/// <summary>
/// Adopts a low-level MPI group that was created with any of the low-level MPI facilities.
/// The resulting <c>Group</c> object will manage the lifetime of the low-level MPI group,
/// and will call <see cref="Unsafe.MPI_Group_free"/> when it is disposed or finalized.
/// </summary>
/// <remarks>
/// This constructor should only be used in rare cases where the program
/// is manipulating MPI groups through the low-level MPI interface.
/// </remarks>
public static Group Adopt(MPI_Group group)
{
if (group == Unsafe.MPI_GROUP_NULL)
return null;
Group result = new Group();
result.group = group;
return result;
}
/// <summary>
/// Compare two MPI groups.
/// </summary>
/// <list>
/// <listheader>
/// <term>Value</term>
/// <description>Description</description>
/// </listheader>
/// <item>
/// <term><see cref="Comparison.Identical"/></term>
/// <description>The two <c>Group</c> objects represent the same group.</description>
/// </item>
/// <item>
/// <term><see cref="Comparison.Congruent"/></term>
/// <description>
/// The two <c>Group</c> objects contain the same processes with the same ranks,
/// but represent different groups.
/// </description>
/// </item>
/// <item>
/// <term><see cref="Comparison.Similar"/></term>
/// <description>
/// The two <c>Group</c> objects contain the same processes, but with different ranks.
/// </description>
/// </item>
/// <item>
/// <term><see cref="Comparison.Unequal"/></term>
/// <descsription>The two <c>Group</c> objects are different.</descsription>
/// </item>
/// </list>
public Comparison Compare(Group other)
{
int result;
unsafe
{
int errorCode = Unsafe.MPI_Group_compare(group, other.group, out result);
if (errorCode != Unsafe.MPI_SUCCESS)
throw Environment.TranslateErrorIntoException(errorCode);
}
return Unsafe.ComparisonFromInt(result);
}
/// <summary>
/// Translates the ranks of processes in this group to the ranks of the same processes within a different group.
/// </summary>
/// <param name="ranks">The rank values in this group that will be translated.</param>
/// <param name="other">The group whose ranks we are translating to.</param>
/// <returns>
/// An integer array containing the ranks of the processes in <paramref name="other"/> that correspond to
/// the ranks of the same processes in this group. For processes that are in this group but not
/// <paramref name="other"/>, the resulting array will contain <see cref="Group.NoProcess"/>.
/// </returns>
public int[] TranslateRanks(int[] ranks, Group other)
{
int[] result = new int[ranks.Length];
unsafe
{
int errorCode = Unsafe.MPI_Group_translate_ranks(group, ranks.Length, ranks, other.group, result);
if (errorCode != Unsafe.MPI_SUCCESS)
throw Environment.TranslateErrorIntoException(errorCode);
}
return result;
}
