Attempt to smuggle SOCKET through to uv_poll_init_socket on windows.

src/gevent/libuv/_corecffi_build.py

@@ -45,7 +45,12 @@ _cdef = _cdef.replace('#define GEVENT_UV_OS_SOCK_T int', '')
 
 _cdef = _cdef.replace('GEVENT_ST_NLINK_T', st_nlink_type())
 _cdef = _cdef.replace("GEVENT_STRUCT_DONE _;", '...;')
-_cdef = _cdef.replace("GEVENT_UV_OS_SOCK_T", 'int' if not WIN else 'SOCKET')
+# uv_os_sock_t is int on POSIX and SOCKET on Win32, but socket is
+# just another name for handle, which is just another name for 'void*'
+# which we will treat as an 'unsigned long' or 'unsigned long long'
+# since it comes through 'fileno()' where it has been cast as an int.
+_void_pointer_as_integer = 'unsigned long' if system_bits() == 32 else 'unsigned long long'
+_cdef = _cdef.replace("GEVENT_UV_OS_SOCK_T", 'int' if not WIN else _void_pointer_as_integer)
 
 
 setup_py_dir = os.path.abspath(os.path.join(thisdir, '..', '..', '..'))

src/gevent/libuv/_corecffi_cdef.c

@@ -300,10 +300,16 @@ int uv_signal_stop(uv_signal_t *handle);
 // Unix any file descriptor that would be accepted by poll(2) can be
 // used.
 int uv_poll_init(uv_loop_t *loop, uv_poll_t *handle, int fd);
-// Initialize the handle using a socket descriptor. On Unix this is identical to uv_poll_init(). On windows it takes a SOCKET handle.
-// The socket is set to non-blocking mode.
-// On Windows, how to get the SOCKET type defined?
-//int uv_poll_init_socket(uv_loop_t* loop, uv_poll_t* handle, GEVENT_UV_OS_SOCK_T socket);
+
+// Initialize the handle using a socket descriptor. On Unix this is
+// identical to uv_poll_init(). On windows it takes a SOCKET handle;
+// SOCKET handles are another name for HANDLE objects in win32, and
+// those are defined as PVOID, even though they are not actually
+// pointers (they're small integers). CPython and PyPy both return
+// the SOCKET (as cast to an int) from the socket.fileno() method.
+// libuv uses ``uv_os_sock_t`` for this type, which is defined as an
+// int on unix.
+int uv_poll_init_socket(uv_loop_t* loop, uv_poll_t* handle, GEVENT_UV_OS_SOCK_T socket);
 int uv_poll_start(uv_poll_t *handle, int events, uv_poll_cb cb);
 int uv_poll_stop(uv_poll_t *handle);
 

src/gevent/libuv/watcher.py

@@ -3,6 +3,7 @@
 from __future__ import absolute_import, print_function
 
 import functools
+import sys
 import weakref
 
 import gevent.libuv._corecffi as _corecffi # pylint:disable=no-name-in-module,import-error
@@ -28,7 +29,6 @@ def _dbg(*args, **kwargs):
 
 def _pid_dbg(*args, **kwargs):
     import os
-    import sys
     kwargs['file'] = sys.stderr
     print(os.getpid(), *args, **kwargs)
 
@@ -224,6 +224,12 @@ class io(_base.IoMixin, watcher):
     def _watcher_ffi_start(self):
         self._watcher_start(self._watcher, self._events, self._watcher_callback)
 
+    if sys.platform.startswith('win32'):
+        # We can only handle sockets. We smuggle the SOCKET through disguised
+        # as a fileno
+        _watcher_init = watcher._LIB.uv_poll_init_socket
+
+
     class _multiplexwatcher(object):
 
         def __init__(self, events, watcher):