#include <stdint.h>
#include <zephyr/kernel.h>
#include <zephyr/posix/fcntl.h>

Macros
#define	EFD_IN_USE 0x1 __DEPRECATED_MACRO

#define	EFD_SEMAPHORE 0x2

#define	EFD_NONBLOCK O_NONBLOCK

#define	EFD_FLAGS_SET (EFD_SEMAPHORE \| EFD_NONBLOCK) __DEPRECATED_MACRO

Typedefs
typedef uint64_t	eventfd_t

Functions
int	eventfd (unsigned int initval, int flags)
	Create a file descriptor for event notification.

int	eventfd_read (int fd, eventfd_t *value)
	Read from an eventfd.

int	eventfd_write (int fd, eventfd_t value)
	Write to an eventfd.

Macro Definition Documentation

◆ EFD_FLAGS_SET

#define EFD_FLAGS_SET (EFD_SEMAPHORE | EFD_NONBLOCK) __DEPRECATED_MACRO

◆ EFD_IN_USE

#define EFD_IN_USE 0x1 __DEPRECATED_MACRO

◆ EFD_NONBLOCK

#define EFD_NONBLOCK O_NONBLOCK

◆ EFD_SEMAPHORE

#define EFD_SEMAPHORE 0x2

Typedef Documentation

◆ eventfd_t

typedef uint64_t eventfd_t

Function Documentation

◆ eventfd()

int eventfd	(	unsigned int	initval,
		int	flags
	)

Create a file descriptor for event notification.

The returned file descriptor can be used with POSIX read/write calls or with the eventfd_read/eventfd_write functions.

It also supports polling and by including an eventfd in a call to poll, it is possible to signal and wake the polling thread by simply writing to the eventfd.

When using read() and write() on an eventfd, the size must always be at least 8 bytes or the operation will fail with EINVAL.

Returns: New eventfd file descriptor on success, -1 on error

◆ eventfd_read()

int eventfd_read	(	int	fd,
		eventfd_t *	value
	)

Read from an eventfd.

If call is successful, the value parameter will have the value 1

Parameters

fd	File descriptor
value	Pointer for storing the read value

Returns: 0 on success, -1 on error

◆ eventfd_write()

int eventfd_write	(	int	fd,
		eventfd_t	value
	)

Write to an eventfd.