Chdir和Setuid和Setgid线程安全吗？

Question

Are os. Chdir, os.Setuid and os.Setgid thread-safe in Go?

In otherwords, if I do a os.Chdir (or the other two functions) in two different goroutines running in parallel, is it going change directory for the working goroutine or the whole process (which can cause problems)?

I couldn't find any information in the documentation.

Answer 1

Under the hood, os.Chdir just calls the chdir() system call:

   211  func Chdir(dir string) error {
   212      if e := syscall.Chdir(dir); e != nil {
   213          return &PathError{"chdir", dir, e}
   214      }
   215      return nil
   216  }

So it affects the entire process. The same is true for os.Setuid and os.Setgid.

It is probably safe to call these from multiple goroutines at the same time, because executing a system call halts the scheduler; but beware of race conditions.