12.38

    code in directory chapter12/code/12.38

    files:

    • sbuf.h, sbuf.c: prethreading package from section 12.5.4 in book. differences
      are that add new functions sbuf_full, sbuf_empty.
    • tiny.h, tiny.c: origin tiny server from section 11.6 in book. differences are
      we seperate function declarations into a .h file
    • main.c: listen new connections, create threads and adjust threads number dynamicly

    see new functions in sbuf, sbuf_full and sbuf_empty

    1. /* Empty buf? */
    2. int sbuf_empty(sbuf_t *sp) {
    3.   int e;
    4.   P(&sp->mutex);                          /* Lock the buffer */
    5.   e = sp->front == sp->rear;
    6.   V(&sp->mutex);                          /* Lock the buffer */
    7.   return e;
    8. }
    10. /* Full buf? */
    11. int sbuf_full(sbuf_t *sp) {
    12.   int f;
    13.   P(&sp->mutex);                          /* Lock the buffer */
    14.   f = (sp->rear - sp->front) == sp->n;
    15.   V(&sp->mutex);                          /* Lock the buffer */
    16.   return f;
    17. }

    main.c

    1. !INCLUDE "./code/12.38/main.c"

    run server

    1. (cd chapter12/code/12.38; make && ./main)

    open another terminal and benchmark it

    1. wrk -d4 http://localhost:5000

    output

    1. Running 4s test @ http://localhost:5000
    2.   2 threads and 10 connections
    3.   Thread Stats   Avg      Stdev     Max   +/- Stdev
    4.     Latency   130.44us  183.40us   9.03ms   98.06%
    5.     Req/Sec    11.08k     5.09k   17.78k    53.66%
    6.   90380 requests in 4.10s, 19.74MB read
    7. Requests/sec:  22039.72
    8. Transfer/sec:      4.81MB