C2BqPool: Expire waiters on Surface switching

Wake up and expire C2Fence waiters for the old Surface when the Surface
is switched to a new Surface.

This was merged before, but mistakenly reverted by a merge conflict
resolution.

Bug: 235330851
Change-Id: I8260fcb00a40c78863717b731a5593981aa1bf49
diff --git a/media/codec2/hal/client/output.cpp b/media/codec2/hal/client/output.cpp
index ce706cc..4eebd1c 100644
--- a/media/codec2/hal/client/output.cpp
+++ b/media/codec2/hal/client/output.cpp
@@ -217,6 +217,7 @@
     sp<GraphicBuffer> buffers[BufferQueueDefs::NUM_BUFFER_SLOTS];
     std::weak_ptr<_C2BlockPoolData>
             poolDatas[BufferQueueDefs::NUM_BUFFER_SLOTS];
+    std::shared_ptr<C2SurfaceSyncMemory> oldMem;
     {
         std::scoped_lock<std::mutex> l(mMutex);
         bool stopped = mStopped;
@@ -238,7 +239,7 @@
             }
             return false;
         }
-        std::shared_ptr<C2SurfaceSyncMemory> oldMem = mSyncMem;
+        oldMem = mSyncMem;
         C2SyncVariables *oldSync = mSyncMem ? mSyncMem->mem() : nullptr;
         if (oldSync) {
             oldSync->lock();
@@ -314,11 +315,26 @@
             newSync->unlock();
         }
     }
+    {
+        std::scoped_lock<std::mutex> l(mOldMutex);
+        mOldMem = oldMem;
+    }
     ALOGD("remote graphic buffer migration %zu/%zu",
           success, tryNum);
     return true;
 }
 
+void OutputBufferQueue::expireOldWaiters() {
+    std::scoped_lock<std::mutex> l(mOldMutex);
+    if (mOldMem) {
+        C2SyncVariables *oldSync = mOldMem->mem();
+        if (oldSync) {
+            oldSync->notifyAll();
+        }
+        mOldMem.reset();
+    }
+}
+
 void OutputBufferQueue::stop() {
     std::scoped_lock<std::mutex> l(mMutex);
     mStopped = true;