Don't try compacting ivars on Classes that are "too complex"

Too complex classes use a hash table to store ivs, and should always pin
their IVs.  We shouldn't touch those classes in compaction.

common.mk

@@ -3006,7 +3006,9 @@ class.$(OBJEXT): {$(VPATH)}subst.h
 class.$(OBJEXT): {$(VPATH)}thread_$(THREAD_MODEL).h
 class.$(OBJEXT): {$(VPATH)}thread_native.h
 class.$(OBJEXT): {$(VPATH)}vm_core.h
+class.$(OBJEXT): {$(VPATH)}vm_debug.h
 class.$(OBJEXT): {$(VPATH)}vm_opts.h
+class.$(OBJEXT): {$(VPATH)}vm_sync.h
 compar.$(OBJEXT): $(hdrdir)/ruby/ruby.h
 compar.$(OBJEXT): $(top_srcdir)/internal/basic_operators.h
 compar.$(OBJEXT): $(top_srcdir)/internal/compar.h
@@ -3441,6 +3443,7 @@ compile.$(OBJEXT): {$(VPATH)}vm_callinfo.h
 compile.$(OBJEXT): {$(VPATH)}vm_core.h
 compile.$(OBJEXT): {$(VPATH)}vm_debug.h
 compile.$(OBJEXT): {$(VPATH)}vm_opts.h
+compile.$(OBJEXT): {$(VPATH)}vm_sync.h
 compile.$(OBJEXT): {$(VPATH)}yjit.h
 complex.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h
 complex.$(OBJEXT): $(CCAN_DIR)/container_of/container_of.h
@@ -3480,6 +3483,7 @@ complex.$(OBJEXT): {$(VPATH)}backward/2/stdarg.h
 complex.$(OBJEXT): {$(VPATH)}complex.c
 complex.$(OBJEXT): {$(VPATH)}config.h
 complex.$(OBJEXT): {$(VPATH)}constant.h
+complex.$(OBJEXT): {$(VPATH)}debug_counter.h
 complex.$(OBJEXT): {$(VPATH)}defines.h
 complex.$(OBJEXT): {$(VPATH)}encoding.h
 complex.$(OBJEXT): {$(VPATH)}id.h
@@ -3648,7 +3652,9 @@ complex.$(OBJEXT): {$(VPATH)}subst.h
 complex.$(OBJEXT): {$(VPATH)}thread_$(THREAD_MODEL).h
 complex.$(OBJEXT): {$(VPATH)}thread_native.h
 complex.$(OBJEXT): {$(VPATH)}vm_core.h
+complex.$(OBJEXT): {$(VPATH)}vm_debug.h
 complex.$(OBJEXT): {$(VPATH)}vm_opts.h
+complex.$(OBJEXT): {$(VPATH)}vm_sync.h
 cont.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h
 cont.$(OBJEXT): $(CCAN_DIR)/container_of/container_of.h
 cont.$(OBJEXT): $(CCAN_DIR)/list/list.h
@@ -4075,6 +4081,7 @@ debug.$(OBJEXT): {$(VPATH)}vm_callinfo.h
 debug.$(OBJEXT): {$(VPATH)}vm_core.h
 debug.$(OBJEXT): {$(VPATH)}vm_debug.h
 debug.$(OBJEXT): {$(VPATH)}vm_opts.h
+debug.$(OBJEXT): {$(VPATH)}vm_sync.h
 debug_counter.$(OBJEXT): $(hdrdir)/ruby/ruby.h
 debug_counter.$(OBJEXT): {$(VPATH)}assert.h
 debug_counter.$(OBJEXT): {$(VPATH)}backward/2/assume.h
@@ -6175,6 +6182,7 @@ enumerator.$(OBJEXT): {$(VPATH)}backward/2/stdalign.h
 enumerator.$(OBJEXT): {$(VPATH)}backward/2/stdarg.h
 enumerator.$(OBJEXT): {$(VPATH)}config.h
 enumerator.$(OBJEXT): {$(VPATH)}constant.h
+enumerator.$(OBJEXT): {$(VPATH)}debug_counter.h
 enumerator.$(OBJEXT): {$(VPATH)}defines.h
 enumerator.$(OBJEXT): {$(VPATH)}encoding.h
 enumerator.$(OBJEXT): {$(VPATH)}enumerator.c
@@ -6344,7 +6352,9 @@ enumerator.$(OBJEXT): {$(VPATH)}subst.h
 enumerator.$(OBJEXT): {$(VPATH)}thread_$(THREAD_MODEL).h
 enumerator.$(OBJEXT): {$(VPATH)}thread_native.h
 enumerator.$(OBJEXT): {$(VPATH)}vm_core.h
+enumerator.$(OBJEXT): {$(VPATH)}vm_debug.h
 enumerator.$(OBJEXT): {$(VPATH)}vm_opts.h
+enumerator.$(OBJEXT): {$(VPATH)}vm_sync.h
 error.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h
 error.$(OBJEXT): $(CCAN_DIR)/container_of/container_of.h
 error.$(OBJEXT): $(CCAN_DIR)/list/list.h
@@ -6783,6 +6793,7 @@ eval.$(OBJEXT): {$(VPATH)}vm.h
 eval.$(OBJEXT): {$(VPATH)}vm_core.h
 eval.$(OBJEXT): {$(VPATH)}vm_debug.h
 eval.$(OBJEXT): {$(VPATH)}vm_opts.h
+eval.$(OBJEXT): {$(VPATH)}vm_sync.h
 explicit_bzero.$(OBJEXT): {$(VPATH)}config.h
 explicit_bzero.$(OBJEXT): {$(VPATH)}explicit_bzero.c
 explicit_bzero.$(OBJEXT): {$(VPATH)}internal/attr/format.h
@@ -8489,7 +8500,9 @@ iseq.$(OBJEXT): {$(VPATH)}thread_native.h
 iseq.$(OBJEXT): {$(VPATH)}util.h
 iseq.$(OBJEXT): {$(VPATH)}vm_callinfo.h
 iseq.$(OBJEXT): {$(VPATH)}vm_core.h
+iseq.$(OBJEXT): {$(VPATH)}vm_debug.h
 iseq.$(OBJEXT): {$(VPATH)}vm_opts.h
+iseq.$(OBJEXT): {$(VPATH)}vm_sync.h
 iseq.$(OBJEXT): {$(VPATH)}yjit.h
 load.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h
 load.$(OBJEXT): $(CCAN_DIR)/container_of/container_of.h
@@ -9235,6 +9248,7 @@ marshal.$(OBJEXT): {$(VPATH)}backward/2/stdarg.h
 marshal.$(OBJEXT): {$(VPATH)}builtin.h
 marshal.$(OBJEXT): {$(VPATH)}config.h
 marshal.$(OBJEXT): {$(VPATH)}constant.h
+marshal.$(OBJEXT): {$(VPATH)}debug_counter.h
 marshal.$(OBJEXT): {$(VPATH)}defines.h
 marshal.$(OBJEXT): {$(VPATH)}encindex.h
 marshal.$(OBJEXT): {$(VPATH)}encoding.h
@@ -9408,7 +9422,9 @@ marshal.$(OBJEXT): {$(VPATH)}thread_$(THREAD_MODEL).h
 marshal.$(OBJEXT): {$(VPATH)}thread_native.h
 marshal.$(OBJEXT): {$(VPATH)}util.h
 marshal.$(OBJEXT): {$(VPATH)}vm_core.h
+marshal.$(OBJEXT): {$(VPATH)}vm_debug.h
 marshal.$(OBJEXT): {$(VPATH)}vm_opts.h
+marshal.$(OBJEXT): {$(VPATH)}vm_sync.h
 math.$(OBJEXT): $(hdrdir)/ruby/ruby.h
 math.$(OBJEXT): $(top_srcdir)/internal/bignum.h
 math.$(OBJEXT): $(top_srcdir)/internal/class.h
@@ -10664,6 +10680,7 @@ object.$(OBJEXT): {$(VPATH)}backward/2/stdarg.h
 object.$(OBJEXT): {$(VPATH)}builtin.h
 object.$(OBJEXT): {$(VPATH)}config.h
 object.$(OBJEXT): {$(VPATH)}constant.h
+object.$(OBJEXT): {$(VPATH)}debug_counter.h
 object.$(OBJEXT): {$(VPATH)}defines.h
 object.$(OBJEXT): {$(VPATH)}encoding.h
 object.$(OBJEXT): {$(VPATH)}id.h
@@ -10839,7 +10856,9 @@ object.$(OBJEXT): {$(VPATH)}thread_native.h
 object.$(OBJEXT): {$(VPATH)}util.h
 object.$(OBJEXT): {$(VPATH)}variable.h
 object.$(OBJEXT): {$(VPATH)}vm_core.h
+object.$(OBJEXT): {$(VPATH)}vm_debug.h
 object.$(OBJEXT): {$(VPATH)}vm_opts.h
+object.$(OBJEXT): {$(VPATH)}vm_sync.h
 pack.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h
 pack.$(OBJEXT): $(CCAN_DIR)/container_of/container_of.h
 pack.$(OBJEXT): $(CCAN_DIR)/list/list.h
@@ -12440,6 +12459,7 @@ proc.$(OBJEXT): {$(VPATH)}backward/2/stdalign.h
 proc.$(OBJEXT): {$(VPATH)}backward/2/stdarg.h
 proc.$(OBJEXT): {$(VPATH)}config.h
 proc.$(OBJEXT): {$(VPATH)}constant.h
+proc.$(OBJEXT): {$(VPATH)}debug_counter.h
 proc.$(OBJEXT): {$(VPATH)}defines.h
 proc.$(OBJEXT): {$(VPATH)}encoding.h
 proc.$(OBJEXT): {$(VPATH)}eval_intern.h
@@ -12611,7 +12631,9 @@ proc.$(OBJEXT): {$(VPATH)}subst.h
 proc.$(OBJEXT): {$(VPATH)}thread_$(THREAD_MODEL).h
 proc.$(OBJEXT): {$(VPATH)}thread_native.h
 proc.$(OBJEXT): {$(VPATH)}vm_core.h
+proc.$(OBJEXT): {$(VPATH)}vm_debug.h
 proc.$(OBJEXT): {$(VPATH)}vm_opts.h
+proc.$(OBJEXT): {$(VPATH)}vm_sync.h
 proc.$(OBJEXT): {$(VPATH)}yjit.h
 process.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h
 process.$(OBJEXT): $(CCAN_DIR)/container_of/container_of.h
@@ -15299,9 +15321,11 @@ rjit_c.$(OBJEXT): {$(VPATH)}thread_$(THREAD_MODEL).h
 rjit_c.$(OBJEXT): {$(VPATH)}thread_native.h
 rjit_c.$(OBJEXT): {$(VPATH)}vm_callinfo.h
 rjit_c.$(OBJEXT): {$(VPATH)}vm_core.h
+rjit_c.$(OBJEXT): {$(VPATH)}vm_debug.h
 rjit_c.$(OBJEXT): {$(VPATH)}vm_exec.h
 rjit_c.$(OBJEXT): {$(VPATH)}vm_insnhelper.h
 rjit_c.$(OBJEXT): {$(VPATH)}vm_opts.h
+rjit_c.$(OBJEXT): {$(VPATH)}vm_sync.h
 rjit_c.$(OBJEXT): {$(VPATH)}yjit.h
 ruby-runner.$(OBJEXT): {$(VPATH)}config.h
 ruby-runner.$(OBJEXT): {$(VPATH)}internal/compiler_is.h
@@ -17168,6 +17192,7 @@ struct.$(OBJEXT): {$(VPATH)}backward/2/stdarg.h
 struct.$(OBJEXT): {$(VPATH)}builtin.h
 struct.$(OBJEXT): {$(VPATH)}config.h
 struct.$(OBJEXT): {$(VPATH)}constant.h
+struct.$(OBJEXT): {$(VPATH)}debug_counter.h
 struct.$(OBJEXT): {$(VPATH)}defines.h
 struct.$(OBJEXT): {$(VPATH)}encoding.h
 struct.$(OBJEXT): {$(VPATH)}id.h
@@ -17337,7 +17362,9 @@ struct.$(OBJEXT): {$(VPATH)}subst.h
 struct.$(OBJEXT): {$(VPATH)}thread_$(THREAD_MODEL).h
 struct.$(OBJEXT): {$(VPATH)}thread_native.h
 struct.$(OBJEXT): {$(VPATH)}vm_core.h
+struct.$(OBJEXT): {$(VPATH)}vm_debug.h
 struct.$(OBJEXT): {$(VPATH)}vm_opts.h
+struct.$(OBJEXT): {$(VPATH)}vm_sync.h
 symbol.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h
 symbol.$(OBJEXT): $(CCAN_DIR)/container_of/container_of.h
 symbol.$(OBJEXT): $(CCAN_DIR)/list/list.h
@@ -19052,6 +19079,7 @@ vm_backtrace.$(OBJEXT): {$(VPATH)}backward/2/stdarg.h
 vm_backtrace.$(OBJEXT): {$(VPATH)}config.h
 vm_backtrace.$(OBJEXT): {$(VPATH)}constant.h
 vm_backtrace.$(OBJEXT): {$(VPATH)}debug.h
+vm_backtrace.$(OBJEXT): {$(VPATH)}debug_counter.h
 vm_backtrace.$(OBJEXT): {$(VPATH)}defines.h
 vm_backtrace.$(OBJEXT): {$(VPATH)}encoding.h
 vm_backtrace.$(OBJEXT): {$(VPATH)}eval_intern.h
@@ -19223,7 +19251,9 @@ vm_backtrace.$(OBJEXT): {$(VPATH)}thread_$(THREAD_MODEL).h
 vm_backtrace.$(OBJEXT): {$(VPATH)}thread_native.h
 vm_backtrace.$(OBJEXT): {$(VPATH)}vm_backtrace.c
 vm_backtrace.$(OBJEXT): {$(VPATH)}vm_core.h
+vm_backtrace.$(OBJEXT): {$(VPATH)}vm_debug.h
 vm_backtrace.$(OBJEXT): {$(VPATH)}vm_opts.h
+vm_backtrace.$(OBJEXT): {$(VPATH)}vm_sync.h
 vm_dump.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h
 vm_dump.$(OBJEXT): $(CCAN_DIR)/container_of/container_of.h
 vm_dump.$(OBJEXT): $(CCAN_DIR)/list/list.h
@@ -19840,7 +19870,9 @@ vm_trace.$(OBJEXT): {$(VPATH)}thread_$(THREAD_MODEL).h
 vm_trace.$(OBJEXT): {$(VPATH)}thread_native.h
 vm_trace.$(OBJEXT): {$(VPATH)}trace_point.rbinc
 vm_trace.$(OBJEXT): {$(VPATH)}vm_core.h
+vm_trace.$(OBJEXT): {$(VPATH)}vm_debug.h
 vm_trace.$(OBJEXT): {$(VPATH)}vm_opts.h
+vm_trace.$(OBJEXT): {$(VPATH)}vm_sync.h
 vm_trace.$(OBJEXT): {$(VPATH)}vm_trace.c
 vm_trace.$(OBJEXT): {$(VPATH)}yjit.h
 weakmap.$(OBJEXT): $(CCAN_DIR)/check_type/check_type.h

ext/objspace/depend

@@ -378,6 +378,7 @@ objspace.o: $(top_srcdir)/ccan/container_of/container_of.h
 objspace.o: $(top_srcdir)/ccan/list/list.h
 objspace.o: $(top_srcdir)/ccan/str/str.h
 objspace.o: $(top_srcdir)/constant.h
+objspace.o: $(top_srcdir)/debug_counter.h
 objspace.o: $(top_srcdir)/id_table.h
 objspace.o: $(top_srcdir)/internal.h
 objspace.o: $(top_srcdir)/internal/array.h
@@ -402,7 +403,9 @@ objspace.o: $(top_srcdir)/shape.h
 objspace.o: $(top_srcdir)/symbol.h
 objspace.o: $(top_srcdir)/thread_pthread.h
 objspace.o: $(top_srcdir)/vm_core.h
+objspace.o: $(top_srcdir)/vm_debug.h
 objspace.o: $(top_srcdir)/vm_opts.h
+objspace.o: $(top_srcdir)/vm_sync.h
 objspace.o: objspace.c
 objspace.o: {$(VPATH)}id.h
 objspace_dump.o: $(RUBY_EXTCONF_H)
@@ -613,7 +616,9 @@ objspace_dump.o: $(top_srcdir)/symbol.h
 objspace_dump.o: $(top_srcdir)/thread_pthread.h
 objspace_dump.o: $(top_srcdir)/vm_callinfo.h
 objspace_dump.o: $(top_srcdir)/vm_core.h
+objspace_dump.o: $(top_srcdir)/vm_debug.h
 objspace_dump.o: $(top_srcdir)/vm_opts.h
+objspace_dump.o: $(top_srcdir)/vm_sync.h
 objspace_dump.o: objspace.h
 objspace_dump.o: objspace_dump.c
 objspace_dump.o: {$(VPATH)}id.h

gc.c

@@ -10608,8 +10608,10 @@ gc_update_object_references(rb_objspace_t *objspace, VALUE obj)
         update_cvc_tbl(objspace, obj);
         update_superclasses(objspace, obj);
 
-        for (attr_index_t i = 0; i < RCLASS_IV_COUNT(obj); i++) {
+        if (!rb_shape_obj_too_complex(obj)) {
-            UPDATE_IF_MOVED(objspace, RCLASS_IVPTR(obj)[i]);
+            for (attr_index_t i = 0; i < RCLASS_IV_COUNT(obj); i++) {
+                UPDATE_IF_MOVED(objspace, RCLASS_IVPTR(obj)[i]);
+            }
         }
 
         update_class_ext(objspace, RCLASS_EXT(obj));

internal/class.h

@@ -19,6 +19,7 @@
 #include "shape.h"
 #include "ruby_assert.h"
 #include "vm_core.h"
+#include "vm_sync.h"
 #include "method.h"             /* for rb_cref_t */
 
 #ifdef RCLASS_SUPER
@@ -111,6 +112,44 @@ struct RClass_and_rb_classext_t {
 #define RCLASS_SUPERCLASSES_INCLUDE_SELF FL_USER2
 #define RICLASS_ORIGIN_SHARED_MTBL FL_USER3
 
+static inline st_table *
+RCLASS_IV_HASH(VALUE obj)
+{
+    RUBY_ASSERT(RB_TYPE_P(obj, RUBY_T_CLASS) || RB_TYPE_P(obj, RUBY_T_MODULE));
+    RUBY_ASSERT(rb_shape_obj_too_complex(obj));
+    return (st_table *)RCLASS_IVPTR(obj);
+}
+
+static inline void
+RCLASS_SET_IV_HASH(VALUE obj, const st_table *tbl)
+{
+    RUBY_ASSERT(RB_TYPE_P(obj, RUBY_T_CLASS) || RB_TYPE_P(obj, RUBY_T_MODULE));
+    RUBY_ASSERT(rb_shape_obj_too_complex(obj));
+    RCLASS_IVPTR(obj) = (VALUE *)tbl;
+}
+
+static inline uint32_t
+RCLASS_IV_COUNT(VALUE obj)
+{
+    RUBY_ASSERT(RB_TYPE_P(obj, RUBY_T_CLASS) || RB_TYPE_P(obj, RUBY_T_MODULE));
+    if (rb_shape_obj_too_complex(obj)) {
+        uint32_t count;
+
+        // "Too complex" classes could have their IV hash mutated in
+        // parallel, so lets lock around getting the hash size.
+        RB_VM_LOCK_ENTER();
+        {
+            count = (uint32_t)rb_st_table_size(RCLASS_IV_HASH(obj));
+        }
+        RB_VM_LOCK_LEAVE();
+
+        return count;
+    }
+    else {
+        return rb_shape_get_shape_by_id(RCLASS_SHAPE_ID(obj))->next_iv_index;
+    }
+}
+
 /* class.c */
 void rb_class_subclass_add(VALUE super, VALUE klass);
 void rb_class_remove_from_super_subclasses(VALUE);

shape.h

@@ -213,14 +213,6 @@ RBASIC_IV_COUNT(VALUE obj)
     return rb_shape_get_shape_by_id(rb_shape_get_shape_id(obj))->next_iv_index;
 }
 
-static inline uint32_t
-RCLASS_IV_COUNT(VALUE obj)
-{
-    RUBY_ASSERT(RB_TYPE_P(obj, RUBY_T_CLASS) || RB_TYPE_P(obj, RUBY_T_MODULE));
-    uint32_t ivc = rb_shape_get_shape_by_id(RCLASS_SHAPE_ID(obj))->next_iv_index;
-    return ivc;
-}
-
 rb_shape_t *rb_shape_traverse_from_new_root(rb_shape_t *initial_shape, rb_shape_t *orig_shape);
 
 bool rb_shape_set_shape_id(VALUE obj, shape_id_t shape_id);

variable.c

@@ -63,22 +63,6 @@ static void setup_const_entry(rb_const_entry_t *, VALUE, VALUE, rb_const_flag_t)
 static VALUE rb_const_search(VALUE klass, ID id, int exclude, int recurse, int visibility);
 static st_table *generic_iv_tbl_;
 
-static inline st_table *
-RCLASS_IV_HASH(VALUE obj)
-{
-    RUBY_ASSERT(RB_TYPE_P(obj, RUBY_T_CLASS) || RB_TYPE_P(obj, RUBY_T_MODULE));
-    RUBY_ASSERT(rb_shape_obj_too_complex(obj));
-    return (st_table *)RCLASS_IVPTR(obj);
-}
-
-static inline void
-RCLASS_SET_IV_HASH(VALUE obj, const st_table *tbl)
-{
-    RUBY_ASSERT(RB_TYPE_P(obj, RUBY_T_CLASS) || RB_TYPE_P(obj, RUBY_T_MODULE));
-    RUBY_ASSERT(rb_shape_obj_too_complex(obj));
-    RCLASS_IVPTR(obj) = (VALUE *)tbl;
-}
-
 void
 Init_var_tables(void)
 {

yjit/src/cruby_bindings.inc.rs

@@ -983,6 +983,7 @@ extern "C" {
     pub fn rb_gvar_get(arg1: ID) -> VALUE;
     pub fn rb_gvar_set(arg1: ID, arg2: VALUE) -> VALUE;
     pub fn rb_ensure_iv_list_size(obj: VALUE, len: u32, newsize: u32);
+    pub fn rb_vm_barrier();
     pub fn rb_obj_as_string_result(str_: VALUE, obj: VALUE) -> VALUE;
     pub fn rb_str_concat_literals(num: usize, strary: *const VALUE) -> VALUE;
     pub fn rb_ec_str_resurrect(ec: *mut rb_execution_context_struct, str_: VALUE) -> VALUE;
@@ -1005,7 +1006,6 @@ extern "C" {
     pub fn rb_iseq_line_no(iseq: *const rb_iseq_t, pos: usize) -> ::std::os::raw::c_uint;
     pub fn rb_iseqw_to_iseq(iseqw: VALUE) -> *const rb_iseq_t;
     pub fn rb_iseq_label(iseq: *const rb_iseq_t) -> VALUE;
-    pub fn rb_vm_barrier();
     pub fn rb_profile_frames(
         start: ::std::os::raw::c_int,
         limit: ::std::os::raw::c_int,