src/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   base::CheckedNumeric<size_t> s = GLImageMemory::BytesPerPixel(format);
  21   s *= size.width();
  22   s *= size.height();
  23   if (!s.IsValid())
  24     return false;
  25   *size_in_bytes = s.ValueOrDie();
  26   return true;
  27 }
  28
  29 }  // namespace
  30
  31 GLImageSharedMemory::GLImageSharedMemory(const gfx::Size& size,
  32                                          unsigned internalformat)
  33     : GLImageMemory(size, internalformat) {
  34 }
  35
  36 GLImageSharedMemory::~GLImageSharedMemory() {
  37   DCHECK(!shared_memory_);
  38 }
  39
  40 bool GLImageSharedMemory::Initialize(const gfx::GpuMemoryBufferHandle& handle,
  41                                      gfx::GpuMemoryBuffer::Format format) {
  42   size_t size_in_bytes;
  43   if (!SizeInBytes(GetSize(), format, &size_in_bytes))
  44     return false;
  45
  46   if (!base::SharedMemory::IsHandleValid(handle.handle))
  47     return false;
  48
  49   base::SharedMemory shared_memory(handle.handle, true);
  50
  51   // Duplicate the handle.
  52   base::SharedMemoryHandle duped_shared_memory_handle;
  53   if (!shared_memory.ShareToProcess(base::GetCurrentProcessHandle(),
  54                                     &duped_shared_memory_handle)) {
  55     DVLOG(0) << "Failed to duplicate shared memory handle.";
  56     return false;
  57   }
  58
  59   scoped_ptr<base::SharedMemory> duped_shared_memory(
  60       new base::SharedMemory(duped_shared_memory_handle, true));
  61   if (!duped_shared_memory->Map(size_in_bytes)) {
  62     DVLOG(0) << "Failed to map shared memory.";
  63     return false;
  64   }
  65
  66   if (!GLImageMemory::Initialize(
  67           static_cast<unsigned char*>(duped_shared_memory->memory()), format)) {
  68     return false;
  69   }
  70
  71   DCHECK(!shared_memory_);
  72   shared_memory_ = duped_shared_memory.Pass();
  73   return true;
  74 }
  75
  76 void GLImageSharedMemory::Destroy(bool have_context) {
  77   GLImageMemory::Destroy(have_context);
  78   shared_memory_.reset();
  79 }
  80
  81 }  // namespace gfx