[idd] scheduler: retain frames for publication deadlines

Prepare each acquired content frame into one of two private GPU
candidates so the IddCx frame can be released without copying it to
IVSHMEM immediately.

Wake a high-resolution publisher at the client deadline and send the
newest completed candidate. Preserve accumulated damage across
superseded candidates, include the scheduling hold in end-to-end timing,
and keep transport work on the existing physical copy queue.

idd/LGIdd/CFrameScheduler.h

@@ -54,6 +54,7 @@ private:
   };
 
   mutable SRWLOCK m_lock = SRWLOCK_INIT;
+  HANDLE          m_wakeEvent = nullptr;
   Client          m_clients[LGMP_MAX_CLIENTS] = {};
   Schedule        m_schedule                  = {};
   bool            m_scheduling                = false;
@@ -61,11 +62,8 @@ private:
 
   uint64_t m_lastArrival    = 0;
   uint64_t m_guestPeriod    = 0;
-  uint64_t m_guestJitter    = 0;
   uint64_t m_workEstimate   = 0;
   uint64_t m_nextDeadline   = 0;
-  unsigned m_arrivalSamples = 0;
-  unsigned m_timingSamples  = 0;
 
   uint32_t m_lastPublishedFrameSerial = 0;
 
@@ -79,11 +77,15 @@ private:
   uint64_t m_lastLogPublished = 0;
 
   Client * FindClient(uint32_t clientID);
-  void ElectOwner(uint64_t now);
-  void ApplyFeedback(Client& client, const KVMFRFrameSchedule& schedule);
+  bool ElectOwner(uint64_t now);
+  bool ApplyFeedback(Client& client, const KVMFRFrameSchedule& schedule);
   void AdvanceDeadline(uint64_t now);
+  void WakePublisher() const;
 
 public:
+  CFrameScheduler();
+  ~CFrameScheduler();
+
   static uint64_t Nanotime();
 
   void Reset();
@@ -91,10 +93,14 @@ public:
     uint64_t now);
   bool UpdateSchedule(const KVMFRFrameSchedule& schedule, uint64_t now);
   bool GetSchedule(Schedule& schedule) const;
+  HANDLE GetWakeEvent() const { return m_wakeEvent; }
   void ObserveFrame(uint64_t now);
-  bool SelectFrame(uint64_t now, bool force, uint32_t& generation);
+  void ForceFrame();
+  bool GetPublishTarget(uint64_t now, uint64_t& target,
+    uint32_t& generation, bool& periodic);
+  void FrameSuperseded();
   void FramePublished(uint32_t generation, uint32_t frameSerial,
-    uint64_t now);
+    uint64_t now, bool periodic);
   void RecordFrameTiming(uint64_t duration);
   void LogStatistics(uint64_t now);
 };