| 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 | x->done = 0; |
| 76 | init_waitqueue_head(&x->wait); |
| 77 | } |
| 78 | |
| 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 long wait_for_completion_interruptible_timeout( |
| 85 | struct completion *x, unsigned long timeout); |
| 86 | extern long wait_for_completion_killable_timeout( |
| 87 | struct completion *x, unsigned long timeout); |
| 88 | extern bool try_wait_for_completion(struct completion *x); |
| 89 | extern bool completion_done(struct completion *x); |
| 90 | |
| 91 | extern void complete(struct completion *); |
| 92 | extern void complete_all(struct completion *); |
| 93 | |
| 94 | /** |
| 95 | * INIT_COMPLETION - reinitialize a completion structure |
| 96 | * @x: completion structure to be reinitialized |
| 97 | * |
| 98 | * This macro should be used to reinitialize a completion structure so it can |
| 99 | * be reused. This is especially important after complete_all() is used. |
| 100 | */ |
| 101 | #define INIT_COMPLETION(x) ((x).done = 0) |
| 102 | |
| 103 | |
| 104 | #endif |