Goroutines and WaitGroup in Go

Starting concurrent work and waiting for it.

func fanOut(jobs []string) {
    var wg sync.WaitGroup
    for _, job := range jobs {
        wg.Add(1)
        go func(name string) {
            defer wg.Done()
            fmt.Println("working on", name)
        }(job)
    }
    wg.Wait()
}

How it works

1. go func() launches a goroutine.
2. wg.Add/wg.Done track outstanding work.
3. wg.Wait blocks until every goroutine finishes.

Keywords and builtins used here

• defer
• for
• func
• go
• range
• string
• var

The run, in numbers

Lines

11

Characters to type

179

Tokens

60

Three-star pace

95 tpm

At the three-star pace of 95 tokens a minute, this run takes about 38 seconds.

Type this snippet

Step 1 of 3 in Goroutines, step 1 of 25 in Concurrency.

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