Question

所以我有这个发生器，应该输出的第一个数字是1804289383.

但是，我得到的数字是134519520，有时，最后几位数会有所不同，但通常在这个数字附近。

知道为什么吗？我有类似的代码打印出所需的数字，但这不起作用。

#include <stdio.h>
#include <pthread.h>
#define MAX_NUM 10
#define MAX_RAND_NUM 100
#define SIZE 10

pthread_mutex_t the_mutex;
pthread_cond_t cond;
int buffer[SIZE];
int num_of_items = 0;

void *producer(void *ptr)
{   
    int i  = 0;
    int rand_num = 0;
    int rear = 0;   
    srandom((unsigned int)0);


        rand_num = random();
    pthread_mutex_lock(&the_mutex);
    while (num_of_items = SIZE) {
        pthread_cond_wait(&cond,&the_mutex);
    }//end of while loop
      buffer[rear] = rand_num;
      rear = (rear + 1) % SIZE;
      num_of_items +=1;
      printf("Producer on loop %d it stored %d \n",i,rand_num);
      pthread_cond_signal(&cond);
      pthread_mutex_unlock(&the_mutex);

        pthread_exit(0);
}

void *consumer(void *ptr)
{       int i  = 0;
        int rand_num = 0;
    int front = 0;

    pthread_mutex_lock(&the_mutex);
        while (num_of_items == 0) pthread_cond_wait(&cond,&the_mutex);
            printf("Consumer on loop %d it stored %d \n",i,buffer);
        //buffer[0] = 0;
        front = (front + 1) % SIZE;
        num_of_items -= 1;
            pthread_cond_signal(&cond);
            pthread_mutex_unlock(&the_mutex);

            pthread_exit(0);
}

int main(int argc, char **argv)
{
   pthread_t pro,con;
   pthread_mutex_init(&the_mutex,0);
   pthread_cond_init(&cond,0);

   pthread_create(&con,0,consumer,0);
   pthread_create(&pro,0,producer,0);
   pthread_join(pro,0);
   pthread_join(con,0);
   pthread_cond_destroy(&cond);

   pthread_mutex_destroy(&the_mutex);
}

Answer 1

问题在于：

printf("Consumer on loop %d it stored %d \n",i,buffer);

buffer衰减到指针，但您尝试将其打印为int。你得到的那个大数字是地址的整数表示。也许你打算做buffer[i]或其他什么。

这看起来也很可疑：

while (num_of_items = SIZE)

可能应该是==。

如果你的编译器没有警告你这两件事，你应该寻找更好的，或者提高你的警告水平。

数字生成器不会在C中打印出预期的第一个数字

1 个答案: