refactor OpFinishHandle to support CQEHandler

[wokron]

No description provided.

[Copilot]

Pull request overview

Refactors OpFinishHandle to be handler-driven via a new CQEHandlerLike concept, enabling different CQE result-processing strategies (e.g., simple result capture vs. buffer-selection metadata) while keeping the runtime’s CQE dispatch operating on a common base handle type.

Changes:

• Introduces CQEHandler types (SimpleCQEHandler, SelectBufferCQEHandler) and makes OpFinishHandle a template over a CQEHandlerLike.
• Replaces direct OpFinishHandle* CQE casting with OpFinishHandleBase* across runtime and tests.
• Refactors awaiter helpers to construct awaiters with appropriate CQE handlers (including select-buffer operations).

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
tests/test_ring.cpp	Updates tests to use OpFinishHandle<SimpleCQEHandler> and base-pointer CQE dispatch.
tests/test_op_finish_handle.cpp	Updates handle types to the templated OpFinishHandle<SimpleCQEHandler> and base-pointer casting.
tests/test_op_awaiter.cpp	Updates CQE dispatch casting to OpFinishHandleBase*.
tests/test_awaiter_operations.cpp	Updates CQE dispatch casting to OpFinishHandleBase*.
include/condy/runtime.hpp	Runtime CQE processing now treats common work items as OpFinishHandleBase*.
include/condy/finish_handles.hpp	Introduces OpFinishHandleBase + handler-templated OpFinishHandle, and updates mixins/aliases accordingly.
include/condy/cqe_handler.hpp	Adds CQE handler implementations (SimpleCQEHandler, SelectBufferCQEHandler).
include/condy/concepts.hpp	Adds CQEHandlerLike concept and updates OpFinishHandleLike to return detail::Action.
include/condy/awaiters.hpp	Refactors awaiters to be parameterized by CQEHandlerLike (+ SQE128 flag).
include/condy/awaiter_operations.hpp	Updates factory helpers to construct awaiters with the appropriate CQE handlers.

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[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated 10 comments.

Comments suppressed due to low confidence (1)

tests/test_op_finish_handle.cpp:69

• io_uring_sqe_set_data(sqe, &handle) stores a derived pointer, but the completion path casts io_uring_cqe_get_data(cqe) to OpFinishHandleBase* via static_cast (no offset adjustment). Store a base pointer in user_data (or cast to the exact derived type first and then upcast) to avoid UB and to keep cancellation address matching consistent.

        auto handle_ptr = static_cast<condy::OpFinishHandleBase *>(
            io_uring_cqe_get_data(cqe));
        io_uring_cqe mock_cqe = *cqe;
        mock_cqe.res = 42;
        handle_ptr->handle_cqe(&mock_cqe);
        (*handle_ptr)();

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