1. A method performed by a scheduler of a process executing on a computer system, the method comprising: detecting that a first execution context preempted and blocked by an entity other than the scheduler in a first critical region while executing on a processing resource of the scheduler, the first critical region is a set of instructions in the first execution context whose execution becomes contingent on data corresponding to the processing resource; and ensuring that the first execution context resumes execution on the processing resource in response to an indication to the scheduler from the entity that caused the block indicating the first execution context becoming unblocked and without the scheduler providing any knowledge of the preemption to the first execution context.