1/* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#ifndef ART_RUNTIME_GLOBALS_H_ 18#define ART_RUNTIME_GLOBALS_H_ 19 20#include <stddef.h> 21#include <stdint.h> 22#include "read_barrier_c.h" 23#include "read_barrier_option.h" 24 25namespace art { 26 27static constexpr size_t KB = 1024; 28static constexpr size_t MB = KB * KB; 29static constexpr size_t GB = KB * KB * KB; 30 31// Runtime sizes. 32static constexpr size_t kBitsPerByte = 8; 33static constexpr size_t kBitsPerByteLog2 = 3; 34static constexpr int kBitsPerIntPtrT = sizeof(intptr_t) * kBitsPerByte; 35 36// Required stack alignment 37static constexpr size_t kStackAlignment = 16; 38 39// System page size. We check this against sysconf(_SC_PAGE_SIZE) at runtime, but use a simple 40// compile-time constant so the compiler can generate better code. 41static constexpr int kPageSize = 4096; 42 43// Required object alignment 44static constexpr size_t kObjectAlignment = 8; 45static constexpr size_t kLargeObjectAlignment = kPageSize; 46 47// Whether or not this is a debug build. Useful in conditionals where NDEBUG isn't. 48#if defined(NDEBUG) 49static constexpr bool kIsDebugBuild = false; 50#else 51static constexpr bool kIsDebugBuild = true; 52#endif 53 54// Whether or not this is a target (vs host) build. Useful in conditionals where ART_TARGET isn't. 55#if defined(ART_TARGET) 56static constexpr bool kIsTargetBuild = true; 57#else 58static constexpr bool kIsTargetBuild = false; 59#endif 60 61// Garbage collector constants. 62static constexpr bool kMovingCollector = true; 63static constexpr bool kMarkCompactSupport = false && kMovingCollector; 64// True if we allow moving classes. 65static constexpr bool kMovingClasses = !kMarkCompactSupport; 66 67// If true, the quick compiler embeds class pointers in the compiled 68// code, if possible. 69static constexpr bool kEmbedClassInCode = true; 70 71#ifdef USE_BAKER_READ_BARRIER 72static constexpr bool kUseBakerReadBarrier = true; 73#else 74static constexpr bool kUseBakerReadBarrier = false; 75#endif 76 77#ifdef USE_BROOKS_READ_BARRIER 78static constexpr bool kUseBrooksReadBarrier = true; 79#else 80static constexpr bool kUseBrooksReadBarrier = false; 81#endif 82 83#ifdef USE_TABLE_LOOKUP_READ_BARRIER 84static constexpr bool kUseTableLookupReadBarrier = true; 85#else 86static constexpr bool kUseTableLookupReadBarrier = false; 87#endif 88 89static constexpr bool kUseBakerOrBrooksReadBarrier = kUseBakerReadBarrier || kUseBrooksReadBarrier; 90static constexpr bool kUseReadBarrier = 91 kUseBakerReadBarrier || kUseBrooksReadBarrier || kUseTableLookupReadBarrier; 92 93// Debugging flag that forces the generation of read barriers, but 94// does not trigger the use of the concurrent copying GC. 95// 96// TODO: Remove this flag when the read barriers compiler 97// instrumentation is completed. 98static constexpr bool kForceReadBarrier = false; 99// TODO: Likewise, remove this flag when kForceReadBarrier is removed 100// and replace it with kUseReadBarrier. 101static constexpr bool kEmitCompilerReadBarrier = kForceReadBarrier || kUseReadBarrier; 102 103// If true, references within the heap are poisoned (negated). 104#ifdef USE_HEAP_POISONING 105static constexpr bool kPoisonHeapReferences = true; 106#else 107static constexpr bool kPoisonHeapReferences = false; 108#endif 109 110// If true, enable the tlab allocator by default. 111#ifdef ART_USE_TLAB 112static constexpr bool kUseTlab = true; 113#else 114static constexpr bool kUseTlab = false; 115#endif 116 117// Kinds of tracing clocks. 118enum class TraceClockSource { 119 kThreadCpu, 120 kWall, 121 kDual, // Both wall and thread CPU clocks. 122}; 123 124#if defined(__linux__) 125static constexpr TraceClockSource kDefaultTraceClockSource = TraceClockSource::kDual; 126#else 127static constexpr TraceClockSource kDefaultTraceClockSource = TraceClockSource::kWall; 128#endif 129 130static constexpr bool kDefaultMustRelocate = true; 131 132static constexpr bool kArm32QuickCodeUseSoftFloat = false; 133 134} // namespace art 135 136#endif // ART_RUNTIME_GLOBALS_H_ 137