bpo-27456: Ensure TCP_NODELAY is set on linux (#4231)

1 files changed, 22 insertions, 21 deletions

diff --git a/Lib/asyncio/base_events.py b/Lib/asyncio/base_events.py
index 80d2b69..398497d 100644
--- a/Lib/asyncio/base_events.py
+++ b/Lib/asyncio/base_events.py
@@ -82,18 +82,24 @@ def _set_reuseport(sock):
                              'SO_REUSEPORT defined but not implemented.')
 
 
-def _is_stream_socket(sock):
-    # Linux's socket.type is a bitmask that can include extra info
-    # about socket, therefore we can't do simple
-    # `sock_type == socket.SOCK_STREAM`.
-    return (sock.type & socket.SOCK_STREAM) == socket.SOCK_STREAM
+def _is_stream_socket(sock_type):
+    if hasattr(socket, 'SOCK_NONBLOCK'):
+        # Linux's socket.type is a bitmask that can include extra info
+        # about socket (like SOCK_NONBLOCK bit), therefore we can't do simple
+        # `sock_type == socket.SOCK_STREAM`, see
+        # https://github.com/torvalds/linux/blob/v4.13/include/linux/net.h#L77
+        # for more details.
+        return (sock_type & 0xF) == socket.SOCK_STREAM
+    else:
+        return sock_type == socket.SOCK_STREAM
 
 
-def _is_dgram_socket(sock):
-    # Linux's socket.type is a bitmask that can include extra info
-    # about socket, therefore we can't do simple
-    # `sock_type == socket.SOCK_DGRAM`.
-    return (sock.type & socket.SOCK_DGRAM) == socket.SOCK_DGRAM
+def _is_dgram_socket(sock_type):
+    if hasattr(socket, 'SOCK_NONBLOCK'):
+        # See the comment in `_is_stream_socket`.
+        return (sock_type & 0xF) == socket.SOCK_DGRAM
+    else:
+        return sock_type == socket.SOCK_DGRAM
 
 
 def _ipaddr_info(host, port, family, type, proto):
@@ -106,14 +112,9 @@ def _ipaddr_info(host, port, family, type, proto):
             host is None:
         return None
 
-    if type == socket.SOCK_STREAM:
-        # Linux only:
-        #    getaddrinfo() can raise when socket.type is a bit mask.
-        #    So if socket.type is a bit mask of SOCK_STREAM, and say
-        #    SOCK_NONBLOCK, we simply return None, which will trigger
-        #    a call to getaddrinfo() letting it process this request.
+    if _is_stream_socket(type):
         proto = socket.IPPROTO_TCP
-    elif type == socket.SOCK_DGRAM:
+    elif _is_dgram_socket(type):
         proto = socket.IPPROTO_UDP
     else:
         return None
@@ -758,7 +759,7 @@ class BaseEventLoop(events.AbstractEventLoop):
             if sock is None:
                 raise ValueError(
                     'host and port was not specified and no sock specified')
-            if not _is_stream_socket(sock):
+            if not _is_stream_socket(sock.type):
                 # We allow AF_INET, AF_INET6, AF_UNIX as long as they
                 # are SOCK_STREAM.
                 # We support passing AF_UNIX sockets even though we have
@@ -808,7 +809,7 @@ class BaseEventLoop(events.AbstractEventLoop):
                                        allow_broadcast=None, sock=None):
         """Create datagram connection."""
         if sock is not None:
-            if not _is_dgram_socket(sock):
+            if not _is_dgram_socket(sock.type):
                 raise ValueError(
                     f'A UDP Socket was expected, got {sock!r}')
             if (local_addr or remote_addr or
@@ -1036,7 +1037,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         else:
             if sock is None:
                 raise ValueError('Neither host/port nor sock were specified')
-            if not _is_stream_socket(sock):
+            if not _is_stream_socket(sock.type):
                 raise ValueError(f'A Stream Socket was expected, got {sock!r}')
             sockets = [sock]
 
@@ -1059,7 +1060,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         This method is a coroutine.  When completed, the coroutine
         returns a (transport, protocol) pair.
         """
-        if not _is_stream_socket(sock):
+        if not _is_stream_socket(sock.type):
             raise ValueError(f'A Stream Socket was expected, got {sock!r}')
 
         transport, protocol = await self._create_connection_transport(