different number of thread is created-CodePudding

I am learning pthread and i am using vs code to run the c code. As per the vs code docs, i installed MSY2S2 MSY and it is installed.

when i run this code:

#include <stdio.h>
#include<stdlib.h>
#include <pthread.h>

void *bin_finding(void *p){
  int* ptr = (int*)p;
  printf("%d", *ptr);
  // printf("%s", "hello");
}


int main(){
  int data_count = 10;
  int num_of_thread = 4;
  int equalDivisionCount = data_count/num_of_thread;
  int excessCount = data_count%num_of_thread;
  int indexCount[num_of_thread];

  int i;
  pthread_t tid[num_of_thread];
  for(i=0; i<4; i  ){
    indexCount[i] = i;
    pthread_create(&tid[i], NULL, bin_finding, &indexCount[i]);
 }
    return 0;
}

when i click run and debug in left most option, it gives different result everytime.

sometime i get 0 sometime 01 sometime 0123

so slmost every run is different and most common is 0.

if anybody, please help me in this.

CodePudding user response：

Your program is exiting before all threads of execution get a chance to finish.

Use a second loop, after the first, containing calls to pthread_join to wait for each of your threads to fully execute:

for (int i = 0; i < num_of_thread; i  )
    pthread_join(tid[i], NULL);