// The workgroup version
func usingWorkgroup(workers, generate int) {
// This is a Worker function. The workgroup will start however many of these
// you specify. In this example, it will start one for each CPU (see below).
workhorse := func(worker int, work workgroup.Work) {
time.Sleep(time.Duration(rand.Int63n(1000)) * time.Millisecond)
log.Printf("workgroup: worker %d handing work %d.", worker, work)
}
// This is a Work-Generator. It simply feeds work to each Worker goroutine
// as each is ready for Work. Although the Workers are goroutines, a
// workgroup uses sync.WaitGroup interanlly so this goroutine will block
// on the out channel until a Worker reads from the channel.
// The completion of this signals the workgroup's cleanup process (all the
// Workers will complete their work.)
workUnits := workgroup.Generator(func(out chan<- workgroup.Work) {
for i := 0; i < generate; i++ {
out <- i
}
})
// This configures and initates the workgroup.
// FanOut specifies how many Workers to start.
// Drain specifies the Generator function.
// With provides the Worker function.
workgroup.FanOut(workers).Drain(workUnits).With(workhorse).Go()
// This is just to show that Go blocks.
log.Printf("Done: elapsed:+%v", time.Now())
}
// Another equivalent workgroup version but optimized for space, shaving two lines from above's.
func usingOptimizedWorkgroup(workers, generate int) {
workgroup.FanOut(workers).Drain(workgroup.Generator(func(out chan<- workgroup.Work) {
for i := 0; i < generate; i++ {
out <- i
}
})).With(func(worker int, work workgroup.Work) {
time.Sleep(time.Duration(rand.Int63n(1000)) * time.Millisecond)
log.Printf("workgroup: worker %d handing work %d.", worker, work)
}).Go()
// This is just to show that Go blocks.
log.Printf("Done: elapsed:+%v", time.Now())
}