go/src/testing/allocs.go

// AllocsPerRun returns the average number of allocations during calls to f.
// Although the return value has type float64, it will always be an integral value.
//
// To compute the number of allocations, the function will first be run once as
// a warm-up. The average number of allocations over the specified number of
// runs will then be measured and returned.
//
// AllocsPerRun sets GOMAXPROCS to 1 during its measurement and will restore
// it before returning.
func AllocsPerRun(runs int, f func()) (avg float64) { … }