context-timeout.go

package main

import (
	"context"
	"time"

	"github.com/gildas/go-errors"
	"github.com/gildas/go-logger"
)

func fastjob(result chan interface{}) {
	time.Sleep(50 * time.Millisecond)
	result <- "Job Done"
}

func slowjob(result chan interface{}) {
	time.Sleep(10 * time.Second)
	result <- "Job Done"
}

func jobRunner(ctx context.Context, job func(chan interface{})) error {
	log := logger.Must(logger.FromContext(ctx))
	reschan := make(chan interface{})

	// Run the job
	go job(reschan)

	// Wait for results
	start := time.Now()
	for {
		select {
		case result := <-reschan:
			log.Infof("Success results: %+v in %s", result, time.Since(start))
			return nil
		case <-ctx.Done():
			log.Errorf("Timeout encountered after %s", time.Since(start))
			return errors.HTTPStatusRequestTimeout.WithStack()
		}
	}
}

func main() {
	log := logger.Create("CONTEXT", &logger.StdoutStream{Unbuffered: true})

	logctx := log.ToContext(context.Background())
	log.Infof("Running a fast job")
	log1 := log.Record("job", "fastjob")
	ctx1, cancel1 := context.WithTimeout(logctx, 1 * time.Second)
	defer cancel1()
	if err := jobRunner(ctx1, fastjob); err != nil {
		log1.Errorf("Error was encountered", err)
	}

	log.Infof("Running a slow job")
	log2 := log.Record("job", "slowjob")
	ctx2, cancel2 := context.WithTimeout(logctx, 1 * time.Second)
	defer cancel2()
	if err := jobRunner(ctx2, slowjob); err != nil {
		log2.Errorf("Error was encountered", err)
	}
}

Logger output:

23:38:06.000  INFO CONTEXT: Running a fast job (scope=main, tid=2645317, topic=main)
23:38:06.000  INFO CONTEXT: Success results: Job Done in 50.196358ms (scope=main, tid=2645320, topic=main)
23:38:06.000  INFO CONTEXT: Running a slow job (scope=main, tid=2645320, topic=main)
23:38:07.000 ERROR CONTEXT: Timeout encountered after 1.001048114s (scope=main, tid=2645319, topic=main)
23:38:07.000 ERROR CONTEXT: (err={}, job=slowjob, scope=main, tid=2645319, topic=main)
    Error was encountered, Error: Request Timeout
    github.com/gildas/go-errors.WithStack
    	.../[email protected]/wrappers.go:27
    github.com/gildas/go-errors.Error.WithStack
    	.../[email protected]/error.go:117
    main.jobRunner
    	.../context-timeout.go:37
    main.main
    	.../context-timeout.go:58
    runtime.main
    	/go/runtime/proc.go:225
    runtime.goexit
    	go/runtime/asm_amd64.s:1371