Pointer incrementing

[farmergeoff2003]

Hi, I am trying to increment the pointer I send when creating a pthread but it doesn't compile. The increment is at line 30, its written in C. How can I get this to work?

Main:

//create all producers
	for (i = 0; i < nproducers; i++)
    {
		pcount[i] = 0;
		pthread_create (&tid_produce[i], NULL, producer, &pcount[i]);
    }

Function:

void *producer(void *param) 
{
	buffer_item item;
	int i;
	
	while (go == 0)
	{
		sem_wait(&empty);
		sem_wait(&mutex);
		
		//sleep for period of time less than thread max time
		sleep( rand() % threadTime );
		
		//generate a random number 1 - 100
		item = rand() % 100 + 1;
		
		if(buffer_insert_item(item) != 0)
		{
			//print buffer stats if user opts in cmd
			if( toupper(printFull[5][0]) == 'Y' )
			{
				//printf("pindex: %d\n", pindex);
				printf("All buffers full. Producer %d waits.\n\n", (int)pthread_self() );
			}
		}
		else
		{	
			//increment total produced
			totProduced++;
			(*param)++; /* <---------------- HERE !!!!!!!!!!!!!! */
			
			//print buffer stats if user opts in cmd
			if( toupper(printFull[5][0]) == 'Y' )
			{
				printf("Producer %d writes %d", (unsigned int)pthread_self(), item);
				printResults();
			}
		}
		
		//signal the consumer thread
		sem_post(&full);       
		sem_post(&mutex);
	}
}

[Peter87]

You can't dereference a void pointer. If pcount[i] is an int you have to cast the pointer to an int pointer before dereferencing it. (*(int*) param)++;

[farmergeoff2003]

When I change it as you suggested and compile I get:

error: invalid type argument of âunary *â

I swapped what you wrote with line 30, is that right?

[Peter87]

Yes.

[farmergeoff2003]

That config yields the error I specified above at compile time.

[farmergeoff2003]

I don't know why or how but it compiled, ran, and worked!