[PATCH] present: Block for wait_fence in present_execute

[Keith Packard]

Pend presentation until wait_fence is also triggered by having the
SyncFence trigger invoke present_execute once triggered.

Signed-off-by: Keith Packard <keithp at keithp.com>
---

The present code wasn't waiting for the 'wait_fence' to be triggered
before performing the presentation operation; this patch pends the
request using the Sync trigger callback mechanism.

 present/present.c       | 34 +++++++++++++++++++++++++++++++++-
 present/present_event.c |  2 --
 present/present_fence.c | 29 ++++++++++++++++++++++++++++-
 present/present_priv.h  | 15 +++++++++++++++
 4 files changed, 76 insertions(+), 4 deletions(-)

diff --git a/present/present.c b/present/present.c
index 67d7f6e..16dc381 100644
--- a/present/present.c
+++ b/present/present.c
@@ -453,6 +453,26 @@ present_check_flip_window (WindowPtr window)
 }
 
 /*
+ * Called when the wait fence is triggered; just gets the current msc/ust and
+ * calls present_execute again. That will re-check the fence and pend the
+ * request again if it's still not actually ready
+ */
+static void
+present_wait_fence_triggered(void *param)
+{
+    present_vblank_ptr  vblank = param;
+    WindowPtr           window = vblank->window;
+    uint64_t            ust = 0, crtc_msc = 0;
+
+    if (window) {
+        present_window_priv_ptr     window_priv = present_get_window_priv(window, TRUE);
+        if (window_priv)
+            (void) present_get_ust_msc(window, window_priv->crtc, &ust, &crtc_msc);
+    }
+    present_execute(vblank, ust, crtc_msc);
+}
+
+/*
  * Once the required MSC has been reached, execute the pending request.
  *
  * For requests to actually present something, either blt contents to
@@ -469,7 +489,10 @@ present_execute(present_vblank_ptr vblank, uint64_t ust, uint64_t crtc_msc)
     present_screen_priv_ptr     screen_priv = present_screen_priv(window->drawable.pScreen);
 
     if (vblank->wait_fence) {
-        /* XXX check fence, queue if not ready */
+        if (!present_fence_check_triggered(vblank->wait_fence)) {
+            present_fence_set_callback(vblank->wait_fence, present_wait_fence_triggered, vblank);
+            return;
+        }
     }
 
     xorg_list_del(&vblank->event_queue);
@@ -654,6 +677,12 @@ present_pixmap(WindowPtr window,
             target_msc--;
     }
 
+    if (wait_fence) {
+        vblank->wait_fence = present_fence_create(wait_fence);
+        if (!vblank->wait_fence)
+            goto no_mem;
+    }
+
     if (idle_fence) {
         vblank->idle_fence = present_fence_create(idle_fence);
         if (!vblank->idle_fence)
@@ -764,6 +793,9 @@ present_vblank_destroy(present_vblank_ptr vblank)
     if (vblank->update)
         RegionDestroy(vblank->update);
 
+    if (vblank->wait_fence)
+        present_fence_destroy(vblank->wait_fence);
+
     if (vblank->idle_fence)
         present_fence_destroy(vblank->idle_fence);
 
diff --git a/present/present_event.c b/present/present_event.c
index a30bc82..a8f7176 100644
--- a/present/present_event.c
+++ b/present/present_event.c
@@ -26,8 +26,6 @@
 
 #include "present_priv.h"
 
-#include "present_priv.h"
-
 RESTYPE present_event_type;
 
 static int
diff --git a/present/present_fence.c b/present/present_fence.c
index db5efca..e09657d 100644
--- a/present/present_fence.c
+++ b/present/present_fence.c
@@ -37,6 +37,8 @@
 struct present_fence {
     SyncTrigger         trigger;
     SyncFence           *fence;
+    void                (*callback)(void *param);
+    void                *param;
 };
 
 /*
@@ -45,12 +47,18 @@ struct present_fence {
 static Bool
 present_fence_sync_check_trigger(SyncTrigger *trigger, XSyncValue oldval)
 {
-    return FALSE;
+    struct present_fence        *present_fence = container_of(trigger, struct present_fence, trigger);
+
+    return present_fence->callback != NULL;
 }
 
 static void
 present_fence_sync_trigger_fired(SyncTrigger *trigger)
 {
+    struct present_fence        *present_fence = container_of(trigger, struct present_fence, trigger);
+
+    if (present_fence->callback)
+        (*present_fence->callback)(present_fence->param);
 }
 
 static void
@@ -101,6 +109,25 @@ present_fence_set_triggered(struct present_fence *present_fence)
             (*present_fence->fence->funcs.SetTriggered) (present_fence->fence);
 }
 
+Bool
+present_fence_check_triggered(struct present_fence *present_fence)
+{
+    if (!present_fence)
+        return TRUE;
+    if (!present_fence->fence)
+        return TRUE;
+    return (*present_fence->fence->funcs.CheckTriggered)(present_fence->fence);
+}
+
+void
+present_fence_set_callback(struct present_fence *present_fence,
+                           void (*callback) (void *param),
+                           void *param)
+{
+    present_fence->callback = callback;
+    present_fence->param = param;
+}
+
 XID
 present_fence_id(struct present_fence *present_fence)
 {
diff --git a/present/present_priv.h b/present/present_priv.h
index 40c88dd..500c7c2 100644
--- a/present/present_priv.h
+++ b/present/present_priv.h
@@ -249,6 +249,14 @@ present_fence_destroy(struct present_fence *present_fence);
 void
 present_fence_set_triggered(struct present_fence *present_fence);
 
+Bool
+present_fence_check_triggered(struct present_fence *present_fence);
+
+void
+present_fence_set_callback(struct present_fence *present_fence,
+                           void (*callback)(void *param),
+                           void *param);
+
 XID
 present_fence_id(struct present_fence *present_fence);
 
@@ -271,6 +279,13 @@ void
 present_destroy_notifies(present_notify_ptr notifies, int num_notifies);
 
 /*
+ * present_redirect.c
+ */
+
+WindowPtr
+present_redirect(ClientPtr client, WindowPtr target);
+
+/*
  * present_request.c
  */
 int
-- 
1.8.4.2