Allow nil error channel in WriteNoreplyRequest

Not allocating a channel at all doubles the speed of the noop test.
Now we're pushing just over 1M noop/sec (compared to x11perf/Xlib,
which pushes 13M noop/sec)

2 files changed, 21 insertions, 20 deletions

diff --git a/noop.go b/noop.go
index 3b9aae3..ebe0e1c 100644
--- a/noop.go
+++ b/noop.go
@@ -18,21 +18,11 @@ func main () {
 		return
 	}
 
-	err := make(chan interface{})
-	go func (err chan interface{}) {
-		for {
-			e := <- err
-			if e != nil {
-				println("Unexpected error!")
-			}
-		}
-	}(err)
-
 	noopRequest := []byte{127, 0, 0, 1}
 
 	fmt.Printf("Sending %d noop requests: ", *iter)
 	for i := uint(0); i < *iter; i++ {
-		c.WriteNoreplyRequest(noopRequest, err)
+		c.WriteNoreplyRequest(noopRequest, nil)
 	}
 	c.Flush()
 	fmt.Println("Done.")
diff --git a/xgob.go b/xgob.go
index a9e5d39..cfd5f2e 100644
--- a/xgob.go
+++ b/xgob.go
@@ -42,6 +42,7 @@ type Reply struct {
 type Connection struct {
 	Setup				ConnectionBlock
 	Event				chan Event
+	Error				chan Error
 	conn				io.ReadWriteCloser
 	out					*bufio.Writer
 	reply				map[uint64]chan interface {}
@@ -53,6 +54,7 @@ type Connection struct {
 }
 
 const events_before_readblock = 10000
+const errors_before_readblock = 10000
 
 func parse_display (name string) (host string, protocol string, display int, screen int) {
     if len(name) == 0 {
@@ -265,27 +267,35 @@ func (c *Connection) registerReply (reply chan interface{}) {
 	defer c.replyMutex.Unlock()
 
 	c.lastRequestWritten++
-	c.reply[c.lastRequestWritten] = reply
+	if reply != nil {
+		c.reply[c.lastRequestWritten] = reply
+	}
 }
 
 func (c *Connection) postReply (seq uint64, reply interface{}) {
 	c.replyMutex.Lock()
 	defer c.replyMutex.Unlock()
 
-	if c.reply[seq] == nil {
-		println("Error: Unexpected sequence", seq)
-		return
-	}
-
 	if seq != c.lastSequenceRead {
 		c.reply[c.lastSequenceRead] = nil, false
 	}
 	for i := c.lastSequenceRead + 1; i < seq; i++ {
-		c.reply[i] <- nil
-		c.reply[i] = nil, false
+		if target := c.reply[i]; target != nil {
+			target <- nil
+			c.reply[i] = nil, false
+		}
 	}
 
-	c.reply[seq] <- reply
+	if target := c.reply[seq]; target != nil {
+		target <- reply
+	} else {
+		error, ok := reply.(Error)
+		if ok {
+			c.Error <- error
+		} else {
+			println("Unexpected reply to sequence", seq)
+		}
+	}
 	c.lastSequenceRead = seq
 }
 
@@ -338,6 +348,7 @@ func (c *Connection)connect_auth(name string, data string) {
 	}
 	c.out = bufio.NewWriter(c.conn)
 	c.Event = make (chan Event, events_before_readblock)
+	c.Error = make (chan Error, errors_before_readblock)
 	c.reply = make (map [uint64]chan interface{})
 	go c.read(in)
 }