1. A computer-implemented method for reporting a synchronization event in a runtime system of a computer system, comprising: at a computer system including at least one processor and memory storing at least one program, the at least one processor executing the at least one program to perform the operations of: monitoring a synchronization primitive in a runtime system of the computer system; detecting a synchronization operation performed on the synchronization primitive by a thread in the runtime system; incrementing an enumerator for the synchronization primitive when the synchronization operation satisfies predetermined criteria; and reporting a synchronization event that includes data relating to the synchronization operation performed on the synchronization primitive.