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

/*
 *  include/linux/eventfd.h
 *
 *  Copyright (C) 2007  Davide Libenzi <davidel@xmailserver.org>
 *
 */

#ifndef _LINUX_EVENTFD_H
#define _LINUX_EVENTFD_H

#include <linux/fcntl.h>
#include <linux/file.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);
int eventfd_signal(struct eventfd_ctx *ctx, int n);

#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)
{

}

#endif

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