gh-113538: Revert "gh-113538: Add asycio.Server.{close,abort}_clients (#114432)" (#116632)

Revert "gh-113538: Add asycio.Server.{close,abort}_clients (#114432)"

Reason: The new test doesn't always pass:
https://github.com/python/cpython/pull/116423#issuecomment-1989425489

This reverts commit 1d0d49a7e8.

Lib/asyncio/base_events.py

@@ -279,9 +279,7 @@ class Server(events.AbstractServer):
                  ssl_handshake_timeout, ssl_shutdown_timeout=None):
         self._loop = loop
         self._sockets = sockets
-        # Weak references so we don't break Transport's ability to
-        # detect abandoned transports
-        self._clients = weakref.WeakSet()
+        self._active_count = 0
         self._waiters = []
         self._protocol_factory = protocol_factory
         self._backlog = backlog
@@ -294,13 +292,14 @@ class Server(events.AbstractServer):
     def __repr__(self):
         return f'<{self.__class__.__name__} sockets={self.sockets!r}>'
 
-    def _attach(self, transport):
+    def _attach(self):
         assert self._sockets is not None
-        self._clients.add(transport)
+        self._active_count += 1
 
-    def _detach(self, transport):
-        self._clients.discard(transport)
-        if len(self._clients) == 0 and self._sockets is None:
+    def _detach(self):
+        assert self._active_count > 0
+        self._active_count -= 1
+        if self._active_count == 0 and self._sockets is None:
             self._wakeup()
 
     def _wakeup(self):
@@ -349,17 +348,9 @@ class Server(events.AbstractServer):
             self._serving_forever_fut.cancel()
             self._serving_forever_fut = None
 
-        if len(self._clients) == 0:
+        if self._active_count == 0:
             self._wakeup()
 
-    def close_clients(self):
-        for transport in self._clients.copy():
-            transport.close()
-
-    def abort_clients(self):
-        for transport in self._clients.copy():
-            transport.abort()
-
     async def start_serving(self):
         self._start_serving()
         # Skip one loop iteration so that all 'loop.add_reader'

Lib/asyncio/events.py

@@ -175,14 +175,6 @@ class AbstractServer:
         """Stop serving.  This leaves existing connections open."""
         raise NotImplementedError
 
-    def close_clients(self):
-        """Close all active connections."""
-        raise NotImplementedError
-
-    def abort_clients(self):
-        """Close all active connections immediately."""
-        raise NotImplementedError
-
     def get_loop(self):
         """Get the event loop the Server object is attached to."""
         raise NotImplementedError

Lib/asyncio/proactor_events.py

@@ -63,7 +63,7 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
         self._called_connection_lost = False
         self._eof_written = False
         if self._server is not None:
-            self._server._attach(self)
+            self._server._attach()
         self._loop.call_soon(self._protocol.connection_made, self)
         if waiter is not None:
             # only wake up the waiter when connection_made() has been called
@@ -167,7 +167,7 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
             self._sock = None
             server = self._server
             if server is not None:
-                server._detach(self)
+                server._detach()
                 self._server = None
             self._called_connection_lost = True
 

Lib/asyncio/selector_events.py

@@ -791,7 +791,7 @@ class _SelectorTransport(transports._FlowControlMixin,
         self._paused = False  # Set when pause_reading() called
 
         if self._server is not None:
-            self._server._attach(self)
+            self._server._attach()
         loop._transports[self._sock_fd] = self
 
     def __repr__(self):
@@ -868,8 +868,6 @@ class _SelectorTransport(transports._FlowControlMixin,
         if self._sock is not None:
             _warn(f"unclosed transport {self!r}", ResourceWarning, source=self)
             self._sock.close()
-            if self._server is not None:
-                self._server._detach(self)
 
     def _fatal_error(self, exc, message='Fatal error on transport'):
         # Should be called from exception handler only.
@@ -908,7 +906,7 @@ class _SelectorTransport(transports._FlowControlMixin,
             self._loop = None
             server = self._server
             if server is not None:
-                server._detach(self)
+                server._detach()
                 self._server = None
 
     def get_write_buffer_size(self):