This paper proposes an innovative technique for the generation of interleavings for concurrent program testing. Operations on shared variables are tracked. Every time a shared variable is read, the read value is chosen among the values that the variable could hold in some interleaving consistent with the past observed events.

The problem of choosing possible read values is far from simple due to the fact that past decisions affect future ones. Our solution is computationally intensive and, therefore, impractical as is. However, it lead us to new heuristics for noise generation using embedded sleep statements.