Added locking to exiftool

osxphotos/exiftool.py

@@ -17,6 +17,7 @@ import pathlib
 import re
 import shutil
 import subprocess
+import threading
 from abc import ABC, abstractmethod
 from functools import lru_cache  # pylint: disable=syntax-error
 
@@ -249,6 +250,7 @@ class ExifTool:
         self._exiftoolproc = _ExifToolProc(
             exiftool=exiftool, large_file_support=large_file_support
         )
+        self._lock = threading.Lock()
         self._read_exif()
 
     @property
@@ -352,6 +354,7 @@ class ExifTool:
         if not commands:
             raise TypeError("must provide one or more command to run")
 
+        with self._lock:
             if self._context_mgr and self.overwrite:
                 commands = list(commands)
                 commands.append("-overwrite_original")