[svn-r7789] Purpose:

    Bug fix & code cleanups

Description:
    Change our use of MPI derived datatypes to not create datatypes with
"0-sized" lengths, which causes the LANL Q machine to hang.

    Also, get rid of "prefer MPI derived datatypes" environment variable since
it has no advantage.

Platforms tested:
    FreeBSD 4.9 (sleipnir) w & w/o parallel
    h5committest

1 files changed, 47 insertions, 161 deletions

diff --git a/src/H5Smpio.c b/src/H5Smpio.c
index d147977..92974c3 100644
--- a/src/H5Smpio.c
+++ b/src/H5Smpio.c
@@ -40,44 +40,39 @@
 static int             interface_initialize_g = 0;
 
 static herr_t
-H5S_mpio_all_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derived_types,
+H5S_mpio_all_type( const H5S_t *space, size_t elmt_size,
 		     /* out: */
 		     MPI_Datatype *new_type,
 		     size_t *count,
 		     hsize_t *extra_offset,
-		     hbool_t *use_view,
 		     hbool_t *is_derived_type );
 static herr_t
-H5S_mpio_none_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derived_types,
+H5S_mpio_none_type( const H5S_t *space, size_t elmt_size,
 		     /* out: */
 		     MPI_Datatype *new_type,
 		     size_t *count,
 		     hsize_t *extra_offset,
-		     hbool_t *use_view,
 		     hbool_t *is_derived_type );
 static herr_t
-H5S_mpio_hyper_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derived_types,
+H5S_mpio_hyper_type( const H5S_t *space, size_t elmt_size,
 		     /* out: */
 		     MPI_Datatype *new_type,
 		     size_t *count,
 		     hsize_t *extra_offset,
-		     hbool_t *use_view,
 		     hbool_t *is_derived_type );
 static herr_t
-H5S_mpio_hyper_contig_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derived_types,
+H5S_mpio_hyper_contig_type( const H5S_t *space, size_t elmt_size,
 		     /* out: */
 		     MPI_Datatype *new_type,
 		     size_t *count,
 		     hsize_t *extra_offset,
-		     hbool_t *use_view,
 		     hbool_t *is_derived_type );
 static herr_t
-H5S_mpio_space_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derived_types,
+H5S_mpio_space_type( const H5S_t *space, size_t elmt_size,
 		     /* out: */
 		     MPI_Datatype *new_type,
 		     size_t *count,
 		     hsize_t *extra_offset,
-		     hbool_t *use_view,
 		     hbool_t *is_derived_type );
 static herr_t
 H5S_mpio_spaces_xfer(H5F_t *f, const H5O_layout_t *layout, size_t elmt_size,
@@ -96,7 +91,6 @@ H5S_mpio_spaces_xfer(H5F_t *f, const H5O_layout_t *layout, size_t elmt_size,
  *		*count		  how many objects of the new_type in selection
  *				  (useful if this is the buffer type for xfer)
  *		*extra_offset     Number of bytes of offset within dataset
- *		*use_view         0 if view not needed, 1 if needed
  *		*is_derived_type  0 if MPI primitive type, 1 if derived
  *
  * Programmer:	rky 980813
@@ -104,27 +98,20 @@ H5S_mpio_spaces_xfer(H5F_t *f, const H5O_layout_t *layout, size_t elmt_size,
  * Modifications:
  *
  *      Quincey Koziol, June 18, 2002
- *      Added 'extra_offset' and 'use_view' parameters
- *
- *      Quincey Koziol, June 19, 2002
- *      Added 'prefer_derived_types' flag to choose whether MPI derived types
- *      should be created or not.
+ *      Added 'extra_offset' parameter
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5S_mpio_all_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derived_types,
+H5S_mpio_all_type( const H5S_t *space, size_t elmt_size,
 		     /* out: */
 		     MPI_Datatype *new_type,
 		     size_t *count,
 		     hsize_t *extra_offset,
-		     hbool_t *use_view,
 		     hbool_t *is_derived_type )
 {
     hsize_t	total_bytes;
     unsigned		u;
-    int         mpi_code;               /* MPI return code */
-    herr_t      ret_value=SUCCEED;       /* Return value */
 
     FUNC_ENTER_NOINIT(H5S_mpio_all_type);
 
@@ -136,33 +123,13 @@ H5S_mpio_all_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derived_
     for (u=0; u<space->extent.u.simple.rank; ++u)
         total_bytes *= space->extent.u.simple.size[u];
 
-    /* Check if we should prefer creating a derived type */
-    if(prefer_derived_types) {
-        /* fill in the return values */
-        H5_CHECK_OVERFLOW(total_bytes, hsize_t, int);
-        if (MPI_SUCCESS != (mpi_code=MPI_Type_contiguous( (int)total_bytes, MPI_BYTE, new_type )))
-            HMPI_GOTO_ERROR(FAIL, "MPI_Type_contiguous failed", mpi_code);
-        if(MPI_SUCCESS != (mpi_code=MPI_Type_commit(new_type)))
-            HMPI_GOTO_ERROR(FAIL, "MPI_Type_commit failed", mpi_code);
-        *count = 1;
-        *extra_offset = 0;
-        *use_view = 1;
-        *is_derived_type = 1;
-    } /* end if */
-    else {
-        /* fill in the return values */
-        *new_type = MPI_BYTE;
-        H5_ASSIGN_OVERFLOW(*count, total_bytes, hsize_t, size_t);
-        *extra_offset = 0;
-        *use_view = 0;
-        *is_derived_type = 0;
-    } /* end else */
+    /* fill in the return values */
+    *new_type = MPI_BYTE;
+    H5_ASSIGN_OVERFLOW(*count, total_bytes, hsize_t, size_t);
+    *extra_offset = 0;
+    *is_derived_type = 0;
 
-done:
-#ifdef H5Smpi_DEBUG
-    HDfprintf(stdout, "Leave %s total_bytes=%Hu\n", FUNC, total_bytes );
-#endif
-    FUNC_LEAVE_NOAPI(ret_value);
+    FUNC_LEAVE_NOAPI(SUCCEED);
 } /* H5S_mpio_all_type() */
 
 
@@ -177,7 +144,6 @@ done:
  *		*count		  how many objects of the new_type in selection
  *				  (useful if this is the buffer type for xfer)
  *		*extra_offset     Number of bytes of offset within dataset
- *		*use_view         0 if view not needed, 1 if needed
  *		*is_derived_type  0 if MPI primitive type, 1 if derived
  *
  * Programmer:	Quincey Koziol, October 29, 2002
@@ -187,45 +153,22 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5S_mpio_none_type( const H5S_t *space, size_t UNUSED elmt_size, hbool_t prefer_derived_types,
+H5S_mpio_none_type( const H5S_t UNUSED *space, size_t UNUSED elmt_size,
 		     /* out: */
 		     MPI_Datatype *new_type,
 		     size_t *count,
 		     hsize_t *extra_offset,
-		     hbool_t *use_view,
 		     hbool_t *is_derived_type )
 {
-    int         mpi_code;               /* MPI return code */
-    herr_t      ret_value=SUCCEED;      /* Return value */
-
     FUNC_ENTER_NOINIT(H5S_mpio_none_type);
 
-    /* Check args */
-    assert(space);
-
-    /* Check if we should prefer creating a derived type */
-    if(prefer_derived_types) {
-        /* fill in the return values */
-        if (MPI_SUCCESS != (mpi_code=MPI_Type_contiguous(0, MPI_BYTE, new_type )))
-            HMPI_GOTO_ERROR(FAIL, "MPI_Type_contiguous failed", mpi_code);
-        if(MPI_SUCCESS != (mpi_code=MPI_Type_commit(new_type)))
-            HMPI_GOTO_ERROR(FAIL, "MPI_Type_commit failed", mpi_code);
-        *count = 1;
-        *extra_offset = 0;
-        *use_view = 1;
-        *is_derived_type = 1;
-    } /* end if */
-    else {
-        /* fill in the return values */
-        *new_type = MPI_BYTE;
-        *count = 0;
-        *extra_offset = 0;
-        *use_view = 0;
-        *is_derived_type = 0;
-    } /* end else */
+    /* fill in the return values */
+    *new_type = MPI_BYTE;
+    *count = 0;
+    *extra_offset = 0;
+    *is_derived_type = 0;
 
-done:
-    FUNC_LEAVE_NOAPI(ret_value);
+    FUNC_LEAVE_NOAPI(SUCCEED);
 } /* H5S_mpio_none_type() */
 
 
@@ -240,7 +183,6 @@ done:
  *		*count		  how many objects of the new_type in selection
  *				  (useful if this is the buffer type for xfer)
  *		*extra_offset     Number of bytes of offset within dataset
- *		*use_view         0 if view not needed, 1 if needed
  *		*is_derived_type  0 if MPI primitive type, 1 if derived
  *
  * Programmer:	rky 980813
@@ -253,22 +195,17 @@ done:
  *		    H5S_MAX_RANK.
  *
  *      Quincey Koziol, June 18, 2002
- *      Added 'extra_offset' and 'use_view' parameters.  Also accomodate
+ *      Added 'extra_offset' parameter.  Also accomodate
  *      selection offset in MPI type built.
  *
- *      Quincey Koziol, June 19, 2002
- *      Added 'prefer_derived_types' flag to choose whether MPI derived types
- *      should be created or not.  (Ignored for this routine)
- *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5S_mpio_hyper_type( const H5S_t *space, size_t elmt_size, hbool_t UNUSED prefer_derived_types,
+H5S_mpio_hyper_type( const H5S_t *space, size_t elmt_size,
 		     /* out: */
 		     MPI_Datatype *new_type,
 		     size_t *count,
 		     hsize_t *extra_offset,
-		     hbool_t *use_view,
 		     hbool_t *is_derived_type )
 {
     struct dim {	/* less hassle than malloc/free & ilk */
@@ -549,7 +486,6 @@ H5S_mpio_hyper_type( const H5S_t *space, size_t elmt_size, hbool_t UNUSED prefer
     /* fill in the remaining return values */
     *count = 1;			/* only have to move one of these suckers! */
     *extra_offset = 0;
-    *use_view = 1;
     *is_derived_type = 1;
     HGOTO_DONE(SUCCEED);
 
@@ -558,7 +494,6 @@ empty:
     *new_type = MPI_BYTE;
     *count = 0;
     *extra_offset = 0;
-    *use_view = 1;      /* Note that this 'use_view' could go either way, but go with '1' for now */
     *is_derived_type = 0;
 
 done:
@@ -581,26 +516,20 @@ done:
  *		*count		  how many objects of the new_type in selection
  *				  (useful if this is the buffer type for xfer)
  *		*extra_offset     Number of bytes of offset within dataset
- *		*use_view         0 if view not needed, 1 if needed
  *		*is_derived_type  0 if MPI primitive type, 1 if derived
  *
  * Programmer:	Quincey Koziol, 2002/06/17
  *
  * Modifications:
  *
- *      Quincey Koziol, June 19, 2002
- *      Added 'prefer_derived_types' flag to choose whether MPI derived types
- *      should be created or not.
- *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5S_mpio_hyper_contig_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derived_types,
+H5S_mpio_hyper_contig_type( const H5S_t *space, size_t elmt_size,
 		     /* out: */
 		     MPI_Datatype *new_type,
 		     size_t *count,
 		     hsize_t *extra_offset,
-		     hbool_t *use_view,
 		     hbool_t *is_derived_type )
 {
     hsize_t	total_bytes;    /* Number of bytes in selection */
@@ -611,8 +540,6 @@ H5S_mpio_hyper_contig_type( const H5S_t *space, size_t elmt_size, hbool_t prefer
     hssize_t    offset[H5O_LAYOUT_NDIMS];       /* Offset in selection */
     int   	ndims;          /* Number of dimensions of dataset */
     int         i;              /* Local index */
-    int         mpi_code;               /* MPI return code */
-    herr_t      ret_value=SUCCEED;       /* Return value */
 
     FUNC_ENTER_NOINIT(H5S_mpio_hyper_contig_type);
 
@@ -625,7 +552,7 @@ H5S_mpio_hyper_contig_type( const H5S_t *space, size_t elmt_size, hbool_t prefer
     /* Compute the number of bytes in selection */
     total_bytes = (hsize_t)elmt_size*nelem;
 
-    /* Set up convenient aliased */
+    /* Set up convenient alias */
     ndims=space->extent.u.simple.rank;
 
     /* Initialize row sizes for each dimension */
@@ -643,33 +570,13 @@ H5S_mpio_hyper_contig_type( const H5S_t *space, size_t elmt_size, hbool_t prefer
     for(i=0,byte_offset=0; i<ndims; i++)
         byte_offset+=offset[i]*slab[i];
 
-    /* Check if we should prefer creating a derived type */
-    if(prefer_derived_types) {
-        /* fill in the return values */
-        H5_CHECK_OVERFLOW(total_bytes, hsize_t, int);
-        if (MPI_SUCCESS != (mpi_code=MPI_Type_contiguous( (int)total_bytes, MPI_BYTE, new_type )))
-            HMPI_GOTO_ERROR(FAIL, "MPI_Type_contiguous failed", mpi_code);
-        if(MPI_SUCCESS != (mpi_code=MPI_Type_commit(new_type)))
-            HMPI_GOTO_ERROR(FAIL, "MPI_Type_commit failed", mpi_code);
-        *count = 1;
-        *extra_offset = byte_offset;
-        *use_view = 1;
-        *is_derived_type = 1;
-    } /* end if */
-    else {
-        /* fill in the return values */
-        *new_type = MPI_BYTE;
-        H5_ASSIGN_OVERFLOW(*count, total_bytes, hsize_t, size_t);
-        *extra_offset = byte_offset;
-        *use_view = 0;
-        *is_derived_type = 0;
-    } /* end else */
+    /* fill in the return values */
+    *new_type = MPI_BYTE;
+    H5_ASSIGN_OVERFLOW(*count, total_bytes, hsize_t, size_t);
+    *extra_offset = byte_offset;
+    *is_derived_type = 0;
 
-done:
-#ifdef H5Smpi_DEBUG
-    HDfprintf(stdout, "Leave %s total_bytes=%Hu\n", FUNC, total_bytes );
-#endif
-    FUNC_LEAVE_NOAPI(ret_value);
+    FUNC_LEAVE_NOAPI(SUCCEED);
 } /* end H5S_mpio_hyper_contig_type() */
 
 
@@ -685,7 +592,6 @@ done:
  *		*count		  how many objects of the new_type in selection
  *				  (useful if this is the buffer type for xfer)
  *		*extra_offset     Number of bytes of offset within dataset
- *		*use_view         0 if view not needed, 1 if needed
  *		*is_derived_type  0 if MPI primitive type, 1 if derived
  *
  * Programmer:	rky 980813
@@ -693,24 +599,18 @@ done:
  * Modifications:
  *
  *      Quincey Koziol, June 18, 2002
- *      Added 'extra_offset' and 'use_view' parameters
- *
- *      Quincey Koziol, June 19, 2002
- *      Added 'prefer_derived_types' flag to choose whether MPI derived types
- *      should be created or not.
+ *      Added 'extra_offset' parameter
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5S_mpio_space_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derived_types,
+H5S_mpio_space_type( const H5S_t *space, size_t elmt_size,
 		     /* out: */
 		     MPI_Datatype *new_type,
 		     size_t *count,
 		     hsize_t *extra_offset,
-		     hbool_t *use_view,
 		     hbool_t *is_derived_type )
 {
-    int		err;
     herr_t	ret_value = SUCCEED;
 
     FUNC_ENTER_NOINIT(H5S_mpio_space_type);
@@ -724,14 +624,14 @@ H5S_mpio_space_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derive
         case H5S_SIMPLE:
             switch(space->select.type) {
                 case H5S_SEL_NONE:
-                    if ( H5S_mpio_none_type( space, elmt_size, prefer_derived_types,
-                        /* out: */ new_type, count, extra_offset, use_view, is_derived_type ) <0)
+                    if ( H5S_mpio_none_type( space, elmt_size,
+                        /* out: */ new_type, count, extra_offset, is_derived_type ) <0)
                         HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL,"couldn't convert \"all\" selection to MPI type");
                     break;
 
                 case H5S_SEL_ALL:
-                    if ( H5S_mpio_all_type( space, elmt_size, prefer_derived_types,
-                        /* out: */ new_type, count, extra_offset, use_view, is_derived_type ) <0)
+                    if ( H5S_mpio_all_type( space, elmt_size,
+                        /* out: */ new_type, count, extra_offset, is_derived_type ) <0)
                         HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL,"couldn't convert \"all\" selection to MPI type");
                     break;
 
@@ -742,15 +642,15 @@ H5S_mpio_space_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derive
 
                 case H5S_SEL_HYPERSLABS:
                     if((*space->select.is_contiguous)(space)) {
-                        err = H5S_mpio_hyper_contig_type( space, elmt_size, prefer_derived_types,
-                            /* out: */ new_type, count, extra_offset, use_view, is_derived_type );
+                        if(H5S_mpio_hyper_contig_type( space, elmt_size,
+                                /* out: */ new_type, count, extra_offset, is_derived_type )<0)
+                            HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL,"couldn't convert \"all\" selection to MPI type");
                     } /* end if */
                     else {
-                        err = H5S_mpio_hyper_type( space, elmt_size, prefer_derived_types,
-                            /* out: */ new_type, count, extra_offset, use_view, is_derived_type );
+                        if(H5S_mpio_hyper_type( space, elmt_size,
+                                /* out: */ new_type, count, extra_offset, is_derived_type )<0)
+                            HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL,"couldn't convert \"all\" selection to MPI type");
                     } /* end else */
-                    if (err<0)
-                        HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL,"couldn't convert \"all\" selection to MPI type");
                     break;
 
                 default:
@@ -761,7 +661,7 @@ H5S_mpio_space_type( const H5S_t *space, size_t elmt_size, hbool_t prefer_derive
 
         case H5S_COMPLEX:
             /* not yet implemented */
-            ret_value = FAIL;
+            HGOTO_ERROR(H5E_DATASPACE, H5E_UNSUPPORTED, FAIL, "complex data spaces are not supported yet");
             break;
 
         default:
@@ -813,12 +713,7 @@ done:
  *
  *      QAK - 2002/06/18
  *      Removed 'dc_plist' parameter, since it was not used.  Also, switch to
- *      getting the 'use_view' and 'extra_offset' settings for each selection.
- *
- *      Quincey Koziol, June 19, 2002
- *      Use 'prefer_derived_types' flag (from HDF5_MPI_PREFER_DERIVED_TYPES
- *      environment variable) to choose whether MPI derived types should be
- *      preferred or not.
+ *      getting the 'extra_offset' setting for each selection.
  *
  *-------------------------------------------------------------------------
  */
@@ -832,12 +727,9 @@ H5S_mpio_spaces_xfer(H5F_t *f, const H5O_layout_t *layout, size_t elmt_size,
     size_t	 mpi_buf_count, mpi_file_count;       /* Number of "objects" to transfer */
     hsize_t	 mpi_buf_offset, mpi_file_offset;       /* Offset within dataset where selection (ie. MPI type) begins */
     MPI_Datatype mpi_buf_type, mpi_file_type;   /* MPI types for buffer (memory) and file */
-    hbool_t	 mbt_use_view=0,        /* Whether we need to use a view for the buffer (memory) type */
-		 mft_use_view=0;        /* Whether we need to use a view for the file type */
     hbool_t	 mbt_is_derived=0,      /* Whether the buffer (memory) type is derived and needs to be free'd */
 		 mft_is_derived=0;      /* Whether the file type is derived and needs to be free'd */
     hbool_t	 plist_is_setup=0;      /* Whether the dxpl has been customized */
-    hbool_t	 prefer_derived_types=0;/* Whether to prefer MPI derived types or not */
     uint8_t	*buf=(uint8_t *)_buf;   /* Alias for pointer arithmetic */
     int         mpi_code;               /* MPI return code */
     herr_t	 ret_value = SUCCEED;   /* Return value */
@@ -854,27 +746,21 @@ H5S_mpio_spaces_xfer(H5F_t *f, const H5O_layout_t *layout, size_t elmt_size,
     /* Make certain we have the correct type of property list */
     assert(TRUE==H5P_isa_class(dxpl_id,H5P_DATASET_XFER));
 
-    /* Get the preference for MPI derived types */
-    /* (Set via the "HDF5_MPI_PREFER_DERIVED_TYPES" environment variable for now) */
-    prefer_derived_types= H5S_mpi_prefer_derived_types_g;
-
     /* create the MPI buffer type */
-    if (H5S_mpio_space_type( mem_space, elmt_size, prefer_derived_types,
+    if (H5S_mpio_space_type( mem_space, elmt_size,
 			       /* out: */
 			       &mpi_buf_type,
 			       &mpi_buf_count,
 			       &mpi_buf_offset,
-			       &mbt_use_view,
 			       &mbt_is_derived )<0)
     	HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL,"couldn't create MPI buf type");
 
     /* create the MPI file type */
-    if ( H5S_mpio_space_type( file_space, elmt_size, prefer_derived_types,
+    if ( H5S_mpio_space_type( file_space, elmt_size,
 			       /* out: */
 			       &mpi_file_type,
 			       &mpi_file_count,
 			       &mpi_file_offset,
-			       &mft_use_view,
 			       &mft_is_derived )<0)
     	HGOTO_ERROR(H5E_DATASPACE, H5E_BADTYPE, FAIL,"couldn't create MPI file type");
 
@@ -891,7 +777,7 @@ H5S_mpio_spaces_xfer(H5F_t *f, const H5O_layout_t *layout, size_t elmt_size,
      * Pass buf type, file type to the file driver. Request an MPI type
      * transfer (instead of an elementary byteblock transfer).
      */
-    if(H5FD_mpio_setup(dxpl_id, mpi_buf_type, mpi_file_type, (unsigned)(mbt_use_view || mft_use_view))<0)
+    if(H5FD_mpio_setup(dxpl_id, mpi_buf_type, mpi_file_type)<0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set MPI-I/O properties");
     plist_is_setup=1;