1#ifndef _LINUX_TIMER_H 2#define _LINUX_TIMER_H 3 4#include <linux/config.h> 5#include <linux/list.h> 6 7/* 8 * In Linux 2.4, static timers have been removed from the kernel. 9 * Timers may be dynamically created and destroyed, and should be initialized 10 * by a call to init_timer() upon creation. 11 * 12 * The "data" field enables use of a common timeout function for several 13 * timeouts. You can use this field to distinguish between the different 14 * invocations. 15 */ 16struct timer_list { 17 struct list_head list; 18 unsigned long expires; 19 unsigned long data; 20 void (*function)(unsigned long); 21}; 22 23extern void add_timer(struct timer_list * timer); 24extern int del_timer(struct timer_list * timer); 25 26#ifdef CONFIG_SMP 27extern int del_timer_sync(struct timer_list * timer); 28extern void sync_timers(void); 29#else 30#define del_timer_sync(t) del_timer(t) 31#define sync_timers() do { } while (0) 32#endif 33 34/* 35 * mod_timer is a more efficient way to update the expire field of an 36 * active timer (if the timer is inactive it will be activated) 37 * mod_timer(a,b) is equivalent to del_timer(a); a->expires = b; add_timer(a). 38 * If the timer is known to be not pending (ie, in the handler), mod_timer 39 * is less efficient than a->expires = b; add_timer(a). 40 */ 41int mod_timer(struct timer_list *timer, unsigned long expires); 42 43extern void it_real_fn(unsigned long); 44 45static inline void init_timer(struct timer_list * timer) 46{ 47 timer->list.next = timer->list.prev = NULL; 48} 49 50static inline int timer_pending (const struct timer_list * timer) 51{ 52 return timer->list.next != NULL; 53} 54 55/* 56 * These inlines deal with timer wrapping correctly. You are 57 * strongly encouraged to use them 58 * 1. Because people otherwise forget 59 * 2. Because if the timer wrap changes in future you wont have to 60 * alter your driver code. 61 * 62 * time_after(a,b) returns true if the time a is after time b. 63 * 64 * Do this with "<0" and ">=0" to only test the sign of the result. A 65 * good compiler would generate better code (and a really good compiler 66 * wouldn't care). Gcc is currently neither. 67 */ 68#define time_after(a,b) ((long)(b) - (long)(a) < 0) 69#define time_before(a,b) time_after(b,a) 70 71#define time_after_eq(a,b) ((long)(a) - (long)(b) >= 0) 72#define time_before_eq(a,b) time_after_eq(b,a) 73 74#endif 75