tests/.../http_server: be spawn friendly

Make SimpleHttpServer work when using the 'spawn' method of
multiprocessing.

Instead of trying to pickle the HTTPServer and friends to the new
process, buffer any config calls and then start the server only in the
new process.

1 files changed, 44 insertions, 15 deletions

diff --git a/tests/testutils/http_server.py b/tests/testutils/http_server.py
index b72e745c5..57e813f71 100644
--- a/tests/testutils/http_server.py
+++ b/tests/testutils/http_server.py
@@ -81,30 +81,59 @@ class AuthHTTPServer(HTTPServer):
         super().__init__(*args, **kwargs)
 
 
-class SimpleHttpServer(multiprocessing.Process):
+class SimpleHttpServer():
+    # pylint: disable=attribute-defined-outside-init
+
     def __init__(self):
-        super().__init__()
-        self.server = AuthHTTPServer(('127.0.0.1', 0), RequestHandler)
-        self.started = False
+        self._reset()
+
+    def _reset(self):
+        self._process = None
+        self._port = None
+        self._anonymous_dir = None
+        self._user_list = []
 
     def start(self):
-        self.started = True
-        super().start()
+        assert self._process is None, "Server already running."
+        queue = multiprocessing.SimpleQueue()
+
+        self._process = multiprocessing.Process(
+            target=_run_server,
+            args=(queue, self._anonymous_dir, self._user_list),
+        )
 
-    def run(self):
-        self.server.serve_forever()
+        self._process.start()
+        self._port = queue.get()
 
     def stop(self):
-        if not self.started:
-            return
-        self.terminate()
-        self.join()
+        assert self._process is not None, "Server not running."
+        self._process.terminate()
+        self._process.join()
+        self._reset()
 
     def allow_anonymous(self, cwd):
-        self.server.anonymous_dir = cwd
+        assert self._process is None, "Can't modify server after start()."
+        assert self._anonymous_dir is None, "Only one anonymous_dir is supported."
+        self._anonymous_dir = cwd
 
     def add_user(self, user, password, cwd):
-        self.server.users[user] = (password, cwd)
+        assert self._process is None, "Can't modify server after start()."
+        self._user_list.append((user, password, cwd))
 
     def base_url(self):
-        return 'http://127.0.0.1:{}'.format(self.server.server_port)
+        assert self._port is not None
+        return 'http://127.0.0.1:{}'.format(self._port)
+
+
+def _run_server(queue, anonymous_dir, user_list):
+    server = AuthHTTPServer(('127.0.0.1', 0), RequestHandler)
+
+    if anonymous_dir is not None:
+        server.anonymous_dir = anonymous_dir
+
+    for user, password, cwd in user_list:
+        server.users[user] = (password, cwd)
+
+    queue.put(server.server_port)
+
+    server.serve_forever()