| /* |
| * Copyright (C) 2017 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. |
| */ |
| |
| package com.android.internal.os; |
| |
| import android.annotation.Nullable; |
| import android.os.SystemClock; |
| import android.util.Slog; |
| |
| /** |
| * The base class of all KernelUidCpuTimeReaders. |
| * |
| * This class is NOT designed to be thread-safe or accessed by more than one caller (due to |
| * the nature of {@link #readDelta(Callback)}). |
| */ |
| public abstract class KernelUidCpuTimeReaderBase<T extends KernelUidCpuTimeReaderBase.Callback> { |
| protected static final boolean DEBUG = false; |
| // Throttle interval in milliseconds |
| private static final long DEFAULT_THROTTLE_INTERVAL = 10_000L; |
| |
| private final String TAG = this.getClass().getSimpleName(); |
| private long mLastTimeReadMs = Long.MIN_VALUE; |
| private long mThrottleInterval = DEFAULT_THROTTLE_INTERVAL; |
| |
| // A generic Callback interface (used by readDelta) to be extended by subclasses. |
| public interface Callback { |
| } |
| |
| public void readDelta(@Nullable T cb) { |
| if (SystemClock.elapsedRealtime() < mLastTimeReadMs + mThrottleInterval) { |
| if (DEBUG) { |
| Slog.d(TAG, "Throttle"); |
| } |
| return; |
| } |
| readDeltaImpl(cb); |
| mLastTimeReadMs = SystemClock.elapsedRealtime(); |
| } |
| |
| protected abstract void readDeltaImpl(@Nullable T cb); |
| |
| public void setThrottleInterval(long throttleInterval) { |
| if (throttleInterval >= 0) { |
| mThrottleInterval = throttleInterval; |
| } |
| } |
| } |