FIX: exit program on ctrl-C

tomorrow/tomorrow.py

@@ -1,23 +1,46 @@
 from functools import wraps
 
+import concurrent.futures
 from concurrent.futures import ThreadPoolExecutor
 
 
-class Tomorrow():
+EXECUTORS = []
+
 
+class Tomorrow():
+    """
+    Result wrapper that captures __getattr__ calls in order to 
+    wait on futures when any attribute of the Tomorrow object is accessed
+    """
     def __init__(self, future, timeout):
         self._future = future
         self._timeout = timeout
 
     def __getattr__(self, name):
-        result = self._wait()
-        return result.__getattribute__(name)
+        """
+        When an attribute of the Tomorrow object is accessed, resolve obj._future
+        """
+        try:
+            result = self._wait()
+            return result.__getattribute__(name)
+        except KeyboardInterrupt:
+            exit()
+            raise
 
-    def _wait(self):
-        return self._future.result(self._timeout)
+    def _wait(self, timeout=None):
+        """
+        Wait on a future that only causes side effects and 
+        has no return value that is accessed with a __getattr__ call
+        """
+        if not timeout:
+            timeout = self._timeout
+        return self._future.result(timeout)
 
 
 def async(n, base_type, timeout=None):
+    """
+    Base function for @threads and (eventually) @processes decorators
+    """
     def decorator(f):
         if isinstance(n, int):
             pool = base_type(n)
@@ -28,6 +51,9 @@ def decorator(f):
                 "Invalid type: %s"
                 % type(base_type)
             )
+
+        EXECUTORS.append(pool)
+
         @wraps(f)
         def wrapped(*args, **kwargs):
             return Tomorrow(
@@ -39,4 +65,18 @@ def wrapped(*args, **kwargs):
 
 
 def threads(n, timeout=None):
+    """
+    Decorator for threaded execution
+    """
     return async(n, ThreadPoolExecutor, timeout)
+
+
+def exit():
+    """
+    Clean up all future objects and resume execution in the main thread
+    Allows for program exit when an interrupt signal is received
+    """
+    for executor in EXECUTORS:
+        executor._threads.clear()
+    concurrent.futures.thread._threads_queues.clear()
+