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P4251: clarify CERN project description #30

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4 changes: 2 additions & 2 deletions source/2026-07-july/d4251-ioawaitable-cuda.md
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Expand Up @@ -606,7 +606,7 @@ Several independent projects have arrived at the same design: coroutine-based as

**cuda-oxide (NVIDIA Labs, Rust).**<sup>[35]</sup> NVIDIA's own research lab implemented the same mechanism in Rust. Their `DeviceFuture` submits GPU work, enqueues a `cuLaunchHostFunc` callback that sets an `AtomicBool` and wakes a Tokio `Waker`, and the async runtime resumes the task on the next poll. Zero busy-wait. The three-state machine (Idle, Executing, Complete) is structurally identical to a network socket future. When NVIDIA's own research lab arrives at the same `cudaLaunchHostFunc`-to-async-runtime pattern independently, in a different language, the convergence is a data point about where the pattern fits naturally.

**CERN wp1.7-coroutine-tests.**<sup>[34]</sup> The ATLAS and LHCb experiments at CERN are evaluating C++20 coroutine patterns for task scheduling, including a Gaudi-framework-inspired coroutine hierarchy and CUDA examples. The project's [`StreamIoAwaitable`](https://github.com/cern-nextgen/wp1.7-coroutine-tests/blob/5049a37d7e74b6e2241b39dca5c81ff3aaece0e3/examples/capy_stream_await.hpp) is built directly on Capy's IoAwaitable protocol: `await_suspend(std::coroutine_handle<>, boost::capy::io_env const*)` enqueues a `cudaLaunchHostFunc` callback that, on CUDA-stream completion, posts the coroutine handle back to `env->executor` - the same `cudaLaunchHostFunc`-to-coroutine resumption described here, implemented independently against Capy's `io_env`.
**CERN wp1.7-coroutine-tests.**<sup>[34]</sup> The CERN Next Generation Triggers project is evaluating C++20 coroutine patterns for task scheduling in CPU-GPU computing systems for experimental high-energy physics. The repository contains demonstrations of selected notification mechanisms and libraries. The example[`StreamIoAwaitable`](https://github.com/cern-nextgen/wp1.7-coroutine-tests/blob/5049a37d7e74b6e2241b39dca5c81ff3aaece0e3/examples/capy_stream_await.hpp) is built directly on Capy's IoAwaitable protocol: `await_suspend(std::coroutine_handle<>, boost::capy::io_env const*)` enqueues a `cudaLaunchHostFunc` callback that, on CUDA-stream completion, posts the coroutine handle back to `env->executor` - the same `cudaLaunchHostFunc`-to-coroutine resumption described here, implemented independently against Capy's `io_env`.

**Taro (University of Wisconsin-Madison).**<sup>[36]</sup> A C++20 coroutine task-graph system for CPU-GPU workloads. GPU tasks suspend the CPU thread via coroutines when waiting for GPU completion, allowing other tasks to run. Uses `cudaLaunchHostFunc` for the callback. Published at Euro-Par 2024 and presented at CppCon 2023. Reported 40-80% speedup over blocking approaches.

Expand Down Expand Up @@ -817,7 +817,7 @@ Eric Niebler, Micha&lstrok; Dominiak, Lewis Baker, Lucian Radu Teodorescu, Lee H

Richard Smith and Gor Nishanov for P0981R0 (HALO analysis). Chuanqi Xu for the `[[clang::coro_await_elidable]]` attribute and P2477R3 (coroutine allocation elision). Dietmar K&uuml;hl and Maikel Nadolski for P3552R3 (`std::execution::task`). Lewis Baker for cppcoro, the operator `co_await` and symmetric transfer blog posts, and P3425R1 (operation-state sizes). Michael Wong for P4029R0 (SG14 priority list).

Michael Garland and the NVIDIA stdexec team for the nvexec GPU schedulers and the Maxwell FDTD benchmark. The CERN wp1.7 team for their C++20 coroutine task-scheduling experiments and the Capy IoAwaitable integration. Dian-Lun Lin (University of Wisconsin-Madison) for Taro and its CppCon 2023 presentation. The NVIDIA Labs team for cuda-oxide. Jiqun Tu (NVIDIA) and Ellery Russell (Schr&ouml;dinger) for the Desmond coroutine integration presented at GTC 2024. The TTG/PaRSEC team for demonstrating coroutine-based heterogeneous GPU dispatch at DOE Exascale scale.
Michael Garland and the NVIDIA stdexec team for the nvexec GPU schedulers and the Maxwell FDTD benchmark. The CERN Next Generation Triggers project for their C++20 coroutine task-scheduling experiments and the Capy IoAwaitable integration. Dian-Lun Lin (University of Wisconsin-Madison) for Taro and its CppCon 2023 presentation. The NVIDIA Labs team for cuda-oxide. Jiqun Tu (NVIDIA) and Ellery Russell (Schr&ouml;dinger) for the Desmond coroutine integration presented at GTC 2024. The TTG/PaRSEC team for demonstrating coroutine-based heterogeneous GPU dispatch at DOE Exascale scale.

This paper was generated with AI assistance (Claude, via Cursor).

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