Cleanup: Re-organise source dir

[userspace-rcu.git] / src / urcu-pointer.h

diff --git a/src/urcu-pointer.h b/src/urcu-pointer.h
new file mode 100644 (file)
index 0000000..dc1a0da
--- /dev/null
+++ b/src/urcu-pointer.h
@@ -0,0 +1,129 @@
+#ifndef _URCU_POINTER_H
+#define _URCU_POINTER_H
+
+/*
+ * urcu-pointer.h
+ *
+ * Userspace RCU header. Operations on pointers.
+ *
+ * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
+ *
+ * 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
+ *
+ * IBM's contributions to this file may be relicensed under LGPLv2 or later.
+ */
+
+#include <urcu/compiler.h>
+#include <urcu/arch.h>
+#include <urcu/uatomic.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if defined(_LGPL_SOURCE) || defined(URCU_INLINE_SMALL_FUNCTIONS)
+
+#include <urcu/static/urcu-pointer.h>
+
+/*
+ * rcu_dereference(ptr)
+ *
+ * Fetch a RCU-protected pointer. Typically used to copy the variable ptr to a
+ * local variable.
+ */
+#define rcu_dereference                _rcu_dereference
+
+/*
+ * type *rcu_cmpxchg_pointer(type **ptr, type *new, type *old)
+ * type *rcu_xchg_pointer(type **ptr, type *new)
+ * void rcu_set_pointer(type **ptr, type *new)
+ *
+ * RCU pointer updates.
+ * @ptr: address of the pointer to modify
+ * @new: new pointer value
+ * @old: old pointer value (expected)
+ *
+ * return: old pointer value
+ */
+#define rcu_cmpxchg_pointer    _rcu_cmpxchg_pointer
+#define rcu_xchg_pointer       _rcu_xchg_pointer
+#define rcu_set_pointer                _rcu_set_pointer
+
+#else /* !(defined(_LGPL_SOURCE) || defined(URCU_INLINE_SMALL_FUNCTIONS)) */
+
+extern void *rcu_dereference_sym(void *p);
+#define rcu_dereference(p)                                                  \
+       __extension__                                                        \
+       ({                                                                   \
+               __typeof__(p) _________p1 =     URCU_FORCE_CAST(__typeof__(p), \
+                       rcu_dereference_sym(URCU_FORCE_CAST(void *, p)));    \
+               (_________p1);                                               \
+       })
+
+extern void *rcu_cmpxchg_pointer_sym(void **p, void *old, void *_new);
+#define rcu_cmpxchg_pointer(p, old, _new)                                   \
+       __extension__                                                        \
+       ({                                                                   \
+               __typeof__(*(p)) _________pold = (old);                      \
+               __typeof__(*(p)) _________pnew = (_new);                     \
+               __typeof__(*(p)) _________p1 = URCU_FORCE_CAST(__typeof__(*(p)), \
+                       rcu_cmpxchg_pointer_sym(URCU_FORCE_CAST(void **, p), \
+                                               _________pold,               \
+                                               _________pnew));             \
+               (_________p1);                                               \
+       })
+
+extern void *rcu_xchg_pointer_sym(void **p, void *v);
+#define rcu_xchg_pointer(p, v)                                              \
+       __extension__                                                        \
+       ({                                                                   \
+               __typeof__(*(p)) _________pv = (v);                          \
+               __typeof__(*(p)) _________p1 = URCU_FORCE_CAST(__typeof__(*(p)), \
+                       rcu_xchg_pointer_sym(URCU_FORCE_CAST(void **, p),    \
+                                            _________pv));                  \
+               (_________p1);                                               \
+       })
+
+/*
+ * Note: rcu_set_pointer_sym returns @v because we don't want to break
+ * the ABI. At the API level, rcu_set_pointer() now returns void. Use of
+ * the return value is therefore deprecated, and will cause a build
+ * error.
+ */
+extern void *rcu_set_pointer_sym(void **p, void *v);
+#define rcu_set_pointer(p, v)                                               \
+       do {                                                                 \
+               __typeof__(*(p)) _________pv = (v);                          \
+               (void) rcu_set_pointer_sym(URCU_FORCE_CAST(void **, p),      \
+                                           _________pv);                    \
+       } while (0)
+
+#endif /* !(defined(_LGPL_SOURCE) || defined(URCU_INLINE_SMALL_FUNCTIONS)) */
+
+/*
+ * void rcu_assign_pointer(type *ptr, type *new)
+ *
+ * Same as rcu_set_pointer, but takes the pointer to assign to rather than its
+ * address as first parameter. Provided for compatibility with the Linux kernel
+ * RCU semantic.
+ */
+#define rcu_assign_pointer(p, v)       rcu_set_pointer((&p), (v))
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _URCU_POINTER_H */