Wasm on the Web (#1990)

* `linera-execution::wasm::wasmer`: set up dependencies for the Web

* `linera-{execution,witty}`: allow non-`Send` types in `UserData`

* `.github/workflows`: enable testing the `wasmer` feature on the Web

* `linera-execution`: don't use `wasmer/js-default` on native targets

* `linera-execution`: make the `wasmtime` backend non-`Send` safe

* `linera-witty`: turn on required `wasmer` features

.github/workflows/rust.yml

@@ -80,7 +80,7 @@ jobs:
           --locked \
           --target wasm32-unknown-unknown \
           --no-default-features \
-          --features web
+          --features web,wasmer
     - name: Compile the workspace with the default features (build)
       run: |
         cargo build --locked

Cargo.toml

@@ -148,7 +148,7 @@ wasm-bindgen = "0.2.92"
 wasm-bindgen-test = "0.3.42"
 wasm-encoder = "0.24.1"
 wasm-instrument = "0.4.0"
-wasmer = { version = "4.3.0-alpha.1", features = ["singlepass"] }
+wasmer = { version = "4.3.0-alpha.1", default-features = false }
 wasmer-compiler-singlepass = "4.3.0-alpha.1"
 wasmparser = "0.101.1"
 wasmtime = "1.0"
@@ -217,3 +217,8 @@ opt-level = 3
 version = "0.4.1"
 git = "https://github.com/Twey/rust-indexed-db"
 branch = "no-uuid-wasm-bindgen"
+
+[patch.crates-io.wasmer]
+version = "4.3.0-alpha.1"
+git = "https://github.com/Twey/wasmer"
+branch = "non-send-environments"

examples/Cargo.toml

@@ -57,3 +57,8 @@ strip = 'debuginfo'
 
 [profile.bench]
 debug = true
+
+[patch.crates-io.wasmer]
+version = "4.3.0-alpha.1"
+git = "https://github.com/Twey/wasmer"
+branch = "non-send-environments"

linera-execution/Cargo.toml

@@ -59,15 +59,16 @@ thiserror.workspace = true
 tracing = { workspace = true, features = ["log"] }
 wasm-encoder = { workspace = true, optional = true }
 wasm-instrument = { workspace = true, optional = true, features = ["sign_ext"] }
-wasmer = { workspace = true, optional = true }
 wasmparser = { workspace = true, optional = true }
 wasmtime = { workspace = true, optional = true }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 tokio = { workspace = true, features = ["rt-multi-thread"] }
+wasmer = { workspace = true, optional = true, features = ["sys-default", "singlepass"] }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 tokio = { workspace = true, features = ["rt"] }
+wasmer = { workspace = true, optional = true, features = ["js-default"] }
 
 [dev-dependencies]
 anyhow.workspace = true
@@ -87,3 +88,8 @@ cfg_aliases.workspace = true
 
 [package.metadata.cargo-machete]
 ignored = ["serde_bytes"]
+
+[patch.crates-io.wasmer]
+version = "4.3.0-alpha.1"
+git = "https://github.com/Twey/wasmer"
+branch = "non-send-environments"

linera-execution/build.rs

@@ -3,11 +3,13 @@
 
 fn main() {
     cfg_aliases::cfg_aliases! {
+        web: { all(target_arch = "wasm32", feature = "web") },
+
         with_fs: { all(not(target_arch = "wasm32"), feature = "fs") },
         with_metrics: { all(not(target_arch = "wasm32"), feature = "metrics") },
         with_testing: { any(test, feature = "test") },
         with_tokio_multi_thread: { not(target_arch = "wasm32") },
-        with_wasmer: { all(not(target_arch = "wasm32"), feature = "wasmer") },
+        with_wasmer: { feature = "wasmer" },
         with_wasmtime: { all(not(target_arch = "wasm32"), feature = "wasmtime") },
 
         // If you change this, don't forget to update `WasmRuntime` and

linera-execution/src/lib.rs

@@ -72,10 +72,10 @@ pub type UserContractCode = Arc<dyn UserContractModule + Send + Sync + 'static>;
 pub type UserServiceCode = Arc<dyn UserServiceModule + Send + Sync + 'static>;
 
 /// An implementation of [`UserContract`].
-pub type UserContractInstance = Box<dyn UserContract + Send + Sync + 'static>;
+pub type UserContractInstance = Box<dyn UserContract + 'static>;
 
 /// An implementation of [`UserService`].
-pub type UserServiceInstance = Box<dyn UserService + Send + Sync + 'static>;
+pub type UserServiceInstance = Box<dyn UserService + 'static>;
 
 /// A factory trait to obtain a [`UserContract`] from a [`UserContractModule`]
 pub trait UserContractModule {

linera-execution/src/test_utils/mock_application.rs

@@ -195,7 +195,7 @@ impl UserContractModule for MockApplication {
     fn instantiate(
         &self,
         runtime: ContractSyncRuntime,
-    ) -> Result<Box<dyn UserContract + Send + Sync + 'static>, ExecutionError> {
+    ) -> Result<Box<dyn UserContract + 'static>, ExecutionError> {
         Ok(Box::new(self.create_mock_instance(runtime)))
     }
 }
@@ -204,7 +204,7 @@ impl UserServiceModule for MockApplication {
     fn instantiate(
         &self,
         runtime: ServiceSyncRuntime,
-    ) -> Result<Box<dyn UserService + Send + Sync + 'static>, ExecutionError> {
+    ) -> Result<Box<dyn UserService + 'static>, ExecutionError> {
         Ok(Box::new(self.create_mock_instance(runtime)))
     }
 }

linera-execution/src/wasm/system_api.rs

@@ -79,7 +79,7 @@ pub struct ContractSystemApi<Caller>(PhantomData<Caller>);
 impl<Caller, Runtime> ContractSystemApi<Caller>
 where
     Caller: Instance<UserData = SystemApiData<Runtime>>,
-    Runtime: ContractRuntime + Send + 'static,
+    Runtime: ContractRuntime + 'static,
 {
     /// Returns the ID of the current chain.
     fn get_chain_id(caller: &mut Caller) -> Result<ChainId, RuntimeError> {
@@ -360,7 +360,7 @@ pub struct ServiceSystemApi<Caller>(PhantomData<Caller>);
 impl<Caller, Runtime> ServiceSystemApi<Caller>
 where
     Caller: Instance<UserData = SystemApiData<Runtime>>,
-    Runtime: ServiceRuntime + Send + 'static,
+    Runtime: ServiceRuntime + 'static,
 {
     /// Returns the ID of the current chain.
     fn get_chain_id(caller: &mut Caller) -> Result<ChainId, RuntimeError> {
@@ -514,7 +514,7 @@ pub struct ViewSystemApi<Caller>(PhantomData<Caller>);
 impl<Caller, Runtime> ViewSystemApi<Caller>
 where
     Caller: Instance<UserData = SystemApiData<Runtime>>,
-    Runtime: BaseRuntime + WriteBatch + Send + 'static,
+    Runtime: BaseRuntime + WriteBatch + 'static,
 {
     /// Creates a new promise to check if the `key` is in storage.
     fn contains_key_new(caller: &mut Caller, key: Vec<u8>) -> Result<u32, RuntimeError> {

linera-execution/src/wasm/wasmer.rs

@@ -13,7 +13,7 @@ use linera_witty::{
 };
 use tokio::sync::Mutex;
 use wasm_instrument::{gas_metering, parity_wasm};
-use wasmer::{sys::EngineBuilder, Cranelift, Engine, Module, Singlepass, Store};
+use wasmer::{Engine, Module, Store};
 
 use super::{
     module_cache::ModuleCache,
@@ -28,8 +28,15 @@ use crate::{
 
 /// An [`Engine`] instance configured to run application services.
 static SERVICE_ENGINE: Lazy<Engine> = Lazy::new(|| {
-    let compiler_config = Cranelift::new();
-    EngineBuilder::new(compiler_config).into()
+    #[cfg(web)]
+    {
+        wasmer::Engine::default()
+    }
+
+    #[cfg(not(web))]
+    {
+        wasmer::sys::EngineBuilder::new(wasmer::Cranelift::new()).into()
+    }
 });
 
 /// A cache of compiled contract modules, with their respective [`Engine`] instances.
@@ -65,7 +72,7 @@ impl WasmContractModule {
 
 impl<Runtime> WasmerContractInstance<Runtime>
 where
-    Runtime: ContractRuntime + WriteBatch + Clone + Send + Sync + Unpin + 'static,
+    Runtime: ContractRuntime + WriteBatch + Clone + Unpin + 'static,
 {
     /// Prepares a runtime instance to call into the Wasm contract.
     pub fn prepare(
@@ -100,7 +107,7 @@ impl WasmServiceModule {
 
 impl<Runtime> WasmerServiceInstance<Runtime>
 where
-    Runtime: ServiceRuntime + WriteBatch + Clone + Send + Sync + Unpin + 'static,
+    Runtime: ServiceRuntime + WriteBatch + Clone + Unpin + 'static,
 {
     /// Prepares a runtime instance to call into the Wasm service.
     pub fn prepare(service_module: &Module, runtime: Runtime) -> Result<Self, WasmExecutionError> {
@@ -118,7 +125,7 @@ where
 
 impl<Runtime> crate::UserContract for WasmerContractInstance<Runtime>
 where
-    Runtime: ContractRuntime + Send + Unpin + 'static,
+    Runtime: ContractRuntime + Unpin + 'static,
 {
     fn instantiate(
         &mut self,
@@ -160,10 +167,7 @@ where
     }
 }
 
-impl<Runtime> crate::UserService for WasmerServiceInstance<Runtime>
-where
-    Runtime: Send + 'static,
-{
+impl<Runtime: 'static> crate::UserService for WasmerServiceInstance<Runtime> {
     fn handle_query(
         &mut self,
         _context: QueryContext,
@@ -253,17 +257,21 @@ impl CachedContractModule {
 
     /// Creates a new [`Engine`] to compile a contract bytecode.
     fn create_compilation_engine() -> Engine {
-        let mut compiler_config = Singlepass::default();
-        compiler_config.canonicalize_nans(true);
+        #[cfg(not(web))]
+        {
+            let mut compiler_config = wasmer::Singlepass::default();
+            compiler_config.canonicalize_nans(true);
+
+            wasmer::sys::EngineBuilder::new(compiler_config).into()
+        }
 
-        EngineBuilder::new(compiler_config).into()
+        #[cfg(web)]
+        wasmer::Engine::default()
     }
 
     /// Creates a [`Module`] from a compiled contract using a headless [`Engine`].
     pub fn create_execution_instance(&self) -> Result<(Engine, Module), anyhow::Error> {
-        use wasmer::NativeEngineExt;
-
-        let engine = Engine::headless();
+        let engine = Engine::default();
         let store = Store::new(engine.clone());
         let module = unsafe { Module::deserialize(&store, &*self.compiled_bytecode) }?;
         Ok((engine, module))