sync.c

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/* $XConsortium: sync.c /main/13 1996/12/16 16:51:55 rws $ */
/* $XFree86: xc/programs/Xserver/Xext/sync.c,v 3.3 1997/01/18 06:53:00 dawes Exp $ */
/*

Copyright (c) 1991, 1993  X Consortium

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

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 X CONSORTIUM 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 X Consortium 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 X Consortium.


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.

*/

#define NEED_REPLIES
#define NEED_EVENTS
#include <stdio.h>
#include "X.h"
#include "Xproto.h"
#include "Xmd.h"
#include "misc.h"
#include "os.h"
#include "extnsionst.h"
#include "dixstruct.h"
#include "resource.h"
#include "opaque.h"
#define _SYNC_SERVER
#include "sync.h"
#include "syncstr.h"

/*
 * Local Global Variables
 */
static int      SyncReqCode;
static int      SyncEventBase;
static int      SyncErrorBase;
static RESTYPE  RTCounter = 0;
static RESTYPE  RTAwait;
static RESTYPE  RTAlarm;
static RESTYPE  RTAlarmClient;
static int SyncNumSystemCounters = 0;
static SyncCounter **SysCounterList = NULL;

#define IsSystemCounter(pCounter) \
    (pCounter && (pCounter->client == NULL))

/* these are all the alarm attributes that pertain to the alarm's trigger */
#define XSyncCAAllTrigger \
    (XSyncCACounter | XSyncCAValueType | XSyncCAValue | XSyncCATestType)

static int
FreeAlarm(
#if NeedFunctionPrototypes
    pointer /* addr */,
    XID /* id */
#endif
);

static int
FreeAlarmClient(
#if NeedFunctionPrototypes
    pointer /* value */,
    XID /* id */
#endif
);

static int
FreeAwait(
#if NeedFunctionPrototypes
    pointer /* addr */,
    XID /* id */
#endif
);

static void
ServertimeBracketValues(
#if NeedFunctionPrototypes
    pointer /* pCounter */,
    CARD64 * /* pbracket_less */,
    CARD64 * /* pbracket_greater */
#endif
);

static void
ServertimeQueryValue(
#if NeedFunctionPrototypes
    pointer /* pCounter */,
    CARD64 * /* pValue_return */
#endif
);

static void
ServertimeWakeupHandler(
#if NeedFunctionPrototypes
    pointer /* env */,
    int /* rc */,
    pointer /* LastSelectMask */
#endif
);

static int 
SyncInitTrigger(
#if NeedFunctionPrototypes
    ClientPtr /* client */,
    SyncTrigger * /* pTrigger */,
    XSyncCounter /* counter */,
    Mask /* changes */
#endif
);

static void
SAlarmNotifyEvent(
#if NeedFunctionPrototypes
    xSyncAlarmNotifyEvent * /* from */,
    xSyncAlarmNotifyEvent * /* to */
#endif
);

static void
SCounterNotifyEvent(
#if NeedFunctionPrototypes
    xSyncCounterNotifyEvent * /* from */,
    xSyncCounterNotifyEvent * /* to */
#endif
);

static void
ServertimeBlockHandler(
#if NeedFunctionPrototypes
    pointer  /* env */,
    struct timeval ** /* wt */,
    pointer  /* LastSelectMask */
#endif
);

static int
SyncAddTriggerToCounter(
#if NeedFunctionPrototypes
    SyncTrigger * /* pTrigger */
#endif
);

extern void
SyncAlarmCounterDestroyed(
#if NeedFunctionPrototypes
    SyncTrigger * /* pTrigger */
#endif
);

static void
SyncAlarmTriggerFired(
#if NeedFunctionPrototypes
    SyncTrigger * /* pTrigger */
#endif
);

static void
SyncAwaitTriggerFired(
#if NeedFunctionPrototypes
    SyncTrigger * /* pTrigger */
#endif
);

static int
SyncChangeAlarmAttributes(
#if NeedFunctionPrototypes
    ClientPtr /* client */,
    SyncAlarm * /* pAlarm */,
    Mask /* mask */,
    CARD32 * /* values */
#endif
);

static Bool
SyncCheckTriggerNegativeComparison(
#if NeedFunctionPrototypes
    SyncTrigger * /* pTrigger */,
    CARD64 /* oldval */
#endif
);

static Bool
SyncCheckTriggerNegativeTransition(
#if NeedFunctionPrototypes
    SyncTrigger * /* pTrigger */,
    CARD64 /* oldval */
#endif
);

static Bool
SyncCheckTriggerPositiveComparison(
#if NeedFunctionPrototypes
    SyncTrigger * /* pTrigger */,
    CARD64 /* oldval */
#endif
);

static Bool
SyncCheckTriggerPositiveTransition(
#if NeedFunctionPrototypes
    SyncTrigger * /* pTrigger */,
    CARD64 /* oldval */
#endif
);

static SyncCounter *
SyncCreateCounter(
#if NeedFunctionPrototypes
    ClientPtr /* client */,
    XSyncCounter /* id */,
    CARD64 /* initialvalue */
#endif
);

static void SyncComputeBracketValues(
#if NeedFunctionPrototypes
    SyncCounter * /* pCounter */,
    Bool /* startOver */
#endif
);

static void
SyncDeleteTriggerFromCounter(
#if NeedFunctionPrototypes
    SyncTrigger * /* pTrigger */
#endif
);

static Bool
SyncEventSelectForAlarm(
#if NeedFunctionPrototypes
    SyncAlarm * /* pAlarm */,
    ClientPtr /* client */,
    Bool /* wantevents */
#endif
);

static void
SyncInitServerTime(
#if NeedFunctionPrototypes
    void
#endif
);

static void 
SyncResetProc(
#if NeedFunctionPrototypes
    ExtensionEntry * /* extEntry */
#endif
);

static void
SyncSendAlarmNotifyEvents(
#if NeedFunctionPrototypes
    SyncAlarm * /* pAlarm */
#endif
);

static void
SyncSendCounterNotifyEvents(
#if NeedFunctionPrototypes
    ClientPtr /* client */,
    SyncAwait ** /* ppAwait */,
    int /* num_events */
#endif
);

static DISPATCH_PROC(ProcSyncAwait);
static DISPATCH_PROC(ProcSyncChangeAlarm);
static DISPATCH_PROC(ProcSyncChangeCounter);
static DISPATCH_PROC(ProcSyncCreateAlarm);
static DISPATCH_PROC(ProcSyncCreateCounter);
static DISPATCH_PROC(ProcSyncDestroyAlarm);
static DISPATCH_PROC(ProcSyncDestroyCounter);
static DISPATCH_PROC(ProcSyncDispatch);
static DISPATCH_PROC(ProcSyncGetPriority);
static DISPATCH_PROC(ProcSyncInitialize);
static DISPATCH_PROC(ProcSyncListSystemCounters);
static DISPATCH_PROC(ProcSyncListSystemCounters);
static DISPATCH_PROC(ProcSyncQueryAlarm);
static DISPATCH_PROC(ProcSyncQueryCounter);
static DISPATCH_PROC(ProcSyncSetCounter);
static DISPATCH_PROC(ProcSyncSetPriority);
static DISPATCH_PROC(SProcSyncAwait);
static DISPATCH_PROC(SProcSyncChangeAlarm);
static DISPATCH_PROC(SProcSyncChangeCounter);
static DISPATCH_PROC(SProcSyncCreateAlarm);
static DISPATCH_PROC(SProcSyncCreateCounter);
static DISPATCH_PROC(SProcSyncDestroyAlarm);
static DISPATCH_PROC(SProcSyncDestroyCounter);
static DISPATCH_PROC(SProcSyncDispatch);
static DISPATCH_PROC(SProcSyncDispatch);
static DISPATCH_PROC(SProcSyncGetPriority);
static DISPATCH_PROC(SProcSyncInitialize);
static DISPATCH_PROC(SProcSyncListSystemCounters);
static DISPATCH_PROC(SProcSyncQueryAlarm);
static DISPATCH_PROC(SProcSyncQueryCounter);
static DISPATCH_PROC(SProcSyncSetCounter);
static DISPATCH_PROC(SProcSyncSetPriority);

/*  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
SyncDeleteTriggerFromCounter(pTrigger)
    SyncTrigger *pTrigger;
{
    SyncTriggerList *pCur, *pPrev = NULL;

    /* pCounter needs to be stored in pTrigger before calling here. */

    if (!pTrigger->pCounter)
	return;

    for (pCur = pTrigger->pCounter->pTriglist; pCur; pCur = pCur->next)
    {
	if (pCur->pTrigger == pTrigger)
	{
	    if (pPrev)
		pPrev->next = pCur->next;
	    else
		pTrigger->pCounter->pTriglist = pCur->next;
	    xfree(pCur);
	    break;
	}
    }

    if (IsSystemCounter(pTrigger->pCounter))
	SyncComputeBracketValues(pTrigger->pCounter, /*startOver*/ TRUE);
}


static int
SyncAddTriggerToCounter(pTrigger)
    SyncTrigger *pTrigger;
{
    SyncTriggerList *pCur;

    if (!pTrigger->pCounter)
	return Success;

    /* don't do anything if it's already there */
    for (pCur = pTrigger->pCounter->pTriglist; pCur; pCur = pCur->next)
    {
	if (pCur->pTrigger == pTrigger)
	    return Success;
    }

    if (!(pCur = (SyncTriggerList *)xalloc(sizeof(SyncTriggerList))))
	return BadAlloc;

    pCur->pTrigger = pTrigger;
    pCur->next = pTrigger->pCounter->pTriglist;
    pTrigger->pCounter->pTriglist = pCur;

    if (IsSystemCounter(pTrigger->pCounter))
	SyncComputeBracketValues(pTrigger->pCounter, /*startOver*/ TRUE);

    return Success;
}


/*  Below are four possible functions that can be plugged into 
 *  pTrigger->CheckTrigger, corresponding to the four possible
 *  test-types.  These functions are called after the counter's
 *  value changes but are also passed the old counter value
 *  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->pCounter == NULL.
 *  This is because the spec says that a trigger with a counter value 
 *  of None is always TRUE.
 */

static Bool
SyncCheckTriggerPositiveComparison(pTrigger, oldval)
    SyncTrigger *pTrigger;
    CARD64	oldval;
{
    return (pTrigger->pCounter == NULL ||
	    XSyncValueGreaterOrEqual(pTrigger->pCounter->value,
				     pTrigger->test_value));
}

static Bool
SyncCheckTriggerNegativeComparison(pTrigger, oldval)
    SyncTrigger *pTrigger;
    CARD64	oldval;
{
    return (pTrigger->pCounter == NULL ||
	    XSyncValueLessOrEqual(pTrigger->pCounter->value,
				  pTrigger->test_value));
}

static Bool
SyncCheckTriggerPositiveTransition(pTrigger, oldval)
    SyncTrigger *pTrigger;
    CARD64	oldval;
{
    return (pTrigger->pCounter == NULL ||
	    (XSyncValueLessThan(oldval, pTrigger->test_value) &&
	     XSyncValueGreaterOrEqual(pTrigger->pCounter->value,
				      pTrigger->test_value)));
}

static Bool
SyncCheckTriggerNegativeTransition(pTrigger, oldval)
    SyncTrigger *pTrigger;
    CARD64	oldval;
{
    return (pTrigger->pCounter == NULL ||
	    (XSyncValueGreaterThan(oldval, pTrigger->test_value) &&
	     XSyncValueLessOrEqual(pTrigger->pCounter->value,
				   pTrigger->test_value)));
}



static int 
SyncInitTrigger(client, pTrigger, counter, changes) 
    ClientPtr	     client;    /* so we can set errorValue */
    SyncTrigger      *pTrigger;
    XSyncCounter     counter; 
    Mask	     changes;
{
    SyncCounter *pCounter = pTrigger->pCounter;
    int		status;
    Bool	newcounter = FALSE;

    if (changes & XSyncCACounter)
    {
	if (counter == None)
	    pCounter = NULL;
	else if (!(pCounter = (SyncCounter *)SecurityLookupIDByType(
			client, counter, RTCounter, SecurityReadAccess)))
	{
	    client->errorValue = counter;
	    return SyncErrorBase + XSyncBadCounter;
	}
	if (pCounter != pTrigger->pCounter)
	{ /* new counter for trigger */
	    SyncDeleteTriggerFromCounter(pTrigger);
	    pTrigger->pCounter = pCounter;
	    newcounter = TRUE;
	}
    }

    /* if system counter, ask it what the current value is */

    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)
    {