test/sysperf/umtx1.c

   1 /*
   2  * umtx1.c
   3  */
   4
   5 #include <sys/types.h>
   6 #include <sys/wait.h>
   7 #include <sys/errno.h>
   8 #include <pthread.h>
   9 #include <machine/cpufunc.h>
  10 #include <machine/atomic.h>
  11 #include "blib.h"
  12
  13 static void *do_child(void *arg);
  14 static void *do_parent(void *arg);
  15
  16 u_int mtx;
  17 u_long total;
  18
  19 int
  20 main(int ac, char **av)
  21 {
  22         pthread_t td1;
  23         pthread_t td2;
  24         int n;
  25         int k;
  26         int status;
  27
  28         printf("tests umtx hand-off loop\n");
  29         for (n = 1; n; --n) {
  30                 if (fork() == 0) {
  31                         start_timing();
  32                         for (k = 0; k < 10; ++k) {
  33                                 pthread_create(&td1, NULL, do_child, NULL);
  34                                 pthread_create(&td2, NULL, do_parent, NULL);
  35                                 pthread_join(td2, NULL);
  36                                 pthread_join(td1, NULL);
  37                         }
  38                         stop_timing(total, "total");
  39                         _exit(0);
  40                 }
  41         }
  42         while (wait3(&status, 0, NULL) <= 0 || errno == EINTR)
  43                 ;
  44
  45         return 0;
  46 }
  47
  48 static
  49 void *
  50 do_child(void *arg __unused)
  51 {
  52         for (;;) {
  53                 while (mtx == 0)
  54                         umtx_sleep(&mtx, 0, 0);
  55                 if (atomic_swap_int(&mtx, 0) == 2) {
  56                         umtx_wakeup(&mtx, 0);
  57                         pthread_yield();
  58                         break;
  59                 }
  60                 umtx_wakeup(&mtx, 0);
  61         }
  62         return NULL;
  63 }
  64
  65 static
  66 void *
  67 do_parent(void *arg __unused)
  68 {
  69         int j;
  70         int loops;
  71
  72         for (j = 0; j < 1000000; ++j) {
  73                 atomic_swap_int(&mtx, 1);
  74                 umtx_wakeup(&mtx, 0);
  75                 pthread_yield();
  76                 while (mtx == 1)
  77                         umtx_sleep(&mtx, 1, 0);
  78         }
  79         start_timing();
  80         for (j = 0; j < 1000000; ++j) {
  81                 atomic_swap_int(&mtx, 1);
  82                 umtx_wakeup(&mtx, 0);
  83                 while (mtx == 1)
  84                         umtx_sleep(&mtx, 1, 0);
  85         }
  86         stop_timing(j, "mtx1");
  87         atomic_add_long(&total, j * 2);
  88
  89         atomic_swap_int(&mtx, 2);
  90         umtx_wakeup(&mtx, 0);
  91         while (mtx == 2)
  92                 umtx_sleep(&mtx, 2, 0);
  93
  94         return NULL;
  95 }