* gc.c (rb_objspace_call_finalizer): control GC execution during

  force firnalizations at the end of interpreter process.
  [Bug #10768]
  1) Prohibit incremental GC while running Ruby-level finalizers
     to avoid any danger.
  2) Prohibit GC while invoking T_DATA/T_FILE data structure
     because these operations break object relations consistency.
  This patch can introduce another memory consuming issue because
  Ruby-level finalizers can run after (2), GC is disabled.
  However, basically object consistency was broken at (2) as I
  described above. So that running Ruby-level finalizers contains
  danger originally. Because of this point, I need to suggest to
  remove these 3 lines (invoking remaining finalizers). And add a
  rule to add that finalizers should not add new finalizers, or
  say there is no guarantee to invoke finalizers that added by
  another finalizer.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49684 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 9 insertions, 12 deletions

diff --git a/gc.c b/gc.c
index e35c1664ad..c84da503ea 100644
--- a/gc.c
+++ b/gc.c
@@ -1209,10 +1209,8 @@ static void heap_page_free(rb_objspace_t *objspace, struct heap_page *page);
 void
 rb_objspace_free(rb_objspace_t *objspace)
 {
-#if 0
     if (is_lazy_sweeping(heap_eden))
 	rb_bug("lazy sweeping underway when freeing object space");
-#endif
 
     if (objspace->profile.records) {
 	free(objspace->profile.records);
@@ -2568,6 +2566,10 @@ rb_objspace_call_finalizer(rb_objspace_t *objspace)
     finalize_deferred(objspace);
     assert(heap_pages_deferred_final == 0);
 
+    gc_rest(objspace);
+    /* prohibit incremental GC */
+    objspace->flags.dont_incremental = 1;
+
     /* force to run finalizer */
     while (finalizer_table->num_entries) {
 	struct force_finalize_list *list = 0;
@@ -2582,10 +2584,13 @@ rb_objspace_call_finalizer(rb_objspace_t *objspace)
 	}
     }
 
-    /* finalizers are part of garbage collection */
+    /* prohibit GC because force T_DATA finalizers can break an object graph consistency */
+    dont_gc = 1;
+
+    /* running data/file finalizers are part of garbage collection */
     gc_enter(objspace, "rb_objspace_call_finalizer");
 
-    /* run data object's finalizers */
+    /* run data/file object's finalizers */
     for (i = 0; i < heap_allocated_pages; i++) {
 	p = heap_pages_sorted[i]->start; pend = p + heap_pages_sorted[i]->total_slots;
 	while (p < pend) {
@@ -2625,14 +2630,6 @@ rb_objspace_call_finalizer(rb_objspace_t *objspace)
     st_free_table(finalizer_table);
     finalizer_table = 0;
     ATOMIC_SET(finalizing, 0);
-
-#if 0
-    /*
-     * finish any lazy sweeps that may have been started
-     * when finalizing the objects in the heap
-     */
-    gc_rest(objspace);
-#endif
 }
 
 static inline int