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// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/memory/discardable_memory_allocator_android.h"
#include <sys/types.h>
#include <unistd.h>
#include "base/memory/discardable_memory.h"
#include "base/memory/scoped_ptr.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "base/strings/stringprintf.h"
#include "build/build_config.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace base {
namespace internal {
const char kAllocatorName[] = "allocator-for-testing";
const size_t kPageSize = 4096;
const size_t kMinAshmemRegionSize =
DiscardableMemoryAllocator::kMinAshmemRegionSize;
class DiscardableMemoryAllocatorTest : public testing::Test {
protected:
DiscardableMemoryAllocatorTest() : allocator_(kAllocatorName) {}
DiscardableMemoryAllocator allocator_;
};
void WriteToDiscardableMemory(DiscardableMemory* memory, size_t size) {
// Write to the first and the last pages only to avoid paging in up to 64
// MBytes.
static_cast<char*>(memory->Memory())[0] = 'a';
static_cast<char*>(memory->Memory())[size - 1] = 'a';
}
TEST_F(DiscardableMemoryAllocatorTest, Basic) {
const size_t size = 128;
scoped_ptr<DiscardableMemory> memory(allocator_.Allocate(size));
ASSERT_TRUE(memory);
WriteToDiscardableMemory(memory.get(), size);
}
TEST_F(DiscardableMemoryAllocatorTest, LargeAllocation) {
// Note that large allocations should just use DiscardableMemoryAndroidSimple
// instead.
const size_t size = 64 * 1024 * 1024;
scoped_ptr<DiscardableMemory> memory(allocator_.Allocate(size));
ASSERT_TRUE(memory);
WriteToDiscardableMemory(memory.get(), size);
}
TEST_F(DiscardableMemoryAllocatorTest, ChunksArePageAligned) {
scoped_ptr<DiscardableMemory> memory(allocator_.Allocate(kPageSize));
ASSERT_TRUE(memory);
EXPECT_EQ(0U, reinterpret_cast<uint64_t>(memory->Memory()) % kPageSize);
WriteToDiscardableMemory(memory.get(), kPageSize);
}
TEST_F(DiscardableMemoryAllocatorTest, AllocateFreeAllocate) {
scoped_ptr<DiscardableMemory> memory(allocator_.Allocate(kPageSize));
// Extra allocation that prevents the region from being deleted when |memory|
// gets deleted.
scoped_ptr<DiscardableMemory> memory_lock(allocator_.Allocate(kPageSize));
ASSERT_TRUE(memory);
void* const address = memory->Memory();
memory->Unlock(); // Tests that the reused chunk is being locked correctly.
memory.reset();
memory = allocator_.Allocate(kPageSize);
ASSERT_TRUE(memory);
// The previously freed chunk should be reused.
EXPECT_EQ(address, memory->Memory());
WriteToDiscardableMemory(memory.get(), kPageSize);
}
TEST_F(DiscardableMemoryAllocatorTest, FreeingWholeAshmemRegionClosesAshmem) {
scoped_ptr<DiscardableMemory> memory(allocator_.Allocate(kPageSize));
ASSERT_TRUE(memory);
const int kMagic = 0xdeadbeef;
*static_cast<int*>(memory->Memory()) = kMagic;
memory.reset();
// The previous ashmem region should have been closed thus it should not be
// reused.
memory = allocator_.Allocate(kPageSize);
ASSERT_TRUE(memory);
EXPECT_NE(kMagic, *static_cast<const int*>(memory->Memory()));
}
TEST_F(DiscardableMemoryAllocatorTest, AllocateUsesBestFitAlgorithm) {
scoped_ptr<DiscardableMemory> memory1(allocator_.Allocate(3 * kPageSize));
ASSERT_TRUE(memory1);
scoped_ptr<DiscardableMemory> memory2(allocator_.Allocate(2 * kPageSize));
ASSERT_TRUE(memory2);
scoped_ptr<DiscardableMemory> memory3(allocator_.Allocate(1 * kPageSize));
ASSERT_TRUE(memory3);
void* const address_3 = memory3->Memory();
memory1.reset();
// Don't free |memory2| to avoid merging the 3 blocks together.
memory3.reset();
memory1 = allocator_.Allocate(1 * kPageSize);
ASSERT_TRUE(memory1);
// The chunk whose size is closest to the requested size should be reused.
EXPECT_EQ(address_3, memory1->Memory());
WriteToDiscardableMemory(memory1.get(), kPageSize);
}
TEST_F(DiscardableMemoryAllocatorTest, MergeFreeChunks) {
scoped_ptr<DiscardableMemory> memory1(allocator_.Allocate(kPageSize));
ASSERT_TRUE(memory1);
scoped_ptr<DiscardableMemory> memory2(allocator_.Allocate(kPageSize));
ASSERT_TRUE(memory2);
scoped_ptr<DiscardableMemory> memory3(allocator_.Allocate(kPageSize));
ASSERT_TRUE(memory3);
scoped_ptr<DiscardableMemory> memory4(allocator_.Allocate(kPageSize));
ASSERT_TRUE(memory4);
void* const memory1_address = memory1->Memory();
memory1.reset();
memory3.reset();
// Freeing |memory2| (located between memory1 and memory3) should merge the
// three free blocks together.
memory2.reset();
memory1 = allocator_.Allocate(3 * kPageSize);
EXPECT_EQ(memory1_address, memory1->Memory());
}
TEST_F(DiscardableMemoryAllocatorTest, MergeFreeChunksAdvanced) {
scoped_ptr<DiscardableMemory> memory1(allocator_.Allocate(4 * kPageSize));
ASSERT_TRUE(memory1);
scoped_ptr<DiscardableMemory> memory2(allocator_.Allocate(4 * kPageSize));
ASSERT_TRUE(memory2);
void* const memory1_address = memory1->Memory();
memory1.reset();
memory1 = allocator_.Allocate(2 * kPageSize);
memory2.reset();
// At this point, the region should be in this state:
// 8 KBytes (used), 24 KBytes (free).
memory2 = allocator_.Allocate(6 * kPageSize);
EXPECT_EQ(
static_cast<const char*>(memory2->Memory()),
static_cast<const char*>(memory1_address) + 2 * kPageSize);
}
TEST_F(DiscardableMemoryAllocatorTest, MergeFreeChunksAdvanced2) {
scoped_ptr<DiscardableMemory> memory1(allocator_.Allocate(4 * kPageSize));
ASSERT_TRUE(memory1);
scoped_ptr<DiscardableMemory> memory2(allocator_.Allocate(4 * kPageSize));
ASSERT_TRUE(memory2);
void* const memory1_address = memory1->Memory();
memory1.reset();
memory1 = allocator_.Allocate(2 * kPageSize);
scoped_ptr<DiscardableMemory> memory3(allocator_.Allocate(2 * kPageSize));
// At this point, the region should be in this state:
// 8 KBytes (used), 8 KBytes (used), 16 KBytes (used).
memory3.reset();
memory2.reset();
// At this point, the region should be in this state:
// 8 KBytes (used), 24 KBytes (free).
memory2 = allocator_.Allocate(6 * kPageSize);
EXPECT_EQ(
static_cast<const char*>(memory2->Memory()),
static_cast<const char*>(memory1_address) + 2 * kPageSize);
}
TEST_F(DiscardableMemoryAllocatorTest, MergeFreeChunksAndDeleteAshmemRegion) {
scoped_ptr<DiscardableMemory> memory1(allocator_.Allocate(4 * kPageSize));
ASSERT_TRUE(memory1);
scoped_ptr<DiscardableMemory> memory2(allocator_.Allocate(4 * kPageSize));
ASSERT_TRUE(memory2);
memory1.reset();
memory1 = allocator_.Allocate(2 * kPageSize);
scoped_ptr<DiscardableMemory> memory3(allocator_.Allocate(2 * kPageSize));
// At this point, the region should be in this state:
// 8 KBytes (used), 8 KBytes (used), 16 KBytes (used).
memory1.reset();
memory3.reset();
// At this point, the region should be in this state:
// 8 KBytes (free), 8 KBytes (used), 8 KBytes (free).
const int kMagic = 0xdeadbeef;
*static_cast<int*>(memory2->Memory()) = kMagic;
memory2.reset();
// The whole region should have been deleted.
memory2 = allocator_.Allocate(2 * kPageSize);
EXPECT_NE(kMagic, *static_cast<int*>(memory2->Memory()));
}
TEST_F(DiscardableMemoryAllocatorTest,
TooLargeFreeChunksDontCauseTooMuchFragmentationWhenRecycled) {
// Keep |memory_1| below allocated so that the ashmem region doesn't get
// closed when |memory_2| is deleted.
scoped_ptr<DiscardableMemory> memory_1(allocator_.Allocate(64 * 1024));
ASSERT_TRUE(memory_1);
scoped_ptr<DiscardableMemory> memory_2(allocator_.Allocate(32 * 1024));
ASSERT_TRUE(memory_2);
void* const address = memory_2->Memory();
memory_2.reset();
const size_t size = 16 * 1024;
memory_2 = allocator_.Allocate(size);
ASSERT_TRUE(memory_2);
EXPECT_EQ(address, memory_2->Memory());
WriteToDiscardableMemory(memory_2.get(), size);
scoped_ptr<DiscardableMemory> memory_3(allocator_.Allocate(size));
// The unused tail (16 KBytes large) of the previously freed chunk should be
// reused.
EXPECT_EQ(static_cast<char*>(address) + size, memory_3->Memory());
WriteToDiscardableMemory(memory_3.get(), size);
}
TEST_F(DiscardableMemoryAllocatorTest, UseMultipleAshmemRegions) {
// Leave one page untouched at the end of the ashmem region.
const size_t size = kMinAshmemRegionSize - kPageSize;
scoped_ptr<DiscardableMemory> memory1(allocator_.Allocate(size));
ASSERT_TRUE(memory1);
WriteToDiscardableMemory(memory1.get(), size);
scoped_ptr<DiscardableMemory> memory2(
allocator_.Allocate(kMinAshmemRegionSize));
ASSERT_TRUE(memory2);
WriteToDiscardableMemory(memory2.get(), kMinAshmemRegionSize);
// The last page of the first ashmem region should be used for this
// allocation.
scoped_ptr<DiscardableMemory> memory3(allocator_.Allocate(kPageSize));
ASSERT_TRUE(memory3);
WriteToDiscardableMemory(memory3.get(), kPageSize);
EXPECT_EQ(memory3->Memory(), static_cast<char*>(memory1->Memory()) + size);
}
} // namespace internal
} // namespace base
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