1#ifndef __LINUX_COMPLETION_H
2#define __LINUX_COMPLETION_H
3
4/*
5 * (C) Copyright 2001 Linus Torvalds
6 *
7 * Atomic wait-for-completion handler data structures.
8 * See kernel/sched/completion.c for details.
9 */
10
11#include <linux/wait.h>
12
13/*
14 * struct completion - structure used to maintain state for a "completion"
15 *
16 * This is the opaque structure used to maintain the state for a "completion".
17 * Completions currently use a FIFO to queue threads that have to wait for
18 * the "completion" event.
19 *
20 * See also:  complete(), wait_for_completion() (and friends _timeout,
21 * _interruptible, _interruptible_timeout, and _killable), init_completion(),
22 * reinit_completion(), and macros DECLARE_COMPLETION(),
23 * DECLARE_COMPLETION_ONSTACK().
24 */
25struct completion {
26	unsigned int done;
27	wait_queue_head_t wait;
28};
29
30#define COMPLETION_INITIALIZER(work) \
31	{ 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
32
33#define COMPLETION_INITIALIZER_ONSTACK(work) \
34	({ init_completion(&work); work; })
35
36/**
37 * DECLARE_COMPLETION - declare and initialize a completion structure
38 * @work:  identifier for the completion structure
39 *
40 * This macro declares and initializes a completion structure. Generally used
41 * for static declarations. You should use the _ONSTACK variant for automatic
42 * variables.
43 */
44#define DECLARE_COMPLETION(work) \
45	struct completion work = COMPLETION_INITIALIZER(work)
46
47/*
48 * Lockdep needs to run a non-constant initializer for on-stack
49 * completions - so we use the _ONSTACK() variant for those that
50 * are on the kernel stack:
51 */
52/**
53 * DECLARE_COMPLETION_ONSTACK - declare and initialize a completion structure
54 * @work:  identifier for the completion structure
55 *
56 * This macro declares and initializes a completion structure on the kernel
57 * stack.
58 */
59#ifdef CONFIG_LOCKDEP
60# define DECLARE_COMPLETION_ONSTACK(work) \
61	struct completion work = COMPLETION_INITIALIZER_ONSTACK(work)
62#else
63# define DECLARE_COMPLETION_ONSTACK(work) DECLARE_COMPLETION(work)
64#endif
65
66/**
67 * init_completion - Initialize a dynamically allocated completion
68 * @x:  pointer to completion structure that is to be initialized
69 *
70 * This inline function will initialize a dynamically created completion
71 * structure.
72 */
73static inline void init_completion(struct completion *x)
74{
75	x->done = 0;
76	init_waitqueue_head(&x->wait);
77}
78
79/**
80 * reinit_completion - reinitialize a completion structure
81 * @x:  pointer to completion structure that is to be reinitialized
82 *
83 * This inline function should be used to reinitialize a completion structure so it can
84 * be reused. This is especially important after complete_all() is used.
85 */
86static inline void reinit_completion(struct completion *x)
87{
88	x->done = 0;
89}
90
91extern void wait_for_completion(struct completion *);
92extern void wait_for_completion_io(struct completion *);
93extern int wait_for_completion_interruptible(struct completion *x);
94extern int wait_for_completion_killable(struct completion *x);
95extern unsigned long wait_for_completion_timeout(struct completion *x,
96						   unsigned long timeout);
97extern unsigned long wait_for_completion_io_timeout(struct completion *x,
98						    unsigned long timeout);
99extern long wait_for_completion_interruptible_timeout(
100	struct completion *x, unsigned long timeout);
101extern long wait_for_completion_killable_timeout(
102	struct completion *x, unsigned long timeout);
103extern bool try_wait_for_completion(struct completion *x);
104extern bool completion_done(struct completion *x);
105
106extern void complete(struct completion *);
107extern void complete_all(struct completion *);
108
109#endif
110