> > > Ok I see. But what should we do to prevent this? Simply ignore the > > > request and log a warning? > > > > That's seems like simplest choice to me... Or if you still prefer to > > allow it - put a special comment that it is user responsibility to > > handle such possible race-condition (inside his CB function or so). > > The issue is that a warning can be easily overlooked and the application > may assume that they can free up resources whereas the callback was > never reset and may still access them. Yes, could happen, in principle. > I wonder if this could be enforced with RTE_BUILD_BUG_ON somehow. I don't think it is possible, as the value can change at runtime.
> Or at least by checking that the cb value is not NULL with RTE_ASSERT? assert() would work, but general rule of thumb - don't panic() in library functions, but return an error. After another thought - might be allowing user to call it at run-time and just documenting it properly is enough. After all there are few ways to overcome the problem in user CB function itself. Konstantin
