Annotation of sys/sys/timeout.h, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: timeout.h,v 1.16 2003/06/03 01:27:31 art Exp $ */
2: /*
3: * Copyright (c) 2000-2001 Artur Grabowski <art@openbsd.org>
4: * All rights reserved.
5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: *
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. The name of the author may not be used to endorse or promote products
13: * derived from this software without specific prior written permission.
14: *
15: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
16: * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17: * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18: * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21: * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22: * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23: * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24: * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
27: #ifndef _SYS_TIMEOUT_H_
28: #define _SYS_TIMEOUT_H_
29:
30: /*
31: * Interface for handling time driven events in the kernel.
32: *
33: * The basic component of this API is the struct timeout. The user should not
34: * touch the internals of this structure, but it's the users responsibility
35: * to allocate and deallocate timeouts.
36: *
37: * The functions used to manipulate timeouts are:
38: * - timeout_set(timeout, function, argument)
39: * Initializes a timeout struct to call the function with the argument.
40: * A timeout only needs to be initialized once.
41: * - timeout_add(timeout, ticks)
42: * Schedule this timeout to run in "ticks" ticks (there are hz ticks in
43: * one second). You may not touch the timeout with timeout_set once the
44: * timeout is scheduled. A second call to timeout_add with an already
45: * scheduled timeout will cause the old timeout to be canceled and the
46: * new will be scheduled.
47: * - timeout_del(timeout)
48: * Remove the timeout from the timeout queue. It's legal to remove
49: * a timeout that has already happened.
50: *
51: * These functions may be called in interrupt context (anything below splhigh).
52: */
53:
54: struct circq {
55: struct circq *next; /* next element */
56: struct circq *prev; /* previous element */
57: };
58:
59: struct timeout {
60: struct circq to_list; /* timeout queue, don't move */
61: void (*to_func)(void *); /* function to call */
62: void *to_arg; /* function argument */
63: int to_time; /* ticks on event */
64: int to_flags; /* misc flags */
65: };
66:
67: /*
68: * flags in the to_flags field.
69: */
70: #define TIMEOUT_ONQUEUE 2 /* timeout is on the todo queue */
71: #define TIMEOUT_INITIALIZED 4 /* timeout is initialized */
72: #define TIMEOUT_TRIGGERED 8 /* timeout is running or ran */
73: /*
74: * special macros
75: *
76: * timeout_pending(to) - is this timeout already scheduled to run?
77: * timeout_initialized(to) - is this timeout initialized?
78: */
79: #define timeout_pending(to) ((to)->to_flags & TIMEOUT_ONQUEUE)
80: #define timeout_initialized(to) ((to)->to_flags & TIMEOUT_INITIALIZED)
81: #define timeout_triggered(to) ((to)->to_flags & TIMEOUT_TRIGGERED)
82:
83: #ifdef _KERNEL
84: void timeout_set(struct timeout *, void (*)(void *), void *);
85: void timeout_add(struct timeout *, int);
86: void timeout_del(struct timeout *);
87:
88: void timeout_startup(void);
89:
90: /*
91: * called once every hardclock. returns non-zero if we need to schedule a
92: * softclock.
93: */
94: int timeout_hardclock_update(void);
95: #endif /* _KERNEL */
96:
97: #endif /* _SYS_TIMEOUT_H_ */
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