[fpc-devel] serial under linux, SerOpen blocks

[Henry Vermaak]

On 18/08/11 12:00, Armin Diehl wrote:
> Hi Marco,
>
> minicom calls open with O_NONBLOCK and resets O_NONBLOCK directly after
> the open call:
>
> open("/dev/ttyUSB0", O_RDWR|O_NOCTTY|O_NONBLOCK) = 3
> fcntl(3, F_GETFL) = 0x8802 (flags O_RDWR|O_NONBLOCK|O_LARGEFILE)
> fcntl(3, F_SETFL, O_RDWR|O_LARGEFILE) = 0
>
> doing the same in serial.pp should not change the blocking behaviour of
> serial.pp.
>
> function SerOpen(const DeviceName: String): TSerialHandle;
> begin
> Result := fpopen(DeviceName, O_RDWR or O_NOCTTY or O_NONBLOCK); // AD:
> O_NONBLOCK was missing
> if result > -1 then
> fpfcntl(Result,F_SETFL,O_RDWR or O_NOCTTY); //AD: non blocking off again

Better use F_GETFL first, then flags &= ~O_NONBLOCK, like minicom does.

Henry