Essentially, I’m looking for a function like PostMessage(), but that is synchronous, so it doesn’t return until the message has been processed. It doesn’t necessarily have to be a function that does that (Because I don’t think that there is any) but I’m looking for a way to track the amount of time it takes for a windows message to get processed starting from the time it enters the message queue. SendMessage() would’ve been very useful but it bypasses the message queue. It’s also probably useful to mention that I’m sending the message to a completely different program so it’s not on the same thread.