Store layout info in dex files
Store layout info for code sections inside of the oat file. This will
be used to advise the kernel when dex files are loaded in
a follow up CL.
Added unit test in dex2oat_test.
Bug: 63178181
Test: test-art-host
(cherry-picked from commit 75c5ed6e75f70002db5fa7c609137c04dd2bdf40)
Change-Id: I4777506886bde42ff0affdac412a8395e8013a40
diff --git a/runtime/dex_file_layout.h b/runtime/dex_file_layout.h
new file mode 100644
index 0000000..40cc912
--- /dev/null
+++ b/runtime/dex_file_layout.h
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_RUNTIME_DEX_FILE_LAYOUT_H_
+#define ART_RUNTIME_DEX_FILE_LAYOUT_H_
+
+#include <cstdint>
+#include <iosfwd>
+
+namespace art {
+
+class DexFile;
+
+enum class LayoutType : uint8_t {
+ // Layout of things that are randomly used. These should be advised to random access.
+ // Without layout, this is the default mode when loading a dex file.
+ kLayoutTypeSometimesUsed,
+ // Layout of things that are only used during startup, these can be madvised after launch.
+ kLayoutTypeStartupOnly,
+ // Layout of things that are hot (commonly accessed), these should be pinned or madvised will
+ // need.
+ kLayoutTypeHot,
+ // Layout of things that are needed probably only once (class initializers). These can be
+ // madvised during trim events.
+ kLayoutTypeUsedOnce,
+ // Layout of things that are thought to be unused. These things should be advised to random
+ // access.
+ kLayoutTypeUnused,
+ // Unused value, just the number of elements in the enum.
+ kLayoutTypeCount,
+};
+std::ostream& operator<<(std::ostream& os, const LayoutType& collector_type);
+
+enum class MadviseState : uint8_t {
+ // Madvise based on a file that was just loaded.
+ kMadviseStateAtLoad,
+ // Madvise based after launch is finished.
+ kMadviseStateFinishedLaunch,
+ // Trim by madvising code that is unlikely to be too important in the future.
+ kMadviseStateFinishedTrim,
+};
+std::ostream& operator<<(std::ostream& os, const MadviseState& collector_type);
+
+// A dex layout section such as code items or strings. Each section is composed of subsections
+// that are layed out ajacently to each other such as (hot, unused, startup, etc...).
+class DexLayoutSection {
+ public:
+ // A subsection is a a continuous range of dex file that is all part of the same layout hint.
+ class Subsection {
+ public:
+ // Use uint32_t to handle 32/64 bit cross compilation.
+ uint32_t offset_ = 0u;
+ uint32_t size_ = 0u;
+
+ void Madvise(const DexFile* dex_file, int advice) const;
+ };
+
+ Subsection parts_[static_cast<size_t>(LayoutType::kLayoutTypeCount)];
+};
+
+// A set of dex layout sections, currently there is only one section for code and one for strings.
+class DexLayoutSections {
+ public:
+ enum class SectionType : uint8_t {
+ kSectionTypeCode,
+ kSectionTypeStrings,
+ kSectionCount,
+ };
+
+ // Advise access about the dex file based on layout. The caller is expected to have already
+ // madvised to MADV_RANDOM.
+ void Madvise(const DexFile* dex_file, MadviseState state) const;
+
+ DexLayoutSection sections_[static_cast<size_t>(SectionType::kSectionCount)];
+};
+
+std::ostream& operator<<(std::ostream& os, const DexLayoutSections::SectionType& collector_type);
+std::ostream& operator<<(std::ostream& os, const DexLayoutSection& section);
+std::ostream& operator<<(std::ostream& os, const DexLayoutSections& sections);
+
+} // namespace art
+
+#endif // ART_RUNTIME_DEX_FILE_LAYOUT_H_