lfstack: make cds_lfs_empty argument const

[urcu.git] / include / urcu / lfstack.h

diff --git a/include/urcu/lfstack.h b/include/urcu/lfstack.h
index 77af43bf18069df89619f85be6ac46178980de5c..2a3073d695b7ae479d2a848420b15c7b70be647e 100644 (file)
--- a/include/urcu/lfstack.h
+++ b/include/urcu/lfstack.h
@@ -84,6 +84,11 @@ typedef union {
        struct __cds_lfs_stack *_s;
        struct cds_lfs_stack *s;
 } __attribute__((__transparent_union__)) cds_lfs_stack_ptr_t;
+
+typedef union {
+       const struct __cds_lfs_stack *_s;
+       const struct cds_lfs_stack *s;
+} __attribute__((__transparent_union__)) cds_lfs_stack_const_ptr_t;
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif
@@ -141,7 +146,7 @@ extern void __cds_lfs_init(struct __cds_lfs_stack *s);
  *
  * No memory barrier is issued. No mutual exclusion is required.
  */
-extern bool cds_lfs_empty(cds_lfs_stack_ptr_t s);
+extern bool cds_lfs_empty(cds_lfs_stack_const_ptr_t s);
 
 /*
  * cds_lfs_push: push a node into the stack.
@@ -276,9 +281,25 @@ static inline cds_lfs_stack_ptr_t cds_lfs_stack_cast(struct cds_lfs_stack *s)
        return ret;
 }
 
+static inline cds_lfs_stack_const_ptr_t cds_lfs_stack_const_cast(const struct __cds_lfs_stack *s)
+{
+       cds_lfs_stack_const_ptr_t ret = {
+               ._s = s,
+       };
+       return ret;
+}
+
+static inline cds_lfs_stack_const_ptr_t cds_lfs_stack_const_cast(const struct cds_lfs_stack *s)
+{
+       cds_lfs_stack_const_ptr_t ret = {
+               .s = s,
+       };
+       return ret;
+}
+
 template<typename T> static inline bool cds_lfs_empty(T s)
 {
-       return cds_lfs_empty(cds_lfs_stack_cast(s));
+       return cds_lfs_empty(cds_lfs_stack_const_cast(s));
 }
 
 template<typename T> static inline bool cds_lfs_push(T s,