Add missing get/set MPI.File info functions

.gitignore

@@ -3,3 +3,4 @@ libjuliampi.dylib
 *.cov
 *.mem
 Manifest.toml
+.vscode

src/io.jl

@@ -4,7 +4,7 @@ FileHandle() = FileHandle(FILE_NULL.val)
 
 module File
 
-import MPI: MPI, @mpichk, _doc_external, MPIPtr, libmpi, refcount_inc, refcount_dec,
+import MPI: MPI, @mpichk, _doc_external, MPIPtr, libmpi, refcount_inc, refcount_dec, free,
     Comm, MPI_Comm, FileHandle, MPI_File, Info, MPI_Info, FILE_NULL,
     Datatype, MPI_Datatype, MPI_Offset, Status, Buffer, Buffer_send
 import Base: close
@@ -71,6 +71,38 @@ function close(file::FileHandle)
     return nothing
 end
 
+# Info
+"""
+    MPI.File.get_info(file::FileHandle)
+
+Returns the hints for a file that are actually being used by MPI.
+
+# External links
+$(_doc_external("MPI_File_get_info"))
+"""
+function get_info(file::FileHandle)
+    file_info = Info(init=false)
+    @mpichk ccall((:MPI_File_get_info, libmpi), Cint,
+        (MPI_File, Ptr{MPI_Info}), file, file_info)
+    refcount_inc()
+    finalizer(free, file_info)
+    return file_info
+end
+
+"""
+    MPI.File.set_info!(file::FileHandle, info::Info)
+
+Collectively sets new values for the hints associated with a MPI.File.FileHandle.
+
+# External links
+$(_doc_external("MPI_File_set_info"))
+"""
+function set_info!(file::FileHandle, info::Info)
+    @mpichk ccall((:MPI_File_set_info, libmpi), Cint,
+        (MPI_File, MPI_Info), file, info)
+    return file
+end
+
 # View
 """
     MPI.File.set_view!(file::FileHandle, disp::Integer, etype::Datatype, filetype::Datatype, datarep::AbstractString; kwargs...)
@@ -322,7 +354,7 @@ $(_doc_external("MPI_File_write_ordered"))
 function write_ordered(file::FileHandle, buf::Buffer)
     stat_ref = Ref{Status}(MPI.STATUS_EMPTY)
     # int MPI_File_write_ordered(MPI_File fh, const void *buf, int count,
-    #              MPI_Datatype datatype, MPI_Status *status)    
+    #              MPI_Datatype datatype, MPI_Status *status)
     @mpichk ccall((:MPI_File_write_ordered, libmpi), Cint,
                   (MPI_File, MPIPtr, Cint, MPI_Datatype, Ptr{Status}),
                   file, buf.data, buf.count, buf.datatype, stat_ref)
@@ -335,7 +367,7 @@ write_ordered(file::FileHandle, buf) = write_ordered(file, Buffer_send(buf))
     SEEK_SET = MPI.MPI_SEEK_SET
     SEEK_CUR = MPI.MPI_SEEK_CUR
     SEEK_END = MPI.MPI_SEEK_END
-end    
+end
 
 """
     MPI.File.seek_shared(file::FileHandle, offset::Integer, whence::Seek=SEEK_SET)

test/test_io.jl

@@ -45,3 +45,39 @@ data = zeros(Int64, 1)
 MPI.File.read_at_all!(fh, rank*2, data)
 @test data == [rank == 0 ? -1 : rank+1]
 close(fh)
+
+MPI.Barrier(comm)
+
+# File Info hints
+fh = MPI.File.open(comm, filename, read=true)
+fh_info = MPI.File.get_info(fh)
+
+# File Info hints are implementation specific
+# so test MPICH dervived implementations
+if MPI.MPI_LIBRARY in (MPI.MPICH, MPI.MicrosoftMPI, MPI.IntelMPI, MPI.MVAPICH, MPI.CrayMPICH)
+
+    # MPICH sets some default MPI-IO hints
+    @test length(keys(fh_info)) > 0
+
+    # Test that default info hints on mpi-io implementation are present
+    # cb_buffer_size is one of the reserved MPI 3.1 keywords
+    @test parse(Int, fh_info[:cb_buffer_size]) > 0
+
+    # Test that we can attach custom info to an existing FileHandle
+    MPI.File.set_info!(fh, MPI.Info(:cb_buffer_size=>33554432))
+    fh_info = MPI.File.get_info(fh)
+    @test parse(Int, fh_info[:cb_buffer_size]) == 33554432
+
+elseif MPI.MPI_LIBRARY == MPI.OpenMPI
+
+    # OpenMPI does not set any MPI-IO hints by default
+    @test length(keys(fh_info)) == 0
+
+    # Test that default info hints on mpi-io implementation are present
+    @test parse(Int, fh_info[:coll_write_bufsize]) > 0
+
+    # Test that we can attach custom info to an existing FileHandle
+    MPI.File.set_info!(fh, MPI.Info(:coll_write_bufsize=>33554432))
+    fh_info = MPI.File.get_info(fh)
+    @test parse(Int, fh_info[:coll_write_bufsize]) == 33554432
+end