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[ASYNCIFY] Avoid dependency on the names of exports #24382

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Merged
merged 1 commit into from
May 21, 2025
Merged

[ASYNCIFY] Avoid dependency on the names of exports #24382

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182 changes: 110 additions & 72 deletions src/lib/libasync.js
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Original file line number Diff line number Diff line change
Expand Up @@ -35,7 +35,7 @@ addToLibrary({
// Asyncify code that is shared between mode 1 (original) and mode 2 (JSPI).
//
#if ASYNCIFY == 1 && MEMORY64
rewindArguments: {},
rewindArguments: new Map(),
#endif
instrumentWasmImports(imports) {
#if EMBIND_GEN_MODE
Expand Down Expand Up @@ -99,13 +99,54 @@ addToLibrary({
}
},
#if ASYNCIFY == 1 && MEMORY64
saveRewindArguments(funcName, passedArguments) {
return Asyncify.rewindArguments[funcName] = Array.from(passedArguments)
saveRewindArguments(func, passedArguments) {
return Asyncify.rewindArguments.set(func, Array.from(passedArguments));
},
restoreRewindArguments(funcName) {
return Asyncify.rewindArguments[funcName] || []
restoreRewindArguments(func) {
#if ASSERTIONS
assert(Asyncify.rewindArguments.has(func));
#endif
return Asyncify.rewindArguments.get(func);
},
#endif

instrumentFunction(original) {
var wrapper = (...args) => {
#if ASYNCIFY_DEBUG >= 2
dbg(`ASYNCIFY: ${' '.repeat(Asyncify.exportCallStack.length)} try ${original}`);
#endif
#if ASYNCIFY == 1
Asyncify.exportCallStack.push(original);
try {
#endif
#if ASYNCIFY == 1 && MEMORY64
Asyncify.saveRewindArguments(original, args);
#endif
return original(...args);
#if ASYNCIFY == 1
} finally {
if (!ABORT) {
var top = Asyncify.exportCallStack.pop();
#if ASSERTIONS
assert(top === original);
#endif
#if ASYNCIFY_DEBUG >= 2
dbg(`ASYNCIFY: ${' '.repeat(Asyncify.exportCallStack.length)} finally ${original}`);
#endif
Asyncify.maybeStopUnwind();
}
}
#endif
};
#if ASYNCIFY == 1
Asyncify.funcWrappers.set(original, wrapper);
#endif
#if MAIN_MODULE || ASYNCIFY_LAZY_LOAD_CODE
wrapper.orig = original;
#endif
return wrapper;
},

instrumentWasmExports(exports) {
#if EMBIND_GEN_MODE
// Instrumenting is not needed when generating code.
Expand All @@ -121,48 +162,27 @@ addToLibrary({
var ret = {};
for (let [x, original] of Object.entries(exports)) {
if (typeof original == 'function') {
#if ASYNCIFY == 2
#if ASYNCIFY == 2
// Wrap all exports with a promising WebAssembly function.
let isAsyncifyExport = exportPattern.test(x);
if (isAsyncifyExport) {
Asyncify.asyncExports.add(original);
original = Asyncify.makeAsyncFunction(original);
}
#endif
ret[x] = (...args) => {
#if ASYNCIFY_DEBUG >= 2
dbg(`ASYNCIFY: ${' '.repeat(Asyncify.exportCallStack.length)} try ${x}`);
#endif
#if ASYNCIFY == 1
Asyncify.exportCallStack.push(x);
try {
#endif
#if ASYNCIFY == 1 && MEMORY64
Asyncify.saveRewindArguments(x, args);
#endif
return original(...args);
#if ASYNCIFY == 1
} finally {
if (!ABORT) {
var y = Asyncify.exportCallStack.pop();
#if ASSERTIONS
assert(y === x);
var wrapper = Asyncify.instrumentFunction(original);
#if ASYNCIFY_LAZY_LOAD_CODE
original.exportName = x;
#endif
#if ASYNCIFY_DEBUG >= 2
dbg(`ASYNCIFY: ${' '.repeat(Asyncify.exportCallStack.length)} finally ${x}`);
#endif
Asyncify.maybeStopUnwind();
}
}
#endif
};
#if MAIN_MODULE
ret[x].orig = original;
#endif
} else {
ret[x] = wrapper;

} else {
ret[x] = original;
}
}
#if ASYNCIFY_LAZY_LOAD_CODE
Asyncify.updateFunctionMapping(ret);
#endif
return ret;
},

Expand All @@ -187,24 +207,54 @@ addToLibrary({
// We must track which wasm exports are called into and
// exited, so that we know where the call stack began,
// which is where we must call to rewind it.
// This list contains the original Wasm exports.
exportCallStack: [],
callStackNameToId: {},
callStackIdToName: {},
callstackFuncToId: new Map(),
callStackIdToFunc: new Map(),
// Maps wasm functions to their corresponding wrapper function.
funcWrappers: new Map(),
callStackId: 0,
asyncPromiseHandlers: null, // { resolve, reject } pair for when *all* asynchronicity is done
sleepCallbacks: [], // functions to call every time we sleep

getCallStackId(funcName) {
#if ASYNCIFY_LAZY_LOAD_CODE
updateFunctionMapping(newExports) {
#if ASYNCIFY_DEBUG
dbg('updateFunctionMapping', Asyncify.callStackIdToFunc);
#endif
#if ASSERTIONS
assert(!Asyncify.exportCallStack.length);
#endif
Asyncify.callStackIdToFunc.forEach((func, id) => {
#if ASSERTIONS
assert(funcName);
assert(func.exportName);
assert(newExports[func.exportName]);
assert(newExports[func.exportName].orig);
#endif
var newFunc = newExports[func.exportName].orig;
Asyncify.callStackIdToFunc.set(id, newFunc)
Asyncify.callstackFuncToId.set(newFunc, id);
#if MEMORY64
var args = Asyncify.rewindArguments.get(func);
if (args) {
Asyncify.rewindArguments.set(newFunc, args);
Asyncify.rewindArguments.delete(func);
}
#endif
var id = Asyncify.callStackNameToId[funcName];
if (id === undefined) {
id = Asyncify.callStackId++;
Asyncify.callStackNameToId[funcName] = id;
Asyncify.callStackIdToName[id] = funcName;
});
},
#endif

getCallStackId(func) {
#if ASSERTIONS
assert(func);
#endif
if (!Asyncify.callstackFuncToId.has(func)) {
var id = Asyncify.callStackId++;
Asyncify.callstackFuncToId.set(func, id);
Asyncify.callStackIdToFunc.set(id, func);
}
return id;
return Asyncify.callstackFuncToId.get(func);
},

maybeStopUnwind() {
Expand Down Expand Up @@ -246,7 +296,7 @@ addToLibrary({
// An asyncify data structure has three fields:
// 0 current stack pos
// 4 max stack pos
// 8 id of function at bottom of the call stack (callStackIdToName[id] == name of js function)
// 8 id of function at bottom of the call stack (callStackIdToFunc[id] == wasm func)
//
// The Asyncify ABI only interprets the first two fields, the rest is for the runtime.
// We also embed a stack in the same memory region here, right next to the structure.
Expand Down Expand Up @@ -274,38 +324,24 @@ addToLibrary({
{{{ makeSetValue('ptr', C_STRUCTS.asyncify_data_s.rewind_id, 'rewindId', 'i32') }}};
},

getDataRewindFuncName(ptr) {
getDataRewindFunc(ptr) {
var id = {{{ makeGetValue('ptr', C_STRUCTS.asyncify_data_s.rewind_id, 'i32') }}};
var name = Asyncify.callStackIdToName[id];
#if ASSERTIONS
assert(name, `id ${id} not found in callStackIdToName`);
#endif
return name;
},

#if RELOCATABLE
getDataRewindFunc__deps: [ '$resolveGlobalSymbol' ],
#endif
getDataRewindFunc(name) {
var func = wasmExports[name];
#if RELOCATABLE
// Exported functions in side modules are not listed in `wasmExports`,
// So we should use `resolveGlobalSymbol` helper function, which is defined in `library_dylink.js`.
if (!func) {
func = resolveGlobalSymbol(name, false).sym;
}
#endif
var func = Asyncify.callStackIdToFunc.get(id);
#if ASSERTIONS
assert(func, `export not found: ${name}`);
assert(func, `id ${id} not found in callStackIdToFunc`);
#endif
return func;
},

doRewind(ptr) {
var name = Asyncify.getDataRewindFuncName(ptr);
var func = Asyncify.getDataRewindFunc(name);
var original = Asyncify.getDataRewindFunc(ptr);
#if ASYNCIFY_DEBUG
dbg('ASYNCIFY: doRewind:', name);
dbg('ASYNCIFY: doRewind:', original);
#endif
var func = Asyncify.funcWrappers.get(original);
#if ASSERTIONS
assert(original);
assert(func);
#endif
// Once we have rewound and the stack we no longer need to artificially
// keep the runtime alive.
Expand All @@ -315,7 +351,7 @@ addToLibrary({
// can just call the function with no args at all since and the engine will produce zeros
// for all arguments. However, for i64 arguments we get `undefined cannot be converted to
// BigInt`.
return func(...Asyncify.restoreRewindArguments(name));
return func(...Asyncify.restoreRewindArguments(original));
#else
return func();
#endif
Expand Down Expand Up @@ -510,6 +546,7 @@ addToLibrary({
});
},

#if ASYNCIFY_LAZY_LOAD_CODE
emscripten_lazy_load_code__async: true,
emscripten_lazy_load_code: () => Asyncify.handleSleep((wakeUp) => {
// Update the expected wasm binary file to be the lazy one.
Expand All @@ -519,6 +556,7 @@ addToLibrary({
// Load the new wasm.
createWasm();
}),
#endif

_load_secondary_module__sig: 'v',
_load_secondary_module: async function() {
Expand Down
2 changes: 1 addition & 1 deletion test/test_core.py
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Original file line number Diff line number Diff line change
Expand Up @@ -9863,7 +9863,7 @@ def setUp(self):
settings={'INITIAL_MEMORY': '2200mb', 'GLOBAL_BASE': '2gb'})

# MEMORY64=1
wasm64 = make_run('wasm64', emcc_args=['-O1', '-Wno-experimental', '--profiling-funcs'],
wasm64 = make_run('wasm64', emcc_args=['-Wno-experimental', '--profiling-funcs'],
settings={'MEMORY64': 1}, require_wasm64=True, require_node=True)
wasm64_v8 = make_run('wasm64_v8', emcc_args=['-Wno-experimental', '--profiling-funcs'],
settings={'MEMORY64': 1}, require_wasm64=True, require_v8=True)
Expand Down
1 change: 1 addition & 0 deletions tools/maint/gen_sig_info.py
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Original file line number Diff line number Diff line change
Expand Up @@ -395,6 +395,7 @@ def main(args):
'USE_SDL': 0,
'MAX_WEBGL_VERSION': 0,
'AUTO_JS_LIBRARIES': 0,
'ASYNCIFY_LAZY_LOAD_CODE': 1,
'ASYNCIFY': 1}, cxx=True, extra_cflags=['-std=c++20'])
extract_sig_info(sig_info, {'LEGACY_GL_EMULATION': 1}, ['-DGLES'])
extract_sig_info(sig_info, {'USE_GLFW': 2, 'FULL_ES3': 1, 'MAX_WEBGL_VERSION': 2})
Expand Down