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      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_RUNTIME_GC_SPACE_MALLOC_SPACE_H_
     18 #define ART_RUNTIME_GC_SPACE_MALLOC_SPACE_H_
     19 
     20 #include "space.h"
     21 
     22 #include <ostream>
     23 #include <valgrind.h>
     24 #include <memcheck/memcheck.h>
     25 
     26 namespace art {
     27 namespace gc {
     28 
     29 namespace collector {
     30   class MarkSweep;
     31 }  // namespace collector
     32 
     33 namespace space {
     34 
     35 class ZygoteSpace;
     36 
     37 // TODO: Remove define macro
     38 #define CHECK_MEMORY_CALL(call, args, what) \
     39   do { \
     40     int rc = call args; \
     41     if (UNLIKELY(rc != 0)) { \
     42       errno = rc; \
     43       PLOG(FATAL) << # call << " failed for " << what; \
     44     } \
     45   } while (false)
     46 
     47 // A common parent of DlMallocSpace and RosAllocSpace.
     48 class MallocSpace : public ContinuousMemMapAllocSpace {
     49  public:
     50   typedef void(*WalkCallback)(void *start, void *end, size_t num_bytes, void* callback_arg);
     51 
     52   SpaceType GetType() const {
     53     return kSpaceTypeMallocSpace;
     54   }
     55 
     56   // Allocate num_bytes allowing the underlying space to grow.
     57   virtual mirror::Object* AllocWithGrowth(Thread* self, size_t num_bytes,
     58                                           size_t* bytes_allocated, size_t* usable_size,
     59                                           size_t* bytes_tl_bulk_allocated) = 0;
     60   // Allocate num_bytes without allowing the underlying space to grow.
     61   virtual mirror::Object* Alloc(Thread* self, size_t num_bytes, size_t* bytes_allocated,
     62                                 size_t* usable_size, size_t* bytes_tl_bulk_allocated) = 0;
     63   // Return the storage space required by obj. If usable_size isn't null then it is set to the
     64   // amount of the storage space that may be used by obj.
     65   virtual size_t AllocationSize(mirror::Object* obj, size_t* usable_size) = 0;
     66   virtual size_t Free(Thread* self, mirror::Object* ptr)
     67       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) = 0;
     68   virtual size_t FreeList(Thread* self, size_t num_ptrs, mirror::Object** ptrs)
     69       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) = 0;
     70 
     71   // Returns the maximum bytes that could be allocated for the given
     72   // size in bulk, that is the maximum value for the
     73   // bytes_allocated_bulk out param returned by MallocSpace::Alloc().
     74   virtual size_t MaxBytesBulkAllocatedFor(size_t num_bytes) = 0;
     75 
     76 #ifndef NDEBUG
     77   virtual void CheckMoreCoreForPrecondition() {}  // to be overridden in the debug build.
     78 #else
     79   void CheckMoreCoreForPrecondition() {}  // no-op in the non-debug build.
     80 #endif
     81 
     82   void* MoreCore(intptr_t increment);
     83 
     84   // Hands unused pages back to the system.
     85   virtual size_t Trim() = 0;
     86 
     87   // Perform a mspace_inspect_all which calls back for each allocation chunk. The chunk may not be
     88   // in use, indicated by num_bytes equaling zero.
     89   virtual void Walk(WalkCallback callback, void* arg) = 0;
     90 
     91   // Returns the number of bytes that the space has currently obtained from the system. This is
     92   // greater or equal to the amount of live data in the space.
     93   virtual size_t GetFootprint() = 0;
     94 
     95   // Returns the number of bytes that the heap is allowed to obtain from the system via MoreCore.
     96   virtual size_t GetFootprintLimit() = 0;
     97 
     98   // Set the maximum number of bytes that the heap is allowed to obtain from the system via
     99   // MoreCore. Note this is used to stop the mspace growing beyond the limit to Capacity. When
    100   // allocations fail we GC before increasing the footprint limit and allowing the mspace to grow.
    101   virtual void SetFootprintLimit(size_t limit) = 0;
    102 
    103   // Removes the fork time growth limit on capacity, allowing the application to allocate up to the
    104   // maximum reserved size of the heap.
    105   void ClearGrowthLimit() {
    106     growth_limit_ = NonGrowthLimitCapacity();
    107   }
    108 
    109   // Override capacity so that we only return the possibly limited capacity
    110   size_t Capacity() const {
    111     return growth_limit_;
    112   }
    113 
    114   // The total amount of memory reserved for the alloc space.
    115   size_t NonGrowthLimitCapacity() const {
    116     return GetMemMap()->Size();
    117   }
    118 
    119   // Change the non growth limit capacity by shrinking or expanding the map. Currently, only
    120   // shrinking is supported.
    121   void ClampGrowthLimit();
    122 
    123   void Dump(std::ostream& os) const;
    124 
    125   void SetGrowthLimit(size_t growth_limit);
    126 
    127   virtual MallocSpace* CreateInstance(MemMap* mem_map, const std::string& name, void* allocator,
    128                                       uint8_t* begin, uint8_t* end, uint8_t* limit,
    129                                       size_t growth_limit, bool can_move_objects) = 0;
    130 
    131   // Splits ourself into a zygote space and new malloc space which has our unused memory. When true,
    132   // the low memory mode argument specifies that the heap wishes the created space to be more
    133   // aggressive in releasing unused pages. Invalidates the space its called on.
    134   ZygoteSpace* CreateZygoteSpace(const char* alloc_space_name, bool low_memory_mode,
    135                                  MallocSpace** out_malloc_space) NO_THREAD_SAFETY_ANALYSIS;
    136   virtual uint64_t GetBytesAllocated() = 0;
    137   virtual uint64_t GetObjectsAllocated() = 0;
    138 
    139   // Returns the class of a recently freed object.
    140   mirror::Class* FindRecentFreedObject(const mirror::Object* obj);
    141 
    142   bool CanMoveObjects() const OVERRIDE {
    143     return can_move_objects_;
    144   }
    145 
    146   void DisableMovingObjects() {
    147     can_move_objects_ = false;
    148   }
    149 
    150  protected:
    151   MallocSpace(const std::string& name, MemMap* mem_map, uint8_t* begin, uint8_t* end,
    152               uint8_t* limit, size_t growth_limit, bool create_bitmaps, bool can_move_objects,
    153               size_t starting_size, size_t initial_size);
    154 
    155   static MemMap* CreateMemMap(const std::string& name, size_t starting_size, size_t* initial_size,
    156                               size_t* growth_limit, size_t* capacity, uint8_t* requested_begin);
    157 
    158   // When true the low memory mode argument specifies that the heap wishes the created allocator to
    159   // be more aggressive in releasing unused pages.
    160   virtual void* CreateAllocator(void* base, size_t morecore_start, size_t initial_size,
    161                                 size_t maximum_size, bool low_memory_mode) = 0;
    162 
    163   virtual void RegisterRecentFree(mirror::Object* ptr)
    164       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
    165       EXCLUSIVE_LOCKS_REQUIRED(lock_);
    166 
    167   virtual accounting::ContinuousSpaceBitmap::SweepCallback* GetSweepCallback() {
    168     return &SweepCallback;
    169   }
    170 
    171   // Recent allocation buffer.
    172   static constexpr size_t kRecentFreeCount = kDebugSpaces ? (1 << 16) : 0;
    173   static constexpr size_t kRecentFreeMask = kRecentFreeCount - 1;
    174   std::pair<const mirror::Object*, mirror::Class*> recent_freed_objects_[kRecentFreeCount];
    175   size_t recent_free_pos_;
    176 
    177   static size_t bitmap_index_;
    178 
    179   // Used to ensure mutual exclusion when the allocation spaces data structures are being modified.
    180   Mutex lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
    181 
    182   // The capacity of the alloc space until such time that ClearGrowthLimit is called.
    183   // The underlying mem_map_ controls the maximum size we allow the heap to grow to. The growth
    184   // limit is a value <= to the mem_map_ capacity used for ergonomic reasons because of the zygote.
    185   // Prior to forking the zygote the heap will have a maximally sized mem_map_ but the growth_limit_
    186   // will be set to a lower value. The growth_limit_ is used as the capacity of the alloc_space_,
    187   // however, capacity normally can't vary. In the case of the growth_limit_ it can be cleared
    188   // one time by a call to ClearGrowthLimit.
    189   size_t growth_limit_;
    190 
    191   // True if objects in the space are movable.
    192   bool can_move_objects_;
    193 
    194   // Starting and initial sized, used when you reset the space.
    195   const size_t starting_size_;
    196   const size_t initial_size_;
    197 
    198  private:
    199   static void SweepCallback(size_t num_ptrs, mirror::Object** ptrs, void* arg)
    200       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
    201 
    202   DISALLOW_COPY_AND_ASSIGN(MallocSpace);
    203 };
    204 
    205 }  // namespace space
    206 }  // namespace gc
    207 }  // namespace art
    208 
    209 #endif  // ART_RUNTIME_GC_SPACE_MALLOC_SPACE_H_
    210