#include <win32k.h>

Include dependency graph for input.c:

Macros
#define	LAST_RIT_EVENT_UPDATE_INTERVAL 1000UL

Functions
	DBG_DEFAULT_CHANNEL (UserInput)

static DWORD FASTCALL	IntLastInputTick (BOOL bUpdate)

VOID FASTCALL	DoTheScreenSaver (VOID)

static NTSTATUS NTAPI	OpenInputDevice (PHANDLE pHandle, PFILE_OBJECT ppObject, CONST WCHAR pszDeviceName)

VOID NTAPI	RawInputThreadMain (VOID)

NTSTATUS NTAPI	InitInputImpl (VOID)

BOOL FASTCALL	IntBlockInput (PTHREADINFO pti, BOOL BlockIt)

BOOL APIENTRY	NtUserBlockInput (BOOL BlockIt)

BOOL FASTCALL	IsRemoveAttachThread (PTHREADINFO pti)

NTSTATUS FASTCALL	UserAttachThreadInput (PTHREADINFO ptiFrom, PTHREADINFO ptiTo, BOOL fAttach)

BOOL APIENTRY	NtUserAttachThreadInput (IN DWORD idAttach, IN DWORD idAttachTo, IN BOOL fAttach)

UINT APIENTRY	NtUserSendInput (UINT nInputs, LPINPUT pInput, INT cbSize)

Variables
PTHREADINFO	ptiRawInput

PKTIMER	MasterTimer = NULL

PATTACHINFO	gpai = NULL

INT	paiCount = 0

HANDLE	ghKeyboardDevice = NULL

static DWORD	LastInputTick = 0

static HANDLE	ghMouseDevice

Macro Definition Documentation

◆ LAST_RIT_EVENT_UPDATE_INTERVAL

#define LAST_RIT_EVENT_UPDATE_INTERVAL 1000UL

Definition at line 17 of file input.c.

Function Documentation

◆ DBG_DEFAULT_CHANNEL()

DBG_DEFAULT_CHANNEL ( UserInput )

◆ DoTheScreenSaver()

VOID FASTCALL DoTheScreenSaver ( VOID )

Definition at line 64 of file input.c.

{
    DWORD Test, TO;
 
    if (gspv.iScrSaverTimeout > 0) // Zero means Off.
    {
        Test = EngGetTickCount32();
        Test = Test - LastInputTick;
        TO = 1000 * gspv.iScrSaverTimeout;
        if (Test > TO)
        {
            TRACE("Screensaver Message Start! Tick %lu Timeout %d \n", Test, gspv.iScrSaverTimeout);
 
            if (ppiScrnSaver) // We are or we are not the screensaver, prevent reentry...
            {
                if (!(ppiScrnSaver->W32PF_flags & W32PF_IDLESCREENSAVER))
                {
                    ppiScrnSaver->W32PF_flags |= W32PF_IDLESCREENSAVER;
                    ERR("Screensaver is Idle\n");
                }
            }
            else
            {
                PUSER_MESSAGE_QUEUE ForegroundQueue = IntGetFocusMessageQueue();
                if (ForegroundQueue && ForegroundQueue->spwndActive)
                    UserPostMessage(hwndSAS, WM_LOGONNOTIFY, LN_START_SCREENSAVE, 1); // lParam 1 == Secure
                else
                    UserPostMessage(hwndSAS, WM_LOGONNOTIFY, LN_START_SCREENSAVE, 0);
            }
        }
    }
}

Referenced by HungAppSysTimerProc().

◆ InitInputImpl()

NTSTATUS NTAPI InitInputImpl ( VOID )

Definition at line 376 of file input.c.

{
    MasterTimer = ExAllocatePoolWithTag(NonPagedPool, sizeof(KTIMER), USERTAG_SYSTEM);
    if (!MasterTimer)
    {
        ERR("Failed to allocate memory\n");
        ASSERT(FALSE);
        return STATUS_UNSUCCESSFUL;
    }
    KeInitializeTimer(MasterTimer);
 
    return STATUS_SUCCESS;
}

Referenced by DriverEntry().

◆ IntBlockInput()

BOOL FASTCALL IntBlockInput	(	PTHREADINFO	pti,
		BOOL	BlockIt
	)

Definition at line 391 of file input.c.

{
    PTHREADINFO OldBlock;
    ASSERT(pti);
 
    if(!pti->rpdesk || ((pti->TIF_flags & TIF_INCLEANUP) && BlockIt))
    {
        /*
         * Fail blocking if exiting the thread
         */
 
        return FALSE;
    }
 
    /*
     * FIXME: Check access rights of the window station
     *        e.g. services running in the service window station cannot block input
     */
    if(!ThreadHasInputAccess(pti) ||
       !IntIsActiveDesktop(pti->rpdesk))
    {
        EngSetLastError(ERROR_ACCESS_DENIED);
        return FALSE;
    }
 
    ASSERT(pti->rpdesk);
    OldBlock = pti->rpdesk->BlockInputThread;
    if(OldBlock)
    {
        if(OldBlock != pti)
        {
            EngSetLastError(ERROR_ACCESS_DENIED);
            return FALSE;
        }
        pti->rpdesk->BlockInputThread = (BlockIt ? pti : NULL);
        return OldBlock == NULL;
    }
 
    pti->rpdesk->BlockInputThread = (BlockIt ? pti : NULL);
    return OldBlock == NULL;
}

Referenced by ExitThreadCallback(), and NtUserBlockInput().

◆ IntLastInputTick()

static DWORD FASTCALL IntLastInputTick ( BOOL bUpdate )

static

Definition at line 39 of file input.c.

{
    if (bUpdate)
    {
        LastInputTick = EngGetTickCount32();
        if (gpsi)
        {
            gpsi->dwLastRITEventTickCount = LastInputTick;
            if (gpsi->dwLastRITEventTickCount - gpsi->dwLastSystemRITEventTickCountUpdate >
                LAST_RIT_EVENT_UPDATE_INTERVAL)
            {
                SharedUserData->LastSystemRITEventTickCount = LastInputTick;
                gpsi->dwLastSystemRITEventTickCountUpdate = LastInputTick;
            }
        }
    }
    return LastInputTick;
}

Referenced by RawInputThreadMain().

◆ IsRemoveAttachThread()

BOOL FASTCALL IsRemoveAttachThread ( PTHREADINFO pti )

Definition at line 453 of file input.c.

{
    NTSTATUS Status;
    PATTACHINFO pai;
    BOOL Ret = TRUE;
    PTHREADINFO ptiFrom = NULL, ptiTo = NULL;
 
    do
    {
       if (!gpai) return TRUE;
 
       pai = gpai; // Bottom of the list.
 
       do
       {
          if (pai->pti2 == pti)
          {
             ptiFrom = pai->pti1;
             ptiTo = pti;
             break;
          }
          if (pai->pti1 == pti)
          {
             ptiFrom = pti;
             ptiTo = pai->pti2;
             break;
          }
          pai = pai->paiNext;
 
       } while (pai);
 
       if (!pai && !ptiFrom && !ptiTo) break;
 
       Status = UserAttachThreadInput(ptiFrom, ptiTo, FALSE);
       if (!NT_SUCCESS(Status)) Ret = FALSE;
 
    } while (Ret);
 
    return Ret;
}

Referenced by ExitThreadCallback().

◆ NtUserAttachThreadInput()

BOOL APIENTRY NtUserAttachThreadInput	(	IN DWORD	idAttach,
		IN DWORD	idAttachTo,
		IN BOOL	fAttach
	)

Definition at line 681 of file input.c.

{
  NTSTATUS Status;
  PTHREADINFO pti, ptiTo;
  BOOL Ret = FALSE;
 
  UserEnterExclusive();
  TRACE("Enter NtUserAttachThreadInput %s\n",(fAttach ? "TRUE" : "FALSE" ));
 
  pti = IntTID2PTI(UlongToHandle(idAttach));
  ptiTo = IntTID2PTI(UlongToHandle(idAttachTo));
 
  if ( !pti || !ptiTo )
  {
     TRACE("AttachThreadInput pti or ptiTo NULL.\n");
     EngSetLastError(ERROR_INVALID_PARAMETER);
     goto Exit;
  }
 
  Status = UserAttachThreadInput( pti, ptiTo, fAttach);
  if (!NT_SUCCESS(Status))
  {
     TRACE("AttachThreadInput Error Status 0x%x. \n",Status);
     EngSetLastError(RtlNtStatusToDosError(Status));
  }
  else Ret = TRUE;
 
Exit:
  TRACE("Leave NtUserAttachThreadInput, ret=%d\n",Ret);
  UserLeave();
  return Ret;
}

◆ NtUserBlockInput()

BOOL APIENTRY NtUserBlockInput ( BOOL BlockIt )

Definition at line 435 of file input.c.

{
    BOOL ret;
 
    TRACE("Enter NtUserBlockInput\n");
    UserEnterExclusive();
 
    ret = IntBlockInput(PsGetCurrentThreadWin32Thread(), BlockIt);
 
    UserLeave();
    TRACE("Leave NtUserBlockInput, ret=%i\n", ret);
 
    return ret;
}

Referenced by BlockInput().

◆ NtUserSendInput()

UINT APIENTRY NtUserSendInput	(	UINT	nInputs,
		LPINPUT	pInput,
		INT	cbSize
	)

Definition at line 724 of file input.c.

{
    PTHREADINFO pti;
    UINT uRet = 0;
 
    TRACE("Enter NtUserSendInput\n");
    UserEnterExclusive();
 
    pti = PsGetCurrentThreadWin32Thread();
    ASSERT(pti);
 
    if (!pti->rpdesk)
    {
        goto cleanup;
    }
 
    if (!nInputs || !pInput || cbSize != sizeof(INPUT))
    {
        EngSetLastError(ERROR_INVALID_PARAMETER);
        goto cleanup;
    }
 
    /*
     * FIXME: Check access rights of the window station
     *        e.g. services running in the service window station cannot block input
     */
    if (!ThreadHasInputAccess(pti) ||
        !IntIsActiveDesktop(pti->rpdesk))
    {
        EngSetLastError(ERROR_ACCESS_DENIED);
        goto cleanup;
    }
 
    while (nInputs--)
    {
        INPUT SafeInput;
        NTSTATUS Status;
 
        Status = MmCopyFromCaller(&SafeInput, pInput++, sizeof(INPUT));
        if (!NT_SUCCESS(Status))
        {
            SetLastNtError(Status);
            goto cleanup;
        }
 
        switch (SafeInput.type)
        {
            case INPUT_MOUSE:
                if (UserSendMouseInput(&SafeInput.mi, TRUE))
                    uRet++;
                break;
            case INPUT_KEYBOARD:
                if (UserSendKeyboardInput(&SafeInput.ki, TRUE))
                    uRet++;
                break;
            case INPUT_HARDWARE:
                FIXME("INPUT_HARDWARE not supported!\n");
                break;
            default:
                ERR("SendInput(): Invalid input type: 0x%x\n", SafeInput.type);
                break;
        }
    }
 
cleanup:
    TRACE("Leave NtUserSendInput, ret=%u\n", uRet);
    UserLeave();
    return uRet;
}

Referenced by keybd_event(), mouse_event(), and SendInput().

◆ OpenInputDevice()

static NTSTATUS NTAPI OpenInputDevice	(	PHANDLE	pHandle,
		PFILE_OBJECT *	ppObject,
		CONST WCHAR *	pszDeviceName
	)

static

Definition at line 104 of file input.c.

{
    UNICODE_STRING DeviceName;
    OBJECT_ATTRIBUTES ObjectAttributes;
    NTSTATUS Status;
    IO_STATUS_BLOCK Iosb;
 
    RtlInitUnicodeString(&DeviceName, pszDeviceName);
 
    InitializeObjectAttributes(&ObjectAttributes,
                               &DeviceName,
                               OBJ_KERNEL_HANDLE,
                               NULL,
                               NULL);
 
    Status = ZwOpenFile(pHandle,
                        FILE_ALL_ACCESS,
                        &ObjectAttributes,
                        &Iosb,
                        0,
                        0);
    if (NT_SUCCESS(Status) && ppObject)
    {
        Status = ObReferenceObjectByHandle(*pHandle, SYNCHRONIZE, NULL, KernelMode, (PVOID*)ppObject, NULL);
        ASSERT(NT_SUCCESS(Status));
    }
 
    return Status;
}

Referenced by RawInputThreadMain().

◆ RawInputThreadMain()

VOID NTAPI RawInputThreadMain ( VOID )

Definition at line 140 of file input.c.

{
    NTSTATUS MouStatus = STATUS_UNSUCCESSFUL, KbdStatus = STATUS_UNSUCCESSFUL, Status;
    IO_STATUS_BLOCK MouIosb, KbdIosb;
    PFILE_OBJECT pKbdDevice = NULL, pMouDevice = NULL;
    LARGE_INTEGER ByteOffset;
    //LARGE_INTEGER WaitTimeout;
    PVOID WaitObjects[4], pSignaledObject = NULL;
    KWAIT_BLOCK WaitBlockArray[RTL_NUMBER_OF(WaitObjects)];
    ULONG cWaitObjects = 0, cMaxWaitObjects = 2;
    MOUSE_INPUT_DATA MouseInput;
    KEYBOARD_INPUT_DATA KeyInput;
    PVOID ShutdownEvent;
    HWINSTA hWinSta;
 
    ByteOffset.QuadPart = (LONGLONG)0;
    //WaitTimeout.QuadPart = (LONGLONG)(-10000000);
 
    ptiRawInput = GetW32ThreadInfo();
    ptiRawInput->TIF_flags |= TIF_SYSTEMTHREAD;
    ptiRawInput->pClientInfo->dwTIFlags = ptiRawInput->TIF_flags;
 
    TRACE("Raw Input Thread %p\n", ptiRawInput);
 
    KeSetPriorityThread(&PsGetCurrentThread()->Tcb,
                        LOW_REALTIME_PRIORITY + 3);
 
    Status = ObOpenObjectByPointer(InputWindowStation,
                                   0,
                                   NULL,
                                   MAXIMUM_ALLOWED,
                                   ExWindowStationObjectType,
                                   UserMode,
                                   (PHANDLE)&hWinSta);
    if (NT_SUCCESS(Status))
    {
        UserSetProcessWindowStation(hWinSta);
    }
    else
    {
        ASSERT(FALSE);
        /* Failed to open the interactive winsta! What now? */
    }
 
    UserEnterExclusive();
    StartTheTimers();
    UserLeave();
 
    NT_ASSERT(ghMouseDevice == NULL);
    NT_ASSERT(ghKeyboardDevice == NULL);
 
    PoRequestShutdownEvent(&ShutdownEvent);
    for (;;)
    {
        if (!ghMouseDevice)
        {
            /* Check if mouse device already exists */
            Status = OpenInputDevice(&ghMouseDevice, &pMouDevice, L"\\Device\\PointerClass0" );
            if (NT_SUCCESS(Status))
            {
                ++cMaxWaitObjects;
                TRACE("Mouse connected!\n");
            }
        }
        if (!ghKeyboardDevice)
        {
            /* Check if keyboard device already exists */
            Status = OpenInputDevice(&ghKeyboardDevice, &pKbdDevice, L"\\Device\\KeyboardClass0");
            if (NT_SUCCESS(Status))
            {
                ++cMaxWaitObjects;
                TRACE("Keyboard connected!\n");
                // Get and load keyboard attributes.
                UserInitKeyboard(ghKeyboardDevice);
                UserEnterExclusive();
                // Register the Window hotkey.
                UserRegisterHotKey(PWND_BOTTOM, IDHK_WINKEY, MOD_WIN, 0);
                // Register the Window Snap hotkey.
                UserRegisterHotKey(PWND_BOTTOM, IDHK_SNAP_LEFT, MOD_WIN, VK_LEFT);
                UserRegisterHotKey(PWND_BOTTOM, IDHK_SNAP_RIGHT, MOD_WIN, VK_RIGHT);
                UserRegisterHotKey(PWND_BOTTOM, IDHK_SNAP_UP, MOD_WIN, VK_UP);
                UserRegisterHotKey(PWND_BOTTOM, IDHK_SNAP_DOWN, MOD_WIN, VK_DOWN);
                // Register the debug hotkeys.
                SetDebugHotKeys();
                UserLeave();
            }
        }
 
        /* Reset WaitHandles array */
        cWaitObjects = 0;
        WaitObjects[cWaitObjects++] = ShutdownEvent;
        WaitObjects[cWaitObjects++] = MasterTimer;
 
        if (ghMouseDevice)
        {
            /* Try to read from mouse if previous reading is not pending */
            if (MouStatus != STATUS_PENDING)
            {
                MouStatus = ZwReadFile(ghMouseDevice,
                                       NULL,
                                       NULL,
                                       NULL,
                                       &MouIosb,
                                       &MouseInput,
                                       sizeof(MOUSE_INPUT_DATA),
                                       &ByteOffset,
                                       NULL);
            }
 
            if (MouStatus == STATUS_PENDING)
                WaitObjects[cWaitObjects++] = &pMouDevice->Event;
        }
 
        if (ghKeyboardDevice)
        {
            /* Try to read from keyboard if previous reading is not pending */
            if (KbdStatus != STATUS_PENDING)
            {
                KbdStatus = ZwReadFile(ghKeyboardDevice,
                                       NULL,
                                       NULL,
                                       NULL,
                                       &KbdIosb,
                                       &KeyInput,
                                       sizeof(KEYBOARD_INPUT_DATA),
                                       &ByteOffset,
                                       NULL);
 
            }
            if (KbdStatus == STATUS_PENDING)
                WaitObjects[cWaitObjects++] = &pKbdDevice->Event;
        }
 
        /* If all objects are pending, wait for them */
        if (cWaitObjects == cMaxWaitObjects)
        {
            Status = KeWaitForMultipleObjects(cWaitObjects,
                                              WaitObjects,
                                              WaitAny,
                                              UserRequest,
                                              KernelMode,
                                              TRUE,
                                              NULL,//&WaitTimeout,
                                              WaitBlockArray);
 
            if ((Status >= STATUS_WAIT_0) &&
                (Status < (STATUS_WAIT_0 + (LONG)cWaitObjects)))
            {
                /* Some device has finished reading */
                pSignaledObject = WaitObjects[Status - STATUS_WAIT_0];
 
                /* Check if it is mouse or keyboard and update status */
                if ((MouStatus == STATUS_PENDING) &&
                    (pSignaledObject == &pMouDevice->Event))
                {
                    MouStatus = MouIosb.Status;
                }
                else if ((KbdStatus == STATUS_PENDING) &&
                         (pSignaledObject == &pKbdDevice->Event))
                {
                    KbdStatus = KbdIosb.Status;
                }
                else if (pSignaledObject == MasterTimer)
                {
                    ProcessTimers();
                }
                else if (pSignaledObject == ShutdownEvent)
                {
                    break;
                }
                else ASSERT(FALSE);
            }
        }
 
        /* Have we successed reading from mouse? */
        if (NT_SUCCESS(MouStatus) && MouStatus != STATUS_PENDING)
        {
            TRACE("MouseEvent\n");
 
            /* Set LastInputTick */
            IntLastInputTick(TRUE);
 
            /* Process data */
            UserEnterExclusive();
            UserProcessMouseInput(&MouseInput);
            UserLeave();
        }
        else if (MouStatus != STATUS_PENDING)
            ERR("Failed to read from mouse: %x.\n", MouStatus);
 
        /* Have we successed reading from keyboard? */
        if (NT_SUCCESS(KbdStatus) && KbdStatus != STATUS_PENDING)
        {
            TRACE("KeyboardEvent: %s %04x\n",
                  (KeyInput.Flags & KEY_BREAK) ? "up" : "down",
                  KeyInput.MakeCode);
 
            /* Set LastInputTick */
            IntLastInputTick(TRUE);
 
            /* Process data */
            UserEnterExclusive();
            UserProcessKeyboardInput(&KeyInput);
            UserLeave();
        }
        else if (KbdStatus != STATUS_PENDING)
            ERR("Failed to read from keyboard: %x.\n", KbdStatus);
    }
 
    if (ghMouseDevice)
    {
        (void)ZwCancelIoFile(ghMouseDevice, &MouIosb);
        ObCloseHandle(ghMouseDevice, KernelMode);
        ObDereferenceObject(pMouDevice);
        ghMouseDevice = NULL;
    }
 
    if (ghKeyboardDevice)
    {
        (void)ZwCancelIoFile(ghKeyboardDevice, &KbdIosb);
        ObCloseHandle(ghKeyboardDevice, KernelMode);
        ObDereferenceObject(pKbdDevice);
        ghKeyboardDevice = NULL;
    }
 
    ERR("Raw Input Thread Exit!\n");
}

Referenced by UserSystemThreadProc().

◆ UserAttachThreadInput()

NTSTATUS FASTCALL UserAttachThreadInput	(	PTHREADINFO	ptiFrom,
		PTHREADINFO	ptiTo,
		BOOL	fAttach
	)

Definition at line 496 of file input.c.

{
    MSG msg;
    PATTACHINFO pai;
    PCURICON_OBJECT CurIcon;
 
    /* Can not be the same thread. */
    if (ptiFrom == ptiTo) return STATUS_INVALID_PARAMETER;
 
    /* Do not attach to system threads or between different desktops. */
    if (ptiFrom->TIF_flags & TIF_DONTATTACHQUEUE ||
        ptiTo->TIF_flags & TIF_DONTATTACHQUEUE ||
        ptiFrom->rpdesk != ptiTo->rpdesk)
        return STATUS_ACCESS_DENIED;
 
    /* MSDN Note:
       Keyboard and mouse events received by both threads are processed by the thread specified by the idAttachTo.
     */
 
    /* If Attach set, allocate and link. */
    if (fAttach)
    {
        pai = ExAllocatePoolWithTag(PagedPool, sizeof(ATTACHINFO), USERTAG_ATTACHINFO);
        if (!pai) return STATUS_NO_MEMORY;
 
        pai->paiNext = gpai;
        pai->pti1 = ptiFrom;
        pai->pti2 = ptiTo;
        gpai = pai;
        paiCount++;
        ERR("Attach Allocated! ptiFrom 0x%p  ptiTo 0x%p paiCount %d\n",ptiFrom,ptiTo,paiCount);
 
        if (ptiTo->MessageQueue != ptiFrom->MessageQueue)
        {
 
           ptiTo->MessageQueue->iCursorLevel -= ptiFrom->iCursorLevel;
 
           if (ptiFrom->MessageQueue == gpqForeground)
           {
              ERR("ptiFrom is Foreground\n");
              ptiTo->MessageQueue->spwndActive  = ptiFrom->MessageQueue->spwndActive;
              ptiTo->MessageQueue->spwndFocus   = ptiFrom->MessageQueue->spwndFocus;
              ptiTo->MessageQueue->spwndCapture = ptiFrom->MessageQueue->spwndCapture;
              ptiTo->MessageQueue->QF_flags    ^= ((ptiTo->MessageQueue->QF_flags ^ ptiFrom->MessageQueue->QF_flags) & QF_CAPTURELOCKED);
              RtlCopyMemory(&ptiTo->MessageQueue->CaretInfo,
                            &ptiFrom->MessageQueue->CaretInfo,
                            sizeof(ptiTo->MessageQueue->CaretInfo));
              IntSetFocusMessageQueue(NULL);
              IntSetFocusMessageQueue(ptiTo->MessageQueue);
              gptiForeground = ptiTo;
           }
           else
           {
              ERR("ptiFrom NOT Foreground\n");
              if ( ptiTo->MessageQueue->spwndActive == 0 )
                  ptiTo->MessageQueue->spwndActive = ptiFrom->MessageQueue->spwndActive;
              if ( ptiTo->MessageQueue->spwndFocus == 0 )
                  ptiTo->MessageQueue->spwndFocus  = ptiFrom->MessageQueue->spwndFocus;
           }
 
           CurIcon = ptiFrom->MessageQueue->CursorObject;
 
           MsqDestroyMessageQueue(ptiFrom);
 
           if (CurIcon)
           {
              // Could be global. Keep it above the water line!
              UserReferenceObject(CurIcon);
           }
 
           if (CurIcon && UserObjectInDestroy(UserHMGetHandle(CurIcon)))
           {
              UserDereferenceObject(CurIcon);
              CurIcon = NULL;
           }
 
           ptiFrom->MessageQueue = ptiTo->MessageQueue;
 
           // Pass cursor From if To is null. Pass test_SetCursor parent_id == current pti ID.
           if (CurIcon && ptiTo->MessageQueue->CursorObject == NULL)
           {
              ERR("ptiTo receiving ptiFrom Cursor\n");
              ptiTo->MessageQueue->CursorObject = CurIcon;
           }
 
           ptiFrom->MessageQueue->cThreads++;
           ERR("ptiTo S Share count %u\n", ptiFrom->MessageQueue->cThreads);
 
           IntReferenceMessageQueue(ptiTo->MessageQueue);
        }
        else
        {
           ERR("Attach Threads are already associated!\n");
        }
    }
    else /* If clear, unlink and free it. */
    {
        BOOL Hit = FALSE;
        PATTACHINFO *ppai;
 
        if (!gpai) return STATUS_INVALID_PARAMETER;
 
        /* Search list and free if found or return false. */
        ppai = &gpai;
        while (*ppai != NULL)
        {
           if ( (*ppai)->pti2 == ptiTo && (*ppai)->pti1 == ptiFrom )
           {
              pai = *ppai;
              /* Remove it from the list */
              *ppai = (*ppai)->paiNext;
              ExFreePoolWithTag(pai, USERTAG_ATTACHINFO);
              paiCount--;
              Hit = TRUE;
              break;
           }
           ppai = &((*ppai)->paiNext);
        }
 
        if (!Hit) return STATUS_INVALID_PARAMETER;
 
        ERR("Attach Free! ptiFrom 0x%p  ptiTo 0x%p paiCount %d\n",ptiFrom,ptiTo,paiCount);
 
        if (ptiTo->MessageQueue == ptiFrom->MessageQueue)
        {
           PWND spwndActive = ptiTo->MessageQueue->spwndActive;
           PWND spwndFocus  = ptiTo->MessageQueue->spwndFocus;
 
           if (gptiForeground == ptiFrom)
           {
              ERR("ptiTo is now pti FG.\n");
              // MessageQueue foreground is set so switch threads.
              gptiForeground = ptiTo;
           }
           ptiTo->MessageQueue->cThreads--;
           ERR("ptiTo E Share count %u\n", ptiTo->MessageQueue->cThreads);
           ASSERT(ptiTo->MessageQueue->cThreads >= 1);
 
           IntDereferenceMessageQueue(ptiTo->MessageQueue);
 
           ptiFrom->MessageQueue = MsqCreateMessageQueue(ptiFrom);
 
           if (spwndActive)
           {
              if (spwndActive->head.pti == ptiFrom)
              {
                 ptiFrom->MessageQueue->spwndActive = spwndActive;
                 ptiTo->MessageQueue->spwndActive = 0;
              }
           }
           if (spwndFocus)
           {
              if (spwndFocus->head.pti == ptiFrom)
              {
                 ptiFrom->MessageQueue->spwndFocus = spwndFocus;
                 ptiTo->MessageQueue->spwndFocus = 0;
              }
           }
           ptiTo->MessageQueue->iCursorLevel -= ptiFrom->iCursorLevel;
        }
        else
        {
           ERR("Detaching Threads are not associated!\n");
        }
    }
    /* Note that key state, which can be ascertained by calls to the GetKeyState
       or GetKeyboardState function, is reset after a call to AttachThreadInput.
       ATM which one?
     */
    RtlCopyMemory(ptiTo->MessageQueue->afKeyState, gafAsyncKeyState, sizeof(gafAsyncKeyState));
 
    ptiTo->MessageQueue->msgDblClk.message = 0;
 
    /* Generate mouse move message */
    msg.message = WM_MOUSEMOVE;
    msg.wParam = UserGetMouseButtonsState();
    msg.lParam = MAKELPARAM(gpsi->ptCursor.x, gpsi->ptCursor.y);
    msg.pt = gpsi->ptCursor;
    co_MsqInsertMouseMessage(&msg, 0, 0, TRUE);
 
    return STATUS_SUCCESS;
}