diff options
| -rw-r--r-- | src/serialport/qserialport_p.h | 2 | ||||
| -rw-r--r-- | src/serialport/qserialport_win.cpp | 17 |
2 files changed, 17 insertions, 2 deletions
diff --git a/src/serialport/qserialport_p.h b/src/serialport/qserialport_p.h index 29c1d5a..81febed 100644 --- a/src/serialport/qserialport_p.h +++ b/src/serialport/qserialport_p.h @@ -206,6 +206,8 @@ public: bool getDcb(DCB *dcb); OVERLAPPED *waitForNotified(int msecs); + qint64 queuedBytesCount(QSerialPort::Direction direction) const; + bool completeAsyncCommunication(qint64 bytesTransferred); bool completeAsyncRead(qint64 bytesTransferred); bool completeAsyncWrite(qint64 bytesTransferred); diff --git a/src/serialport/qserialport_win.cpp b/src/serialport/qserialport_win.cpp index 6d5dac0..e356e4c 100644 --- a/src/serialport/qserialport_win.cpp +++ b/src/serialport/qserialport_win.cpp @@ -437,10 +437,13 @@ bool QSerialPortPrivate::completeAsyncRead(qint64 bytesTransferred) readStarted = false; bool result = true; - if (bytesTransferred == ReadChunkSize) + if (bytesTransferred == ReadChunkSize + || queuedBytesCount(QSerialPort::Input) > 0) { result = startAsyncRead(); - else if (readBufferMaxSize == 0 || readBufferMaxSize > buffer.size()) + } else if (readBufferMaxSize == 0 + || readBufferMaxSize > buffer.size()) { result = startAsyncCommunication(); + } if (bytesTransferred > 0) emitReadyRead(); @@ -598,6 +601,16 @@ OVERLAPPED *QSerialPortPrivate::waitForNotified(int msecs) return overlapped; } +qint64 QSerialPortPrivate::queuedBytesCount(QSerialPort::Direction direction) const +{ + COMSTAT comstat; + if (::ClearCommError(handle, Q_NULLPTR, &comstat) == 0) + return -1; + return (direction == QSerialPort::Input) + ? comstat.cbInQue + : ((direction == QSerialPort::Output) ? comstat.cbOutQue : -1); +} + inline bool QSerialPortPrivate::initialize() { Q_Q(QSerialPort); |