Rechercher une page de manuel
epoll_wait
Langue: en
Version: 23 October 2002 (fedora - 16/08/07)
Section: 2 (Appels système)
NAME
epoll_wait - wait for an I/O event on an epoll file descriptorSYNOPSIS
#include <sys/epoll.h> int epoll_wait(int epfd, struct epoll_event * events, int maxevents, int timeout);
DESCRIPTION
Wait for events on the epoll file descriptor epfd for a maximum time of timeout milliseconds. The memory area pointed to by events will contain the events that will be available for the caller. Up to maxevents are returned by epoll_wait(2). The maxevents parameter must be greater than zero. Specifying a timeout of -1 makes epoll_wait(2) wait indefinitely, while specifying a timeout equal to zero makes epoll_wait(2) to return immediately even if no events are available (return code equal to zero). The struct epoll_event is defined as :typedef union epoll_data { void *ptr; int fd; __uint32_t u32; __uint64_t u64; } epoll_data_t; struct epoll_event { __uint32_t events; /* Epoll events */ epoll_data_t data; /* User data variable */ };
The data of each returned structure will contain the same data the user set with a epoll_ctl(2) (EPOLL_CTL_ADD,EPOLL_CTL_MOD) while the events member will contain the returned event bit field.
RETURN VALUE
When successful, epoll_wait(2) returns the number of file descriptors ready for the requested I/O, or zero if no file descriptor became ready during the requested timeout milliseconds. When an error occurs, epoll_wait(2) returns -1 and errno is set appropriately.ERRORS
- EBADF
- epfd is not a valid file descriptor.
- EFAULT
- The memory area pointed to by events is not accessible with write permissions.
- EINTR
- The call was interrupted by a signal handler before any of the requested events occurred or the timeout expired.
- EINVAL
- epfd is not an epoll file descriptor, or maxevents is less than or equal to zero.
CONFORMING TO
epoll_wait(2) is Linux specific, and was introduced in kernel 2.5.44.SEE ALSO
epoll_create(2), epoll_ctl(2), epoll(7)Contenus ©2006-2024 Benjamin Poulain
Design ©2006-2024 Maxime Vantorre