freebsd-dev/usr.sbin/ppp/timer.c
Brian Somers 76ce2d4bcb When adjusting timer::rest, round to the closest TICKUNIT usecs
value.

This has minimal impact here, but if ppp ever needs to frequently
remove timers before they've timed out, it can badly skew the next
item in the timer list without this change.

The correct fix would be to store usecs in `rest' rather than
TICKUNITs, but the math is easier if we just round...
2000-03-14 01:46:34 +00:00

283 lines
7.0 KiB
C

/*
* PPP Timer Processing Module
*
* Written by Toshiharu OHNO (tony-o@iij.ad.jp)
*
* Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the Internet Initiative Japan, Inc. The name of the
* IIJ may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $FreeBSD$
*
* TODO:
*/
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <sys/time.h>
#include <termios.h>
#include "log.h"
#include "sig.h"
#include "timer.h"
#include "descriptor.h"
#include "prompt.h"
#define RESTVAL(t) \
((t).it_value.tv_sec * SECTICKS + (t).it_value.tv_usec / TICKUNIT + \
((((t).it_value.tv_usec % TICKUNIT) >= (TICKUNIT >> 1)) ? 1 : 0))
static struct pppTimer *TimerList = NULL, *ExpiredList = NULL;
static void StopTimerNoBlock(struct pppTimer *);
static const char *
tState2Nam(u_int state)
{
static const char * const StateNames[] = { "stopped", "running", "expired" };
if (state >= sizeof StateNames / sizeof StateNames[0])
return "unknown";
return StateNames[state];
}
void
timer_Stop(struct pppTimer *tp)
{
int omask;
omask = sigblock(sigmask(SIGALRM));
StopTimerNoBlock(tp);
sigsetmask(omask);
}
void
timer_Start(struct pppTimer *tp)
{
struct itimerval itimer;
struct pppTimer *t, *pt;
u_long ticks = 0;
int omask;
omask = sigblock(sigmask(SIGALRM));
if (tp->state != TIMER_STOPPED)
StopTimerNoBlock(tp);
if (tp->load == 0) {
log_Printf(LogTIMER, "%s timer[%p] has 0 load!\n", tp->name, tp);
sigsetmask(omask);
return;
}
/* Adjust our first delta so that it reflects what's really happening */
if (TimerList && getitimer(ITIMER_REAL, &itimer) == 0)
TimerList->rest = RESTVAL(itimer);
pt = NULL;
for (t = TimerList; t; t = t->next) {
if (ticks + t->rest >= tp->load)
break;
ticks += t->rest;
pt = t;
}
tp->state = TIMER_RUNNING;
tp->rest = tp->load - ticks;
if (t)
log_Printf(LogTIMER, "timer_Start: Inserting %s timer[%p] before %s "
"timer[%p], delta = %ld\n", tp->name, tp, t->name, t, tp->rest);
else
log_Printf(LogTIMER, "timer_Start: Inserting %s timer[%p]\n", tp->name, tp);
/* Insert given *tp just before *t */
tp->next = t;
if (pt) {
pt->next = tp;
} else {
TimerList = tp;
timer_InitService(t != NULL); /* [re]Start the Timer Service */
}
if (t)
t->rest -= tp->rest;
sigsetmask(omask);
}
static void
StopTimerNoBlock(struct pppTimer *tp)
{
struct pppTimer *t, *pt;
/*
* A RUNNING timer must be removed from TimerList (->next list).
* A STOPPED timer isn't in any list, but may have a bogus [e]next field.
* An EXPIRED timer is in the ->enext list.
*/
if (tp->state == TIMER_STOPPED)
return;
pt = NULL;
for (t = TimerList; t != tp && t != NULL; t = t->next)
pt = t;
if (t) {
if (pt)
pt->next = t->next;
else {
TimerList = t->next;
if (TimerList == NULL) /* Last one ? */
timer_TermService(); /* Terminate Timer Service */
}
if (t->next) {
if (!pt) { /* t (tp) was the first in the list */
struct itimerval itimer;
if (getitimer(ITIMER_REAL, &itimer) == 0)
t->rest = RESTVAL(itimer);
}
t->next->rest += t->rest;
if (!pt) /* t->next is now the first in the list */
timer_InitService(1);
}
} else {
/* Search for any pending expired timers */
pt = NULL;
for (t = ExpiredList; t != tp && t != NULL; t = t->enext)
pt = t;
if (t) {
if (pt)
pt->enext = t->enext;
else
ExpiredList = t->enext;
} else if (tp->state == TIMER_RUNNING)
log_Printf(LogERROR, "Oops, %s timer not found!!\n", tp->name);
}
tp->next = tp->enext = NULL;
tp->state = TIMER_STOPPED;
}
static void
TimerService(void)
{
struct pppTimer *tp, *exp, *next;
if (log_IsKept(LogTIMER)) {
static time_t t; /* Only show timers globally every second */
time_t n = time(NULL);
if (n > t)
timer_Show(LogTIMER, NULL);
t = n;
}
tp = TimerList;
if (tp) {
tp->rest = 0;
/* Multiple timers might expire at once. Create a list of expired timers */
exp = NULL;
do {
tp->state = TIMER_EXPIRED;
next = tp->next;
tp->enext = exp;
exp = tp;
tp = next;
} while (tp && tp->rest == 0);
TimerList = tp;
if (TimerList != NULL) /* Any timers remaining ? */
timer_InitService(1); /* Restart the Timer Service */
else
timer_TermService(); /* Stop the Timer Service */
/* Process all expired timers */
while (exp) {
ExpiredList = exp->enext;
exp->enext = NULL;
if (exp->func)
(*exp->func)(exp->arg);
exp = ExpiredList;
}
}
}
void
timer_Show(int LogLevel, struct prompt *prompt)
{
struct itimerval itimer;
struct pppTimer *pt;
u_long rest = 0;
/* Adjust our first delta so that it reflects what's really happening */
if (TimerList && getitimer(ITIMER_REAL, &itimer) == 0)
TimerList->rest = RESTVAL(itimer);
#define SECS(val) ((val) / SECTICKS)
#define HSECS(val) (((val) % SECTICKS) * 100 / SECTICKS)
#define DISP \
"%s timer[%p]: freq = %ld.%02lds, next = %lu.%02lus, state = %s\n", \
pt->name, pt, SECS(pt->load), HSECS(pt->load), SECS(rest), \
HSECS(rest), tState2Nam(pt->state)
if (!prompt)
log_Printf(LogLevel, "---- Begin of Timer Service List---\n");
for (pt = TimerList; pt; pt = pt->next) {
rest += pt->rest;
if (prompt)
prompt_Printf(prompt, DISP);
else
log_Printf(LogLevel, DISP);
}
if (!prompt)
log_Printf(LogLevel, "---- End of Timer Service List ---\n");
}
void
timer_InitService(int restart)
{
struct itimerval itimer;
if (TimerList) {
if (!restart)
sig_signal(SIGALRM, (void (*)(int))TimerService);
itimer.it_interval.tv_sec = 0;
itimer.it_interval.tv_usec = 0;
itimer.it_value.tv_sec = TimerList->rest / SECTICKS;
itimer.it_value.tv_usec = (TimerList->rest % SECTICKS) * TICKUNIT;
if (setitimer(ITIMER_REAL, &itimer, NULL) == -1)
log_Printf(LogERROR, "Unable to set itimer (%s)\n", strerror(errno));
}
}
void
timer_TermService(void)
{
struct itimerval itimer;
itimer.it_interval.tv_usec = itimer.it_interval.tv_sec = 0;
itimer.it_value.tv_usec = itimer.it_value.tv_sec = 0;
if (setitimer(ITIMER_REAL, &itimer, NULL) == -1)
log_Printf(LogERROR, "Unable to set itimer (%s)\n", strerror(errno));
sig_signal(SIGALRM, SIG_IGN);
}