updated PR

Author: JaredCrean2

src/mpi-base.jl

@@ -4,10 +4,8 @@ typealias MPIDatatype Union{Char,
                             Float32, Float64, Complex64, Complex128}
 
 # Define a function mpitype(T) that returns the MPI datatype code
-# for a given type T.  This works better with precompilation
-# than a dictionary (since DataType keys need to be re-hashed at runtime),
-# and also allows the datatype code to be inlined at compile-time.
-
+# for a given type T.  The dictonary is defined in __init__ so 
+# the module can be precompiled
 
 # accessor function for getting MPI datatypes
 # use a function in case more behavior is needed later
@@ -120,10 +118,17 @@ function Comm_size(comm::Comm)
     Int(size[])
 end
 
-function Type_create_struct{T <: Any}(::Type{T})  # <: Any effectively 
+function type_create{T <: Any}(::Type{T})  # <: Any effectively 
                                                   # limits T to being a Type
 
-  @assert isbits(T)
+  if !isbits(T)
+    throw(ArgumentError("Type must be isbits()"))
+  end
+
+  if haskey(mpitype_dict, T)  # if the datatype already exists
+    return nothing
+  end
+
   # get the data from the type
   fieldtypes = T.types
   offsets = fieldoffsets(T)
@@ -135,6 +140,12 @@ function Type_create_struct{T <: Any}(::Type{T})  # <: Any effectively
   types = zeros(Cint, nfields)
   for i=1:nfields
     displacements[i] = offsets[i]
+
+    # create an MPI_Datatype for the current field if it does not exist yet
+    if !haskey(mpitype_dict, fieldtypes[i])
+      type_create(fieldtypes[i])
+    end
+
     types[i] = mpitype(fieldtypes[i])
   end
 
@@ -146,16 +157,15 @@ function Type_create_struct{T <: Any}(::Type{T})  # <: Any effectively
         newtype_ref, flag)
 
   if flag[] != 0
-    println(STDERR, "Warning: MPI_TYPE_CREATE_STRUCT returned non-zero exit stats")
+    throw(ErrorException("MPI_Type_create_struct returned non-zero exit status"))
   end
 
   # commit the datatatype
   flag2 = Ref{Cint}()
-
   ccall(MPI_TYPE_COMMIT, Void, (Ptr{Cint}, Ptr{Cint}), newtype_ref, flag2)
 
   if flag2[] != 0
-    println(STDERR, "Warning: MPI_TYPE_COMMIT returned non-zero exit status")
+    throw(ErrorException("MPI_Type_commit returned non-zero exit status"))
   end
 
   # add it to the dictonary of known types

test/test_datatype.jl

@@ -3,34 +3,38 @@ using MPI
 
 MPI.Init()
 
+#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
+
+# send to next higher process, with wraparound
+dest = (comm_rank % comm_size) + 1
+if comm_rank > 1
+  src = comm_rank - 1
+else
+  src = comm_size
+end
+
+
+# test simple type 
+
 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
+MPI.type_create(Boundary)
 
 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
+# receive the 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)
@@ -39,10 +43,42 @@ 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.a == (src + i)
   @test bndry_i.b == i % 64
   @test bndry_i.c == (src + i) % 127
 end
 
+
+# test nested types
+immutable Boundary2
+  a::UInt32
+  b::Tuple{Int, UInt8}
+end
+
+MPI.type_create(Boundary2)
+
+arr = Array(Boundary2, 3)
+arr_recv = Array(Boundary2, 3)
+
+for i=1:3
+  arr[i] = Boundary2( (comm_rank + i) % 127, ( Int(i + comm_rank), UInt8(i % 64) ) )
+end
+
+req_send = MPI.Isend(arr, dest - 1, 1, MPI.COMM_WORLD)
+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) % 127
+  @test bndry_i.b[1] == (src + i)
+  @test bndry_i.b[2] == (i % 64)
+end
+
+
+
 MPI.Barrier(MPI.COMM_WORLD)
 MPI.Finalize()