X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=CodingStyle;h=2f24ee396f057ded30413ad71e80e46797d10be9;hb=2d344ba5be310b085806b6e6b80833039465722b;hp=2ee189faf0f4bfe4b2734aeebce182392ef41943;hpb=b93e69830a5606712f1ec0132e250839afbd87c4;p=sliver-openvswitch.git

diff --git a/CodingStyle b/CodingStyle
index 2ee189faf..2f24ee396 100644
--- a/CodingStyle
+++ b/CodingStyle
@@ -249,6 +249,18 @@ details.  (Some compilers also assume that the "if" branch is the more
 common case, so this can be a real form of optimization as well.)
 
 
+RETURN VALUES
+
+  For functions that return a success or failure indication, prefer
+one of the following return value conventions:
+
+    * An "int" where 0 indicates success and a positive errno value
+      indicates a reason for failure.
+
+    * A "bool" where true indicates success and false indicates
+      failure.
+
+
 MACROS
 
   Don't define an object-like macro if an enum can be used instead.
@@ -286,6 +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
@@ -432,8 +459,8 @@ precedence makes it necessary, or unless the operands are themselves
 expressions that use && and ||.  Thus:
 
     if (!isdigit((unsigned char)s[0])
-            || !isdigit((unsigned char)s[1])
-            || !isdigit((unsigned char)s[2])) {
+        || !isdigit((unsigned char)s[1])
+        || !isdigit((unsigned char)s[2])) {
         printf("string %s does not start with 3-digit code\n", s);
     }
 
@@ -474,9 +501,8 @@ global variables.
 
 C DIALECT
 
-  Try to avoid using GCC extensions where possible.
-
-  Some C99 extensions are OK:
+  Some C99 features are OK because they are widely implemented even in
+older compilers:
 
     * Flexible array members (e.g. struct { int foo[]; }).
 
@@ -491,9 +517,8 @@ C DIALECT
       only take on the values 0 or 1, because this behavior can't be
       simulated on C89 compilers.
 
-  Don't use other C99 extensions, and especially:
-
-    * Don't use // comments.
+  Don't use other C99 features that are not widely implemented in
+older compilers:
 
     * Don't use designated initializers (e.g. don't write "struct foo
       foo = {.a = 1};" or "int a[] = {[2] = 5};").
@@ -505,3 +530,11 @@ C DIALECT
 
     * Don't put a trailing comma in an enum declaration (e.g. don't
       write "enum { x = 1, };").
+
+  As a matter of style, avoid // comments.
+
+  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.