Line data Source code
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.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 : * and macros DECLARE_COMPLETION(), DECLARE_COMPLETION_ONSTACK(), and
23 : * INIT_COMPLETION().
24 : */
25 : struct 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: completion structure that is to be initialized
69 : *
70 : * This inline function will initialize a dynamically created completion
71 : * structure.
72 : */
73 : static inline void init_completion(struct completion *x)
74 : {
75 22 : x->done = 0;
76 11 : init_waitqueue_head(&x->wait);
77 : }
78 11 :
79 : extern void wait_for_completion(struct completion *);
80 : extern int wait_for_completion_interruptible(struct completion *x);
81 : extern int wait_for_completion_killable(struct completion *x);
82 : extern unsigned long wait_for_completion_timeout(struct completion *x,
83 : unsigned long timeout);
84 : extern unsigned long wait_for_completion_interruptible_timeout(
85 : struct completion *x, unsigned long timeout);
86 : extern bool try_wait_for_completion(struct completion *x);
87 : extern bool completion_done(struct completion *x);
88 :
89 : extern void complete(struct completion *);
90 : extern void complete_all(struct completion *);
91 1 :
92 : /**
93 : * INIT_COMPLETION: - reinitialize a completion structure
94 : * @x: completion structure to be reinitialized
95 : *
96 : * This macro should be used to reinitialize a completion structure so it can
97 : * be reused. This is especially important after complete_all() is used.
98 : */
99 : #define INIT_COMPLETION(x) ((x).done = 0)
100 :
101 :
102 : #endif
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