local _M = { }
  
  -- 超时次数
  local heartTimeoutCount 		= 0
  -- 加速次数
  local heartQuickCount 			= 0
  -- 上次检查心跳时间
  local lastHeartCheckTime		= 0
  -- 下次进入定时检查的时间
  local nextCheckTime				= 0
  -- 心跳误差允许范围
  local HEART_BEAT_ERROR_LIMIT 	= 1
  -- 最大超时次数
  local HEART_TIMEOUT_COUNT_MAX 	= 20
  -- 最大加速次数
  local HEART_QUICK_COUNT_MAX 	= 5
  -- 心跳定时间隔
  local HEART_TIMER_INTERVAL 		= 5
  
  local function check_heart_beat(agent, now)
  	-- 充值等操作不检查心跳
  	local role = agent.role
  	if role.ignoreHeartbeat then
  		lastHeartCheckTime = now - HEART_TIMER_INTERVAL
  		heartTimeoutCount = 0
  		return
  	end
  	if lastHeartCheckTime - now > HEART_TIMER_INTERVAL or
  		now - lastHeartCheckTime > HEART_TIMER_INTERVAL then
  		heartTimeoutCount = heartTimeoutCount + 1
  		if heartTimeoutCount >= HEART_TIMEOUT_COUNT_MAX then
  			skynet.error("timeout! then agent will shut down by self", agent.client_fd, role:getProperty("name"), role:getProperty("id"))
  			skynet.call(agent.gate_serv, "lua", "kick", agent.client_fd)
  			heartTimeoutCount = 0
  		end
  	else
  		heartTimeoutCount = 0
  	end
  end
  

  function _M:update(agent)
  	local now = skynet.timex()
  	local role = agent.role
  	if now >= nextCheckTime then
  		pcall(check_heart_beat, agent, now)
  		nextCheckTime = now + HEART_TIMER_INTERVAL
  	end

  	pcall(role.onRecoverTimer, role, now)

  end
  
  function _M:heart_beat(agent)
  	local now = skynet.timex()
  	if now == lastHeartCheckTime then
  		return
  	end
  	if now - lastHeartCheckTime <= HEART_TIMER_INTERVAL - HEART_BEAT_ERROR_LIMIT then
  		heartQuickCount = heartQuickCount + 1
  		if heartQuickCount == HEART_QUICK_COUNT_MAX then
  			-- 将错误写入日志
  			local role = agent.role
  			skynet.error("Warning, heart beating is too quick, shut down the agent", agent.client_fd, role:getProperty("name"), role:getProperty("id"))
  			-- skynet.call(agent.gate_serv, "lua", "kick", agent.client_fd)
  			role:warningHeartTooQuick()
  			heartQuickCount = 0
  		end
  	else
  		heartQuickCount = 0
  	end
  	lastHeartCheckTime = now
  end
  
  function _M:reset()
  	heartTimeoutCount = 0
  	heartQuickCount = 0
  	lastHeartCheckTime = skynet.timex()
  end
  
  return _M