dri2: Add reference counting to DRI2

Asynchronous request like SwapBuffers can still reference Drawable after
the Drawable has been freed. DRI2Drawable cleanup should be delayed
until all asynchronous operations have completed.

Reference counted DRI2Drawable helps to keep DRI2Drawable around until
all request on it has completed.

Signed-off-by: Pauli Nieminen <ext-pauli.nieminen@nokia.com>

1 files changed, 30 insertions, 2 deletions

diff --git a/hw/xfree86/dri2/dri2.c b/hw/xfree86/dri2/dri2.c
index f97f60ea0..9f262aeef 100644
--- a/hw/xfree86/dri2/dri2.c
+++ b/hw/xfree86/dri2/dri2.c
@@ -83,6 +83,7 @@ typedef struct _DRI2Drawable {
     CARD64		 last_swap_ust; /* ust at completion of most recent swap */
     int			 swap_limit; /* for N-buffering */
     unsigned long	 serialNumber;
+    unsigned		 refcnt;
 } DRI2DrawableRec;
 
 typedef struct _DRI2Screen {
@@ -190,12 +191,14 @@ DRI2AllocateDrawable(DrawablePtr pDraw)
     pPriv->last_swap_ust = 0;
     list_init(&pPriv->reference_list);
     pPriv->serialNumber = DRI2DrawableSerial(pDraw);
+    pPriv->refcnt = 0;
 
     if (pDraw->type == DRAWABLE_WINDOW) {
 	pWin = (WindowPtr) pDraw;
 	dixSetPrivate(&pWin->devPrivates, dri2WindowPrivateKey, pPriv);
     } else {
 	pPixmap = (PixmapPtr) pDraw;
+	pPixmap->refcnt++;
 	dixSetPrivate(&pPixmap->devPrivates, dri2PixmapPrivateKey, pPriv);
     }
 
@@ -251,6 +254,8 @@ DRI2AddDrawableRef(DRI2DrawablePtr pPriv, XID id, XID dri2_id,
 	if (!AddResource(id, dri2DrawableRes, pPriv))
 	    return BadAlloc;
 
+    pPriv->refcnt++;
+
     ref->id = id;
     ref->dri2_id = dri2_id; 
     ref->invalidate = invalidate;
@@ -309,6 +314,7 @@ static int DRI2DrawableGone(pointer p, XID id)
 
     list_for_each_entry_safe(ref, next, &pPriv->reference_list, link) {
 	if (ref->dri2_id == id) {
+	    pPriv->refcnt--;
 	    list_del(&ref->link);
 	    /* If this was the last ref under this X drawable XID,
 	     * unregister the X drawable resource. */
@@ -319,13 +325,15 @@ static int DRI2DrawableGone(pointer p, XID id)
 	}
 
 	if (ref->id == id) {
+	    pPriv->refcnt--;
 	    list_del(&ref->link);
 	    FreeResourceByType(ref->dri2_id, dri2DrawableRes, TRUE);
 	    free(ref);
 	}
     }
 
-    if (!list_is_empty(&pPriv->reference_list))
+
+    if (pPriv->refcnt > 0)
 	return Success;
 
     pDraw = pPriv->drawable;
@@ -336,6 +344,7 @@ static int DRI2DrawableGone(pointer p, XID id)
     } else {
 	pPixmap = (PixmapPtr) pDraw;
 	dixSetPrivate(&pPixmap->devPrivates, dri2PixmapPrivateKey, NULL);
+	pDraw->pScreen->DestroyPixmap(pPixmap);
     }
 
     if (pPriv->buffers != NULL) {
@@ -696,6 +705,13 @@ DRI2WaitMSCComplete(int client_index, DRI2DrawablePtr pPriv, int frame,
 {
     ClientPtr client = clients[client_index];
 
+    pPriv->refcnt--;
+
+    if (pPriv->refcnt == 0) {
+	DRI2DrawableGone(pPriv, 0);
+	return;
+    }
+
     ProcDRI2WaitMSCReply(client, ((CARD64)tv_sec * 1000000) + tv_usec,
 			 frame, pPriv->swap_count);
 
@@ -753,7 +769,12 @@ DRI2SwapComplete(int client_index, DRI2DrawablePtr pPriv, int frame,
 
     pPriv->swapsPending--;
     pPriv->swap_count++;
+    pPriv->refcnt--;
 
+    if (pPriv->refcnt == 0) {
+	DRI2DrawableGone(pPriv, 0);
+	return;
+    }
 
     if (pDraw) {
 	BoxRec          box;
@@ -837,6 +858,7 @@ DRI2SwapBuffers(ClientPtr client, DRI2DrawablePtr pPriv, CARD64 target_msc,
 	RegionInit(&region, &box, 0);
 
 	pPriv->swapsPending++;
+	pPriv->refcnt++;
 
 	(*ds->CopyRegion)(pDraw, &region, pDestBuffer, pSrcBuffer);
 	DRI2SwapComplete(client->index, pPriv, target_msc, 0, 0, DRI2_BLIT_COMPLETE,
@@ -878,10 +900,12 @@ DRI2SwapBuffers(ClientPtr client, DRI2DrawablePtr pPriv, CARD64 target_msc,
     }
 
     pPriv->swapsPending++;
+    pPriv->refcnt++;
     ret = (*ds->ScheduleSwap)(client, pDraw, pDestBuffer, pSrcBuffer,
 			      swap_target, divisor, remainder, func, data);
     if (!ret) {
 	pPriv->swapsPending--; /* didn't schedule */
+	pPriv->refcnt--;
         xf86DrvMsg(pScreen->myNum, X_ERROR,
 		   "[DRI2] %s: driver failed to schedule swap\n", __func__);
 	return BadDrawable;
@@ -952,6 +976,8 @@ DRI2WaitMSC(ClientPtr client, DRI2DrawablePtr pPriv, CARD64 target_msc,
     if (pDraw == NULL)
 	return BadDrawable;
 
+    pPriv->refcnt++;
+
     /* Old DDX just completes immediately */
     if (!ds->ScheduleWaitMSC) {
 	DRI2WaitMSCComplete(client->index, pPriv, target_msc, 0, 0);
@@ -960,8 +986,10 @@ DRI2WaitMSC(ClientPtr client, DRI2DrawablePtr pPriv, CARD64 target_msc,
     }
 
     ret = (*ds->ScheduleWaitMSC)(client, pDraw, target_msc, divisor, remainder);
-    if (!ret)
+    if (!ret) {
+	pPriv->refcnt--;
 	return BadDrawable;
+    }
 
     return Success;
 }