1 files changed, 99 insertions, 0 deletions
diff --git a/libdexfile/dex/dex_file_layout.cc b/libdexfile/dex/dex_file_layout.cc
new file mode 100644
index 0000000000..1e36e05f50
--- /dev/null
+++ b/libdexfile/dex/dex_file_layout.cc
@@ -0,0 +1,99 @@
+/*
+ * 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.
+ */
+
+#include "dex_file_layout.h"
+
+#include <sys/mman.h>
+
+#include "dex_file.h"
+
+namespace art {
+
+int DexLayoutSection::MadviseLargestPageAlignedRegion(const uint8_t* begin,
+                                                      const uint8_t* end,
+                                                      int advice) {
+  DCHECK_LE(begin, end);
+  begin = AlignUp(begin, kPageSize);
+  end = AlignDown(end, kPageSize);
+  if (begin < end) {
+    // TODO: remove the direct dependency on madvise here.
+    int result = madvise(const_cast<uint8_t*>(begin), end - begin, advice);
+    if (result != 0) {
+      PLOG(WARNING) << "madvise failed " << result;
+    }
+    return result;
+  }
+  return 0;
+}
+
+void DexLayoutSection::Subsection::Madvise(const DexFile* dex_file, int advice) const {
+  DCHECK(dex_file != nullptr);
+  DCHECK_LT(start_offset_, dex_file->Size());
+  DCHECK_LE(end_offset_, dex_file->Size());
+  MadviseLargestPageAlignedRegion(dex_file->Begin() + start_offset_,
+                                  dex_file->Begin() + end_offset_,
+                                  advice);
+}
+
+void DexLayoutSections::Madvise(const DexFile* dex_file, MadviseState state) const {
+  // The dex file is already defaulted to random access everywhere.
+  for (const DexLayoutSection& section : sections_) {
+    switch (state) {
+      case MadviseState::kMadviseStateAtLoad: {
+        section.parts_[static_cast<size_t>(LayoutType::kLayoutTypeStartupOnly)].Madvise(
+            dex_file,
+            MADV_WILLNEED);
+        section.parts_[static_cast<size_t>(LayoutType::kLayoutTypeHot)].Madvise(
+            dex_file,
+            MADV_WILLNEED);
+        break;
+      }
+      case MadviseState::kMadviseStateFinishedLaunch: {
+        section.parts_[static_cast<size_t>(LayoutType::kLayoutTypeStartupOnly)].Madvise(
+            dex_file,
+            MADV_DONTNEED);
+        break;
+      }
+      case MadviseState::kMadviseStateFinishedTrim: {
+        section.parts_[static_cast<size_t>(LayoutType::kLayoutTypeSometimesUsed)].Madvise(
+            dex_file,
+            MADV_DONTNEED);
+        section.parts_[static_cast<size_t>(LayoutType::kLayoutTypeUsedOnce)].Madvise(
+            dex_file,
+            MADV_DONTNEED);
+        break;
+      }
+    }
+  }
+}
+
+std::ostream& operator<<(std::ostream& os, const DexLayoutSection& section) {
+  for (size_t i = 0; i < static_cast<size_t>(LayoutType::kLayoutTypeCount); ++i) {
+    const DexLayoutSection::Subsection& part = section.parts_[i];
+    os << static_cast<LayoutType>(i) << "("
+       << part.start_offset_ << "-" << part.end_offset_ << ") ";
+  }
+  return os;
+}
+
+std::ostream& operator<<(std::ostream& os, const DexLayoutSections& sections) {
+  for (size_t i = 0; i < static_cast<size_t>(DexLayoutSections::SectionType::kSectionCount); ++i) {
+    os << static_cast<DexLayoutSections::SectionType>(i) << ":" << sections.sections_[i] << "\n";
+  }
+  return os;
+}
+
+}  // namespace art