}

func BenchmarkMutexSpin(b *testing.B) {
	b.ResetTimer()
	b.ReportAllocs()

	// This benchmark models a situation where spinning in the mutex should be
	// profitable. To achieve this we create a goroutine per-proc.
	// These goroutines access considerable amount of local data so that
	// unnecessary rescheduling is penalized by cache misses.
	m := NewDRWMutex(ds, "")
	var acc0, acc1 uint64
	b.RunParallel(func(pb *testing.PB) {