timer.c revision 41799 
1/*
2 *		PPP Timer Processing Module
3 *
4 *	    Written by Toshiharu OHNO (tony-o@iij.ad.jp)
5 *
6 *   Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
7 *
8 * Redistribution and use in source and binary forms are permitted
9 * provided that the above copyright notice and this paragraph are
10 * duplicated in all such forms and that any documentation,
11 * advertising materials, and other materials related to such
12 * distribution and use acknowledge that the software was developed
13 * by the Internet Initiative Japan, Inc.  The name of the
14 * IIJ may not be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19 *
20 * $Id: timer.c,v 1.31 1998/06/27 14:18:11 brian Exp $
21 *
22 *  TODO:
23 */
24
25#include <errno.h>
26#include <signal.h>
27#include <stdio.h>
28#include <sys/time.h>
29#include <termios.h>
30
31#include "log.h"
32#include "sig.h"
33#include "timer.h"
34#include "descriptor.h"
35#include "prompt.h"
36
37static struct pppTimer *TimerList = NULL;
38
39static void StopTimerNoBlock(struct pppTimer *);
40
41static const char *
42tState2Nam(u_int state)
43{
44  static const char *StateNames[] = { "stopped", "running", "expired" };
45
46  if (state >= sizeof StateNames / sizeof StateNames[0])
47    return "unknown";
48  return StateNames[state];
49}
50
51void
52timer_Stop(struct pppTimer * tp)
53{
54  int omask;
55
56  omask = sigblock(sigmask(SIGALRM));
57  StopTimerNoBlock(tp);
58  sigsetmask(omask);
59}
60
61void
62timer_Start(struct pppTimer * tp)
63{
64  struct pppTimer *t, *pt;
65  u_long ticks = 0;
66  int omask;
67
68  omask = sigblock(sigmask(SIGALRM));
69
70  if (tp->state != TIMER_STOPPED)
71    StopTimerNoBlock(tp);
72
73  if (tp->load == 0) {
74    log_Printf(LogTIMER, "%s timer[%p] has 0 load!\n", tp->name, tp);
75    sigsetmask(omask);
76    return;
77  }
78  pt = NULL;
79  for (t = TimerList; t; t = t->next) {
80    if (ticks + t->rest >= tp->load)
81      break;
82    ticks += t->rest;
83    pt = t;
84  }
85
86  tp->state = TIMER_RUNNING;
87  tp->rest = tp->load - ticks;
88
89  if (t)
90    log_Printf(LogTIMER, "timer_Start: Inserting %s timer[%p] before %s "
91              "timer[%p], delta = %ld\n", tp->name, tp, t->name, t, tp->rest);
92  else
93    log_Printf(LogTIMER, "timer_Start: Inserting %s timer[%p]\n", tp->name, tp);
94
95  /* Insert given *tp just before *t */
96  tp->next = t;
97  if (pt) {
98    pt->next = tp;
99  } else {
100    TimerList = tp;
101    timer_InitService(0);	/* Start the Timer Service */
102  }
103  if (t)
104    t->rest -= tp->rest;
105
106  sigsetmask(omask);
107}
108
109static void
110StopTimerNoBlock(struct pppTimer * tp)
111{
112  struct pppTimer *t, *pt;
113
114  /*
115   * A RUNNING timer must be removed from TimerList (->next list).
116   * A STOPPED timer isn't in any list, but may have a bogus [e]next field.
117   * An EXPIRED timer is in the ->enext list.
118   */
119  if (tp->state != TIMER_RUNNING) {
120    tp->next = NULL;
121    tp->state = TIMER_STOPPED;
122    return;
123  }
124  pt = NULL;
125  for (t = TimerList; t != tp && t != NULL; t = t->next)
126    pt = t;
127  if (t) {
128    if (pt) {
129      pt->next = t->next;
130    } else {
131      TimerList = t->next;
132      if (TimerList == NULL)	/* Last one ? */
133	timer_TermService();	/* Terminate Timer Service */
134    }
135    if (t->next)
136      t->next->rest += tp->rest;
137  } else
138    log_Printf(LogERROR, "Oops, %s timer not found!!\n", tp->name);
139
140  tp->next = NULL;
141  tp->state = TIMER_STOPPED;
142}
143
144static void
145TimerService(void)
146{
147  struct pppTimer *tp, *exp, *next;
148
149  if (log_IsKept(LogTIMER)) {
150    static time_t t;		/* Only show timers globally every second */
151    time_t n = time(NULL);
152
153    if (n > t)
154      timer_Show(LogTIMER, NULL);
155    t = n;
156  }
157
158  tp = TimerList;
159  if (tp) {
160    tp->rest = 0;
161
162    /* Multiple timers might expire at once. Create a list of expired timers */
163    exp = NULL;
164    do {
165      tp->state = TIMER_EXPIRED;
166      next = tp->next;
167      tp->enext = exp;
168      exp = tp;
169      tp = next;
170    } while (tp && tp->rest == 0);
171
172    TimerList = tp;
173    if (TimerList != NULL)	/* Any timers remaining ? */
174      timer_InitService(1);	/* Restart the Timer Service */
175    else
176      timer_TermService();	/* Stop the Timer Service */
177
178    /* Process all expired timers */
179    while (exp) {
180      next = exp->enext;
181      exp->enext = NULL;
182      if (exp->func)
183        (*exp->func)(exp->arg);
184      exp = next;
185    }
186  }
187}
188
189void
190timer_Show(int LogLevel, struct prompt *prompt)
191{
192  struct pppTimer *pt;
193  int rest = 0;
194
195#define SECS(val)	((val) / SECTICKS)
196#define HSECS(val)	(((val) % SECTICKS) * 100 / SECTICKS)
197#define DISP								\
198  "%s timer[%p]: freq = %ld.%02lds, next = %d.%02ds, state = %s\n",	\
199  pt->name, pt, SECS(pt->load), HSECS(pt->load), SECS(rest),		\
200  HSECS(rest), tState2Nam(pt->state)
201
202  if (!prompt)
203    log_Printf(LogLevel, "---- Begin of Timer Service List---\n");
204
205  for (pt = TimerList; pt; pt = pt->next) {
206    rest += pt->rest;
207    if (prompt)
208      prompt_Printf(prompt, DISP);
209    else
210      log_Printf(LogLevel, DISP);
211  }
212
213  if (!prompt)
214    log_Printf(LogLevel, "---- End of Timer Service List ---\n");
215}
216
217void
218timer_InitService(int restart)
219{
220  struct itimerval itimer;
221
222  if (TimerList) {
223    if (!restart)
224      sig_signal(SIGALRM, (void (*)(int))TimerService);
225    itimer.it_interval.tv_sec = 0;
226    itimer.it_interval.tv_usec = 0;
227    itimer.it_value.tv_sec = TimerList->rest / SECTICKS;
228    itimer.it_value.tv_usec = (TimerList->rest % SECTICKS) * TICKUNIT;
229    if (setitimer(ITIMER_REAL, &itimer, NULL) == -1)
230      log_Printf(LogERROR, "Unable to set itimer (%s)\n", sys_errlist[errno]);
231  }
232}
233
234void
235timer_TermService(void)
236{
237  struct itimerval itimer;
238
239  itimer.it_interval.tv_usec = itimer.it_interval.tv_sec = 0;
240  itimer.it_value.tv_usec = itimer.it_value.tv_sec = 0;
241  if (setitimer(ITIMER_REAL, &itimer, NULL) == -1)
242    log_Printf(LogERROR, "Unable to set itimer (%s)\n", sys_errlist[errno]);
243  sig_signal(SIGALRM, SIG_IGN);
244}
245