Hi.
I’m trying to read efficiently from a serial port, using QNX 6.3.
Instead of an always polling procedure:
while (1)
read(fd, buff, 1)
I’m trying to use the SIGIO signal. The problem is that I cannot
generate it 
In my program I have
[code:1:b1c8369a8a]
#include <sys/wait.h>
#include <ioctl.h>
main
{
…
signal(SIGIO, sigio_handler);
…
pid_t pgrp = getpid();
int on = 1;
memset(&gData, 0, sizeof(gyro_data_t));
/* Open Serial port for reading GYRO */
gData.gfd = open(SERIAL_PORT_GYRO, O_RDONLY | O_NOCTTY |
O_NONBLOCK);
DBGP(“Serial " SERIAL_PORT_GYRO " opened:
%d\n”, gData.gfd);
if(gData.gfd < 0)
errexit("open " SERIAL_PORT_GYRO);
/* set the process receiving SIGIO signals /
if(ioctl(gData.gfd, SIOCSPGRP, &pgrp) < 0)
errexit(“ioctl SIOCSPGRP”);
/ allow receipt of asynchronous I/O signals */
if(ioctl(gData.gfd, FIOASYNC, &on) < 0)
errexit(“ioctl FIOASYNC”);
}
[/code:1:b1c8369a8a]
It opens the serial port in non-blocking mode. Later I try to set
which process should receive the SIGIO and SIGURG signals. And,
finally, I set the anynchronous mode too.
The problem is that ioctl(gData.gfd, SIOCSPGRP, &pgrp) returns:
ioctl SIOCSPGRP: Function not implemented
The SIGCSPGRP label is not even declared in
/usr/include/sys/ioctl.h but it seems to recognize it…
If I try ioctl(gData.gfd, TIOCSPGRP, &pgrp), since TIOCSPGRP is
defined in ioctl.h, it says:
ioctl TIOCSPGRP: Inappropiate I/O control operation
If I try fcntl(gData.gfd, F_SETOWN, &pgrp), since F_SETOWN is
declared in fcntl.h, it says:
fcntl F_SETOWN: Function not implemented
I’m following some examples for qnx that I found in internet:
http://www.pjwstk.edu.pl/~jms/qnx/help/tcpip_4.25_en/prog_guide/sock_advanced_tut.html
http://cvs.qnx.com/cgi-bin/cvsweb.cgi/lib/socket/rcmd.c?rev=1.1
they use the first solution… but it doesn’t work with me
The SIGIO doesn’t come. And if I generate it with raise(SIGIO), it
comes then, but doesn’t appear any more
Any suggestion??
Thanks!
Dario