Add a test for parallel reads of independent files using MPI subgroups

2 files changed, 7 insertions, 34 deletions

diff --git a/src/H5FDmpio.h b/src/H5FDmpio.h
index f02afe6..6ee0a1a 100644
--- a/src/H5FDmpio.h
+++ b/src/H5FDmpio.h
@@ -29,29 +29,6 @@
 #endif /* H5_HAVE_PARALLEL */
 
 #ifdef H5_HAVE_PARALLEL
-#if 0 /* delete this eventually */
-#define H5FD_GET_MPI_RANK_AND_SIZE(rank,size, f) { \
-  (rank) = 0; (size) = 1;                          \
-  if (H5F_HAS_FEATURE((f), H5FD_FEAT_HAS_MPI)) {   \
-      (rank) = H5F_mpi_get_rank((f));              \
-      (size) = H5F_mpi_get_size((f));              \
-  } else {                                         \
-      int mpi_initialized = 0, mpi_finalized = 0;  \
-      MPI_Initialized(&mpi_initialized);           \
-      MPI_Finalized(&mpi_finalized);               \
-      if (mpi_initialized && !mpi_finalized) {     \
-          MPI_Comm_rank(MPI_COMM_WORLD, &(rank));  \
-          MPI_Comm_size(MPI_COMM_WORLD, &(size));  \
-      }                                            \
-  }}
-  
-#define H5FD_GET_MPI_COMM(comm, f) {               \
-  if (H5F_HAS_FEATURE((f), H5FD_FEAT_HAS_MPI))     \
-      (comm) = H5F_mpi_get_comm((f));              \
-  else (comm) = MPI_COMM_WORLD;                    \
-  }
-#endif /* delete this eventually */
-
 /*Turn on H5FDmpio_debug if H5F_DEBUG is on */
 #ifdef H5F_DEBUG
 #ifndef H5FDmpio_DEBUG
diff --git a/src/H5Fsuper.c b/src/H5Fsuper.c
index a34a7fd..a3b1fed 100644
--- a/src/H5Fsuper.c
+++ b/src/H5Fsuper.c
@@ -359,9 +359,6 @@ H5F__super_read(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t initial
 
     /* Find the superblock */
 #ifdef H5_HAVE_PARALLEL
-#if 0
-    H5FD_GET_MPI_RANK_AND_SIZE(mpi_rank, mpi_size, f);
-#else
     if(H5F_HAS_FEATURE(f, H5FD_FEAT_HAS_MPI)) {
 
         if((mpi_rank = H5F_mpi_get_rank(f)) < 0)
@@ -370,9 +367,15 @@ H5F__super_read(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t initial
         if((mpi_size = H5F_mpi_get_size(f)) < 0)
             HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTGET, FAIL, "can't retrieve MPI communicator size")
     }
-#endif
+
     /* If we are an MPI application with at least two processes, the
      * following superblock signature location optimization is applicable.
+     *
+     * Note:: For parallel applications which don't setup for using the
+     * HDF5 MPIO driver, we will arrive here with mpi_size == 1.
+     * This occurs because of the variable initialization (above) and the
+     * fact that we have skipped actually calling MPI functions to determine
+     * our MPI rank and size.
      */
     if ( mpi_size > 1 ) {
         MPI_Comm this_comm = MPI_COMM_NULL;
@@ -381,12 +384,6 @@ H5F__super_read(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t initial
 	    if(H5FD_locate_signature(&fdio_info, &super_addr) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "unable to locate file signature")
         }
-#if 0
-	H5FD_GET_MPI_COMM(this_comm, f);
-        if (( this_comm == MPI_COMM_NULL ) ||
-            ( MPI_Bcast(&super_addr,sizeof(super_addr), MPI_BYTE, 0, this_comm) != MPI_SUCCESS))
-            HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "unable to locate file signature")
-#else
         HDassert(H5F_HAS_FEATURE(f, H5FD_FEAT_HAS_MPI));
 
         if ( MPI_COMM_NULL == (this_comm = H5F_mpi_get_comm(f)) )
@@ -395,7 +392,6 @@ H5F__super_read(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t initial
         if ( MPI_SUCCESS != 
             (mpi_result = MPI_Bcast(&super_addr,sizeof(super_addr), MPI_BYTE, 0, this_comm)))
             HMPI_GOTO_ERROR(FAIL, "MPI_Bcast failed", mpi_result)
-#endif
     }
     else {
     /* Locate the signature as per per the serial library */