[svn-r5677] Purpose:

    Code improvement

Description:
    Some small code cleanups and took out the code the was turning off the
    metadata cache for parallel I/O (!)

Platforms tested:
    IRIX64 6.5 (modi4) w/parallel

10 files changed, 52 insertions, 71 deletions

diff --git a/src/H5D.c b/src/H5D.c
index 3b14c43..5c9b123 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -38,7 +38,7 @@
 #ifdef H5_HAVE_PARALLEL
 /* Remove this if H5R_DATASET_REGION is no longer used in this file */
 #   include "H5Rpublic.h"
-#endif
+#endif /*H5_HAVE_PARALLEL*/
 
 #define PABLO_MASK	H5D_mask
 
@@ -1544,7 +1544,7 @@ H5D_create(H5G_entry_t *loc, const char *name, const H5T_t *type,
     /* If MPIO is used, no filter support yet. */
     if(IS_H5FD_MPIO(f) && dcpl_pline.nfilters > 0) 
         HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, NULL, "Parallel I/O does not support filters yet");
-#endif
+#endif /*H5_HAVE_PARALLEL*/
     
     /* Initialize the dataset object */
     if(NULL == (new_dset = H5D_new(dcpl_id)))
@@ -1724,13 +1724,13 @@ H5D_create(H5G_entry_t *loc, const char *name, const H5T_t *type,
      * space allocate time is early; otherwise delay allocation until H5Dwrite.
      */
 #ifdef H5_HAVE_PARALLEL
-    if (0==efl.nused && H5F_arr_create(f, &(new_dset->layout))<0) {
-	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, 
-			"unable to initialize storage");
-    } else if(0<efl.nused) {
+    if (0==efl.nused) {
+        if(H5F_arr_create(f, &(new_dset->layout))<0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize storage");
+    } /* end if */
+    else
 	new_dset->layout.addr = HADDR_UNDEF;
-    }
-#else
+#else /*H5_HAVE_PARALLEL*/
     if (0==efl.nused) {
         if(dcpl_layout==H5D_CHUNKED || (dcpl_layout==H5D_CONTIGUOUS && 
                 space_time==H5D_SPACE_ALLOC_EARLY)) {
@@ -1739,11 +1739,10 @@ H5D_create(H5G_entry_t *loc, const char *name, const H5T_t *type,
         } /* end if */
         else
 	    new_dset->layout.addr = HADDR_UNDEF;
-	
-    } else {
+    } /* end if */
+    else
         new_dset->layout.addr = HADDR_UNDEF;
-    }
-#endif
+#endif /*H5_HAVE_PARALLEL*/
 
     /* Update layout message */
     if (H5O_modify (&(new_dset->ent), H5O_LAYOUT, 0, 0, &(new_dset->layout))<0)
@@ -1779,13 +1778,12 @@ H5D_create(H5G_entry_t *loc, const char *name, const H5T_t *type,
 #ifdef H5_HAVE_PARALLEL
     if (H5D_init_storage(new_dset, space)<0)
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize storage");
-#else
-    if(dcpl_layout==H5D_CHUNKED || (dcpl_layout==H5D_CONTIGUOUS && 
-            fill_time==H5D_FILL_TIME_ALLOC && ((space_time==H5D_SPACE_ALLOC_EARLY && !efl.nused) ||
-            (efl.nused))))
+#else /*H5_HAVE_PARALLEL*/
+    if(fill_time==H5D_FILL_TIME_ALLOC &&
+        ((space_time==H5D_SPACE_ALLOC_EARLY && !efl.nused) || (efl.nused)))
 	if (H5D_init_storage(new_dset, space)<0)
 	    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize storage");
-#endif
+#endif /*H5_HAVE_PARALLEL*/
     
     /* Success */
     ret_value = new_dset;
@@ -2017,7 +2015,7 @@ H5D_open_oid(H5G_entry_t *ent)
     /* If MPIO is used, no filter support yet. */
     if(IS_H5FD_MPIO(dataset->ent.file) && pline.nfilters > 0)
         HGOTO_ERROR (H5E_DATASET, H5E_UNSUPPORTED, NULL, "Parallel IO does not support filters yet");
-#endif
+#endif /*H5_HAVE_PARALLEL*/
     
     /*
      * Get the raw data layout info.  It's actually stored in two locations:
@@ -2223,7 +2221,7 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
     H5FD_mpio_xfer_t xfer_mode;		/*xfer_mode for this request */
     hbool_t	xfer_mode_changed=0;	/*xfer_mode needs restore */
     hbool_t	doing_mpio=0;		/*This is an MPIO access */
-#endif
+#endif /*H5_HAVE_PARALLEL*/
 #ifdef H5S_DEBUG
     H5_timer_t	timer;
 #endif
@@ -2416,7 +2414,7 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
 	} /* end if */
 #endif
     } /* end if */
-#endif
+#endif /*H5_HAVE_PARALLEL*/
     /*
      * This is the general case.
      */
@@ -2546,7 +2544,7 @@ done:
 #endif
 	dx->xfer_mode = xfer_mode;
     } /* end if */
-#endif
+#endif /*H5_HAVE_PARALLEL*/
     /* Release selection iterators */
     H5S_sel_iter_release(file_space,&file_iter);
     H5S_sel_iter_release(mem_space,&mem_iter);
@@ -2639,7 +2637,7 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
     H5FD_mpio_xfer_t	xfer_mode;	/*xfer_mode for this request */
     hbool_t	xfer_mode_changed=0;	/*xfer_mode needs restore */
     hbool_t	doing_mpio=0;		/*This is an MPIO access */
-#endif
+#endif /*H5_HAVE_PARALLEL*/
 #ifdef H5S_DEBUG
     H5_timer_t	timer;
 #endif
@@ -2678,7 +2676,7 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
     /* support parallel access of that yet */
     if (IS_H5FD_MPIO(dataset->ent.file) && H5T_get_class(mem_type)==H5T_VLEN)
         HGOTO_ERROR (H5E_DATASET, H5E_UNSUPPORTED, FAIL, "Parallel IO does not support writing VL datatypes yet");
-#endif
+#endif /*H5_HAVE_PARALLEL*/
 #ifdef H5_HAVE_PARALLEL
     /* If MPIO is used, no dataset region reference support yet. */
     /* This is because they use the global heap in the file and we don't */
@@ -2687,7 +2685,7 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
             H5T_get_class(mem_type)==H5T_REFERENCE &&
             H5T_get_ref_type(mem_type)==H5R_DATASET_REGION)
         HGOTO_ERROR (H5E_DATASET, H5E_UNSUPPORTED, FAIL, "Parallel IO does not support writing region reference datatypes yet");
-#endif
+#endif /*H5_HAVE_PARALLEL*/
 
     if (0==(H5F_get_intent(dataset->ent.file) & H5F_ACC_RDWR))
 	HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "no write intent on file");
@@ -2843,7 +2841,7 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
 	} /* end if */
 #endif
     } /* end if */
-#endif
+#endif /*H5_HAVE_PARALLEL*/
     /*
      * This is the general case.
      */
@@ -2981,7 +2979,7 @@ done:
 #endif
 	dx->xfer_mode = xfer_mode;
     } /* end if */
-#endif
+#endif /*H5_HAVE_PARALLEL*/
     /* Release selection iterators */
     H5S_sel_iter_release(file_space,&file_iter);
     H5S_sel_iter_release(mem_space,&mem_iter);
diff --git a/src/H5Dseq.c b/src/H5Dseq.c
index 6ea4d53..0a4da84 100644
--- a/src/H5Dseq.c
+++ b/src/H5Dseq.c
@@ -167,7 +167,7 @@ H5F_seq_readv(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
 #ifdef H5_HAVE_PARALLEL
     H5FD_mpio_xfer_t xfer_mode=H5FD_MPIO_INDEPENDENT;
     H5P_genplist_t *plist=NULL;                 /* Property list */
-#endif
+#endif /* H5_HAVE_PARALLEL */
     herr_t      ret_value = SUCCEED;            /* Return value */
    
     FUNC_ENTER_NOAPI(H5F_seq_readv, FAIL);
@@ -209,7 +209,7 @@ H5F_seq_readv(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     /* Collective MPIO access is unsupported for non-contiguous datasets */
     if (H5D_CONTIGUOUS!=layout->type && H5FD_MPIO_COLLECTIVE==xfer_mode)
         HGOTO_ERROR (H5E_DATASET, H5E_READERROR, FAIL, "collective access on non-contiguous datasets not supported yet");
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
     /* Get necessary properties from property list */
     if(H5P_get(dc_plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
@@ -243,7 +243,7 @@ H5F_seq_readv(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
                             HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL,
                               "collective access with unequal number of blocks not supported yet");
                     }
-#endif
+#endif /* H5_HAVE_PARALLEL */
                     /* Note: We can't use data sieve buffers for datasets in external files
                      *  because the 'addr' of all external files is set to 0 (above) and
                      *  all datasets in external files would alias to the same set of
@@ -549,7 +549,7 @@ H5F_seq_writev(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
 #ifdef H5_HAVE_PARALLEL
     H5FD_mpio_xfer_t xfer_mode=H5FD_MPIO_INDEPENDENT;
     H5P_genplist_t *plist=NULL;                 /* Property list */
-#endif
+#endif /* H5_HAVE_PARALLEL */
     herr_t      ret_value = SUCCEED;            /* Return value */
    
     FUNC_ENTER_NOAPI(H5F_seq_writev, FAIL);
@@ -593,7 +593,7 @@ H5F_seq_writev(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
         HGOTO_ERROR (H5E_DATASET, H5E_WRITEERROR, FAIL,
            "collective access on non-contiguous datasets not supported yet");
     }
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
     /* Get necessary properties from property list */
     if(H5P_get(dc_plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
@@ -626,7 +626,7 @@ H5F_seq_writev(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
                         if (max != min)
                             HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "collective access with unequal number of blocks not supported yet");
                     }
-#endif
+#endif /* H5_HAVE_PARALLEL */
                     /* Note: We can't use data sieve buffers for datasets in external files
                      *  because the 'addr' of all external files is set to 0 (above) and
                      *  all datasets in external files would alias to the same set of
diff --git a/src/H5F.c b/src/H5F.c
index fcf0d84..12999b0 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -218,7 +218,7 @@ H5F_init_interface(void)
             H5_mpi_1_metawrite_g = (int)HDstrtol (s, NULL, 0);
         }
     }
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
     /*
      * Initialize the atom group for the file IDs. There are two groups:
@@ -304,7 +304,7 @@ H5F_init_interface(void)
 	if ((status=H5FD_MULTI)<0) goto end_registration;
 #ifdef H5_HAVE_PARALLEL
 	if ((status=H5FD_MPIO)<0) goto end_registration;
-#endif
+#endif /* H5_HAVE_PARALLEL */
 #ifdef H5_HAVE_STREAM
 	if ((status=H5FD_STREAM)<0) goto end_registration;
 #endif
@@ -1337,9 +1337,6 @@ H5F_new(H5F_file_t *shared, hid_t fcpl_id, hid_t fapl_id)
 {
     H5F_t	*f=NULL, *ret_value=NULL;
     int		n;
-#ifdef H5_HAVE_PARALLEL
-    hid_t       driver_id = -1;
-#endif /* H5_HAVE_PARALLEL */
     H5P_genplist_t *plist;              /* Property list */
  
     FUNC_ENTER_NOINIT(H5F_new);
@@ -1391,20 +1388,6 @@ H5F_new(H5F_file_t *shared, hid_t fcpl_id, hid_t fapl_id)
         if(H5P_get(plist, H5F_ACS_SIEVE_BUF_SIZE_NAME, &(f->shared->sieve_buf_size)) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get sieve buffer size");  
 
-#ifdef H5_HAVE_PARALLEL
-	/*
-	 * Disable cache if file is open using MPIO driver.  Parallel
-	 * does not permit caching.  (maybe able to relax it for
-	 * read only open.)
-	 */
-        if(H5P_get(plist, H5F_ACS_FILE_DRV_ID_NAME, &driver_id) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get driver ID");
-	if (H5FD_MPIO==driver_id){
-	    f->shared->rdcc_nbytes = 0;
-	    f->shared->mdc_nelmts = 0;
-	}
-#endif
-
 	/*
 	 * Create a meta data cache with the specified number of elements.
 	 * The cache might be created with a different number of elements and
diff --git a/src/H5FD.c b/src/H5FD.c
index f0e1aad..d905fdf 100644
--- a/src/H5FD.c
+++ b/src/H5FD.c
@@ -2233,7 +2233,7 @@ H5FD_read(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t siz
     /* collective transfer. */
     /* The no-op case */
     if (0==size) HRETURN(SUCCEED);
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
     /* Check if this information is in the metadata accumulator */
     if((file->feature_flags&H5FD_FEAT_ACCUMULATE_METADATA) && type!=H5FD_MEM_DRAW) {
@@ -2457,7 +2457,7 @@ H5FD_write(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t si
     /* collective transfer. */
     /* The no-op case */
     if (0==size) HRETURN(SUCCEED);
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
     /* Check for accumulating metadata */
     if((file->feature_flags&H5FD_FEAT_ACCUMULATE_METADATA) && type!=H5FD_MEM_DRAW) {
diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c
index 842c6e4..3fee0d9 100644
--- a/src/H5FDmpio.c
+++ b/src/H5FDmpio.c
@@ -1878,4 +1878,4 @@ H5FD_mpio_haddr_to_MPIOff(haddr_t addr, MPI_Offset *mpi_off/*out*/)
 
     FUNC_LEAVE(ret_value);
 }
-#endif /*H5_HAVE_PARALLEL*/
+#endif /* H5_HAVE_PARALLEL */
diff --git a/src/H5FDmpio.h b/src/H5FDmpio.h
index db85bb2..c5133f3 100644
--- a/src/H5FDmpio.h
+++ b/src/H5FDmpio.h
@@ -17,7 +17,7 @@
 #   define H5FD_MPIO	(H5FD_mpio_init())
 #else
 #   define H5FD_MPIO	(-1)
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
 /* Type of I/O for data transfer properties */
 typedef enum H5FD_mpio_xfer_t {
@@ -68,6 +68,6 @@ __DLL__ int H5FD_mpio_mpi_size(H5FD_t *_file);
 }
 #endif
 
-#endif /*H5_HAVE_PARALLEL*/
+#endif /* H5_HAVE_PARALLEL */
 
 #endif
diff --git a/src/H5Farray.c b/src/H5Farray.c
index b019ee8..cefed52 100644
--- a/src/H5Farray.c
+++ b/src/H5Farray.c
@@ -149,7 +149,7 @@ H5F_arr_read(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
 #ifdef H5_HAVE_PARALLEL
     H5FD_mpio_xfer_t xfer_mode=H5FD_MPIO_INDEPENDENT;
     H5P_genplist_t *plist=NULL;                 /* Property list */
-#endif
+#endif /* H5_HAVE_PARALLEL */
     herr_t      ret_value = SUCCEED;            /* Return value */
    
     FUNC_ENTER_NOAPI(H5F_arr_read, FAIL);
@@ -198,7 +198,7 @@ H5F_arr_read(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     /* Collective MPIO access is unsupported for non-contiguous datasets */
     if (H5D_CONTIGUOUS!=layout->type && H5FD_MPIO_COLLECTIVE==xfer_mode)
 	HGOTO_ERROR (H5E_DATASET, H5E_READERROR, FAIL, "collective access on non-contiguous datasets not supported yet");
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
     /* Get necessary properties from property list */
     if(H5P_get(dc_plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
@@ -273,7 +273,7 @@ H5F_arr_read(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
                 if (max != min)
                     HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL, "collective access with unequal number of blocks not supported yet");
             }
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
             for (z=0; z<nelmts; z++) {
                 /* Read directly from file if the dataset is in an external file */
@@ -390,7 +390,7 @@ H5F_arr_write(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
 #ifdef H5_HAVE_PARALLEL
     H5FD_mpio_xfer_t xfer_mode=H5FD_MPIO_INDEPENDENT;
     H5P_genplist_t *plist=NULL;                 /* Property list */
-#endif
+#endif /* H5_HAVE_PARALLEL */
     herr_t      ret_value = SUCCEED;            /* Return value */
    
     FUNC_ENTER_NOAPI(H5F_arr_write, FAIL);
@@ -438,7 +438,7 @@ H5F_arr_write(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     
     if (H5D_CONTIGUOUS!=layout->type && H5FD_MPIO_COLLECTIVE==xfer_mode)
 	HGOTO_ERROR (H5E_DATASET, H5E_WRITEERROR, FAIL, "collective access on non-contiguous datasets not supported yet");
-#endif
+#endif /* H5_HAVE_PARALLEL */
     
     /* Get necessary properties from property list */
     if(H5P_get(dc_plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
@@ -515,7 +515,7 @@ H5F_arr_write(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
                 if (max != min)
                     HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "collective access with unequal number of blocks not supported yet");
             }
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
             for (z=0; z<nelmts; z++) {
 
diff --git a/src/H5Fpublic.h b/src/H5Fpublic.h
index 36261cc..72a0011 100644
--- a/src/H5Fpublic.h
+++ b/src/H5Fpublic.h
@@ -50,7 +50,7 @@
  * desired flags.
  */
 #define H5F_MPIO_DEBUG_KEY "H5F_mpio_debug_key"
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
 /* The difference between a single file and a set of mounted files */
 typedef enum H5F_scope_t {
diff --git a/src/H5Fseq.c b/src/H5Fseq.c
index 6ea4d53..0a4da84 100644
--- a/src/H5Fseq.c
+++ b/src/H5Fseq.c
@@ -167,7 +167,7 @@ H5F_seq_readv(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
 #ifdef H5_HAVE_PARALLEL
     H5FD_mpio_xfer_t xfer_mode=H5FD_MPIO_INDEPENDENT;
     H5P_genplist_t *plist=NULL;                 /* Property list */
-#endif
+#endif /* H5_HAVE_PARALLEL */
     herr_t      ret_value = SUCCEED;            /* Return value */
    
     FUNC_ENTER_NOAPI(H5F_seq_readv, FAIL);
@@ -209,7 +209,7 @@ H5F_seq_readv(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     /* Collective MPIO access is unsupported for non-contiguous datasets */
     if (H5D_CONTIGUOUS!=layout->type && H5FD_MPIO_COLLECTIVE==xfer_mode)
         HGOTO_ERROR (H5E_DATASET, H5E_READERROR, FAIL, "collective access on non-contiguous datasets not supported yet");
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
     /* Get necessary properties from property list */
     if(H5P_get(dc_plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
@@ -243,7 +243,7 @@ H5F_seq_readv(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
                             HGOTO_ERROR(H5E_DATASET, H5E_READERROR, FAIL,
                               "collective access with unequal number of blocks not supported yet");
                     }
-#endif
+#endif /* H5_HAVE_PARALLEL */
                     /* Note: We can't use data sieve buffers for datasets in external files
                      *  because the 'addr' of all external files is set to 0 (above) and
                      *  all datasets in external files would alias to the same set of
@@ -549,7 +549,7 @@ H5F_seq_writev(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
 #ifdef H5_HAVE_PARALLEL
     H5FD_mpio_xfer_t xfer_mode=H5FD_MPIO_INDEPENDENT;
     H5P_genplist_t *plist=NULL;                 /* Property list */
-#endif
+#endif /* H5_HAVE_PARALLEL */
     herr_t      ret_value = SUCCEED;            /* Return value */
    
     FUNC_ENTER_NOAPI(H5F_seq_writev, FAIL);
@@ -593,7 +593,7 @@ H5F_seq_writev(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
         HGOTO_ERROR (H5E_DATASET, H5E_WRITEERROR, FAIL,
            "collective access on non-contiguous datasets not supported yet");
     }
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
     /* Get necessary properties from property list */
     if(H5P_get(dc_plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
@@ -626,7 +626,7 @@ H5F_seq_writev(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
                         if (max != min)
                             HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "collective access with unequal number of blocks not supported yet");
                     }
-#endif
+#endif /* H5_HAVE_PARALLEL */
                     /* Note: We can't use data sieve buffers for datasets in external files
                      *  because the 'addr' of all external files is set to 0 (above) and
                      *  all datasets in external files would alias to the same set of
diff --git a/src/H5S.c b/src/H5S.c
index bf8cf51..8297909 100644
--- a/src/H5S.c
+++ b/src/H5S.c
@@ -43,7 +43,7 @@ static size_t			H5S_nconv_g = 0;	/*entries used*/
 #ifdef H5_HAVE_PARALLEL
 /* Global var whose value can be set from environment variable also */
 hbool_t         H5_mpi_opt_types_g = TRUE;
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
 /* Declare a free list to manage the H5S_simple_t struct */
 H5FL_DEFINE(H5S_simple_t);
@@ -98,7 +98,7 @@ H5S_init_interface(void)
             H5_mpi_opt_types_g = (int)HDstrtol (s, NULL, 0);
         }
     }
-#endif
+#endif /* H5_HAVE_PARALLEL */
 
     FUNC_LEAVE(SUCCEED);
 }