Revert "bpo-36801: Fix waiting in StreamWriter.drain for closing SSL transport (GH-13098)" (GH-13328)

This reverts commit 93aa57ac6594d1cc30d147720fc8a7a4e1ca2d3e.

1 files changed, 8 insertions, 13 deletions

diff --git a/Lib/asyncio/streams.py b/Lib/asyncio/streams.py
index 50badd6b24..d6531f88a7 100644
--- a/Lib/asyncio/streams.py
+++ b/Lib/asyncio/streams.py
@@ -208,9 +208,6 @@ class FlowControlMixin(protocols.Protocol):
         self._drain_waiter = waiter
         await waiter
 
-    def _get_close_waiter(self, stream):
-        raise NotImplementedError
-
 
 class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
     """Helper class to adapt between Protocol and StreamReader.
@@ -268,9 +265,6 @@ class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
             return False
         return True
 
-    def _get_close_waiter(self, stream):
-        return self._closed
-
     def __del__(self):
         # Prevent reports about unhandled exceptions.
         # Better than self._closed._log_traceback = False hack
@@ -326,7 +320,7 @@ class StreamWriter:
         return self._transport.is_closing()
 
     async def wait_closed(self):
-        await self._protocol._get_close_waiter(self)
+        await self._protocol._closed
 
     def get_extra_info(self, name, default=None):
         return self._transport.get_extra_info(name, default)
@@ -344,12 +338,13 @@ class StreamWriter:
             if exc is not None:
                 raise exc
         if self._transport.is_closing():
-            # Wait for protocol.connection_lost() call
-            # Raise connection closing error if any,
-            # ConnectionResetError otherwise
-            fut = self._protocol._get_close_waiter(self)
-            await fut
-            raise ConnectionResetError('Connection lost')
+            # Yield to the event loop so connection_lost() may be
+            # called.  Without this, _drain_helper() would return
+            # immediately, and code that calls
+            #     write(...); await drain()
+            # in a loop would never call connection_lost(), so it
+            # would not see an error when the socket is closed.
+            await sleep(0, loop=self._loop)
         await self._protocol._drain_helper()