Interrupted system call

Keyword: GDB epoll_wait select sem_wat

We are using GDB to debug multithreading with epoll_wait select sem_watCode-1 may be returned abnormally. The error cause is: interrupted system call. This is because

During GDB debugging, an interrupt command is inserted at the breakpoint.ProgramWhen the program is executed at the breakpoint, A sigtrap signal will be sent, and the program is switched to the execution interrupt, and GDB will stop the program for debugging. for functions that are blocked, such as sem_wait \ Wait \ read, if they are blocked during debugging, they may receive signals sent by the debugger and return non-0 values.
   To solve this problem, you need to ignore the "error" returned by receiving debugging signals in the Code:

For example

If (-1 = epoll_wait ())

{

If (Errno!=Eintr)

{
         Return-1;

}
}