Watch for SurfaceFlinger death

The ComposerService object wasn't watching for SurfaceFlinger
restarts, which doesn't usually matter because the app framework
restarts when SurfaceFlinger dies.  However, mediaserver continues
to run, which means its ComposerService object was trying to use
a dead handle, and playback of DRM movies was failing.

This adds a DeathRecipient listener and some logic to re-establish
the SurfaceFlinger connection.

Bug 6645813

Change-Id: I07581b881d3835601aa57d5358c8259d93bc4515

1 files changed, 37 insertions, 2 deletions

diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 814036e..9b43ae8 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -46,14 +46,49 @@ ANDROID_SINGLETON_STATIC_INSTANCE(ComposerService);
 
 ComposerService::ComposerService()
 : Singleton<ComposerService>() {
+    Mutex::Autolock _l(mLock);
+    connectLocked();
+}
+
+void ComposerService::connectLocked() {
     const String16 name("SurfaceFlinger");
     while (getService(name, &mComposerService) != NO_ERROR) {
         usleep(250000);
     }
+    assert(mComposerService != NULL);
+
+    // Create the death listener.
+    class DeathObserver : public IBinder::DeathRecipient {
+        ComposerService& mComposerService;
+        virtual void binderDied(const wp<IBinder>& who) {
+            ALOGW("ComposerService remote (surfaceflinger) died [%p]",
+                  who.unsafe_get());
+            mComposerService.composerServiceDied();
+        }
+     public:
+        DeathObserver(ComposerService& mgr) : mComposerService(mgr) { }
+    };
+
+    mDeathObserver = new DeathObserver(*const_cast<ComposerService*>(this));
+    mComposerService->asBinder()->linkToDeath(mDeathObserver);
+}
+
+/*static*/ sp<ISurfaceComposer> ComposerService::getComposerService() {
+    ComposerService& instance = ComposerService::getInstance();
+    Mutex::Autolock _l(instance.mLock);
+    if (instance.mComposerService == NULL) {
+        ComposerService::getInstance().connectLocked();
+        assert(instance.mComposerService != NULL);
+        ALOGD("ComposerService reconnected");
+    }
+    return instance.mComposerService;
 }
 
-sp<ISurfaceComposer> ComposerService::getComposerService() {
-    return ComposerService::getInstance().mComposerService;
+void ComposerService::composerServiceDied()
+{
+    Mutex::Autolock _l(mLock);
+    mComposerService = NULL;
+    mDeathObserver = NULL;
 }
 
 // ---------------------------------------------------------------------------