CppCon 2015

Almost every programmer knows about and fears race conditions on memory where one strand of execution may concurrently update data in use by another strand of execution, leading to an inconsistent and usually dangerous inconsistent read of program state. Almost every programmer therefore is aware of mutexes, memory ordering, semaphores and the other techniques used to serialise access to memory.

Interestingly, most programmers are but vaguely aware of potential race conditions on the filing system, and as a result write code which assumes that the filing system does not suddenly change out from underneath you when you are working on it. This assumption of a static filing system introduces many potential security bugs never mind ways of crashing your program, and of course creating data loss and corruption.

This workshop will cover some of the ways in which filing system races can confound, and what portable idioms and patterns you should employ to prevent misoperation, even across networked Samba shares. Finally, an introduction of the proposed Boost library AFIO will be made which can help application developers writing filing system race free code portably.