Source code reorganization:
[disorder] / clients / playrtp-mem.c
1 /*
2 * This file is part of DisOrder.
3 * Copyright (C) 2007 Richard Kettlewell
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
18 * USA
19 */
20 /** @file clients/playrtp-mem.c
21 * @brief RTP player memory management
22 */
23
24 #include "common.h"
25
26 #include <pthread.h>
27
28 #include "mem.h"
29 #include "vector.h"
30 #include "heap.h"
31 #include "playrtp.h"
32
33 /** @brief Linked list of free packets
34 *
35 * This is a linked list of formerly used packets. For preference we re-use
36 * packets that have already been used rather than unused ones, to limit the
37 * size of the program's working set. If there are no free packets in the list
38 * we try @ref next_free_packet instead.
39 *
40 * Must hold @ref lock when accessing this.
41 */
42 static union free_packet *free_packets;
43
44 /** @brief Array of new free packets
45 *
46 * There are @ref count_free_packets ready to use at this address. If there
47 * are none left we allocate more memory.
48 *
49 * Must hold @ref lock when accessing this.
50 */
51 static union free_packet *next_free_packet;
52
53 /** @brief Count of new free packets at @ref next_free_packet
54 *
55 * Must hold @ref lock when accessing this.
56 */
57 static size_t count_free_packets;
58
59 /** @brief Lock protecting packet allocator */
60 static pthread_mutex_t mem_lock = PTHREAD_MUTEX_INITIALIZER;
61
62 /** @brief Return a new packet */
63 struct packet *playrtp_new_packet(void) {
64 struct packet *p;
65
66 pthread_mutex_lock(&mem_lock);
67 if(free_packets) {
68 p = &free_packets->p;
69 free_packets = free_packets->next;
70 } else {
71 if(!count_free_packets) {
72 next_free_packet = xcalloc(1024, sizeof (union free_packet));
73 count_free_packets = 1024;
74 }
75 p = &(next_free_packet++)->p;
76 --count_free_packets;
77 }
78 pthread_mutex_unlock(&mem_lock);
79 return p;
80 }
81
82 /** @brief Free a packet */
83 void playrtp_free_packet(struct packet *p) {
84 union free_packet *u = (union free_packet *)p;
85 pthread_mutex_lock(&mem_lock);
86 u->next = free_packets;
87 free_packets = u;
88 pthread_mutex_unlock(&mem_lock);
89 }
90
91
92 /*
93 Local Variables:
94 c-basic-offset:2
95 comment-column:40
96 fill-column:79
97 indent-tabs-mode:nil
98 End:
99 */