fix(wasi): avoid deadlock caused by child thread abort when the main thread is in Atomics.wait

.github/workflows/main.yml

@@ -18,12 +18,12 @@ on:
   workflow_dispatch:
 
 env:
-  WASI_VERSION: '25'
-  WASI_VERSION_FULL: '25.0'
-  WASI_SDK_PATH: './wasi-sdk-25.0'
-  EM_VERSION: '3.1.64'
+  WASI_VERSION: '27'
+  WASI_VERSION_FULL: '27.0'
+  WASI_SDK_PATH: './wasi-sdk-27.0'
+  EM_VERSION: '4.0.1'
   EM_CACHE_FOLDER: 'emsdk-cache'
-  NODE_VERSION: '22.15.0'
+  NODE_VERSION: '22.16.0'
 
 jobs:
   build:
@@ -77,7 +77,7 @@ jobs:
 
     - uses: actions/setup-node@v3
       with:
-        node-version: ${{ env.NODE_VERSION }}
+        node-version: ${{ matrix.target == 'wasm64-unknown-emscripten' && '24.5.0' || env.NODE_VERSION }}
         registry-url: 'https://registry.npmjs.org'
       env:
         NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}

packages/core/src/worker.ts

@@ -1,7 +1,8 @@
 import {
   ThreadMessageHandler,
   type ThreadMessageHandlerOptions,
-  type LoadPayload
+  type LoadPayload,
+  type WorkerMessageEvent
 } from '@emnapi/wasi-threads'
 import type { NapiModule } from './emnapi/index'
 import type { InstantiatedSource } from './load'
@@ -21,7 +22,24 @@ export class MessageHandler extends ThreadMessageHandler {
     if (typeof options.onLoad !== 'function') {
       throw new TypeError('options.onLoad is not a function')
     }
-    super(options)
+    const userOnError = options.onError
+    super({
+      ...options,
+      onError: (err, type) => {
+        const emnapi_thread_crashed = this.instance?.exports.emnapi_thread_crashed as () => void
+        if (typeof emnapi_thread_crashed === 'function') {
+          emnapi_thread_crashed()
+        } /* else {
+          tryWakeUpPthreadJoin(this.instance!)
+        } */
+
+        if (typeof userOnError === 'function') {
+          userOnError(err, type)
+        } else {
+          throw err
+        }
+      }
+    })
     this.napiModule = undefined
   }
 
@@ -38,21 +56,39 @@ export class MessageHandler extends ThreadMessageHandler {
     return source
   }
 
-  public override handle (e: any): void {
+  public override handle (e: WorkerMessageEvent): void {
     super.handle(e)
     if (e?.data?.__emnapi__) {
       const type = e.data.__emnapi__.type
       const payload = e.data.__emnapi__.payload
-
-      if (type === 'async-worker-init') {
-        this.handleAfterLoad(e, () => {
-          this.napiModule!.initWorker(payload.arg)
-        })
-      } else if (type === 'async-work-execute') {
-        this.handleAfterLoad(e, () => {
-          this.napiModule!.executeAsyncWork(payload.work)
-        })
+      try {
+        if (type === 'async-worker-init') {
+          this.handleAfterLoad(e, () => {
+            this.napiModule!.initWorker(payload.arg)
+          })
+        } else if (type === 'async-work-execute') {
+          this.handleAfterLoad(e, () => {
+            this.napiModule!.executeAsyncWork(payload.work)
+          })
+        }
+      } catch (err) {
+        this.onError(err, type)
       }
     }
   }
 }
+
+// function tryWakeUpPthreadJoin (instance: WebAssembly.Instance): void {
+//   // https://github.com/WebAssembly/wasi-libc/blob/574b88da481569b65a237cb80daf9a2d5aeaf82d/libc-top-half/musl/src/thread/pthread_join.c#L18-L21
+//   const pthread_self = instance.exports.pthread_self as () => number
+//   const memory = instance.exports.memory as WebAssembly.Memory
+//   if (typeof pthread_self === 'function') {
+//     const selfThread = pthread_self()
+//     if (selfThread && memory) {
+//       // https://github.com/WebAssembly/wasi-libc/blob/574b88da481569b65a237cb80daf9a2d5aeaf82d/libc-top-half/musl/src/internal/pthread_impl.h#L45
+//       const detatchState = new Int32Array(memory.buffer, selfThread + 7 * 4 /** detach_state */, 1)
+//       Atomics.store(detatchState, 0, 0)
+//       Atomics.notify(detatchState, 0, Infinity)
+//     }
+//   }
+// }

packages/emnapi/CMakeLists.txt

@@ -61,6 +61,7 @@ set(ENAPI_BASIC_SRC
   "${CMAKE_CURRENT_SOURCE_DIR}/src/node_api.c"
   "${CMAKE_CURRENT_SOURCE_DIR}/src/async_cleanup_hook.c"
   "${CMAKE_CURRENT_SOURCE_DIR}/src/async_context.c"
+  "${CMAKE_CURRENT_SOURCE_DIR}/src/wasi_wait.c"
 )
 set(EMNAPI_THREADS_SRC
   "${CMAKE_CURRENT_SOURCE_DIR}/src/async_work.c"

packages/emnapi/README.md

@@ -816,8 +816,9 @@ Now emnapi has 3 implementations of async work and 2 implementations of TSFN:
 There are some limitations on browser about wasi-libc's pthread implementation, for example
 `pthread_mutex_lock` may call `__builtin_wasm_memory_atomic_wait32`(`memory.atomic.wait32`)
 which is disallowed in browser JS main thread. While Emscripten's pthread implementation
-has considered usage in browser. If you need to run your addon with multithreaded features on browser,
-we recommend you use Emscripten A & D, or bare wasm32 C & E.
+has considered usage in browser. This issue can be solved by upgrading `wasi-sdk` to v26+
+and emnapi v1.5.0+ then pass `--export=emnapi_thread_crashed` to the linker. If you need to
+run your addon with multithreaded features, we recommend you use A & D or C & E.
 
 Note: For browsers, all the multithreaded features relying on Web Workers (Emscripten pthread also relying on Web Workers)
 require cross-origin isolation to enable `SharedArrayBuffer`. You can make a page cross-origin isolated
@@ -879,6 +880,7 @@ elseif(CMAKE_C_COMPILER_TARGET STREQUAL "wasm32-wasi-threads")
     "-Wl,--export-if-defined=node_api_module_get_api_version_v1"
     "-Wl,--export=malloc"
     "-Wl,--export=free"
+    "-Wl,--export=emnapi_thread_crashed"
     "-Wl,--import-undefined"
     "-Wl,--export-table"
   )

packages/emnapi/common.gypi

@@ -310,6 +310,7 @@
               'src/async_cleanup_hook.c',
               'src/async_context.c',
               'src/async_work.c',
+              'src/wasi_wait.c',
               'src/threadsafe_function.c',
               'src/uv/uv-common.c',
               'src/uv/threadpool.c',
@@ -372,6 +373,16 @@
                       ]
                     },
                   }],
+                  ['OS == "wasi"', {
+                    'ldflags': [
+                      '-Wl,--export=emnapi_thread_crashed',
+                    ],
+                    'xcode_settings': {
+                      'OTHER_LDFLAGS': [
+                        '-Wl,--export=emnapi_thread_crashed',
+                      ],
+                    },
+                  }],
                   ['OS != "wasi"', {
                     'defines': [
                       'PAGESIZE=65536'

packages/emnapi/emnapi.gyp

@@ -55,6 +55,7 @@
         'src/node_api.c',
         'src/async_cleanup_hook.c',
         'src/async_context.c',
+        'src/wasi_wait.c',
       ],
       'link_settings': {
         'target_conditions': [
@@ -88,6 +89,22 @@
             ]
           },
         }],
+        ['OS == "wasi"', {
+          'link_settings': {
+            'target_conditions': [
+              ['_type == "executable"', {
+                'ldflags': [
+                  '-Wl,--export=emnapi_thread_crashed',
+                ],
+                'xcode_settings': {
+                  'OTHER_LDFLAGS': [
+                    '-Wl,--export=emnapi_thread_crashed',
+                  ],
+                },
+              }],
+            ]
+          },
+        }],
       ]
     },
     {
@@ -98,6 +115,7 @@
         'src/node_api.c',
         'src/async_cleanup_hook.c',
         'src/async_context.c',
+        'src/wasi_wait.c',
 
         'src/uv/uv-common.c',
         'src/uv/threadpool.c',

packages/emnapi/src/core/async.ts

@@ -67,11 +67,6 @@ var uvThreadpoolReady: Promise<void> & { ready: boolean } = new Promise<void>((r
 }) as any
 uvThreadpoolReady.ready = false
 
-/** @__sig i */
-export function _emnapi_is_main_browser_thread (): number {
-  return (typeof window !== 'undefined' && typeof document !== 'undefined' && !ENVIRONMENT_IS_NODE) ? 1 : 0
-}
-
 /** @__sig vppi */
 export function _emnapi_after_uvthreadpool_ready (callback: number, q: number, type: number): void {
   if (uvThreadpoolReady.ready) {

packages/emnapi/src/core/init.ts

@@ -109,10 +109,12 @@ export var napiModule: INapiModule = {
           const moduleHandle = scope.add(napiModule)
           instance.exports[nodeRegisterModuleSymbol](to64('exportsHandle'), to64('moduleHandle'), to64('5'))
         } catch (err) {
+          if (err !== 'unwind') {
+            throw err
+          }
+        } finally {
           emnapiCtx.isolate.closeScope(scope)
-          throw err
         }
-        emnapiCtx.isolate.closeScope(scope)
         napiModule.loaded = true
         delete napiModule.envObject
         return napiModule.exports
@@ -150,6 +152,10 @@ export var napiModule: INapiModule = {
           const napiValue = napi_register_wasm_v1(to64('_envObject.id'), to64('exportsHandle'))
           napiModule.exports = (!napiValue) ? exports : emnapiCtx.jsValueFromNapiValue(napiValue)!
         })
+      } catch (e) {
+        if (e !== 'unwind') {
+          throw e
+        }
       } finally {
         emnapiCtx.closeScope(envObject, scope)
       }

packages/emnapi/src/emnapi_internal.h

@@ -105,6 +105,11 @@ EMNAPI_INTERNAL_EXTERN void _emnapi_env_unref(napi_env env);
 EMNAPI_INTERNAL_EXTERN void _emnapi_ctx_increase_waiting_request_counter();
 EMNAPI_INTERNAL_EXTERN void _emnapi_ctx_decrease_waiting_request_counter();
 
+EMNAPI_INTERNAL_EXTERN int _emnapi_is_main_browser_thread();
+EMNAPI_INTERNAL_EXTERN int _emnapi_is_main_runtime_thread();
+EMNAPI_INTERNAL_EXTERN double _emnapi_get_now();
+EMNAPI_INTERNAL_EXTERN void _emnapi_unwind();
+
 #if defined(__EMSCRIPTEN_PTHREADS__) || defined(_REENTRANT)
 #define EMNAPI_HAVE_THREADS 1
 #else

packages/emnapi/src/emscripten/init.ts

@@ -80,10 +80,12 @@ export function emnapiInit (options: InitOptions): any {
       const moduleHandle = scope.add(emnapiModule)
       Module[emscriptenExportedSymbol](to64('exportsHandle'), to64('moduleHandle'), to64('5'))
     } catch (err) {
+      if (err !== 'unwind') {
+        throw err
+      }
+    } finally {
       emnapiCtx.isolate.closeScope(scope)
-      throw err
     }
-    emnapiCtx.isolate.closeScope(scope)
     emnapiModule.loaded = true
     delete emnapiModule.envObject
     return emnapiModule.exports
@@ -118,10 +120,12 @@ NODE_MODULE_VERSION ${NODE_MODULE_VERSION}.`)
       emnapiModule.exports = (!napiValue) ? exports : emnapiCtx.jsValueFromNapiValue(napiValue)!
     })
   } catch (err) {
+    if (err !== 'unwind') {
+      throw err
+    }
+  } finally {
     emnapiCtx.closeScope(envObject, scope)
-    throw err
   }
-  emnapiCtx.closeScope(envObject, scope)
   emnapiModule.loaded = true
   delete emnapiModule.envObject
   return emnapiModule.exports

packages/emnapi/src/util.ts

@@ -1,4 +1,4 @@
-import { runtimeKeepalivePop, runtimeKeepalivePush } from 'emscripten:runtime'
+import { ENVIRONMENT_IS_NODE, ENVIRONMENT_IS_PTHREAD, runtimeKeepalivePop, runtimeKeepalivePush } from 'emscripten:runtime'
 import { from64, makeSetValue, makeDynCall } from 'emscripten:parse-tools'
 import { emnapiCtx } from 'emnapi:shared'
 
@@ -119,6 +119,34 @@ export function _emnapi_ctx_decrease_waiting_request_counter (): void {
   emnapiCtx.decreaseWaitingRequestCounter()
 }
 
+/**
+ * @__sig i
+ */
+export function _emnapi_is_main_runtime_thread (): number {
+  return ENVIRONMENT_IS_PTHREAD ? 0 : 1
+}
+
+/**
+ * @__sig i
+ */
+export function _emnapi_is_main_browser_thread (): number {
+  return (typeof window !== 'undefined' && typeof document !== 'undefined' && !ENVIRONMENT_IS_NODE) ? 1 : 0
+}
+
+/**
+ * @__sig v
+ */
+export function _emnapi_unwind (): never {
+  throw 'unwind'
+}
+
+/**
+ * @__sig d
+ */
+export function _emnapi_get_now (): double {
+  return performance.timeOrigin + performance.now()
+}
+
 export function $emnapiSetValueI64 (result: Pointer<int64_t>, numberValue: number): void {
   let tempDouble: number