1 files changed, 96 insertions, 0 deletions
diff --git a/src/gallium/include/pipe/p_refcnt.h b/src/gallium/include/pipe/p_refcnt.h
new file mode 100644
index 0000000000..1f9088b3e9
--- /dev/null
+++ b/src/gallium/include/pipe/p_refcnt.h
@@ -0,0 +1,96 @@
+/**************************************************************************
+ * 
+ * Copyright 2009 VMware, Inc.
+ * All Rights Reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * 
+ **************************************************************************/
+
+#ifndef P_REFCNT_H
+#define P_REFCNT_H
+
+
+#include "p_defines.h"
+#include "p_atomic.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+struct pipe_reference
+{
+   struct pipe_atomic count;
+};
+
+
+static INLINE void
+pipe_reference_init(struct pipe_reference *reference, unsigned count)
+{
+   p_atomic_set(&reference->count, count);
+}
+
+
+static INLINE bool
+pipe_is_referenced(struct pipe_reference *reference)
+{
+   return p_atomic_read(&reference->count) != 0;
+}
+
+
+/**
+ * Set 'ptr' to point to 'reference' and update reference counting.
+ * The old thing pointed to, if any, will be unreferenced first.
+ * 'reference' may be NULL.
+ */
+static INLINE bool
+pipe_reference(struct pipe_reference **ptr, struct pipe_reference *reference)
+{
+   bool destroy = FALSE;
+
+   if(*ptr != reference) {
+      /* bump the reference.count first */
+      if (reference) {
+         assert(pipe_is_referenced(reference));
+         p_atomic_inc(&reference->count);
+      }
+   
+      if (*ptr) {
+         assert(pipe_is_referenced(*ptr));
+         if (p_atomic_dec_zero(&(*ptr)->count)) {
+            destroy = TRUE;
+         }
+      }
+   
+      *ptr = reference;
+   }
+
+   return destroy;
+}
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* P_REFCNT_H */