* gc.c: introduce macros to remove magic number.

  GC_HEAP_FREE_SLOTS_MIN_RATIO = 0.3: guarantee minimum empty slots
                                      ratio after sweep.
  GC_HEAP_FREE_SLOTS_MAX_RATIO = 0.8: allow to free pages 0.2 (= 1-0.8)
                                      of current existing slots.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45948 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 18 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index a46e60ea71..cdd712a89a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+Thu May 15 18:42:49 2014  Koichi Sasada  <ko1@atdot.net>
+
+	* gc.c: introduce macros to remove magic number.
+
+	  GC_HEAP_FREE_SLOTS_MIN_RATIO = 0.3: guarantee minimum empty slots
+	                                      ratio after sweep.
+	  GC_HEAP_FREE_SLOTS_MAX_RATIO = 0.8: allow to free pages 0.2 (= 1-0.8)
+	                                      of current existing slots.
+
 Thu May 15 17:32:51 2014  Hiroshi Shirosaki  <h.shirosaki@gmail.com>
 
 	* thread_win32.c (rb_w32_stack_overflow_handler): use Structured
diff --git a/gc.c b/gc.c
index abac6b9910..a36752c420 100644
--- a/gc.c
+++ b/gc.c
@@ -116,6 +116,13 @@ rb_gc_guarded_ptr_val(volatile VALUE *ptr, VALUE val)
 #define GC_HEAP_OLDOBJECT_LIMIT_FACTOR 2.0
 #endif
 
+#ifndef GC_HEAP_FREE_SLOTS_MIN_RATIO
+#define GC_HEAP_FREE_SLOTS_MIN_RATIO 0.3
+#endif
+#ifndef GC_HEAP_FREE_SLOTS_MAX_RATIO
+#define GC_HEAP_FREE_SLOTS_MAX_RATIO 0.8
+#endif
+
 #ifndef GC_MALLOC_LIMIT_MIN
 #define GC_MALLOC_LIMIT_MIN (16 * 1024 * 1024 /* 16MB */)
 #endif
@@ -2902,11 +2909,11 @@ gc_before_sweep(rb_objspace_t *objspace)
     heap_pages_swept_slots = 0;
     total_limit_slot = objspace_total_slot(objspace);
 
-    heap_pages_min_free_slots = (size_t)(total_limit_slot * 0.30);
+    heap_pages_min_free_slots = (size_t)(total_limit_slot * GC_HEAP_FREE_SLOTS_MIN_RATIO);
     if (heap_pages_min_free_slots < gc_params.heap_free_slots) {
 	heap_pages_min_free_slots = gc_params.heap_free_slots;
     }
-    heap_pages_max_free_slots = (size_t)(total_limit_slot * 0.80);
+    heap_pages_max_free_slots = (size_t)(total_limit_slot * GC_HEAP_FREE_SLOTS_MAX_RATIO);
     if (heap_pages_max_free_slots < gc_params.heap_init_slots) {
 	heap_pages_max_free_slots = gc_params.heap_init_slots;
     }