Implemented shared memory for Wasmer in preparation for multithreading

Fixed linter

Fixed clippy

Cleaned up some merge leftover

lib/api/src/js/mod.rs

@@ -73,7 +73,6 @@ 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;
 }
 

lib/api/src/sys/imports.rs

@@ -1,11 +1,12 @@
 //! The import module contains the implementation data structures and helper functions used to
 //! manipulate and access a wasm module's imports including memories, tables, globals, and
 //! functions.
-use crate::{Exports, Extern, Module};
+use crate::{AsStoreMut, Exports, Extern, Memory, Module};
 use std::collections::HashMap;
 use std::fmt;
 use wasmer_compiler::LinkError;
 use wasmer_types::ImportError;
+use wasmer_vm::VMSharedMemory;
 
 /// All of the import data used when instantiating.
 ///
@@ -111,6 +112,36 @@ impl Imports {
             .insert((ns.to_string(), name.to_string()), val.into());
     }
 
+    /// Imports (any) shared memory into the imports.
+    /// (if the module does not import memory then this function is ignored)
+    pub fn import_shared_memory(
+        &mut self,
+        module: &Module,
+        store: &mut impl AsStoreMut,
+    ) -> Option<VMSharedMemory> {
+        // Determine if shared memory needs to be created and imported
+        let shared_memory = module
+            .imports()
+            .memories()
+            .next()
+            .map(|a| *a.ty())
+            .map(|ty| {
+                let style = store.as_store_ref().tunables().memory_style(&ty);
+                VMSharedMemory::new(&ty, &style).unwrap()
+            });
+
+        if let Some(memory) = shared_memory {
+            self.define(
+                "env",
+                "memory",
+                Memory::new_from_existing(store, memory.clone().into()),
+            );
+            Some(memory)
+        } else {
+            None
+        }
+    }
+
     /// Returns the contents of a namespace as an `Exports`.
     ///
     /// Returns `None` if the namespace doesn't exist.

lib/api/src/sys/mod.rs

@@ -57,8 +57,8 @@ pub mod vm {
     //! The `vm` module re-exports wasmer-vm types.
 
     pub use wasmer_vm::{
-        MemoryError, MemoryStyle, TableStyle, VMExtern, VMMemory, VMMemoryDefinition, VMTable,
-        VMTableDefinition,
+        MemoryError, MemoryStyle, TableStyle, VMExtern, VMMemory, VMMemoryDefinition,
+        VMOwnedMemory, VMSharedMemory, VMTable, VMTableDefinition,
     };
 }