fix(wasm): ccall({async:true}) — fixes ASYNCIFY streaming#34
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Root cause of all WASM hanging: Module._wasm_generate_async() is a
DIRECT function call that does NOT return a Promise even with ASYNCIFY.
Only Module.ccall('fn', ..., {async: true}) makes Emscripten create
the async wrapper that properly unwinds/rewinds the C stack.
The try/catch was silently falling through to Module._wasm_generate()
(the sync version), blocking the entire main thread.
Fix: replace Module._wasm_generate_async() with Module.ccall() using
{async: true}. Add ccall/cwrap to EXPORTED_RUNTIME_METHODS.
This is the documented Emscripten ASYNCIFY pattern:
https://emscripten.org/docs/porting/asyncify.html#making-async-web-apis-behave-as-if-they-were-synchronous
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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The actual root cause of ALL WASM hanging
Module._wasm_generate_async(ptr, 0.7, 256)is a direct C function call. Even with ASYNCIFY enabled, direct calls do NOT return Promises. Theawaitresolves immediately, and whenemscripten_sleep(0)fires inside the C code, the ASYNCIFY unwind has nowhere to go — it hangs.The
try/catchwas then callingModule._wasm_generate()(sync), which blocks the entire main thread. We never saw the error because the catch was silent.Fix
Replace with
Module.ccall('wasm_generate_async', ..., {async: true}). This is Emscripten's documented ASYNCIFY pattern —ccallwith{async: true}creates a proper async wrapper that returns a Promise and correctly handles sleep/unwind/rewind cycles.Added
ccallandcwraptoEXPORTED_RUNTIME_METHODS.This explains everything
🤖 Generated with Claude Code