checkpoint harmony

[sbp.git] / src / edu / berkeley / sbp / GSS.java

diff --git a/src/edu/berkeley/sbp/GSS.java b/src/edu/berkeley/sbp/GSS.java
index 6316aad..86c93b2 100644 (file)
--- a/src/edu/berkeley/sbp/GSS.java
+++ b/src/edu/berkeley/sbp/GSS.java
@@ -288,7 +288,19 @@ class GSS {
                     if (r.position.pos==0) r.finish(n, r.zero(), n.phase(), holder);
                     else                   r.reduce(n, r.position.pos-1, n.phase(), holder);
                 } else {
-                    r.reduce(n, n2);
+                    Forest[] holder = new Forest[r.position.pos];
+                    if (r.position.pos<=0) throw new Error("called wrong form of reduce()");
+                    int pos = r.position.pos-1;
+                    Forest old = holder[pos];
+                    holder[pos] = n.pending();
+                    if (pos==0) {
+                        System.arraycopy(holder, 0, r.position.holder, 0, holder.length);
+                        Forest rex = r.position.rewrite(n.phase().getLocation());
+                        r.finish(n2, rex, n.phase(), holder);
+                    } else {
+                        r.reduce(n2, pos-1, n.phase(), holder);
+                    }
+                    holder[pos] = old;
                 }
             }
             public void performEmptyReductions() { state.invokeReductions(token, this, null, null); }