module DEBUGGER__::UI_DAP

def recv_request
  IO.select([@sock])
  @session.process_group.sync do
    raise RetryBecauseCantRead unless IO.select([@sock], nil, nil, 0)
    case @sock.gets
    when /Content-Length: (\d+)/
      b = @sock.read(2)
      raise b.inspect unless b == "\r\n"
      l = @sock.read($1.to_i)
      show_protocol :>, l
      JSON.load(l)
    when nil
      nil
    else
      raise "unrecognized line: #{l} (#{l.size} bytes)"
    end
  end
rescue RetryBecauseCantRead
  retry
end