Merge #3119

3119: Added LinearMemory trait r=ptitSeb a=ptitSeb

Added LinearMemory trait, to describe memory used in runtime.

Co-authored-by: John Sharratt's Shared Account <[email protected]>
Co-authored-by: ptitSeb <[email protected]>

lib/api/src/js/export.rs

@@ -7,6 +7,7 @@ use std::fmt;
 use wasm_bindgen::{JsCast, JsValue};
 use wasmer_types::{ExternType, FunctionType, GlobalType, MemoryType, TableType};
 
+/// Represents linear memory that is managed by the javascript runtime
 #[derive(Clone, Debug, PartialEq)]
 pub struct VMMemory {
     pub(crate) memory: Memory,
@@ -20,6 +21,11 @@ impl VMMemory {
     pub(crate) fn new(memory: Memory, ty: MemoryType) -> Self {
         Self { memory, ty }
     }
+
+    /// Attempts to clone this memory (if its clonable)
+    pub(crate) fn try_clone(&self) -> Option<VMMemory> {
+        Some(self.clone())
+    }
 }
 
 #[derive(Clone, Debug, PartialEq)]

lib/api/src/js/externals/memory.rs

@@ -6,7 +6,6 @@ use crate::js::{MemoryAccessError, MemoryType};
 use std::marker::PhantomData;
 use std::mem::MaybeUninit;
 use std::slice;
-use thiserror::Error;
 #[cfg(feature = "tracing")]
 use tracing::warn;
 
@@ -16,22 +15,7 @@ use wasmer_types::Pages;
 
 use super::MemoryView;
 
-/// Error type describing things that can go wrong when operating on Wasm Memories.
-#[derive(Error, Debug, Clone, PartialEq, Hash)]
-pub enum MemoryError {
-    /// The operation would cause the size of the memory to exceed the maximum or would cause
-    /// an overflow leading to unindexable memory.
-    #[error("The memory could not grow: current size {} pages, requested increase: {} pages", current.0, attempted_delta.0)]
-    CouldNotGrow {
-        /// The current size in pages.
-        current: Pages,
-        /// The attempted amount to grow by in pages.
-        attempted_delta: Pages,
-    },
-    /// A user defined error value, used for error cases not listed above.
-    #[error("A user-defined error occurred: {0}")]
-    Generic(String),
-}
+pub use wasmer_types::MemoryError;
 
 #[wasm_bindgen]
 extern "C" {
@@ -113,7 +97,25 @@ impl Memory {
             .map_err(|_e| MemoryError::Generic("Error while creating the memory".to_owned()))?;
 
         let vm_memory = VMMemory::new(js_memory, ty);
-        Ok(Self::from_vm_export(store, vm_memory))
+        let handle = StoreHandle::new(store.objects_mut(), vm_memory);
+        Ok(Self::from_vm_extern(store, handle.internal_handle()))
+    }
+
+    /// Creates a new host `Memory` from provided JavaScript memory.
+    pub fn new_raw(
+        store: &mut impl AsStoreMut,
+        js_memory: js_sys::WebAssembly::Memory,
+        ty: MemoryType,
+    ) -> Result<Self, MemoryError> {
+        let vm_memory = VMMemory::new(js_memory, ty);
+        let handle = StoreHandle::new(store.objects_mut(), vm_memory);
+        Ok(Self::from_vm_extern(store, handle.internal_handle()))
+    }
+
+    /// Create a memory object from an existing memory and attaches it to the store
+    pub fn new_from_existing(new_store: &mut impl AsStoreMut, memory: VMMemory) -> Self {
+        let handle = StoreHandle::new(new_store.objects_mut(), memory);
+        Self::from_vm_extern(new_store, handle.internal_handle())
     }
 
     /// Returns the [`MemoryType`] of the `Memory`.
@@ -193,12 +195,6 @@ impl Memory {
         Ok(Pages(new_pages))
     }
 
-    pub(crate) fn from_vm_export(store: &mut impl AsStoreMut, vm_memory: VMMemory) -> Self {
-        Self {
-            handle: StoreHandle::new(store.objects_mut(), vm_memory),
-        }
-    }
-
     pub(crate) fn from_vm_extern(
         store: &mut impl AsStoreMut,
         internal: InternalStoreHandle<VMMemory>,
@@ -210,6 +206,12 @@ impl Memory {
         }
     }
 
+    /// Attempts to clone this memory (if its clonable)
+    pub fn try_clone(&self, store: &impl AsStoreRef) -> Option<VMMemory> {
+        let mem = self.handle.get(store.as_store_ref().objects());
+        mem.try_clone()
+    }
+
     /// Checks whether this `Global` can be used with the given context.
     pub fn is_from_store(&self, store: &impl AsStoreRef) -> bool {
         self.handle.store_id() == store.as_store_ref().objects().id()

lib/api/src/js/externals/mod.rs

@@ -46,7 +46,7 @@ impl Extern {
     }
 
     /// Create an `Extern` from an `wasmer_compiler::Export`.
-    pub fn from_vm_export(store: &mut impl AsStoreMut, export: Export) -> Self {
+    pub fn from_vm_extern(store: &mut impl AsStoreMut, export: Export) -> Self {
         match export {
             Export::Function(f) => Self::Function(Function::from_vm_extern(store, f)),
             Export::Memory(m) => Self::Memory(Memory::from_vm_extern(store, m)),

lib/api/src/js/function_env.rs

@@ -36,7 +36,7 @@ impl<T> FunctionEnv<T> {
     }
 
     /// Get the data as reference
-    pub fn as_ref<'a>(&self, store: &'a impl AsStoreMut) -> &'a T
+    pub fn as_ref<'a>(&self, store: &'a impl AsStoreRef) -> &'a T
     where
         T: Any + Send + 'static + Sized,
     {
@@ -112,6 +112,11 @@ impl<T: Send + 'static> FunctionEnvMut<'_, T> {
         self.func_env.as_mut(&mut self.store_mut)
     }
 
+    /// Borrows a new immmutable reference
+    pub fn as_ref(&self) -> FunctionEnv<T> {
+        self.func_env.clone()
+    }
+
     /// Borrows a new mutable reference
     pub fn as_mut<'a>(&'a mut self) -> FunctionEnvMut<'a, T> {
         FunctionEnvMut {

lib/api/src/js/imports.rs

@@ -174,6 +174,32 @@ impl Imports {
         }
         imports
     }
+
+    /// Iterates through all the imports in this structure
+    pub fn iter<'a>(&'a self) -> ImportsIterator<'a> {
+        ImportsIterator::new(self)
+    }
+}
+
+pub struct ImportsIterator<'a> {
+    iter: std::collections::hash_map::Iter<'a, (String, String), Extern>,
+}
+
+impl<'a> ImportsIterator<'a> {
+    fn new(imports: &'a Imports) -> Self {
+        let iter = imports.map.iter();
+        Self { iter }
+    }
+}
+
+impl<'a> Iterator for ImportsIterator<'a> {
+    type Item = (&'a str, &'a str, &'a Extern);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.iter
+            .next()
+            .map(|(k, v)| (k.0.as_str(), k.1.as_str(), v))
+    }
 }
 
 impl IntoIterator for &Imports {

lib/api/src/js/instance.rs

@@ -105,7 +105,7 @@ impl Instance {
                     })?;
                 let export: Export =
                     Export::from_js_value(js_export, &mut store, extern_type)?.into();
-                let extern_ = Extern::from_vm_export(&mut store, export);
+                let extern_ = Extern::from_vm_extern(&mut store, export);
                 Ok((name.to_string(), extern_))
             })
             .collect::<Result<Exports, InstantiationError>>()?;

lib/api/src/js/mod.rs

@@ -73,6 +73,12 @@ pub use crate::js::types::{
 pub use crate::js::value::Value;
 pub use crate::js::value::Value as Val;
 
+pub mod vm {
+    //! The `vm` module re-exports wasmer-vm types.
+
+    pub use crate::js::export::VMMemory;
+}
+
 pub use wasmer_types::is_wasm;
 pub use wasmer_types::{
     Bytes, ExportIndex, GlobalInit, LocalFunctionIndex, Pages, ValueType, WASM_MAX_PAGES,

lib/api/src/js/native.rs

@@ -11,7 +11,6 @@ use std::marker::PhantomData;
 
 use crate::js::externals::Function;
 use crate::js::store::{AsStoreMut, AsStoreRef, StoreHandle};
-use crate::js::FunctionEnv;
 use crate::js::{FromToNativeWasmType, RuntimeError, WasmTypeList};
 // use std::panic::{catch_unwind, AssertUnwindSafe};
 use crate::js::export::VMFunction;

lib/api/src/js/store.rs

@@ -263,6 +263,11 @@ mod objects {
             self.id
         }
 
+        /// Sets the ID of this store
+        pub fn set_id(&mut self, id: StoreId) {
+            self.id = id;
+        }
+
         /// Returns a pair of mutable references from two handles.
         ///
         /// Panics if both handles point to the same object.

lib/api/src/sys/externals/memory.rs

@@ -11,7 +11,7 @@ use std::slice;
 #[cfg(feature = "tracing")]
 use tracing::warn;
 use wasmer_types::Pages;
-use wasmer_vm::{InternalStoreHandle, MemoryError, StoreHandle, VMExtern, VMMemory};
+use wasmer_vm::{InternalStoreHandle, LinearMemory, MemoryError, StoreHandle, VMExtern, VMMemory};
 
 use super::MemoryView;
 
@@ -60,6 +60,12 @@ impl Memory {
         })
     }
 
+    /// Create a memory object from an existing memory and attaches it to the store
+    pub fn new_from_existing(new_store: &mut impl AsStoreMut, memory: VMMemory) -> Self {
+        let handle = StoreHandle::new(new_store.objects_mut(), memory);
+        Self::from_vm_extern(new_store, handle.internal_handle())
+    }
+
     /// Returns the [`MemoryType`] of the `Memory`.
     ///
     /// # Example
@@ -142,6 +148,12 @@ impl Memory {
         self.handle.store_id() == store.as_store_ref().objects().id()
     }
 
+    /// Attempts to clone this memory (if its clonable)
+    pub fn try_clone(&self, store: &impl AsStoreRef) -> Option<VMMemory> {
+        let mem = self.handle.get(store.as_store_ref().objects());
+        mem.try_clone().map(|mem| mem.into())
+    }
+
     pub(crate) fn to_vm_extern(&self) -> VMExtern {
         VMExtern::Memory(self.handle.internal_handle())
     }

lib/api/src/sys/externals/memory_view.rs

@@ -5,6 +5,7 @@ use std::marker::PhantomData;
 use std::mem::MaybeUninit;
 use std::slice;
 use wasmer_types::Pages;
+use wasmer_vm::LinearMemory;
 
 use super::memory::MemoryBuffer;
 use super::Memory;

lib/api/src/sys/tunables.rs

@@ -174,4 +174,138 @@ mod tests {
             s => panic!("Unexpected memory style: {:?}", s),
         }
     }
+
+    use std::cell::UnsafeCell;
+    use std::ptr::NonNull;
+    use wasmer_types::{MemoryError, MemoryStyle, MemoryType, Pages, WASM_PAGE_SIZE};
+    use wasmer_vm::{LinearMemory, MaybeInstanceOwned};
+
+    #[derive(Debug)]
+    struct VMTinyMemory {
+        mem: [u8; WASM_PAGE_SIZE],
+    }
+
+    unsafe impl Send for VMTinyMemory {}
+    unsafe impl Sync for VMTinyMemory {}
+
+    impl VMTinyMemory {
+        pub fn new() -> Result<Self, MemoryError> {
+            Ok(VMTinyMemory {
+                mem: [0; WASM_PAGE_SIZE],
+            })
+        }
+    }
+
+    impl LinearMemory for VMTinyMemory {
+        fn ty(&self) -> MemoryType {
+            MemoryType {
+                minimum: Pages::from(1u32),
+                maximum: Some(Pages::from(1u32)),
+                shared: false,
+            }
+        }
+        fn size(&self) -> Pages {
+            Pages::from(1u32)
+        }
+        fn style(&self) -> MemoryStyle {
+            MemoryStyle::Static {
+                bound: Pages::from(1u32),
+                offset_guard_size: 0,
+            }
+        }
+        fn grow(&mut self, delta: Pages) -> Result<Pages, MemoryError> {
+            Err(MemoryError::CouldNotGrow {
+                current: Pages::from(100u32),
+                attempted_delta: delta,
+            })
+        }
+        fn vmmemory(&self) -> NonNull<VMMemoryDefinition> {
+            MaybeInstanceOwned::Host(Box::new(UnsafeCell::new(VMMemoryDefinition {
+                base: self.mem.as_ptr() as _,
+                current_length: WASM_PAGE_SIZE,
+            })))
+            .as_ptr()
+        }
+        fn try_clone(&self) -> Option<Box<dyn LinearMemory + 'static>> {
+            None
+        }
+    }
+
+    impl From<VMTinyMemory> for wasmer_vm::VMMemory {
+        fn from(mem: VMTinyMemory) -> Self {
+            Self(Box::new(mem))
+        }
+    }
+
+    struct TinyTunables;
+    impl Tunables for TinyTunables {
+        fn memory_style(&self, _memory: &MemoryType) -> MemoryStyle {
+            MemoryStyle::Static {
+                bound: Pages::from(1u32),
+                offset_guard_size: 0,
+            }
+        }
+
+        /// Construct a `TableStyle` for the provided `TableType`
+        fn table_style(&self, _table: &TableType) -> TableStyle {
+            TableStyle::CallerChecksSignature
+        }
+        fn create_host_memory(
+            &self,
+            _ty: &MemoryType,
+            _style: &MemoryStyle,
+        ) -> Result<VMMemory, MemoryError> {
+            let memory = VMTinyMemory::new().unwrap();
+            Ok(VMMemory::from_custom(memory))
+        }
+        unsafe fn create_vm_memory(
+            &self,
+            _ty: &MemoryType,
+            _style: &MemoryStyle,
+            _vm_definition_location: NonNull<VMMemoryDefinition>,
+        ) -> Result<VMMemory, MemoryError> {
+            let memory = VMTinyMemory::new().unwrap();
+            Ok(memory.into())
+        }
+
+        /// Create a table owned by the host given a [`TableType`] and a [`TableStyle`].
+        fn create_host_table(&self, ty: &TableType, style: &TableStyle) -> Result<VMTable, String> {
+            VMTable::new(ty, style)
+        }
+
+        /// Create a table owned by the VM given a [`TableType`] and a [`TableStyle`].
+        ///
+        /// # Safety
+        /// - `vm_definition_location` must point to a valid location in VM memory.
+        unsafe fn create_vm_table(
+            &self,
+            ty: &TableType,
+            style: &TableStyle,
+            vm_definition_location: NonNull<VMTableDefinition>,
+        ) -> Result<VMTable, String> {
+            VMTable::from_definition(ty, style, vm_definition_location)
+        }
+    }
+
+    #[test]
+    fn check_linearmemory() {
+        let tunables = TinyTunables {};
+        let vmmemory = tunables.create_host_memory(
+            &MemoryType::new(1u32, Some(100u32), true),
+            &MemoryStyle::Static {
+                bound: Pages::from(1u32),
+                offset_guard_size: 0u64,
+            },
+        );
+        let mut vmmemory = vmmemory.unwrap();
+        assert!(vmmemory.grow(Pages::from(2u32)).is_err());
+        assert_eq!(vmmemory.size(), Pages::from(1u32));
+        assert_eq!(
+            vmmemory.grow(Pages::from(0u32)).err().unwrap(),
+            MemoryError::CouldNotGrow {
+                current: Pages::from(100u32),
+                attempted_delta: Pages::from(0u32)
+            }
+        );
+    }
 }