Merge "Add micro-benchmark for media metrics"

cc_test {

    name: "mediametrics_benchmarks",

    srcs: ["mediametrics_benchmarks.cpp"],

    shared_libs: ["libbinder", "libmediametrics",],

    static_libs: ["libgoogle-benchmark"],

}

This benchmark may fail occasionally, probably due to the binder queue being full.

If that happens, just re-run it and it will usually work eventually.

adb shell /data/nativetest64/media\_metrics/media\_metrics

/*

 * Copyright (C) 2020 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.

 */

#include <media/MediaMetricsItem.h>

#include <benchmark/benchmark.h>

class MyItem : public android::mediametrics::BaseItem {

public:

    static bool mySubmitBuffer() {

        // Deliberately lame so that we're measuring just the cost to deliver things to the service.

        return submitBuffer("", 0);

    }

};

static void BM_SubmitBuffer(benchmark::State& state)

{

    while (state.KeepRunning()) {

        MyItem myItem;

        bool ok = myItem.mySubmitBuffer();

        if (ok == false) {

            // submitBuffer() currently uses one-way binder IPC, which provides unreliable delivery

            // with at-most-one guarantee.

            // It is expected that the call may occasionally fail if the one-way queue is full.

            // The Iterations magic number below was tuned to reduce, but not eliminate, failures.

            state.SkipWithError("failed");

            return;

        }

        benchmark::ClobberMemory();

    }

}

BENCHMARK(BM_SubmitBuffer)->Iterations(4000);   // Adjust magic number until test runs

BENCHMARK_MAIN();