Port::WaitResult
SerialPort::WaitDataPending(OverlappedEvent &overlapped,
unsigned timeout_ms) const
{
int nbytes = GetDataPending();
if (nbytes > 0)
return WaitResult::READY;
else if (nbytes < 0)
return WaitResult::FAILED;
::SetCommMask(hPort, EV_RXCHAR);
DWORD dwCommModemStatus;
if (!::WaitCommEvent(hPort, &dwCommModemStatus, overlapped.GetPointer())) {
if (::GetLastError() != ERROR_IO_PENDING)
return WaitResult::FAILED;
switch (overlapped.Wait(timeout_ms)) {
case OverlappedEvent::FINISHED:
break;
case OverlappedEvent::TIMEOUT:
/* the operation may still be running, we have to cancel it */
::CancelIo(hPort);
::SetCommMask(hPort, 0);
overlapped.Wait();
return WaitResult::TIMEOUT;
case OverlappedEvent::CANCELED:
/* the operation may still be running, we have to cancel it */
::CancelIo(hPort);
::SetCommMask(hPort, 0);
overlapped.Wait();
return WaitResult::CANCELLED;
}
DWORD result;
if (!::GetOverlappedResult(hPort, overlapped.GetPointer(), &result, FALSE))
return WaitResult::FAILED;
}
if ((dwCommModemStatus & EV_RXCHAR) == 0)
return WaitResult::FAILED;
return GetDataPending() > 0
? WaitResult::READY
: WaitResult::FAILED;
}
void
SerialPort::Run()
{
assert(Thread::IsInside());
DWORD dwBytesTransferred;
BYTE inbuf[1024];
// JMW added purging of port on open to prevent overflow
Flush();
#ifndef _WIN32_WCE
OverlappedEvent osStatus, osReader;
if (!osStatus.Defined() || !osReader.Defined())
// error creating event; abort
return;
#endif
// Specify a set of events to be monitored for the port.
if (is_widcomm)
SetRxTimeout(180);
else {
::SetCommMask(hPort, EV_RXCHAR);
SetRxTimeout(0);
}
while (!CheckStopped()) {
#ifndef _WIN32_WCE
WaitResult result = WaitDataPending(osStatus, INFINITE);
switch (result) {
case WaitResult::READY:
break;
case WaitResult::TIMEOUT:
continue;
case WaitResult::FAILED:
case WaitResult::CANCELLED:
::Sleep(100);
continue;
}
int nbytes = GetDataPending();
if (nbytes <= 0) {
::Sleep(100);
continue;
}
// Start reading data
if ((size_t)nbytes > sizeof(inbuf))
nbytes = sizeof(inbuf);
if (!::ReadFile(hPort, inbuf, nbytes, &dwBytesTransferred,
osReader.GetPointer())) {
if (::GetLastError() != ERROR_IO_PENDING) {
// Error in ReadFile() occured
::Sleep(100);
continue;
}
if (osReader.Wait() != OverlappedEvent::FINISHED) {
::CancelIo(hPort);
::SetCommMask(hPort, 0);
osReader.Wait();
continue;
}
if (!::GetOverlappedResult(hPort, osReader.GetPointer(),
&dwBytesTransferred, FALSE))
continue;
}
#else
if (is_widcomm) {
/* WaitCommEvent() doesn't work with the Widcomm Bluetooth
driver, it blocks for 11 seconds, regardless whether data is
received. This workaround polls for input manually.
Observed on an iPaq hx4700 with WM6. */
} else {
// Wait for an event to occur for the port.
DWORD dwCommModemStatus;
if (!::WaitCommEvent(hPort, &dwCommModemStatus, 0)) {
// error reading from port
Sleep(100);
continue;
}
if ((dwCommModemStatus & EV_RXCHAR) == 0)
/* no data available */
continue;
}
// Read the data from the serial port.
if (!ReadFile(hPort, inbuf, 1024, &dwBytesTransferred, NULL) ||
dwBytesTransferred == 0) {
Sleep(100);
continue;
}
#endif
DataReceived(inbuf, dwBytesTransferred);
}
Flush();
}
void
SerialPort::Run()
{
assert(Thread::IsInside());
DWORD dwBytesTransferred;
BYTE inbuf[1024];
// JMW added purging of port on open to prevent overflow
Flush();
OverlappedEvent osStatus, osReader;
if (!osStatus.Defined() || !osReader.Defined())
// error creating event; abort
return;
// Specify a set of events to be monitored for the port.
::SetCommMask(hPort, EV_RXCHAR);
SetRxTimeout(0);
while (!CheckStopped()) {
WaitResult result = WaitDataPending(osStatus, INFINITE);
switch (result) {
case WaitResult::READY:
break;
case WaitResult::TIMEOUT:
continue;
case WaitResult::FAILED:
case WaitResult::CANCELLED:
::Sleep(100);
continue;
}
int nbytes = GetDataPending();
if (nbytes <= 0) {
::Sleep(100);
continue;
}
// Start reading data
if ((size_t)nbytes > sizeof(inbuf))
nbytes = sizeof(inbuf);
if (!::ReadFile(hPort, inbuf, nbytes, &dwBytesTransferred,
osReader.GetPointer())) {
if (::GetLastError() != ERROR_IO_PENDING) {
// Error in ReadFile() occured
::Sleep(100);
continue;
}
if (osReader.Wait() != OverlappedEvent::FINISHED) {
::CancelIo(hPort);
::SetCommMask(hPort, 0);
osReader.Wait();
continue;
}
if (!::GetOverlappedResult(hPort, osReader.GetPointer(),
&dwBytesTransferred, FALSE))
continue;
}
DataReceived(inbuf, dwBytesTransferred);
}
Flush();
}