Support set notify_on_release & release_agent

Support set notify_on_release & release_agent

Signed-off-by: Qingyuan Hou <qingyuan.hou@linux.alibaba.com>

src/cgroup.rs

@@ -260,6 +260,22 @@ impl Cgroup {
             .try_for_each(|sub| sub.to_controller().add_task_by_tgid(&pid))
     }
 
+    /// Set notify_on_release to the control group.
+    pub fn set_notify_on_release(&self, enable: bool) -> Result<()> {
+        self.subsystems()
+            .iter()
+            .try_for_each(|sub| sub.to_controller().set_notify_on_release(enable))
+    }
+
+    /// Set release_agent
+    pub fn set_release_agent(&self, path: &str) -> Result<()> {
+        self.hier
+            .root_control_group()
+            .subsystems()
+            .iter()
+            .try_for_each(|sub| sub.to_controller().set_release_agent(path))
+    }
+
     /// Returns an Iterator that can be used to iterate over the tasks that are currently in the
     /// control group.
     pub fn tasks(&self) -> Vec<CgroupPid> {

src/lib.rs

@@ -246,6 +246,12 @@ pub trait Controller {
     /// Does this controller already exist?
     fn exists(&self) -> bool;
 
+    /// Set notify_on_release
+    fn set_notify_on_release(&self, enable: bool) -> Result<()>;
+
+    /// Set release_agent
+    fn set_release_agent(&self, path: &str) -> Result<()>;
+
     /// Delete the controller.
     fn delete(&self) -> Result<()>;
 
@@ -290,6 +296,22 @@ where
         }
     }
 
+    /// Set notify_on_release
+    fn set_notify_on_release(&self, enable: bool) -> Result<()> {
+        self.open_path("notify_on_release", true)
+            .and_then(|mut file| {
+                write!(file, "{}", enable as i32)
+                    .map_err(|e| Error::with_cause(ErrorKind::WriteFailed, e))
+            })
+    }
+
+    /// Set release_agent
+    fn set_release_agent(&self, path: &str) -> Result<()> {
+        self.open_path("release_agent", true).and_then(|mut file| {
+            file.write_all(path.as_bytes())
+                .map_err(|e| Error::with_cause(ErrorKind::WriteFailed, e))
+        })
+    }
     /// Does this controller already exist?
     fn exists(&self) -> bool {
         self.get_path().exists()