gecko-dev/widget/nsShmImage.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef __mozilla_widget_nsShmImage_h__
#define __mozilla_widget_nsShmImage_h__

#if defined(MOZ_X11)
#  define MOZ_HAVE_SHMIMAGE
#endif

#ifdef MOZ_HAVE_SHMIMAGE

#  include "mozilla/gfx/2D.h"
#  include "nsIWidget.h"
#  include "Units.h"

#  include <X11/Xlib-xcb.h>
#  include <xcb/shm.h>

class nsShmImage {
  // bug 1168843, compositor thread may create shared memory instances that are
  // destroyed by main thread on shutdown, so this must use thread-safe RC to
  // avoid hitting assertion
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(nsShmImage)

 public:
  static bool UseShm();

  already_AddRefed<mozilla::gfx::DrawTarget> CreateDrawTarget(
      const mozilla::LayoutDeviceIntRegion& aRegion);

  void Put(const mozilla::LayoutDeviceIntRegion& aRegion);

  nsShmImage(Display* aDisplay, Drawable aWindow, Visual* aVisual,
             unsigned int aDepth);

 private:
  ~nsShmImage();

  bool InitExtension();

  bool CreateShmSegment();
  void DestroyShmSegment();

  bool CreateImage(const mozilla::gfx::IntSize& aSize);
  void DestroyImage();

  void WaitIfPendingReply();

  Display* mDisplay;
  xcb_connection_t* mConnection;
  Window mWindow;
  Visual* mVisual;
  unsigned int mDepth;

  mozilla::gfx::SurfaceFormat mFormat;
  mozilla::gfx::IntSize mSize;
  int mStride;

  xcb_pixmap_t mPixmap;
  xcb_gcontext_t mGC;
  xcb_get_input_focus_cookie_t mSyncRequest;
  bool mRequestPending;

  xcb_shm_seg_t mShmSeg;
  int mShmId;
  uint8_t* mShmAddr;
};

#endif  // MOZ_HAVE_SHMIMAGE

#endif