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#ifndef __LINUX_COMPLETION_H
#define __LINUX_COMPLETION_H
/*
* (C) Copyright 2001 Linus Torvalds
*
* Atomic wait-for-completion handler data structures.
* See kernel/sched.c for details.
*/
#include <linux/wait.h>
struct completion {
unsigned int done;
wait_queue_head_t wait;
};
#define COMPLETION_INITIALIZER(work) \
{ 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
#define COMPLETION_INITIALIZER_ONSTACK(work) \
({ init_completion(&work); work; })
#define DECLARE_COMPLETION(work) \
struct completion work = COMPLETION_INITIALIZER(work)
/*
* Lockdep needs to run a non-constant initializer for on-stack
* completions - so we use the _ONSTACK() variant for those that
* are on the kernel stack:
*/
#ifdef CONFIG_LOCKDEP
# define DECLARE_COMPLETION_ONSTACK(work) \
struct completion work = COMPLETION_INITIALIZER_ONSTACK(work)
#else
# define DECLARE_COMPLETION_ONSTACK(work) DECLARE_COMPLETION(work)
#endif
static inline void init_completion(struct completion *x)
{
x->done = 0;
init_waitqueue_head(&x->wait);
}
extern void wait_for_completion(struct completion *);
extern int wait_for_completion_interruptible(struct completion *x);
extern int wait_for_completion_killable(struct completion *x);
extern unsigned long wait_for_completion_timeout(struct completion *x,
unsigned long timeout);
extern unsigned long wait_for_completion_interruptible_timeout(
struct completion *x, unsigned long timeout);
extern void complete(struct completion *);
extern void complete_all(struct completion *);
#define INIT_COMPLETION(x) ((x).done = 0)
/**
* try_wait_for_completion - try to decrement a completion without blocking
* @x: completion structure
*
* Returns: 0 if a decrement cannot be done without blocking
* 1 if a decrement succeeded.
*
* If a completion is being used as a counting completion,
* attempt to decrement the counter without blocking. This
* enables us to avoid waiting if the resource the completion
* is protecting is not available.
*/
static inline bool try_wait_for_completion(struct completion *x)
{
int ret = 1;
spin_lock_irq(&x->wait.lock);
if (!x->done)
ret = 0;
else
x->done--;
spin_unlock_irq(&x->wait.lock);
return ret;
}
/**
* completion_done - Test to see if a completion has any waiters
* @x: completion structure
*
* Returns: 0 if there are waiters (wait_for_completion() in progress)
* 1 if there are no waiters.
*
*/
static inline bool completion_done(struct completion *x)
{
int ret = 1;
spin_lock_irq(&x->wait.lock);
if (!x->done)
ret = 0;
spin_unlock_irq(&x->wait.lock);
return ret;
}
#endif
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