Current File : //usr/local/go119/src/cmd/go/init_test.go
// Copyright 2018 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 main_test
import (
"internal/testenv"
"os/exec"
"sync/atomic"
"testing"
)
// BenchmarkExecGoEnv measures how long it takes for 'go env GOARCH' to run.
// Since 'go' is executed, remember to run 'go install cmd/go' before running
// the benchmark if any changes were done.
func BenchmarkExecGoEnv(b *testing.B) {
testenv.MustHaveExec(b)
gotool, err := testenv.GoTool()
if err != nil {
b.Fatal(err)
}
// We collect extra metrics.
var n, userTime, systemTime int64
b.ResetTimer()
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
cmd := exec.Command(gotool, "env", "GOARCH")
if err := cmd.Run(); err != nil {
b.Fatal(err)
}
atomic.AddInt64(&n, 1)
atomic.AddInt64(&userTime, int64(cmd.ProcessState.UserTime()))
atomic.AddInt64(&systemTime, int64(cmd.ProcessState.SystemTime()))
}
})
b.ReportMetric(float64(userTime)/float64(n), "user-ns/op")
b.ReportMetric(float64(systemTime)/float64(n), "sys-ns/op")
}
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