added documentation

V2/sleep/src/lib.rs

@@ -22,6 +22,9 @@ fn clock_nanosleep(_clk_id: libc::c_int,
     unsafe { libc::nanosleep(rqtp as *const _, rmtp as *mut _) }
 }
 
+/// Sleeps for the given duration.
+///
+/// Uses `clock_nanosleep` on linux and `nanosleep` on darwin.
 pub fn sleep(duration: Duration) -> Result<Duration, libc::c_int> {
     let ts = duration_to_timespec(duration);
     let mut remain = libc::timespec {
@@ -48,15 +51,31 @@ fn timespec_to_duration(timespec: libc::timespec) -> Duration {
     Duration::new(timespec.tv_sec as u64, timespec.tv_nsec as u32)
 }
 
+/// Set scheduler policy and priority for process with given pid.
+///
+/// If `pid` equals zero, the policy of the calling process will be set.
+///
+/// # Examples
+///
+/// ```rust
+/// // set *round-robin* policy (default) and priority 99 (realtime) for own process
+/// set_scheduler(0, libc::SCHED_RR, 99);
+/// ```
 #[cfg(target_os = "linux")]
-pub fn set_scheduler(policy: i32, priority: i32) -> libc::c_int {
+pub fn set_scheduler(pid: libc::pid_t, policy: libc::c_int, priority: libc::c_int) -> libc::c_int {
-    let pid: libc::pid_t = 0;
     let param = libc::sched_param { sched_priority: priority };
-
+    unsafe { libc::sched_setscheduler(pid, policy, &param) }
-    unsafe { libc::sched_setscheduler(pid as libc::pid_t, policy as libc::c_int, &param) }
 }
 
+/// Set scheduler *round-robin* policy (default) and priority for own process.
+///
+/// # Examples
+///
+/// ```rust
+/// // set *round-robin* policy (default) and priority 99 (realtime)
+/// set_priority(99);
+/// ```
 #[cfg(target_os = "linux")]
 pub fn set_priority(priority: i32) -> libc::c_int {
-    set_scheduler(libc::SCHED_RR, priority)
+    set_scheduler(0, libc::SCHED_RR, priority)
 }