let thread_id = null;
let buf_offset = null;
let exports = null;
let flags = null;

function done() {
    postMessage('done');
}

async function init_wasm(tid, memory, offset, notify_flags, stack_base) {
    thread_id = tid;
    buf_offset = offset;

    const result = await WebAssembly.instantiateStreaming(fetch('wasm/multi.wasm'), {
        env: { 'memory': memory }
    });

    exports = result.instance.exports;
    //console.log(tid, 'init');
    exports.set_sp(stack_base - thread_id * 4096);

    flags = notify_flags;
    done();
}

function do_work(num, callback) {
    //console.log(thread_id, 'work');
    exports.write_a_number(buf_offset, thread_id, thread_id * num); 
    done();
}

onmessage = (e) => {
    if (e.data.type === 0) {
        init_wasm(e.data.thread_id, e.data.memory, e.data.buffer_offset, e.data.flags, e.data.stack_base);
    } else if (e.data.type === 1) {
        do_work(e.data.num);
    }
}