Re: Ada Tasks and Keyboard I/O

[Dale Stanbrough <dale@goanna.cs.rmit.EDU.AU>]

David H. Haley writes:

"I have developed a software package in Ada and thought it would be nice
 to have the time perodically updated on the screen while waiting for the
 user to input a value from the keyboard.
 
 This "sounds" easy enough to do using tasks; however, once the program
 reaches the Get(My_Number) statement all other tasks come to a grinding
 halt waiting for this keyboard I/O to occur <grr>.
 
 Any ideas how I can accomplish the requirement in para 1 ? I am using 
 Meridian OpenAda Dos ver 4.1.4, an ADA 83 compiler."


Link with 

	bamp -I
	
to provide task preemption, then as one of the first things your program
does (perhaps even in a task elaboration section)...

	task_control.pre_emption_on;

This will prevent iio.get from hogging all the limelight.

Package task_control is described as (on p32 of the compiler's user guide)...

	package Task_Control is
		procedure Pre_Emption_On;
		procedure Pre_Emption_Off;
		
		procedure Set_Time_Slice (Quota : Duration);
	
	end Task_Control;


I always did have quite a soft spot for the Meridian Ada compiler. It
seemed to (almost) always do what was expected of it.

Dale