[ruby-dev:14748] Re: [BUG] $_ on thread switching

なかだです。

At Sat, 8 Sep 2001 04:39:07 +0900,
[e-mail] (Yukihiro Matsumoto) wrote:
> その後、歯磨きしながら考えてたら、以下のパッチで直りそうです。
> 駆け込みでやや不安なのですが。

　残念ながら完全ではないようです。子スレッドから関数を読んだ中
でスイッチすると、元の$_には書き戻せません。

$ cat bug.rb
def foo(t)
  p [:foo, $_ = "foo", Thread.current]
  t.run
end

p [:main, $_ = "main", Thread.current]

t = Thread.new do
  p [:sub, $_ = "sub", Thread.current]
  Thread.stop
  foo(Thread.main)
end
foo(t)
Thread.stop
p [:main, $_, Thread.current]

$ ./miniruby bug.rb
[:main, "main", #<Thread:0x401e1140 run>]
[:sub, "sub", #<Thread:0x401d79ec run>]
[:foo, "foo", #<Thread:0x401e1140 run>]
[:foo, "foo", #<Thread:0x401d79ec run>]
[:main, "sub", #<Thread:0x401e1140 run>]

　一応[ruby-dev:14747]で書いた案のパッチをつけます。これもやっ
ぱり完全ではなくて、make testでエラーが出るんですが、どこから出
てるのがよく分かりません。

$ make test
-e:1:in `sub': $_ value need to be String (nil given) (TypeError)
        from -e:1
test succeeded


Index: env.h
===================================================================
RCS file: /cvs/ruby/src/ruby/env.h,v
retrieving revision 1.7
diff -u -2 -p -r1.7 env.h
--- env.h	2001/02/14 05:51:57	1.7
+++ env.h	2001/09/07 19:42:33
@@ -14,8 +14,15 @@
 #define ENV_H
 
+enum framevar_type {
+    fvar_lastline,
+    fvar_backref,
+    framevar_last
+};
+
 extern struct FRAME {
     VALUE self;
     int argc;
     VALUE *argv;
+    VALUE fvars[framevar_last];
     ID last_func;
     VALUE last_class;
Index: eval.c
===================================================================
RCS file: /cvs/ruby/src/ruby/eval.c,v
retrieving revision 1.202
diff -u -2 -p -r1.202 eval.c
--- eval.c	2001/09/03 05:37:42	1.202
+++ eval.c	2001/09/07 20:34:13
@@ -510,4 +510,8 @@ static struct FRAME *top_frame;
 static struct SCOPE *top_scope;
 
+#define INIT_FVARS(f) {			\
+    (f)->fvars[fvar_lastline] = Qnil;	\
+    (f)->fvars[fvar_backref] = Qnil;	\
+}
 #define PUSH_FRAME() {			\
     struct FRAME _frame;		\
@@ -520,4 +524,5 @@ static struct SCOPE *top_scope;
     _frame.argc = 0;			\
     _frame.argv = 0;			\
+    INIT_FVARS(&_frame);		\
     _frame.flags = FRAME_ALLOCA;	\
     ruby_frame = &_frame;		\
@@ -1041,4 +1046,5 @@ ruby_init()
 	ruby_cref = top_cref;
 	ruby_frame->cbase = (VALUE)ruby_cref;
+	INIT_FVARS(ruby_frame);
 	rb_define_global_const("TOPLEVEL_BINDING", rb_f_binding(ruby_top_self));
 #ifdef __MACOS__
@@ -1709,5 +1715,5 @@ copy_node_scope(node, rval)
 }
 
-#define MATCH_DATA ruby_scope->local_vars[node->nd_cnt]
+#define MATCH_DATA ruby_frame->fvars[fvar_backref]
 
 static char* is_defined _((VALUE, NODE*, char*));
@@ -4519,11 +4525,10 @@ rb_call0(klass, recv, id, argc, argv, bo
 			}
 			ruby_frame->argc = opt;
-			ruby_frame->argv = local_vars+2;
+			ruby_frame->argv = local_vars;
 		    }
 
 		    if (local_vars) {
 			if (i > 0) {
-			    /* +2 for $_ and $~ */
-			    MEMCPY(local_vars+2, argv, VALUE, i);
+			    MEMCPY(local_vars, argv, VALUE, i);
 			}
 			argv += i; argc -= i;
@@ -5852,5 +5857,5 @@ rb_f_local_variables()
     if (tbl) {
 	n = *tbl++;
-	for (i=2; i<n; i++) {	/* skip first 2 ($_ and $~) */
+	for (i=0; i<n; i++) {
 	    if (tbl[i] == 0) continue;  /* skip flip states */
 	    rb_ary_push(ary, rb_str_new2(rb_id2name(tbl[i])));
Index: gc.c
===================================================================
RCS file: /cvs/ruby/src/ruby/gc.c,v
retrieving revision 1.72
diff -u -2 -p -r1.72 gc.c
--- gc.c	2001/07/20 15:19:28	1.72
+++ gc.c	2001/09/07 20:08:15
@@ -908,4 +908,5 @@ rb_gc_mark_frame(frame)
 {
     mark_locations_array(frame->argv, frame->argc);
+    mark_locations_array(frame->fvars, framevar_last);
     rb_gc_mark(frame->cbase);
 }
Index: parse.y
===================================================================
RCS file: /cvs/ruby/src/ruby/parse.y,v
retrieving revision 1.119
diff -u -2 -p -r1.119 parse.y
--- parse.y	2001/09/05 06:54:53	1.119
+++ parse.y	2001/09/07 20:29:54
@@ -3587,5 +3587,4 @@ yylex()
 	    /* fall through */
 	  case '~':		/* $~: match-data */
-	    local_cnt(c);
 	    /* fall through */
 	  case '*':		/* $*: argv */
@@ -4122,6 +4121,4 @@ match_gen(node1, node2)
     NODE *node2;
 {
-    local_cnt('~');
-
     switch (nd_type(node1)) {
       case NODE_DREGX:
@@ -4612,6 +4609,4 @@ cond0(node)
       case NODE_DREGX_ONCE:
 	warning_unless_e_option("regex literal in condition");
-	local_cnt('_');
-	local_cnt('~');
 	return NEW_MATCH2(node, NEW_GVAR(rb_intern("$_")));
 
@@ -4636,6 +4631,4 @@ cond0(node)
 	    warn_unless_e_option("regex literal in condition");
 	    nd_set_type(node, NODE_MATCH);
-	    local_cnt('_');
-	    local_cnt('~');
 	}
 	else {
@@ -4795,11 +4788,7 @@ local_append(id)
 {
     if (lvtbl->tbl == 0) {
-	lvtbl->tbl = ALLOC_N(ID, 4);
+	lvtbl->tbl = ALLOC_N(ID, 2);
 	lvtbl->tbl[0] = 0;
-	lvtbl->tbl[1] = '_';
-	lvtbl->tbl[2] = '~';
-	lvtbl->cnt = 2;
-	if (id == '_') return 0;
-	if (id == '~') return 1;
+	lvtbl->cnt = 0;
     }
     else {
@@ -4832,5 +4821,5 @@ local_id(id)
 
     if (lvtbl == 0) return Qfalse;
-    for (i=3, max=lvtbl->cnt+1; i<max; i++) {
+    for (i=1, max=lvtbl->cnt+1; i<max; i++) {
 	if (lvtbl->tbl[i] == id) return Qtrue;
     }
@@ -5164,24 +5153,8 @@ rb_is_instance_id(id)
 }
 
-static void
-special_local_set(c, val)
-    char c;
-    VALUE val;
-{
-    int cnt;
-
-    top_local_init();
-    cnt = local_cnt(c);
-    top_local_setup();
-    ruby_scope->local_vars[cnt] = val;
-}
-
 VALUE
 rb_backref_get()
 {
-    if (ruby_scope->local_vars) {
-	return ruby_scope->local_vars[1];
-    }
-    return Qnil;
+    return ruby_frame->fvars[fvar_backref];
 }
 
@@ -5190,10 +5163,5 @@ rb_backref_set(val)
     VALUE val;
 {
-    if (ruby_scope->local_vars) {
-	ruby_scope->local_vars[1] = val;
-    }
-    else {
-	special_local_set('~', val);
-    }
+    ruby_frame->fvars[fvar_backref] = val;
 }
 
@@ -5201,8 +5169,5 @@ VALUE
 rb_lastline_get()
 {
-    if (ruby_scope->local_vars) {
-	return ruby_scope->local_vars[0];
-    }
-    return Qnil;
+    return ruby_frame->fvars[fvar_lastline];
 }
 
@@ -5211,9 +5176,4 @@ rb_lastline_set(val)
     VALUE val;
 {
-    if (ruby_scope->local_vars) {
-	ruby_scope->local_vars[0] = val;
-    }
-    else {
-	special_local_set('_', val);
-    }
+    ruby_frame->fvars[fvar_lastline] = val;
 }


-- 
--- 僕の前にBugはない。
--- 僕の後ろにBugはできる。
    中田 伸悦