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-rw-r--r--src/H5S.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/src/H5S.c b/src/H5S.c
index 3a8a799..5544d5e 100644
--- a/src/H5S.c
+++ b/src/H5S.c
@@ -43,6 +43,13 @@ static htri_t H5S_is_simple(const H5S_t *sdim);
static herr_t H5S_encode(H5S_t *obj, unsigned char *buf, size_t *nalloc);
static H5S_t *H5S_decode(const unsigned char *buf);
+#ifdef H5_HAVE_PARALLEL
+htri_t H5S_get_collective_io_consensus(const H5F_t *file,
+ const htri_t local_opinion,
+ const unsigned flags);
+#endif /* H5_HAVE_PARALLEL */
+
+
#ifdef H5S_DEBUG
/* Names of the selection names, for debugging */
static const char *H5S_sel_names[]={
@@ -1396,6 +1403,103 @@ done:
/*-------------------------------------------------------------------------
+ * Function: H5S_get_collective_io_consensus
+ *
+ * Purpose: Compare notes with all other processes involved in this I/O
+ * and see if all are go for collective I/O.
+ *
+ * If all are, return TRUE.
+ *
+ * If any process can't manage collective I/O, then collective
+ * I/O is impossible, and we return FALSE.
+ *
+ * If the flags indicate that collective I/O is impossible,
+ * skip the interprocess communication and just return FALSE.
+ *
+ * In any error is detected, return FAIL.
+ *
+ * Return: Success: TRUE or FALSE
+ *
+ * Failure: FAIL
+ *
+ * Programmer: JRM -- 8/30/04
+ *
+ * Modifications:
+ *
+ * None.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifdef H5_HAVE_PARALLEL
+htri_t
+H5S_get_collective_io_consensus(const H5F_t *file,
+ const htri_t local_opinion,
+ const unsigned flags)
+{
+ htri_t ret_value = FAIL; /* will update if successful */
+ MPI_Comm comm;
+ int int_local_opinion;
+ int consensus;
+ int mpi_result;
+
+ FUNC_ENTER_NOAPI(H5S_get_collective_io_consensus, NULL);
+
+ HDassert ( ( local_opinion == TRUE ) || ( local_opinion == FALSE ) );
+
+ /* Don't do the interprocess communication unless the Parallel I/O
+ * conversion flag is set -- there may not be other processes to
+ * talk to.
+ */
+ if ( ! ( flags & flags&H5S_CONV_PAR_IO_POSSIBLE ) ) {
+
+ HGOTO_DONE(FALSE);
+ }
+
+ comm = H5F_mpi_get_comm(file);
+
+ if ( comm == MPI_COMM_NULL )
+ HGOTO_ERROR(H5E_DATASPACE, H5E_CANTGET, FAIL, \
+ "can't retrieve MPI communicator")
+
+ if ( local_opinion == TRUE ) {
+
+ int_local_opinion = 1;
+
+ } else {
+
+ int_local_opinion = 0;
+ }
+
+ mpi_result = MPI_Allreduce((void *)(&int_local_opinion),
+ (void *)(&consensus),
+ 1,
+ MPI_INT,
+ MPI_LAND,
+ comm);
+
+ if ( mpi_result != MPI_SUCCESS )
+ HMPI_GOTO_ERROR(FAIL, "MPI_Allreduce failed", mpi_result)
+
+ if ( consensus ) {
+
+ ret_value = TRUE;
+
+ } else {
+
+ ret_value = FALSE;
+ }
+
+done:
+
+ FUNC_LEAVE_NOAPI(ret_value);
+
+} /* H5S_get_collective_io_consensus() */
+
+#endif /* H5_HAVE_PARALLEL */
+
+
+/*-------------------------------------------------------------------------
* Function: H5S_find
*
* Purpose: Given two data spaces (MEM_SPACE and FILE_SPACE) this
@@ -1423,6 +1527,10 @@ done:
* along with other data whose scope is the conversion path (like path
* statistics).
*
+ * John Mainzer, 8/30/04
+ * Modified code to check with all other processes that have the
+ * file open before OKing collective I/O.
+ *
*-------------------------------------------------------------------------
*/
H5S_conv_t *
@@ -1481,6 +1589,12 @@ const H5O_layout_t *layout
if(opt==FAIL)
HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, NULL, "invalid check for direct IO dataspace ");
+ opt = H5S_get_collective_io_consensus(file, opt, flags);
+
+ if ( opt == FAIL )
+ HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, NULL, \
+ "check for collective I/O consensus failed.");
+
/* Check if we can use the optimized parallel I/O routines */
if(opt==TRUE) {
/* Set the pointers to the MPI-specific routines */
@@ -1523,6 +1637,12 @@ const H5O_layout_t *layout
if(opt==FAIL)
HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, NULL, "invalid check for direct IO dataspace ");
+ opt = H5S_get_collective_io_consensus(file, opt, flags);
+
+ if ( opt == FAIL )
+ HGOTO_ERROR(H5E_DATASPACE, H5E_BADRANGE, NULL, \
+ "check for collective I/O consensus failed.");
+
/* Check if we can use the optimized parallel I/O routines */
if(opt==TRUE) {
/* Set the pointers to the MPI-specific routines */