eventfd - create a file descriptor for event notification

[t0bro]

In Linux and FreeBSD there is possibility to use a file descriptor to produce and process user events. For now such functionality absent in Embox OS.

https://man7.org/linux/man-pages/man2/eventfd.2.html

eventfd() creates an "eventfd object" that can be used as an event wait/notify mechanism by user-space applications, and by the kernel to notify user-space applications of events. The object contains an unsigned 64-bit integer (uint64_t) counter that is maintained by the kernel. This counter is initialized with the value specified in the argument initval. ... As its return value, eventfd() returns a new file descriptor that can be used to refer to the eventfd object. ... The returned file descriptor supports poll (and analogously epoll) and select.