components/html_viewer/discardable_memory_allocator_unittest.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/html_viewer/discardable_memory_allocator.h"
   6
   7 #include "base/memory/discardable_memory.h"
   8 #include "testing/gtest/include/gtest/gtest.h"
   9
  10 namespace html_viewer {
  11 namespace {
  12
  13 const size_t kOneKilobyte = 1024;
  14 const size_t kAlmostOneMegabyte = 1023 * kOneKilobyte;
  15 const size_t kOneMegabyte = 1024 * kOneKilobyte;
  16
  17 TEST(DiscardableMemoryAllocator, Basic) {
  18   DiscardableMemoryAllocator allocator(kOneMegabyte);
  19   scoped_ptr<base::DiscardableMemory> chunk;
  20   // Make sure the chunk is locked when allocated. In debug mode, we will
  21   // dcheck.
  22   chunk = allocator.AllocateLockedDiscardableMemory(kOneKilobyte);
  23   chunk->Unlock();
  24
  25   // Make sure we can lock a chunk.
  26   EXPECT_TRUE(chunk->Lock());
  27   chunk->Unlock();
  28 }
  29
  30 TEST(DiscardableMemoryAllocator, DiscardChunks) {
  31   DiscardableMemoryAllocator allocator(kOneMegabyte);
  32
  33   scoped_ptr<base::DiscardableMemory> chunk_to_remove =
  34       allocator.AllocateLockedDiscardableMemory(kAlmostOneMegabyte);
  35   chunk_to_remove->Unlock();
  36
  37   // Allocating a second chunk should deallocate the first one due to memory
  38   // pressure, since we only have one megabyte available.
  39   scoped_ptr<base::DiscardableMemory> chunk_to_keep =
  40       allocator.AllocateLockedDiscardableMemory(kAlmostOneMegabyte);
  41
  42   // Fail to get a lock because allocating the second chunk removed the first.
  43   EXPECT_FALSE(chunk_to_remove->Lock());
  44
  45   chunk_to_keep->Unlock();
  46 }
  47
  48 TEST(DiscardableMemoryAllocator, DontDiscardLiveChunks) {
  49   DiscardableMemoryAllocator allocator(kOneMegabyte);
  50
  51   scoped_ptr<base::DiscardableMemory> chunk_one =
  52       allocator.AllocateLockedDiscardableMemory(kAlmostOneMegabyte);
  53   scoped_ptr<base::DiscardableMemory> chunk_two =
  54       allocator.AllocateLockedDiscardableMemory(kAlmostOneMegabyte);
  55   scoped_ptr<base::DiscardableMemory> chunk_three =
  56       allocator.AllocateLockedDiscardableMemory(kAlmostOneMegabyte);
  57
  58   // These accesses will fail if the underlying weak ptr has been deallocated.
  59   EXPECT_NE(nullptr, chunk_one->data());
  60   EXPECT_NE(nullptr, chunk_two->data());
  61   EXPECT_NE(nullptr, chunk_three->data());
  62
  63   chunk_one->Unlock();
  64   chunk_two->Unlock();
  65   chunk_three->Unlock();
  66 }
  67
  68 }  // namespace
  69 }  // namespace html_viewer