feat(vm) Ability to use exports after the instance has been freed

lib/api/src/externals/function.rs

@@ -58,6 +58,12 @@ pub struct Function {
     pub(crate) exported: ExportFunction,
 }
 
+impl Drop for Function {
+    fn drop(&mut self) {
+        println!("Dropping `wasmer::Function`");
+    }
+}
+
 impl Function {
     /// Creates a new host `Function` (dynamic) with the provided signature.
     ///
@@ -100,6 +106,7 @@ impl Function {
                 vmctx,
                 signature: ty.clone(),
                 call_trampoline: None,
+                instance_allocator: None,
             },
         }
     }
@@ -152,6 +159,7 @@ impl Function {
                 vmctx,
                 signature: ty.clone(),
                 call_trampoline: None,
+                instance_allocator: None,
             },
         }
     }
@@ -196,6 +204,7 @@ impl Function {
                 signature,
                 kind: VMFunctionKind::Static,
                 call_trampoline: None,
+                instance_allocator: None,
             },
         }
     }
@@ -252,6 +261,7 @@ impl Function {
                 vmctx,
                 signature,
                 call_trampoline: None,
+                instance_allocator: None,
             },
         }
     }
@@ -474,7 +484,7 @@ impl Function {
         Ok(results.into_boxed_slice())
     }
 
-    pub(crate) fn from_export(store: &Store, wasmer_export: ExportFunction) -> Self {
+    pub(crate) fn from_vm_export(store: &Store, wasmer_export: ExportFunction) -> Self {
         if let Some(trampoline) = wasmer_export.call_trampoline {
             Self {
                 store: store.clone(),

lib/api/src/externals/global.rs

@@ -180,7 +180,7 @@ impl Global {
         Ok(())
     }
 
-    pub(crate) fn from_export(store: &Store, wasmer_export: ExportGlobal) -> Self {
+    pub(crate) fn from_vm_export(store: &Store, wasmer_export: ExportGlobal) -> Self {
         Self {
             store: store.clone(),
             global: wasmer_export.from,
@@ -218,6 +218,7 @@ impl<'a> Exportable<'a> for Global {
     fn to_export(&self) -> Export {
         ExportGlobal {
             from: self.global.clone(),
+            instance_allocator: None,
         }
         .into()
     }

lib/api/src/externals/memory.rs

@@ -220,7 +220,7 @@ impl Memory {
         unsafe { MemoryView::new(base as _, length as u32) }
     }
 
-    pub(crate) fn from_export(store: &Store, wasmer_export: ExportMemory) -> Self {
+    pub(crate) fn from_vm_export(store: &Store, wasmer_export: ExportMemory) -> Self {
         Self {
             store: store.clone(),
             memory: wasmer_export.from,
@@ -248,6 +248,7 @@ impl<'a> Exportable<'a> for Memory {
     fn to_export(&self) -> Export {
         ExportMemory {
             from: self.memory.clone(),
+            instance_allocator: None,
         }
         .into()
     }

lib/api/src/externals/mod.rs

@@ -46,13 +46,13 @@ impl Extern {
         }
     }
 
-    /// Create an `Extern` from an `Export`.
-    pub fn from_export(store: &Store, export: Export) -> Self {
+    /// Create an `Extern` from an `wasmer_vm::Export`.
+    pub fn from_vm_export(store: &Store, export: Export) -> Self {
         match export {
-            Export::Function(f) => Self::Function(Function::from_export(store, f)),
-            Export::Memory(m) => Self::Memory(Memory::from_export(store, m)),
-            Export::Global(g) => Self::Global(Global::from_export(store, g)),
-            Export::Table(t) => Self::Table(Table::from_export(store, t)),
+            Export::Function(f) => Self::Function(Function::from_vm_export(store, f)),
+            Export::Memory(m) => Self::Memory(Memory::from_vm_export(store, m)),
+            Export::Global(g) => Self::Global(Global::from_vm_export(store, g)),
+            Export::Table(t) => Self::Table(Table::from_vm_export(store, t)),
         }
     }
 }

lib/api/src/externals/table.rs

@@ -139,7 +139,7 @@ impl Table {
         Ok(())
     }
 
-    pub(crate) fn from_export(store: &Store, wasmer_export: ExportTable) -> Self {
+    pub(crate) fn from_vm_export(store: &Store, wasmer_export: ExportTable) -> Self {
         Self {
             store: store.clone(),
             table: wasmer_export.from,
@@ -156,6 +156,7 @@ impl<'a> Exportable<'a> for Table {
     fn to_export(&self) -> Export {
         ExportTable {
             from: self.table.clone(),
+            instance_allocator: None,
         }
         .into()
     }

lib/api/src/instance.rs

@@ -80,7 +80,7 @@ impl Instance {
             .map(|export| {
                 let name = export.name().to_string();
                 let export = handle.lookup(&name).expect("export");
-                let extern_ = Extern::from_export(store, export);
+                let extern_ = Extern::from_vm_export(store, export);
                 (name, extern_)
             })
             .collect::<Exports>();
@@ -115,3 +115,9 @@ impl fmt::Debug for Instance {
             .finish()
     }
 }
+
+impl Drop for Instance {
+    fn drop(&mut self) {
+        println!("Dropping `wasmer::Instance`");
+    }
+}

lib/api/src/native.rs

@@ -70,6 +70,7 @@ where
             signature,
             kind: other.arg_kind,
             call_trampoline: None,
+            instance_allocator: None,
         }
     }
 }
@@ -90,6 +91,7 @@ where
                 signature,
                 kind: other.arg_kind,
                 call_trampoline: None,
+                instance_allocator: None,
             },
         }
     }

lib/api/src/types.rs

@@ -81,8 +81,9 @@ impl ValFuncRef for Val {
             kind: wasmer_vm::VMFunctionKind::Static,
             vmctx: item.vmctx,
             call_trampoline: None,
+            instance_allocator: None,
         };
-        let f = Function::from_export(store, export);
+        let f = Function::from_vm_export(store, export);
         Self::FuncRef(f)
     }
 }

lib/c-api/src/wasm_c_api/wasi/mod.rs

@@ -335,7 +335,7 @@ unsafe fn wasi_get_imports_inner(
                         import_type.name()
                     ),
                 }));
-            let inner = Extern::from_export(store, export);
+            let inner = Extern::from_vm_export(store, export);
 
             Some(Box::new(wasm_extern_t {
                 instance: None,

lib/deprecated/runtime-core/src/module.rs

@@ -159,12 +159,12 @@ impl Module {
 
                         (
                             (namespace, name),
-                            new::wasmer::Extern::from_export(store, Export::Function(function)),
+                            new::wasmer::Extern::from_vm_export(store, Export::Function(function)),
                         )
                     }
                     export => (
                         (namespace, name),
-                        new::wasmer::Extern::from_export(store, export),
+                        new::wasmer::Extern::from_vm_export(store, export),
                     ),
                 })
                 .for_each(|((namespace, name), extern_)| {

lib/vm/src/export.rs

@@ -2,6 +2,7 @@
 // Attributions: https://github.com/wasmerio/wasmer/blob/master/ATTRIBUTIONS.md
 
 use crate::global::Global;
+use crate::instance::InstanceAllocator;
 use crate::memory::{Memory, MemoryStyle};
 use crate::table::{Table, TableStyle};
 use crate::vmcontext::{VMFunctionBody, VMFunctionEnvironment, VMFunctionKind, VMTrampoline};
@@ -38,6 +39,9 @@ pub struct ExportFunction {
     /// Address of the function call trampoline owned by the same VMContext that owns the VMFunctionBody.
     /// May be None when the function is a host-function (FunctionType == Dynamic or vmctx == nullptr).
     pub call_trampoline: Option<VMTrampoline>,
+    /// A reference to the instance, to ensure it's not deallocated
+    /// before the function.
+    pub instance_allocator: Option<InstanceAllocator>,
 }
 
 /// # Safety
@@ -59,6 +63,9 @@ impl From<ExportFunction> for Export {
 pub struct ExportTable {
     /// Pointer to the containing `Table`.
     pub from: Arc<dyn Table>,
+    /// A reference to the instance, to ensure it's not deallocated
+    /// before the table.
+    pub instance_allocator: Option<InstanceAllocator>,
 }
 
 /// # Safety
@@ -100,6 +107,9 @@ impl From<ExportTable> for Export {
 pub struct ExportMemory {
     /// Pointer to the containing `Memory`.
     pub from: Arc<dyn Memory>,
+    /// A reference to the instance, to ensure it's not deallocated
+    /// before the memory.
+    pub instance_allocator: Option<InstanceAllocator>,
 }
 
 /// # Safety
@@ -141,6 +151,9 @@ impl From<ExportMemory> for Export {
 pub struct ExportGlobal {
     /// The global declaration, used for compatibility checking.
     pub from: Arc<Global>,
+    /// A reference to the instance, to ensure it's not deallocated
+    /// before the global.
+    pub instance_allocator: Option<InstanceAllocator>,
 }
 
 /// # Safety