[LTP] [RFC PATCH 1/2] tst_test: Add test multiplex function

[Steve Muckle]

On 03/06/2019 07:24 AM, Cyril Hrubis wrote:
> The test multiplex function is intended for running the test function in
> a loop for a different settings. The indended purpose is to run tests
> for both libc wrapper and raw syscall as well as for different syscall
> variants.
> 
> The commit itself adds a test_multiplex() function into the tst_test
> structure, if set this function is called in a loop before each test
> iteration and is responsible for changing the test variant into next
> one. The iterations continue until the function returns zero.
> 
> Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
> CC: Mark Salyzyn <salyzyn@android.com>
> CC: Steve Muckle <smuckle@google.com>
> CC: Jan Stancek <jstancek@redhat.com>

Approach seems good to me.

Reviewed-by: Steve Muckle <smuckle@google.com>

> ---
>   include/tst_test.h | 14 ++++++++++++++
>   lib/tst_test.c     | 11 +++++++++--
>   2 files changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/include/tst_test.h b/include/tst_test.h
> index da41f776d..b747b24d5 100644
> --- a/include/tst_test.h
> +++ b/include/tst_test.h
> @@ -146,6 +146,20 @@ struct tst_test {
>   	 */
>   	int all_filesystems:1;
>   
> +	/*
> +	 * If set this function is used to mutiplex between different test
> +	 * variants.
> +	 *
> +	 * Multiplexers are the way how to run the same test for different
> +	 * settings. The intended use is to test different syscall
> +	 * wrappers/variants but the API is generic and does not limit the
> +	 * usage in any way.
> +	 *
> +	 * Each time the function is called it switches to next test variant,
> +	 * returns zero if all variants has been iterated over.
> +	 */
> +	int (*test_multiplex)(void);
> +
>   	/* Minimal device size in megabytes */
>   	unsigned int dev_min_size;
>   
> diff --git a/lib/tst_test.c b/lib/tst_test.c
> index 7dd890b8d..6b033c879 100644
> --- a/lib/tst_test.c
> +++ b/lib/tst_test.c
> @@ -1009,8 +1009,15 @@ static void testrun(void)
>   		if (!cont)
>   			break;
>   
> -		run_tests();
> -		heartbeat();
> +		if (tst_test->test_multiplex) {
> +			while (tst_test->test_multiplex()) {
> +				run_tests();
> +				heartbeat();
> +			}
> +		} else {
> +			run_tests();
> +			heartbeat();
> +		}
>   	}
>   
>   	do_test_cleanup();
>