CLEANUP: fd: use a union in fd_rm_from_fd_list() to shut aliasing warnings
Enabling strict aliasing fails in fd.c when using the double-word CAS,
let's get rid of the (void**)(void*)&cur_list junk and use a union
instead. This way the compiler knows they do alias.
diff --git a/src/fd.c b/src/fd.c
index 5f43233..8eea0f5 100644
--- a/src/fd.c
+++ b/src/fd.c
@@ -179,7 +179,11 @@
void fd_rm_from_fd_list(volatile struct fdlist *list, int fd, int off)
{
#if defined(HA_HAVE_CAS_DW) || defined(HA_CAS_IS_8B)
- volatile struct fdlist_entry cur_list, next_list;
+ volatile union {
+ struct fdlist_entry ent;
+ uint64_t u64;
+ uint32_t u32[2];
+ } cur_list, next_list;
#endif
int old;
int new = -2;
@@ -188,24 +192,24 @@
int last;
lock_self:
#if (defined(HA_CAS_IS_8B) || defined(HA_HAVE_CAS_DW))
- next_list.next = next_list.prev = -2;
- cur_list = *(volatile struct fdlist_entry *)(((char *)&fdtab[fd]) + off);
+ next_list.ent.next = next_list.ent.prev = -2;
+ cur_list.ent = *(volatile struct fdlist_entry *)(((char *)&fdtab[fd]) + off);
/* First, attempt to lock our own entries */
do {
/* The FD is not in the FD cache, give up */
- if (unlikely(cur_list.next <= -3))
+ if (unlikely(cur_list.ent.next <= -3))
return;
- if (unlikely(cur_list.prev == -2 || cur_list.next == -2))
+ if (unlikely(cur_list.ent.prev == -2 || cur_list.ent.next == -2))
goto lock_self;
} while (
#ifdef HA_CAS_IS_8B
- unlikely(!_HA_ATOMIC_CAS(((void **)(void *)&_GET_NEXT(fd, off)), ((void **)(void *)&cur_list), (*(void **)(void *)&next_list))))
+ unlikely(!_HA_ATOMIC_CAS(((uint64_t *)&_GET_NEXT(fd, off)), (uint64_t *)&cur_list.u64, next_list.u64))
#else
- unlikely(!_HA_ATOMIC_DWCAS(((void *)&_GET_NEXT(fd, off)), ((void *)&cur_list), ((void *)&next_list))))
+ unlikely(!_HA_ATOMIC_DWCAS(((long *)&_GET_NEXT(fd, off)), (uint32_t *)&cur_list.u32, &next_list.u32))
#endif
- ;
- next = cur_list.next;
- prev = cur_list.prev;
+ );
+ next = cur_list.ent.next;
+ prev = cur_list.ent.prev;
#else
lock_self_next: