public void processVertex(String name) {
    LOG.info("Vertex succeeded: {}", name);
    finishedVertices.add(name);
    queue.offer(VERTEX_FINISH_TOKEN);
  }
DynamicPartitionPruner takes a list of assigned partitions at runtime (split
generation) and prunes them using events generated during execution of the
dag.
ql/src/java/org/apache/hadoop/hive/ql/exec/tez/DynamicPartitionPruner.java