| /* |
| * Copyright (C) 2011 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_RUNTIME_GLOBALS_H_ |
| #define ART_RUNTIME_RUNTIME_GLOBALS_H_ |
| |
| #include "base/globals.h" |
| |
| namespace art { |
| |
| // Size of Dex virtual registers. |
| static constexpr size_t kVRegSize = 4; |
| |
| // Returns whether the given memory offset can be used for generating |
| // an implicit null check. |
| static inline bool CanDoImplicitNullCheckOn(uintptr_t offset) { |
| return offset < gPageSize; |
| } |
| |
| // Required object alignment |
| static constexpr size_t kObjectAlignmentShift = 3; |
| static constexpr size_t kObjectAlignment = 1u << kObjectAlignmentShift; |
| static constexpr size_t kLargeObjectAlignment = kMaxPageSize; |
| static_assert(kLargeObjectAlignment <= 16 * KB, "Consider redesign if more than 16K is required."); |
| |
| // Garbage collector constants. |
| static constexpr bool kMovingCollector = true; |
| static constexpr bool kMarkCompactSupport = false && kMovingCollector; |
| // True if we allow moving classes. |
| static constexpr bool kMovingClasses = !kMarkCompactSupport; |
| // When using the Concurrent Copying (CC) collector, if |
| // `ART_USE_GENERATIONAL_CC` is true, enable generational collection by default, |
| // i.e. use sticky-bit CC for minor collections and (full) CC for major |
| // collections. |
| // This default value can be overridden with the runtime option |
| // `-Xgc:[no]generational_cc`. |
| // |
| // TODO(b/67628039): Consider either: |
| // - renaming this to a better descriptive name (e.g. |
| // `ART_USE_GENERATIONAL_CC_BY_DEFAULT`); or |
| // - removing `ART_USE_GENERATIONAL_CC` and having a fixed default value. |
| // Any of these changes will require adjusting users of this preprocessor |
| // directive and the corresponding build system environment variable (e.g. in |
| // ART's continuous testing). |
| #ifdef ART_USE_GENERATIONAL_CC |
| static constexpr bool kEnableGenerationalCCByDefault = true; |
| #else |
| static constexpr bool kEnableGenerationalCCByDefault = false; |
| #endif |
| |
| // If true, enable the tlab allocator by default. |
| #ifdef ART_USE_TLAB |
| static constexpr bool kUseTlab = true; |
| #else |
| static constexpr bool kUseTlab = false; |
| #endif |
| |
| // Kinds of tracing clocks. |
| enum class TraceClockSource { |
| kThreadCpu, |
| kWall, |
| kDual, // Both wall and thread CPU clocks. |
| }; |
| |
| #if defined(__linux__) |
| static constexpr TraceClockSource kDefaultTraceClockSource = TraceClockSource::kDual; |
| #else |
| static constexpr TraceClockSource kDefaultTraceClockSource = TraceClockSource::kWall; |
| #endif |
| |
| static constexpr bool kDefaultMustRelocate = true; |
| |
| // Size of a heap reference. |
| static constexpr size_t kHeapReferenceSize = sizeof(uint32_t); |
| |
| } // namespace art |
| |
| #endif // ART_RUNTIME_RUNTIME_GLOBALS_H_ |