将go例程中的多个结果聚合到单个数组中

Question

I have the following function which spins off a given amount of go routines

func (r *Runner) Execute() {
    var wg sync.WaitGroup
    wg.Add(len(r.pipelines))
    for _, p := range r.pipelines {
        go executePipeline(p, &wg)
    }

    wg.Wait()

    errs := ....//contains list of errors reported by any/all go routines

}

I was thinking there might be some way with channels, but I can't seem to figure it out.

Answer 1

One way to do this is using mutexes if you can make executePipeline retuen errors:

// ...
for _, p := range r.pipelines {
    go func(p pipelineType) {
        if err := executePipeline(p, &wg); err != nil {
            mu.Lock()
            errs = append(errs, err)
            mu.UnLock()
        }
    }(p)
}

To use a channel, you can have a separate goroutine listning for errors:

errCh := make(chan error)

go func() {
    for e := range errCh {
        errs = append(errs, e)
    }
}

and in the Execute function, make the following changes:

// ...
wg.Add(len(r.pipelines))
for _, p := range r.pipelines {
    go func(p pipelineType) {
        if err := executePipeline(p, &wg); err != nil {
            errCh <- err
        }
    }(p)
}

wg.Wait()
close(errCh)

You can always use @zerkms method listed above if the number of goroutines is not high.

instead of returning error from executePipleline and using a anonymous function wrapper, you can always make above changes within the function itself.