async_state which doesn't work well

Cargo.toml

@@ -1,5 +1,11 @@
 [workspace]
-members = ["unit_struct", "build_script", "stateful", "async_trait"]
+members = [
+    "unit_struct",
+    "build_script",
+    "stateful",
+    "async_trait",
+    "async_state",
+]
 resolver = "2"
 
 [workspace.dependencies]

README.md

@@ -35,5 +35,3 @@ The struct has state and the trait required methods take `&self` or `&mut self`
 ### async_trait
 
 The approach can work well with async.
-
-**Note**: Depends on `async-trait` crate.

async_state/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "async_state"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+ic-cdk.workspace = true
+once_cell  = "1"
+[lib]
+crate-type = ["cdylib"]

async_state/src/lib.rs

@@ -0,0 +1,46 @@
+// ic_cdk::generate!({path: "../../counter.did", service : Canister, trait: Counter});
+
+// Expand Start
+trait Counter {
+    async fn inc(&mut self);
+    fn read(&self) -> u64;
+}
+
+#[export_name = "canister_update inc"]
+fn __canister_method_inc() {
+    ic_cdk::setup();
+    ic_cdk::spawn(async {
+        let _result = CANISTER.lock().unwrap().inc().await;
+        ic_cdk::api::call::reply(())
+    });
+}
+
+#[export_name = "canister_query read"]
+fn __canister_method_read() {
+    ic_cdk::setup();
+    ic_cdk::spawn(async {
+        let result = CANISTER.lock().unwrap().read();
+        ic_cdk::api::call::reply((result,))
+    });
+}
+
+use once_cell::sync::Lazy;
+use std::sync::Mutex;
+static CANISTER: Lazy<Mutex<Canister>> = Lazy::new(|| Mutex::new(Default::default()));
+
+// Expand End
+
+#[derive(Default)]
+struct Canister {
+    counter: u64,
+}
+
+impl Counter for Canister {
+    async fn inc(&mut self) {
+        self.counter += 1;
+    }
+
+    fn read(&self) -> u64 {
+        self.counter
+    }
+}

async_trait/Cargo.toml

@@ -7,7 +7,6 @@ edition = "2021"
 
 [dependencies]
 ic-cdk.workspace = true
-async-trait = "0.1"
 
 [lib]
 crate-type = ["cdylib"]

async_trait/src/lib.rs

@@ -1,7 +1,6 @@
 // ic_cdk::generate!({path: "../../counter.did", service : Canister, trait: Counter});
 
 // Expand Start
-#[async_trait::async_trait]
 trait Counter {
     async fn inc();
     async fn read() -> u64;
@@ -34,7 +33,6 @@ thread_local! {
 
 struct Canister;
 
-#[async_trait::async_trait]
 impl Counter for Canister {
     async fn inc() {
         COUNTER.set(COUNTER.get() + 1);

dfx.json

@@ -27,6 +27,13 @@
             "candid": "counter.did",
             "wasm": "target/wasm32-unknown-unknown/release/async_trait.wasm",
             "shrink": true
+        },
+        "async_state": {
+            "type": "custom",
+            "build": "sh build.sh async_state",
+            "candid": "counter.did",
+            "wasm": "target/wasm32-unknown-unknown/release/async_state.wasm",
+            "shrink": true
         }
     }
 }

rust-toolchain.toml

@@ -0,0 +1,3 @@
+[toolchain]
+channel = "beta"
+targets = ["wasm32-unknown-unknown"]