File: events.c

package info (click to toggle)
netdiag 1.2-1
  • links: PTS
  • area: main
  • in suites: buster, sid
  • size: 3,268 kB
  • sloc: ansic: 23,895; sh: 5,544; makefile: 328; awk: 130
file content (306 lines) | stat: -rw-r--r-- 5,800 bytes parent folder | download | duplicates (5)
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
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
/*
 *	Copyright (c) 1999-2003 Rinet Corp., Novosibirsk, Russia
 *
 * Redistribution and use in source forms, with and without modification,
 * are permitted provided that this entire comment appears intact.
 *
 * THIS SOURCE CODE IS PROVIDED ``AS IS'' WITHOUT ANY WARRANTIES OF ANY KIND.
 */

#ifdef	HAVE_CONFIG_H
#include <config.h>
#endif

#include <sys/types.h>
#include <sys/time.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>

#include "events.h"

#define	dprintf(x)	/* nope */

static EVENT *first_event = 0;	/* first system event in table */

/*
 * Subtract 2 timeval structs: out = out - in. Out result always greater 0.
 */
void
tv_sub(out, in)
	struct timeval *out;
	const struct timeval *in;
{
	if (out->tv_sec > in->tv_sec) {
		out->tv_sec -= in->tv_sec;
		if (out->tv_usec >= in->tv_usec) {
			out->tv_usec -= in->tv_usec;
		} else {
			out->tv_sec--;
			out->tv_usec += 1000000L - in->tv_usec;
		}
	} else if (out->tv_sec == in->tv_sec) {
		out->tv_sec = 0L;
		out->tv_usec -= in->tv_usec;
		if (out->tv_usec < 1)
			out->tv_usec = 100L;	/* not zero anyway */
	} else {
		out->tv_sec = 0L;
		out->tv_usec = 100L;	/* not zero anyway */
	}
}

void
tv_add(out, in)
	struct timeval *out;
	const struct timeval *in;
{
	out->tv_sec += in->tv_sec;
	out->tv_usec += in->tv_usec;
	if (out->tv_usec >= 1000000L) {
		out->tv_sec++;
		out->tv_usec -= 1000000L;
	}
}

/*
 * Round timeval to seconds.
 */
u_long
tv_round(in)
	const struct timeval *in;
{
	u_long sec = in->tv_sec;
	if (in->tv_usec >= 500000L)
		sec++;
	return sec;
}

/*
 * Return time difference in milliseconds.
 */
u_long
tv_diff(tvp1, tvp2)
	const struct timeval *tvp1, *tvp2;
{
	struct timeval diff;

	if (!timerisset(tvp1) || !timerisset(tvp2))
		return 0;

	if (timercmp(tvp1, tvp2, >)) {
		diff = *tvp1;
		tv_sub(&diff, tvp2);
	} else {
		diff = *tvp2;
		tv_sub(&diff, tvp1);
	}
	return (diff.tv_sec * 1000 + diff.tv_usec / 1000);
}

/*
 * Shift the time to be sharp at (12am + N * period), local time.
 */
void
tv_sharp(tvp, period)
	struct timeval *tvp;
	int period;
{
	time_t defect;
	struct tm *tm;

	if (!tvp) return;

	tm = localtime((time_t *)&tvp->tv_sec);
	defect = tm->tm_sec + 60 * tm->tm_min + 3600 * tm->tm_hour;
	defect %= period;
	period -= defect;
	if (period < 1) period = 1;
	tvp->tv_sec += period;
	tvp->tv_usec = (long)random() % 1000000L;
}

/*
 * Execute pending event and schedule the next nearest.
 */
int
select_event(tvp)
	struct timeval *tvp;
{
	EVENT *ep, *next_event;
	struct timeval now, gap, earliest;

	gettimeofday(&now, 0);
	gap.tv_sec = 0;
	gap.tv_usec = 1000L; /* 0.001sec grip */
	tv_add(&gap, &now);
again:
	next_event = 0;
	timerclear(&earliest);

	for (ep = first_event; ep; ep = ep->next) {
		/* skip over the empty slots */
		if (!ep->func) continue;

		if (timercmp(&gap, &ep->tv, >)) {
			void (*func)() = ep->func;
			ep->func = 0;		/* free event slot before */

			dprintf(("-call_event(%p/%p)", func, ep->arg));

			(*func)(ep->arg);	/* call event function */
			goto again;

		} else if (!timerisset(&earliest) ||
			   timercmp(&ep->tv, &earliest, <)) {
			earliest = ep->tv;
			next_event = ep;
		}
	}
	if (!next_event) {	/* no more awaiting events */

		dprintf(("select_event: no timeout"));

		return 1;	/* timeout undefined */
	}
	if (tvp) {
		tv_sub(&earliest, &now);
		*tvp = earliest;

		dprintf(("=wait_event(%p/%p): timeout=%u.%03d",
			 next_event->func, next_event->arg,
			 (unsigned)tvp->tv_sec, (int)(tvp->tv_usec / 1000)));
	}
	return 0;	/* timeout defined */
}

/*
 * Add the new system event to be executed at the given time.
 */
int
add_event(tvp, func, arg)
	struct timeval *tvp;
	void (*func)(void *);
	void *arg;
{
	EVENT *ep, *prev = 0, *next = 0;
	struct timeval now, gap;

	if (!tvp) {
		gettimeofday(&now, 0);
		gap.tv_sec = 0;
		gap.tv_usec = 250000L; /* 0.25sec mean a bit later */
		tv_add(&gap, &now);
		tvp = &gap;
	}

	/*
	 * The same event in queue may cause a looping! Prevent it.
	 */
	for (ep = first_event; ep; ep = ep->next) {
		if (ep->func == func && ep->arg == arg) {
			ep->tv = *tvp;
			dprintf(("=add_event(%p/%p): modify time", func, arg));
			return 0;
		}
	}

	/*
	 * Search for first empty or last event slot.
	 */
	for (ep = first_event; ep; ep = ep->next) {
		if (!ep->func) {
			next = ep->next;
			break;
		}
		prev = ep;
	}
	if (!ep && (ep = (EVENT *)malloc(sizeof(EVENT))) == 0)
		return -1;
	memset(ep, 0, sizeof(EVENT));
	ep->tv = *tvp;
	ep->func = func;
	ep->arg = arg;
	if (next) ep->next = next;
	else if (prev) prev->next = ep;
	if (!first_event) first_event = ep;

#ifdef	notdef
	{
		char at_time[50];
		strftime(at_time, sizeof(at_time), "%T",
			 localtime((time_t *)&ep->tv.tv_sec));
		dprintf(("+add_event(%p/%p): schedule=%s.%03d",
			 func, arg, at_time, (int)(tvp->tv_usec / 1000)));
	}
#endif
	return 0;
}

/*
 * Remove system event from queue if any.
 */
int
remove_event(func, arg)
	void (*func)(void *);
	void *arg;
{
	int found = 0;
	EVENT *ep;

	for (ep = first_event; ep; ep = ep->next) {
		if ((!func || ep->func == func) && ep->arg == arg) {
			ep->func = 0;
			found++;
		}
	}
	return found;
}

/*
 * Modify existing system event in queue for the new function argument.
 */
int
change_event(func, arg, new_arg)
	void (*func)(void *);
	void *arg, *new_arg;
{
	int found = 0;
	EVENT *ep;

	for (ep = first_event; ep; ep = ep->next) {
		if ((!func || ep->func == func) && ep->arg == arg) {
			ep->arg = new_arg;
			found++;
		}
	}
	return found;
}

EVENT *
find_event(func, arg)
	void (*func)(void *);
	void *arg;
{
	EVENT *ep;

	for (ep = first_event; ep; ep = ep->next) {
		if (ep->func == func && ep->arg == arg)
			return ep;
	}
	return 0;
}

void
free_events()
{
	EVENT *ep, *next;

	ep = first_event;
	while (ep) {
		next = ep->next;
		free(ep);
		ep = next;
	}
	first_event = 0;
}