X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=include%2Furcu%2Fwfstack.h;h=38e5b6b2dcb3099dec87f8a6b3fb4f5750e93fb1;hb=HEAD;hp=0890f5c1a54b7d8e590196cf6553ce12f5b7e001;hpb=087bce43020d2b45dab2dd8ecd6b0d6949c626f3;p=urcu.git

diff --git a/include/urcu/wfstack.h b/include/urcu/wfstack.h
index 0890f5c..66d4150 100644
--- a/include/urcu/wfstack.h
+++ b/include/urcu/wfstack.h
@@ -1,26 +1,12 @@
+// SPDX-FileCopyrightText: 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
 #ifndef _URCU_WFSTACK_H
 #define _URCU_WFSTACK_H
 
 /*
- * urcu/wfstack.h
- *
  * Userspace RCU library - Stack with wait-free push, blocking traversal.
- *
- * Copyright 2010-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <pthread.h>
@@ -110,6 +96,11 @@ typedef union {
 	struct __cds_wfs_stack *_s;
 	struct cds_wfs_stack *s;
 } __attribute__((__transparent_union__)) cds_wfs_stack_ptr_t;
+
+typedef union {
+	const struct __cds_wfs_stack *_s;
+	const struct cds_wfs_stack *s;
+} __attribute__((__transparent_union__)) cds_wfs_stack_const_ptr_t;
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif
@@ -181,7 +172,7 @@ extern void __cds_wfs_init(struct __cds_wfs_stack *s);
  *
  * No memory barrier is issued. No mutual exclusion is required.
  */
-extern bool cds_wfs_empty(cds_wfs_stack_ptr_t u_stack);
+extern bool cds_wfs_empty(cds_wfs_stack_const_ptr_t u_stack);
 
 /*
  * cds_wfs_push: push a node into the stack.
@@ -386,9 +377,25 @@ static inline cds_wfs_stack_ptr_t cds_wfs_stack_cast(struct cds_wfs_stack *s)
 	return ret;
 }
 
+static inline cds_wfs_stack_const_ptr_t cds_wfs_stack_const_cast(const struct __cds_wfs_stack *s)
+{
+	cds_wfs_stack_const_ptr_t ret = {
+		._s = s,
+	};
+	return ret;
+}
+
+static inline cds_wfs_stack_const_ptr_t cds_wfs_stack_const_cast(const struct cds_wfs_stack *s)
+{
+	cds_wfs_stack_const_ptr_t ret = {
+		.s = s,
+	};
+	return ret;
+}
+
 template<typename T> static inline bool cds_wfs_empty(T s)
 {
-	return cds_wfs_empty(cds_wfs_stack_cast(s));
+	return cds_wfs_empty(cds_wfs_stack_const_cast(s));
 }
 
 template<typename T> static inline int cds_wfs_push(T s, struct cds_wfs_node *node)