Introduce a simple timer API....

One can use add_timer or schedule_timer to add a timer. After
the timeout time has been reached the callback will be called.
One can call add_time/schedule_timer and del_timer from within
the callback.
changes/88/3188/1
Holger Freyther 14 years ago
parent 5677ae35ba
commit 5f75598c28
  1. 2
      Makefile.am
  2. 8
      configure.in
  3. 70
      include/openbsc/timer.h
  4. 2
      src/Makefile.am
  5. 34
      src/select.c
  6. 168
      src/timer.c
  7. 1
      tests/Makefile.am
  8. 5
      tests/timer/Makefile.am
  9. 62
      tests/timer/timer_test.c

@ -1,7 +1,7 @@
AUTOMAKE_OPTIONS = foreign dist-bzip2 1.6
INCLUDES = $(all_includes) -I$(top_srcdir)/include
SUBDIRS = include src
SUBDIRS = include src tests
#dist-hook:
# rm -rf `find $(distdir) -name .svn`

@ -16,4 +16,10 @@ AC_CHECK_HEADERS(mISDNif.h)
dnl Checks for typedefs, structures and compiler characteristics
AC_OUTPUT(include/openbsc/Makefile include/Makefile src/Makefile Makefile)
AC_OUTPUT(
include/openbsc/Makefile
include/Makefile
src/Makefile
tests/Makefile
tests/timer/Makefile
Makefile)

@ -0,0 +1,70 @@
/*
* (C) 2008 by Holger Hans Peter Freyther <zecke@selfish.org>
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#ifndef TIMER_H
#define TIMER_H
#include <sys/time.h>
#include "linuxlist.h"
/**
* Timer management:
* - Create a struct timer_list
* - Fill out timeout and use add_timer or
* use schedule_timer to schedule a timer in
* x seconds and microseconds from now...
* - Use del_timer to remove the timer
*
* Internally:
* - We hook into select.c to give a timeval of the
* nearest timer. On already passed timers we give
* it a 0 to immediately fire after the select
* - update_timers will call the callbacks and remove
* the timers.
*
*/
struct timer_list {
struct llist_head entry;
struct timeval timeout;
int active : 1;
int handled : 1;
void (*cb)(void*);
void *data;
};
/**
* timer management
*/
void add_timer(struct timer_list *timer);
void schedule_timer(struct timer_list *timer, int seconds, int microseconds);
void del_timer(struct timer_list *timer);
int timer_pending(struct timer_list *timer);
/**
* internal timer list management
*/
struct timeval *nearest_timer();
void prepare_timers();
void update_timers();
#endif

@ -4,7 +4,7 @@ AM_CFLAGS=-Wall
sbin_PROGRAMS = bsc_hack db_test
bsc_hack_SOURCES = bsc_hack.c misdn.c abis_rsl.c abis_nm.c gsm_04_08.c gsm_data.c \
gsm_subscriber.c msgb.c select.c chan_alloc.c
gsm_subscriber.c msgb.c select.c chan_alloc.c timer.c
db_test_SOURCES = db_test.c db.c
db_test_LDADD = -ldl -ldbi

@ -21,6 +21,7 @@
#include <fcntl.h>
#include <openbsc/select.h>
#include <openbsc/linuxlist.h>
#include <openbsc/timer.h>
static int maxfd = 0;
static LLIST_HEAD(bsc_fds);
@ -74,24 +75,29 @@ int bsc_select_main()
FD_SET(ufd->fd, &exceptset);
}
i = select(maxfd+1, &readset, &writeset, &exceptset, NULL);
if (i > 0) {
/* call registered callback functions */
llist_for_each_entry(ufd, &bsc_fds, list) {
int flags = 0;
prepare_timers();
i = select(maxfd+1, &readset, &writeset, &exceptset, nearest_timer());
if (i < 0)
return i;
if (FD_ISSET(ufd->fd, &readset))
flags |= BSC_FD_READ;
/* fire timers */
update_timers();
if (FD_ISSET(ufd->fd, &writeset))
flags |= BSC_FD_WRITE;
/* call registered callback functions */
llist_for_each_entry(ufd, &bsc_fds, list) {
int flags = 0;
if (FD_ISSET(ufd->fd, &readset))
flags |= BSC_FD_READ;
if (FD_ISSET(ufd->fd, &writeset))
flags |= BSC_FD_WRITE;
if (FD_ISSET(ufd->fd, &exceptset))
flags |= BSC_FD_EXCEPT;
if (FD_ISSET(ufd->fd, &exceptset))
flags |= BSC_FD_EXCEPT;
if (flags)
ufd->cb(ufd, flags);
}
if (flags)
ufd->cb(ufd, flags);
}
return i;
}

@ -0,0 +1,168 @@
/*
* (C) 2008 by Holger Hans Peter Freyther <zecke@selfish.org>
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include <assert.h>
#include <string.h>
#include <openbsc/timer.h>
static LLIST_HEAD(timer_list);
static struct timeval s_nearest_time;
static struct timeval s_select_time;
#define MICRO_SECONDS 1000000LL
#define TIME_SMALLER(left, right) \
(left.tv_sec*MICRO_SECONDS+left.tv_usec) <= (right.tv_sec*MICRO_SECONDS+right.tv_usec)
void add_timer(struct timer_list *timer)
{
struct timer_list *list_timer;
/* TODO: Optimize and remember the closest item... */
timer->active = 1;
/* this might be called from within update_timers */
llist_for_each_entry(list_timer, &timer_list, entry)
if (timer == list_timer)
return;
llist_add(&timer->entry, &timer_list);
}
void schedule_timer(struct timer_list *timer, int seconds, int microseconds)
{
struct timeval current_time;
gettimeofday(&current_time, NULL);
unsigned long long currentTime = current_time.tv_sec * MICRO_SECONDS + current_time.tv_usec;
currentTime += seconds * MICRO_SECONDS + microseconds;
timer->timeout.tv_sec = currentTime / MICRO_SECONDS;
timer->timeout.tv_usec = currentTime % MICRO_SECONDS;
add_timer(timer);
}
void del_timer(struct timer_list *timer)
{
if (timer_pending(timer)) {
timer->active = 0;
llist_del(&timer->entry);
}
}
int timer_pending(struct timer_list *timer)
{
return timer->active;
}
/*
* if we have a nearest time return the delta between the current
* time and the time of the nearest timer.
* If the nearest timer timed out return NULL and then we will
* dispatch everything after the select
*/
struct timeval *nearest_timer()
{
struct timeval current_time;
if (s_nearest_time.tv_sec == 0 && s_nearest_time.tv_usec == 0)
return NULL;
if (gettimeofday(&current_time, NULL) == -1)
return NULL;
unsigned long long nearestTime = s_nearest_time.tv_sec * MICRO_SECONDS + s_nearest_time.tv_usec;
unsigned long long currentTime = current_time.tv_sec * MICRO_SECONDS + current_time.tv_usec;
if (nearestTime < currentTime) {
s_select_time.tv_sec = 0;
s_select_time.tv_usec = 0;
} else {
s_select_time.tv_sec = (nearestTime - currentTime) / MICRO_SECONDS;
s_select_time.tv_usec = (nearestTime - currentTime) % MICRO_SECONDS;
}
return &s_select_time;
}
/*
* Find the nearest time and update s_nearest_time
*/
void prepare_timers()
{
struct timer_list *timer, *nearest_timer = NULL;
llist_for_each_entry(timer, &timer_list, entry) {
if (!nearest_timer || TIME_SMALLER(timer->timeout, nearest_timer->timeout)) {
nearest_timer = timer;
}
}
if (nearest_timer) {
s_nearest_time = nearest_timer->timeout;
} else {
memset(&s_nearest_time, 0, sizeof(struct timeval));
}
}
/*
* fire all timers... and remove them
*/
void update_timers()
{
struct timeval current_time;
struct timer_list *timer, *tmp;
gettimeofday(&current_time, NULL);
/*
* The callbacks might mess with our list and in this case
* even llist_for_each_entry_safe is not safe to use. To allow
* del_timer, add_timer, schedule_timer to be called from within
* the callback we jump through some loops.
*
* First we set the handled flag of each active timer to zero,
* then we iterate over the list and execute the callbacks. As the
* list might have been changed (specially the next) from within
* the callback we have to start over again. Once every callback
* is dispatched we will remove the non-active from the list.
*
* TODO: If this is a performance issue we can poison a global
* variable in add_timer and del_timer and only then restart.
*/
llist_for_each_entry(timer, &timer_list, entry) {
timer->handled = 0;
}
restart:
llist_for_each_entry(timer, &timer_list, entry) {
if (!timer->handled && TIME_SMALLER(timer->timeout, current_time)) {
timer->handled = 1;
timer->active = 0;
(*timer->cb)(timer->data);
goto restart;
}
}
llist_for_each_entry_safe(timer, tmp, &timer_list, entry) {
timer->handled = 0;
if (!timer->active) {
llist_del(&timer->entry);
}
}
}

@ -0,0 +1 @@
SUBDIRS = timer

@ -0,0 +1,5 @@
INCLUDES = $(all_includes) -I$(top_srcdir)/include
bin_PROGRAMS = timer_test
timer_test_SOURCES = timer_test.c $(top_srcdir)/src/timer.c $(top_srcdir)/src/select.c

@ -0,0 +1,62 @@
/*
* (C) 2008 by Holger Hans Peter Freyther <zecke@selfish.org>
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include <stdio.h>
#include <openbsc/timer.h>
#include <openbsc/select.h>
static void timer_fired(unsigned long data);
static struct timer_list timer_one = {
.cb = timer_fired,
.data = (void*)1,
};
static struct timer_list timer_two = {
.cb = timer_fired,
.data = (void*)2,
};
static void timer_fired(unsigned long data)
{
printf("Fired timer: %lu\n", data);
if (data == 1) {
schedule_timer(&timer_one, 3, 0);
del_timer(&timer_two);
} else if (data == 2) {
printf("Should not be fired... bug in del_timer\n");
} else {
printf("wtf... wrong data\n");
}
}
int main(int argc, char** argv)
{
printf("Starting... timer\n");
schedule_timer(&timer_one, 3, 0);
schedule_timer(&timer_two, 5, 0);
while (1) {
bsc_select_main();
}
}
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