How to get event when device creation is completed by mknod on linux Ubuntu 8.04?

ankur_hill · 08-05-2009, 03:58 AM

Hi,

I need to use a device (/dev/ttyS5) which is created by a process which is launched by my program.

However, after launching the process, it takes some time for /dev/ttyS5 device to come up.

hence i need to use sleep() for for 3~4 seconds after launching the process and hope that device becomes ready by that time.

is there any way to get some kind or signal or event by which i can know if device is ready? sleep() is really bad way to handle this situation.

regards,
Anks

PS: Child process that I am launching is not written by me. hence its not possible for me to modify its source code.

jf.argentino · 08-05-2009, 07:59 AM

Maybe a trick like:

Code:

while (open ("/dev/ttyS5", "r") < 0) {
   usleep (100000);
}

ankur_hill · 08-06-2009, 07:21 AM

Quote:

Originally Posted by jf.argentino

Maybe a trick like:

Code:

while (open ("/dev/ttyS5", "r") < 0) {
   usleep (100000);
}

Yes that is a nice trick! actually i was thinking if it would be possible to receive some event when device is ready. but i guess this is the only way.

thanks Argentino!

regards,
Ankur