worker message structure

Author: toyobayashi

packages/emnapi/src/core/async.ts

@@ -72,7 +72,15 @@ function spawnThread (startArg: number, threadId?: Int32Array): number {
     const threadIdBuffer = new SharedArrayBuffer(4)
     const id = new Int32Array(threadIdBuffer)
     Atomics.store(id, 0, -1)
-    postMessage({ cmd: 'thread-spawn', startArg, threadId: id })
+    postMessage({
+      __emnapi__: {
+        type: 'thread-spawn',
+        payload: {
+          startArg,
+          threadId: id
+        }
+      }
+    })
     Atomics.wait(id, 0, -1)
     const tid = Atomics.load(id, 0)
     return tid
@@ -84,16 +92,19 @@ function spawnThread (startArg: number, threadId?: Int32Array): number {
   const worker = onCreateWorker()
 
   worker.onmessage = function (e: any) {
-    if (e.data.cmd === 'loaded') {
-      if (typeof worker.unref === 'function') {
-        worker.unref()
-      }
-      if (!e.data.success) {
-        err(e.data.message)
-        err(e.data.stack)
+    if (e.data.__emnapi__) {
+      const type = e.data.__emnapi__.type
+      const payload = e.data.__emnapi__.payload
+      if (type === 'loaded') {
+        if (typeof worker.unref === 'function') {
+          worker.unref()
+        }
+        if (payload.err) {
+          err(payload.err)
+        }
+      } else if (type === 'thread-spawn') {
+        spawnThread(payload.startArg, payload.threadId)
       }
-    } else if (e.data.cmd === 'thread-spawn') {
-      spawnThread(e.data.startArg, e.data.threadId)
     }
   }
   worker.onerror = (e: any) => {
@@ -121,19 +132,22 @@ function spawnThread (startArg: number, threadId?: Int32Array): number {
   nextTid++
   // napiModule.PThread.pthreads[tid] = worker
   // worker.pthread_ptr = tid
-  const payload = {
-    cmd: 'load',
-    wasmModule,
-    wasmMemory,
-    tid,
-    arg: startArg
+  const msg = {
+    __emnapi__: {
+      type: 'load',
+      payload: {
+        wasmModule,
+        wasmMemory,
+        tid,
+        arg: startArg
+      }
+    }
   }
-  // console.log(payload)
   if (threadId) {
     Atomics.store(threadId, 0, tid)
     Atomics.notify(threadId, 0)
   }
-  worker.postMessage(payload)
+  worker.postMessage(msg)
   return tid
 }
 napiModule.spawnThread = spawnThread

packages/test/worker.js

@@ -91,16 +91,32 @@ function instantiate (wasmMemory, wasmModule, tid, arg) {
   })
 
   wasi.initialize(instanceProxy)
-  postMessage({ cmd: 'loaded', success: true })
+  postMessage({
+    __emnapi__: {
+      type: 'loaded',
+      payload: {
+        err: null
+      }
+    }
+  })
   instance.exports.wasi_thread_start(tid, arg)
 }
 
 self.onmessage = function (e) {
-  if (e.data.cmd === 'load') {
-    try {
-      instantiate(e.data.wasmMemory, e.data.wasmModule, e.data.tid, e.data.arg)
-    } catch (err) {
-      postMessage({ cmd: 'loaded', success: false, message: err.message, stack: err.stack })
+  if (e.data.__emnapi__) {
+    const type = e.data.__emnapi__.type
+    const payload = e.data.__emnapi__.payload
+    if (type === 'load') {
+      try {
+        instantiate(payload.wasmMemory, payload.wasmModule, payload.tid, payload.arg)
+      } catch (err) {
+        postMessage({
+          __emnapi__: {
+            type: 'loaded',
+            payload: { err }
+          }
+        })
+      }
     }
   }
 }