ui/gl/gl_image_shared_memory.cc

   1 // Copyright 2014 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 "ui/gl/gl_image_shared_memory.h"
   6
   7 #include "base/logging.h"
   8 #include "base/numerics/safe_math.h"
   9 #include "base/process/process_handle.h"
  10
  11 namespace gfx {
  12 namespace {
  13
  14 // Returns true if the size is valid and false otherwise.
  15 bool SizeInBytes(const gfx::Size& size,
  16                  gfx::GpuMemoryBuffer::Format format,
  17                  size_t* size_in_bytes) {
  18   if (size.IsEmpty())
  19     return false;
  20
  21   if (!GLImageMemory::ValidSize(size, format))
  22     return false;
  23
  24   size_t stride_in_bytes = 0;
  25   if (!GLImageMemory::StrideInBytes(size.width(), format, &stride_in_bytes))
  26     return false;
  27   base::CheckedNumeric<size_t> s = stride_in_bytes;
  28   s *= size.height();
  29   if (!s.IsValid())
  30     return false;
  31   *size_in_bytes = s.ValueOrDie();
  32   return true;
  33 }
  34
  35 }  // namespace
  36
  37 GLImageSharedMemory::GLImageSharedMemory(const gfx::Size& size,
  38                                          unsigned internalformat)
  39     : GLImageMemory(size, internalformat) {
  40 }
  41
  42 GLImageSharedMemory::~GLImageSharedMemory() {
  43   DCHECK(!shared_memory_);
  44 }
  45
  46 bool GLImageSharedMemory::Initialize(const gfx::GpuMemoryBufferHandle& handle,
  47                                      gfx::GpuMemoryBuffer::Format format) {
  48   size_t size_in_bytes;
  49   if (!SizeInBytes(GetSize(), format, &size_in_bytes))
  50     return false;
  51
  52   if (!base::SharedMemory::IsHandleValid(handle.handle))
  53     return false;
  54
  55   base::SharedMemory shared_memory(handle.handle, true);
  56
  57   // Duplicate the handle.
  58   base::SharedMemoryHandle duped_shared_memory_handle;
  59   if (!shared_memory.ShareToProcess(base::GetCurrentProcessHandle(),
  60                                     &duped_shared_memory_handle)) {
  61     DVLOG(0) << "Failed to duplicate shared memory handle.";
  62     return false;
  63   }
  64
  65   scoped_ptr<base::SharedMemory> duped_shared_memory(
  66       new base::SharedMemory(duped_shared_memory_handle, true));
  67   if (!duped_shared_memory->Map(size_in_bytes)) {
  68     DVLOG(0) << "Failed to map shared memory.";
  69     return false;
  70   }
  71
  72   if (!GLImageMemory::Initialize(
  73           static_cast<unsigned char*>(duped_shared_memory->memory()), format)) {
  74     return false;
  75   }
  76
  77   DCHECK(!shared_memory_);
  78   shared_memory_ = duped_shared_memory.Pass();
  79   return true;
  80 }
  81
  82 void GLImageSharedMemory::Destroy(bool have_context) {
  83   GLImageMemory::Destroy(have_context);
  84   shared_memory_.reset();
  85 }
  86
  87 }  // namespace gfx