Wasm32-wasi target support

Cargo.toml

@@ -72,6 +72,7 @@ rustdoc-args = ["--cfg", "docsrs"]
 targets = [
   "aarch64-apple-ios",
   "aarch64-linux-android",
+  "wasm32-wasi",
   "x86_64-apple-darwin",
   "x86_64-pc-windows-msvc",
   "x86_64-unknown-dragonfly",

src/poll.rs

@@ -635,7 +635,6 @@ impl Registry {
     ///
     /// Event sources registered with this `Registry` will be registered with
     /// the original `Registry` and `Poll` instance.
-    #[cfg(not(target_os = "wasi"))]
     pub fn try_clone(&self) -> io::Result<Registry> {
         self.selector
             .try_clone()

src/sys/shell/selector.rs

@@ -11,7 +11,6 @@ pub type Events = Vec<Event>;
 pub struct Selector {}
 
 impl Selector {
-    #[cfg(not(target_os = "wasi"))]
     pub fn try_clone(&self) -> io::Result<Selector> {
         os_required!();
     }

src/sys/wasi/mod.rs

@@ -110,6 +110,13 @@ impl Selector {
         }
     }
 
+    pub(crate) fn try_clone(&self) -> io::Result<Selector> {
+        Ok(Selector {
+            id: self.id,
+            subscriptions: self.subscriptions.clone(),
+        })
+    }
+
     #[cfg(feature = "net")]
     pub(crate) fn register(
         &self,