Kill a blocking thread in C's pthread gracefully?

Question

Say I have a thread that's something like this:

void my_thread(char *device_name) {
    int fd = open(device_name, O_RDONLY);
    struct input_event ev;

    while(1) {
        read(fd, &ev, sizeof(struct input_event));
        /* do something */
    }
}

How do I stop such a thread? One way is using pthread_cancel, but I'd rather do it more gracefully. Something like pthread_kill perhaps? In such case, however, would the read method unblock (as I presume it should) and how would the thread handle the signal? Or is it the process that should handle it?

I'd be very grateful for an advice!

Answer 1

The answer to this is to not do anything that will block without a timeout. For IO, you shouldn't call read() until you know the call will not block. For example, use poll() or select() on the path first in order to determine the status.