optimise: rm useless inputBarrier (#290)

connection_impl.go

@@ -43,7 +43,6 @@ type connection struct {
 	writeTrigger    chan error
 	inputBuffer     *LinkBuffer
 	outputBuffer    *LinkBuffer
-	inputBarrier    *barrier
 	outputBarrier   *barrier
 	supportZeroCopy bool
 	maxSize         int // The maximum size of data between two Release().
@@ -323,7 +322,7 @@ func (c *connection) init(conn Conn, opts *options) (err error) {
 	c.writeTrigger = make(chan error, 1)
 	c.bookSize, c.maxSize = pagesize, pagesize
 	c.inputBuffer, c.outputBuffer = NewLinkBuffer(pagesize), NewLinkBuffer()
-	c.inputBarrier, c.outputBarrier = barrierPool.Get().(*barrier), barrierPool.Get().(*barrier)
+	c.outputBarrier = barrierPool.Get().(*barrier)
 
 	c.initNetFD(conn) // conn must be *netFD{}
 	c.initFDOperator()

connection_reactor.go

@@ -71,7 +71,6 @@ func (c *connection) closeBuffer() {
 	// so we need to check the buffer length, and if it's an "unclean" close operation, let's give up to reuse the buffer
 	if c.inputBuffer.Len() == 0 || onConnect != nil || onRequest != nil {
 		c.inputBuffer.Close()
-		barrierPool.Put(c.inputBarrier)
 	}
 	if c.outputBuffer.Len() == 0 || onConnect != nil || onRequest != nil {
 		c.outputBuffer.Close()