diff --git a/rpyc/core/async_.py b/rpyc/core/async_.py
index 07d819b7..336c8bbe 100644
--- a/rpyc/core/async_.py
+++ b/rpyc/core/async_.py
@@ -6,7 +6,7 @@
 
 # Magic borrowed from helpers.py..
 SERVE_INTERVAL = 0.0
-SLEEP_INTERVAL = 0.1
+SLEEP_INTERVAL = 0.001
 
 
 class AsyncResult(object):
@@ -53,7 +53,7 @@ def wait(self):
         # the reply for our seq is served. The callback is this class
         # so __call__ sets our obj and _is_ready to true.
         while not (self._is_ready or self.expired):
-            if self._conn.acquire_recvlock(timeout=SLEEP_INTERVAL, wait_for_lock=False):
+            if self._conn.acquire_recvlock(timeout=SLEEP_INTERVAL, wait_for_lock=True):
                 # Now that we can satisfy the precondition our _is_ready state is static...
                 # Serve a connection if another thread didn't already handle this results callback...
                 try:
diff --git a/rpyc/core/protocol.py b/rpyc/core/protocol.py
index 2b317c4f..a7a243cf 100644
--- a/rpyc/core/protocol.py
+++ b/rpyc/core/protocol.py
@@ -487,9 +487,11 @@ def _serve_bound(self, timeout, wait_for_lock):
                 remote_thread_id, message = this_thread._deque.popleft()
                 if len(this_thread._deque) == 0:
                     this_thread._event.clear()
-            elif self._recvlock._is_owned():  # enter pool
+            elif not self.acquire_recvlock(wait_for_lock=False):  # enter pool
                 self._thread_pool.append(this_thread)
                 wait_for_event = True
+            else:
+                self.release_recvlock()
 
         if message_available:  # just process
             this_thread._remote_thread_id = remote_thread_id
@@ -505,13 +507,14 @@ def _serve_bound(self, timeout, wait_for_lock):
                 if isinstance(exception, EOFError):
                     self.close()  # sends close async request
 
+                self.release_recvlock()
                 with self._lock:
                     for thread in self._thread_pool:
                         thread._event.set()
                         break
 
                 raise
-            finally:
+            else:
                 self.release_recvlock()
         else:
             while True:
@@ -529,8 +532,9 @@ def _serve_bound(self, timeout, wait_for_lock):
 
                         else:
                             this_thread._event.clear()
-                            if self._recvlock._is_owned():  # another thread was faster
+                            if not self.acquire_recvlock(wait_for_lock=False):  # another thread was faster
                                 continue
+                            self.release_recvlock()
                         self._thread_pool.remove(this_thread)  # leave pool, as we aren't waiting
                         break
                     else:  # timeout
@@ -730,8 +734,10 @@ def async_request(self, handler, *args, **kwargs):  # serving
         timeout = kwargs.pop("timeout", None)
         if kwargs:
             raise TypeError("got unexpected keyword argument(s) {list(kwargs.keys()}")
-        res = AsyncResult(self, timeout)
+        res = AsyncResult(self)
         self._async_request(handler, args, res)
+        if timeout is not None:
+            res.set_expiry(timeout)
         return res
 
     @property
diff --git a/tests/__init__.py b/tests/__init__.py
new file mode 100644
index 00000000..9d9b39e6
--- /dev/null
+++ b/tests/__init__.py
@@ -0,0 +1,17 @@
+import sys
+import rpyc
+from pathlib import Path
+
+def load_tests(loader, standard_tests, pattern):
+    # Hook rpyc logger, unittest verbosity, and system paths
+    #rpyc.core.DEFAULT_CONFIG['logger'] = rpyc.lib.setup_logger()
+    rpyc_tests_path = Path(__file__).absolute().parent
+    rpyc_path = rpyc_tests_path.parent
+    for p in [str(rpyc_path), str(rpyc_tests_path)]:
+        if p not in sys.path:
+            sys.path.insert(0, p)
+
+    # Discover on tests and add paths
+    tests = loader.discover(start_dir=rpyc_tests_path, pattern=pattern, top_level_dir=rpyc_path)
+    standard_tests.addTests(tests)
+    return standard_tests