Raymond Tree Based Algorithm For Mutual Exclusion in distributed Systems Raymond Tree Based Algorithm Token – based Sites are logically arranged as a directed tree such that the edges of the tree are having directions toward the site(Tree Root) that has the token. Every site has a local variable called holder that points to an immediate neighbour node on a directed path to the root node. Holder of root is self pointed. Every site keeps a FIFO queue called request Q that stores the requests sent by neighbouring site to this site. Releasing the CS If its request Q is non-empty, then deletes the top entry from queue and sends the token to that site, and sets the holder value to the target node. If the request Q is empty, then the site sends a REQUEST message to the site which is pointed at by the holder variable. Raymond-tree Example: D send request for token to enters into CS REQUEST PRIVILEGE (Image content with a tree diagram with nodes A, B, C, D, E, F, G and arrows/labels): Node T (likely representing Token/Root) Node A (parent of B and C) Node B (parent of D and E) H_B = A RQ_B = D Arrow labeled REQUEST pointing from D to B Node C (parent of F and G) Node D (child of B) H_D = B RQ_D = D (This seems like a self-reference in the queue, might be D sent the request, so it's in its own queue initially or related to its own request.) Nodes E, F, G (children)