WIP: Kevent

kernel/context/switch.rs

@@ -8,7 +8,7 @@ use super::{contexts, Context, Status, CONTEXT_ID};
 /// # Safety
 ///
 /// Do not call this while holding locks!
-pub unsafe fn switch() {
+pub unsafe fn switch() -> bool {
     use core::ops::DerefMut;
 
     // Set the global lock to avoid the unsafe operations below from causing issues
@@ -48,10 +48,9 @@ pub unsafe fn switch() {
     }
 
     if to_ptr as usize == 0 {
-        // TODO: Sleep, wait for interrupt
         // Unset global lock if no context found
         arch::context::CONTEXT_SWITCH_LOCK.store(false, Ordering::SeqCst);
-        return;
+        return false;
     }
 
     //println!("Switch {} to {}", (&*from_ptr).id, (&*to_ptr).id);
@@ -64,4 +63,6 @@ pub unsafe fn switch() {
     CONTEXT_ID.store((&mut *to_ptr).id, Ordering::SeqCst);
 
     (&mut *from_ptr).arch.switch_to(&mut (&mut *to_ptr).arch);
+
+    true
 }

kernel/lib.rs

@@ -162,8 +162,11 @@ pub extern fn kmain() {
     loop {
         unsafe {
             interrupt::disable();
-            context::switch();
-            interrupt::enable_and_nop();
+            if context::switch() {
+                interrupt::enable_and_nop();
+            } else {
+                interrupt::enable_and_halt();
+            }
         }
     }
 }

kernel/scheme/debug.rs

@@ -48,7 +48,7 @@ impl Scheme for DebugScheme {
             if i > 0 {
                 return Ok(i);
             } else {
-                unsafe { context::switch(); }
+                unsafe { context::switch(); } //TODO: Block
             }
         }
     }

kernel/scheme/event.rs

@@ -0,0 +1,33 @@
+use core::{mem, str};
+
+use arch::interrupt::irq::{ACKS, COUNTS, acknowledge};
+use syscall::error::*;
+use syscall::scheme::Scheme;
+
+pub struct EventScheme;
+
+impl Scheme for EventScheme {
+    fn open(&self, _path: &[u8], _flags: usize) -> Result<usize> {
+        Ok(
+    }
+
+    fn dup(&self, file: usize) -> Result<usize> {
+        Ok(file)
+    }
+
+    fn read(&self, file: usize, buffer: &mut [u8]) -> Result<usize> {
+        Ok(0)
+    }
+
+    fn write(&self, file: usize, buffer: &[u8]) -> Result<usize> {
+        Ok(0)
+    }
+
+    fn fsync(&self, _file: usize) -> Result<usize> {
+        Ok(0)
+    }
+
+    fn close(&self, _file: usize) -> Result<usize> {
+        Ok(0)
+    }
+}

kernel/scheme/user.rs

@@ -52,7 +52,7 @@ impl UserInner {
                 }
             }
 
-            unsafe { context::switch(); }
+            unsafe { context::switch(); } //TODO: Block
         }
     }
 
@@ -163,7 +163,7 @@ impl UserInner {
                 if i > 0 {
                     return Ok(i * packet_size);
                 } else {
-                    unsafe { context::switch(); }
+                    unsafe { context::switch(); } //TODO: Block
                 }
             }
         } else {
@@ -230,7 +230,12 @@ impl Scheme for UserScheme {
 
     fn seek(&self, file: usize, position: usize, whence: usize) -> Result<usize> {
         let inner = self.inner.upgrade().ok_or(Error::new(ENODEV))?;
-        inner.call(SYS_FSYNC, file, position, whence)
+        inner.call(SYS_LSEEK, file, position, whence)
+    }
+
+    fn fevent(&self, file: usize, flags: usize) -> Result<usize> {
+        let inner = self.inner.upgrade().ok_or(Error::new(ENODEV))?;
+        inner.call(SYS_FEVENT, file, flags, 0)
     }
 
     fn fstat(&self, file: usize, stat: &mut Stat) -> Result<usize> {

kernel/syscall/fs.rs

@@ -98,6 +98,24 @@ pub fn dup(fd: usize) -> Result<usize> {
     scheme.dup(file.number)
 }
 
+/// Register events for file
+pub fn fevent(fd: usize, flags: usize) -> Result<usize> {
+    let file = {
+        let contexts = context::contexts();
+        let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
+        let context = context_lock.read();
+        let file = context.get_file(fd).ok_or(Error::new(EBADF))?;
+        file
+    };
+
+    let scheme = {
+        let schemes = scheme::schemes();
+        let scheme = schemes.get(file.scheme).ok_or(Error::new(EBADF))?;
+        scheme.clone()
+    };
+    scheme.fevent(file.number, flags)
+}
+
 /// Get the canonical path of the file
 pub fn fpath(fd: usize, buf: &mut [u8]) -> Result<usize> {
     let file = {

kernel/syscall/mod.rs

@@ -45,6 +45,7 @@ pub extern fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize
             SYS_CLONE => clone(b, stack),
             SYS_YIELD => sched_yield(),
             SYS_GETCWD => getcwd(validate_slice_mut(b as *mut u8, c)?),
+            SYS_FEVENT => fevent(b, c),
             SYS_FPATH => fpath(b, validate_slice_mut(c as *mut u8, d)?),
             SYS_PHYSMAP => physmap(b, c, d),
             SYS_PHYSUNMAP => physunmap(b),

kernel/syscall/process.rs

@@ -618,7 +618,6 @@ pub fn sched_yield() -> Result<usize> {
 }
 
 pub fn waitpid(pid: usize, status_ptr: usize, flags: usize) -> Result<usize> {
-    //TODO: Implement status_ptr and options
     loop {
         {
             let mut exited = false;
@@ -644,6 +643,6 @@ pub fn waitpid(pid: usize, status_ptr: usize, flags: usize) -> Result<usize> {
             }
         }
 
-        unsafe { context::switch(); }
+        unsafe { context::switch(); } //TODO: Block
     }
 }