rem: dc_t* cell = NULL;
add: pd_t* cell = NULL;
context: dc_t* new_cell(char* domain, code_t code){	dc_t* cell = NULL; 		if(!domain)		return NULL;		/* the cell is in share memory */	cell = (dc_t*)shm_malloc(sizeof(dc_t));    	/* if there is no space return just NULL */	if(!cell)		return NULL;		/* otherwise, fill in the structure fields */	/* domain name */	cell->domain = (char*)shm_malloc((1+strlen(domain))*sizeof(char));	strcpy(cell->domain, domain);	/* domain code */	cell->code = code; 	cell->dhash = compute_hash(domain);    	/* return the newly allocated in share memory cell */	return cell;}