numa_topology.h

Go to the documentation of this file.

// BSD 3-Clause License
// Copyright (c) 2024, 🍀☀🌕🌥 🌊
// See the LICENSE file in the project root for full license information.
 
#pragma once
 
#include <cstddef>
#include <vector>
 
namespace kcenon::thread
{
 
struct numa_node
{
    int node_id{-1};                   
    std::vector<int> cpu_ids;          
    std::size_t memory_size_bytes{0};  
};
 
class numa_topology
{
public:
    numa_topology() = default;
 
    [[nodiscard]] static auto detect() -> numa_topology;
 
    [[nodiscard]] auto get_node_for_cpu(int cpu_id) const -> int;
 
    [[nodiscard]] auto get_distance(int node1, int node2) const -> int;
 
    [[nodiscard]] auto is_same_node(int cpu1, int cpu2) const -> bool;
 
    [[nodiscard]] auto is_numa_available() const -> bool;
 
    [[nodiscard]] auto node_count() const -> std::size_t;
 
    [[nodiscard]] auto cpu_count() const -> std::size_t;
 
    [[nodiscard]] auto get_nodes() const -> const std::vector<numa_node>&;
 
    [[nodiscard]] auto get_cpus_for_node(int node_id) const -> std::vector<int>;
 
private:
    std::vector<numa_node> nodes_;              
    std::vector<int> cpu_to_node_;              
    std::vector<std::vector<int>> distances_;   
    std::size_t total_cpus_{0};                 
 
    static auto detect_linux() -> numa_topology;
 
    static auto create_fallback() -> numa_topology;
};
 
} // namespace kcenon::thread