Remove unused exceptions, fix pep 8 formatting errors and fix _NOT_SE…

…T in recv_nowait()
python · nanjekyejoannah · Jun 10, 2020 · May 7, 2020 · May 7, 2020 · May 7, 2020
commit 9577395e4c0867514974ea546aaa757bc5608735
diff --git a/Lib/test/support/interpreters.py b/Lib/test/support/interpreters.py
@@ -1,20 +1,20 @@
 """Subinterpreters High Level Module."""
 
 import _xxsubinterpreters as _interpreters
+
 # aliases:
 from _xxsubinterpreters import (
-    ChannelError, ChannelNotFoundError,
-    ChannelEmptyError, ChannelNotEmptyError, NotReceivedError,
+    ChannelError, ChannelNotFoundError, ChannelEmptyError,
     is_shareable,
 )
 
+
 __all__ = [
     'Interpreter', 'get_current', 'get_main', 'create', 'list_all',
     'SendChannel', 'RecvChannel',
     'create_channel', 'list_all_channels', 'is_shareable',
     'ChannelError', 'ChannelNotFoundError',
-    'ChannelEmptyError', 'ChannelNotEmptyError',
-    'NotReceivedError',
+    'ChannelEmptyError',
     ]
 
 
@@ -25,20 +25,23 @@ def create(*, isolated=True):
     id = _interpreters.create(isolated=isolated)
     return Interpreter(id, isolated=isolated)
 
+
 def list_all():
     """
     Get all existing interpreters.
     """
     return [Interpreter(id) for id in
             _interpreters.list_all()]
 
+
 def get_current():
     """
     Get the currently running interpreter.
     """
     id = _interpreters.get_current()
     return Interpreter(id)
 
+
 def get_main():
     """
     Get the main interpreter.
@@ -100,6 +103,7 @@ def create_channel():
     cid = _interpreters.channel_create()
     return (RecvChannel(cid), SendChannel(cid))
 
+
 def list_all_channels():
     """
     Get all open channels.
@@ -108,6 +112,9 @@ def list_all_channels():
             for cid in _interpreters.channel_list_all()]
 
 
+_NOT_SET = object()
+
+
 class RecvChannel:
     """
     The RecvChannel object represents
@@ -131,22 +138,19 @@ def recv(self, *, _delay=10 / 1000):  # 10 milliseconds
             obj = _interpreters.channel_recv(self._id, sentinel)
         return obj
 
-    def recv_nowait(self, default=None):
+    def recv_nowait(self, default=_NOT_SET):
         """
         Like recv(), but return the default
         instead of waiting.
 
         This function is blocked by a missing low-level
         implementation of channel_recv_wait().
         """
-        if default is None:
-            default = _NOT_SET
         if default is _NOT_SET:
             return _interpreters.channel_recv(self._id)
         else:
             return _interpreters.channel_recv(self._id, default)
 
-_NOT_SET = object()
 
 class SendChannel:
     """

diff --git a/Lib/test/test_interpreters.py b/Lib/test/test_interpreters.py
@@ -8,6 +8,7 @@
 import _xxsubinterpreters as _interpreters
 from test.support import interpreters
 
+
 def _captured_script(script):
     r, w = os.pipe()
     indented = script.replace('\n', '\n                ')
@@ -19,6 +20,7 @@ def _captured_script(script):
         """)
     return wrapped, open(r)
 
+
 def clean_up_interpreters():
     for interp in interpreters.list_all():
         if interp.id == 0:  # main
@@ -28,12 +30,14 @@ def clean_up_interpreters():
         except RuntimeError:
             pass  # already destroyed
 
+
 def _run_output(interp, request, shared=None):
     script, rpipe = _captured_script(request)
     with rpipe:
         interp.run(script)
         return rpipe.read()
 
+
 @contextlib.contextmanager
 def _running(interp):
     r, w = os.pipe()
@@ -519,7 +523,6 @@ def test_send_recv_nowait_same_interpreter(self):
             assert obj == orig
             """))
 
-
         r, s = interpreters.create_channel()
 
         def f():

diff --git a/Modules/_xxsubinterpretersmodule.c b/Modules/_xxsubinterpretersmodule.c
@@ -1167,8 +1167,6 @@ static PyObject *ChannelNotFoundError;
 static PyObject *ChannelClosedError;
 static PyObject *ChannelEmptyError;
 static PyObject *ChannelNotEmptyError;
-static PyObject *ChannelReleasedError;
-static PyObject *NotReceivedError;
 
 static int
 channel_exceptions_init(PyObject *ns)
@@ -1205,27 +1203,6 @@ channel_exceptions_init(PyObject *ns)
         return -1;
     }
 
-     // An operation tried to use a released channel.
-    ChannelReleasedError = PyErr_NewException(
-            "_interpreters.ChannelReleasedError", ChannelClosedError, NULL);
-    if (ChannelReleasedError == NULL) {
-        return -1;
-    }
-    if (PyDict_SetItemString(ns, "ChannelReleasedError", ChannelReleasedError) != 0) {
-        return -1;
-    }
-
-    // An operation trying to send an object when Nothing was waiting
-    // to receive it
-    NotReceivedError = PyErr_NewException(
-            "_interpreters.NotReceivedError", ChannelError, NULL);
-    if (NotReceivedError == NULL) {
-        return -1;
-    }
-    if (PyDict_SetItemString(ns, "NotReceivedError", NotReceivedError) != 0) {
-        return -1;
-    }
-
     // An operation tried to pop from an empty channel.
     ChannelEmptyError = PyErr_NewException(
             "_xxsubinterpreters.ChannelEmptyError", ChannelError, NULL);