From 59bfd2bbed9576ecdfc01720ca47215c47d7475a Mon Sep 17 00:00:00 2001
From: Dan Stoza <stoza@google.com>
Date: Thu, 14 May 2015 09:27:25 -0700
Subject: [PATCH] SurfaceFlinger: Handle EGL errors more cleanly

Adds some more safety checking for cases where we get an error while
trying to create the EGLImage. The checking puts the Layer into a
failed state after detecting an error, since the shadow queue may no
longer be synchronized.

Bug: 20957332
Change-Id: I68b4c40eab3e58731b875ed5752f2c7d17f14bcb
(cherry picked from commit 65476f3332641066a99e22338bf5cf49ce4af642)
---
 services/surfaceflinger/Layer.cpp | 21 ++++++++++++++++++++-
 services/surfaceflinger/Layer.h   |  1 +
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 2b733e905..8d8af522f 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -84,7 +84,8 @@ Layer::Layer(SurfaceFlinger* flinger, const sp<Client>& client,
         mQueueItemLock(),
         mQueueItemCondition(),
         mQueueItems(),
-        mLastFrameNumberReceived(0)
+        mLastFrameNumberReceived(0),
+        mUpdateTexImageFailed(false)
 {
     mCurrentCrop.makeInvalid();
     mFlinger->getRenderEngine().genTextures(1, &mTextureName);
@@ -1313,6 +1314,24 @@ Region Layer::latchBuffer(bool& recomputeVisibleRegions)
             Mutex::Autolock lock(mQueueItemLock);
             mQueueItems.removeAt(0);
             android_atomic_dec(&mQueuedFrames);
+            return outDirtyRegion;
+        } else if (updateResult != NO_ERROR || mUpdateTexImageFailed) {
+            // This can occur if something goes wrong when trying to create the
+            // EGLImage for this buffer. If this happens, the buffer has already
+            // been released, so we need to clean up the queue and bug out
+            // early.
+            {
+                Mutex::Autolock lock(mQueueItemLock);
+                mQueueItems.clear();
+                android_atomic_and(0, &mQueuedFrames);
+            }
+
+            // Once we have hit this state, the shadow queue may no longer
+            // correctly reflect the incoming BufferQueue's contents, so even if
+            // updateTexImage starts working, the only safe course of action is
+            // to continue to ignore updates.
+            mUpdateTexImageFailed = true;
+
             return outDirtyRegion;
         }
 
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 947da854c..4e222b740 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -419,6 +419,7 @@ private:
     Condition mQueueItemCondition;
     Vector<BufferItem> mQueueItems;
     uint64_t mLastFrameNumberReceived;
+    bool mUpdateTexImageFailed; // This is only modified from the main thread
 };
 
 // ---------------------------------------------------------------------------