summaryrefslogtreecommitdiffstats
path: root/usr.sbin/mrouted/callout.c
blob: f3daa22d74fca2cb1835be6c33bc27aecac5e9cf (plain)
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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
/*
 * The mrouted program is covered by the license in the accompanying file
 * named "LICENSE".  Use of the mrouted program represents acceptance of
 * the terms and conditions listed in that file.
 *
 * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
 * Leland Stanford Junior University.
 *
 *
 * $FreeBSD$
 */

#include "defs.h"

/* the code below implements a callout queue */
static int id = 0;
static struct timeout_q  *Q = 0; /* pointer to the beginning of timeout queue */

static int in_callout = 0;

struct timeout_q {
	struct timeout_q *next;		/* next event */
	int        	 id;  
	cfunc_t          func;    	/* function to call */
	char	   	 *data;		/* func's data */
	int            	 time;		/* time offset to next event*/
};

#ifdef IGMP_DEBUG
static void print_Q __P((void));
#else
#define	print_Q()	
#endif

void
callout_init()
{
    Q = (struct timeout_q *) 0;
}


/*
 * signal handler for SIGALARM that is called once every second
 */
void
age_callout_queue()
{
    struct timeout_q *ptr;
    
    if (in_callout)
	return;

    in_callout = 1;
    ptr = Q;
    
    while (ptr) {
	if (!ptr->time) {
	    /* timeout has happened */
	    Q = Q->next;

	    in_callout = 0;
	    if (ptr->func)
		ptr->func(ptr->data);
	    in_callout = 1;
	    
	    free(ptr);
	    ptr = Q;
	}
	else {
	    ptr->time --;
#ifdef IGMP_DEBUG
	    log(LOG_DEBUG,0,"[callout, age_callout_queue] -- time (%d)", ptr->time);
#endif /* IGMP_DEBUG */
	    in_callout = 0; return;
	}
    }
    in_callout = 0;
    return;
}


/* 
 * sets the timer
 */
int
timer_setTimer(delay, action, data)
    int 	delay;  	/* number of units for timeout */
    cfunc_t	action; 	/* function to be called on timeout */
    char  	*data;  	/* what to call the timeout function with */
{
    struct     timeout_q  *ptr, *node, *prev;
    
    if (in_callout)
	return -1;

    in_callout = 1;
    
    /* create a node */	
    node = (struct timeout_q *)malloc(sizeof(struct timeout_q));
    if (node == 0) {
	log(LOG_WARNING, 0, "Malloc Failed in timer_settimer\n");
	in_callout = 0;
	return -1;
    }
    node->func = action; 
    node->data = data;
    node->time = delay; 
    node->next = 0;	
    node->id   = ++id;
    
    prev = ptr = Q;
    
    /* insert node in the queue */
    
    /* if the queue is empty, insert the node and return */
    if (!Q)
	Q = node;
    else {
	/* chase the pointer looking for the right place */
	while (ptr) {
	    
	    if (delay < ptr->time) {
		/* right place */
		
		node->next = ptr;
		if (ptr == Q)
		    Q = node;
		else
		    prev->next = node;
		ptr->time -= node->time;
		print_Q();
		in_callout = 0;
		return node->id;
	    } else  {
		/* keep moving */
		
		delay -= ptr->time; node->time = delay;
		prev = ptr;
		ptr = ptr->next;
	    }
	}
	prev->next = node;
    }
    print_Q();
    in_callout = 0;
    return node->id;
}


/* clears the associated timer */
void
timer_clearTimer(timer_id)
    int  timer_id;
{
    struct timeout_q  *ptr, *prev;
    
    if (in_callout)
        return;
    if (!timer_id)
	return;

    in_callout = 1;
    
    prev = ptr = Q;
    
    /*
     * find the right node, delete it. the subsequent node's time
     * gets bumped up
     */
    
    print_Q();
    while (ptr) {
	if (ptr->id == timer_id) {
	    /* got the right node */
	    
	    /* unlink it from the queue */
	    if (ptr == Q)
		Q = Q->next;
	    else
		prev->next = ptr->next;
	    
	    /* increment next node if any */
	    if (ptr->next != 0)
		(ptr->next)->time += ptr->time;
	    
	    free(ptr->data);
	    free(ptr);
	    print_Q();
	    in_callout = 0;
	    return;
	}
	prev = ptr;
	ptr = ptr->next;
    }
    print_Q();
    in_callout = 0;
}

#ifdef IGMP_DEBUG
/*
 * debugging utility
 */
static void
print_Q()
{
    struct timeout_q  *ptr;
    
    for(ptr = Q; ptr; ptr = ptr->next)
	log(LOG_DEBUG,0,"(%d,%d) ", ptr->id, ptr->time);
}
#endif /* IGMP_DEBUG */
int
secs_remaining( timer_id)
    int  timer_id;
{
    struct timeout_q  *ptr;
    int left=0;

    for (ptr = Q; ptr && ptr->id != timer_id; ptr = ptr->next)
       left += ptr->time;

    if (!ptr) /* not found */
       return 0;

    return left + ptr->time;
}
OpenPOWER on IntegriCloud