Can someone explain the mistake in this code

[jinnejeevansai]

I was trying to write a program to copy data in one file to another file,but my code was not responding,it was asking for input,can someone explain the problem in my code.

#include<stdio.h>
#include<pthread.h>
#include<semaphore.h>
#include<stdlib.h>
#define size 5
char a[size][100];
FILE *fp1,*fp2;
int count=0,c1=0,c2=0;
sem_t empty,full;
pthread_mutex_t mutex;
void *fun1()
{       int n=3;
	while(n--)
	{
		sem_wait(&empty);
		pthread_mutex_lock(&mutex);
		if(produce())
		{
			printf("error");
		}
		/*	else
			c1++;*/
		pthread_mutex_unlock(&mutex);
		sem_post(&full);
	}
	pthread_exit(NULL);
}
void *fun2()
{       int n=3;
	while(n--)
	{
		sem_wait(&full);
		pthread_mutex_lock(&mutex);
		if(consume())
		{
			printf("error");
		}
		/*	else
			c2++;*/
		pthread_mutex_unlock(&mutex);
		sem_post(&empty);
	}
	pthread_exit(NULL);
}
int produce()
{       
	if(count<size)
	{
		fgets(a[count],100,fp1);
		count++;
	}
	return 0;
}
int consume()
{      
	if(count>0)
	{
		fputs(a[count],fp2);
		count--;
	}
	return 0;
}
int main(int argc,char *argv[])
{
	int rc,i;
	pthread_t pthread[5];
	pthread_t cthread[2];
	fp1= fopen(argv[1],"r");
	fp2= fopen(argv[2],"w");
	pthread_attr_t attr;
	pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_JOINABLE);
	sem_init(&full,0,0);
	sem_init(&empty,0,size);
	pthread_mutex_init(&mutex,NULL);
	for(i=0;i<5;i++)
	{
		rc=pthread_create(&pthread[i],&attr,fun1,NULL);
		if(rc)
		{
			printf("pthread %d creation error",i);
		}
	}
	for(i=0;i<2;i++)
	{
		rc=pthread_create(&cthread[i],&attr,fun2,NULL);
		if(rc)
		{
			printf("cthread creation error");
		}
	}
	for(i=0;i<5;i++)
	pthread_join(pthread[i],NULL);
	for(i=0;i<2;i++)
	pthread_join(cthread[i],NULL);
	pthread_exit(NULL);
}

[weaknessforcats]

I did not debug your code but I sis notice that in several places you identify a fatal error condition but you do not stop the program. The program after that point is unstable.

I would start by putting an exit(1) after those fatal errors and see if that helps.