[PATCH] present: Leave vblank on window list until flip complete

[Keith Packard]

If the window is destroyed, then we've got cleanup work to do, even if
the vblank has already been executed -- we need to clear the window
pointer so that we don't try to deliver events to it.

Leaving it on the window list meant that when walking that list, we
need to know whether the vblank is waiting to be executed or waiting
for the flip to complete, so a new 'queued' flag was added to the
vblank to distinguish between the two states.

Signed-off-by: Keith Packard <keithp at keithp.com>
---
 present/present.c      | 14 +++++++++-----
 present/present_priv.h |  7 ++++---
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/present/present.c b/present/present.c
index f9eef6b..bedb9f2 100644
--- a/present/present.c
+++ b/present/present.c
@@ -348,6 +348,8 @@ present_flip_notify(present_vblank_ptr vblank, uint64_t ust, uint64_t crtc_msc)
 
     present_flip_idle(screen);
 
+    xorg_list_del(&vblank->event_queue);
+
     /* Transfer reference for pixmap and fence from vblank to screen_priv */
     screen_priv->flip_crtc = vblank->crtc;
     screen_priv->flip_window = vblank->window;
@@ -378,14 +380,12 @@ present_event_notify(uint64_t event_id, uint64_t ust, uint64_t msc)
     DebugPresent(("\te %lld ust %lld msc %lld\n", event_id, ust, msc));
     xorg_list_for_each_entry_safe(vblank, tmp, &present_exec_queue, event_queue) {
         if (vblank->event_id == event_id) {
-            xorg_list_del(&vblank->event_queue);
             present_execute(vblank, ust, msc);
             return;
         }
     }
     xorg_list_for_each_entry_safe(vblank, tmp, &present_flip_queue, event_queue) {
         if (vblank->event_id == event_id) {
-            xorg_list_del(&vblank->event_queue);
             present_flip_notify(vblank, ust, msc);
             return;
         }
@@ -447,7 +447,7 @@ present_check_flip_window (WindowPtr window)
 
     /* Now check any queued vblanks */
     xorg_list_for_each_entry(vblank, &window_priv->vblank, window_list) {
-        if (vblank->flip && !present_check_flip(vblank->crtc, window, vblank->pixmap, FALSE, NULL, 0, 0))
+        if (vblank->queued && vblank->flip && !present_check_flip(vblank->crtc, window, vblank->pixmap, FALSE, NULL, 0, 0))
             vblank->flip = FALSE;
     }
 }
@@ -496,16 +496,17 @@ present_execute(present_vblank_ptr vblank, uint64_t ust, uint64_t crtc_msc)
     }
 
     xorg_list_del(&vblank->event_queue);
+    vblank->queued = FALSE;
+
     if (vblank->pixmap && vblank->window) {
 
         if (vblank->flip && screen_priv->flip_pending == NULL && !screen_priv->unflip_event_id) {
 
             DebugPresent(("\tf %p %8lld: %08lx -> %08lx\n", vblank, crtc_msc, vblank->pixmap->drawable.id, vblank->window->drawable.id));
-            /* Prepare to flip by removing from the window/screen lists
+            /* Prepare to flip by placing it in the flip queue and
              * and sticking it into the flip_pending field
              */
             screen_priv->flip_pending = vblank;
-            xorg_list_del(&vblank->window_list);
 
             xorg_list_add(&vblank->event_queue, &present_flip_queue);
             /* Try to flip
@@ -696,10 +697,12 @@ present_pixmap(WindowPtr window,
                       target_crtc));
 
     xorg_list_add(&vblank->event_queue, &present_exec_queue);
+    vblank->queued = TRUE;
     if (target_msc >= crtc_msc) {
         ret = present_queue_vblank(screen, target_crtc, vblank->event_id, target_msc);
         if (ret != Success) {
             xorg_list_del(&vblank->event_queue);
+            vblank->queued = FALSE;
             goto failure;
         }
     } else
@@ -732,6 +735,7 @@ present_abort_vblank(ScreenPtr screen, RRCrtcPtr crtc, uint64_t event_id, uint64
     xorg_list_for_each_entry_safe(vblank, tmp, &present_exec_queue, event_queue) {
         if (vblank->event_id == event_id) {
             xorg_list_del(&vblank->event_queue);
+            vblank->queued = FALSE;
             return;
         }
     }
diff --git a/present/present_priv.h b/present/present_priv.h
index 500c7c2..8d3e007 100644
--- a/present/present_priv.h
+++ b/present/present_priv.h
@@ -69,9 +69,10 @@ struct present_vblank {
     present_fence_ptr   wait_fence;
     present_notify_ptr  notifies;
     int                 num_notifies;
-    Bool                flip;
-    Bool                sync_flip;
-    Bool                abort_flip;
+    Bool                queued;         /* on present_exec_queue */
+    Bool                flip;           /* planning on using flip */
+    Bool                sync_flip;      /* do flip synchronous to vblank */
+    Bool                abort_flip;     /* aborting this flip */
 };
 
 typedef struct present_screen_priv {
-- 
1.8.4.4