[idd] scheduler: pipeline timing owner deliveries

Allow the timing owner to keep one delivery pending on each independent
owner queue instead of waiting for the client to release every frame.

Count shared fallback deliveries against the same two-frame limit and
match republished frames across all active lanes. This hides the client
release round trip without allowing a third delivery for the owner.

idd/LGIdd/CIndirectDeviceContext.cpp

@@ -1499,6 +1499,7 @@ bool CIndirectDeviceContext::PostSharedOwnerFrame(unsigned frameIndex,
   const CFrameScheduler::Schedule& schedule)
 {
   if (frameIndex >= LGMP_Q_FRAME_BUFFER_LEN || !schedule.clientID ||
+      m_frameDelivery[frameIndex].sharedOwnerPending ||
       lgmpHostQueuePending(m_frameQueue) >= LGMP_Q_FRAME_LEN)
     return false;
 
@@ -1591,31 +1592,43 @@ int CIndirectDeviceContext::FindAvailableOwnerQueue(
   return -1;
 }
 
-int CIndirectDeviceContext::FindOwnerDelivery(uint32_t clientID) const
-{
-  for (unsigned i = 0; i < LGMP_Q_FRAME_LEN; ++i)
-    if (m_ownerDelivery[i].active &&
-        m_ownerDelivery[i].clientID == clientID)
-      return static_cast<int>(i);
-
-  return -1;
-}
-
-int CIndirectDeviceContext::FindSharedOwnerDelivery(
+unsigned CIndirectDeviceContext::CountOwnerDeliveries(
   uint32_t clientID) const
 {
-  for (unsigned i = 0; i < LGMP_Q_FRAME_BUFFER_LEN; ++i)
-    if (m_frameDelivery[i].sharedOwnerPending &&
-        m_frameDelivery[i].sharedOwnerClientID == clientID)
-      return static_cast<int>(i);
+  unsigned count = 0;
+  for (const OwnerDelivery& delivery : m_ownerDelivery)
+    if (delivery.active && delivery.clientID == clientID)
+      ++count;
 
-  return -1;
+  for (const FrameDelivery& delivery : m_frameDelivery)
+    if (delivery.sharedOwnerPending &&
+        delivery.sharedOwnerClientID == clientID)
+      ++count;
+
+  return count;
 }
 
-bool CIndirectDeviceContext::HasOwnerDelivery(uint32_t clientID) const
+bool CIndirectDeviceContext::HasMatchingOwnerDelivery(
+  uint32_t clientID, unsigned frameIndex, uint64_t token) const
 {
-  return FindOwnerDelivery(clientID) >= 0 ||
-    FindSharedOwnerDelivery(clientID) >= 0;
+  for (const OwnerDelivery& delivery : m_ownerDelivery)
+    if (delivery.active                    &&
+        delivery.clientID   == clientID    &&
+        delivery.frameIndex == frameIndex  &&
+        delivery.token      == token)
+      return true;
+
+  for (unsigned i = 0; i < LGMP_Q_FRAME_BUFFER_LEN; ++i)
+  {
+    const FrameDelivery& delivery = m_frameDelivery[i];
+    if (i == frameIndex                              &&
+        delivery.sharedOwnerPending                 &&
+        delivery.sharedOwnerClientID == clientID    &&
+        delivery.sharedOwnerToken    == token)
+      return true;
+  }
+
+  return false;
 }
 
 int CIndirectDeviceContext::FindAvailableFrameBuffer() const
@@ -1668,8 +1681,12 @@ bool CIndirectDeviceContext::FrameBufferAvailable(
 
   AcquireSRWLockShared(&m_framePublishLock);
   bool deliveryAvailable;
+  // Pipeline one frame through each independent owner lane. Count the shared
+  // fallback against the same limit so it cannot become a third delivery for
+  // the same owner.
   if (schedule.clientID)
-    deliveryAvailable = !HasOwnerDelivery(schedule.clientID) &&
+    deliveryAvailable =
+      CountOwnerDeliveries(schedule.clientID) < LGMP_Q_FRAME_LEN &&
       (FindAvailableOwnerQueue(0) >= 0 ||
        lgmpHostQueuePending(m_frameQueue) < LGMP_Q_FRAME_LEN);
   else
@@ -1936,7 +1953,7 @@ bool CIndirectDeviceContext::PublishFrameBuffer(unsigned frameIndex,
   bool published     = false;
   if (schedule.clientID)
   {
-    if (HasOwnerDelivery(schedule.clientID))
+    if (CountOwnerDeliveries(schedule.clientID) >= LGMP_Q_FRAME_LEN)
       status = LGMP_ERR_QUEUE_FULL;
     else
     {
@@ -2016,34 +2033,19 @@ bool CIndirectDeviceContext::RepublishFrameBuffer(
   }
 
   const uint64_t scheduleToken = FrameScheduleToken(schedule);
-  const int existingSharedDelivery =
-    FindSharedOwnerDelivery(schedule.clientID);
-  if (existingSharedDelivery >= 0)
+  const uint32_t frameSerial   = m_frame[frameIndex]->frameSerial;
+  if (HasMatchingOwnerDelivery(schedule.clientID,
+      static_cast<unsigned>(frameIndex), scheduleToken))
   {
-    const FrameDelivery& delivery =
-      m_frameDelivery[existingSharedDelivery];
-    const bool delivered = existingSharedDelivery == frameIndex &&
-      delivery.sharedOwnerToken == scheduleToken;
-    const uint32_t frameSerial = m_frame[frameIndex]->frameSerial;
     ReleaseSRWLockExclusive(&m_framePublishLock);
-    if (delivered)
-      m_frameScheduler.FrameRepublished(schedule, frameSerial);
-    return delivered;
+    m_frameScheduler.FrameRepublished(schedule, frameSerial);
+    return true;
   }
 
-  const int existingDelivery =
-    FindOwnerDelivery(schedule.clientID);
-  if (existingDelivery >= 0)
+  if (CountOwnerDeliveries(schedule.clientID) >= LGMP_Q_FRAME_LEN)
   {
-    const OwnerDelivery& owner = m_ownerDelivery[existingDelivery];
-    const bool delivered = owner.frameIndex ==
-        static_cast<unsigned>(frameIndex) &&
-      owner.token == scheduleToken;
-    const uint32_t frameSerial = m_frame[frameIndex]->frameSerial;
     ReleaseSRWLockExclusive(&m_framePublishLock);
-    if (delivered)
-      m_frameScheduler.FrameRepublished(schedule, frameSerial);
-    return delivered;
+    return false;
   }
 
   const int ownerQueueIndex =
@@ -2052,15 +2054,12 @@ bool CIndirectDeviceContext::RepublishFrameBuffer(
   {
     const bool published = PostSharedOwnerFrame(
       static_cast<unsigned>(frameIndex), schedule);
-    const uint32_t frameSerial = m_frame[frameIndex]->frameSerial;
     ReleaseSRWLockExclusive(&m_framePublishLock);
     if (published)
       m_frameScheduler.FrameRepublished(schedule, frameSerial);
     return published;
   }
 
-  const uint32_t frameSerial = m_frame[frameIndex]->frameSerial;
-
   unsigned recipientCount = 0;
   const LGMP_STATUS status = lgmpHostQueuePostForClients(
     m_frameOwnerQueue[ownerQueueIndex], scheduleToken,

idd/LGIdd/CIndirectDeviceContext.h

@@ -189,9 +189,9 @@ private:
   void ProcessFrameDeliveries();
   int FindAvailableFrameBuffer() const;
   int FindAvailableOwnerQueue(unsigned preferredIndex) const;
-  int FindOwnerDelivery(uint32_t clientID) const;
-  int FindSharedOwnerDelivery(uint32_t clientID) const;
-  bool HasOwnerDelivery(uint32_t clientID) const;
+  unsigned CountOwnerDeliveries(uint32_t clientID) const;
+  bool HasMatchingOwnerDelivery(uint32_t clientID, unsigned frameIndex,
+    uint64_t token) const;
   SharedFramePostResult PostSharedFrame(unsigned frameIndex,
     uint32_t excludeClientID, uint64_t now);
   bool PostSharedOwnerFrame(unsigned frameIndex,