多线程tcp(多线程tcp端口扫描器报告)

看下对应端口的服务，有并发量的限制吧

QT界面中，点击开始键。 开启thread线程，建立TCP连接。 并在主线程中运行thread对象中的sendData函数，实现TCP发送数据。

线程是计算机任务执行的最小单位，多线程也就是说一台计算机同时可以干好几件事，例如同时打字和听音乐，而单线程就是打字时只能打字，其他的干不了。 udp和tcp是两种协议，网络协议是分层的，他们都是传输层协议。所以协议就是一组约定的规则，没有规矩不成方圆嘛。
这只是两种不同的网络协议而已，QQ聊天之类常用UDP，而网络连接常用TCP，相对而言TCP比较安全。

使用完成端口(IOCP来实现); 搜索关键词 完成端口 或 IOCP即可.

看源代码会比较好。 #define TCP_A_RETRANSMISSION0x0001#define TCP_A_OUT_OF_ORDER0x0200/* RETRANSMISSION/FAST RETRANSMISSION/OUT-OF-ORDER* If the segment contains data (or is a SYN or a FIN) and* if it does not advance the sequence number, it must be one* of these three.* Only test for this if we know what the seq number should be* (tcpd->fwd->nextseq)** Note that a simple KeepAlive is not a retransmission*//* If there were >=2 duplicate ACKs in the reverse direction* (there might be duplicate acks missing from the trace)* and if this sequence number matches those ACKs* and if the packet occurs within 20ms of the last* duplicate ack* then this is a fast retransmission*//* If the segment came <3ms since the segment with the highest* seen sequence number and it doesn't look like a retransmission* then it is an OUT-OF-ORDER segment.* (3ms is an arbitrary number)*/这个大概是说序号有跳跃，就是原来的序号+片段长度<新序号，而且不是快速重传，那就是乱序/* Check for spurious retransmission. If the current seq + segment length* is less then the receivers lastask, the packet contains duplicated* data and may be considered spurious. */