From b49df996594adb8679886548eb60b713f91ecd4c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20W=C3=B6rner?= <git@simon-woerner.de>
Date: Mon, 3 Apr 2017 18:03:59 +0200
Subject: [PATCH] added realtime parameter

---
 V2/sleep/src/lib.rs  | 30 ++++++++++++++++++++++--------
 V2/sleep/src/main.rs | 16 ++++++++++++++--
 2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/V2/sleep/src/lib.rs b/V2/sleep/src/lib.rs
index 77b6231..abf4202 100644
--- a/V2/sleep/src/lib.rs
+++ b/V2/sleep/src/lib.rs
@@ -1,7 +1,6 @@
 extern crate libc;
 
 use std::time::Duration;
-use libc::{c_int, c_long, time_t, timespec};
 
 const CLOCK_MONOTONIC: i32 = 1;
 
@@ -15,9 +14,9 @@ fn clock_nanosleep(_clk_id: libc::c_int, _flags: libc::c_int, rqtp: *const libc:
     unsafe { libc::nanosleep(rqtp as *const _, rmtp as *mut _) }
 }
 
-pub fn sleep(duration: Duration) -> Result<Duration, c_int> {
+pub fn sleep(duration: Duration) -> Result<Duration, libc::c_int> {
     let ts = duration_to_timespec(duration);
-    let mut remain = timespec {
+    let mut remain = libc::timespec {
         tv_sec: 0,
         tv_nsec: 0,
     };
@@ -30,13 +29,28 @@ pub fn sleep(duration: Duration) -> Result<Duration, c_int> {
     }
 }
 
-fn duration_to_timespec(duration: Duration) -> timespec {
-    timespec {
-        tv_sec: duration.as_secs() as time_t,
-        tv_nsec: duration.subsec_nanos() as c_long,
+fn duration_to_timespec(duration: Duration) -> libc::timespec {
+    libc::timespec {
+        tv_sec: duration.as_secs() as libc::time_t,
+        tv_nsec: duration.subsec_nanos() as libc::c_long,
     }
 }
 
-fn timespec_to_duration(timespec: timespec) -> Duration {
+fn timespec_to_duration(timespec: libc::timespec) -> Duration {
     Duration::new(timespec.tv_sec as u64, timespec.tv_nsec as u32)
 }
+
+#[cfg(target_os = "linux")]
+pub fn set_scheduler(policy: i32, priority: i32) -> libc::c_int {
+    let pid: libc::pid_t = 0;
+    let param = libc::sched_param {
+        sched_priority: priority
+    };
+
+    unsafe { libc::sched_setscheduler(pid as libc::pid_t, policy as libc::c_int, &param) }
+}
+
+#[cfg(target_os = "linux")]
+pub fn set_priority(priority: i32) -> libc::c_int {
+    set_scheduler(libc::SCHED_RR, priority)
+}
diff --git a/V2/sleep/src/main.rs b/V2/sleep/src/main.rs
index 06c8a23..0799d0b 100644
--- a/V2/sleep/src/main.rs
+++ b/V2/sleep/src/main.rs
@@ -8,8 +8,8 @@ use std::fs::File;
 use std::path::Path;
 use std::time::Duration;
 
-use argparse::{ArgumentParser, Print, Store};
-use sleep::sleep;
+use argparse::{ArgumentParser, Print, Store, StoreTrue};
+use sleep::{set_priority, sleep};
 use time::precise_time_ns;
 
 fn duration_from_ns(duration_ns: u64) -> Duration {
@@ -79,6 +79,7 @@ fn main() {
     let mut max: u64 = 100_000_000;
     let mut step: u64 = 1_000_000;
     let mut count: u64 = 100;
+    let mut realtime: bool = false;
     let mut output: String = "".to_string();
     let mut file: Option<File> = None;
 
@@ -97,6 +98,9 @@ fn main() {
         ap.refer(&mut count)
             .add_option(&["--loop"], Store,
             "Count of measurements per period");
+        ap.refer(&mut realtime)
+            .add_option(&["--rt"], StoreTrue,
+            "Output file");
         ap.refer(&mut output)
             .add_option(&["-o", "--out"], Store,
             "Output file");
@@ -105,6 +109,14 @@ fn main() {
         ap.parse_args_or_exit();
     }
 
+    if realtime {
+        let ret = set_priority(99);
+        
+        if ret != 0 {
+            panic!("Set realtime priority failed.");
+        }
+    }
+
     if output != "" {
         file = Some(File::create(Path::new(output.as_str()))
             .expect(format!("Open file '{}' failed", output).as_str()));