From 0013d31655b4747660231618302b81cda8266e06 Mon Sep 17 00:00:00 2001
From: Kunshan Wang <wks1986@gmail.com>
Date: Fri, 18 Oct 2024 19:35:22 +0800
Subject: [PATCH] Querying number of removed entries and bins

This is for the Rust part of the binding to visualize the number of
entries and bins removed in specific work packets.
---
 include/ruby/st.h |  4 ++--
 internal/mmtk.h   | 14 +++++++-------
 st.c              | 11 +++++++++--
 3 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/include/ruby/st.h b/include/ruby/st.h
index fdd6835a732061..83d57ec6416e1e 100644
--- a/include/ruby/st.h
+++ b/include/ruby/st.h
@@ -190,8 +190,8 @@ void rb_hash_bulk_insert_into_st_table(long, const VALUE *, VALUE);
 #if USE_MMTK
 size_t rb_mmtk_st_get_num_entries(const st_table *tab);
 void rb_mmtk_st_get_size_info(const st_table *tab, size_t *entries_start, size_t *entries_bound, size_t *bins_num);
-void rb_mmtk_st_update_entries_range(st_table *tab, size_t begin, size_t end, bool weak_keys, bool weak_records, bool forward);
-void rb_mmtk_st_update_bins_range(st_table *tab, size_t begin, size_t end);
+size_t rb_mmtk_st_update_entries_range(st_table *tab, size_t begin, size_t end, bool weak_keys, bool weak_records, bool forward);
+size_t rb_mmtk_st_update_bins_range(st_table *tab, size_t begin, size_t end);
 void rb_mmtk_st_update_dedup_table(st_table *tab);
 #endif
 
diff --git a/internal/mmtk.h b/internal/mmtk.h
index bc09731c3f5fd0..800766ce7f3abd 100644
--- a/internal/mmtk.h
+++ b/internal/mmtk.h
@@ -103,13 +103,13 @@ typedef struct MMTk_RubyUpcalls {
                              size_t *entries_start,
                              size_t *entries_bound,
                              size_t *bins_num);
-    void (*st_update_entries_range)(struct st_table *table,
-                                    size_t begin,
-                                    size_t end,
-                                    bool weak_keys,
-                                    bool weak_records,
-                                    bool forward);
-    void (*st_update_bins_range)(struct st_table *table, size_t begin, size_t end);
+    size_t (*st_update_entries_range)(struct st_table *table,
+                                      size_t begin,
+                                      size_t end,
+                                      bool weak_keys,
+                                      bool weak_records,
+                                      bool forward);
+    size_t (*st_update_bins_range)(struct st_table *table, size_t begin, size_t end);
 } MMTk_RubyUpcalls;
 
 typedef struct MMTk_RawVecOfObjRef {
diff --git a/st.c b/st.c
index ac511589dd2031..c10f54b055d79a 100644
--- a/st.c
+++ b/st.c
@@ -2380,7 +2380,7 @@ rb_mmtk_st_maybe_update_key_record(st_data_t *slot, bool weak, bool forward)
     return delete_entry;
 }
 
-void
+size_t
 rb_mmtk_st_update_entries_range(st_table *tab, size_t begin, size_t end, bool weak_keys, bool weak_records, bool forward)
 {
     // Either the keys or the values must be weak, otherwise it is a strong table.
@@ -2417,15 +2417,19 @@ rb_mmtk_st_update_entries_range(st_table *tab, size_t begin, size_t end, bool we
     }
 
     rbimpl_atomic_size_sub(&tab->num_entries, deleted_entries);
+
+    return deleted_entries;
 }
 
-void
+size_t
 rb_mmtk_st_update_bins_range(st_table *tab, size_t begin, size_t end)
 {
     RUBY_ASSERT(end <= get_bins_num(tab));
 
     unsigned int const size_ind = get_size_ind(tab);
 
+    size_t deleted_bins = 0;
+
     // Delete bins that point to deleted entries.
     for (st_index_t ind = begin; ind < end; ind++) {
         st_index_t bin = get_bin(tab->bins, size_ind, ind);
@@ -2435,8 +2439,11 @@ rb_mmtk_st_update_bins_range(st_table *tab, size_t begin, size_t end)
         st_table_entry *entry = &tab->entries[bin - ENTRY_BASE];
         if (DELETED_ENTRY_P(entry)) {
             MARK_BIN_DELETED(tab, ind);
+            deleted_bins++;
         }
     }
+
+    return deleted_bins;
 }
 
 // Update a deduplication table.