1, Ethernet frame structure
2, TCP packet structure
3, TCP / IP three-way handshake in the role of SYN
Synchronization request
4. How to ensure the reliability of the TCP protocol
Three-way handshake, automatic retransmission, sliding window
5, the timing of the handshake occurred
1, blocking mode socket
Before accept
2, non-blocking socket
Before then accept select
6, a signal processing mode in Linux
1) Ignore
2) default processing
3, signal registration signal processing
7, how to avoid the zombie process
1) the parent wait wait for the child process exits, resource recovery
2) SIGCHLD signal. The child process exits will trigger SIGCHILD. Parent processes this signal and call wait
3) handle the process orphaned process (parent process first exit), orphaned by the init process will recycle
