at_exit list

* vm_core.h (rb_vm_struct): make at_exit a single linked list but
  not RArray, not to mark the registered functions by the write
  barrier.  based on the patches by Evan Phoenix.
  [ruby-core:73908] [Bug #12095]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54484 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Mon Apr  4 23:37:05 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* vm_core.h (rb_vm_struct): make at_exit a single linked list but
+	  not RArray, not to mark the registered functions by the write
+	  barrier.  based on the patches by Evan Phoenix.
+	  [ruby-core:73908] [Bug #12095]
+
 Mon Apr  4 17:43:45 2016  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c: change deafult value of

ext/-test-/vm/at_exit.c

@@ -0,0 +1,44 @@
+#include <ruby/ruby.h>
+#include <ruby/vm.h>
+
+static void
+do_nothing(ruby_vm_t *vm)
+{
+}
+
+static void
+print_begin(ruby_vm_t *vm)
+{
+    printf("begin\n");
+}
+
+static void
+print_end(ruby_vm_t *vm)
+{
+    printf("end\n");
+}
+
+static VALUE
+register_at_exit(VALUE self, VALUE t)
+{
+    switch (t) {
+      case Qtrue:
+	ruby_vm_at_exit(print_begin);
+	break;
+      case Qfalse:
+	ruby_vm_at_exit(print_end);
+	break;
+      default:
+	ruby_vm_at_exit(do_nothing);
+	break;
+    }
+    return self;
+}
+
+void
+Init_at_exit(void)
+{
+    VALUE m = rb_define_module("Bug");
+    VALUE c = rb_define_class_under(m, "VM", rb_cObject);
+    rb_define_singleton_method(c, "register_at_exit", register_at_exit, 1);
+}

ext/-test-/vm/extconf.rb

@@ -0,0 +1 @@
+create_makefile('-test-/vm/at_exit')

test/-ext-/vm/test_at_exit.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: false
+class TestVM < Test::Unit::TestCase
+
+  # [Bug #12095]
+  def test_at_exit
+
+    assert_in_out_err([], <<-"end;", %w[begin end]) # do
+      require '-test-/vm/at_exit'
+      Bug::VM.register_at_exit(false)
+      1000.times do
+        Bug::VM.register_at_exit(nil)
+        ["x"]*1000
+      end
+      GC.start
+      Bug::VM.register_at_exit(true)
+    end;
+  end
+end
+

vm.c

@@ -468,20 +468,25 @@ rb_frame_pop(void)
 void
 ruby_vm_at_exit(void (*func)(rb_vm_t *))
 {
-    rb_ary_push((VALUE)&GET_VM()->at_exit, (VALUE)func);
+    rb_vm_t *vm = GET_VM();
+    rb_at_exit_list *nl = ALLOC(rb_at_exit_list);
+    nl->func = func;
+    nl->next = vm->at_exit;
+    vm->at_exit = nl;
 }
 
 static void
 ruby_vm_run_at_exit_hooks(rb_vm_t *vm)
 {
-    VALUE hook = (VALUE)&vm->at_exit;
+    rb_at_exit_list *l = vm->at_exit;
 
-    while (RARRAY_LEN(hook) > 0) {
-	typedef void rb_vm_at_exit_func(rb_vm_t*);
-	rb_vm_at_exit_func *func = (rb_vm_at_exit_func*)rb_ary_pop(hook);
+    while (l) {
+	rb_at_exit_list* t = l->next;
+	rb_vm_at_exit_func *func = l->func;
+	free(l);
+	l = t;
 	(*func)(vm);
     }
-    rb_ary_free(hook);
 }
 
 /* Env */
@@ -2172,8 +2177,6 @@ vm_init2(rb_vm_t *vm)
     MEMZERO(vm, rb_vm_t, 1);
     rb_vm_living_threads_init(vm);
     vm->src_encoding_index = -1;
-    vm->at_exit.basic.flags = (T_ARRAY | RARRAY_EMBED_FLAG) & ~RARRAY_EMBED_LEN_MASK; /* len set 0 */
-    rb_obj_hide((VALUE)&vm->at_exit);
 
     vm_default_params_setup(vm);
 }

vm_core.h

@@ -462,6 +462,14 @@ enum ruby_basic_operators {
 #define GetVMPtr(obj, ptr) \
   GetCoreDataFromValue((obj), rb_vm_t, (ptr))
 
+struct rb_vm_struct;
+typedef void rb_vm_at_exit_func(struct rb_vm_struct*);
+
+typedef struct rb_at_exit_list {
+    rb_vm_at_exit_func *func;
+    struct rb_at_exit_list *next;
+} rb_at_exit_list;
+
 struct rb_objspace;
 struct rb_objspace *rb_objspace_alloc(void);
 void rb_objspace_free(struct rb_objspace *);
@@ -530,11 +538,7 @@ typedef struct rb_vm_struct {
 
     struct rb_objspace *objspace;
 
-    /*
-     * @shyouhei notes that this is not for storing normal Ruby
-     * objects so do *NOT* mark this when you GC.
-     */
-    struct RArray at_exit;
+    rb_at_exit_list *at_exit;
 
     VALUE *defined_strings;
     st_table *frozen_strings;