io: introduce qio_channel_create_socket_watch

Sockets are not in the same namespace as file descriptors on Windows.
As an initial step, introduce separate APIs for file descriptor and
socket watches.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/io/channel-watch.h

@@ -39,7 +39,7 @@
  * monitor the file descriptor @fd for the
  * I/O conditions in @condition. This is able
  * monitor block devices, character devices,
- * sockets, pipes but not plain files.
+ * pipes but not plain files or, on Win32, sockets.
  *
  * Returns: the new main loop source
  */
@@ -47,6 +47,24 @@ GSource *qio_channel_create_fd_watch(QIOChannel *ioc,
                                      int fd,
                                      GIOCondition condition);
 
+/**
+ * qio_channel_create_socket_watch:
+ * @ioc: the channel object
+ * @fd: the file descriptor
+ * @condition: the I/O condition
+ *
+ * Create a new main loop source that is able to
+ * monitor the file descriptor @fd for the
+ * I/O conditions in @condition. This is equivalent
+ * to qio_channel_create_fd_watch on POSIX systems
+ * but not on Windows.
+ *
+ * Returns: the new main loop source
+ */
+GSource *qio_channel_create_socket_watch(QIOChannel *ioc,
+                                         int fd,
+                                         GIOCondition condition);
+
 /**
  * qio_channel_create_fd_pair_watch:
  * @ioc: the channel object

io/channel-socket.c

@@ -714,7 +714,7 @@ static GSource *qio_channel_socket_create_watch(QIOChannel *ioc,
                                                 GIOCondition condition)
 {
     QIOChannelSocket *sioc = QIO_CHANNEL_SOCKET(ioc);
-    return qio_channel_create_fd_watch(ioc,
+    return qio_channel_create_socket_watch(ioc,
                                            sioc->fd,
                                            condition);
 }

io/channel-watch.c

@@ -172,6 +172,21 @@ GSource *qio_channel_create_fd_watch(QIOChannel *ioc,
     return source;
 }
 
+#ifdef CONFIG_WIN32
+GSource *qio_channel_create_socket_watch(QIOChannel *ioc,
+                                         int socket,
+                                         GIOCondition condition)
+{
+    abort();
+}
+#else
+GSource *qio_channel_create_socket_watch(QIOChannel *ioc,
+                                         int socket,
+                                         GIOCondition condition)
+{
+    return qio_channel_create_fd_watch(ioc, socket, condition);
+}
+#endif
 
 GSource *qio_channel_create_fd_pair_watch(QIOChannel *ioc,
                                           int fdread,