Race condition

"Critical race" redirects here. For the academic movement, see Critical race theory.
Race condition in a logic circuit. Here, ∆t1 and ∆t2 represent the propagation delays of the logic elements. When the input value A changes from low to high, the circuit outputs a short spike of duration (∆t1 + ∆t2) − ∆t2 = ∆t1.

A race condition or race hazard is the condition of an electronics, software, or other system where the system's substantive behavior is dependent on the sequence or timing of other uncontrollable events, leading to unexpected or inconsistent results. It becomes a bug when one or more of the possible behaviors is undesirable.

The term race condition was already in use by 1954, for example in David A. Huffman's doctoral thesis "The synthesis of sequential switching circuits".[1]

Race conditions can occur especially in logic circuits or multithreaded or distributed software programs. Using mutual exclusion can prevent race conditions in distributed software systems.

  1. ^ Huffman, David A. "The synthesis of sequential switching circuits." (1954).