core: scheduler::ScopedEventId

refs #2295

Change-Id: I17bc949882bebadbf4d19aaede4c634a12121787
diff --git a/core/scheduler.hpp b/core/scheduler.hpp
index c674429..a4b43c1 100644
--- a/core/scheduler.hpp
+++ b/core/scheduler.hpp
@@ -1,11 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014  Regents of the University of California,
- *                     Arizona Board of Regents,
- *                     Colorado State University,
- *                     University Pierre & Marie Curie, Sorbonne University,
- *                     Washington University in St. Louis,
- *                     Beijing Institute of Technology
+ * Copyright (c) 2014,  Regents of the University of California,
+ *                      Arizona Board of Regents,
+ *                      Colorado State University,
+ *                      University Pierre & Marie Curie, Sorbonne University,
+ *                      Washington University in St. Louis,
+ *                      Beijing Institute of Technology,
+ *                      The University of Memphis
  *
  * This file is part of NFD (Named Data Networking Forwarding Daemon).
  * See AUTHORS.md for complete list of NFD authors and contributors.
@@ -20,7 +21,7 @@
  *
  * You should have received a copy of the GNU General Public License along with
  * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
- **/
+ */
 
 #ifndef NFD_CORE_SCHEDULER_HPP
 #define NFD_CORE_SCHEDULER_HPP
@@ -48,6 +49,49 @@
 void
 cancel(const EventId& eventId);
 
+/** \brief cancels an event automatically upon destruction
+ */
+class ScopedEventId : noncopyable
+{
+public:
+  ScopedEventId();
+
+  /** \brief implicit constructor from EventId
+   *  \param event the event to be cancelled upon destruction
+   */
+  ScopedEventId(const EventId& event);
+
+  /** \brief move constructor
+   */
+  ScopedEventId(ScopedEventId&& other);
+
+  /** \brief assigns an event
+   *
+   *  If a different event has been assigned to this instance previously,
+   *  that event will be cancelled immediately.
+   */
+  ScopedEventId&
+  operator=(const EventId& event);
+
+  /** \brief cancels the event
+   */
+  ~ScopedEventId();
+
+  /** \brief cancels the event manually
+   */
+  void
+  cancel();
+
+  /** \brief releases the event so that it won't be disconnected
+   *         when this ScopedEventId is destructed
+   */
+  void
+  release();
+
+private:
+  EventId m_event;
+};
+
 } // namespace scheduler
 
 using scheduler::EventId;