These improvement suggestion came about after working on SERVER-93077 (which deals with running commands that block)

In operation_context.h, getExpirationDateForWaitForValue() is private so the current solution to calculate a deadline is 
Date_t::now() + Milliseconds(SOME_NUM). Thus, getExpirationDateForWaitForValue() cannot be called on an OperationContext object. Could this introduce discrepancies between opCtx's notion of time and what Date_t returns?

Moreover, in interruptible.h, there exists a runWithDeadline method that takes a Date_t but not an equivalent method in terms of function that can take a time parameter (such as milliseconds) that indicates how long to run for. Perhaps adding that method should be taken into consideration?