// Copyright 2013 The Go Authors.  All rights reserved.// Use of this source code is governed by a BSD-style// license that can be found in the LICENSE file. package testing import (	"runtime") // 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) {	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(1)) 	// Warm up the function	f() 	// Measure the starting statistics	var memstats runtime.MemStats	runtime.ReadMemStats(&memstats)	mallocs := 0 - memstats.Mallocs 	// Run the function the specified number of times	for i := 0; i < runs; i++ {		f()	} 	// Read the final statistics	runtime.ReadMemStats(&memstats)	mallocs += memstats.Mallocs 	// Average the mallocs over the runs (not counting the warm-up).	// We are forced to return a float64 because the API is silly, but do	// the division as integers so we can ask if AllocsPerRun()==1	// instead of AllocsPerRun()<2.	return float64(mallocs / uint64(runs))}