Add classes for event-handling

The new classes Event and EventSource can be used as a simple mechanism
for implementing event-based callbacks in the simulators.

tests/test_event.cpp

@@ -0,0 +1,78 @@
+/* Copyright 2013 Uni Research AS
+ * This file is licensed under GPL3, see http://www.opm-project.org/
+*/
+#include <config.h>
+
+/* --- Boost.Test boilerplate --- */
+#if HAVE_DYNAMIC_BOOST_TEST
+#define BOOST_TEST_DYN_LINK
+#endif
+
+#define NVERBOSE  // Suppress own messages when throw()ing
+
+#define BOOST_TEST_MODULE EventTest
+#include <boost/test/unit_test.hpp>
+
+/* --- our own headers --- */
+#include <opm/core/utility/Event.hpp>
+
+using namespace std;
+using namespace Opm;
+
+// idiomatic implementation of generator and receiver
+struct EventGenerator {
+    EventSource eventSource_;
+    Event& event () { return eventSource_; }
+    void action () { eventSource_.signal (); }
+};
+
+struct EventReceiver {
+    int numOfCalls;
+    EventReceiver () : numOfCalls (0) { }
+    void handler () { ++numOfCalls; }
+private:
+    // make sure bind() doesn't implement copy constructor
+    EventReceiver (EventReceiver&);
+};
+
+// declare a generator, a receiver and connect them
+struct EventFixture {
+    EventGenerator gen;
+    EventReceiver recv;
+    void register_handler () {
+        gen.event().add<EventReceiver,&EventReceiver::handler>(recv);
+    }
+
+    EventFixture () {
+        register_handler();
+    }
+};
+
+BOOST_FIXTURE_TEST_SUITE(EventTest, EventFixture)
+
+BOOST_AUTO_TEST_CASE(none)
+{
+    BOOST_REQUIRE_EQUAL (recv.numOfCalls, 0);
+}
+
+BOOST_AUTO_TEST_CASE(once)
+{
+    gen.action();
+    BOOST_REQUIRE_EQUAL (recv.numOfCalls, 1);
+}
+
+BOOST_AUTO_TEST_CASE(twice)
+{
+    gen.action();
+    gen.action();
+    BOOST_REQUIRE_EQUAL (recv.numOfCalls, 2);
+}
+
+BOOST_AUTO_TEST_CASE(reg_twice)
+{
+    register_handler();
+    gen.action();
+    BOOST_REQUIRE_EQUAL (recv.numOfCalls, 2);
+}
+
+BOOST_AUTO_TEST_SUITE_END()