bart | 6584b69 | 2009-06-21 10:11:15 +0000 | [diff] [blame] | 1 | /* -*- mode: C; c-basic-offset: 3; -*- */ |
| 2 | /* |
| 3 | This file is part of drd, a thread error detector. |
| 4 | |
| 5 | Copyright (C) 2006-2009 Bart Van Assche <bart.vanassche@gmail.com>. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or |
| 8 | modify it under the terms of the GNU General Public License as |
| 9 | published by the Free Software Foundation; either version 2 of the |
| 10 | License, or (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, but |
| 13 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 20 | 02111-1307, USA. |
| 21 | |
| 22 | The GNU General Public License is contained in the file COPYING. |
| 23 | */ |
| 24 | |
| 25 | /* |
| 26 | * Block allocator for second-level bitmap nodes. Each node consists of |
| 27 | * an OSetGen node and a struct bitmap2. The code below allocates |
| 28 | * NODES_PER_CHUNK nodes at a time. |
| 29 | */ |
| 30 | |
| 31 | |
| 32 | #include "drd_basics.h" /* DRD_() */ |
| 33 | #include "drd_bitmap.h" /* struct bitmap2 */ |
| 34 | #include "pub_drd_bitmap.h" |
| 35 | #include "pub_tool_basics.h" /* Addr, SizeT */ |
| 36 | #include "pub_tool_libcassert.h" /* tl_assert() */ |
| 37 | #include "pub_tool_libcbase.h" /* VG_ROUNDUP() */ |
| 38 | #include "pub_tool_libcprint.h" /* VG_(message)() */ |
| 39 | #include "pub_tool_mallocfree.h" /* VG_(malloc), VG_(free) */ |
| 40 | |
| 41 | |
| 42 | #define NODES_PER_CHUNCK 512 |
| 43 | |
| 44 | |
| 45 | /* Local type definitions. */ |
| 46 | |
| 47 | struct block_allocator_chunk { |
| 48 | struct block_allocator_chunk* next; |
| 49 | struct block_allocator_chunk* prev; |
| 50 | int nallocated; |
| 51 | void* data; |
| 52 | void* data_end; |
| 53 | void* first_free; |
| 54 | }; |
| 55 | |
| 56 | |
| 57 | /* Local variables. */ |
| 58 | |
| 59 | static SizeT s_bm2_node_size; |
| 60 | static struct block_allocator_chunk* s_first; |
| 61 | |
| 62 | |
| 63 | /* Function definitions. */ |
| 64 | |
| 65 | /** |
| 66 | * Allocate a new chunk and insert it at the start of the doubly-linked list |
| 67 | * s_first. |
| 68 | */ |
| 69 | static struct block_allocator_chunk* allocate_new_chunk(void) |
| 70 | { |
| 71 | struct block_allocator_chunk* p; |
| 72 | int i; |
| 73 | |
| 74 | tl_assert(s_bm2_node_size > 0); |
| 75 | |
| 76 | p = VG_(malloc)("drd.bitmap.bac", |
| 77 | sizeof(*p) + NODES_PER_CHUNCK * s_bm2_node_size); |
| 78 | tl_assert(p); |
| 79 | p->next = s_first; |
| 80 | if (s_first) |
| 81 | p->next->prev = p; |
| 82 | s_first = p; |
| 83 | p->prev = 0; |
| 84 | p->nallocated = 0; |
| 85 | p->data = (char*)p + sizeof(*p); |
| 86 | tl_assert(p->data); |
| 87 | p->data_end = (char*)(p->data) + NODES_PER_CHUNCK * s_bm2_node_size; |
| 88 | p->first_free = p->data; |
| 89 | for (i = 0; i < NODES_PER_CHUNCK - 1; i++) |
| 90 | { |
| 91 | *(void**)((char*)(p->data) + i * s_bm2_node_size) |
| 92 | = (char*)(p->data) + (i + 1) * s_bm2_node_size; |
| 93 | } |
| 94 | tl_assert(i == NODES_PER_CHUNCK - 1); |
| 95 | *(void**)((char*)(p->data) + i * s_bm2_node_size) = NULL; |
| 96 | |
| 97 | return p; |
| 98 | } |
| 99 | |
| 100 | /** Free a chunk and remove it from the list of chunks. */ |
| 101 | static void free_chunk(struct block_allocator_chunk* const p) |
| 102 | { |
| 103 | tl_assert(p); |
| 104 | tl_assert(p->nallocated == 0); |
| 105 | |
| 106 | if (p == s_first) |
| 107 | s_first = p->next; |
| 108 | else if (p->prev) |
| 109 | p->prev->next = p->next; |
| 110 | if (p->next) |
| 111 | p->next->prev = p->prev; |
| 112 | VG_(free)(p); |
| 113 | } |
| 114 | |
| 115 | /** Allocate a node. */ |
| 116 | void* DRD_(bm2_alloc_node)(HChar* const ec, const SizeT szB) |
| 117 | { |
| 118 | /* |
| 119 | * If szB < sizeof(struct bitmap2) then this function has been called to |
| 120 | * allocate an AVL tree root node. Otherwise it has been called to allocate |
bart | 31b983d | 2010-02-21 14:52:59 +0000 | [diff] [blame^] | 121 | * an AVL tree branch or leaf node. |
bart | 6584b69 | 2009-06-21 10:11:15 +0000 | [diff] [blame] | 122 | */ |
| 123 | if (szB < sizeof(struct bitmap2)) |
| 124 | return VG_(malloc)(ec, szB); |
| 125 | |
| 126 | while (True) |
| 127 | { |
| 128 | struct block_allocator_chunk* p; |
| 129 | |
| 130 | if (s_bm2_node_size == 0) |
| 131 | s_bm2_node_size = szB; |
| 132 | else |
| 133 | tl_assert(s_bm2_node_size == szB); |
| 134 | |
| 135 | for (p = s_first; p; p = p->next) |
| 136 | { |
| 137 | if (p->first_free) |
| 138 | { |
| 139 | void* result; |
| 140 | |
| 141 | p->nallocated++; |
| 142 | result = p->first_free; |
| 143 | p->first_free = *(void**)(p->first_free); |
| 144 | return result; |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | allocate_new_chunk(); |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | /** Free a node. */ |
| 153 | void DRD_(bm2_free_node)(void* const bm2) |
| 154 | { |
| 155 | struct block_allocator_chunk* p; |
| 156 | |
| 157 | tl_assert(s_bm2_node_size > 0); |
| 158 | tl_assert(bm2); |
| 159 | |
| 160 | for (p = s_first; p; p = p->next) |
| 161 | { |
| 162 | if (p->data <= bm2 && bm2 < p->data_end) |
| 163 | { |
| 164 | /* Free the memory that was allocated for a non-root AVL tree node. */ |
| 165 | tl_assert(((char*)bm2 - (char*)(p->data)) % s_bm2_node_size == 0); |
| 166 | *(void**)bm2 = p->first_free; |
| 167 | p->first_free = bm2; |
| 168 | tl_assert(p->nallocated >= 1); |
| 169 | if (--(p->nallocated) == 0) |
| 170 | free_chunk(p); |
| 171 | return; |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | /* Free the memory that was allocated for an AVL tree root node. */ |
| 176 | VG_(free)(bm2); |
| 177 | } |