BUG/MINOR: threads: fix multiple use of argument inside HA_ATOMIC_UPDATE_{MIN,MAX}()
Just like in previous patch, it happens that HA_ATOMIC_UPDATE_MIN() and
HA_ATOMIC_UPDATE_MAX() would evaluate the (val) argument up to 3 times.
However this time it affects both thread and non-thread versions. It's
strange because the copy was properly performed for the (new) argument
in order to avoid this. Anyway it was done for the "val" one as well.
A quick code inspection showed that this currently has no effect as
these macros are fairly limited in usage.
It would be best to backport this for long-term stability (till 1.8)
but it will not fix an existing bug.
(cherry picked from commit a4d9ee3d1cc7b321be420742263b67620036bb71)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 1b04543c708364ab403ecd09758eafb23b6de916)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/include/common/hathreads.h b/include/common/hathreads.h
index 5fe76a77..6d8716b 100644
--- a/include/common/hathreads.h
+++ b/include/common/hathreads.h
@@ -135,20 +135,22 @@
#define HA_ATOMIC_STORE(val, new) ({*(val) = new;})
#define HA_ATOMIC_UPDATE_MAX(val, new) \
({ \
+ typeof(val) __val = (val); \
typeof(*(val)) __new_max = (new); \
\
- if (*(val) < __new_max) \
- *(val) = __new_max; \
- *(val); \
+ if (*__val < __new_max) \
+ *__val = __new_max; \
+ *__val; \
})
#define HA_ATOMIC_UPDATE_MIN(val, new) \
({ \
+ typeof(val) __val = (val); \
typeof(*(val)) __new_min = (new); \
\
- if (*(val) > __new_min) \
- *(val) = __new_min; \
- *(val); \
+ if (*__val > __new_min) \
+ *__val = __new_min; \
+ *__val; \
})
#define HA_BARRIER() do { } while (0)
@@ -410,21 +412,23 @@
#define HA_ATOMIC_UPDATE_MAX(val, new) \
({ \
- typeof(*(val)) __old_max = *(val); \
+ typeof(val) __val = (val); \
+ typeof(*(val)) __old_max = *__val; \
typeof(*(val)) __new_max = (new); \
\
while (__old_max < __new_max && \
- !HA_ATOMIC_CAS(val, &__old_max, __new_max)); \
- *(val); \
+ !HA_ATOMIC_CAS(__val, &__old_max, __new_max)); \
+ *__val; \
})
#define HA_ATOMIC_UPDATE_MIN(val, new) \
({ \
- typeof(*(val)) __old_min = *(val); \
+ typeof(val) __val = (val); \
+ typeof(*(val)) __old_min = *__val; \
typeof(*(val)) __new_min = (new); \
\
while (__old_min > __new_min && \
- !HA_ATOMIC_CAS(val, &__old_min, __new_min)); \
- *(val); \
+ !HA_ATOMIC_CAS(__val, &__old_min, __new_min)); \
+ *__val; \
})
#define HA_BARRIER() pl_barrier()