序
本文主要研究一下tunny
Worker
代码语言：javascript复制type Worker interface {
// Process will synchronously perform a job and return the result.
Process(interface{}) interface{}
// BlockUntilReady is called before each job is processed and must block the
// calling goroutine until the Worker is ready to process the next job.
BlockUntilReady()
// Interrupt is called when a job is cancelled. The worker is responsible
// for unblocking the Process implementation.
Interrupt()
// Terminate is called when a Worker is removed from the processing pool
// and is responsible for cleaning up any held resources.
Terminate()
}
Worker接口定义了Process、BlockUntilReady、Interrupt、Terminate方法
closureWorker
代码语言：javascript复制type closureWorker struct {
processor func(interface{}) interface{}
}
func (w *closureWorker) Process(payload interface{}) interface{} {
return w.processor(payload)
}
func (w *closureWorker) BlockUntilReady() {}
func (w *closureWorker) Interrupt() {}
func (w *closureWorker) Terminate() {}
closureWorker定义了processor属性，它实现了Worker接口的Process、BlockUntilReady、Interrupt、Terminate方法，其中Process方法委托给processor
callbackWorker
代码语言：javascript复制type callbackWorker struct{}
func (w *callbackWorker) Process(payload interface{}) interface{} {
f, ok := payload.(func())
if !ok {
return ErrJobNotFunc
}
f()
return nil
}
func (w *callbackWorker) BlockUntilReady() {}
func (w *callbackWorker) Interrupt() {}
func (w *callbackWorker) Terminate() {}
callbackWorker定义了processor属性，它实现了Worker接口的Process、BlockUntilReady、Interrupt、Terminate方法，其中Process方法执行的是payload函数
Pool
代码语言：javascript复制type Pool struct {
queuedJobs int64
ctor func() Worker
workers []*workerWrapper
reqChan chan workRequest
workerMut sync.Mutex
}
func New(n int, ctor func() Worker) *Pool {
p := &Pool{
ctor: ctor,
reqChan: make(chan workRequest),
}
p.SetSize(n)
return p
}
func NewFunc(n int, f func(interface{}) interface{}) *Pool {
return New(n, func() Worker {
return &closureWorker{
processor: f,
}
})
}
func NewCallback(n int) *Pool {
return New(n, func() Worker {
return &callbackWorker{}
})
}
Pool定义了queuedJobs、ctor、workers、reqChan、workerMut属性；New方法根据n和ctor创建Pool；NewFunc方法根据n和f来创建closureWorker；NewCallback方法创建callbackWorker
Process
代码语言：javascript复制func (p *Pool) Process(payload interface{}) interface{} {
atomic.AddInt64(&p.queuedJobs, 1)
request, open := <-p.reqChan
if !open {
panic(ErrPoolNotRunning)
}
request.jobChan <- payload
payload, open = <-request.retChan
if !open {
panic(ErrWorkerClosed)
}
atomic.AddInt64(&p.queuedJobs, -1)
return payload
}
Process方法首先递增queuedJobs，然后从reqChan读取request，然后往jobChan写入payload，之后再等待retChan，最后递减queuedJobs
SetSize
代码语言：javascript复制func (p *Pool) SetSize(n int) {
p.workerMut.Lock()
defer p.workerMut.Unlock()
lWorkers := len(p.workers)
if lWorkers == n {
return
}
// Add extra workers if N > len(workers)
for i := lWorkers; i < n; i {
p.workers = append(p.workers, newWorkerWrapper(p.reqChan, p.ctor()))
}
// Asynchronously stop all workers > N
for i := n; i < lWorkers; i {
p.workers[i].stop()
}
// Synchronously wait for all workers > N to stop
for i := n; i < lWorkers; i {
p.workers[i].join()
}
// Remove stopped workers from slice
p.workers = p.workers[:n]
}
SetSize方法首先通过workerMut加锁，然后根据lWorkers创建newWorkerWrapper，之后执行worker.stop，再执行worker.join()，然后清空workers
Close
代码语言：javascript复制func (p *Pool) Close() {
p.SetSize(0)
close(p.reqChan)
}
Close方法执行SetSize(0)及close(p.reqChan)
实例
代码语言：javascript复制func TestFuncJob(t *testing.T) {
pool := NewFunc(10, func(in interface{}) interface{} {
intVal := in.(int)
return intVal * 2
})
defer pool.Close()
for i := 0; i < 10; i {
ret := pool.Process(10)
if exp, act := 20, ret.(int); exp != act {
t.Errorf("Wrong result: %v != %v", act, exp)
}
}
}
TestFuncJob通过NewFunc创建pool，
小结
tunny的Worker接口定义了Process、BlockUntilReady、Interrupt、Terminate方法；NewFunc方法创建的是closureWorker，NewCallback方法创建的是callbackWorker。
doc
- tunny
