issue #488: fix shutdown damage caused in 6ca2677de5

os._exit() subverted calm shutdown, meaning unix.Listener never had a
chance to cleanup its socket.

Move unix.Listener socket cleanup into its class so it is automatic
during shutdown, rather than cutpasted for each consumer.

Disable the watcher thread in the MuxProcess, it is useless.

Add .sock extension to /tmp/mitogen_unix_*, so we can write a test.

ansible_mitogen/process.py

@@ -179,10 +179,6 @@ class MuxProcess(object):
             cls.worker_sock = None
             self = cls()
             self.worker_main()
-            # Test frameworks living somewhere higher on the stack of the
-            # original parent process may try to catch sys.exit(), so do a C
-            # level exit instead.
-            os._exit(0)
 
     def worker_main(self):
         """
@@ -193,10 +189,19 @@ class MuxProcess(object):
         self._setup_master()
         self._setup_services()
 
-        # Let the parent know our listening socket is ready.
-        mitogen.core.io_op(self.child_sock.send, b('1'))
-        # Block until the socket is closed, which happens on parent exit.
-        mitogen.core.io_op(self.child_sock.recv, 1)
+        try:
+            # Let the parent know our listening socket is ready.
+            mitogen.core.io_op(self.child_sock.send, b('1'))
+            # Block until the socket is closed, which happens on parent exit.
+            mitogen.core.io_op(self.child_sock.recv, 1)
+        finally:
+            self.broker.shutdown()
+            self.broker.join()
+
+            # Test frameworks living somewhere higher on the stack of the
+            # original parent process may try to catch sys.exit(), so do a C
+            # level exit instead.
+            os._exit(0)
 
     def _enable_router_debug(self):
         if 'MITOGEN_ROUTER_DEBUG' in os.environ:
@@ -236,10 +241,14 @@ class MuxProcess(object):
         """
         Construct a Router, Broker, and mitogen.unix listener
         """
-        self.router = mitogen.master.Router(max_message_size=4096 * 1048576)
+        self.broker = mitogen.master.Broker(install_watcher=False)
+        self.router = mitogen.master.Router(
+            broker=self.broker,
+            max_message_size=4096 * 1048576,
+        )
         self._setup_responder(self.router.responder)
-        mitogen.core.listen(self.router.broker, 'shutdown', self.on_broker_shutdown)
-        mitogen.core.listen(self.router.broker, 'exit', self.on_broker_exit)
+        mitogen.core.listen(self.broker, 'shutdown', self.on_broker_shutdown)
+        mitogen.core.listen(self.broker, 'exit', self.on_broker_exit)
         self.listener = mitogen.unix.Listener(
             router=self.router,
             path=self.unix_listener_path,
@@ -273,12 +282,6 @@ class MuxProcess(object):
         threads to exit gracefully.
         """
         self.pool.stop(join=False)
-        try:
-            os.unlink(self.listener.path)
-        except OSError as e:
-            # Prevent a shutdown race with the parent process.
-            if e.args[0] != errno.ENOENT:
-                raise
 
     def on_broker_exit(self):
         """

mitogen/unix.py

@@ -60,7 +60,7 @@ def is_path_dead(path):
 
 
 def make_socket_path():
-    return tempfile.mktemp(prefix='mitogen_unix_')
+    return tempfile.mktemp(prefix='mitogen_unix_', suffix='.sock')
 
 
 class Listener(mitogen.core.BasicStream):
@@ -88,8 +88,17 @@ class Listener(mitogen.core.BasicStream):
         self.receive_side = mitogen.core.Side(self, self._sock.fileno())
         router.broker.start_receive(self)
 
+    def _unlink_socket(self):
+        try:
+            os.unlink(self.path)
+        except OSError as e:
+            # Prevent a shutdown race with the parent process.
+            if e.args[0] != errno.ENOENT:
+                raise
+
     def on_shutdown(self, broker):
         broker.stop_receive(self)
+        self._unlink_socket()
         self._sock.close()
         self.receive_side.closed = True