/src/net.cpp

    Mat bottom_blob = blob_mats[bottom_blob_index];
    if (opt.lightmode)
    {
        // delete after taken in light mode
        blob_mats[bottom_blob_index].release();
        // deep copy for inplace forward if data is shared
        if (layer->support_inplace && *bottom_blob.refcount != 1)
        {
            bottom_blob = bottom_blob.clone();
        }
    }

====================
上面的release，是不是应该放到clone的所在的if里面？理解这个release是由于前面bottom_blob 拷贝构造函数refcount++，以及后面clone没有refcount--，所以要release。如果不满足后面的if条件，那就没有clone，这个release是不是不应该有。

Start in src/net.cpp at the shown bottom_blob handling, and trace the refcount effects of the copy, release, and conditional clone. Confirm the intended ownership behavior for both branches; the issue is complete when the release placement is resolved and the relevant behavior is covered by the repository's existing validation.