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

[Andreas Rheinhardt]

Guo, Yejun:
> 
> 
>> -----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(-)
>>
>> diff --git a/libavfilter/dnn/dnn_backend_native_layer_conv2d.c
>> b/libavfilter/dnn/dnn_backend_native_layer_conv2d.c
>> index 2b83896da9..2e5aacdc2b 100644
>> --- a/libavfilter/dnn/dnn_backend_native_layer_conv2d.c
>> +++ b/libavfilter/dnn/dnn_backend_native_layer_conv2d.c
>> @@ -38,6 +38,9 @@ typedef struct ThreadCommonParam{  typedef struct
>> ThreadParam{
>>      ThreadCommonParam *thread_common_param;
>>      int thread_start, thread_end;
>> +#if HAVE_PTHREAD_CANCEL
>> +    pthread_t thread;
>> +#endif
>>  } ThreadParam;
>>
>>  int ff_dnn_load_layer_conv2d(Layer *layer, AVIOContext *model_file_context,
>> int file_size, int operands_num) @@ -187,7 +190,6 @@ int
>> ff_dnn_execute_layer_conv2d(DnnOperand *operands, const int32_t
>> *input_opera
>>      int thread_num = (ctx->options.conv2d_threads <= 0 ||
>> ctx->options.conv2d_threads > av_cpu_count())
>>          ? (av_cpu_count() + 1) : (ctx->options.conv2d_threads);  #if
>> HAVE_PTHREAD_CANCEL
>> -    pthread_t *thread_id = av_malloc_array(thread_num, sizeof(*thread_id));
>>      int thread_stride;
>>  #endif
>>      ThreadParam **thread_param = av_malloc_array(thread_num,
>> sizeof(*thread_param)); @@ -230,17 +232,15 @@ int
>> ff_dnn_execute_layer_conv2d(DnnOperand *operands, const int32_t
>> *input_opera
>>          thread_param[i]->thread_common_param =
>> &thread_common_param;
>>          thread_param[i]->thread_start = thread_stride * i + pad_size;
>>          thread_param[i]->thread_end = (i == thread_num - 1) ? (height -
>> pad_size) : (thread_param[i]->thread_start + thread_stride);
>> -        pthread_create(&thread_id[i], NULL,
>> dnn_execute_layer_conv2d_thread, (void *)thread_param[i]);
>> +        pthread_create(&thread_param[i]->thread, NULL,
>> + dnn_execute_layer_conv2d_thread, (void *)thread_param[i]);
>>      }
>>
>>      //join threads, res gets function return
>>      for (int i = 0; i < thread_num; i++){
>> -        pthread_join(thread_id[i], NULL);
>> +        pthread_join(thread_param[i]->thread, NULL);
>>      }
>>
>>      //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.

Anyway, applied this patchset with the changes you requested.

- Andreas