SIGALRM和sleep（）C ++

Question

I am currently designing a small line following robot that navigates via IR beacons. It is all coded in C++ however integrating the line following and IR receiving seems to have broken it. The IR uses an interrupt service routine to look for an IR signal using an interval timer and SIGALRM. The pathfinding function, along with several of the other robot operations, use sleep(). It has now come to my attention that you cannot use SIGALRM and sleep() in the same program as the SIGALRM wakes the process up prematurely. Is there a good workaround for this besides simply ridding the whole program of sleep() functions?

Answer 1

One band-aid fix is to use the nanosleep function instead of sleep . If nanosleep wakes up prematurely, it stores the remaining time into the time structure, so you can re-try. You can wrap this in your own function that resembles sleep . Since nanosleep isn't ever implemented with SIGALRM , there is no reason why it would wake up prematurely. Be sure to use sigaction to set up your alarm signal handler, and specify SA_RESTART in the flags, all the same. This allows your signal not to disturb restartable system calls.