Twizzler crate stubs

Cargo.toml

@@ -20,6 +20,7 @@ members = [
     "src/lib/twizzler-futures",
     "src/lib/dynlink",
     "src/lib/secgate",
+    "src/lib/twizzler",
     "src/rt/monitor",
     "src/rt/monitor-api",
     "src/rt/monitor/tests/montest",

src/lib/twizzler-abi/src/syscall/create.rs

@@ -43,35 +43,31 @@ impl ObjectSource {
     }
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Ord, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Ord, Eq, Default)]
 #[repr(C)]
 /// The backing memory type for this object. Currently doesn't do anything.
 pub enum BackingType {
     /// The default, let the kernel decide based on the [LifetimeType] of the object.
+    #[default]
     Normal = 0,
 }
 
-impl Default for BackingType {
-    fn default() -> Self {
-        Self::Normal
-    }
-}
-
-#[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Ord, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Ord, Eq, Default)]
 #[repr(C)]
 /// The base lifetime type of the object. Note that this does not ensure that the object is stored
 /// in a specific type of memory, the kernel is allowed to migrate objects with the Normal
 /// [BackingType] as it sees fit. For more information on object lifetime, see [the book](https://twizzler-operating-system.github.io/nightly/book/object_lifetime.html).
 pub enum LifetimeType {
     /// This object is volatile, and is expected to be deleted after a power cycle.
+    #[default]
     Volatile = 0,
     /// This object is persistent, and should be deleted only after an explicit delete call.
     Persistent = 1,
 }
 
 bitflags! {
     /// Flags to pass to the object create system call.
-    #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+    #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Default)]
     pub struct ObjectCreateFlags: u32 {
     }
 }
@@ -83,7 +79,7 @@ bitflags! {
     }
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Ord, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, PartialOrd, Ord, Eq, Default)]
 #[repr(C)]
 /// Full object creation specification, minus ties.
 pub struct ObjectCreate {

src/lib/twizzler/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "twizzler"
+version = "0.99.0"
+edition = "2021"
+
+[dependencies]
+bitflags = "2"
+thiserror = "2"
+twizzler-rt-abi = { path = "../../abi/rt-abi" }
+twizzler-abi = { path = "../../lib/twizzler-abi" }

src/lib/twizzler/src/alloc.rs

@@ -0,0 +1,4 @@
+pub mod arena;
+pub mod invbox;
+
+pub trait Allocator {}

src/lib/twizzler/src/alloc/arena.rs

@@ -0,0 +1,14 @@
+use super::Allocator;
+use crate::object::Object;
+
+pub struct ArenaAllocator {
+    obj: Object<ArenaBase>,
+}
+
+#[repr(C)]
+pub struct ArenaBase {}
+
+#[repr(C)]
+pub struct ArenaObjBase {}
+
+impl Allocator for ArenaAllocator {}

src/lib/twizzler/src/alloc/invbox.rs

@@ -0,0 +1,5 @@
+use crate::{marker::Invariant, ptr::InvPtr};
+
+pub struct InvBox<T: Invariant> {
+    raw: InvPtr<T>,
+}

src/lib/twizzler/src/collections.rs

@@ -0,0 +1 @@
+pub mod vec;

src/lib/twizzler/src/lib.rs

@@ -0,0 +1,11 @@
+#![feature(negative_impls)]
+#![feature(auto_traits)]
+#![feature(strict_provenance)]
+#![feature(allocator_api)]
+
+pub mod alloc;
+pub mod collections;
+pub mod marker;
+pub mod object;
+pub mod ptr;
+pub mod tx;

src/lib/twizzler/src/marker.rs

@@ -0,0 +1,58 @@
+//! Marker types for invariance, store side-effects, and base types.
+
+/// Indicates that a type is _invariant_ and thus can be stored in an object.
+///
+/// # Safety
+/// The implementation must ensure that the type is invariant, meaning that the type must:
+///   - Be FFI safe.
+///   - Be stable in-memory (independent of architecture). This means, among other things, that the
+///     type must be fixed-width. For example, usize is not `Invariant`.
+pub unsafe trait Invariant {}
+
+unsafe impl Invariant for u8 {}
+unsafe impl Invariant for u16 {}
+unsafe impl Invariant for u32 {}
+unsafe impl Invariant for u64 {}
+unsafe impl Invariant for bool {}
+unsafe impl Invariant for i8 {}
+unsafe impl Invariant for i16 {}
+unsafe impl Invariant for i32 {}
+unsafe impl Invariant for i64 {}
+
+unsafe impl Invariant for f64 {}
+unsafe impl Invariant for f32 {}
+
+unsafe impl Invariant for () {}
+
+unsafe impl<T: Invariant, const N: usize> Invariant for [T; N] {}
+
+unsafe impl<T: Invariant> Invariant for (T,) {}
+
+unsafe impl<T: Invariant> Invariant for Option<T> {}
+unsafe impl<R: Invariant, E: Invariant> Invariant for Result<R, E> {}
+
+/// The type may move between objects without side effects. Notably, this is
+/// not implemented for invariant pointers or types that contain them, since an invariant pointer
+/// may reference an object's Foreign Object Table. This is a little restrictive (technically
+/// intra-object pointers are safe to move intra-object), but it's the best we can do at
+/// compile-time.
+///
+/// # Safety
+/// The implementation must ensure that no store side effects must occur when writing this value to
+/// object memory.
+pub unsafe auto trait StoreCopy {}
+
+/// A zero-sized phantom marker for indicating that the containing type has a side effect when
+/// storing (e.g. it has an invariant pointer).
+#[derive(Copy, Clone, PartialEq, PartialOrd, Ord, Eq, Hash, Debug)]
+pub struct PhantomStoreEffect;
+
+impl !StoreCopy for PhantomStoreEffect {}
+impl !Unpin for PhantomStoreEffect {}
+
+pub trait BaseType {
+    /// The fingerprint of this type.
+    fn fingerprint() -> u64 {
+        0
+    }
+}

src/lib/twizzler/src/object.rs

@@ -0,0 +1,115 @@
+//! Traits and types for working with objects.
+
+use std::marker::PhantomData;
+
+use fot::FotEntry;
+use twizzler_abi::{
+    meta::MetaInfo,
+    object::{ObjID, MAX_SIZE, NULLPAGE_SIZE},
+};
+use twizzler_rt_abi::object::ObjectHandle;
+
+use crate::{marker::BaseType, ptr::Ref};
+
+mod builder;
+mod fot;
+mod meta;
+
+/// Operations common to structured objects.
+pub trait TypedObject {
+    /// The base type of this object.
+    type Base: BaseType;
+
+    /// Returns a resolved reference to the object's base.
+    fn base(&self) -> Ref<'_, Self::Base>;
+}
+
+/// Operations common to all objects, with raw pointers.
+pub trait RawObject {
+    /// Get the underlying runtime handle for this object.
+    fn handle(&self) -> &ObjectHandle;
+
+    /// Get the object ID.
+    fn id(&self) -> ObjID {
+        self.handle().id()
+    }
+
+    /// Get a const pointer to the object base.
+    fn base_ptr<T>(&self) -> *const T {
+        self.lea(NULLPAGE_SIZE, size_of::<T>()).unwrap().cast()
+    }
+
+    /// Get a mut pointer to the object base.
+    fn base_mut_ptr<T>(&self) -> *mut T {
+        self.lea_mut(NULLPAGE_SIZE, size_of::<T>()).unwrap().cast()
+    }
+
+    /// Get a const pointer to the object metadata.
+    fn meta_ptr(&self) -> *const MetaInfo {
+        self.handle().meta().cast()
+    }
+
+    /// Get a mut pointer to the object metadata.
+    fn meta_mut_ptr(&self) -> *mut MetaInfo {
+        self.handle().meta().cast()
+    }
+
+    /// Get a const pointer to a given FOT entry.
+    fn fote_ptr(&self, idx: usize) -> Option<*const FotEntry> {
+        let offset: isize = (1 + idx).try_into().ok()?;
+        unsafe { Some((self.meta_ptr() as *const FotEntry).offset(-offset)) }
+    }
+
+    /// Get a mut pointer to a given FOT entry.
+    fn fote_ptr_mut(&self, idx: usize) -> Option<*mut FotEntry> {
+        let offset: isize = (1 + idx).try_into().ok()?;
+        unsafe { Some((self.meta_mut_ptr() as *mut FotEntry).offset(-offset)) }
+    }
+
+    /// Get a const pointer to given range of the object.
+    fn lea(&self, offset: usize, _len: usize) -> Option<*const u8> {
+        Some(unsafe { self.handle().start().add(offset) as *const u8 })
+    }
+
+    /// Get a mut pointer to given range of the object.
+    fn lea_mut(&self, offset: usize, _len: usize) -> Option<*mut u8> {
+        Some(unsafe { self.handle().start().add(offset) as *mut u8 })
+    }
+
+    /// If the pointer is local to this object, return the offset into the object. Otherwise, return
+    /// None.
+    fn ptr_local(&self, ptr: *const u8) -> Option<usize> {
+        if ptr.addr() >= self.handle().start().addr()
+            && ptr.addr() < self.handle().start().addr() + MAX_SIZE
+        {
+            Some(ptr.addr() - self.handle().start().addr())
+        } else {
+            None
+        }
+    }
+}
+
+impl RawObject for ObjectHandle {
+    fn handle(&self) -> &ObjectHandle {
+        self
+    }
+}
+
+pub struct Object<Base> {
+    handle: ObjectHandle,
+    _pd: PhantomData<*const Base>,
+}
+
+impl<Base> RawObject for Object<Base> {
+    fn handle(&self) -> &ObjectHandle {
+        &self.handle
+    }
+}
+
+impl<Base: BaseType> TypedObject for Object<Base> {
+    type Base = Base;
+
+    fn base(&self) -> Ref<'_, Self::Base> {
+        todo!()
+    }
+}

src/lib/twizzler/src/object/builder.rs

@@ -0,0 +1,53 @@
+use std::{alloc::AllocError, marker::PhantomData, mem::MaybeUninit};
+
+use thiserror::Error;
+use twizzler_abi::syscall::{ObjectCreate, ObjectCreateError};
+use twizzler_rt_abi::object::{MapError, ObjectHandle};
+
+use super::RawObject;
+use crate::marker::BaseType;
+
+#[derive(Clone, Copy, Debug, Error)]
+/// Possible errors from creating an object.
+pub enum CreateError {
+    #[error(transparent)]
+    Create(#[from] ObjectCreateError),
+    #[error(transparent)]
+    Map(#[from] MapError),
+    #[error(transparent)]
+    Alloc(#[from] AllocError),
+}
+
+/// An object builder, for constructing objects using a builder API.
+pub struct ObjectBuilder<Base: BaseType> {
+    spec: ObjectCreate,
+    _pd: PhantomData<Base>,
+}
+
+impl<Base: BaseType> ObjectBuilder<Base> {
+    /// Make a new object builder.
+    pub fn new(spec: ObjectCreate) -> Self {
+        Self {
+            spec,
+            _pd: PhantomData,
+        }
+    }
+}
+
+impl<Base: BaseType> Default for ObjectBuilder<Base> {
+    fn default() -> Self {
+        Self::new(ObjectCreate::default())
+    }
+}
+
+/// An uninitialized object, used during object construction.
+pub struct UninitObject<T> {
+    handle: ObjectHandle,
+    _pd: PhantomData<*mut MaybeUninit<T>>,
+}
+
+impl<T> RawObject for UninitObject<T> {
+    fn handle(&self) -> &ObjectHandle {
+        &self.handle
+    }
+}

src/lib/twizzler/src/object/fot.rs

@@ -0,0 +1,34 @@
+use std::sync::atomic::AtomicU32;
+
+use thiserror::Error;
+
+bitflags::bitflags! {
+    #[repr(C)]
+    #[derive(Copy, Clone, Debug, PartialEq, PartialOrd, Ord, Eq, Hash)]
+    pub struct FotFlags : u32 {
+        const RESERVED = 1;
+        const ACTIVE = 2;
+        const RESOLVER = 4;
+    }
+}
+
+pub type ResolverFn = extern "C" fn(ResolveRequest) -> Result<FotResolve, FotError>;
+
+#[derive(Copy, Clone, Debug, PartialEq, PartialOrd, Ord, Eq, Hash, Error)]
+pub enum FotError {
+    #[error("invalid FOT index")]
+    InvalidIndex,
+    #[error("invalid FOT entry")]
+    InvalidFotEntry,
+}
+
+pub struct ResolveRequest {}
+
+pub struct FotResolve {}
+
+#[repr(C)]
+pub struct FotEntry {
+    pub values: [u64; 2],
+    pub resolver: u64,
+    pub flags: AtomicU32,
+}

src/lib/twizzler/src/object/meta.rs

@@ -0,0 +1 @@
+pub use twizzler_abi::meta::*;

src/lib/twizzler/src/ptr.rs

@@ -0,0 +1,7 @@
+mod global;
+mod invariant;
+mod resolved;
+
+pub use global::*;
+pub use invariant::*;
+pub use resolved::*;

src/lib/twizzler/src/ptr/global.rs

@@ -0,0 +1,11 @@
+use std::marker::PhantomData;
+
+use twizzler_abi::object::ObjID;
+
+#[derive(Copy, Clone, Debug, Default, PartialEq, PartialOrd, Ord, Eq, Hash)]
+/// A global pointer, containing a fully qualified object ID and offset.
+pub struct GlobalPtr<T> {
+    id: ObjID,
+    offset: usize,
+    _pd: PhantomData<*const T>,
+}