Re: [PATCH] Don't run forever in gdb.base/structs.c

[Pedro Alves <palves@redhat.com>]

On 10/01/2014 10:02 PM, Doug Evans wrote:

> If gdb crashes during testing tests may be left to free-run, eating cpu.
> 
> This patch fixes one of the more egregious cases since several versions
> of the program are built.
> 
> I've got patches to fix others.
> Just seeing if folks want to comment on this first.
> 
> IWBN to have the harness itself cleanup, and I think there's something
> we can do there, but that's not always robust either, and I think
> multiple levels of robustness would be useful.

Agreed.

> Since this testcase is an egregious one, and since this patch simple,
> I'm starting with this.

Looks fine with me.

We already do something like this in many tests even.  E.g., of the
top of my head:

$ grep -rn "Don't run forever.  Run just short of it :)" *
gdb.base/watch_thread_num.c:55:    /* Don't run forever.  Run just short of it :)  */
gdb.mi/nsintrall.c:55:    /* Don't run forever.  Run just short of it :)  */
gdb.mi/nsmoribund.c:35:  /* Don't run forever.  Run just short of it :)  */
gdb.threads/pending-step.c:54:    /* Don't run forever.  Run just short of it :)  */
gdb.threads/watchthreads.c:71:    /* Don't run forever.  Run just short of it :)  */
gdb.threads/threadapply.c:72:    /* Don't run forever.  Run just short of it :)  */
gdb.threads/thread-specific.c:42:    /* Don't run forever.  Run just short of it :)  */
gdb.threads/thread-specific.c:56:    /* Don't run forever.  Run just short of it :)  */
gdb.threads/schedlock.c:55:    /* Don't run forever.  Run just short of it :)  */

In a few other tests, we use "alarm()", though IMO it's best to avoid
that if possible, to expose the test on as much targets as possible.
E.g., alarm() IIRC isn't available on mingw unless you
specify __USE_MINGW_ALARM.  Bare metal targets may have trouble
with it too, etc.

Thanks,
Pedro Alves