* gc.c: allow to tune growth of heap by environment variable

  RUBY_HEAP_SLOTS_GROWTH_FACTOR. patched by tmm1(Aman Gupta).
  [Feature #8015] [ruby-core:53131]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39746 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 29 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 92f52a64ce..8cfed4f470 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Wed Mar 13 23:25:59 2013  Narihiro Nakamura  <[email protected]>
+
+	* gc.c: allow to tune growth of heap by environment variable
+	  RUBY_HEAP_SLOTS_GROWTH_FACTOR. patched by tmm1(Aman Gupta).
+	  [Feature #8015] [ruby-core:53131]
+
 Wed Mar 13 19:43:46 2013  Kazuhiro NISHIYAMA  <[email protected]>
 
 	* doc/irb/irb.rd.ja: fix typo
diff --git a/gc.c b/gc.c
index ace7a0882a..bd95073edc 100644
--- a/gc.c
+++ b/gc.c
@@ -71,11 +71,13 @@
 #endif
 #define HEAP_MIN_SLOTS 10000
 #define FREE_MIN  4096
+#define HEAP_GROWTH_FACTOR 1.8
 
 typedef struct {
     unsigned int initial_malloc_limit;
     unsigned int initial_heap_min_slots;
     unsigned int initial_free_min;
+    double initial_growth_factor;
 #if defined(ENABLE_VM_OBJSPACE) && ENABLE_VM_OBJSPACE
     int gc_stress;
 #endif
@@ -85,6 +87,7 @@ static ruby_gc_params_t initial_params = {
     GC_MALLOC_LIMIT,
     HEAP_MIN_SLOTS,
     FREE_MIN,
+    HEAP_GROWTH_FACTOR,
 #if defined(ENABLE_VM_OBJSPACE) && ENABLE_VM_OBJSPACE
     FALSE,
 #endif
@@ -287,6 +290,7 @@ int *ruby_initial_gc_stress_ptr = &rb_objspace.gc_stress;
 #define initial_malloc_limit	initial_params.initial_malloc_limit
 #define initial_heap_min_slots	initial_params.initial_heap_min_slots
 #define initial_free_min	initial_params.initial_free_min
+#define initial_growth_factor	initial_params.initial_growth_factor
 
 #define is_lazy_sweeping(objspace) ((objspace)->heap.sweep_slots != 0)
 
@@ -605,7 +609,7 @@ initial_expand_heap(rb_objspace_t *objspace)
 static void
 set_heaps_increment(rb_objspace_t *objspace)
 {
-    size_t next_heaps_length = (size_t)(heaps_used * 1.8);
+    size_t next_heaps_length = (size_t)(heaps_used * initial_growth_factor);
 
     if (next_heaps_length == heaps_used) {
         next_heaps_length++;
@@ -3290,7 +3294,7 @@ rb_gc_disable(void)
 void
 rb_gc_set_params(void)
 {
-    char *malloc_limit_ptr, *heap_min_slots_ptr, *free_min_ptr;
+    char *malloc_limit_ptr, *heap_min_slots_ptr, *free_min_ptr, *growth_factor_ptr;
 
     if (rb_safe_level() > 0) return;
 
@@ -3317,6 +3321,17 @@ rb_gc_set_params(void)
 	}
     }
 
+    growth_factor_ptr = getenv("RUBY_HEAP_SLOTS_GROWTH_FACTOR");
+    if (growth_factor_ptr != NULL) {
+	double growth_factor_f = strtod(growth_factor_ptr, NULL);
+	if (RTEST(ruby_verbose))
+	    fprintf(stderr, "heap_slots_growth_factor=%f (%f)\n",
+		    growth_factor_f, initial_growth_factor);
+	if (growth_factor_f > 1) {
+	    initial_growth_factor = growth_factor_f;
+	}
+    }
+
     free_min_ptr = getenv("RUBY_FREE_MIN");
     if (free_min_ptr != NULL) {
 	int free_min_i = atoi(free_min_ptr);
diff --git a/test/ruby/test_gc.rb b/test/ruby/test_gc.rb
index 793ef3918e..bed58f3830 100644
--- a/test/ruby/test_gc.rb
+++ b/test/ruby/test_gc.rb
@@ -108,6 +108,12 @@ class TestGc < Test::Unit::TestCase
     assert_in_out_err([env, "-W0", "-e", "exit"], "", [], [], "[ruby-core:39795]")
     assert_in_out_err([env, "-W1", "-e", "exit"], "", [], [], "[ruby-core:39795]")
     assert_in_out_err([env, "-w", "-e", "exit"], "", [], /heap_min_slots=100000/, "[ruby-core:39795]")
+
+    env = {
+      "RUBY_HEAP_SLOTS_GROWTH_FACTOR" => "2.0"
+    }
+    assert_normal_exit("exit", "", :child_env => env)
+    assert_in_out_err([env, "-w", "-e", "exit"], "", [], /heap_slots_growth_factor=2.0/, "")
   end
 
   def test_profiler_enabled