- Add free list to be used for sweep phase of mark-sweep collector.

vm/freelist_test.cc

+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "vm/assert.h"
+#include "vm/freelist.h"
+#include "vm/unit_test.h"
+
+namespace dart {
+
+TEST_CASE(FreeList) {
+  FreeList* free_list = new FreeList();
+  intptr_t kBlobSize = 1 * MB;
+  intptr_t kSmallObjectSize = 4 * kWordSize;
+  intptr_t kMediumObjectSize = 16 * kWordSize;
+  intptr_t kLargeObjectSize = 8 * KB;
+  uword blob = reinterpret_cast<uword>(malloc(kBlobSize));
+  // Enqueue the large blob as one free block.
+  free_list->Free(blob, kBlobSize);
+  // Allocate a small object. Expect it to be positioned as the first element.
+  uword small_object = free_list->TryAllocate(kSmallObjectSize);
+  EXPECT_EQ(blob, small_object);
+  // Freeing and allocating should give us the same memory back.
+  free_list->Free(small_object, kSmallObjectSize);
+  small_object = free_list->TryAllocate(kSmallObjectSize);
+  EXPECT_EQ(blob, small_object);
+  // Splitting the remainder further with small and medium objects.
+  uword small_object2 = free_list->TryAllocate(kSmallObjectSize);
+  EXPECT_EQ(blob + kSmallObjectSize, small_object2);
+  uword med_object = free_list->TryAllocate(kMediumObjectSize);
+  EXPECT_EQ(small_object2 + kSmallObjectSize, med_object);
+  // Allocate a large object.
+  uword large_object = free_list->TryAllocate(kLargeObjectSize);
+  EXPECT_EQ(med_object + kMediumObjectSize, large_object);
+  // Make sure that small objects can still split the remainder.
+  uword small_object3 = free_list->TryAllocate(kSmallObjectSize);
+  EXPECT_EQ(large_object + kLargeObjectSize, small_object3);
+  // Split the large object.
+  free_list->Free(large_object, kLargeObjectSize);
+  uword small_object4 = free_list->TryAllocate(kSmallObjectSize);
+  EXPECT_EQ(large_object, small_object4);
+  // Get the full remainder of the large object.
+  large_object = free_list->TryAllocate(kLargeObjectSize - kSmallObjectSize);
+  EXPECT_EQ(small_object4 + kSmallObjectSize, large_object);
+  // Get another large object from the large unallocated remainder.
+  uword large_object2 = free_list->TryAllocate(kLargeObjectSize);
+  EXPECT_EQ(small_object3 + kSmallObjectSize, large_object2);
+  // Delete the memory associated with the test.
+  free(reinterpret_cast<void*>(blob));
+  delete free_list;
+}
+
+}  // namespace dart