Merge pull request #234 from codelerity/gstiterator

neilcsmith-net · web-flow · commit 95e37e9f7004 · 2021-01-08T12:10:02.000Z
Stop GstIterator keeping references alive until GC.
diff --git a/src/org/freedesktop/gstreamer/Bin.java b/src/org/freedesktop/gstreamer/Bin.java
@@ -1,5 +1,5 @@
 /* 
- * Copyright (c) 2019 Neil C Smith
+ * Copyright (c) 2021 Neil C Smith
  * Copyright (c) 2016 Christophe Lafolet
  * Copyright (c) 2009 Levente Farkas
  * Copyright (C) 2007 Wayne Meissner
@@ -24,12 +24,12 @@
 
 import static org.freedesktop.gstreamer.lowlevel.GstBinAPI.GSTBIN_API;
 
-import com.sun.jna.Pointer;
 import java.util.EnumSet;
 import java.util.List;
 import org.freedesktop.gstreamer.glib.NativeFlags;
 import org.freedesktop.gstreamer.glib.Natives;
 import org.freedesktop.gstreamer.lowlevel.GstAPI.GstCallback;
+import org.freedesktop.gstreamer.lowlevel.GstIteratorPtr;
 import org.freedesktop.gstreamer.lowlevel.GstObjectPtr;
 
 /**
@@ -145,8 +145,8 @@ public void removeMany(Element... elements) {
         GSTBIN_API.gst_bin_remove_many(this, elements);
     }
 
-    private List<Element> elementList(Pointer iter) {
-        return new GstIterator<Element>(iter, Element.class).asList();
+    private List<Element> elementList(GstIteratorPtr iter) {
+        return GstIterator.asList(iter, Element.class);
     }
 
     /**
diff --git a/src/org/freedesktop/gstreamer/Element.java b/src/org/freedesktop/gstreamer/Element.java
@@ -31,10 +31,11 @@
 
 import org.freedesktop.gstreamer.lowlevel.GstAPI.GstCallback;
 import org.freedesktop.gstreamer.lowlevel.GstContextPtr;
+import org.freedesktop.gstreamer.lowlevel.GstIteratorPtr;
+import org.freedesktop.gstreamer.lowlevel.GstObjectPtr;
 
 import static org.freedesktop.gstreamer.lowlevel.GstElementAPI.GSTELEMENT_API;
 import static org.freedesktop.gstreamer.lowlevel.GObjectAPI.GOBJECT_API;
-import org.freedesktop.gstreamer.lowlevel.GstObjectPtr;
 
 /**
  * Abstract base class for all pipeline elements.
@@ -82,7 +83,7 @@ public class Element extends GstObject {
     protected Element(Initializer init) {
         super(init);
     }
-    
+
     Element(Handle handle, boolean needRef) {
         super(handle, needRef);
     }
@@ -346,7 +347,7 @@ public Pad getStaticPad(String padname) {
      * @return the List of {@link Pad}s.
      */
     public List<Pad> getPads() {
-        return new GstIterator<Pad>(GSTELEMENT_API.gst_element_iterate_pads(this), Pad.class).asList();
+        return padList(GSTELEMENT_API.gst_element_iterate_pads(this));
     }
 
     /**
@@ -355,7 +356,7 @@ public List<Pad> getPads() {
      * @return the List of {@link Pad}s.
      */
     public List<Pad> getSrcPads() {
-        return new GstIterator<Pad>(GSTELEMENT_API.gst_element_iterate_src_pads(this), Pad.class).asList();
+        return padList(GSTELEMENT_API.gst_element_iterate_src_pads(this));
     }
 
     /**
@@ -364,7 +365,11 @@ public List<Pad> getSrcPads() {
      * @return the List of {@link Pad}s.
      */
     public List<Pad> getSinkPads() {
-        return new GstIterator<Pad>(GSTELEMENT_API.gst_element_iterate_sink_pads(this), Pad.class).asList();
+        return padList(GSTELEMENT_API.gst_element_iterate_sink_pads(this));
+    }
+    
+    private List<Pad> padList(GstIteratorPtr iter) {
+        return GstIterator.asList(iter, Pad.class);
     }
 
     /**
@@ -770,7 +775,7 @@ public void setContext(Context context) {
 
     /**
      * Gets the context with the context_type set on the element or NULL.
-     * 
+     *
      * @param context_type
      * @return a context or NULL
      */
@@ -780,11 +785,11 @@ public Context getContext(String context_type) {
     }
 
     static class Handle extends GstObject.Handle {
-        
+
         public Handle(GstObjectPtr ptr, boolean ownsHandle) {
             super(ptr, ownsHandle);
         }
-        
+
     }
 
 }
diff --git a/src/org/freedesktop/gstreamer/GstIterator.java b/src/org/freedesktop/gstreamer/GstIterator.java
@@ -1,7 +1,5 @@
 /* 
- * Copyright (c) 2019 Neil C Smith
- * Copyright (c) 2009 Levente Farkas
- * Copyright (c) 2007 Wayne Meissner
+ * Copyright (c) 2021 Neil C Smith
  * 
  * This file is part of gstreamer-java.
  *
@@ -19,96 +17,32 @@
  */
 package org.freedesktop.gstreamer;
 
-import com.sun.jna.Pointer;
-
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 
+import org.freedesktop.gstreamer.glib.NativeObject;
+import org.freedesktop.gstreamer.lowlevel.GstIteratorPtr;
+import org.freedesktop.gstreamer.lowlevel.GstTypes;
 import org.freedesktop.gstreamer.lowlevel.GType;
 import org.freedesktop.gstreamer.lowlevel.GValueAPI;
-import org.freedesktop.gstreamer.lowlevel.GstTypes;
-import org.freedesktop.gstreamer.glib.NativeObject;
-import org.freedesktop.gstreamer.lowlevel.GPointer;
 
 import static org.freedesktop.gstreamer.lowlevel.GstIteratorAPI.GSTITERATOR_API;
 
 /**
- *
+ * Utility class for working with gstiterator.
  */
-class GstIterator<T extends NativeObject> extends NativeObject implements java.lang.Iterable<T> {
-
-    private final GType gtype;
-
-    GstIterator(Pointer ptr, Class<T> cls) {
-        super(new Handle(new GPointer(ptr), true));
-        gtype = GstTypes.typeFor(cls);
-    }
-
-    @Override
-    public Iterator<T> iterator() {
-        return new IteratorImpl();
-    }
-
-    public List<T> asList() {
-        List<T> list = new LinkedList<T>();
-        for (T t : this) {
-            list.add(t);
-        }
-        return Collections.unmodifiableList(list);
-    }
-
-    class IteratorImpl implements java.util.Iterator<T> {
-
-        final GValueAPI.GValue gValue;
-
-        T next;
-
-        IteratorImpl() {
-            gValue = new GValueAPI.GValue(gtype);
-            next = getNext();
-        }
-
-        private T getNext() {
-            if (GSTITERATOR_API.gst_iterator_next(getRawPointer(), gValue) == 1) {
-                T result = (T) gValue.getValue();
-                // reset cached structure or we get a memory leak
-                gValue.reset();
-                return result;
-            } else {
-                return null;
-            }
-        }
-
-        @Override
-        public boolean hasNext() {
-            return next != null;
-        }
-
-        @Override
-        public T next() {
-            T result = next;
-            next = getNext();
-            return result;
-        }
-
-        @Override
-        public void remove() {
-            throw new UnsupportedOperationException("Items cannot be removed.");
-        }
-    }
+class GstIterator {
     
-    private static final class Handle extends NativeObject.Handle {
-
-        public Handle(GPointer ptr, boolean ownsHandle) {
-            super(ptr, ownsHandle);
-        }
-
-        @Override
-        protected void disposeNativeHandle(GPointer ptr) {
-            GSTITERATOR_API.gst_iterator_free(ptr.getPointer());
-        }
-        
+    static <T extends NativeObject> List<T> asList(GstIteratorPtr iter, Class<T> type) {
+        final GType gtype = GstTypes.typeFor(type);
+        final GValueAPI.GValue gValue = new GValueAPI.GValue(gtype);
+        List<T> list = new ArrayList<>();
+        while (GSTITERATOR_API.gst_iterator_next(iter, gValue) == 1) {
+            list.add((T) gValue.getValue());
+        }
+        gValue.reset();
+        GSTITERATOR_API.gst_iterator_free(iter);
+        return list;
     }
+    
 }
diff --git a/src/org/freedesktop/gstreamer/lowlevel/GstBinAPI.java b/src/org/freedesktop/gstreamer/lowlevel/GstBinAPI.java
@@ -1,4 +1,5 @@
 /* 
+ * Copyright (c) 2021 Neil C Smith
  * Copyright (c) 2009 Levente Farkas
  * Copyright (c) 2007, 2008 Wayne Meissner
  * 
@@ -43,12 +44,12 @@ public interface GstBinAPI extends com.sun.jna.Library {
     @CallerOwnsReturn Element gst_bin_get_by_name(Bin bin, String name);
     @CallerOwnsReturn Element gst_bin_get_by_name_recurse_up(Bin bin, String name);
     @CallerOwnsReturn Element gst_bin_get_by_interface(Bin bin, GType iface);
-    Pointer gst_bin_iterate_elements(Bin bin);
-    Pointer gst_bin_iterate_sorted(Bin bin);
-    Pointer gst_bin_iterate_recurse(Bin bin);
-    Pointer gst_bin_iterate_sinks(Bin bin);
-    Pointer gst_bin_iterate_sources(Bin bin);
-    Pointer gst_bin_iterate_all_by_interface(Bin bin, GType iface);
+    GstIteratorPtr gst_bin_iterate_elements(Bin bin);
+    GstIteratorPtr gst_bin_iterate_sorted(Bin bin);
+    GstIteratorPtr gst_bin_iterate_recurse(Bin bin);
+    GstIteratorPtr gst_bin_iterate_sinks(Bin bin);
+    GstIteratorPtr gst_bin_iterate_sources(Bin bin);
+    GstIteratorPtr gst_bin_iterate_all_by_interface(Bin bin, GType iface);
 
     //Debugging
     void gst_debug_bin_to_dot_file (Bin bin, int details, String file_name);
diff --git a/src/org/freedesktop/gstreamer/lowlevel/GstElementAPI.java b/src/org/freedesktop/gstreamer/lowlevel/GstElementAPI.java
@@ -1,4 +1,5 @@
 /* 
+ * Copyright (c) 2021 Neil C Smith
  * Copyright (c) 2009 Levente Farkas
  * Copyright (c) 2007, 2008 Wayne Meissner
  * 
@@ -83,9 +84,9 @@ boolean gst_element_seek(Element elem, double rate, Format format, int flags,
     boolean gst_element_link_pads_filtered(Element src, String srcpadname, Element dest, String destpadname,
             Caps filter);
     
-    Pointer gst_element_iterate_pads(Element element);
-    Pointer gst_element_iterate_src_pads(Element element);
-    Pointer gst_element_iterate_sink_pads(Element element);
+    GstIteratorPtr gst_element_iterate_pads(Element element);
+    GstIteratorPtr gst_element_iterate_src_pads(Element element);
+    GstIteratorPtr gst_element_iterate_sink_pads(Element element);
     /* factory management */
     ElementFactory gst_element_get_factory(Element element);
     @CallerOwnsReturn Bus gst_element_get_bus(Element element);
diff --git a/src/org/freedesktop/gstreamer/lowlevel/GstIteratorAPI.java b/src/org/freedesktop/gstreamer/lowlevel/GstIteratorAPI.java
@@ -1,7 +1,5 @@
 /* 
- * Copyright (c) 2016 Neil C Smith
- * Copyright (c) 2009 Levente Farkas
- * Copyright (c) 2007, 2008 Wayne Meissner
+ * Copyright (c) 2021 Neil C Smith
  * 
  * This file is part of gstreamer-java.
  *
@@ -20,15 +18,14 @@
 
 package org.freedesktop.gstreamer.lowlevel;
 
-import com.sun.jna.Pointer;
-
 /**
  * GstIterator functions
  */
 public interface GstIteratorAPI extends com.sun.jna.Library {
+    
     GstIteratorAPI GSTITERATOR_API = GstNative.load(GstIteratorAPI.class);
 
-    void gst_iterator_free(Pointer iter);
-    int gst_iterator_next(Pointer iter, GValueAPI.GValue next);
-    void gst_iterator_resync(Pointer iter);
+    void gst_iterator_free(GstIteratorPtr iter);
+    int gst_iterator_next(GstIteratorPtr iter, GValueAPI.GValue next);
+    void gst_iterator_resync(GstIteratorPtr iter);
 }
diff --git a/src/org/freedesktop/gstreamer/lowlevel/GstIteratorPtr.java b/src/org/freedesktop/gstreamer/lowlevel/GstIteratorPtr.java
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2021 Neil C Smith
+ * 
+ * This file is part of gstreamer-java.
+ *
+ * This code is free software: you can redistribute it and/or modify it under the terms of the GNU
+ * Lesser General Public License version 3 only, as published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
+ * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License version 3 for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License version 3 along with
+ * this work. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.freedesktop.gstreamer.lowlevel;
+
+import com.sun.jna.Pointer;
+
+/**
+ * GstIterator pointer.
+ */
+public class GstIteratorPtr extends GPointer {
+
+    public GstIteratorPtr() {
+    }
+
+    public GstIteratorPtr(Pointer ptr) {
+        super(ptr);
+    }
+
+}
diff --git a/test/org/freedesktop/gstreamer/GarbageCollectionTest.java b/test/org/freedesktop/gstreamer/GarbageCollectionTest.java
@@ -23,6 +23,7 @@
 import static org.junit.Assert.assertTrue;
 
 import java.lang.ref.WeakReference;
+import java.util.List;
 
 import org.junit.After;
 import org.junit.AfterClass;
@@ -76,16 +77,45 @@ public void testBin() throws Exception {
         
         assertEquals("source not returned", e1, bin.getElementByName("source"));
         assertEquals("sink not returned", e2, bin.getElementByName("sink"));
-        WeakReference<Element> binRef = new WeakReference<Element>(bin);
+        GCTracker binTracker = new GCTracker(bin);
         bin = null;
-        assertTrue("Bin not garbage collected", GCTracker.waitGC(binRef));
-        WeakReference<Element> e1Ref = new WeakReference<Element>(e1);
-        WeakReference<Element> e2Ref = new WeakReference<Element>(e2);
+        assertTrue("Bin not garbage collected", binTracker.waitGC());
+        assertTrue("Bin not destroyed", binTracker.waitDestroyed());
+        GCTracker e1Tracker = new GCTracker(e1);
+        GCTracker e2Tracker = new GCTracker(e2);
         e1 = null;
         e2 = null;
         
-        assertTrue("First Element not garbage collected", GCTracker.waitGC(e1Ref));
-        assertTrue("Second Element not garbage collected", GCTracker.waitGC(e2Ref));
+        assertTrue("First Element not garbage collected", e1Tracker.waitGC());
+        assertTrue("First Element not destroyed", e1Tracker.waitDestroyed());
+        assertTrue("Second Element not garbage collected", e2Tracker.waitGC());
+        assertTrue("Second Element not destroyed", e2Tracker.waitDestroyed());
+        
+    }
+    
+    @Test
+    public void testBinParsed() throws Exception {
+        Bin bin = Gst.parseBinFromDescription("fakesrc name=source ! fakesink name=sink", false);
+        int binRefCount = bin.getRefCount();
+        List<Element> children = bin.getElements();
+        assertEquals("Iteration increased Bin refcount", binRefCount, bin.getRefCount());
+        assertEquals("Wrong number of child elements", 2, children.size());
+        Element e1 = children.get(0);
+        Element e2 = children.get(1);
+        GCTracker binTracker = new GCTracker(bin);
+        bin = null;
+        assertTrue("Bin not garbage collected", binTracker.waitGC());
+        assertTrue("Bin not destroyed", binTracker.waitDestroyed());
+        GCTracker e1Tracker = new GCTracker(e1);
+        GCTracker e2Tracker = new GCTracker(e2);
+        children = null;
+        e1 = null;
+        e2 = null;
+        
+        assertTrue("First Element not garbage collected", e1Tracker.waitGC());
+        assertTrue("First Element not destroyed", e1Tracker.waitDestroyed());
+        assertTrue("Second Element not garbage collected", e2Tracker.waitGC());
+        assertTrue("Second Element not destroyed", e2Tracker.waitDestroyed());
         
     }
     @Test
