Fix thread-local memory leaks.

3 files changed, 48 insertions, 2 deletions

diff --git a/src/main/java/com/amazon/carbonado/repo/map/MapRepository.java b/src/main/java/com/amazon/carbonado/repo/map/MapRepository.java
index 7fbe16a..ac847f1 100644
--- a/src/main/java/com/amazon/carbonado/repo/map/MapRepository.java
+++ b/src/main/java/com/amazon/carbonado/repo/map/MapRepository.java
@@ -90,6 +90,11 @@ class MapRepository extends AbstractRepository<MapTransaction>
     }

 

     @Override

+    protected void finalize() {

+        close();

+    }

+

+    @Override

     protected Log getLog() {

         return null;

     }

diff --git a/src/main/java/com/amazon/carbonado/txn/TransactionManager.java b/src/main/java/com/amazon/carbonado/txn/TransactionManager.java
index 19aec4d..6ae3b2e 100644
--- a/src/main/java/com/amazon/carbonado/txn/TransactionManager.java
+++ b/src/main/java/com/amazon/carbonado/txn/TransactionManager.java
@@ -157,6 +157,9 @@ public abstract class TransactionManager<Txn> {
         for (TransactionScope<?> scope : mAllScopes.keySet()) {

             scope.close();

         }

+

+        mAllScopes.clear();

+        mLocalScope.remove();

     }

 

     public synchronized boolean isClosed() {

@@ -270,4 +273,32 @@ public abstract class TransactionManager<Txn> {
      * Aborts and closes the given internal transaction.

      */

     protected abstract void abortTxn(Txn txn) throws PersistException;

+

+    static class Closed extends TransactionManager<Object> {

+        static final Closed THE = new Closed();

+

+        @Override

+        protected IsolationLevel selectIsolationLevel(Transaction parent, IsolationLevel level) {

+            return IsolationLevel.SERIALIZABLE;

+        }

+

+        @Override

+        protected boolean supportsForUpdate() {

+            return true;

+        }

+

+        @Override

+        protected Object createTxn(Object parent, IsolationLevel level) throws Exception {

+            throw new IllegalStateException("Transaction manager is closed");

+        }

+

+        @Override

+        protected boolean commitTxn(Object txn) throws PersistException {

+            return false;

+        }

+

+        @Override

+        protected void abortTxn(Object txn) throws PersistException {

+        }

+    }

 }

diff --git a/src/main/java/com/amazon/carbonado/txn/TransactionScope.java b/src/main/java/com/amazon/carbonado/txn/TransactionScope.java
index 2110ff6..7ff5997 100644
--- a/src/main/java/com/amazon/carbonado/txn/TransactionScope.java
+++ b/src/main/java/com/amazon/carbonado/txn/TransactionScope.java
@@ -43,9 +43,16 @@ import com.amazon.carbonado.spi.ExceptionTransformer;
  * @see TransactionManager

  */

 public class TransactionScope<Txn> {

-    final TransactionManager<Txn> mTxnMgr;

     final Lock mLock;

 

+    // Note: Cannot be final because it needs to be replaced by close

+    // method. Access doesn't need to be synchronized, because only one thread

+    // ever accesses scope instances. The close method might be called by a

+    // separate thread, in which case the closed transaction manager reference

+    // might not be immediately visible by the thread which needs it. This is

+    // not harmful.

+    TransactionManager<Txn> mTxnMgr;

+

     TransactionImpl<Txn> mActive;

 

     // Tracks all registered cursors by storage type.

@@ -55,8 +62,8 @@ public class TransactionScope<Txn> {
     private boolean mDetached;

 

     TransactionScope(TransactionManager<Txn> txnMgr, boolean closed) {

-        mTxnMgr = txnMgr;

         mLock = new ReentrantLock(true);

+        mTxnMgr = txnMgr;

         if (closed) {

             mLock.lock();

             try {

@@ -332,6 +339,9 @@ public class TransactionScope<Txn> {
             }

         } finally {

             mClosed = true;

+            // Swap TransactionManager out with a dummy one, to allow the

+            // original one to get freed.

+            mTxnMgr = (TransactionManager<Txn>) TransactionManager.Closed.THE;

             mLock.unlock();

         }

     }