Locks and barriers in checkpointing and recovery

Dependency tracking between communicating tasks is an important concept in backward error recovery for parallel applications. One can extend the traditional dependence tracking model for message passing systems to track dependencies between shared memory and task private states for shared memory applications. The objective of this paper is to analyze the issues generated by locks and barriers in parallel applications so that we can checkpoint tasks at any time (even when holding or waiting for locks and barriers). In particular we attempt to extend earlier dependency tracking mechanisms to locks and barriers. We address both coordinated and uncoordinated checkpointing schemes.