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   size_t stride_in_bytes = 0;
  22   if (!GLImageMemory::StrideInBytes(size.width(), format, &stride_in_bytes))
  23     return false;
  24   base::CheckedNumeric<size_t> s = stride_in_bytes;
  25   s *= size.height();
  26   if (!s.IsValid())
  27     return false;
  28   *size_in_bytes = s.ValueOrDie();
  29   return true;
  30 }
  31
  32 }  // namespace
  33
  34 GLImageSharedMemory::GLImageSharedMemory(const gfx::Size& size,
  35                                          unsigned internalformat)
  36     : GLImageMemory(size, internalformat) {
  37 }
  38
  39 GLImageSharedMemory::~GLImageSharedMemory() {
  40   DCHECK(!shared_memory_);
  41 }
  42
  43 bool GLImageSharedMemory::Initialize(const gfx::GpuMemoryBufferHandle& handle,
  44                                      gfx::GpuMemoryBuffer::Format format) {
  45   size_t size_in_bytes;
  46   if (!SizeInBytes(GetSize(), format, &size_in_bytes))
  47     return false;
  48
  49   if (!base::SharedMemory::IsHandleValid(handle.handle))
  50     return false;
  51
  52   base::SharedMemory shared_memory(handle.handle, true);
  53
  54   // Duplicate the handle.
  55   base::SharedMemoryHandle duped_shared_memory_handle;
  56   if (!shared_memory.ShareToProcess(base::GetCurrentProcessHandle(),
  57                                     &duped_shared_memory_handle)) {
  58     DVLOG(0) << "Failed to duplicate shared memory handle.";
  59     return false;
  60   }
  61
  62   scoped_ptr<base::SharedMemory> duped_shared_memory(
  63       new base::SharedMemory(duped_shared_memory_handle, true));
  64   if (!duped_shared_memory->Map(size_in_bytes)) {
  65     DVLOG(0) << "Failed to map shared memory.";
  66     return false;
  67   }
  68
  69   if (!GLImageMemory::Initialize(
  70           static_cast<unsigned char*>(duped_shared_memory->memory()), format)) {
  71     return false;
  72   }
  73
  74   DCHECK(!shared_memory_);
  75   shared_memory_ = duped_shared_memory.Pass();
  76   return true;
  77 }
  78
  79 void GLImageSharedMemory::Destroy(bool have_context) {
  80   GLImageMemory::Destroy(have_context);
  81   shared_memory_.reset();
  82 }
  83
  84 }  // namespace gfx