hints for adding sigsuspend().

[castilma]

I'm a rust beginner and I'd like to practice a bit by adding sigsuspend. But I need some hints.

I thought adding it to SigSet right after wait. Regarding the name I'd choose suspend, since wait had the prefix sig stripped, too.

If sigsuspend returns, it always returns the same value. Is it necessary to return that value to the caller?

Do I have to add some special documentation because it may not return?

[asomers]

I'm a rust beginner and I'd like to practice a bit by adding sigsuspend. But I need some hints.

I thought adding it to SigSet right after wait. Regarding the name I'd choose suspend, since wait had the prefix sig stripped, too.

Makes sense.

If sigsuspend returns, it always returns the same value. Is it necessary to return that value to the caller?

Not in the success case. But it might also fail with EFAULT.

Do I have to add some special documentation because it may not return?

No.

[castilma]

Not in the success case. But it might also fail with EFAULT.

There is no 'success' case. It never returns with a success. It's always an 'error' case, where errno is set to distinguish between the errors. And since errno is global, I don't have to return it explicitly, right?

[asomers]

For this function, failing with EINTR is considered success. And the global errno shouldn't be used in Rust programs. Instead, each function should return its own error code. So to wrap sigsuspend for Rust, I suggest that your wrapper check errno. If EINTR, then return Ok(()). Otherwise, return Err(errno).