freebsd-dev/lib/libatm/timer.c
Poul-Henning Kamp 1820df7a2d Add new files for HARP3
Host ATM Research Platform (HARP), Network Computing Services, Inc.
This software was developed with the support of the Defense Advanced
Research Projects Agency (DARPA).
1998-09-15 08:23:17 +00:00

262 lines
4.8 KiB
C

/*
*
* ===================================
* HARP | Host ATM Research Platform
* ===================================
*
*
* This Host ATM Research Platform ("HARP") file (the "Software") is
* made available by Network Computing Services, Inc. ("NetworkCS")
* "AS IS". NetworkCS does not provide maintenance, improvements or
* support of any kind.
*
* NETWORKCS MAKES NO WARRANTIES OR REPRESENTATIONS, EXPRESS OR IMPLIED,
* INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE, AS TO ANY ELEMENT OF THE
* SOFTWARE OR ANY SUPPORT PROVIDED IN CONNECTION WITH THIS SOFTWARE.
* In no event shall NetworkCS be responsible for any damages, including
* but not limited to consequential damages, arising from or relating to
* any use of the Software or related support.
*
* Copyright 1994-1998 Network Computing Services, Inc.
*
* Copies of this Software may be made, however, the above copyright
* notice must be reproduced on all copies.
*
* @(#) $Id: timer.c,v 1.4 1998/07/16 15:50:26 johnc Exp $
*
*/
/*
* User Space Library Functions
* ----------------------------
*
* Timer functions
*
*/
#ifndef lint
static char *RCSid = "@(#) $Id: timer.c,v 1.4 1998/07/16 15:50:26 johnc Exp $";
#endif
#include <sys/types.h>
#include <sys/param.h>
#include <errno.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netatm/port.h>
#include <netatm/queue.h>
#include <netatm/atm.h>
#include <netatm/atm_if.h>
#include <netatm/atm_sap.h>
#include <netatm/atm_sys.h>
#include <netatm/atm_ioctl.h>
#include "libatm.h"
Harp_timer *harp_timer_head;
int harp_timer_exec;
/*
* Process a HARP timer tick
*
* This function is called via the SIGALRM signal. It increments
* harp_timer_exec. The user should check this flag frequently and
* call timer_proc when it is set.
*
* Arguments:
* None
*
* Returns:
* None
*
*/
static void
timer_tick()
{
/*
* Bump the timer flag
*/
harp_timer_exec++;
}
/*
* Process HARP timers
*
* This function is called after a SIGALRM signal is posted. It runs
* down the list of timer entries, calling the specified functions
* for any timers that have expired.
*
* Arguments:
* None
*
* Returns:
* None
*
*/
void
timer_proc()
{
Harp_timer *htp;
void (*f)();
/*
* Reset marks in all timers on the queue
*/
for (htp = harp_timer_head; htp; htp = htp->ht_next) {
htp->ht_mark = -1;
}
/*
* Run through timer chain decrementing each timer.
* If an expired timer is found, take the timer block
* off the chain and call the specified function. A
* timer's action can result in other timers being
* cancelled (taken off the queue), so every time we
* call a user function, we start over from the top of
* the list.
*/
timer_cont:
for (htp = harp_timer_head; htp; htp = htp->ht_next) {
/*
* Make sure we only process each entry once and
* don't process entries that are put on the queue
* by user functions we call for this tick
*/
if (htp->ht_mark == -1) {
/*
* Decrement the timer and mark that we've
* processed the entry
*/
htp->ht_ticks -= harp_timer_exec;
htp->ht_mark = 1;
/*
* Check whether the timer is expired
*/
if (htp->ht_ticks <= 0) {
/*
* Unlink the timer block and call
* the user function
*/
f = htp->ht_func;
UNLINK(htp, Harp_timer, harp_timer_head,
ht_next);
f(htp);
/*
* Start over
*/
goto timer_cont;
}
}
}
/*
* Reset the timer exec flag
*/
harp_timer_exec = 0;
}
/*
* Start the timer
*
* Set up the SIGALRM signal handler and set up the real-time
* timer to tick once per second.
*
* Arguments:
* None
*
* Returns:
* 0 success
* errno reason for failure
*
*/
int
init_timer()
{
int rc = 0;
struct itimerval timeval;
/*
* Clear the timer flag
*/
harp_timer_exec = 0;
/*
* Set up signal handler
*/
if ((int)signal(SIGALRM, timer_tick) == -1) {
return(errno);
}
/*
* Start timer
*/
timeval.it_value.tv_sec = 1;
timeval.it_value.tv_usec = 0;
timeval.it_interval.tv_sec = 1;
timeval.it_interval.tv_usec = 0;
if (setitimer(ITIMER_REAL, &timeval,
(struct itimerval *)0) == -1) {
rc = errno;
(void)signal(SIGALRM, SIG_DFL);
}
return(rc);
}
/*
* Block timers from firing
*
* Block the SIGALRM signal.
*
* Arguments:
* None
*
* Returns:
* mask the previous blocked signal mask
*
*/
int
block_timer()
{
/*
* Block the SIGALRM signal
*/
return(sigblock(sigmask(SIGALRM)));
}
/*
* Re-enable timers
*
* Restore the signal mask (presumably one that was returned by
* block_timer).
*
* Arguments:
* mask the signal mask to be restored
*
* Returns:
* mask the previous blocked signal mask
*
*/
void
enable_timer(mask)
int mask;
{
/*
* Set the signal mask
*/
sigsetmask(mask);
return;
}