Replace syscall::Scheme with KernelScheme.

src/scheme/debug.rs

@@ -1,12 +1,11 @@
 use core::sync::atomic::{AtomicUsize, Ordering};
-use spin::{Once, RwLock, RwLockReadGuard, RwLockWriteGuard};
+use spin::{Once, RwLock};
 
 use crate::arch::debug::Writer;
 use crate::event;
 use crate::scheme::*;
 use crate::sync::WaitQueue;
 use crate::syscall::flag::{EventFlags, EVENT_READ, F_GETFL, F_SETFL, O_ACCMODE, O_NONBLOCK};
-use crate::syscall::scheme::Scheme;
 use crate::syscall::usercopy::UserSliceRo;
 use crate::syscall::usercopy::UserSliceWo;
 
@@ -22,19 +21,7 @@ struct Handle {
     flags: usize,
 }
 
-static HANDLES: Once<RwLock<BTreeMap<usize, Handle>>> = Once::new();
-
-fn init_handles() -> RwLock<BTreeMap<usize, Handle>> {
-    RwLock::new(BTreeMap::new())
-}
-
-fn handles() -> RwLockReadGuard<'static, BTreeMap<usize, Handle>> {
-    HANDLES.call_once(init_handles).read()
-}
-
-fn handles_mut() -> RwLockWriteGuard<'static, BTreeMap<usize, Handle>> {
-    HANDLES.call_once(init_handles).write()
-}
+static HANDLES: RwLock<BTreeMap<usize, Handle>> = RwLock::new(BTreeMap::new());
 
 /// Add to the input queue
 pub fn debug_input(data: u8) {
@@ -47,7 +34,7 @@ pub fn debug_notify() {
         return;
     };
 
-    for (id, _handle) in handles().iter() {
+    for (id, _handle) in HANDLES.read().iter() {
         event::trigger(scheme_id, *id, EVENT_READ);
     }
 }
@@ -61,9 +48,9 @@ impl DebugScheme {
     }
 }
 
-impl Scheme for DebugScheme {
-    fn open(&self, path: &str, flags: usize, uid: u32, _gid: u32) -> Result<usize> {
-        if uid != 0 {
+impl KernelScheme for DebugScheme {
+    fn kopen(&self, path: &str, flags: usize, ctx: CallerCtx) -> Result<OpenResult> {
+        if ctx.uid != 0 {
             return Err(Error::new(EPERM));
         }
 
@@ -71,16 +58,16 @@ impl Scheme for DebugScheme {
             return Err(Error::new(ENOENT));
         }
 
-        let id = NEXT_ID.fetch_add(1, Ordering::SeqCst);
-        handles_mut().insert(id, Handle {
+        let id = NEXT_ID.fetch_add(1, Ordering::Relaxed);
+        HANDLES.write().insert(id, Handle {
             flags: flags & ! O_ACCMODE
         });
 
-        Ok(id)
+        Ok(OpenResult::SchemeLocal(id))
     }
 
     fn fcntl(&self, id: usize, cmd: usize, arg: usize) -> Result<usize> {
-        let mut handles = handles_mut();
+        let mut handles = HANDLES.write();
         if let Some(handle) = handles.get_mut(&id) {
             match cmd {
                 F_GETFL => Ok(handle.flags),
@@ -97,36 +84,34 @@ impl Scheme for DebugScheme {
 
     fn fevent(&self, id: usize, _flags: EventFlags) -> Result<EventFlags> {
         let _handle = {
-            let handles = handles();
+            let handles = HANDLES.read();
             *handles.get(&id).ok_or(Error::new(EBADF))?
         };
 
         Ok(EventFlags::empty())
     }
 
-    fn fsync(&self, id: usize) -> Result<usize> {
+    fn fsync(&self, id: usize) -> Result<()> {
         let _handle = {
-            let handles = handles();
+            let handles = HANDLES.read();
             *handles.get(&id).ok_or(Error::new(EBADF))?
         };
 
-        Ok(0)
+        Ok(())
     }
 
     /// Close the file `number`
-    fn close(&self, id: usize) -> Result<usize> {
+    fn close(&self, id: usize) -> Result<()> {
         let _handle = {
-            let mut handles = handles_mut();
+            let mut handles = HANDLES.write();
             handles.remove(&id).ok_or(Error::new(EBADF))?
         };
 
-        Ok(0)
+        Ok(())
     }
-}
-impl crate::scheme::KernelScheme for DebugScheme {
     fn kread(&self, id: usize, buf: UserSliceWo) -> Result<usize> {
         let handle = {
-            let handles = handles();
+            let handles = HANDLES.read();
             *handles.get(&id).ok_or(Error::new(EBADF))?
         };
 
@@ -136,7 +121,7 @@ impl crate::scheme::KernelScheme for DebugScheme {
 
     fn kwrite(&self, id: usize, buf: UserSliceRo) -> Result<usize> {
         let _handle = {
-            let handles = handles();
+            let handles = HANDLES.read();
             *handles.get(&id).ok_or(Error::new(EBADF))?
         };
 
@@ -156,7 +141,7 @@ impl crate::scheme::KernelScheme for DebugScheme {
     }
     fn kfpath(&self, id: usize, buf: UserSliceWo) -> Result<usize> {
         let _handle = {
-            let handles = handles();
+            let handles = HANDLES.read();
             *handles.get(&id).ok_or(Error::new(EBADF))?
         };