If the signal handler returns, the process continues executing the normal sequence of instructions it was executing when the signal was caught.
如果信号处理器返回，则进程继续执行信号被捕获时正在执行的正常的指令序列。
2
When a signal that is being caught is handled by a process, the normal sequence of instructions being executed by the process is temporarily interrupted by the signal handler.
当进程处理所捕获的信号时，正在执行的正常指令序列就会被信号处理器临时中断。
3
It's well known that underwater acoustic channel is a coherent multi-path channel, which brings difficulties in signal processing because of the complexity of the received signalsequence.