Dont reset SharedRealm ptr (realm#4478)

beeender · web-flow · commit 1fe5b9f81003 · 2017-04-12T17:31:25.000+08:00
- Keep the SharedRealm ptr valid when close it. To allow the is_closed checking could throw in the Object Store and it can be converted to a friendly Java exception. - Check if SharedRealm is closed when create collection iterator. Throw an ISE if it is. Fix realm#4471 .
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -9,6 +9,7 @@
 * Crash caused by JNI couldn't find `OsObject.notifyChangeListeners` when ProGuard is enabled (#4461).
 * Incompatible return type of `RealmSchema.getAll()` and `BaseRealm.getSchema()` (#4443).
 * Memory leaked when synced Realm was initialized (#4465).
+* An `IllegalStateException` will be thrown when starting iterating `OrderedRealmCollection` if the Realm is closed (#4471).
 
 ### Internal
 
diff --git a/realm/realm-library/src/androidTest/java/io/realm/internal/CollectionTests.java b/realm/realm-library/src/androidTest/java/io/realm/internal/CollectionTests.java
@@ -486,6 +486,14 @@ public void onChange(Collection element) {
         addRowAsync();
     }
 
+    @Test
+    public void collectionIterator_newInstance_throwsWhenSharedRealmIsClosed() {
+        final Collection collection = new Collection(sharedRealm, table.where());
+        sharedRealm.close();
+        thrown.expect(IllegalStateException.class);
+        new TestIterator(collection);
+    }
+
     @Test
     public void getMode() {
         Collection collection = new Collection(sharedRealm, table.where());
diff --git a/realm/realm-library/src/androidTest/java/io/realm/internal/SharedRealmTests.java b/realm/realm-library/src/androidTest/java/io/realm/internal/SharedRealmTests.java
@@ -53,7 +53,9 @@ public void setUp() {
 
     @After
     public void tearDown() {
-        sharedRealm.close();
+        if (sharedRealm != null) {
+            sharedRealm.close();
+        }
     }
 
     @Test
@@ -100,6 +102,13 @@ public void isInTransaction() {
         assertFalse(sharedRealm.isInTransaction());
     }
 
+    @Test
+    public void isInTransaction_returnFalseWhenRealmClosed() {
+        sharedRealm.close();
+        assertFalse(sharedRealm.isInTransaction());
+        sharedRealm = null;
+    }
+
     @Test
     public void removeTable() {
         sharedRealm.beginTransaction();
@@ -231,4 +240,19 @@ public void onSchemaVersionChanged(long currentVersion) {
         assertTrue(listenerCalled.get());
         assertEquals(before + 1, schemaVersionFromListener.get());
     }
+
+    @Test
+    public void isClosed() {
+        sharedRealm.close();
+        assertTrue(sharedRealm.isClosed());
+        sharedRealm = null;
+    }
+
+    @Test
+    public void close_twice() {
+        sharedRealm.close();
+        sharedRealm.close();
+        assertTrue(sharedRealm.isClosed());
+        sharedRealm = null;
+    }
 }
diff --git a/realm/realm-library/src/main/cpp/io_realm_internal_SharedRealm.cpp b/realm/realm-library/src/main/cpp/io_realm_internal_SharedRealm.cpp
@@ -225,7 +225,9 @@ JNIEXPORT void JNICALL Java_io_realm_internal_SharedRealm_nativeCloseSharedRealm
 
     auto shared_realm = *(reinterpret_cast<SharedRealm*>(shared_realm_ptr));
     // Close the SharedRealm only. Let the finalizer daemon thread free the SharedRealm
-    shared_realm->close();
+    if (!shared_realm->is_closed()) {
+        shared_realm->close();
+    }
 }
 
 JNIEXPORT void JNICALL Java_io_realm_internal_SharedRealm_nativeBeginTransaction(JNIEnv* env, jclass,
diff --git a/realm/realm-library/src/main/java/io/realm/internal/Collection.java b/realm/realm-library/src/main/java/io/realm/internal/Collection.java
@@ -32,6 +32,9 @@
 @Keep
 public class Collection implements NativeObject {
 
+    private static final String CLOSED_REALM_MESSAGE =
+            "This Realm instance has already been closed, making it unusable.";
+
     private static class CollectionObserverPair<T> extends ObserverPairList.ObserverPair<T, Object> {
         public CollectionObserverPair(T observer, Object listener) {
             super(observer, listener);
@@ -94,6 +97,10 @@ public static abstract class Iterator<T> implements java.util.Iterator<T> {
         protected int pos = -1;
 
         public Iterator(Collection collection) {
+            if (collection.sharedRealm.isClosed()) {
+                throw new IllegalStateException(CLOSED_REALM_MESSAGE);
+            }
+
             this.iteratorCollection = collection;
 
             if (collection.isSnapshot) {
diff --git a/realm/realm-library/src/main/java/io/realm/internal/SharedRealm.java b/realm/realm-library/src/main/java/io/realm/internal/SharedRealm.java
@@ -176,7 +176,7 @@ public interface SchemaVersionListener {
 
     private final RealmConfiguration configuration;
 
-    private long nativePtr;
+    final private long nativePtr;
     final Context context;
     private long lastSchemaVersion;
     private final SchemaVersionListener schemaChangeListener;
@@ -319,7 +319,7 @@ public long getLastSnapshotVersion() {
     }
 
     public boolean isClosed() {
-        return nativePtr == 0 || nativeIsClosed(nativePtr);
+        return nativeIsClosed(nativePtr);
     }
 
     public void writeCopy(File file, byte[] key) {
@@ -368,12 +368,9 @@ public void close() {
             realmNotifier.close();
         }
         synchronized (context) {
-            if (nativePtr != 0) {
-                nativeCloseSharedRealm(nativePtr);
-                // It is OK to clear the nativePtr. It has been saved to the NativeObjectReference when adding to the
-                // context.
-                nativePtr = 0;
-            }
+            nativeCloseSharedRealm(nativePtr);
+            // Don't reset the nativePtr since we still rely on Object Store to check if the given SharedRealm ptr
+            // is closed or not.
         }
     }
 

Original file line number	Diff line number	Diff line change
`@@ -225,7 +225,9 @@ JNIEXPORT void JNICALL Java_io_realm_internal_SharedRealm_nativeCloseSharedRealm`
`225`	`225`
`226`	`226`	`auto shared_realm = (reinterpret_cast<SharedRealm>(shared_realm_ptr));`
`227`	`227`	`// Close the SharedRealm only. Let the finalizer daemon thread free the SharedRealm`
`228`		`- shared_realm->close();`
	`228`	`+ if (!shared_realm->is_closed()) {`
	`229`	`+ shared_realm->close();`
	`230`	`+ }`
`229`	`231`	`}`
`230`	`232`
`231`	`233`	`JNIEXPORT void JNICALL Java_io_realm_internal_SharedRealm_nativeBeginTransaction(JNIEnv* env, jclass,`
Original file line number	Diff line number	Diff line change
`@@ -176,7 +176,7 @@ public interface SchemaVersionListener {`
`176`	`176`
`177`	`177`	`private final RealmConfiguration configuration;`
`178`	`178`
`179`		`- private long nativePtr;`
	`179`	`+ final private long nativePtr;`
`180`	`180`	`final Context context;`
`181`	`181`	`private long lastSchemaVersion;`
`182`	`182`	`private final SchemaVersionListener schemaChangeListener;`
`@@ -319,7 +319,7 @@ public long getLastSnapshotVersion() {`
`319`	`319`	`}`
`320`	`320`
`321`	`321`	`public boolean isClosed() {`
`322`		`- return nativePtr == 0 \|\| nativeIsClosed(nativePtr);`
	`322`	`+ return nativeIsClosed(nativePtr);`
`323`	`323`	`}`
`324`	`324`
`325`	`325`	`public void writeCopy(File file, byte[] key) {`
`@@ -368,12 +368,9 @@ public void close() {`
`368`	`368`	`realmNotifier.close();`
`369`	`369`	`}`
`370`	`370`	`synchronized (context) {`
`371`		`- if (nativePtr != 0) {`
`372`		`- nativeCloseSharedRealm(nativePtr);`
`373`		`- // It is OK to clear the nativePtr. It has been saved to the NativeObjectReference when adding to the`
`374`		`- // context.`
`375`		`- nativePtr = 0;`
`376`		`- }`
	`371`	`+ nativeCloseSharedRealm(nativePtr);`
	`372`	`+ // Don't reset the nativePtr since we still rely on Object Store to check if the given SharedRealm ptr`
	`373`	`+ // is closed or not.`
`377`	`374`	`}`
`378`	`375`	`}`
`379`	`376`