lf_fifo don't use union anymore, just for one ==

1 files changed, 61 insertions, 0 deletions

diff --git a/lf_cas.h b/lf_cas.h
new file mode 100644
index 0000000..1a21bf1
--- /dev/null
+++ b/lf_cas.h
@@ -0,0 +1,61 @@
+/*
+ * File     : lf_cas.h
+ * Author   : Jérémy Zurcher  <jeremy@asynk.ch>
+ * Date     : 01/11/09 
+ * License  :
+ *
+ *  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, sublicense, 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 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
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 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 _LF_CAS_H_
+#define _LF_CAS_H_
+
+# ifdef __cplusplus
+extern "C" {
+# endif /* __cplusplus */
+
+struct lf_pointer;
+
+typedef struct lf_pointer {
+    volatile struct lf_pointer *ptr;
+    volatile unsigned int count;
+} lf_pointer_t;
+
+
+/* CMPXCHG8B m64   Compare EDX:EAX with m64. If equal, set ZF and load ECX:EBX into m64. Else, clear ZF and load m64 into EDX:EAX. */
+static inline unsigned int cas( volatile lf_pointer_t *mem,
+                                volatile lf_pointer_t old,
+                                volatile lf_pointer_t new ) {
+    char result;
+    __asm__ __volatile__("lock; cmpxchg8b %0; setz %1;"
+            : "=m"(*mem), "=q"(result)
+            : "m"(*mem), "d" (old.count), "a" (old.ptr),
+            "c" (new.count), "b" (new.ptr)
+            : "memory");
+    return (int)result;
+}
+
+# ifdef __cplusplus
+}
+# endif /* __cplusplus */
+
+# endif /* _LF_CAS_H_ */
+