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Commit f460f55c authored by Jesse Hall's avatar Jesse Hall
Browse files

Set the swap interval of virtual display surfaces to 0 

This prevents slow/malicious virtual display consumers from
backpressuring SurfaceFlinger and preventing it from updating other
displays.

Bug: 10193714
Change-Id: I3e877d97202628d2d9abea24b66576f38299c14d
parent 687821c0

services/surfaceflinger/DisplayDevice.cpp

+12 −1
Original line number Original line Diff line number Diff line
@@ -63,7 +63,6 @@ DisplayDevice::DisplayDevice( 
      mDisplaySurface(displaySurface),

      mDisplaySurface(displaySurface),

      mDisplay(EGL_NO_DISPLAY),

      mDisplay(EGL_NO_DISPLAY),

      mSurface(EGL_NO_SURFACE),

      mSurface(EGL_NO_SURFACE),

      mContext(EGL_NO_CONTEXT),

      mDisplayWidth(), mDisplayHeight(), mFormat(),

      mDisplayWidth(), mDisplayHeight(), mFormat(),

      mFlags(),

      mFlags(),

      mPageFlipCount(),

      mPageFlipCount(),
@@ -79,6 +78,16 @@ DisplayDevice::DisplayDevice( 
    int format;

    int format;

    window->query(window, NATIVE_WINDOW_FORMAT, &format);

    window->query(window, NATIVE_WINDOW_FORMAT, &format);





    // Make sure that composition can never be stalled by a virtual display

    // consumer that isn't processing buffers fast enough. We have to do this

    // in two places:

    // * Here, in case the display is composed entirely by HWC.

    // * In makeCurrent(), using eglSwapInterval. Some EGL drivers set the

    //   window's swap interval in eglMakeCurrent, so they'll override the

    //   interval we set here.

    if (mType >= DisplayDevice::DISPLAY_VIRTUAL)

        window->setSwapInterval(window, 0);



    /*

    /*

     * Create our display's surface

     * Create our display's surface

     */

     */
@@ -253,6 +262,8 @@ EGLBoolean DisplayDevice::makeCurrent(EGLDisplay dpy, EGLContext ctx) const { 
    if (sur != mSurface) {

    if (sur != mSurface) {

        result = eglMakeCurrent(dpy, mSurface, mSurface, ctx);

        result = eglMakeCurrent(dpy, mSurface, mSurface, ctx);

        if (result == EGL_TRUE) {

        if (result == EGL_TRUE) {

            if (mType >= DisplayDevice::DISPLAY_VIRTUAL)

                eglSwapInterval(dpy, 0);

            setViewportAndProjection();

            setViewportAndProjection();

        }

        }

    }

    }

services/surfaceflinger/DisplayDevice.h

+0 −1
Original line number Original line Diff line number Diff line
@@ -170,7 +170,6 @@ private: 




    EGLDisplay      mDisplay;

    EGLDisplay      mDisplay;

    EGLSurface      mSurface;

    EGLSurface      mSurface;

    EGLContext      mContext;

    int             mDisplayWidth;

    int             mDisplayWidth;

    int             mDisplayHeight;

    int             mDisplayHeight;

    PixelFormat     mFormat;

    PixelFormat     mFormat;