version 3.0

common/thread/atomic.h

@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2010-2011 Juli Mallett. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef	COMMON_THREAD_ATOMIC_H
+#define	COMMON_THREAD_ATOMIC_H
+
+template<typename T>
+class Atomic {
+	T val_;
+public:
+	Atomic(void)
+	: val_()
+	{ }
+
+	template<typename Ta>
+	Atomic(Ta arg)
+	: val_(arg)
+	{ }
+
+	~Atomic()
+	{ }
+	
+	T val () const							{ return val_; }
+	bool operator == (T v) const		{ return (v == val_); }
+	bool operator != (T v) const		{ return (v != val_); }
+
+	/*
+	 * Note that these are deliberately not operator overloads, to force
+	 * deliberate use of this class.
+	 */
+
+#if defined(__GNUC__)
+	template<typename Ta>
+	T add(Ta arg)
+	{
+		return (__sync_add_and_fetch (&val_, arg));
+	}
+
+	template<typename Ta>
+	T subtract(Ta arg)
+	{
+		return (__sync_sub_and_fetch (&val_, arg));
+	}
+
+	template<typename Ta>
+	T set(Ta arg)
+	{
+		return (__sync_or_and_fetch (&val_, arg));
+	}
+
+	template<typename Ta>
+	T mask(Ta arg)
+	{
+		return (__sync_and_and_fetch (&val_, arg));
+	}
+
+	template<typename Ta>
+	T clear(Ta arg)
+	{
+		return (__sync_and_and_fetch (&val_, ~arg));
+	}
+
+	template<typename To, typename Tn>
+	bool cmpset(To oldval, Tn newval)
+	{
+		return (__sync_bool_compare_and_swap (&val_, oldval, newval));
+	}
+#else
+#error "No support for atomic operations for your compiler.  Why not add some?"
+#endif
+};
+
+#endif /* !COMMON_THREAD_ATOMIC_H */