+ /// Event priorities, to provide tie-breakers for events scheduled
+ /// at the same cycle. Most events are scheduled at the default
+ /// priority; these values are used to control events that need to
+ /// be ordered within a cycle.
+
+ /// Minimum priority
+ static const Priority Minimum_Pri = SCHAR_MIN;
+
+ /// If we enable tracing on a particular cycle, do that as the
+ /// very first thing so we don't miss any of the events on
+ /// that cycle (even if we enter the debugger).
+ static const Priority Debug_Enable_Pri = -101;
+
+ /// Breakpoints should happen before anything else (except
+ /// enabling trace output), so we don't miss any action when
+ /// debugging.
+ static const Priority Debug_Break_Pri = -100;
+
+ /// CPU switches schedule the new CPU's tick event for the
+ /// same cycle (after unscheduling the old CPU's tick event).
+ /// The switch needs to come before any tick events to make
+ /// sure we don't tick both CPUs in the same cycle.
+ static const Priority CPU_Switch_Pri = -31;
+
+ /// For some reason "delayed" inter-cluster writebacks are
+ /// scheduled before regular writebacks (which have default
+ /// priority). Steve?
+ static const Priority Delayed_Writeback_Pri = -1;
+
+ /// Default is zero for historical reasons.
+ static const Priority Default_Pri = 0;
+
+ /// DVFS update event leads to stats dump therefore given a lower priority
+ /// to ensure all relevant states have been updated
+ static const Priority DVFS_Update_Pri = 31;
+
+ /// Serailization needs to occur before tick events also, so
+ /// that a serialize/unserialize is identical to an on-line
+ /// CPU switch.
+ static const Priority Serialize_Pri = 32;
+
+ /// CPU ticks must come after other associated CPU events
+ /// (such as writebacks).
+ static const Priority CPU_Tick_Pri = 50;
+
+ /// If we want to exit a thread in a CPU, it comes after CPU_Tick_Pri
+ static const Priority CPU_Exit_Pri = 64;
+
+ /// Statistics events (dump, reset, etc.) come after
+ /// everything else, but before exit.
+ static const Priority Stat_Event_Pri = 90;
+
+ /// Progress events come at the end.
+ static const Priority Progress_Event_Pri = 95;
+
+ /// If we want to exit on this cycle, it's the very last thing
+ /// we do.
+ static const Priority Sim_Exit_Pri = 100;
+
+ /// Maximum priority
+ static const Priority Maximum_Pri = SCHAR_MAX;
+};
+
+/*
+ * An item on an event queue. The action caused by a given
+ * event is specified by deriving a subclass and overriding the
+ * process() member function.
+ *
+ * Caution, the order of members is chosen to maximize data packing.
+ */
+class Event : public EventBase, public Serializable
+{
+ friend class EventQueue;
+