epoll_create1()

Purpose

Creates an epoll instance and returns a file descriptor used by epoll_ctl() and epoll_wait().

Header

#include <sys/epoll.h>

Prototype

int epoll_create1(int flags);

Parameters

• flags: normally EPOLL_CLOEXEC or 0.

Return Value

• Success: returns a new epoll file descriptor.
• Failure: returns -1 and sets errno.

Minimal Example

int epfd = epoll_create1(EPOLL_CLOEXEC);
if (epfd < 0) {
    perror("epoll_create1");
}

Common Pitfalls

• Prefer EPOLL_CLOEXEC to avoid leaking the fd across exec().
• Close the epoll fd during cleanup.
• epoll_create() is older; prefer epoll_create1() for new code.

Related Topics

• Event Loop