eventfd.h File Reference

Linux-compatible event notification file descriptor (<sys/eventfd.h>) More...

#include <zephyr/zvfs/eventfd.h>

Include dependency graph for eventfd.h:

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Macros
#define	EFD_SEMAPHORE   ZVFS_EFD_SEMAPHORE
	Semaphore-mode flag: each read decrements the counter by 1 instead of resetting to 0.
#define	EFD_NONBLOCK   ZVFS_EFD_NONBLOCK
	Non-blocking flag: reads and writes return EAGAIN instead of blocking.

Typedefs
typedef zvfs_eventfd_t	eventfd_t
	Counter value type for eventfd operations.

Functions
int	eventfd (unsigned int initval, int flags)
	Create a file descriptor for event notification.
int	eventfd_read (int fd, eventfd_t *value)
	Read the current counter value from an eventfd.
int	eventfd_write (int fd, eventfd_t value)
	Add a value to an eventfd counter.

Detailed Description

Linux-compatible event notification file descriptor (<sys/eventfd.h>)

eventfd provides a lightweight, kernel-managed counter that can be used for event notification between threads or between a kernel component and user space. It integrates with poll/select/epoll.

Note

eventfd is a Linux extension, not part of POSIX.1-2017, but is widely available on Linux and implemented here for compatibility.

Definition in file eventfd.h.