bjorn3 · oligamiq · Sep 21, 2025 · Sep 22, 2025 · Sep 22, 2025 · Sep 22, 2025
diff --git a/src/wasi.ts b/src/wasi.ts
@@ -817,6 +817,7 @@ export default class WASI {
         in_ptr: number,
         out_ptr: number,
         nsubscriptions: number,
+        stored_events_count_ptr: number,
       ): number {
         if (nsubscriptions === 0) {
           return wasi.ERRNO_INVAL;
@@ -852,9 +853,9 @@ export default class WASI {
 
         // Perform the wait
         const endTime =
-          (s.flags & wasi.SUBCLOCKFLAGS_SUBSCRIPTION_CLOCK_ABSTIME) !== 0
+          ((s.flags & wasi.SUBCLOCKFLAGS_SUBSCRIPTION_CLOCK_ABSTIME) !== 0
             ? timeout
-            : getNow() + timeout;
+            : getNow() + timeout) - s.precision;
         while (endTime > getNow()) {
           // block until the timeout is reached
         }
@@ -863,6 +864,8 @@ export default class WASI {
         const event = new wasi.Event(s.userdata, wasi.ERRNO_SUCCESS, eventtype);
         event.write_bytes(buffer, out_ptr);
 
+        buffer.setUint32(stored_events_count_ptr, 1, true);
+
         return wasi.ERRNO_SUCCESS;
       },
       proc_exit(exit_code: number) {

diff --git a/src/wasi_defs.ts b/src/wasi_defs.ts
@@ -306,6 +306,7 @@ export class Subscription {
     public eventtype: number,
     public clockid: number,
     public timeout: bigint,
+    public precision: bigint,
     public flags: number,
   ) {}
 
@@ -315,7 +316,8 @@ export class Subscription {
       view.getUint8(ptr + 8),
       view.getUint32(ptr + 16, true),
       view.getBigUint64(ptr + 24, true),
-      view.getUint16(ptr + 36, true),
+      view.getBigUint64(ptr + 32, true),
+      view.getUint16(ptr + 40, true),
     );
   }
 }
@@ -325,12 +327,19 @@ export class Event {
     public userdata: bigint,
     public error: number,
     public eventtype: number,
+    // `eventtype::clock` events ignore this fields
+    public fd_readwrite_nbytes: bigint = 0n,
+    public fd_readwrite_flags: number = 0,
   ) {}
 
   write_bytes(view: DataView, ptr: number) {
     view.setBigUint64(ptr, this.userdata, true);
     view.setUint16(ptr + 8, this.error, true);
     view.setUint8(ptr + 10, this.eventtype);
+    if (this.eventtype !== EVENTTYPE_CLOCK) {
+        view.setBigUint64(ptr + 16, this.fd_readwrite_nbytes, true);
+        view.setUint16(ptr + 24, this.fd_readwrite_flags, true);
+    }
   }
 }
 

diff --git a/threads/bun.lockb b/threads/bun.lockb
diff --git a/threads/examples/bun.lockb b/threads/examples/bun.lockb
diff --git a/threads/examples/common_check/common.wasm b/threads/examples/common_check/common.wasm
diff --git a/threads/examples/common_check/index.html b/threads/examples/common_check/index.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+
+<div id="terminal"></div>
+
+<script type="module" src="./index.ts"></script>
+</body>
+</html>
diff --git a/threads/examples/common_check/index.ts b/threads/examples/common_check/index.ts
@@ -0,0 +1,60 @@
+import { Fd } from "@bjorn3/browser_wasi_shim";
+import { Terminal } from "@xterm/xterm";
+import { FitAddon } from "xterm-addon-fit";
+import { WASIFarm } from "../../src";
+import { wait_async_polyfill } from "../../src";
+
+import "@xterm/xterm/css/xterm.css";
+
+wait_async_polyfill();
+
+const term = new Terminal({
+  convertEol: true,
+});
+const terminalElement = document.getElementById("terminal");
+
+if (!terminalElement) {
+  throw new Error("No terminal element found");
+}
+
+term.open(terminalElement);
+
+const fitAddon = new FitAddon();
+term.loadAddon(fitAddon);
+fitAddon.fit();
+
+term.writeln("Initializing...");
+
+class XtermStdio extends Fd {
+  term: Terminal;
+
+  constructor(term: Terminal) {
+    super();
+    this.term = term;
+  }
+  fd_write(data: Uint8Array) /*: {ret: number, nwritten: number}*/ {
+    const str = new TextDecoder().decode(data);
+    this.term.write(str);
+    console.log(str);
+    return { ret: 0, nwritten: data.byteLength };
+  }
+}
+
+const farm = new WASIFarm(
+  new XtermStdio(term),
+  new XtermStdio(term),
+  new XtermStdio(term),
+  [],
+);
+
+const worker = new Worker("./worker.ts", { type: "module" });
+
+worker.postMessage({
+  wasi_ref: farm.get_ref(),
+});
+
+worker.onmessage = (e) => {
+  if (e.data.done) {
+    term.writeln("All Done!!");
+  }
+};
diff --git a/threads/examples/common_check/main.rs b/threads/examples/common_check/main.rs
@@ -0,0 +1,51 @@
+// https://doc.rust-lang.org/book/ch16-02-message-passing.html
+// rustc +nightly --target wasm32-wasip1-threads main.rs -o common.wasm -Cstrip=debuginfo -Clto=fat
+// wasm-opt -Oz --enable-multivalue -o common_opt.wasm common.wasm
+
+use std::thread;
+
+fn main() {
+    let args = std::env::args().collect::<Vec<_>>();
+    match args[0].as_str() {
+        "unreachable" => {
+            unreachable!();
+        }
+        "unreachable_child" => {
+            thread::spawn(|| {
+                unreachable!();
+            });
+            loop {}
+        }
+        "exit" => {
+            println!("exit {}", args[1]);
+            std::process::exit(args[1].parse().unwrap());
+        }
+        "exit_child" => {
+            thread::spawn(move || {
+                println!("exit {}", args[1]);
+                std::process::exit(args[1].parse().unwrap());
+            });
+            loop {}
+        }
+        "panic" => {
+            panic!("panic!");
+        }
+        "panic_child" => {
+            thread::spawn(|| {
+                panic!("panic!");
+            });
+            loop {}
+        }
+        "ok" => {
+            println!("ok");
+        }
+        "ok_child" => {
+            thread::spawn(|| {
+                println!("ok");
+            })
+            .join()
+            .unwrap();
+        }
+        _ => unreachable!(),
+    }
+}
diff --git a/threads/examples/common_check/thread_spawn.ts b/threads/examples/common_check/thread_spawn.ts
@@ -0,0 +1,5 @@
+import { thread_spawn_on_worker } from "../../src";
+
+self.onmessage = (event) => {
+  thread_spawn_on_worker(event.data);
+};
diff --git a/threads/examples/common_check/worker.ts b/threads/examples/common_check/worker.ts
@@ -0,0 +1,78 @@
+import { WASIFarmAnimal } from "../../src";
+
+import { wait_async_polyfill } from "../../src/index.js";
+
+wait_async_polyfill();
+
+self.onmessage = async (e) => {
+  const { wasi_ref } = e.data;
+
+  const wasm = await WebAssembly.compileStreaming(fetch("./common.wasm"));
+
+  const run = async (args: string[]) => {
+    const wasi = new WASIFarmAnimal(
+      wasi_ref,
+      args, // args\
+      [], // env
+      {
+        can_thread_spawn: true,
+        thread_spawn_worker_url: new URL("./thread_spawn.ts", import.meta.url)
+          .href,
+        // thread_spawn_worker_url: "./thread_spawn.ts",
+        thread_spawn_wasm: wasm,
+        worker_background_worker_url: new URL(
+          "./worker_background.ts",
+          import.meta.url,
+        ).href,
+      },
+    );
+
+    await wasi.wait_worker_background_worker();
+
+    try {
+      const code = await wasi.async_start_on_thread();
+      console.log(`"${args[0]}" exit code:`, code);
+      return code;
+    } catch (e) {
+      console.error(`"${args[0]}" error:`, e);
+      return "error";
+    }
+  };
+
+  const code = await run(["unreachable"]);
+  if (code !== "error") {
+    throw new Error("unreachable test failed");
+  }
+  const code2 = await run(["unreachable_child"]);
+  if (code2 !== "error") {
+    throw new Error("exit test failed");
+  }
+  const code3 = await run(["exit", "42"]);
+  if (code3 !== 42) {
+    throw new Error("exit test failed");
+  }
+  const code4 = await run(["exit_child", "43"]);
+  if (code4 !== 43) {
+    throw new Error("exit test failed");
+  }
+  const code5 = await run(["panic"]);
+  if (code5 !== "error") {
+    throw new Error("panic test failed");
+  }
+  const code6 = await run(["panic_child"]);
+  if (code6 !== "error") {
+    throw new Error("panic test failed");
+  }
+  const code7 = await run(["ok"]);
+  if (code7 !== 0) {
+    throw new Error("ok test failed");
+  }
+  const code8 = await run(["ok_child"]);
+  if (code8 !== 0) {
+    throw new Error("ok test failed");
+  }
+
+  console.log("All tests passed");
+
+  self.postMessage({ done: true });
+};
diff --git a/threads/examples/common_check/worker_background.ts b/threads/examples/common_check/worker_background.ts
@@ -0,0 +1,8 @@
+// @ts-ignore
+import worker_background_worker from "../node_modules/@oligami/browser_wasi_shim-threads/dist/worker_background_worker.min.js";
+
+import { wait_async_polyfill } from "../../src/index.js";
+
+wait_async_polyfill();
+
+worker_background_worker();