1 files changed, 122 insertions, 0 deletions
diff --git a/base/refcnt.hh b/base/refcnt.hh
new file mode 100644
index 000000000..5bc62ae23
--- /dev/null
+++ b/base/refcnt.hh
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2003 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * 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;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 THE COPYRIGHT
+ * OWNER 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 __REFCNT_HH__
+#define __REFCNT_HH__
+
+class RefCounted
+{
+  private:
+    int count;
+
+  private:
+    RefCounted(const RefCounted &);
+
+  public:
+    RefCounted() : count(0) {}
+    virtual ~RefCounted() {}
+
+    void incref() { ++count; }
+    void decref() { if (--count <= 0) delete this; }
+};
+
+template <class T>
+class RefCountingPtr
+{
+  private:
+    T *data;
+
+    void copy(T *d) {
+        data = d;
+        if (data)
+            data->incref();
+    }
+    void del() {
+        if (data)
+            data->decref();
+    }
+
+  public:
+    RefCountingPtr() : data(NULL) {}
+    RefCountingPtr(T *data) { copy(data); }
+    RefCountingPtr(const RefCountingPtr& r) { copy(r.data); }
+    ~RefCountingPtr() { del(); }
+
+    T *operator->() { return data; }
+    T &operator*() { return *data; }
+    T *get() { return data; }
+
+    const T *operator->() const { return data; }
+    const T &operator*() const { return *data; }
+    const T *get() const { return data; }
+
+    RefCountingPtr &operator=(T *p) {
+        if (data != p) {
+            del();
+            copy(p);
+        }
+        return *this;
+    }
+
+    RefCountingPtr &operator=(const RefCountingPtr& r) {
+        if (data != r.data) {
+            del();
+            copy(r.data);
+        }
+        return *this;
+    }
+
+    bool operator!() const { return data == 0; }
+    operator bool() const { return data != 0; }
+};
+
+template<class T>
+bool operator==(const RefCountingPtr<T> &l, const RefCountingPtr<T> &r)
+{ return l.get() == r.get(); }
+
+template<class T>
+bool operator==(const RefCountingPtr<T> &l, const T *r)
+{ return l.get() == r; }
+
+template<class T>
+bool operator==(const T &l, const RefCountingPtr<T> &r)
+{ return l == r.get(); }
+
+template<class T>
+bool operator!=(const RefCountingPtr<T> &l, const RefCountingPtr<T> &r)
+{ return l.get() != r.get(); }
+
+template<class T>
+bool operator!=(const RefCountingPtr<T> &l, const T *r)
+{ return l.get() != r; }
+
+template<class T>
+bool operator!=(const T &l, const RefCountingPtr<T> &r)
+{ return l != r.get(); }
+
+#endif // __REFCNT_HH__