From 83d97d4b2e05430442989b7bc26c980ca7e2855b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BC=8A=E6=AC=A7?= <m13776491897@163.com>
Date: Mon, 11 Dec 2023 20:36:10 +0800
Subject: [PATCH] Add WASI support by tokio_wasi (#11)

* Try to add WASI target support.

* Enable tokio_wasi by wasi feature.

* Add the impl for wasi environment.

* Use target_os instead of feature.

* Remove unused tokio_wasi module, use offical tokio instead.

* Use same original `tokio`.

* Pin tokio's version.
---
 Cargo.toml          | 21 +++++++++++++--------
 src/lib.rs          |  4 ++--
 src/rt_tokio/mod.rs | 10 +++++++++-
 3 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 8d5676f..d9177a1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,22 +12,27 @@ repository = "https://github.com/futursolo/prokio"
 rust-version = "1.60.0"
 
 [dependencies]
-futures = { version = "0.3", default-features = false, features = ["std", "async-await"] }
+futures = { version = "0.3", default-features = false, features = [
+  "std",
+  "async-await",
+] }
 pin-project = "1.0.11"
 pinned = "0.1.0"
+once_cell = "1"
+
+[target.'cfg(all(target_arch = "wasm32", not(target_os = "wasi")))'.dependencies]
+wasm-bindgen-futures = { version = "0.4" }
+gloo = { version = "0.11" }
 
-[target.'cfg(target_arch = "wasm32")'.dependencies]
-wasm-bindgen-futures = "0.4"
-gloo = "0.8"
+[target.'cfg(any(not(target_arch = "wasm32"), target_os = "wasi"))'.dependencies]
+tokio = { version = "1.35", features = ["rt", "time"] }
+tokio-stream = { version = "0.1.14", features = ["time"] }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 num_cpus = "1.13"
-once_cell = "1"
-tokio = { version = "1.21.1", features = ["rt", "time"] }
-tokio-stream = { version = "0.1", features = ["time"] }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
-tokio = { version = "1.19", features = ["full"] }
+tokio = { version = "1", features = ["full"] }
 
 [features]
 default = []
diff --git a/src/lib.rs b/src/lib.rs
index 1c4fd12..025cc98 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -56,10 +56,10 @@ pub mod fmt;
 pub mod pinned;
 pub mod time;
 
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", not(target_os = "wasi")))]
 #[path = "rt_wasm_bindgen/mod.rs"]
 mod imp;
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(any(not(target_arch = "wasm32"), target_os = "wasi"))]
 #[path = "rt_tokio/mod.rs"]
 mod imp;
 
diff --git a/src/rt_tokio/mod.rs b/src/rt_tokio/mod.rs
index 4b3929a..6bc06d2 100644
--- a/src/rt_tokio/mod.rs
+++ b/src/rt_tokio/mod.rs
@@ -14,7 +14,15 @@ use local_worker::LocalWorker;
 pub(crate) fn get_default_runtime_size() -> usize {
     // We use num_cpus as std::thread::available_parallelism() does not take
     // system resource constraint (e.g.: cgroups) into consideration.
-    num_cpus::get()
+    #[cfg(not(target_os = "wasi"))]
+    {
+        num_cpus::get()
+    }
+    // WASI does not support multi-threading at this moment.
+    #[cfg(target_os = "wasi")]
+    {
+        1
+    }
 }
 
 #[inline(always)]