1 files changed, 43 insertions, 0 deletions
diff --git a/third_party/rust/nix/test/sys/test_resource.rs b/third_party/rust/nix/test/sys/test_resource.rs
new file mode 100644
index 0000000000..8b12a9495b
--- /dev/null
+++ b/third_party/rust/nix/test/sys/test_resource.rs
@@ -0,0 +1,43 @@
+use nix::sys::resource::{getrlimit, setrlimit, Resource};
+use nix::sys::resource::{getrusage, UsageWho};
+
+/// Tests the RLIMIT_NOFILE functionality of getrlimit(), where the resource RLIMIT_NOFILE refers
+/// to the maximum file descriptor number that can be opened by the process (aka the maximum number
+/// of file descriptors that the process can open, since Linux 4.5).
+///
+/// We first fetch the existing file descriptor maximum values using getrlimit(), then edit the
+/// soft limit to make sure it has a new and distinct value to the hard limit. We then setrlimit()
+/// to put the new soft limit in effect, and then getrlimit() once more to ensure the limits have
+/// been updated.
+#[test]
+pub fn test_resource_limits_nofile() {
+    let (mut soft_limit, hard_limit) =
+        getrlimit(Resource::RLIMIT_NOFILE).unwrap();
+
+    soft_limit -= 1;
+    assert_ne!(soft_limit, hard_limit);
+    setrlimit(Resource::RLIMIT_NOFILE, soft_limit, hard_limit).unwrap();
+
+    let (new_soft_limit, _) = getrlimit(Resource::RLIMIT_NOFILE).unwrap();
+    assert_eq!(new_soft_limit, soft_limit);
+}
+
+#[test]
+pub fn test_self_cpu_time() {
+    // Make sure some CPU time is used.
+    let mut numbers: Vec<i32> = (1..1_000_000).collect();
+    numbers.iter_mut().for_each(|item| *item *= 2);
+
+    // FIXME: this is here to help ensure the compiler does not optimize the whole
+    // thing away. Replace the assert with test::black_box once stabilized.
+    assert_eq!(numbers[100..200].iter().sum::<i32>(), 30_100);
+
+    let usage = getrusage(UsageWho::RUSAGE_SELF)
+        .expect("Failed to call getrusage for SELF");
+    let rusage = usage.as_ref();
+
+    let user = usage.user_time();
+    assert!(user.tv_sec() > 0 || user.tv_usec() > 0);
+    assert_eq!(user.tv_sec(), rusage.ru_utime.tv_sec);
+    assert_eq!(user.tv_usec(), rusage.ru_utime.tv_usec);
+}