## The `onSignal' callback

Event number: 43
Generated for: System and APL (child task) objects

The `onSignal` callback allows Parent and Child tasks to send messages to each other, with associated data. It is invoked in an `APL` object belonging to a parent task when the child task executes the `Signal` method of its `System` object. Conversely, it is invoked in the `System` object of a child task when the Parent executes the `Signal` method of its `APL` child task object.

During the callback, ŒWARG contains the data (which can be any APL array or overlay) which the calling task passed as the argument to the `Signal` method.

The event-specific parameters in ŒEV are (in index origin 1):

            ŒEV[6]         Task ID for the task which sent the signal

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

Topic: APLX Help : System Classes : Callbacks : onSignal

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