Rework toggling the state of read notifier on unbuffered socket

To avoid infinite loop on unbuffered socket, previous implementation
always disabled the read notifications before emitting a readyRead()
signal. So, it's very likely that the socket will toggle the state of
notifier twice (on->off->on) in one notification cycle.

This patch prevents this unnecessary toggling by deferring the
notification disabling in canReadNotification() to the next
notification cycle.

Change-Id: Iebc5a7ad18a6f40ea1cf63e7f1b12f6c180cbf7a
Reviewed-by: Markus Goetz (Woboq GmbH) <markus@woboq.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/network/socket/qudpsocket.cpp b/src/network/socket/qudpsocket.cpp
index c406009069..083648bc23 100644
--- a/src/network/socket/qudpsocket.cpp
+++ b/src/network/socket/qudpsocket.cpp
@@ -398,7 +398,8 @@ qint64 QUdpSocket::readDatagram(char *data, qint64 maxSize, QHostAddress *addres
         readBytes = d->socketEngine->readDatagram(data, maxSize);
     }
 
-    d_func()->socketEngine->setReadNotificationEnabled(true);
+    d->hasPendingData = false;
+    d->socketEngine->setReadNotificationEnabled(true);
     if (readBytes < 0)
         d->setErrorAndEmit(d->socketEngine->error(), d->socketEngine->errorString());
     return readBytes;