Re: [Qemu-block] [PATCH 4/6] tests: check if qemu-nbd is still alive before waiting

[Eric Blake]

On 11/16/18 9:53 AM, Daniel P. Berrangé wrote:
> If the qemu-nbd UNIX socket has not shown up, the tests will sleep a bit
> and then check again repeatedly for upto 30 seconds. This is pointless

s/upto/up to/

> if the qemu-nbd process has quit due to an error, so check whether the
> pid is still alive before waiting and retrying.

"But our tests are perfect and qemu-nbd never fails" :)

Yes, this makes sense.  Not 3.1 material on its own (after all, our 
testsuite isn't showing such failures, so we aren't wasting that time at 
the moment) - but worth including if the later patches end up in 3.1.

> Signed-off-by: Daniel P. Berrangé <address@hidden>
> ---
>   tests/qemu-iotests/common.nbd | 10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)

Reviewed-by: Eric Blake <address@hidden>

> diff --git a/tests/qemu-iotests/common.nbd b/tests/qemu-iotests/common.nbd
> index f920a578f1..61e9e90fee 100644
> --- a/tests/qemu-iotests/common.nbd
> +++ b/tests/qemu-iotests/common.nbd
> @@ -37,11 +37,19 @@ function nbd_server_stop()
>   
>   function nbd_server_wait_for_unix_socket()
>   {
> +    pid=$1
> +
>       for ((i = 0; i < 300; i++))
>       do
>           if [ -r "$nbd_unix_socket" ]; then
>               return
>           fi
> +        kill -s 0 $pid 2>/dev/null
> +        if test $? != 0
> +        then
> +            echo "qemu-nbd unexpectedly quit"
> +            exit 1

Maybe the echo should be redirected to stderr.  But we aren't 
consistently doing that in other tests (_init_error does it, but other 
spots in check are not), so I'm not changing it.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org