MPI_Aint sendtype_extent = 0, recvtype_extent = 0; /* Datatype extent */
MPI_Aint true_lb = 0, sendtype_true_extent = 0, recvtype_true_extent = 0;
MPI_Comm shmem_comm, leader_comm;
MPI_Aint sendtype_extent = 0, recvtype_extent = 0; /* Datatype extent */
MPI_Aint true_lb = 0, sendtype_true_extent = 0, recvtype_true_extent = 0;
MPI_Comm shmem_comm, leader_comm;