[cogl/cogl-1.16] poll: Add _cogl_poll_renderer_modify_fd

[Neil Roberts <nroberts src gnome org>]

commit 651a2775b534962430c51809aab55059cb339a08
Author: Neil Roberts <neil linux intel com>
Date:   Fri Jun 28 12:15:26 2013 +0100

    poll: Add _cogl_poll_renderer_modify_fd
    
    _cogl_poll_rendererer_modify_fd can be used internally to modify the
    event mask on an FD to be polled. This will be used in the Wayland
    backend to start blocking on write whenever flushing the display fills
    the socket's buffer. Modifying the FD's events causes the poll age to
    increase.
    
    Reviewed-by: Robert Bragg <robert linux intel com>
    
    (cherry picked from commit 8bc0df53ee508687b87e547c1cbac5e8d7d5fc80)

 cogl/cogl-poll-private.h |    5 +++++
 cogl/cogl-poll.c         |   19 +++++++++++++++++++
 2 files changed, 24 insertions(+), 0 deletions(-)
---
diff --git a/cogl/cogl-poll-private.h b/cogl/cogl-poll-private.h
index 3dfaa2b..2a24128 100644
--- a/cogl/cogl-poll-private.h
+++ b/cogl/cogl-poll-private.h
@@ -43,6 +43,11 @@ _cogl_poll_renderer_add_fd (CoglRenderer *renderer,
                             CoglPollDispatchCallback dispatch,
                             void *user_data);
 
+void
+_cogl_poll_renderer_modify_fd (CoglRenderer *renderer,
+                               int fd,
+                               CoglPollFDEvent events);
+
 typedef struct _CoglPollSource CoglPollSource;
 
 CoglPollSource *
diff --git a/cogl/cogl-poll.c b/cogl/cogl-poll.c
index 10d1560..cb62327 100644
--- a/cogl/cogl-poll.c
+++ b/cogl/cogl-poll.c
@@ -152,6 +152,25 @@ _cogl_poll_renderer_remove_fd (CoglRenderer *renderer, int fd)
 }
 
 void
+_cogl_poll_renderer_modify_fd (CoglRenderer *renderer,
+                               int fd,
+                               CoglPollFDEvent events)
+{
+  int fd_index = find_pollfd (renderer, fd);
+
+  if (fd_index == -1)
+    g_warn_if_reached ();
+  else
+    {
+      CoglPollFD *pollfd =
+        &g_array_index (renderer->poll_sources, CoglPollFD, fd_index);
+
+      pollfd->events = events;
+      renderer->poll_fds_age++;
+    }
+}
+
+void
 _cogl_poll_renderer_add_fd (CoglRenderer *renderer,
                             int fd,
                             CoglPollFDEvent events,