diff options
Diffstat (limited to 'include/openvswitch')
-rw-r--r-- | include/openvswitch/util.h | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/include/openvswitch/util.h b/include/openvswitch/util.h index 228b185c3..2d81e3574 100644 --- a/include/openvswitch/util.h +++ b/include/openvswitch/util.h @@ -145,6 +145,49 @@ OVS_NO_RETURN void ovs_assert_failure(const char *, const char *, const char *); #define INIT_CONTAINER(OBJECT, POINTER, MEMBER) \ ((OBJECT) = NULL, ASSIGN_CONTAINER(OBJECT, POINTER, MEMBER)) +/* Multi-variable container iterators. + * + * The following macros facilitate safe iteration over data structures + * contained in objects. It does so by using an internal iterator variable of + * the type of the member object pointer (i.e: pointer to the data structure). + */ + +/* Multi-variable iterator variable name. + * Returns the name of the internal iterator variable. + */ +#define ITER_VAR(NAME) NAME ## __iterator__ + +/* Multi-variable initialization. Creates an internal iterator variable that + * points to the provided pointer. The type of the iterator variable is + * ITER_TYPE*. It must be the same type as &VAR->MEMBER. + * + * The _EXP version evaluates the extra expressions once. + */ +#define INIT_MULTIVAR(VAR, MEMBER, POINTER, ITER_TYPE) \ + INIT_MULTIVAR_EXP(VAR, MEMBER, POINTER, ITER_TYPE, (void) 0) + +#define INIT_MULTIVAR_EXP(VAR, MEMBER, POINTER, ITER_TYPE, ...) \ + ITER_TYPE *ITER_VAR(VAR) = ( __VA_ARGS__ , (ITER_TYPE *) POINTER) + +/* Multi-variable condition. + * Evaluates the condition expression (that must be based on the internal + * iterator variable). Only if the result of expression is true, the OBJECT is + * set to the object containing the current value of the iterator variable. + * + * It is up to the caller to make sure it is safe to run OBJECT_CONTAINING on + * the pointers that verify the condition. + */ +#define CONDITION_MULTIVAR(VAR, MEMBER, EXPR) \ + ((EXPR) ? \ + (((VAR) = OBJECT_CONTAINING(ITER_VAR(VAR), VAR, MEMBER)), 1) : \ + (((VAR) = NULL), 0)) + +/* Multi-variable update. + * Sets the iterator value to NEXT_ITER. + */ +#define UPDATE_MULTIVAR(VAR, NEXT_ITER) \ + (ITER_VAR(VAR) = NEXT_ITER) + /* Returns the number of elements in ARRAY. */ #define ARRAY_SIZE(ARRAY) __ARRAY_SIZE(ARRAY) |