlock VALUE_OBJ_CLASS_SPEC { |
duke@435 | 28 | friend class VMStructs; |
duke@435 | 29 | |
duke@435 | 30 | public: |
duke@435 | 31 | struct Header { |
duke@435 | 32 | size_t _length; // the length in segments |
duke@435 | 33 | bool _used; // Used bit |
duke@435 | 34 | }; |
duke@435 | 35 | |
duke@435 | 36 | protected: |
duke@435 | 37 | union { |
duke@435 | 38 | Header _header; |
duke@435 | 39 | int64_t _padding[ (sizeof(Header) + sizeof(int64_t)-1) / sizeof(int64_t) ]; |
duke@435 | 40 | // pad to 0 mod 8 |
duke@435 | 41 | }; |
duke@435 | 42 | |
duke@435 | 43 | public: |
duke@435 | 44 | // Initialization |
duke@435 | 45 | void initialize(size_t length) { _header._length = length; set_used(); } |
duke@435 | 46 | |
duke@435 | 47 | // Accessors |
duke@435 | 48 | void* allocated_space() const { return (void*)(this + 1); } |
duke@435 | 49 | size_t length() const { return _header._length; } |
duke@435 | 50 | |
duke@435 | 51 | // Used/free |
duke@435 | 52 | void set_used() { _header._used = true; } |
duke@435 | 53 | void set_free() { _header._used = false; } |
duke@435 | 54 | bool free() { return !_header._used; } |
duke@435 | 55 | }; |
duke@435 | 56 | |
duke@435 | 57 | class FreeBlock: public HeapBlock { |
duke@435 | 58 | friend class VMStructs; |
duke@435 | 59 | protected: |
duke@435 | 60 | FreeBlock* _link; |
duke@435 | 61 | |
duke@435 | 62 | public: |
duke@435 | 63 | // Initialization |
duke@435 | 64 | void initialize(size_t length) { HeapBlock::initialize(length); _link= NULL; } |
duke@435 | 65 | |
duke@435 | 66 | // Merging |
duke@435 | 67 | void set_length(size_t l) { _header._length = l; } |
duke@435 | 68 | |
duke@435 | 69 | // Accessors |
duke@435 | 70 | FreeBlock* link() const { return _link; } |
duke@435 | 71 | void set_link(FreeBlock* link) { _link = link; } |
duke@435 | 72 | }; |
duke@435 | 73 | |
duke@435 | 74 | class CodeHeap : public CHeapObj { |
duke@435 | 75 | friend class VMStructs; |
duke@435 | 76 | private: |
duke@435 | 77 | VirtualSpace _memory; // the memory holding the blocks |
duke@435 | 78 | VirtualSpace _segmap; // the memory holding the segment map |
duke@435 | 79 | |
duke@435 | 80 | size_t _number_of_committed_segments; |
duke@435 | 81 | size_t _number_of_reserved_segments; |
duke@435 | 82 | size_t _segment_size; |
duke@435 | 83 | int _log2_segment_size; |
duke@435 | 84 | |
duke@435 | 85 | size_t _next_segment; |
duke@435 | 86 | |
duke@435 | 87 | FreeBlock* _freelist; |
duke@435 | 88 | size_t _free_segments; // No. of segments in freelist |
duke@435 | 89 | |
duke@435 | 90 | // Helper functions |
duke@435 | 91 | size_t number_of_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; } |
duke@435 | 92 | size_t size(size_t number_of_segments) const { return number_of_segments << _log2_segment_size; } |
duke@435 | 93 | |
duke@435 | 94 | size_t segment_for(void* p) const { return ((char*)p - _memory.low()) >> _log2_segment_size; } |
duke@435 | 95 | HeapBlock* block_at(size_t i) const { return (HeapBlock*)(_memory.low() + (i << _log2_segment_size)); } |
duke@435 | 96 | |
duke@435 | 97 | void mark_segmap_as_free(size_t beg, size_t end); |
duke@435 | 98 | void mark_segmap_as_used(size_t beg, size_t end); |
duke@435 | 99 | |
duke@435 | 100 | // Freelist management helpers |
duke@435 | 101 | FreeBlock* following_block(FreeBlock *b); |
duke@435 | 102 | void insert_after(FreeBlock* a, FreeBlock* b); |
duke@435 | 103 | void merge_right (FreeBlock* a); |
duke@435 | 104 | |
duke@435 | 105 | // Toplevel freelist management |
duke@435 | 106 | void add_to_freelist(HeapBlock *b); |
duke@435 | 107 | FreeBlock* search_freelist(size_t length); |
duke@435 | 108 | |
duke@435 | 109 | // Iteration helpers |
duke@435 | 110 | void* next_free(HeapBlock* b) const; |
duke@435 | 111 | HeapBlock* first_block() const; |
duke@435 | 112 | HeapBlock* next_block(HeapBlock* b) const; |
duke@435 | 113 | HeapBlock* block_start(void* p) const; |
duke@435 | 114 | |
duke@435 | 115 | // to perform additional actions on creation of executable code |
duke@435 | 116 | void on_code_mapping(char* base, size_t size); |
duke@435 | 117 | |
duke@435 | 118 | public: |
duke@435 | 119 | CodeHeap(); |
duke@435 | 120 | |
duke@435 | 121 | // Heap extents |
duke@435 | 122 | bool reserve(size_t reserved_size, size_t committed_size, size_t segment_size); |
duke@435 | 123 | void release(); // releases all allocated memory |
duke@435 | 124 | bool expand_by(size_t size); // expands commited memory by size |
duke@435 | 125 | void shrink_by(size_t size); // shrinks commited memory by size |
duke@435 | 126 | void clear(); // clears all heap contents |
duke@435 | 127 | |
duke@435 | 128 | // Memory allocation |
duke@435 | 129 | void* allocate (size_t size); // allocates a block of size or returns NULL |
duke@435 | 130 | void deallocate(void* p); // deallocates a block |
duke@435 | 131 | |
duke@435 | 132 | // Attributes |
duke@435 | 133 | void* begin() const { return _memory.low (); } |
duke@435 | 134 | void* end() const { return _memory.high(); } |
duke@435 | 135 | bool contains(void* p) const { return begin() <= p && p < end(); } |
duke@435 | 136 | void* find_start(void* p) const; // returns the block containing p or NULL |
duke@435 | 137 | size_t alignment_unit() const; // alignment of any block |
duke@435 | 138 | size_t alignment_offset() const; // offset of first byte of any block, within the enclosing alignment unit |
duke@435 | 139 | static size_t header_size(); // returns the header size for each heap block |
duke@435 | 140 | |
duke@435 | 141 | // Returns reserved area high and low addresses |
duke@435 | 142 | char *low_boundary() const { return _memory.low_boundary (); } |
duke@435 | 143 | char *high_boundary() const { return _memory.high_boundary(); } |
duke@435 | 144 | |
duke@435 | 145 | // Iteration |
duke@435 | 146 | |
duke@435 | 147 | // returns the first block or NULL |
duke@435 | 148 | void* first() const { return next_free(first_block()); } |
duke@435 | 149 | // returns the next block given a block p or NULL |
duke@435 | 150 | void* next(void* p) const { return next_free(next_block(block_start(p))); } |
duke@435 | 151 | |
duke@435 | 152 | // Statistics |
duke@435 | 153 | size_t capacity() const; |
duke@435 | 154 | size_t max_capacity() const; |
duke@435 | 155 | size_t allocated_capacity() const; |
duke@435 | 156 | size_t unallocated_capacity() const { return max_capacity() - allocated_capacity(); } |
duke@435 | 157 | |
duke@435 | 158 | // Debugging |
duke@435 | 159 | void verify(); |
duke@435 | 160 | void print() PRODUCT_RETURN; |
duke@435 | 161 | }; |