параметров отклоняются, потому что они приходят из события экспозиции и связаны с геометрией окна и не геометрии совместно используемой памяти, прикрепленной к XImage, используемым в XShmPutImage вызова.
В частности, если окно только что изменилось (например, оконным менеджером) и было увеличено, а для изменения размера произошло событие ConfigureNotify. Теперь, с новым событием Expose, он будет иметь большую ширину/высоту, которая будет превышать ширину/высоту области общей памяти, о которой знает сервер.
Это ответственность клиента в поле окна изменения размера событий [и т.д.] и демонтаж/воссоздают общую область памяти с увеличенным размером. Это не делается и является источником ошибки.
Примечание: Просто чтобы быть совершенно ясно на этом, сервер может только отчет на ошибки и не ничего сделать по нескольким причинам:
- Сервер знает о окне [и его изменении размера].
- Он знает о XImage, его общей области памяти и размера
- Но они связаны только во время XShmPutImage вызова [AFAIK]
- Даже если сервер мог связать их, он не мог настроить shmarea
- это потому, что он не имеет возможности восстановить связь shmarea на стороне клиента
- только клиент может сделать это с помощью
XShmDetach/XShmAttach
Ниже приведены обновленные версии соответствующих исходных файлов с фиксацией c5c765bc7e. Они немного почищены, поэтому остаются только самые родственные части. Некоторые линии были усечены или завернуты, чтобы исключить горизонтальную прокрутку.
Файлы были аннотированы NOTE и NOTE/BUG, которые я использовал при их анализе.
GUI/main.asm Верхний уровень общего основного цикла. Ничего не видно, чтобы увидеть здесь.
; FILE: gui/Main.asm
; _____________________________________________________________________________
;| |
;| ..::FreshLib::.. Free, open source. Licensed under "BSD 2-clause" license." |
;|_____________________________________________________________________________|
;
; Description: Main procedure of GUI application library.
;
; Target OS: Any
;
; Dependencies:
;
; Notes: Organize the main message/event loop needed by every GUI engine.
; This file contains only OS independent part and includes OS dependent
; files.
;______________________________________________________________________________
module "Main library"
proc Run
begin
.mainloop:
stdcall ProcessSystemEvents
jc .terminate
mov eax, [pApplication]
test eax, eax
jz .eventok
get ecx, eax, TApplication:OnIdle
jecxz .eventok
stdcall ecx, eax
.eventok:
stdcall WaitForSystemEvent
jmp .mainloop
.terminate:
DebugMsg "Terminate GUI application!"
return
endp
include '%TargetOS%/Main.asm'
endmodule
GUI/Linux/main.asm обработчики событий
; FILE: gui/Linux/Main.asm
; _____________________________________________________________________________
;| |
;| ..::FreshLib::.. Free, open source. Licensed under "BSD 2-clause" license." |
;|_____________________________________________________________________________|
;
; Description: Main procedure of GUI application library.
;
; Target OS: Linux
;
; Dependencies:
;
; Notes: Organize the main message/event loop needed by every GUI engine.
;______________________________________________________________________________
body ProcessSystemEvents
; NOTE: this is the storage for the dequeued event -- all dispatch routines
; should use it and process it
.event XEvent
rb 256
begin
push ebx ecx edx
.event_loop:
; check for quit
get eax, [pApplication], TApplication:MainWindow
test eax, eax
jz .continue ; ???????????
cmp dword [eax], 0
jne .continue
cinvoke XFlush, [hApplicationDisplay]
xor eax, eax
mov [fGlobalTerminate], 1
stc
pop edx ecx ebx
return
; NOTE: it is wasteful for the main loop to call WaitForSystemEvent, then call
; us and we do XPending on the first loop -- we already know we have at least
; one event waiting in the queue
.continue:
cinvoke XPending, [hApplicationDisplay]
test eax, eax
jz .noevents
push edi ecx
lea edi, [.event]
mov ecx, sizeof.XEvent/4
xor eax, eax
rep stosd
pop ecx edi
lea ebx, [.event]
cinvoke XNextEvent, [hApplicationDisplay], ebx
stdcall __ProcessOneSystemEvent, ebx
jmp .event_loop
.noevents:
clc
pop edx ecx ebx
return
endp
body WaitForSystemEvent
.event XEvent
begin
push eax ecx edx
lea eax, [.event]
cinvoke XPeekEvent, [hApplicationDisplay], eax
pop edx ecx eax
return
endp
proc __ProcessOneSystemEvent, .linux_event
begin
pushad
mov ebx, [.linux_event]
; mov eax, [ebx+XEvent.type]
; cmp eax, [ShmCompletionEvent]
; je .shm_completion
stdcall _GetWindowStruct, [ebx+XEvent.window]
jc .notprocessed
test eax, eax
jz .notprocessed
mov esi, eax
mov ecx, [ebx+XEvent.type]
cmp ecx, LASTEvent
jae .notprocessed
mov ecx, [.jump_table+4*ecx]
jecxz .notprocessed
jmp ecx
.notprocessed:
popad
stc
return
.finish:
popad
clc
return
;.shm_completion:
; DebugMsg "Put back completion event!"
;
; int3
; cinvoke XPutBackEvent, [hApplicationDisplay], ebx
; jmp .finish
;.........................................................................
; seMove and seResize events.
;-------------------------------------------------------------------------
.moveresize:
; NOTE/BUG!!!!: we must not only process a resize/move request, but we must also
; adjust the size of the shmarea attached to the XImage -- that is _not_ being
; done. (e.g.) if the window is enlarged, the shmarea must be enlarged
cinvoke XCheckTypedWindowEvent, [hApplicationDisplay],
[ebx+XConfigureEvent.window], ConfigureNotify, ebx
test eax, eax
jnz .moveresize
; resize event...
mov eax, [esi+TWindow._width]
mov edx, [esi+TWindow._height]
cmp eax, [ebx+XConfigureEvent.width]
jne .resize
cmp edx, [ebx+XConfigureEvent.height]
je .is_move
.resize:
exec esi, TWindow:EventResize, [ebx+XConfigureEvent.width],
[ebx+XConfigureEvent.height]
; move event...
.is_move:
mov eax, [esi+TWindow._x]
mov edx, [esi+TWindow._y]
cmp eax, [ebx+XConfigureEvent.x]
jne .move
cmp eax, [ebx+XConfigureEvent.y]
je .finish
.move:
exec esi, TWindow:EventMove,
[ebx+XConfigureEvent.x], [ebx+XConfigureEvent.y]
jmp .finish
;.........................................................................
; DestroyNotify handler it invalidates the handle in TWindow structure and
; then destroys TWindow.
.destroy:
test esi, esi
jz .finish
mov [esi+TWindow.handle], 0
destroy esi
jmp .finish
;.........................................................................
; Window paint event
.expose:
get edi, esi, TWindow:ImgScreen
; NOTE:BUG!!!!!
;
; if the window has been resized (e.g. enlarged), these values are wrong!
; they relate to the _window_ but _not_ the shmarea that is attached to the
; XImage
;
; however, DrawImageRect will call XShmPutImage with these values, they
; will exceed the geometry of what the X server knows about the shmarea and
; it will return BadValue and _suppress_ the completion event for XShmPutImage
stdcall DrawImageRect, [esi+TWindow.handle], edi,
[ebx+XExposeEvent.x],[ebx+XExposeEvent.y],
[ebx+XExposeEvent.x], [ebx+XExposeEvent.y],
[ebx+XExposeEvent.width], [ebx+XExposeEvent.height]
jmp .finish
;.........................................................................
; Mouse event handlers
.mousemove:
cinvoke XCheckTypedWindowEvent, [hApplicationDisplay],
[ebx+XConfigureEvent.window], MotionNotify, ebx
test eax, eax
jnz .mousemove
stdcall ServeMenuMouseMove, [ebx+XMotionEvent.window],
[ebx+XMotionEvent.x], [ebx+XMotionEvent.y],
[ebx+XMotionEvent.state]
jc .finish
cinvoke XCheckTypedWindowEvent, [hApplicationDisplay],
[ebx+XMotionEvent.window], MotionNotify, ebx
test eax, eax
jnz .mousemove
mov edi, [__MouseTarget]
test edi, edi
jz .search_target_move
stdcall __GetRelativeXY, edi, [ebx+XMotionEvent.x], [ebx+XMotionEvent.y]
jmp .target_move
.search_target_move:
exec esi, TWindow:ChildByXY, [ebx+XMotionEvent.x],
[ebx+XMotionEvent.y], TRUE
mov edi, eax
.target_move:
cmp edi, [__LastPointedWindow]
je .move_event
cmp [__LastPointedWindow], 0
je .leave_ok
exec [__LastPointedWindow], TWindow:EventMouseLeave
.leave_ok:
mov [__LastPointedWindow], edi
exec edi, TWindow:EventMouseEnter
.move_event:
exec edi, TWindow:EventMouseMove, ecx, edx, [ebx+XMotionEvent.state]
jmp .finish
;.........................................................................
; event jump table
.jump_table dd 0 ; event 0
dd 0 ; event 1
dd .key_press ; KeyPress = 2
dd .key_release ; KeyRelease = 3
dd .mouse_btn_press ; ButtonPress = 4
dd .mouse_btn_release ; ButtonRelease = 5
dd .mousemove ; MotionNotify = 6
dd 0 ; EnterNotify = 7
dd 0 ; LeaveNotify = 8
dd .focusin ; FocusIn = 9
dd .focusout ; FocusOut = 10
dd 0 ; KeymapNotify = 11
dd .expose ; Expose = 12
dd 0 ; GraphicsExpose = 13
dd 0 ; NoExpose = 14
dd 0 ; VisibilityNotify = 15
dd 0 ; CreateNotify = 16
dd .destroy ; DestroyNotify = 17
dd 0 ; UnmapNotify = 18
dd 0 ; MapNotify = 19
dd 0 ; MapRequest = 20
dd 0 ; ReparentNotify = 21
dd .moveresize ; ConfigureNotify = 22
dd 0 ; ConfigureRequest = 23
dd 0 ; GravityNotify = 24
dd 0 ; ResizeRequest = 25
dd 0 ; CirculateNotify = 26
dd 0 ; CirculateRequest = 27
dd 0 ; PropertyNotify = 28
dd 0 ; SelectionClear = 29
dd 0 ; SelectionRequest = 30
dd 0 ; SelectionNotify = 31
dd 0 ; ColormapNotify = 32
dd .clientmessage ; ClientMessage = 33
dd .mapping_notify ; MappingNotify = 34
графика/Linux/images.asm Изображение рисунок кода [включая функцию DrawImageRect ] и код создания/уничтожения общей памяти.
; FILE: graphics/Linux/images.asm
; _____________________________________________________________________________
;| |
;| ..::FreshLib::.. Free, open source. Licensed under "BSD 2-clause" license." |
;|_____________________________________________________________________________|
;
; Description: Memory based images manipulation library.
;
; Target OS: Linux
;
; Dependencies: memory.asm
;
; Notes:
;______________________________________________________________________________
uses libX11, xshm
struct TImage
.width dd ? ; width in pixels.
.height dd ? ; height in pixels.
.pPixels dd ? ; pointer to the pixel memory.
; os dependent data
.ximage dd ?
.shminfo XShmSegmentInfo
ends
body CreateImage
begin
pushad
stdcall GetMem, sizeof.TImage
jc .finish
mov esi, eax
xor eax, eax
inc eax
mov ecx, [.width]
mov edx, [.height]
cmp ecx, 0
cmovle ecx, eax
cmp edx, 0
cmovle edx, eax
mov [esi+TImage.width], ecx
mov [esi+TImage.height], edx
lea eax, [4*ecx]
imul eax, edx
cinvoke shmget, IPC_PRIVATE, eax, IPC_CREAT or 777o
test eax, eax
js .error
mov [esi+TImage.shminfo.ShmID], eax
cinvoke shmat, eax, 0, 0
cmp eax, -1
je .error_free
mov [esi+TImage.shminfo.Addr], eax
mov [esi+TImage.pPixels], eax
mov [esi+TImage.shminfo.fReadOnly], 1
lea ebx, [esi+TImage.shminfo]
cinvoke XShmCreateImage, [hApplicationDisplay], 0, $20, ZPixmap, eax,
ebx, [esi+TImage.width], [esi+TImage.height]
mov [esi+TImage.ximage], eax
cinvoke XShmAttach, [hApplicationDisplay], ebx
clc
mov [esp+4*regEAX], esi
.finish:
popad
return
.error_free:
cinvoke shmctl, [ebx+XShmSegmentInfo.ShmID], IPC_RMID, 0
.error:
stdcall FreeMem, esi
stc
jmp .finish
endp
body DestroyImage
begin
pushad
mov esi, [.ptrImage]
test esi, esi
jz .finish
lea eax, [esi+TImage.shminfo]
cinvoke XShmDetach, [hApplicationDisplay], eax
cinvoke XDestroyImage, [esi+TImage.ximage]
cinvoke shmdt, [esi+TImage.shminfo.Addr]
cinvoke shmctl, [esi+TImage.shminfo.ShmID], IPC_RMID, 0
stdcall FreeMem, esi
.finish:
popad
return
endp
;if used ___CheckCompletionEvent
;___CheckCompletionEvent:
;
;virtual at esp+4
; .display dd ?
; .pEvent dd ?
; .user dd ?
;end virtual
;
;; timeout
; stdcall GetTimestamp
; cmp eax, [.user]
; jbe @f
;
; DebugMsg "Timeout!"
;
; mov eax, 1
; retn
;
;@@:
; mov eax, [.pEvent] ;.pEvent
; mov eax, [eax+XEvent.type]
;
; cmp eax, [ShmCompletionEvent]
; sete al
; movzx eax, al
; retn
;end if
body DrawImageRect
.event XEvent
rb 256
begin
pushad
mov esi, [.pImage]
test esi, esi
jz .exit
mov ebx, [esi+TImage.ximage]
; NOTE: is this necessary? it seems wasteful to create and destroy a GC
; repeatedly. Dunno, does this _have_ to be done here, _every_ time?
cinvoke XCreateGC, [hApplicationDisplay], [.where], 0, 0
mov edi, eax
; NOTE/BUG: The return ShmCompletionEvent will be suppressed due to a BadValue
; if the X/Y and width/height parameters given to us by caller exceed the
; geometry/range of the shmarea attached to .ximage
;
; the routine that calls us is .expose and it _is_ giving us bad values. it is
; passing us X/Y width/height related to an exposure event of the .where
; _window_ which we put in the call. The X server will compare these against
; the size of the shmarea of TImage.xmage and complain if we exceed the bounds
cinvoke XShmPutImage, [hApplicationDisplay], [.where], edi,
[esi+TImage.ximage], [.xSrc], [.ySrc], [.xDst], [.yDst],
[.width], [.height], TRUE
; NOTE/BUG: this code should _not_ be looping on XCheckTypedEvent because it
; disrupts the normal event processing. if we want to be "synchronous" on this
; we should loop on the main event dispatcher (ProcessSystemEvents) and let it
; dispatch to a callback we create. we can set a "pending" flag that our [not
; yet existent] dispatch routine can clear
; THIS CODE SOMETIMES CAUSES HANGS!
stdcall GetTimestamp
lea esi, [eax+20]
.loop:
lea eax, [.event]
cinvoke XCheckTypedEvent, [hApplicationDisplay], [ShmCompletionEvent],
eax
test eax, eax
jnz .finish
stdcall GetTimestamp
cmp eax, esi
jb .loop
.finish:
cinvoke XFreeGC, [hApplicationDisplay], edi
.exit:
popad
return
endp
Xext/shm.c код сервера X, который проверяет и обрабатывает XShmPutImage вызов.
// FILE: Xext/shm.c
static int
ProcShmPutImage(ClientPtr client)
{
GCPtr pGC;
DrawablePtr pDraw;
long length;
ShmDescPtr shmdesc;
REQUEST(xShmPutImageReq);
REQUEST_SIZE_MATCH(xShmPutImageReq);
VALIDATE_DRAWABLE_AND_GC(stuff->drawable, pDraw, DixWriteAccess);
VERIFY_SHMPTR(stuff->shmseg, stuff->offset, FALSE, shmdesc, client);
// NOTE: value must be _exactly_ 0/1
if ((stuff->sendEvent != xTrue) && (stuff->sendEvent != xFalse))
return BadValue;
if (stuff->format == XYBitmap) {
if (stuff->depth != 1)
return BadMatch;
length = PixmapBytePad(stuff->totalWidth, 1);
}
else if (stuff->format == XYPixmap) {
if (pDraw->depth != stuff->depth)
return BadMatch;
length = PixmapBytePad(stuff->totalWidth, 1);
length *= stuff->depth;
}
else if (stuff->format == ZPixmap) {
if (pDraw->depth != stuff->depth)
return BadMatch;
length = PixmapBytePad(stuff->totalWidth, stuff->depth);
}
else {
client->errorValue = stuff->format;
return BadValue;
}
// NOTE/BUG: The following block is the "check parameters" code. If the
// given drawing parameters of the request (e.g. X, Y, width, height) [or
// combinations thereof] exceed the geometry/size of the shmarea, the
// BadValue error is being returned here and the code to send a return
// event will _not_ be executed. The bug isn't really here, it's on the
// client side, but it's the client side bug that causes the event to be
// suppressed
/*
* There's a potential integer overflow in this check:
* VERIFY_SHMSIZE(shmdesc, stuff->offset, length * stuff->totalHeight,
* client);
* the version below ought to avoid it
*/
if (stuff->totalHeight != 0 &&
length > (shmdesc->size - stuff->offset)/stuff->totalHeight) {
client->errorValue = stuff->totalWidth;
return BadValue;
}
if (stuff->srcX > stuff->totalWidth) {
client->errorValue = stuff->srcX;
return BadValue;
}
if (stuff->srcY > stuff->totalHeight) {
client->errorValue = stuff->srcY;
return BadValue;
}
if ((stuff->srcX + stuff->srcWidth) > stuff->totalWidth) {
client->errorValue = stuff->srcWidth;
return BadValue;
}
if ((stuff->srcY + stuff->srcHeight) > stuff->totalHeight) {
client->errorValue = stuff->srcHeight;
return BadValue;
}
// NOTE: this is where the drawing takes place
if ((((stuff->format == ZPixmap) && (stuff->srcX == 0)) ||
((stuff->format != ZPixmap) &&
(stuff->srcX < screenInfo.bitmapScanlinePad) &&
((stuff->format == XYBitmap) ||
((stuff->srcY == 0) &&
(stuff->srcHeight == stuff->totalHeight))))) &&
((stuff->srcX + stuff->srcWidth) == stuff->totalWidth))
(*pGC->ops->PutImage) (pDraw, pGC, stuff->depth,
stuff->dstX, stuff->dstY,
stuff->totalWidth, stuff->srcHeight,
stuff->srcX, stuff->format,
shmdesc->addr + stuff->offset +
(stuff->srcY * length));
else
doShmPutImage(pDraw, pGC, stuff->depth, stuff->format,
stuff->totalWidth, stuff->totalHeight,
stuff->srcX, stuff->srcY,
stuff->srcWidth, stuff->srcHeight,
stuff->dstX, stuff->dstY, shmdesc->addr + stuff->offset);
// NOTE: this is where the return event gets sent
if (stuff->sendEvent) {
xShmCompletionEvent ev = {
.type = ShmCompletionCode,
.drawable = stuff->drawable,
.minorEvent = X_ShmPutImage,
.majorEvent = ShmReqCode,
.shmseg = stuff->shmseg,
.offset = stuff->offset
};
WriteEventsToClient(client, 1, (xEvent *) &ev);
}
return Success;
}
Это не совсем четкий вопрос. Существует ряд возможных причин, включая, но не ограничиваясь неопределенным поведением. Кроме того, это c или C++? –
@iharob Ну, фактический код написан на языке ассемблера (FASM). Но IMHO, программисты C/C++ должны быть более компетентными в программировании XLib, XShm и Linux. Если вы напишете то, что не ясно, я могу отредактировать вопрос, чтобы сделать его лучше. – johnfound
Не могли бы вы разместить свой код XShmPutImage вместе с кодом, связанным с настройкой Shm и обработкой XEvent. Я посмотрел исходный код X-сервера, и у меня есть идея, но эта информация может помочь мне опубликовать ответ. –