Merge "Fix one race condition between start and stop."

}

Result<Success> Service::Start() {

    bool disabled = (flags_ & (SVC_DISABLED | SVC_RESET));

    // Starting a service removes it from the disabled or reset state and

    // immediately takes it out of the restarting state if it was in there.

    flags_ &= (~(SVC_DISABLED|SVC_RESTARTING|SVC_RESET|SVC_RESTART|SVC_DISABLED_START));

    // Running processes require no additional work --- if they're in the

    // process of exiting, we've ensured that they will immediately restart

    // on exit, unless they are ONESHOT.

    // on exit, unless they are ONESHOT. For ONESHOT service, if it's in

    // stopping status, we just set SVC_RESTART flag so it will get restarted

    // in Reap().

    if (flags_ & SVC_RUNNING) {

        if ((flags_ & SVC_ONESHOT) && disabled) {

            flags_ |= SVC_RESTART;

        }

        // It is not an error to try to start a service that is already running.

        return Success();

    }