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

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

You will find attached to this Email the modifications you asked.

The X server doesn't freeze anymore when clipboard restarts on xdmcp,
certainly fixed by the cygwin patches.

I added a rate-limit of clipboard_generation which disables restart after
XWIN_CLIPBOARD_RETRIES retries (defined to 40 in winclipboard.h)
and a sleep(XWIN_CLIPBOARD_DELAY) before retries (defined to 1 in
winclipboard.h)

I hope you will like this new version,

Thank you
Michel Hummel

2010/9/29 Michel Hummel <hummel.michel@gmail.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
>>
>

Attachment: XWin_patch_restart_clipboard1.9.patch
Description: Binary data

Attachment: XWin_patch_remove_xdmcp_tricks1.9.patch
Description: Binary data

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