redox/kernel/context/event.rs

81 lines
2.2 KiB
Rust

use alloc::arc::{Arc, Weak};
use collections::BTreeMap;
use spin::{Once, RwLock, RwLockReadGuard, RwLockWriteGuard};
use context;
use sync::WaitQueue;
use syscall::data::Event;
type EventList = Weak<WaitQueue<Event>>;
type Registry = BTreeMap<(usize, usize), BTreeMap<(usize, usize), EventList>>;
static REGISTRY: Once<RwLock<Registry>> = Once::new();
/// Initialize registry, called if needed
fn init_registry() -> RwLock<Registry> {
RwLock::new(Registry::new())
}
/// Get the global schemes list, const
fn registry() -> RwLockReadGuard<'static, Registry> {
REGISTRY.call_once(init_registry).read()
}
/// Get the global schemes list, mutable
pub fn registry_mut() -> RwLockWriteGuard<'static, Registry> {
REGISTRY.call_once(init_registry).write()
}
pub fn register(fd: usize, scheme_id: usize, event_id: usize) -> bool {
let (context_id, events) = {
let contexts = context::contexts();
let context_lock = contexts.current().expect("event::register: No context");
let context = context_lock.read();
(context.id, Arc::downgrade(&context.events))
};
let mut registry = registry_mut();
let entry = registry.entry((scheme_id, event_id)).or_insert_with(|| {
BTreeMap::new()
});
if entry.contains_key(&(context_id, fd)) {
false
} else {
entry.insert((context_id, fd), events);
true
}
}
pub fn unregister(fd: usize, scheme_id: usize, event_id: usize) {
let mut registry = registry_mut();
let mut remove = false;
if let Some(entry) = registry.get_mut(&(scheme_id, event_id)) {
entry.remove(&(context::context_id(), fd));
if entry.is_empty() {
remove = true;
}
}
if remove {
registry.remove(&(scheme_id, event_id));
}
}
pub fn trigger(scheme_id: usize, event_id: usize, flags: usize, data: usize) {
let registry = registry();
if let Some(event_lists) = registry.get(&(scheme_id, event_id)) {
for entry in event_lists.iter() {
if let Some(event_list) = entry.1.upgrade() {
event_list.send(Event {
id: (entry.0).1,
flags: flags,
data: data
});
}
}
}
}