Switch to using context managers for acquiring and releasing locks.

django/core/handlers/wsgi.py

@@ -210,8 +210,7 @@ class WSGIHandler(base.BaseHandler):
         # Set up middleware if needed. We couldn't do this earlier, because
         # settings weren't available.
         if self._request_middleware is None:
-            self.initLock.acquire()
-            try:
+            with self.initLock:
                 try:
                     # Check that middleware is still uninitialised.
                     if self._request_middleware is None:
@@ -220,8 +219,6 @@ class WSGIHandler(base.BaseHandler):
                     # Unload whatever middleware we got
                     self._request_middleware = None
                     raise
-            finally:
-                self.initLock.release()
 
         set_script_prefix(base.get_script_name(environ))
         signals.request_started.send(sender=self.__class__)

django/core/mail/backends/console.py

@@ -16,19 +16,17 @@ class EmailBackend(BaseEmailBackend):
         """Write all messages to the stream in a thread-safe way."""
         if not email_messages:
             return
-        self._lock.acquire()
-        try:
-            stream_created = self.open()
-            for message in email_messages:
-                self.stream.write('%s\n' % message.message().as_string())
-                self.stream.write('-'*79)
-                self.stream.write('\n')
-                self.stream.flush()  # flush after each message
-            if stream_created:
-                self.close()
-        except:
-            if not self.fail_silently:
-                raise
-        finally:
-            self._lock.release()
+        with self._lock:
+            try:
+                stream_created = self.open()
+                for message in email_messages:
+                    self.stream.write('%s\n' % message.message().as_string())
+                    self.stream.write('-'*79)
+                    self.stream.write('\n')
+                    self.stream.flush()  # flush after each message
+                if stream_created:
+                    self.close()
+            except:
+                if not self.fail_silently:
+                    raise
         return len(email_messages)

django/core/mail/backends/smtp.py

@@ -80,8 +80,7 @@ class EmailBackend(BaseEmailBackend):
         """
         if not email_messages:
             return
-        self._lock.acquire()
-        try:
+        with self._lock:
             new_conn_created = self.open()
             if not self.connection:
                 # We failed silently on open().
@@ -94,8 +93,6 @@ class EmailBackend(BaseEmailBackend):
                     num_sent += 1
             if new_conn_created:
                 self.close()
-        finally:
-            self._lock.release()
         return num_sent
 
     def _send(self, email_message):