Merge branch 'issue#37'

Author: Benedikt Schmitt

filelock.py

@@ -105,6 +105,29 @@ def __str__(self):
 
 # Classes
 # ------------------------------------------------
+
+# This is a helper class which is returned by :meth:`BaseFileLock.acquire`
+# and wraps the lock to make sure __enter__ is not called twice when entering
+# the with statement.
+# If we would simply return *self*, the lock would be acquired again
+# in the *__enter__* method of the BaseFileLock, but not released again
+# automatically.
+#
+# :seealso: issue #37 (memory leak)
+class _Acquire_ReturnProxy(object):
+
+    def __init__(self, lock):
+        self.lock = lock
+        return None
+
+    def __enter__(self):
+        return self.lock
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.lock.release()
+        return None
+
+
 class BaseFileLock(object):
     """
     Implements the base class of a file lock.
@@ -239,12 +262,11 @@ def acquire(self, timeout=None, poll_intervall=0.05):
         with self._thread_lock:
             self._lock_counter += 1
 
+        lock_id = id(self)
+        lock_filename = self._lock_file
+        start_time = time.time()
         try:
-            start_time = time.time()
             while True:
-                lock_id = id(self)
-                lock_filename = self._lock_file
-
                 with self._thread_lock:
                     if not self.is_locked:
                         logger().debug('Attempting to acquire lock %s on %s', lock_id, lock_filename)
@@ -268,26 +290,7 @@ def acquire(self, timeout=None, poll_intervall=0.05):
                 self._lock_counter = max(0, self._lock_counter - 1)
 
             raise
-
-        # This class wraps the lock to make sure __enter__ is not called
-        # twiced when entering the with statement.
-        # If we would simply return *self*, the lock would be acquired again
-        # in the *__enter__* method of the BaseFileLock, but not released again
-        # automatically.
-        class ReturnProxy(object):
-
-            def __init__(self, lock):
-                self.lock = lock
-                return None
-
-            def __enter__(self):
-                return self.lock
-
-            def __exit__(self, exc_type, exc_value, traceback):
-                self.lock.release()
-                return None
-
-        return ReturnProxy(lock = self)
+        return _Acquire_ReturnProxy(lock = self)
 
     def release(self, force = False):
         """