redox/kernel/context/context.rs
2016-09-17 09:23:36 -06:00

96 lines
2.4 KiB
Rust

use alloc::arc::Arc;
use alloc::boxed::Box;
use collections::Vec;
use spin::Mutex;
use arch;
use super::file::File;
use super::memory::{Memory, SharedMemory};
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub enum Status {
Runnable,
Blocked,
Exited(usize)
}
/// A context, which identifies either a process or a thread
#[derive(Debug)]
pub struct Context {
/// The ID of this context
pub id: usize,
/// Status of context
pub status: Status,
/// Context running or not
pub running: bool,
/// The architecture specific context
pub arch: arch::context::Context,
/// Kernel stack
pub kstack: Option<Box<[u8]>>,
/// Executable image
pub image: Vec<SharedMemory>,
/// User heap
pub heap: Option<SharedMemory>,
/// User stack
pub stack: Option<Memory>,
/// The open files in the scheme
pub files: Arc<Mutex<Vec<Option<File>>>>
}
impl Context {
/// Create a new context
pub fn new(id: usize) -> Context {
Context {
id: id,
status: Status::Blocked,
running: false,
arch: arch::context::Context::new(),
kstack: None,
image: Vec::new(),
heap: None,
stack: None,
files: Arc::new(Mutex::new(Vec::new()))
}
}
/// Add a file to the lowest available slot.
/// Return the file descriptor number or None if no slot was found
pub fn add_file(&mut self, file: File) -> Option<usize> {
let mut files = self.files.lock();
for (i, mut file_option) in files.iter_mut().enumerate() {
if file_option.is_none() {
*file_option = Some(file);
return Some(i);
}
}
let len = files.len();
if len < super::CONTEXT_MAX_FILES {
files.push(Some(file));
Some(len)
} else {
None
}
}
/// Get a file
pub fn get_file(&self, i: usize) -> Option<File> {
let files = self.files.lock();
if i < files.len() {
files[i]
} else {
None
}
}
/// Remove a file
// TODO: adjust files vector to smaller size if possible
pub fn remove_file(&mut self, i: usize) -> Option<File> {
let mut files = self.files.lock();
if i < files.len() {
files[i].take()
} else {
None
}
}
}