1 files changed, 56 insertions, 0 deletions
diff --git a/base/callback.hh b/base/callback.hh
new file mode 100644
index 000000000..a1d23b5ed
--- /dev/null
+++ b/base/callback.hh
@@ -0,0 +1,56 @@
+/*
+ * 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 __CALLBACK_HH__
+#define __CALLBACK_HH__
+
+#include <list>
+
+class Callback {
+  public:
+    virtual ~Callback() {}
+    virtual void process() = 0;
+};
+
+class CallbackQueue
+{
+  protected:
+    std::list<Callback *> callbacks;
+
+  public:
+    void add(Callback *callback) { callbacks.push_back(callback); }
+    bool empty() const { return callbacks.empty(); }
+    void processOne() {
+        Callback *c = callbacks.front();
+        callbacks.pop_front();
+        c->process();
+    }
+    void processAll() { while (!empty()) processOne(); }
+};
+
+#endif // __CALLBACK_HH__