1 /*
2 * Copyright (c) 2004, 2011, Oracle and/or its affiliates. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * - Neither the name of Oracle nor the names of its
16 * contributors may be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
20 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * This source code is provided to illustrate the usage of a given feature
34 * or technique and has been deliberately simplified. Additional steps
35 * required for a production-quality application, such as security checks,
36 * input validation and proper error handling, might not be present in
37 * this sample code.
38 */
39
40
41 /* Allocations from large blocks, no individual free's */
42
43 #include "hprof.h"
44
45 /*
46 * This file contains some allocation code that allows you
47 * to have space allocated via larger blocks of space.
48 * The only free allowed is of all the blocks and all the elements.
49 * Elements can be of different alignments and fixed or variable sized.
50 * The space allocated never moves.
51 *
52 */
53
54 /* Get the real size allocated based on alignment and bytes needed */
55 static int
56 real_size(int alignment, int nbytes)
57 {
58 if ( alignment > 1 ) {
59 int wasted;
60
61 wasted = alignment - ( nbytes % alignment );
62 if ( wasted != alignment ) {
63 nbytes += wasted;
64 }
65 }
66 return nbytes;
67 }
68
69 /* Add a new current_block to the Blocks* chain, adjust size if nbytes big. */
70 static void
71 add_block(Blocks *blocks, int nbytes)
72 {
73 int header_size;
74 int block_size;
75 BlockHeader *block_header;
76
77 HPROF_ASSERT(blocks!=NULL);
78 HPROF_ASSERT(nbytes>0);
79
80 header_size = real_size(blocks->alignment, sizeof(BlockHeader));
81 block_size = blocks->elem_size*blocks->population;
82 if ( nbytes > block_size ) {
83 block_size = real_size(blocks->alignment, nbytes);
84 }
85 block_header = (BlockHeader*)HPROF_MALLOC(block_size+header_size);
86 block_header->next = NULL;
87 block_header->bytes_left = block_size;
88 block_header->next_pos = header_size;
89
90 /* Link in new block */
91 if ( blocks->current_block != NULL ) {
92 blocks->current_block->next = block_header;
93 }
94 blocks->current_block = block_header;
95 if ( blocks->first_block == NULL ) {
96 blocks->first_block = block_header;
97 }
98 }
99
100 /* Initialize a new Blocks */
101 Blocks *
102 blocks_init(int alignment, int elem_size, int population)
103 {
104 Blocks *blocks;
105
106 HPROF_ASSERT(alignment>0);
107 HPROF_ASSERT(elem_size>0);
108 HPROF_ASSERT(population>0);
109
110 blocks = (Blocks*)HPROF_MALLOC(sizeof(Blocks));
111 blocks->alignment = alignment;
112 blocks->elem_size = elem_size;
113 blocks->population = population;
114 blocks->first_block = NULL;
115 blocks->current_block = NULL;
116 return blocks;
117 }
118
119 /* Allocate bytes from a Blocks area. */
120 void *
121 blocks_alloc(Blocks *blocks, int nbytes)
122 {
123 BlockHeader *block;
124 int pos;
125 void *ptr;
126
127 HPROF_ASSERT(blocks!=NULL);
128 HPROF_ASSERT(nbytes>=0);
129 if ( nbytes == 0 ) {
130 return NULL;
131 }
132
133 block = blocks->current_block;
134 nbytes = real_size(blocks->alignment, nbytes);
135 if ( block == NULL || block->bytes_left < nbytes ) {
136 add_block(blocks, nbytes);
137 block = blocks->current_block;
138 }
139 pos = block->next_pos;
140 ptr = (void*)(((char*)block)+pos);
141 block->next_pos += nbytes;
142 block->bytes_left -= nbytes;
143 return ptr;
144 }
145
146 /* Terminate the Blocks */
147 void
148 blocks_term(Blocks *blocks)
149 {
150 BlockHeader *block;
151
152 HPROF_ASSERT(blocks!=NULL);
153
154 block = blocks->first_block;
155 while ( block != NULL ) {
156 BlockHeader *next_block;
157
158 next_block = block->next;
159 HPROF_FREE(block);
160 block = next_block;
161 }
162 HPROF_FREE(blocks);
163 }