是多线程下的processPresenceAvailableAgent（）函数线程安全

Question

下面是我声明的函数。当我从客户端获取一个xmpp节时，只调用此函数。如果我的条件满足，那么我将一些信息添加到concurrentHashmap中。从多个线程调用 processPresenceAvailableAgent 函数。我在这里打电话给获取，包含密钥（）， putifabsent （）函数。到目前为止，我知道concurrenthashmap的这些函数集是线程安全的，但我调用多个函数，所以这些复合代码块也是线程安全的吗？请解释我

  

private ConcurrentHashMap＆gt; agentInfoMapByOpCode;

public void processPresenceAvailableAgent(Packet packet)
{
    if(debug)logger.debug("start-----------processPresenceAvailableAgent()");
    String opcode=  packet.getAttribute("opcode");         
    String fromJID= packet.getStanzaFrom()!=null?packet.getStanzaFrom().toString():null;
    ConcurrentHashMap agentInfoMap=agentInfoMapByOpCode.get(opcode);
    if(agentInfoMap==null)
    {
        agentInfoMap=new ConcurrentHashMap();   
        agentInfoMapByOpCode.putIfAbsent(opcode,agentInfoMap);  
    }

    if(!agentInfoMap.containsKey(fromJID))
    {
        AgentInfo ainfo=new AgentInfo();
        ainfo.setUserJID(fromJID);
        ainfo.setOnlineStatus("available");
        ainfo.setOperatorCode(opcode);
        agentInfoMap.putIfAbsent(fromJID,ainfo);
        addNewAgentToAgentQueue(opcode,fromJID);
        if(debug)
        {
            logger.debug("agent " + fromJID+ " has been added");
            logger.debug("agentinfo map size()=" + agentInfoMap.size()+" for operator code "+opcode);
        }
    }
    assignAgentToNewVisitor(opcode);  //check visitor waiting queue and send visitor available chat request message to agent
    if(debug)logger.debug("end-----------processPresenceAvailableAgent()");
}