From f70b894b8829c064e39646c9b5f6d304d13bb16d Mon Sep 17 00:00:00 2001
From: Koichi Sasada <ko1@atdot.net>
Date: Sun, 20 Dec 2020 03:23:41 +0900
Subject: [PATCH] sync RCLASS_CONST_TBL()

RCLASS_CONST_TBL() is shared resource so we need to sync with
other ractors.
---
 variable.c | 91 +++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 62 insertions(+), 29 deletions(-)

diff --git a/variable.c b/variable.c
index 3b1462b9de..b780446f19 100644
--- a/variable.c
+++ b/variable.c
@@ -2349,7 +2349,13 @@ autoload_const_set(struct autoload_const *ac)
     VALUE klass = ac->mod;
     ID id = ac->id;
     check_before_mod_set(klass, id, ac->value, "constant");
-    const_tbl_update(ac);
+
+    RB_VM_LOCK_ENTER();
+    {
+        const_tbl_update(ac);
+    }
+    RB_VM_LOCK_LEAVE();
+
     return 0;			/* ignored */
 }
 
@@ -2782,8 +2788,13 @@ rb_local_constants(VALUE mod)
 
     if (!tbl) return rb_ary_new2(0);
 
-    ary = rb_ary_new2(rb_id_table_size(tbl));
-    rb_id_table_foreach(tbl, rb_local_constants_i, (void *)ary);
+    RB_VM_LOCK_ENTER();
+    {
+        ary = rb_ary_new2(rb_id_table_size(tbl));
+        rb_id_table_foreach(tbl, rb_local_constants_i, (void *)ary);
+    }
+    RB_VM_LOCK_LEAVE();
+
     return ary;
 }
 
@@ -2795,7 +2806,11 @@ rb_mod_const_at(VALUE mod, void *data)
 	tbl = st_init_numtable();
     }
     if (RCLASS_CONST_TBL(mod)) {
-	rb_id_table_foreach(RCLASS_CONST_TBL(mod), sv_i, tbl);
+        RB_VM_LOCK_ENTER();
+        {
+            rb_id_table_foreach(RCLASS_CONST_TBL(mod), sv_i, tbl);
+        }
+        RB_VM_LOCK_LEAVE();
     }
     return tbl;
 }
@@ -2971,20 +2986,24 @@ static void
 set_namespace_path(VALUE named_namespace, VALUE namespace_path)
 {
     struct rb_id_table *const_table = RCLASS_CONST_TBL(named_namespace);
-    if (!RCLASS_IV_TBL(named_namespace)) {
-        RCLASS_IV_TBL(named_namespace) = st_init_numtable();
-    }
-    rb_class_ivar_set(named_namespace, classpath, namespace_path);
-    if (const_table) {
-        rb_id_table_foreach(const_table, set_namespace_path_i, &namespace_path);
+
+    RB_VM_LOCK_ENTER();
+    {
+        if (!RCLASS_IV_TBL(named_namespace)) {
+            RCLASS_IV_TBL(named_namespace) = st_init_numtable();
+        }
+        rb_class_ivar_set(named_namespace, classpath, namespace_path);
+        if (const_table) {
+            rb_id_table_foreach(const_table, set_namespace_path_i, &namespace_path);
+        }
     }
+    RB_VM_LOCK_LEAVE();
 }
 
 void
 rb_const_set(VALUE klass, ID id, VALUE val)
 {
     rb_const_entry_t *ce;
-    struct rb_id_table *tbl = RCLASS_CONST_TBL(klass);
 
     if (NIL_P(klass)) {
 	rb_raise(rb_eTypeError, "no class/module to define constant %"PRIsVALUE"",
@@ -2996,21 +3015,28 @@ rb_const_set(VALUE klass, ID id, VALUE val)
     }
 
     check_before_mod_set(klass, id, val, "constant");
-    if (!tbl) {
-	RCLASS_CONST_TBL(klass) = tbl = rb_id_table_create(0);
-	rb_clear_constant_cache();
-	ce = ZALLOC(rb_const_entry_t);
-	rb_id_table_insert(tbl, id, (VALUE)ce);
-	setup_const_entry(ce, klass, val, CONST_PUBLIC);
-    }
-    else {
-        struct autoload_const ac = {
-            .mod = klass, .id = id,
-            .value = val, .flag = CONST_PUBLIC,
-            /* fill the rest with 0 */
-        };
-	const_tbl_update(&ac);
+
+    RB_VM_LOCK_ENTER();
+    {
+        struct rb_id_table *tbl = RCLASS_CONST_TBL(klass);
+        if (!tbl) {
+            RCLASS_CONST_TBL(klass) = tbl = rb_id_table_create(0);
+            rb_clear_constant_cache();
+            ce = ZALLOC(rb_const_entry_t);
+            rb_id_table_insert(tbl, id, (VALUE)ce);
+            setup_const_entry(ce, klass, val, CONST_PUBLIC);
+        }
+        else {
+            struct autoload_const ac = {
+                .mod = klass, .id = id,
+                .value = val, .flag = CONST_PUBLIC,
+                /* fill the rest with 0 */
+            };
+            const_tbl_update(&ac);
+        }
     }
+    RB_VM_LOCK_LEAVE();
+
     /*
      * Resolve and cache class name immediately to resolve ambiguity
      * and avoid order-dependency on const_tbl
@@ -3589,10 +3615,17 @@ MJIT_FUNC_EXPORTED rb_const_entry_t *
 rb_const_lookup(VALUE klass, ID id)
 {
     struct rb_id_table *tbl = RCLASS_CONST_TBL(klass);
-    VALUE val;
 
-    if (tbl && rb_id_table_lookup(tbl, id, &val)) {
-	return (rb_const_entry_t *)val;
+    if (tbl) {
+        VALUE val;
+        bool r;
+        RB_VM_LOCK_ENTER();
+        {
+            r = rb_id_table_lookup(tbl, id, &val);
+        }
+        RB_VM_LOCK_LEAVE();
+
+        if (r) return (rb_const_entry_t *)val;
     }
-    return 0;
+    return NULL;
 }