在循环中联接线程 - 转换错误

Question

所以我正在尝试在 for 循环中加入线程，但它给了我错误：

从"pthread_t* {aka long unsigned int*}"到 'pthread_t {aka long unsigned int}'。

代码如下，任何帮助将不胜感激！提前感谢！

#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
#include <stdlib.h>
#include <time.h>
#include <pthread.h>
int threadArray[10][10];
int arrayVar[2];
using namespace std;
void *calc(void *arg){
  int startPoint = arrayVar[0];
  int endPoint = arrayVar[1];
  int newArray[10][10];
  int calculated;
  for (int i = startPoint ; i < endPoint; i++){
    for (int j = 0; j < 10; j++){
      calculated = (threadArray[i][j] * 2 + 4) * 2 + 4;
      newArray[i][j] = calculated;
    }
  }
  for (int i = startPoint; i < endPoint; i++){
      for (int j = 0; j < 10; j++){
        cout << newArray[i][j] << " ";
      }
      cout << endl;
   }
  return NULL;
}
int main(){
  int rc;
  int start = 0;
  int end;
  ifstream numFile;
  numFile.open("numbers.txt");
  if (numFile.is_open()){
    for (int row = 0; row < 10; row++){
      std::string line;
      std::getline(numFile, line);
      std::stringstream iss(line);
      for (int col = 0; col < 10; col++){
    std::string num;
    std::getline(iss, num, ' ');
    std::stringstream converter(num);
    converter >> threadArray[row][col];
      }
    }
    cout << "Original 2D Array" << endl << endl;
    for (int i = 0; i < 10; i++){
      for (int j = 0; j < 10; j++){
    cout << threadArray[i][j] << " ";
      }
      cout << endl;
    }
    cout << endl;
  }
    srand (time(NULL) );
    const int rowArray[3] = {1, 2, 5};
    int arrayIndex = rand() % 3;
    int noOfRows = (rowArray[arrayIndex]);
    end = noOfRows;
    int noOfThreads = 10 / noOfRows;
    pthread_t threads[noOfThreads];
    arrayVar[2];
    cout << "2D Array Altered" << endl << endl;
    for (int t = 0; t < noOfThreads; t++){
      arrayVar[0] = start;
      arrayVar[1] = end;
      rc = pthread_create(&threads[t], NULL, calc, NULL);
      start = start + noOfRows;
      end = end + noOfRows;
    }
    for (int t = 0; t < noOfThreads; t++){
      rc = pthread_join(&threads[t], NULL);
    }
    pthread_exit(NULL);
}

Answer 1

我认为threads[t]实际上只是pid，它是一个整数，你应该通过值传入

pthread_join(threads[t], NULL)