kernel-ark/include/linux/timer.h
Oleg Nesterov fd450b7318 [PATCH] timers: introduce try_to_del_timer_sync()
This patch splits del_timer_sync() into 2 functions.  The new one,
try_to_del_timer_sync(), returns -1 when it hits executing timer.

It can be used in interrupt context, or when the caller hold locks which
can prevent completion of the timer's handler.

NOTE.  Currently it can't be used in interrupt context in UP case, because
->running_timer is used only with CONFIG_SMP.

Should the need arise, it is possible to kill #ifdef CONFIG_SMP in
set_running_timer(), it is cheap.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:16 -07:00

93 lines
2.4 KiB
C

#ifndef _LINUX_TIMER_H
#define _LINUX_TIMER_H
#include <linux/config.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
struct timer_base_s;
struct timer_list {
struct list_head entry;
unsigned long expires;
unsigned long magic;
void (*function)(unsigned long);
unsigned long data;
struct timer_base_s *base;
};
#define TIMER_MAGIC 0x4b87ad6e
extern struct timer_base_s __init_timer_base;
#define TIMER_INITIALIZER(_function, _expires, _data) { \
.function = (_function), \
.expires = (_expires), \
.data = (_data), \
.base = &__init_timer_base, \
.magic = TIMER_MAGIC, \
}
void fastcall init_timer(struct timer_list * timer);
/***
* timer_pending - is a timer pending?
* @timer: the timer in question
*
* timer_pending will tell whether a given timer is currently pending,
* or not. Callers must ensure serialization wrt. other operations done
* to this timer, eg. interrupt contexts, or other CPUs on SMP.
*
* return value: 1 if the timer is pending, 0 if not.
*/
static inline int timer_pending(const struct timer_list * timer)
{
return timer->entry.next != NULL;
}
extern void add_timer_on(struct timer_list *timer, int cpu);
extern int del_timer(struct timer_list * timer);
extern int __mod_timer(struct timer_list *timer, unsigned long expires);
extern int mod_timer(struct timer_list *timer, unsigned long expires);
extern unsigned long next_timer_interrupt(void);
/***
* add_timer - start a timer
* @timer: the timer to be added
*
* The kernel will do a ->function(->data) callback from the
* timer interrupt at the ->expired point in the future. The
* current time is 'jiffies'.
*
* The timer's ->expired, ->function (and if the handler uses it, ->data)
* fields must be set prior calling this function.
*
* Timers with an ->expired field in the past will be executed in the next
* timer tick.
*/
static inline void add_timer(struct timer_list * timer)
{
__mod_timer(timer, timer->expires);
}
#ifdef CONFIG_SMP
extern int try_to_del_timer_sync(struct timer_list *timer);
extern int del_timer_sync(struct timer_list *timer);
#else
# define try_to_del_timer_sync(t) del_timer(t)
# define del_timer_sync(t) del_timer(t)
#endif
#define del_singleshot_timer_sync(t) del_timer_sync(t)
extern void init_timers(void);
extern void run_local_timers(void);
extern void it_real_fn(unsigned long);
#endif