sync.c

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    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,
			     origmask & XSyncCAAllTrigger)) != Success)
	return status;

    /* XXX spec does not really say to do this - needs clarification */
    pAlarm->state = XSyncAlarmActive;
    return Success;
}


static SyncCounter *
SyncCreateCounter(client, id, initialvalue)
    ClientPtr	client;
    XSyncCounter id;
    CARD64      initialvalue;
{
    SyncCounter *pCounter;

    if (!(pCounter = (SyncCounter *) xalloc(sizeof(SyncCounter))))
	return (SyncCounter *)NULL;

    if (!AddResource(id, RTCounter, (pointer) pCounter))
    {
	xfree((pointer) pCounter);
	return (SyncCounter *)NULL;
    }

    pCounter->client = client;
    pCounter->id = id;
    pCounter->value = initialvalue;
    pCounter->pTriglist = NULL;
    pCounter->beingDestroyed = FALSE;
    pCounter->pSysCounterInfo = NULL;
    return pCounter;
}

static int FreeCounter(
#if NeedFunctionPrototypes
    pointer /*env*/,
    XID     /*id*/
#endif
);

/*
 * ***** System Counter utilities
 */

pointer 
SyncCreateSystemCounter(name, initial, resolution, counterType,
			QueryValue, BracketValues)
    char           *name;
    CARD64          initial;
    CARD64          resolution;
    SyncCounterType counterType;
    void            (*QueryValue) ();
    void            (*BracketValues) ();
{
    SyncCounter    *pCounter;

    SysCounterList = (SyncCounter **)xrealloc(SysCounterList,
			    (SyncNumSystemCounters+1)*sizeof(SyncCounter *));
    if (!SysCounterList)
	return (pointer)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);
	if (RTCounter == 0)
	{
	    return (pointer)NULL;
	}
    }

    pCounter = SyncCreateCounter((ClientPtr)NULL, FakeClientID(0), initial);

    if (pCounter)
    {
	SysCounterInfo *psci;

	psci = (SysCounterInfo *)xalloc(sizeof(SysCounterInfo));
	if (!psci)
	{
	    FreeResource(pCounter->id, RT_NONE);
	    return (pointer) 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 (pointer) pCounter;
}

void
SyncDestroySystemCounter(pSysCounter)
    pointer pSysCounter;
{
    SyncCounter *pCounter = (SyncCounter *)pSysCounter;
    FreeResource(pCounter->id, RT_NONE);
}

static void
SyncComputeBracketValues(pCounter, startOver)
    SyncCounter *pCounter;
    Bool startOver;
{
    SyncTriggerList *pCur;
    SyncTrigger *pTrigger;
    SysCounterInfo *psci = pCounter->pSysCounterInfo;
    CARD64 *pnewgtval = NULL;
    CARD64 *pnewltval = NULL;
    SyncCounterType ct;

    if (!pCounter)
	return;

    ct = pCounter->pSysCounterInfo->counterType;
    if (ct == XSyncCounterNeverChanges)
	return;

    if (startOver)
    {
	XSyncMaxValue(&psci->bracket_greater);
	XSyncMinValue(&psci->bracket_less);
    }

    for (pCur = pCounter->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 == XSyncPositiveTransition &&
		   ct != XSyncCounterNeverIncreases)
		 ||
		 (pTrigger->test_type == XSyncNegativeTransition &&
		  ct != XSyncCounterNeverDecreases)
		 )
	{
	    if (XSyncValueLessThan(pCounter->value, pTrigger->test_value))
	    {
		if (XSyncValueLessThan(pTrigger->test_value,
				       psci->bracket_greater))
		{
		    psci->bracket_greater = pTrigger->test_value;
		    pnewgtval = &psci->bracket_greater;
		}
		else
		if (XSyncValueGreaterThan(pTrigger->test_value,
					  psci->bracket_less))
		{
		    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(addr, id)
    pointer         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);

    SyncDeleteTriggerFromCounter(&pAlarm->trigger);

    xfree(pAlarm);
    return Success;
}


/*
 * ** Cleanup after the destruction of a Counter
 */
/* ARGSUSED */
static int
FreeCounter(env, id)
    pointer         env;
    XID             id;
{
    SyncCounter     *pCounter = (SyncCounter *) env;
    SyncTriggerList *ptl, *pnext;

    pCounter->beingDestroyed = TRUE;
    /* tell all the counter's triggers that the counter has been destroyed */
    for (ptl = pCounter->pTriglist; ptl; ptl = pnext)
    {
	(*ptl->pTrigger->CounterDestroyed)(ptl->pTrigger);
	pnext = ptl->next;
	xfree(ptl); /* destroy the trigger list as we go */
    }
    if (IsSystemCounter(pCounter))
    {
	int i, found = 0;

	xfree(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--;
    }
    xfree(pCounter);
    return Success;
}

/*
 * ** Cleanup after Await
 */
/* ARGSUSED */
static int
FreeAwait(addr, id)
    pointer         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.
	 */
	SyncCounter *pCounter = pAwait->trigger.pCounter;
	if (pCounter && !pCounter->beingDestroyed)
	    SyncDeleteTriggerFromCounter(&pAwait->trigger);
    }
    xfree(pAwaitUnion);
    return Success;
}

/* loosely based on dix/events.c/OtherClientGone */
static int
FreeAlarmClient(value, id)
    pointer value; /* must conform to DeleteType */
    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;
	    xfree(pCur);
	    return(Success);
	}
    }
    FatalError("alarm client not on event list");
    /*NOTREACHED*/
}


/*
 * *****  Proc functions
 */


/*
 * ** Initialize the extension
 */
static int 
ProcSyncInitialize(client)
    ClientPtr       client;
{
    xSyncInitializeReply  rep;
    int   n;

    REQUEST_SIZE_MATCH(xSyncInitializeReq);

    rep.type = X_Reply;
    rep.sequenceNumber = client->sequence;
    rep.majorVersion = SYNC_MAJOR_VERSION;
    rep.minorVersion = SYNC_MINOR_VERSION;
    rep.length = 0;

    if (client->swapped)
    {
	swaps(&rep.sequenceNumber, n);
    }
    WriteToClient(client, sizeof(rep), (char *) &rep);
    return (client->noClientException);
}

/*
 * ** Get list of system counters available through the extension
 */
static int 
ProcSyncListSystemCounters(client)
    ClientPtr       client;
{
    xSyncListSystemCountersReply  rep;
    int i, len;
    xSyncSystemCounter *list, *walklist;
    
    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 += (sz_xSyncSystemCounter + strlen(name) + 3) & ~3;
    }

    if (len)
    {
	walklist = list = (xSyncSystemCounter *) ALLOCATE_LOCAL(len);
	if (!list)
	    return BadAlloc;
    }

    rep.length = len >> 2;

    if (client->swapped)
    {
	register 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]->id;
	walklist->resolution_hi = XSyncValueHigh32(psci->resolution);
	walklist->resolution_lo = XSyncValueLow32(psci->resolution);
	namelen = strlen(psci->name);
	walklist->name_length = namelen;

	if (client->swapped)
	{
	    register 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) + 
				((sz_xSyncSystemCounter + namelen + 3) & ~3));
    }

    WriteToClient(client, sizeof(rep), (char *) &rep);
    if (len) 
    {
	WriteToClient(client, len, (char *) list);
	DEALLOCATE_LOCAL(list);
    }

    return (client->noClientException);
}

/*
 * ** Set client Priority
 */
static int 
ProcSyncSetPriority(client)
    ClientPtr       client;
{
    REQUEST(xSyncSetPriorityReq);
    ClientPtr priorityclient;

    REQUEST_SIZE_MATCH(xSyncSetPriorityReq);

    if (stuff->id == None)
	priorityclient = client;
    else if (!(priorityclient = LookupClient(stuff->id, client)))
    {
	client->errorValue = stuff->id;
	return BadMatch;
    }

    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(client)
    ClientPtr       client;
{
    REQUEST(xSyncGetPriorityReq);
    xSyncGetPriorityReply rep;
    ClientPtr priorityclient;

    REQUEST_SIZE_MATCH(xSyncGetPriorityReq);

    if (stuff->id == None)
	priorityclient = client;
    else if (!(priorityclient = LookupClient(stuff->id, client)))
    {
	client->errorValue = stuff->id;
	return BadMatch;
    }