相当于GCD串行调度队列

Question

Is there Go equivalent of Apple's GCD serial dispatch queue?

So far I have only found a solution that is a channel of functions.

work := make(chan func()) 

I would have a function receive from this channel and call the received functions. The functions must be executed in FIFO order.

Is there a better method or structure to do this in Go?

This shouldn't make a difference but I am looking to queue SQL queries to run in FIFO for this.

Answer 1

@OneOfOne, it was close but not quite.

I ended up making a Serial Dispatch Queue implementation in Go available here.

It is basically a go routine that blocks on a channel of type func() and runs the functions that are passed in order.

Implementation:

//Package serialqueue provides a serial queue for functions. 
//Queue items are processed in First In First Out (FIFO) order. 
package serialqueue

//New returns a new serial queue.
//Enqueue items like queueObj <- func() {doWork(data)}
func New() chan func() {
    //create channel of type function
    var queue = make(chan func())

    //spawn go routine to read and run functions in the channel
    go func() {
        for true {
            nextFunction := <-queue
            nextFunction()
        }
    }()

    return queue
}

Usage: (demonstrating writing to a string in the correct order)

//Package serialqueue provides provides tests for github.com/ansonl/serialqueue. 
package serialqueue_test

import (
    "testing"
    "fmt"
    "sync"
    "github.com/ansonl/serialqueue"
    )

func TestQueue(t *testing.T) {
    //Create new serial queue
    queue := serialqueue.New()

    //Number of times to loop
    var loops = 100

    //Queue output will be added here
    var queueOutput string

    //WaitGroup for determining when queue output is finished
    var wg sync.WaitGroup

    //Create function to place in queue
    var printTest = func(i int) {
        queueOutput = fmt.Sprintf("%v%v",queueOutput, i)
        wg.Done()
    }

    //Add functions to queue
    var i int;
    for i=0;i<loops;i++ {
        wg.Add(1)
        t:=i
        queue <- func() {printTest(t)}
    }

    //Generate correct output
    var correctOutput string
    for i=0;i<loops;i++ {
        correctOutput = fmt.Sprintf("%v%v", correctOutput, i)       
    }

    //Wait until all functions in queue are done
    wg.Wait()

    //Compare queue output with correct output
    if queueOutput != correctOutput {
        t.Errorf("Serial Queue produced %v, want %v", queueOutput, correctOutput);
    }
}

Hope this helps someone with the same issue!