Method MPI.Op_create()

Method Op_create

Op Op_create(function(object, object:void) ufun, int commute)

Description

Creates a user-defined MPI operation.

Parameter ufun

The function that implements the MPI.Op to be created.

Parameter commute

Set to 1 if the operation commutes.

Example

void my_add_fun(object invec, object outvec) {
	for (int i = 0; i < sizeof(outvec); i++) {
	outvec[i] += invec[i];
}
int main() {
	MPI.Op myadd;
	MPI.IntArray ia = MPI.IntArray(10), results;
	MPI.Init();
	myadd = MPI.Op_create(my_add_fun, 1);
	for (int i = 0; i < sizeof(ia); i++)
		ia[i] = random(1000);
	if (!MPI.world->rank) results = MPI.IntArray(sizeof(ia));
	MPI.world->Reduce(ia, results, 0);
	if (!MPI.world->rank)
		for (int i; i < sizeof(results); i++)
			write("%02d: %d\n", i, results[i]);
	MPI.Finalize();
	return 0;
}

Note

User-defined MPI operations may not call any MPI operations themselves.

See also

MPI.Comm->Reduce(), MPI_Op_create(3)