Prefetch the native library from native code by parsing /proc/pid/maps.

base/android/library_loader/library_prefetcher_unittest.cc

+// Copyright 2015 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/android/library_loader/library_prefetcher.h"
+
+#include <string>
+#include <vector>
+#include "base/debug/proc_maps_linux.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace android {
+
+namespace {
+const uint8 kRead = base::debug::MappedMemoryRegion::READ;
+const uint8 kReadPrivate = base::debug::MappedMemoryRegion::READ |
+                           base::debug::MappedMemoryRegion::PRIVATE;
+const uint8 kExecutePrivate = base::debug::MappedMemoryRegion::EXECUTE |
+                              base::debug::MappedMemoryRegion::PRIVATE;
+}  // namespace
+
+TEST(NativeLibraryPrefetcherTest, TestIsGoodToPrefetchNoRange) {
+  const base::debug::MappedMemoryRegion regions[4] = {
+      base::debug::MappedMemoryRegion{0x4000, 0x5000, 10, kReadPrivate, ""},
+      base::debug::MappedMemoryRegion{0x4000, 0x5000, 10, kReadPrivate, "foo"},
+      base::debug::MappedMemoryRegion{
+          0x4000, 0x5000, 10, kReadPrivate, "foobar.apk"},
+      base::debug::MappedMemoryRegion{
+          0x4000, 0x5000, 10, kReadPrivate, "libchromium.so"}};
+  for (int i = 0; i < 4; ++i) {
+    ASSERT_FALSE(NativeLibraryPrefetcher::IsGoodToPrefetch(regions[i]));
+  }
+}
+
+TEST(NativeLibraryPrefetcherTest, TestIsGoodToPrefetchUnreadableRange) {
+  const base::debug::MappedMemoryRegion region = {
+      0x4000, 0x5000, 10, kExecutePrivate, "base.apk"};
+  ASSERT_FALSE(NativeLibraryPrefetcher::IsGoodToPrefetch(region));
+}
+
+TEST(NativeLibraryPrefetcherTest, TestIsGoodToPrefetchSkipSharedRange) {
+  const base::debug::MappedMemoryRegion region = {
+      0x4000, 0x5000, 10, kRead, "base.apk"};
+  ASSERT_FALSE(NativeLibraryPrefetcher::IsGoodToPrefetch(region));
+}
+
+TEST(NativeLibraryPrefetcherTest, TestIsGoodToPrefetchLibchromeRange) {
+  const base::debug::MappedMemoryRegion region = {
+      0x4000, 0x5000, 10, kReadPrivate, "libchrome.so"};
+  ASSERT_TRUE(NativeLibraryPrefetcher::IsGoodToPrefetch(region));
+}
+
+TEST(NativeLibraryPrefetcherTest, TestIsGoodToPrefetchBaseApkRange) {
+  const base::debug::MappedMemoryRegion region = {
+      0x4000, 0x5000, 10, kReadPrivate, "base.apk"};
+  ASSERT_TRUE(NativeLibraryPrefetcher::IsGoodToPrefetch(region));
+}
+
+TEST(NativeLibraryPrefetcherTest,
+     TestTakeOnlyLibchromeRangesIfPossibleNoLibchrome) {
+  std::vector<base::debug::MappedMemoryRegion> regions;
+  regions.push_back(
+      base::debug::MappedMemoryRegion{0x1, 0x2, 0, kReadPrivate, "base.apk"});
+  regions.push_back(
+      base::debug::MappedMemoryRegion{0x3, 0x4, 0, kReadPrivate, "base.apk"});
+  std::vector<std::pair<uintptr_t, uintptr_t>> ranges;
+  NativeLibraryPrefetcher::TakeOnlyLibchromeRangesIfPossible(regions, &ranges);
+  EXPECT_EQ(ranges.size(), 2U);
+  EXPECT_EQ(ranges[0].first, 0x1U);
+  EXPECT_EQ(ranges[0].second, 0x2U);
+  EXPECT_EQ(ranges[1].first, 0x3U);
+  EXPECT_EQ(ranges[1].second, 0x4U);
+}
+
+TEST(NativeLibraryPrefetcherTest,
+     TestTakeOnlyLibchromeRangesIfPossibleHasLibchrome) {
+  std::vector<base::debug::MappedMemoryRegion> regions;
+  regions.push_back(
+      base::debug::MappedMemoryRegion{0x1, 0x2, 0, kReadPrivate, "base.apk"});
+  regions.push_back(base::debug::MappedMemoryRegion{
+      0x6, 0x7, 0, kReadPrivate, "libchrome.so"});
+  regions.push_back(
+      base::debug::MappedMemoryRegion{0x3, 0x4, 0, kReadPrivate, "base.apk"});
+  std::vector<std::pair<uintptr_t, uintptr_t>> ranges;
+  NativeLibraryPrefetcher::TakeOnlyLibchromeRangesIfPossible(regions, &ranges);
+  EXPECT_EQ(ranges.size(), 1U);
+  EXPECT_EQ(ranges[0].first, 0x6U);
+  EXPECT_EQ(ranges[0].second, 0x7U);
+}
+
+}  // namespace android
+}  // namespace base