Dijkstra–Scholten algorithm

The Dijkstra-Scholten Algorithm is an algorithm for detecting termination in a distributed system. The algorithm was proposed by Dijkstra and Scholten in 1980.

Algorithm

Dijkstra-Scholten's algorithm is a tree-based algorithm which can be described by the following:

• The initiator of a computation is the root of the tree.
• Upon receiving a computational message:
  • If the receiving process is currently not in the computation: the process joins the tree by becoming a child of the sender of the message. (No acknowledgement message is sent at this point.)
  • If the receiving process is already in the computation: the process immediately sends an acknowledgement message to the sender of the message.
• When a process has no more children and has become idle, the process detaches itself from the tree by sending an acknowledgement message to its tree parent.
• Termination occurs when the initiator has no children and has become idle.