Unsafe aliasing in rust when dropping the builder

[edwin0cheng]

Hi, I am trying to use this crate in Firefox 86.0.1 (linux), and when calling :

await initThreadPool(navigator.hardwareConcurrency)

I got the following errors :

Uncaught (in promise) Error: recursive use of an object detected which would lead to unsafe aliasing in rust
    __wbindgen_throw webpack://ra-wasm-demo/../pkg/wasm_demo.js?:500
    free webpack://ra-wasm-demo/../pkg/wasm_demo.js?:380
    startWorkers webpack://ra-wasm-demo/../pkg/snippets/wasm-bindgen-rayon-3d2df09ebec17a22/src/workerHelpers.js?:100
    __wbg_startWorkers_914655bb4d5bb5e1 webpack://ra-wasm-demo/../pkg/wasm_demo.js?:511
    initThreadPool webpack://ra-wasm-demo/../pkg/wasm_demo.js?:194
    <anonymous> webpack://ra-wasm-demo/./index.js?:148
    disposable webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/standalone/browser/standaloneLanguages.js?:90
    fire webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/base/common/event.js?:481
    _getOrCreateMode webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/common/services/modeServiceImpl.js?:96
    _createModeAndGetLanguageIdentifier webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/common/services/modeServiceImpl.js?:84
    create webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/common/services/modeServiceImpl.js?:72
    LanguageSelection webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/common/services/modeServiceImpl.js?:27
    create webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/common/services/modeServiceImpl.js?:70
    createTextModel webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/standalone/browser/standaloneCodeEditor.js?:331
    StandaloneEditor webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/standalone/browser/standaloneCodeEditor.js?:194
    create webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/standalone/browser/standaloneEditor.js?:123
    withAllStandaloneServices webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/standalone/browser/standaloneEditor.js?:110
    create webpack://ra-wasm-demo/./node_modules/monaco-editor/esm/vs/editor/standalone/browser/standaloneEditor.js?:122
    <anonymous> webpack://ra-wasm-demo/./index.js?:342
    js http://127.0.0.1:8080/app.bundle.js:63
    __webpack_require__ http://127.0.0.1:8080/app.bundle.js:7656
    <anonymous> http://127.0.0.1:8080/app.bundle.js:7916
    <anonymous> http://127.0.0.1:8080/app.bundle.js:7919
app.bundle.js line 30 > eval:500:15
    <anonymous> webpack://ra-wasm-demo/./index.js?:322

According rustwasm/wasm-bindgen#1578 , this seem to be relate to &'mut and &' holder in different places but I could run it in Chromium without a problem.

[edwin0cheng]

I finally found out that Firefox raise an exception of " waiting is not allowed on this thread" and then I put everything inside another WebWorker and it works now.

[RReverser]

Yes, it's something Chrome plans to forbid too, but hasn't done so yet.