7. Spinning vs. Yielding

Example: Q6,7 main-signal.c

     1	#include <stdio.h>
     2
     3	#include "common_threads.h"
     4
     5	int done = 0;
     6
     7	void* worker(void* arg) {
     8	    printf("this should print first\n");
     9	    done = 1;
    10	    return NULL;
    11	}
    12
    13	int main(int argc, char *argv[]) {
    14	    pthread_t p;
    15	    Pthread_create(&p, NULL, worker, NULL);
    16	    while (done == 0)
    17		;
    18	    printf("this should print last\n");
    19	    return 0;
    20	}

valgrind warns about a possible data race, but the warning is spurious and the code is correct.

Improve using sched_yield()