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 */
16 struct timer_list {
17 struct list_head list;
18 unsigned long expires;
19 unsigned long data;
20 void (*function)(unsigned long);
21 };
22
23 extern void add_timer(struct timer_list * timer);
24 extern int del_timer(struct timer_list * timer);
25
26 #ifdef CONFIG_SMP
27 extern int del_timer_sync(struct timer_list * timer);
28 extern 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 */
41 int mod_timer(struct timer_list *timer, unsigned long expires);
42
43 extern void it_real_fn(unsigned long);
44
init_timer(struct timer_list * timer)45 static inline void init_timer(struct timer_list * timer)
46 {
47 timer->list.next = timer->list.prev = NULL;
48 }
49
timer_pending(const struct timer_list * timer)50 static 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