Simplify H5PB_vfd_swmr__update_index(), which figures in

my investigation of shadow-file freespace leaks.

Copy the tick number from the H5F_shared_t to a temporary variable
and use the temporary instead of spelling out `shared->tick_num`.

Assert that every entry on the tick list is dirty, since clean
entries will not appear on the tick list.  Mark each corresponding
shadow-index entry dirty, and set its "tick of last change" to the
current tick and "tick of last flush" to 0.  This makes the scan
for entries that do not appear on the tick list more believable.

Lower staircase in the loop that scans for shadow-index entries that
did not appear on the tick list.  Log indicies that are marked for
reclamation.

1 files changed, 23 insertions, 21 deletions

diff --git a/src/H5PB.c b/src/H5PB.c
index 1ae72a2..6544603 100644
--- a/src/H5PB.c
+++ b/src/H5PB.c
@@ -1669,6 +1669,8 @@ H5PB_vfd_swmr__update_index(H5F_t *f,
                             uint32_t * idx_ent_not_in_tl_ptr,
                             uint32_t * idx_ent_not_in_tl_flushed_ptr)
 {
+    H5F_shared_t * const shared = f->shared;
+    const uint64_t tick_num = shared->tick_num;
     uint32_t i;
     uint32_t idx_ent_added = 0;
     uint32_t idx_ent_modified = 0;
@@ -1676,7 +1678,6 @@ H5PB_vfd_swmr__update_index(H5F_t *f,
     uint32_t idx_ent_not_in_tl_flushed = 0;
     H5PB_t * pb_ptr = NULL;
     H5PB_entry_t *entry;
-    H5F_shared_t *shared = f->shared;
     H5FD_vfd_swmr_idx_entry_t * ie_ptr = NULL;
     H5FD_vfd_swmr_idx_entry_t * idx = NULL;
     herr_t ret_value = SUCCEED;         /* Return value */
@@ -1726,7 +1727,7 @@ H5PB_vfd_swmr__update_index(H5F_t *f,
                 HDfprintf(stderr,
                     "\n\nmax mdf index len (%" PRIu32 ") exceeded.\n\n",
                     shared->mdf_idx_len);
-                HDfprintf(stderr, "tick = %" PRIu64 ".\n", shared->tick_num);
+                HDfprintf(stderr, "tick = %" PRIu64 ".\n", tick_num);
                 exit(EXIT_FAILURE);
             }
 
@@ -1752,10 +1753,10 @@ H5PB_vfd_swmr__update_index(H5F_t *f,
         /* entry->size could have changed */
         ie_ptr->length               = (uint32_t)entry->size;
         ie_ptr->entry_ptr            = entry->image_ptr;
-        ie_ptr->tick_of_last_change  = shared->tick_num;
-        ie_ptr->clean                = !entry->is_dirty;
-
-        ie_ptr->tick_of_last_flush = ie_ptr->clean ? shared->tick_num : 0;
+        ie_ptr->tick_of_last_change  = tick_num;
+        assert(entry->is_dirty);
+        ie_ptr->clean                = false;
+        ie_ptr->tick_of_last_flush = 0;
     }
 
     /* scan the metadata file index for entries that don't appear in the 
@@ -1765,27 +1766,28 @@ H5PB_vfd_swmr__update_index(H5F_t *f,
      */
     for ( i = 0; i < shared->mdf_idx_entries_used; i++ ) {
 
-        HDassert( ( i == 0 ) || 
-                  ( idx[i - 1].hdf5_page_offset < idx[i].hdf5_page_offset ) );
-
-        if ( idx[i].tick_of_last_change < shared->tick_num ) {
+        HDassert(i == 0 ||
+                 idx[i - 1].hdf5_page_offset < idx[i].hdf5_page_offset);
 
-            idx_ent_not_in_tl++;
+        ie_ptr = idx + i;
 
-            ie_ptr = idx + i;
+        if (ie_ptr->tick_of_last_change == tick_num)
+            continue;
 
-            if (!ie_ptr->clean) {
+        idx_ent_not_in_tl++;
 
-                H5PB__SEARCH_INDEX(pb_ptr, ie_ptr->hdf5_page_offset, \
-                                   entry, FAIL);
+        if (ie_ptr->clean)
+            continue;
 
-                if (entry == NULL || !entry->is_dirty) {
+        H5PB__SEARCH_INDEX(pb_ptr, ie_ptr->hdf5_page_offset, entry, FAIL);
 
-                    idx_ent_not_in_tl_flushed++;
-                    ie_ptr->clean = TRUE;
-                    ie_ptr->tick_of_last_flush = shared->tick_num;
-                }
-            }
+        if (entry == NULL || !entry->is_dirty) {
+            hlog_fast(shadow_index_reclaim,
+                "Marking shadow index slot %" PRIu32 " clean at tick %" PRIu64,
+                i, tick_num);
+            idx_ent_not_in_tl_flushed++;
+            ie_ptr->clean = TRUE;
+            ie_ptr->tick_of_last_flush = tick_num;
         }
     }