How can I execute synchronously a xdotool process in an Elisp function?

Question

I want to perform a repetitive task using Emacs and another program (which, unfortunately, runs under X). I have then set up an elisp function and a xdotool script to do the two parts of the work. The elisp function uses a cl-loop to iterate over the lines of a temporary buffer I create.

I'd like the two to be synchronized, so that Emacs

• cannot continue until the xdotool script has finished
• it can also check the return code (potentially stopping if the script fails).

I'd normally do this with call-process-shell-command, but for some reason, then xdotool won't accept mouse clicks. I found in another question that calling the process asynchronously solves the problem, and indeed it does:

           (let ((async-shell-command-display-buffer nil))
             (shell-command "/home/alessandro/xorg-session.sh&"
                    nil
                    nil)
             )
           (sleep-for 5)

but then I can no longer wait for the process, and I'm forced to use an extremely fragile sleep-for. How can I do both? I.e., running a xdotool, but synchronously and checking for its success? I've heard about sentinels, but I don't think they can help here (due to the cl-loop).

Thanks!