Initial work

Signed-off-by: Levente Kurusa <lkurusa@acm.org>

src/cpu.rs

@@ -0,0 +1,94 @@
+/* CPU controller */
+use std::path::PathBuf;
+use std::io::{Read, Write};
+
+use {CpuResources, Controllers, Controller, Resources, ControllIdentifier, Subsystem};
+
+#[derive(Debug, Clone)]
+pub struct CpuController{
+    base: PathBuf,
+    path: PathBuf,
+}
+
+#[derive(Debug)]
+pub struct Cpu {
+    pub stat: String,
+}
+
+impl Controller for CpuController {
+    fn control_type(self: &Self) -> Controllers { Controllers::Cpu}
+    fn get_path<'a>(self: &'a Self) -> &'a PathBuf { &self.path }
+    fn get_path_mut<'a>(self: &'a mut Self) -> &'a mut PathBuf { &mut self.path }
+    fn get_base<'a>(self: &'a Self) -> &'a PathBuf { &self.base }
+
+    fn apply(self: &Self, res: &Resources) {
+        /* get the resources that apply to this controller */
+        let res: &CpuResources = &res.cpu;
+
+        if res.update_values {
+            /* apply pid_max */
+            self.set_shares(res.shares);
+            self.set_cfs_period(res.period);
+            self.set_cfs_quota(res.quota as u64);
+            /* TODO: rt properties (CONFIG_RT_GROUP_SCHED) are not yet supported */
+        }
+    }
+}
+
+impl ControllIdentifier for CpuController {
+    fn controller_type() -> Controllers {
+        Controllers::Cpu
+    }
+}
+
+impl<'a> From<&'a Subsystem> for &'a CpuController {
+    fn from(sub: &'a Subsystem) -> &'a CpuController {
+        unsafe {
+            match sub {
+                Subsystem::Cpu(c) => c,
+                _ => {
+                    assert_eq!(1, 0);
+                    ::std::mem::uninitialized()
+                },
+            }
+        }
+    }
+}
+
+impl CpuController {
+    pub fn new(oroot: PathBuf) -> Self {
+        let mut root = oroot;
+        root.push(Self::controller_type().to_string());
+        Self {
+            base: root.clone(),
+            path: root,
+        }
+    }
+    pub fn cpu(self: &Self) -> Cpu {
+        Cpu {
+            stat: self.open_path("cpu.stat", false).and_then(|mut file| {
+                let mut s = String::new();
+                let _ = file.read_to_string(&mut s);
+                Some(s)
+            }).unwrap_or("".to_string()),
+        }
+    }
+
+    pub fn set_shares(self: &Self, shares: u64) {
+        self.open_path("cpu.shares", true).and_then(|mut file| {
+            file.write_all(shares.to_string().as_ref()).ok()
+        });
+    }
+
+    pub fn set_cfs_period(self: &Self, us: u64) {
+        self.open_path("cpu.cfs_period_us", true).and_then(|mut file| {
+            file.write_all(us.to_string().as_ref()).ok()
+        });
+    }
+
+    pub fn set_cfs_quota(self: &Self, us: u64) {
+        self.open_path("cpu.cfs_quota_us", true).and_then(|mut file| {
+            file.write_all(us.to_string().as_ref()).ok()
+        });
+    }
+}