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⚡ (patch) De-coroutine pure-forwarder functions in the enumerator #4

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Merged
kammce merged 1 commit into from
Sep 21, 2026
Merged

⚡ (patch) De-coroutine pure-forwarder functions in the enumerator #4

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18 changes: 14 additions & 4 deletions v1/modules/enumerator.cppm
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Original file line number Diff line number Diff line change
Expand Up @@ -405,7 +405,7 @@ private:
async::future<usize> driver_read(async::context& p_context,
mem::scatter_span<byte> p_buffer) override
{
co_return co_await m_ctrl_ep->read(p_context, p_buffer);
return m_ctrl_ep->read(p_context, p_buffer);
}

async::future<usize> driver_write(
Expand All @@ -426,7 +426,7 @@ private:
async::future<usize> driver_read(async::context&,
mem::scatter_span<byte>) override
{
co_return 0;
return async::future<usize>(0);
}

async::future<usize> driver_write(
Expand All @@ -435,7 +435,7 @@ private:
{
auto const length = p_buffer.length();
total_length += length;
co_return length;
return async::future<usize>(length);
}

usize total_length = 0;
Expand Down Expand Up @@ -501,10 +501,14 @@ private:
co_await m_ctrl_ep->write(p_context, {});
}

// The increment is reordered ahead of the stall so this can tail-forward
// its future directly. Behaviorally equivalent even if stall() throws -
// run() only ever exits by propagating an exception, so nothing ever
// reads m_retry_counter again once that happens either way.
hal::task send_error_to_host(async::context& p_context)
{
co_await m_ctrl_ep->stall(p_context, true);
m_retry_counter += 1;
return m_ctrl_ep->stall(p_context, true);
}

hal::task handle_standard_device_request(async::context& p_context,
Expand Down Expand Up @@ -842,6 +846,12 @@ private:
co_await send_error_to_host(p_context);
}

// TODO(#3): `header` below is a stack-local borrowed by `payload` across
// the co_await, which is what keeps this a coroutine (a whole ramp/resume
// /destroy triple for one tail call). Hoisting it to a member would let
// this collapse to `return write_and_flush(...);` - see issue for the
// one caveat to confirm first (the three call sites in
// handle_str_descriptors must not have overlapping in-flight uses of it).
hal::task write_string_view(async::context& p_context,
std::u16string_view p_str,
u16 p_max_length)
Expand Down
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