blast: Queue transactions by applying client

Do not update SurfaceFlinger until all the fences in a transaction
have signaled. While waiting on the fences, place the transaction
in a queue with other transactions that were applied by the
same SurfaceComposerClient.

Test: Transaction_test
Bug: 80477568

Change-Id: I6b866bfa955d5eafef28016a0c5de7c3862f1837
diff --git a/services/surfaceflinger/tests/BufferGenerator.h b/services/surfaceflinger/tests/BufferGenerator.h
new file mode 100644
index 0000000..a3ffe86
--- /dev/null
+++ b/services/surfaceflinger/tests/BufferGenerator.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <condition_variable>
+#include <mutex>
+
+#include <ui/GraphicBuffer.h>
+
+namespace android {
+
+class SurfaceManager;
+class EglManager;
+class Program;
+
+class BufferGenerator {
+public:
+    BufferGenerator();
+    ~BufferGenerator();
+
+    /* Get a new fence */
+    status_t get(sp<GraphicBuffer>* outBuffer, sp<Fence>* outFence);
+
+    /* Static callback that sets the fence on a particular instance */
+    static void setBuffer(const sp<GraphicBuffer>& buffer, int32_t fence, void* fenceGenerator);
+
+private:
+    bool mInitialized = false;
+
+    std::unique_ptr<SurfaceManager> mSurfaceManager;
+    std::unique_ptr<EglManager> mEglManager;
+    std::unique_ptr<Program> mProgram;
+
+    std::condition_variable_any mConditionVariable;
+
+    sp<GraphicBuffer> mGraphicBuffer;
+    int32_t mFence = -1;
+    bool mPending = false;
+
+    using Epoch = std::chrono::time_point<std::chrono::steady_clock>;
+    Epoch mEpoch = std::chrono::steady_clock::now();
+};
+
+} // namespace android