dix/os: Merge priority computation into SmartScheduleClient

 Backported from X.org:

 commit 7762a602c1dfdd8cfcf2b8c2281cf4d683d05216
 Author: Keith Packard <keithp@keithp.com>
 Date:   Thu May 19 15:05:55 2016 -0700

    dix/os: Merge priority computation into SmartScheduleClient

    Instead of having scheduling done in two places (one in
    WaitForSomething, and the other in SmartScheduleClient), just stick
    all of the scheduling in SmartScheduleClient.

    Signed-off-by: Keith Packard <keithp@keithp.com>
    Reviewed-by: Adam Jackson <ajax@redhat.com>

 Backported-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

2 files changed, 18 insertions, 48 deletions

diff --git a/nx-X11/programs/Xserver/dix/dispatch.c b/nx-X11/programs/Xserver/dix/dispatch.c
index 7b2aa7b3d..68c207e33 100644
--- a/nx-X11/programs/Xserver/dix/dispatch.c
+++ b/nx-X11/programs/Xserver/dix/dispatch.c
@@ -240,15 +240,13 @@ void        InitProcVectors(void);
 int
 SmartScheduleClient (int *clientReady, int nready)
 {
-    ClientPtr	pClient;
     int		i;
     int		client;
-    int		bestPrio, best = 0;
+    ClientPtr	pClient, best = NULL;
     int		bestRobin, robin;
     long	now = SmartScheduleTime;
     long	idle;
 
-    bestPrio = -0x7fffffff;
     bestRobin = 0;
     idle = 2 * SmartScheduleSlice;
     for (i = 0; i < nready; i++)
@@ -264,13 +262,19 @@ SmartScheduleClient (int *clientReady, int nready)
 	pClient->smart_check_tick = now;
 	
 	/* check priority to select best client */
-	robin = (pClient->index - SmartLastIndex[pClient->smart_priority-SMART_MIN_PRIORITY]) & 0xff;
-	if (pClient->smart_priority > bestPrio ||
-	    (pClient->smart_priority == bestPrio && robin > bestRobin))
+	robin = (pClient->index -
+	         SmartLastIndex[pClient->smart_priority -
+                                SMART_MIN_PRIORITY]) & 0xff;
+
+	/* pick the best client */
+	if (!best ||
+	    pClient->priority > best->priority ||
+	    (pClient->priority == best->priority &&
+	     (pClient->smart_priority > best->smart_priority ||
+	      (pClient->smart_priority == best->smart_priority && robin > bestRobin))))
 	{
-	    bestPrio = pClient->smart_priority;
+	    best = pClient;
 	    bestRobin = robin;
-	    best = client;
 	}
 #ifdef SMART_DEBUG
 	if ((now - SmartLastPrint) >= 5000)
@@ -284,8 +288,7 @@ SmartScheduleClient (int *clientReady, int nready)
 	SmartLastPrint = now;
     }
 #endif
-    pClient = clients[best];
-    SmartLastIndex[bestPrio-SMART_MIN_PRIORITY] = pClient->index;
+    SmartLastIndex[best->smart_priority - SMART_MIN_PRIORITY] = best->index;
     /*
      * Set current client pointer
      */
@@ -314,7 +317,7 @@ SmartScheduleClient (int *clientReady, int nready)
     {
 	SmartScheduleSlice = SmartScheduleInterval;
     }
-    return best;
+    return best->index;
 }
 
 #ifndef NXAGENT_SERVER
diff --git a/nx-X11/programs/Xserver/os/WaitFor.c b/nx-X11/programs/Xserver/os/WaitFor.c
index 3ac2e1c7e..02c460f0c 100644
--- a/nx-X11/programs/Xserver/os/WaitFor.c
+++ b/nx-X11/programs/Xserver/os/WaitFor.c
@@ -544,17 +544,14 @@ WaitForSomething(int *pClientsReady)
 #ifndef WIN32
 	for (i=0; i<howmany(XFD_SETSIZE, NFDBITS); i++)
 	{
-	    int highest_priority = 0;
-
 	    while (clientsReadable.fds_bits[i])
 	    {
-	        int client_priority, client_index;
+		int client_index;
 
 		curclient = ffs (clientsReadable.fds_bits[i]) - 1;
 		client_index = /* raphael: modified */
 			ConnectionTranslation[curclient + (i * (sizeof(fd_mask) * 8))];
 #else
-	int highest_priority = 0;
 	fd_set savedClientsReadable;
 	XFD_COPYSET(&clientsReadable, &savedClientsReadable);
 	for (i = 0; i < XFD_SETCOUNT(&savedClientsReadable); i++)
@@ -564,40 +561,10 @@ WaitForSomething(int *pClientsReady)
 	    curclient = XFD_FD(&savedClientsReadable, i);
 	    client_index = GetConnectionTranslation(curclient);
 #endif
-#ifdef XSYNC
-		/*  We implement "strict" priorities.
-		 *  Only the highest priority client is returned to
-		 *  dix.  If multiple clients at the same priority are
-		 *  ready, they are all returned.  This means that an
-		 *  aggressive client could take over the server.
-		 *  This was not considered a big problem because
-		 *  aggressive clients can hose the server in so many 
-		 *  other ways :)
-		 */
-		client_priority = clients[client_index]->priority;
-		if (nready == 0 || client_priority > highest_priority)
-		{
-		    /*  Either we found the first client, or we found
-		     *  a client whose priority is greater than all others
-		     *  that have been found so far.  Either way, we want 
-		     *  to initialize the list of clients to contain just
-		     *  this client.
-		     */
-		    pClientsReady[0] = client_index;
-		    highest_priority = client_priority;
-		    nready = 1;
-		}
-		/*  the following if makes sure that multiple same-priority 
-		 *  clients get batched together
-		 */
-		else if (client_priority == highest_priority)
-#endif
-		{
-		    pClientsReady[nready++] = client_index;
-		}
+	    pClientsReady[nready++] = client_index;
 #ifndef WIN32
-		clientsReadable.fds_bits[i] &= ~(((fd_mask)1L) << curclient);
-	    }
+	    clientsReadable.fds_bits[i] &= ~(((fd_mask)1L) << curclient);
+	}
 #else
 	    FD_CLR(curclient, &clientsReadable);
 #endif