Improvements to mask distort efficiency.

Via incremental caching and reduced malloc/free cycles.

Author: masterpiga

src/develop/blend.c

@@ -273,8 +273,12 @@ static void _refine_with_detail_mask(dt_iop_module_t *self,
   float *lum = dt_masks_calc_detail_mask(piece, threshold, detail);
   if(lum == NULL) goto error;
 
+  // src_hash encodes what the thresholded mask depends on (scharr data + slider value),
+  // so the distortion cache is invalidated when the details slider changes.
+  const dt_hash_t src_hash = dt_hash(p->scharr.hash, &level, sizeof(level));
+
   // here we have the slightly blurred full detail mask available
-  float *warp_mask = dt_dev_distort_detail_mask(piece, lum, self);
+  float *warp_mask = dt_dev_distort_detail_mask(piece, lum, self, src_hash);
   dt_free_align(lum);
 
   if(warp_mask == NULL) goto error;
@@ -815,8 +819,12 @@ static void _refine_with_detail_mask_cl(dt_iop_module_t *self,
   out = NULL;
   blur = NULL;
 
+  // src_hash encodes what the thresholded mask depends on (scharr data + slider value),
+  // so the distortion cache is invalidated when the details slider changes.
+  const dt_hash_t src_hash = dt_hash(p->scharr.hash, &level, sizeof(level));
+
   // here we have the slightly blurred full detail mask available
-  float *warp_mask = dt_dev_distort_detail_mask(piece, lum, self);
+  float *warp_mask = dt_dev_distort_detail_mask(piece, lum, self, src_hash);
   dt_free_align(lum);
   if(warp_mask == NULL)
   {

src/develop/develop.c

@@ -1373,11 +1373,16 @@ static void _dev_add_history_item(dt_develop_t *dev,
      || module != dev->gui_module)
     dt_dev_invalidate_all(dev);
 
+  dt_pthread_mutex_unlock(&dev->history_mutex);
+
+  // Signal after releasing history_mutex to avoid deadlock: raising
+  // DT_SIGNAL_DEVELOP_HISTORY_CHANGE while holding history_mutex can trigger
+  // signal handlers (e.g. neural_restore) that call dt_control_get_mouse_over_id,
+  // which acquires global_mutex — conflicting with dt_dev_zoom_move and
+  // dt_dev_get_viewport_params which hold global_mutex and then acquire history_mutex.
   if(need_end_record)
     dt_dev_undo_end_record(dev);
 
-  dt_pthread_mutex_unlock(&dev->history_mutex);
-
   if(dev->gui_attached)
   {
     /* signal that history has changed */