// Copyright 2017, OpenCensus Authors // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package trace_test import ( "fmt" "go.opencensus.io/trace" "golang.org/x/net/context" ) // This example shows how to use StartSpan and (*Span).End to capture // a function execution in a Span. It assumes that the function // has a context.Context argument. func ExampleStartSpan() { printEvens := func(ctx context.Context) { ctx, span := trace.StartSpan(ctx, "my/package.Function") defer span.End() for i := 0; i < 10; i++ { if i%2 == 0 { fmt.Printf("Even!\n") } } } ctx := context.Background() printEvens(ctx) }