aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.4.3/libstdc++-v3/include/ext/atomicity.h
diff options
context:
space:
mode:
Diffstat (limited to 'gcc-4.4.3/libstdc++-v3/include/ext/atomicity.h')
-rw-r--r--gcc-4.4.3/libstdc++-v3/include/ext/atomicity.h113
1 files changed, 113 insertions, 0 deletions
diff --git a/gcc-4.4.3/libstdc++-v3/include/ext/atomicity.h b/gcc-4.4.3/libstdc++-v3/include/ext/atomicity.h
new file mode 100644
index 000000000..bb891e8af
--- /dev/null
+++ b/gcc-4.4.3/libstdc++-v3/include/ext/atomicity.h
@@ -0,0 +1,113 @@
+// Support for atomic operations -*- C++ -*-
+
+// Copyright (C) 2004, 2005, 2006, 2008, 2009 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, 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 General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file atomicity.h
+ * This is an internal header file, included by other library headers.
+ * You should not attempt to use it directly.
+ */
+
+#ifndef _GLIBCXX_ATOMICITY_H
+#define _GLIBCXX_ATOMICITY_H 1
+
+#include <bits/c++config.h>
+#include <bits/gthr.h>
+#include <bits/atomic_word.h>
+
+_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
+
+ // Functions for portable atomic access.
+ // To abstract locking primitives across all thread policies, use:
+ // __exchange_and_add_dispatch
+ // __atomic_add_dispatch
+#ifdef _GLIBCXX_ATOMIC_BUILTINS_4
+ static inline _Atomic_word
+ __exchange_and_add(volatile _Atomic_word* __mem, int __val)
+ { return __sync_fetch_and_add(__mem, __val); }
+
+ static inline void
+ __atomic_add(volatile _Atomic_word* __mem, int __val)
+ { __sync_fetch_and_add(__mem, __val); }
+#else
+ _Atomic_word
+ __attribute__ ((__unused__))
+ __exchange_and_add(volatile _Atomic_word*, int);
+
+ void
+ __attribute__ ((__unused__))
+ __atomic_add(volatile _Atomic_word*, int);
+#endif
+
+ static inline _Atomic_word
+ __exchange_and_add_single(_Atomic_word* __mem, int __val)
+ {
+ _Atomic_word __result = *__mem;
+ *__mem += __val;
+ return __result;
+ }
+
+ static inline void
+ __atomic_add_single(_Atomic_word* __mem, int __val)
+ { *__mem += __val; }
+
+ static inline _Atomic_word
+ __attribute__ ((__unused__))
+ __exchange_and_add_dispatch(_Atomic_word* __mem, int __val)
+ {
+#ifdef __GTHREADS
+ if (__gthread_active_p())
+ return __exchange_and_add(__mem, __val);
+ else
+ return __exchange_and_add_single(__mem, __val);
+#else
+ return __exchange_and_add_single(__mem, __val);
+#endif
+ }
+
+ static inline void
+ __attribute__ ((__unused__))
+ __atomic_add_dispatch(_Atomic_word* __mem, int __val)
+ {
+#ifdef __GTHREADS
+ if (__gthread_active_p())
+ __atomic_add(__mem, __val);
+ else
+ __atomic_add_single(__mem, __val);
+#else
+ __atomic_add_single(__mem, __val);
+#endif
+ }
+
+_GLIBCXX_END_NAMESPACE
+
+// Even if the CPU doesn't need a memory barrier, we need to ensure
+// that the compiler doesn't reorder memory accesses across the
+// barriers.
+#ifndef _GLIBCXX_READ_MEM_BARRIER
+#define _GLIBCXX_READ_MEM_BARRIER __asm __volatile ("":::"memory")
+#endif
+#ifndef _GLIBCXX_WRITE_MEM_BARRIER
+#define _GLIBCXX_WRITE_MEM_BARRIER __asm __volatile ("":::"memory")
+#endif
+
+#endif