int (*match_fun)(void*, void*, simgrid::kernel::activity::CommImpl*),
void (*copy_data_fun)(smx_activity_t, void*, size_t), void* data,
double rate);
int (*match_fun)(void*, void*, simgrid::kernel::activity::CommImpl*),
void (*copy_data_fun)(smx_activity_t, void*, size_t), void* data,
double rate);