initial state (xorg-server 1.10.2)

1 files changed, 2925 insertions, 0 deletions

diff --git a/Xext/sync.c b/Xext/sync.c
new file mode 100644
index 0000000..36dd278
--- /dev/null
+++ b/Xext/sync.c
@@ -0,0 +1,2925 @@
+/*
+
+Copyright 1991, 1993, 1998  The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of The Open Group shall
+not be used in advertising or otherwise to promote the sale, use or
+other dealings in this Software without prior written authorization
+from The Open Group.
+
+
+Copyright 1991, 1993 by Digital Equipment Corporation, Maynard, Massachusetts,
+and Olivetti Research Limited, Cambridge, England.
+
+                        All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and that
+both that copyright notice and this permission notice appear in
+supporting documentation, and that the names of Digital or Olivetti
+not be used in advertising or publicity pertaining to distribution of the
+software without specific, written prior permission.  Digital and Olivetti
+make no representations about the suitability of this software
+for any purpose.  It is provided "as is" without express or implied warranty.
+
+DIGITAL AND OLIVETTI DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS, IN NO EVENT SHALL THEY BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
+USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.
+
+*/
+
+#ifdef HAVE_DIX_CONFIG_H
+#include <dix-config.h>
+#endif
+
+#include <string.h>
+
+#include <X11/X.h>
+#include <X11/Xproto.h>
+#include <X11/Xmd.h>
+#include "scrnintstr.h"
+#include "os.h"
+#include "extnsionst.h"
+#include "dixstruct.h"
+#include "pixmapstr.h"
+#include "resource.h"
+#include "opaque.h"
+#include <X11/extensions/syncproto.h>
+#include "syncsrv.h"
+#include "syncsdk.h"
+#include "protocol-versions.h"
+
+#include <stdio.h>
+#if !defined(WIN32)
+#include <sys/time.h>
+#endif
+
+#include "modinit.h"
+
+/*
+ * Local Global Variables
+ */
+static int      SyncEventBase;
+static int      SyncErrorBase;
+static RESTYPE  RTCounter = 0;
+static RESTYPE  RTAwait;
+static RESTYPE  RTAlarm;
+static RESTYPE  RTAlarmClient;
+static RESTYPE  RTFence;
+static int SyncNumSystemCounters = 0;
+static SyncCounter **SysCounterList = NULL;
+static int SyncNumInvalidCounterWarnings = 0;
+#define MAX_INVALID_COUNTER_WARNINGS	   5
+
+static const char *WARN_INVALID_COUNTER_COMPARE =
+"Warning: Non-counter XSync object using Counter-only\n"
+"         comparison.  Result will never be true.\n";
+
+static const char *WARN_INVALID_COUNTER_ALARM =
+"Warning: Non-counter XSync object used in alarm.  This is\n"
+"         the result of a programming error in the X server.\n";
+
+#define IsSystemCounter(pCounter) \
+    (pCounter && (pCounter->sync.client == NULL))
+
+/* these are all the alarm attributes that pertain to the alarm's trigger */
+#define XSyncCAAllTrigger \
+    (XSyncCACounter | XSyncCAValueType | XSyncCAValue | XSyncCATestType)
+
+static void SyncComputeBracketValues(SyncCounter *);
+
+static void SyncInitServerTime(void);
+
+static void SyncInitIdleTime(void);
+
+static Bool
+SyncCheckWarnIsCounter(const SyncObject* pSync, const char *warning)
+{
+    if (pSync && (SYNC_COUNTER != pSync->type))
+    {
+	if (SyncNumInvalidCounterWarnings++ < MAX_INVALID_COUNTER_WARNINGS)
+	{
+	    ErrorF("%s", warning);
+	    ErrorF("         Counter type: %d\n", pSync->type);
+	}
+
+	return FALSE;
+    }
+
+    return TRUE;
+}
+
+/*  Each counter maintains a simple linked list of triggers that are
+ *  interested in the counter.  The two functions below are used to
+ *  delete and add triggers on this list.
+ */
+static void
+SyncDeleteTriggerFromSyncObject(SyncTrigger *pTrigger)
+{
+    SyncTriggerList *pCur;
+    SyncTriggerList *pPrev;
+    SyncCounter *pCounter;
+
+    /* pSync needs to be stored in pTrigger before calling here. */
+
+    if (!pTrigger->pSync)
+	return;
+
+    pPrev = NULL;
+    pCur = pTrigger->pSync->pTriglist;
+
+    while (pCur)
+    {
+	if (pCur->pTrigger == pTrigger)
+	{
+	    if (pPrev)
+		pPrev->next = pCur->next;
+	    else
+		pTrigger->pSync->pTriglist = pCur->next;
+
+	    free(pCur);
+	    break;
+	}
+	
+	pPrev = pCur;
+	pCur = pCur->next;
+    }
+
+    if (SYNC_COUNTER == pTrigger->pSync->type)
+    {
+	pCounter = (SyncCounter *)pTrigger->pSync;
+
+	if (IsSystemCounter(pCounter))
+	    SyncComputeBracketValues(pCounter);
+    } else if (SYNC_FENCE == pTrigger->pSync->type) {
+	SyncFence* pFence = (SyncFence*) pTrigger->pSync;
+	pFence->funcs.DeleteTrigger(pTrigger);
+    }
+}
+
+
+static int
+SyncAddTriggerToSyncObject(SyncTrigger *pTrigger)
+{
+    SyncTriggerList *pCur;
+    SyncCounter *pCounter;
+
+    if (!pTrigger->pSync)
+	return Success;
+
+    /* don't do anything if it's already there */
+    for (pCur = pTrigger->pSync->pTriglist; pCur; pCur = pCur->next)
+    {
+	if (pCur->pTrigger == pTrigger)
+	    return Success;
+    }
+
+    if (!(pCur = malloc(sizeof(SyncTriggerList))))
+	return BadAlloc;
+
+    pCur->pTrigger = pTrigger;
+    pCur->next = pTrigger->pSync->pTriglist;
+    pTrigger->pSync->pTriglist = pCur;
+
+    if (SYNC_COUNTER == pTrigger->pSync->type)
+    {
+	pCounter = (SyncCounter *)pTrigger->pSync;
+
+	if (IsSystemCounter(pCounter))
+	    SyncComputeBracketValues(pCounter);
+    } else if (SYNC_FENCE == pTrigger->pSync->type) {
+	SyncFence* pFence = (SyncFence*) pTrigger->pSync;
+	pFence->funcs.AddTrigger(pTrigger);
+    }
+
+    return Success;
+}
+
+
+/*  Below are five possible functions that can be plugged into
+ *  pTrigger->CheckTrigger for counter sync objects, corresponding to
+ *  the four possible test-types, and the one possible function that
+ *  can be plugged into pTrigger->CheckTrigger for fence sync objects.
+ *  These functions are called after the sync object's state changes
+ *  but are also passed the old state so they can inspect both the old
+ *  and new values.  (PositiveTransition and NegativeTransition need to
+ *  see both pieces of information.)  These functions return the truth
+ *  value of the trigger.
+ *
+ *  All of them include the condition pTrigger->pSync == NULL.
+ *  This is because the spec says that a trigger with a sync value
+ *  of None is always TRUE.
+ */
+
+static Bool
+SyncCheckTriggerPositiveComparison(SyncTrigger *pTrigger, CARD64 oldval)
+{
+    SyncCounter *pCounter;
+
+    /* Non-counter sync objects should never get here because they
+     * never trigger this comparison. */
+    if (!SyncCheckWarnIsCounter(pTrigger->pSync, WARN_INVALID_COUNTER_COMPARE))
+	return FALSE;
+
+    pCounter = (SyncCounter *)pTrigger->pSync;
+
+    return (pCounter == NULL ||
+	    XSyncValueGreaterOrEqual(pCounter->value, pTrigger->test_value));
+}
+
+static Bool
+SyncCheckTriggerNegativeComparison(SyncTrigger *pTrigger,  CARD64 oldval)
+{
+    SyncCounter *pCounter;
+
+    /* Non-counter sync objects should never get here because they
+     * never trigger this comparison. */
+    if (!SyncCheckWarnIsCounter(pTrigger->pSync, WARN_INVALID_COUNTER_COMPARE))
+	return FALSE;
+
+    pCounter = (SyncCounter *)pTrigger->pSync;
+
+    return (pCounter == NULL ||
+	    XSyncValueLessOrEqual(pCounter->value, pTrigger->test_value));
+}
+
+static Bool
+SyncCheckTriggerPositiveTransition(SyncTrigger *pTrigger, CARD64 oldval)
+{
+    SyncCounter *pCounter;
+
+    /* Non-counter sync objects should never get here because they
+     * never trigger this comparison. */
+    if (!SyncCheckWarnIsCounter(pTrigger->pSync, WARN_INVALID_COUNTER_COMPARE))
+	return FALSE;
+
+    pCounter = (SyncCounter *)pTrigger->pSync;
+
+    return (pCounter == NULL ||
+	    (XSyncValueLessThan(oldval, pTrigger->test_value) &&
+	     XSyncValueGreaterOrEqual(pCounter->value, pTrigger->test_value)));
+}
+
+static Bool
+SyncCheckTriggerNegativeTransition(SyncTrigger *pTrigger, CARD64 oldval)
+{
+    SyncCounter *pCounter;
+
+    /* Non-counter sync objects should never get here because they
+     * never trigger this comparison. */
+    if (!SyncCheckWarnIsCounter(pTrigger->pSync, WARN_INVALID_COUNTER_COMPARE))
+	return FALSE;
+
+    pCounter = (SyncCounter *)pTrigger->pSync;
+
+    return (pCounter == NULL ||
+	    (XSyncValueGreaterThan(oldval, pTrigger->test_value) &&
+	     XSyncValueLessOrEqual(pCounter->value, pTrigger->test_value)));
+}
+
+static Bool
+SyncCheckTriggerFence(SyncTrigger *pTrigger, CARD64 unused)
+{
+    SyncFence* pFence = (SyncFence*) pTrigger->pSync;
+    (void)unused;
+
+    return (pFence == NULL ||
+	    pFence->funcs.CheckTriggered(pFence));
+}
+
+static int
+SyncInitTrigger(ClientPtr client, SyncTrigger *pTrigger, XID syncObject,
+		RESTYPE resType, Mask changes)
+{
+    SyncObject *pSync = pTrigger->pSync;
+    SyncCounter *pCounter = NULL;
+    int		rc;
+    Bool	newSyncObject = FALSE;
+
+    if (changes & XSyncCACounter)
+    {
+	if (syncObject == None)
+	    pSync = NULL;
+	else if (Success != (rc = dixLookupResourceByType ((pointer *)&pSync,
+				syncObject, resType, client, DixReadAccess)))
+	{
+	    client->errorValue = syncObject;
+	    return rc;
+	}
+	if (pSync != pTrigger->pSync)
+	{ /* new counter for trigger */
+	    SyncDeleteTriggerFromSyncObject(pTrigger);
+	    pTrigger->pSync = pSync;
+	    newSyncObject = TRUE;
+	}
+    }
+
+    /* if system counter, ask it what the current value is */
+
+    if (pSync && SYNC_COUNTER == pSync->type)
+    {
+	pCounter = (SyncCounter *)pSync;
+
+	if (IsSystemCounter(pCounter))
+	{
+	    (*pCounter->pSysCounterInfo->QueryValue) ((pointer) pCounter,
+						      &pCounter->value);
+	}
+    }
+
+    if (changes & XSyncCAValueType)
+    {
+	if (pTrigger->value_type != XSyncRelative &&
+	    pTrigger->value_type != XSyncAbsolute)
+	{
+	    client->errorValue = pTrigger->value_type;
+	    return BadValue;
+	}
+    }
+
+    if (changes & XSyncCATestType)
+    {
+
+	if (pSync && SYNC_FENCE == pSync->type)
+	{
+	    pTrigger->CheckTrigger = SyncCheckTriggerFence;
+	}
+	else
+	{
+	    /* select appropriate CheckTrigger function */
+
+	    switch (pTrigger->test_type)
+	    {
+	    case XSyncPositiveTransition:
+		pTrigger->CheckTrigger = SyncCheckTriggerPositiveTransition;
+		break;
+	    case XSyncNegativeTransition:
+		pTrigger->CheckTrigger = SyncCheckTriggerNegativeTransition;
+		break;
+	    case XSyncPositiveComparison:
+		pTrigger->CheckTrigger = SyncCheckTriggerPositiveComparison;
+		break;
+	    case XSyncNegativeComparison:
+		pTrigger->CheckTrigger = SyncCheckTriggerNegativeComparison;
+		break;
+	    default:
+		client->errorValue = pTrigger->test_type;
+		return BadValue;
+	    }
+	}
+    }
+
+    if (changes & (XSyncCAValueType | XSyncCAValue))
+    {
+	if (pTrigger->value_type == XSyncAbsolute)
+	    pTrigger->test_value = pTrigger->wait_value;
+	else /* relative */
+	{
+	    Bool overflow;
+	    if (pCounter == NULL)
+		return BadMatch;
+
+	    XSyncValueAdd(&pTrigger->test_value, pCounter->value,
+			  pTrigger->wait_value, &overflow);
+	    if (overflow)
+	    {
+		client->errorValue = XSyncValueHigh32(pTrigger->wait_value);
+		return BadValue;
+	    }
+	}
+    }
+
+    /*  we wait until we're sure there are no errors before registering
+     *  a new counter on a trigger
+     */
+    if (newSyncObject)
+    {
+	if ((rc = SyncAddTriggerToSyncObject(pTrigger)) != Success)
+	    return rc;
+    }
+    else if (pCounter && IsSystemCounter(pCounter))
+    {
+	SyncComputeBracketValues(pCounter);
+    }
+
+    return Success;
+}
+
+/*  AlarmNotify events happen in response to actions taken on an Alarm or
+ *  the counter used by the alarm.  AlarmNotify may be sent to multiple
+ *  clients.  The alarm maintains a list of clients interested in events.
+ */
+static void
+SyncSendAlarmNotifyEvents(SyncAlarm *pAlarm)
+{
+    SyncAlarmClientList *pcl;
+    xSyncAlarmNotifyEvent ane;
+    SyncTrigger *pTrigger = &pAlarm->trigger;
+    SyncCounter *pCounter;
+
+    if (!SyncCheckWarnIsCounter(pTrigger->pSync, WARN_INVALID_COUNTER_ALARM))
+	return;
+
+    pCounter = (SyncCounter *)pTrigger->pSync;
+
+    UpdateCurrentTime();
+
+    ane.type = SyncEventBase + XSyncAlarmNotify;
+    ane.kind = XSyncAlarmNotify;
+    ane.alarm = pAlarm->alarm_id;
+    if (pTrigger->pSync && SYNC_COUNTER == pTrigger->pSync->type)
+    {
+	ane.counter_value_hi = XSyncValueHigh32(pCounter->value);
+	ane.counter_value_lo = XSyncValueLow32(pCounter->value);
+    }
+    else
+    { /* XXX what else can we do if there's no counter? */
+	ane.counter_value_hi = ane.counter_value_lo = 0;
+    }
+
+    ane.alarm_value_hi = XSyncValueHigh32(pTrigger->test_value);
+    ane.alarm_value_lo = XSyncValueLow32(pTrigger->test_value);
+    ane.time = currentTime.milliseconds;
+    ane.state = pAlarm->state;
+
+    /* send to owner */
+    if (pAlarm->events)
+	WriteEventsToClient(pAlarm->client, 1, (xEvent *) &ane);
+
+    /* send to other interested clients */
+    for (pcl = pAlarm->pEventClients; pcl; pcl = pcl->next)
+	WriteEventsToClient(pcl->client, 1, (xEvent *) &ane);
+}
+
+
+/*  CounterNotify events only occur in response to an Await.  The events
+ *  go only to the Awaiting client.
+ */
+static void
+SyncSendCounterNotifyEvents(ClientPtr client, SyncAwait **ppAwait,
+			    int num_events)
+{
+    xSyncCounterNotifyEvent *pEvents, *pev;
+    int i;
+
+    if (client->clientGone)
+	return;
+    pev = pEvents = malloc(num_events * sizeof(xSyncCounterNotifyEvent));
+    if (!pEvents)
+	return;
+    UpdateCurrentTime();
+    for (i = 0; i < num_events; i++, ppAwait++, pev++)
+    {
+	SyncTrigger *pTrigger = &(*ppAwait)->trigger;
+	pev->type = SyncEventBase + XSyncCounterNotify;
+	pev->kind = XSyncCounterNotify;
+	pev->counter = pTrigger->pSync->id;
+	pev->wait_value_lo = XSyncValueLow32(pTrigger->test_value);
+	pev->wait_value_hi = XSyncValueHigh32(pTrigger->test_value);
+	if (SYNC_COUNTER == pTrigger->pSync->type)
+	{
+	    SyncCounter *pCounter = (SyncCounter *)pTrigger->pSync;
+
+	    pev->counter_value_lo = XSyncValueLow32(pCounter->value);
+	    pev->counter_value_hi = XSyncValueHigh32(pCounter->value);
+	}
+	else
+	{
+	    pev->counter_value_lo = 0;
+	    pev->counter_value_hi = 0;
+	}
+
+	pev->time = currentTime.milliseconds;
+	pev->count = num_events - i - 1; /* events remaining */
+	pev->destroyed = pTrigger->pSync->beingDestroyed;
+    }
+    /* swapping will be taken care of by this */
+    WriteEventsToClient(client, num_events, (xEvent *)pEvents);
+    free(pEvents);
+}
+
+
+/* This function is called when an alarm's counter is destroyed.
+ * It is plugged into pTrigger->CounterDestroyed (for alarm triggers).
+ */
+static void
+SyncAlarmCounterDestroyed(SyncTrigger *pTrigger)
+{
+    SyncAlarm *pAlarm = (SyncAlarm *)pTrigger;
+
+    pAlarm->state = XSyncAlarmInactive;
+    SyncSendAlarmNotifyEvents(pAlarm);
+    pTrigger->pSync = NULL;
+}
+
+
+/*  This function is called when an alarm "goes off."
+ *  It is plugged into pTrigger->TriggerFired (for alarm triggers).
+ */
+static void
+SyncAlarmTriggerFired(SyncTrigger *pTrigger)
+{
+    SyncAlarm *pAlarm = (SyncAlarm *)pTrigger;
+    SyncCounter *pCounter;
+    CARD64 new_test_value;
+
+    if (!SyncCheckWarnIsCounter(pTrigger->pSync, WARN_INVALID_COUNTER_ALARM))
+	return;
+
+    pCounter = (SyncCounter *)pTrigger->pSync;
+
+    /* no need to check alarm unless it's active */
+    if (pAlarm->state != XSyncAlarmActive)
+	return;
+
+    /*  " if the counter value is None, or if the delta is 0 and
+     *    the test-type is PositiveComparison or NegativeComparison,
+     *    no change is made to value (test-value) and the alarm
+     *    state is changed to Inactive before the event is generated."
+     */
+    if (pCounter == NULL
+	|| (XSyncValueIsZero(pAlarm->delta)
+	    && (pAlarm->trigger.test_type == XSyncPositiveComparison
+		|| pAlarm->trigger.test_type == XSyncNegativeComparison)))
+	pAlarm->state = XSyncAlarmInactive;
+
+    new_test_value = pAlarm->trigger.test_value;
+
+    if (pAlarm->state == XSyncAlarmActive)
+    {
+	Bool overflow;
+	CARD64 oldvalue;
+	SyncTrigger *paTrigger = &pAlarm->trigger;
+	SyncCounter *paCounter;
+
+	if (!SyncCheckWarnIsCounter(paTrigger->pSync,
+				    WARN_INVALID_COUNTER_ALARM))
+	    return;
+
+	paCounter = (SyncCounter *)pTrigger->pSync;
+
+	/* "The alarm is updated by repeatedly adding delta to the
+	 *  value of the trigger and re-initializing it until it
+	 *  becomes FALSE."
+	 */
+	oldvalue = paTrigger->test_value;
+
+	/* XXX really should do something smarter here */
+
+	do
+	{
+	    XSyncValueAdd(&paTrigger->test_value, paTrigger->test_value,
+			  pAlarm->delta, &overflow);
+	} while (!overflow &&
+	      (*paTrigger->CheckTrigger)(paTrigger,
+					paCounter->value));
+
+	new_test_value = paTrigger->test_value;
+	paTrigger->test_value = oldvalue;
+
+	/* "If this update would cause value to fall outside the range
+	 *  for an INT64...no change is made to value (test-value) and
+	 *  the alarm state is changed to Inactive before the event is
+	 *  generated."
+	 */
+	if (overflow)
+	{
+	    new_test_value = oldvalue;
+	    pAlarm->state = XSyncAlarmInactive;
+	}
+    }
+    /*  The AlarmNotify event has to have the "new state of the alarm"
+     *  which we can't be sure of until this point.  However, it has
+     *  to have the "old" trigger test value.  That's the reason for
+     *  all the newvalue/oldvalue shuffling above.  After we send the
+     *  events, give the trigger its new test value.
+     */
+    SyncSendAlarmNotifyEvents(pAlarm);
+    pTrigger->test_value = new_test_value;
+}
+
+
+/*  This function is called when an Await unblocks, either as a result
+ *  of the trigger firing OR the counter being destroyed.
+ *  It goes into pTrigger->TriggerFired AND pTrigger->CounterDestroyed
+ *  (for Await triggers).
+ */
+static void
+SyncAwaitTriggerFired(SyncTrigger *pTrigger)
+{
+    SyncAwait *pAwait = (SyncAwait *)pTrigger;
+    int numwaits;
+    SyncAwaitUnion *pAwaitUnion;
+    SyncAwait **ppAwait;
+    int num_events = 0;
+
+    pAwaitUnion = (SyncAwaitUnion *)pAwait->pHeader;
+    numwaits = pAwaitUnion->header.num_waitconditions;
+    ppAwait = malloc(numwaits * sizeof(SyncAwait *));
+    if (!ppAwait)
+	goto bail;
+
+    pAwait = &(pAwaitUnion+1)->await;
+
+    /* "When a client is unblocked, all the CounterNotify events for
+     *  the Await request are generated contiguously. If count is 0
+     *  there are no more events to follow for this request. If
+     *  count is n, there are at least n more events to follow."
+     *
+     *  Thus, it is best to find all the counters for which events
+     *  need to be sent first, so that an accurate count field can
+     *  be stored in the events.
+     */
+    for ( ; numwaits; numwaits--, pAwait++)
+    {
+	CARD64 diff;
+	Bool overflow, diffgreater, diffequal;
+
+	/* "A CounterNotify event with the destroyed flag set to TRUE is
+	 *  always generated if the counter for one of the triggers is
+	 *  destroyed."
+	 */
+	if (pAwait->trigger.pSync->beingDestroyed)
+	{
+	    ppAwait[num_events++] = pAwait;
+	    continue;
+	}
+	
+	if (SYNC_COUNTER == pAwait->trigger.pSync->type)
+	{
+	    SyncCounter *pCounter = (SyncCounter *) pAwait->trigger.pSync;
+
+	    /* "The difference between the counter and the test value is
+	     *  calculated by subtracting the test value from the value of
+	     *  the counter."
+	     */
+	    XSyncValueSubtract(&diff, pCounter->value,
+			       pAwait->trigger.test_value, &overflow);
+
+	    /* "If the difference lies outside the range for an INT64, an
+	     *  event is not generated."
+	     */
+	    if (overflow)
+		continue;
+	    diffgreater = XSyncValueGreaterThan(diff, pAwait->event_threshold);
+	    diffequal   = XSyncValueEqual(diff, pAwait->event_threshold);
+
+	    /* "If the test-type is PositiveTransition or
+	     *  PositiveComparison, a CounterNotify event is generated if
+	     *  the difference is at least event-threshold. If the test-type
+	     *  is NegativeTransition or NegativeComparison, a CounterNotify
+	     *  event is generated if the difference is at most
+	     *  event-threshold."
+	     */
+
+	    if ( ((pAwait->trigger.test_type == XSyncPositiveComparison ||
+		   pAwait->trigger.test_type == XSyncPositiveTransition)
+		  && (diffgreater || diffequal))
+		 ||
+		 ((pAwait->trigger.test_type == XSyncNegativeComparison ||
+		   pAwait->trigger.test_type == XSyncNegativeTransition)
+		  && (!diffgreater) /* less or equal */
+		 )
+	       )
+	    {
+		ppAwait[num_events++] = pAwait;
+	    }
+	}
+    }
+    if (num_events)
+	SyncSendCounterNotifyEvents(pAwaitUnion->header.client, ppAwait,
+				    num_events);
+    free(ppAwait);
+
+bail:
+    /* unblock the client */
+    AttendClient(pAwaitUnion->header.client);
+    /* delete the await */
+    FreeResource(pAwaitUnion->header.delete_id, RT_NONE);
+}
+
+
+/*  This function should always be used to change a counter's value so that
+ *  any triggers depending on the counter will be checked.
+ */
+void
+SyncChangeCounter(SyncCounter *pCounter, CARD64 newval)
+{
+    SyncTriggerList       *ptl, *pnext;
+    CARD64 oldval;
+
+    oldval = pCounter->value;
+    pCounter->value = newval;
+
+    /* run through triggers to see if any become true */
+    for (ptl = pCounter->sync.pTriglist; ptl; ptl = pnext)
+    {
+	pnext = ptl->next;
+	if ((*ptl->pTrigger->CheckTrigger)(ptl->pTrigger, oldval))
+	    (*ptl->pTrigger->TriggerFired)(ptl->pTrigger);
+    }
+
+    if (IsSystemCounter(pCounter))
+    {
+	SyncComputeBracketValues(pCounter);
+    }
+}
+
+
+/* loosely based on dix/events.c/EventSelectForWindow */
+static Bool
+SyncEventSelectForAlarm(SyncAlarm *pAlarm, ClientPtr client, Bool wantevents)
+{
+    SyncAlarmClientList *pClients;
+
+    if (client == pAlarm->client) /* alarm owner */
+    {
+	pAlarm->events = wantevents;
+	return Success;
+    }
+
+    /* see if the client is already on the list (has events selected) */
+
+    for (pClients = pAlarm->pEventClients; pClients;
+	 pClients = pClients->next)
+    {
+	if (pClients->client == client)
+	{
+	    /* client's presence on the list indicates desire for
+	     * events.  If the client doesn't want events, remove it
+	     * from the list.  If the client does want events, do
+	     * nothing, since it's already got them.
+	     */
+	    if (!wantevents)
+	    {
+		FreeResource(pClients->delete_id, RT_NONE);
+	    }
+	    return Success;
+	}
+    }
+
+    /*  if we get here, this client does not currently have
+     *  events selected on the alarm
+     */
+
+    if (!wantevents)
+	/* client doesn't want events, and we just discovered that it
+	 * doesn't have them, so there's nothing to do.
+	 */
+	return Success;
+
+    /* add new client to pAlarm->pEventClients */
+
+    pClients = malloc(sizeof(SyncAlarmClientList));
+    if (!pClients)
+	return BadAlloc;
+
+    /*  register it as a resource so it will be cleaned up
+     *  if the client dies
+     */
+
+    pClients->delete_id = FakeClientID(client->index);
+
+    /* link it into list after we know all the allocations succeed */
+    pClients->next = pAlarm->pEventClients;
+    pAlarm->pEventClients = pClients;
+    pClients->client = client;
+
+    if (!AddResource(pClients->delete_id, RTAlarmClient, pAlarm))
+	return BadAlloc;
+
+    return Success;
+}
+
+/*
+ * ** SyncChangeAlarmAttributes ** This is used by CreateAlarm and ChangeAlarm
+ */
+static int
+SyncChangeAlarmAttributes(ClientPtr client, SyncAlarm *pAlarm, Mask mask,
+			  CARD32 *values)
+{
+    int		   status;
+    XSyncCounter   counter;
+    Mask	   origmask = mask;
+
+    counter =
+	pAlarm->trigger.pSync ? pAlarm->trigger.pSync->id : None;
+
+    while (mask)
+    {
+	int    index2 = lowbit(mask);
+	mask &= ~index2;
+	switch (index2)
+	{
+	  case XSyncCACounter:
+	    mask &= ~XSyncCACounter;
+	    /* sanity check in SyncInitTrigger */
+	    counter = *values++;
+	    break;
+
+	  case XSyncCAValueType:
+	    mask &= ~XSyncCAValueType;
+	    /* sanity check in SyncInitTrigger */
+	    pAlarm->trigger.value_type = *values++;
+	    break;
+
+	  case XSyncCAValue:
+	    mask &= ~XSyncCAValue;
+	    XSyncIntsToValue(&pAlarm->trigger.wait_value, values[1], values[0]);
+	    values += 2;
+	    break;
+
+	  case XSyncCATestType:
+	    mask &= ~XSyncCATestType;
+	    /* sanity check in SyncInitTrigger */
+	    pAlarm->trigger.test_type = *values++;
+	    break;
+
+	  case XSyncCADelta:
+	    mask &= ~XSyncCADelta;
+	    XSyncIntsToValue(&pAlarm->delta, values[1], values[0]);
+	    values += 2;
+	    break;
+
+	  case XSyncCAEvents:
+	    mask &= ~XSyncCAEvents;
+	    if ((*values != xTrue) && (*values != xFalse))
+	    {
+		client->errorValue = *values;
+		return BadValue;
+	    }
+	    status = SyncEventSelectForAlarm(pAlarm, client,
+					     (Bool)(*values++));
+	    if (status != Success)
+		return status;
+	    break;
+
+	  default:
+	    client->errorValue = mask;
+	    return BadValue;
+	}
+    }
+
+    /* "If the test-type is PositiveComparison or PositiveTransition
+     *  and delta is less than zero, or if the test-type is
+     *  NegativeComparison or NegativeTransition and delta is
+     *  greater than zero, a Match error is generated."
+     */
+    if (origmask & (XSyncCADelta|XSyncCATestType))
+    {
+	CARD64 zero;
+	XSyncIntToValue(&zero, 0);
+	if ((((pAlarm->trigger.test_type == XSyncPositiveComparison) ||
+	      (pAlarm->trigger.test_type == XSyncPositiveTransition))
+	     && XSyncValueLessThan(pAlarm->delta, zero))
+	    ||
+	    (((pAlarm->trigger.test_type == XSyncNegativeComparison) ||
+	      (pAlarm->trigger.test_type == XSyncNegativeTransition))
+	     && XSyncValueGreaterThan(pAlarm->delta, zero))
+	   )
+	{
+	    return BadMatch;
+	}
+    }
+
+    /* postpone this until now, when we're sure nothing else can go wrong */
+    if ((status = SyncInitTrigger(client, &pAlarm->trigger, counter, RTCounter,
+			     origmask & XSyncCAAllTrigger)) != Success)
+	return status;
+
+    /* XXX spec does not really say to do this - needs clarification */
+    pAlarm->state = XSyncAlarmActive;
+    return Success;
+}
+
+static SyncObject *
+SyncCreate(ClientPtr client, XID id, unsigned char type)
+{
+    SyncObject *pSync;
+
+    switch (type) {
+    case SYNC_COUNTER:
+	pSync = malloc(sizeof(SyncCounter));
+	break;
+    case SYNC_FENCE:
+	pSync = (SyncObject*)dixAllocateObjectWithPrivates(SyncFence,
+							   PRIVATE_SYNC_FENCE);
+	break;
+    default:
+	return NULL;
+    }
+
+    if (!pSync)
+	return NULL;
+
+    pSync->client = client;
+    pSync->id = id;
+    pSync->pTriglist = NULL;
+    pSync->beingDestroyed = FALSE;
+    pSync->type = type;
+
+    return pSync;
+}
+
+
+static SyncCounter *
+SyncCreateCounter(ClientPtr client, XSyncCounter id, CARD64 initialvalue)
+{
+    SyncCounter *pCounter;
+
+    if (!(pCounter = (SyncCounter *)SyncCreate(client,
+					       id,
+					       SYNC_COUNTER)))
+	return NULL;
+
+    pCounter->value = initialvalue;
+    pCounter->pSysCounterInfo = NULL;
+
+    if (!AddResource(id, RTCounter, (pointer) pCounter))
+	return NULL;
+
+    return pCounter;
+}
+
+static int FreeCounter(void *, XID);
+
+/*
+ * ***** System Counter utilities
+ */
+
+pointer
+SyncCreateSystemCounter(
+	char *name,
+	CARD64 initial,
+	CARD64 resolution,
+	SyncCounterType counterType,
+	void (*QueryValue)(pointer /* pCounter */,
+	      	           CARD64 * /* pValue_return */),
+	void (*BracketValues)(pointer /* pCounter */,
+	       	              CARD64 * /* pbracket_less */,
+	                      CARD64 * /* pbracket_greater */)
+	)
+{
+    SyncCounter    *pCounter;
+
+    SysCounterList = realloc(SysCounterList,
+			    (SyncNumSystemCounters+1)*sizeof(SyncCounter *));
+    if (!SysCounterList)
+	return NULL;
+
+    /* this function may be called before SYNC has been initialized, so we
+     * have to make sure RTCounter is created.
+     */
+    if (RTCounter == 0)
+    {
+	RTCounter = CreateNewResourceType(FreeCounter, "SyncCounter");
+	if (RTCounter == 0)
+	{
+	    return NULL;
+	}
+    }
+
+    pCounter = SyncCreateCounter(NULL, FakeClientID(0), initial);
+
+    if (pCounter)
+    {
+	SysCounterInfo *psci;
+
+	psci = malloc(sizeof(SysCounterInfo));
+	if (!psci)
+	{
+	    FreeResource(pCounter->sync.id, RT_NONE);
+	    return pCounter;
+	}
+	pCounter->pSysCounterInfo = psci;
+	psci->name = name;
+	psci->resolution = resolution;
+	psci->counterType = counterType;
+	psci->QueryValue = QueryValue;
+	psci->BracketValues = BracketValues;
+	XSyncMaxValue(&psci->bracket_greater);
+	XSyncMinValue(&psci->bracket_less);
+	SysCounterList[SyncNumSystemCounters++] = pCounter;
+    }
+    return pCounter;
+}
+
+void
+SyncDestroySystemCounter(pointer pSysCounter)
+{
+    SyncCounter *pCounter = (SyncCounter *)pSysCounter;
+    FreeResource(pCounter->sync.id, RT_NONE);
+}
+
+static void
+SyncComputeBracketValues(SyncCounter *pCounter)
+{
+    SyncTriggerList *pCur;
+    SyncTrigger *pTrigger;
+    SysCounterInfo *psci;
+    CARD64 *pnewgtval = NULL;
+    CARD64 *pnewltval = NULL;
+    SyncCounterType ct;
+
+    if (!pCounter)
+	return;
+
+    psci = pCounter->pSysCounterInfo;
+    ct = pCounter->pSysCounterInfo->counterType;
+    if (ct == XSyncCounterNeverChanges)
+	return;
+
+    XSyncMaxValue(&psci->bracket_greater);
+    XSyncMinValue(&psci->bracket_less);
+
+    for (pCur = pCounter->sync.pTriglist; pCur; pCur = pCur->next)
+    {
+	pTrigger = pCur->pTrigger;
+	
+        if (pTrigger->test_type == XSyncPositiveComparison &&
+	    ct != XSyncCounterNeverIncreases)
+	{
+	    if (XSyncValueLessThan(pCounter->value, pTrigger->test_value) &&
+		XSyncValueLessThan(pTrigger->test_value,
+				   psci->bracket_greater))
+	    {
+		psci->bracket_greater = pTrigger->test_value;
+		pnewgtval = &psci->bracket_greater;
+	    }
+	}
+	else if (pTrigger->test_type == XSyncNegativeComparison &&
+		 ct != XSyncCounterNeverDecreases)
+	{
+	    if (XSyncValueGreaterThan(pCounter->value, pTrigger->test_value) &&
+		XSyncValueGreaterThan(pTrigger->test_value,
+				      psci->bracket_less))
+	    {
+		psci->bracket_less = pTrigger->test_value;
+		pnewltval = &psci->bracket_less;
+	    }
+	}
+	else if (pTrigger->test_type == XSyncNegativeTransition &&
+		   ct != XSyncCounterNeverIncreases)
+	{
+	    if (XSyncValueGreaterThan(pCounter->value, pTrigger->test_value) &&
+		XSyncValueGreaterThan(pTrigger->test_value, psci->bracket_less))
+	    {
+		psci->bracket_less = pTrigger->test_value;
+		pnewltval = &psci->bracket_less;
+	    } else if (XSyncValueEqual(pCounter->value, pTrigger->test_value) &&
+		       XSyncValueLessThan(pTrigger->test_value,
+					  psci->bracket_greater))
+	    {
+	        /*
+		 * The value is exactly equal to our threshold.  We want one
+		 * more event in the positive direction to ensure we pick up
+		 * when the value *exceeds* this threshold.
+		 */
+	        psci->bracket_greater = pTrigger->test_value;
+		pnewgtval = &psci->bracket_greater;
+	    }
+	}
+        else if (pTrigger->test_type == XSyncPositiveTransition &&
+		  ct != XSyncCounterNeverDecreases)
+	{
+	    if (XSyncValueLessThan(pCounter->value, pTrigger->test_value) &&
+		XSyncValueLessThan(pTrigger->test_value, psci->bracket_greater))
+	    {
+		psci->bracket_greater = pTrigger->test_value;
+		pnewgtval = &psci->bracket_greater;
+	    } else if (XSyncValueEqual(pCounter->value, pTrigger->test_value) &&
+		       XSyncValueGreaterThan(pTrigger->test_value,
+					     psci->bracket_less))
+	    {
+	        /*
+		 * The value is exactly equal to our threshold.  We want one
+		 * more event in the negative direction to ensure we pick up
+		 * when the value is less than this threshold.
+		 */
+	        psci->bracket_less = pTrigger->test_value;
+		pnewltval = &psci->bracket_less;
+	    }
+	}
+    } /* end for each trigger */
+
+    if (pnewgtval || pnewltval)
+    {
+	(*psci->BracketValues)((pointer)pCounter, pnewltval, pnewgtval);
+    }
+}
+
+/*
+ * *****  Resource delete functions
+ */
+
+/* ARGSUSED */
+static int
+FreeAlarm(void *addr, XID id)
+{
+    SyncAlarm      *pAlarm = (SyncAlarm *) addr;
+
+    pAlarm->state = XSyncAlarmDestroyed;
+
+    SyncSendAlarmNotifyEvents(pAlarm);
+
+    /* delete event selections */
+
+    while (pAlarm->pEventClients)
+	FreeResource(pAlarm->pEventClients->delete_id, RT_NONE);
+
+    SyncDeleteTriggerFromSyncObject(&pAlarm->trigger);
+
+    free(pAlarm);
+    return Success;
+}
+
+
+/*
+ * ** Cleanup after the destruction of a Counter
+ */
+/* ARGSUSED */
+static int
+FreeCounter(void *env, XID id)
+{
+    SyncCounter     *pCounter = (SyncCounter *) env;
+    SyncTriggerList *ptl, *pnext;
+
+    pCounter->sync.beingDestroyed = TRUE;
+    /* tell all the counter's triggers that the counter has been destroyed */
+    for (ptl = pCounter->sync.pTriglist; ptl; ptl = pnext)
+    {
+	(*ptl->pTrigger->CounterDestroyed)(ptl->pTrigger);
+	pnext = ptl->next;
+	free(ptl); /* destroy the trigger list as we go */
+    }
+    if (IsSystemCounter(pCounter))
+    {
+	int i, found = 0;
+
+	free(pCounter->pSysCounterInfo);
+
+	/* find the counter in the list of system counters and remove it */
+
+	if (SysCounterList)
+	{
+	    for (i = 0; i < SyncNumSystemCounters; i++)
+	    {
+		if (SysCounterList[i] == pCounter)
+		{
+		    found = i;
+		    break;
+		}
+	    }
+	    if (found < (SyncNumSystemCounters-1))
+	    {
+		for (i = found; i < SyncNumSystemCounters-1; i++)
+		{
+		    SysCounterList[i] = SysCounterList[i+1];
+		}
+	    }
+	}
+	SyncNumSystemCounters--;
+    }
+    free(pCounter);
+    return Success;
+}
+
+/*
+ * ** Cleanup after Await
+ */
+/* ARGSUSED */
+static int
+FreeAwait(void *addr, XID id)
+{
+    SyncAwaitUnion *pAwaitUnion = (SyncAwaitUnion *) addr;
+    SyncAwait *pAwait;
+    int numwaits;
+
+    pAwait = &(pAwaitUnion+1)->await; /* first await on list */
+
+    /* remove triggers from counters */
+
+    for (numwaits = pAwaitUnion->header.num_waitconditions; numwaits;
+	 numwaits--, pAwait++)
+    {
+	/* If the counter is being destroyed, FreeCounter will delete
+	 * the trigger list itself, so don't do it here.
+	 */
+	SyncObject *pSync = pAwait->trigger.pSync;
+	if (pSync && !pSync->beingDestroyed)
+	    SyncDeleteTriggerFromSyncObject(&pAwait->trigger);
+    }
+    free(pAwaitUnion);
+    return Success;
+}
+
+/* loosely based on dix/events.c/OtherClientGone */
+static int
+FreeAlarmClient(void *value, XID id)
+{
+    SyncAlarm *pAlarm = (SyncAlarm *)value;
+    SyncAlarmClientList *pCur, *pPrev;
+
+    for (pPrev = NULL, pCur = pAlarm->pEventClients;
+	 pCur;
+	 pPrev = pCur, pCur = pCur->next)
+    {
+	if (pCur->delete_id == id)
+	{
+	    if (pPrev)
+		pPrev->next = pCur->next;
+	    else
+		pAlarm->pEventClients = pCur->next;
+	    free(pCur);
+	    return Success;
+	}
+    }
+    FatalError("alarm client not on event list");
+    /*NOTREACHED*/
+}
+
+
+/*
+ * *****  Proc functions
+ */
+
+
+/*
+ * ** Initialize the extension
+ */
+static int
+ProcSyncInitialize(ClientPtr client)
+{
+    xSyncInitializeReply  rep;
+    int   n;
+
+    REQUEST_SIZE_MATCH(xSyncInitializeReq);
+
+    memset(&rep, 0, sizeof(xSyncInitializeReply));
+    rep.type = X_Reply;
+    rep.sequenceNumber = client->sequence;
+    rep.majorVersion = SERVER_SYNC_MAJOR_VERSION;
+    rep.minorVersion = SERVER_SYNC_MINOR_VERSION;
+    rep.length = 0;
+
+    if (client->swapped)
+    {
+	swaps(&rep.sequenceNumber, n);
+    }
+    WriteToClient(client, sizeof(rep), (char *) &rep);
+    return Success;
+}
+
+/*
+ * ** Get list of system counters available through the extension
+ */
+static int
+ProcSyncListSystemCounters(ClientPtr client)
+{
+    xSyncListSystemCountersReply  rep;
+    int i, len;
+    xSyncSystemCounter *list = NULL, *walklist = NULL;
+
+    REQUEST_SIZE_MATCH(xSyncListSystemCountersReq);
+
+    rep.type = X_Reply;
+    rep.sequenceNumber = client->sequence;
+    rep.nCounters = SyncNumSystemCounters;
+
+    for (i = len = 0; i < SyncNumSystemCounters; i++)
+    {
+	char *name = SysCounterList[i]->pSysCounterInfo->name;
+	/* pad to 4 byte boundary */
+	len += pad_to_int32(sz_xSyncSystemCounter + strlen(name));
+    }
+
+    if (len)
+    {
+	walklist = list = malloc(len);
+	if (!list)
+	    return BadAlloc;
+    }
+
+    rep.length = bytes_to_int32(len);
+
+    if (client->swapped)
+    {
+	char n;
+	swaps(&rep.sequenceNumber, n);
+	swapl(&rep.length, n);
+	swapl(&rep.nCounters, n);
+    }
+
+    for (i = 0; i < SyncNumSystemCounters; i++)
+    {
+	int namelen;
+	char *pname_in_reply;
+	SysCounterInfo *psci = SysCounterList[i]->pSysCounterInfo;
+
+	walklist->counter = SysCounterList[i]->sync.id;
+	walklist->resolution_hi = XSyncValueHigh32(psci->resolution);
+	walklist->resolution_lo = XSyncValueLow32(psci->resolution);
+	namelen = strlen(psci->name);
+	walklist->name_length = namelen;
+
+	if (client->swapped)
+	{
+	    char n;
+	    swapl(&walklist->counter, n);
+	    swapl(&walklist->resolution_hi, n);
+	    swapl(&walklist->resolution_lo, n);
+	    swaps(&walklist->name_length, n);
+	}
+
+	pname_in_reply = ((char *)walklist) + sz_xSyncSystemCounter;
+	strncpy(pname_in_reply, psci->name, namelen);
+	walklist = (xSyncSystemCounter *) (((char *)walklist) +
+				pad_to_int32(sz_xSyncSystemCounter + namelen));
+    }
+
+    WriteToClient(client, sizeof(rep), (char *) &rep);
+    if (len)
+    {
+	WriteToClient(client, len, (char *) list);
+	free(list);
+    }
+
+    return Success;
+}
+
+/*
+ * ** Set client Priority
+ */
+static int
+ProcSyncSetPriority(ClientPtr client)
+{
+    REQUEST(xSyncSetPriorityReq);
+    ClientPtr priorityclient;
+    int rc;
+
+    REQUEST_SIZE_MATCH(xSyncSetPriorityReq);
+
+    if (stuff->id == None)
+	priorityclient = client;
+    else {
+	rc = dixLookupClient(&priorityclient, stuff->id, client,
+			     DixSetAttrAccess);
+	if (rc != Success)
+	    return rc;
+    }
+
+    if (priorityclient->priority != stuff->priority)
+    {
+	priorityclient->priority = stuff->priority;
+
+	/*  The following will force the server back into WaitForSomething
+	 *  so that the change in this client's priority is immediately
+	 *  reflected.
+	 */
+	isItTimeToYield = TRUE;
+	dispatchException |= DE_PRIORITYCHANGE;
+    }
+    return Success;
+}
+
+/*
+ * ** Get client Priority
+ */
+static int
+ProcSyncGetPriority(ClientPtr client)
+{
+    REQUEST(xSyncGetPriorityReq);
+    xSyncGetPriorityReply rep;
+    ClientPtr priorityclient;
+    int rc;
+
+    REQUEST_SIZE_MATCH(xSyncGetPriorityReq);
+
+    if (stuff->id == None)
+	priorityclient = client;
+    else {
+	rc = dixLookupClient(&priorityclient, stuff->id, client,
+			     DixGetAttrAccess);
+	if (rc != Success)
+	    return rc;
+    }
+
+    rep.type = X_Reply;
+    rep.length = 0;
+    rep.sequenceNumber = client->sequence;
+    rep.priority = priorityclient->priority;
+
+    if (client->swapped)
+    {
+	char n;
+	swaps(&rep.sequenceNumber, n);
+	swapl(&rep.priority, n);
+    }
+
+    WriteToClient(client, sizeof(xSyncGetPriorityReply), (char *) &rep);
+
+    return Success;
+}
+
+/*
+ * ** Create a new counter
+ */
+static int
+ProcSyncCreateCounter(ClientPtr client)
+{
+    REQUEST(xSyncCreateCounterReq);
+    CARD64          initial;
+
+    REQUEST_SIZE_MATCH(xSyncCreateCounterReq);
+
+    LEGAL_NEW_RESOURCE(stuff->cid, client);
+
+    XSyncIntsToValue(&initial, stuff->initial_value_lo, stuff->initial_value_hi);
+    if (!SyncCreateCounter(client, stuff->cid, initial))
+	return BadAlloc;
+
+    return Success;
+}
+
+/*
+ * ** Set Counter value
+ */
+static int
+ProcSyncSetCounter(ClientPtr client)
+{
+    REQUEST(xSyncSetCounterReq);
+    SyncCounter    *pCounter;
+    CARD64	   newvalue;
+    int	rc;
+
+    REQUEST_SIZE_MATCH(xSyncSetCounterReq);
+
+    rc = dixLookupResourceByType((pointer *)&pCounter, stuff->cid, RTCounter,
+				 client, DixWriteAccess);
+    if (rc != Success)
+	return rc;
+
+    if (IsSystemCounter(pCounter))
+    {
+	client->errorValue = stuff->cid;
+	return BadAccess;
+    }
+
+    XSyncIntsToValue(&newvalue, stuff->value_lo, stuff->value_hi);
+    SyncChangeCounter(pCounter, newvalue);
+    return Success;
+}
+
+/*
+ * ** Change Counter value
+ */
+static int
+ProcSyncChangeCounter(ClientPtr client)
+{
+    REQUEST(xSyncChangeCounterReq);
+    SyncCounter    *pCounter;
+    CARD64          newvalue;
+    Bool	    overflow;
+    int	rc;
+
+    REQUEST_SIZE_MATCH(xSyncChangeCounterReq);
+
+    rc = dixLookupResourceByType((pointer *)&pCounter, stuff->cid, RTCounter,
+				 client, DixWriteAccess);
+    if (rc != Success)
+	return rc;
+
+    if (IsSystemCounter(pCounter))
+    {
+	client->errorValue = stuff->cid;
+	return BadAccess;
+    }
+
+    XSyncIntsToValue(&newvalue, stuff->value_lo, stuff->value_hi);
+    XSyncValueAdd(&newvalue, pCounter->value, newvalue, &overflow);
+    if (overflow)
+    {
+	/* XXX 64 bit value can't fit in 32 bits; do the best we can */
+	client->errorValue = stuff->value_hi;
+	return BadValue;
+    }
+    SyncChangeCounter(pCounter, newvalue);
+    return Success;
+}
+
+/*
+ * ** Destroy a counter
+ */
+static int
+ProcSyncDestroyCounter(ClientPtr client)
+{
+    REQUEST(xSyncDestroyCounterReq);
+    SyncCounter    *pCounter;
+    int rc;
+
+    REQUEST_SIZE_MATCH(xSyncDestroyCounterReq);
+
+    rc = dixLookupResourceByType((pointer *)&pCounter, stuff->counter, RTCounter,
+				 client, DixDestroyAccess);
+    if (rc != Success)
+	return rc;
+
+    if (IsSystemCounter(pCounter))
+    {
+	client->errorValue = stuff->counter;
+	return BadAccess;
+    }
+    FreeResource(pCounter->sync.id, RT_NONE);
+    return Success;
+}
+
+static SyncAwaitUnion*
+SyncAwaitPrologue(ClientPtr client, int items)
+{
+    SyncAwaitUnion *pAwaitUnion;
+
+    /*  all the memory for the entire await list is allocated
+     *  here in one chunk
+     */
+    pAwaitUnion = malloc((items+1) * sizeof(SyncAwaitUnion));
+    if (!pAwaitUnion)
+	return NULL;
+
+    /* first item is the header, remainder are real wait conditions */
+
+    pAwaitUnion->header.delete_id = FakeClientID(client->index);
+    pAwaitUnion->header.client = client;
+    pAwaitUnion->header.num_waitconditions = 0;
+
+    if (!AddResource(pAwaitUnion->header.delete_id, RTAwait, pAwaitUnion))
+	return NULL;
+
+    return pAwaitUnion;
+}
+
+static void
+SyncAwaitEpilogue(ClientPtr client, int items, SyncAwaitUnion *pAwaitUnion)
+{
+    SyncAwait *pAwait;
+    int i;
+
+    IgnoreClient(client);
+
+    /* see if any of the triggers are already true */
+
+    pAwait = &(pAwaitUnion+1)->await; /* skip over header */
+    for (i = 0; i < items; i++, pAwait++)
+    {
+	CARD64 value;
+
+	/*  don't have to worry about NULL counters because the request
+	 *  errors before we get here out if they occur
+	 */
+	switch (pAwait->trigger.pSync->type) {
+	case SYNC_COUNTER:
+	    value = ((SyncCounter *)pAwait->trigger.pSync)->value;
+	    break;
+	default:
+	    XSyncIntToValue(&value, 0);
+	}
+
+	if ((*pAwait->trigger.CheckTrigger)(&pAwait->trigger, value))
+	{
+	    (*pAwait->trigger.TriggerFired)(&pAwait->trigger);
+	    break; /* once is enough */
+	}
+    }
+}
+
+/*
+ * ** Await
+ */
+static int
+ProcSyncAwait(ClientPtr client)
+{
+    REQUEST(xSyncAwaitReq);
+    int             len, items;
+    int             i;
+    xSyncWaitCondition *pProtocolWaitConds;
+    SyncAwaitUnion *pAwaitUnion;
+    SyncAwait	   *pAwait;
+    int		   status;
+
+    REQUEST_AT_LEAST_SIZE(xSyncAwaitReq);
+
+    len = client->req_len << 2;
+    len -= sz_xSyncAwaitReq;
+    items = len / sz_xSyncWaitCondition;
+
+    if (items * sz_xSyncWaitCondition != len)
+    {
+	return BadLength;
+    }
+    if (items == 0)
+    {
+	client->errorValue = items; /* XXX protocol change */
+	return BadValue;
+    }
+
+    if (!(pAwaitUnion = SyncAwaitPrologue(client, items)))
+	return BadAlloc;
+
+    /* don't need to do any more memory allocation for this request! */
+
+    pProtocolWaitConds = (xSyncWaitCondition *) & stuff[1];
+
+    pAwait = &(pAwaitUnion+1)->await; /* skip over header */
+    for (i = 0; i < items; i++, pProtocolWaitConds++, pAwait++)
+    {
+	if (pProtocolWaitConds->counter == None) /* XXX protocol change */
+	{
+	    /*  this should take care of removing any triggers created by
+	     *  this request that have already been registered on sync objects
+	     */
+	    FreeResource(pAwaitUnion->header.delete_id, RT_NONE);
+	    client->errorValue = pProtocolWaitConds->counter;
+	    return SyncErrorBase + XSyncBadCounter;
+	}
+
+	/* sanity checks are in SyncInitTrigger */
+	pAwait->trigger.pSync = NULL;
+	pAwait->trigger.value_type = pProtocolWaitConds->value_type;
+	XSyncIntsToValue(&pAwait->trigger.wait_value,
+			 pProtocolWaitConds->wait_value_lo,
+			 pProtocolWaitConds->wait_value_hi);
+	pAwait->trigger.test_type = pProtocolWaitConds->test_type;
+
+	status = SyncInitTrigger(client, &pAwait->trigger,
+				 pProtocolWaitConds->counter, RTCounter,
+				 XSyncCAAllTrigger);
+	if (status != Success)
+	{
+	    /*  this should take care of removing any triggers created by
+	     *  this request that have already been registered on sync objects
+	     */
+	    FreeResource(pAwaitUnion->header.delete_id, RT_NONE);
+	    return status;
+	}
+	/* this is not a mistake -- same function works for both cases */
+	pAwait->trigger.TriggerFired = SyncAwaitTriggerFired;
+	pAwait->trigger.CounterDestroyed = SyncAwaitTriggerFired;
+	XSyncIntsToValue(&pAwait->event_threshold,
+			 pProtocolWaitConds->event_threshold_lo,
+			 pProtocolWaitConds->event_threshold_hi);
+	pAwait->pHeader = &pAwaitUnion->header;
+	pAwaitUnion->header.num_waitconditions++;
+    }
+
+    SyncAwaitEpilogue(client, items, pAwaitUnion);
+
+    return Success;
+}
+
+
+/*
+ * ** Query a counter
+ */
+static int
+ProcSyncQueryCounter(ClientPtr client)
+{
+    REQUEST(xSyncQueryCounterReq);
+    xSyncQueryCounterReply rep;
+    SyncCounter    *pCounter;
+    int rc;
+
+    REQUEST_SIZE_MATCH(xSyncQueryCounterReq);
+
+    rc = dixLookupResourceByType((pointer *)&pCounter, stuff->counter,
+				 RTCounter, client, DixReadAccess);
+    if (rc != Success)
+	return rc;
+
+    rep.type = X_Reply;
+    rep.length = 0;
+    rep.sequenceNumber = client->sequence;
+
+    /* if system counter, ask it what the current value is */
+
+    if (IsSystemCounter(pCounter))
+    {
+	(*pCounter->pSysCounterInfo->QueryValue) ((pointer) pCounter,
+						  &pCounter->value);
+    }
+
+    rep.value_hi = XSyncValueHigh32(pCounter->value);
+    rep.value_lo = XSyncValueLow32(pCounter->value);
+    if (client->swapped)
+    {
+	char n;
+	swaps(&rep.sequenceNumber, n);
+	swapl(&rep.length, n);
+	swapl(&rep.value_hi, n);
+	swapl(&rep.value_lo, n);
+    }
+    WriteToClient(client, sizeof(xSyncQueryCounterReply), (char *) &rep);
+    return Success;
+}
+
+
+/*
+ * ** Create Alarm
+ */
+static int
+ProcSyncCreateAlarm(ClientPtr client)
+{
+    REQUEST(xSyncCreateAlarmReq);
+    SyncAlarm      *pAlarm;
+    int             status;
+    unsigned long   len, vmask;
+    SyncTrigger	    *pTrigger;
+
+    REQUEST_AT_LEAST_SIZE(xSyncCreateAlarmReq);
+
+    LEGAL_NEW_RESOURCE(stuff->id, client);
+
+    vmask = stuff->valueMask;
+    len = client->req_len - bytes_to_int32(sizeof(xSyncCreateAlarmReq));
+    /* the "extra" call to Ones accounts for the presence of 64 bit values */
+    if (len != (Ones(vmask) + Ones(vmask & (XSyncCAValue|XSyncCADelta))))
+	return BadLength;
+
+    if (!(pAlarm = malloc(sizeof(SyncAlarm))))
+    {
+	return BadAlloc;
+    }
+
+    /* set up defaults */
+
+    pTrigger = &pAlarm->trigger;
+    pTrigger->pSync = NULL;
+    pTrigger->value_type = XSyncAbsolute;
+    XSyncIntToValue(&pTrigger->wait_value, 0L);
+    pTrigger->test_type = XSyncPositiveComparison;
+    pTrigger->TriggerFired = SyncAlarmTriggerFired;
+    pTrigger->CounterDestroyed = SyncAlarmCounterDestroyed;
+    status = SyncInitTrigger(client, pTrigger, None, RTCounter,
+			     XSyncCAAllTrigger);
+    if (status != Success)
+    {
+	free(pAlarm);
+	return status;
+    }
+
+    pAlarm->client = client;
+    pAlarm->alarm_id = stuff->id;
+    XSyncIntToValue(&pAlarm->delta, 1L);
+    pAlarm->events = TRUE;
+    pAlarm->state = XSyncAlarmInactive;
+    pAlarm->pEventClients = NULL;
+    status = SyncChangeAlarmAttributes(client, pAlarm, vmask,
+				       (CARD32 *)&stuff[1]);
+    if (status != Success)
+    {
+	free(pAlarm);
+	return status;
+    }
+
+    if (!AddResource(stuff->id, RTAlarm, pAlarm))
+	return BadAlloc;
+
+    /*  see if alarm already triggered.  NULL counter will not trigger
+     *  in CreateAlarm and sets alarm state to Inactive.
+     */
+
+    if (!pTrigger->pSync)
+    {
+	pAlarm->state = XSyncAlarmInactive; /* XXX protocol change */
+    }
+    else
+    {
+	SyncCounter *pCounter;
+
+	if (!SyncCheckWarnIsCounter(pTrigger->pSync,
+				    WARN_INVALID_COUNTER_ALARM))
+	{
+	    FreeResource(stuff->id, RT_NONE);
+	    return BadAlloc;
+	}
+
+	pCounter = (SyncCounter *)pTrigger->pSync;
+
+	if ((*pTrigger->CheckTrigger)(pTrigger, pCounter->value))
+	    (*pTrigger->TriggerFired)(pTrigger);
+    }
+
+    return Success;
+}
+
+/*
+ * ** Change Alarm
+ */
+static int
+ProcSyncChangeAlarm(ClientPtr client)
+{
+    REQUEST(xSyncChangeAlarmReq);
+    SyncAlarm   *pAlarm;
+    SyncCounter *pCounter = NULL;
+    long        vmask;
+    int         len, status;
+
+    REQUEST_AT_LEAST_SIZE(xSyncChangeAlarmReq);
+
+    status = dixLookupResourceByType((pointer *)&pAlarm, stuff->alarm, RTAlarm,
+				     client, DixWriteAccess);
+    if (status != Success)
+	return status;
+
+    vmask = stuff->valueMask;
+    len = client->req_len - bytes_to_int32(sizeof(xSyncChangeAlarmReq));
+    /* the "extra" call to Ones accounts for the presence of 64 bit values */
+    if (len != (Ones(vmask) + Ones(vmask & (XSyncCAValue|XSyncCADelta))))
+	return BadLength;
+
+    if ((status = SyncChangeAlarmAttributes(client, pAlarm, vmask,
+					    (CARD32 *)&stuff[1])) != Success)
+	return status;
+
+    if (SyncCheckWarnIsCounter(pAlarm->trigger.pSync,
+			       WARN_INVALID_COUNTER_ALARM))
+	pCounter = (SyncCounter *)pAlarm->trigger.pSync;
+
+    /*  see if alarm already triggered.  NULL counter WILL trigger
+     *  in ChangeAlarm.
+     */
+
+    if (!pCounter ||
+	(*pAlarm->trigger.CheckTrigger)(&pAlarm->trigger, pCounter->value))
+    {
+	(*pAlarm->trigger.TriggerFired)(&pAlarm->trigger);
+    }
+    return Success;
+}
+
+static int
+ProcSyncQueryAlarm(ClientPtr client)
+{
+    REQUEST(xSyncQueryAlarmReq);
+    SyncAlarm      *pAlarm;
+    xSyncQueryAlarmReply rep;
+    SyncTrigger    *pTrigger;
+    int rc;
+
+    REQUEST_SIZE_MATCH(xSyncQueryAlarmReq);
+
+    rc = dixLookupResourceByType((pointer *)&pAlarm, stuff->alarm, RTAlarm,
+				 client, DixReadAccess);
+    if (rc != Success)
+	return rc;
+
+    rep.type = X_Reply;
+    rep.length = bytes_to_int32(sizeof(xSyncQueryAlarmReply) - sizeof(xGenericReply));
+    rep.sequenceNumber = client->sequence;
+
+    pTrigger = &pAlarm->trigger;
+    rep.counter = (pTrigger->pSync) ? pTrigger->pSync->id : None;
+
+#if 0 /* XXX unclear what to do, depends on whether relative value-types
+       * are "consumed" immediately and are considered absolute from then
+       * on.
+       */
+    rep.value_type = pTrigger->value_type;
+    rep.wait_value_hi = XSyncValueHigh32(pTrigger->wait_value);
+    rep.wait_value_lo = XSyncValueLow32(pTrigger->wait_value);
+#else
+    rep.value_type = XSyncAbsolute;
+    rep.wait_value_hi = XSyncValueHigh32(pTrigger->test_value);
+    rep.wait_value_lo = XSyncValueLow32(pTrigger->test_value);
+#endif
+
+    rep.test_type = pTrigger->test_type;
+    rep.delta_hi = XSyncValueHigh32(pAlarm->delta);
+    rep.delta_lo = XSyncValueLow32(pAlarm->delta);
+    rep.events = pAlarm->events;
+    rep.state = pAlarm->state;
+
+    if (client->swapped)
+    {
+	char n;
+	swaps(&rep.sequenceNumber, n);
+	swapl(&rep.length, n);
+	swapl(&rep.counter, n);
+	swapl(&rep.wait_value_hi, n);
+	swapl(&rep.wait_value_lo, n);
+	swapl(&rep.test_type, n);
+	swapl(&rep.delta_hi, n);
+	swapl(&rep.delta_lo, n);
+    }
+
+    WriteToClient(client, sizeof(xSyncQueryAlarmReply), (char *) &rep);
+    return Success;
+}
+
+static int
+ProcSyncDestroyAlarm(ClientPtr client)
+{
+    SyncAlarm *pAlarm;
+    int rc;
+    REQUEST(xSyncDestroyAlarmReq);
+
+    REQUEST_SIZE_MATCH(xSyncDestroyAlarmReq);
+
+    rc = dixLookupResourceByType((pointer *)&pAlarm, stuff->alarm, RTAlarm,
+				 client, DixDestroyAccess);
+    if (rc != Success)
+	return rc;
+
+    FreeResource(stuff->alarm, RT_NONE);
+    return Success;
+}
+
+static int
+ProcSyncCreateFence(ClientPtr client)
+{
+    REQUEST(xSyncCreateFenceReq);
+    DrawablePtr pDraw;
+    SyncFence *pFence;
+    int rc;
+
+    REQUEST_SIZE_MATCH(xSyncCreateFenceReq);
+
+    rc = dixLookupDrawable(&pDraw, stuff->d, client, M_ANY, DixGetAttrAccess);
+    if (rc != Success)
+	return rc;
+
+    LEGAL_NEW_RESOURCE(stuff->fid, client);
+
+    if (!(pFence = (SyncFence *)SyncCreate(client,
+					   stuff->fid,
+					   SYNC_FENCE)))
+	return BadAlloc;
+
+    miSyncInitFence(pDraw->pScreen, pFence, stuff->initially_triggered);
+
+    if (!AddResource(stuff->fid, RTFence, (pointer) pFence))
+	return BadAlloc;
+
+    return client->noClientException;
+}
+
+static int
+FreeFence(void *obj, XID id)
+{
+    SyncFence *pFence = (SyncFence *) obj;
+
+    miSyncDestroyFence(pFence);
+
+    return Success;
+}
+
+int SyncVerifyFence(SyncFence **ppSyncFence, XID fid,
+		    ClientPtr client, Mask mode)
+{
+    int rc = dixLookupResourceByType((pointer *)ppSyncFence, fid, RTFence,
+				     client, mode);
+
+    if (rc != Success)
+	client->errorValue = fid;
+
+    return rc;
+}
+
+static int
+ProcSyncTriggerFence(ClientPtr client)
+{
+    REQUEST(xSyncTriggerFenceReq);
+    SyncFence *pFence;
+    int rc;
+
+    REQUEST_SIZE_MATCH(xSyncTriggerFenceReq);
+
+    rc = dixLookupResourceByType((pointer *)&pFence, stuff->fid, RTFence,
+				 client, DixWriteAccess);
+    if (rc != Success)
+	return rc;
+
+    miSyncTriggerFence(pFence);
+
+    return client->noClientException;
+}
+
+static int
+ProcSyncResetFence(ClientPtr client)
+{
+    REQUEST(xSyncResetFenceReq);
+    SyncFence *pFence;
+    int rc;
+
+    REQUEST_SIZE_MATCH(xSyncResetFenceReq);
+
+    rc = dixLookupResourceByType((pointer *)&pFence, stuff->fid, RTFence,
+				 client, DixWriteAccess);
+    if (rc != Success)
+	return rc;
+
+    if (pFence->funcs.CheckTriggered(pFence) != TRUE)
+	return BadMatch;
+
+    pFence->funcs.Reset(pFence);
+
+    return client->noClientException;
+}
+
+static int
+ProcSyncDestroyFence(ClientPtr client)
+{
+    REQUEST(xSyncDestroyFenceReq);
+    SyncFence *pFence;
+    int rc;
+
+    REQUEST_SIZE_MATCH(xSyncDestroyFenceReq);
+
+    rc = dixLookupResourceByType((pointer *)&pFence, stuff->fid, RTFence,
+				 client, DixDestroyAccess);
+    if (rc != Success)
+	return rc;
+
+    FreeResource(stuff->fid, RT_NONE);
+    return client->noClientException;
+}
+
+static int
+ProcSyncQueryFence(ClientPtr client)
+{
+    REQUEST(xSyncQueryFenceReq);
+    xSyncQueryFenceReply rep;
+    SyncFence *pFence;
+    int rc;
+
+    REQUEST_SIZE_MATCH(xSyncQueryFenceReq);
+
+    rc = dixLookupResourceByType((pointer *)&pFence, stuff->fid,
+				 RTFence, client, DixReadAccess);
+    if (rc != Success)
+	return rc;
+
+    rep.type = X_Reply;
+    rep.length = 0;
+    rep.sequenceNumber = client->sequence;
+
+    rep.triggered = pFence->funcs.CheckTriggered(pFence);
+
+    if (client->swapped)
+    {
+	char n;
+	swaps(&rep.sequenceNumber, n);
+	swapl(&rep.length, n);
+    }
+
+    WriteToClient(client, sizeof(xSyncQueryFenceReply), (char *) &rep);
+    return client->noClientException;
+}
+
+static int
+ProcSyncAwaitFence(ClientPtr client)
+{
+    REQUEST(xSyncAwaitFenceReq);
+    SyncAwaitUnion *pAwaitUnion;
+    SyncAwait *pAwait;
+    /* Use CARD32 rather than XSyncFence because XIDs are hard-coded to
+     * CARD32 in protocol definitions */
+    CARD32 *pProtocolFences;
+    int status;
+    int len;
+    int items;
+    int i;
+
+    REQUEST_AT_LEAST_SIZE(xSyncAwaitFenceReq);
+
+    len = client->req_len << 2;
+    len -= sz_xSyncAwaitFenceReq;
+    items = len / sizeof(CARD32);
+
+    if (items * sizeof(CARD32) != len)
+    {
+	return BadLength;
+    }
+    if (items == 0)
+    {
+	client->errorValue = items;
+	return BadValue;
+    }
+
+    if (!(pAwaitUnion = SyncAwaitPrologue(client, items)))
+	return BadAlloc;
+
+    /* don't need to do any more memory allocation for this request! */
+
+    pProtocolFences = (CARD32 *) & stuff[1];
+
+    pAwait = &(pAwaitUnion+1)->await; /* skip over header */
+    for (i = 0; i < items; i++, pProtocolFences++, pAwait++)
+    {
+	if (*pProtocolFences == None)
+	{
+	    /*  this should take care of removing any triggers created by
+	     *  this request that have already been registered on sync objects
+	     */
+	    FreeResource(pAwaitUnion->header.delete_id, RT_NONE);
+	    client->errorValue = *pProtocolFences;
+	    return SyncErrorBase + XSyncBadFence;
+	}
+
+	pAwait->trigger.pSync = NULL;
+	/* Provide acceptable values for these unused fields to
+	 * satisfy SyncInitTrigger's validation logic
+	 */
+	pAwait->trigger.value_type = XSyncAbsolute;
+	XSyncIntToValue(&pAwait->trigger.wait_value, 0);
+	pAwait->trigger.test_type = 0;
+
+	status = SyncInitTrigger(client, &pAwait->trigger,
+				 *pProtocolFences, RTFence,
+				 XSyncCAAllTrigger);
+	if (status != Success)
+	{
+	    /*  this should take care of removing any triggers created by
+	     *  this request that have already been registered on sync objects
+	     */
+	    FreeResource(pAwaitUnion->header.delete_id, RT_NONE);
+	    return status;
+	}
+	/* this is not a mistake -- same function works for both cases */
+	pAwait->trigger.TriggerFired = SyncAwaitTriggerFired;
+	pAwait->trigger.CounterDestroyed = SyncAwaitTriggerFired;
+	/* event_threshold is unused for fence syncs */
+	XSyncIntToValue(&pAwait->event_threshold, 0);
+	pAwait->pHeader = &pAwaitUnion->header;
+	pAwaitUnion->header.num_waitconditions++;
+    }
+
+    SyncAwaitEpilogue(client, items, pAwaitUnion);
+
+    return client->noClientException;
+}
+
+/*
+ * ** Given an extension request, call the appropriate request procedure
+ */
+static int
+ProcSyncDispatch(ClientPtr client)
+{
+    REQUEST(xReq);
+
+    switch (stuff->data)
+    {
+      case X_SyncInitialize:
+	return ProcSyncInitialize(client);
+      case X_SyncListSystemCounters:
+	return ProcSyncListSystemCounters(client);
+      case X_SyncCreateCounter:
+	return ProcSyncCreateCounter(client);
+      case X_SyncSetCounter:
+	return ProcSyncSetCounter(client);
+      case X_SyncChangeCounter:
+	return ProcSyncChangeCounter(client);
+      case X_SyncQueryCounter:
+	return ProcSyncQueryCounter(client);
+      case X_SyncDestroyCounter:
+	return ProcSyncDestroyCounter(client);
+      case X_SyncAwait:
+	return ProcSyncAwait(client);
+      case X_SyncCreateAlarm:
+	return ProcSyncCreateAlarm(client);
+      case X_SyncChangeAlarm:
+	return ProcSyncChangeAlarm(client);
+      case X_SyncQueryAlarm:
+	return ProcSyncQueryAlarm(client);
+      case X_SyncDestroyAlarm:
+	return ProcSyncDestroyAlarm(client);
+      case X_SyncSetPriority:
+	return ProcSyncSetPriority(client);
+      case X_SyncGetPriority:
+	return ProcSyncGetPriority(client);
+      case X_SyncCreateFence:
+	return ProcSyncCreateFence(client);
+      case X_SyncTriggerFence:
+	return ProcSyncTriggerFence(client);
+      case X_SyncResetFence:
+	return ProcSyncResetFence(client);
+      case X_SyncDestroyFence:
+	return ProcSyncDestroyFence(client);
+      case X_SyncQueryFence:
+	return ProcSyncQueryFence(client);
+      case X_SyncAwaitFence:
+	return ProcSyncAwaitFence(client);
+      default:
+	return BadRequest;
+    }
+}
+
+/*
+ * Boring Swapping stuff ...
+ */
+
+static int
+SProcSyncInitialize(ClientPtr client)
+{
+    REQUEST(xSyncInitializeReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncInitializeReq);
+
+    return ProcSyncInitialize(client);
+}
+
+static int
+SProcSyncListSystemCounters(ClientPtr client)
+{
+    REQUEST(xSyncListSystemCountersReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncListSystemCountersReq);
+
+    return ProcSyncListSystemCounters(client);
+}
+
+static int
+SProcSyncCreateCounter(ClientPtr client)
+{
+    REQUEST(xSyncCreateCounterReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncCreateCounterReq);
+    swapl(&stuff->cid, n);
+    swapl(&stuff->initial_value_lo, n);
+    swapl(&stuff->initial_value_hi, n);
+
+    return ProcSyncCreateCounter(client);
+}
+
+static int
+SProcSyncSetCounter(ClientPtr client)
+{
+    REQUEST(xSyncSetCounterReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncSetCounterReq);
+    swapl(&stuff->cid, n);
+    swapl(&stuff->value_lo, n);
+    swapl(&stuff->value_hi, n);
+
+    return ProcSyncSetCounter(client);
+}
+
+static int
+SProcSyncChangeCounter(ClientPtr client)
+{
+    REQUEST(xSyncChangeCounterReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncChangeCounterReq);
+    swapl(&stuff->cid, n);
+    swapl(&stuff->value_lo, n);
+    swapl(&stuff->value_hi, n);
+
+    return ProcSyncChangeCounter(client);
+}
+
+static int
+SProcSyncQueryCounter(ClientPtr client)
+{
+    REQUEST(xSyncQueryCounterReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncQueryCounterReq);
+    swapl(&stuff->counter, n);
+
+    return ProcSyncQueryCounter(client);
+}
+
+static int
+SProcSyncDestroyCounter(ClientPtr client)
+{
+    REQUEST(xSyncDestroyCounterReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncDestroyCounterReq);
+    swapl(&stuff->counter, n);
+
+    return ProcSyncDestroyCounter(client);
+}
+
+static int
+SProcSyncAwait(ClientPtr client)
+{
+    REQUEST(xSyncAwaitReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_AT_LEAST_SIZE(xSyncAwaitReq);
+    SwapRestL(stuff);
+
+    return ProcSyncAwait(client);
+}
+
+static int
+SProcSyncCreateAlarm(ClientPtr client)
+{
+    REQUEST(xSyncCreateAlarmReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_AT_LEAST_SIZE(xSyncCreateAlarmReq);
+    swapl(&stuff->id, n);
+    swapl(&stuff->valueMask, n);
+    SwapRestL(stuff);
+
+    return ProcSyncCreateAlarm(client);
+}
+
+static int
+SProcSyncChangeAlarm(ClientPtr client)
+{
+    REQUEST(xSyncChangeAlarmReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_AT_LEAST_SIZE(xSyncChangeAlarmReq);
+    swapl(&stuff->alarm, n);
+    swapl(&stuff->valueMask, n);
+    SwapRestL(stuff);
+    return ProcSyncChangeAlarm(client);
+}
+
+static int
+SProcSyncQueryAlarm(ClientPtr client)
+{
+    REQUEST(xSyncQueryAlarmReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncQueryAlarmReq);
+    swapl(&stuff->alarm, n);
+
+    return ProcSyncQueryAlarm(client);
+}
+
+static int
+SProcSyncDestroyAlarm(ClientPtr client)
+{
+    REQUEST(xSyncDestroyAlarmReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncDestroyAlarmReq);
+    swapl(&stuff->alarm, n);
+
+    return ProcSyncDestroyAlarm(client);
+}
+
+static int
+SProcSyncSetPriority(ClientPtr client)
+{
+    REQUEST(xSyncSetPriorityReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncSetPriorityReq);
+    swapl(&stuff->id, n);
+    swapl(&stuff->priority, n);
+
+    return ProcSyncSetPriority(client);
+}
+
+static int
+SProcSyncGetPriority(ClientPtr client)
+{
+    REQUEST(xSyncGetPriorityReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncGetPriorityReq);
+    swapl(&stuff->id, n);
+
+    return ProcSyncGetPriority(client);
+}
+
+static int
+SProcSyncCreateFence(ClientPtr client)
+{
+    REQUEST(xSyncCreateFenceReq);
+    char n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncCreateFenceReq);
+    swapl(&stuff->fid, n);
+
+    return ProcSyncCreateFence(client);
+}
+
+static int
+SProcSyncTriggerFence(ClientPtr client)
+{
+    REQUEST(xSyncTriggerFenceReq);
+    char n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncTriggerFenceReq);
+    swapl(&stuff->fid, n);
+
+    return ProcSyncTriggerFence(client);
+}
+
+static int
+SProcSyncResetFence(ClientPtr client)
+{
+    REQUEST(xSyncResetFenceReq);
+    char n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncResetFenceReq);
+    swapl(&stuff->fid, n);
+
+    return ProcSyncResetFence(client);
+}
+
+static int
+SProcSyncDestroyFence(ClientPtr client)
+{
+    REQUEST(xSyncDestroyFenceReq);
+    char n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncDestroyFenceReq);
+    swapl(&stuff->fid, n);
+
+    return ProcSyncDestroyFence(client);
+}
+
+static int
+SProcSyncQueryFence(ClientPtr client)
+{
+    REQUEST(xSyncQueryFenceReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_SIZE_MATCH (xSyncQueryFenceReq);
+    swapl(&stuff->fid, n);
+
+    return ProcSyncQueryFence(client);
+}
+
+static int
+SProcSyncAwaitFence(ClientPtr client)
+{
+    REQUEST(xSyncAwaitFenceReq);
+    char   n;
+
+    swaps(&stuff->length, n);
+    REQUEST_AT_LEAST_SIZE(xSyncAwaitFenceReq);
+    SwapRestL(stuff);
+
+    return ProcSyncAwaitFence(client);
+}
+
+static int
+SProcSyncDispatch(ClientPtr client)
+{
+    REQUEST(xReq);
+
+    switch (stuff->data)
+    {
+      case X_SyncInitialize:
+	return SProcSyncInitialize(client);
+      case X_SyncListSystemCounters:
+	return SProcSyncListSystemCounters(client);
+      case X_SyncCreateCounter:
+	return SProcSyncCreateCounter(client);
+      case X_SyncSetCounter:
+	return SProcSyncSetCounter(client);
+      case X_SyncChangeCounter:
+	return SProcSyncChangeCounter(client);
+      case X_SyncQueryCounter:
+	return SProcSyncQueryCounter(client);
+      case X_SyncDestroyCounter:
+	return SProcSyncDestroyCounter(client);
+      case X_SyncAwait:
+	return SProcSyncAwait(client);
+      case X_SyncCreateAlarm:
+	return SProcSyncCreateAlarm(client);
+      case X_SyncChangeAlarm:
+	return SProcSyncChangeAlarm(client);
+      case X_SyncQueryAlarm:
+	return SProcSyncQueryAlarm(client);
+      case X_SyncDestroyAlarm:
+	return SProcSyncDestroyAlarm(client);
+      case X_SyncSetPriority:
+	return SProcSyncSetPriority(client);
+      case X_SyncGetPriority:
+	return SProcSyncGetPriority(client);
+      case X_SyncCreateFence:
+	return SProcSyncCreateFence(client);
+      case X_SyncTriggerFence:
+	return SProcSyncTriggerFence(client);
+      case X_SyncResetFence:
+	return SProcSyncResetFence(client);
+      case X_SyncDestroyFence:
+	return SProcSyncDestroyFence(client);
+      case X_SyncQueryFence:
+	return SProcSyncQueryFence(client);
+      case X_SyncAwaitFence:
+	return SProcSyncAwaitFence(client);
+      default:
+	return BadRequest;
+    }
+}
+
+/*
+ * Event Swapping
+ */
+
+static void
+SCounterNotifyEvent(xSyncCounterNotifyEvent *from, xSyncCounterNotifyEvent *to)
+{
+    to->type = from->type;
+    to->kind = from->kind;
+    cpswaps(from->sequenceNumber, to->sequenceNumber);
+    cpswapl(from->counter, to->counter);
+    cpswapl(from->wait_value_lo, to->wait_value_lo);
+    cpswapl(from->wait_value_hi, to->wait_value_hi);
+    cpswapl(from->counter_value_lo, to->counter_value_lo);
+    cpswapl(from->counter_value_hi, to->counter_value_hi);
+    cpswapl(from->time, to->time);
+    cpswaps(from->count, to->count);
+    to->destroyed = from->destroyed;
+}
+
+
+static void
+SAlarmNotifyEvent(xSyncAlarmNotifyEvent *from, xSyncAlarmNotifyEvent *to)
+{
+    to->type = from->type;
+    to->kind = from->kind;
+    cpswaps(from->sequenceNumber, to->sequenceNumber);
+    cpswapl(from->alarm, to->alarm);
+    cpswapl(from->counter_value_lo, to->counter_value_lo);
+    cpswapl(from->counter_value_hi, to->counter_value_hi);
+    cpswapl(from->alarm_value_lo, to->alarm_value_lo);
+    cpswapl(from->alarm_value_hi, to->alarm_value_hi);
+    cpswapl(from->time, to->time);
+    to->state = from->state;
+}
+
+/*
+ * ** Close everything down. ** This is fairly simple for now.
+ */
+/* ARGSUSED */
+static void
+SyncResetProc(ExtensionEntry *extEntry)
+{
+    free(SysCounterList);
+    SysCounterList = NULL;
+    RTCounter = 0;
+}
+
+/*
+ * ** Initialise the extension.
+ */
+void
+SyncExtensionInit(void)
+{
+    ExtensionEntry *extEntry;
+    int 	    s;
+
+    for (s = 0; s < screenInfo.numScreens; s++)
+	miSyncSetup(screenInfo.screens[s]);
+
+    if (RTCounter == 0)
+    {
+	RTCounter = CreateNewResourceType(FreeCounter, "SyncCounter");
+    }
+    RTAlarm = CreateNewResourceType(FreeAlarm, "SyncAlarm");
+    RTAwait = CreateNewResourceType(FreeAwait, "SyncAwait");
+    RTFence = CreateNewResourceType(FreeFence, "SyncFence");
+    if (RTAwait)
+	RTAwait |= RC_NEVERRETAIN;
+    RTAlarmClient = CreateNewResourceType(FreeAlarmClient, "SyncAlarmClient");
+    if (RTAlarmClient)
+	RTAlarmClient |= RC_NEVERRETAIN;
+
+    if (RTCounter == 0 || RTAwait == 0 || RTAlarm == 0 ||
+	RTAlarmClient == 0 ||
+	(extEntry = AddExtension(SYNC_NAME,
+				 XSyncNumberEvents, XSyncNumberErrors,
+				 ProcSyncDispatch, SProcSyncDispatch,
+				 SyncResetProc,
+				 StandardMinorOpcode)) == NULL)
+    {
+	ErrorF("Sync Extension %d.%d failed to Initialise\n",
+		SYNC_MAJOR_VERSION, SYNC_MINOR_VERSION);
+	return;
+    }
+
+    SyncEventBase = extEntry->eventBase;
+    SyncErrorBase = extEntry->errorBase;
+    EventSwapVector[SyncEventBase + XSyncCounterNotify] = (EventSwapPtr) SCounterNotifyEvent;
+    EventSwapVector[SyncEventBase + XSyncAlarmNotify] = (EventSwapPtr) SAlarmNotifyEvent;
+
+    SetResourceTypeErrorValue(RTCounter, SyncErrorBase + XSyncBadCounter);
+    SetResourceTypeErrorValue(RTAlarm, SyncErrorBase + XSyncBadAlarm);
+    SetResourceTypeErrorValue(RTFence, SyncErrorBase + XSyncBadFence);
+
+    /*
+     * Although SERVERTIME is implemented by the OS layer, we initialise it
+     * here because doing it in OsInit() is too early. The resource database
+     * is not initialised when OsInit() is called. This is just about OK
+     * because there is always a servertime counter.
+     */
+    SyncInitServerTime();
+    SyncInitIdleTime();
+
+#ifdef DEBUG
+    fprintf(stderr, "Sync Extension %d.%d\n",
+	    SYNC_MAJOR_VERSION, SYNC_MINOR_VERSION);
+#endif
+}
+
+
+/*
+ * ***** SERVERTIME implementation - should go in its own file in OS directory?
+ */
+
+
+
+static pointer ServertimeCounter;
+static XSyncValue Now;
+static XSyncValue *pnext_time;
+
+#define GetTime()\
+{\
+    unsigned long millis = GetTimeInMillis();\
+    unsigned long maxis = XSyncValueHigh32(Now);\
+    if (millis < XSyncValueLow32(Now)) maxis++;\
+    XSyncIntsToValue(&Now, millis, maxis);\
+}
+
+/*
+*** Server Block Handler
+*** code inspired by multibuffer extension (now deprecated)
+ */
+/*ARGSUSED*/
+static void
+ServertimeBlockHandler(void *env, struct timeval **wt, void *LastSelectMask)
+{
+    XSyncValue delay;
+    unsigned long timeout;
+
+    if (pnext_time)
+    {
+        GetTime();
+
+        if (XSyncValueGreaterOrEqual(Now, *pnext_time))
+	{
+            timeout = 0;
+        }
+	else
+	{
+	    Bool overflow;
+            XSyncValueSubtract(&delay, *pnext_time, Now, &overflow);
+	    (void)overflow;
+            timeout = XSyncValueLow32(delay);
+        }
+        AdjustWaitForDelay(wt, timeout); /* os/utils.c */
+    }
+}
+
+/*
+*** Wakeup Handler
+ */
+/*ARGSUSED*/
+static void
+ServertimeWakeupHandler(void *env, int rc, void *LastSelectMask)
+{
+    if (pnext_time)
+    {
+        GetTime();
+
+        if (XSyncValueGreaterOrEqual(Now, *pnext_time))
+	{
+            SyncChangeCounter(ServertimeCounter, Now);
+        }
+    }
+}
+
+static void
+ServertimeQueryValue(void *pCounter, CARD64 *pValue_return)
+{
+    GetTime();
+    *pValue_return = Now;
+}
+
+static void
+ServertimeBracketValues(void *pCounter, CARD64 *pbracket_less,
+			CARD64 *pbracket_greater)
+{
+    if (!pnext_time && pbracket_greater)
+    {
+	RegisterBlockAndWakeupHandlers(ServertimeBlockHandler,
+				       ServertimeWakeupHandler,
+				       NULL);
+    }
+    else if (pnext_time && !pbracket_greater)
+    {
+	RemoveBlockAndWakeupHandlers(ServertimeBlockHandler,
+				     ServertimeWakeupHandler,
+				     NULL);
+    }
+    pnext_time = pbracket_greater;
+}
+
+static void
+SyncInitServerTime(void)
+{
+    CARD64 resolution;
+
+    XSyncIntsToValue(&Now, GetTimeInMillis(), 0);
+    XSyncIntToValue(&resolution, 4);
+    ServertimeCounter = SyncCreateSystemCounter("SERVERTIME", Now, resolution,
+			    XSyncCounterNeverDecreases,
+			    ServertimeQueryValue, ServertimeBracketValues);
+    pnext_time = NULL;
+}
+
+
+
+/*
+ * IDLETIME implementation
+ */
+
+static SyncCounter *IdleTimeCounter;
+static XSyncValue *pIdleTimeValueLess;
+static XSyncValue *pIdleTimeValueGreater;
+
+static void
+IdleTimeQueryValue (pointer pCounter, CARD64 *pValue_return)
+{
+    CARD32 idle = GetTimeInMillis() - lastDeviceEventTime.milliseconds;
+    XSyncIntsToValue (pValue_return, idle, 0);
+}
+
+static void
+IdleTimeBlockHandler(pointer env, struct timeval **wt, pointer LastSelectMask)
+{
+    XSyncValue idle, old_idle;
+    SyncTriggerList *list = IdleTimeCounter->sync.pTriglist;
+    SyncTrigger *trig;
+
+    if (!pIdleTimeValueLess && !pIdleTimeValueGreater)
+	return;
+
+    old_idle = IdleTimeCounter->value;
+    IdleTimeQueryValue (NULL, &idle);
+    IdleTimeCounter->value = idle; /* push, so CheckTrigger works */
+
+    if (pIdleTimeValueLess &&
+        XSyncValueLessOrEqual (idle, *pIdleTimeValueLess))
+    {
+	/*
+	 * We've been idle for less than the threshold value, and someone
+	 * wants to know about that, but now we need to know whether they
+	 * want level or edge trigger.  Check the trigger list against the
+	 * current idle time, and if any succeed, bomb out of select()
+	 * immediately so we can reschedule.
+	 */
+
+	for (list = IdleTimeCounter->sync.pTriglist; list; list = list->next) {
+	    trig = list->pTrigger;
+	    if (trig->CheckTrigger(trig, old_idle)) {
+		AdjustWaitForDelay(wt, 0);
+		break;
+	    }
+	}
+	/* 
+	 * We've been called exactly on the idle time, but we have a
+	 * NegativeTransition trigger which requires a transition from an
+	 * idle time greater than this.  Schedule a wakeup for the next
+	 * millisecond so we won't miss a transition.
+	 */
+	if (XSyncValueEqual (idle, *pIdleTimeValueLess))
+	    AdjustWaitForDelay(wt, 1);
+    }
+    else if (pIdleTimeValueGreater)
+    {
+	/*
+	 * There's a threshold in the positive direction.  If we've been
+	 * idle less than it, schedule a wakeup for sometime in the future.
+	 * If we've been idle more than it, and someone wants to know about
+	 * that level-triggered, schedule an immediate wakeup.
+	 */
+	unsigned long timeout = -1;
+
+	if (XSyncValueLessThan (idle, *pIdleTimeValueGreater)) {
+	    XSyncValue value;
+	    Bool overflow;
+
+	    XSyncValueSubtract (&value, *pIdleTimeValueGreater,
+	                        idle, &overflow);
+	    timeout = min(timeout, XSyncValueLow32 (value));
+	} else {
+	    for (list = IdleTimeCounter->sync.pTriglist; list; list = list->next) {
+		trig = list->pTrigger;
+		if (trig->CheckTrigger(trig, old_idle)) {
+		    timeout = min(timeout, 0);
+		    break;
+		}
+	    }
+	}
+
+	AdjustWaitForDelay (wt, timeout);
+    }
+
+    IdleTimeCounter->value = old_idle; /* pop */
+}
+
+static void
+IdleTimeWakeupHandler (pointer env, int rc, pointer LastSelectMask)
+{
+    XSyncValue idle;
+
+    if (!pIdleTimeValueLess && !pIdleTimeValueGreater)
+	return;
+
+    IdleTimeQueryValue (NULL, &idle);
+
+    if ((pIdleTimeValueGreater &&
+         XSyncValueGreaterOrEqual (idle, *pIdleTimeValueGreater)) ||
+        (pIdleTimeValueLess &&
+	 XSyncValueLessOrEqual (idle, *pIdleTimeValueLess)))
+    {
+	SyncChangeCounter (IdleTimeCounter, idle);
+    }
+}
+
+static void
+IdleTimeBracketValues (pointer pCounter, CARD64 *pbracket_less,
+                       CARD64 *pbracket_greater)
+{
+    Bool registered = (pIdleTimeValueLess || pIdleTimeValueGreater);
+
+    if (registered && !pbracket_less && !pbracket_greater)
+    {
+	RemoveBlockAndWakeupHandlers(IdleTimeBlockHandler,
+	                             IdleTimeWakeupHandler,
+	                             NULL);
+    }
+    else if (!registered && (pbracket_less || pbracket_greater))
+    {
+	RegisterBlockAndWakeupHandlers(IdleTimeBlockHandler,
+	                               IdleTimeWakeupHandler,
+	                               NULL);
+    }
+
+    pIdleTimeValueGreater = pbracket_greater;
+    pIdleTimeValueLess    = pbracket_less;
+}
+
+static void
+SyncInitIdleTime (void)
+{
+    CARD64 resolution;
+    XSyncValue idle;
+
+    IdleTimeQueryValue (NULL, &idle);
+    XSyncIntToValue (&resolution, 4);
+
+    IdleTimeCounter = SyncCreateSystemCounter ("IDLETIME", idle, resolution,
+                                               XSyncCounterUnrestricted,
+                                               IdleTimeQueryValue,
+                                               IdleTimeBracketValues);
+
+    pIdleTimeValueLess = pIdleTimeValueGreater = NULL;
+}