Remove one level of indirection for Context::name.

src/arch/x86_64/interrupt/syscall.rs

@@ -142,7 +142,7 @@ interrupt_stack!(syscall, |stack| {
             let context = contexts.current();
             if let Some(current) = context {
                 let current = current.read();
-                println!("Warning: Context {} used deprecated `int 0x80` construct", *current.name.read());
+                println!("Warning: Context {} used deprecated `int 0x80` construct", current.name);
             } else {
                 println!("Warning: Unknown context used deprecated `int 0x80` construct");
             }

src/context/context.rs

@@ -1,9 +1,8 @@
 use alloc::{
     boxed::Box,
     collections::VecDeque,
-    string::{String},
     sync::Arc,
-    vec::Vec,
+    vec::Vec, borrow::Cow,
 };
 use core::{
     alloc::GlobalAlloc,
@@ -128,7 +127,7 @@ pub struct ContextSnapshot {
 impl ContextSnapshot {
     //TODO: Should this accept &mut Context to ensure name/files will not change?
     pub fn new(context: &Context) -> Self {
-        let name = context.name.read().clone();
+        let name = context.name.clone().into_owned().into_boxed_str();
         let mut files = Vec::new();
         for descriptor_opt in context.files.read().iter() {
             let description = if let Some(descriptor) = descriptor_opt {
@@ -240,7 +239,8 @@ pub struct Context {
     /// mappings are universal and independent on address spaces or contexts.
     pub addr_space: Option<Arc<RwLock<AddrSpace>>>,
     /// The name of the context
-    pub name: Arc<RwLock<Box<str>>>,
+    // TODO: fixed size ArrayString?
+    pub name: Cow<'static, str>,
     /// The open files in the scheme
     pub files: Arc<RwLock<Vec<Option<FileDescriptor>>>>,
     /// Signal actions
@@ -372,7 +372,7 @@ impl Context {
             ksig: None,
             ksig_restore: false,
             addr_space: None,
-            name: Arc::new(RwLock::new(String::new().into_boxed_str())),
+            name: Cow::Borrowed(""),
             files: Arc::new(RwLock::new(Vec::new())),
             actions: Self::empty_actions(),
             regs: None,

src/context/mod.rs

@@ -3,6 +3,7 @@
 //! For resources on contexts, please consult [wikipedia](https://en.wikipedia.org/wiki/Context_switch) and  [osdev](https://wiki.osdev.org/Context_Switching)
 use core::sync::atomic::Ordering;
 
+use alloc::borrow::Cow;
 use alloc::sync::Arc;
 
 use spin::{RwLock, RwLockReadGuard, RwLockWriteGuard};
@@ -69,6 +70,7 @@ pub fn init() {
     let context_lock = contexts.insert_context_raw(id).expect("could not initialize first context");
     let mut context = context_lock.write();
     context.sched_affinity = Some(crate::cpu_id());
+    context.name = Cow::Borrowed("kmain");
 
     self::arch::EMPTY_CR3.call_once(|| unsafe { RmmA::table(TableKind::User) });
 

src/debugger.rs

@@ -161,7 +161,7 @@ pub unsafe fn debugger(target_id: Option<crate::context::ContextId>) {
     for (id, context_lock) in crate::context::contexts().iter() {
         if target_id.map_or(false, |target_id| *id != target_id) { continue; }
         let context = context_lock.read();
-        println!("{}: {}", (*id).into(), context.name.read());
+        println!("{}: {}", (*id).into(), context.name);
 
         // Switch to context page table to ensure syscall debug and stack dump will work
         if let Some(ref space) = context.addr_space {

src/lib.rs

@@ -73,7 +73,6 @@ extern crate spin;
 #[cfg(feature = "slab")]
 extern crate slab_allocator;
 
-use alloc::string::ToString;
 use core::sync::atomic::{AtomicUsize, Ordering};
 
 use crate::scheme::SchemeNamespace;
@@ -205,7 +204,7 @@ pub fn kmain(cpus: usize, bootstrap: Bootstrap) -> ! {
             context.rns = SchemeNamespace::from(1);
             context.ens = SchemeNamespace::from(1);
             context.status = context::Status::Runnable;
-            *context.name.write() = "bootstrap".to_string().into_boxed_str();
+            context.name = "bootstrap".into();
         },
         Err(err) => {
             panic!("failed to spawn userspace_init: {:?}", err);
@@ -267,7 +266,7 @@ pub extern fn ksignal(signal: usize) {
         let contexts = context::contexts();
         if let Some(context_lock) = contexts.current() {
             let context = context_lock.read();
-            info!("NAME {}", *context.name.read());
+            info!("NAME {}", context.name);
         }
     }
 

src/panic.rs

@@ -24,7 +24,7 @@ pub extern "C" fn rust_begin_unwind(info: &PanicInfo) -> ! {
         let contexts = context::contexts();
         if let Some(context_lock) = contexts.current() {
             let context = context_lock.read();
-            println!("NAME: {}", *context.name.read());
+            println!("NAME: {}", context.name);
 
             if let Some((a, b, c, d, e, f)) = context.syscall {
                 println!("SYSCALL: {}", syscall::debug::format_call(a, b, c, d, e, f));

src/scheme/proc.rs

@@ -324,7 +324,7 @@ impl ProcScheme {
                 Operation::Memory { .. } => OperationData::Memory(MemData::default()),
                 Operation::Trace => OperationData::Trace(TraceData::default()),
                 Operation::Static(_) => OperationData::Static(StaticData::new(
-                    target.name.read().clone().into()
+                    target.name.clone().into_owned().into_bytes().into()
                 )),
                 Operation::AddrSpace { .. } => OperationData::Offset(0),
                 _ => OperationData::Other,
@@ -814,7 +814,7 @@ impl Scheme for ProcScheme {
                 // Return read events
                 Ok(read * mem::size_of::<PtraceEvent>())
             }
-            Operation::Name => read_from(buf, context::contexts().get(info.pid).ok_or(Error::new(ESRCH))?.read().name.read().as_bytes(), &mut 0),
+            Operation::Name => read_from(buf, context::contexts().get(info.pid).ok_or(Error::new(ESRCH))?.read().name.as_bytes(), &mut 0),
             Operation::Sigstack => read_from(buf, &context::contexts().get(info.pid).ok_or(Error::new(ESRCH))?.read().sigstack.unwrap_or(!0).to_ne_bytes(), &mut 0),
             Operation::Attr(attr) => {
                 let src_buf = match (attr, &*Arc::clone(context::contexts().get(info.pid).ok_or(Error::new(ESRCH))?).read()) {
@@ -1031,8 +1031,8 @@ impl Scheme for ProcScheme {
                 Ok(mem::size_of::<u64>())
             },
             Operation::Name => {
-                let utf8 = alloc::string::String::from_utf8(buf.to_vec()).map_err(|_| Error::new(EINVAL))?.into_boxed_str();
-                *context::contexts().get(info.pid).ok_or(Error::new(ESRCH))?.read().name.write() = utf8;
+                let utf8 = alloc::string::String::from_utf8(buf.to_vec()).map_err(|_| Error::new(EINVAL))?;
+                context::contexts().get(info.pid).ok_or(Error::new(ESRCH))?.write().name = utf8.into();
                 Ok(buf.len())
             }
             Operation::Sigstack => {

src/scheme/sys/block.rs

@@ -14,7 +14,7 @@ pub fn resource() -> Result<Vec<u8>> {
             let contexts = context::contexts();
             for (id, context_lock) in contexts.iter() {
                 let context = context_lock.read();
-                rows.push((*id, context.name.read().clone(), context.status_reason));
+                rows.push((*id, context.name.clone(), context.status_reason));
             }
         }
 

src/scheme/sys/context.rs

@@ -116,7 +116,7 @@ pub fn resource() -> Result<Vec<u8>> {
                                affinity,
                                cpu_time_string,
                                memory_string,
-                               *context.name.read()));
+                               context.name));
         }
     }
 

src/scheme/sys/exe.rs

@@ -1,19 +1,8 @@
-use alloc::{
-    boxed::Box,
-    vec::Vec,
-};
+use alloc::vec::Vec;
 
 use crate::context;
-use crate::syscall::error::{Error, ESRCH, Result};
+use crate::syscall::error::Result;
 
 pub fn resource() -> Result<Vec<u8>> {
-    let name = {
-        let contexts = context::contexts();
-        let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
-        let context = context_lock.read();
-        let name = context.name.read();
-        let name_bytes: Box<[u8]> = name.clone().into();
-        name_bytes.into_vec()
-    };
-    Ok(name)
+    Ok(context::current()?.read().name.clone().into_owned().into_bytes())
 }

src/scheme/sys/iostat.rs

@@ -16,7 +16,7 @@ pub fn resource() -> Result<Vec<u8>> {
             let contexts = context::contexts();
             for (id, context_lock) in contexts.iter() {
                 let context = context_lock.read();
-                rows.push((*id, context.name.read().clone(), context.files.read().clone()));
+                rows.push((*id, context.name.clone(), context.files.read().clone()));
             }
         }
 

src/scheme/sys/syscall.rs

@@ -15,7 +15,7 @@ pub fn resource() -> Result<Vec<u8>> {
             let contexts = context::contexts();
             for (id, context_lock) in contexts.iter() {
                 let context = context_lock.read();
-                rows.push((*id, context.name.read().clone(), context.syscall));
+                rows.push((*id, context.name.clone(), context.syscall));
             }
         }
 

src/scheme/user.rs

@@ -294,7 +294,7 @@ impl UserInner {
             let context_lock = Arc::clone(context::contexts().current().ok_or(Error::new(ESRCH))?);
             let context = context_lock.read();
             if map.size % PAGE_SIZE != 0 {
-                log::warn!("Unaligned map size for context {:?}", context.name.try_read().as_deref());
+                log::warn!("Unaligned map size for context `{}`", context.name);
             }
             // TODO: Faster, cleaner mechanism to get descriptor
             let scheme = self.scheme_id.load(Ordering::SeqCst);

src/syscall/process.rs

@@ -42,7 +42,7 @@ fn empty<'lock>(context_lock: &'lock RwLock<Context>, mut context: RwLockWriteGu
 
         for grant in addr_space.grants.into_iter() {
             let unmap_result = if reaping {
-                log::error!("{}: {}: Grant should not exist: {:?}", context.id.into(), *context.name.read(), grant);
+                log::error!("{}: {}: Grant should not exist: {:?}", context.id.into(), context.name, grant);
 
                 grant.unmap(mapper, &mut InactiveFlusher::new())
             } else {