[FFmpeg-devel] [PATCH 15/23] dnn/dnn_backend_native_layer_conv2d: Join two arrays, avoid allocation

[Andreas Rheinhardt]

Guo, Yejun:
> 
> 
>> -----Original Message-----
>>>> -----Original Message-----
>>>> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
>>>> Andreas Rheinhardt
>>>> Sent: 2021年3月11日 5:55
>>>> To: ffmpeg-devel at ffmpeg.org
>>>> Cc: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
>>>> Subject: [FFmpeg-devel] [PATCH 15/23]
>>>> dnn/dnn_backend_native_layer_conv2d: Join two arrays, avoid allocation
>>>>
>>>> Fixes Coverity issue #1473507.
>>>>
>>>> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
>>>> ---
>>>>  libavfilter/dnn/dnn_backend_native_layer_conv2d.c | 10 +++++-----
>>>>  1 file changed, 5 insertions(+), 5 deletions(-)
>>>>      }
>>>>
>>>>      //release memory
>>>> -    av_freep(&thread_id);
>>>> -
>>>>      for (int i = 0; i < thread_num; i++){
>>>>          av_freep(&thread_param[i]);
>>>>      }
>>>
>>> LGMT, and just one question: shall we reduce the allocation as less as
>> possible? thanks.
>>>
>> If it is doable without too much effort as is here, then the answer is
>> yes. Actually, one could go even further than what this patchset did:
>> One could keep the thread_param array instead of constantly allocating
>> and freeing it. With much more effort, one could even keep the threads.
> 
> thanks, and is the reason that: we need to check the return value for dynamic
> allocation, and also need some effort to make sure to free it for all possible
> paths in the code followed?
> 
Yes, reducing the amount of allocations also reduces the amount of
checks and frees one has to perform. You can see the latter in this
patchset, namely in this patch and in the one that stopped allocating
thread_param separately (which enabled to remove the loop for freeing them).

- Andreas