挂起XShmPutImage事件通知

Hanging of XShmPutImage event notification

本文关键字:通知 事件 XShmPutImage 挂起      更新时间:2023-10-16

我使用XShm扩展在Linux中绘制和操作图像。

为了不让屏幕闪烁,我将send_event = TRUE传递给XShmPutImage,然后在调用XScmPutImage之后立即使用XIfEvent等待事件。

通过这种方式,我正在进行图像绘制阻塞,以便在图像显示在窗口表面之前不更改图像。

通常一切都很好。但有时,当我进行密集的图像绘制时,事件似乎永远不会发生,绘制过程会挂起。

在哪里查找问题?使用XIfEvent是否适合此任务?事件如何从消息队列中消失?

在某些情况下,XShmPutImage是否可能不发送事件(如果send_event=TRUE)或发送不同于ShmCompletion的事件?(例如内部错误或其他什么?)

编辑:

经过进一步的研究,我发现只有当窗口管理器密集地向窗口生成事件时,才会发生这种挂起。例如,当我通过拖动窗口的角来调整窗口大小时。

第2版:

我尝试了几种方法来解决这个问题,但没有成功。最后,我被迫使用了一些超时时间,并在一段时间后取消了等待。但这当然是肮脏的黑客,我无论如何都想修复它。

那么,如果send_event=TRUE,XShmPutImage不发送事件的原因是什么?或者该事件是否可能从消息队列中消失

第3版:

以下是有问题的代码(FASM):

        cinvoke XShmPutImage, ......, TRUE
    .loop:
        lea     eax, [.event]
        cinvoke XCheckTypedEvent, [Display], [ShmCompletionEvent], eax
        test    eax, eax
        jz      .loop      ; there is no message

注意:无论事件检查是否挂起,XShmPutImage总是返回TRUE,所以我没有在它之后进行错误检查。

第4版:

由于请求,我发布了绘图功能的全部代码。代码使用了FASM的一些宏库,但至少想法很清楚(我希望)

请注意,此代码包含将事件等待时间限制为20ms的变通方法代码。如果没有这个超时,等待循环将永远挂起。XShm事件的编号通过调用XShmGetEventBase获取,如Xhm文档中所建议的。

; Draws the image on a OS provided window surface.
proc DrawImageRect, .where, .pImage, .xDst, .yDst, .xSrc, .ySrc, .width, .height
.event XEvent
       rb 256
begin
        pushad
        mov     esi, [.pImage]
        test    esi, esi
        jz      .exit
        mov     ebx, [esi+TImage.ximage]
        cinvoke XCreateGC, [hApplicationDisplay], [.where], 0, 0
        mov     edi, eax

        cinvoke XShmPutImage, [hApplicationDisplay], [.where], edi, [esi+TImage.ximage], [.xSrc], [.ySrc], [.xDst], [.yDst], [.width], [.height], TRUE
        stdcall GetTimestamp
        lea     esi, [eax+20]    ; 20ms timeout
.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

这是应用程序的主事件循环的代码。

过程__ProcessOneSystemEvent只是将事件分派给GUI对象,并忽略它不使用的所有事件。它根本不处理ShmCompletionEvent

应用程序中创建的所有窗口的事件掩码为:ExposureMask+FocusChangeMask+KeyPressMask+KeyReleaseMask+ButtonPressMask+ButtonReleaseMask+EnterWindowMask+LeaveWindowMask+PointerMotionMask+StructureNotifyMask

proc ProcessSystemEvents
  .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
.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

完整的源代码在存储库中可用,但这是一个非常大的项目,不容易导航。所讨论的来源在签入8453c99b1283def8中。

文件:"freshlib/graphics/images.asm""freshlib/graphics/Linux/images.asm"是关于图像绘制的。

文件:"freshlib/gui/Main.asm""freshlib/kui/Linux/Main.asm"是关于应用程序中的常规事件处理的。

X服务器在做什么

如果传递给XShmPutImage的参数超过调用中连接到XImage的共享内存区域的几何结构,则X服务器可以并且抑制ShmCompletionEvent。服务器根据先前存储的给定共享区域的限制检查X/Y和宽度/高度,如果调用参数超出范围,服务器将返回BadValue取消绘制操作,取消完成事件。

以上正是您的库中正在发生的事情。方法如下:

  1. 主要的事件调度程序是ProcessSystemEvents。它执行XEventNext,并根据事件类型,使用跳转表.jump_table将其分派给特定于事件的处理程序函数
  2. Expose事件的特定于事件的函数是.expose
  3. .expose函数将使用XExposeEvent结构中的X/Y和width/height值来调用DrawImageRect。这是错误的,是错误的真正来源,我们将立即看到
  4. DrawImageRect将在对XShmPutImage的调用中传递这些值
  5. X服务器XShmPutImage的处理程序将检查这些参数,如果这些参数超出范围,则将拒绝

参数被拒绝,因为它们来自曝光事件,并且与窗口的几何结构有关,而不是连接到XShmPutImage调用中使用的XImage的共享内存的几何结构。

具体地说,如果窗口刚刚被调整大小(例如,由窗口管理器)并且已经被放大,并且先前存在用于调整大小的ConfigureNotify事件。现在,有了一个新的Expose事件,它将具有更大的宽度/高度,这将超过服务器所知道的共享内存区域的宽度/宽度。

客户端负责字段窗口大小调整事件等,并拆除/重新创建具有放大大小的共享内存区域。这不是正在执行的,而是错误的来源。

注意:为了完全清楚这一点,服务器只能报告错误,不能对此采取任何措施,原因如下:

  1. 服务器知道窗口[及其大小调整]
  2. 它知道XImage,它的共享内存区域和大小
  3. 但它们仅在XShmPutImage调用[AFAIK]期间关联
  4. 即使服务器可以关联它们,它也无法调整shmarea
  5. 这是因为它无法将shmrea重新链接到客户端
  6. 只有客户端可以通过XShmDetach/XShmAttach执行此操作

以下是c5c765bc7e提交的相关源文件的修订版本。它们已经被清理了一点,所以只剩下最密切相关的部分。某些行已被截断或换行以消除水平滚动。

这些文件已经用NOTENOTE/BUG进行了注释,这是我在分析它们时所做的。


gui/Main.asm顶级通用主循环。这里没什么可看的。

; 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事件处理程序

; 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

graphics/Linux/images.asm图像绘制代码[包括DrawImageRect函数]和共享内存创建/销毁代码。

; 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检查和处理XShmPutImage调用的X服务器代码。

// 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;
}

您的源代码将是我们可以分析的最终部分,但由于我对Assembly的了解很少,我将在宏级别上给您一个答案。我还不知道确切的答案

如果事件太多,只是它造成了这个问题,而不是正常发生的事件,这意味着你的框架耗尽了虚拟内存,或者在前一个框架释放内存之前触发了另一个事件帧。在这种情况下,你可以做的事情很少

  1. 试着检查是否有内存泄漏。。一帧事件结束后,在触发新的帧对象之前,请尝试清理内存或正确结束该帧对象
  2. 您还可以开发一种机制,使第二帧等待第一帧结束。在C/C++中,我们使用了许多同步方法,如Mutexselect系统调用。如果你的设计遵循这种模式,那么你可以做这些
  3. 如果你有权在任何地方更改分配给你的窗口的内存,试着增加它。因为有一点是肯定的(根据你的解释),这是内存问题

在Edit 3上回复看起来您正在调用某个方法cinvoke。我不知道它是如何在内部处理even的。你为什么不直接在C中实现它呢?我相信无论你在做什么目标,你都会得到一些交叉编译器。