From 6e16419c18da08323e6f6177c9065ccf1dfd1eaf Mon Sep 17 00:00:00 2001
From: "Brian S. O'Neill" <bronee@gmail.com>
Date: Tue, 12 Apr 2011 18:00:10 +0000
Subject: Handle concurrent close while copying cursor contents.

---
 .../amazon/carbonado/cursor/AbstractCursor.java    | 73 +++++++++++-----------
 1 file changed, 38 insertions(+), 35 deletions(-)

(limited to 'src/main/java/com/amazon/carbonado/cursor')

diff --git a/src/main/java/com/amazon/carbonado/cursor/AbstractCursor.java b/src/main/java/com/amazon/carbonado/cursor/AbstractCursor.java
index a7be434..17e9f51 100644
--- a/src/main/java/com/amazon/carbonado/cursor/AbstractCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/AbstractCursor.java
@@ -21,6 +21,7 @@ package com.amazon.carbonado.cursor;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.NoSuchElementException;
 
 import com.amazon.carbonado.Cursor;
 import com.amazon.carbonado.FetchException;
@@ -39,17 +40,18 @@ public abstract class AbstractCursor<S> implements Cursor<S> {
     public int copyInto(Collection<? super S> c) throws FetchException {
         try {
             int count = 0;
-            while (hasNext()) {
-                c.add(next());
-                count++;
+            try {
+                while (hasNext()) {
+                    c.add(next());
+                    count++;
+                }
+            } catch (NoSuchElementException e) {
+                // Race condition cause by concurrent repository close.
+                silentClose();
             }
             return count;
         } catch (FetchException e) {
-            try {
-                close();
-            } catch (Exception e2) {
-                // Don't care.
-            }
+            silentClose();
             throw e;
         }
     }
@@ -57,17 +59,18 @@ public abstract class AbstractCursor<S> implements Cursor<S> {
     public int copyInto(Collection<? super S> c, int limit) throws FetchException {
         try {
             int count = 0;
-            while (--limit >= 0 && hasNext()) {
-                c.add(next());
-                count++;
+            try {
+                while (--limit >= 0 && hasNext()) {
+                    c.add(next());
+                    count++;
+                }
+            } catch (NoSuchElementException e) {
+                // Race condition cause by concurrent repository close.
+                silentClose();
             }
             return count;
         } catch (FetchException e) {
-            try {
-                close();
-            } catch (Exception e2) {
-                // Don't care.
-            }
+            silentClose();
             throw e;
         }
     }
@@ -78,11 +81,7 @@ public abstract class AbstractCursor<S> implements Cursor<S> {
             copyInto(list);
             return list;
         } catch (FetchException e) {
-            try {
-                close();
-            } catch (Exception e2) {
-                // Don't care.
-            }
+            silentClose();
             throw e;
         }
     }
@@ -93,11 +92,7 @@ public abstract class AbstractCursor<S> implements Cursor<S> {
             copyInto(list, limit);
             return list;
         } catch (FetchException e) {
-            try {
-                close();
-            } catch (Exception e2) {
-                // Don't care.
-            }
+            silentClose();
             throw e;
         }
     }
@@ -112,19 +107,27 @@ public abstract class AbstractCursor<S> implements Cursor<S> {
 
         try {
             int count = 0;
-            while (--amount >= 0 && hasNext()) {
-                next();
-                count++;
+            try {
+                while (--amount >= 0 && hasNext()) {
+                    next();
+                    count++;
+                }
+            } catch (NoSuchElementException e) {
+                // Race condition cause by concurrent repository close.
+                silentClose();
             }
-
             return count;
         } catch (FetchException e) {
-            try {
-                close();
-            } catch (Exception e2) {
-                // Don't care.
-            }
+            silentClose();
             throw e;
         }
     }
+
+    private void silentClose() {
+        try {
+            close();
+        } catch (Exception e2) {
+            // Don't care.
+        }
+    }
 }
-- 
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