C++ 中的并发编程如何与先进的硬件架构（如多核处理器）交互？

#include <vector>
#include <thread>

using namespace std;

// 矩阵乘法函数
vector<vector<int>> multiply(const vector<vector<int>>& a, const vector<vector<int>>& b) {
  int n = a.size();
  vector<vector<int>> result(n, vector<int>(n, 0));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      for (int k = 0; k < n; k++) {
        result[i][j] += a[i][k] * b[k][j];
      }
    }
  }
  return result;
}

// 多线程矩阵乘法
void parallel_multiply(const vector<vector<int>>& a, const vector<vector<int>>& b, vector<vector<int>>& result) {
  int n = a.size();
  vector<thread> threads;

  // 为每个行创建线程
  for (int i = 0; i < n; i++) {
    threads.push_back(thread([i, &a, &b, &result] {
      for (int j = 0; j < n; j++) {
        for (int k = 0; k < n; k++) {
          result[i][j] += a[i][k] * b[k][j];
        }
      }
    }));
  }
  
  // 等待线程完成
  for (thread& t : threads) {
    t.join();
  }
}

// 测试函数
int main() {
  // 创建两个随机矩阵
  int n = 1000;
  vector<vector<int>> a(n, vector<int>(n, rand() % 10));
  vector<vector<int>> b(n, vector<int>(n, rand() % 10));
  
  // 执行单线程和多线程矩阵乘法
  vector<vector<int>> single_thread_result = multiply(a, b);
  vector<vector<int>> parallel_thread_result(n, vector<int>(n, 0));
  parallel_multiply(a, b, parallel_thread_result);
  
  // 检查两个结果是否相等
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      if (single_thread_result[i][j] != parallel_thread_result[i][j]) {
        cout << "Matrices not equal!" << endl;
        return 1;
      }
    }
  }
  cout << "Matrices equal." << endl;
  return 0;
}