GRIP, Network Tables, and mutual exclusion

[RoboPirate]

I've been trying to determine the cause of occasional crashes of our robot code. We are using GRIP running on the RoboRIO and access the network tables in our robot code.

I can't find any method in NetworkTable to ensure that we get a coherent set of information from the camera. We access multiple sub-tables in our target processing (width, height, X, and Y centers). However, there doesn't seem to be any guarantee that each table we fetch is referring to the same image. There is no mutual exclusion for the table so, in theory, GRIP could be updating the table at about the same time we are accessing it, giving us a set of sub-tables that don't go together.

Do the task priorities in RTLinux guarantee that this won't happen or is there some mutex mechanism I haven't found?