[linux.git] / include / linux / eventfd.h

/*
 *  include/linux/eventfd.h
 *
 *  Copyright (C) 2007  Davide Libenzi <[email protected]>
 *
 */

#ifndef _LINUX_EVENTFD_H
#define _LINUX_EVENTFD_H

#include <linux/fcntl.h>
#include <linux/file.h>
#include <linux/wait.h>

/*
 * CAREFUL: Check include/asm-generic/fcntl.h when defining
 * new flags, since they might collide with O_* ones. We want
 * to re-use O_* flags that couldn't possibly have a meaning
 * from eventfd, in order to leave a free define-space for
 * shared O_* flags.
 */
#define EFD_SEMAPHORE (1 << 0)
#define EFD_CLOEXEC O_CLOEXEC
#define EFD_NONBLOCK O_NONBLOCK

#define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
#define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE)

#ifdef CONFIG_EVENTFD

struct file *eventfd_file_create(unsigned int count, int flags);
struct eventfd_ctx *eventfd_ctx_get(struct eventfd_ctx *ctx);
void eventfd_ctx_put(struct eventfd_ctx *ctx);
struct file *eventfd_fget(int fd);
struct eventfd_ctx *eventfd_ctx_fdget(int fd);
struct eventfd_ctx *eventfd_ctx_fileget(struct file *file);
__u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n);
ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, __u64 *cnt);
int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_t *wait,
				  __u64 *cnt);

#else /* CONFIG_EVENTFD */

/*
 * Ugly ugly ugly error layer to support modules that uses eventfd but
 * pretend to work in !CONFIG_EVENTFD configurations. Namely, AIO.
 */
static inline struct file *eventfd_file_create(unsigned int count, int flags)
{
	return ERR_PTR(-ENOSYS);
}

static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd)
{
	return ERR_PTR(-ENOSYS);
}

static inline int eventfd_signal(struct eventfd_ctx *ctx, int n)
{
	return -ENOSYS;
}

static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
{

}

static inline ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait,
				       __u64 *cnt)
{
	return -ENOSYS;
}

static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx,
						wait_queue_t *wait, __u64 *cnt)
{
	return -ENOSYS;
}

#endif

#endif /* _LINUX_EVENTFD_H */
Commit	Line	Data
e1ad7468 DL	1	/*
	2	* include/linux/eventfd.h
	3	*
	4	* Copyright (C) 2007 Davide Libenzi <[email protected]>
	5	*
	6	*/
	7
	8	#ifndef _LINUX_EVENTFD_H
	9	#define _LINUX_EVENTFD_H
	10
b087498e	11	#include <linux/fcntl.h>
13389010	12	#include <linux/file.h>
cb289d62	13	#include <linux/wait.h>
b087498e	14
bcd0b235 DL	15	/*
	16	* CAREFUL: Check include/asm-generic/fcntl.h when defining
	17	* new flags, since they might collide with O_* ones. We want
	18	* to re-use O_* flags that couldn't possibly have a meaning
	19	* from eventfd, in order to leave a free define-space for
	20	* shared O_* flags.
	21	*/
	22	#define EFD_SEMAPHORE (1 << 0)
b087498e	23	#define EFD_CLOEXEC O_CLOEXEC
e7d476df	24	#define EFD_NONBLOCK O_NONBLOCK
b087498e	25
bcd0b235 DL	26	#define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC \| O_NONBLOCK)
	27	#define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS \| EFD_SEMAPHORE)
	28
13389010 DL	29	#ifdef CONFIG_EVENTFD
13389010 DL	30
562787a5	31	struct file *eventfd_file_create(unsigned int count, int flags);
13389010 DL	32	struct eventfd_ctx eventfd_ctx_get(struct eventfd_ctx ctx);
13389010 DL	33	void eventfd_ctx_put(struct eventfd_ctx *ctx);
e1ad7468	34	struct file *eventfd_fget(int fd);
13389010 DL	35	struct eventfd_ctx *eventfd_ctx_fdget(int fd);
13389010 DL	36	struct eventfd_ctx eventfd_ctx_fileget(struct file file);
ee62c6b2	37	__u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n);
cb289d62 DL	38	ssize_t eventfd_ctx_read(struct eventfd_ctx ctx, int no_wait, __u64 cnt);
	39	int eventfd_ctx_remove_wait_queue(struct eventfd_ctx ctx, wait_queue_t wait,
	40	__u64 *cnt);
e1ad7468 DL	41
	42	#else /* CONFIG_EVENTFD */
	43
13389010 DL	44	/*
	45	* Ugly ugly ugly error layer to support modules that uses eventfd but
	46	* pretend to work in !CONFIG_EVENTFD configurations. Namely, AIO.
	47	*/
562787a5 DL	48	static inline struct file *eventfd_file_create(unsigned int count, int flags)
	49	{
	50	return ERR_PTR(-ENOSYS);
	51	}
	52
13389010 DL	53	static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd)
	54	{
	55	return ERR_PTR(-ENOSYS);
	56	}
	57
	58	static inline int eventfd_signal(struct eventfd_ctx *ctx, int n)
	59	{
	60	return -ENOSYS;
	61	}
	62
	63	static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
	64	{
	65
	66	}
e1ad7468	67
cb289d62 DL	68	static inline ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait,
	69	__u64 *cnt)
	70	{
	71	return -ENOSYS;
	72	}
	73
	74	static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx,
	75	wait_queue_t wait, __u64 cnt)
	76	{
	77	return -ENOSYS;
	78	}
	79
13389010	80	#endif
e1ad7468	81
e1ad7468 DL	82	#endif /* _LINUX_EVENTFD_H */
e1ad7468 DL	83