Home | History | Annotate | Download | only in base
      1 /*
      2  * Copyright (C) 2013 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_LIBARTBASE_BASE_ALLOCATOR_H_
     18 #define ART_LIBARTBASE_BASE_ALLOCATOR_H_
     19 
     20 #include <type_traits>
     21 
     22 #include "base/atomic.h"
     23 #include "base/macros.h"
     24 
     25 namespace art {
     26 
     27 static constexpr bool kEnableTrackingAllocator = false;
     28 
     29 class Allocator {
     30  public:
     31   static Allocator* GetMallocAllocator();
     32   static Allocator* GetNoopAllocator();
     33 
     34   Allocator() {}
     35   virtual ~Allocator() {}
     36 
     37   virtual void* Alloc(size_t) = 0;
     38   virtual void Free(void*) = 0;
     39 
     40  private:
     41   DISALLOW_COPY_AND_ASSIGN(Allocator);
     42 };
     43 
     44 // Used by TrackedAllocators.
     45 enum AllocatorTag {
     46   kAllocatorTagHeap,
     47   kAllocatorTagMonitorList,
     48   kAllocatorTagClassTable,
     49   kAllocatorTagInternTable,
     50   kAllocatorTagMaps,
     51   kAllocatorTagLOS,
     52   kAllocatorTagSafeMap,
     53   kAllocatorTagLOSMaps,
     54   kAllocatorTagReferenceTable,
     55   kAllocatorTagHeapBitmap,
     56   kAllocatorTagHeapBitmapLOS,
     57   kAllocatorTagMonitorPool,
     58   kAllocatorTagLOSFreeList,
     59   kAllocatorTagVerifier,
     60   kAllocatorTagRememberedSet,
     61   kAllocatorTagModUnionCardSet,
     62   kAllocatorTagModUnionReferenceArray,
     63   kAllocatorTagJNILibraries,
     64   kAllocatorTagCompileTimeClassPath,
     65   kAllocatorTagOatFile,
     66   kAllocatorTagDexFileVerifier,
     67   kAllocatorTagRosAlloc,
     68   kAllocatorTagCount,  // Must always be last element.
     69 };
     70 std::ostream& operator<<(std::ostream& os, const AllocatorTag& tag);
     71 
     72 namespace TrackedAllocators {
     73 
     74 // Running count of number of bytes used for this kind of allocation. Increased by allocations,
     75 // decreased by deallocations.
     76 extern Atomic<size_t> g_bytes_used[kAllocatorTagCount];
     77 
     78 // Largest value of bytes used seen.
     79 extern volatile size_t g_max_bytes_used[kAllocatorTagCount];
     80 
     81 // Total number of bytes allocated of this kind.
     82 extern Atomic<uint64_t> g_total_bytes_used[kAllocatorTagCount];
     83 
     84 void Dump(std::ostream& os);
     85 
     86 inline void RegisterAllocation(AllocatorTag tag, size_t bytes) {
     87   g_total_bytes_used[tag].FetchAndAddSequentiallyConsistent(bytes);
     88   size_t new_bytes = g_bytes_used[tag].FetchAndAddSequentiallyConsistent(bytes) + bytes;
     89   if (g_max_bytes_used[tag] < new_bytes) {
     90     g_max_bytes_used[tag] = new_bytes;
     91   }
     92 }
     93 
     94 inline void RegisterFree(AllocatorTag tag, size_t bytes) {
     95   g_bytes_used[tag].FetchAndSubSequentiallyConsistent(bytes);
     96 }
     97 
     98 }  // namespace TrackedAllocators
     99 
    100 // Tracking allocator for use with STL types, tracks how much memory is used.
    101 template<class T, AllocatorTag kTag>
    102 class TrackingAllocatorImpl : public std::allocator<T> {
    103  public:
    104   typedef typename std::allocator<T>::value_type value_type;
    105   typedef typename std::allocator<T>::size_type size_type;
    106   typedef typename std::allocator<T>::difference_type difference_type;
    107   typedef typename std::allocator<T>::pointer pointer;
    108   typedef typename std::allocator<T>::const_pointer const_pointer;
    109   typedef typename std::allocator<T>::reference reference;
    110   typedef typename std::allocator<T>::const_reference const_reference;
    111 
    112   // Used internally by STL data structures.
    113   template <class U>
    114   TrackingAllocatorImpl(
    115       const TrackingAllocatorImpl<U, kTag>& alloc ATTRIBUTE_UNUSED) noexcept {}
    116 
    117   // Used internally by STL data structures.
    118   TrackingAllocatorImpl() noexcept {
    119     static_assert(kTag < kAllocatorTagCount, "kTag must be less than kAllocatorTagCount");
    120   }
    121 
    122   // Enables an allocator for objects of one type to allocate storage for objects of another type.
    123   // Used internally by STL data structures.
    124   template <class U>
    125   struct rebind {
    126     typedef TrackingAllocatorImpl<U, kTag> other;
    127   };
    128 
    129   pointer allocate(size_type n, const_pointer hint ATTRIBUTE_UNUSED = 0) {
    130     const size_t size = n * sizeof(T);
    131     TrackedAllocators::RegisterAllocation(GetTag(), size);
    132     return reinterpret_cast<pointer>(malloc(size));
    133   }
    134 
    135   template <typename PT>
    136   void deallocate(PT p, size_type n) {
    137     const size_t size = n * sizeof(T);
    138     TrackedAllocators::RegisterFree(GetTag(), size);
    139     free(p);
    140   }
    141 
    142   static constexpr AllocatorTag GetTag() {
    143     return kTag;
    144   }
    145 };
    146 
    147 template<class T, AllocatorTag kTag>
    148 // C++ doesn't allow template typedefs. This is a workaround template typedef which is
    149 // TrackingAllocatorImpl<T> if kEnableTrackingAllocator is true, std::allocator<T> otherwise.
    150 using TrackingAllocator = typename std::conditional<kEnableTrackingAllocator,
    151                                                     TrackingAllocatorImpl<T, kTag>,
    152                                                     std::allocator<T>>::type;
    153 
    154 }  // namespace art
    155 
    156 #endif  // ART_LIBARTBASE_BASE_ALLOCATOR_H_
    157