add new interfaces for TextureCache to unbind the bound image asynchronous load callbacks.

cocos/renderer/CCTextureCache.cpp

@@ -141,6 +141,28 @@ void TextureCache::addImageAsync(const std::string &path, const std::function<vo
     _sleepCondition.notify_one();
 }
 
+void TextureCache::unbindImageAsync(const std::string& filename)
+{
+    std::string fullpath = FileUtils::getInstance()->fullPathForFilename(filename);
+    auto found = std::find_if(_imageInfoQueue->begin(), _imageInfoQueue->end(), [&](ImageInfo* ptr)->bool{ return ptr->asyncStruct->filename == fullpath; });
+    if (found != _imageInfoQueue->end())
+    {
+        _imageInfoMutex.lock();
+        (*found)->asyncStruct->callback = nullptr;
+        _imageInfoMutex.unlock();
+    }
+}
+
+void TextureCache::unbindAllImageAsync()
+{
+    if (_imageInfoQueue && !_imageInfoQueue->empty())
+    {
+        _imageInfoMutex.lock();
+        std::for_each(_imageInfoQueue->begin(), _imageInfoQueue->end(), [](ImageInfo* ptr) { ptr->asyncStruct->callback = nullptr; });
+        _imageInfoMutex.unlock();
+    }
+}
+
 void TextureCache::loadImage()
 {
     AsyncStruct *asyncStruct = nullptr;

cocos/renderer/CCTextureCache.h

@@ -118,6 +118,18 @@ public:
     * @since v0.8
     */
     virtual void addImageAsync(const std::string &filepath, const std::function<void(Texture2D*)>& callback);
+    
+    /* Unbind a specified bound image asynchronous callback
+     * In the case an object who was bound to an image asynchronous callback was destroyed before the callback is invoked,
+     * the object always need to unbind this callback manually.
+     * @since v3.1
+     */
+    virtual void unbindImageAsync(const std::string &filename);
+    
+    /* Unbind all bound image asynchronous load callbacks
+     * @since v3.1
+     */
+    virtual void unbindAllImageAsync();
 
     /** Returns a Texture2D object given an Image.
     * If the image was not previously loaded, it will create a new Texture2D object and it will return it.

tests/cpp-tests/Classes/Texture2dTest/Texture2dTest.cpp

@@ -1533,6 +1533,7 @@ void TextureAsync::onEnter()
 
 TextureAsync::~TextureAsync()
 {
+    Director::getInstance()->getTextureCache()->unbindAllImageAsync();
     Director::getInstance()->getTextureCache()->removeAllTextures();
 }