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#include <emscripten.h>
#include <stdio.h>
double result = 0.0;
EMSCRIPTEN_KEEPALIVE
void inc_result() {
puts("inc result");
// this will be called twice, leading to 4.2 as the final result.
// (we use floating-point numbers here to make sure that the final result is
// returned using the proper type, and not an int)
result += 2.1;
}
EMSCRIPTEN_KEEPALIVE
double get_result() {
return result;
}
EM_ASYNC_JS(double, foo, (int timeout), {
await new Promise(resolve => setTimeout(
() => {
// Do a simple call back into compiled code synchronously. This is
// allowed (an async one would not).
_inc_result();
// Do the same with ccall.
ccall("inc_result");
// Finish the async operation.
out("resolving promise");
resolve();
},
timeout
));
// Do another simple call back into compiled code synchronously.
return _get_result();
});
// Test out void return and no params.
EM_ASYNC_JS(void, bar, (), {
return;
});
int main() {
printf("foo returned: %f\n", foo(10));
bar();
return 0;
}
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