Adding upstream version 3.8.1.upstream/3.8.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 91 insertions, 0 deletions

diff --git a/src/libutil/ref.h b/src/libutil/ref.h
new file mode 100644
index 0000000..2a3fd8d
--- /dev/null
+++ b/src/libutil/ref.h
@@ -0,0 +1,91 @@
+/*-
+ * Copyright 2016 Vsevolod Stakhov
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef REF_H_
+#define REF_H_
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+
+/**
+ * @file ref.h
+ * A set of macros to handle refcounts
+ */
+
+typedef void (*ref_dtor_cb_t)(void *data);
+
+typedef struct ref_entry_s {
+	unsigned int refcount;
+	ref_dtor_cb_t dtor;
+} ref_entry_t;
+
+#define REF_INIT(obj, dtor_cb)                           \
+	do {                                                 \
+		if ((obj) != NULL) {                             \
+			(obj)->ref.refcount = 0;                     \
+			(obj)->ref.dtor = (ref_dtor_cb_t) (dtor_cb); \
+		}                                                \
+	} while (0)
+
+#define REF_INIT_RETAIN(obj, dtor_cb)                    \
+	do {                                                 \
+		if ((obj) != NULL) {                             \
+			(obj)->ref.refcount = 1;                     \
+			(obj)->ref.dtor = (ref_dtor_cb_t) (dtor_cb); \
+		}                                                \
+	} while (0)
+
+#ifdef HAVE_ATOMIC_BUILTINS
+#define REF_RETAIN_ATOMIC(obj)                                             \
+	do {                                                                   \
+		if ((obj) != NULL) {                                               \
+			__atomic_add_fetch(&(obj)->ref.refcount, 1, __ATOMIC_RELEASE); \
+		}                                                                  \
+	} while (0)
+
+#define REF_RELEASE_ATOMIC(obj)                                                                    \
+	do {                                                                                           \
+		if ((obj) != NULL) {                                                                       \
+			unsigned int _rc_priv = __atomic_sub_fetch(&(obj)->ref.refcount, 1, __ATOMIC_ACQ_REL); \
+			if (_rc_priv == 0 && (obj)->ref.dtor) {                                                \
+				(obj)->ref.dtor(obj);                                                              \
+			}                                                                                      \
+		}                                                                                          \
+	} while (0)
+
+#else
+#define REF_RETAIN_ATOMIC REF_RETAIN
+#define REF_RELEASE_ATOMIC REF_RELEASE_ATOMIC
+#endif
+
+#define REF_RETAIN(obj)            \
+	do {                           \
+		if ((obj) != NULL) {       \
+			(obj)->ref.refcount++; \
+		}                          \
+	} while (0)
+
+#define REF_RELEASE(obj)                                         \
+	do {                                                         \
+		if ((obj) != NULL) {                                     \
+			if (--(obj)->ref.refcount == 0 && (obj)->ref.dtor) { \
+				(obj)->ref.dtor(obj);                            \
+			}                                                    \
+		}                                                        \
+	} while (0)
+
+#endif /* REF_H_ */