302 lines
9.2 KiB
C
302 lines
9.2 KiB
C
/*
|
||
* tkError.c --
|
||
*
|
||
* This file provides a high-performance mechanism for
|
||
* selectively dealing with errors that occur in talking
|
||
* to the X server. This is useful, for example, when
|
||
* communicating with a window that may not exist.
|
||
*
|
||
* Copyright (c) 1990-1993 The Regents of the University of California.
|
||
* All rights reserved.
|
||
*
|
||
* Permission is hereby granted, without written agreement and without
|
||
* license or royalty fees, to use, copy, modify, and distribute this
|
||
* software and its documentation for any purpose, provided that the
|
||
* above copyright notice and the following two paragraphs appear in
|
||
* all copies of this software.
|
||
*
|
||
* IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
|
||
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
|
||
* OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
|
||
* CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||
*
|
||
* THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
|
||
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
|
||
* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
|
||
* ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
|
||
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
|
||
*/
|
||
|
||
#ifndef lint
|
||
static char rcsid[] = "$Header: /user6/ouster/wish/RCS/tkError.c,v 1.12 93/06/16 17:14:52 ouster Exp $ SPRITE (Berkeley)";
|
||
#endif
|
||
|
||
#include "tkConfig.h"
|
||
#include "tkInt.h"
|
||
|
||
/*
|
||
* Forward references to procedures declared later in this file:
|
||
*/
|
||
|
||
static int ErrorProc _ANSI_ARGS_((Display *display,
|
||
XErrorEvent *errEventPtr));
|
||
|
||
/*
|
||
*--------------------------------------------------------------
|
||
*
|
||
* Tk_CreateErrorHandler --
|
||
*
|
||
* Arrange for all a given procedure to be invoked whenever
|
||
* certain errors occur.
|
||
*
|
||
* Results:
|
||
* The return value is a token identifying the handler;
|
||
* it must be passed to Tk_DeleteErrorHandler to delete the
|
||
* handler.
|
||
*
|
||
* Side effects:
|
||
* If an X error occurs that matches the error, request,
|
||
* and minor arguments, then errorProc will be invoked.
|
||
* ErrorProc should have the following structure:
|
||
*
|
||
* int
|
||
* errorProc(clientData, errorEventPtr)
|
||
* caddr_t clientData;
|
||
* XErrorEvent *errorEventPtr;
|
||
* {
|
||
* }
|
||
*
|
||
* The clientData argument will be the same as the clientData
|
||
* argument to this procedure, and errorEvent will describe
|
||
* the error. If errorProc returns 0, it means that it
|
||
* completely "handled" the error: no further processing
|
||
* should be done. If errorProc returns 1, it means that it
|
||
* didn't know how to deal with the error, so we should look
|
||
* for other error handlers, or invoke the default error
|
||
* handler if no other handler returns zero. Handlers are
|
||
* invoked in order of age: youngest handler first.
|
||
*
|
||
* Note: errorProc will only be called for errors associated
|
||
* with X requests made AFTER this call, but BEFORE the handler
|
||
* is deleted by calling Tk_DeleteErrorHandler.
|
||
*
|
||
*--------------------------------------------------------------
|
||
*/
|
||
|
||
Tk_ErrorHandler
|
||
Tk_CreateErrorHandler(display, error, request, minorCode, errorProc, clientData)
|
||
Display *display; /* Display for which to handle
|
||
* errors. */
|
||
int error; /* Consider only errors with this
|
||
* error_code (-1 means consider
|
||
* all errors). */
|
||
int request; /* Consider only errors with this
|
||
* major request code (-1 means
|
||
* consider all major codes). */
|
||
int minorCode; /* Consider only errors with this
|
||
* minor request code (-1 means
|
||
* consider all minor codes). */
|
||
Tk_ErrorProc *errorProc; /* Procedure to invoke when a
|
||
* matching error occurs. NULL means
|
||
* just ignore matching errors. */
|
||
ClientData clientData; /* Arbitrary value to pass to
|
||
* errorProc. */
|
||
{
|
||
register TkErrorHandler *errorPtr;
|
||
register TkDisplay *dispPtr;
|
||
|
||
/*
|
||
* Find the display. If Tk doesn't know about this display then
|
||
* it's an error: panic.
|
||
*/
|
||
|
||
for (dispPtr = tkDisplayList; ; dispPtr = dispPtr->nextPtr) {
|
||
if (dispPtr->display == display) {
|
||
break;
|
||
}
|
||
if (dispPtr == NULL) {
|
||
panic("Unknown display passed to Tk_CreateErrorHandler");
|
||
}
|
||
}
|
||
|
||
/*
|
||
* Make sure that X calls us whenever errors occur.
|
||
*/
|
||
|
||
if (dispPtr->defaultHandler == NULL) {
|
||
dispPtr->defaultHandler = XSetErrorHandler(ErrorProc);
|
||
}
|
||
|
||
/*
|
||
* Create the handler record.
|
||
*/
|
||
|
||
errorPtr = (TkErrorHandler *) ckalloc(sizeof(TkErrorHandler));
|
||
errorPtr->dispPtr = dispPtr;
|
||
errorPtr->firstRequest = NextRequest(display);
|
||
errorPtr->lastRequest = -1;
|
||
errorPtr->error = error;
|
||
errorPtr->request = request;
|
||
errorPtr->minorCode = minorCode;
|
||
errorPtr->errorProc = errorProc;
|
||
errorPtr->clientData = clientData;
|
||
errorPtr->nextPtr = dispPtr->errorPtr;
|
||
dispPtr->errorPtr = errorPtr;
|
||
|
||
return (Tk_ErrorHandler) errorPtr;
|
||
}
|
||
|
||
/*
|
||
*--------------------------------------------------------------
|
||
*
|
||
* Tk_DeleteErrorHandler --
|
||
*
|
||
* Do not use an error handler anymore.
|
||
*
|
||
* Results:
|
||
* None.
|
||
*
|
||
* Side effects:
|
||
* The handler denoted by the "handler" argument will not
|
||
* be invoked for any X errors associated with requests
|
||
* made after this call. However, if errors arrive later
|
||
* for requests made BEFORE this call, then the handler
|
||
* will still be invoked. Call XSync if you want to be
|
||
* sure that all outstanding errors have been received
|
||
* and processed.
|
||
*
|
||
*--------------------------------------------------------------
|
||
*/
|
||
|
||
void
|
||
Tk_DeleteErrorHandler(handler)
|
||
Tk_ErrorHandler handler; /* Token for handler to delete;
|
||
* was previous return value from
|
||
* Tk_CreateErrorHandler. */
|
||
{
|
||
register TkErrorHandler *errorPtr = (TkErrorHandler *) handler;
|
||
register TkDisplay *dispPtr = errorPtr->dispPtr;
|
||
|
||
errorPtr->lastRequest = NextRequest(dispPtr->display) - 1;
|
||
|
||
/*
|
||
* Every once-in-a-while, cleanup handlers that are no longer
|
||
* active. We probably won't be able to free the handler that
|
||
* was just deleted (need to wait for any outstanding requests to
|
||
* be processed by server), but there may be previously-deleted
|
||
* handlers that are now ready for garbage collection. To reduce
|
||
* the cost of the cleanup, let a few dead handlers pile up, then
|
||
* clean them all at once. This adds a bit of overhead to errors
|
||
* that might occur while the dead handlers are hanging around,
|
||
* but reduces the overhead of scanning the list to clean up
|
||
* (particularly if there are many handlers that stay around
|
||
* forever).
|
||
*/
|
||
|
||
dispPtr->deleteCount += 1;
|
||
if (dispPtr->deleteCount >= 10) {
|
||
register TkErrorHandler *prevPtr;
|
||
TkErrorHandler *nextPtr;
|
||
int lastSerial;
|
||
|
||
dispPtr->deleteCount = 0;
|
||
lastSerial = LastKnownRequestProcessed(dispPtr->display);
|
||
errorPtr = dispPtr->errorPtr;
|
||
for (errorPtr = dispPtr->errorPtr, prevPtr = NULL;
|
||
errorPtr != NULL; errorPtr = nextPtr) {
|
||
nextPtr = errorPtr->nextPtr;
|
||
if ((errorPtr->lastRequest != -1)
|
||
&& (errorPtr->lastRequest <= lastSerial)) {
|
||
if (prevPtr == NULL) {
|
||
dispPtr->errorPtr = nextPtr;
|
||
} else {
|
||
prevPtr->nextPtr = nextPtr;
|
||
}
|
||
ckfree((char *) errorPtr);
|
||
continue;
|
||
}
|
||
prevPtr = errorPtr;
|
||
}
|
||
}
|
||
}
|
||
|
||
/*
|
||
*--------------------------------------------------------------
|
||
*
|
||
* ErrorProc --
|
||
*
|
||
* This procedure is invoked by the X system when error
|
||
* events arrive.
|
||
*
|
||
* Results:
|
||
* If it returns, the return value is zero. However,
|
||
* it is possible that one of the error handlers may
|
||
* just exit.
|
||
*
|
||
* Side effects:
|
||
* This procedure does two things. First, it uses the
|
||
* serial # in the error event to eliminate handlers whose
|
||
* expiration serials are now in the past. Second, it
|
||
* invokes any handlers that want to deal with the error.
|
||
*
|
||
*--------------------------------------------------------------
|
||
*/
|
||
|
||
static int
|
||
ErrorProc(display, errEventPtr)
|
||
Display *display; /* Display for which error
|
||
* occurred. */
|
||
register XErrorEvent *errEventPtr; /* Information about error. */
|
||
{
|
||
register TkDisplay *dispPtr;
|
||
register TkErrorHandler *errorPtr;
|
||
|
||
/*
|
||
* See if we know anything about the display. If not, then
|
||
* invoke the default error handler.
|
||
*/
|
||
|
||
for (dispPtr = tkDisplayList; ; dispPtr = dispPtr->nextPtr) {
|
||
if (dispPtr == NULL) {
|
||
goto couldntHandle;
|
||
}
|
||
if (dispPtr->display == display) {
|
||
break;
|
||
}
|
||
}
|
||
|
||
/*
|
||
* Otherwise invoke any relevant handlers for the error, in order.
|
||
*/
|
||
|
||
for (errorPtr = dispPtr->errorPtr; errorPtr != NULL;
|
||
errorPtr = errorPtr->nextPtr) {
|
||
if ((errorPtr->firstRequest > errEventPtr->serial)
|
||
|| ((errorPtr->error != -1)
|
||
&& (errorPtr->error != errEventPtr->error_code))
|
||
|| ((errorPtr->request != -1)
|
||
&& (errorPtr->request != errEventPtr->request_code))
|
||
|| ((errorPtr->minorCode != -1)
|
||
&& (errorPtr->minorCode != errEventPtr->minor_code))
|
||
|| ((errorPtr->lastRequest != -1)
|
||
&& (errorPtr->lastRequest < errEventPtr->serial))) {
|
||
continue;
|
||
}
|
||
if (errorPtr->errorProc == NULL) {
|
||
return 0;
|
||
} else {
|
||
if ((*errorPtr->errorProc)(errorPtr->clientData,
|
||
errEventPtr) == 0) {
|
||
return 0;
|
||
}
|
||
}
|
||
}
|
||
|
||
/*
|
||
* We couldn't handle the error. Use the default handler.
|
||
*/
|
||
|
||
couldntHandle:
|
||
return (*dispPtr->defaultHandler)(display, errEventPtr);
|
||
}
|