1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/thebes/gfxBaseSharedMemorySurface.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,198 @@
1.4 +// vim:set ts=4 sts=4 sw=4 et cin:
1.5 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef GFX_SHARED_MEMORYSURFACE_H
1.11 +#define GFX_SHARED_MEMORYSURFACE_H
1.12 +
1.13 +#include "mozilla/ipc/Shmem.h"
1.14 +#include "mozilla/ipc/SharedMemory.h"
1.15 +
1.16 +#include "gfxASurface.h"
1.17 +#include "gfxImageSurface.h"
1.18 +#include "pratom.h"
1.19 +
1.20 +typedef struct _cairo_user_data_key cairo_user_data_key_t;
1.21 +
1.22 +struct SharedImageInfo {
1.23 + int32_t width;
1.24 + int32_t height;
1.25 + gfxImageFormat format;
1.26 + int32_t readCount;
1.27 +};
1.28 +
1.29 +inline SharedImageInfo*
1.30 +GetShmInfoPtr(const mozilla::ipc::Shmem& aShmem)
1.31 +{
1.32 + return reinterpret_cast<SharedImageInfo*>
1.33 + (aShmem.get<char>() + aShmem.Size<char>() - sizeof(SharedImageInfo));
1.34 +}
1.35 +
1.36 +extern const cairo_user_data_key_t SHM_KEY;
1.37 +
1.38 +template <typename Base, typename Sub>
1.39 +class gfxBaseSharedMemorySurface : public Base {
1.40 + typedef mozilla::ipc::SharedMemory SharedMemory;
1.41 + typedef mozilla::ipc::Shmem Shmem;
1.42 + friend class gfxReusableSharedImageSurfaceWrapper;
1.43 +
1.44 +public:
1.45 + virtual ~gfxBaseSharedMemorySurface()
1.46 + {
1.47 + MOZ_COUNT_DTOR(gfxBaseSharedMemorySurface);
1.48 + }
1.49 +
1.50 + /**
1.51 + * Return a new gfxSharedImageSurface around a shmem segment newly
1.52 + * allocated by this function. |aAllocator| is the object used to
1.53 + * allocate the new shmem segment. Null is returned if creating
1.54 + * the surface failed.
1.55 + *
1.56 + * NB: the *caller* is responsible for freeing the Shmem allocated
1.57 + * by this function.
1.58 + */
1.59 + template<class ShmemAllocator>
1.60 + static already_AddRefed<Sub>
1.61 + Create(ShmemAllocator* aAllocator,
1.62 + const gfxIntSize& aSize,
1.63 + gfxImageFormat aFormat,
1.64 + SharedMemory::SharedMemoryType aShmType = SharedMemory::TYPE_BASIC)
1.65 + {
1.66 + return Create<ShmemAllocator, false>(aAllocator, aSize, aFormat, aShmType);
1.67 + }
1.68 +
1.69 + /**
1.70 + * Return a new gfxSharedImageSurface that wraps a shmem segment
1.71 + * already created by the Create() above. Bad things will happen
1.72 + * if an attempt is made to wrap any other shmem segment. Null is
1.73 + * returned if creating the surface failed.
1.74 + */
1.75 + static already_AddRefed<Sub>
1.76 + Open(const Shmem& aShmem)
1.77 + {
1.78 + SharedImageInfo* shmInfo = GetShmInfoPtr(aShmem);
1.79 + gfxIntSize size(shmInfo->width, shmInfo->height);
1.80 + if (!gfxASurface::CheckSurfaceSize(size))
1.81 + return nullptr;
1.82 +
1.83 + gfxImageFormat format = (gfxImageFormat)shmInfo->format;
1.84 + long stride = gfxImageSurface::ComputeStride(size, format);
1.85 +
1.86 + nsRefPtr<Sub> s =
1.87 + new Sub(size,
1.88 + stride,
1.89 + format,
1.90 + aShmem);
1.91 + // We didn't create this Shmem and so don't free it on errors
1.92 + return (s->CairoStatus() != 0) ? nullptr : s.forget();
1.93 + }
1.94 +
1.95 + template<class ShmemAllocator>
1.96 + static already_AddRefed<Sub>
1.97 + CreateUnsafe(ShmemAllocator* aAllocator,
1.98 + const gfxIntSize& aSize,
1.99 + gfxImageFormat aFormat,
1.100 + SharedMemory::SharedMemoryType aShmType = SharedMemory::TYPE_BASIC)
1.101 + {
1.102 + return Create<ShmemAllocator, true>(aAllocator, aSize, aFormat, aShmType);
1.103 + }
1.104 +
1.105 + Shmem& GetShmem() { return mShmem; }
1.106 +
1.107 + static bool IsSharedImage(gfxASurface *aSurface)
1.108 + {
1.109 + return (aSurface
1.110 + && aSurface->GetType() == gfxSurfaceType::Image
1.111 + && aSurface->GetData(&SHM_KEY));
1.112 + }
1.113 +
1.114 +protected:
1.115 + gfxBaseSharedMemorySurface(const gfxIntSize& aSize, long aStride,
1.116 + gfxImageFormat aFormat,
1.117 + const Shmem& aShmem)
1.118 + : Base(aShmem.get<unsigned char>(), aSize, aStride, aFormat)
1.119 + {
1.120 + MOZ_COUNT_CTOR(gfxBaseSharedMemorySurface);
1.121 +
1.122 + mShmem = aShmem;
1.123 + this->SetData(&SHM_KEY, this, nullptr);
1.124 + }
1.125 +
1.126 +private:
1.127 + void WriteShmemInfo()
1.128 + {
1.129 + SharedImageInfo* shmInfo = GetShmInfoPtr(mShmem);
1.130 + shmInfo->width = this->mSize.width;
1.131 + shmInfo->height = this->mSize.height;
1.132 + shmInfo->format = this->mFormat;
1.133 + shmInfo->readCount = 0;
1.134 + }
1.135 +
1.136 + int32_t
1.137 + ReadLock()
1.138 + {
1.139 + SharedImageInfo* shmInfo = GetShmInfoPtr(mShmem);
1.140 + return PR_ATOMIC_INCREMENT(&shmInfo->readCount);
1.141 + }
1.142 +
1.143 + int32_t
1.144 + ReadUnlock()
1.145 + {
1.146 + SharedImageInfo* shmInfo = GetShmInfoPtr(mShmem);
1.147 + return PR_ATOMIC_DECREMENT(&shmInfo->readCount);
1.148 + }
1.149 +
1.150 + int32_t
1.151 + GetReadCount()
1.152 + {
1.153 + SharedImageInfo* shmInfo = GetShmInfoPtr(mShmem);
1.154 + return shmInfo->readCount;
1.155 + }
1.156 +
1.157 + static size_t GetAlignedSize(const gfxIntSize& aSize, long aStride)
1.158 + {
1.159 + #define MOZ_ALIGN_WORD(x) (((x) + 3) & ~3)
1.160 + return MOZ_ALIGN_WORD(sizeof(SharedImageInfo) + aSize.height * aStride);
1.161 + }
1.162 +
1.163 + template<class ShmemAllocator, bool Unsafe>
1.164 + static already_AddRefed<Sub>
1.165 + Create(ShmemAllocator* aAllocator,
1.166 + const gfxIntSize& aSize,
1.167 + gfxImageFormat aFormat,
1.168 + SharedMemory::SharedMemoryType aShmType)
1.169 + {
1.170 + if (!gfxASurface::CheckSurfaceSize(aSize))
1.171 + return nullptr;
1.172 +
1.173 + Shmem shmem;
1.174 + long stride = gfxImageSurface::ComputeStride(aSize, aFormat);
1.175 + size_t size = GetAlignedSize(aSize, stride);
1.176 + if (!Unsafe) {
1.177 + if (!aAllocator->AllocShmem(size, aShmType, &shmem))
1.178 + return nullptr;
1.179 + } else {
1.180 + if (!aAllocator->AllocUnsafeShmem(size, aShmType, &shmem))
1.181 + return nullptr;
1.182 + }
1.183 +
1.184 + nsRefPtr<Sub> s =
1.185 + new Sub(aSize, stride, aFormat, shmem);
1.186 + if (s->CairoStatus() != 0) {
1.187 + aAllocator->DeallocShmem(shmem);
1.188 + return nullptr;
1.189 + }
1.190 + s->WriteShmemInfo();
1.191 + return s.forget();
1.192 + }
1.193 +
1.194 + Shmem mShmem;
1.195 +
1.196 + // Calling these is very bad, disallow it
1.197 + gfxBaseSharedMemorySurface(const gfxBaseSharedMemorySurface&);
1.198 + gfxBaseSharedMemorySurface& operator=(const gfxBaseSharedMemorySurface&);
1.199 +};
1.200 +
1.201 +#endif /* GFX_SHARED_MEMORYSURFACE_H */
