Merge branch '4.6' of git@scm.dev.nokia.troll.no:qt/oslo-staging-1 into 4.6

1 files changed, 11 insertions, 2 deletions

diff --git a/src/network/socket/qnativesocketengine_win.cpp b/src/network/socket/qnativesocketengine_win.cpp
index 81bffd9..8257545 100644
--- a/src/network/socket/qnativesocketengine_win.cpp
+++ b/src/network/socket/qnativesocketengine_win.cpp
@@ -994,9 +994,9 @@ qint64 QNativeSocketEnginePrivate::nativeWrite(const char *data, qint64 len)
 {
     Q_Q(QNativeSocketEngine);
     qint64 ret = 0;
-    // don't send more than 49152 per call to WSASendTo to avoid getting a WSAENOBUFS
+    qint64 bytesToSend = len;
+
     for (;;) {
-        qint64 bytesToSend = qMin<qint64>(49152, len - ret);
         WSABUF buf;
         buf.buf = (char*)data + ret;
         buf.len = bytesToSend;
@@ -1014,6 +1014,12 @@ qint64 QNativeSocketEnginePrivate::nativeWrite(const char *data, qint64 len)
                 continue;
         } else if (WSAGetLastError() == WSAEWOULDBLOCK) {
             break;
+        } else if (WSAGetLastError() == WSAENOBUFS) {
+            // this function used to not send more than 49152 per call to WSASendTo
+            // to avoid getting a WSAENOBUFS. However this is a performance regression
+            // and we think it only appears with old windows versions. We now handle the
+            // WSAENOBUFS and hope it never appears anyway.
+            // just go on, the next loop run we will try a smaller number
         } else {
             int err = WSAGetLastError();
             WS_ERROR_DEBUG(err);
@@ -1029,6 +1035,9 @@ qint64 QNativeSocketEnginePrivate::nativeWrite(const char *data, qint64 len)
             }
             break;
         }
+
+        // for next send:
+        bytesToSend = qMin<qint64>(49152, len - ret);
     }
 
 #if defined (QNATIVESOCKETENGINE_DEBUG)