Function foreach

src/linux/cgroups.cpp:194–209

Make sure all subsystems are enabled and not busy.

  // Make sure all subsystems are enabled and not busy.
  foreach (const string& subsystem, strings::tokenize(subsystems, ",")) {
    Try<bool> result = enabled(subsystem);
    if (result.isError()) {
      return Error(result.error());
    } else if (!result.get()) {
      return Error("'" + subsystem + "' is not enabled by the kernel");
    }

    result = busy(subsystem);
    if (result.isError()) {
      return Error(result.error());
    } else if (result.get()) {
      return Error(
          "'" + subsystem + "' is already attached to another hierarchy");
    }
  }

  // Create the directory for the hierarchy.
  Try<Nothing> mkdir = os::mkdir(hierarchy);