get return value from 2 threads in C
- by polslinux
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <stdint.h>
#include <inttypes.h>
typedef struct tmp_num{
int tmp_1;
int tmp_2;
}t_num;
t_num t_nums;
void *num_mezzo_1(void *num_orig);
void *num_mezzo_2(void *num_orig);
int main(int argc, char *argv[]){
pthread_t thread1, thread2;
int tmp=0,rc1,rc2,num;
num=atoi(argv[1]);
if(num <= 3){
printf("Questo è un numero primo: %d\n", num);
exit(0);
}
if( (rc1=pthread_create( &thread1, NULL, &num_mezzo_1, (void *)&num)) ){
printf("Creazione del thread fallita: %d\n", rc1);
exit(1);
}
if( (rc2=pthread_create( &thread2, NULL, &num_mezzo_2, (void *)&num)) ){
printf("Creazione del thread fallita: %d\n", rc2);
exit(1);
}
t_nums.tmp_1 = 0;
t_nums.tmp_2 = 0;
pthread_join(thread1, (void **)(&t_nums.tmp_1));
pthread_join(thread2, (void **)(&t_nums.tmp_2));
tmp=t_nums.tmp_1+t_nums.tmp_2;
printf("%d %d %d\n", tmp, t_nums.tmp_1, t_nums.tmp_2);
if(tmp>2){
printf("Questo NON è un numero primo: %d\n", num);
}
else{
printf("Questo è un numero primo: %d\n", num);
}
exit(0);
}
void *num_mezzo_1(void *num_orig){
int cont_1;
int *n_orig=(int *)num_orig;
t_nums.tmp_1 = 0;
for(cont_1=1; cont_1<=(*n_orig/2); cont_1++){
if((*n_orig % cont_1) == 0){
(t_nums.tmp_1)++;
}
}
pthread_exit((void *)(&t_nums.tmp_1));
return NULL;
}
void *num_mezzo_2(void *num_orig){
int cont_2;
int *n_orig=(int *)num_orig;
t_nums.tmp_2 = 0;
for(cont_2=((*n_orig/2)+1); cont_2<=*n_orig; cont_2++){
if((*n_orig % cont_2) == 0){
(t_nums.tmp_2)++;
}
}
pthread_exit((void *)(&t_nums.tmp_2));
return NULL;
}
How this program works: i have to input a number and this program will calculate if it is a prime number or not (i know that it is a bad algorithm but i only need to learn pthread).
The problem is that the returned values are too much big.For example if i write "12" the value of tmp tmp_1 tmp_2 into the main are 12590412 6295204 6295208.Why i got those numbers??
