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
main(int ac,char ** av)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 *
do_child(void * arg __unused)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 *
do_parent(void * arg __unused)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 }
96