XWin/Clipboard/Crash/Hang - Patch Take 2
Wilks, Dan
Dan_Wilks@intuit.com
Sat May 8 04:51:00 GMT 2004
Harold L Hunt II wrote:
> I'm including the small fix from winclipboardwndproc.c in the next
> release, but the changes to the debug messages should probably be
> done using the newer logging functions that accept a log level and
> verb.
I think the small fix got lost. At least I couldn't find it in
the clipboard window proc. No worries it gave me time to look into
the problem some more.
This patch should solve XWin crashing (silently quitting) while
copying or pasting after using another Windows application which
utilizes the clipboard chain. Remote desktop is one such application.
If further crashes occur using XWin -logverbose 3 will be able to generate
hopefully useful information from the clipboard.
ChangeLog:
* winclipboard.h: Add extern prototypes for winDebug, winErrorFVerb
copied from winmsg.h.
* winclipboardinit.c (winFixClipboardChain): Post rather than send the
reinit message to the clipboard window. Sending the message caused,
or possibly just exacerbated an existing, race condition that would
cause the X server to hang when coming back from a remote desktop
session.
* winclipboardwndproc.c (winProcessXEventsTimeout): switch to new
logging api's.
(winClipboardWindowProc): switch to new logging api's. Add some
additional debug logging. Make best effort to prevent our window
appearing twice in the clipboard chain. Also detect loops when they
occur and try to behave in a reasonable way.
Patch:
Index: winclipboard.h
===================================================================
RCS file: /cvs/xorg/xc/programs/Xserver/hw/xwin/winclipboard.h,v
retrieving revision 1.1.4.1.2.14
diff -u -p -r1.1.4.1.2.14 winclipboard.h
--- winclipboard.h 23 Apr 2004 18:17:29 -0000 1.1.4.1.2.14
+++ winclipboard.h 7 May 2004 15:32:27 -0000
@@ -84,6 +84,8 @@
extern char *display;
extern void ErrorF (const char* /*f*/, ...);
+extern void winDebug (const char *format, ...);
+extern void winErrorFVerb (int verb, const char *format, ...);
/*
Index: winclipboardinit.c
===================================================================
RCS file: /cvs/xorg/xc/programs/Xserver/hw/xwin/winclipboardinit.c,v
retrieving revision 1.1.4.1.2.8
diff -u -p -r1.1.4.1.2.8 winclipboardinit.c
--- winclipboardinit.c 23 Apr 2004 18:17:29 -0000 1.1.4.1.2.8
+++ winclipboardinit.c 7 May 2004 15:32:27 -0000
@@ -135,6 +135,6 @@ winFixClipboardChain (void)
if (g_fClipboard
&& g_hwndClipboard)
{
- SendMessage (g_hwndClipboard, WM_WM_REINIT, 0, 0);
+ PostMessage (g_hwndClipboard, WM_WM_REINIT, 0, 0);
}
}
Index: winclipboardwndproc.c
===================================================================
RCS file: /cvs/xorg/xc/programs/Xserver/hw/xwin/winclipboardwndproc.c,v
retrieving revision 1.1.4.1.2.20
diff -u -p -r1.1.4.1.2.20 winclipboardwndproc.c
--- winclipboardwndproc.c 26 Apr 2004 19:53:49 -0000 1.1.4.1.2.20
+++ winclipboardwndproc.c 7 May 2004 15:32:27 -0000
@@ -102,8 +102,8 @@ winProcessXEventsTimeout (HWND hwnd, int
&tv); /* No timeout */
if (iReturn <= 0)
{
- ErrorF ("winProcessXEventsTimeout - Call to select () failed: %d.
"
- "Bailing.\n", iReturn);
+ winErrorFVerb (1, "winProcessXEventsTimeout - Call to select () "
+ "failed: %d. Bailing.\n", iReturn);
break;
}
@@ -145,9 +145,7 @@ winClipboardWindowProc (HWND hwnd, UINT
{
case WM_DESTROY:
{
-#if 0
- ErrorF ("winClipboardWindowProc - WM_DESTROY\n");
-#endif
+ winDebug ("winClipboardWindowProc - WM_DESTROY\n");
/* Remove ourselves from the clipboard chain */
ChangeClipboardChain (hwnd, s_hwndNextViewer);
@@ -161,24 +159,61 @@ winClipboardWindowProc (HWND hwnd, UINT
case WM_CREATE:
{
-#if 0
- ErrorF ("winClipboardWindowProc - WM_CREATE\n");
-#endif
+ winDebug ("winClipboardWindowProc - WM_CREATE\n");
/* Add ourselves to the clipboard viewer chain */
s_hwndNextViewer = SetClipboardViewer (hwnd);
+ if (s_hwndNextViewer == hwnd)
+ {
+ s_hwndNextViewer = NULL;
+ winErrorFVerb (1, "winClipboardWindowProc - WM_CREATE: "
+ "attempted to set next window to ourselves.");
+ }
}
return 0;
case WM_CHANGECBCHAIN:
{
+ static Bool s_fProcessingChangeCBChain = FALSE;
+ winDebug ("winClipboardWindowProc - WM_CHANGECBCHAIN: wParam(%x) "
+ "lParam(%x) s_hwndNextViewer(%x)\n",
+ wParam, lParam, s_hwndNextViewer);
+
+
+ /*
+ * We've occasionally seen a loop in the clipboard chain. Break
+ * it on the first hint of recursion.
+ */
+ if (! s_fProcessingChangeCBChain)
+ {
+ s_fProcessingChangeCBChain = TRUE;
+ }
+ else
+ {
+ winErrorFVerb (1, "winClipboardWindowProc - WM_CHANGECBCHAIN - "
+ "Nested calls detected. Bailing.\n");
+ winDebug ("winClipboardWindowProc - WM_CHANGECBCHAIN: Exit\n");
+ return 0;
+ }
+
if ((HWND) wParam == s_hwndNextViewer)
- s_hwndNextViewer = (HWND) lParam;
+ {
+ s_hwndNextViewer = (HWND) lParam;
+ if (s_hwndNextViewer == hwnd)
+ {
+ s_hwndNextViewer = NULL;
+ winErrorFVerb (1, "winClipboardWindowProc -
WM_CHANGECBCHAIN: "
+ "attempted to set next window to
ourselves.");
+ }
+ }
else if (s_hwndNextViewer)
SendMessage (s_hwndNextViewer, message,
wParam, lParam);
+
+ s_fProcessingChangeCBChain = FALSE;
}
+ winDebug ("winClipboardWindowProc - WM_CHANGECBCHAIN: Exit\n");
return 0;
case WM_WM_REINIT:
@@ -196,21 +231,58 @@ winClipboardWindowProc (HWND hwnd, UINT
* expensive than just putting ourselves back into the chain.
*/
- s_fCBCInitialized = FALSE;
- ChangeClipboardChain (hwnd, s_hwndNextViewer);
- s_hwndNextViewer = NULL;
- s_fCBCInitialized = FALSE;
- s_hwndNextViewer = SetClipboardViewer (hwnd);
+ winDebug ("winClipboardWindowProc - WM_WM_REINIT: Enter\n");
+ if (hwnd != GetClipboardViewer ())
+ {
+ winDebug (" WM_WM_REINIT: Replacing us(%x) with %x at head "
+ "of chain\n", hwnd, s_hwndNextViewer);
+ s_fCBCInitialized = FALSE;
+ ChangeClipboardChain (hwnd, s_hwndNextViewer);
+ s_hwndNextViewer = NULL;
+ s_fCBCInitialized = FALSE;
+ winDebug (" WM_WM_REINIT: Putting us back at head of
chain.\n");
+ s_hwndNextViewer = SetClipboardViewer (hwnd);
+ if (s_hwndNextViewer == hwnd)
+ {
+ s_hwndNextViewer = NULL;
+ winErrorFVerb (1, "winClipboardWindowProc - WM_WM_REINIT: "
+ "attempted to set next window to
ourselves.\n");
+ }
+ }
+ else
+ {
+ winDebug (" WM_WM_REINIT: already at head of viewer chain.\n");
+ }
}
+ winDebug ("winClipboardWindowProc - WM_WM_REINIT: Exit\n");
return 0;
case WM_DRAWCLIPBOARD:
{
+ static Bool s_fProcessingDrawClipboard = FALSE;
Display *pDisplay = g_pClipboardDisplay;
Window iWindow = g_iClipboardWindow;
int iReturn;
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD: Enter\n");
+
+ /*
+ * We've occasionally seen a loop in the clipboard chain. Break
+ * it on the first hint of recursion.
+ */
+ if (! s_fProcessingDrawClipboard)
+ {
+ s_fProcessingDrawClipboard = TRUE;
+ }
+ else
+ {
+ winErrorFVerb (1, "winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+ "Nested calls detected. Bailing.\n");
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD: Exit\n");
+ return 0;
+ }
+
/* Pass the message on the next window in the clipboard viewer chain
*/
if (s_hwndNextViewer)
SendMessage (s_hwndNextViewer, message, 0, 0);
@@ -219,6 +291,8 @@ winClipboardWindowProc (HWND hwnd, UINT
if (!s_fCBCInitialized)
{
s_fCBCInitialized = TRUE;
+ s_fProcessingDrawClipboard = FALSE;
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD: Exit\n");
return 0;
}
@@ -233,10 +307,11 @@ winClipboardWindowProc (HWND hwnd, UINT
/* Bail when we still own the clipboard */
if (hwnd == GetClipboardOwner ())
{
-#if 0
- ErrorF ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
"We own the clipboard, returning.\n");
-#endif
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD: Exit\n");
+ s_fProcessingDrawClipboard = FALSE;
return 0;
}
@@ -248,11 +323,10 @@ winClipboardWindowProc (HWND hwnd, UINT
if (!IsClipboardFormatAvailable (CF_TEXT)
&& !IsClipboardFormatAvailable (CF_UNICODETEXT))
{
-#if 0
- ErrorF ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
"Clipboard does not contain CF_TEXT nor "
"CF_UNICODETEXT.\n");
-#endif
/*
* We need to make sure that the X Server has processed
@@ -264,17 +338,15 @@ winClipboardWindowProc (HWND hwnd, UINT
iReturn = XGetSelectionOwner (pDisplay, XA_PRIMARY);
if (iReturn == g_iClipboardWindow)
{
-#if 0
- ErrorF ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
"PRIMARY selection is owned by us.\n");
-#endif
XSetSelectionOwner (pDisplay,
XA_PRIMARY,
None,
CurrentTime);
}
else if (BadWindow == iReturn || BadAtom == iReturn)
- ErrorF ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+ winErrorFVerb (1, "winClipboardWindowProc - WM_DRAWCLIPBOARD -
"
"XGetSelection failed for PRIMARY: %d\n", iReturn);
/* Release CLIPBOARD selection if owned */
@@ -284,10 +356,8 @@ winClipboardWindowProc (HWND hwnd, UINT
False));
if (iReturn == g_iClipboardWindow)
{
-#if 0
- ErrorF ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
"CLIPBOARD selection is owned by us.\n");
-#endif
XSetSelectionOwner (pDisplay,
XInternAtom (pDisplay,
"CLIPBOARD",
@@ -296,9 +366,11 @@ winClipboardWindowProc (HWND hwnd, UINT
CurrentTime);
}
else if (BadWindow == iReturn || BadAtom == iReturn)
- ErrorF ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+ winErrorFVerb (1, "winClipboardWindowProc - WM_DRAWCLIPBOARD -
"
"XGetSelection failed for CLIPBOARD: %d\n", iReturn);
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD: Exit\n");
+ s_fProcessingDrawClipboard = FALSE;
return 0;
}
@@ -309,16 +381,14 @@ winClipboardWindowProc (HWND hwnd, UINT
CurrentTime);
if (iReturn == BadAtom || iReturn == BadWindow)
{
- ErrorF ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+ winErrorFVerb (1, "winClipboardWindowProc - WM_DRAWCLIPBOARD - "
"Could not reassert ownership of PRIMARY\n");
}
-#if 0
else
{
- ErrorF ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
"Reasserted ownership of PRIMARY\n");
}
-#endif
/* Reassert ownership of the CLIPBOARD */
iReturn = XSetSelectionOwner (pDisplay,
@@ -329,20 +399,21 @@ winClipboardWindowProc (HWND hwnd, UINT
CurrentTime);
if (iReturn == BadAtom || iReturn == BadWindow)
{
- ErrorF ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+ winErrorFVerb (1, "winClipboardWindowProc - WM_DRAWCLIPBOARD - "
"Could not reassert ownership of CLIPBOARD\n");
}
-#if 0
else
{
- ErrorF ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD - "
"Reasserted ownership of CLIPBOARD\n");
}
-#endif
/* Flush the pending SetSelectionOwner event now */
XFlush (pDisplay);
+
+ s_fProcessingDrawClipboard = FALSE;
}
+ winDebug ("winClipboardWindowProc - WM_DRAWCLIPBOARD: Exit\n");
return 0;
@@ -368,9 +439,7 @@ winClipboardWindowProc (HWND hwnd, UINT
Window iWindow = g_iClipboardWindow;
Bool fConvertToUnicode;
-#if 0
- ErrorF ("winClipboardWindowProc - WM_RENDER*FORMAT - Hello.\n");
-#endif
+ winDebug ("winClipboardWindowProc - WM_RENDER*FORMAT - Hello.\n");
/* Flag whether to convert to Unicode or not */
if (message == WM_RENDERALLFORMATS)
@@ -389,7 +458,7 @@ winClipboardWindowProc (HWND hwnd, UINT
CurrentTime);
if (iReturn == BadAtom || iReturn == BadWindow)
{
- ErrorF ("winClipboardWindowProc - WM_RENDER*FORMAT - "
+ winErrorFVerb (1, "winClipboardWindowProc - WM_RENDER*FORMAT - "
"XConvertSelection () failed\n");
break;
}
@@ -407,7 +476,7 @@ winClipboardWindowProc (HWND hwnd, UINT
if (!OpenClipboard (hwnd))
{
- ErrorF ("winClipboardWindowProc - WM_RENDER*FORMATS - "
+ winErrorFVerb (1, "winClipboardWindowProc -
WM_RENDER*FORMATS - "
"OpenClipboard () failed: %08x\n",
GetLastError ());
break;
@@ -415,7 +484,7 @@ winClipboardWindowProc (HWND hwnd, UINT
if (!EmptyClipboard ())
{
- ErrorF ("winClipboardWindowProc - WM_RENDER*FORMATS - "
+ winErrorFVerb (1, "winClipboardWindowProc -
WM_RENDER*FORMATS - "
"EmptyClipboard () failed: %08x\n",
GetLastError ());
break;
@@ -465,16 +534,14 @@ winClipboardWindowProc (HWND hwnd, UINT
if (!CloseClipboard ())
{
- ErrorF ("winClipboardWindowProc - WM_RENDERALLFORMATS - "
+ winErrorFVerb (1, "winClipboardWindowProc -
WM_RENDERALLFORMATS - "
"CloseClipboard () failed: %08x\n",
GetLastError ());
break;
}
}
-#if 0
- ErrorF ("winClipboardWindowProc - WM_RENDER*FORMAT - Returning.\n");
-#endif
+ winDebug ("winClipboardWindowProc - WM_RENDER*FORMAT -
Returning.\n");
return 0;
}
}
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