摘要
本文在分析了嵌入式实时操作系统WebitOS及其协议栈的TCP层发送和接收的基础上,指出了在基于静态优先级调度的实时抢占式系统中,负责TCP发送和接收的两个任务,在对TCP连接的同一个Socket进行操作时,如果这两个任务的优先级不同而发生抢占,就会使得Socket的状态出现异常,并导致TCP发送失败。为此,提出了动态改变优先级和在TCP层建立独立的发送任务两种算法,并对这两种算法进行了分析和评价。
This paper is based on the analysis of an ERTOS WebitOS and of the sending and receiving methods of TCP layer of its protocol stack,points out that in a embedded real-time system,when the two tasks which are separately responsible for sending and receiving operate the socket of this TCP connection,a singularity of the socket states and TCP sending failure will occur because of the preemption between the two tasks which have different priorities. So two algorithms are designed- changing priority dynamically and establishing sending-task for TCP layer,and the analysis and evaluation for them are made.
出处
《计算机科学》
CSCD
北大核心
2004年第9期117-118,127,共3页
Computer Science
基金
国家自然科学基金(69873007)