[Xcb] How to wake up the GUI thread in XCB?

[Cosmin Apreutesei]

> Uhm, which "[1]"?

Sorry: http://xcb.freedesktop.org/manual/group__XCB__Core__API.html#ga537e3cea89389382533957444eaa13fd

> Eventfd works, too. ;-)

Same thing :)

[context: I know that using XCB in conjunction with other UNIX APIs
doesn't seem like a big deal for UNIX people because they assume the
user will use C, after all it's a C API, and all other headers are
available, etc., what's the big deal, right? But XCB made efforts to
keep binary compat between 32bit and 64bit, avoid using macros etc. so
it will be easy to bind to hi-level languages without having to buy
into huge runtimes like Qt and GTK. That's what I'm trying to do, I'm
trying to make a portable GUI lib for LuaJIT[1] so I am looking for a
solution that will have as few dependencies as possible to other UNIX
APIs to avoid having to bind those too and having them as
dependencies. To a C programer it looks like I complain a lot for no
reason.]

[1] https://luapower.com/nw