src/share/vm/utilities/bitMap.cpp

rev 6150 : 8037959: BitMap::resize frees old map before copying memory if !in_resource_area
Summary: Add reallocate functionality to ArrayAllocator and use it from BitMap::resize
Reviewed-by:

@@ -22,10 +22,11 @@
  *
  */
 
 #include "precompiled.hpp"
 #include "memory/allocation.inline.hpp"
+#include "memory/resourceArea.hpp"
 #include "utilities/bitMap.inline.hpp"
 #include "utilities/copy.hpp"
 #ifdef TARGET_OS_FAMILY_linux
 # include "os_linux.inline.hpp"
 #endif

@@ -65,20 +66,18 @@
 
   _size = size_in_bits;
   idx_t new_size_in_words = size_in_words();
   if (in_resource_area) {
     _map = NEW_RESOURCE_ARRAY(bm_word_t, new_size_in_words);
-  } else {
-    if (old_map != NULL) {
-      _map_allocator.free();
-    }
-    _map = _map_allocator.allocate(new_size_in_words);
-  }
   Copy::disjoint_words((HeapWord*)old_map, (HeapWord*) _map,
                        MIN2(old_size_in_words, new_size_in_words));
+  } else {
+    _map = _map_allocator.reallocate(new_size_in_words);
+  }
+
   if (new_size_in_words > old_size_in_words) {
-    clear_range_of_words(old_size_in_words, size_in_words());
+    clear_range_of_words(old_size_in_words, new_size_in_words);
   }
 }
 
 void BitMap::set_range_within_word(idx_t beg, idx_t end) {
   // With a valid range (beg <= end), this test ensures that end != 0, as

@@ -534,10 +533,76 @@
     tty->print("%c", at(index) ? '1' : '0');
   }
   tty->cr();
 }
 
+class TestBitMap : public AllStatic {
+  const static BitMap::idx_t BITMAP_SIZE = 1024;
+  static void fillBitMap(BitMap& map) {
+    map.set_bit(1);
+    map.set_bit(3);
+    map.set_bit(17);
+    map.set_bit(512);
+  }
+
+  static void testResize(bool in_resource_area) {
+    {
+      BitMap map(0, in_resource_area);
+      map.resize(BITMAP_SIZE, in_resource_area);
+      fillBitMap(map);
+
+      BitMap map2(BITMAP_SIZE, in_resource_area);
+      fillBitMap(map2);
+      assert(map.is_same(map2), "could be");
+    }
+
+    {
+      BitMap map(128, in_resource_area);
+      map.resize(BITMAP_SIZE, in_resource_area);
+      fillBitMap(map);
+
+      BitMap map2(BITMAP_SIZE, in_resource_area);
+      fillBitMap(map2);
+      assert(map.is_same(map2), "could be");
+    }
+
+    {
+      BitMap map(BITMAP_SIZE, in_resource_area);
+      map.resize(BITMAP_SIZE, in_resource_area);
+      fillBitMap(map);
+
+      BitMap map2(BITMAP_SIZE, in_resource_area);
+      fillBitMap(map2);
+      assert(map.is_same(map2), "could be");
+    }
+  }
+
+  static void testResizeResource() {
+    ResourceMark rm;
+    testResize(true);
+  }
+
+  static void testResizeNonResource() {
+    testResize(false);
+    {
+      uintx bitmap_bytes = BITMAP_SIZE / BitsPerByte;
+      UIntFlagSetting fs(ArrayAllocatorMallocLimit, bitmap_bytes / 4);
+      testResize(false);
+    }
+  }
+
+ public:
+  static void test() {
+    testResizeResource();
+    testResizeNonResource();
+  }
+
+};
+
+void TestBitMap_test() {
+  TestBitMap::test();
+}
 #endif
 
 
 BitMap2D::BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot)
   : _bits_per_slot(bits_per_slot)