src/content/common/gpu/client/gpu_memory_buffer_impl_shm.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/common/gpu/client/gpu_memory_buffer_impl_shm.h"
   6
   7 #include "base/numerics/safe_math.h"
   8 #include "ui/gl/gl_bindings.h"
   9
  10 namespace content {
  11
  12 GpuMemoryBufferImplShm::GpuMemoryBufferImplShm(const gfx::Size& size,
  13                                                unsigned internalformat)
  14     : GpuMemoryBufferImpl(size, internalformat) {}
  15
  16 GpuMemoryBufferImplShm::~GpuMemoryBufferImplShm() {}
  17
  18 // static
  19 void GpuMemoryBufferImplShm::AllocateSharedMemoryForChildProcess(
  20     const gfx::Size& size,
  21     unsigned internalformat,
  22     base::ProcessHandle child_process,
  23     const AllocationCallback& callback) {
  24   DCHECK(IsLayoutSupported(size, internalformat));
  25   gfx::GpuMemoryBufferHandle handle;
  26   base::SharedMemory shared_memory;
  27   if (!shared_memory.CreateAnonymous(size.GetArea() *
  28                                      BytesPerPixel(internalformat))) {
  29     handle.type = gfx::EMPTY_BUFFER;
  30     return;
  31   }
  32   handle.type = gfx::SHARED_MEMORY_BUFFER;
  33   shared_memory.GiveToProcess(child_process, &handle.handle);
  34   callback.Run(handle);
  35 }
  36
  37 // static
  38 bool GpuMemoryBufferImplShm::IsLayoutSupported(const gfx::Size& size,
  39                                                unsigned internalformat) {
  40   base::CheckedNumeric<int> buffer_size = size.width();
  41   buffer_size *= size.height();
  42   buffer_size *= BytesPerPixel(internalformat);
  43   return buffer_size.IsValid();
  44 }
  45
  46 // static
  47 bool GpuMemoryBufferImplShm::IsUsageSupported(unsigned usage) {
  48   switch (usage) {
  49     case GL_IMAGE_MAP_CHROMIUM:
  50       return true;
  51     default:
  52       return false;
  53   }
  54 }
  55
  56 // static
  57 bool GpuMemoryBufferImplShm::IsConfigurationSupported(const gfx::Size& size,
  58                                                       unsigned internalformat,
  59                                                       unsigned usage) {
  60   return IsLayoutSupported(size, internalformat) && IsUsageSupported(usage);
  61 }
  62
  63 bool GpuMemoryBufferImplShm::Initialize() {
  64   DCHECK(IsLayoutSupported(size_, internalformat_));
  65   scoped_ptr<base::SharedMemory> shared_memory(new base::SharedMemory());
  66   if (!shared_memory->CreateAnonymous(size_.GetArea() *
  67                                       BytesPerPixel(internalformat_)))
  68     return false;
  69   shared_memory_ = shared_memory.Pass();
  70   DCHECK(!shared_memory_->memory());
  71   return true;
  72 }
  73
  74 bool GpuMemoryBufferImplShm::InitializeFromHandle(
  75     gfx::GpuMemoryBufferHandle handle) {
  76   DCHECK(IsLayoutSupported(size_, internalformat_));
  77   if (!base::SharedMemory::IsHandleValid(handle.handle))
  78     return false;
  79   shared_memory_.reset(new base::SharedMemory(handle.handle, false));
  80   DCHECK(!shared_memory_->memory());
  81   return true;
  82 }
  83
  84 void* GpuMemoryBufferImplShm::Map() {
  85   DCHECK(!mapped_);
  86   if (!shared_memory_->Map(size_.GetArea() * BytesPerPixel(internalformat_)))
  87     return NULL;
  88   mapped_ = true;
  89   return shared_memory_->memory();
  90 }
  91
  92 void GpuMemoryBufferImplShm::Unmap() {
  93   DCHECK(mapped_);
  94   shared_memory_->Unmap();
  95   mapped_ = false;
  96 }
  97
  98 uint32 GpuMemoryBufferImplShm::GetStride() const {
  99   return size_.width() * BytesPerPixel(internalformat_);
 100 }
 101
 102 gfx::GpuMemoryBufferHandle GpuMemoryBufferImplShm::GetHandle() const {
 103   gfx::GpuMemoryBufferHandle handle;
 104   handle.type = gfx::SHARED_MEMORY_BUFFER;
 105   handle.handle = shared_memory_->handle();
 106   return handle;
 107 }
 108
 109 }  // namespace content