[client] allow frame updates to be triggered by a timed event

This is a major change to how the LG client performs it's updates. In
the past LG would operate a fixed FPS regardless of incoming update
speed and/or frequency. This change allows LG to dynamically increase
it's FPS in order to better sync with the guest as it's rate changes.

VERSION

@@ -1 +1 @@
-B1-205-g01bfd2e090+1
+B1-206-g756b57400b+1

client/renderers/EGL/texture.c

@@ -421,7 +421,7 @@ enum EGL_TexStatus egl_texture_bind(EGL_Texture * texture)
 
     if (texture->tex[s.s].sync != 0)
     {
-      switch(glClientWaitSync(texture->tex[s.s].sync, 0, 0))
+      switch(glClientWaitSync(texture->tex[s.s].sync, 0, 20000000))
       {
         case GL_ALREADY_SIGNALED:
         case GL_CONDITION_SATISFIED:

client/src/main.c

@@ -62,6 +62,7 @@ static int renderThread(void * unused);
 static int frameThread (void * unused);
 
 static LGEvent  *e_startup = NULL;
+static LGEvent  *e_frame   = NULL;
 static LGThread *t_spice   = NULL;
 static LGThread *t_render  = NULL;
 static LGThread *t_cursor  = NULL;
@@ -149,7 +150,7 @@ static int renderThread(void * unused)
 
   unsigned int resyncCheck = 0;
   struct timespec time;
-  clock_gettime(CLOCK_MONOTONIC, &time);
+  clock_gettime(CLOCK_REALTIME, &time);
 
   while(state.running)
   {
@@ -161,7 +162,7 @@ static int renderThread(void * unused)
       resyncCheck = 0;
 
       struct timespec tmp;
-      clock_gettime(CLOCK_MONOTONIC, &tmp);
+      clock_gettime(CLOCK_REALTIME, &tmp);
       if (tmp.tv_nsec - time.tv_nsec < 0)
       {
         tmp.tv_sec -= time.tv_sec - 1;
@@ -172,12 +173,6 @@ static int renderThread(void * unused)
         tmp.tv_sec  -= time.tv_sec;
         tmp.tv_nsec -= time.tv_nsec;
       }
-      const unsigned long diff = tmp.tv_sec * 1000000000 + tmp.tv_nsec;
-      if (diff > state.frameTime)
-      {
-        DEBUG_INFO("Timer drift detected, %lu is > %lu", diff, state.frameTime);
-        clock_gettime(CLOCK_MONOTONIC, &time);
-      }
     }
 
     if (state.lgr->render_begin && !state.lgr->render_begin(state.lgrData,
@@ -227,8 +222,6 @@ static int renderThread(void * unused)
       state.resizeDone = true;
     }
 
-    if (state.frameTime > 0)
-    {
     uint64_t nsec = time.tv_nsec + state.frameTime;
     if(nsec > 1e9)
     {
@@ -238,8 +231,7 @@ static int renderThread(void * unused)
     else
       time.tv_nsec = nsec;
 
-      clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &time, NULL);
-    }
+    lgWaitEventAbs(e_frame, &time);
   }
 
   state.running = false;
@@ -474,6 +466,7 @@ static int frameThread(void * unused)
     }
     lgmpClientMessageDone(queue);
     ++state.frameCount;
+    lgSignalEvent(e_frame);
   }
 
   lgmpClientUnsubscribe(&queue);
@@ -1443,6 +1436,13 @@ static int lg_run()
     return -1;
   }
 
+  // setup the new frame event
+  if (!(e_frame = lgCreateEvent(true, 0)))
+  {
+    DEBUG_ERROR("failed to create the frame event");
+    return -1;
+  }
+
   // start the renderThread so we don't just display junk
   if (!lgCreateThread("renderThread", renderThread, NULL, &t_render))
   {
@@ -1555,11 +1555,18 @@ static void lg_shutdown()
   if (t_render)
   {
     lgSignalEvent(e_startup);
+    lgSignalEvent(e_frame);
     lgJoinThread(t_render, NULL);
   }
 
   lgmpClientFree(&state.lgmp);
 
+  if (e_frame)
+  {
+    lgFreeEvent(e_frame);
+    e_frame = NULL;
+  }
+
   if (e_startup)
   {
     lgFreeEvent(e_startup);

common/include/common/event.h

@@ -20,6 +20,7 @@ Place, Suite 330, Boston, MA 02111-1307 USA
 #pragma once
 
 #include <stdbool.h>
+#include <time.h>
 
 #define TIMEOUT_INFINITE ((unsigned int)~0)
 
@@ -35,3 +36,7 @@ bool      lgResetEvent (LGEvent * handle);
 // os specific method to wrap/convert a native event into a LGEvent
 // for windows this is an event HANDLE
 LGEvent * lgWrapEvent(void * handle);
+
+// Posix specific, not implmented/possible in windows
+bool lgWaitEventAbs(LGEvent * handle, struct timespec * ts);
+bool lgWaitEventNS (LGEvent * handle, unsigned int timeout);

common/src/platform/linux/event.c

@@ -72,7 +72,7 @@ void lgFreeEvent(LGEvent * handle)
   free(handle);
 }
 
-bool lgWaitEvent(LGEvent * handle, unsigned int timeout)
+bool lgWaitEventAbs(LGEvent * handle, struct timespec * ts)
 {
   assert(handle);
 
@@ -82,29 +82,32 @@ bool lgWaitEvent(LGEvent * handle, unsigned int timeout)
     return false;
   }
 
-  while(!atomic_load(&handle->flag))
+  bool ret = true;
+  while(ret && !atomic_load(&handle->flag))
   {
-    if (timeout == TIMEOUT_INFINITE)
+    if (!ts)
     {
       if (pthread_cond_wait(&handle->cond, &handle->mutex) != 0)
       {
         DEBUG_ERROR("Wait to wait on the condition");
-        return false;
+        ret = false;
       }
     }
     else
     {
-      struct timespec ts;
-      ts.tv_sec  = timeout / 1000;
-      ts.tv_nsec = (timeout % 1000) * 1000000;
-      switch(pthread_cond_timedwait(&handle->cond, &handle->mutex, &ts))
+      switch(pthread_cond_timedwait(&handle->cond, &handle->mutex, ts))
       {
+        case 0:
+          break;
+
         case ETIMEDOUT:
-          return false;
+          ret = false;
+          break;
 
         default:
+          ret = false;
           DEBUG_ERROR("Timed wait failed");
-          return false;
+          break;
       }
     }
   }
@@ -118,7 +121,31 @@ bool lgWaitEvent(LGEvent * handle, unsigned int timeout)
     return false;
   }
 
-  return true;
+  return ret;
+}
+
+bool lgWaitEventNS(LGEvent * handle, unsigned int timeout)
+{
+  if (timeout == TIMEOUT_INFINITE)
+    return lgWaitEventAbs(handle, NULL);
+
+  struct timespec ts;
+  clock_gettime(CLOCK_REALTIME, &ts);
+  uint64_t nsec = ts.tv_nsec + timeout;
+  if(nsec > 1e9)
+  {
+    ts.tv_nsec = nsec - 1e9;
+    ++ts.tv_sec;
+  }
+  else
+    ts.tv_nsec = nsec;
+
+  return lgWaitEventAbs(handle, &ts);
+}
+
+bool lgWaitEvent(LGEvent * handle, unsigned int timeout)
+{
+  return lgWaitEventNS(handle, timeout * 1000000);
 }
 
 bool lgSignalEvent(LGEvent * handle)