We present a simple and wait-free implementation of a snapshot shared data structure suitable for real-time systems with sporadic tasks. Snapshot mechanisms give the means to a real-time task to read a globally consistent set of variable values while other concurrent tasks are updating them. Such a mechanism can be used to solve a variety of communication and synchronization problems, including system monitoring and control of real-time applications. Typical snapshot implementations are based on mutual exclusion, which causes blocking. Besides from causing reduced overall system performance, blocking also complicates the scheduling analysis and can cause serious problems as priority inversion or dead-locks. To address those problems researc...