start_thread 中的线程在 start_activity 线程(主线程)在信号量上休眠时访问 packetList 是否安全。如果没有,那么我如何在它们之间共享资源,请注意访问权限只会被读取,而 packetList 不会被更改。
            class A{
                Vector<packet> packetList;
                A()
                {
                    //packetList initialized here
                }
                void start_thread()
                {
                //start a thread here
                }
                void start_activity()
                {
                    while(true)
                    {
                        //possibly sleep on semephore
                        //do work
                    }
                }
            }