discardable_shared_memory_unittest.cc

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/memory/discardable_shared_memory.h"

#include <fcntl.h>
#include <stdint.h>

#include <algorithm>

#include "base/files/scoped_file.h"
#include "base/memory/page_size.h"
#include "base/memory/shared_memory_tracker.h"
#include "base/tracing_buildflags.h"
#include "build/build_config.h"
#include "testing/gtest/include/gtest/gtest.h"

#if BUILDFLAG(ENABLE_BASE_TRACING)
#include "base/trace_event/memory_allocator_dump.h"  // no-presubmit-check
#include "base/trace_event/process_memory_dump.h"    // no-presubmit-check
#endif  // BUILDFLAG(ENABLE_BASE_TRACING)

namespace base {

class TestDiscardableSharedMemory : public DiscardableSharedMemory { … };

TEST(DiscardableSharedMemoryTest, CreateAndMap) { … }

TEST(DiscardableSharedMemoryTest, CreateFromHandle) { … }

TEST(DiscardableSharedMemoryTest, LockAndUnlock) { … }

TEST(DiscardableSharedMemoryTest, Purge) { … }

TEST(DiscardableSharedMemoryTest, PurgeAfterClose) { … }

TEST(DiscardableSharedMemoryTest, LastUsed) { … }

TEST(DiscardableSharedMemoryTest, LockShouldAlwaysFailAfterSuccessfulPurge) { … }

#if BUILDFLAG(IS_ANDROID)
TEST(DiscardableSharedMemoryTest, LockShouldFailIfPlatformLockPagesFails) {
  const uint32_t kDataSize = 1024;

  // This test cannot succeed on devices without a proper ashmem device
  // because Lock() will always succeed.
  if (!DiscardableSharedMemory::IsAshmemDeviceSupportedForTesting())
    return;

  DiscardableSharedMemory memory1;
  bool rv1 = memory1.CreateAndMap(kDataSize);
  ASSERT_TRUE(rv1);

  base::UnsafeSharedMemoryRegion region = memory1.DuplicateRegion();
  int fd = region.GetPlatformHandle();
  DiscardableSharedMemory memory2(std::move(region));
  bool rv2 = memory2.Map(kDataSize);
  ASSERT_TRUE(rv2);

  // Unlock() the first page of memory, so we can test Lock()ing it.
  memory2.Unlock(0, base::GetPageSize());
  // To cause ashmem_pin_region() to fail, we arrange for it to be called with
  // an invalid file-descriptor, which requires a valid-looking fd (i.e. we
  // can't just Close() |memory|), but one on which the operation is invalid.
  // We can overwrite the |memory| fd with a handle to a different file using
  // dup2(), which has the nice properties that |memory| still has a valid fd
  // that it can close, etc without errors, but on which ashmem_pin_region()
  // will fail.
  base::ScopedFD null(open("/dev/null", O_RDONLY));
  ASSERT_EQ(fd, dup2(null.get(), fd));

  // Now re-Lock()ing the first page should fail.
  DiscardableSharedMemory::LockResult lock_rv =
      memory2.Lock(0, base::GetPageSize());
  EXPECT_EQ(DiscardableSharedMemory::FAILED, lock_rv);
}
#endif  // BUILDFLAG(IS_ANDROID)

TEST(DiscardableSharedMemoryTest, LockAndUnlockRange) { … }

TEST(DiscardableSharedMemoryTest, MappedSize) { … }

TEST(DiscardableSharedMemoryTest, Close) { … }

TEST(DiscardableSharedMemoryTest, ZeroSize) { … }

// This test checks that zero-filled pages are returned after purging a segment
// when DISCARDABLE_SHARED_MEMORY_ZERO_FILL_ON_DEMAND_PAGES_AFTER_PURGE is
// defined and MADV_REMOVE is supported.
#if defined(DISCARDABLE_SHARED_MEMORY_ZERO_FILL_ON_DEMAND_PAGES_AFTER_PURGE)
TEST(DiscardableSharedMemoryTest, ZeroFilledPagesAfterPurge) { … }
#endif

#if BUILDFLAG(ENABLE_BASE_TRACING)
TEST(DiscardableSharedMemoryTest, TracingOwnershipEdges) { … }
#endif  // BUILDFLAG(ENABLE_BASE_TRACING)

}  // namespace base
chromium/base/memory/discardable_shared_memory_unittest.cc
