func ConcurrencySpec(c nanospec.Context) {
r := NewRunner()
r.AddSpec(VerySlowDummySpec)
start := time.Now()
r.Run()
end := time.Now()
totalTime := end.Sub(start).Nanoseconds()
// If the spec is executed single-threadedly, then it would take
// at least 4*DELAY to execute. If executed multi-threadedly, it
// would take at least 2*DELAY to execute, because the first spec
// needs to be executed fully before the other specs are found, but
// after that the other specs can be executed in parallel.
expectedMaxTime := int64(math.Floor(2.9 * DELAY))
if totalTime > expectedMaxTime {
c.Errorf("Expected the run to take less than %v ms but it took %v ms",
expectedMaxTime/MILLISECOND, totalTime/MILLISECOND)
}
runCounts := countSpecNames(r.executed)
c.Expect(runCounts["Child A"]).Equals(1)
c.Expect(runCounts["Child B"]).Equals(1)
c.Expect(runCounts["Child C"]).Equals(1)
c.Expect(runCounts["Child D"]).Equals(1)
}
