2 files changed, 49 insertions, 27 deletions

diff --git a/src/jvm/clojure/lang/LockingTransaction.java b/src/jvm/clojure/lang/LockingTransaction.java
index b9ea39c0..fe0bbd3c 100644
--- a/src/jvm/clojure/lang/LockingTransaction.java
+++ b/src/jvm/clojure/lang/LockingTransaction.java
@@ -203,16 +203,22 @@ Object run(IFn fn) throws Exception{
 				for(Map.Entry<Ref, Object> e : vals.entrySet())
 					{
 					Ref ref = e.getKey();
-//				ref.tvals = new Ref.TVal(e.getValue(), commitPoint, msecs, null);
-					if(ref.tvals != null)
-						ref.tvals.prior = null;
-					ref.tvals = new Ref.TVal(e.getValue(), commitPoint, msecs, ref.tvals);
-					//auto-trim
-//				for(Ref.TVal tv = ref.tvals; tv != null; tv = tv.prior)
-//					{
-//					if(tv.msecs <= msecs)
-//						tv.prior = null;
-//					}
+					if(ref.tvals == null)
+						{
+						ref.tvals = new Ref.TVal(e.getValue(), commitPoint, msecs);
+						}
+					else if(ref.faults.get() > 0)
+						{
+						ref.tvals = new Ref.TVal(e.getValue(), commitPoint, msecs, ref.tvals);
+						ref.faults.set(0);
+						}
+					else
+						{
+						ref.tvals = ref.tvals.next;
+						ref.tvals.val = e.getValue();
+						ref.tvals.point = commitPoint;
+						ref.tvals.msecs = msecs;
+						}
 					}
 				done = true;
 				info.status.set(COMMITTED);
@@ -239,8 +245,7 @@ Object run(IFn fn) throws Exception{
 
 
 Object doGet(Ref ref) throws Exception{
-	if(//true ||
-			info.running())
+	if(info.running())
 		{
 		if(vals.containsKey(ref))
 			return vals.get(ref);
@@ -249,17 +254,19 @@ Object doGet(Ref ref) throws Exception{
 			ref.lock.readLock().lock();
 			if(ref.tvals == null)
 				throw new IllegalStateException(ref.toString() + " is unbound.");
-			for(Ref.TVal ver = ref.tvals; ver != null; ver = ver.prior)
+			Ref.TVal ver = ref.tvals;
+			do
 				{
 				if(ver.point <= readPoint)
 					return ver.val;
-				}
+				} while((ver = ver.prior) != ref.tvals);
 			}
 		finally
 			{
 			ref.lock.readLock().unlock();
 			}
 		//no version of val precedes the read point
+		ref.faults.incrementAndGet();
 		throw retryex;
 		}
 	else
@@ -268,8 +275,7 @@ Object doGet(Ref ref) throws Exception{
 }
 
 Object doSet(Ref ref, Object val) throws Exception{
-	if(//true ||
-			info.running())
+	if(info.running())
 		{
 		if(commutes.containsKey(ref))
 			throw new IllegalStateException("Can't set after commute");
@@ -286,16 +292,14 @@ Object doSet(Ref ref, Object val) throws Exception{
 }
 
 void doTouch(Ref ref) throws Exception{
-	if(//true ||
-			info.running())
+	if(info.running())
 		lock(ref);
 	else
 		throw retryex;
 }
 
 Object doCommute(Ref ref, IFn fn) throws Exception{
-	if(//true ||
-			info.running())
+	if(info.running())
 		{
 		if(!vals.containsKey(ref))
 			{
diff --git a/src/jvm/clojure/lang/Ref.java b/src/jvm/clojure/lang/Ref.java
index cd89a7b3..6c1f9bcd 100644
--- a/src/jvm/clojure/lang/Ref.java
+++ b/src/jvm/clojure/lang/Ref.java
@@ -13,6 +13,7 @@
 package clojure.lang;
 
 import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 public class Ref implements IFn, Comparable<Ref>{
@@ -26,16 +27,28 @@ public int compareTo(Ref o){
 }
 
 public static class TVal{
-	final Object val;
-	final long point;
+	Object val;
+	long point;
 	long msecs;
 	TVal prior;
+	TVal next;
 
 	TVal(Object val, long point, long msecs, TVal prior){
 		this.val = val;
 		this.point = point;
+		this.msecs = msecs;
 		this.prior = prior;
+		this.next = prior.next;
+		this.prior.next = this;
+		this.next.prior = this;
+	}
+
+	TVal(Object val, long point, long msecs){
+		this.val = val;
+		this.point = point;
 		this.msecs = msecs;
+		this.next = this;
+		this.prior = this;
 	}
 
 }
@@ -43,6 +56,9 @@ public static class TVal{
 
 final static AtomicLong ids = new AtomicLong();
 TVal tvals;
+
+AtomicInteger faults;
+
 transient volatile InheritableThreadLocal<Binding> dvals;
 final ReentrantReadWriteLock lock;
 LockingTransaction.Info tinfo;
@@ -52,13 +68,14 @@ public Ref(){
 	this.tvals = null;
 	this.dvals = null;
 	this.tinfo = null;
+	faults = new AtomicInteger();
 	lock = new ReentrantReadWriteLock();
 	id = ids.getAndIncrement();
 }
 
 public Ref(Object initVal){
 	this();
-	tvals = new TVal(initVal, 0, System.currentTimeMillis(), null);
+	tvals = new TVal(initVal, 0, System.currentTimeMillis());
 }
 
 //ok out of transaction
@@ -150,15 +167,15 @@ boolean isBound(){
 		}
 }
 
+
 void trimHistory(){
-	long ctp = Transaction.completedThroughPoint();
 	try
 		{
 		lock.writeLock().lock();
-		for(TVal tv = tvals; tv != null; tv = tv.prior)
+		if(tvals != null)
 			{
-			if(tv.point <= ctp)
-				tv.prior = null;
+			tvals.next = tvals;
+			tvals.prior = tvals;
 			}
 		}
 	finally
@@ -167,6 +184,7 @@ void trimHistory(){
 		}
 }
 
+
 final public IFn fn(){
 	return (IFn) currentVal();
 }