Information representative of a graph-based program specification has components, and directed links between ports of said components, defining a dependency between said components. A directed link exists between a port of a first component and a port of a second component. The first component specifies first-component execution code that when compiled enables execution of a first task. The second component specifies second-component execution code that when compiled enables execution of a second task. Compiling the graph-based program specification includes grafting first control code to said first-component execution code, which changes a state of said second component to a pending state, an active state, or a suppressed state. Based on said state, said first control code causes at least one of: invoking said second component if said state changes from pending to active, or suppressing said second component if said state changes from pending to suppressed.