我的set在ConcurrentMap中是否是线程安全的？(will my set be thread safe within a ConcurrentMap?)

 我有以下代码。 即使集合本身不是线程安全的，它是否是线程安全的？ 
 
private ConcurrentMap<REGISTRY, Set<CONTACT_ROLES>> proxyRoles = new ConcurrentHashMap<REGISTRY, Set<CONTACT_ROLES>>(); 


    public void setProxyRoles(ConcurrentMap<REGISTRY, Set<CONTACT_ROLES>> proxyRoles) {
        this.proxyRoles = proxyRoles;
    }

    public ConcurrentMap<REGISTRY, Set<CONTACT_ROLES>> getProxyRoles() {
        return proxyRoles;
    }

    public synchronized void addProxyRole(REGISTRY reg, CONTACT_ROLES role) {
        if(proxyRoles.get(reg) == null){
            proxyRoles.put(reg, new HashSet<CONTACT_ROLES>());
        }
        proxyRoles.get(reg).add(role);

    }
 
 编辑： 
 
 经过一些非常好的答案，我明白我的解决方案不安全，我google了一下，找到了一个很好的替代ConcurrentSkipListSet中的集合 

I have the following code. Will it be thread safe even if the set itself is not thread safe?
 
private ConcurrentMap<REGISTRY, Set<CONTACT_ROLES>> proxyRoles = new ConcurrentHashMap<REGISTRY, Set<CONTACT_ROLES>>(); 


    public void setProxyRoles(ConcurrentMap<REGISTRY, Set<CONTACT_ROLES>> proxyRoles) {
        this.proxyRoles = proxyRoles;
    }

    public ConcurrentMap<REGISTRY, Set<CONTACT_ROLES>> getProxyRoles() {
        return proxyRoles;
    }

    public synchronized void addProxyRole(REGISTRY reg, CONTACT_ROLES role) {
        if(proxyRoles.get(reg) == null){
            proxyRoles.put(reg, new HashSet<CONTACT_ROLES>());
        }
        proxyRoles.get(reg).add(role);

    }
 
EDIT:
 
After some very good answers I understand that my solution would not be safe and I googled a bit and found a good replacement for my set in a ConcurrentSkipListSet

原文：https://stackoverflow.com/questions/9313382