The Tor Browser: widget/shared/nsShmImage.cpp@b8a032363ba2 (annotated)

widget/shared/nsShmImage.cpp@b8a032363ba2 (annotated)

widget/shared/nsShmImage.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; 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/. */
 #if defined(MOZ_WIDGET_GTK)
 #include <gtk/gtk.h>
 #include <gdk/gdkx.h>
 #elif defined(MOZ_WIDGET_QT)
 #include <QWindow>
 #endif
 #include "nsShmImage.h"
 #include "gfxPlatform.h"
 #include "gfxImageSurface.h"
 #ifdef MOZ_HAVE_SHMIMAGE
 using namespace mozilla::ipc;
 // If XShm isn't available to our client, we'll try XShm once, fail,
 // set this to false and then never try again.
 static bool gShmAvailable = true;
 bool nsShmImage::UseShm()
 {
     return gfxPlatform::GetPlatform()->
         ScreenReferenceSurface()->GetType() == gfxSurfaceType::Image
         && gShmAvailable;
 }
 already_AddRefed<nsShmImage>
 nsShmImage::Create(const gfxIntSize& aSize,
                    Visual* aVisual, unsigned int aDepth)
 {
     Display* dpy = DISPLAY();
     nsRefPtr<nsShmImage> shm = new nsShmImage();
     shm->mImage = XShmCreateImage(dpy, aVisual, aDepth,
                                   ZPixmap, nullptr,
                                   &(shm->mInfo),
                                   aSize.width, aSize.height);
     if (!shm->mImage) {
         return nullptr;
     }
     size_t size = SharedMemory::PageAlignedSize(
         shm->mImage->bytes_per_line * shm->mImage->height);
     shm->mSegment = new SharedMemorySysV();
     if (!shm->mSegment->Create(size) || !shm->mSegment->Map(size)) {
         return nullptr;
     }
     shm->mInfo.shmid = shm->mSegment->GetHandle();
     shm->mInfo.shmaddr =
         shm->mImage->data = static_cast<char*>(shm->mSegment->memory());
     shm->mInfo.readOnly = False;
     int xerror = 0;
 #if defined(MOZ_WIDGET_GTK)
     gdk_error_trap_push();
     Status attachOk = XShmAttach(dpy, &shm->mInfo);
     XSync(dpy, False);
     xerror = gdk_error_trap_pop();
 #elif defined(MOZ_WIDGET_QT)
     Status attachOk = XShmAttach(dpy, &shm->mInfo);
 #endif
     if (!attachOk || xerror) {
         // Assume XShm isn't available, and don't attempt to use it
         // again.
         gShmAvailable = false;
         return nullptr;
     }
     shm->mXAttached = true;
     shm->mSize = aSize;
     switch (shm->mImage->depth) {
     case 32:
         if ((shm->mImage->red_mask == 0xff0000) &&
             (shm->mImage->green_mask == 0xff00) &&
             (shm->mImage->blue_mask == 0xff)) {
             shm->mFormat = gfxImageFormat::ARGB32;
             break;
         }
         goto unsupported;
     case 24:
         // Only xRGB is supported.
         if ((shm->mImage->red_mask == 0xff0000) &&
             (shm->mImage->green_mask == 0xff00) &&
             (shm->mImage->blue_mask == 0xff)) {
             shm->mFormat = gfxImageFormat::RGB24;
             break;
         }
         goto unsupported;
     case 16:
         shm->mFormat = gfxImageFormat::RGB16_565; break;
     unsupported:
     default:
         NS_WARNING("Unsupported XShm Image format!");
         gShmAvailable = false;
         return nullptr;
     }
     return shm.forget();
 }
 already_AddRefed<gfxASurface>
 nsShmImage::AsSurface()
 {
     return nsRefPtr<gfxASurface>(
         new gfxImageSurface(static_cast<unsigned char*>(mSegment->memory()),
                             mSize,
                             mImage->bytes_per_line,
                             mFormat)
         ).forget();
 }
 #if (MOZ_WIDGET_GTK == 2)
 void
 nsShmImage::Put(GdkWindow* aWindow, GdkRectangle* aRects, GdkRectangle* aEnd)
 {
     GdkDrawable* gd;
     gint dx, dy;
     gdk_window_get_internal_paint_info(aWindow, &gd, &dx, &dy);
     Display* dpy = gdk_x11_get_default_xdisplay();
     Drawable d = GDK_DRAWABLE_XID(gd);
     GC gc = XCreateGC(dpy, d, 0, nullptr);
     for (GdkRectangle* r = aRects; r < aEnd; r++) {
         XShmPutImage(dpy, d, gc, mImage,
                      r->x, r->y,
                      r->x - dx, r->y - dy,
                      r->width, r->height,
                      False);
     }
     XFreeGC(dpy, gc);
     // FIXME/bug 597336: we need to ensure that the shm image isn't
     // scribbled over before all its pending XShmPutImage()s complete.
     // However, XSync() is an unnecessarily heavyweight
     // synchronization mechanism; other options are possible.  If this
     // XSync is shown to hurt responsiveness, we need to explore the
     // other options.
     XSync(dpy, False);
 }
 #elif (MOZ_WIDGET_GTK == 3)
 void
 nsShmImage::Put(GdkWindow* aWindow, cairo_rectangle_list_t* aRects)
 {
     Display* dpy = gdk_x11_get_default_xdisplay();
     Drawable d = GDK_WINDOW_XID(aWindow);
     int dx = 0, dy = 0;
     GC gc = XCreateGC(dpy, d, 0, nullptr);
     cairo_rectangle_t r;
     for (int i = 0; i < aRects->num_rectangles; i++) {
         r = aRects->rectangles[i];
         XShmPutImage(dpy, d, gc, mImage,
                      r.x, r.y,
                      r.x - dx, r.y - dy,
                      r.width, r.height,
                      False);
     }
     XFreeGC(dpy, gc);
     // FIXME/bug 597336: we need to ensure that the shm image isn't
     // scribbled over before all its pending XShmPutImage()s complete.
     // However, XSync() is an unnecessarily heavyweight
     // synchronization mechanism; other options are possible.  If this
     // XSync is shown to hurt responsiveness, we need to explore the
     // other options.
     XSync(dpy, False);
 }
 #elif defined(MOZ_WIDGET_QT)
 void
 nsShmImage::Put(QWindow* aWindow, QRect& aRect)
 {
     Display* dpy = gfxQtPlatform::GetXDisplay(aWindow);
     Drawable d = aWindow->winId();
     GC gc = XCreateGC(dpy, d, 0, nullptr);
     // Avoid out of bounds painting
     QRect inter = aRect.intersected(aWindow->geometry());
     XShmPutImage(dpy, d, gc, mImage,
                  inter.x(), inter.y(),
                  inter.x(), inter.y(),
                  inter.width(), inter.height(),
                  False);
     XFreeGC(dpy, gc);
 }
 #endif
 already_AddRefed<gfxASurface>
 nsShmImage::EnsureShmImage(const gfxIntSize& aSize, Visual* aVisual, unsigned int aDepth,
                nsRefPtr<nsShmImage>& aImage)
 {
     if (!aImage || aImage->Size() != aSize) {
         // Because we XSync() after XShmAttach() to trap errors, we
         // know that the X server has the old image's memory mapped
         // into its address space, so it's OK to destroy the old image
         // here even if there are outstanding Puts.  The Detach is
         // ordered after the Puts.
         aImage = nsShmImage::Create(aSize, aVisual, aDepth);
     }
     return !aImage ? nullptr : aImage->AsSurface();
 }
 #endif  // defined(MOZ_X11) && defined(MOZ_HAVE_SHAREDMEMORYSYSV)

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widget/shared/nsShmImage.cpp@b8a032363ba2 (annotated)

widget/shared/nsShmImage.cpp