]> code.delx.au - pulseaudio/blob - src/pulsecore/memchunk.c
rework memory block management to be thread-safe and mostly lock-free.
[pulseaudio] / src / pulsecore / memchunk.c
1 /* $Id$ */
2
3 /***
4 This file is part of PulseAudio.
5
6 PulseAudio is free software; you can redistribute it and/or modify
7 it under the terms of the GNU Lesser General Public License as
8 published by the Free Software Foundation; either version 2.1 of the
9 License, or (at your option) any later version.
10
11 PulseAudio is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with PulseAudio; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
19 USA.
20 ***/
21
22 #ifdef HAVE_CONFIG_H
23 #include <config.h>
24 #endif
25
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <assert.h>
29 #include <string.h>
30
31 #include <pulse/xmalloc.h>
32
33 #include "memchunk.h"
34
35 void pa_memchunk_make_writable(pa_memchunk *c, size_t min) {
36 pa_memblock *n;
37 size_t l;
38 void *tdata, *sdata;
39
40 assert(c);
41 assert(c->memblock);
42
43 if (pa_memblock_is_read_only(c->memblock) &&
44 pa_memblock_get_length(c->memblock) >= c->index+min)
45 return;
46
47 l = c->length;
48 if (l < min)
49 l = min;
50
51 n = pa_memblock_new(pa_memblock_get_pool(c->memblock), l);
52 tdata = pa_memblock_acquire(n);
53 sdata = pa_memblock_acquire(c->memblock);
54 memcpy(tdata, (uint8_t*) sdata + c->index, c->length);
55 pa_memblock_release(n);
56 pa_memblock_release(c->memblock);
57 pa_memblock_unref(c->memblock);
58 c->memblock = n;
59 c->index = 0;
60 }
61
62 void pa_memchunk_reset(pa_memchunk *c) {
63 assert(c);
64
65 c->memblock = NULL;
66 c->length = c->index = 0;
67 }