Use the "tail queue" from queue(3) for the delayed free list of shadow images.

Delete the little-used free-list length, dl_len, and just count up the list
entries when diagnostic code needs the length.

Extract the code for deferring shadow-image free into a new subroutine,
`vfd_swmr_idx_entry_defer_free()`.

Rename type `deferred_free_head_t` as `deferred_free_queue_t`.

Remove the disused H5F__LL_{REMOVE,PREPEND} macros.

Add some diagnostic code and #if 0'd assertions.

Change `qsort(ptr, n, sizeof(type), cmp)` to
`qsort(ptr, n, sizeof(*ptr), cmp)`.

Use a `continue` statement to lower a staircase in
H5F_update_vfd_swmr_metadata_file().

Add vfd_swmr_mdf_idx_entry_remove() to delete a shadow index entry and add the
image at that entry to a deferred-free list.  Call it whenever a page is
evicted.

Update the comment in H5PB_remove_entry() that asks if we need to remove shadow
index entries: now we *do* remove them.  Remove shadow index entries in
H5PB__evict_entry().  Also mention in the comment that the index-entry removal
performed by H5PB__evict_entry() ought to be sufficient.

1 files changed, 1 insertions, 3 deletions

diff --git a/src/H5Fint.c b/src/H5Fint.c
index 282a9de..661ec40 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -1117,9 +1117,7 @@ H5F__new(H5F_shared_t *shared, unsigned flags, hid_t fcpl_id, hid_t fapl_id, H5F
 
         f->shared->vfd_swmr_md_fd           = -1;
         f->shared->fs_man_md                = NULL;
-        f->shared->dl_head_ptr              = NULL;
-        f->shared->dl_tail_ptr              = NULL;
-        f->shared->dl_len                   = 0;
+        TAILQ_INIT(&f->shared->old_images);
 
         /* Get the VOL connector info */
         if(H5F__set_vol_conn(f) < 0)