Polling

Implementation of POSIX polling. More...

Topics
	Events for the poll() function
	Masks representing event types for poll()

Files
file	poll.h
	Definitions for the poll() function.

Data Structures
struct	pollfd
	Structure representing a single file descriptor used by poll(). More...

Typedefs
typedef __uint32_t	nfds_t
	Type representing a number of file descriptors.

Functions
int	poll (struct pollfd fds[], nfds_t nfds, int timeout)
	Poll a group of file descriptors for activity.

Detailed Description

Implementation of POSIX polling.

Typedef Documentation

nfds_t

typedef __uint32_t nfds_t

Type representing a number of file descriptors.

Function Documentation

poll()

int poll	(	struct pollfd	fds[],
		nfds_t	nfds,
		int	timeout )

Poll a group of file descriptors for activity.

This function will poll a group of file descriptors to check for the events specified on them. The function shall block for the specified period of time (in milliseconds) waiting for an event to occur. The function shall return as soon as at least one fd matches the events specified (or one of the error conditions), or when timeout expires.

Parameters

fds	The file descriptors to check, and what events to look for on each.
nfds	Number of elements in fds.
timeout	Maximum amount of time to block, in milliseconds. Pass 0 to ensure the function does not block and -1 to block for an "infinite" amount of time, until an event occurs.

Returns

-1 on error (sets errno as appropriate), or the number of file descriptors that matched the event flags before the function returns.

See also

Events for the poll() function