Class DoneSignalPort


  • public final class DoneSignalPort
    extends AbstractModelPort<Void>
    Used to coordinate processing between operators that have a processing dependency but no explicit data dependency. An example would be one operator that writes data to a temporary file and another operator that reads from that file. Note that this is a rarely-used feature.
    • Method Detail

      • getMetadataType

        public Class<? extends PortMetadata> getMetadataType()
        Description copied from class: LogicalPort
        Returns the class of metadata that this port uses
        Specified by:
        getMetadataType in class LogicalPort
        Returns:
        the class of metadata that this port uses
      • signalDone

        public void signalDone​(ExecutionContext ctx)
        Signals downstream operators that we are done
        Parameters:
        ctx - the execution context
      • waitDone

        public void waitDone​(ExecutionContext ctx)
        Waits until upstream operator has sent the done signal
        Parameters:
        ctx - the execution context
      • getOutput

        public static DoneSignalPort getOutput​(LogicalOperator op)
        Returns the done signal port from the given operator if it defines one, throwing an exception if none found
        Parameters:
        op - the operator
        Returns:
        the done signal port