pub fn unix_fd_add<F>(fd: RawFd, condition: IOCondition, func: F) -> SourceId
Adds a closure to be called by the main loop the returned
Source is attached to whenever a
UNIX file descriptor reaches the given IO condition.
func will be called repeatedly while the file descriptor matches the given IO condition
until it returns
The default main loop almost always is the main loop of the main thread. Thus, the closure is called on the main thread.