dmonitoring : use memory cache to avoid malloc/free on every frame (#1599)

* use memory cache

* use template function to return buffer

* inline function

* const size_t

* use std::vector instead of kj::array

selfdrive/modeld/models/dmonitoring.cc

@@ -26,6 +26,14 @@ void dmonitoring_init(DMonitoringModelState* s) {
   s->is_rhd_checked = false;
 }
 
+template <class T>
+static inline T *get_buffer(std::vector<T> &buf, const size_t size) {
+  if (buf.size() < size) {
+    buf.resize(size);
+  }
+  return buf.data();
+}
+
 DMonitoringResult dmonitoring_eval_frame(DMonitoringModelState* s, void* stream_buf, int width, int height) {
 
   uint8_t *raw_buf = (uint8_t*) stream_buf;
@@ -39,8 +47,7 @@ DMonitoringResult dmonitoring_eval_frame(DMonitoringModelState* s, void* stream_
   int resized_width = MODEL_WIDTH;
   int resized_height = MODEL_HEIGHT;
 
-  uint8_t *cropped_buf = new uint8_t[cropped_width*cropped_height*3/2];
-  uint8_t *cropped_y_buf = cropped_buf;
+  uint8_t *cropped_y_buf = get_buffer(s->cropped_buf, cropped_width*cropped_height*3/2);
   uint8_t *cropped_u_buf = cropped_y_buf + (cropped_width * cropped_height);
   uint8_t *cropped_v_buf = cropped_u_buf + ((cropped_width/2) * (cropped_height/2));
 
@@ -53,8 +60,7 @@ DMonitoringResult dmonitoring_eval_frame(DMonitoringModelState* s, void* stream_
     }
   } else {
     // not tested
-    uint8_t *premirror_cropped_buf = new uint8_t[cropped_width*cropped_height*3/2];
-    uint8_t *premirror_cropped_y_buf = premirror_cropped_buf;
+    uint8_t *premirror_cropped_y_buf = get_buffer(s->premirror_cropped_buf, cropped_width*cropped_height*3/2);
     uint8_t *premirror_cropped_u_buf = premirror_cropped_y_buf + (cropped_width * cropped_height);
     uint8_t *premirror_cropped_v_buf = premirror_cropped_u_buf + ((cropped_width/2) * (cropped_height/2));
     for (int r = 0; r < height/2; r++) {
@@ -70,10 +76,9 @@ DMonitoringResult dmonitoring_eval_frame(DMonitoringModelState* s, void* stream_
                        cropped_u_buf, cropped_width/2,
                        cropped_v_buf, cropped_width/2,
                        cropped_width, cropped_height);
-    delete[] premirror_cropped_buf;
   }
 
-  uint8_t *resized_buf = new uint8_t[resized_width*resized_height*3/2];
+  uint8_t *resized_buf = get_buffer(s->resized_buf, resized_width*resized_height*3/2);
   uint8_t *resized_y_buf = resized_buf;
   uint8_t *resized_u_buf = resized_y_buf + (resized_width * resized_height);
   uint8_t *resized_v_buf = resized_u_buf + ((resized_width/2) * (resized_height/2));
@@ -90,8 +95,7 @@ DMonitoringResult dmonitoring_eval_frame(DMonitoringModelState* s, void* stream_
                     mode);
 
   int yuv_buf_len = (MODEL_WIDTH/2) * (MODEL_HEIGHT/2) * 6; // Y|u|v -> y|y|y|y|u|v
-
-  float *net_input_buf = new float[yuv_buf_len];
+  float *net_input_buf = get_buffer(s->net_input_buf, yuv_buf_len);
   // one shot conversion, O(n) anyway
   // yuvframe2tensor, normalize
   for (int r = 0; r < MODEL_HEIGHT/2; r++) {
@@ -120,10 +124,7 @@ DMonitoringResult dmonitoring_eval_frame(DMonitoringModelState* s, void* stream_
   //fwrite(net_input_buf, MODEL_HEIGHT*MODEL_WIDTH*3/2, sizeof(float), dump_yuv_file2);
   //fclose(dump_yuv_file2);
 
-  delete[] cropped_buf;
-  delete[] resized_buf;
   s->m->execute(net_input_buf, yuv_buf_len);
-  delete[] net_input_buf;
 
   DMonitoringResult ret = {0};
   memcpy(&ret.face_orientation, &s->output[0], sizeof ret.face_orientation);

selfdrive/modeld/models/dmonitoring.h

@@ -1,10 +1,8 @@
-#ifndef DMONITORING_H
-#define DMONITORING_H
-
+#pragma once
+#include <vector>
 #include "common/util.h"
 #include "commonmodel.h"
 #include "runners/run.h"
-
 #include "messaging.hpp"
 
 #ifdef __cplusplus
@@ -31,6 +29,10 @@ typedef struct DMonitoringModelState {
   bool is_rhd;
   bool is_rhd_checked;
   float output[OUTPUT_SIZE];
+  std::vector<uint8_t> resized_buf;
+  std::vector<uint8_t> cropped_buf;
+  std::vector<uint8_t> premirror_cropped_buf;
+  std::vector<float> net_input_buf;
 } DMonitoringModelState;
 
 void dmonitoring_init(DMonitoringModelState* s);
@@ -42,4 +44,3 @@ void dmonitoring_free(DMonitoringModelState* s);
 }
 #endif
 
-#endif