wakeupchannel.rs

pub trait WakeupChannel : Drop {
	fn wakeup(&self)
}

pub trait WakeupBuilder {
	fn create(callback: Fn<()>) -> WakeupChannel
}

mod apple {

struct AppleWakeupBuilder {
	queue: ffi::dispatch_queue_t
}

impl WakeupBuilder for AppleWakeupBuilder {
	fn create(callback: Fn<()>) -> AppleWakeupChannel {
		let add_flag = ffi::_dispatch_source_type_data_add;
		let evt_source = unsafe {
			ffi::dispatch_source_create(add_flag, 0, 0, self.queue)
		};
		let wakeup_channel = AppleWakeupChannel {
			evt_source: evt_source,
			callback: callback
		};
		let channel_ptr = &wakeup_channel as *const _ as *const c_void;
		unsafe {
			//need box here to have stable memory address that we can make rust forget about easily
			//when being invoked by libdispatch
			ffi::dispatch_set_context(wakeup_channel.evt_source, channel_ptr);
			ffi::dispatch_source_set_event_handler_f(wakeup_channel.evt_source, &wakeup_event_handler);
			ffi::dispatch_resume(wakeup_channel.evt_source);
		}
		wakeup_channel
	}
}

#[no_mangle]
extern "C" unsafe fn wakeup_event_handler(context: *const c_void) {
	let wakeup_channel : &AppleWakeupChannel = &*(context as *const AppleWakeupChannel);
	wakeup_channel.invoke();
}

struct AppleWakeupChannel {
	evt_source: dispatch_source_t
	callback: Fn<()>
}

impl AppleWakeupChannel {
	fn invoke(&self) {
		self.callback();
	}
}

impl WakeupChannel for AppleWakeupChannel {
	fn wakeup(&self) {
		dispatch_source_merge_data(self.source, 1u64);
	}
}

impl Drop for AppleWakeupChannel {
	fn drop(&mut self) {
		unsafe { ffi::dispatch_release(self.evt_source); }
	}
}

}