indexing

	description:

		"[
			Singleton representing the thread subsytem. Use EM_SHARED_SUBSYSTEMS
			to access this class.
		]"

	date: "$Date$"
	revision: "$Revision$"

class EM_THREAD_SUBSYSTEM

inherit
	EM_SUBSYSTEM

	EM_CONSTANTS
		export {NONE} all end

	SDL_FUNCTIONS_EXTERNAL
		export {NONE} all end

create {EM_SHARED_SUBSYSTEMS}
	make

feature {NONE} -- Initialization

	make is
		do
		ensure
			not_enabled: not is_enabled
		end

feature -- Status report

	is_enabled: BOOLEAN is
			-- Is the thread subsystem enabled?
		do
			Result := 0 /= sdl_was_init_external (Em_init_thread)
		end

feature -- Subsystem management

	enable is
			-- Enable EiffelMedia thread subsystem.
		local
			i: INTEGER
		do
			i := sdl_init_external (Em_init_thread)
			if i >= 0 then
					-- TODO
			end
		end

	disable is
			-- Disable EiffelMedia thread subsystem.
		do
				-- TODO
			sdl_quit_sub_system_external (Em_init_thread)
		ensure then
			disabled: not is_enabled
		end
feature  -- lowlevel callback dispatcher
		dispatcher: INT_VOIDP_ANONYMOUS_CALLBACK_DISPATCHER is
		once
			create Result.make (receiver)
		end
		
		receiver: EM_THREAD_CALLBACK is
				-- on_callback is called whenever a new thread is created!
				once
					create Result.make
				end
feature -- needed: a working mutex to lock the whole thread subsystem!

	thread_creation : EM_SEMAPHORE is
			-- semaphore to lock the whole thread_system. i think we need this, because we only have one callback singleton ...
			-- (i could be wrong though ;)
			once
		--io.put_string("thread_creation%N")
				create Result.make(1)
			end
	io_system : EM_MUTEX is
			-- mutex to lock the whole thread_system
			once
			--	io.put_string("io_system%N")
				create Result.make
			end

end