creating new datatype works, tests pass

Author: JaredCrean2

deps/CMakeLists.txt

@@ -74,6 +74,8 @@ FortranCInterface_HEADER(jlmpi_f2c.h MACRO_NAMESPACE "JLMPI_" SYMBOLS
   MPI_TESTALL
   MPI_TESTANY
   MPI_TESTSOME
+  MPI_TYPE_COMMIT
+  MPI_TYPE_CREATE_STRUCT
   MPI_UNPACK
   MPI_WAIT
   MPI_WAITALL

src/mpi-base.jl

@@ -120,31 +120,36 @@ function Comm_size(comm::Comm)
     Int(size[])
 end
 
-function Type_create_struct{T <: DataType}(::Type{T})
+function Type_create_struct{T <: Any}(::Type{T})  # <: Any effectively 
+                                                  # limits T to being a Type
 
   @assert isbits(T)
+  # get the data from the type
   fieldtypes = T.types
   offsets = fieldoffsets(T)
   nfields = Cint(length(fieldtypes))
 
+  # put data in MPI format
   blocklengths = ones(Cint, nfields)
-  displacements = zeros(Cint, nfields)
+  displacements = zeros(Csize_t, nfields)  # size_t == MPI_Aint ?
   types = zeros(Cint, nfields)
   for i=1:nfields
     displacements[i] = offsets[i]
     types[i] = mpitype(fieldtypes[i])
   end
 
+  # create the datatype
   newtype_ref = Ref{Cint}()
   flag = Ref{Cint}()
-  ccall(MPI_TYPE_CREATE_STRUCT, Void, (Ptr{Cint}, Ptr{Cint}, Ptr{Cint}, 
-        Ptr{Cint}, Ptr{Cint}), &nfields, blocklengths, displacements, types, 
+  ccall(MPI_TYPE_CREATE_STRUCT, Void, (Ptr{Cint}, Ptr{Cint}, Ptr{Csize_t}, 
+        Ptr{Cint}, Ptr{Cint}, Ptr{Cint}), &nfields, blocklengths, displacements, types, 
         newtype_ref, flag)
 
   if flag[] != 0
     println(STDERR, "Warning: MPI_TYPE_CREATE_STRUCT returned non-zero exit stats")
   end
 
+  # commit the datatatype
   flag2 = Ref{Cint}()
 
   ccall(MPI_TYPE_COMMIT, Void, (Ptr{Cint}, Ptr{Cint}), newtype_ref, flag2)
@@ -153,6 +158,7 @@ function Type_create_struct{T <: DataType}(::Type{T})
     println(STDERR, "Warning: MPI_TYPE_COMMIT returned non-zero exit status")
   end
 
+  # add it to the dictonary of known types
   mpitype_dict[T] = newtype_ref[]
 
   return nothing

test/test_datatype.jl

@@ -0,0 +1,48 @@
+using Base.Test
+using MPI
+
+MPI.Init()
+
+immutable Boundary
+  c::UInt16  # force some padding to be inserted
+  a::Int
+  b::UInt8
+end
+
+MPI.Type_create_struct(Boundary)
+#MPI.mpitype_dict[Boundary] = MPI.mpitype_dict[Int]
+comm_size = MPI.Comm_size(MPI.COMM_WORLD)
+comm_rank = MPI.Comm_rank(MPI.COMM_WORLD) + 1
+
+arr = Array(Boundary, 3)
+for i=1:3
+  arr[i] = Boundary( (comm_rank + i) % 127, i + comm_rank, i % 64)
+end
+
+# send to next higher process, with wraparound
+dest = (comm_rank % comm_size) + 1
+req_send = MPI.Isend(arr, dest - 1, 1, MPI.COMM_WORLD)
+
+# receive teh message
+arr_recv = Array(Boundary, 3)
+if comm_rank > 1
+  src = comm_rank - 1
+else
+  src = comm_size
+end
+
+req_recv = MPI.Irecv!(arr_recv, src - 1, 1, MPI.COMM_WORLD)
+
+MPI.Wait!(req_send)
+MPI.Wait!(req_recv)
+
+# check received array
+for i=1:3
+  bndry_i = arr_recv[i]
+  @test bndry_i.a == src + i
+  @test bndry_i.b == i % 64
+  @test bndry_i.c == (src + i) % 127
+end
+
+MPI.Barrier(MPI.COMM_WORLD)
+MPI.Finalize()