Ruby中循环引用导致lighttpd中的ruby fcgi脚本执行失败（Mac OS）

require_relative '../pmu_dao/dao'
require_relative '../pmu_service/user_service'
require_relative '../pmu_dao/db_conn_pool'
require_relative '../pmu_communication/comm8n'
require_relative '../pmu_common/common'
...
def start_fcgi

FCGI.each_request do |fcgi|
@logger.info("receive a request: ")
fcgi_out = fcgi.out
fcgi_in = fcgi.in
#fcgi_env = fcgi.env

fcgi_out.print "Content-Type: application/json"
#should be 2 /r/n, else will be error
fcgi_out.print "/r/n/r/n"

#post param is a json string
post_param = get_post_param(fcgi_in)
@logger.info("get the input param from client: /n" + post_param)

if post_param == nil || post_param.empty?
@logger.info("empty input param")
fcgi_out.print "the is the empty page."
fcgi_out.print "/r/n/r/n"
else
#the json string containing the Header and the content
#so parse the Header object from json first
header = JSON.parse(post_param["data"]["Header"])
#then create a Message object for the dispatcher
message = PMU_COMM8N::Message.new(header, post_param["data"]["Content"])
#after dispatch return the HandlerResult object
resp_msg = @msg_disp.dispatch_message(message)
#write result to client
fcgi_out.print resp_msg
fcgi_out.print "/r/n/r/n"
end