improve error message

packages/wasi-threads/src/thread-manager.ts

@@ -54,11 +54,18 @@ export interface ThreadManagerOptionsChild extends ThreadManagerOptionsBase {
 const WASI_THREADS_MAX_TID = 0x1FFFFFFF
 
 export function checkSharedWasmMemory (wasmMemory?: WebAssembly.Memory | null): void {
- if (wasmMemory ? !isSharedArrayBuffer(wasmMemory.buffer) : (typeof SharedArrayBuffer === 'undefined')) {
- throw new Error(
- 'Multithread features require shared wasm memory. ' +
- 'Try to compile with `-matomics -mbulk-memory` and use `--import-memory --shared-memory` during linking'
- )
+ if (wasmMemory) {
+ if (!isSharedArrayBuffer(wasmMemory.buffer)) {
+ throw new Error(
+ 'Multithread features require shared wasm memory. ' +
+ 'Try to compile with `-matomics -mbulk-memory` and use `--import-memory --shared-memory` during linking, ' +
+ 'then create WebAssembly.Memory with `shared: true` option'
+ )
+ }
+ } else {
+ if (typeof SharedArrayBuffer === 'undefined') {
+ throw new Error('Current environment does not support SharedArrayBuffer, threads are not available!')
+ }
  }
 }
 

packages/wasi-threads/src/wasi-threads.ts

@@ -132,9 +132,24 @@ export class WASIThreads {
  }
 
  const threadSpawn = (startArg: number, errorOrTid?: number): number => {
- checkSharedWasmMemory(this.wasmMemory)
-
+ const EAGAIN = 6
  const isNewABI = errorOrTid !== undefined
+
+ try {
+ checkSharedWasmMemory(this.wasmMemory)
+ } catch (err) {
+ this.PThread?.printErr(err.stack)
+ if (isNewABI) {
+ const struct = new Int32Array(this.wasmMemory.buffer, errorOrTid!, 2)
+ Atomics.store(struct, 0, 1)
+ Atomics.store(struct, 1, EAGAIN)
+ Atomics.notify(struct, 1)
+ return 1
+ } else {
+ return -EAGAIN
+ }
+ }
+
  if (!isNewABI) {
  const malloc = this.wasmInstance.exports.malloc as Function
  errorOrTid = wasm64 ? Number(malloc(BigInt(8))) : malloc(8)
@@ -211,8 +226,6 @@ export class WASIThreads {
  }
  }
  } catch (e) {
- const EAGAIN = 6
-
  Atomics.store(struct, 0, 1)
  Atomics.store(struct, 1, EAGAIN)
  Atomics.notify(struct, 1)