cyclic: make clients embed a struct cyclic_info in their own data structure
There are of course not a whole lot of examples in-tree yet, but
before they appear, let's make this API change: Instead of separately
allocating a 'struct cyclic_info', make the users embed such an
instance in their own structure, and make the convention that the
callback simply receives the 'struct cyclic_info *', from which the
clients can get their own data using the container_of() macro.
This has a number of advantages.
First, it means cyclic_register() simply cannot fail, simplifying the
code. The necessary storage will simply be allocated automatically
when the client's own structure is allocated (often via
uclass_priv_auto or similar).
Second, code for which CONFIG_CYCLIC is just an option can more easily
be written without #ifdefs, if we just provide an empty struct
cyclic_info {}. For example, the nested CONFIG_IS_ENABLED()s in
https://lore.kernel.org/u-boot/20240316201416.211480-1-marek.vasut+renesas@mailbox.org/
are mostly due to the existence of the 'struct cyclic_info *' member
being guarded by #ifdef CONFIG_CYCLIC.
And we do probably want to avoid the extra memory overhead of that
member when !CONFIG_CYCLIC. But that is automatic if, instead of a
'struct cyclic_info *', one simply embeds a 'struct cyclic_info',
which will have size 0 when !CONFIG_CYCLIC. Also, the no-op
cyclic_register() function can just unconditionally be called, and the
compiler will see that (1) the callback is referenced, so not emit a
warning for a maybe-unused function and (2) see that it can actually
never be reached, so not emit any code for it.
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
diff --git a/test/common/cyclic.c b/test/common/cyclic.c
index 461f8cf..51a07c5 100644
--- a/test/common/cyclic.c
+++ b/test/common/cyclic.c
@@ -12,22 +12,27 @@
#include <linux/delay.h>
/* Test that cyclic function is called */
-static bool cyclic_active = false;
+static struct cyclic_test {
+ struct cyclic_info cyclic;
+ bool called;
+} cyclic_test;
-static void cyclic_test(void *ctx)
+static void test_cb(struct cyclic_info *c)
{
- cyclic_active = true;
+ struct cyclic_test *t = container_of(c, struct cyclic_test, cyclic);
+ t->called = true;
}
static int dm_test_cyclic_running(struct unit_test_state *uts)
{
- cyclic_active = false;
- ut_assertnonnull(cyclic_register(cyclic_test, 10 * 1000, "cyclic_demo",
- NULL));
+ cyclic_test.called = false;
+ cyclic_register(&cyclic_test.cyclic, test_cb, 10 * 1000, "cyclic_test");
/* Execute all registered cyclic functions */
schedule();
- ut_asserteq(true, cyclic_active);
+ ut_asserteq(true, cyclic_test.called);
+
+ cyclic_unregister(&cyclic_test.cyclic);
return 0;
}