🐲 An optimization in worker channel

ants.go

@@ -25,6 +25,7 @@ package ants
 import (
 	"errors"
 	"math"
+	"runtime"
 )
 
 const (
@@ -35,6 +36,30 @@ const (
 	DefaultCleanIntervalTime = 5
 )
 
+var (
+	// Error types for the Ants API.
+	ErrInvalidPoolSize   = errors.New("invalid size for pool")
+	ErrInvalidPoolExpiry = errors.New("invalid expiry for pool")
+	ErrPoolClosed        = errors.New("this pool has been closed")
+
+	// workerChanCap determines whether the channel of a worker should be a buffered channel
+	// to get the best performance, inspired by fasthttp.
+	// https://github.com/valyala/fasthttp/blob/master/workerpool.go#L139
+	workerChanCap = func() int {
+		// Use blocking workerChan if GOMAXPROCS=1.
+		// This immediately switches Serve to WorkerFunc, which results
+		// in higher performance (under go1.5 at least).
+		if runtime.GOMAXPROCS(0) == 1 {
+			return 0
+		}
+
+		// Use non-blocking workerChan if GOMAXPROCS>1,
+		// since otherwise the Serve caller (Acceptor) may lag accepting
+		// new connections if WorkerFunc is CPU-bound.
+		return 1
+	}()
+)
+
 // Init a instance pool when importing ants.
 var defaultAntsPool, _ = NewPool(DefaultAntsPoolSize)
 
@@ -62,10 +87,3 @@ func Free() int {
 func Release() {
 	defaultAntsPool.Release()
 }
-
-// Error types for the Ants API.
-var (
-	ErrInvalidPoolSize   = errors.New("invalid size for pool")
-	ErrInvalidPoolExpiry = errors.New("invalid expiry for pool")
-	ErrPoolClosed        = errors.New("this pool has been closed")
-)

pool.go

@@ -28,8 +28,6 @@ import (
 	"time"
 )
 
-type sig struct{}
-
 type f func()
 
 // Pool accept the tasks from client,it limits the total
@@ -222,7 +220,7 @@ func (p *Pool) getWorker() *Worker {
 	} else if w == nil {
 		w = &Worker{
 			pool: p,
-			task: make(chan f, 1),
+			task: make(chan f, workerChanCap),
 		}
 		w.run()
 		p.incRunning()

pool_func.go

@@ -224,7 +224,7 @@ func (p *PoolWithFunc) getWorker() *WorkerWithFunc {
 	} else if w == nil {
 		w = &WorkerWithFunc{
 			pool: p,
-			args: make(chan interface{}, 1),
+			args: make(chan interface{}, workerChanCap),
 		}
 		w.run()
 		p.incRunning()