Robin Randhawa
1e10cac3e1
Brute-forcing this at present. Would be better to wrap this conditionally for the architecture.
91 lines
2.5 KiB
Rust
91 lines
2.5 KiB
Rust
//! # Context management
|
|
//!
|
|
//! For resources on contexts, please consult [wikipedia](https://en.wikipedia.org/wiki/Context_switch) and [osdev](https://wiki.osdev.org/Context_Switching)
|
|
use alloc::boxed::Box;
|
|
use core::alloc::{GlobalAlloc, Layout};
|
|
use core::sync::atomic::Ordering;
|
|
use spin::{Once, RwLock, RwLockReadGuard, RwLockWriteGuard};
|
|
|
|
pub use self::context::{Context, ContextId, ContextSnapshot, Status, WaitpidKey};
|
|
pub use self::list::ContextList;
|
|
pub use self::switch::switch;
|
|
|
|
#[cfg(target_arch = "aarch64")]
|
|
#[path = "arch/aarch64.rs"]
|
|
mod arch;
|
|
|
|
#[cfg(target_arch = "x86_64")]
|
|
#[path = "arch/x86_64.rs"]
|
|
mod arch;
|
|
|
|
/// Context struct
|
|
mod context;
|
|
|
|
/// Context list
|
|
mod list;
|
|
|
|
/// Context switch function
|
|
mod switch;
|
|
|
|
/// File struct - defines a scheme and a file number
|
|
pub mod file;
|
|
|
|
/// Memory struct - contains a set of pages for a context
|
|
pub mod memory;
|
|
|
|
/// Signal handling
|
|
pub mod signal;
|
|
|
|
/// Timeout handling
|
|
pub mod timeout;
|
|
|
|
/// Limit on number of contexts
|
|
pub const CONTEXT_MAX_CONTEXTS: usize = (isize::max_value() as usize) - 1;
|
|
|
|
/// Maximum context files
|
|
pub const CONTEXT_MAX_FILES: usize = 65_536;
|
|
|
|
/// Contexts list
|
|
static CONTEXTS: Once<RwLock<ContextList>> = Once::new();
|
|
|
|
#[thread_local]
|
|
static CONTEXT_ID: context::AtomicContextId = context::AtomicContextId::default();
|
|
|
|
pub fn init() {
|
|
let mut contexts = contexts_mut();
|
|
let context_lock = contexts.new_context().expect("could not initialize first context");
|
|
let mut context = context_lock.write();
|
|
let mut fx = unsafe { Box::from_raw(crate::ALLOCATOR.alloc(Layout::from_size_align_unchecked(1024, 16)) as *mut [u8; 1024]) };
|
|
for b in fx.iter_mut() {
|
|
*b = 0;
|
|
}
|
|
|
|
context.arch.set_fx(fx.as_ptr() as usize);
|
|
context.kfx = Some(fx);
|
|
context.status = Status::Runnable;
|
|
context.running = true;
|
|
context.cpu_id = Some(crate::cpu_id());
|
|
CONTEXT_ID.store(context.id, Ordering::SeqCst);
|
|
}
|
|
|
|
/// Initialize contexts, called if needed
|
|
fn init_contexts() -> RwLock<ContextList> {
|
|
RwLock::new(ContextList::new())
|
|
}
|
|
|
|
/// Get the global schemes list, const
|
|
pub fn contexts() -> RwLockReadGuard<'static, ContextList> {
|
|
//call once will init_contexts only once during the kernel's exececution, otherwise it will return the current context via a
|
|
//cache.
|
|
CONTEXTS.call_once(init_contexts).read()
|
|
}
|
|
|
|
/// Get the global schemes list, mutable
|
|
pub fn contexts_mut() -> RwLockWriteGuard<'static, ContextList> {
|
|
CONTEXTS.call_once(init_contexts).write()
|
|
}
|
|
|
|
pub fn context_id() -> ContextId {
|
|
CONTEXT_ID.load(Ordering::SeqCst)
|
|
}
|