fix: this functions has internal subprocess calls

Author: roelofvandijkO

s2p/initialization.py

@@ -10,6 +10,7 @@
 import rasterio
 import numpy as np
 import rpcm
+from multiprocessing import cpu_count
 
 from s2p import common
 from s2p import geographiclib
@@ -346,6 +347,7 @@ def is_this_tile_useful(x, y, w, h, images, images_sizes, border_margin, cfg):
     mask = masking.image_tile_mask(x, y, w, h, roi_msk, cld_msk, wat_msk,
                                    images_sizes[0], border_margin=border_margin, temporary_dir=cfg['temporary_dir'])
     if not mask.any():
+
         return False, None
     return True, mask
 
@@ -379,10 +381,12 @@ def tiles_full_info(cfg, tw, th, tiles_txt, create_masks=False):
             with rasterio.open(img['img'], 'r') as f:
                 images_sizes.append(f.shape)
 
+        # compute all masks in parallel as numpy arrays
+        n_workers = cfg["max_processes"] if cfg["max_processes"] is not None else cpu_count()
         # compute all masks in parallel as numpy arrays
         tiles_usefulnesses = parallel.launch_calls(is_this_tile_useful,
                                                    tiles_coords,
-                                                   cfg['max_processes'],
+                                                   min(n_workers, cpu_count()//2),  # internal subprocess calls!,
                                                    cfg['images'],
                                                    images_sizes,
                                                    cfg['border_margin'],