Re: [Chicken-hackers] Fixing the "process" procedure to be safe against execve() errors

[felix . winkelmann]

> The the way things are done in the current version of Chicken is wonky
> because the outline is like this:
>
>        child = fork();
>        if (!child) {
>            // This code runs in the child process.
>            execve(exefile, argv, envp);
>            // Not only is the errno value not returned to the parent,
>            // but there is no call to exit() at all. So the child
>            // keeps running the user's Scheme program after a failed
>            // execve() until the program error-exits. Since the parent
>            // also continues running the Scheme program, there are now
>            // two copies of it running concurrently.
>        }
>

If the execve fails, an exception is thrown - so doing that already indicates
that the user has something particular in mind. I understand that the situation
of having 2 different processes handling this scenario is rather icky, yet
it is essentially a UNIXism that one has to deal with, regardless of language
(which doesn't mean that it couldn't be improved, of course).


felix