Merge pull request #462 from claresinger/fix-mpi

Great, thanks!

Author: pdziekan

libmpdata++/concurr/detail/distmem.hpp

@@ -108,13 +108,13 @@ namespace libmpdataxx
 #if !defined(USE_MPI)
           if (
             // mvapich2
-            std::getenv("MV2_COMM_WORLD_RANK") != NULL ||
+            std::getenv("MV2_COMM_WORLD_RANK") != NULL && std::atoi(std::getenv("MV2_COMM_WORLD_SIZE")) > 1 ||
             // mpich
-            std::getenv("PMI_RANK") != NULL ||
+            std::getenv("PMI_RANK") != NULL && std::atoi(std::getenv("PMI_SIZE")) > 1 ||
             // openmpi
-            std::getenv("OMPI_COMM_WORLD_RANK") != NULL ||
+            std::getenv("OMPI_COMM_WORLD_RANK") != NULL && std::atoi(std::getenv("OMPI_COMM_WORLD_SIZE")) > 1 ||
             // lam
-            std::getenv("LAMRANK") != NULL
+            std::getenv("LAMRANK") != NULL && std::atoi(std::getenv("LAMSIZE")) > 1
           ) throw std::runtime_error("mpirun environment variable detected but libmpdata++ was compiled with MPI disabled");
 #else
           // init mpi here, since distmem is constructed before hdf5