[PATCH] nptl: Fix nptl/tst-cancel31 fail sometimes

[Carlos O'Donell]

On 3/24/26 3:48 AM, mengqinggang wrote:
> tst-cancel31 fail on la32 qemu-system with a single-core
> system sometimes.

LGTM. Pushed.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

> IF the test and a infinite loop run on a same x86_64 core,
> the test also fail sometimes.
>    taskset -c 0 make test t=nptl/tst-cancel31
>    taskset -c 0 ./a.out (a.out is a infinite loop)
> 
> After writeopener thread opens the file, it may switch to
> main thread and find redundant files.

Agreed.

writeopener
   fd = open (arg, O_WRONLY);

             main
              support_descriptors_check (descrs);
              Fails because writeopener had an open descriptor

   xclose (fd);

The test fails if main executes between the open and close
of writeopener.

> 
> pthread_cancel and pthread_join writeopener thread
> before support_descriptors_check.
> ---
>   nptl/tst-cancel31.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/nptl/tst-cancel31.c b/nptl/tst-cancel31.c
> index e9ffef3b41..8909879ff4 100644
> --- a/nptl/tst-cancel31.c
> +++ b/nptl/tst-cancel31.c
> @@ -43,7 +43,9 @@ writeopener (void *arg)
>     for (;;)
>       {
>         fd = open (arg, O_WRONLY);
> +      pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, 0);
>         xclose (fd);
> +      pthread_setcancelstate (PTHREAD_CANCEL_ENABLE, 0);

OK.

>       }
>     return NULL;
>   }
> @@ -74,7 +76,7 @@ do_test (void)
>   
>     srand (1);
>   
> -  xpthread_create (NULL, writeopener, name);
> +  pthread_t tw = xpthread_create (NULL, writeopener, name);
>     for (int i = 0; i < iter_count; i++)
>       {
>         pthread_t td = xpthread_create (NULL, leaker, name);
> @@ -88,6 +90,9 @@ do_test (void)
>         xpthread_join (td);
>       }
>   
> +  pthread_cancel (tw);
> +  xpthread_join (tw);

OK.

> +
>     support_descriptors_check (descrs);
>   
>     support_descriptors_free (descrs);


-- 
Cheers,
Carlos.