--- stdin appears to block until a select() tests it, thus slowing system code execution way down. ---
My MPC860T app executes UDP recvfrom()'s and sendto()'s at regular intervals. The recvfrom() UDP pkt data is queued with a buffer descriptor for transmission on a QMC channel to an external device. The data read from the device on a QMC channel is queued with a buffer descriptor for subsequent sendto(). But if I do not constantly execute a select() (timeout = 10us) on stdin (serial keyboard - not being used often) at a fast enough rate (i.e. if the select() is executed in it's own thread and doesn't get scheduled frequently enough) the code execution slows way down, and I find that the queued QMC channel data, residing in the circular queues doesn't get transmitted fast enough and the queues grow and grow. Doing no select() on stdin basically shuts the QMC buff desc processing down. It's as though, even with no serial chars coming in, stdin blocks until the select() tests it. I need to avoid this blocking, yet still periodically check for a serial key input on stdin. Any ideas out there in Linux Embedded-land? Thanks, Steven ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
