Set CLOEXEC flag on the descriptors The received systemd descriptors don't have `O_CLOEXEC` set because they are received over `exec`. Thus if the process executes a child the child gets polluted with the descriptors. To prevent this, we set `O_CLOEXEC` during initialization. However this also required restructuring of the code because `libsystemd` doesn't provide temporary access to the descriptors - only permanent one. Thus we have to "validate" the descriptors eagerly. We still store the invalid ones as errors to make sure the errors get reported accurately.

use std::io;
use std::ffi::OsStr;
use std::process::{Command, Child};

mod comm;

enum Test {}

impl comm::Test for Test {
    const SOCKET_ADDR: &'static str = "localhost:4242";

    fn spawn_slave(program_name: &OsStr) -> io::Result<Child> {
        Command::new(program_name)
            .env("SYSTEMD_SOCKET_INTEGRATION_TEST", "slave")
            .spawn()
    }
}

#[test]
fn main() {
    comm::main::<Test>();
}