core: avoid shutdown() in IoLogger on WSL; closes #333.

mitogen/core.py

@@ -108,6 +108,7 @@ try:
 except NameError:
     BaseException = Exception
 
+IS_WSL = 'Microsoft' in os.uname()[2]
 PY3 = sys.version_info > (3,)
 if PY3:
     b = str.encode
@@ -1920,7 +1921,9 @@ class IoLogger(BasicStream):
     def on_shutdown(self, broker):
         """Shut down the write end of the logging socket."""
         _v and LOG.debug('%r.on_shutdown()', self)
-        self._wsock.shutdown(socket.SHUT_WR)
+        if not IS_WSL:
+            # #333: WSL generates invalid readiness indication on shutdown()
+            self._wsock.shutdown(socket.SHUT_WR)
         self._wsock.close()
         self.transmit_side.close()
 

mitogen/parent.py

@@ -68,7 +68,6 @@ from mitogen.core import LOG
 from mitogen.core import IOLOG
 
 
-IS_WSL = 'Microsoft' in os.uname()[2]
 itervalues = getattr(dict, 'itervalues', dict.values)
 
 if mitogen.core.PY3:
@@ -178,7 +177,7 @@ def disable_echo(fd):
     old = termios.tcgetattr(fd)
     new = cfmakeraw(old)
     flags = getattr(termios, 'TCSASOFT', 0)
-    if not IS_WSL:
+    if not mitogen.core.IS_WSL:
         # issue #319: Windows Subsystem for Linux as of July 2018 throws EINVAL
         # if TCSAFLUSH is specified.
         flags |= termios.TCSAFLUSH