void increment_sent_messages_count(int src, int dst, int tag);
unsigned int get_received_messages_count(int src, int dst, int tag);
void increment_received_messages_count(int src, int dst, int tag);
void increment_sent_messages_count(int src, int dst, int tag);
unsigned int get_received_messages_count(int src, int dst, int tag);
void increment_received_messages_count(int src, int dst, int tag);