From: bdemsky <bdemsky>
Date: Mon, 14 Sep 2009 23:59:06 +0000 (+0000)
Subject: add support for alokika's locking scheme to simulator
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=70b157e37a9c15fdccb972d3a9101c9594214681;p=IRC.git

add support for alokika's locking scheme to simulator
---

diff --git a/Robust/TransSim/FlexScheduler.java b/Robust/TransSim/FlexScheduler.java
index 6e19ba25..3aa06b75 100644
--- a/Robust/TransSim/FlexScheduler.java
+++ b/Robust/TransSim/FlexScheduler.java
@@ -13,16 +13,26 @@ public class FlexScheduler {
     r=new Random(100);
     eq=new PriorityQueue();
     backoff=new int[e.numThreads()];
+    objtoinfo=new Hashtable();
+    threadinfo=new ThreadInfo[e.numThreads()];
+    blocked=new boolean[e.numThreads()];
+
     for(int i=0;i<e.numThreads();i++) {
-      backoff[i]=1;
+      backoff[i]=BACKOFFSTART;
+      threadinfo[i]=new ThreadInfo(this);
     }
   }
 
+  //Where to start the backoff delay at
+  public static final int BACKOFFSTART=1;
+
+  //Commit options
   public static final int LAZY=0;
   public static final int COMMIT=1;
   public static final int ATTACK=2;
   public static final int POLITE=3;
   public static final int KARMA=4;
+  public static final int LOCK=5;
 
   PriorityQueue eq;
   int policy;
@@ -35,11 +45,19 @@ public class FlexScheduler {
   Event[] currentevents;
   Random r;
   int[] backoff;
+  Hashtable objtoinfo;
+  ThreadInfo[] threadinfo;
+  
+  boolean[] blocked;
 
   public boolean isEager() {
     return policy==ATTACK||policy==POLITE||policy==KARMA;
   }
 
+  public boolean isLock() {
+    return policy==LOCK;
+  }
+
   public int getAborts() {
     return abortcount;
   }
@@ -114,22 +132,44 @@ public class FlexScheduler {
     //Remove everything we put in object sets
     for(int i=0;i<trans.numEvents();i++) {
       int object=trans.getObject(i);
-      if (object!=-1&&rdobjmap.containsKey(new Integer(object))) {
-	((Set)rdobjmap.get(new Integer(object))).remove(new Integer(ev.getThread()));
+      Integer obj=new Integer(object);
+      if (object!=-1&&rdobjmap.containsKey(obj)) {
+	((Set)rdobjmap.get(obj)).remove(new Integer(ev.getThread()));
       }
-      if (object!=-1&&wrobjmap.containsKey(new Integer(object))) {
-	((Set)wrobjmap.get(new Integer(object))).remove(new Integer(ev.getThread()));
+      if (object!=-1&&wrobjmap.containsKey(obj)) {
+	((Set)wrobjmap.get(obj)).remove(new Integer(ev.getThread()));
+      }
+      if (object!=-1&&objtoinfo.containsKey(obj)) {
+	ObjectInfo oi=(ObjectInfo)objtoinfo.get(obj);
+	if (oi.getOwner()==ev.getThread()) {
+	  oi.releaseOwner();
+      
+	  //wake up one waiter
+	  for(Iterator waitit=oi.getWaiters().iterator();waitit.hasNext();) {
+	    //requeue everyone who was waiting on us and start them back up
+	    Event waiter=(Event)waitit.next();
+	    waitit.remove();
+	    waiter.setTime(currtime);
+	    threadinfo[waiter.getThread()].setStall(false);
+	    eq.add(waiter);
+	    break;
+	  }
+
+	}
       }
     }
     
-    //See if we have been flagged as aborted
+    //See if we have been flagged as aborted for the lazy case
     boolean abort=aborted[ev.getThread()];
     aborted[ev.getThread()]=false;
     if (!abort) {
       if (trans.numEvents()>1||trans.getEvent(0)!=Transaction.DELAY) {
 	commitcount++;
       }
-      backoff[ev.getThread()]=1;
+      //Reset our backoff counter
+      backoff[ev.getThread()]=BACKOFFSTART;
+
+
       //abort the other threads
       for(int i=0;i<trans.numEvents();i++) {
 	int object=trans.getObject(i);
@@ -150,7 +190,7 @@ public class FlexScheduler {
 	  }
 	  for(Iterator abit=abortset.iterator();abit.hasNext();) {
 	    Integer threadid=(Integer)abit.next();
-	    if (policy==LAZY) {
+	    if (policy==LAZY||policy==LOCK) {
 	      aborted[threadid]=true;
 	    } else if (policy==COMMIT) {
 	      reschedule(threadid, currtime);
@@ -212,6 +252,7 @@ public class FlexScheduler {
 
   //Takes as parameter -- current transaction read event ev, conflicting
   //set of threads, and the current time
+  //Returning false causes current transaction not continue to be scheduled
 
   public boolean handleConflicts(Event ev, Set threadstokill, int time) {
     if (policy==ATTACK) {
@@ -241,7 +282,6 @@ public class FlexScheduler {
       if (opponenttime>ev.getTransaction().getTime(ev.getEvent())) {
 	//kill ourself
 	reschedule(ev.getThread(), time+r.nextInt(backoff[ev.getThread()]));
-	backoff[ev.getThread()]*=2;
 	abortcount++;
 	return false;
       } else {
@@ -249,7 +289,6 @@ public class FlexScheduler {
 	for(Iterator thit=threadstokill.iterator();thit.hasNext();) {
 	  Integer thread=(Integer)thit.next();
 	  reschedule(thread, time+r.nextInt(backoff[thread.intValue()]));
-	  backoff[thread.intValue()]*=2;
 	  abortcount++;
 	}
 	return true;	
@@ -260,6 +299,9 @@ public class FlexScheduler {
     return true;
   }
 
+  //Handle current event (read, write, delay) in a transaction and
+  //enqueue the next one
+
   public void enqueueEvent(Event ev, Transaction trans) {
     //just enqueue next event
     int event=ev.getEvent();
@@ -269,10 +311,33 @@ public class FlexScheduler {
     //process the current event
     if (operation==Transaction.READ) {
       Integer obj=new Integer(object);
+
+      //check for lock based approach
+      if (isLock()) {
+	if (!objtoinfo.containsKey(obj)) {
+	  objtoinfo.put(obj, new ObjectInfo(this));
+	}
+	ObjectInfo oi=(ObjectInfo)objtoinfo.get(obj);
+	if (oi.isOwned()&&oi.getOwner()!=ev.getThread()) {
+	  //we're going to wait
+	  if (!threadinfo[oi.getOwner()].isStalled()) {
+	    //don't wait on stalled threads, we could deadlock
+	    threadinfo[ev.getThread()].setStall(true);
+	    oi.addWaiter(ev);
+	    return;
+	  }
+	} else {
+	  //we have object
+	  oi.setOwner(ev.getThread());
+	}
+      }
+
+      //record read event
       if (!rdobjmap.containsKey(obj))
 	rdobjmap.put(obj,new HashSet());
       ((Set)rdobjmap.get(obj)).add(new Integer(ev.getThread()));
       if (isEager()) {
+	//do eager contention management
 	Set conflicts=rdConflictSet(ev.getThread(), object);
 	if (conflicts!=null)
 	  if (!handleConflicts(ev, conflicts, currtime))
@@ -280,9 +345,32 @@ public class FlexScheduler {
       }
     } else if (operation==Transaction.WRITE) {
       Integer obj=new Integer(object);
+
+      //grab lock
+      if (isLock()) {
+	if (!objtoinfo.containsKey(obj)) {
+	  objtoinfo.put(obj, new ObjectInfo(this));
+	}
+	ObjectInfo oi=(ObjectInfo)objtoinfo.get(obj);
+	if (oi.isOwned()&&oi.getOwner()!=ev.getThread()) {
+	  //we're going to wait
+	  if (!threadinfo[oi.getOwner()].isStalled()) {
+	    //don't wait on stalled threads, we could deadlock
+	    threadinfo[ev.getThread()].setStall(true);
+	    oi.addWaiter(ev);
+	    return;
+	  }
+	} else {
+	  //we have object
+	  oi.setOwner(ev.getThread());
+	}
+      }
+
+      //record write event
       if (!wrobjmap.containsKey(obj))
 	wrobjmap.put(obj,new HashSet());
       ((Set)wrobjmap.get(obj)).add(new Integer(ev.getThread()));
+
       if (isEager()) {
 	Set conflicts=wrConflictSet(ev.getThread(), object);
 	if (conflicts!=null)
@@ -330,6 +418,10 @@ public class FlexScheduler {
     public int getTime() {
       return time;
     }
+    
+    public void setTime(int time) {
+      this.time=time;
+    }
 
     public int getThread() {
       return threadid;
@@ -344,6 +436,7 @@ public class FlexScheduler {
       valid=true;
     }
 
+    //break ties to allow commits to occur earliest
     public int compareTo(Object o) {
       Event e=(Event)o;
       int delta=time-e.time;
@@ -358,7 +451,4 @@ public class FlexScheduler {
       return 0;
     }
   }
-
-
-
 }
\ No newline at end of file
diff --git a/Robust/TransSim/TransSim.java b/Robust/TransSim/TransSim.java
index 0e27a9a7..4d439913 100644
--- a/Robust/TransSim/TransSim.java
+++ b/Robust/TransSim/TransSim.java
@@ -1,12 +1,12 @@
 public class TransSim {
   public static void main(String[] args) {
-    int numThreads=32;
-    int numTrans=100;
+    int numThreads=16;
+    int numTrans=20;
     int deltaTrans=0;
-    int numObjects=500;
+    int numObjects=4000;
     int numAccesses=20;
     int deltaAccesses=5;
-    int readPercent=30;
+    int readPercent=20;
     //time for operation
     int delay=20;
     int deltaDelay=4;
@@ -25,6 +25,15 @@ public class TransSim {
       int besttime=ls.getTime();
       tlazy+=ls.getTime();
 
+      //Lock object accesses
+      ls=new FlexScheduler(e, FlexScheduler.LOCK);
+      ls.dosim();
+      System.out.println("Lock Abort="+ls.getTime());
+      System.out.println("Aborts="+ls.getAborts()+" Commit="+ls.getCommits());
+      if (ls.getTime()<besttime)
+	besttime=ls.getTime();
+      tcommit+=ls.getTime();
+
       //Kill others at commit
       ls=new FlexScheduler(e, FlexScheduler.COMMIT);
       ls.dosim();