| // 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. |
| |
| #ifndef BASE_ANDROID_LIBRARY_LOADER_LIBRARY_PREFETCHER_H_ |
| #define BASE_ANDROID_LIBRARY_LOADER_LIBRARY_PREFETCHER_H_ |
| |
| #include <jni.h> |
| |
| #include <stdint.h> |
| #include <string> |
| |
| #include "base/debug/proc_maps_linux.h" |
| #include "base/gtest_prod_util.h" |
| |
| namespace base { |
| namespace android { |
| |
| // Forks and waits for a process prefetching the native library. This is done in |
| // a forked process for the following reasons: |
| // - Isolating the main process from mistakes in the parsing. If the parsing |
| // returns an incorrect address, only the forked process will crash. |
| // - Not inflating the memory used by the main process uselessly, which could |
| // increase its likelihood to be killed. |
| // The forked process has background priority and, since it is not declared to |
| // the Android runtime, can be killed at any time, which is not an issue here. |
| class BASE_EXPORT NativeLibraryPrefetcher { |
| public: |
| // Finds the ranges matching the native library, forks a low priority |
| // process pre-fetching these ranges and wait()s for it. |
| // Returns true for success. |
| static bool ForkAndPrefetchNativeLibrary(); |
| |
| private: |
| using AddressRange = std::pair<uintptr_t, uintptr_t>; |
| // Returns true if the region matches native code or data. |
| static bool IsGoodToPrefetch(const base::debug::MappedMemoryRegion& region); |
| // Filters the regions to keep only libchrome ranges if possible. |
| static void FilterLibchromeRangesOnlyIfPossible( |
| const std::vector<base::debug::MappedMemoryRegion>& regions, |
| std::vector<AddressRange>* ranges); |
| // Finds the ranges matching the native library in /proc/self/maps. |
| // Returns true for success. |
| static bool FindRanges(std::vector<AddressRange>* ranges); |
| |
| FRIEND_TEST_ALL_PREFIXES(NativeLibraryPrefetcherTest, |
| TestIsGoodToPrefetchNoRange); |
| FRIEND_TEST_ALL_PREFIXES(NativeLibraryPrefetcherTest, |
| TestIsGoodToPrefetchUnreadableRange); |
| FRIEND_TEST_ALL_PREFIXES(NativeLibraryPrefetcherTest, |
| TestIsGoodToPrefetchSkipSharedRange); |
| FRIEND_TEST_ALL_PREFIXES(NativeLibraryPrefetcherTest, |
| TestIsGoodToPrefetchLibchromeRange); |
| FRIEND_TEST_ALL_PREFIXES(NativeLibraryPrefetcherTest, |
| TestIsGoodToPrefetchBaseApkRange); |
| FRIEND_TEST_ALL_PREFIXES(NativeLibraryPrefetcherTest, |
| TestFilterLibchromeRangesOnlyIfPossibleNoLibchrome); |
| FRIEND_TEST_ALL_PREFIXES(NativeLibraryPrefetcherTest, |
| TestFilterLibchromeRangesOnlyIfPossibleHasLibchrome); |
| |
| DISALLOW_IMPLICIT_CONSTRUCTORS(NativeLibraryPrefetcher); |
| }; |
| |
| } // namespace android |
| } // namespace base |
| |
| #endif // BASE_ANDROID_LIBRARY_LOADER_LIBRARY_PREFETCHER_H_ |