<commit_before>use std::iter::repeat;
use std::collections::VecDeque;
use std::collections::BinaryHeap;
use std::cmp::Ordering;

fn max(a: u32, b: u32) -> u32 { if a > b { a } else { b } }

#[derive(Clone, PartialEq, Eq)]
struct Edge {
    vertex: u32,
    weight: f32,
}

impl Edge {
    pub fn new(vertex_: u32, weight_: f32) -> Edge {
        Edge{vertex: vertex_, weight: weight_,}
    }
}

impl Ord for Edge {
    fn cmp(&self, other: &Self) -> Ordering {
        (self.weight, &self.vertex).cmp(&(other.weight, &other.vertex))
    }
}

impl PartialOrd for Edge {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

struct Graph {
    nodes: Vec<Vec<Edge>>,
}

impl Graph {
    pub fn new() -> Graph { Graph{nodes: Vec::new(),} }

    pub fn add_edge(&mut self, src: u32, dst: u32, weight: f32) {
        let len = self.nodes.len();

        if (max(src, dst)) > len as u32 {
            let new_len = (max(src, dst) + 1) as usize;
            self.nodes.extend(repeat(Vec::new()).take(new_len - len))
        }
        self.nodes[src as usize].push(Edge::new(dst, weight));
    }
    pub fn bfs(&self, src: u32) {
        let mut queue: VecDeque<u32> = VecDeque::new();
        let len = self.nodes.len();
        let mut visited = vec!(false ; len);

        queue.push_front(src);

        while let Some(current) = queue.pop_back() {
            if !visited[current as usize] {
                println!("current: {}" , current);
                visited[current as usize] = true;
            } else { continue ; }

            for n in &self.nodes[current as usize] {
                let neighbor: u32 = n.vertex;
                queue.push_front(neighbor);
            }
        }
    }
    pub fn dfs(&self, src: u32) {
        let mut stack: Vec<u32> = Vec::new();
        let len = self.nodes.len() as usize;
        let mut visited = vec!(false ; len);

        stack.push(src);

        while let Some(current) = stack.pop() {
            if !visited[current as usize] {
                println!("current: {}" , current);
                visited[current as usize] = true;
            } else { continue ; }

            for n in &self.nodes[current as usize] {
                let neighbor: u32 = n.vertex;
                stack.push(neighbor);
            }
        }
    }

    pub fn dijkstra(&self, src: u32, dst: u32) {
      let mut dist: Vec<f32> = Vec::new();
      let mut prev: Vec<u32> = Vec::new();
      let mut q = BinaryHeap::new();
      const max_weight: f32 = std::f32::MAX;

      // init dist, prev table
      for i in 0..self.nodes.len() {
        dist.push(max_weight);
        prev.push(0);
      }

      // We're at `start`, with a zero cost
      dist[src as usize] = 0.0;
      q.push(Edge::new(src, dist[src as usize]));

      //while (!q.is_empty()) {
      while let Some(u) = q.pop() {
        //let u: Edge = el.unwrap();

        // loop for all edges connected to
        for v in self.nodes[u.vertex as usize].iter() {

          let alt: f32 = dist[u.vertex as usize] + v.weight; // accumulate shortest dist from source

          if (alt < dist[v.vertex as usize]) {
            dist[v.vertex as usize] = alt; // keep the shortest dist from src to v
            prev[v.vertex as usize] = u.vertex;

            q.push(Edge::new(v.vertex, dist[v.vertex as usize])); // Add unvisited v into the Q to be processed
          }
        }
      }

      let mut shortestPath: Vec<u32> = Vec::new();
      let mut curr: u32 = dst;

      shortestPath.push(curr);

      while (curr != src) {
        curr = prev[curr as usize];
        shortestPath.push(curr);
      }

      shortestPath.reverse();

      for v in shortestPath.iter() {
        println!("{}", v);
      }
    }
}

fn main() {
    let mut g1 = Graph::new();
    g1.add_edge(0, 1, 1.0);
    g1.add_edge(0, 2, 4.0);
    g1.add_edge(1, 0, 1.0);
    g1.add_edge(1, 2, 2.0);
    g1.add_edge(1, 3, 6.0);
    g1.add_edge(2, 0, 4.0);
    g1.add_edge(2, 1, 2.0);
    g1.add_edge(2, 3, 3.0);
    g1.add_edge(3, 1, 6.0);
    g1.add_edge(3, 2, 3.0);

    g1.bfs(3);

    println!("\n");

    g1.dfs(3);

    g1.dijkstra(0, 2);
}<commit_msg>fixed compile error in dijkstra<commit_after>use std::iter::repeat;
use std::collections::VecDeque;
use std::collections::BinaryHeap;
use std::cmp::Ordering;

fn max(a: u32, b: u32) -> u32 { if a > b { a } else { b } }

#[derive(Clone)]
struct Edge {
    vertex: u32,
    weight: f32,
}

impl Edge {
    pub fn new(vertex_: u32, weight_: f32) -> Edge {
        Edge{vertex: vertex_, weight: weight_,}
    }
}

impl Ord for Edge {
    fn cmp(&self, other: &Self) -> Ordering {
        self.partial_cmp(other).unwrap()
    }
}

impl Eq for Edge {}

//impl Eq for Edge {}

impl PartialOrd for Edge {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        (self.weight, self.vertex).partial_cmp(&(other.weight, other.vertex))
    }
}

impl PartialEq for Edge {
    fn eq(&self, other: &Self) -> bool {
        (self.weight, &self.vertex) == (other.weight, &other.vertex)
    }
}

struct Graph {
    nodes: Vec<Vec<Edge>>,
}

impl Graph {
    pub fn new() -> Graph { Graph{nodes: Vec::new(),} }

    pub fn add_edge(&mut self, src: u32, dst: u32, weight: f32) {
        let len = self.nodes.len();

        if (max(src, dst)) > len as u32 {
            let new_len = (max(src, dst) + 1) as usize;
            self.nodes.extend(repeat(Vec::new()).take(new_len - len))
        }
        self.nodes[src as usize].push(Edge::new(dst, weight));
    }
    pub fn bfs(&self, src: u32) {
        let mut queue: VecDeque<u32> = VecDeque::new();
        let len = self.nodes.len();
        let mut visited = vec!(false ; len);

        queue.push_front(src);

        while let Some(current) = queue.pop_back() {
            if !visited[current as usize] {
                println!("current: {}" , current);
                visited[current as usize] = true;
            } else { continue ; }

            for n in &self.nodes[current as usize] {
                let neighbor: u32 = n.vertex;
                queue.push_front(neighbor);
            }
        }
    }
    pub fn dfs(&self, src: u32) {
        let mut stack: Vec<u32> = Vec::new();
        let len = self.nodes.len() as usize;
        let mut visited = vec!(false ; len);

        stack.push(src);

        while let Some(current) = stack.pop() {
            if !visited[current as usize] {
                println!("current: {}" , current);
                visited[current as usize] = true;
            } else { continue ; }

            for n in &self.nodes[current as usize] {
                let neighbor: u32 = n.vertex;
                stack.push(neighbor);
            }
        }
    }

    pub fn dijkstra(&self, src: u32, dst: u32) {
      let mut dist: Vec<f32> = Vec::new();
      let mut prev: Vec<u32> = Vec::new();
      let mut q = BinaryHeap::new();
      const max_weight: f32 = std::f32::MAX;

      // init dist, prev table
      for i in 0..self.nodes.len() {
        dist.push(max_weight);
        prev.push(0);
      }

      // We're at `start`, with a zero cost
      dist[src as usize] = 0.0;
      q.push(Edge::new(src, dist[src as usize]));

      //while (!q.is_empty()) {
      while let Some(u) = q.pop() {
        //let u: Edge = el.unwrap();

        // loop for all edges connected to
        for v in self.nodes[u.vertex as usize].iter() {

          let alt: f32 = dist[u.vertex as usize] + v.weight; // accumulate shortest dist from source

          if (alt < dist[v.vertex as usize]) {
            dist[v.vertex as usize] = alt; // keep the shortest dist from src to v
            prev[v.vertex as usize] = u.vertex;

            q.push(Edge::new(v.vertex, dist[v.vertex as usize])); // Add unvisited v into the Q to be processed
          }
        }
      }

      let mut shortestPath: Vec<u32> = Vec::new();
      let mut curr: u32 = dst;

      shortestPath.push(curr);

      while (curr != src) {
        curr = prev[curr as usize];
        shortestPath.push(curr);
      }

      shortestPath.reverse();

      for v in shortestPath.iter() {
        println!("{}", v);
      }
    }
}

fn main() {
    let mut g1 = Graph::new();
    g1.add_edge(0, 1, 1.0);
    g1.add_edge(0, 2, 4.0);
    g1.add_edge(1, 0, 1.0);
    g1.add_edge(1, 2, 2.0);
    g1.add_edge(1, 3, 6.0);
    g1.add_edge(2, 0, 4.0);
    g1.add_edge(2, 1, 2.0);
    g1.add_edge(2, 3, 3.0);
    g1.add_edge(3, 1, 6.0);
    g1.add_edge(3, 2, 3.0);

    g1.bfs(3);

    println!("\n");

    g1.dfs(3);

    g1.dijkstra(0, 2);
}<|endoftext|>


<commit_before>use metadata;
use frame;
use subframe;

use metadata::{Metadata, StreamInfo};
use frame::frame_parser;
use utility::{
  ErrorKind, ByteStream, ReadStream, StreamProducer, many_metadata,
};

use std::io;
use std::usize;
use std::fs::File;

/// FLAC stream that decodes and hold file information.
pub struct Stream
 {
  info: StreamInfo,
  metadata: Vec<Metadata>,
  producer: P,
}

/// Alias for a FLAC stream produced from `Read`.
pub type StreamReader<R>  = Stream<ReadStream<R>>;

/// Alias for a FLAC stream produced from a byte stream buffer.
pub type StreamBuffer<'a> = Stream<ByteStream<'a>>;

impl
 Stream
 where P: StreamProducer {
  /// Constructor for the default state of a FLAC stream.
  #[inline]
  pub fn new<R: io::Read>(reader: R) -> Result<StreamReader<R>, ErrorKind> {
    let producer = ReadStream::new(reader);

    Stream::from_stream_producer(producer)
  }

  /// Returns information for the current stream.
  #[inline]
  pub fn info(&self) -> StreamInfo {
    self.info
  }

  /// Returns a slice of `Metadata`
  ///
  /// This slice excludes `StreamInfo`, which is located in `Stream::info`.
  /// Everything else is related to metadata for the FLAC stream is in the
  /// slice.
  #[inline]
  pub fn metadata(&self) -> &[Metadata] {
    &self.metadata
  }

  /// Constructs a decoder with the given file name.
  ///
  /// # Failures
  ///
  /// * `ErrorKind::IO(io::ErrorKind::NotFound)` is returned when the given
  ///   filename isn't found.
  /// * `ErrorKind::IO(io::ErrorKind::InvalidData)` is returned when the data
  ///   within the file isn't valid FLAC data.
  /// * Several different parser specific errors that are structured as
  ///   `ErrorKind::<parser_name>Parser`.
  /// * Several different invalidation specific errors that are
  ///   structured as `ErrorKind::Invalid<invalidation_name>`.
  #[inline]
  pub fn from_file(filename: &str) -> Result<StreamReader<File>, ErrorKind> {
    File::open(filename).map_err(|e| ErrorKind::IO(e.kind()))
                        .and_then(|file| {
      let producer = ReadStream::new(file);

      Stream::from_stream_producer(producer)
    })
  }

  /// Constructs a decoder with the given buffer.
  ///
  /// This constructor assumes that an entire FLAC file is in the buffer.
  ///
  /// # Failures
  ///
  /// * `ErrorKind::IO(io::ErrorKind::InvalidData)` is returned when the data
  ///   within the file isn't valid FLAC data.
  /// * Several different parser specific errors that are structured as
  ///   `ErrorKind::<parser_name>Parser`.
  /// * Several different invalidation specific errors that are
  ///   structured as `ErrorKind::Invalid<invalidation_name>`.
  #[inline]
  pub fn from_buffer(buffer: &[u8]) -> Result<StreamBuffer, ErrorKind> {
    let producer = ByteStream::new(buffer);

    Stream::from_stream_producer(producer)
  }

  fn from_stream_producer(mut producer: P) -> Result<Self, ErrorKind> {
    let mut stream_info = StreamInfo::new();
    let mut metadata    = Vec::new();

    many_metadata(&mut producer, |block| {
      if let metadata::Data::StreamInfo(info) = block.data {
        stream_info = info;
      } else {
        metadata.push(block);
      }
    }).map(|_| {
      Stream {
        info: stream_info,
        metadata: metadata,
        producer: producer,
      }
    })
  }

  /// Returns an iterator over the decoded samples.
  #[inline]
  pub fn iter(&mut self) -> Iter
 {
    let samples_left = self.info.total_samples;
    let channels     = self.info.channels as usize;
    let block_size   = self.info.max_block_size as usize;
    let buffer_size  = block_size * channels;

    Iter {
      stream: self,
      channel: 0,
      block_size: 0,
      sample_index: 0,
      samples_left: samples_left,
    }
  }

  fn next_frame(&mut self) -> Option<usize> {
    let stream_info = &self.info;
    let buffer      = &mut self.output;

    loop {
      match self.producer.parse(|i| frame_parser(i, stream_info, buffer)) {
        Ok(frame)                  => {
          let channels    = frame.header.channels as usize;
          let block_size  = frame.header.block_size as usize;
          let mut channel = 0;

          for subframe in &frame.subframes[0..channels] {
            let start  = channel * block_size;
            let end    = (channel + 1) * block_size;
            let output = &mut buffer[start..end];

            subframe::decode(&subframe, block_size, output);

            channel += 1;
          }

          frame::decode(frame.header.channel_assignment, buffer);

          return Some(block_size);
        }
        Err(ErrorKind::EndOfInput) => return None,
        Err(ErrorKind::Continue)   => continue,
        Err(_)                     => return None,
      }
    }
  }
}

/// An iterator over a reference of the decoded FLAC stream.
pub struct Iter<'a, P> where P: 'a + StreamProducer {
  stream: &'a mut Stream
,
  channel: usize,
  block_size: usize,
  sample_index: usize,
  samples_left: u64,
}

impl<'a, P> Iterator for Iter<'a, P> where P: StreamProducer {
  type Item = i32;

  fn next(&mut self) -> Option<Self::Item> {
    if self.sample_index == self.block_size {
      if let Some(block_size) = self.stream.next_frame() {
        self.sample_index = 0;
        self.block_size   = block_size;
      } else {
        return None;
      }
    }

    let channels = self.stream.info.channels as usize;
    let index    = self.sample_index + (self.channel * self.block_size);
    let sample   = self.stream.output[index];

    self.channel += 1;

    // Reset current channel
    if self.channel == channels {
      self.channel       = 0;
      self.sample_index += 1;
      self.samples_left -= 1;
    }

    Some(sample)
  }

  fn size_hint(&self) -> (usize, Option<usize>) {
    let samples_left = self.samples_left as usize;
    let max_value    = usize::max_value() as u64;

    // There is a chance that samples_left will be larger than a usize since
    // it is a u64. Make the upper bound None when it is.
    if self.samples_left > max_value {
      (samples_left, None)
    } else {
      (samples_left, Some(samples_left))
    }
  }
}

impl<'a, P> IntoIterator for &'a mut Stream

 where P: StreamProducer {
  type Item     = i32;
  type IntoIter = Iter<'a, P>;

  #[inline]
  fn into_iter(self) -> Self::IntoIter {
    self.iter()
  }
}
<commit_msg>Add buffer to `Iter`<commit_after>use metadata;
use frame;
use subframe;

use metadata::{Metadata, StreamInfo};
use frame::frame_parser;
use utility::{
  ErrorKind, ByteStream, ReadStream, StreamProducer, many_metadata,
};

use std::io;
use std::usize;
use std::fs::File;

/// FLAC stream that decodes and hold file information.
pub struct Stream
 {
  info: StreamInfo,
  metadata: Vec<Metadata>,
  producer: P,
}

/// Alias for a FLAC stream produced from `Read`.
pub type StreamReader<R>  = Stream<ReadStream<R>>;

/// Alias for a FLAC stream produced from a byte stream buffer.
pub type StreamBuffer<'a> = Stream<ByteStream<'a>>;

impl
 Stream
 where P: StreamProducer {
  /// Constructor for the default state of a FLAC stream.
  #[inline]
  pub fn new<R: io::Read>(reader: R) -> Result<StreamReader<R>, ErrorKind> {
    let producer = ReadStream::new(reader);

    Stream::from_stream_producer(producer)
  }

  /// Returns information for the current stream.
  #[inline]
  pub fn info(&self) -> StreamInfo {
    self.info
  }

  /// Returns a slice of `Metadata`
  ///
  /// This slice excludes `StreamInfo`, which is located in `Stream::info`.
  /// Everything else is related to metadata for the FLAC stream is in the
  /// slice.
  #[inline]
  pub fn metadata(&self) -> &[Metadata] {
    &self.metadata
  }

  /// Constructs a decoder with the given file name.
  ///
  /// # Failures
  ///
  /// * `ErrorKind::IO(io::ErrorKind::NotFound)` is returned when the given
  ///   filename isn't found.
  /// * `ErrorKind::IO(io::ErrorKind::InvalidData)` is returned when the data
  ///   within the file isn't valid FLAC data.
  /// * Several different parser specific errors that are structured as
  ///   `ErrorKind::<parser_name>Parser`.
  /// * Several different invalidation specific errors that are
  ///   structured as `ErrorKind::Invalid<invalidation_name>`.
  #[inline]
  pub fn from_file(filename: &str) -> Result<StreamReader<File>, ErrorKind> {
    File::open(filename).map_err(|e| ErrorKind::IO(e.kind()))
                        .and_then(|file| {
      let producer = ReadStream::new(file);

      Stream::from_stream_producer(producer)
    })
  }

  /// Constructs a decoder with the given buffer.
  ///
  /// This constructor assumes that an entire FLAC file is in the buffer.
  ///
  /// # Failures
  ///
  /// * `ErrorKind::IO(io::ErrorKind::InvalidData)` is returned when the data
  ///   within the file isn't valid FLAC data.
  /// * Several different parser specific errors that are structured as
  ///   `ErrorKind::<parser_name>Parser`.
  /// * Several different invalidation specific errors that are
  ///   structured as `ErrorKind::Invalid<invalidation_name>`.
  #[inline]
  pub fn from_buffer(buffer: &[u8]) -> Result<StreamBuffer, ErrorKind> {
    let producer = ByteStream::new(buffer);

    Stream::from_stream_producer(producer)
  }

  fn from_stream_producer(mut producer: P) -> Result<Self, ErrorKind> {
    let mut stream_info = StreamInfo::new();
    let mut metadata    = Vec::new();

    many_metadata(&mut producer, |block| {
      if let metadata::Data::StreamInfo(info) = block.data {
        stream_info = info;
      } else {
        metadata.push(block);
      }
    }).map(|_| {
      Stream {
        info: stream_info,
        metadata: metadata,
        producer: producer,
      }
    })
  }

  /// Returns an iterator over the decoded samples.
  #[inline]
  pub fn iter(&mut self) -> Iter
 {
    let samples_left = self.info.total_samples;
    let channels     = self.info.channels as usize;
    let block_size   = self.info.max_block_size as usize;
    let buffer_size  = block_size * channels;

    Iter {
      stream: self,
      channel: 0,
      block_size: 0,
      sample_index: 0,
      samples_left: samples_left,
      buffer: vec![0; buffer_size]
    }
  }

  fn next_frame(&mut self) -> Option<usize> {
    let stream_info = &self.info;
    let buffer      = &mut self.output;

    loop {
      match self.producer.parse(|i| frame_parser(i, stream_info, buffer)) {
        Ok(frame)                  => {
          let channels    = frame.header.channels as usize;
          let block_size  = frame.header.block_size as usize;
          let mut channel = 0;

          for subframe in &frame.subframes[0..channels] {
            let start  = channel * block_size;
            let end    = (channel + 1) * block_size;
            let output = &mut buffer[start..end];

            subframe::decode(&subframe, block_size, output);

            channel += 1;
          }

          frame::decode(frame.header.channel_assignment, buffer);

          return Some(block_size);
        }
        Err(ErrorKind::EndOfInput) => return None,
        Err(ErrorKind::Continue)   => continue,
        Err(_)                     => return None,
      }
    }
  }
}

/// An iterator over a reference of the decoded FLAC stream.
pub struct Iter<'a, P> where P: 'a + StreamProducer {
  stream: &'a mut Stream
,
  channel: usize,
  block_size: usize,
  sample_index: usize,
  samples_left: u64,
  buffer: Vec<i32>,
}

impl<'a, P> Iterator for Iter<'a, P> where P: StreamProducer {
  type Item = i32;

  fn next(&mut self) -> Option<Self::Item> {
    if self.sample_index == self.block_size {
      if let Some(block_size) = self.stream.next_frame() {
        self.sample_index = 0;
        self.block_size   = block_size;
      } else {
        return None;
      }
    }

    let channels = self.stream.info.channels as usize;
    let index    = self.sample_index + (self.channel * self.block_size);
    let sample   = self.stream.output[index];

    self.channel += 1;

    // Reset current channel
    if self.channel == channels {
      self.channel       = 0;
      self.sample_index += 1;
      self.samples_left -= 1;
    }

    Some(sample)
  }

  fn size_hint(&self) -> (usize, Option<usize>) {
    let samples_left = self.samples_left as usize;
    let max_value    = usize::max_value() as u64;

    // There is a chance that samples_left will be larger than a usize since
    // it is a u64. Make the upper bound None when it is.
    if self.samples_left > max_value {
      (samples_left, None)
    } else {
      (samples_left, Some(samples_left))
    }
  }
}

impl<'a, P> IntoIterator for &'a mut Stream

 where P: StreamProducer {
  type Item     = i32;
  type IntoIter = Iter<'a, P>;

  #[inline]
  fn into_iter(self) -> Self::IntoIter {
    self.iter()
  }
}
<|endoftext|>


<commit_before>#[macro_use]
extern crate bitflags;
extern crate libc;

extern crate wayland_commons;
#[cfg(feature = "native_lib")]
#[macro_use]
extern crate wayland_sys;

mod display;
mod event_queue;
mod proxy;

pub use proxy::{NewProxy, Proxy};
pub use display::Display;
pub use event_queue::EventQueue;
#[cfg(feature = "native_lib")]
pub use generated::c_api as protocol;

#[cfg(feature = "native_lib")]
pub mod sys {
    pub use super::generated::c_interfaces as protocol_interfaces;
}

mod generated {
    #![allow(dead_code, non_camel_case_types, unused_unsafe, unused_variables)]
    #![allow(non_upper_case_globals, non_snake_case, unused_imports)]
    #![allow(missing_docs)]

    #[cfg(feature = "native_lib")]
    pub mod c_interfaces {
        include!(concat!(env!("OUT_DIR"), "/wayland_c_interfaces.rs"));
    }
    #[cfg(feature = "native_lib")]
    pub mod c_api {
        pub(crate) use {NewProxy, Proxy};
        pub(crate) use wayland_commons::{AnonymousObject, Interface, MessageGroup};
        pub(crate) use wayland_sys as sys;
        include!(concat!(env!("OUT_DIR"), "/wayland_c_api.rs"));
    }
}
<commit_msg>client: add missing export<commit_after>#[macro_use]
extern crate bitflags;
extern crate libc;

extern crate wayland_commons;
#[cfg(feature = "native_lib")]
#[macro_use]
extern crate wayland_sys;

mod display;
mod event_queue;
mod proxy;

pub use proxy::{NewProxy, Proxy};
pub use display::Display;
pub use event_queue::{EventQueue, QueueToken};
#[cfg(feature = "native_lib")]
pub use generated::c_api as protocol;

#[cfg(feature = "native_lib")]
pub mod sys {
    pub use super::generated::c_interfaces as protocol_interfaces;
}

mod generated {
    #![allow(dead_code, non_camel_case_types, unused_unsafe, unused_variables)]
    #![allow(non_upper_case_globals, non_snake_case, unused_imports)]
    #![allow(missing_docs)]

    #[cfg(feature = "native_lib")]
    pub mod c_interfaces {
        include!(concat!(env!("OUT_DIR"), "/wayland_c_interfaces.rs"));
    }
    #[cfg(feature = "native_lib")]
    pub mod c_api {
        pub(crate) use {NewProxy, Proxy};
        pub(crate) use wayland_commons::{AnonymousObject, Interface, MessageGroup};
        pub(crate) use wayland_sys as sys;
        include!(concat!(env!("OUT_DIR"), "/wayland_c_api.rs"));
    }
}
<|endoftext|>


<commit_before>// Copyright (c) 2017 Rene van der Meer
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

//! Raspberry Pi system-related tools.
//!
//! Use `DeviceInfo` to identify what Raspberry Pi model and SoC the software is
//! running on. This information is used internally to calculate the correct memory
//! locations for the various BCM283x peripherals.

use std::fmt;
use std::fs::File;
use std::io::{BufReader, BufRead};
use std::result;

const BCM2708_PERIPHERAL_BASE: u32 = 0x20000000;
const BCM2709_PERIPHERAL_BASE: u32 = 0x3f000000;
const BCM2710_PERIPHERAL_BASE: u32 = 0x3f000000;
const GPIO_OFFSET: u32 = 0x200000;

quick_error! {
    #[derive(Debug)]
/// Errors that can occur when trying to identify the Raspberry Pi hardware.
    pub enum Error {
/// Unknown SoC.
///
/// Based on the output of `/proc/cpuinfo`, it wasn't possible to identify the SoC used by the
/// Raspberry Pi. While running the library on an unknown Raspberry Pi model is acceptable,
/// identifying the SoC is required because the memory address for the GPIO peripheral
/// depends on it.
        UnknownSoC { description("unknown SoC") }
/// Can't access `/proc/cpuinfo`.
///
/// Unable to read the contents of `/proc/cpuinfo`. This could be an issue with permissions, or
/// a Linux distribution is used that doesn't provide access to this virtual file.
        CantAccessProcCPUInfo { description("can't access /proc/cpuinfo") }
    }
}

/// Result type returned from methods that can have `system::Error`s.
pub type Result<T> = result::Result<T, Error>;

#[derive(Debug, PartialEq, Copy, Clone)]
/// Identifiable Raspberry Pi models.
pub enum Model {
    RaspberryPiA,
    RaspberryPiAPlus,
    RaspberryPiB,
    RaspberryPiBPlus,
    RaspberryPi2B,
    RaspberryPi3B,
    RaspberryPiComputeModule,
    RaspberryPiComputeModule3,
    RaspberryPiZero,
    RaspberryPiZeroW,
    Unknown,
}

impl fmt::Display for Model {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            Model::RaspberryPiA => write!(f, "Raspberry Pi A"),
            Model::RaspberryPiAPlus => write!(f, "Raspberry Pi A+"),
            Model::RaspberryPiB => write!(f, "Raspberry Pi B"),
            Model::RaspberryPiBPlus => write!(f, "Raspberry Pi B+"),
            Model::RaspberryPi2B => write!(f, "Raspberry Pi 2 B"),
            Model::RaspberryPi3B => write!(f, "Raspberry Pi 3 B"),
            Model::RaspberryPiComputeModule => write!(f, "Raspberry Pi Compute Module"),
            Model::RaspberryPiComputeModule3 => write!(f, "Raspberry Pi Compute Module 3"),
            Model::RaspberryPiZero => write!(f, "Raspberry Pi Zero"),
            Model::RaspberryPiZeroW => write!(f, "Raspberry Pi Zero W"),
            Model::Unknown => write!(f, "Unknown"),
        }
    }
}

#[derive(Debug, PartialEq, Copy, Clone)]
/// Identifiable Raspberry Pi SoCs.
pub enum SoC {
    BCM2835,
    BCM2836,
    BCM2837,
}

impl fmt::Display for SoC {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            SoC::BCM2835 => write!(f, "BCM2835"),
            SoC::BCM2836 => write!(f, "BCM2836"),
            SoC::BCM2837 => write!(f, "BCM2837"),
        }
    }
}

/// Retrieves Raspberry Pi device information.
pub struct DeviceInfo {
    model: Model,
    soc: SoC,
    peripheral_base: u32,
    gpio_offset: u32,
}

impl DeviceInfo {
    /// Constructs a new `DeviceInfo`.
    pub fn new() -> Result<DeviceInfo> {
        // Parse hardware/revision from /proc/cpuinfo to figure out model/SoC
        let proc_cpuinfo = BufReader::new(match File::open("/proc/cpuinfo") {
            Err(_) => return Err(Error::CantAccessProcCPUInfo),
            Ok(file) => file,
        });

        let mut hardware: String = String::new();
        let mut revision: String = String::new();
        for line_result in proc_cpuinfo.lines() {
            if let Some(line) = line_result.ok() {
                if line.starts_with("Hardware\t: ") {
                    hardware = String::from(&line[11..]);
                } else if line.starts_with("Revision\t: ") {
                    revision = String::from(&line[11..]).to_lowercase();
                }
            }
        }

        let model = if revision.len() >= 6 {
            // Newer revisions consist of at least 6 characters
            match &revision[revision.len() - 3..revision.len() - 1] {
                "00" => Model::RaspberryPiA,
                "01" => Model::RaspberryPiB,
                "02" => Model::RaspberryPiAPlus,
                "03" => Model::RaspberryPiBPlus,
                "04" => Model::RaspberryPi2B,
                "06" => Model::RaspberryPiComputeModule,
                "08" => Model::RaspberryPi3B,
                "09" => Model::RaspberryPiZero,
                "0a" => Model::RaspberryPiComputeModule3,
                "0c" => Model::RaspberryPiZeroW,
                _ => Model::Unknown,
            }
        } else if revision.len() == 4 {
            // Older revisions are 4 characters long
            match &revision[..] {
                "0007" | "0008" | "0009" => Model::RaspberryPiA,
                "0002" | "0003" | "0004" | "0005" | "0006" | "000d" | "000e" | "000f" => {
                    Model::RaspberryPiB
                }
                "0012" => Model::RaspberryPiAPlus,
                "0010" | "0013" => Model::RaspberryPiBPlus,
                "0011" => Model::RaspberryPiComputeModule,
                _ => Model::Unknown,
            }
        } else {
            Model::Unknown
        };

        // Make sure we're actually running on a supported SoC
        match &hardware[..] {
            "BCM2708" | "BCM2835" => {
                Ok(DeviceInfo {
                    model: model,
                    soc: SoC::BCM2835,
                    peripheral_base: BCM2708_PERIPHERAL_BASE,
                    gpio_offset: GPIO_OFFSET,
                })
            }
            "BCM2709" | "BCM2836" => {
                Ok(DeviceInfo {
                    model: model,
                    soc: SoC::BCM2836,
                    peripheral_base: BCM2709_PERIPHERAL_BASE,
                    gpio_offset: GPIO_OFFSET,
                })
            }
            "BCM2710" | "BCM2837" => {
                Ok(DeviceInfo {
                    model: model,
                    soc: SoC::BCM2837,
                    peripheral_base: BCM2710_PERIPHERAL_BASE,
                    gpio_offset: GPIO_OFFSET,
                })
            }
            _ => return Err(Error::UnknownSoC),
        }
    }

    /// Returns a reference to the Raspberry Pi model identified by parsing the contents of `/proc/cpuinfo`.
    pub fn model(&self) -> &Model {
        &self.model
    }

    /// Returns a reference to the SoC identified by parsing the contents of `/proc/cpuinfo`.
    pub fn soc(&self) -> &SoC {
        &self.soc
    }

    /// Returns the base memory address for the BCM283x peripherals.
    pub fn peripheral_base(&self) -> u32 {
        self.peripheral_base
    }

    /// Returns the offset memory address for the GPIO section.
    pub fn gpio_offset(&self) -> u32 {
        self.gpio_offset
    }
}
<commit_msg>Add additional revision codes for old models<commit_after>// Copyright (c) 2017 Rene van der Meer
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

//! Raspberry Pi system-related tools.
//!
//! Use `DeviceInfo` to identify what Raspberry Pi model and SoC the software is
//! running on. This information is used internally to calculate the correct memory
//! locations for the various BCM283x peripherals.

use std::fmt;
use std::fs::File;
use std::io::{BufReader, BufRead};
use std::result;

const BCM2708_PERIPHERAL_BASE: u32 = 0x20000000;
const BCM2709_PERIPHERAL_BASE: u32 = 0x3f000000;
const BCM2710_PERIPHERAL_BASE: u32 = 0x3f000000;
const GPIO_OFFSET: u32 = 0x200000;

quick_error! {
    #[derive(Debug)]
/// Errors that can occur when trying to identify the Raspberry Pi hardware.
    pub enum Error {
/// Unknown SoC.
///
/// Based on the output of `/proc/cpuinfo`, it wasn't possible to identify the SoC used by the
/// Raspberry Pi. While running the library on an unknown Raspberry Pi model is acceptable,
/// identifying the SoC is required because the memory address for the GPIO peripheral
/// depends on it.
        UnknownSoC { description("unknown SoC") }
/// Can't access `/proc/cpuinfo`.
///
/// Unable to read the contents of `/proc/cpuinfo`. This could be an issue with permissions, or
/// a Linux distribution is used that doesn't provide access to this virtual file.
        CantAccessProcCPUInfo { description("can't access /proc/cpuinfo") }
    }
}

/// Result type returned from methods that can have `system::Error`s.
pub type Result<T> = result::Result<T, Error>;

#[derive(Debug, PartialEq, Copy, Clone)]
/// Identifiable Raspberry Pi models.
pub enum Model {
    RaspberryPiA,
    RaspberryPiAPlus,
    RaspberryPiB,
    RaspberryPiBPlus,
    RaspberryPi2B,
    RaspberryPi3B,
    RaspberryPiComputeModule,
    RaspberryPiComputeModule3,
    RaspberryPiZero,
    RaspberryPiZeroW,
    Unknown,
}

impl fmt::Display for Model {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            Model::RaspberryPiA => write!(f, "Raspberry Pi A"),
            Model::RaspberryPiAPlus => write!(f, "Raspberry Pi A+"),
            Model::RaspberryPiB => write!(f, "Raspberry Pi B"),
            Model::RaspberryPiBPlus => write!(f, "Raspberry Pi B+"),
            Model::RaspberryPi2B => write!(f, "Raspberry Pi 2 B"),
            Model::RaspberryPi3B => write!(f, "Raspberry Pi 3 B"),
            Model::RaspberryPiComputeModule => write!(f, "Raspberry Pi Compute Module"),
            Model::RaspberryPiComputeModule3 => write!(f, "Raspberry Pi Compute Module 3"),
            Model::RaspberryPiZero => write!(f, "Raspberry Pi Zero"),
            Model::RaspberryPiZeroW => write!(f, "Raspberry Pi Zero W"),
            Model::Unknown => write!(f, "Unknown"),
        }
    }
}

#[derive(Debug, PartialEq, Copy, Clone)]
/// Identifiable Raspberry Pi SoCs.
pub enum SoC {
    BCM2835,
    BCM2836,
    BCM2837,
}

impl fmt::Display for SoC {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            SoC::BCM2835 => write!(f, "BCM2835"),
            SoC::BCM2836 => write!(f, "BCM2836"),
            SoC::BCM2837 => write!(f, "BCM2837"),
        }
    }
}

/// Retrieves Raspberry Pi device information.
pub struct DeviceInfo {
    model: Model,
    soc: SoC,
    peripheral_base: u32,
    gpio_offset: u32,
}

impl DeviceInfo {
    /// Constructs a new `DeviceInfo`.
    pub fn new() -> Result<DeviceInfo> {
        // Parse hardware/revision from /proc/cpuinfo to figure out model/SoC
        let proc_cpuinfo = BufReader::new(match File::open("/proc/cpuinfo") {
            Err(_) => return Err(Error::CantAccessProcCPUInfo),
            Ok(file) => file,
        });

        let mut hardware: String = String::new();
        let mut revision: String = String::new();
        for line_result in proc_cpuinfo.lines() {
            if let Some(line) = line_result.ok() {
                if line.starts_with("Hardware\t: ") {
                    hardware = String::from(&line[11..]);
                } else if line.starts_with("Revision\t: ") {
                    revision = String::from(&line[11..]).to_lowercase();
                }
            }
        }

        let model = if revision.len() >= 6 {
            // Newer revisions consist of at least 6 characters
            match &revision[revision.len() - 3..revision.len() - 1] {
                "00" => Model::RaspberryPiA,
                "01" => Model::RaspberryPiB,
                "02" => Model::RaspberryPiAPlus,
                "03" => Model::RaspberryPiBPlus,
                "04" => Model::RaspberryPi2B,
                "06" => Model::RaspberryPiComputeModule,
                "08" => Model::RaspberryPi3B,
                "09" => Model::RaspberryPiZero,
                "0a" => Model::RaspberryPiComputeModule3,
                "0c" => Model::RaspberryPiZeroW,
                _ => Model::Unknown,
            }
        } else if revision.len() == 4 {
            // Older revisions are 4 characters long
            match &revision[..] {
                "0007" | "0008" | "0009" | "0015" => Model::RaspberryPiA,
                "Beta" | "0002" | "0003" | "0004" | "0005" | "0006" | "000d" | "000e" | "000f" => {
                    Model::RaspberryPiB
                }
                "0012" => Model::RaspberryPiAPlus,
                "0010" | "0013" => Model::RaspberryPiBPlus,
                "0011" | "0014" => Model::RaspberryPiComputeModule,
                _ => Model::Unknown,
            }
        } else {
            Model::Unknown
        };

        // Make sure we're actually running on a supported SoC
        match &hardware[..] {
            "BCM2708" | "BCM2835" => {
                Ok(DeviceInfo {
                    model: model,
                    soc: SoC::BCM2835,
                    peripheral_base: BCM2708_PERIPHERAL_BASE,
                    gpio_offset: GPIO_OFFSET,
                })
            }
            "BCM2709" | "BCM2836" => {
                Ok(DeviceInfo {
                    model: model,
                    soc: SoC::BCM2836,
                    peripheral_base: BCM2709_PERIPHERAL_BASE,
                    gpio_offset: GPIO_OFFSET,
                })
            }
            "BCM2710" | "BCM2837" => {
                Ok(DeviceInfo {
                    model: model,
                    soc: SoC::BCM2837,
                    peripheral_base: BCM2710_PERIPHERAL_BASE,
                    gpio_offset: GPIO_OFFSET,
                })
            }
            _ => return Err(Error::UnknownSoC),
        }
    }

    /// Returns a reference to the Raspberry Pi model identified by parsing the contents of `/proc/cpuinfo`.
    pub fn model(&self) -> &Model {
        &self.model
    }

    /// Returns a reference to the SoC identified by parsing the contents of `/proc/cpuinfo`.
    pub fn soc(&self) -> &SoC {
        &self.soc
    }

    /// Returns the base memory address for the BCM283x peripherals.
    pub fn peripheral_base(&self) -> u32 {
        self.peripheral_base
    }

    /// Returns the offset memory address for the GPIO section.
    pub fn gpio_offset(&self) -> u32 {
        self.gpio_offset
    }
}
<|endoftext|>


<commit_before>//! Threads that can borrow variables from the stack.
//!
//! Create a scope when spawned threads need to access variables on the stack:
//!
//! ```
//! use crossbeam_utils::thread;
//!
//! let people = vec![
//!     "Alice".to_string(),
//!     "Bob".to_string(),
//!     "Carol".to_string(),
//! ];
//!
//! thread::scope(|scope| {
//!     for person in &people {
//!         scope.spawn(move || {
//!             println!("Hello, {}!", person);
//!         });
//!     }
//! }).unwrap();
//! ```
//!
//! # Why scoped threads?
//!
//! Suppose we wanted to re-write the previous example using plain threads:
//!
//! ```ignore
//! use std::thread;
//!
//! let people = vec![
//!     "Alice".to_string(),
//!     "Bob".to_string(),
//!     "Carol".to_string(),
//! ];
//!
//! let mut threads = Vec::new();
//!
//! for person in &people {
//!     threads.push(thread::spawn(move || {
//!         println!("Hello, {}!", person);
//!     }));
//! }
//!
//! for thread in threads {
//!     thread.join().unwrap();
//! }
//! ```
//!
//! This doesn't work because the borrow checker complains about `people` not living long enough:
//!
//! ```text
//! error[E0597]: `people` does not live long enough
//!   --> src/main.rs:12:20
//!    |
//! 12 |     for person in &people {
//!    |                    ^^^^^^ borrowed value does not live long enough
//! ...
//! 21 | }
//!    | - borrowed value only lives until here
//!    |
//!    = note: borrowed value must be valid for the static lifetime...
//! ```
//!
//! The problem here is that spawned threads are not allowed to borrow variables on stack because
//! the compiler cannot prove they will be joined before `people` is destroyed.
//!
//! Scoped threads are a mechanism to guarantee to the compiler that spawned threads will be joined
//! before the scope ends.
//!
//! # How scoped threads work
//!
//! If a variable is borrowed by a thread, the thread must complete before the variable is
//! destroyed. Threads spawned using [`std::thread::spawn`] can only borrow variables with the
//! `'static` lifetime because the borrow checker cannot be sure when the thread will complete.
//!
//! A scope creates a clear boundary between variables outside the scope and threads inside the
//! scope. Whenever a scope spawns a thread, it promises to join the thread before the scope ends.
//! This way we guarantee to the borrow checker that scoped threads only live within the scope and
//! can safely access variables outside it.
//!
//! [`std::thread::spawn`]: https://doc.rust-lang.org/std/thread/fn.spawn.html

use std::any::Any;
use std::cell::RefCell;
use std::collections::HashMap;
use std::fmt;
use std::io;
use std::marker::PhantomData;
use std::mem;
use std::panic;
use std::sync::{Arc, Mutex};
use std::thread::{self, ThreadId};

/// Like [`std::thread::spawn`], but without lifetime bounds on the closure.
///
/// [`std::thread::spawn`]: https://doc.rust-lang.org/stable/std/thread/fn.spawn.html
pub unsafe fn spawn_unchecked<'env, F, T>(f: F) -> thread::JoinHandle<T>
where
    F: FnOnce() -> T,
    F: Send + 'env,
    T: Send + 'static,
{
    let builder = thread::Builder::new();
    builder_spawn_unchecked(builder, f).unwrap()
}

/// Like [`std::thread::Builder::spawn`], but without lifetime bounds on the closure.
///
/// [`std::thread::Builder::spawn`]:
///     https://doc.rust-lang.org/nightly/std/thread/struct.Builder.html#method.spawn
pub unsafe fn builder_spawn_unchecked<'env, F, T>(
    builder: thread::Builder,
    f: F,
) -> io::Result<thread::JoinHandle<T>>
where
    F: FnOnce() -> T,
    F: Send + 'env,
    T: Send + 'static,
{
    let closure: Box<FnBox<T> + Send + 'env> = Box::new(f);
    let closure: Box<FnBox<T> + Send + 'static> = mem::transmute(closure);
    builder.spawn(move || closure.call_box())
}

/// Creates a new `Scope` for [*scoped thread spawning*](struct.Scope.html#method.spawn).
///
/// No matter what happens, before the `Scope` is dropped, it is guaranteed that all the unjoined
/// spawned scoped threads are joined.
///
/// `thread::scope()` returns `Ok(())` if all the unjoined spawned threads did not panic. It returns
/// `Err(e)` if one of them panics with `e`. If many of them panic, it is still guaranteed that all
/// the threads are joined, and `thread::scope()` returns `Err(e)` with `e` from a panicking thread.
///
/// # Examples
///
/// Creating and using a scope:
///
/// ```
/// crossbeam_utils::thread::scope(|scope| {
///     scope.spawn(|| println!("Exiting scope"));
///     scope.spawn(|| println!("Running child thread in scope"));
/// }).unwrap();
/// ```
pub fn scope<'env, F, R>(f: F) -> thread::Result<R>
where
    F: FnOnce(&Scope<'env>) -> R,
{
    let scope = Scope {
        joins: RefCell::new(Vec::new()),
        _marker: PhantomData,
    };

    // Execute the scoped function, but catch any panics.
    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| f(&scope)));
    // Join all remaining spawned threads.
    let mut panics = scope.join_all();

    if panics.is_empty() {
        result.map_err(|res| Box::new(vec![res]) as _)
    } else {
        if let Err(err) = result {
            panics.reserve(1);
            panics.insert(0, err);
        }

        Err(Box::new(panics))
    }
}

pub struct Scope<'env> {
    /// The list of the thread join jobs.
    joins: RefCell<Vec<Box<FnBox<thread::Result<()>> + 'env>>>,
    // !Send + !Sync
    _marker: PhantomData<*const ()>,
}

impl<'env> Scope<'env> {
    /// Create a scoped thread.
    ///
    /// `spawn` is similar to the [`spawn`] function in Rust's standard library. The difference is
    /// that this thread is scoped, meaning that it's guaranteed to terminate before the current
    /// stack frame goes away, allowing you to reference the parent stack frame directly. This is
    /// ensured by having the parent thread join on the child thread before the scope exits.
    ///
    /// [`spawn`]: https://doc.rust-lang.org/std/thread/fn.spawn.html
    pub fn spawn<'scope, F, T>(&'scope self, f: F) -> ScopedJoinHandle<'scope, T>
    where
        F: FnOnce() -> T,
        F: Send + 'env,
        T: Send + 'env,
    {
        self.builder().spawn(f).unwrap()
    }

    /// Generates the base configuration for spawning a scoped thread, from which configuration
    /// methods can be chained.
    pub fn builder<'scope>(&'scope self) -> ScopedThreadBuilder<'scope, 'env> {
        ScopedThreadBuilder {
            scope: self,
            builder: thread::Builder::new(),
        }
    }

    /// Join all remaining threads and return all potential error payloads
    fn join_all(self) -> Vec<Box<Any + Send + 'static>> {
        self
            .joins
            .into_inner()
            .into_iter()
            .filter_map(|join| join.call_box().err())
            .collect()
    }
}

impl<'env> fmt::Debug for Scope<'env> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "Scope {{ ... }}")
    }
}

/// Scoped thread configuration. Provides detailed control over the properties and behavior of new
/// scoped threads.
pub struct ScopedThreadBuilder<'scope, 'env: 'scope> {
    scope: &'scope Scope<'env>,
    builder: thread::Builder,
}

impl<'scope, 'env> ScopedThreadBuilder<'scope, 'env> {
    /// Names the thread-to-be. Currently the name is used for identification only in panic
    /// messages.
    pub fn name(mut self, name: String) -> ScopedThreadBuilder<'scope, 'env> {
        self.builder = self.builder.name(name);
        self
    }

    /// Sets the size of the stack for the new thread.
    pub fn stack_size(mut self, size: usize) -> ScopedThreadBuilder<'scope, 'env> {
        self.builder = self.builder.stack_size(size);
        self
    }

    /// Spawns a new thread, and returns a join handle for it.
    pub fn spawn<F, T>(self, f: F) -> io::Result<ScopedJoinHandle<'scope, T>>
    where
        F: FnOnce() -> T,
        F: Send + 'env,
        T: Send + 'env,
    {
        let result = Arc::new(Mutex::new(None));

        let join_handle = unsafe {
            let mut thread_result = Arc::clone(&result);
            builder_spawn_unchecked(self.builder, move || {
                *thread_result.lock().unwrap() = Some(f());
            })
        }?;

        let thread = join_handle.thread().clone();
        let join_state = JoinState::<T>::new(join_handle, result);

        let handle = ScopedJoinHandle {
            inner: Arc::new(Mutex::new(Some(join_state))),
            thread,
            _marker: PhantomData,
        };

        let deferred_handle = Arc::clone(&handle.inner);
        self.scope.joins.borrow_mut().push(Box::new(move || {
            let state = deferred_handle.lock().unwrap().take();
            if let Some(state) = state {
                state.join().map(|_| ())
            } else {
                Ok(())
            }
        }));

        Ok(handle)
    }
}

unsafe impl<'scope, T> Send for ScopedJoinHandle<'scope, T> {}
unsafe impl<'scope, T> Sync for ScopedJoinHandle<'scope, T> {}

/// A handle to a scoped thread
pub struct ScopedJoinHandle<'scope, T: 'scope> {
    inner: Arc<Mutex<Option<JoinState<T>>>>,
    thread: thread::Thread,
    _marker: PhantomData<&'scope T>,
}

impl<'scope, T> ScopedJoinHandle<'scope, T> {
    /// Waits for the associated thread to finish.
    ///
    /// If the child thread panics, [`Err`] is returned with the parameter given to [`panic`].
    ///
    /// [`Err`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Err
    /// [`panic`]: https://doc.rust-lang.org/std/macro.panic.html
    ///
    /// # Panics
    ///
    /// This function may panic on some platforms if a thread attempts to join itself or otherwise
    /// may create a deadlock with joining threads.
    pub fn join(self) -> thread::Result<T> {
        let state = self.inner.lock().unwrap().take();
        state.unwrap().join()
    }

    /// Gets the underlying [`std::thread::Thread`] handle.
    ///
    /// [`std::thread::Thread`]: https://doc.rust-lang.org/std/thread/struct.Thread.html
    pub fn thread(&self) -> &thread::Thread {
        &self.thread
    }
}

impl<'scope, T> fmt::Debug for ScopedJoinHandle<'scope, T> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "ScopedJoinHandle {{ ... }}")
    }
}

type ScopedThreadResult<T> = Arc<Mutex<Option<T>>>;

struct JoinState<T> {
    join_handle: thread::JoinHandle<()>,
    result: ScopedThreadResult<T>,
}

impl<T> JoinState<T> {
    fn new(join_handle: thread::JoinHandle<()>, result: ScopedThreadResult<T>) -> JoinState<T> {
        JoinState {
            join_handle,
            result,
        }
    }

    fn join(self) -> thread::Result<T> {
        let result = self.result;
        self.join_handle
            .join()
            .map(|_| result.lock().unwrap().take().unwrap())
    }
}

trait FnBox<T> {
    fn call_box(self: Box<Self>) -> T;
}

impl<T, F: FnOnce() -> T> FnBox<T> for F {
    fn call_box(self: Box<Self>) -> T {
        (*self)()
    }
}

/// Returns a `usize` that identifies the current thread.
///
/// Each thread is associated with an 'index'. While there are no particular guarantees, indices
/// usually tend to be consecutive numbers between 0 and the number of running threads.
///
/// Since this function accesses TLS, `None` might be returned if the current thread's TLS is
/// tearing down.
#[inline]
pub fn current_index() -> Option<usize> {
    REGISTRATION.try_with(|reg| reg.index).ok()
}

/// The global registry keeping track of registered threads and indices.
struct ThreadIndices {
    /// Mapping from `ThreadId` to thread index.
    mapping: HashMap<ThreadId, usize>,

    /// A list of free indices.
    free_list: Vec<usize>,

    /// The next index to allocate if the free list is empty.
    next_index: usize,
}

lazy_static! {
    static ref THREAD_INDICES: Mutex<ThreadIndices> = Mutex::new(ThreadIndices {
        mapping: HashMap::new(),
        free_list: Vec::new(),
        next_index: 0,
    });
}

/// A registration of a thread with an index.
///
/// When dropped, unregisters the thread and frees the reserved index.
struct Registration {
    index: usize,
    thread_id: ThreadId,
}

impl Drop for Registration {
    fn drop(&mut self) {
        let mut indices = THREAD_INDICES.lock().unwrap();
        indices.mapping.remove(&self.thread_id);
        indices.free_list.push(self.index);
    }
}

thread_local! {
    static REGISTRATION: Registration = {
        let thread_id = thread::current().id();
        let mut indices = THREAD_INDICES.lock().unwrap();

        let index = match indices.free_list.pop() {
            Some(i) => i,
            None => {
                let i = indices.next_index;
                indices.next_index += 1;
                i
            }
        };
        indices.mapping.insert(thread_id, index);

        Registration {
            index,
            thread_id,
        }
    };
}
<commit_msg>Remove unchecked spawn functions (#44)<commit_after>//! Threads that can borrow variables from the stack.
//!
//! Create a scope when spawned threads need to access variables on the stack:
//!
//! ```
//! use crossbeam_utils::thread;
//!
//! let people = vec![
//!     "Alice".to_string(),
//!     "Bob".to_string(),
//!     "Carol".to_string(),
//! ];
//!
//! thread::scope(|scope| {
//!     for person in &people {
//!         scope.spawn(move || {
//!             println!("Hello, {}!", person);
//!         });
//!     }
//! }).unwrap();
//! ```
//!
//! # Why scoped threads?
//!
//! Suppose we wanted to re-write the previous example using plain threads:
//!
//! ```ignore
//! use std::thread;
//!
//! let people = vec![
//!     "Alice".to_string(),
//!     "Bob".to_string(),
//!     "Carol".to_string(),
//! ];
//!
//! let mut threads = Vec::new();
//!
//! for person in &people {
//!     threads.push(thread::spawn(move || {
//!         println!("Hello, {}!", person);
//!     }));
//! }
//!
//! for thread in threads {
//!     thread.join().unwrap();
//! }
//! ```
//!
//! This doesn't work because the borrow checker complains about `people` not living long enough:
//!
//! ```text
//! error[E0597]: `people` does not live long enough
//!   --> src/main.rs:12:20
//!    |
//! 12 |     for person in &people {
//!    |                    ^^^^^^ borrowed value does not live long enough
//! ...
//! 21 | }
//!    | - borrowed value only lives until here
//!    |
//!    = note: borrowed value must be valid for the static lifetime...
//! ```
//!
//! The problem here is that spawned threads are not allowed to borrow variables on stack because
//! the compiler cannot prove they will be joined before `people` is destroyed.
//!
//! Scoped threads are a mechanism to guarantee to the compiler that spawned threads will be joined
//! before the scope ends.
//!
//! # How scoped threads work
//!
//! If a variable is borrowed by a thread, the thread must complete before the variable is
//! destroyed. Threads spawned using [`std::thread::spawn`] can only borrow variables with the
//! `'static` lifetime because the borrow checker cannot be sure when the thread will complete.
//!
//! A scope creates a clear boundary between variables outside the scope and threads inside the
//! scope. Whenever a scope spawns a thread, it promises to join the thread before the scope ends.
//! This way we guarantee to the borrow checker that scoped threads only live within the scope and
//! can safely access variables outside it.
//!
//! [`std::thread::spawn`]: https://doc.rust-lang.org/std/thread/fn.spawn.html

use std::any::Any;
use std::cell::RefCell;
use std::collections::HashMap;
use std::fmt;
use std::io;
use std::marker::PhantomData;
use std::mem;
use std::panic;
use std::sync::{Arc, Mutex};
use std::thread::{self, ThreadId};

/// Creates a new `Scope` for [*scoped thread spawning*](struct.Scope.html#method.spawn).
///
/// No matter what happens, before the `Scope` is dropped, it is guaranteed that all the unjoined
/// spawned scoped threads are joined.
///
/// `thread::scope()` returns `Ok(())` if all the unjoined spawned threads did not panic. It returns
/// `Err(e)` if one of them panics with `e`. If many of them panic, it is still guaranteed that all
/// the threads are joined, and `thread::scope()` returns `Err(e)` with `e` from a panicking thread.
///
/// # Examples
///
/// Creating and using a scope:
///
/// ```
/// crossbeam_utils::thread::scope(|scope| {
///     scope.spawn(|| println!("Exiting scope"));
///     scope.spawn(|| println!("Running child thread in scope"));
/// }).unwrap();
/// ```
pub fn scope<'env, F, R>(f: F) -> thread::Result<R>
where
    F: FnOnce(&Scope<'env>) -> R,
{
    let scope = Scope {
        joins: RefCell::new(Vec::new()),
        _marker: PhantomData,
    };

    // Execute the scoped function, but catch any panics.
    let result = panic::catch_unwind(panic::AssertUnwindSafe(|| f(&scope)));
    // Join all remaining spawned threads.
    let mut panics = scope.join_all();

    if panics.is_empty() {
        result.map_err(|res| Box::new(vec![res]) as _)
    } else {
        if let Err(err) = result {
            panics.reserve(1);
            panics.insert(0, err);
        }

        Err(Box::new(panics))
    }
}

pub struct Scope<'env> {
    /// The list of the thread join jobs.
    joins: RefCell<Vec<Box<FnBox<thread::Result<()>> + 'env>>>,
    // !Send + !Sync
    _marker: PhantomData<*const ()>,
}

impl<'env> Scope<'env> {
    /// Create a scoped thread.
    ///
    /// `spawn` is similar to the [`spawn`] function in Rust's standard library. The difference is
    /// that this thread is scoped, meaning that it's guaranteed to terminate before the current
    /// stack frame goes away, allowing you to reference the parent stack frame directly. This is
    /// ensured by having the parent thread join on the child thread before the scope exits.
    ///
    /// [`spawn`]: https://doc.rust-lang.org/std/thread/fn.spawn.html
    pub fn spawn<'scope, F, T>(&'scope self, f: F) -> ScopedJoinHandle<'scope, T>
    where
        F: FnOnce() -> T,
        F: Send + 'env,
        T: Send + 'env,
    {
        self.builder().spawn(f).unwrap()
    }

    /// Generates the base configuration for spawning a scoped thread, from which configuration
    /// methods can be chained.
    pub fn builder<'scope>(&'scope self) -> ScopedThreadBuilder<'scope, 'env> {
        ScopedThreadBuilder {
            scope: self,
            builder: thread::Builder::new(),
        }
    }

    /// Join all remaining threads and return all potential error payloads
    fn join_all(self) -> Vec<Box<Any + Send + 'static>> {
        self
            .joins
            .into_inner()
            .into_iter()
            .filter_map(|join| join.call_box().err())
            .collect()
    }
}

impl<'env> fmt::Debug for Scope<'env> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "Scope {{ ... }}")
    }
}

/// Scoped thread configuration. Provides detailed control over the properties and behavior of new
/// scoped threads.
pub struct ScopedThreadBuilder<'scope, 'env: 'scope> {
    scope: &'scope Scope<'env>,
    builder: thread::Builder,
}

impl<'scope, 'env> ScopedThreadBuilder<'scope, 'env> {
    /// Names the thread-to-be. Currently the name is used for identification only in panic
    /// messages.
    pub fn name(mut self, name: String) -> ScopedThreadBuilder<'scope, 'env> {
        self.builder = self.builder.name(name);
        self
    }

    /// Sets the size of the stack for the new thread.
    pub fn stack_size(mut self, size: usize) -> ScopedThreadBuilder<'scope, 'env> {
        self.builder = self.builder.stack_size(size);
        self
    }

    /// Spawns a new thread, and returns a join handle for it.
    pub fn spawn<F, T>(self, f: F) -> io::Result<ScopedJoinHandle<'scope, T>>
    where
        F: FnOnce() -> T,
        F: Send + 'env,
        T: Send + 'env,
    {
        let result = Arc::new(Mutex::new(None));

        let join_handle = {
            let mut thread_result = Arc::clone(&result);

            let closure = move || {
                *thread_result.lock().unwrap() = Some(f());
            };
            let closure: Box<FnBox<()> + Send + 'env> = Box::new(closure);
            let closure: Box<FnBox<()> + Send + 'static> = unsafe { mem::transmute(closure) };

            self.builder.spawn(move || closure.call_box())?
        };

        let thread = join_handle.thread().clone();
        let join_state = JoinState::<T>::new(join_handle, result);

        let handle = ScopedJoinHandle {
            inner: Arc::new(Mutex::new(Some(join_state))),
            thread,
            _marker: PhantomData,
        };

        let deferred_handle = Arc::clone(&handle.inner);
        self.scope.joins.borrow_mut().push(Box::new(move || {
            let state = deferred_handle.lock().unwrap().take();
            if let Some(state) = state {
                state.join().map(|_| ())
            } else {
                Ok(())
            }
        }));

        Ok(handle)
    }
}

unsafe impl<'scope, T> Send for ScopedJoinHandle<'scope, T> {}
unsafe impl<'scope, T> Sync for ScopedJoinHandle<'scope, T> {}

/// A handle to a scoped thread
pub struct ScopedJoinHandle<'scope, T: 'scope> {
    inner: Arc<Mutex<Option<JoinState<T>>>>,
    thread: thread::Thread,
    _marker: PhantomData<&'scope T>,
}

impl<'scope, T> ScopedJoinHandle<'scope, T> {
    /// Waits for the associated thread to finish.
    ///
    /// If the child thread panics, [`Err`] is returned with the parameter given to [`panic`].
    ///
    /// [`Err`]: https://doc.rust-lang.org/std/result/enum.Result.html#variant.Err
    /// [`panic`]: https://doc.rust-lang.org/std/macro.panic.html
    ///
    /// # Panics
    ///
    /// This function may panic on some platforms if a thread attempts to join itself or otherwise
    /// may create a deadlock with joining threads.
    pub fn join(self) -> thread::Result<T> {
        let state = self.inner.lock().unwrap().take();
        state.unwrap().join()
    }

    /// Gets the underlying [`std::thread::Thread`] handle.
    ///
    /// [`std::thread::Thread`]: https://doc.rust-lang.org/std/thread/struct.Thread.html
    pub fn thread(&self) -> &thread::Thread {
        &self.thread
    }
}

impl<'scope, T> fmt::Debug for ScopedJoinHandle<'scope, T> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "ScopedJoinHandle {{ ... }}")
    }
}

type ScopedThreadResult<T> = Arc<Mutex<Option<T>>>;

struct JoinState<T> {
    join_handle: thread::JoinHandle<()>,
    result: ScopedThreadResult<T>,
}

impl<T> JoinState<T> {
    fn new(join_handle: thread::JoinHandle<()>, result: ScopedThreadResult<T>) -> JoinState<T> {
        JoinState {
            join_handle,
            result,
        }
    }

    fn join(self) -> thread::Result<T> {
        let result = self.result;
        self.join_handle
            .join()
            .map(|_| result.lock().unwrap().take().unwrap())
    }
}

trait FnBox<T> {
    fn call_box(self: Box<Self>) -> T;
}

impl<T, F: FnOnce() -> T> FnBox<T> for F {
    fn call_box(self: Box<Self>) -> T {
        (*self)()
    }
}

/// Returns a `usize` that identifies the current thread.
///
/// Each thread is associated with an 'index'. While there are no particular guarantees, indices
/// usually tend to be consecutive numbers between 0 and the number of running threads.
///
/// Since this function accesses TLS, `None` might be returned if the current thread's TLS is
/// tearing down.
#[inline]
pub fn current_index() -> Option<usize> {
    REGISTRATION.try_with(|reg| reg.index).ok()
}

/// The global registry keeping track of registered threads and indices.
struct ThreadIndices {
    /// Mapping from `ThreadId` to thread index.
    mapping: HashMap<ThreadId, usize>,

    /// A list of free indices.
    free_list: Vec<usize>,

    /// The next index to allocate if the free list is empty.
    next_index: usize,
}

lazy_static! {
    static ref THREAD_INDICES: Mutex<ThreadIndices> = Mutex::new(ThreadIndices {
        mapping: HashMap::new(),
        free_list: Vec::new(),
        next_index: 0,
    });
}

/// A registration of a thread with an index.
///
/// When dropped, unregisters the thread and frees the reserved index.
struct Registration {
    index: usize,
    thread_id: ThreadId,
}

impl Drop for Registration {
    fn drop(&mut self) {
        let mut indices = THREAD_INDICES.lock().unwrap();
        indices.mapping.remove(&self.thread_id);
        indices.free_list.push(self.index);
    }
}

thread_local! {
    static REGISTRATION: Registration = {
        let thread_id = thread::current().id();
        let mut indices = THREAD_INDICES.lock().unwrap();

        let index = match indices.free_list.pop() {
            Some(i) => i,
            None => {
                let i = indices.next_index;
                indices.next_index += 1;
                i
            }
        };
        indices.mapping.insert(thread_id, index);

        Registration {
            index,
            thread_id,
        }
    };
}
<|endoftext|>


<commit_before>//! Standard symbolic constants and types
//!
use {Error, Result, NixPath, AsExtStr, from_ffi};
use errno::Errno;
use fcntl::{fcntl, Fd, OFlag, O_NONBLOCK, O_CLOEXEC, FD_CLOEXEC};
use fcntl::FcntlArg::{F_SETFD, F_SETFL};
use libc::{c_char, c_void, c_int, size_t, pid_t, off_t};
use std::{mem, ptr};
use std::ffi::CString;

#[cfg(any(target_os = "linux", target_os = "android"))]
pub use self::linux::*;

mod ffi {
    use libc::{c_char, c_int, size_t};
    pub use libc::{close, read, write, pipe, ftruncate, unlink};
    pub use libc::funcs::posix88::unistd::fork;

    extern {
        // duplicate a file descriptor
        // doc: http://man7.org/linux/man-pages/man2/dup.2.html
        pub fn dup(oldfd: c_int) -> c_int;
        pub fn dup2(oldfd: c_int, newfd: c_int) -> c_int;

        // change working directory
        // doc: http://man7.org/linux/man-pages/man2/chdir.2.html
        pub fn chdir(path: *const c_char) -> c_int;

        // execute program
        // doc: http://man7.org/linux/man-pages/man2/execve.2.html
        pub fn execve(filename: *const c_char, argv: *const *const c_char, envp: *const *const c_char) -> c_int;

        // run the current process in the background
        // doc: http://man7.org/linux/man-pages/man3/daemon.3.html
        pub fn daemon(nochdir: c_int, noclose: c_int) -> c_int;

        // sets the hostname to the value given
        // doc: http://man7.org/linux/man-pages/man2/gethostname.2.html
        pub fn gethostname(name: *mut c_char, len: size_t) -> c_int;

        // gets the hostname
        // doc: http://man7.org/linux/man-pages/man2/gethostname.2.html
        pub fn sethostname(name: *const c_char, len: size_t) -> c_int;
    }
}

#[derive(Clone, Copy)]
pub enum Fork {
    Parent(pid_t),
    Child
}

impl Fork {
    pub fn is_child(&self) -> bool {
        match *self {
            Fork::Child => true,
            _ => false
        }
    }

    pub fn is_parent(&self) -> bool {
        match *self {
            Fork::Parent(_) => true,
            _ => false
        }
    }
}

pub fn fork() -> Result<Fork> {
    use self::Fork::*;

    let res = unsafe { ffi::fork() };

    if res < 0 {
        return Err(Error::Sys(Errno::last()));
    } else if res == 0 {
        Ok(Child)
    } else {
        Ok(Parent(res))
    }
}

#[inline]
pub fn dup(oldfd: Fd) -> Result<Fd> {
    let res = unsafe { ffi::dup(oldfd) };

    if res < 0 {
        return Err(Error::Sys(Errno::last()));
    }

    Ok(res)
}

#[inline]
pub fn dup2(oldfd: Fd, newfd: Fd) -> Result<Fd> {
    let res = unsafe { ffi::dup2(oldfd, newfd) };

    if res < 0 {
        return Err(Error::Sys(Errno::last()));
    }

    Ok(res)
}

pub fn dup3(oldfd: Fd, newfd: Fd, flags: OFlag) -> Result<Fd> {
    dup3_polyfill(oldfd, newfd, flags)
}

#[inline]
fn dup3_polyfill(oldfd: Fd, newfd: Fd, flags: OFlag) -> Result<Fd> {
    use errno::EINVAL;

    if oldfd == newfd {
        return Err(Error::Sys(Errno::EINVAL));
    }

    let fd = try!(dup2(oldfd, newfd));

    if flags.contains(O_CLOEXEC) {
        if let Err(e) = fcntl(fd, F_SETFD(FD_CLOEXEC)) {
            let _ = close(fd);
            return Err(e);
        }
    }

    Ok(fd)
}

#[inline]
pub fn chdir<P: ?Sized + NixPath>(path: &P) -> Result<()> {
    let res = try!(path.with_nix_path(|osstr| {
        unsafe { ffi::chdir(osstr.as_ext_str()) }
    }));

    if res != 0 {
        return Err(Error::Sys(Errno::last()));
    }

    return Ok(())
}

#[inline]
pub fn execve(filename: &CString, args: &[CString], env: &[CString]) -> Result<()> {
    let mut args_p: Vec<*const c_char> = args.iter().map(|s| s.as_ptr()).collect();
    args_p.push(ptr::null());

    let mut env_p: Vec<*const c_char> = env.iter().map(|s| s.as_ptr()).collect();
    env_p.push(ptr::null());

    let res = unsafe {
        ffi::execve(filename.as_ptr(), args_p.as_ptr(), env_p.as_ptr())
    };

    if res != 0 {
        return Err(Error::Sys(Errno::last()));
    }

    unreachable!()
}

pub fn daemon(nochdir: bool, noclose: bool) -> Result<()> {
    let res = unsafe { ffi::daemon(nochdir as c_int, noclose as c_int) };
    from_ffi(res)
}

pub fn sethostname(name: &[u8]) -> Result<()> {
    let ptr = name.as_ptr() as *const c_char;
    let len = name.len() as size_t;

    let res = unsafe { ffi::sethostname(ptr, len) };
    from_ffi(res)
}

pub fn gethostname(name: &mut [u8]) -> Result<()> {
    let ptr = name.as_mut_ptr() as *mut c_char;
    let len = name.len() as size_t;

    let res = unsafe { ffi::gethostname(ptr, len) };
    from_ffi(res)
}

pub fn close(fd: Fd) -> Result<()> {
    let res = unsafe { ffi::close(fd) };
    from_ffi(res)
}

pub fn read(fd: Fd, buf: &mut [u8]) -> Result<usize> {
    let res = unsafe { ffi::read(fd, buf.as_mut_ptr() as *mut c_void, buf.len() as size_t) };

    if res < 0 {
        return Err(Error::Sys(Errno::last()));
    }

    return Ok(res as usize)
}

pub fn write(fd: Fd, buf: &[u8]) -> Result<usize> {
    let res = unsafe { ffi::write(fd, buf.as_ptr() as *const c_void, buf.len() as size_t) };

    if res < 0 {
        return Err(Error::Sys(Errno::last()));
    }

    return Ok(res as usize)
}

pub fn pipe() -> Result<(Fd, Fd)> {
    unsafe {
        let mut res;
        let mut fds: [c_int; 2] = mem::uninitialized();

        res = ffi::pipe(fds.as_mut_ptr());

        if res < 0 {
            return Err(Error::Sys(Errno::last()));
        }

        Ok((fds[0], fds[1]))
    }
}

pub fn pipe2(flags: OFlag) -> Result<(Fd, Fd)> {
    unsafe {
        let mut res;
        let mut fds: [c_int; 2] = mem::uninitialized();

        res = ffi::pipe(fds.as_mut_ptr());

        if res < 0 {
            return Err(Error::Sys(Errno::last()));
        }

        try!(pipe2_setflags(fds[0], fds[1], flags));

        Ok((fds[0], fds[1]))
    }
}

fn pipe2_setflags(fd1: Fd, fd2: Fd, flags: OFlag) -> Result<()> {
    let mut res = Ok(());

    if flags.contains(O_CLOEXEC) {
        res = res
            .and_then(|_| fcntl(fd1, F_SETFD(FD_CLOEXEC)))
            .and_then(|_| fcntl(fd2, F_SETFD(FD_CLOEXEC)));
    }

    if flags.contains(O_NONBLOCK) {
        res = res
            .and_then(|_| fcntl(fd1, F_SETFL(O_NONBLOCK)))
            .and_then(|_| fcntl(fd2, F_SETFL(O_NONBLOCK)));
    }

    match res {
        Ok(_) => Ok(()),
        Err(e) => {
            let _ = close(fd1);
            let _ = close(fd2);
            return Err(e);
        }
    }
}

pub fn ftruncate(fd: Fd, len: off_t) -> Result<()> {
    if unsafe { ffi::ftruncate(fd, len) } < 0 {
        Err(Error::Sys(Errno::last()))
    } else {
        Ok(())
    }
}

pub fn isatty(fd: Fd) -> Result<bool> {
    use libc;

    if unsafe { libc::isatty(fd) } == 1 {
        Ok(true)
    } else {
        match Errno::last() {
            // ENOTTY means `fd` is a valid file descriptor, but not a TTY, so
            // we return `Ok(false)`
            Errno::ENOTTY => Ok(false),
            err => Err(Error::Sys(err))
        }
    }
}

pub fn unlink<P: ?Sized + NixPath>(path: &P) -> Result<()> {
    let res = try!(path.with_nix_path(|osstr| {
    unsafe {
        ffi::unlink(osstr.as_ext_str())
    }
    }));
    from_ffi(res)
}

#[cfg(any(target_os = "linux", target_os = "android"))]
mod linux {
    use sys::syscall::{syscall, SYSPIVOTROOT};
    use errno::Errno;
    use {Error, Result, NixPath};

    pub fn pivot_root<P1: ?Sized + NixPath, P2: ?Sized + NixPath>(
            new_root: &P1, put_old: &P2) -> Result<()> {
        let res = try!(try!(new_root.with_nix_path(|new_root| {
            put_old.with_nix_path(|put_old| {
                unsafe {
                    syscall(SYSPIVOTROOT, new_root, put_old)
                }
            })
        })));

        if res != 0 {
            return Err(Error::Sys(Errno::last()));
        }

        Ok(())
    }
}
<commit_msg>feat: add chroot syscall<commit_after>//! Standard symbolic constants and types
//!
use {Error, Result, NixPath, AsExtStr, from_ffi};
use errno::Errno;
use fcntl::{fcntl, Fd, OFlag, O_NONBLOCK, O_CLOEXEC, FD_CLOEXEC};
use fcntl::FcntlArg::{F_SETFD, F_SETFL};
use libc::{c_char, c_void, c_int, size_t, pid_t, off_t};
use std::{mem, ptr};
use std::ffi::CString;

#[cfg(any(target_os = "linux", target_os = "android"))]
pub use self::linux::*;

mod ffi {
    use libc::{c_char, c_int, size_t};
    pub use libc::{close, read, write, pipe, ftruncate, unlink};
    pub use libc::funcs::posix88::unistd::fork;

    extern {
        // duplicate a file descriptor
        // doc: http://man7.org/linux/man-pages/man2/dup.2.html
        pub fn dup(oldfd: c_int) -> c_int;
        pub fn dup2(oldfd: c_int, newfd: c_int) -> c_int;

        // change working directory
        // doc: http://man7.org/linux/man-pages/man2/chdir.2.html
        pub fn chdir(path: *const c_char) -> c_int;

        // execute program
        // doc: http://man7.org/linux/man-pages/man2/execve.2.html
        pub fn execve(filename: *const c_char, argv: *const *const c_char, envp: *const *const c_char) -> c_int;

        // run the current process in the background
        // doc: http://man7.org/linux/man-pages/man3/daemon.3.html
        pub fn daemon(nochdir: c_int, noclose: c_int) -> c_int;

        // sets the hostname to the value given
        // doc: http://man7.org/linux/man-pages/man2/gethostname.2.html
        pub fn gethostname(name: *mut c_char, len: size_t) -> c_int;

        // gets the hostname
        // doc: http://man7.org/linux/man-pages/man2/gethostname.2.html
        pub fn sethostname(name: *const c_char, len: size_t) -> c_int;

        // change root directory
        // doc: http://man7.org/linux/man-pages/man2/gethostname.2.html
        pub fn chroot(path: *const c_char) -> c_int;
    }
}

#[derive(Clone, Copy)]
pub enum Fork {
    Parent(pid_t),
    Child
}

impl Fork {
    pub fn is_child(&self) -> bool {
        match *self {
            Fork::Child => true,
            _ => false
        }
    }

    pub fn is_parent(&self) -> bool {
        match *self {
            Fork::Parent(_) => true,
            _ => false
        }
    }
}

pub fn fork() -> Result<Fork> {
    use self::Fork::*;

    let res = unsafe { ffi::fork() };

    if res < 0 {
        return Err(Error::Sys(Errno::last()));
    } else if res == 0 {
        Ok(Child)
    } else {
        Ok(Parent(res))
    }
}

#[inline]
pub fn dup(oldfd: Fd) -> Result<Fd> {
    let res = unsafe { ffi::dup(oldfd) };

    if res < 0 {
        return Err(Error::Sys(Errno::last()));
    }

    Ok(res)
}

#[inline]
pub fn dup2(oldfd: Fd, newfd: Fd) -> Result<Fd> {
    let res = unsafe { ffi::dup2(oldfd, newfd) };

    if res < 0 {
        return Err(Error::Sys(Errno::last()));
    }

    Ok(res)
}

pub fn dup3(oldfd: Fd, newfd: Fd, flags: OFlag) -> Result<Fd> {
    dup3_polyfill(oldfd, newfd, flags)
}

#[inline]
fn dup3_polyfill(oldfd: Fd, newfd: Fd, flags: OFlag) -> Result<Fd> {
    use errno::EINVAL;

    if oldfd == newfd {
        return Err(Error::Sys(Errno::EINVAL));
    }

    let fd = try!(dup2(oldfd, newfd));

    if flags.contains(O_CLOEXEC) {
        if let Err(e) = fcntl(fd, F_SETFD(FD_CLOEXEC)) {
            let _ = close(fd);
            return Err(e);
        }
    }

    Ok(fd)
}

#[inline]
pub fn chdir<P: ?Sized + NixPath>(path: &P) -> Result<()> {
    let res = try!(path.with_nix_path(|osstr| {
        unsafe { ffi::chdir(osstr.as_ext_str()) }
    }));

    if res != 0 {
        return Err(Error::Sys(Errno::last()));
    }

    return Ok(())
}

#[inline]
pub fn execve(filename: &CString, args: &[CString], env: &[CString]) -> Result<()> {
    let mut args_p: Vec<*const c_char> = args.iter().map(|s| s.as_ptr()).collect();
    args_p.push(ptr::null());

    let mut env_p: Vec<*const c_char> = env.iter().map(|s| s.as_ptr()).collect();
    env_p.push(ptr::null());

    let res = unsafe {
        ffi::execve(filename.as_ptr(), args_p.as_ptr(), env_p.as_ptr())
    };

    if res != 0 {
        return Err(Error::Sys(Errno::last()));
    }

    unreachable!()
}

pub fn daemon(nochdir: bool, noclose: bool) -> Result<()> {
    let res = unsafe { ffi::daemon(nochdir as c_int, noclose as c_int) };
    from_ffi(res)
}

pub fn sethostname(name: &[u8]) -> Result<()> {
    let ptr = name.as_ptr() as *const c_char;
    let len = name.len() as size_t;

    let res = unsafe { ffi::sethostname(ptr, len) };
    from_ffi(res)
}

pub fn gethostname(name: &mut [u8]) -> Result<()> {
    let ptr = name.as_mut_ptr() as *mut c_char;
    let len = name.len() as size_t;

    let res = unsafe { ffi::gethostname(ptr, len) };
    from_ffi(res)
}

pub fn close(fd: Fd) -> Result<()> {
    let res = unsafe { ffi::close(fd) };
    from_ffi(res)
}

pub fn read(fd: Fd, buf: &mut [u8]) -> Result<usize> {
    let res = unsafe { ffi::read(fd, buf.as_mut_ptr() as *mut c_void, buf.len() as size_t) };

    if res < 0 {
        return Err(Error::Sys(Errno::last()));
    }

    return Ok(res as usize)
}

pub fn write(fd: Fd, buf: &[u8]) -> Result<usize> {
    let res = unsafe { ffi::write(fd, buf.as_ptr() as *const c_void, buf.len() as size_t) };

    if res < 0 {
        return Err(Error::Sys(Errno::last()));
    }

    return Ok(res as usize)
}

pub fn pipe() -> Result<(Fd, Fd)> {
    unsafe {
        let mut res;
        let mut fds: [c_int; 2] = mem::uninitialized();

        res = ffi::pipe(fds.as_mut_ptr());

        if res < 0 {
            return Err(Error::Sys(Errno::last()));
        }

        Ok((fds[0], fds[1]))
    }
}

pub fn pipe2(flags: OFlag) -> Result<(Fd, Fd)> {
    unsafe {
        let mut res;
        let mut fds: [c_int; 2] = mem::uninitialized();

        res = ffi::pipe(fds.as_mut_ptr());

        if res < 0 {
            return Err(Error::Sys(Errno::last()));
        }

        try!(pipe2_setflags(fds[0], fds[1], flags));

        Ok((fds[0], fds[1]))
    }
}

fn pipe2_setflags(fd1: Fd, fd2: Fd, flags: OFlag) -> Result<()> {
    let mut res = Ok(());

    if flags.contains(O_CLOEXEC) {
        res = res
            .and_then(|_| fcntl(fd1, F_SETFD(FD_CLOEXEC)))
            .and_then(|_| fcntl(fd2, F_SETFD(FD_CLOEXEC)));
    }

    if flags.contains(O_NONBLOCK) {
        res = res
            .and_then(|_| fcntl(fd1, F_SETFL(O_NONBLOCK)))
            .and_then(|_| fcntl(fd2, F_SETFL(O_NONBLOCK)));
    }

    match res {
        Ok(_) => Ok(()),
        Err(e) => {
            let _ = close(fd1);
            let _ = close(fd2);
            return Err(e);
        }
    }
}

pub fn ftruncate(fd: Fd, len: off_t) -> Result<()> {
    if unsafe { ffi::ftruncate(fd, len) } < 0 {
        Err(Error::Sys(Errno::last()))
    } else {
        Ok(())
    }
}

pub fn isatty(fd: Fd) -> Result<bool> {
    use libc;

    if unsafe { libc::isatty(fd) } == 1 {
        Ok(true)
    } else {
        match Errno::last() {
            // ENOTTY means `fd` is a valid file descriptor, but not a TTY, so
            // we return `Ok(false)`
            Errno::ENOTTY => Ok(false),
            err => Err(Error::Sys(err))
        }
    }
}

pub fn unlink<P: ?Sized + NixPath>(path: &P) -> Result<()> {
    let res = try!(path.with_nix_path(|osstr| {
    unsafe {
        ffi::unlink(osstr.as_ext_str())
    }
    }));
    from_ffi(res)
}

#[inline]
pub fn chroot<P: ?Sized + NixPath>(path: &P) -> Result<()> {
    let res = try!(path.with_nix_path(|osstr| {
        unsafe { ffi::chroot(osstr.as_ext_str()) }
    }));

    if res != 0 {
        return Err(Error::Sys(Errno::last()));
    }

    Ok(())
}

#[cfg(any(target_os = "linux", target_os = "android"))]
mod linux {
    use sys::syscall::{syscall, SYSPIVOTROOT};
    use errno::Errno;
    use {Error, Result, NixPath};

    pub fn pivot_root<P1: ?Sized + NixPath, P2: ?Sized + NixPath>(
            new_root: &P1, put_old: &P2) -> Result<()> {
        let res = try!(try!(new_root.with_nix_path(|new_root| {
            put_old.with_nix_path(|put_old| {
                unsafe {
                    syscall(SYSPIVOTROOT, new_root, put_old)
                }
            })
        })));

        if res != 0 {
            return Err(Error::Sys(Errno::last()));
        }

        Ok(())
    }
}
<|endoftext|>


<commit_before>use metric::{Measured, Line, Grapheme, Metric};
use super::{NodeLink, LeafRepr };

use self::Value::*;

use std::cell::Cell;
use std::convert;
use std::default::Default;
use std::fmt;
use std::ops;

/// A lazily-evaluated field
#[derive(Clone, Debug)]
struct Lazy<T: Copy>(Cell<Option<T>>);

impl<T> Lazy<T>
where T: Copy {

    #[inline]
    pub fn get_or_else<F>(&self, f: F) -> T
    where F: FnOnce() -> T {
        if let Some(value) = self.0.get() {
            value
        } else {
            let value = f();
            self.0.set(Some(value));
            value
        }
    }

    #[inline]
    pub fn new() -> Self {
        Lazy(Cell::new(None))
    }

}

impl<T> Default for Lazy<T>
where T: Copy {
    fn default() -> Self {
        Self::new()
    }
}

macro_rules! lazy_field {
    ($method: ident, $field: ident, $ty:ty) => {
        #[inline] fn $method(&self) -> $ty {
            self.$field.get_or_else(|| { self.value.$method() })
        }

    }
}

/// A `Node`.
#[derive(Clone, Debug, Default)]
pub struct Node { len: Lazy<usize>
                , weight: Lazy<usize>
                , line_count: Lazy<Line>
                , line_weight: Lazy<Line>
                , grapheme_count: Lazy<Grapheme>
                , grapheme_weight: Lazy<Grapheme>
                , pub value: Value
                }

impl Node {
    pub fn new(value: Value) -> Self {
        Node { value: value, ..Default::default() }
    }

    pub fn spanning(&self, i: usize, span_len: usize) -> (&Node, usize)
    where Node: Measured<usize> {
        assert!(self.len() >= span_len);
        match **self {
            Branch { ref right, ref left } if <Node as Measured<usize>>::measure_weight(self) < i => {
                // if this node is a branch, and the weight is less than the
                // index, where the span begins, then the first index of the
                // span is on the right side
                let span_i = or_zero!(i, left.len());
                assert!(or_zero!(right.len(), span_i) >= span_len);
                right.spanning(span_i, span_len)
            }
          , Branch { ref left, .. }
            // if the left child is long enough to contain the entire span,
            // walk to the left child
            if or_zero!(left.len(), i) >= span_len => left.spanning(i, span_len)
         ,  Leaf(_) | Branch {..} =>
            // if this function has walked as far as a leaf node,
            // then that leaf must be the spanning node. return it;
            //
            // otherwise, if the node is a branch node and the span is longer
            // than the left child, then this node must be the minimum
            // spanning node
            (self, i)
        }
    }
}

impl fmt::Display for Node {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.strings()
            .fold(Ok(()), |r, string| r.and_then(|_| write!(f, "{}", string)))
    }
}

impl convert::Into<NodeLink> for Node {
    #[inline] fn into(self) -> NodeLink {
        NodeLink::new(self)
    }
}

impl ops::Deref for Node {
    type Target = Value;
    fn deref(&self) -> &Value { &self.value }
}

impl Measured<usize> for Node {

        #[inline] fn to_byte_index(&self, index: usize) -> Option<usize>  {
             Some(index)
        }

        lazy_field!(measure, len, usize);
        lazy_field!(measure_weight, weight, usize);

}

impl Measured<Grapheme> for Node {

        #[inline] fn to_byte_index(&self, index: Grapheme) -> Option<usize>  {
            self.value.to_byte_index(index)
        }

        lazy_field!(measure, grapheme_count, Grapheme);
        lazy_field!(measure_weight, grapheme_weight, Grapheme);

}

impl Measured<Line> for Node {

        #[inline] fn to_byte_index(&self, index: Line) -> Option<usize>  {
            self.value.to_byte_index(index)
        }

        lazy_field!(measure, line_count, Line);
        lazy_field!(measure_weight, line_weight, Line);

}

impl<M> ops::Index<M> for Node
where M: Metric
    , Node: Measured<M>
    , LeafRepr: Measured<M>
    {
    type Output = str;

    fn index(&self, i: M) -> &str {
        let len = self.measure();
        assert!( i < len
               , "Node::index: index {:?} out of bounds (length {:?})", i, len);
        match **self {
            Leaf(ref string) => {
                let idx = string.to_byte_index(i)
                                .expect("index out of bounds!");
                &string[idx..idx+1]
            }
          , Branch { ref right, .. } if len < i =>
                &right[i - len]
          , Branch { ref left, .. } => &left[i]
        }
    }
}

/// A `Node` in the `Rope`'s tree.
///
/// A `Node` is either a `Leaf` holding a `String`, or a
/// a `Branch` concatenating together two `Node`s.
#[derive(Clone, Debug)]
pub enum Value {
    /// A leaf node
    Leaf(LeafRepr)
  , /// A branch concatenating together `l`eft and `r`ight nodes.
    Branch { /// The left branch node
             left: NodeLink
           , /// The right branch node
             right: NodeLink }
}

impl Value {
    #[inline]
    pub fn new_branch(left: NodeLink, right: NodeLink) -> Self {
        Branch { left: left, right: right }
    }
}

impl<M> Measured<M> for Value
where M: Metric
    , LeafRepr: Measured<M>
    , Node: Measured<M>
{
    fn to_byte_index(&self, index: M) -> Option<usize> {
        unimplemented!()
    }

    fn measure(&self) -> M {
        match *self {
            Leaf(ref r) => r.measure()
          , Branch { ref left, ref right } =>
                left.measure() + right.measure()
        }
    }

    fn measure_weight(&self) -> M {
        match *self {
            Leaf(ref r) => r.measure_weight()
          , Branch { ref left, ref right } =>
                left.measure()
        }
    }

}

impl convert::Into<Node> for Value {
    #[inline] fn into(self) -> Node {
        Node::new(self)
    }
}

impl Default for Value {
    fn default() -> Self {
        Leaf(LeafRepr::default())
    }
}
<commit_msg>feat(node): nicer fmt::Debug implementation for lazy fields<commit_after>use metric::{Measured, Line, Grapheme, Metric};
use super::{NodeLink, LeafRepr };

use self::Value::*;

use std::cell::Cell;
use std::convert;
use std::default::Default;
use std::fmt;
use std::ops;

/// A lazily-evaluated field
#[derive(Clone)]
struct Lazy<T: Copy>(Cell<Option<T>>);

impl<T> Lazy<T>
where T: Copy {

    #[inline]
    pub fn get_or_else<F>(&self, f: F) -> T
    where F: FnOnce() -> T {
        if let Some(value) = self.0.get() {
            value
        } else {
            let value = f();
            self.0.set(Some(value));
            value
        }
    }

    #[inline]
    pub fn new() -> Self {
        Lazy(Cell::new(None))
    }

}

impl<T> Default for Lazy<T>
where T: Copy {
    fn default() -> Self {
        Self::new()
    }
}

impl<T> fmt::Debug for Lazy<T>
where T: fmt::Debug
    , T: Copy {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self.0.get() { Some(value) => value.fmt(f)
                           , None => write!(f, "?")

        }
    }
}
macro_rules! lazy_field {
    ($method: ident, $field: ident, $ty:ty) => {
        #[inline] fn $method(&self) -> $ty {
            self.$field.get_or_else(|| { self.value.$method() })
        }

    }
}

/// A `Node`.
#[derive(Clone, Debug, Default)]
pub struct Node { len: Lazy<usize>
                , weight: Lazy<usize>
                , line_count: Lazy<Line>
                , line_weight: Lazy<Line>
                , grapheme_count: Lazy<Grapheme>
                , grapheme_weight: Lazy<Grapheme>
                , pub value: Value
                }

impl Node {
    pub fn new(value: Value) -> Self {
        Node { value: value, ..Default::default() }
    }

    pub fn spanning(&self, i: usize, span_len: usize) -> (&Node, usize)
    where Node: Measured<usize> {
        assert!(self.len() >= span_len);
        match **self {
            Branch { ref right, ref left } if <Node as Measured<usize>>::measure_weight(self) < i => {
                // if this node is a branch, and the weight is less than the
                // index, where the span begins, then the first index of the
                // span is on the right side
                let span_i = or_zero!(i, left.len());
                assert!(or_zero!(right.len(), span_i) >= span_len);
                right.spanning(span_i, span_len)
            }
          , Branch { ref left, .. }
            // if the left child is long enough to contain the entire span,
            // walk to the left child
            if or_zero!(left.len(), i) >= span_len => left.spanning(i, span_len)
         ,  Leaf(_) | Branch {..} =>
            // if this function has walked as far as a leaf node,
            // then that leaf must be the spanning node. return it;
            //
            // otherwise, if the node is a branch node and the span is longer
            // than the left child, then this node must be the minimum
            // spanning node
            (self, i)
        }
    }
}

impl fmt::Display for Node {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.strings()
            .fold(Ok(()), |r, string| r.and_then(|_| write!(f, "{}", string)))
    }
}

impl convert::Into<NodeLink> for Node {
    #[inline] fn into(self) -> NodeLink {
        NodeLink::new(self)
    }
}

impl ops::Deref for Node {
    type Target = Value;
    fn deref(&self) -> &Value { &self.value }
}

impl Measured<usize> for Node {

        #[inline] fn to_byte_index(&self, index: usize) -> Option<usize>  {
             Some(index)
        }

        lazy_field!(measure, len, usize);
        lazy_field!(measure_weight, weight, usize);

}

impl Measured<Grapheme> for Node {

        #[inline] fn to_byte_index(&self, index: Grapheme) -> Option<usize>  {
            self.value.to_byte_index(index)
        }

        lazy_field!(measure, grapheme_count, Grapheme);
        lazy_field!(measure_weight, grapheme_weight, Grapheme);

}

impl Measured<Line> for Node {

        #[inline] fn to_byte_index(&self, index: Line) -> Option<usize>  {
            self.value.to_byte_index(index)
        }

        lazy_field!(measure, line_count, Line);
        lazy_field!(measure_weight, line_weight, Line);

}

impl<M> ops::Index<M> for Node
where M: Metric
    , Node: Measured<M>
    , LeafRepr: Measured<M>
    {
    type Output = str;

    fn index(&self, i: M) -> &str {
        let len = self.measure();
        assert!( i < len
               , "Node::index: index {:?} out of bounds (length {:?})", i, len);
        match **self {
            Leaf(ref string) => {
                let idx = string.to_byte_index(i)
                                .expect("index out of bounds!");
                &string[idx..idx+1]
            }
          , Branch { ref right, .. } if len < i =>
                &right[i - len]
          , Branch { ref left, .. } => &left[i]
        }
    }
}

/// A `Node` in the `Rope`'s tree.
///
/// A `Node` is either a `Leaf` holding a `String`, or a
/// a `Branch` concatenating together two `Node`s.
#[derive(Clone, Debug)]
pub enum Value {
    /// A leaf node
    Leaf(LeafRepr)
  , /// A branch concatenating together `l`eft and `r`ight nodes.
    Branch { /// The left branch node
             left: NodeLink
           , /// The right branch node
             right: NodeLink }
}

impl Value {
    #[inline]
    pub fn new_branch(left: NodeLink, right: NodeLink) -> Self {
        Branch { left: left, right: right }
    }
}

impl<M> Measured<M> for Value
where M: Metric
    , LeafRepr: Measured<M>
    , Node: Measured<M>
{
    fn to_byte_index(&self, index: M) -> Option<usize> {
        unimplemented!()
    }

    fn measure(&self) -> M {
        match *self {
            Leaf(ref r) => r.measure()
          , Branch { ref left, ref right } =>
                left.measure() + right.measure()
        }
    }

    fn measure_weight(&self) -> M {
        match *self {
            Leaf(ref r) => r.measure_weight()
          , Branch { ref left, ref right } =>
                left.measure()
        }
    }

}

impl convert::Into<Node> for Value {
    #[inline] fn into(self) -> Node {
        Node::new(self)
    }
}

impl Default for Value {
    fn default() -> Self {
        Leaf(LeafRepr::default())
    }
}
<|endoftext|>