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type Student struct {
	Name   string
	Age    int32
	Remark [1024]byte
}

var buf, _ = json.Marshal(Student{Name: "Geektutu", Age: 25})

func unmarsh() {
	stu := &Student{}
	json.Unmarshal(buf, stu)
}

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var studentPool = sync.Pool{
    New: func() interface{} { 
        return new(Student) 
    },
}

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stu := studentPool.Get().(*Student)
json.Unmarshal(buf, stu)
studentPool.Put(stu)

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package main

import (
	"fmt"
	"github.com/gammazero/workerpool"
)

func main() {
	wp := workerpool.New(2)
	requests := []string{"alpha", "beta", "gamma", "delta", "epsilon"}

	for _, r := range requests {
		r := r
		wp.Submit(func() {
			fmt.Println("Handling request:", r)
		})
	}

	wp.StopWait()
}

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func (p *WorkerPool) Submit(task func()) {
	if task != nil {
		p.taskQueue <- task
	}
}

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func (p *WorkerPool) SubmitWait(task func()) {
	if task == nil {
		return
	}
	doneChan := make(chan struct{})
	p.taskQueue <- func() {
		task()
		close(doneChan)
	}
	<-doneChan
}

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func New(maxWorkers int) *WorkerPool {
	// There must be at least one worker.
	if maxWorkers < 1 {
		maxWorkers = 1
	}

	pool := &WorkerPool{
		maxWorkers:  maxWorkers,
		taskQueue:   make(chan func(), 1),
		workerQueue: make(chan func()),
		stopSignal:  make(chan struct{}),
		stoppedChan: make(chan struct{}),
	}

	// Start the task dispatcher.
	go pool.dispatch()

	return pool
}

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// dispatch sends the next queued task to an available worker.
func (p *WorkerPool) dispatch() {
	defer close(p.stoppedChan)
	timeout := time.NewTimer(idleTimeout)
	var workerCount int
	var idle bool

Loop:
	for {
		if p.waitingQueue.Len() != 0 {
			if !p.processWaitingQueue() {
				break Loop
			}
			continue
		}

		select {
		case task, ok := <-p.taskQueue:
			if !ok {
				break Loop
			}
			// Got a task to do.
			select {
			case p.workerQueue <- task:
			default:
				// Create a new worker, if not at max.
				if workerCount < p.maxWorkers {
					go startWorker(task, p.workerQueue)
					workerCount++
				} else {
					// Enqueue task to be executed by next available worker.
					p.waitingQueue.PushBack(task)
					atomic.StoreInt32(&p.waiting, int32(p.waitingQueue.Len()))
				}
			}
			idle = false
		case <-timeout.C:
			// Timed out waiting for work to arrive.  Kill a ready worker if
			// pool has been idle for a whole timeout.
			if idle && workerCount > 0 {
				if p.killIdleWorker() {
					workerCount--
				}
			}
			idle = true
			timeout.Reset(idleTimeout)
		}
	}

	// If instructed to wait, then run tasks that are already queued.
	if p.wait {
		p.runQueuedTasks()
	}

	// Stop all remaining workers as they become ready.
	for workerCount > 0 {
		p.workerQueue <- nil
		workerCount--
	}

	timeout.Stop()
}

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func (p *WorkerPool) processWaitingQueue() bool {
	select {
	case task, ok := <-p.taskQueue:
		if !ok {
			return false
		}
		p.waitingQueue.PushBack(task)
	case p.workerQueue <- p.waitingQueue.Front().(func()):
		// A worker was ready, so gave task to worker.
		p.waitingQueue.PopFront()
	}
	atomic.StoreInt32(&p.waiting, int32(p.waitingQueue.Len()))
	return true
}