--- /dev/null
+/*
+ * Copyright (c) 2003-2005 The BISON Project
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+package peersim.edsim;
+
+import peersim.core.*;
+import peersim.cdsim.CDProtocol;
+
+/**
+ * This class is used to wrap a {@link CDProtocol} instance into an event so
+ * that it can be used in the event based simulation engine. This class is
+ * responsible for calling {@link CDProtocol#nextCycle} and also to schedule the
+ * consecutive cycle. In the configuration of an event driven simulation
+ * {@link CDProtocol}s can be configured using {@link CDScheduler}, which places
+ * appropriate instances of this events in the queue.
+ *
+ * <p>
+ * Note that reimplementing method {@link #nextDelay} of this class allows for
+ * arbitrary scheduling, including adaptively changing or irregular cycle
+ * lengths, etc.
+ *
+ * @see CDScheduler
+ * @see CDProtocol
+ */
+public class NextCycleEvent implements Cloneable {
+
+ // =============================== initialization ======================
+ // =====================================================================
+
+ /**
+ * Reads configuration to initialize the object. Extending classes should
+ * have a constructor with the same signature, often as simple as
+ * <code>super(n)</code>.
+ */
+ public NextCycleEvent(String n) {
+ }
+
+ // --------------------------------------------------------------------
+
+ /**
+ * Returns a clone of the object. Overriding this method is necessary and
+ * typically is as simple as <code>return super.clone()</code>. In general,
+ * always use <code>super.clone()</code> to obtain the object to be returned
+ * on which you can perform optional deep cloning operations (arrays, etc).
+ */
+ public Object clone() throws CloneNotSupportedException {
+
+ return super.clone();
+ }
+
+ // ========================== methods ==================================
+ // =====================================================================
+
+ /**
+ * Executes the nextCycle method of the protocol, and schedules the next
+ * call using the delay returned by {@link #nextDelay}. If the next
+ * execution time as defined by the delay is outside of the valid times as
+ * defined by {@link CDScheduler#sch}, then the next event is not scheduled.
+ * Note that this means that this protocol will no longer be scheduled
+ * because the next event after the next event is scheduled by the next
+ * event.
+ */
+ public final void execute() {
+
+ int pid = CommonState.getPid();
+ Node node = CommonState.getNode();
+ CDProtocol cdp = (CDProtocol) node.getProtocol(pid);
+ cdp.nextCycle(node, pid);
+ long delay = nextDelay(CDScheduler.sch[pid].step);
+
+ if (CommonState.getTime() + delay < CDScheduler.sch[pid].until)
+ EDSimulator.add(delay, this, node, pid);
+ }
+
+ // --------------------------------------------------------------------
+
+ /**
+ * Calculates the delay until the next execution of the protocol. This
+ * default implementation returns a constant delay equal to the step
+ * parameter (cycle length in this case) of the schedule of this event (as
+ * set in the config file).
+ */
+ protected long nextDelay(long step) {
+
+ return step;
+ }
+
+}
