Add benchmark suite comparing Corosio and Asio performance

[sgerbino]

Implement comprehensive benchmarks for scheduler and socket I/O operations, with equivalent Asio implementations for fair comparison.

Benchmarks added:

• io_context: handler posting throughput, multi-threaded scaling
• socket throughput: unidirectional and bidirectional transfer rates
• socket latency: ping-pong round-trip times and concurrent connections

Directory structure:
bench/
├── common/benchmark.hpp - Shared timing utilities and statistics
├── corosio/ - Corosio benchmarks using capy::task<>
└── asio/ - Asio benchmarks using asio::awaitable<>

Both benchmark suites use coroutines for apples-to-apples comparison. TCP_NODELAY is enabled on all sockets to ensure fair latency measurements.

Also adds socket::native_handle() to expose the underlying file descriptor, enabling socket option configuration (e.g., TCP_NODELAY) from user code.

Summary by CodeRabbit

• New Features

  • Added a public API to access underlying native socket handles, enabling advanced use cases requiring direct interaction with platform-specific socket descriptors.

• Chores

  • Enhanced build system to support benchmark compilation configuration.

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[coderabbitai]

📝 Walkthrough

Walkthrough

The pull request adds native socket handle access through a new platform-dependent public API. A native_handle_type type alias and corresponding native_handle() method are introduced across the socket interface hierarchy, with implementations for both epoll (POSIX) and IOCP (Windows) platforms. CMake benchmarking support is also configured.

Changes

Cohort / File(s)	Summary
Build Configuration CMakeLists.txt	Added conditional benchmarking wiring: when BOOST_COROSIO_BUILD_BENCH is enabled, asio is appended to include libraries and a bench subdirectory is registered.
Public Socket Interface include/boost/corosio/socket.hpp	Introduced platform-dependent native_handle_type alias (uintptr_t on Windows, int on POSIX). Added pure virtual native_handle() const noexcept to socket_impl base class and corresponding public method to socket class.
POSIX Platform Implementation src/corosio/src/detail/epoll/sockets.hpp	Updated epoll_socket_impl::native_handle() return type from int to native_handle_type while maintaining const, noexcept, and override qualifiers.
Windows Platform Implementation src/corosio/src/detail/iocp/sockets.hpp	Added public native_handle() const noexcept override method to win_socket_impl that delegates to internal implementation and casts result to native_handle_type.
Socket Implementation src/corosio/src/socket.cpp	Implemented socket::native_handle() const noexcept that returns an invalid handle if impl is null, otherwise delegates to impl_.get().native_handle().

Sequence Diagram

sequenceDiagram
    participant Client
    participant socket
    participant socket_impl
    participant Platform as epoll/iocp<br/>Implementation

    Client->>socket: native_handle()
    socket->>socket_impl: Check if impl exists
    alt impl is null
        socket_impl-->>socket: Return invalid handle<br/>(~0ull or -1)
    else impl exists
        socket->>Platform: native_handle()
        Platform->>Platform: Return platform-specific<br/>handle (fd_ or SOCKET)
        Platform-->>socket: native_handle_type
    end
    socket-->>Client: native_handle_type

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Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Poem

🐰 A burrow deep where sockets dwell,
Now native handles we can tell!
Cross platform magic, Windows, POSIX too,
With native_handle() shining through! ✨
The rabbit's warren grows more strong,
Each implementation right along!

🚥 Pre-merge checks | ✅ 1 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Title check	⚠️ Warning	The title describes adding a benchmark suite, but the changeset primarily adds a native_handle() API to the socket class; benchmarking support is only a secondary configuration change in CMakeLists.txt.	Update the title to reflect the primary changes: consider 'Add native_handle() API to socket class and benchmark suite' or focus on the main API addition if that's the core intent.

✅ Passed checks (1 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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✨ Finishing touches

• 📝 Generate docstrings

---

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[cppalliance-bot]

An automated preview of the documentation is available at https://74.corosio.prtest3.cppalliance.org/index.html

If more commits are pushed to the pull request, the docs will rebuild at the same URL.

2026-01-23 19:48:06 UTC