Collapse status of context into one status variable

kernel/context/context.rs

@@ -5,18 +5,22 @@ use arch;
 use super::file::File;
 use super::memory::Memory;
 
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum Status {
+    Runnable,
+    Blocked,
+    Exited
+}
+
 /// A context, which identifies either a process or a thread
 #[derive(Debug)]
 pub struct Context {
     /// The ID of this context
     pub id: usize,
-    //TODO: Status enum
+    /// Status of context
-    /// Running or not
+    pub status: Status,
+    /// Context running or not
     pub running: bool,
-    /// Blocked or not
-    pub blocked: bool,
-    /// Exited or not`
-    pub exited: bool,
     /// The architecture specific context
     pub arch: arch::context::Context,
     /// Kernel stack
@@ -36,9 +40,8 @@ impl Context {
     pub fn new(id: usize) -> Context {
         Context {
             id: id,
+            status: Status::Blocked,
             running: false,
-            blocked: true,
-            exited: false,
             arch: arch::context::Context::new(),
             kstack: None,
             image: Vec::new(),

kernel/context/mod.rs

@@ -3,7 +3,7 @@
 use core::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};
 use spin::{Once, RwLock, RwLockReadGuard, RwLockWriteGuard};
 
-pub use self::context::Context;
+pub use self::context::{Context, Status};
 pub use self::list::ContextList;
 pub use self::switch::switch;
 
@@ -38,8 +38,8 @@ 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();
+    context.status = Status::Runnable;
     context.running = true;
-    context.blocked = false;
     CONTEXT_ID.store(context.id, Ordering::SeqCst);
 }
 

kernel/context/switch.rs

@@ -1,7 +1,7 @@
 use core::sync::atomic::Ordering;
 
 use arch;
-use super::{contexts, Context, CONTEXT_ID};
+use super::{contexts, Context, Status, CONTEXT_ID};
 
 /// Switch to the next context
 ///
@@ -28,7 +28,7 @@ pub unsafe fn switch() {
     for (pid, context_lock) in contexts().iter() {
         if *pid > (*from_ptr).id {
             let mut context = context_lock.write();
-            if ! context.running && ! context.blocked && ! context.exited {
+            if context.status == Status::Runnable && ! context.running {
                 to_ptr = context.deref_mut() as *mut Context;
                 break;
             }
@@ -39,7 +39,7 @@ pub unsafe fn switch() {
         for (pid, context_lock) in contexts().iter() {
             if *pid < (*from_ptr).id {
                 let mut context = context_lock.write();
-                if ! context.running && ! context.blocked && ! context.exited {
+                if context.status == Status::Runnable && ! context.running {
                     to_ptr = context.deref_mut() as *mut Context;
                     break;
                 }

kernel/lib.rs

@@ -149,7 +149,7 @@ pub extern fn kmain() {
     match context::contexts_mut().spawn(userspace_init) {
         Ok(context_lock) => {
             let mut context = context_lock.write();
-            context.blocked = false;
+            context.status = context::Status::Runnable;
         },
         Err(err) => {
             panic!("failed to spawn userspace_init: {:?}", err);

kernel/syscall/process.rs

@@ -228,7 +228,7 @@ pub fn clone(flags: usize, stack_base: usize) -> Result<usize> {
 
             context.arch.set_page_table(unsafe { new_table.address() });
 
-            context.blocked = false;
+            context.status = context::Status::Runnable;
         }
     }
 
@@ -247,7 +247,7 @@ pub fn exit(status: usize) -> ! {
         context.image.clear();
         drop(context.heap.take());
         drop(context.stack.take());
-        context.exited = true;
+        context.status = context::Status::Exited;
     }
 
     unsafe { context::switch(); }