1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
|
diff --git a/include/refcount.h b/include/refcount.h
index 785b052..533fdfe 100644
--- a/include/refcount.h
+++ b/include/refcount.h
@@ -31,10 +31,11 @@
/* An opaque type. You must not access these values directly. */
typedef unsigned int refcount_t;
-/* Initialize REF with REFERENCES. */
+/* Initialize REF with REFERENCES. REFERENCES must not be zero. */
static inline void
refcount_init (refcount_t *ref, unsigned int references)
{
+ assert (references > 0 || !"references must not be zero!");
*ref = references;
}
@@ -47,6 +48,7 @@ refcount_ref (refcount_t *ref)
unsigned int r;
r = __atomic_add_fetch (ref, 1, __ATOMIC_RELAXED);
assert (r != UINT_MAX || !"refcount overflowed!");
+ assert (r != 1 || !"refcount detected use after free!");
return r;
}
@@ -101,10 +103,12 @@ union _references {
uint64_t value;
};
-/* Initialize REF with HARD and WEAK references. */
+/* Initialize REF with HARD and WEAK references. HARD and WEAK must
+ not both be zero. */
static inline void
refcounts_init (refcounts_t *ref, uint32_t hard, uint32_t weak)
{
+ assert ((hard != 0 || weak != 0) || !"references must not both be zero!");
ref->references = (struct references) { .hard = hard, .weak = weak };
}
@@ -119,6 +123,8 @@ refcounts_ref (refcounts_t *ref, struct references *result)
union _references r;
r.value = __atomic_add_fetch (&ref->value, op.value, __ATOMIC_RELAXED);
assert (r.references.hard != UINT32_MAX || !"refcount overflowed!");
+ assert (! (r.references.hard == 1 && r.references.weak == 0)
+ || !"refcount detected use after free!");
if (result)
*result = r.references;
}
@@ -208,6 +214,8 @@ refcounts_ref_weak (refcounts_t *ref, struct references *result)
union _references r;
r.value = __atomic_add_fetch (&ref->value, op.value, __ATOMIC_RELAXED);
assert (r.references.weak != UINT32_MAX || !"refcount overflowed!");
+ assert (! (r.references.hard == 0 && r.references.weak == 1)
+ || !"refcount detected use after free!");
if (result)
*result = r.references;
}
|
