尽管使用临界区{ OpenMP } ，数据仍处于竞争状态

Question

I'm trying to adapt this pascal triangle program to a parallel program using openMp. I used the for directive to parallelize the printPas function for loop, and put the conditional statements inside of the critical section so only one thread can print at a time, but it seems like I'm still getting a data race because my output is really inconsistent.

The code:

#include <stdio.h>

#ifndef N
#define N 2
#endif
unsigned int t1[2*N+1], t2[2*N+1];
unsigned int *e=t1, *r=t2;
int l = 0;

//the problem is here in this function
void printPas() {
  #pragma omp parallel for private(l)
  for (l=0; l<2*N+1; l++) {
    #pragma omp critical
    if (e[l]==0)
      printf("      ");
    else
      printf("%6u", e[l]);
  }
  printf("\n");

}

void update() {
  r[0] = e[1];
#pragma omp parallel for
  for (int u=1; u<2*N; u++)
    r[u] = e[u-1]+e[u+1];
  r[2*N] = e[2*N-1];
  unsigned int *tmp = e; e=r; r=tmp; 
}

int main() {
  e[N] = 1;
  for (int i=0; i<N; i++) {
    printPas();
    update();
  }
  printPas();
}

转载于:https://stackoverflow.com/questions/53111292/data-race-despite-using-critical-section-openmp

Answer 1

https://blog.csdn.net/qq_39776901/article/details/78395444