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      1 /*
      2  * Copyright 2013 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #ifndef SkDiscardableMemoryPool_DEFINED
      9 #define SkDiscardableMemoryPool_DEFINED
     10 
     11 #include "SkDiscardableMemory.h"
     12 #include "SkMutex.h"
     13 
     14 #ifndef SK_LAZY_CACHE_STATS
     15     #ifdef SK_DEBUG
     16         #define SK_LAZY_CACHE_STATS 1
     17     #else
     18         #define SK_LAZY_CACHE_STATS 0
     19     #endif
     20 #endif
     21 
     22 /**
     23  *  An implementation of Discardable Memory that manages a fixed-size
     24  *  budget of memory.  When the allocated memory exceeds this size,
     25  *  unlocked blocks of memory are purged.  If all memory is locked, it
     26  *  can exceed the memory-use budget.
     27  */
     28 class SkDiscardableMemoryPool : public SkDiscardableMemory::Factory {
     29 public:
     30     virtual ~SkDiscardableMemoryPool() { }
     31 
     32     virtual size_t getRAMUsed() = 0;
     33     virtual void setRAMBudget(size_t budget) = 0;
     34     virtual size_t getRAMBudget() = 0;
     35 
     36     /** purges all unlocked DMs */
     37     virtual void dumpPool() = 0;
     38 
     39     #if SK_LAZY_CACHE_STATS
     40     /**
     41      * These two values are a count of the number of successful and
     42      * failed calls to SkDiscardableMemory::lock() for all DMs managed
     43      * by this pool.
     44      */
     45     virtual int getCacheHits() = 0;
     46     virtual int getCacheMisses() = 0;
     47     virtual void resetCacheHitsAndMisses() = 0;
     48     #endif
     49 
     50     /**
     51      *  This non-global pool can be used for unit tests to verify that
     52      *  the pool works.
     53      *  Without mutex, will be not be thread safe.
     54      */
     55     static SkDiscardableMemoryPool* Create(
     56             size_t size, SkBaseMutex* mutex = nullptr);
     57 };
     58 
     59 /**
     60  *  Returns (and creates if needed) a threadsafe global
     61  *  SkDiscardableMemoryPool.
     62  */
     63 SkDiscardableMemoryPool* SkGetGlobalDiscardableMemoryPool();
     64 
     65 #if !defined(SK_DEFAULT_GLOBAL_DISCARDABLE_MEMORY_POOL_SIZE)
     66 #define SK_DEFAULT_GLOBAL_DISCARDABLE_MEMORY_POOL_SIZE (128 * 1024 * 1024)
     67 #endif
     68 
     69 #endif  // SkDiscardableMemoryPool_DEFINED
     70