Cleanup Redox repo, update Rust, remove old target

kernel/src/scheme/event.rs

@@ -0,0 +1,74 @@
+use alloc::arc::{Arc, Weak};
+use collections::BTreeMap;
+use core::{mem, slice};
+use core::sync::atomic::{AtomicUsize, Ordering};
+use spin::RwLock;
+
+use context;
+use sync::WaitQueue;
+use syscall::data::Event;
+use syscall::error::*;
+use syscall::scheme::Scheme;
+
+pub struct EventScheme {
+    next_id: AtomicUsize,
+    handles: RwLock<BTreeMap<usize, Weak<WaitQueue<Event>>>>
+}
+
+impl EventScheme {
+    pub fn new() -> EventScheme {
+        EventScheme {
+            next_id: AtomicUsize::new(0),
+            handles: RwLock::new(BTreeMap::new())
+        }
+    }
+}
+
+impl Scheme for EventScheme {
+    fn open(&self, _path: &[u8], _flags: usize, _uid: u32, _gid: u32) -> Result<usize> {
+        let handle = {
+            let contexts = context::contexts();
+            let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
+            let context = context_lock.read();
+            context.events.clone()
+        };
+
+        let id = self.next_id.fetch_add(1, Ordering::SeqCst);
+        self.handles.write().insert(id, Arc::downgrade(&handle));
+
+        Ok(id)
+    }
+
+    fn dup(&self, id: usize, _buf: &[u8]) -> Result<usize> {
+        let handle = {
+            let handles = self.handles.read();
+            let handle_weak = handles.get(&id).ok_or(Error::new(EBADF))?;
+            handle_weak.upgrade().ok_or(Error::new(EBADF))?
+        };
+
+        let new_id = self.next_id.fetch_add(1, Ordering::SeqCst);
+        self.handles.write().insert(new_id, Arc::downgrade(&handle));
+        Ok(new_id)
+    }
+
+    fn read(&self, id: usize, buf: &mut [u8]) -> Result<usize> {
+        let handle = {
+            let handles = self.handles.read();
+            let handle_weak = handles.get(&id).ok_or(Error::new(EBADF))?;
+            handle_weak.upgrade().ok_or(Error::new(EBADF))?
+        };
+
+        let event_buf = unsafe { slice::from_raw_parts_mut(buf.as_mut_ptr() as *mut Event, buf.len()/mem::size_of::<Event>()) };
+        Ok(handle.receive_into(event_buf, true) * mem::size_of::<Event>())
+    }
+
+    fn fsync(&self, id: usize) -> Result<usize> {
+        let handles = self.handles.read();
+        let handle_weak = handles.get(&id).ok_or(Error::new(EBADF))?;
+        handle_weak.upgrade().ok_or(Error::new(EBADF)).and(Ok(0))
+    }
+
+    fn close(&self, id: usize) -> Result<usize> {
+        self.handles.write().remove(&id).ok_or(Error::new(EBADF)).and(Ok(0))
+    }
+}