Here's another update...
I've located what goes wrong when Cygwin/X crashes.
In shadow.c, shadowSetup() sets all functionpointers, pScreen->CreateGC,
pScreen->PaintWindowBackground etc..
then in the functions shadowCreateGC, shadowPaintWindow etc.. the screen privates are
retreived ,shadowScrPriv(), then the function pointers are set again using the unwrap
macro
#define unwrap(priv, real, mem) {\
real->mem = priv->mem; \
}
In shadowPaintWindow for example.
shadowScrPriv(pScreen); //retreive screen privates
if(what == PW_BACKGROUND) {
unwrap (pScrPriv, pScreen, PaintWindowBackground); //set the function pointer
(*pScreen->PaintWindowBackground) (pWindow, prgn, what); //paint
wrap (pScrPriv, pScreen, PaintWindowBackground, shadowPaintWindow);
98% of the time the functionpointers are set correctly, although sometimes they are
completely bananas and are set to 0x99 or 0xff which causes XWin to crash immediately.
I've "corrected" the effect of this bug by adding if(((int)pScreen->GetImage &
0xffffff00) == NULL)
pScreen->GetImage = 0x4b8bf9;
and respectively for pScreen->PaintWindowBackground etc...
So now whenever a functionpointer gets corrupted XWin doesn't crash and I can debug
and continue monitoring the functionpointers. It must be because shadowScrPriv(),
shadow.h
#define shadowGetScrPriv(pScr) ((shadowScrPrivPtr)
(pScr)->devPrivates[shadowScrPrivateIndex].ptr)
#define shadowScrPriv(pScr) shadowScrPrivPtr pScrPriv = shadowGetScrPriv(pScr)
retreives incorrect screen privates. But why? I'm not familiar enough with the code to
figure it out.
Hopefully some of you will have some ideas on this ;)
Cheers,
Sebastian Habyters are set correctly, alth
