1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/lazy/SkPurgeableMemoryBlock.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,94 @@
1.4 +/*
1.5 + * Copyright 2013 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef SkPurgeableMemoryBlock_DEFINED
1.12 +#define SkPurgeableMemoryBlock_DEFINED
1.13 +
1.14 +#include "SkTypes.h"
1.15 +
1.16 +class SkPurgeableMemoryBlock : public SkNoncopyable {
1.17 +
1.18 +public:
1.19 + /**
1.20 + * Whether or not this platform has an implementation for purgeable memory.
1.21 + */
1.22 + static bool IsSupported();
1.23 +
1.24 + /**
1.25 + * Create a new purgeable memory block of 'size' bytes. Returns NULL if not supported on this
1.26 + * platform or on failure.
1.27 + * @param size Number of bytes requested.
1.28 + * @return A new block, or NULL on failure.
1.29 + */
1.30 + static SkPurgeableMemoryBlock* Create(size_t size);
1.31 +
1.32 +#ifdef SK_DEBUG
1.33 + /**
1.34 + * Whether the platform supports one shot purge of all unpinned blocks. If so,
1.35 + * PurgeAllUnpinnedBlocks will be used to test a purge. Otherwise, purge will be called on
1.36 + * individual blocks.
1.37 + */
1.38 + static bool PlatformSupportsPurgingAllUnpinnedBlocks();
1.39 +
1.40 + /**
1.41 + * Purge all unpinned blocks at once, if the platform supports it.
1.42 + */
1.43 + static bool PurgeAllUnpinnedBlocks();
1.44 +
1.45 + // If PlatformSupportsPurgingAllUnpinnedBlocks returns true, this will not be called, so it can
1.46 + // simply return false.
1.47 + bool purge();
1.48 +
1.49 + bool isPinned() const { return fPinned; }
1.50 +#endif
1.51 +
1.52 + ~SkPurgeableMemoryBlock();
1.53 +
1.54 + /**
1.55 + * Output parameter for pin(), stating whether the data has been retained.
1.56 + */
1.57 + enum PinResult {
1.58 + /**
1.59 + * The data has been purged, or this is the first call to pin.
1.60 + */
1.61 + kUninitialized_PinResult,
1.62 +
1.63 + /**
1.64 + * The data has been retained. The memory contains the same data it held when unpin() was
1.65 + * called.
1.66 + */
1.67 + kRetained_PinResult,
1.68 + };
1.69 +
1.70 + /**
1.71 + * Pin the memory for use. Must not be called while already pinned.
1.72 + * @param PinResult Whether the data was retained. Ignored on failure.
1.73 + * @return Pointer to the pinned data on success. NULL on failure.
1.74 + */
1.75 + void* pin(PinResult*);
1.76 +
1.77 + /**
1.78 + * Unpin the data so it can be purged if necessary.
1.79 + */
1.80 + void unpin();
1.81 +
1.82 +private:
1.83 + void* fAddr;
1.84 + size_t fSize;
1.85 + bool fPinned;
1.86 +#ifdef SK_BUILD_FOR_ANDROID
1.87 + int fFD;
1.88 +#endif
1.89 +
1.90 + // Unimplemented default constructor is private, to prevent manual creation.
1.91 + SkPurgeableMemoryBlock();
1.92 +
1.93 + // The correct way to create a new one is from the static Create.
1.94 + SkPurgeableMemoryBlock(size_t);
1.95 +};
1.96 +
1.97 +#endif // SkPurgeableMemoryBlock_DEFINED
