If you were designing a standard library of a high level language (like Rust, C++, etc.) what would it do if while getting the current time of day (e.g. SystemTime::now()) it encountered a failed kernel system call (e.g. to clock_gettime) and why?
What do you think the existing implementations do?
- Return error or raise exception
- Return 0
- Return undefined values (like stack garbage)
- Panic/crash/segfault
Return an error, respectively, in a language that supports it, raise an exception.
In my systems, nearly every call returns a status, and it is advisable to check this status. I had a number of long calls with windows programmers who complained about my system failing at some point, and most often, the reason was an ignored Non-OK status return at some point in the past.
Like “Your system loses the file I’m writing!”. FileSystem_Open() returned a non-OK value (I don’t remember the reason, but there was one). FileSystem_Write() returned a non-OK value (file pointer invalid). FileSystem_Close() returned a non-OK value (file pointer invalid). And he complains about a file that is not there…