globals.h revision 3d21bdf8894e780d349c481e5c9e29fe1556051c 
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#if defined(ART_USE_OPTIMIZING_COMPILER)
62static constexpr bool kUseOptimizingCompiler = true;
63#else
64static constexpr bool kUseOptimizingCompiler = false;
65#endif
66
67// Garbage collector constants.
68static constexpr bool kMovingCollector = true;
69static constexpr bool kMarkCompactSupport = false && kMovingCollector;
70// True if we allow moving classes.
71static constexpr bool kMovingClasses = !kMarkCompactSupport;
72
73// If true, the quick compiler embeds class pointers in the compiled
74// code, if possible.
75static constexpr bool kEmbedClassInCode = true;
76
77#ifdef USE_BAKER_READ_BARRIER
78static constexpr bool kUseBakerReadBarrier = true;
79#else
80static constexpr bool kUseBakerReadBarrier = false;
81#endif
82
83#ifdef USE_BROOKS_READ_BARRIER
84static constexpr bool kUseBrooksReadBarrier = true;
85#else
86static constexpr bool kUseBrooksReadBarrier = false;
87#endif
88
89#ifdef USE_TABLE_LOOKUP_READ_BARRIER
90static constexpr bool kUseTableLookupReadBarrier = true;
91#else
92static constexpr bool kUseTableLookupReadBarrier = false;
93#endif
94
95static constexpr bool kUseBakerOrBrooksReadBarrier = kUseBakerReadBarrier || kUseBrooksReadBarrier;
96static constexpr bool kUseReadBarrier = kUseBakerReadBarrier || kUseBrooksReadBarrier ||
97    kUseTableLookupReadBarrier;
98
99// If true, references within the heap are poisoned (negated).
100#ifdef ART_HEAP_POISONING
101static constexpr bool kPoisonHeapReferences = true;
102#else
103static constexpr bool kPoisonHeapReferences = false;
104#endif
105
106// If true, enable the tlab allocator by default.
107#ifdef ART_USE_TLAB
108static constexpr bool kUseTlab = true;
109#else
110static constexpr bool kUseTlab = false;
111#endif
112
113// Kinds of tracing clocks.
114enum class TraceClockSource {
115  kThreadCpu,
116  kWall,
117  kDual,  // Both wall and thread CPU clocks.
118};
119
120#if defined(__linux__)
121static constexpr TraceClockSource kDefaultTraceClockSource = TraceClockSource::kDual;
122#else
123static constexpr TraceClockSource kDefaultTraceClockSource = TraceClockSource::kWall;
124#endif
125
126static constexpr bool kDefaultMustRelocate = true;
127
128static constexpr bool kArm32QuickCodeUseSoftFloat = false;
129
130}  // namespace art
131
132#endif  // ART_RUNTIME_GLOBALS_H_
133