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:
~SkDiscardableMemoryPool()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