84 lines
2.4 KiB
Rust
84 lines
2.4 KiB
Rust
use collections::BTreeMap;
|
|
use core::mem;
|
|
use core::sync::atomic::Ordering;
|
|
use spin::RwLock;
|
|
|
|
use arch;
|
|
use syscall::{Result, Error};
|
|
use super::context::Context;
|
|
|
|
/// Context list type
|
|
pub struct ContextList {
|
|
map: BTreeMap<usize, RwLock<Context>>,
|
|
next_id: usize
|
|
}
|
|
|
|
impl ContextList {
|
|
/// Create a new context list.
|
|
pub fn new() -> Self {
|
|
ContextList {
|
|
map: BTreeMap::new(),
|
|
next_id: 1
|
|
}
|
|
}
|
|
|
|
/// Get the nth context.
|
|
pub fn get(&self, id: usize) -> Option<&RwLock<Context>> {
|
|
self.map.get(&id)
|
|
}
|
|
|
|
/// Get the current context.
|
|
pub fn current(&self) -> Option<&RwLock<Context>> {
|
|
self.map.get(&super::CONTEXT_ID.load(Ordering::SeqCst))
|
|
}
|
|
|
|
pub fn iter(&self) -> ::collections::btree_map::Iter<usize, RwLock<Context>> {
|
|
self.map.iter()
|
|
}
|
|
|
|
/// Create a new context.
|
|
pub fn new_context(&mut self) -> Result<&RwLock<Context>> {
|
|
if self.next_id >= super::CONTEXT_MAX_CONTEXTS {
|
|
self.next_id = 1;
|
|
}
|
|
|
|
while self.map.contains_key(&self.next_id) {
|
|
self.next_id += 1;
|
|
}
|
|
|
|
if self.next_id >= super::CONTEXT_MAX_CONTEXTS {
|
|
return Err(Error::TryAgain);
|
|
}
|
|
|
|
let id = self.next_id;
|
|
self.next_id += 1;
|
|
|
|
assert!(self.map.insert(id, RwLock::new(Context::new(id))).is_none());
|
|
|
|
Ok(self.map.get(&id).expect("Failed to insert new context. ID is out of bounds."))
|
|
}
|
|
|
|
/// Spawn a context from a function.
|
|
pub fn spawn(&mut self, func: extern fn()) -> Result<&RwLock<Context>> {
|
|
let context_lock = self.new_context()?;
|
|
{
|
|
let mut context = context_lock.write();
|
|
let mut stack = vec![0; 65536].into_boxed_slice();
|
|
let offset = stack.len() - mem::size_of::<usize>();
|
|
unsafe {
|
|
let offset = stack.len() - mem::size_of::<usize>();
|
|
let func_ptr = stack.as_mut_ptr().offset(offset as isize);
|
|
*(func_ptr as *mut usize) = func as usize;
|
|
}
|
|
context.arch.set_page_table(unsafe { arch::paging::ActivePageTable::new().address() });
|
|
context.arch.set_stack(stack.as_ptr() as usize + offset);
|
|
context.kstack = Some(stack);
|
|
}
|
|
Ok(context_lock)
|
|
}
|
|
|
|
pub fn remove(&mut self, id: usize) -> Option<RwLock<Context>> {
|
|
self.map.remove(&id)
|
|
}
|
|
}
|