Kokkos::TeamThreadRange

Kokkos::TeamThreadRange

Header File: Kokkos_Core.hpp

Usage:

  parallel_for(TeamThreadRange(team,range), [=] (int i) {...});
  parallel_reduce(TeamThreadRange(team,begin,end), 
    [=] (int i, double& lsum) {...},sum);

TeamThreadRange is an execution policy which can be used for nested parallel patterns. In contrast to global policies, the public interface for nested policies is implemented as functions, in order to enable implicit templating on the execution space type via the team handle.

Synopsis

 template<class TeamMemberType, class iType>
  /* implementation defined */ T TeamThreadRange(const TeamMemberType& team, iType count);
 template<class TeamMemberType, class iType1, class iType2>
  /* implementation defined */ T TeamThreadRange(const TeamMemberType& team, iType1 begin, iType2 end);

Description

• template<class TeamMemberType, class iType>
  /* Implementation defined */ T TeamThreadRange(const TeamMemberType& team, iType count);

  Splits the index range 0 to count-1 over the threads of the team.

  • Arguments

    • team: a handle to the calling team execution context.
    • count: index range length.

  • Returns

    • Implementation defined type.

  • Requirements

    • TeamMemberType meets the requirements of TeamHandle
    • std::is_integral<iType>::value is true.
    • Every member thread of team must call the lexically same operation. I.e. it is not legal to have some threads call this function in one branch, and the other threads of team call it in another branch.
    • count >= 0 is true;

• template<class TeamMemberType, class iType1, class iType2>
  /* Implementation defined */ T TeamThreadRange(const TeamMemberType& team, iType1 begin, iType2 end);

  Splits the index range begin to end-1 over the threads of the team.

  • Arguments

    • team: a handle to the calling team execution context.
    • begin: index range begin.
    • end: index range end.

  • Returns

    • Implementation defined type.

  • Requirements

    • TeamMemberType meets the requirements of TeamHandle
    • std::is_integral<iType1>::value is true.
    • std::is_integral<iType2>::value is true.
    • Every member thread of team must call the lexically same operation. I.e. it is not legal to have some threads call this function in one branch, and the other threads of team call it in another branch.
    • end >= begin is true;

Examples

 typedef TeamPolicy<>::member_type team_handle;
 parallel_for(TeamPolicy<>(N,AUTO,4), KOKKOS_LAMBDA (const team_handle& team) {
   int n = team.league_rank();
   parallel_for(TeamThreadRange(team,M), [&] (const int& i) {
     A(n,i) = B(n) + i;
   });
   team.team_barrier();
   int team_sum;
   parallel_reduce(TeamThreadRange(team,M), [&] (const int& i, int& lsum) {
     lsum += A(n,i);
   },team_sum);
   single(PerTeam(team),[&] () {
     A_rowsum(n) += team_sum;
   });
 });