how many open() calls?

QNX DEVELOPERS Realtime and Embedded
1

Hi.

How many open() calls can one make for a single pathname “/dev/ser1” handled by devc-ser8250?

The question put another way:

How many OCB can we have for a serial port?

How many processes can open the same serial port, at the same time?

2

another thing,

What will happen when two processes try to write onto the same serial port?
and what will happen when two processes try to read from the same serial port?

Thanks in Advance,

3

I think the number of open call is limited by the number of connection per process as specify in the kernel. I believe this can be increase via option to procnto.

Two simultaneous write won`t cause a problem, they will be process in order. Multiple read, I guess will results in data being receive in an undefined order, meaning one process will get some data and the other some other data. Which data goes where is undefined.