From 52a83c1d0ea2e0806ce3934aab5c566d6c9e3451 Mon Sep 17 00:00:00 2001
From: Nilay Vaish <nilay@cs.wisc.edu>
Date: Thu, 20 Mar 2014 09:14:14 -0500
Subject: [PATCH] ruby: consumer: avoid accessing wakeup times when waking up
 Each consumer object maintains a set of tick values when the object is
 supposed to wakeup and do some processing.  As of now, the object accesses
 this set both when scheduling a wakeup event and when the object actually
 wakes up.  The set is accessed during wakeup to remove the current tick value
 from the set.  This functionality is now being moved to the scheduling
 function where ticks are removed at a later time.

---
 src/mem/ruby/common/Consumer.cc |  7 +++++++
 src/mem/ruby/common/Consumer.hh | 28 ++--------------------------
 2 files changed, 9 insertions(+), 26 deletions(-)

diff --git a/src/mem/ruby/common/Consumer.cc b/src/mem/ruby/common/Consumer.cc
index 9f3735709..59605d51b 100644
--- a/src/mem/ruby/common/Consumer.cc
+++ b/src/mem/ruby/common/Consumer.cc
@@ -28,6 +28,8 @@
 
 #include "mem/ruby/common/Consumer.hh"
 
+using namespace std;
+
 void
 Consumer::scheduleEvent(Cycles timeDelta)
 {
@@ -43,4 +45,9 @@ Consumer::scheduleEventAbsolute(Tick evt_time)
         em->schedule(evt, evt_time);
         insertScheduledWakeupTime(evt_time);
     }
+
+    Tick t = em->clockEdge();
+    set<Tick>::iterator bit = m_scheduled_wakeups.begin();
+    set<Tick>::iterator eit = m_scheduled_wakeups.lower_bound(t);
+    m_scheduled_wakeups.erase(bit,eit);
 }
diff --git a/src/mem/ruby/common/Consumer.hh b/src/mem/ruby/common/Consumer.hh
index 57ee69f3e..20f2bdd0f 100644
--- a/src/mem/ruby/common/Consumer.hh
+++ b/src/mem/ruby/common/Consumer.hh
@@ -44,7 +44,7 @@ class Consumer
 {
   public:
     Consumer(ClockedObject *_em)
-        : m_last_scheduled_wakeup(0), em(_em)
+        : em(_em)
     {
     }
 
@@ -56,18 +56,6 @@ class Consumer
     virtual void print(std::ostream& out) const = 0;
     virtual void storeEventInfo(int info) {}
 
-    const Tick&
-    getLastScheduledWakeup() const
-    {
-        return m_last_scheduled_wakeup;
-    }
-
-    void
-    setLastScheduledWakeup(const Tick& time)
-    {
-        m_last_scheduled_wakeup = time;
-    }
-
     bool
     alreadyScheduled(Tick time)
     {
@@ -80,20 +68,12 @@ class Consumer
         m_scheduled_wakeups.insert(time);
     }
 
-    void
-    removeScheduledWakeupTime(Tick time)
-    {
-        assert(alreadyScheduled(time));
-        m_scheduled_wakeups.erase(time);
-    }
-
     void scheduleEventAbsolute(Tick timeAbs);
 
   protected:
     void scheduleEvent(Cycles timeDelta);
 
   private:
-    Tick m_last_scheduled_wakeup;
     std::set<Tick> m_scheduled_wakeups;
     ClockedObject *em;
 
@@ -105,11 +85,7 @@ class Consumer
           {
           }
 
-          void process()
-          {
-              m_consumer_ptr->wakeup();
-              m_consumer_ptr->removeScheduledWakeupTime(when());
-          }
+          void process() { m_consumer_ptr->wakeup(); }
 
       private:
           Consumer* m_consumer_ptr;
-- 
2.30.2