c.md

Misc

• A regexp for a pointer arg for batch-replacement purposes: ["/_a-zA-Z>-]+
• poll vs epoll: return from poll requires to do O(n) scan to find the FDs that got triggered, whereas epoll gives them right away at O(1).

Time measuring macros to quickly insert in a code

#define TIME_MEASURE_PROLOG(postfix) \
    struct timespec start##postfix;                 \
    clock_gettime(CLOCK_REALTIME, &start##postfix);

#define TIME_MEASURE_EPILOG(postfix)                                    \
    {   struct timespec end##postfix;                                   \
        clock_gettime(CLOCK_REALTIME, &end##postfix);                   \
        fprintf(stderr, "@@@ #" # postfix " code took %f sec\n", (end##postfix.tv_sec - start##postfix.tv_sec) + \
                (end##postfix.tv_nsec - start##postfix.tv_nsec) / 1e9);   }

// usage:
//     TIME_MEASURE_PROLOG(1);
//     some_stuff();
//     TIME_MEASURE_EPILOG(1);