errgroup

Overview

errgroup is a Go module that provides Context cancellation, error propagation and synchronisation for goroutines running fallible functions.

Usage

Creating an errgroup

As per the Go proverb, the zero value of the errgroup.Group is useful, and you can simply create a errgroup.Group as follows and begin using it:

var eg errgroup.Group

You can also configure the behaviour of an errgroup.Group by providing some errgroup.Configurer's to the errgroup.New function. For example:

var (
    ctx, cc = errgroup.WithCancel(ctx.Background())
    eg      = errgroup.New(cc)
)

Using an errgroup

Once you have created an errgroup.Group, you can begin using it by calling errgroup.Group.Go. Then, you can call errgroup.Group.Wait to wait for the result:

var fs []func() error

// ...

for _, f := range fs {
    _ = eg.Go(f)
}

errs := eg.Wait()
fmt.Println(errs)

Documentation

Documentation for errgroup can be found here.