What is Epollout?

EPOLLOUT The associated file is available for write(2) operations. EPOLLRDHUP (since Linux 2.6. 17) Stream socket peer closed connection, or shut down writing half of connection. (This flag is especially useful for writing simple code to detect peer shutdown when using edge-triggered monitoring.)

What is Epollin?

EPOLLIN //Indicates that the corresponding file descriptor is readable (including the normal shutdown of the opposite SOCKET); EPOLLOUT //Indicates that the corresponding file descriptor is writable; EPOLLPRI //Indicates that the corresponding file descriptor has urgent data to read (this should indicate that out-of- …

What is Epollhup?

EPOLLHUP is UNMASKABLE event (…). It means that after we received EOF , poll always returns immediately, making impossible poll() on write() in state CLOSE_WAIT . One solution is evident — to set EPOLLHUP if and only if shutdown has been made in both directions.

What is Eagain?

EAGAIN is often raised when performing non-blocking I/O. It means “there is no data available right now, try again later”. It might (or might not) be the same as EWOULDBLOCK , which means “your thread would have to block in order to do that”. Follow this answer to receive notifications.

What is Kevent?

The proposed Linux kevent API is a new unified event handling interface, similar in spirit to completion ports and the FreeBSD/ OS X kqueue interface.

What is Epoll in Linux?

epoll is a Linux kernel system call for a scalable I/O event notification mechanism, first introduced in version 2.5. 44 of the Linux kernel. Its function is to monitor multiple file descriptors to see whether I/O is possible on any of them.

What is Kevent in Linux?

The kevent() system call is used to register events with the queue, and return any pending events to the user. The changelist argument is a pointer to an array of kevent structures, as defined in . All changes contained in the changelist are applied before any pending events are read from the queue.

What is O_rdonly?

O_RDONLY. Open for reading only. O_WRONLY. Open for writing only. O_RDWR.