I have a function to create Istio VirtualService objects. I am using goroutines to execute my function concurrently, starting 100 workers.

            var data map[string]string
            for _, data = range MapList {
                wg.Add(1)
                limit.Execute(func() {
                    go func(data map[string]string) {
                        defer wg.Done()
                        _,_ = m.createVirtualServices(ctx, data, namespace)
                    }(data)
                })
                wg.Wait()
            }

this takes exact same time to execute if I'd just loop over seMapList and execute my function.

Why?

CodePudding user response：

Because you are waiting for the goroutine to complete right after you start it. Try this instead:

            for _, data = range MapList {
                wg.Add(1)
                limit.Execute(func() {
                    go func(data map[string]string) {
                        defer wg.Done()
                        _,_ = m.createVirtualServices(ctx, data, namespace)
                    }(data)
                })
            }
            wg.Wait() // Wait for them after all goroutines are created