diff options
| author | Thiago Macieira <thiago.macieira@intel.com> | 2017-08-13 12:07:37 -0700 |
|---|---|---|
| committer | Thiago Macieira <thiago.macieira@intel.com> | 2017-08-27 16:38:50 +0000 |
| commit | 23d52de3214976ffaaa2331b4b16fe0079afc8dd (patch) | |
| tree | 33cc617fa6ca360e88b5f2ee90359f95d0d2d82b | |
| parent | 5de734bc18dcf7cf660684c44b5fc6b886a7b88b (diff) | |
QUdpSocket: use faster ways to get datagram size on Linux and macOS
With MSG_TRUNC on Linux, recv/recvfrom/recvmsg will return the full size
of the datagram, even if it won't fit the buffer you passed. On Darwin,
we have a getsockopt() option to get that value.
Change-Id: I6e9274c1e7444ad48c81fffd14da7d5b93815f90
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
| -rw-r--r-- | src/network/socket/qnativesocketengine_unix.cpp | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/src/network/socket/qnativesocketengine_unix.cpp b/src/network/socket/qnativesocketengine_unix.cpp index 13ceb4c612..a8f756dc31 100644 --- a/src/network/socket/qnativesocketengine_unix.cpp +++ b/src/network/socket/qnativesocketengine_unix.cpp @@ -834,7 +834,7 @@ bool QNativeSocketEnginePrivate::nativeHasPendingDatagrams() const QT_SOCKLEN_T storageSize = sizeof(storage); memset(&storage, 0, storageSize); - // Peek 0 bytes into the next message. The size of the message may + // Peek 1 bytes into the next message. The size of the message may // well be 0, so we can't check recvfrom's return value. ssize_t readBytes; do { @@ -855,8 +855,20 @@ bool QNativeSocketEnginePrivate::nativeHasPendingDatagrams() const qint64 QNativeSocketEnginePrivate::nativePendingDatagramSize() const { - QVarLengthArray<char, 8192> udpMessagePeekBuffer(8192); ssize_t recvResult = -1; +#ifdef Q_OS_LINUX + // Linux can return the actual datagram size if we use MSG_TRUNC + char c; + EINTR_LOOP(recvResult, ::recv(socketDescriptor, &c, 1, MSG_PEEK | MSG_TRUNC)); +#elif defined(SO_NREAD) + // macOS can return the actual datagram size if we use SO_NREAD + int value; + socklen_t valuelen = sizeof(value); + recvResult = getsockopt(socketDescriptor, SOL_SOCKET, SO_NREAD, &value, &valuelen); + if (recvResult != -1) + recvResult = value; +#else + QVarLengthArray<char, 8192> udpMessagePeekBuffer(8192); for (;;) { // the data written to udpMessagePeekBuffer is discarded, so @@ -872,6 +884,7 @@ qint64 QNativeSocketEnginePrivate::nativePendingDatagramSize() const udpMessagePeekBuffer.resize(udpMessagePeekBuffer.size() * 2); } +#endif #if defined (QNATIVESOCKETENGINE_DEBUG) qDebug("QNativeSocketEnginePrivate::nativePendingDatagramSize() == %zd", recvResult); |