/* Returns true if EAGAIN encountered. Emits (or queues) bytesWritten for any buffers written.
* If stopAfterWritingOneBuffer is true, return immediately if a single buffer is written, rather than
* attempting to drain the whole queue.
* Doesn't modify notifier.
*/
bool VirtualSerialDevice::tryFlushPendingBuffers(QMutexLocker& locker, FlushPendingOptions flags)
{
while (pendingWrites.count() > 0) {
// Try writing everything we've got, until we hit EAGAIN
const QByteArray& data = pendingWrites[0];
qint64 bytesWritten;
bool needToWait = tryWrite(data.constData(), data.size(), bytesWritten);
if (needToWait) {
if (bytesWritten > 0) {
// We wrote some of the data, update the pending queue
QByteArray remainder = data.mid(bytesWritten);
pendingWrites.removeFirst();
pendingWrites.insert(0, remainder);
}
return needToWait;
} else {
pendingWrites.removeFirst();
if (flags & EmitBytesWrittenAsync) {
emit AsyncCall_emitBytesWrittenIfNeeded(bytesWritten);
} else {
emitBytesWrittenIfNeeded(locker, bytesWritten);
}
if (flags & StopAfterWritingOneBuffer) return false;
// Otherwise go round loop again
}
}
return false; // no EAGAIN encountered
}
void VirtualSerialDevice::doWriteCompleted(QMutexLocker &locker)
{
// Must be locked on entry
ResetEvent(d->writeOverlapped.hEvent);
qint64 len = pendingWrites.first().length();
pendingWrites.removeFirst();
if (pendingWrites.count() > 0) {
// Get the next write started before notifying in case client calls waitForBytesWritten in their slot
writeNextBuffer(locker);
}
emitBytesWrittenIfNeeded(locker, len);
}
