On Fri, 2023-01-27 at 17:03 -0500, Willem de Bruijn wrote:
On Fri, Jan 27, 2023 at 1:16 PM Andrei Gherzan andrei.gherzan@canonical.com wrote:
The tx and rx test programs are used in a couple of test scripts including "udpgro_bench.sh". Taking this as an example, when the rx/tx programs are invoked subsequently, there is a chance that the rx one is not ready to accept socket connections. This racing bug could fail the test with at least one of the following:
./udpgso_bench_tx: connect: Connection refused ./udpgso_bench_tx: sendmsg: Connection refused ./udpgso_bench_tx: write: Connection refused
This change addresses this by adding routines that retry the socket operations with an exponential back off algorithm from 100ms to 2s.
Fixes: 3a687bef148d ("selftests: udp gso benchmark") Signed-off-by: Andrei Gherzan andrei.gherzan@canonical.com
Synchronizing the two processes is indeed tricky.
Perhaps more robust is opening an initial TCP connection, with SO_RCVTIMEO to bound the waiting time. That covers all tests in one go.
Another option would be waiting for the listener(tcp)/receiver(udp) socket to show up in 'ss' output before firing-up the client - quite alike what mptcp self-tests are doing.
Cheers,
Paolo