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author | Brian Carlstrom <bdc@google.com> | 2013-07-12 13:46:57 -0700 |
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committer | Brian Carlstrom <bdc@google.com> | 2013-07-12 17:49:01 -0700 |
commit | 7940e44f4517de5e2634a7e07d58d0fb26160513 (patch) | |
tree | ac90242d96229a6942f6e24ab137bc1f8f2e0025 /runtime/gc_map.h | |
parent | 5cd9e3b122f276f610980cbaf0d2ad6ed4cd9088 (diff) | |
download | art-7940e44f4517de5e2634a7e07d58d0fb26160513.zip art-7940e44f4517de5e2634a7e07d58d0fb26160513.tar.gz art-7940e44f4517de5e2634a7e07d58d0fb26160513.tar.bz2 |
Create separate Android.mk for main build targets
The runtime, compiler, dex2oat, and oatdump now are in seperate trees
to prevent dependency creep. They can now be individually built
without rebuilding the rest of the art projects. dalvikvm and jdwpspy
were already this way. Builds in the art directory should behave as
before, building everything including tests.
Change-Id: Ic6b1151e5ed0f823c3dd301afd2b13eb2d8feb81
Diffstat (limited to 'runtime/gc_map.h')
-rw-r--r-- | runtime/gc_map.h | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/runtime/gc_map.h b/runtime/gc_map.h new file mode 100644 index 0000000..473b39a --- /dev/null +++ b/runtime/gc_map.h @@ -0,0 +1,111 @@ +/* + * Copyright (C) 2012 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_SRC_GC_MAP_H_ +#define ART_SRC_GC_MAP_H_ + +#include <stdint.h> + +#include "base/logging.h" +#include "base/macros.h" + +namespace art { + +// Lightweight wrapper for native PC offset to reference bit maps. +class NativePcOffsetToReferenceMap { + public: + NativePcOffsetToReferenceMap(const uint8_t* data) : data_(data) { + CHECK(data_ != NULL); + } + + // The number of entries in the table. + size_t NumEntries() const { + return data_[2] | (data_[3] << 8); + } + + // Return address of bitmap encoding what are live references. + const uint8_t* GetBitMap(size_t index) const { + size_t entry_offset = index * EntryWidth(); + return &Table()[entry_offset + NativeOffsetWidth()]; + } + + // Get the native PC encoded in the table at the given index. + uintptr_t GetNativePcOffset(size_t index) const { + size_t entry_offset = index * EntryWidth(); + uintptr_t result = 0; + for (size_t i = 0; i < NativeOffsetWidth(); ++i) { + result |= Table()[entry_offset + i] << (i * 8); + } + return result; + } + + // Does the given offset have an entry? + bool HasEntry(uintptr_t native_pc_offset) { + for (size_t i = 0; i < NumEntries(); ++i) { + if (GetNativePcOffset(i) == native_pc_offset) { + return true; + } + } + return false; + } + + // Finds the bitmap associated with the native pc offset. + const uint8_t* FindBitMap(uintptr_t native_pc_offset) { + size_t num_entries = NumEntries(); + size_t index = Hash(native_pc_offset) % num_entries; + size_t misses = 0; + while (GetNativePcOffset(index) != native_pc_offset) { + index = (index + 1) % num_entries; + misses++; + DCHECK_LT(misses, num_entries) << "Failed to find offset: " << native_pc_offset; + } + return GetBitMap(index); + } + + static uint32_t Hash(uint32_t native_offset) { + uint32_t hash = native_offset; + hash ^= (hash >> 20) ^ (hash >> 12); + hash ^= (hash >> 7) ^ (hash >> 4); + return hash; + } + + // The number of bytes used to encode registers. + size_t RegWidth() const { + return (static_cast<size_t>(data_[0]) | (static_cast<size_t>(data_[1]) << 8)) >> 3; + } + + private: + // Skip the size information at the beginning of data. + const uint8_t* Table() const { + return data_ + 4; + } + + // Number of bytes used to encode a native offset. + size_t NativeOffsetWidth() const { + return data_[0] & 7; + } + + // The width of an entry in the table. + size_t EntryWidth() const { + return NativeOffsetWidth() + RegWidth(); + } + + const uint8_t* const data_; // The header and table data +}; + +} // namespace art + +#endif // ART_SRC_GC_MAP_H_ |