From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 27 Aug 2018 04:58:15 +0000 (+0900)
Subject: refcnt: introduce DEFINE_ATOMIC_REF_UNREF_FUNC() macro and friends
X-Git-Tag: v240~791^2~3
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1d3044e275d9d933ad5a84b7ec259065b2c7e710;p=thirdparty%2Fsystemd.git

refcnt: introduce DEFINE_ATOMIC_REF_UNREF_FUNC() macro and friends
---

diff --git a/src/basic/refcnt.h b/src/basic/refcnt.h
index d2be6086d2b..40f9a84a22c 100644
--- a/src/basic/refcnt.h
+++ b/src/basic/refcnt.h
@@ -14,3 +14,41 @@ typedef struct {
 #define REFCNT_DEC(r) (__sync_sub_and_fetch(&(r)._value, 1))
 
 #define REFCNT_INIT ((RefCount) { ._value = 1 })
+
+#define _DEFINE_ATOMIC_REF_FUNC(type, name, scope)                    \
+        scope type *name##_ref(type *p) {                               \
+                if (!p)                                                 \
+                        return NULL;                                    \
+                                                                        \
+                assert_se(REFCNT_INC(p->n_ref) >= 2);                   \
+                return p;                                               \
+        }
+
+#define _DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func, scope)       \
+        scope type *name##_unref(type *p) {                             \
+                if (!p)                                                 \
+                        return NULL;                                    \
+                                                                        \
+                if (REFCNT_DEC(p->n_ref) > 0)                           \
+                        return NULL;                                    \
+                                                                        \
+                return free_func(p);                                    \
+        }
+
+#define DEFINE_ATOMIC_REF_FUNC(type, name)    \
+        _DEFINE_ATOMIC_REF_FUNC(type, name,)
+#define DEFINE_PUBLIC_ATOMIC_REF_FUNC(type, name)     \
+        _DEFINE_ATOMIC_REF_FUNC(type, name, _public_)
+
+#define DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func)       \
+        _DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func,)
+#define DEFINE_PUBLIC_ATOMIC_UNREF_FUNC(type, name, free_func)        \
+        _DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func, _public_)
+
+#define DEFINE_ATOMIC_REF_UNREF_FUNC(type, name, free_func)   \
+        DEFINE_ATOMIC_REF_FUNC(type, name);                   \
+        DEFINE_ATOMIC_UNREF_FUNC(type, name, free_func);
+
+#define DEFINE_PUBLIC_ATOMIC_REF_UNREF_FUNC(type, name, free_func)   \
+        DEFINE_PUBLIC_ATOMIC_REF_FUNC(type, name);                   \
+        DEFINE_PUBLIC_ATOMIC_UNREF_FUNC(type, name, free_func);