/**
* Checks for all registered job vertices if their in-/out-degree is correct.
*
* @return <code>null</code> if the in-/out-degree of all vertices is correct or the first job
* vertex whose in-/out-degree is incorrect.
*/
public AbstractJobVertex areVertexDegreesCorrect() {
// Check input vertices
final Iterator<AbstractJobInputVertex> iter = getInputVertices();
while (iter.hasNext()) {
final AbstractJobVertex jv = iter.next();
if (jv.getNumberOfForwardConnections() < 1 || jv.getNumberOfBackwardConnections() > 0) {
return jv;
}
}
// Check task vertices
final Iterator<JobTaskVertex> iter2 = getTaskVertices();
while (iter2.hasNext()) {
final AbstractJobVertex jv = iter2.next();
if (jv.getNumberOfForwardConnections() < 1 || jv.getNumberOfBackwardConnections() < 1) {
return jv;
}
}
// Check output vertices
final Iterator<AbstractJobOutputVertex> iter3 = getOutputVertices();
while (iter3.hasNext()) {
final AbstractJobVertex jv = iter3.next();
if (jv.getNumberOfForwardConnections() > 0 || jv.getNumberOfBackwardConnections() < 1) {
return jv;
}
}
return null;
}
