Event loop - Wikipedia, the free encyclopedia

Event loop - Wikipedia, the free encyclopedia

In computer science, the event loop, message dispatcher, message loop or message pump is a programming construct that waits for and dispatches events or messages in a program. It works by polling some internal or external "event provider", which generally blocks until an event has arrived, and then calls the relevant event handler ("dispatches the event"). The event-loop may be used in conjunction with a reactor, if the event provider follows the file interface (which can be select()ed or poll()ed). The event loop almost always operates asynchronously with the message originator.

When the event loop forms the central control flow construct of a program, as it often does, and is thus at the highest level of control within the program, it may be termed the main loop or main event loop.