Merge "Avoid excessive logging when the necessary proc file is unavailable." into oc-dev

    private SparseArray<long[]> mLastUidCpuFreqTimeMs = new SparseArray<>();

    // We check the existence of proc file a few times (just in case it is not ready yet when we

    // start reading) and if it is not available, we simply ignore further read requests.

    private static final int TOTAL_READ_ERROR_COUNT = 5;

    private int mReadErrorCounter;

    private boolean mProcFileAvailable;

    public void readDelta(@Nullable Callback callback) {

        if (!mProcFileAvailable && mReadErrorCounter >= TOTAL_READ_ERROR_COUNT) {

            return;

        }

        try (BufferedReader reader = new BufferedReader(new FileReader(UID_TIMES_PROC_FILE))) {

            readDelta(reader, callback);

            mProcFileAvailable = true;

        } catch (IOException e) {

            mReadErrorCounter++;

            Slog.e(TAG, "Failed to read " + UID_TIMES_PROC_FILE + ": " + e);

        }

    }