Selectively enable tests for asyncore.readwrite based on the presence

of poll support in the select module (since this is the only case in
which readwrite can be called). [GSoC - Alan McIntyre]

Lib/test/test_asyncore.py

@@ -106,87 +106,83 @@ class HelperFunctionTests(unittest.TestCase):
         asyncore._exception(tr2)
         self.assertEqual(tr2.error_handled, True)
 
-##    Commented out these tests because test a non-documented function
-##    (which is actually public, why it's not documented?). Anyway, the
-##    tests *and* the function uses constants in the select module that
-##    are not present in Windows systems (see this thread:
-##    http://mail.python.org/pipermail/python-list/2001-October/109973.html)
-##    Note even that these constants are mentioned in the select
-##    documentation, as a parameter of "poll" method "register", but are
-##    not explicit declared as constants of the module.
-##    .    Facundo Batista
-##
-##    def test_readwrite(self):
-##        # Check that correct methods are called by readwrite()
-##
-##        class testobj:
-##            def __init__(self):
-##                self.read = False
-##                self.write = False
-##                self.expt = False
-##
-##            def handle_read_event(self):
-##                self.read = True
-##
-##            def handle_write_event(self):
-##                self.write = True
-##
-##            def handle_expt_event(self):
-##                self.expt = True
-##
-##            def handle_error(self):
-##                self.error_handled = True
-##
-##        for flag in (select.POLLIN, select.POLLPRI):
-##            tobj = testobj()
-##            self.assertEqual(tobj.read, False)
-##            asyncore.readwrite(tobj, flag)
-##            self.assertEqual(tobj.read, True)
-##
-##            # check that ExitNow exceptions in the object handler method
-##            # bubbles all the way up through asyncore readwrite call
-##            tr1 = exitingdummy()
-##            self.assertRaises(asyncore.ExitNow, asyncore.readwrite, tr1, flag)
-##
-##            # check that an exception other than ExitNow in the object handler
-##            # method causes the handle_error method to get called
-##            tr2 = crashingdummy()
-##            asyncore.readwrite(tr2, flag)
-##            self.assertEqual(tr2.error_handled, True)
-##
-##        tobj = testobj()
-##        self.assertEqual(tobj.write, False)
-##        asyncore.readwrite(tobj, select.POLLOUT)
-##        self.assertEqual(tobj.write, True)
-##
-##        # check that ExitNow exceptions in the object handler method
-##        # bubbles all the way up through asyncore readwrite call
-##        tr1 = exitingdummy()
-##        self.assertRaises(asyncore.ExitNow, asyncore.readwrite, tr1,
-##                          select.POLLOUT)
-##
-##        # check that an exception other than ExitNow in the object handler
-##        # method causes the handle_error method to get called
-##        tr2 = crashingdummy()
-##        asyncore.readwrite(tr2, select.POLLOUT)
-##        self.assertEqual(tr2.error_handled, True)
-##
-##        for flag in (select.POLLERR, select.POLLHUP, select.POLLNVAL):
-##            tobj = testobj()
-##            self.assertEqual(tobj.expt, False)
-##            asyncore.readwrite(tobj, flag)
-##            self.assertEqual(tobj.expt, True)
-##
-##            # check that ExitNow exceptions in the object handler method
-##            # bubbles all the way up through asyncore readwrite calls
-##            tr1 = exitingdummy()
-##            self.assertRaises(asyncore.ExitNow, asyncore.readwrite, tr1, flag)
-##
-##            # check that an exception other than ExitNow in the object handler
-##            # method causes the handle_error method to get called
-##            tr2 = crashingdummy()
-##            asyncore.readwrite(tr2, flag)
-##            self.assertEqual(tr2.error_handled, True)
+    # asyncore.readwrite uses constants in the select module that
+    # are not present in Windows systems (see this thread:
+    # http://mail.python.org/pipermail/python-list/2001-October/109973.html)
+    # These constants should be present as long as poll is available
+
+    if hasattr(select, 'poll'):
+        def test_readwrite(self):
+            # Check that correct methods are called by readwrite()
+
+            class testobj:
+                def __init__(self):
+                    self.read = False
+                    self.write = False
+                    self.expt = False
+
+                def handle_read_event(self):
+                    self.read = True
+
+                def handle_write_event(self):
+                    self.write = True
+
+                def handle_expt_event(self):
+                    self.expt = True
+
+                def handle_error(self):
+                    self.error_handled = True
+
+            for flag in (select.POLLIN, select.POLLPRI):
+                tobj = testobj()
+                self.assertEqual(tobj.read, False)
+                asyncore.readwrite(tobj, flag)
+                self.assertEqual(tobj.read, True)
+
+                # check that ExitNow exceptions in the object handler method
+                # bubbles all the way up through asyncore readwrite call
+                tr1 = exitingdummy()
+                self.assertRaises(asyncore.ExitNow, asyncore.readwrite, tr1, flag)
+
+                # check that an exception other than ExitNow in the object handler
+                # method causes the handle_error method to get called
+                tr2 = crashingdummy()
+                asyncore.readwrite(tr2, flag)
+                self.assertEqual(tr2.error_handled, True)
+
+            tobj = testobj()
+            self.assertEqual(tobj.write, False)
+            asyncore.readwrite(tobj, select.POLLOUT)
+            self.assertEqual(tobj.write, True)
+
+            # check that ExitNow exceptions in the object handler method
+            # bubbles all the way up through asyncore readwrite call
+            tr1 = exitingdummy()
+            self.assertRaises(asyncore.ExitNow, asyncore.readwrite, tr1,
+                              select.POLLOUT)
+
+            # check that an exception other than ExitNow in the object handler
+            # method causes the handle_error method to get called
+            tr2 = crashingdummy()
+            asyncore.readwrite(tr2, select.POLLOUT)
+            self.assertEqual(tr2.error_handled, True)
+
+            for flag in (select.POLLERR, select.POLLHUP, select.POLLNVAL):
+                tobj = testobj()
+                self.assertEqual(tobj.expt, False)
+                asyncore.readwrite(tobj, flag)
+                self.assertEqual(tobj.expt, True)
+
+                # check that ExitNow exceptions in the object handler method
+                # bubbles all the way up through asyncore readwrite calls
+                tr1 = exitingdummy()
+                self.assertRaises(asyncore.ExitNow, asyncore.readwrite, tr1, flag)
+
+                # check that an exception other than ExitNow in the object handler
+                # method causes the handle_error method to get called
+                tr2 = crashingdummy()
+                asyncore.readwrite(tr2, flag)
+                self.assertEqual(tr2.error_handled, True)
 
     def test_closeall(self):
         self.closeall_check(False)