Commit a03e3caa authored by Marie Zhussupova's avatar Marie Zhussupova Committed by Shuah Khan
Browse files

kunit: Add example parameterized test with shared resource management using the Resource API 

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.

Link: https://lore.kernel.org/r/20250826091341.1427123-6-davidgow@google.com


Reviewed-by: default avatarRae Moar <rmoar@google.com>
Reviewed-by: default avatarDavid Gow <davidgow@google.com>
Signed-off-by: default avatarMarie Zhussupova <marievic@google.com>
Signed-off-by: default avatarDavid Gow <davidgow@google.com>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent b820b907

lib/kunit/kunit-example-test.c

+113 −0
Original line number Diff line number Diff line
@@ -277,6 +277,117 @@ 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.

	 */

	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 +407,8 @@ 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),

	{}

};