Fix a deadlock with the system message queue by ensuring the system message
queue is unlocked while the actual message is being processed.
diff --git a/windows/message.c b/windows/message.c
index 60c08de..f5ed7fd 100644
--- a/windows/message.c
+++ b/windows/message.c
@@ -93,12 +93,17 @@
* MSG_TranslateMouseMsg
*
* Translate an mouse hardware event into a real mouse message.
- * Return value indicates whether the translated message must be passed
- * to the user, left in the queue, or skipped entirely (in this case
- * HIWORD contains hit test code).
+ *
+ * Returns:
+ *
+ * SYSQ_MSG_ABANDON - abandon the peek message loop
+ * SYSQ_MSG_CONTINUE - leave the message in the queue and
+ * continue with the translation loop
+ * SYSQ_MSG_ACCEPT - proceed to process the translated message
*/
static DWORD MSG_TranslateMouseMsg( HWND hTopWnd, DWORD first, DWORD last,
- MSG *msg, BOOL remove, WND* pWndScope )
+ MSG *msg, BOOL remove, WND* pWndScope,
+ INT16 *pHitTest, POINT16 *pScreen_pt, BOOL *pmouseClick )
{
static DWORD dblclk_time_limit = 0;
static UINT16 clk_message = 0;
@@ -107,39 +112,42 @@
WND *pWnd;
HWND hWnd;
- INT16 ht, hittest, sendSC = 0;
+ INT16 ht, hittest;
UINT message = msg->message;
POINT16 screen_pt, pt;
HANDLE16 hQ = GetFastQueue16();
MESSAGEQUEUE *queue = (MESSAGEQUEUE *)QUEUE_Lock(hQ);
- BOOL eatMsg = FALSE;
BOOL mouseClick = ((message == WM_LBUTTONDOWN) ||
(message == WM_RBUTTONDOWN) ||
(message == WM_MBUTTONDOWN))?1:0;
- SYSQ_STATUS ret = 0;
DWORD retvalue;
- /* Find the window */
+ /* Find the window to dispatch this mouse message to */
CONV_POINT32TO16( &msg->pt, &pt );
- ht = hittest = HTCLIENT;
hWnd = GetCapture();
+
+ /* If no capture HWND, find window which contains the mouse position.
+ * Also find the position of the cursor hot spot (hittest) */
if( !hWnd )
{
ht = hittest = WINPOS_WindowFromPoint( pWndScope, pt, &pWnd );
if( !pWnd ) pWnd = WIN_GetDesktop();
else WIN_LockWndPtr(pWnd);
hWnd = pWnd->hwndSelf;
- sendSC = 1;
}
else
{
+ ht = hittest = HTCLIENT;
pWnd = WIN_FindWndPtr(hWnd);
if (queue)
ht = PERQDATA_GetCaptureInfo( queue->pQData );
}
+ /* Save hittest for return */
+ *pHitTest = hittest;
+
/* stop if not the right queue */
if (pWnd->hmemTaskQ != hQ)
@@ -166,6 +174,7 @@
goto END;
}
+ /* Was it a mouse click message */
if( mouseClick )
{
/* translate double clicks -
@@ -184,14 +193,17 @@
}
}
}
+ /* save mouse position */
screen_pt = pt;
+ *pScreen_pt = pt;
if (hittest != HTCLIENT)
{
message += WM_NCMOUSEMOVE - WM_MOUSEMOVE;
msg->wParam = hittest;
}
- else ScreenToClient16( hWnd, &pt );
+ else
+ ScreenToClient16( hWnd, &pt );
/* check message filter */
@@ -202,14 +214,73 @@
goto END;
}
+ /* Update global hCursorQueue */
hCursorQueue = queue->self;
+
+ /* Update static double click conditions */
+ if( remove && mouseClick )
+ {
+ if( mouseClick == 1 )
+ {
+ /* set conditions */
+ dblclk_time_limit = msg->time;
+ clk_message = msg->message;
+ clk_hwnd = hWnd;
+ clk_pos = screen_pt;
+ } else
+ /* got double click - zero them out */
+ dblclk_time_limit = clk_hwnd = 0;
+ }
+
QUEUE_Unlock(queue);
+ /* Update message params */
+ msg->hwnd = hWnd;
+ msg->message = message;
+ msg->lParam = MAKELONG( pt.x, pt.y );
+ retvalue = SYSQ_MSG_ACCEPT;
+END:
+ WIN_ReleaseWndPtr(pWnd);
+
+ /* Return mouseclick flag */
+ *pmouseClick = mouseClick;
+
+ return retvalue;
+}
+
+
+/***********************************************************************
+ * MSG_ProcessMouseMsg
+ *
+ * Processes a translated mouse hardware event.
+ * The passed in msg structure should contain the updated hWnd,
+ * lParam, wParam and message fields from MSG_TranslateMouseMsg.
+ *
+ * Returns:
+ *
+ * SYSQ_MSG_SKIP - Message should be skipped entirely (in this case
+ * HIWORD contains hit test code). Continue translating..
+ * SYSQ_MSG_ACCEPT - the translated message must be passed to the user
+ * MSG_PeekHardwareMsg should return TRUE.
+ */
+static DWORD MSG_ProcessMouseMsg( MSG *msg, BOOL remove, INT16 hittest,
+ POINT16 screen_pt, BOOL mouseClick )
+{
+ WND *pWnd;
+ HWND hWnd = msg->hwnd;
+ INT16 sendSC = (GetCapture() == 0);
+ UINT message = msg->message;
+ BOOL eatMsg = FALSE;
+ DWORD retvalue;
+
+ pWnd = WIN_FindWndPtr(hWnd);
+
/* call WH_MOUSE */
if (HOOK_IsHooked( WH_MOUSE ))
{
+ SYSQ_STATUS ret = 0;
MOUSEHOOKSTRUCT16 *hook = SEGPTR_NEW(MOUSEHOOKSTRUCT16);
if( hook )
{
@@ -226,7 +297,6 @@
retvalue = MAKELONG((INT16)SYSQ_MSG_SKIP, hittest);
goto END;
}
-
}
@@ -236,17 +306,6 @@
{
HWND hwndTop = WIN_GetTopParent( hWnd );
- if( mouseClick == 1 )
- {
- /* set conditions */
- dblclk_time_limit = msg->time;
- clk_message = msg->message;
- clk_hwnd = hWnd;
- clk_pos = screen_pt;
- } else
- /* got double click - zero them out */
- dblclk_time_limit = clk_hwnd = 0;
-
if( sendSC )
{
/* Send the WM_PARENTNOTIFY,
@@ -285,9 +344,6 @@
goto END;
}
- msg->hwnd = hWnd;
- msg->message = message;
- msg->lParam = MAKELONG( pt.x, pt.y );
retvalue = SYSQ_MSG_ACCEPT;
END:
WIN_ReleaseWndPtr(pWnd);
@@ -344,6 +400,17 @@
msg->hwnd = hWnd;
msg->message = message;
+ return SYSQ_MSG_ACCEPT;
+}
+
+
+/***********************************************************************
+ * MSG_ProcessKbdMsg
+ *
+ * Processes a translated keyboard message
+ */
+static DWORD MSG_ProcessKbdMsg( MSG *msg, BOOL remove )
+{
return (HOOK_CallHooks16( WH_KEYBOARD, remove ? HC_ACTION : HC_NOREMOVE,
LOWORD (msg->wParam), msg->lParam )
? SYSQ_MSG_SKIP : SYSQ_MSG_ACCEPT);
@@ -496,27 +563,36 @@
DWORD status = SYSQ_MSG_ACCEPT;
MESSAGEQUEUE *sysMsgQueue = QUEUE_GetSysQueue();
- int kbd_msg;
+ enum { MOUSE_MSG = 0, KEYBOARD_MSG, HARDWARE_MSG } msgType;
QMSG *nextqmsg, *qmsg = 0;
+ BOOL bRet = FALSE;
/* FIXME: there has to be a better way to do this */
joySendMessages();
EnterCriticalSection(&sysMsgQueue->cSection);
- qmsg = sysMsgQueue->firstMsg;
-
/* If the queue is empty, attempt to fill it */
if (!sysMsgQueue->msgCount && THREAD_IsWin16( THREAD_Current() )
&& EVENT_Pending())
{
LeaveCriticalSection(&sysMsgQueue->cSection);
+
EVENT_WaitNetEvent( FALSE, TRUE );
+
EnterCriticalSection(&sysMsgQueue->cSection);
}
- for ( kbd_msg = 0; qmsg; qmsg = nextqmsg)
+ /* Loop through the Q and translate the message we wish to process
+ * while we own the lock. Based on the translation status (abandon/cont/accept)
+ * we then process the message accordingly
+ */
+
+ for ( qmsg = sysMsgQueue->firstMsg; qmsg; qmsg = nextqmsg )
{
+ INT16 hittest;
+ POINT16 screen_pt;
+ BOOL mouseClick;
*msg = qmsg->msg;
@@ -526,13 +602,13 @@
if ((msg->message >= WM_MOUSEFIRST) && (msg->message <= WM_MOUSELAST))
{
-
HWND hWndScope = (HWND)qmsg->extraInfo;
WND *tmpWnd = (Options.managed && IsWindow(hWndScope) )
? WIN_FindWndPtr(hWndScope) : WIN_GetDesktop();
- status = MSG_TranslateMouseMsg(hwnd, first, last, msg, remove,tmpWnd );
- kbd_msg = 0;
+ status = MSG_TranslateMouseMsg(hwnd, first, last, msg, remove, tmpWnd,
+ &hittest, &screen_pt, &mouseClick );
+ msgType = MOUSE_MSG;
WIN_ReleaseWndPtr(tmpWnd);
@@ -540,11 +616,12 @@
else if ((msg->message >= WM_KEYFIRST) && (msg->message <= WM_KEYLAST))
{
status = MSG_TranslateKbdMsg(hwnd, first, last, msg, remove);
- kbd_msg = 1;
+ msgType = KEYBOARD_MSG;
}
else /* Non-standard hardware event */
{
HARDWAREHOOKSTRUCT16 *hook;
+ msgType = HARDWARE_MSG;
if ((hook = SEGPTR_NEW(HARDWAREHOOKSTRUCT16)))
{
BOOL ret;
@@ -565,18 +642,48 @@
}
}
+
switch (LOWORD(status))
{
case SYSQ_MSG_ACCEPT:
+ {
+ /* Remove the message from the system msg Q while it is still locked,
+ * before accepting it */
+ if (remove)
+ {
+ if (HOOK_IsHooked( WH_JOURNALRECORD )) MSG_JournalRecordMsg( msg );
+ QUEUE_RemoveMsg( sysMsgQueue, qmsg );
+ }
+ /* Now actually process the message, after we unlock the system msg Q.
+ * We should not hold on to the crst since SendMessage calls during processing
+ * will potentially cause callbacks to PeekMessage from the application.
+ * If we're holding the crst and QUEUE_WaitBits is called with a
+ * QS_SENDMESSAGE mask we will deadlock in hardware_event() when a
+ * message is being posted to the Q.
+ */
+ LeaveCriticalSection(&sysMsgQueue->cSection);
+ if( msgType == KEYBOARD_MSG )
+ status = MSG_ProcessKbdMsg( msg, remove );
+ else if ( msgType == MOUSE_MSG )
+ status = MSG_ProcessMouseMsg( msg, remove, hittest, screen_pt, mouseClick );
+
+ /* Reclaim the sys msg Q crst */
+ EnterCriticalSection(&sysMsgQueue->cSection);
+
+ /* Pass the translated message to the user if it was accepted */
+ if (status == SYSQ_MSG_ACCEPT)
break;
+ /* If not accepted, fall through into the SYSQ_MSG_SKIP case */
+ }
+
case SYSQ_MSG_SKIP:
if (HOOK_IsHooked( WH_CBT ))
{
- if( kbd_msg )
+ if( msgType == KEYBOARD_MSG )
HOOK_CallHooks16( WH_CBT, HCBT_KEYSKIPPED,
LOWORD (msg->wParam), msg->lParam );
- else
+ else if ( msgType == MOUSE_MSG )
{
MOUSEHOOKSTRUCT16 *hook = SEGPTR_NEW(MOUSEHOOKSTRUCT16);
if (hook)
@@ -592,28 +699,33 @@
}
}
+ /* If the message was removed earlier set up nextqmsg so that we start
+ * at the top of the queue again. We need to do this since our next pointer
+ * could be invalid due to us unlocking the system message Q to process the message.
+ * If not removed just refresh nextqmsg to point to the next msg.
+ */
if (remove)
- QUEUE_RemoveMsg( sysMsgQueue, qmsg );
- /* continue */
+ nextqmsg = sysMsgQueue->firstMsg;
+ else
+ nextqmsg = qmsg->nextMsg;
+ continue;
+
case SYSQ_MSG_CONTINUE:
continue;
case SYSQ_MSG_ABANDON:
- LeaveCriticalSection(&sysMsgQueue->cSection);
- return FALSE;
+ bRet = FALSE;
+ goto END;
}
- if (remove)
- {
- if (HOOK_IsHooked( WH_JOURNALRECORD )) MSG_JournalRecordMsg( msg );
- QUEUE_RemoveMsg( sysMsgQueue, qmsg );
- }
- LeaveCriticalSection(&sysMsgQueue->cSection);
- return TRUE;
+ bRet = TRUE;
+ goto END;
}
+
+END:
LeaveCriticalSection(&sysMsgQueue->cSection);
- return FALSE;
+ return bRet;
}
