1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/*
Copyright (C) (2004 - 2006) (Venkata Ramana Enaganti) <ramana@intraperson.com>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* autofs packet malloc cache management*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "msg.h"
#include "thread.h"
#include "mpacket.h"
/*cache size of used memory.*/
#define PACKET_CACHE_MAX 150 /*OPTIMIZE*/
static struct {
Packet *list;
int count;
pthread_mutex_t lock;
} pcache;
/*use junk if available otherwise malloc
returns more then one packet if available*/
static Packet *packet_get_free_list( void )
{
Packet *list;
if( pcache.count > 0 )
{
pthread_mutex_lock( &pcache.lock );
if( pcache.count <= 0 )
{
pthread_mutex_unlock( &pcache.lock );
goto dalloc;
}
list = pcache.list;
pcache.list = NULL;
pcache.count = 0;
pthread_mutex_unlock( &pcache.lock );
return list;
}
dalloc:
list = ( Packet * ) malloc( sizeof(Packet) );
if( list )
list->next = NULL;
return list;
}
/*PERFORMANCE:
Not thread safe. To be called from single thread only.*/
Packet *packet_allocate( void )
{
static Packet *list = NULL;
Packet *pkt;
while( ! list && ! ( list = packet_get_free_list() ) )
{
msglog( MSG_ALERT, "packet_allocate: " \
"could not get free packet list" );
sleep( 1 );
}
pkt = list;
list = list->next;
return pkt;
}
/*thread safe*/
void packet_free( Packet *pk )
{
Packet *tmp;
if( ! pk ) return;
if( pcache.count < PACKET_CACHE_MAX )
{
pthread_mutex_lock( &pcache.lock );
tmp = pcache.list;
pcache.list = pk;
pk->next = tmp;
pcache.count++;
pthread_mutex_unlock( &pcache.lock );
return;
}
else free( pk );
}
static void packet_clean( void )
{
Packet *pk, *tmp;
pk = pcache.list;
while( pk )
{
tmp = pk;
pk = pk->next;
free( tmp );
}
pthread_mutex_destroy( &pcache.lock );
}
void packet_init( void )
{
pcache.list = NULL;
pcache.count = 0;
thread_mutex_init(&pcache.lock);
if( atexit( packet_clean ) )
{
packet_clean();
msglog( MSG_FATAL, "packet_init: " \
"could not register cleanup method" );
}
}
|