65 lines
1.6 KiB
ReStructuredText
65 lines
1.6 KiB
ReStructuredText
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.. _libcudacxx-extended-api-thread-groups:
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Thread Groups
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=============
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.. code:: cuda
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struct ThreadGroup {
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static constexpr cuda::thread_scope thread_scope;
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Integral size() const;
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Integral thread_rank() const;
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void sync() const;
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};
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The *ThreadGroup concept* defines the requirements of a type that represents a group of cooperating threads.
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The `CUDA Cooperative Groups Library <https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#group-collectives>`_
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provides a number of types that satisfy this concept.
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Data Members
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------------
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.. list-table::
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:widths: 25 75
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:header-rows: 0
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* - ``thread_scope``
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- The scope at which ``ThreadGroup::sync()`` synchronizes memory operations and thread execution.
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Member Functions
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----------------
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.. list-table::
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:widths: 25 75
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:header-rows: 0
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* - ``size``
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- Returns the number of participating threads.
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* - ``thread_rank``
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- Returns a unique value for each participating thread (``0 <= ThreadGroup::thread_rank() < ThreadGroup::size()``).
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* - ``sync``
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- Synchronizes the participating threads.
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Notes
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-----
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This concept is defined for documentation purposes but is not materialized in the library.
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Example
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-------
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.. code:: cuda
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#include <cuda/atomic>
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#include <cuda/std/cstddef>
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struct single_thread_group {
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static constexpr cuda::thread_scope thread_scope = cuda::thread_scope::thread_scope_thread;
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cuda::std::size_t size() const { return 1; }
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cuda::std::size_t thread_rank() const { return 0; }
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void sync() const {}
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};
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`See it on Godbolt <https://godbolt.org/z/6c16KxqY7>`_
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