## The `Signal' method

Argument: Any
Result: None

Valid for: System and APL (child task) object

The `Signal` method allows the child task to send a message to the parent, and vice versa. It is used in conjunction with the `onSignal` event, as follows:

- If the parent wants to send a signal to the child, it invokes the `Signal` method in the APL (child task) object. This causes an `onSignal` event to trigger in the System object of the child task.

- Conversely, if the child task wishes to send a signal to the parent, it invokes the `Signal` method in its own System object. This causes an `onSignal` event to trigger in the APL (child task) object of the parent.

In both cases, the `Signal` method optionally takes an argument, which can be any APL array (or an APLX overlay created using ŚOV). This is typically used to send a command to the other task, or to return a result to it. Any argument to the `Signal` method is available to the receiving task as the ŚWARG system variable during the execution of the callback.

See the section on APLX Multi-tasking for more details.

Topic: APLX Help : System Classes : Methods : Signal

[ Previous | Next | Contents | Index ]