enforce Cursor.renew() to be tied to the same TX

Author: greenrobot

objectbox-java/src/main/java/io/objectbox/Box.java

@@ -74,7 +74,7 @@ Cursor<T> getReader() {
                     throw new IllegalStateException("Illegal reader TX state");
                 }
                 tx.renew();
-                cursor.renew(tx);
+                cursor.renew();
             } else {
                 cursor = store.beginReadTx().createCursor(entityClass);
                 threadLocalReader.set(cursor);

objectbox-java/src/main/java/io/objectbox/Cursor.java

@@ -116,7 +116,7 @@ protected static native long collect004000(long cursor, long keyIfComplete, int
 
     static native void nativeSetBoxStoreForEntities(long cursor, Object boxStore);
 
-    protected Transaction tx;
+    protected final Transaction tx;
     protected final long cursor;
     protected final EntityInfo entityInfo;
     protected final BoxStore boxStoreForEntities;
@@ -264,9 +264,11 @@ protected <TARGET> Cursor<TARGET> getRelationTargetCursor(Class<TARGET> targetCl
         return tx.createCursor(targetClass);
     }
 
-    public void renew(Transaction tx) {
+    /**
+     * To be used in combination with {@link Transaction#renew()}.
+     * */
+    public void renew() {
         nativeRenew(cursor, tx.internalHandle());
-        this.tx = tx;
     }
 
     @Internal

objectbox-java/src/main/java/io/objectbox/Transaction.java

@@ -131,13 +131,16 @@ public void reset() {
         nativeReset(transaction);
     }
 
-    /** For read transactions. */
+    /**
+     * For read transactions, this releases important native resources that hold on versions of potential old data.
+     * To continue, use {@link #renew()}.
+     */
     public void recycle() {
         checkOpen();
         nativeRecycle(transaction);
     }
 
-    /** Efficient for read transactions. */
+    /** Renews a previously recycled transaction (see {@link #recycle()}). Efficient for read transactions. */
     public void renew() {
         checkOpen();
         initialCommitCount = store.commitCount;

tests/objectbox-java-test/src/main/java/io/objectbox/CursorTest.java

@@ -316,10 +316,9 @@ public void testRenew() throws IOException {
 
         Transaction transaction = store.beginReadTx();
         Cursor<TestEntity> cursor = transaction.createCursor(TestEntity.class);
-        transaction.close();
-        transaction = store.beginReadTx();
-        cursor.renew(transaction);
-        assertSame(transaction, cursor.getTx());
+        transaction.recycle();
+        transaction.renew();
+        cursor.renew();
         assertEquals("orange", cursor.get(1).getSimpleString());
 
         cursor.close();