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Commit 547e6653 authored by Chet Haase's avatar Chet Haase
Browse files

Don't null the reference to Bitmap pixels until we're really ready 

A change in the VM triggers a native memory error more aggressively than before,
showing that there's a bug in the logic of recycling bitmaps. Since the pixel
memory is allocated on the Java heap, nulling out the reference to that memory
in the Java level Bitmap object can cause that memory to get collected at any time.
Meanwhile, we may have a reference to that memory at the native level for rendering
purposes, causing an error if/when we access that memory after it has been collected
by the VM.

The fix is to avoid setting the reference to the pixels to null unless we are
not referring to it in native code. This is determined at the time we call
recycle() - we return a boolean to indicate whether the native code is still
using the memory. if not, the Java code can null out the reference and allow the
VM to collect it. Otherwise, it will get collected later when the encompassing
Bitmap object is collected.

Issue #7339156 HTML5 tests crash the app (Vellamo)

Change-Id: I3a0d6b9a6c5dd3b86cc2b0ff7719007e774b5e3c
parent d6e3ad54

core/jni/android/graphics/Bitmap.cpp

+4 −4
Original line number Diff line number Diff line
@@ -261,14 +261,14 @@ static void Bitmap_destructor(JNIEnv* env, jobject, SkBitmap* bitmap) { 
    delete bitmap;

}



static void Bitmap_recycle(JNIEnv* env, jobject, SkBitmap* bitmap) {

static jboolean Bitmap_recycle(JNIEnv* env, jobject, SkBitmap* bitmap) {

#ifdef USE_OPENGL_RENDERER

    if (android::uirenderer::Caches::hasInstance()) {

        android::uirenderer::Caches::getInstance().resourceCache.recycle(bitmap);

        return;

        return android::uirenderer::Caches::getInstance().resourceCache.recycle(bitmap);

    }

#endif // USE_OPENGL_RENDERER

    bitmap->setPixels(NULL, NULL);

    return true;

}



// These must match the int values in Bitmap.java
@@ -665,7 +665,7 @@ static JNINativeMethod gBitmapMethods[] = { 
    {   "nativeCopy",               "(IIZ)Landroid/graphics/Bitmap;",

        (void*)Bitmap_copy },

    {   "nativeDestructor",         "(I)V", (void*)Bitmap_destructor },

    {   "nativeRecycle",            "(I)V", (void*)Bitmap_recycle },

    {   "nativeRecycle",            "(I)Z", (void*)Bitmap_recycle },

    {   "nativeCompress",           "(IIILjava/io/OutputStream;[B)Z",

        (void*)Bitmap_compress },

    {   "nativeErase",              "(II)V", (void*)Bitmap_erase },

graphics/java/android/graphics/Bitmap.java

+9 −4
Original line number Diff line number Diff line
@@ -201,9 +201,14 @@ public final class Bitmap implements Parcelable { 
     */

    public void recycle() {

        if (!mRecycled) {

            if (nativeRecycle(mNativeBitmap)) {

                // return value indicates whether native pixel object was actually recycled.

                // false indicates that it is still in use at the native level and these

                // objects should not be collected now. They will be collected later when the

                // Bitmap itself is collected.

                mBuffer = null;

            nativeRecycle(mNativeBitmap);

                mNinePatchChunk = null;

            }

            mRecycled = true;

        }

    }
@@ -1391,7 +1396,7 @@ public final class Bitmap implements Parcelable { 
    private static native Bitmap nativeCopy(int srcBitmap, int nativeConfig,

                                            boolean isMutable);

    private static native void nativeDestructor(int nativeBitmap);

    private static native void nativeRecycle(int nativeBitmap);

    private static native boolean nativeRecycle(int nativeBitmap);



    private static native boolean nativeCompress(int nativeBitmap, int format,

                                            int quality, OutputStream stream,

libs/hwui/ResourceCache.cpp

+16 −5
Original line number Diff line number Diff line
@@ -265,27 +265,38 @@ void ResourceCache::destructorLocked(SkiaColorFilter* resource) { 
    }

}



void ResourceCache::recycle(SkBitmap* resource) {

/**

 * Return value indicates whether resource was actually recycled, which happens when RefCnt

 * reaches 0.

 */

bool ResourceCache::recycle(SkBitmap* resource) {

    Mutex::Autolock _l(mLock);

    recycleLocked(resource);

    return recycleLocked(resource);

}



void ResourceCache::recycleLocked(SkBitmap* resource) {

/**

 * Return value indicates whether resource was actually recycled, which happens when RefCnt

 * reaches 0.

 */

bool ResourceCache::recycleLocked(SkBitmap* resource) {

    ssize_t index = mCache->indexOfKey(resource);

    if (index < 0) {

        // not tracking this resource; just recycle the pixel data

        resource->setPixels(NULL, NULL);

        return;

        return true;

    }

    ResourceReference* ref = mCache->valueAt(index);

    if (ref == NULL) {

        // Should not get here - shouldn't get a call to recycle if we're not yet tracking it

        return;

        return true;

    }

    ref->recycled = true;

    if (ref->refCount == 0) {

        deleteResourceReferenceLocked(resource, ref);

        return true;

    }

    // Still referring to resource, don't recycle yet

    return false;

}



/**

libs/hwui/ResourceCache.h

+2 −2
Original line number Diff line number Diff line
@@ -99,8 +99,8 @@ public: 
    void destructorLocked(SkiaShader* resource);

    void destructorLocked(SkiaColorFilter* resource);



    void recycle(SkBitmap* resource);

    void recycleLocked(SkBitmap* resource);

    bool recycle(SkBitmap* resource);

    bool recycleLocked(SkBitmap* resource);



private:

    void deleteResourceReferenceLocked(void* resource, ResourceReference* ref);