[PATCH 3/3] sync: Record the associated Drawable for a shm/fd fence

[Chris Wilson]

Alongside DRI3, SHM fences are used to serialise changes to the Pixmap
shared between the client and the xserver. By recording the associated
Drawable for a particular fence, the driver can reduce the amount of
work required for serialisation (i.e. it only has to serialise access to
one Pixmap, not all).

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 miext/sync/misyncfd.c  |  2 +-
 miext/sync/misyncfd.h  |  3 ++-
 miext/sync/misyncshm.c | 11 ++++++++++-
 miext/sync/misyncshm.h |  4 ++++
 4 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/miext/sync/misyncfd.c b/miext/sync/misyncfd.c
index 93ff85f..b5fe92d 100644
--- a/miext/sync/misyncfd.c
+++ b/miext/sync/misyncfd.c
@@ -52,7 +52,7 @@ miSyncInitFenceFromFD(DrawablePtr pDraw, SyncFence *pFence, int fd, BOOL initial
     if (!priv)
         return BadMatch;
 
-    return (*priv->funcs.CreateFenceFromFd)(pDraw->pScreen, pFence, fd, initially_triggered);
+    return (*priv->funcs.CreateFenceFromFd)(pDraw->pScreen, pFence, pDraw, fd, initially_triggered);
 }
 
 int
diff --git a/miext/sync/misyncfd.h b/miext/sync/misyncfd.h
index c1d05f9..2cb33dc 100644
--- a/miext/sync/misyncfd.h
+++ b/miext/sync/misyncfd.h
@@ -25,11 +25,12 @@
 
 typedef int (*SyncScreenCreateFenceFromFdFunc) (ScreenPtr screen,
                                                 SyncFence *fence,
+                                                DrawablePtr drawable,
                                                 int fd,
                                                 Bool initially_triggered);
 
 typedef int (*SyncScreenGetFenceFdFunc) (ScreenPtr screen,
-                                      SyncFence *fence);
+                                         SyncFence *fence);
 
 #define SYNC_FD_SCREEN_FUNCS_VERSION    1
 
diff --git a/miext/sync/misyncshm.c b/miext/sync/misyncshm.c
index 4d11b57..f954e1e 100644
--- a/miext/sync/misyncshm.c
+++ b/miext/sync/misyncshm.c
@@ -38,6 +38,7 @@
 static DevPrivateKeyRec syncShmFencePrivateKey;
 
 typedef struct _SyncShmFencePrivate {
+    DrawablePtr         pDrawable;
     struct xshmfence    *fence;
     int                 fd;
 } SyncShmFencePrivateRec, *SyncShmFencePrivatePtr;
@@ -121,12 +122,14 @@ miSyncShmScreenDestroyFence(ScreenPtr pScreen, SyncFence * pFence)
 }
 
 static int
-miSyncShmCreateFenceFromFd(ScreenPtr pScreen, SyncFence *pFence, int fd, Bool initially_triggered)
+miSyncShmCreateFenceFromFd(ScreenPtr pScreen, SyncFence *pFence, DrawablePtr draw, int fd, Bool initially_triggered)
 {
     SyncShmFencePrivatePtr      pPriv = SYNC_FENCE_PRIV(pFence);
 
     miSyncInitFence(pScreen, pFence, initially_triggered);
 
+    pPriv->pDrawable = draw;
+
     fd = os_move_fd(fd);
     pPriv->fence = xshmfence_map_shm(fd);
     if (pPriv->fence) {
@@ -184,3 +187,9 @@ _X_EXPORT Bool miSyncShmScreenInit(ScreenPtr pScreen)
     return TRUE;
 }
 
+_X_EXPORT DrawablePtr
+miSyncShmFenceGetDrawable(SyncFence *pFence)
+{
+    SyncShmFencePrivatePtr pPriv = SYNC_FENCE_PRIV(pFence);
+    return pPriv ? pPriv->pDrawable : NULL;
+}
diff --git a/miext/sync/misyncshm.h b/miext/sync/misyncshm.h
index 23c001a..2484970 100644
--- a/miext/sync/misyncshm.h
+++ b/miext/sync/misyncshm.h
@@ -23,6 +23,10 @@
 #ifndef _MISYNCSHM_H_
 #define _MISYNCSHM_H_
 
+#include <misync.h>
+
 extern _X_EXPORT Bool miSyncShmScreenInit(ScreenPtr pScreen);
 
+extern _X_EXPORT DrawablePtr miSyncShmFenceGetDrawable(SyncFence *pFence);
+
 #endif /* _MISYNCSHM_H_ */
-- 
2.0.0.rc2