[svn-r4097] Purpose:

    Bug fixes
Description:
    H5FDmpio.c:
	H5FD_mpio_flush() would try to file seek negative if the
	file->eoa is 0 (e.g., doing mpio on the raw-file of the
	split file driver).  Put in a code to catch this case
	by returning succeed immediately.
    H5S.c:
	SAF test code exposed an error in the HDF5_MPI_OPT_TYPES
	code.  The SAF code was doing collective write to chunked
	storage dataset.  Some processes wanted to flush some chunk
	while some other processes were doing something else but the
	HDF5_MPI_OPT_TYPES code thought the chunk flushing were collective
	calls since it only looked at the condition when H5Dwrite
	was called.  So, it hanged when doing MPI_File_setview.
	For now, turned off the HDF5_MPI_OPT_TYPES code so that the
	SAF code would work.  More long term fix later.
Solution:
Platforms tested:
    eirene (serial and mpich), modi4 -64-serial and -n32-parallel.

2 files changed, 11 insertions, 1 deletions

diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c
index d20471f..76417bc 100644
--- a/src/H5FDmpio.c
+++ b/src/H5FDmpio.c
@@ -1524,6 +1524,9 @@ H5FD_mpio_flush(H5FD_t *_file)
      * Unfortunately, keeping track of EOF is an expensive operation, so
      * we can't just check whether EOF<EOA like with other drivers.
      * Therefore we'll just read the byte at EOA-1 and then write it back. */
+    /* But if eoa is zero, then nothing to flush.  Just return */
+    if (file->eoa == 0)
+	HRETURN(SUCCEED);
     if (haddr_to_MPIOff(file->eoa-1, &mpi_off)<0) {
         HRETURN_ERROR(H5E_INTERNAL, H5E_BADRANGE, FAIL,
                       "cannot convert from haddr_t to MPI_Offset");
diff --git a/src/H5S.c b/src/H5S.c
index 3ce8937..67cf469 100644
--- a/src/H5S.c
+++ b/src/H5S.c
@@ -40,7 +40,7 @@ static size_t			H5S_nconv_g = 0;	/*entries used*/
 
 #ifdef H5_HAVE_PARALLEL
 /* Global var whose value comes from environment variable */
-hbool_t         H5_mpi_opt_types_g = TRUE;
+hbool_t         H5_mpi_opt_types_g = FALSE;
 #endif
 
 /* Declare a free list to manage the H5S_simple_t struct */
@@ -92,9 +92,16 @@ H5S_init_interface(void)
     {
         /* Allow MPI buf-and-file-type optimizations? */
         const char *s = HDgetenv ("HDF5_MPI_OPT_TYPES");
+#ifdef H5FDmpio_DEBUG
+	hbool_t         oldtmp = H5_mpi_opt_types_g ;
+#endif
         if (s && HDisdigit(*s)) {
             H5_mpi_opt_types_g = (int)HDstrtol (s, NULL, 0);
         }
+#ifdef H5FDmpio_DEBUG
+    	fprintf(stdout, "H5_mpi_opt_types_g was %ld became %ld\n",
+		    oldtmp, H5_mpi_opt_types_g);
+#endif
     }
 #endif