1. A system for providing fault tolerant processing in an implantable medical device, comprising: an implantable medical device comprising a processor and memory store, the processor and memory store configured to execute a plurality of threads; temporal and spatial constraints assigned to one or more of the threads; and a kernel, comprising a scheduler configured to divide processing time among the plurality of threads; and a thread monitor configured to monitor execution of threads against the temporal and spatial constraints, the spatial constraints comprising a unique identifier assigned for each thread prior to execution, wherein the unique identifier for each thread that completes is checked against the unique identifier previously assigned, and the thread monitor further configured to issue a response upon violation of either of the constraints by one of the plurality of threads.