On Tue, 12 Aug 2025 at 06:18, Marie Zhussupova marievic@google.com wrote:
Add example_params_test_with_init() to illustrate how to manage shared resources across a parameterized KUnit test. This example showcases the use of the new param_init() function and its registration to a test using the KUNIT_CASE_PARAM_WITH_INIT() macro.
Additionally, the test demonstrates how to directly pass a parameter array to the parameterized test context via kunit_register_params_array() and leveraging the Resource API for shared resource management.
Signed-off-by: Marie Zhussupova marievic@google.com
This looks fine to me. One note below about one of the comments.
Otherwise, Reviewed-by: David Gow davidgow@google.com
Cheers, -- David
Changes in v2:
- kunit_array_gen_params() is now explicitly passed to KUNIT_CASE_PARAM_WITH_INIT() to be consistent with a parameterized test being defined by the existence of the generate_params() function.
- The comments were edited to be more concise.
- The patch header was changed to reflect that this example test's intent is more aligned with showcasing using the Resource API for shared resource management.
- The comments and the commit message were changed to reflect the parameterized testing terminology. See the patch series cover letter change log for the definitions.
lib/kunit/kunit-example-test.c | 118 +++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+)
diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c index 3056d6bc705d..f2819ee58965 100644 --- a/lib/kunit/kunit-example-test.c +++ b/lib/kunit/kunit-example-test.c @@ -277,6 +277,122 @@ static void example_slow_test(struct kunit *test) KUNIT_EXPECT_EQ(test, 1 + 1, 2); }
+/*
- This custom function allocates memory and sets the information we want
- stored in the kunit_resource->data field.
- */
+static int example_resource_init(struct kunit_resource *res, void *context) +{
int *info = kmalloc(sizeof(*info), GFP_KERNEL);if (!info)return -ENOMEM;*info = *(int *)context;res->data = info;return 0;+}
+/*
- This function deallocates memory for the kunit_resource->data field.
- */
+static void example_resource_free(struct kunit_resource *res) +{
kfree(res->data);+}
+/*
- This match function is invoked by kunit_find_resource() to locate
- a test resource based on certain criteria.
- */
+static bool example_resource_alloc_match(struct kunit *test,
struct kunit_resource *res,void *match_data)+{
return res->data && res->free == example_resource_free;+}
+/*
- This is an example of a function that provides a description for each of the
- parameters in a parameterized test.
- */
+static void example_param_array_get_desc(struct kunit *test, const void *p, char *desc) +{
const struct example_param *param = p;snprintf(desc, KUNIT_PARAM_DESC_SIZE,"example check if %d is less than or equal to 3", param->value);+}
+/*
- This function gets passed in the parameterized test context i.e. the
- struct kunit belonging to the parameterized test. You can use this function
- to add resources you want shared across the whole parameterized test or
- for additional setup.
- */
+static int example_param_init(struct kunit *test) +{
int ctx = 3; /* Data to be stored. */size_t arr_size = ARRAY_SIZE(example_params_array);/** This allocates a struct kunit_resource, sets its data field to* ctx, and adds it to the struct kunit's resources list. Note that* this is parameterized test managed. So, it doesn't need to have* a custom exit function to deallocation as it will get cleaned up at* the end of the parameterized test.*/void *data = kunit_alloc_resource(test, example_resource_init, example_resource_free,GFP_KERNEL, &ctx);if (!data)return -ENOMEM;/** Pass the parameter array information to the parameterized test context* struct kunit. Note that you will need to provide kunit_array_gen_params()* as the generator function to KUNIT_CASE_PARAM_WITH_INIT() when registering* a parameter array this route.** Alternatively, since this is a static array we can also use* KUNIT_CASE_PARAM_ARRAY(,DESC) to create a `*_gen_params()` function* and pass that to KUNIT_CASE_PARAM_WITH_INIT() instead of registering* the parameter array here.
Maybe we should note that KUNIT_CASE_PARAM_ARRAY{,_DESC}() doesn't let us set an init function, so would be less useful here.
*/kunit_register_params_array(test, example_params_array, arr_size,example_param_array_get_desc);return 0;+}
+/*
- This is an example of a test that uses shared resources available in the
- parameterized test context.
- */
+static void example_params_test_with_init(struct kunit *test) +{
int threshold;struct kunit_resource *res;const struct example_param *param = test->param_value;/* By design, param pointer will not be NULL. */KUNIT_ASSERT_NOT_NULL(test, param);/** Here we pass test->parent to search for shared resources in the* parameterized test context.*/res = kunit_find_resource(test->parent, example_resource_alloc_match, NULL);KUNIT_ASSERT_NOT_NULL(test, res);/* Since kunit_resource->data is a void pointer we need to typecast it. */threshold = *((int *)res->data);/* Assert that the parameter is less than or equal to a certain threshold. */KUNIT_ASSERT_LE(test, param->value, threshold);/* This decreases the reference count after calling kunit_find_resource(). */kunit_put_resource(res);+}
/*
- Here we make a list of all the test cases we want to add to the test suite
- below.
@@ -296,6 +412,8 @@ static struct kunit_case example_test_cases[] = { KUNIT_CASE(example_static_stub_using_fn_ptr_test), KUNIT_CASE(example_priv_test), KUNIT_CASE_PARAM(example_params_test, example_gen_params),
KUNIT_CASE_PARAM_WITH_INIT(example_params_test_with_init, kunit_array_gen_params,example_param_init, NULL), KUNIT_CASE_SLOW(example_slow_test), {}};
2.51.0.rc0.205.g4a044479a3-goog