Re: XWin crash after the launch of startkde on a remote Red Hat 5 machine

[Michel Hummel <hummel dot michel at gmail dot com>]

Thank you for your comments, I really want to help you on this part of
the X server.
 I will now do :
1/ Adapt the patch to be cygwin Xorg compatible
1/ Split the patch into two separate patches
2/ Publish as soon as possible a new patches version which will take
into account your comments :
*a) WM_DESTROYCLIPBOARD message (Could you be a little more precise
concerning this, I'm not sure to realy understand the issue
*b) Adding a rate-limit on "clipboard_generation" with a static
variable for example ? and a restart delay (500 Milliseconds should be
enough isn't it ?)
*c) Change the comment about ProcEstablishConnection wrapper and inInitClipboard
*d) Merge the cleanup and the restart function into one
*e) Concerning the use of pthread_cleanup_pop at winClipboardProc end,
do you mean : Replace all pthread_exit() call's by a goto error_exit
label which will call pthread_cleanup_pop(1) (The parameter "1" means
that we have to execute it)
*f) Delete the unnecessary whitespace changes
*g) Concerning the winClipboardErrorHandler tricks, This is for the
situation you said : "Window has been deleted by someone else, but we
are still connected to the server" I will add a comment in the sources

Michel Hummel


2010/9/28 Jon TURNEY <jon.turney@dronecode.org.uk>:
> On 24/09/2010 09:15, Michel Hummel wrote:
>>
>> Hi Jon,
>
> Firstly, thanks very much for looking at this.
>
>> You will find attached to this Email a patch (for the git version)
>> which implements for the clipboard thread :
>> ?- Auto cleanup function
>> ?- Auto restart function for unexpected exit of the clipboard or
>> Xerror detection
>> ?- Deletion of XQuery wrapper ?(not needed anymore)
>> ?- Deletion of all the xdmcp related tricks ?(not needed anymore)
>
> For purposes of review it would be easier to split this patch into two
> separate patches, (i) the clipboard thread changes and (ii) removing the
> unneeded xdmcp tricks.
>
>> One thing, this patch deletes the call to EmptyClipboard () in the
>> winProcSetSelectionOwner function of the winclipboardwrappers.c file
>> when an "owned to not owned transition" has been detected. I don't
>> know why but it was freezing the server for 1 or 2 seconds during
>> clipboard's restart in xdmcp connection.
>
> Hmmm... I wonder if that's something to do with how we process the
> WM_DESTROYCLIPBOARD message? ?In any case, this should not be happening.
>
>> It would be fine if you could tell me, when you think this patch and
>> the previous one ( which makes the reset of the server working
>> correctly with clipboard) will be included to the official X server?
>
> We don't have a regular release cycle for the cygwin X server, so I can't
> answer that question accurately.
>
> I shall put your previous patch into the next release and assuming it works
> well, be pushing it upstream sometime before xserver 1.10
>
> I think this patch needs a little more work.
>
> I'm still a little concerned that there is no rate-limiting on the clipboard
> restart mechanism, so in a pathological case (e.g. where some unanticipated
> error causes the clipboard to constantly get disconnected), this will spin
> using all available CPU.
>
> Some detailed comments below.
>
>> ---
>> /home/hummelm/xserver-fc091936e2bddbbab9c9a501edc5a5f08388617e-org/hw/xwin/InitInput.c
>> ? ? ?2010-08-18 22:10:54.000000000 +0200
>> +++ hw/xwin/InitInput.c 2010-09-17 17:03:08.611244200 +0200
>> @@ -127,12 +127,6 @@ InitInput (int argc, char *argv[])
>> ? ? ? winProcEstablishConnectionOrig = InitialVector[2];
>> ? ? ? InitialVector[2] = winProcEstablishConnection;
>> ? ? }
>> - ?if (g_fXdmcpEnabled
>> - ? ? ?&& ProcVector[X_QueryTree] != winProcQueryTree)
>> - ? ?{
>> - ? ? ?winProcQueryTreeOrig = ProcVector[X_QueryTree];
>> - ? ? ?ProcVector[X_QueryTree] = winProcQueryTree;
>> - ? ?}
>> ?#endif
>>
>> ? g_pwinPointer = AddInputDevice (serverClient, winMouseProc, TRUE);
>> ---
>> /home/hummelm/xserver-fc091936e2bddbbab9c9a501edc5a5f08388617e-org/hw/xwin//winclipboardthread.c
>> ? ?2010-08-18 22:10:54.000000000 +0200
>> +++ hw/xwin/winclipboardthread.c ? ? ? ?2010-09-24 16:48:20.689125100
>> +0200
>> @@ -48,6 +48,8 @@
>> ?extern Bool ? ? ? ? ? ?g_fUnicodeClipboard;
>> ?extern unsigned long ? serverGeneration;
>> ?extern Bool ? ? ? ? ? ?g_fClipboardStarted;
>> +extern Bool ? ? ? ? ? ? g_fClipboardLaunched;
>> +extern Bool ? ? ? ? ? ? g_fClipboard;
>> ?extern HWND ? ? ? ? ? ?g_hwndClipboard;
>> ?extern void ? ? ? ? ? ?*g_pClipboardDisplay;
>> ?extern Window ? ? ? ? ?g_iClipboardWindow;
>> @@ -72,8 +74,113 @@ winClipboardErrorHandler (Display *pDisp
>> ?static int
>> ?winClipboardIOErrorHandler (Display *pDisplay);
>>
>> +static void
>> +restartClipboardThread(void *pvNotUsed);
>> +
>> +static void
>> +winClipboardCleanup(void *vfdMessageQueue);
>> +
>>
>> ?/*
>> + * restartClipboardThread activate the ProcEstablishConnection wrapper
>> which will start
>> + * the thread after next client connection
>> + */
>
> This comment doesn't appear to be correct. ?winInitClipboard() starts the
> thread itself.
>
> It looks like this could fight with the ProcEstablishConnection wrapper,
> which will call winInitClipboard() once for each server generation.
>
>> +
>> +static void restartClipboardThread(void *pvNotUsed)
>> +{
>> + ?winDebug("restartClipboardThread - enter \n");
>> + ?if (g_fClipboard)
>> + ? ?{
>> + ? ? ?ErrorF("restartClipboardThread - trying to restart clipboard thread
>> \n");
>> + ? ? ?/* Create the clipboard client thread */
>> + ? ? ?if (!winInitClipboard ())
>> + ? ? ? ?{
>> + ? ? ? ? ?ErrorF ("restartClipboardThread - winClipboardInit "
>> + ? ? ? ? ? ? ? ? ?"failed.\n");
>> + ? ? ? ? ?return;
>> + ? ? ? ?}
>> +
>> + ? ? ?winDebug ("restartClipboardThread - winInitClipboard returned.\n");
>> + ? ? ?/* Flag that clipboard client has been launched */
>> + ? ? ?g_fClipboardLaunched = TRUE;
>> + ? ?}
>> + ?else
>> + ? ?{
>> + ? ? ?ErrorF ("restartClipboardThread - Clipboard disabled ?- Exit from
>> server \n");
>> + ? ? ?return;
>> + ? ?}
>> + ?return;
>> +}
>> +
>> +/*
>> + * winClipboardCleanup clean thread before exit
>> + */
>> +
>> +static void winClipboardCleanup(void *vfdMessageQueue)
>> +{
>> + ?int iReturn;
>> + ?int fdMessageQueue = (int) vfdMessageQueue;
>> +
>> + ?winDebug("winClipboardCleanup - Enter \n");
>> + ?CloseClipboard();
>> + ?/* Close our Windows window */
>> + ?if (g_hwndClipboard )
>> + ? ?{
>> + ? ? ?/* Destroy the Window window (hwnd) */
>> + ? ? ?winDebug("winClipboardCleanup - Destroy Windows window\n");
>> + ? ? ?PostMessage (g_hwndClipboard,WM_DESTROY, 0, 0);
>> + ? ? ?winClipboardFlushWindowsMessageQueue(g_hwndClipboard);
>> + ? ?}
>> +
>> + ?/* Close our X window */
>> + ?if (g_pClipboardDisplay && g_iClipboardWindow)
>> + ? ?{
>> + ? ? ?iReturn = XDestroyWindow (g_pClipboardDisplay, g_iClipboardWindow);
>> + ? ? ?if (iReturn == BadWindow)
>> + ? ? ? ErrorF ("winClipboardCleanup - XDestroyWindow returned
>> BadWindow.\n");
>> + ? ? ?else
>> + ? ? ? winDebug ("winClipboardCleanup - winClipboardProc - XDestroyWindow
>> succeeded.\n");
>> + ? ?}
>> +
>> +
>> +#ifdef HAS_DEVWINDOWS
>> + ?/* Close our Win32 message handle */
>> + ?if (fdMessageQueue)
>> + ? ?close (fdMessageQueue);
>> +#endif
>> +
>> +#if 0
>> + ?/*
>> + ? * FIXME: XCloseDisplay hangs if we call it, as of 2004/03/26. ?The
>> + ? * XSync and XSelectInput calls did not help.
>> + ? */
>> +
>> + ?/* Discard any remaining events */
>> + ?XSync (g_pClipboardDisplay, TRUE);
>> +
>> + ?/* Select event types to watch */
>> + ?XSelectInput (g_pClipboardDisplay,
>> + ? ? ? ? ? ? ? DefaultRootWindow (g_pClipboardDisplay),
>> + ? ? ? ? ? ? ? None);
>> +
>> + ?/* Close our X display */
>> + ?if (g_pClipboardDisplay)
>> + ? ?{
>> + ? ? ?XCloseDisplay (g_pClipboardDisplay);
>> + ? ?}
>> +#endif
>> +
>> + ?/* global clipboard variable reset */
>> + ?g_fClipboardLaunched = FALSE;
>> + ?g_fClipboardStarted = FALSE;
>> + ?g_iClipboardWindow = None;
>> + ?g_hwndClipboard = NULL;
>> + ?g_fUnicodeClipboard = FALSE;
>> + ?g_pClipboardDisplay = NULL;
>> + ?winDebug("winClipboardCleanup - Exit \n");
>> +
>> +}
>
> Rather than 2 separate functions which we pthread_cleanup_push separately,
> but never use independently, can these be combined? ?Or create a cleanup fn
> which calls both of them, and push that?
>
>> +/*
>> ?* Main thread function
>> ?*/
>>
>> @@ -84,9 +191,8 @@ winClipboardProc (void *pvNotUsed)
>> ? int ? ? ? ? ? ? ? ? ?iReturn;
>> ? HWND ? ? ? ? ? ? ? ? hwnd = NULL;
>> ? int ? ? ? ? ? ? ? ? ?iConnectionNumber = 0;
>> -#ifdef HAS_DEVWINDOWS
>> ? int ? ? ? ? ? ? ? ? ?fdMessageQueue = 0;
>> -#else
>> +#ifndef HAS_DEVWINDOWS
>> ? struct timeval ? ? ? ?tvTimeout;
>> ?#endif
>> ? fd_set ? ? ? ? ? ? ? fdsRead;
>> @@ -122,24 +228,6 @@ winClipboardProc (void *pvNotUsed)
>> ? ? ? ErrorF ("winClipboardProc - Warning: Locale not supported by X.\n");
>> ? ? }
>>
>> - ?/* Set jump point for Error exits */
>> - ?iReturn = setjmp (g_jmpEntry);
>> -
>> - ?/* Check if we should continue operations */
>> - ?if (iReturn != WIN_JMP_ERROR_IO
>> - ? ? ?&& iReturn != WIN_JMP_OKAY)
>> - ? ?{
>> - ? ? ?/* setjmp returned an unknown value, exit */
>> - ? ? ?ErrorF ("winClipboardProc - setjmp returned: %d exiting\n",
>> - ? ? ? ? ? ? iReturn);
>> - ? ? ?pthread_exit (NULL);
>> - ? ?}
>> - ?else if (iReturn == WIN_JMP_ERROR_IO)
>> - ? ?{
>> - ? ? ?/* TODO: Cleanup the Win32 window and free any allocated memory */
>> - ? ? ?ErrorF ("winClipboardProc - setjmp returned for IO Error
>> Handler.\n");
>> - ? ? ?pthread_exit (NULL);
>> - ? ?}
>>
>> ? /* Use our generated cookie for authentication */
>> ? winSetAuthorization();
>> @@ -216,6 +304,25 @@ winClipboardProc (void *pvNotUsed)
>> ? iMaxDescriptor = iConnectionNumber + 1;
>> ?#endif
>>
>> + ?/* Adding a cleanup process for thread exit
>> + ? * Warning : A call to pthread_cleanup_push() implies a call to
>> pthread_cleanup_pop() at the same code level (function)
>> + ? * We also use it to automaticaly restart the thread on unexpected exit
>> (ie. pthread_exit() when g_pClipboard != TRUE )
>> + ? * this is a LIFO stack ( Last In First Out ) so adding "restart" then
>> "clean"
>> + ? */
>> + ?/* Install the restart function ?to be called */
>> + ?pthread_cleanup_push(restartClipboardThread, ?NULL);
>> + ?/* ?install the cleanup function to be called at thread exit */
>> + ?pthread_cleanup_push(winClipboardCleanup, (void*) &fdMessageQueue);
>> + ?/* The only way to exit from this loop is to :
>> + ? * 1/ Exit before the installation this cleanup process
>> + ? * 2/ Doing the "expected" Exit (ie. End of the function) which disable
>> the restart
>> + ? * ? ?by setting g_pClipboard to FALSE;
>> + ? * ? ?before calling the cleanup handler :
>> + ? * ?pthread_cleanup_pop(1);
>> + ? * ? ?then the restart handler which will be an Exit handler because
>> g_pClipboard != TRUE :
>> + ? * ?pthread_cleanup_pop(1);
>> + ? */
>> +
>> ? /* Create atoms */
>> ? atomClipboard = XInternAtom (pDisplay, "CLIPBOARD", False);
>> ? atomClipboardManager = XInternAtom (pDisplay, "CLIPBOARD_MANAGER",
>> False);
>> @@ -292,6 +399,26 @@ winClipboardProc (void *pvNotUsed)
>> ? /* Signal that the clipboard client has started */
>> ? g_fClipboardStarted = TRUE;
>>
>> +
>> + ?/* Set jump point for Error exits */
>> + ?iReturn = setjmp (g_jmpEntry);
>> +
>> + ?/* Check if we should continue operations */
>> + ?if (iReturn != WIN_JMP_ERROR_IO
>> + ? ? ?&& iReturn != WIN_JMP_OKAY)
>> + ? ?{
>> + ? ? ?/* setjmp returned an unknown value, exit */
>> + ? ? ?ErrorF ("winClipboardProc - setjmp returned: %d exiting\n",
>> + ? ? ? ? ? ? iReturn);
>> + ? ? ?pthread_exit (NULL);
>> + ? ?}
>> + ?else if (iReturn == WIN_JMP_ERROR_IO)
>> + ? ?{
>> + ? ? ?/* TODO: Cleanup the Win32 window and free any allocated memory */
>> + ? ? ?ErrorF ("winClipboardProc - setjmp returned for IO Error
>> Handler.\n");
>> + ? ? ?pthread_exit (NULL);
>> + ? ?}
>> +
>> ? /* Loop for X events */
>> ? while (1)
>> ? ? {
>> @@ -377,47 +504,10 @@ winClipboardProc (void *pvNotUsed)
>> ? ? ? ?}
>> ? ? }
>>
>> - ?/* Close our X window */
>> - ?if (pDisplay && iWindow)
>> - ? ?{
>> - ? ? ?iReturn = XDestroyWindow (pDisplay, iWindow);
>> - ? ? ?if (iReturn == BadWindow)
>> - ? ? ? ErrorF ("winClipboardProc - XDestroyWindow returned
>> BadWindow.\n");
>> - ? ? ?else
>> - ? ? ? ErrorF ("winClipboardProc - XDestroyWindow succeeded.\n");
>> - ? ?}
>> -
>> -
>> -#ifdef HAS_DEVWINDOWS
>> - ?/* Close our Win32 message handle */
>> - ?if (fdMessageQueue)
>> - ? ?close (fdMessageQueue);
>> -#endif
>> -
>> -#if 0
>> - ?/*
>> - ? * FIXME: XCloseDisplay hangs if we call it, as of 2004/03/26. ?The
>> - ? * XSync and XSelectInput calls did not help.
>> - ? */
>> -
>> - ?/* Discard any remaining events */
>> - ?XSync (pDisplay, TRUE);
>> -
>> - ?/* Select event types to watch */
>> - ?XSelectInput (pDisplay,
>> - ? ? ? ? ? ? ? DefaultRootWindow (pDisplay),
>> - ? ? ? ? ? ? ? None);
>> -
>> - ?/* Close our X display */
>> - ?if (pDisplay)
>> - ? ?{
>> - ? ? ?XCloseDisplay (pDisplay);
>> - ? ?}
>> -#endif
>> -
>> - ?g_iClipboardWindow = None;
>> - ?g_pClipboardDisplay = NULL;
>> - ?g_hwndClipboard = NULL;
>> + ?/* disable the clipboard means thread restart function will kill the
>> server */
>> + ?g_fClipboard = FALSE;
>> + ?pthread_cleanup_pop(1);
>> + ?pthread_cleanup_pop(1);
>
> The use of pthread_cleanup really obscures what's going on here. ?It would
> be clearer just to have a label error_exit: here and goto it from the
> various places which pthread_exit...
>
>>
>> ? return NULL;
>> ?}
>> @@ -431,7 +521,7 @@ static int
>> ?winClipboardErrorHandler (Display *pDisplay, XErrorEvent *pErr)
>> ?{
>> ? char pszErrorMsg[100];
>> -
>> +
>
> No unnecessary whitespace changes, please.
>
>> ? XGetErrorText (pDisplay,
>> ? ? ? ? ? ? ? ? pErr->error_code,
>> ? ? ? ? ? ? ? ? pszErrorMsg,
>> @@ -442,6 +532,13 @@ winClipboardErrorHandler (Display *pDisp
>> ? ? ? ? ?pErr->serial,
>> ? ? ? ? ?pErr->request_code,
>> ? ? ? ? ?pErr->minor_code);
>> +
>> + ?/* If the Xerror is BadWindow Error, restart the thread */
>> + ?if ( pErr->request_code == 24 )
>> + ? {
>> + ? ? ErrorF("winClipboardErrorHandler - Badwindow detected, restarting
>> clipboard thread\n");
>> + ? ? pthread_exit(NULL);
>> + ? }
>
> How do we get into this situation? ?Window has been deleted by someone else,
> but we are still connected to the server?
>
>> ? return 0;
>> ?}
>>
>> ---
>> /home/hummelm/xserver-fc091936e2bddbbab9c9a501edc5a5f08388617e-org/hw/xwin/winclipboardwrappers.c
>> ? 2010-08-18 22:10:54.000000000 +0200
>> +++ hw/xwin/winclipboardwrappers.c ? ? ?2010-09-22 10:06:00.232451900
>> +0200
>> @@ -53,7 +53,6 @@
>> ?*/
>>
>> ?DISPATCH_PROC(winProcEstablishConnection);
>> -DISPATCH_PROC(winProcQueryTree);
>> ?DISPATCH_PROC(winProcSetSelectionOwner);
>>
>>
>> @@ -79,104 +78,6 @@ extern winDispatchProcPtr ? winProcSetSele
>>
>>
>> ?/*
>> - * Wrapper for internal QueryTree function.
>> - * Hides the clipboard client when it is the only client remaining.
>> - */
>> -
>> -int
>> -winProcQueryTree (ClientPtr client)
>> -{
>> - ?int ? ? ? ? ? ? ? ? ?iReturn;
>> -
>> - ?ErrorF ("winProcQueryTree - Hello\n");
>> -
>> - ?/*
>> - ? * This procedure is only used for initialization.
>> - ? * We can unwrap the original procedure at this point
>> - ? * so that this function is no longer called until the
>> - ? * server resets and the function is wrapped again.
>> - ? */
>> - ?ProcVector[X_QueryTree] = winProcQueryTreeOrig;
>> -
>> - ?/*
>> - ? * Call original function and bail if it fails.
>> - ? * NOTE: We must do this first, since we need XdmcpOpenDisplay
>> - ? * to be called before we initialize our clipboard client.
>> - ? */
>> - ?iReturn = (*winProcQueryTreeOrig) (client);
>> - ?if (iReturn != 0)
>> - ? ?{
>> - ? ? ?ErrorF ("winProcQueryTree - ProcQueryTree failed, bailing.\n");
>> - ? ? ?return iReturn;
>> - ? ?}
>> -
>> - ?/* Make errors more obvious */
>> - ?winProcQueryTreeOrig = NULL;
>> -
>> - ?/* Do nothing if clipboard is not enabled */
>> - ?if (!g_fClipboard)
>> - ? ?{
>> - ? ? ?ErrorF ("winProcQueryTree - Clipboard is not enabled, "
>> - ? ? ? ? ? ? "returning.\n");
>> - ? ? ?return iReturn;
>> - ? ?}
>> -
>> - ?/* If the clipboard client has already been started, abort */
>> - ?if (g_fClipboardLaunched)
>> - ? ?{
>> - ? ? ?ErrorF ("winProcQueryTree - Clipboard client already "
>> - ? ? ? ? ? ? "launched, returning.\n");
>> - ? ? ?return iReturn;
>> - ? ?}
>> -
>> - ?/* Startup the clipboard client if clipboard mode is being used */
>> - ?if (g_fXdmcpEnabled && g_fClipboard)
>> - ? ?{
>> - ? ? ?/*
>> - ? ? ? * NOTE: The clipboard client is started here for a reason:
>> - ? ? ? * 1) Assume you are using XDMCP (e.g. XWin -query %hostname%)
>> - ? ? ? * 2) If the clipboard client attaches during X Server startup,
>> - ? ? ? * ? ?then it becomes the "magic client" that causes the X Server
>> - ? ? ? * ? ?to reset if it exits.
>> - ? ? ? * 3) XDMCP calls KillAllClients when it starts up.
>> - ? ? ? * 4) The clipboard client is a client, so it is killed.
>> - ? ? ? * 5) The clipboard client is the "magic client", so the X Server
>> - ? ? ? * ? ?resets itself.
>> - ? ? ? * 6) This repeats ad infinitum.
>> - ? ? ? * 7) We avoid this by waiting until at least one client (could
>> - ? ? ? * ? ?be XDM, could be another client) connects, which makes it
>> - ? ? ? * ? ?almost certain that the clipboard client will not connect
>> - ? ? ? * ? ?until after XDM when using XDMCP.
>> - ? ? ? * 8) Unfortunately, there is another problem.
>> - ? ? ? * 9) XDM walks the list of windows with XQueryTree,
>> - ? ? ? * ? ?killing any client it finds with a window.
>> - ? ? ? * 10)Thus, when using XDMCP we wait until the first call
>> - ? ? ? * ? ?to ProcQueryTree before we startup the clipboard client.
>> - ? ? ? * ? ?This should prevent XDM from finding the clipboard client,
>> - ? ? ? * ? ?since it has not yet created a window.
>> - ? ? ? * 11)Startup when not using XDMCP is handled in
>> - ? ? ? * ? ?winProcEstablishConnection.
>> - ? ? ? */
>> -
>> - ? ? ?/* Create the clipboard client thread */
>> - ? ? ?if (!winInitClipboard ())
>> - ? ? ? {
>> - ? ? ? ? ErrorF ("winProcQueryTree - winClipboardInit "
>> - ? ? ? ? ? ? ? ? "failed.\n");
>> - ? ? ? ? return iReturn;
>> - ? ? ? }
>> -
>> - ? ? ?ErrorF ("winProcQueryTree - winInitClipboard returned.\n");
>> - ? ?}
>> -
>> - ?/* Flag that clipboard client has been launched */
>> - ?g_fClipboardLaunched = TRUE;
>> -
>> - ?return iReturn;
>> -}
>> -
>> -
>> -/*
>> ?* Wrapper for internal EstablishConnection function.
>> ?* Initializes internal clients that must not be started until
>> ?* an external client has connected.
>> @@ -217,18 +118,6 @@ winProcEstablishConnection (ClientPtr cl
>> ? /* Increment call count */
>> ? ++s_iCallCount;
>>
>> - ?/* Wait for CLIP_NUM_CALLS when Xdmcp is enabled */
>> - ?if (g_fXdmcpEnabled
>> - ? ? ?&& !g_fClipboardLaunched
>> - ? ? ?&& s_iCallCount < CLIP_NUM_CALLS)
>> - ? ?{
>> - ? ? ?if (s_iCallCount == 1) ErrorF ("winProcEstablishConnection - Xdmcp,
>> waiting to "
>> - ? ? ? ? ? ? "start clipboard client until %dth call", CLIP_NUM_CALLS);
>> - ? ? ?if (s_iCallCount == CLIP_NUM_CALLS - 1) ErrorF (".\n");
>> - ? ? ?else ErrorF (".");
>> - ? ? ?return (*winProcEstablishConnectionOrig) (client);
>> - ? ?}
>> -
>> ? /*
>> ? ?* This procedure is only used for initialization.
>> ? ?* We can unwrap the original procedure at this point
>> @@ -279,13 +168,6 @@ winProcEstablishConnection (ClientPtr cl
>> ? ? ? ?* ? ?be XDM, could be another client) connects, which makes it
>> ? ? ? ?* ? ?almost certain that the clipboard client will not connect
>> ? ? ? ?* ? ?until after XDM when using XDMCP.
>> - ? ? ? * 8) Unfortunately, there is another problem.
>> - ? ? ? * 9) XDM walks the list of windows with XQueryTree,
>> - ? ? ? * ? ?killing any client it finds with a window.
>> - ? ? ? * 10)Thus, when using XDMCP we wait until CLIP_NUM_CALLS
>> - ? ? ? * ? ?to ProcEstablishCeonnection before we startup the clipboard
>> - ? ? ? * ? ?client. ?This should prevent XDM from finding the clipboard
>> - ? ? ? * ? ?client, since it has not yet created a window.
>> ? ? ? ?*/
>>
>> ? ? ? /* Create the clipboard client thread */
>> @@ -442,7 +324,8 @@ winProcSetSelectionOwner (ClientPtr clie
>>
>> ? ? ? /* Release ownership of the Windows clipboard */
>> ? ? ? OpenClipboard (NULL);
>> - ? ? ?EmptyClipboard ();
>> + ? ? ?/* on clipboard restart ?EmptyClipboard (); makes the X server to
>> freeze ?for 1 or 2 seconds and I don't know why */
>> + ? ? ?/* EmptyClipboard (); */
>> ? ? ? CloseClipboard ();
>>
>> ? ? ? goto winProcSetSelectionOwner_Done;
>
> --
> Jon TURNEY
> Volunteer Cygwin/X X Server maintainer
>

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