Added basic locking (#58)

partcad/src/partcad/assembly.py

@@ -9,6 +9,7 @@
 import copy
 import random
 import string
+import threading
 
 import build123d as b3d
 
@@ -38,6 +39,7 @@ def __init__(self, name=None, config={}):
         else:
             self.location = None
         self.shape = None
+        self.lock = threading.RLock()
 
         # self.children contains all child parts and assemblies
         self.children = []
@@ -48,9 +50,10 @@ def __init__(self, name=None, config={}):
         self.instantiated = False
 
     def do_instantiate(self):
-        if not self.instantiated:
-            self.instantiate(self)
-            self.instantiated = True
+        with self.lock:
+            if not self.instantiated:
+                self.instantiate(self)
+                self.instantiated = True
 
     def add(
         self,

partcad/src/partcad/part.py

@@ -10,11 +10,13 @@
 import math
 import random
 import string
-from . import shape
+import threading
 
 import cadquery as cq
 import build123d as b3d
 
+from . import shape
+
 
 class Part(shape.Shape):
     def __init__(self, name=None, path=None, config={}, shape=None):
@@ -29,6 +31,7 @@ def __init__(self, name=None, path=None, config={}, shape=None):
         self.config = config
         self.path = path
         self.shape = shape
+        self.lock = threading.RLock()
 
         self.desc = None
         if "desc" in config:
@@ -52,9 +55,10 @@ def set_shape(self, shape):
         self.shape = shape
 
     def get_shape(self):
-        if self.shape is None:
-            self.instantiate(self)
-        return self.shape
+        with self.lock:
+            if self.shape is None:
+                self.instantiate(self)
+            return self.shape
 
     def ref_inc(self):
         self.count += 1