Ada protected types - function

Question

I've got a simple package in Ada with procedures and functions. I'd like to have all the functions and procedures in a protected type.
e.g. for a simple .adb file
package body Pack is
procedure procedure1 (B : in out Integer) is
begin
B := new Integer;
end procedure1;
procedure procedure2 (B: in out Integer) is
begin
B.Cont(B.First-1) := 1;
end procedure2;
function procedure3 (B : Integer) return Boolean is
begin
return B.First = B.Last;
end procedure3;
end pack;
and or a simple .ads
package body Pack is
procedure procedure1 (B : in out Integer);
procedure procedure2 (B: in out Integer);
function procedure3 (B : Integer) return Boolean;
end pack;
How would I go about it?

Answer 1

The thing about a protected type is that it protects something (against concurrent access). It’s hard to see from your code what it is you want to protect.
If, say, you wanted to do a thread-safe increment, you might have a spec like
package Pack is
protected type T is
procedure Set (To : Integer);
procedure Increment (By : Integer);
function Get return Integer;
private
Value : Integer := 0;
end T;
end Pack;
(this is far from perfect; you’d like to be able to specify the initial Value when you declare a T, but that’s starting to get complicated).
In this case, the thing to be protected is the Value. You want to be sure that if two tasks call Increment at the “same” time, one with By => 3 and one with By => 4, the Value ends up being incremented by 7.
The body could look like
package body Pack is
protected body T is
procedure Set (To : Integer) is
begin
Value := To;
end Set;
procedure Increment (By : Integer) is
begin
Value := Value + By;
end Increment;
function Get return Integer is
begin
return Value;
end Get;
end T;
end Pack;
Recommended reading: the Wikibooks section on protected types.