Revert "Add GC.stat_size_pool to get stats for a size pool"

This reverts commit 6157619bb6.

We'll wait for comments in the open ticket: https://bugs.ruby-lang.org/issues/18364

gc.c

@@ -10675,101 +10675,6 @@ rb_gc_stat(VALUE key)
     }
 }
 
-
-enum gc_stat_size_pool_sym {
-    gc_stat_size_pool_sym_slot_size,
-    gc_stat_size_pool_sym_heap_allocatable_pages,
-    gc_stat_size_pool_sym_heap_eden_pages,
-    gc_stat_size_pool_sym_heap_eden_slots,
-    gc_stat_size_pool_sym_heap_tomb_pages,
-    gc_stat_size_pool_sym_heap_tomb_slots,
-    gc_stat_size_pool_sym_last
-};
-
-static VALUE gc_stat_size_pool_symbols[gc_stat_size_pool_sym_last];
-
-static void
-setup_gc_stat_size_pool_symbols(void)
-{
-    if (gc_stat_size_pool_symbols[0] == 0) {
-#define S(s) gc_stat_size_pool_symbols[gc_stat_size_pool_sym_##s] = ID2SYM(rb_intern_const(#s))
-        S(slot_size);
-        S(heap_allocatable_pages);
-        S(heap_eden_pages);
-        S(heap_eden_slots);
-        S(heap_tomb_pages);
-        S(heap_tomb_slots);
-#undef S
-    }
-}
-
-static size_t
-gc_stat_size_pool_internal(int size_pool_idx, VALUE hash_or_sym)
-{
-    rb_objspace_t *objspace = &rb_objspace;
-    VALUE hash = Qnil, key = Qnil;
-
-    setup_gc_stat_size_pool_symbols();
-
-    if (RB_TYPE_P(hash_or_sym, T_HASH)) {
-        hash = hash_or_sym;
-    }
-    else if (SYMBOL_P(hash_or_sym)) {
-        key = hash_or_sym;
-    }
-    else {
-        rb_raise(rb_eTypeError, "non-hash or symbol argument");
-    }
-
-    if (size_pool_idx < 0 || size_pool_idx >= SIZE_POOL_COUNT) {
-        rb_raise(rb_eArgError, "size pool index out of range");
-    }
-
-    rb_size_pool_t *size_pool = &size_pools[size_pool_idx];
-
-#define SET(name, attr) \
-    if (key == gc_stat_size_pool_symbols[gc_stat_size_pool_sym_##name]) \
-        return attr; \
-    else if (hash != Qnil) \
-        rb_hash_aset(hash, gc_stat_size_pool_symbols[gc_stat_size_pool_sym_##name], SIZET2NUM(attr));
-
-    SET(slot_size, size_pool->slot_size);
-    SET(heap_allocatable_pages, size_pool->allocatable_pages);
-    SET(heap_eden_pages, SIZE_POOL_EDEN_HEAP(size_pool)->total_pages);
-    SET(heap_eden_slots, SIZE_POOL_EDEN_HEAP(size_pool)->total_slots);
-    SET(heap_tomb_pages, SIZE_POOL_TOMB_HEAP(size_pool)->total_pages);
-    SET(heap_tomb_slots, SIZE_POOL_TOMB_HEAP(size_pool)->total_slots);
-#undef SET
-
-    if (!NIL_P(key)) { /* matched key should return above */
-        rb_raise(rb_eArgError, "unknown key: %"PRIsVALUE, rb_sym2str(key));
-    }
-
-    return 0;
-}
-
-static VALUE
-gc_stat_size_pool(rb_execution_context_t *ec, VALUE self, VALUE size_pool_idx, VALUE arg)
-{
-    if (NIL_P(arg)) {
-        arg = rb_hash_new();
-    }
-    else if (SYMBOL_P(arg)) {
-        size_t value = gc_stat_internal(arg);
-        return SIZET2NUM(value);
-    }
-    else if (RB_TYPE_P(arg, T_HASH)) {
-        // ok
-    }
-    else {
-        rb_raise(rb_eTypeError, "non-hash or symbol given");
-    }
-
-    gc_stat_size_pool_internal(FIX2INT(size_pool_idx), arg);
-
-    return arg;
-}
-
 static VALUE
 gc_stress_get(rb_execution_context_t *ec, VALUE self)
 {

gc.rb

@@ -196,24 +196,6 @@ module GC
     Primitive.gc_stat hash_or_key
   end
 
-  # :nodoc:
-  # call-seq:
-  #    GC.stat_size_pool(size_pool_idx) -> Hash
-  #    GC.stat_size_pool(size_pool_idx, hash) -> Hash
-  #    GC.stat_size_pool(size_pool_idx, :key) -> Numeric
-  #
-  # Returns a Hash containing information about a size pool in the GC.
-  #
-  # The contents of the hash are implementation specific and may be changed in
-  # the future.
-  #
-  # If the optional argument, hash, is given, it is overwritten and returned.
-  #
-  # This method is only expected to work on C Ruby.
-  def self.stat_size_pool size_pool_idx, hash_or_key = nil
-    Primitive.gc_stat_size_pool size_pool_idx, hash_or_key
-  end
-
   #  call-seq:
   #     GC.latest_gc_info -> {:gc_by=>:newobj}
   #     GC.latest_gc_info(hash) -> hash

test/ruby/test_gc.rb

@@ -139,54 +139,6 @@ class TestGc < Test::Unit::TestCase
     end
   end
 
-  def test_stat_size_pool
-    skip 'stress' if GC.stress
-
-    stat_size_pool = {}
-    stat = {}
-    # Initialize to prevent GC in future calls
-    GC.stat_size_pool(0, stat_size_pool)
-    GC.stat(stat)
-
-    GC::INTERNAL_CONSTANTS[:SIZE_POOL_COUNT].times do |i|
-      GC.stat_size_pool(i, stat_size_pool)
-      GC.stat(stat)
-
-      assert_equal GC::INTERNAL_CONSTANTS[:RVALUE_SIZE] * (2**i), stat_size_pool[:slot_size]
-      assert_operator stat_size_pool[:heap_allocatable_pages], :<=, stat[:heap_allocatable_pages]
-      assert_operator stat_size_pool[:heap_eden_pages], :<=, stat[:heap_eden_pages]
-      assert_operator stat_size_pool[:heap_eden_slots], :>=, 0
-      assert_operator stat_size_pool[:heap_tomb_pages], :<=, stat[:heap_tomb_pages]
-      assert_operator stat_size_pool[:heap_tomb_slots], :>=, 0
-    end
-
-    assert_raise(ArgumentError) { GC.stat_size_pool(-1) }
-    assert_raise(ArgumentError) { GC.stat_size_pool(GC::INTERNAL_CONSTANTS[:SIZE_POOL_COUNT]) }
-  end
-
-  def test_stat_size_pool_constraints
-    skip 'stress' if GC.stress
-
-    stat = GC.stat
-    stat_size_pools = []
-    # Initialize to prevent GC in future calls
-    GC::INTERNAL_CONSTANTS[:SIZE_POOL_COUNT].times do |i|
-      stat_size_pools << GC.stat_size_pool(i)
-    end
-    # Get actual stats
-    GC.stat(stat)
-    GC::INTERNAL_CONSTANTS[:SIZE_POOL_COUNT].times do |i|
-      GC.stat_size_pool(i, stat_size_pools[i])
-    end
-
-    stat_size_pools_sum = stat_size_pools[0].keys.to_h { |k| [k, stat_size_pools.sum { |e| e[k] }] }
-
-    assert_equal stat[:heap_allocatable_pages], stat_size_pools_sum[:heap_allocatable_pages]
-    assert_equal stat[:heap_eden_pages], stat_size_pools_sum[:heap_eden_pages]
-    assert_equal stat[:heap_tomb_pages], stat_size_pools_sum[:heap_tomb_pages]
-    assert_equal stat[:heap_available_slots], stat_size_pools_sum[:heap_eden_slots] + stat_size_pools_sum[:heap_tomb_slots]
-  end
-
   def test_latest_gc_info
     skip 'stress' if GC.stress