Added YieldIfNeeded

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@9452 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/os2/app.cpp

@@ -962,6 +962,8 @@ void wxExit()
     wxApp::CleanUp();
 } // end of wxExit
 
+static bool gs_inYield = FALSE;
+
 //
 // Yield to incoming messages
 //
@@ -976,6 +978,8 @@ bool wxYield()
     //
     wxLog::Suspend();
 
+    gs_inYield = TRUE;
+
     //
     // We want to go back to the main message loop
     // if we see a WM_QUIT. (?)
@@ -998,9 +1002,19 @@ bool wxYield()
     // Let the logs be flashed again
     //
     wxLog::Resume();
+    gs_inYield = FALSE;
     return TRUE;
 } // end of wxYield
 
+// Yield to incoming messages; but fail silently if recursion is detected.
+bool wxYieldIfNeeded()
+{
+    if (gs_inYield)
+        return FALSE;
+        
+    return wxYield();
+}
+
 wxIcon wxApp::GetStdIcon(
   int                               nWhich
 ) const