module ActiveSupport::IsolatedExecutionState

def share_with(other)
  # Action Controller streaming spawns a new thread and copy thread locals.
  # We do the same here for backward compatibility, but this is very much a hack
  # and streaming should be rethought.
  context = @isolation_level == :thread ? Thread.current : Fiber.current
  context.active_support_execution_state = other.active_support_execution_state.dup
end