don't kill surfaceflinger when system process dies

Change-Id: I2d3ed87b590f9ccea3fa4af41d92911de070b315

services/surfaceflinger/DisplayHardware/DisplayHardware.cpp

@@ -103,6 +103,11 @@ void DisplayHardware::init(uint32_t dpy)
 {
     mNativeWindow = new FramebufferNativeWindow();
     framebuffer_device_t const * fbDev = mNativeWindow->getDevice();
+    if (!fbDev) {
+        LOGE("Display subsystem failed to initialize. check logs. exiting...");
+        exit(0);
+    }
+
     mDpiX = mNativeWindow->xdpi;
     mDpiY = mNativeWindow->ydpi;
     mRefreshRate = fbDev->fps;

services/surfaceflinger/SurfaceFlinger.cpp

@@ -163,9 +163,34 @@ void SurfaceFlinger::bootFinished()
     const nsecs_t duration = now - mBootTime;
     LOGI("Boot is finished (%ld ms)", long(ns2ms(duration)) );
     mBootFinished = true;
+
+    // wait patiently for the window manager death
+    const String16 name("window");
+    sp<IBinder> window(defaultServiceManager()->getService(name));
+    if (window != 0) {
+        window->linkToDeath(this);
+    }
+
+    // stop boot animation
     property_set("ctl.stop", "bootanim");
 }
 
+void SurfaceFlinger::binderDied(const wp<IBinder>& who)
+{
+    // the window manager died on us. prepare its eulogy.
+
+    // unfreeze the screen in case it was... frozen
+    mFreezeDisplayTime = 0;
+    mFreezeCount = 0;
+    mFreezeDisplay = false;
+
+    // reset screen orientation
+    setOrientation(0, eOrientationDefault, 0);
+
+    // restart the boot-animation
+    property_set("ctl.start", "bootanim");
+}
+
 void SurfaceFlinger::onFirstRef()
 {
     run("SurfaceFlinger", PRIORITY_URGENT_DISPLAY);

services/surfaceflinger/SurfaceFlinger.h

@@ -147,6 +147,7 @@ enum {
 class SurfaceFlinger :
         public BinderService<SurfaceFlinger>,
         public BnSurfaceComposer,
+        public IBinder::DeathRecipient,
         protected Thread
 {
 public:
@@ -192,6 +193,10 @@ public:
 
     sp<Layer> getLayer(const sp<ISurface>& sur) const;
 
+private:
+    // DeathRecipient interface
+    virtual void binderDied(const wp<IBinder>& who);
+
 private:
     friend class Client;
     friend class LayerBase;