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 105