More type annotations.

[python_utils.git] / thread_utils.py

diff --git a/thread_utils.py b/thread_utils.py
index d8c85f46fbcaed33864d591458c64a1cebeb162d..22161275605d76a1199df8f18d536fd04e2fe17b 100644 (file)
--- a/thread_utils.py
+++ b/thread_utils.py
@@ -13,6 +13,19 @@ logger = logging.getLogger(__name__)
 
 
 def current_thread_id() -> str:
+    """Returns a string composed of the parent process' id, the current
+    process' id and the current thread identifier.  The former two are
+    numbers (pids) whereas the latter is a thread id passed during thread
+    creation time.
+
+    >>> ret = current_thread_id()
+    >>> (ppid, pid, tid) = ret.split('/')
+    >>> ppid.isnumeric()
+    True
+    >>> pid.isnumeric()
+    True
+
+    """
     ppid = os.getppid()
     pid = os.getpid()
     tid = threading.current_thread().name
@@ -22,13 +35,33 @@ def current_thread_id() -> str:
 def is_current_thread_main_thread() -> bool:
     """Returns True is the current (calling) thread is the process' main
     thread and False otherwise.
+
+    >>> is_current_thread_main_thread()
+    True
+
+    >>> result = None
+    >>> def thunk():
+    ...     global result
+    ...     result = is_current_thread_main_thread()
+
+    >>> thunk()
+    >>> result
+    True
+
+    >>> import threading
+    >>> thread = threading.Thread(target=thunk)
+    >>> thread.start()
+    >>> thread.join()
+    >>> result
+    False
+
     """
     return threading.current_thread() is threading.main_thread()
 
 
 def background_thread(
     _funct: Optional[Callable],
-) -> Tuple[threading.Thread, threading.Event]:
+) -> Callable[..., Tuple[threading.Thread, threading.Event]]:
     """A function decorator to create a background thread.
 
     *** Please note: the decorated function must take an shutdown ***
@@ -77,7 +110,7 @@ def background_thread(
         return inner_wrapper
 
     if _funct is None:
-        return wrapper
+        return wrapper  # type: ignore
     else:
         return wrapper(_funct)
 
@@ -136,3 +169,9 @@ def periodically_invoke(
         return wrapper_repeat
 
     return decorator_repeat
+
+
+if __name__ == '__main__':
+    import doctest
+
+    doctest.testmod()