Share the post write buffer with the synchronous one in the connection writer

This should prevent messages posted while generating synchronous messages don't get out of order.

diff --git a/connection.go b/connection.go
index 9e025497643cdb28e735753eef7d39f47a33a85a..73b1f4ce68228dcc534e2bfc794f686be248a3bf 100644 (file)
--- a/connection.go
+++ b/connection.go
@@ -93,9 +93,9 @@ type connection struct {
        pieceInclination  []int
        pieceRequestOrder prioritybitmap.PriorityBitmap
 
-       postedBuffer bytes.Buffer
-       uploadTimer  *time.Timer
-       writerCond   sync.Cond
+       writeBuffer bytes.Buffer
+       uploadTimer *time.Timer
+       writerCond  sync.Cond
 }
 
 func (cn *connection) peerHasAllPieces() (all bool, known bool) {
@@ -245,7 +245,7 @@ func (cn *connection) PeerHasPiece(piece int) bool {
 
 func (cn *connection) Post(msg pp.Message) {
        messageTypesPosted.Add(strconv.FormatInt(int64(msg.Type), 10), 1)
-       cn.postedBuffer.Write(msg.MustMarshalBinary())
+       cn.writeBuffer.Write(msg.MustMarshalBinary())
        cn.tickleWriter()
 }
 
@@ -404,7 +404,7 @@ func (cn *connection) fillWriteBuffer(msg func(pp.Message) bool) {
 // connection is writable.
 func (cn *connection) writer(keepAliveTimeout time.Duration) {
        var (
-               buf       bytes.Buffer
+               // buf       bytes.Buffer
                lastWrite time.Time = time.Now()
        )
        var keepAliveTimer *time.Timer
@@ -424,24 +424,25 @@ func (cn *connection) writer(keepAliveTimeout time.Duration) {
                if cn.closed.IsSet() {
                        return
                }
-               buf.Write(cn.postedBuffer.Bytes())
-               cn.postedBuffer.Reset()
-               if buf.Len() == 0 {
+               if cn.writeBuffer.Len() == 0 {
                        cn.fillWriteBuffer(func(msg pp.Message) bool {
                                cn.wroteMsg(&msg)
-                               buf.Write(msg.MustMarshalBinary())
-                               return buf.Len() < 1<<16
+                               cn.writeBuffer.Write(msg.MustMarshalBinary())
+                               return cn.writeBuffer.Len() < 1<<16
                        })
                }
-               if buf.Len() == 0 && time.Since(lastWrite) >= keepAliveTimeout {
-                       buf.Write(pp.Message{Keepalive: true}.MustMarshalBinary())
+               if cn.writeBuffer.Len() == 0 && time.Since(lastWrite) >= keepAliveTimeout {
+                       cn.writeBuffer.Write(pp.Message{Keepalive: true}.MustMarshalBinary())
                        postedKeepalives.Add(1)
                }
-               if buf.Len() == 0 {
+               if cn.writeBuffer.Len() == 0 {
                        // TODO: Minimize wakeups....
                        cn.writerCond.Wait()
                        continue
                }
+               var buf bytes.Buffer
+               buf.Write(cn.writeBuffer.Bytes())
+               cn.writeBuffer.Reset()
                cn.mu().Unlock()
                // log.Printf("writing %d bytes", buf.Len())
                n, err := cn.w.Write(buf.Bytes())