工作线程池

Question

在 http://marcio.io/2015/07/handling-1-million-requests-per-minute-with-golang/ 提供的示例中，该示例已在很多地方被引用。

func (d *Dispatcher) dispatch() {
for {
    select {
    case job := <-JobQueue:
        // a job request has been received
        go func(job Job) {
            // try to obtain a worker job channel that is available.
            // this will block until a worker is idle
            jobChannel := <-d.WorkerPool

            // dispatch the job to the worker job channel
            jobChannel <- job
         }(job)
    }
}
}

调度服务了 MaxWorker 个作业后，工作人员池（chan chan 作业）是否会耗尽？由于<-d.WorkerPool是从渠道中拉取的，作业渠道在第一次调用第一种dispatcher.Run()后没有得到补充？还是我 missing/misreading 什么东西？ WorkerPool 如何通过可用的工作渠道得到补充？

go func(job Job) {
            // try to obtain a worker job channel that is available.
            // this will block until a worker is idle
            jobChannel := <-d.WorkerPool

            // dispatch the job to the worker job channel
            jobChannel <- job
        }(job)

Answer 1

如果你仔细阅读worker的代码，你会发现

w.WorkerPool <- w.JobChannel

每次循环开始，worker本身的channel被放回

我复制下面的整个函数：

func (w Worker) Start() {
    go func() {
        for {
            // register the current worker into the worker queue.
            w.WorkerPool <- w.JobChannel

            select {
            case job := <-w.JobChannel:
                // we have received a work request.
                if err := job.Payload.UploadToS3(); err != nil {
                    log.Errorf("Error uploading to S3: %s", err.Error())
                }

            case <-w.quit:
                // we have received a signal to stop
                return
            }
        }
    }()
}

工作线程池

Worker thread pool

go

threadpool

channel

worker