src/internal/trace/v2/testdata/testprog/annotations.go

   1 // Copyright 2023 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // Tests user tasks, regions, and logging.
   6
   7 //go:build ignore
   8
   9 package main
  10
  11 import (
  12         "context"
  13         "log"
  14         "os"
  15         "runtime/trace"
  16         "sync"
  17 )
  18
  19 func main() {
  20         bgctx, cancel := context.WithCancel(context.Background())
  21         defer cancel()
  22
  23         // Create a pre-existing region. This won't end up in the trace.
  24         preExistingRegion := trace.StartRegion(bgctx, "pre-existing region")
  25
  26         // Start tracing.
  27         if err := trace.Start(os.Stdout); err != nil {
  28                 log.Fatalf("failed to start tracing: %v", err)
  29         }
  30
  31         // Beginning of traced execution.
  32         var wg sync.WaitGroup
  33         ctx, task := trace.NewTask(bgctx, "task0") // EvUserTaskCreate("task0")
  34         wg.Add(1)
  35         go func() {
  36                 defer wg.Done()
  37                 defer task.End() // EvUserTaskEnd("task0")
  38
  39                 trace.WithRegion(ctx, "region0", func() {
  40                         // EvUserRegionBegin("region0", start)
  41                         trace.WithRegion(ctx, "region1", func() {
  42                                 trace.Log(ctx, "key0", "0123456789abcdef") // EvUserLog("task0", "key0", "0....f")
  43                         })
  44                         // EvUserRegionEnd("region0", end)
  45                 })
  46         }()
  47         wg.Wait()
  48
  49         preExistingRegion.End()
  50         postExistingRegion := trace.StartRegion(bgctx, "post-existing region")
  51
  52         // End of traced execution.
  53         trace.Stop()
  54
  55         postExistingRegion.End()
  56 }