Merge pull request #35 from Tim-Zhang/v0.2.3

release: v0.2.3

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,17 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: 'bug, needs-review'
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/enhancement-request.md

@@ -0,0 +1,20 @@
+---
+name: Enhancement request
+about: Suggest an improvement to an existing feature
+title: ''
+labels: enhancement, needs-review
+assignees: ''
+
+---
+
+**Which feature do you think can be improved?**
+
+Specify the feature you think could be made better.
+
+**How can it be improved?**
+
+Describe how specifically you think it could be improved.
+
+**Additional Information**
+
+Anything else to add?

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,20 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: 'feature, needs-review'
+assignees: ''
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.github/workflows/PR-wip-checks.yaml

@@ -0,0 +1,21 @@
+name: Pull request WIP checks
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+      - edited
+      - labeled
+      - unlabeled
+
+jobs:
+  pr_wip_check:
+    runs-on: ubuntu-latest
+    name: WIP Check
+    steps:
+    - name: WIP Check
+      uses: tim-actions/wip-check@1c2a1ca6c110026b3e2297bb2ef39e1747b5a755
+      with:
+        labels: '["do-not-merge", "wip", "rfc"]'
+        keywords: '["WIP", "wip", "RFC", "rfc", "dnm", "DNM", "do-not-merge"]'

.github/workflows/bvt.yaml

@@ -0,0 +1,26 @@
+name: BVT
+on: [pull_request]
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Build
+        run: make debug
+
+  fmt:
+    name: Format Check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: rustup component add rustfmt
+      - run: make fmt
+  test:
+    name: Run Unit Test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: make test
+

.github/workflows/commit-message-check.yaml

@@ -0,0 +1,53 @@
+name: Commit Message Check
+on:
+  pull_request:
+    types:
+      - opened
+      - reopened
+      - synchronize
+
+env:
+  error_msg: |+
+    See the document below for help on formatting commits for the project.
+
+    https://github.com/kata-containers/community/blob/master/CONTRIBUTING.md#patch-forma
+
+jobs:
+  commit-message-check:
+    runs-on: ubuntu-latest
+    name: Commit Message Check
+    steps:
+    - name: Get PR Commits
+      id: 'get-pr-commits'
+      uses: tim-actions/get-pr-commits@v1.0.0
+      with:
+        token: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: DCO Check
+      uses: tim-actions/dco@2fd0504dc0d27b33f542867c300c60840c6dcb20
+      with:
+        commits: ${{ steps.get-pr-commits.outputs.commits }}
+
+    - name: Commit Body Missing Check
+      if: ${{ success() || failure() }}
+      uses: tim-actions/commit-body-check@v1.0.2
+      with:
+        commits: ${{ steps.get-pr-commits.outputs.commits }}
+
+    - name: Check Subject Line Length
+      if: ${{ success() || failure() }}
+      uses: tim-actions/commit-message-checker-with-regex@v0.3.1
+      with:
+        commits: ${{ steps.get-pr-commits.outputs.commits }}
+        pattern: '^.{0,75}(\n.*)*$'
+        error: 'Subject too long (max 75)'
+        post_error: ${{ env.error_msg }}
+
+    - name: Check Body Line Length
+      if: ${{ success() || failure() }}
+      uses: tim-actions/commit-message-checker-with-regex@v0.3.1
+      with:
+        commits: ${{ steps.get-pr-commits.outputs.commits }}
+        pattern: '^.+(\n.{0,72})*$|^.+\n\s*[^a-zA-Z\s\n]|^.+\n\S+$'
+        error: 'Body line too long (max 72)'
+        post_error: ${{ env.error_msg }}

.travis.yml

@@ -1,11 +0,0 @@
-language: rust
-rust:
-  - stable
-  - beta
-  - nightly
-matrix:
-  allow_failures:
-    - rust: nightly
-  fast_finish: true
-script:
-  - cargo build --verbose --all

Cargo.toml

@@ -1,13 +1,15 @@
 [package]
-name = "cgroups"
+name = "cgroups-rs"
 description = "Native Rust crate for managing control groups on Linux"
-repository = "https://github.com/levex/cgroups-rs"
+repository = "https://github.com/kata-containers/cgroups-rs"
 keywords = ["linux", "cgroup", "containers", "isolation"]
 categories = ["os", "api-bindings", "os::unix-apis"]
 license = "MIT OR Apache-2.0"
-version = "0.1.1-alpha.0"
-authors = ["Levente Kurusa <lkurusa@acm.org>", "Sam Wilson <tecywiz121@hotmail.com>"]
+version = "0.2.3"
+authors = ["The Kata Containers community <kata-dev@lists.katacontainers.io>", "Levente Kurusa <lkurusa@acm.org>", "Sam Wilson <tecywiz121@hotmail.com>"]
 edition = "2018"
+homepage = "https://github.com/kata-containers/cgroups-rs"
+readme = "README.md"
 
 [dependencies]
 log = "0.4"

Makefile

@@ -0,0 +1,37 @@
+all: debug fmt test
+
+#
+# Build
+#
+
+.PHONY: debug
+debug:
+	RUSTFLAGS="--deny warnings" cargo build
+
+.PHONY: release
+release:
+	cargo build --release
+
+.PHONY: build
+build: debug
+
+#
+# Tests and linters
+#
+
+.PHONY: test
+test:
+	cargo test -- --color always --nocapture
+
+.PHONY: check
+check: fmt clippy
+
+
+.PHONY: fmt
+fmt:
+	cargo fmt --all -- --check
+
+.PHONY: clippy
+clippy:
+	cargo clippy --all-targets --all-features -- -D warnings
+

README.md

@@ -1,32 +1,36 @@
-# cgroups-rs ![Build](https://travis-ci.org/levex/cgroups-rs.svg?branch=master)
+# cgroups-rs ![Build](https://travis-ci.org/kata-containers/cgroups-rs.svg?branch=master)
 Native Rust library for managing control groups under Linux
 
-Right now the crate only support the original, V1 hierarchy, however support
-is planned for the Unified hierarchy.
+Both v1 and v2 of cgroups are supported.
 
 # Examples
 
 ## Create a control group using the builder pattern
 
 ``` rust
-// Acquire a handle for the V1 cgroup hierarchy.
-let hier = ::hierarchies::V1::new();
+
+
+use cgroups_rs::*;
+use cgroups_rs::cgroup_builder::*;
+
+// Acquire a handle for the cgroup hierarchy.
+let hier = cgroups_rs::hierarchies::auto();
 
 // Use the builder pattern (see the documentation to create the control group)
 //
 // This creates a control group named "example" in the V1 hierarchy.
-let cg: Cgroup = CgroupBuilder::new("example", &v1)
-	.cpu()
-		.shares(85)
-		.done()
-	.build();
+    let cg: Cgroup = CgroupBuilder::new("example")
+        .cpu()
+        .shares(85)
+        .done()
+        .build(hier);
 
 // Now `cg` is a control group that gets 85% of the CPU time in relative to
 // other control groups.
 
 // Get a handle to the CPU controller.
-let cpus: &CpuController = cg.controller_of().unwrap();
-cpus.add_task(1234u64);
+let cpus: &cgroups_rs::cpu::CpuController = cg.controller_of().unwrap();
+cpus.add_task(&CgroupPid::from(1234u64));
 
 // [...]
 

src/blkio.rs

@@ -8,13 +8,13 @@
 //!
 //! See the Kernel's documentation for more information about this subsystem, found at:
 //!  [Documentation/cgroup-v1/blkio-controller.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/blkio-controller.txt)
-use std::fs::File;
-use std::io::{Read, Write};
+use std::io::Write;
 use std::path::PathBuf;
 
 use crate::error::ErrorKind::*;
 use crate::error::*;
 
+use crate::{read_string_from, read_u64_from};
 use crate::{
     BlkIoResources, ControllIdentifier, ControllerInternal, Controllers, Resources, Subsystem,
 };
@@ -344,39 +344,36 @@ impl ControllerInternal for BlkIoController {
         // get the resources that apply to this controller
         let res: &BlkIoResources = &res.blkio;
 
-        if res.update_values {
-            if let Some(weight) = res.weight {
-                let _ = self.set_weight(weight as u64);
-            }
-            if let Some(leaf_weight) = res.leaf_weight {
-                let _ = self.set_leaf_weight(leaf_weight as u64);
-            }
+        if let Some(weight) = res.weight {
+            let _ = self.set_weight(weight as u64);
+        }
+        if let Some(leaf_weight) = res.leaf_weight {
+            let _ = self.set_leaf_weight(leaf_weight as u64);
+        }
 
-            for dev in &res.weight_device {
-                if let Some(weight) = dev.weight {
-                    let _ = self.set_weight_for_device(dev.major, dev.minor, weight as u64);
-                }
-                if let Some(leaf_weight) = dev.leaf_weight {
-                    let _ =
-                        self.set_leaf_weight_for_device(dev.major, dev.minor, leaf_weight as u64);
-                }
+        for dev in &res.weight_device {
+            if let Some(weight) = dev.weight {
+                let _ = self.set_weight_for_device(dev.major, dev.minor, weight as u64);
             }
+            if let Some(leaf_weight) = dev.leaf_weight {
+                let _ = self.set_leaf_weight_for_device(dev.major, dev.minor, leaf_weight as u64);
+            }
+        }
 
-            for dev in &res.throttle_read_bps_device {
-                let _ = self.throttle_read_bps_for_device(dev.major, dev.minor, dev.rate);
-            }
+        for dev in &res.throttle_read_bps_device {
+            let _ = self.throttle_read_bps_for_device(dev.major, dev.minor, dev.rate);
+        }
 
-            for dev in &res.throttle_write_bps_device {
-                let _ = self.throttle_write_bps_for_device(dev.major, dev.minor, dev.rate);
-            }
+        for dev in &res.throttle_write_bps_device {
+            let _ = self.throttle_write_bps_for_device(dev.major, dev.minor, dev.rate);
+        }
 
-            for dev in &res.throttle_read_iops_device {
-                let _ = self.throttle_read_iops_for_device(dev.major, dev.minor, dev.rate);
-            }
+        for dev in &res.throttle_read_iops_device {
+            let _ = self.throttle_read_iops_for_device(dev.major, dev.minor, dev.rate);
+        }
 
-            for dev in &res.throttle_write_iops_device {
-                let _ = self.throttle_write_iops_for_device(dev.major, dev.minor, dev.rate);
-            }
+        for dev in &res.throttle_write_iops_device {
+            let _ = self.throttle_write_iops_for_device(dev.major, dev.minor, dev.rate);
         }
 
         Ok(())
@@ -396,39 +393,17 @@ impl<'a> From<&'a Subsystem> for &'a BlkIoController {
                 Subsystem::BlkIo(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
     }
 }
 
-fn read_string_from(mut file: File) -> Result<String> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => Ok(string.trim().to_string()),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
-fn read_u64_from(mut file: File) -> Result<u64> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => string
-            .trim()
-            .parse()
-            .map_err(|e| Error::with_cause(ParseError, e)),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
 impl BlkIoController {
-    /// Constructs a new `BlkIoController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf, v2: bool) -> Self {
-        let mut root = oroot;
-        if !v2 {
-            root.push(Self::controller_type().to_string());
-        }
+    /// Constructs a new `BlkIoController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf, v2: bool) -> Self {
         Self {
             base: root.clone(),
             path: root,

src/cgroup.rs

@@ -9,8 +9,6 @@
 use crate::error::ErrorKind::*;
 use crate::error::*;
 
-use crate::libc_rmdir;
-
 use crate::{CgroupPid, ControllIdentifier, Controller, Hierarchy, Resources, Subsystem};
 
 use std::collections::HashMap;
@@ -30,20 +28,41 @@ use std::path::{Path, PathBuf};
 /// > specialized behaviour.
 ///
 /// This crate is an attempt at providing a Rust-native way of managing these cgroups.
-pub struct Cgroup<'b> {
+#[derive(Debug)]
+pub struct Cgroup {
     /// The list of subsystems that control this cgroup
     subsystems: Vec<Subsystem>,
 
     /// The hierarchy.
-    hier: Box<&'b dyn Hierarchy>,
+    hier: Box<dyn Hierarchy>,
     path: String,
 }
 
-impl<'b> Cgroup<'b> {
+impl Clone for Cgroup {
+    fn clone(&self) -> Self {
+        Cgroup {
+            subsystems: self.subsystems.clone(),
+            path: self.path.clone(),
+            hier: crate::hierarchies::auto(),
+        }
+    }
+}
+
+impl Default for Cgroup {
+    fn default() -> Self {
+        Cgroup {
+            subsystems: Vec::new(),
+            hier: crate::hierarchies::auto(),
+            path: "".to_string(),
+        }
+    }
+}
+
+impl Cgroup {
     /// Create this control group.
     fn create(&self) {
         if self.hier.v2() {
-            create_v2_cgroup(self.hier.root().clone(), &self.path);
+            let _ret = create_v2_cgroup(self.hier.root().clone(), &self.path);
         } else {
             for subsystem in &self.subsystems {
                 subsystem.to_controller().create();
@@ -58,56 +77,66 @@ impl<'b> Cgroup<'b> {
     /// Create a new control group in the hierarchy `hier`, with name `path`.
     ///
     /// Returns a handle to the control group that can be used to manipulate it.
+    pub fn new<P: AsRef<Path>>(hier: Box<dyn Hierarchy>, path: P) -> Cgroup {
+        let cg = Cgroup::load(hier, path);
+        cg.create();
+        cg
+    }
+
+    /// Create a new control group in the hierarchy `hier`, with name `path` and `relative_paths`
     ///
-    /// Note that if the handle goes out of scope and is dropped, the control group is _not_
-    /// destroyed.
-    pub fn new<P: AsRef<Path>>(hier: Box<&'b dyn Hierarchy>, path: P) -> Cgroup<'b> {
-        let relative_paths = get_cgroups_relative_paths().unwrap();
-        Cgroup::new_with_relative_paths(hier, path, relative_paths)
+    /// Returns a handle to the control group that can be used to manipulate it.
+    ///
+    /// Note that this method is only meaningful for cgroup v1, call it is equivalent to call `new` in the v2 mode
+    pub fn new_with_relative_paths<P: AsRef<Path>>(
+        hier: Box<dyn Hierarchy>,
+        path: P,
+        relative_paths: HashMap<String, String>,
+    ) -> Cgroup {
+        let cg = Cgroup::load_with_relative_paths(hier, path, relative_paths);
+        cg.create();
+        cg
     }
 
     /// Create a handle for a control group in the hierarchy `hier`, with name `path`.
     ///
     /// Returns a handle to the control group (that possibly does not exist until `create()` has
     /// been called on the cgroup.
-    ///
-    /// Note that if the handle goes out of scope and is dropped, the control group is _not_
-    /// destroyed.
-    pub fn load<P: AsRef<Path>>(hier: Box<&'b dyn Hierarchy>, path: P) -> Cgroup<'b> {
-        let relative_paths = get_cgroups_relative_paths().unwrap();
-        Cgroup::load_with_relative_paths(hier, path, relative_paths)
-    }
+    pub fn load<P: AsRef<Path>>(hier: Box<dyn Hierarchy>, path: P) -> Cgroup {
+        let path = path.as_ref();
+        let mut subsystems = hier.subsystems();
+        if path.as_os_str() != "" {
+            subsystems = subsystems
+                .into_iter()
+                .map(|x| x.enter(path))
+                .collect::<Vec<_>>();
+        }
+
+        let cg = Cgroup {
+            path: path.to_str().unwrap().to_string(),
+            subsystems: subsystems,
+            hier,
+        };
 
-    /// Create a new control group in the hierarchy `hier`, with name `path`.
-    /// and relative paths from `/proc/self/cgroup`
-    ///
-    /// Returns a handle to the control group that can be used to manipulate it.
-    ///
-    /// Note that if the handle goes out of scope and is dropped, the control group is _not_
-    /// destroyed.
-    pub fn new_with_relative_paths<P: AsRef<Path>>(
-        hier: Box<&'b dyn Hierarchy>,
-        path: P,
-        relative_paths: HashMap<String, String>,
-    ) -> Cgroup<'b> {
-        let cg = Cgroup::load_with_relative_paths(hier, path, relative_paths);
-        cg.create();
         cg
     }
 
-    /// Create a handle for a control group in the hierarchy `hier`, with name `path`,
-    /// and relative paths from `/proc/self/cgroup`
+    /// Create a handle for a control group in the hierarchy `hier`, with name `path` and `relative_paths`
     ///
     /// Returns a handle to the control group (that possibly does not exist until `create()` has
     /// been called on the cgroup.
     ///
-    /// Note that if the handle goes out of scope and is dropped, the control group is _not_
-    /// destroyed.
+    /// Note that this method is only meaningful for cgroup v1, call it is equivalent to call `load` in the v2 mode
     pub fn load_with_relative_paths<P: AsRef<Path>>(
-        hier: Box<&'b dyn Hierarchy>,
+        hier: Box<dyn Hierarchy>,
         path: P,
         relative_paths: HashMap<String, String>,
-    ) -> Cgroup<'b> {
+    ) -> Cgroup {
+        // relative_paths only valid for cgroup v1
+        if hier.v2() {
+            return Self::load(hier, path);
+        }
+
         let path = path.as_ref();
         let mut subsystems = hier.subsystems();
         if path.as_os_str() != "" {
@@ -130,7 +159,7 @@ impl<'b> Cgroup<'b> {
 
         let cg = Cgroup {
             subsystems: subsystems,
-            hier: hier,
+            hier,
             path: path.to_str().unwrap().to_string(),
         };
 
@@ -148,17 +177,17 @@ impl<'b> Cgroup<'b> {
     /// system call will fail if there are any descendants. Thus, one should check whether it was
     /// actually removed, and remove the descendants first if not. In the future, this behavior
     /// will change.
-    pub fn delete(self) {
+    pub fn delete(&self) -> Result<()> {
         if self.v2() {
             if self.path != "" {
                 let mut p = self.hier.root().clone();
-                p.push(self.path);
-                libc_rmdir(p.to_str().unwrap());
+                p.push(self.path.clone());
+                return fs::remove_dir(p).map_err(|e| Error::with_cause(RemoveFailed, e));
             }
-            return;
+            return Ok(());
         }
 
-        self.subsystems.into_iter().for_each(|sub| match sub {
+        self.subsystems.iter().try_for_each(|sub| match sub {
             Subsystem::Pid(pidc) => pidc.delete(),
             Subsystem::Mem(c) => c.delete(),
             Subsystem::CpuSet(c) => c.delete(),
@@ -173,7 +202,7 @@ impl<'b> Cgroup<'b> {
             Subsystem::HugeTlb(c) => c.delete(),
             Subsystem::Rdma(c) => c.delete(),
             Subsystem::Systemd(c) => c.delete(),
-        });
+        })
     }
 
     /// Apply a set of resource limits to the control group.
@@ -233,6 +262,29 @@ impl<'b> Cgroup<'b> {
         }
     }
 
+    /// Attach a task to the control group by thread group id.
+    pub fn add_task_by_tgid(&self, pid: CgroupPid) -> Result<()> {
+        self.subsystems()
+            .iter()
+            .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> {
@@ -272,7 +324,7 @@ fn enable_controllers(controllers: &Vec<String>, path: &PathBuf) {
     }
 }
 
-fn supported_controllers(p: &PathBuf) -> Vec<String> {
+fn supported_controllers() -> Vec<String> {
     let p = format!("{}/{}", UNIFIED_MOUNTPOINT, "cgroup.controllers");
     let ret = fs::read_to_string(p.as_str());
     ret.unwrap_or(String::new())
@@ -283,7 +335,7 @@ fn supported_controllers(p: &PathBuf) -> Vec<String> {
 
 fn create_v2_cgroup(root: PathBuf, path: &str) -> Result<()> {
     // controler list ["memory", "cpu"]
-    let controllers = supported_controllers(&root);
+    let controllers = supported_controllers();
     let mut fp = root;
 
     // enable for root
@@ -324,13 +376,7 @@ pub fn get_cgroups_relative_paths() -> Result<HashMap<String, String>> {
 
         let keys: Vec<&str> = fl[1].split(',').collect();
         for key in &keys {
-            // this is a workaround, cgroup file are using `name=systemd`,
-            // but if file system the name is `systemd`
-            if *key == "name=systemd" {
-                m.insert("systemd".to_string(), fl[2].to_string());
-            } else {
-                m.insert(key.to_string(), fl[2].to_string());
-            }
+            m.insert(key.to_string(), fl[2].to_string());
         }
     }
     Ok(m)

src/cgroup_builder.rs

@@ -16,12 +16,11 @@
 //! by a call to `build()`.
 //!
 //! ```rust,no_run
-//! # use cgroups::*;
-//! # use cgroups::devices::*;
-//! # use cgroups::cgroup_builder::*;
-//! let h = cgroups::hierarchies::auto();
-//! let h = Box::new(&*h);
-//! let cgroup: Cgroup = CgroupBuilder::new("hello", h)
+//! # use cgroups_rs::*;
+//! # use cgroups_rs::devices::*;
+//! # use cgroups_rs::cgroup_builder::*;
+//! let h = cgroups_rs::hierarchies::auto();
+//! let cgroup: Cgroup = CgroupBuilder::new("hello")
 //!      .memory()
 //!          .kernel_memory_limit(1024 * 1024)
 //!          .memory_hard_limit(1024 * 1024)
@@ -47,8 +46,8 @@
 //!          .limit("2G".to_string(), 2 * 1024 * 1024 * 1024)
 //!          .done()
 //!      .blkio()
-//!          .weight(Some(123))
-//!          .leaf_weight(Some(99))
+//!          .weight(123)
+//!          .leaf_weight(99)
 //!          .weight_device(6, 1, Some(100), Some(55))
 //!          .weight_device(6, 1, Some(100), Some(55))
 //!          .throttle_iops()
@@ -58,12 +57,11 @@
 //!              .read(6, 1, 10)
 //!              .write(11, 1, 100)
 //!          .done()
-//!      .build();
+//!      .build(h);
 //! ```
-use crate::error::*;
 
 use crate::{
-    pid, BlkIoDeviceResource, BlkIoDeviceThrottleResource, Cgroup, DeviceResource, Hierarchy,
+    BlkIoDeviceResource, BlkIoDeviceThrottleResource, Cgroup, DeviceResource, Hierarchy,
     HugePageResource, MaxValue, NetworkPriority, Resources,
 };
 
@@ -71,67 +69,64 @@ macro_rules! gen_setter {
     ($res:ident, $cont:ident, $func:ident, $name:ident, $ty:ty) => {
         /// See the similarly named function in the respective controller.
         pub fn $name(mut self, $name: $ty) -> Self {
-            self.cgroup.resources.$res.update_values = true;
-            self.cgroup.resources.$res.$name = $name;
+            self.cgroup.resources.$res.$name = Some($name);
             self
         }
     };
 }
 
 /// A control group builder instance
-pub struct CgroupBuilder<'a> {
+pub struct CgroupBuilder {
     name: String,
-    hierarchy: Box<&'a dyn Hierarchy>,
     /// Internal, unsupported field: use the associated builders instead.
     resources: Resources,
 }
 
-impl<'a> CgroupBuilder<'a> {
+impl CgroupBuilder {
     /// Start building a control group with the supplied hierarchy and name pair.
     ///
     /// Note that this does not actually create the control group until `build()` is called.
-    pub fn new(name: &'a str, hierarchy: Box<&'a dyn Hierarchy>) -> CgroupBuilder<'a> {
+    pub fn new(name: &str) -> CgroupBuilder {
         CgroupBuilder {
             name: name.to_owned(),
-            hierarchy: hierarchy,
             resources: Resources::default(),
         }
     }
 
     /// Builds the memory resources of the control group.
-    pub fn memory(self) -> MemoryResourceBuilder<'a> {
+    pub fn memory(self) -> MemoryResourceBuilder {
         MemoryResourceBuilder { cgroup: self }
     }
 
     /// Builds the pid resources of the control group.
-    pub fn pid(self) -> PidResourceBuilder<'a> {
+    pub fn pid(self) -> PidResourceBuilder {
         PidResourceBuilder { cgroup: self }
     }
 
     /// Builds the cpu resources of the control group.
-    pub fn cpu(self) -> CpuResourceBuilder<'a> {
+    pub fn cpu(self) -> CpuResourceBuilder {
         CpuResourceBuilder { cgroup: self }
     }
 
     /// Builds the devices resources of the control group, disallowing or
     /// allowing access to certain devices in the system.
-    pub fn devices(self) -> DeviceResourceBuilder<'a> {
+    pub fn devices(self) -> DeviceResourceBuilder {
         DeviceResourceBuilder { cgroup: self }
     }
 
     /// Builds the network resources of the control group, setting class id, or
     /// various priorities on networking interfaces.
-    pub fn network(self) -> NetworkResourceBuilder<'a> {
+    pub fn network(self) -> NetworkResourceBuilder {
         NetworkResourceBuilder { cgroup: self }
     }
 
     /// Builds the hugepage/hugetlb resources available to the control group.
-    pub fn hugepages(self) -> HugepagesResourceBuilder<'a> {
+    pub fn hugepages(self) -> HugepagesResourceBuilder {
         HugepagesResourceBuilder { cgroup: self }
     }
 
     /// Builds the block I/O resources available for the control group.
-    pub fn blkio(self) -> BlkIoResourcesBuilder<'a> {
+    pub fn blkio(self) -> BlkIoResourcesBuilder {
         BlkIoResourcesBuilder {
             cgroup: self,
             throttling_iops: false,
@@ -139,19 +134,19 @@ impl<'a> CgroupBuilder<'a> {
     }
 
     /// Finalize the control group, consuming the builder and creating the control group.
-    pub fn build(self) -> Cgroup<'a> {
-        let cg = Cgroup::new(self.hierarchy, self.name);
-        cg.apply(&self.resources);
+    pub fn build(self, hier: Box<dyn Hierarchy>) -> Cgroup {
+        let cg = Cgroup::new(hier, self.name);
+        let _ret = cg.apply(&self.resources);
         cg
     }
 }
 
 /// A builder that configures the memory controller of a control group.
-pub struct MemoryResourceBuilder<'a> {
-    cgroup: CgroupBuilder<'a>,
+pub struct MemoryResourceBuilder {
+    cgroup: CgroupBuilder,
 }
 
-impl<'a> MemoryResourceBuilder<'a> {
+impl MemoryResourceBuilder {
     gen_setter!(
         memory,
         MemController,
@@ -184,17 +179,17 @@ impl<'a> MemoryResourceBuilder<'a> {
     gen_setter!(memory, MemController, set_swappiness, swappiness, u64);
 
     /// Finish the construction of the memory resources of a control group.
-    pub fn done(self) -> CgroupBuilder<'a> {
+    pub fn done(self) -> CgroupBuilder {
         self.cgroup
     }
 }
 
 /// A builder that configures the pid controller of a control group.
-pub struct PidResourceBuilder<'a> {
-    cgroup: CgroupBuilder<'a>,
+pub struct PidResourceBuilder {
+    cgroup: CgroupBuilder,
 }
 
-impl<'a> PidResourceBuilder<'a> {
+impl PidResourceBuilder {
     gen_setter!(
         pid,
         PidController,
@@ -204,19 +199,18 @@ impl<'a> PidResourceBuilder<'a> {
     );
 
     /// Finish the construction of the pid resources of a control group.
-    pub fn done(self) -> CgroupBuilder<'a> {
+    pub fn done(self) -> CgroupBuilder {
         self.cgroup
     }
 }
 
 /// A builder that configures the cpuset & cpu controllers of a control group.
-pub struct CpuResourceBuilder<'a> {
-    cgroup: CgroupBuilder<'a>,
+pub struct CpuResourceBuilder {
+    cgroup: CgroupBuilder,
 }
 
-impl<'a> CpuResourceBuilder<'a> {
-    // FIXME this should all changed to options.
-    gen_setter!(cpu, CpuSetController, set_cpus, cpus, Option<String>);
+impl CpuResourceBuilder {
+    gen_setter!(cpu, CpuSetController, set_cpus, cpus, String);
     gen_setter!(cpu, CpuSetController, set_mems, mems, String);
     gen_setter!(cpu, CpuController, set_shares, shares, u64);
     gen_setter!(cpu, CpuController, set_cfs_quota, quota, i64);
@@ -225,17 +219,17 @@ impl<'a> CpuResourceBuilder<'a> {
     gen_setter!(cpu, CpuController, set_rt_period, realtime_period, u64);
 
     /// Finish the construction of the cpu resources of a control group.
-    pub fn done(self) -> CgroupBuilder<'a> {
+    pub fn done(self) -> CgroupBuilder {
         self.cgroup
     }
 }
 
 /// A builder that configures the devices controller of a control group.
-pub struct DeviceResourceBuilder<'a> {
-    cgroup: CgroupBuilder<'a>,
+pub struct DeviceResourceBuilder {
+    cgroup: CgroupBuilder,
 }
 
-impl<'a> DeviceResourceBuilder<'a> {
+impl DeviceResourceBuilder {
     /// Restrict (or allow) a device to the tasks inside the control group.
     pub fn device(
         mut self,
@@ -244,8 +238,7 @@ impl<'a> DeviceResourceBuilder<'a> {
         devtype: crate::devices::DeviceType,
         allow: bool,
         access: Vec<crate::devices::DevicePermissions>,
-    ) -> DeviceResourceBuilder<'a> {
-        self.cgroup.resources.devices.update_values = true;
+    ) -> DeviceResourceBuilder {
         self.cgroup.resources.devices.devices.push(DeviceResource {
             major,
             minor,
@@ -257,23 +250,22 @@ impl<'a> DeviceResourceBuilder<'a> {
     }
 
     /// Finish the construction of the devices resources of a control group.
-    pub fn done(self) -> CgroupBuilder<'a> {
+    pub fn done(self) -> CgroupBuilder {
         self.cgroup
     }
 }
 
 /// A builder that configures the net_cls & net_prio controllers of a control group.
-pub struct NetworkResourceBuilder<'a> {
-    cgroup: CgroupBuilder<'a>,
+pub struct NetworkResourceBuilder {
+    cgroup: CgroupBuilder,
 }
 
-impl<'a> NetworkResourceBuilder<'a> {
+impl NetworkResourceBuilder {
     gen_setter!(network, NetclsController, set_class, class_id, u64);
 
     /// Set the priority of the tasks when operating on a networking device defined by `name` to be
     /// `priority`.
-    pub fn priority(mut self, name: String, priority: u64) -> NetworkResourceBuilder<'a> {
-        self.cgroup.resources.network.update_values = true;
+    pub fn priority(mut self, name: String, priority: u64) -> NetworkResourceBuilder {
         self.cgroup
             .resources
             .network
@@ -283,20 +275,19 @@ impl<'a> NetworkResourceBuilder<'a> {
     }
 
     /// Finish the construction of the network resources of a control group.
-    pub fn done(self) -> CgroupBuilder<'a> {
+    pub fn done(self) -> CgroupBuilder {
         self.cgroup
     }
 }
 
 /// A builder that configures the hugepages controller of a control group.
-pub struct HugepagesResourceBuilder<'a> {
-    cgroup: CgroupBuilder<'a>,
+pub struct HugepagesResourceBuilder {
+    cgroup: CgroupBuilder,
 }
 
-impl<'a> HugepagesResourceBuilder<'a> {
+impl HugepagesResourceBuilder {
     /// Limit the usage of certain hugepages (determined by `size`) to be at most `limit` bytes.
-    pub fn limit(mut self, size: String, limit: u64) -> HugepagesResourceBuilder<'a> {
-        self.cgroup.resources.hugepages.update_values = true;
+    pub fn limit(mut self, size: String, limit: u64) -> HugepagesResourceBuilder {
         self.cgroup
             .resources
             .hugepages
@@ -306,26 +297,20 @@ impl<'a> HugepagesResourceBuilder<'a> {
     }
 
     /// Finish the construction of the network resources of a control group.
-    pub fn done(self) -> CgroupBuilder<'a> {
+    pub fn done(self) -> CgroupBuilder {
         self.cgroup
     }
 }
 
 /// A builder that configures the blkio controller of a control group.
-pub struct BlkIoResourcesBuilder<'a> {
-    cgroup: CgroupBuilder<'a>,
+pub struct BlkIoResourcesBuilder {
+    cgroup: CgroupBuilder,
     throttling_iops: bool,
 }
 
-impl<'a> BlkIoResourcesBuilder<'a> {
-    gen_setter!(blkio, BlkIoController, set_weight, weight, Option<u16>);
-    gen_setter!(
-        blkio,
-        BlkIoController,
-        set_leaf_weight,
-        leaf_weight,
-        Option<u16>
-    );
+impl BlkIoResourcesBuilder {
+    gen_setter!(blkio, BlkIoController, set_weight, weight, u16);
+    gen_setter!(blkio, BlkIoController, set_leaf_weight, leaf_weight, u16);
 
     /// Set the weight of a certain device.
     pub fn weight_device(
@@ -334,8 +319,7 @@ impl<'a> BlkIoResourcesBuilder<'a> {
         minor: u64,
         weight: Option<u16>,
         leaf_weight: Option<u16>,
-    ) -> BlkIoResourcesBuilder<'a> {
-        self.cgroup.resources.blkio.update_values = true;
+    ) -> BlkIoResourcesBuilder {
         self.cgroup
             .resources
             .blkio
@@ -350,20 +334,19 @@ impl<'a> BlkIoResourcesBuilder<'a> {
     }
 
     /// Start configuring the I/O operations per second metric.
-    pub fn throttle_iops(mut self) -> BlkIoResourcesBuilder<'a> {
+    pub fn throttle_iops(mut self) -> BlkIoResourcesBuilder {
         self.throttling_iops = true;
         self
     }
 
     /// Start configuring the bytes per second metric.
-    pub fn throttle_bps(mut self) -> BlkIoResourcesBuilder<'a> {
+    pub fn throttle_bps(mut self) -> BlkIoResourcesBuilder {
         self.throttling_iops = false;
         self
     }
 
     /// Limit the read rate of the current metric for a certain device.
-    pub fn read(mut self, major: u64, minor: u64, rate: u64) -> BlkIoResourcesBuilder<'a> {
-        self.cgroup.resources.blkio.update_values = true;
+    pub fn read(mut self, major: u64, minor: u64, rate: u64) -> BlkIoResourcesBuilder {
         let throttle = BlkIoDeviceThrottleResource { major, minor, rate };
         if self.throttling_iops {
             self.cgroup
@@ -382,8 +365,7 @@ impl<'a> BlkIoResourcesBuilder<'a> {
     }
 
     /// Limit the write rate of the current metric for a certain device.
-    pub fn write(mut self, major: u64, minor: u64, rate: u64) -> BlkIoResourcesBuilder<'a> {
-        self.cgroup.resources.blkio.update_values = true;
+    pub fn write(mut self, major: u64, minor: u64, rate: u64) -> BlkIoResourcesBuilder {
         let throttle = BlkIoDeviceThrottleResource { major, minor, rate };
         if self.throttling_iops {
             self.cgroup
@@ -402,7 +384,7 @@ impl<'a> BlkIoResourcesBuilder<'a> {
     }
 
     /// Finish the construction of the blkio resources of a control group.
-    pub fn done(self) -> CgroupBuilder<'a> {
+    pub fn done(self) -> CgroupBuilder {
         self.cgroup
     }
 }

src/cpu.rs

@@ -15,11 +15,11 @@ use std::path::PathBuf;
 
 use crate::error::ErrorKind::*;
 use crate::error::*;
-use crate::{parse_max_value, read_i64_from};
+use crate::{parse_max_value, read_i64_from, read_u64_from};
 
 use crate::{
-    ControllIdentifier, ControllerInternal, Controllers, CpuResources, MaxValue, Resources,
-    Subsystem,
+    ControllIdentifier, ControllerInternal, Controllers, CpuResources, CustomizedAttribute,
+    MaxValue, Resources, Subsystem,
 };
 
 /// A controller that allows controlling the `cpu` subsystem of a Cgroup.
@@ -75,24 +75,15 @@ impl ControllerInternal for CpuController {
         // get the resources that apply to this controller
         let res: &CpuResources = &res.cpu;
 
-        if res.update_values {
-            let _ = self.set_shares(res.shares);
-            if self.shares()? != res.shares as u64 {
-                return Err(Error::new(ErrorKind::Other));
-            }
+        update_and_test!(self, set_shares, res.shares, shares);
+        update_and_test!(self, set_cfs_period, res.period, cfs_period);
+        update_and_test!(self, set_cfs_quota, res.quota, cfs_quota);
 
-            let _ = self.set_cfs_period(res.period);
-            if self.cfs_period()? != res.period as u64 {
-                return Err(Error::new(ErrorKind::Other));
-            }
+        res.attrs.iter().for_each(|(k, v)| {
+            let _ = self.set(k, v);
+        });
 
-            let _ = self.set_cfs_quota(res.quota);
-            if self.cfs_quota()? != res.quota {
-                return Err(Error::new(ErrorKind::Other));
-            }
-
-            // TODO: rt properties (CONFIG_RT_GROUP_SCHED) are not yet supported
-        }
+        // TODO: rt properties (CONFIG_RT_GROUP_SCHED) are not yet supported
 
         Ok(())
     }
@@ -111,31 +102,17 @@ impl<'a> From<&'a Subsystem> for &'a CpuController {
                 Subsystem::Cpu(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
     }
 }
 
-fn read_u64_from(mut file: File) -> Result<u64> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => string
-            .trim()
-            .parse()
-            .map_err(|e| Error::with_cause(ParseError, e)),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
 impl CpuController {
-    /// Contructs a new `CpuController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf, v2: bool) -> Self {
-        let mut root = oroot;
-        if !v2 {
-            root.push(Self::controller_type().to_string());
-        }
+    /// Contructs a new `CpuController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf, v2: bool) -> Self {
         Self {
             base: root.clone(),
             path: root,
@@ -305,6 +282,8 @@ impl CpuController {
     }
 }
 
+impl CustomizedAttribute for CpuController {}
+
 fn parse_cfs_quota_and_period(mut file: File) -> Result<CFSQuotaAndPeriod> {
     let mut content = String::new();
     file.read_to_string(&mut content)

src/cpuacct.rs

@@ -7,13 +7,13 @@
 //!
 //! See the Kernel's documentation for more information about this subsystem, found at:
 //!  [Documentation/cgroup-v1/cpuacct.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/cpuacct.txt)
-use std::fs::File;
-use std::io::{Read, Write};
+use std::io::Write;
 use std::path::PathBuf;
 
 use crate::error::ErrorKind::*;
 use crate::error::*;
 
+use crate::{read_string_from, read_u64_from};
 use crate::{ControllIdentifier, ControllerInternal, Controllers, Resources, Subsystem};
 
 /// A controller that allows controlling the `cpuacct` subsystem of a Cgroup.
@@ -89,38 +89,17 @@ impl<'a> From<&'a Subsystem> for &'a CpuAcctController {
                 Subsystem::CpuAcct(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
     }
 }
 
-fn read_u64_from(mut file: File) -> Result<u64> {
-    let mut string = String::new();
-    let res = file.read_to_string(&mut string);
-    match res {
-        Ok(_) => match string.trim().parse() {
-            Ok(e) => Ok(e),
-            Err(e) => Err(Error::with_cause(ParseError, e)),
-        },
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
-fn read_string_from(mut file: File) -> Result<String> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => Ok(string.trim().to_string()),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
 impl CpuAcctController {
-    /// Contructs a new `CpuAcctController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf) -> Self {
-        let mut root = oroot;
-        root.push(Self::controller_type().to_string());
+    /// Contructs a new `CpuAcctController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf) -> Self {
         Self {
             base: root.clone(),
             path: root,

src/cpuset.rs

@@ -10,13 +10,13 @@
 //!  [Documentation/cgroup-v1/cpusets.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/cpusets.txt)
 
 use log::*;
-use std::fs::File;
-use std::io::{Read, Write};
+use std::io::Write;
 use std::path::PathBuf;
 
 use crate::error::ErrorKind::*;
 use crate::error::*;
 
+use crate::{read_string_from, read_u64_from};
 use crate::{
     ControllIdentifier, ControllerInternal, Controllers, CpuResources, Resources, Subsystem,
 };
@@ -110,12 +110,8 @@ impl ControllerInternal for CpuSetController {
         // get the resources that apply to this controller
         let res: &CpuResources = &res.cpu;
 
-        if res.update_values {
-            if res.cpus.is_some() {
-                let _ = self.set_cpus(res.cpus.as_ref().unwrap().as_str());
-            }
-            let _ = self.set_mems(&res.mems);
-        }
+        update!(self, set_cpus, res.cpus.as_ref());
+        update!(self, set_mems, res.mems.as_ref());
 
         Ok(())
     }
@@ -125,10 +121,6 @@ impl ControllerInternal for CpuSetController {
             return;
         }
         let current = self.get_path();
-        let parent = match current.parent() {
-            Some(p) => p,
-            None => return,
-        };
 
         if current != self.get_base() {
             match copy_from_parent(current.to_str().unwrap(), "cpuset.cpus") {
@@ -204,32 +196,14 @@ impl<'a> From<&'a Subsystem> for &'a CpuSetController {
                 Subsystem::CpuSet(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
     }
 }
 
-fn read_string_from(mut file: File) -> Result<String> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => Ok(string.trim().to_string()),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
-fn read_u64_from(mut file: File) -> Result<u64> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => string
-            .trim()
-            .parse()
-            .map_err(|e| Error::with_cause(ParseError, e)),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
 /// Parse a string like "1,2,4-5,8" into a list of (start, end) tuples.
 fn parse_range(s: String) -> Result<Vec<(u64, u64)>> {
     let mut fin = Vec::new();
@@ -268,12 +242,8 @@ fn parse_range(s: String) -> Result<Vec<(u64, u64)>> {
 }
 
 impl CpuSetController {
-    /// Contructs a new `CpuSetController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf, v2: bool) -> Self {
-        let mut root = oroot;
-        if !v2 {
-            root.push(Self::controller_type().to_string());
-        }
+    /// Contructs a new `CpuSetController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf, v2: bool) -> Self {
         Self {
             base: root.clone(),
             path: root,

src/devices.rs

@@ -155,13 +155,11 @@ impl ControllerInternal for DevicesController {
         // get the resources that apply to this controller
         let res: &DeviceResources = &res.devices;
 
-        if res.update_values {
-            for i in &res.devices {
-                if i.allow {
-                    let _ = self.allow_device(i.devtype, i.major, i.minor, &i.access);
-                } else {
-                    let _ = self.deny_device(i.devtype, i.major, i.minor, &i.access);
-                }
+        for i in &res.devices {
+            if i.allow {
+                let _ = self.allow_device(i.devtype, i.major, i.minor, &i.access);
+            } else {
+                let _ = self.deny_device(i.devtype, i.major, i.minor, &i.access);
             }
         }
 
@@ -182,7 +180,8 @@ impl<'a> From<&'a Subsystem> for &'a DevicesController {
                 Subsystem::Devices(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
@@ -190,10 +189,8 @@ impl<'a> From<&'a Subsystem> for &'a DevicesController {
 }
 
 impl DevicesController {
-    /// Constructs a new `DevicesController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf) -> Self {
-        let mut root = oroot;
-        root.push(Self::controller_type().to_string());
+    /// Constructs a new `DevicesController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf) -> Self {
         Self {
             base: root.clone(),
             path: root,

src/error.rs

@@ -19,6 +19,9 @@ pub enum ErrorKind {
     /// An error occured while trying to read from a control group file.
     ReadFailed,
 
+    /// An error occured while trying to remove a control group.
+    RemoveFailed,
+
     /// An error occured while trying to parse a value from a control group file.
     ///
     /// In the future, there will be some information attached to this field.
@@ -45,7 +48,7 @@ pub enum ErrorKind {
 #[derive(Debug)]
 pub struct Error {
     kind: ErrorKind,
-    cause: Option<Box<StdError + Send + Sync>>,
+    cause: Option<Box<dyn StdError + Send + Sync>>,
 }
 
 impl fmt::Display for Error {
@@ -55,6 +58,7 @@ impl fmt::Display for Error {
             ErrorKind::Common(s) => s.clone(),
             ErrorKind::WriteFailed => "unable to write to a control group file".to_string(),
             ErrorKind::ReadFailed => "unable to read a control group file".to_string(),
+            ErrorKind::RemoveFailed => "unable to remove a control group".to_string(),
             ErrorKind::ParseError => "unable to parse control group file".to_string(),
             ErrorKind::InvalidOperation => "the requested operation is invalid".to_string(),
             ErrorKind::InvalidPath => "the given path is invalid".to_string(),
@@ -62,12 +66,16 @@ impl fmt::Display for Error {
             ErrorKind::Other => "an unknown error".to_string(),
         };
 
-        write!(f, "{}", msg)
+        if let Some(cause) = &self.cause {
+            write!(f, "{} caused by: {:?}", msg, cause)
+        } else {
+            write!(f, "{}", msg)
+        }
     }
 }
 
 impl StdError for Error {
-    fn cause(&self) -> Option<&StdError> {
+    fn cause(&self) -> Option<&dyn StdError> {
         match self.cause {
             Some(ref x) => Some(&**x),
             None => None,

src/events.rs

@@ -60,7 +60,7 @@ fn register_memory_event(
     }
 
     // write to file and set mode to 0700(FIXME)
-    fs::write(&event_control_path, data).map_err(|e| Error::with_cause(WriteFailed, e));
+    fs::write(&event_control_path, data).map_err(|e| Error::with_cause(WriteFailed, e))?;
 
     let mut eventfd_file = unsafe { File::from_raw_fd(eventfd) };
 
@@ -71,7 +71,7 @@ fn register_memory_event(
         loop {
             let mut buf = [0; 8];
             match eventfd_file.read(&mut buf) {
-                Err(err) => {
+                Err(_err) => {
                     return;
                 }
                 Ok(_) => {}

src/freezer.rs

@@ -73,7 +73,8 @@ impl<'a> From<&'a Subsystem> for &'a FreezerController {
                 Subsystem::Freezer(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
@@ -81,12 +82,8 @@ impl<'a> From<&'a Subsystem> for &'a FreezerController {
 }
 
 impl FreezerController {
-    /// Contructs a new `FreezerController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf, v2: bool) -> Self {
-        let mut root = oroot;
-        if !v2 {
-            root.push(Self::controller_type().to_string());
-        }
+    /// Contructs a new `FreezerController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf, v2: bool) -> Self {
         Self {
             base: root.clone(),
             path: root,

src/hierarchies.rs

@@ -8,14 +8,11 @@
 //!
 //! Currently, we only support the cgroupv1 hierarchy, but in the future we will add support for
 //! the Unified Hierarchy.
-use nix::sys::statfs;
 
-use std::fs::{self, File};
-use std::io::BufRead;
-use std::io::BufReader;
-use std::path::{Path, PathBuf};
-
-use log::*;
+use std::fs;
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+use std::path::PathBuf;
 
 use crate::blkio::BlkIoController;
 use crate::cpu::CpuController;
@@ -35,11 +32,82 @@ use crate::{Controllers, Hierarchy, Subsystem};
 
 use crate::cgroup::Cgroup;
 
-/// The standard, original cgroup implementation. Often referred to as "cgroupv1".
-pub struct V1 {
-    mount_point: String,
+/// Process mounts information.
+///
+/// See `proc(5)` for format details.
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub struct Mountinfo {
+    /// Mount pathname relative to the process's root.
+    pub mount_point: PathBuf,
+    /// Filesystem type (main type with optional sub-type).
+    pub fs_type: (String, Option<String>),
+    /// Superblock options.
+    pub super_opts: Vec<String>,
 }
 
+pub(crate) fn parse_mountinfo_for_line(line: &str) -> Option<Mountinfo> {
+    let s_values: Vec<_> = line.split(" - ").collect();
+    if s_values.len() != 2 {
+        return None;
+    }
+
+    let s0_values: Vec<_> = s_values[0].trim().split(' ').collect();
+    let s1_values: Vec<_> = s_values[1].trim().split(' ').collect();
+    if s0_values.len() < 6 || s1_values.len() < 3 {
+        return None;
+    }
+    let mount_point = PathBuf::from(s0_values[4]);
+    let fs_type_values: Vec<_> = s1_values[0].trim().split('.').collect();
+    let fs_type = match fs_type_values.len() {
+        1 => (fs_type_values[0].to_string(), None),
+        2 => (
+            fs_type_values[0].to_string(),
+            Some(fs_type_values[1].to_string()),
+        ),
+        _ => return None,
+    };
+
+    let super_opts: Vec<String> = s1_values[2].trim().split(',').map(String::from).collect();
+    Some(Mountinfo {
+        mount_point,
+        fs_type,
+        super_opts,
+    })
+}
+
+/// Parses the provided mountinfo file.
+fn mountinfo_file(file: &mut File) -> Vec<Mountinfo> {
+    let mut r = Vec::new();
+    for line in BufReader::new(file).lines() {
+        match line {
+            Ok(line) => {
+                if let Some(mi) = parse_mountinfo_for_line(&line) {
+                    if mi.fs_type.0 == "cgroup" {
+                        r.push(mi);
+                    }
+                }
+            }
+            Err(_) => continue,
+        }
+    }
+    r
+}
+
+/// Returns mounts information for the current process.
+pub fn mountinfo_self() -> Vec<Mountinfo> {
+    match File::open("/proc/self/mountinfo") {
+        Ok(mut file) => mountinfo_file(&mut file),
+        Err(_) => vec![],
+    }
+}
+
+/// The standard, original cgroup implementation. Often referred to as "cgroupv1".
+#[derive(Debug)]
+pub struct V1 {
+    mountinfo: Vec<Mountinfo>,
+}
+
+#[derive(Debug)]
 pub struct V2 {
     root: String,
 }
@@ -51,80 +119,71 @@ impl Hierarchy for V1 {
 
     fn subsystems(&self) -> Vec<Subsystem> {
         let mut subs = vec![];
-        if self.check_support(Controllers::Pids) {
-            subs.push(Subsystem::Pid(PidController::new(self.root(), false)));
+
+        // The cgroup writeback feature requires cooperation between memcgs and blkcgs
+        // To avoid exceptions, we should add_task for blkcg before memcg(push BlkIo before Mem)
+        // For more Information: https://www.alibabacloud.com/help/doc-detail/155509.htm
+        if let Some(root) = self.get_mount_point(Controllers::BlkIo) {
+            subs.push(Subsystem::BlkIo(BlkIoController::new(root, false)));
         }
-        if self.check_support(Controllers::Mem) {
-            subs.push(Subsystem::Mem(MemController::new(self.root(), false)));
+        if let Some(root) = self.get_mount_point(Controllers::Mem) {
+            subs.push(Subsystem::Mem(MemController::new(root, false)));
         }
-        if self.check_support(Controllers::CpuSet) {
-            subs.push(Subsystem::CpuSet(CpuSetController::new(self.root(), false)));
+        if let Some(root) = self.get_mount_point(Controllers::Pids) {
+            subs.push(Subsystem::Pid(PidController::new(root, false)));
         }
-        if self.check_support(Controllers::CpuAcct) {
-            subs.push(Subsystem::CpuAcct(CpuAcctController::new(self.root())));
+        if let Some(root) = self.get_mount_point(Controllers::CpuSet) {
+            subs.push(Subsystem::CpuSet(CpuSetController::new(root, false)));
         }
-        if self.check_support(Controllers::Cpu) {
-            subs.push(Subsystem::Cpu(CpuController::new(self.root(), false)));
+        if let Some(root) = self.get_mount_point(Controllers::CpuAcct) {
+            subs.push(Subsystem::CpuAcct(CpuAcctController::new(root)));
         }
-        if self.check_support(Controllers::Devices) {
-            subs.push(Subsystem::Devices(DevicesController::new(self.root())));
+        if let Some(root) = self.get_mount_point(Controllers::Cpu) {
+            subs.push(Subsystem::Cpu(CpuController::new(root, false)));
         }
-        if self.check_support(Controllers::Freezer) {
-            subs.push(Subsystem::Freezer(FreezerController::new(
-                self.root(),
-                false,
-            )));
+        if let Some(root) = self.get_mount_point(Controllers::Devices) {
+            subs.push(Subsystem::Devices(DevicesController::new(root)));
         }
-        if self.check_support(Controllers::NetCls) {
-            subs.push(Subsystem::NetCls(NetClsController::new(self.root())));
+        if let Some(root) = self.get_mount_point(Controllers::Freezer) {
+            subs.push(Subsystem::Freezer(FreezerController::new(root, false)));
         }
-        if self.check_support(Controllers::BlkIo) {
-            subs.push(Subsystem::BlkIo(BlkIoController::new(self.root(), false)));
+        if let Some(root) = self.get_mount_point(Controllers::NetCls) {
+            subs.push(Subsystem::NetCls(NetClsController::new(root)));
         }
-        if self.check_support(Controllers::PerfEvent) {
-            subs.push(Subsystem::PerfEvent(PerfEventController::new(self.root())));
+        if let Some(root) = self.get_mount_point(Controllers::PerfEvent) {
+            subs.push(Subsystem::PerfEvent(PerfEventController::new(root)));
         }
-        if self.check_support(Controllers::NetPrio) {
-            subs.push(Subsystem::NetPrio(NetPrioController::new(self.root())));
+        if let Some(root) = self.get_mount_point(Controllers::NetPrio) {
+            subs.push(Subsystem::NetPrio(NetPrioController::new(root)));
         }
-        if self.check_support(Controllers::HugeTlb) {
-            subs.push(Subsystem::HugeTlb(HugeTlbController::new(
-                self.root(),
-                false,
-            )));
+        if let Some(root) = self.get_mount_point(Controllers::HugeTlb) {
+            subs.push(Subsystem::HugeTlb(HugeTlbController::new(root, false)));
         }
-        if self.check_support(Controllers::Rdma) {
-            subs.push(Subsystem::Rdma(RdmaController::new(self.root())));
+        if let Some(root) = self.get_mount_point(Controllers::Rdma) {
+            subs.push(Subsystem::Rdma(RdmaController::new(root)));
         }
-        if self.check_support(Controllers::Systemd) {
-            subs.push(Subsystem::Systemd(SystemdController::new(
-                self.root(),
-                false,
-            )));
+        if let Some(root) = self.get_mount_point(Controllers::Systemd) {
+            subs.push(Subsystem::Systemd(SystemdController::new(root, false)));
         }
 
         subs
     }
 
     fn root_control_group(&self) -> Cgroup {
-        let b: &Hierarchy = self as &Hierarchy;
-        Cgroup::load(Box::new(&*b), "".to_string())
-    }
-
-    fn check_support(&self, sub: Controllers) -> bool {
-        let root = self.root().read_dir().unwrap();
-        for entry in root {
-            if let Ok(entry) = entry {
-                if entry.file_name().into_string().unwrap() == sub.to_string() {
-                    return true;
-                }
-            }
-        }
-        return false;
+        Cgroup::load(auto(), "".to_string())
     }
 
     fn root(&self) -> PathBuf {
-        PathBuf::from(self.mount_point.clone())
+        self.mountinfo
+            .iter()
+            .find_map(|m| {
+                if m.fs_type.0 == "cgroup" {
+                    return Some(m.mount_point.parent().unwrap());
+                }
+                None
+            })
+            .unwrap()
+            .to_path_buf()
     }
 }
 
@@ -182,12 +241,7 @@ impl Hierarchy for V2 {
     }
 
     fn root_control_group(&self) -> Cgroup {
-        let b: &Hierarchy = self as &Hierarchy;
-        Cgroup::load(Box::new(&*b), "".to_string())
-    }
-
-    fn check_support(&self, _sub: Controllers) -> bool {
-        return false;
+        Cgroup::load(auto(), "".to_string())
     }
 
     fn root(&self) -> PathBuf {
@@ -199,11 +253,19 @@ impl V1 {
     /// Finds where control groups are mounted to and returns a hierarchy in which control groups
     /// can be created.
     pub fn new() -> V1 {
-        let mount_point = find_v1_mount().unwrap();
         V1 {
-            mount_point: mount_point,
+            mountinfo: mountinfo_self(),
         }
     }
+
+    pub fn get_mount_point(&self, controller: Controllers) -> Option<PathBuf> {
+        self.mountinfo.iter().find_map(|m| {
+            if m.fs_type.0 == "cgroup" && m.super_opts.contains(&controller.to_string()) {
+                return Some(m.mount_point.clone());
+            }
+            None
+        })
+    }
 }
 
 impl V2 {
@@ -220,7 +282,9 @@ pub const UNIFIED_MOUNTPOINT: &'static str = "/sys/fs/cgroup";
 
 #[cfg(all(target_os = "linux", not(target_env = "musl")))]
 pub fn is_cgroup2_unified_mode() -> bool {
-    let path = Path::new(UNIFIED_MOUNTPOINT);
+    use nix::sys::statfs;
+
+    let path = std::path::Path::new(UNIFIED_MOUNTPOINT);
     let fs_stat = statfs::statfs(path);
     if fs_stat.is_err() {
         return false;
@@ -260,39 +324,35 @@ pub fn auto() -> Box<dyn Hierarchy> {
     }
 }
 
-fn find_v1_mount() -> Option<String> {
-    // Open mountinfo so we can get a parseable mount list
-    let mountinfo_path = Path::new("/proc/self/mountinfo");
+#[cfg(test)]
+mod tests {
+    use super::*;
 
-    // If /proc isn't mounted, or something else happens, then bail out
-    if mountinfo_path.exists() == false {
-        return None;
-    }
+    #[test]
+    fn test_parse_mount() {
+        let mountinfo = vec![
+            ("29 26 0:26 / /sys/fs/cgroup/cpuset,cpu,cpuacct rw,nosuid,nodev,noexec,relatime shared:10 - cgroup cgroup rw,cpuset,cpu,cpuacct",
+             Mountinfo{mount_point: PathBuf::from("/sys/fs/cgroup/cpuset,cpu,cpuacct"), fs_type: ("cgroup".to_string(), None), super_opts: vec![
+                "rw".to_string(),
+                "cpuset".to_string(),
+                "cpu".to_string(),
+                "cpuacct".to_string(),
+             ]}),
+            ("121 1731 0:42 / /shm rw,nosuid,nodev,noexec,relatime shared:68 master:66 - tmpfs shm rw,size=65536k",
+             Mountinfo{mount_point: PathBuf::from("/shm"), fs_type: ("tmpfs".to_string(), None), super_opts: vec![
+                "rw".to_string(),
+                "size=65536k".to_string(),
+             ]}),
+            ("121 1731 0:42 / /shm rw,nosuid,nodev,noexec,relatime shared:68 master:66 - tmpfs.123 shm rw,size=65536k",
+             Mountinfo{mount_point: PathBuf::from("/shm"), fs_type: ("tmpfs".to_string(), Some("123".to_string())), super_opts: vec![
+                "rw".to_string(),
+                "size=65536k".to_string(),
+             ]}),
+        ];
 
-    let mountinfo_file = File::open(mountinfo_path).unwrap();
-    let mountinfo_reader = BufReader::new(&mountinfo_file);
-    for _line in mountinfo_reader.lines() {
-        let line = _line.unwrap();
-        let mut fields = line.split_whitespace();
-        let index = line.find(" - ").unwrap();
-        let more_fields = line[index + 3..].split_whitespace().collect::<Vec<_>>();
-        if more_fields.len() == 0 {
-            continue;
-        }
-        if more_fields[0] == "cgroup" {
-            if more_fields.len() < 3 {
-                continue;
-            }
-            let cgroups_mount = fields.nth(4).unwrap();
-            if let Some(parent) = std::path::Path::new(cgroups_mount).parent() {
-                if let Some(path) = parent.as_os_str().to_str() {
-                    debug!("found cgroups {:?} from {:?}", path, cgroups_mount);
-                    return Some(path.to_string());
-                }
-            }
-            continue;
+        for mi in mountinfo {
+            let info = parse_mountinfo_for_line(mi.0).unwrap();
+            assert_eq!(info, mi.1)
         }
     }
-
-    None
 }

src/hugetlb.rs

@@ -8,13 +8,12 @@
 //!
 //! See the Kernel's documentation for more information about this subsystem, found at:
 //!  [Documentation/cgroup-v1/hugetlb.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/hugetlb.txt)
-use std::fs::File;
-use std::io::{Read, Write};
+use std::io::Write;
 use std::path::PathBuf;
 
 use crate::error::ErrorKind::*;
 use crate::error::*;
-use crate::flat_keyed_to_vec;
+use crate::{flat_keyed_to_vec, read_u64_from};
 
 use crate::{
     ControllIdentifier, ControllerInternal, Controllers, HugePageResources, Resources, Subsystem,
@@ -54,14 +53,13 @@ impl ControllerInternal for HugeTlbController {
         // get the resources that apply to this controller
         let res: &HugePageResources = &res.hugepages;
 
-        if res.update_values {
-            for i in &res.limits {
-                let _ = self.set_limit_in_bytes(&i.size, i.limit);
-                if self.limit_in_bytes(&i.size)? != i.limit {
-                    return Err(Error::new(Other));
-                }
+        for i in &res.limits {
+            let _ = self.set_limit_in_bytes(&i.size, i.limit);
+            if self.limit_in_bytes(&i.size)? != i.limit {
+                return Err(Error::new(Other));
             }
         }
+
         Ok(())
     }
 }
@@ -79,31 +77,17 @@ impl<'a> From<&'a Subsystem> for &'a HugeTlbController {
                 Subsystem::HugeTlb(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
     }
 }
 
-fn read_u64_from(mut file: File) -> Result<u64> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => string
-            .trim()
-            .parse()
-            .map_err(|e| Error::with_cause(ParseError, e)),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
 impl HugeTlbController {
-    /// Constructs a new `HugeTlbController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf, v2: bool) -> Self {
-        let mut root = oroot;
-        if !v2 {
-            root.push(Self::controller_type().to_string());
-        }
+    /// Constructs a new `HugeTlbController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf, v2: bool) -> Self {
         let sizes = get_hugepage_sizes().unwrap();
         Self {
             base: root.clone(),
@@ -225,10 +209,15 @@ pub const GB: u128 = 1000 * MB;
 pub const TB: u128 = 1000 * GB;
 pub const PB: u128 = 1000 * TB;
 
+#[allow(non_upper_case_globals)]
 pub const KiB: u128 = 1024;
+#[allow(non_upper_case_globals)]
 pub const MiB: u128 = 1024 * KiB;
+#[allow(non_upper_case_globals)]
 pub const GiB: u128 = 1024 * MiB;
+#[allow(non_upper_case_globals)]
 pub const TiB: u128 = 1024 * GiB;
+#[allow(non_upper_case_globals)]
 pub const PiB: u128 = 1024 * TiB;
 
 pub fn get_binary_size_map() -> HashMap<String, u128> {

src/lib.rs

@@ -7,9 +7,29 @@
 use log::*;
 
 use std::collections::HashMap;
-use std::fs::File;
+use std::fs::{self, File};
 use std::io::{BufRead, BufReader, Read, Write};
 use std::path::{Path, PathBuf};
+use std::str::FromStr;
+
+macro_rules! update_and_test {
+    ($self: ident, $set_func:ident, $value:expr, $get_func:ident) => {
+        if let Some(v) = $value {
+            $self.$set_func(v)?;
+            if $self.$get_func()? != v {
+                return Err(Error::new(Other));
+            }
+        }
+    };
+}
+
+macro_rules! update {
+    ($self: ident, $set_func:ident, $value:expr) => {
+        if let Some(v) = $value {
+            let _ = $self.$set_func(v);
+        }
+    };
+}
 
 pub mod blkio;
 pub mod cgroup;
@@ -48,10 +68,11 @@ use crate::pid::PidController;
 use crate::rdma::RdmaController;
 use crate::systemd::SystemdController;
 
+#[doc(inline)]
 pub use crate::cgroup::Cgroup;
 
 /// Contains all the subsystems that are available in this crate.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum Subsystem {
     /// Controller for the `Pid` subsystem, see `PidController` for more information.
     Pid(PidController),
@@ -84,7 +105,7 @@ pub enum Subsystem {
 }
 
 #[doc(hidden)]
-#[derive(Eq, PartialEq, Debug)]
+#[derive(Eq, PartialEq, Debug, Clone)]
 pub enum Controllers {
     Pids,
     Mem,
@@ -118,7 +139,7 @@ impl Controllers {
             Controllers::NetPrio => return "net_prio".to_string(),
             Controllers::HugeTlb => return "hugetlb".to_string(),
             Controllers::Rdma => return "rdma".to_string(),
-            Controllers::Systemd => return "systemd".to_string(),
+            Controllers::Systemd => return "name=systemd".to_string(),
         }
     }
 }
@@ -189,9 +210,28 @@ mod sealed {
             std::path::Path::new(p).exists()
         }
     }
+
+    pub trait CustomizedAttribute: ControllerInternal {
+        fn set(&self, key: &str, value: &str) -> Result<()> {
+            self.open_path(key, true).and_then(|mut file| {
+                file.write_all(value.as_ref())
+                    .map_err(|e| Error::with_cause(WriteFailed, e))
+            })
+        }
+
+        fn get(&self, key: &str) -> Result<String> {
+            self.open_path(key, false).and_then(|mut file: File| {
+                let mut string = String::new();
+                match file.read_to_string(&mut string) {
+                    Ok(_) => Ok(string.trim().to_owned()),
+                    Err(e) => Err(Error::with_cause(ReadFailed, e)),
+                }
+            })
+        }
+    }
 }
 
-pub(crate) use crate::sealed::ControllerInternal;
+pub(crate) use crate::sealed::{ControllerInternal, CustomizedAttribute};
 
 /// A Controller is a subsystem attached to the control group.
 ///
@@ -213,12 +253,21 @@ 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);
+    fn delete(&self) -> Result<()>;
 
     /// Attach a task to this controller.
     fn add_task(&self, pid: &CgroupPid) -> Result<()>;
 
+    /// Attach a task to this controller.
+    fn add_task_by_tgid(&self, pid: &CgroupPid) -> Result<()>;
+
     /// Get the list of tasks that this controller has.
     fn tasks(&self) -> Vec<CgroupPid>;
 
@@ -250,20 +299,38 @@ where
 
         match ::std::fs::create_dir_all(self.get_path()) {
             Ok(_) => self.post_create(),
-            Err(e) => warn!("error create_dir {:?}", e),
+            Err(e) => warn!("error create_dir: {:?} error: {:?}", self.get_path(), e),
         }
     }
 
+    /// 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()
     }
 
     /// Delete the controller.
-    fn delete(&self) {
-        if self.get_path().exists() {
-            libc_rmdir(self.get_path().to_str().unwrap());
+    fn delete(&self) -> Result<()> {
+        if !self.get_path().exists() {
+            return Ok(());
         }
+
+        remove_dir(self.get_path())
     }
 
     /// Attach a task to this controller.
@@ -278,6 +345,14 @@ where
         })
     }
 
+    /// Attach a task to this controller by thread group id.
+    fn add_task_by_tgid(&self, pid: &CgroupPid) -> Result<()> {
+        self.open_path("cgroup.procs", true).and_then(|mut file| {
+            file.write_all(pid.pid.to_string().as_ref())
+                .map_err(|e| Error::with_cause(ErrorKind::WriteFailed, e))
+        })
+    }
+
     /// Get the list of tasks that this controller has.
     fn tasks(&self) -> Vec<CgroupPid> {
         let mut file = "tasks";
@@ -304,6 +379,30 @@ where
     }
 }
 
+// remove_dir aims to remove cgroup path. It does so recursively,
+// by removing any subdirectories (sub-cgroups) first.
+fn remove_dir(dir: &PathBuf) -> Result<()> {
+    // try the fast path first.
+    if fs::remove_dir(dir).is_ok() {
+        return Ok(());
+    }
+
+    if dir.exists() {
+        if dir.is_dir() {
+            for entry in fs::read_dir(dir).map_err(|e| Error::with_cause(ReadFailed, e))? {
+                let entry = entry.map_err(|e| Error::with_cause(ReadFailed, e))?;
+                let path = entry.path();
+                if path.is_dir() {
+                    remove_dir(&path)?;
+                }
+            }
+            fs::remove_dir(dir).map_err(|e| Error::with_cause(RemoveFailed, e))?;
+        }
+    }
+
+    Ok(())
+}
+
 #[doc(hidden)]
 pub trait ControllIdentifier {
     fn controller_type() -> Controllers;
@@ -311,7 +410,7 @@ pub trait ControllIdentifier {
 
 /// Control group hierarchy (right now, only V1 is supported, but in the future Unified will be
 /// implemented as well).
-pub trait Hierarchy {
+pub trait Hierarchy: std::fmt::Debug + Send + Sync {
     /// Returns what subsystems are supported by the hierarchy.
     fn subsystems(&self) -> Vec<Subsystem>;
 
@@ -322,75 +421,79 @@ pub trait Hierarchy {
     fn root_control_group(&self) -> Cgroup;
 
     fn v2(&self) -> bool;
-
-    /// Checks whether a certain subsystem is supported in the hierarchy.
-    ///
-    /// This is an internal function and should not be used.
-    #[doc(hidden)]
-    fn check_support(&self, sub: Controllers) -> bool;
 }
 
 /// Resource limits for the memory subsystem.
 #[derive(Debug, Clone, Eq, PartialEq, Default)]
 pub struct MemoryResources {
-    /// Whether values should be applied to the controller.
-    pub update_values: bool,
     /// How much memory (in bytes) can the kernel consume.
-    pub kernel_memory_limit: i64,
+    pub kernel_memory_limit: Option<i64>,
     /// Upper limit of memory usage of the control group's tasks.
-    pub memory_hard_limit: i64,
+    pub memory_hard_limit: Option<i64>,
     /// How much memory the tasks in the control group can use when the system is under memory
     /// pressure.
-    pub memory_soft_limit: i64,
+    pub memory_soft_limit: Option<i64>,
     /// How much of the kernel's memory (in bytes) can be used for TCP-related buffers.
-    pub kernel_tcp_memory_limit: i64,
+    pub kernel_tcp_memory_limit: Option<i64>,
     /// How much memory and swap together can the tasks in the control group use.
-    pub memory_swap_limit: i64,
+    pub memory_swap_limit: Option<i64>,
     /// Controls the tendency of the kernel to swap out parts of the address space of the tasks to
     /// disk. Lower value implies less likely.
     ///
     /// Note, however, that a value of zero does not mean the process is never swapped out. Use the
     /// traditional `mlock(2)` system call for that purpose.
-    pub swappiness: u64,
+    pub swappiness: Option<u64>,
+    /// Customized key-value attributes
+    ///
+    /// # Usage:
+    /// ```
+    /// let resource = &mut cgroups_rs::Resources::default();
+    /// resource.memory.attrs.insert("memory.numa_balancing", "true".to_string());
+    /// // apply here
+    pub attrs: std::collections::HashMap<&'static str, String>,
 }
 
 /// Resources limits on the number of processes.
 #[derive(Debug, Clone, Eq, PartialEq, Default)]
 pub struct PidResources {
-    /// Whether values should be applied to the controller.
-    pub update_values: bool,
     /// The maximum number of processes that can exist in the control group.
     ///
     /// Note that attaching processes to the control group will still succeed _even_ if the limit
     /// would be violated, however forks/clones inside the control group will have with `EAGAIN` if
     /// they would violate the limit set here.
-    pub maximum_number_of_processes: MaxValue,
+    pub maximum_number_of_processes: Option<MaxValue>,
 }
 
 /// Resources limits about how the tasks can use the CPU.
 #[derive(Debug, Clone, Eq, PartialEq, Default)]
 pub struct CpuResources {
-    /// Whether values should be applied to the controller.
-    pub update_values: bool,
     // cpuset
     /// A comma-separated list of CPU IDs where the task in the control group can run. Dashes
     /// between numbers indicate ranges.
     pub cpus: Option<String>,
     /// Same syntax as the `cpus` field of this structure, but applies to memory nodes instead of
     /// processors.
-    pub mems: String,
+    pub mems: Option<String>,
     // cpu
     /// Weight of how much of the total CPU time should this control group get. Note that this is
     /// hierarchical, so this is weighted against the siblings of this control group.
-    pub shares: u64,
+    pub shares: Option<u64>,
     /// In one `period`, how much can the tasks run in nanoseconds.
-    pub quota: i64,
+    pub quota: Option<i64>,
     /// Period of time in nanoseconds.
-    pub period: u64,
+    pub period: Option<u64>,
     /// This is currently a no-operation.
-    pub realtime_runtime: i64,
+    pub realtime_runtime: Option<i64>,
     /// This is currently a no-operation.
-    pub realtime_period: u64,
+    pub realtime_period: Option<u64>,
+    /// Customized key-value attributes
+    /// # Usage:
+    /// ```
+    /// let resource = &mut cgroups_rs::Resources::default();
+    /// resource.cpu.attrs.insert("cpu.cfs_init_buffer_us", "10".to_string());
+    /// // apply here
+    /// ```
+    pub attrs: std::collections::HashMap<&'static str, String>,
 }
 
 /// A device resource that can be allowed or denied access to.
@@ -411,8 +514,6 @@ pub struct DeviceResource {
 /// Limit the usage of devices for the control group's tasks.
 #[derive(Debug, Clone, Eq, PartialEq, Default)]
 pub struct DeviceResources {
-    /// Whether values should be applied to the controller.
-    pub update_values: bool,
     /// For each device in the list, the limits in the structure are applied.
     pub devices: Vec<DeviceResource>,
 }
@@ -430,12 +531,10 @@ pub struct NetworkPriority {
 /// control group.
 #[derive(Debug, Clone, Eq, PartialEq, Default)]
 pub struct NetworkResources {
-    /// Whether values should be applied to the controller.
-    pub update_values: bool,
     /// The networking class identifier to attach to the packets.
     ///
     /// This can then later be used in iptables and such to have special rules.
-    pub class_id: u64,
+    pub class_id: Option<u64>,
     /// Priority of the egress traffic for each interface.
     pub priorities: Vec<NetworkPriority>,
 }
@@ -453,8 +552,6 @@ pub struct HugePageResource {
 /// Provides the ability to set consumption limit on each type of hugepages.
 #[derive(Debug, Clone, Eq, PartialEq, Default)]
 pub struct HugePageResources {
-    /// Whether values should be applied to the controller.
-    pub update_values: bool,
     /// Set a limit of consumption for each hugepages type.
     pub limits: Vec<HugePageResource>,
 }
@@ -486,8 +583,6 @@ pub struct BlkIoDeviceThrottleResource {
 /// General block I/O resource limits.
 #[derive(Debug, Clone, Eq, PartialEq, Default)]
 pub struct BlkIoResources {
-    /// Whether values should be applied to the controller.
-    pub update_values: bool,
     /// The weight of the control group against descendant nodes.
     pub weight: Option<u16>,
     /// The weight of the control group against sibling nodes.
@@ -619,7 +714,7 @@ impl Subsystem {
         }
     }
 
-    fn to_controller(&self) -> &dyn Controller {
+    pub fn to_controller(&self) -> &dyn Controller {
         match self {
             Subsystem::Pid(cont) => cont,
             Subsystem::Mem(cont) => cont,
@@ -638,7 +733,7 @@ impl Subsystem {
         }
     }
 
-    fn controller_name(&self) -> String {
+    pub fn controller_name(&self) -> String {
         self.to_controller().control_type().to_string()
     }
 }
@@ -762,21 +857,35 @@ pub fn nested_keyed_to_hashmap(mut file: File) -> Result<HashMap<String, HashMap
     Ok(h)
 }
 
-/// fs::remove_dir_all or fs::remove_dir can't work with cgroup directory sometimes.
-/// with error: `Os { code: 1, kind: PermissionDenied, message: "Operation not permitted" }`
-pub fn libc_rmdir(p: &str) {
-    // with int return value
-    let _ = unsafe { libc::rmdir(p.as_ptr() as *const i8) };
-}
-
-/// read and parse an i64 data
-pub fn read_i64_from(mut file: File) -> Result<i64> {
+fn read_from<T>(mut file: File) -> Result<T>
+where
+    T: FromStr,
+    <T as FromStr>::Err: 'static + Send + Sync + std::error::Error,
+{
     let mut string = String::new();
     match file.read_to_string(&mut string) {
         Ok(_) => string
             .trim()
-            .parse()
+            .parse::<T>()
             .map_err(|e| Error::with_cause(ParseError, e)),
         Err(e) => Err(Error::with_cause(ReadFailed, e)),
     }
 }
+
+fn read_string_from(mut file: File) -> Result<String> {
+    let mut string = String::new();
+    match file.read_to_string(&mut string) {
+        Ok(_) => Ok(string.trim().to_string()),
+        Err(e) => Err(Error::with_cause(ReadFailed, e)),
+    }
+}
+
+/// read and parse an u64 data
+fn read_u64_from(file: File) -> Result<u64> {
+    read_from::<u64>(file)
+}
+
+/// read and parse an i64 data
+fn read_i64_from(file: File) -> Result<i64> {
+    read_from::<i64>(file)
+}

src/memory.rs

@@ -9,20 +9,20 @@
 //! See the Kernel's documentation for more information about this subsystem, found at:
 //!  [Documentation/cgroup-v1/memory.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/memory.txt)
 use std::collections::HashMap;
-use std::fs::File;
-use std::io::{Read, Write};
+use std::io::Write;
 use std::path::PathBuf;
 use std::sync::mpsc::Receiver;
 
 use crate::error::ErrorKind::*;
 use crate::error::*;
 use crate::events;
+use crate::{read_i64_from, read_string_from, read_u64_from};
 
 use crate::flat_keyed_to_hashmap;
 
 use crate::{
-    ControllIdentifier, ControllerInternal, Controllers, MaxValue, MemoryResources, Resources,
-    Subsystem,
+    ControllIdentifier, ControllerInternal, Controllers, CustomizedAttribute, MaxValue,
+    MemoryResources, Resources, Subsystem,
 };
 
 /// A controller that allows controlling the `memory` subsystem of a Cgroup.
@@ -453,26 +453,24 @@ impl ControllerInternal for MemController {
         // get the resources that apply to this controller
         let memres: &MemoryResources = &res.memory;
 
-        if memres.update_values {
-            let _ = self.set_limit(memres.memory_hard_limit);
-            let _ = self.set_soft_limit(memres.memory_soft_limit);
-            let _ = self.set_kmem_limit(memres.kernel_memory_limit);
-            let _ = self.set_memswap_limit(memres.memory_swap_limit);
-            let _ = self.set_tcp_limit(memres.kernel_tcp_memory_limit);
-            let _ = self.set_swappiness(memres.swappiness);
-        }
+        update!(self, set_limit, memres.memory_hard_limit);
+        update!(self, set_soft_limit, memres.memory_soft_limit);
+        update!(self, set_kmem_limit, memres.kernel_memory_limit);
+        update!(self, set_memswap_limit, memres.memory_swap_limit);
+        update!(self, set_tcp_limit, memres.kernel_tcp_memory_limit);
+        update!(self, set_swappiness, memres.swappiness);
+
+        memres.attrs.iter().for_each(|(k, v)| {
+            let _ = self.set(k, v);
+        });
 
         Ok(())
     }
 }
 
 impl MemController {
-    /// Contructs a new `MemController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf, v2: bool) -> Self {
-        let mut root = oroot;
-        if !v2 {
-            root.push(Self::controller_type().to_string());
-        }
+    /// Contructs a new `MemController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf, v2: bool) -> Self {
         Self {
             base: root.clone(),
             path: root,
@@ -505,10 +503,11 @@ impl MemController {
     // for v2
     pub fn get_mem(&self) -> Result<SetMemory> {
         let mut m: SetMemory = Default::default();
-        self.get_max_value("memory.high").map(|x| m.high = Some(x));
-        self.get_max_value("memory.low").map(|x| m.low = Some(x));
-        self.get_max_value("memory.max").map(|x| m.max = Some(x));
-        self.get_max_value("memory.min").map(|x| m.min = Some(x));
+        self.get_max_value("memory.high")
+            .map(|x| m.high = Some(x))?;
+        self.get_max_value("memory.low").map(|x| m.low = Some(x))?;
+        self.get_max_value("memory.max").map(|x| m.max = Some(x))?;
+        self.get_max_value("memory.min").map(|x| m.min = Some(x))?;
 
         Ok(m)
     }
@@ -707,6 +706,11 @@ impl MemController {
 
     /// Reset the kernel memory fail counter
     pub fn reset_kmem_fail_count(&self) -> Result<()> {
+        // Ignore kmem because there is no kmem in cgroup v2
+        if self.v2 {
+            return Ok(());
+        }
+
         self.open_path("memory.kmem.failcnt", true)
             .and_then(|mut file| {
                 file.write_all("0".to_string().as_ref())
@@ -716,6 +720,11 @@ impl MemController {
 
     /// Reset the TCP related fail counter
     pub fn reset_tcp_fail_count(&self) -> Result<()> {
+        // Ignore kmem because there is no kmem in cgroup v2
+        if self.v2 {
+            return Ok(());
+        }
+
         self.open_path("memory.kmem.tcp.failcnt", true)
             .and_then(|mut file| {
                 file.write_all("0".to_string().as_ref())
@@ -732,6 +741,15 @@ impl MemController {
             })
     }
 
+    /// Reset the max memory usage recorded
+    pub fn reset_max_usage(&self) -> Result<()> {
+        self.open_path("memory.max_usage_in_bytes", true)
+            .and_then(|mut file| {
+                file.write_all("0".to_string().as_ref())
+                    .map_err(|e| Error::with_cause(WriteFailed, e))
+            })
+    }
+
     /// Set the memory usage limit of the control group, in bytes.
     pub fn set_limit(&self, limit: i64) -> Result<()> {
         let mut file = "memory.limit_in_bytes";
@@ -746,6 +764,11 @@ impl MemController {
 
     /// Set the kernel memory limit of the control group, in bytes.
     pub fn set_kmem_limit(&self, limit: i64) -> Result<()> {
+        // Ignore kmem because there is no kmem in cgroup v2
+        if self.v2 {
+            return Ok(());
+        }
+
         self.open_path("memory.kmem.limit_in_bytes", true)
             .and_then(|mut file| {
                 file.write_all(limit.to_string().as_ref())
@@ -767,6 +790,11 @@ impl MemController {
 
     /// Set how much kernel memory can be used for TCP-related buffers by the control group.
     pub fn set_tcp_limit(&self, limit: i64) -> Result<()> {
+        // Ignore kmem because there is no kmem in cgroup v2
+        if self.v2 {
+            return Ok(());
+        }
+
         self.open_path("memory.kmem.tcp.limit_in_bytes", true)
             .and_then(|mut file| {
                 file.write_all(limit.to_string().as_ref())
@@ -794,11 +822,15 @@ impl MemController {
     ///
     /// Note that a value of zero does not imply that the process will not be swapped out.
     pub fn set_swappiness(&self, swp: u64) -> Result<()> {
-        self.open_path("memory.swappiness", true)
-            .and_then(|mut file| {
-                file.write_all(swp.to_string().as_ref())
-                    .map_err(|e| Error::with_cause(WriteFailed, e))
-            })
+        let mut file = "memory.swappiness";
+        if self.v2 {
+            file = "memory.swap.max"
+        }
+
+        self.open_path(file, true).and_then(|mut file| {
+            file.write_all(swp.to_string().as_ref())
+                .map_err(|e| Error::with_cause(WriteFailed, e))
+        })
     }
 
     pub fn disable_oom_killer(&self) -> Result<()> {
@@ -824,6 +856,8 @@ impl ControllIdentifier for MemController {
     }
 }
 
+impl CustomizedAttribute for MemController {}
+
 impl<'a> From<&'a Subsystem> for &'a MemController {
     fn from(sub: &'a Subsystem) -> &'a MemController {
         unsafe {
@@ -831,50 +865,19 @@ impl<'a> From<&'a Subsystem> for &'a MemController {
                 Subsystem::Mem(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
     }
 }
 
-fn read_u64_from(mut file: File) -> Result<u64> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => string
-            .trim()
-            .parse()
-            .map_err(|e| Error::with_cause(ParseError, e)),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
-fn read_i64_from(mut file: File) -> Result<i64> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => string
-            .trim()
-            .parse()
-            .map_err(|e| Error::with_cause(ParseError, e)),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
-fn read_string_from(mut file: File) -> Result<String> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => Ok(string.trim().to_string()),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use crate::memory::{
         parse_memory_stat, parse_numa_stat, parse_oom_control, MemoryStat, NumaStat, OomControl,
     };
-    use std::collections::HashMap;
-
     static GOOD_VALUE: &str = "\
 total=51189 N0=51189 N1=123
 file=50175 N0=50175 N1=123

src/net_cls.rs

@@ -7,13 +7,13 @@
 //!
 //! See the Kernel's documentation for more information about this subsystem, found at:
 //!  [Documentation/cgroup-v1/net_cls.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/net_cls.txt)
-use std::fs::File;
-use std::io::{Read, Write};
+use std::io::Write;
 use std::path::PathBuf;
 
 use crate::error::ErrorKind::*;
 use crate::error::*;
 
+use crate::read_u64_from;
 use crate::{
     ControllIdentifier, ControllerInternal, Controllers, NetworkResources, Resources, Subsystem,
 };
@@ -47,12 +47,8 @@ impl ControllerInternal for NetClsController {
         // get the resources that apply to this controller
         let res: &NetworkResources = &res.network;
 
-        if res.update_values {
-            let _ = self.set_class(res.class_id);
-            if self.get_class()? != res.class_id {
-                return Err(Error::new(Other));
-            }
-        }
+        update_and_test!(self, set_class, res.class_id, get_class);
+
         return Ok(());
     }
 }
@@ -70,29 +66,17 @@ impl<'a> From<&'a Subsystem> for &'a NetClsController {
                 Subsystem::NetCls(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
     }
 }
 
-fn read_u64_from(mut file: File) -> Result<u64> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => string
-            .trim()
-            .parse()
-            .map_err(|e| Error::with_cause(ParseError, e)),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
 impl NetClsController {
-    /// Constructs a new `NetClsController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf) -> Self {
-        let mut root = oroot;
-        root.push(Self::controller_type().to_string());
+    /// Constructs a new `NetClsController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf) -> Self {
         Self {
             base: root.clone(),
             path: root,

src/net_prio.rs

@@ -8,13 +8,13 @@
 //! See the Kernel's documentation for more information about this subsystem, found at:
 //!  [Documentation/cgroup-v1/net_prio.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/net_prio.txt)
 use std::collections::HashMap;
-use std::fs::File;
-use std::io::{BufRead, BufReader, Read, Write};
+use std::io::{BufRead, BufReader, Write};
 use std::path::PathBuf;
 
 use crate::error::ErrorKind::*;
 use crate::error::*;
 
+use crate::read_u64_from;
 use crate::{
     ControllIdentifier, ControllerInternal, Controllers, NetworkResources, Resources, Subsystem,
 };
@@ -48,10 +48,8 @@ impl ControllerInternal for NetPrioController {
         // get the resources that apply to this controller
         let res: &NetworkResources = &res.network;
 
-        if res.update_values {
-            for i in &res.priorities {
-                let _ = self.set_if_prio(&i.name, i.priority);
-            }
+        for i in &res.priorities {
+            let _ = self.set_if_prio(&i.name, i.priority);
         }
 
         Ok(())
@@ -71,29 +69,17 @@ impl<'a> From<&'a Subsystem> for &'a NetPrioController {
                 Subsystem::NetPrio(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
     }
 }
 
-fn read_u64_from(mut file: File) -> Result<u64> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => string
-            .trim()
-            .parse()
-            .map_err(|e| Error::with_cause(ParseError, e)),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
 impl NetPrioController {
-    /// Constructs a new `NetPrioController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf) -> Self {
-        let mut root = oroot;
-        root.push(Self::controller_type().to_string());
+    /// Constructs a new `NetPrioController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf) -> Self {
         Self {
             base: root.clone(),
             path: root,

src/perf_event.rs

@@ -55,7 +55,8 @@ impl<'a> From<&'a Subsystem> for &'a PerfEventController {
                 Subsystem::PerfEvent(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
@@ -63,10 +64,8 @@ impl<'a> From<&'a Subsystem> for &'a PerfEventController {
 }
 
 impl PerfEventController {
-    /// Constructs a new `PerfEventController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf) -> Self {
-        let mut root = oroot;
-        root.push(Self::controller_type().to_string());
+    /// Constructs a new `PerfEventController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf) -> Self {
         Self {
             base: root.clone(),
             path: root,

src/pid.rs

@@ -8,13 +8,13 @@
 //!
 //! See the Kernel's documentation for more information about this subsystem, found at:
 //!  [Documentation/cgroups-v1/pids.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/pids.txt)
-use std::fs::File;
 use std::io::{Read, Write};
 use std::path::PathBuf;
 
 use crate::error::ErrorKind::*;
 use crate::error::*;
 
+use crate::read_u64_from;
 use crate::{
     parse_max_value, ControllIdentifier, ControllerInternal, Controllers, MaxValue, PidResources,
     Resources, Subsystem,
@@ -50,17 +50,13 @@ impl ControllerInternal for PidController {
         // get the resources that apply to this controller
         let pidres: &PidResources = &res.pid;
 
-        if pidres.update_values {
-            // apply pid_max
-            let _ = self.set_pid_max(pidres.maximum_number_of_processes);
-
-            // now, verify
-            if self.get_pid_max()? == pidres.maximum_number_of_processes {
-                return Ok(());
-            } else {
-                return Err(Error::new(Other));
-            }
-        }
+        // apply pid_max
+        update_and_test!(
+            self,
+            set_pid_max,
+            pidres.maximum_number_of_processes,
+            get_pid_max
+        );
 
         Ok(())
     }
@@ -85,32 +81,18 @@ impl<'a> From<&'a Subsystem> for &'a PidController {
                 Subsystem::Pid(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
     }
 }
 
-fn read_u64_from(mut file: File) -> Result<u64> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => string
-            .trim()
-            .parse()
-            .map_err(|e| Error::with_cause(ParseError, e)),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
 impl PidController {
-    /// Constructors a new `PidController` instance, with `oroot` serving as the controller's root
+    /// Constructors a new `PidController` instance, with `root` serving as the controller's root
     /// directory.
-    pub fn new(oroot: PathBuf, v2: bool) -> Self {
-        let mut root = oroot;
-        if !v2 {
-            root.push(Self::controller_type().to_string());
-        }
+    pub fn new(root: PathBuf, v2: bool) -> Self {
         Self {
             base: root.clone(),
             path: root,

src/rdma.rs

@@ -7,13 +7,13 @@
 //!
 //! See the Kernel's documentation for more information about this subsystem, found at:
 //!  [Documentation/cgroup-v1/rdma.txt](https://www.kernel.org/doc/Documentation/cgroup-v1/rdma.txt)
-use std::fs::File;
-use std::io::{Read, Write};
+use std::io::Write;
 use std::path::PathBuf;
 
 use crate::error::ErrorKind::*;
 use crate::error::*;
 
+use crate::read_string_from;
 use crate::{ControllIdentifier, ControllerInternal, Controllers, Resources, Subsystem};
 
 /// A controller that allows controlling the `rdma` subsystem of a Cgroup.
@@ -58,26 +58,17 @@ impl<'a> From<&'a Subsystem> for &'a RdmaController {
                 Subsystem::Rdma(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
     }
 }
 
-fn read_string_from(mut file: File) -> Result<String> {
-    let mut string = String::new();
-    match file.read_to_string(&mut string) {
-        Ok(_) => Ok(string.trim().to_string()),
-        Err(e) => Err(Error::with_cause(ReadFailed, e)),
-    }
-}
-
 impl RdmaController {
-    /// Constructs a new `RdmaController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf) -> Self {
-        let mut root = oroot;
-        root.push(Self::controller_type().to_string());
+    /// Constructs a new `RdmaController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf) -> Self {
         Self {
             base: root.clone(),
             path: root,

src/systemd.rs

@@ -7,7 +7,6 @@
 //!
 use std::path::PathBuf;
 
-use crate::error::ErrorKind::*;
 use crate::error::*;
 
 use crate::{ControllIdentifier, ControllerInternal, Controllers, Resources, Subsystem};
@@ -53,7 +52,8 @@ impl<'a> From<&'a Subsystem> for &'a SystemdController {
                 Subsystem::Systemd(c) => c,
                 _ => {
                     assert_eq!(1, 0);
-                    ::std::mem::uninitialized()
+                    let v = std::mem::MaybeUninit::uninit();
+                    v.assume_init()
                 }
             }
         }
@@ -61,12 +61,8 @@ impl<'a> From<&'a Subsystem> for &'a SystemdController {
 }
 
 impl SystemdController {
-    /// Constructs a new `SystemdController` with `oroot` serving as the root of the control group.
-    pub fn new(oroot: PathBuf, v2: bool) -> Self {
-        let mut root = oroot;
-        if !v2 {
-            root.push(Self::controller_type().to_string());
-        }
+    /// Constructs a new `SystemdController` with `root` serving as the root of the control group.
+    pub fn new(root: PathBuf, v2: bool) -> Self {
         Self {
             base: root.clone(),
             path: root,

tests/builder.rs

@@ -5,25 +5,24 @@
 //
 
 //! Some simple tests covering the builder pattern for control groups.
-use cgroups::blkio::*;
-use cgroups::cgroup_builder::*;
-use cgroups::cpu::*;
-use cgroups::devices::*;
-use cgroups::hugetlb::*;
-use cgroups::memory::*;
-use cgroups::net_cls::*;
-use cgroups::pid::*;
-use cgroups::*;
+use cgroups_rs::blkio::*;
+use cgroups_rs::cgroup_builder::*;
+use cgroups_rs::cpu::*;
+use cgroups_rs::devices::*;
+use cgroups_rs::hugetlb::*;
+use cgroups_rs::memory::*;
+use cgroups_rs::net_cls::*;
+use cgroups_rs::pid::*;
+use cgroups_rs::*;
 
 #[test]
 pub fn test_cpu_res_build() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
-    let cg: Cgroup = CgroupBuilder::new("test_cpu_res_build", h)
+    let h = cgroups_rs::hierarchies::auto();
+    let cg: Cgroup = CgroupBuilder::new("test_cpu_res_build")
         .cpu()
         .shares(85)
         .done()
-        .build();
+        .build(h);
 
     {
         let cpu: &CpuController = cg.controller_of().unwrap();
@@ -31,20 +30,19 @@ pub fn test_cpu_res_build() {
         assert_eq!(cpu.shares().unwrap(), 85);
     }
 
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 pub fn test_memory_res_build() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
-    let cg: Cgroup = CgroupBuilder::new("test_memory_res_build", h)
+    let h = cgroups_rs::hierarchies::auto();
+    let cg: Cgroup = CgroupBuilder::new("test_memory_res_build")
         .memory()
         .kernel_memory_limit(128 * 1024 * 1024)
         .swappiness(70)
         .memory_hard_limit(1024 * 1024 * 1024)
         .done()
-        .build();
+        .build(h);
 
     {
         let c: &MemController = cg.controller_of().unwrap();
@@ -55,18 +53,17 @@ pub fn test_memory_res_build() {
         assert_eq!(c.memory_stat().limit_in_bytes, 1024 * 1024 * 1024);
     }
 
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 pub fn test_pid_res_build() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
-    let cg: Cgroup = CgroupBuilder::new("test_pid_res_build", h)
+    let h = cgroups_rs::hierarchies::auto();
+    let cg: Cgroup = CgroupBuilder::new("test_pid_res_build")
         .pid()
         .maximum_number_of_processes(MaxValue::Value(123))
         .done()
-        .build();
+        .build(h);
 
     {
         let c: &PidController = cg.controller_of().unwrap();
@@ -74,19 +71,18 @@ pub fn test_pid_res_build() {
         assert_eq!(c.get_pid_max().unwrap(), MaxValue::Value(123));
     }
 
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 #[ignore] // ignore this test for now, not sure why my kernel doesn't like it
 pub fn test_devices_res_build() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
-    let cg: Cgroup = CgroupBuilder::new("test_devices_res_build", h)
+    let h = cgroups_rs::hierarchies::auto();
+    let cg: Cgroup = CgroupBuilder::new("test_devices_res_build")
         .devices()
         .device(1, 6, DeviceType::Char, true, vec![DevicePermissions::Read])
         .done()
-        .build();
+        .build(h);
 
     {
         let c: &DevicesController = cg.controller_of().unwrap();
@@ -102,44 +98,42 @@ pub fn test_devices_res_build() {
             }]
         );
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 pub fn test_network_res_build() {
-    let h = cgroups::hierarchies::auto();
+    let h = cgroups_rs::hierarchies::auto();
     if h.v2() {
         // FIXME add cases for v2
         return;
     }
-    let h = Box::new(&*h);
-    let cg: Cgroup = CgroupBuilder::new("test_network_res_build", h)
+    let cg: Cgroup = CgroupBuilder::new("test_network_res_build")
         .network()
         .class_id(1337)
         .done()
-        .build();
+        .build(h);
 
     {
         let c: &NetClsController = cg.controller_of().unwrap();
         assert!(c.get_class().is_ok());
         assert_eq!(c.get_class().unwrap(), 1337);
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 pub fn test_hugepages_res_build() {
-    let h = cgroups::hierarchies::auto();
+    let h = cgroups_rs::hierarchies::auto();
     if h.v2() {
         // FIXME add cases for v2
         return;
     }
-    let h = Box::new(&*h);
-    let cg: Cgroup = CgroupBuilder::new("test_hugepages_res_build", h)
+    let cg: Cgroup = CgroupBuilder::new("test_hugepages_res_build")
         .hugepages()
         .limit("2MB".to_string(), 4 * 2 * 1024 * 1024)
         .done()
-        .build();
+        .build(h);
 
     {
         let c: &HugeTlbController = cg.controller_of().unwrap();
@@ -149,23 +143,22 @@ pub fn test_hugepages_res_build() {
             4 * 2 * 1024 * 1024
         );
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 #[ignore] // high version kernel not support `blkio.weight`
 pub fn test_blkio_res_build() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
-    let cg: Cgroup = CgroupBuilder::new("test_blkio_res_build", h)
+    let h = cgroups_rs::hierarchies::auto();
+    let cg: Cgroup = CgroupBuilder::new("test_blkio_res_build")
         .blkio()
-        .weight(Some(100))
+        .weight(100)
         .done()
-        .build();
+        .build(h);
 
     {
         let c: &BlkIoController = cg.controller_of().unwrap();
         assert_eq!(c.blkio().weight, 100);
     }
-    cg.delete();
+    cg.delete().unwrap();
 }

tests/cgroup.rs

@@ -5,15 +5,13 @@
 //
 
 //! Simple unit tests about the control groups system.
-use cgroups::memory::{MemController, SetMemory};
-use cgroups::Controller;
-use cgroups::{Cgroup, CgroupPid, Hierarchy, Subsystem};
-use std::collections::HashMap;
+use cgroups_rs::memory::MemController;
+use cgroups_rs::Controller;
+use cgroups_rs::{Cgroup, CgroupPid, Subsystem};
 
 #[test]
 fn test_tasks_iterator() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let pid = libc::pid_t::from(nix::unistd::getpid()) as u64;
     let cg = Cgroup::new(h, String::from("test_tasks_iterator"));
     {
@@ -35,23 +33,19 @@ fn test_tasks_iterator() {
         // Verify that it was indeed removed.
         assert_eq!(tasks.next(), None);
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 fn test_cgroup_with_relative_paths() {
-    if cgroups::hierarchies::is_cgroup2_unified_mode() {
+    if cgroups_rs::hierarchies::is_cgroup2_unified_mode() {
         return;
     }
-    let h = cgroups::hierarchies::auto();
+    let h = cgroups_rs::hierarchies::auto();
     let cgroup_root = h.root();
-    let h = Box::new(&*h);
-    let mut relative_paths = HashMap::new();
-    let mem_relative_path = "/mmm/abc/def";
-    relative_paths.insert("memory".to_string(), mem_relative_path.to_string());
     let cgroup_name = "test_cgroup_with_relative_paths";
 
-    let cg = Cgroup::new_with_relative_paths(h, String::from(cgroup_name), relative_paths);
+    let cg = Cgroup::load(h, String::from(cgroup_name));
     {
         let subsystems = cg.subsystems();
         subsystems.into_iter().for_each(|sub| match sub {
@@ -74,35 +68,29 @@ fn test_cgroup_with_relative_paths() {
                 // cgroup_path = cgroup_root + relative_path + cgroup_name
                 assert_eq!(
                     cgroup_path,
-                    format!(
-                        "{}/memory{}/{}",
-                        cgroup_root.to_str().unwrap(),
-                        mem_relative_path,
-                        cgroup_name
-                    )
+                    format!("{}/memory/{}", cgroup_root.to_str().unwrap(), cgroup_name)
                 );
             }
             _ => {}
         });
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 fn test_cgroup_v2() {
-    if !cgroups::hierarchies::is_cgroup2_unified_mode() {
+    if !cgroups_rs::hierarchies::is_cgroup2_unified_mode() {
         return;
     }
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
-    let cg = Cgroup::new_with_relative_paths(h, String::from("test_v2"), HashMap::new());
+    let h = cgroups_rs::hierarchies::auto();
+    let cg = Cgroup::new(h, String::from("test_v2"));
 
     let mem_controller: &MemController = cg.controller_of().unwrap();
     let (mem, swp, rev) = (4 * 1024 * 1000, 2 * 1024 * 1000, 1024 * 1000);
 
-    let _ = mem_controller.set_limit(mem);
-    let _ = mem_controller.set_memswap_limit(swp);
-    let _ = mem_controller.set_soft_limit(rev);
+    mem_controller.set_limit(mem).unwrap();
+    mem_controller.set_memswap_limit(swp).unwrap();
+    mem_controller.set_soft_limit(rev).unwrap();
 
     let memory_stat = mem_controller.memory_stat();
     println!("memory_stat {:?}", memory_stat);
@@ -113,5 +101,5 @@ fn test_cgroup_v2() {
     println!("memswap {:?}", memswap);
     assert_eq!(swp, memswap.limit_in_bytes);
 
-    cg.delete();
+    cg.delete().unwrap();
 }

tests/cpu.rs

@@ -4,16 +4,12 @@
 //
 
 //! Simple unit tests about the CPU control groups system.
-use cgroups::cpu::CpuController;
-use cgroups::error::ErrorKind;
-use cgroups::{Cgroup, CgroupPid, CpuResources, Hierarchy, Resources};
-
-use std::fs;
+use cgroups_rs::cpu::CpuController;
+use cgroups_rs::Cgroup;
 
 #[test]
 fn test_cfs_quota_and_periods() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("test_cfs_quota_and_periods"));
 
     let cpu_controller: &CpuController = cg.controller_of().unwrap();
@@ -27,7 +23,7 @@ fn test_cfs_quota_and_periods() {
     assert_eq!(100000, current_peroid);
 
     // case 1 set quota
-    let r = cpu_controller.set_cfs_quota(2000);
+    let _ = cpu_controller.set_cfs_quota(2000);
 
     let current_quota = cpu_controller.cfs_quota().unwrap();
     let current_peroid = cpu_controller.cfs_period().unwrap();
@@ -35,14 +31,16 @@ fn test_cfs_quota_and_periods() {
     assert_eq!(100000, current_peroid);
 
     // case 2 set period
-    cpu_controller.set_cfs_period(1000000);
+    cpu_controller.set_cfs_period(1000000).unwrap();
     let current_quota = cpu_controller.cfs_quota().unwrap();
     let current_peroid = cpu_controller.cfs_period().unwrap();
     assert_eq!(2000, current_quota);
     assert_eq!(1000000, current_peroid);
 
     // case 3 set both quota and period
-    cpu_controller.set_cfs_quota_and_period(Some(5000), Some(100000));
+    cpu_controller
+        .set_cfs_quota_and_period(Some(5000), Some(100000))
+        .unwrap();
 
     let current_quota = cpu_controller.cfs_quota().unwrap();
     let current_peroid = cpu_controller.cfs_period().unwrap();
@@ -50,12 +48,14 @@ fn test_cfs_quota_and_periods() {
     assert_eq!(100000, current_peroid);
 
     // case 4 set both quota and period, set quota to -1
-    cpu_controller.set_cfs_quota_and_period(Some(-1), None);
+    cpu_controller
+        .set_cfs_quota_and_period(Some(-1), None)
+        .unwrap();
 
     let current_quota = cpu_controller.cfs_quota().unwrap();
     let current_peroid = cpu_controller.cfs_period().unwrap();
     assert_eq!(-1, current_quota);
     assert_eq!(100000, current_peroid);
 
-    cg.delete();
+    cg.delete().unwrap();
 }

tests/cpuset.rs

@@ -4,16 +4,15 @@
 // SPDX-License-Identifier: Apache-2.0 or MIT
 //
 
-use cgroups::cpuset::CpuSetController;
-use cgroups::error::ErrorKind;
-use cgroups::{Cgroup, CgroupPid, CpuResources, Hierarchy, Resources};
+use cgroups_rs::cpuset::CpuSetController;
+use cgroups_rs::error::ErrorKind;
+use cgroups_rs::{Cgroup, CgroupPid};
 
 use std::fs;
 
 #[test]
 fn test_cpuset_memory_pressure_root_cg() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("test_cpuset_memory_pressure_root_cg"));
     {
         let cpuset: &CpuSetController = cg.controller_of().unwrap();
@@ -22,13 +21,12 @@ fn test_cpuset_memory_pressure_root_cg() {
         let res = cpuset.set_enable_memory_pressure(true);
         assert_eq!(res.unwrap_err().kind(), &ErrorKind::InvalidOperation);
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 fn test_cpuset_set_cpus() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("test_cpuset_set_cpus"));
     {
         let cpuset: &CpuSetController = cg.controller_of().unwrap();
@@ -61,13 +59,12 @@ fn test_cpuset_set_cpus() {
             assert_eq!(format!("{}-{}", set.cpus[0].0, set.cpus[0].1), cpus);
         }
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 fn test_cpuset_set_cpus_add_task() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("test_cpuset_set_cpus_add_task/sub-dir"));
 
     let cpuset: &CpuSetController = cg.controller_of().unwrap();
@@ -92,5 +89,5 @@ fn test_cpuset_set_cpus_add_task() {
     println!("tasks after deleted: {:?}", tasks);
     assert_eq!(0, tasks.len());
 
-    cg.delete();
+    cg.delete().unwrap();
 }

tests/devices.rs

@@ -6,33 +6,34 @@
 
 //! Integration tests about the devices subsystem
 
-use cgroups::devices::{DevicePermissions, DeviceType, DevicesController};
-use cgroups::{Cgroup, DeviceResource, Hierarchy};
+use cgroups_rs::devices::{DevicePermissions, DeviceType, DevicesController};
+use cgroups_rs::{Cgroup, DeviceResource};
 
 #[test]
 fn test_devices_parsing() {
     // now only v2
-    if cgroups::hierarchies::is_cgroup2_unified_mode() {
+    if cgroups_rs::hierarchies::is_cgroup2_unified_mode() {
         return;
     }
 
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("test_devices_parsing"));
     {
         let devices: &DevicesController = cg.controller_of().unwrap();
 
         // Deny access to all devices first
-        devices.deny_device(
-            DeviceType::All,
-            -1,
-            -1,
-            &vec![
-                DevicePermissions::Read,
-                DevicePermissions::Write,
-                DevicePermissions::MkNod,
-            ],
-        );
+        devices
+            .deny_device(
+                DeviceType::All,
+                -1,
+                -1,
+                &vec![
+                    DevicePermissions::Read,
+                    DevicePermissions::Write,
+                    DevicePermissions::MkNod,
+                ],
+            )
+            .unwrap();
         // Acquire the list of allowed devices after we denied all
         let allowed_devices = devices.allowed_devices();
         // Verify that there are no devices that we can access.
@@ -40,7 +41,9 @@ fn test_devices_parsing() {
         assert_eq!(allowed_devices.unwrap(), Vec::new());
 
         // Now add mknod access to /dev/null device
-        devices.allow_device(DeviceType::Char, 1, 3, &vec![DevicePermissions::MkNod]);
+        devices
+            .allow_device(DeviceType::Char, 1, 3, &vec![DevicePermissions::MkNod])
+            .unwrap();
         let allowed_devices = devices.allowed_devices();
         assert!(allowed_devices.is_ok());
         let allowed_devices = allowed_devices.unwrap();
@@ -57,12 +60,14 @@ fn test_devices_parsing() {
         );
 
         // Now deny, this device explicitly.
-        devices.deny_device(DeviceType::Char, 1, 3, &DevicePermissions::all());
+        devices
+            .deny_device(DeviceType::Char, 1, 3, &DevicePermissions::all())
+            .unwrap();
         // Finally, check that.
         let allowed_devices = devices.allowed_devices();
         // Verify that there are no devices that we can access.
         assert!(allowed_devices.is_ok());
         assert_eq!(allowed_devices.unwrap(), Vec::new());
     }
-    cg.delete();
+    cg.delete().unwrap();
 }

tests/hugetlb.rs

@@ -4,27 +4,23 @@
 //
 
 //! Integration tests about the hugetlb subsystem
-use cgroups::hugetlb::{self, HugeTlbController};
-use cgroups::Controller;
-use cgroups::{Cgroup, Hierarchy};
-
-use cgroups::error::ErrorKind::*;
-use cgroups::error::*;
+use cgroups_rs::error::*;
+use cgroups_rs::hugetlb::{self, HugeTlbController};
+use cgroups_rs::Cgroup;
 use std::fs;
 
 #[test]
 fn test_hugetlb_sizes() {
     // now only v2
-    if cgroups::hierarchies::is_cgroup2_unified_mode() {
+    if cgroups_rs::hierarchies::is_cgroup2_unified_mode() {
         return;
     }
 
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("test_hugetlb_sizes"));
     {
         let hugetlb_controller: &HugeTlbController = cg.controller_of().unwrap();
-        let sizes = hugetlb_controller.get_sizes();
+        let _ = hugetlb_controller.get_sizes();
 
         // test sizes count
         let sizes = hugetlb_controller.get_sizes();
@@ -40,7 +36,7 @@ fn test_hugetlb_sizes() {
             assert_no_error(hugetlb_controller.max_usage_in_bytes(&size));
         }
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 fn assert_no_error(r: Result<u64>) {

tests/memory.rs

@@ -4,14 +4,13 @@
 //
 
 //! Integration tests about the hugetlb subsystem
-use cgroups::memory::{MemController, SetMemory};
-use cgroups::Controller;
-use cgroups::{Cgroup, MaxValue};
+use cgroups_rs::memory::{MemController, SetMemory};
+use cgroups_rs::Controller;
+use cgroups_rs::{Cgroup, MaxValue};
 
 #[test]
 fn test_disable_oom_killer() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("test_disable_oom_killer"));
     {
         let mem_controller: &MemController = cg.controller_of().unwrap();
@@ -31,17 +30,16 @@ fn test_disable_oom_killer() {
             assert_eq!(m.oom_control.oom_kill_disable, true);
         }
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 fn set_mem_v2() {
-    let h = cgroups::hierarchies::auto();
+    let h = cgroups_rs::hierarchies::auto();
     if !h.v2() {
         return;
     }
 
-    let h = Box::new(&*h);
     let cg = Cgroup::new(h, String::from("set_mem_v2"));
     {
         let mem_controller: &MemController = cg.controller_of().unwrap();
@@ -89,5 +87,5 @@ fn set_mem_v2() {
         assert_eq!(m.high, Some(MaxValue::Max));
     }
 
-    cg.delete();
+    cg.delete().unwrap();
 }

tests/pids.rs

@@ -5,49 +5,44 @@
 //
 
 //! Integration tests about the pids subsystem
-use cgroups::pid::PidController;
-use cgroups::Controller;
-use cgroups::{Cgroup, CgroupPid, Hierarchy, MaxValue, PidResources, Resources};
+use cgroups_rs::pid::PidController;
+use cgroups_rs::Controller;
+use cgroups_rs::{Cgroup, MaxValue};
 
 use nix::sys::wait::{waitpid, WaitStatus};
-use nix::unistd::{fork, ForkResult, Pid};
+use nix::unistd::{fork, ForkResult};
 
 use libc::pid_t;
 
-use std::thread;
-
 #[test]
 fn create_and_delete_cgroup() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("create_and_delete_cgroup"));
     {
         let pidcontroller: &PidController = cg.controller_of().unwrap();
-        pidcontroller.set_pid_max(MaxValue::Value(1337));
+        pidcontroller.set_pid_max(MaxValue::Value(1337)).unwrap();
         let max = pidcontroller.get_pid_max();
         assert!(max.is_ok());
         assert_eq!(max.unwrap(), MaxValue::Value(1337));
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 fn test_pids_current_is_zero() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("test_pids_current_is_zero"));
     {
         let pidcontroller: &PidController = cg.controller_of().unwrap();
         let current = pidcontroller.get_pid_current();
         assert_eq!(current.unwrap(), 0);
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 fn test_pids_events_is_zero() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("test_pids_events_is_zero"));
     {
         let pidcontroller: &PidController = cg.controller_of().unwrap();
@@ -55,13 +50,12 @@ fn test_pids_events_is_zero() {
         assert!(events.is_ok());
         assert_eq!(events.unwrap(), 0);
     }
-    cg.delete();
+    cg.delete().unwrap();
 }
 
 #[test]
 fn test_pid_events_is_not_zero() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("test_pid_events_is_not_zero"));
     {
         let pids: &PidController = cg.controller_of().unwrap();
@@ -105,5 +99,5 @@ fn test_pid_events_is_not_zero() {
             Err(_) => panic!("failed to fork"),
         }
     }
-    cg.delete();
+    cg.delete().unwrap();
 }

tests/resources.rs

@@ -5,23 +5,21 @@
 //
 
 //! Integration test about setting resources using `apply()`
-use cgroups::pid::PidController;
-use cgroups::{Cgroup, Hierarchy, MaxValue, PidResources, Resources};
+use cgroups_rs::pid::PidController;
+use cgroups_rs::{Cgroup, MaxValue, PidResources, Resources};
 
 #[test]
 fn pid_resources() {
-    let h = cgroups::hierarchies::auto();
-    let h = Box::new(&*h);
+    let h = cgroups_rs::hierarchies::auto();
     let cg = Cgroup::new(h, String::from("pid_resources"));
     {
         let res = Resources {
             pid: PidResources {
-                update_values: true,
-                maximum_number_of_processes: MaxValue::Value(512),
+                maximum_number_of_processes: Some(MaxValue::Value(512)),
             },
             ..Default::default()
         };
-        cg.apply(&res);
+        cg.apply(&res).unwrap();
 
         // verify
         let pidcontroller: &PidController = cg.controller_of().unwrap();
@@ -29,5 +27,5 @@ fn pid_resources() {
         assert_eq!(pid_max.is_ok(), true);
         assert_eq!(pid_max.unwrap(), MaxValue::Value(512));
     }
-    cg.delete();
+    cg.delete().unwrap();
 }