Merge branch 'mainstream'

[sliver-openvswitch.git] / CodingStyle

diff --git a/CodingStyle b/CodingStyle
index 22f0f45..2f24ee3 100644 (file)
--- a/CodingStyle
+++ b/CodingStyle
@@ -298,6 +298,21 @@ the name of each enum.  For example:
     };
 
 
+THREAD SAFETY ANNOTATIONS
+
+  Use the macros in lib/compiler.h to annotate locking requirements.
+For example:
+
+    static struct ovs_mutex mutex = OVS_MUTEX_INITIALIZER;
+    static struct ovs_rwlock rwlock = OVS_RWLOCK_INITIALIZER;
+
+    void function_require_plain_mutex(void) OVS_REQUIRES(mutex);
+    void function_require_rwlock(void) OVS_REQ_RDLOCK(rwlock);
+
+  Pass lock objects, not their addresses, to the annotation macros.
+(Thus we have OVS_REQUIRES(mutex) above, not OVS_REQUIRES(&mutex).)
+
+
 SOURCE FILES
 
   Each source file should state its license in a comment at the very
@@ -518,7 +533,8 @@ older compilers:
 
   As a matter of style, avoid // comments.
 
-  Avoid using GCC extensions unless you also add a fallback for
-non-GCC compilers.  You can, however, use GCC extensions and C99
-features in code that compiles only on GNU/Linux (such as
-lib/netdev-linux.c), because GCC is the system compiler there.
+  Avoid using GCC or Clang extensions unless you also add a fallback
+for other compilers.  You can, however, use C99 features or GCC
+extensions also supported by Clang in code that compiles only on
+GNU/Linux (such as lib/netdev-linux.c), because GCC is the system
+compiler there.