Index: base/android/library_loader/library_prefetcher.h |
diff --git a/base/android/library_loader/library_prefetcher.h b/base/android/library_loader/library_prefetcher.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..64e5e1ecb4b786f6e8c8ad159262c64c6e69ff17 |
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+++ b/base/android/library_loader/library_prefetcher.h |
@@ -0,0 +1,67 @@ |
+// 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_ |