1*1b191cb5SApple OSS Distributions #include <darwintest.h>
2*1b191cb5SApple OSS Distributions #include <darwintest_utils.h>
3*1b191cb5SApple OSS Distributions #include <errno.h>
4*1b191cb5SApple OSS Distributions #include <libproc_internal.h>
5*1b191cb5SApple OSS Distributions #include <stdio.h>
6*1b191cb5SApple OSS Distributions
7*1b191cb5SApple OSS Distributions // waste some time.
8*1b191cb5SApple OSS Distributions static uint64_t
ackermann(uint64_t m,uint64_t n)9*1b191cb5SApple OSS Distributions ackermann(uint64_t m, uint64_t n)
10*1b191cb5SApple OSS Distributions {
11*1b191cb5SApple OSS Distributions if (m == 0) {
12*1b191cb5SApple OSS Distributions return n + 1;
13*1b191cb5SApple OSS Distributions } else if (n == 0) {
14*1b191cb5SApple OSS Distributions return ackermann(m - 1, 1);
15*1b191cb5SApple OSS Distributions } else {
16*1b191cb5SApple OSS Distributions return ackermann(m - 1, ackermann(m, n - 1));
17*1b191cb5SApple OSS Distributions }
18*1b191cb5SApple OSS Distributions }
19*1b191cb5SApple OSS Distributions
20*1b191cb5SApple OSS Distributions T_DECL(int_time, "interrupt time collection")
21*1b191cb5SApple OSS Distributions {
22*1b191cb5SApple OSS Distributions struct proc_threadschedinfo info, info_new;
23*1b191cb5SApple OSS Distributions
24*1b191cb5SApple OSS Distributions // for checking that the kernel filled in values.
25*1b191cb5SApple OSS Distributions info.int_time_ns = (uint64_t)-3;
26*1b191cb5SApple OSS Distributions info_new.int_time_ns = (uint64_t)-3;
27*1b191cb5SApple OSS Distributions
28*1b191cb5SApple OSS Distributions int retval = proc_current_thread_schedinfo((void*)&info, sizeof(info));
29*1b191cb5SApple OSS Distributions T_ASSERT_EQ_INT(retval, 0, "proc_current_thread_schedinfo succeeded");
30*1b191cb5SApple OSS Distributions T_ASSERT_NE(info.int_time_ns, (uint64_t)-3, "info.int_time_ns was filled");
31*1b191cb5SApple OSS Distributions
32*1b191cb5SApple OSS Distributions printf("result: %llu\n", ackermann(3, 10));
33*1b191cb5SApple OSS Distributions
34*1b191cb5SApple OSS Distributions retval = proc_current_thread_schedinfo((void*)&info_new, sizeof(info_new));
35*1b191cb5SApple OSS Distributions T_ASSERT_EQ_INT(retval, 0, "proc_current_thread_schedinfo succeeded (2nd time)");
36*1b191cb5SApple OSS Distributions T_ASSERT_NE(info_new.int_time_ns, (uint64_t)-3, "info.int_time_ns was filled (2nd time)");
37*1b191cb5SApple OSS Distributions
38*1b191cb5SApple OSS Distributions int64_t duration_ns = (int64_t)info_new.int_time_ns - (int64_t)info.int_time_ns;
39*1b191cb5SApple OSS Distributions
40*1b191cb5SApple OSS Distributions printf("before : %lluns\n",
41*1b191cb5SApple OSS Distributions info.int_time_ns);
42*1b191cb5SApple OSS Distributions printf("after : %lluns\n",
43*1b191cb5SApple OSS Distributions info_new.int_time_ns);
44*1b191cb5SApple OSS Distributions printf("duration : %llins\n", duration_ns);
45*1b191cb5SApple OSS Distributions
46*1b191cb5SApple OSS Distributions /*
47*1b191cb5SApple OSS Distributions * If time went backwards, life is missing its monotony.
48*1b191cb5SApple OSS Distributions */
49*1b191cb5SApple OSS Distributions
50*1b191cb5SApple OSS Distributions T_EXPECT_FALSE(duration_ns < 0, "Kernel claims time went forewards");
51*1b191cb5SApple OSS Distributions
52*1b191cb5SApple OSS Distributions /*
53*1b191cb5SApple OSS Distributions * If the kernel says we spent more than 10 seconds in an interrupt context, something is definitely wrong.
54*1b191cb5SApple OSS Distributions */
55*1b191cb5SApple OSS Distributions
56*1b191cb5SApple OSS Distributions int64_t const limit_ns = 10 * (int64_t)NSEC_PER_SEC;
57*1b191cb5SApple OSS Distributions T_EXPECT_FALSE(duration_ns > limit_ns, "Kernel claims we spent less than 10 seconds in interrupt context");
58*1b191cb5SApple OSS Distributions }
59