Home | History | Annotate | Download | only in runtime
      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 
     25 namespace art {
     26 
     27 static constexpr size_t KB = 1024;
     28 static constexpr size_t MB = KB * KB;
     29 static constexpr size_t GB = KB * KB * KB;
     30 
     31 // Runtime sizes.
     32 static constexpr size_t kBitsPerByte = 8;
     33 static constexpr size_t kBitsPerByteLog2 = 3;
     34 static constexpr int kBitsPerIntPtrT = sizeof(intptr_t) * kBitsPerByte;
     35 
     36 // Required stack alignment
     37 static 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.
     41 static constexpr int kPageSize = 4096;
     42 
     43 // Required object alignment
     44 static constexpr size_t kObjectAlignment = 8;
     45 static 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)
     49 static constexpr bool kIsDebugBuild = false;
     50 #else
     51 static 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)
     56 static constexpr bool kIsTargetBuild = true;
     57 #else
     58 static constexpr bool kIsTargetBuild = false;
     59 #endif
     60 
     61 #if defined(ART_USE_OPTIMIZING_COMPILER)
     62 static constexpr bool kUseOptimizingCompiler = true;
     63 #else
     64 static constexpr bool kUseOptimizingCompiler = false;
     65 #endif
     66 
     67 // Garbage collector constants.
     68 static constexpr bool kMovingCollector = true;
     69 static constexpr bool kMarkCompactSupport = false && kMovingCollector;
     70 // True if we allow moving classes.
     71 static constexpr bool kMovingClasses = !kMarkCompactSupport;
     72 
     73 // If true, the quick compiler embeds class pointers in the compiled
     74 // code, if possible.
     75 static constexpr bool kEmbedClassInCode = true;
     76 
     77 #ifdef USE_BAKER_READ_BARRIER
     78 static constexpr bool kUseBakerReadBarrier = true;
     79 #else
     80 static constexpr bool kUseBakerReadBarrier = false;
     81 #endif
     82 
     83 #ifdef USE_BROOKS_READ_BARRIER
     84 static constexpr bool kUseBrooksReadBarrier = true;
     85 #else
     86 static constexpr bool kUseBrooksReadBarrier = false;
     87 #endif
     88 
     89 #ifdef USE_TABLE_LOOKUP_READ_BARRIER
     90 static constexpr bool kUseTableLookupReadBarrier = true;
     91 #else
     92 static constexpr bool kUseTableLookupReadBarrier = false;
     93 #endif
     94 
     95 static constexpr bool kUseBakerOrBrooksReadBarrier = kUseBakerReadBarrier || kUseBrooksReadBarrier;
     96 static constexpr bool kUseReadBarrier = kUseBakerReadBarrier || kUseBrooksReadBarrier ||
     97     kUseTableLookupReadBarrier;
     98 
     99 // If true, references within the heap are poisoned (negated).
    100 #ifdef ART_HEAP_POISONING
    101 static constexpr bool kPoisonHeapReferences = true;
    102 #else
    103 static constexpr bool kPoisonHeapReferences = false;
    104 #endif
    105 
    106 // If true, enable the tlab allocator by default.
    107 #ifdef ART_USE_TLAB
    108 static constexpr bool kUseTlab = true;
    109 #else
    110 static constexpr bool kUseTlab = false;
    111 #endif
    112 
    113 // Kinds of tracing clocks.
    114 enum class TraceClockSource {
    115   kThreadCpu,
    116   kWall,
    117   kDual,  // Both wall and thread CPU clocks.
    118 };
    119 
    120 #if defined(__linux__)
    121 static constexpr TraceClockSource kDefaultTraceClockSource = TraceClockSource::kDual;
    122 #else
    123 static constexpr TraceClockSource kDefaultTraceClockSource = TraceClockSource::kWall;
    124 #endif
    125 
    126 static constexpr bool kDefaultMustRelocate = true;
    127 
    128 static constexpr bool kArm32QuickCodeUseSoftFloat = false;
    129 
    130 }  // namespace art
    131 
    132 #endif  // ART_RUNTIME_GLOBALS_H_
    133