On 11/20/23 12:15 PM, Yuran Pereira wrote:
Hello Yonghong,
On Mon, Nov 20, 2023 at 07:22:59AM -0800, Yonghong Song wrote:
- if (CHECK(!err || errno != ENOENT,
- "bpf_map_lookup_elem(sk_stg_map)",
- "err:%d errno:%d\n", err, errno))
+ if (!ASSERT_NEQ(err, 0, "bpf_map_lookup_elem(sk_stg_map)") ||
!ASSERT_ERR(err, "bpf_map_lookup_elem(sk_stg_map)")
might be simpler than !ASSERT_NEQ(..).
Sure, that makes sense. I'll change it in v3.
- pthread_join(srv_thread, &thread_ret);
- CHECK(IS_ERR(thread_ret), "pthread_join", "thread_ret:%ld",
- PTR_ERR(thread_ret));
+ err = pthread_join(srv_thread, &thread_ret);
+ ASSERT_OK(err, "pthread_join");
The above is not equivalent to the original code.
The original didn't check pthread_join() return as it
is very very unlikely to fail. And check 'thread_ret'
is still needed.
Yes that is true, but the v1 [1] broke the tests because the
ASSERT_OK_PTR(thread_ret, "pthread_join") kept failing, even
though all the asserts within the `server()` function itself
passed.
Also, isn't asserting `thread_ret` technically checking the
`server()` function instead of `pthread_join`? So should we
have two asserts here? One for `server` and one for `pthread_join`
or is it not necessary?
i.e:
```
ASSERT_OK_PTR(thread_ret, "server");
ASSERT_OK(err, "pthread_join");
```
As I mentioned, checking return value of pthread_join()
is not critical as in general pthread_join() not fail.
The test is not to test pthread_join() and if pthread_join()
fails it would be an even bigger problem affecting many other
tests.
Upon taking a second look, I now think that the reason why
`ASSERT_OK_PTR(thread_ret, "pthread_join");` failed in v1 might
have been because it calls `libbpf_get_error` which returns
`-errno` when the pointer is `NULL`.
Since `server`'s return value is not a bpf address, which
`ASSERT_OK_PTR` expects it to be, do you that think we should
explicitly set `errno = 0` prior to returning NULL on server?
That way that assert would pass even when the pointer is NULL
(which is the case when `server` returns successfuly).
Let us just do
ASSERT_OK(IS_ERR(thread_ret), "thread_ret")
[1] - https://lore.kernel.org/lkml/GV1PR10MB6563A0BE91080E6E8EC2651DE8B0A@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
As always, thank you for your feedback.
Yuran Pereira
