memory-leaks - 从 ALAssetRepresentation 获取字节时内存泄漏

Question

我正在上传相机胶卷中的视频和图像。上传完成后，我得到 32 字节的内存泄漏。仪器显示泄漏在下方

   NSUInteger readStatus = [rep getBytes:buffer fromOffset:_startFromByte length:chunkSize error:NULL];

但我看不出那行有什么问题。

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    __block __typeof__(self) _self = self;

    ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset) {
        ALAssetRepresentation *rep = [myasset defaultRepresentation];
        NSUInteger chunkSize = CHUNK_SIZE;
        uint8_t *buffer = malloc(chunkSize);
        NSUInteger readStatus = [rep getBytes:buffer fromOffset:_startFromByte length:chunkSize error:NULL];

        if (readStatus == 0) {
            // Free up memory so we don't leak.
            free(buffer);
            dispatch_sync(dispatch_get_main_queue(), ^ {
                [_self cleanupConnectionSuccessful:NO];
            });
            return;
        }

        NSData *bytes = [NSData dataWithBytes:buffer length:readStatus];
        free(buffer);

        dispatch_sync(dispatch_get_main_queue(), ^ {
            [_self prepareRequestAndUploadData:bytes];
        });
    };

    ALAssetsLibraryAccessFailureBlock failureBlock = ^(NSError *err) {
        NSLog(@"Error: %@", [err localizedDescription]);
    };


    [_assetslibrary assetForURL:_fileUrl resultBlock:resultblock failureBlock:failureBlock];
});

Answer 1

只需添加@autoreleasepool block ，以便清除任何自动释放的对象。看起来 ARC 在 iOS7 之后发生了一些变化

@autoreleasepool {
     NSUInteger readStatus = [rep getBytes:buffer fromOffset:_startFromByte length:chunkSize error:NULL];
}