gistfile1.cpp

unsigned int counter = 0;
pthread_mutex_t mutex 	     = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond_var = PTHREAD_COND_INITIALIZER;

void* thread2_method(void* parameter){
	string s = *(string*)(parameter);

	for(int i=0;i<5;i++){
		pthread_mutex_lock(&mutex);		
	
		counter++;
		cout<<s<<": "<<counter<<endl;
		
		pthread_cond_signal(&cond_var);
		pthread_cond_wait(&cond_var, &mutex);
		
		pthread_mutex_unlock(&mutex);
	}
	return NULL;
}

void* thread1_method(void* parameter){
	string s = *(string*)(parameter);

	for(int i=0;i<5;i++){
		pthread_mutex_lock(&mutex);
		pthread_cond_wait(&cond_var, &mutex);		
		
		counter++;
		cout<<s<<": "<<counter<<endl;

		pthread_cond_signal(&cond_var);
		pthread_mutex_unlock(&mutex);
	}
	return NULL;
}