* vm_method.c (rb_unlink_method_entry, rb_sweep_method_entry):

  added.  Unlinked method entries are collected to
  vm->unlinked_method_entry_list.  On the GC timing, mark all method
  entries which are on all living threads.  Only non-marked method
  entries are collected.  This hack prevents releasing living method
  entry.
  [Performance Consideration] Since this Method Entry GC (MEGC)
  doesn't occuer frequently, MEGC will not be a performance bottleneck.
  However, to traverse living method entries, every control frame push
  needs to clear cfp->me field.  This will be a performance issue
  (because pushing control frame is occurred frequently).
  Bug #2777 [ruby-dev:40457]
* cont.c (fiber_init): init cfp->me.
* gc.c (garbage_collect): kick rb_sweep_method_entry().
* method.h (rb_method_entry_t): add a mark field.
* vm.c (invoke_block_from_c): set passed me.
* vm.c (rb_thread_mark): mark cfp->me.
* vm_core.h (rb_thread_t): add a field passed_me.
* vm_core.h (rb_vm_t): add a field unlinked_method_entry_list.
* vm_insnhelper.c (vm_push_frame): clear cfp->me at all times.
* vm_insnhelper.c (vm_call_bmethod): pass me.
* bootstraptest/test_method.rb: add a test.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27634 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

10 files changed, 122 insertions, 23 deletions

diff --git a/ChangeLog b/ChangeLog
index 542b7a0fee..0dc39f10e0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,38 @@
+Thu May  6 02:16:48 2010  Koichi Sasada  <ko1@atdot.net>
+
+	* vm_method.c (rb_unlink_method_entry, rb_sweep_method_entry):
+	  added.  Unlinked method entries are collected to
+	  vm->unlinked_method_entry_list.  On the GC timing, mark all method
+	  entries which are on all living threads.  Only non-marked method
+	  entries are collected.  This hack prevents releasing living method
+	  entry.
+	  [Performance Consideration] Since this Method Entry GC (MEGC)
+	  doesn't occuer frequently, MEGC will not be a performance bottleneck.
+	  However, to traverse living method entries, every control frame push
+	  needs to clear cfp->me field.  This will be a performance issue
+	  (because pushing control frame is occurred frequently).
+	  Bug #2777 [ruby-dev:40457]
+
+	* cont.c (fiber_init): init cfp->me.
+
+	* gc.c (garbage_collect): kick rb_sweep_method_entry().
+
+	* method.h (rb_method_entry_t): add a mark field.
+
+	* vm.c (invoke_block_from_c): set passed me.
+
+	* vm.c (rb_thread_mark): mark cfp->me.
+
+	* vm_core.h (rb_thread_t): add a field passed_me.
+
+	* vm_core.h (rb_vm_t): add a field unlinked_method_entry_list.
+
+	* vm_insnhelper.c (vm_push_frame): clear cfp->me at all times.
+
+	* vm_insnhelper.c (vm_call_bmethod): pass me.
+
+	* bootstraptest/test_method.rb: add a test.
+
 Wed May  5 22:22:51 2010  wanabe  <s.wanabe@gmail.com>
 
 	* compile.c (iseq_set_sequence): fix check range of ic_index.
diff --git a/bootstraptest/test_method.rb b/bootstraptest/test_method.rb
index 2ce66f6a6a..f57bf6214e 100644
--- a/bootstraptest/test_method.rb
+++ b/bootstraptest/test_method.rb
@@ -1161,3 +1161,17 @@ assert_equal 'ok', %q{
   "hello"[0, 1] ||= "H"
   "ok"
 }
+
+assert_equal 'ok', %q{
+  class C
+    define_method(:foo) do
+      C.class_eval { remove_method(:foo) }
+      super()
+    end
+  end
+  begin
+    C.new.foo
+  rescue NoMethodError
+    'ok'
+  end
+}
diff --git a/cont.c b/cont.c
index 185d8122e4..134cf5d36c 100644
--- a/cont.c
+++ b/cont.c
@@ -771,6 +771,7 @@ fiber_init(VALUE fibval, VALUE proc)
     th->cfp->iseq = 0;
     th->cfp->proc = 0;
     th->cfp->block_iseq = 0;
+    th->cfp->me = 0;
     th->tag = 0;
     th->local_storage = st_init_numtable();
 
diff --git a/gc.c b/gc.c
index 283a5bcf28..b88450d0e6 100644
--- a/gc.c
+++ b/gc.c
@@ -2205,6 +2205,11 @@ garbage_collect(rb_objspace_t *objspace)
     gc_sweep(objspace);
     GC_PROF_SWEEP_TIMER_STOP;
 
+    /* sweep unlinked method entries */
+    if (th->vm->unlinked_method_entry_list) {
+	rb_sweep_method_entry(th->vm);
+    }
+
     GC_PROF_TIMER_STOP;
     if (GC_NOTIFY) printf("end garbage_collect()\n");
     return TRUE;
diff --git a/method.h b/method.h
index 98b89f8cf7..e03f0d2357 100644
--- a/method.h
+++ b/method.h
@@ -74,11 +74,17 @@ typedef struct rb_method_definition_struct {
 
 typedef struct rb_method_entry_struct {
     rb_method_flag_t flag;
+    char mark;
     rb_method_definition_t *def;
     ID called_id;
     VALUE klass;                    /* should be mark */
 } rb_method_entry_t;
 
+struct unlinked_method_entry_list_entry {
+    struct unlinked_method_entry_list_entry *next;
+    rb_method_entry_t *me;
+};
+
 #define UNDEFINED_METHOD_ENTRY_P(me) (!(me) || !(me)->def || (me)->def->type == VM_METHOD_TYPE_UNDEF)
 
 void rb_add_method_cfunc(VALUE klass, ID mid, VALUE (*func)(ANYARGS), int argc, rb_method_flag_t noex);
@@ -92,5 +98,6 @@ int rb_method_entry_arity(const rb_method_entry_t *me);
 
 void rb_mark_method_entry(const rb_method_entry_t *me);
 void rb_free_method_entry(rb_method_entry_t *me);
+void rb_sweep_method_entry(void *vm);
 
 #endif /* METHOD_H */
diff --git a/version.h b/version.h
index 34256b280f..0de1439a0a 100644
--- a/version.h
+++ b/version.h
@@ -1,5 +1,5 @@
 #define RUBY_VERSION "1.9.2"
-#define RUBY_RELEASE_DATE "2010-05-05"
+#define RUBY_RELEASE_DATE "2010-05-06"
 #define RUBY_PATCHLEVEL -1
 #define RUBY_BRANCH_NAME "trunk"
 
@@ -8,7 +8,7 @@
 #define RUBY_VERSION_TEENY 1
 #define RUBY_RELEASE_YEAR 2010
 #define RUBY_RELEASE_MONTH 5
-#define RUBY_RELEASE_DAY 5
+#define RUBY_RELEASE_DAY 6
 
 #include "ruby/version.h"
 
diff --git a/vm.c b/vm.c
index 3a1e37f9ff..e7c9a33df5 100644
--- a/vm.c
+++ b/vm.c
@@ -528,6 +528,7 @@ invoke_block_from_c(rb_thread_t *th, const rb_block_t *block,
     else if (BUILTIN_TYPE(block->iseq) != T_NODE) {
 	const rb_iseq_t *iseq = block->iseq;
 	const rb_control_frame_t *cfp;
+	rb_control_frame_t *ncfp;
 	int i, opt_pc, arg_size = iseq->arg_size;
 	int type = block_proc_is_lambda(block->proc) ?
 	  VM_FRAME_MAGIC_LAMBDA : VM_FRAME_MAGIC_BLOCK;
@@ -544,10 +545,12 @@ invoke_block_from_c(rb_thread_t *th, const rb_block_t *block,
 	opt_pc = vm_yield_setup_args(th, iseq, argc, cfp->sp, blockptr,
 				     type == VM_FRAME_MAGIC_LAMBDA);
 
-	vm_push_frame(th, iseq, type,
-		      self, GC_GUARDED_PTR(block->dfp),
-		      iseq->iseq_encoded + opt_pc, cfp->sp + arg_size, block->lfp,
-		      iseq->local_size - arg_size);
+	ncfp = vm_push_frame(th, iseq, type,
+			     self, GC_GUARDED_PTR(block->dfp),
+			     iseq->iseq_encoded + opt_pc, cfp->sp + arg_size, block->lfp,
+			     iseq->local_size - arg_size);
+	ncfp->me = th->passed_me;
+	th->passed_me = 0;
 
 	if (cref) {
 	    th->cfp->dfp[-1] = (VALUE)cref;
@@ -1636,6 +1639,7 @@ rb_thread_mark(void *ptr)
 	    while (cfp != limit_cfp) {
 		rb_gc_mark(cfp->proc);
 		if (cfp->iseq) rb_gc_mark(cfp->iseq->self);
+		if (cfp->me) ((rb_method_entry_t *)cfp->me)->mark = 1;
 		cfp = RUBY_VM_PREVIOUS_CONTROL_FRAME(cfp);
 	    }
 	}
diff --git a/vm_core.h b/vm_core.h
index b5c1bf0ad9..2174613156 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -307,6 +307,8 @@ typedef struct rb_vm_struct {
     VALUE verbose, debug, progname;
     VALUE coverages;
 
+    struct unlinked_method_entry_list_entry *unlinked_method_entry_list;
+
 #if defined(ENABLE_VM_OBJSPACE) && ENABLE_VM_OBJSPACE
     struct rb_objspace *objspace;
 #endif
@@ -387,6 +389,9 @@ typedef struct rb_thread_struct
     /* for rb_iterate */
     const rb_block_t *passed_block;
 
+    /* for bmethod */
+    const rb_method_entry_t *passed_me;
+
     /* for load(true) */
     VALUE top_self;
     VALUE top_wrapper;
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 5051d00e1e..be084b4126 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -59,6 +59,7 @@ vm_push_frame(rb_thread_t * th, const rb_iseq_t * iseq,
     cfp->lfp = lfp;
     cfp->dfp = sp;
     cfp->proc = 0;
+    cfp->me = 0;
 
 #define COLLECT_PROFILE 0
 #if COLLECT_PROFILE
@@ -419,7 +420,7 @@ vm_call_bmethod(rb_thread_t *th, VALUE recv, int argc, const VALUE *argv,
     VALUE val;
 
     /* control block frame */
-    (cfp-2)->me = me;
+    th->passed_me = me;
 
     GetProcPtr(me->def->body.proc, proc);
     val = rb_vm_invoke_proc(th, proc, recv, argc, argv, blockptr);
diff --git a/vm_method.c b/vm_method.c
index 4c3f16000a..69d50d969b 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -126,6 +126,44 @@ rb_add_method_cfunc(VALUE klass, ID mid, VALUE (*func)(ANYARGS), int argc, rb_me
     }
 }
 
+static void
+rb_unlink_method_entry(rb_method_entry_t *me)
+{
+    struct unlinked_method_entry_list_entry *ume = ALLOC(struct unlinked_method_entry_list_entry);
+    ume->me = me;
+    ume->next = GET_VM()->unlinked_method_entry_list;
+    GET_VM()->unlinked_method_entry_list = ume;
+}
+
+void
+rb_sweep_method_entry(void *pvm)
+{
+    rb_vm_t *vm = pvm;
+    struct unlinked_method_entry_list_entry *ume = vm->unlinked_method_entry_list, *prev_ume = 0, *curr_ume;
+
+    while (ume) {
+	if (ume->me->mark) {
+	    ume->me->mark = 0;
+	    prev_ume = ume;
+	    ume = ume->next;
+	}
+	else {
+	    rb_free_method_entry(ume->me);
+
+	    if (prev_ume == 0) {
+		vm->unlinked_method_entry_list = ume->next;
+	    }
+	    else {
+		prev_ume->next = ume->next;
+	    }
+
+	    curr_ume = ume;
+	    ume = ume->next;
+	    xfree(curr_ume);
+	}
+    }
+}
+
 void
 rb_free_method_entry(rb_method_entry_t *me)
 {
@@ -214,26 +252,15 @@ rb_method_entry_make(VALUE klass, ID mid, rb_method_type_t type,
 	    }
 	}
 
-	/* FIXME: this avoid to free methods used in cfp, but reusing may cause
-	 * another problem when the usage is changed.
-	 */
-	me = old_me;
-
-	if (me->def) {
-	    if (me->def->alias_count == 0)
-		xfree(me->def);
-	    else if (me->def->alias_count > 0)
-		me->def->alias_count--;
-	    me->def = 0;
-	}
-    }
-    else {
-	me = ALLOC(rb_method_entry_t);
+	rb_unlink_method_entry(old_me);
     }
 
+    me = ALLOC(rb_method_entry_t);
+
     rb_clear_cache_by_id(mid);
 
     me->flag = NOEX_WITH_SAFE(noex);
+    me->mark = 0;
     me->called_id = mid;
     me->klass = klass;
     me->def = def;
@@ -453,7 +480,7 @@ remove_method(VALUE klass, ID mid)
 
     rb_vm_check_redefinition_opt_method(me);
     rb_clear_cache_for_undef(klass, mid);
-    rb_free_method_entry(me);
+    rb_unlink_method_entry(me);
 
     CALL_METHOD_HOOK(klass, removed, mid);
 }