android/app/ActivityManager.java

/*
 * Copyright (C) 2007 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 android.app;

import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.pm.IPackageDataObserver;
import android.graphics.Bitmap;
import android.os.RemoteException;
import android.os.Handler;
import android.os.IBinder;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.Parcelable.Creator;
import android.text.TextUtils;
import android.util.Log;

import java.util.List;

/**
 * Interact with the overall activities running in the system.
 */
public class ActivityManager {
    private static String TAG = "ActivityManager";
    private static boolean DEBUG = false;
    private static boolean localLOGV = DEBUG || android.util.Config.LOGV;

    private final Context mContext;
    private final Handler mHandler;

    /*package*/ ActivityManager(Context context, Handler handler) {
        mContext = context;
        mHandler = handler;
    }

    /**
     * Information you can retrieve about tasks that the user has most recently
     * started or visited.
     */
    public static class RecentTaskInfo implements Parcelable {
        /**
         * If this task is currently running, this is the identifier for it.
         * If it is not running, this will be -1.
         */
        public int id;

        /**
         * The original Intent used to launch the task.  You can use this
         * Intent to re-launch the task (if it is no longer running) or bring
         * the current task to the front.
         */
        public Intent baseIntent;

        /**
         * If this task was started from an alias, this is the actual
         * activity component that was initially started; the component of
         * the baseIntent in this case is the name of the actual activity
         * implementation that the alias referred to.  Otherwise, this is null.
         */
        public ComponentName origActivity;

        public RecentTaskInfo() {
        }

        public int describeContents() {
            return 0;
        }

        public void writeToParcel(Parcel dest, int flags) {
            dest.writeInt(id);
            if (baseIntent != null) {
                dest.writeInt(1);
                baseIntent.writeToParcel(dest, 0);
            } else {
                dest.writeInt(0);
            }
            ComponentName.writeToParcel(origActivity, dest);
        }

        public void readFromParcel(Parcel source) {
            id = source.readInt();
            if (source.readInt() != 0) {
                baseIntent = Intent.CREATOR.createFromParcel(source);
            } else {
                baseIntent = null;
            }
            origActivity = ComponentName.readFromParcel(source);
        }

        public static final Creator<RecentTaskInfo> CREATOR
                = new Creator<RecentTaskInfo>() {
            public RecentTaskInfo createFromParcel(Parcel source) {
                return new RecentTaskInfo(source);
            }
            public RecentTaskInfo[] newArray(int size) {
                return new RecentTaskInfo[size];
            }
        };

        private RecentTaskInfo(Parcel source) {
            readFromParcel(source);
        }
    }

    /**
     * Flag for use with {@link #getRecentTasks}: return all tasks, even those
     * that have set their
     * {@link android.content.Intent#FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS} flag.
     */
    public static final int RECENT_WITH_EXCLUDED = 0x0001;

    /**
     * Return a list of the tasks that the user has recently launched, with
     * the most recent being first and older ones after in order.
     *
     * @param maxNum The maximum number of entries to return in the list.  The
     * actual number returned may be smaller, depending on how many tasks the
     * user has started and the maximum number the system can remember.
     *
     * @return Returns a list of RecentTaskInfo records describing each of
     * the recent tasks.
     *
     * @throws SecurityException Throws SecurityException if the caller does
     * not hold the {@link android.Manifest.permission#GET_TASKS} permission.
     */
    public List<RecentTaskInfo> getRecentTasks(int maxNum, int flags)
            throws SecurityException {
        try {
            return ActivityManagerNative.getDefault().getRecentTasks(maxNum,
                    flags);
        } catch (RemoteException e) {
            // System dead, we will be dead too soon!
            return null;
        }
    }

    /**
     * Information you can retrieve about a particular task that is currently
     * "running" in the system.  Note that a running task does not mean the
     * given task actual has a process it is actively running in; it simply
     * means that the user has gone to it and never closed it, but currently
     * the system may have killed its process and is only holding on to its
     * last state in order to restart it when the user returns.
     */
    public static class RunningTaskInfo implements Parcelable {
        /**
         * A unique identifier for this task.
         */
        public int id;

        /**
         * The component launched as the first activity in the task.  This can
         * be considered the "application" of this task.
         */
        public ComponentName baseActivity;

        /**
         * The activity component at the top of the history stack of the task.
         * This is what the user is currently doing.
         */
        public ComponentName topActivity;

        /**
         * Thumbnail representation of the task's current state.
         */
        public Bitmap thumbnail;

        /**
         * Description of the task's current state.
         */
        public CharSequence description;

        /**
         * Number of activities in this task.
         */
        public int numActivities;

        /**
         * Number of activities that are currently running (not stopped
         * and persisted) in this task.
         */
        public int numRunning;

        public RunningTaskInfo() {
        }

        public int describeContents() {
            return 0;
        }

        public void writeToParcel(Parcel dest, int flags) {
            dest.writeInt(id);
            ComponentName.writeToParcel(baseActivity, dest);
            ComponentName.writeToParcel(topActivity, dest);
            if (thumbnail != null) {
                dest.writeInt(1);
                thumbnail.writeToParcel(dest, 0);
            } else {
                dest.writeInt(0);
            }
            TextUtils.writeToParcel(description, dest,
                    Parcelable.PARCELABLE_WRITE_RETURN_VALUE);
            dest.writeInt(numActivities);
            dest.writeInt(numRunning);
        }

        public void readFromParcel(Parcel source) {
            id = source.readInt();
            baseActivity = ComponentName.readFromParcel(source);
            topActivity = ComponentName.readFromParcel(source);
            if (source.readInt() != 0) {
                thumbnail = Bitmap.CREATOR.createFromParcel(source);
            } else {
                thumbnail = null;
            }
            description = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(source);
            numActivities = source.readInt();
            numRunning = source.readInt();
        }

        public static final Creator<RunningTaskInfo> CREATOR = new Creator<RunningTaskInfo>() {
            public RunningTaskInfo createFromParcel(Parcel source) {
                return new RunningTaskInfo(source);
            }
            public RunningTaskInfo[] newArray(int size) {
                return new RunningTaskInfo[size];
            }
        };

        private RunningTaskInfo(Parcel source) {
            readFromParcel(source);
        }
    }

    /**
     * Return a list of the tasks that are currently running, with
     * the most recent being first and older ones after in order.  Note that
     * "running" does not mean any of the task's code is currently loaded or
     * activity -- the task may have been frozen by the system, so that it
     * can be restarted in its previous state when next brought to the
     * foreground.
     *
     * @param maxNum The maximum number of entries to return in the list.  The
     * actual number returned may be smaller, depending on how many tasks the
     * user has started.
     *
     * @return Returns a list of RunningTaskInfo records describing each of
     * the running tasks.
     *
     * @throws SecurityException Throws SecurityException if the caller does
     * not hold the {@link android.Manifest.permission#GET_TASKS} permission.
     */
    public List<RunningTaskInfo> getRunningTasks(int maxNum)
            throws SecurityException {
        try {
            return (List<RunningTaskInfo>)ActivityManagerNative.getDefault()
                    .getTasks(maxNum, 0, null);
        } catch (RemoteException e) {
            // System dead, we will be dead too soon!
            return null;
        }
    }

    /**
     * Information you can retrieve about a particular Service that is
     * currently running in the system.
     */
    public static class RunningServiceInfo implements Parcelable {
        /**
         * The service component.
         */
        public ComponentName service;

        /**
         * If non-zero, this is the process the service is running in.
         */
        public int pid;

        /**
         * The name of the process this service runs in.
         */
        public String process;

        /**
         * Set to true if the service has asked to run as a foreground process.
         */
        public boolean foreground;

        /**
         * The time when the service was first made activity, either by someone
         * starting or binding to it.
         */
        public long activeSince;

        /**
         * Set to true if this service has been explicitly started.
         */
        public boolean started;

        /**
         * Number of clients connected to the service.
         */
        public int clientCount;

        /**
         * Number of times the service's process has crashed while the service
         * is running.
         */
        public int crashCount;

        /**
         * The time when there was last activity in the service (either
         * explicit requests to start it or clients binding to it).
         */
        public long lastActivityTime;

        /**
         * If non-zero, this service is not currently running, but scheduled to
         * restart at the given time.
         */
        public long restarting;

        public RunningServiceInfo() {
        }

        public int describeContents() {
            return 0;
        }

        public void writeToParcel(Parcel dest, int flags) {
            ComponentName.writeToParcel(service, dest);
            dest.writeInt(pid);
            dest.writeString(process);
            dest.writeInt(foreground ? 1 : 0);
            dest.writeLong(activeSince);
            dest.writeInt(started ? 1 : 0);
            dest.writeInt(clientCount);
            dest.writeInt(crashCount);
            dest.writeLong(lastActivityTime);
            dest.writeLong(restarting);
        }

        public void readFromParcel(Parcel source) {
            service = ComponentName.readFromParcel(source);
            pid = source.readInt();
            process = source.readString();
            foreground = source.readInt() != 0;
            activeSince = source.readLong();
            started = source.readInt() != 0;
            clientCount = source.readInt();
            crashCount = source.readInt();
            lastActivityTime = source.readLong();
            restarting = source.readLong();
        }

        public static final Creator<RunningServiceInfo> CREATOR = new Creator<RunningServiceInfo>() {
            public RunningServiceInfo createFromParcel(Parcel source) {
                return new RunningServiceInfo(source);
            }
            public RunningServiceInfo[] newArray(int size) {
                return new RunningServiceInfo[size];
            }
        };

        private RunningServiceInfo(Parcel source) {
            readFromParcel(source);
        }
    }

    /**
     * Return a list of the services that are currently running.
     *
     * @param maxNum The maximum number of entries to return in the list.  The
     * actual number returned may be smaller, depending on how many services
     * are running.
     *
     * @return Returns a list of RunningServiceInfo records describing each of
     * the running tasks.
     */
    public List<RunningServiceInfo> getRunningServices(int maxNum)
            throws SecurityException {
        try {
            return (List<RunningServiceInfo>)ActivityManagerNative.getDefault()
                    .getServices(maxNum, 0);
        } catch (RemoteException e) {
            // System dead, we will be dead too soon!
            return null;
        }
    }

    /**
     * Information you can retrieve about the available memory through
     * {@link ActivityManager#getMemoryInfo}.
     */
    public static class MemoryInfo implements Parcelable {
        /**
         * The total available memory on the system.  This number should not
         * be considered absolute: due to the nature of the kernel, a significant
         * portion of this memory is actually in use and needed for the overall
         * system to run well.
         */
        public long availMem;

        /**
         * The threshold of {@link #availMem} at which we consider memory to be
         * low and start killing background services and other non-extraneous
         * processes.
         */
        public long threshold;

        /**
         * Set to true if the system considers itself to currently be in a low
         * memory situation.
         */
        public boolean lowMemory;

        public MemoryInfo() {
        }

        public int describeContents() {
            return 0;
        }

        public void writeToParcel(Parcel dest, int flags) {
            dest.writeLong(availMem);
            dest.writeLong(threshold);
            dest.writeInt(lowMemory ? 1 : 0);
        }

        public void readFromParcel(Parcel source) {
            availMem = source.readLong();
            threshold = source.readLong();
            lowMemory = source.readInt() != 0;
        }

        public static final Creator<MemoryInfo> CREATOR
                = new Creator<MemoryInfo>() {
            public MemoryInfo createFromParcel(Parcel source) {
                return new MemoryInfo(source);
            }
            public MemoryInfo[] newArray(int size) {
                return new MemoryInfo[size];
            }
        };

        private MemoryInfo(Parcel source) {
            readFromParcel(source);
        }
    }

    public void getMemoryInfo(MemoryInfo outInfo) {
        try {
            ActivityManagerNative.getDefault().getMemoryInfo(outInfo);
        } catch (RemoteException e) {
        }
    }

    /**
     * @hide
     */
    public boolean clearApplicationUserData(String packageName, IPackageDataObserver observer) {
        try {
            return ActivityManagerNative.getDefault().clearApplicationUserData(packageName,
                    observer);
        } catch (RemoteException e) {
            return false;
        }
    }

    /**
     * Information you can retrieve about any processes that are in an error condition.
     */
    public static class ProcessErrorStateInfo implements Parcelable {
        /**
         * Condition codes
         */
        public static final int NO_ERROR = 0;
        public static final int CRASHED = 1;
        public static final int NOT_RESPONDING = 2;

        /**
         * The condition that the process is in.
         */
        public int condition;

        /**
         * The process name in which the crash or error occurred.
         */
        public String processName;

        /**
         * The pid of this process; 0 if none
         */
        public int pid;

        /**
         * The kernel user-ID that has been assigned to this process;
         * currently this is not a unique ID (multiple applications can have
         * the same uid).
         */
        public int uid;

        /**
         * The tag that was provided when the process crashed.
         */
        public String tag;

        /**
         * A short message describing the error condition.
         */
        public String shortMsg;

        /**
         * A long message describing the error condition.
         */
        public String longMsg;

        /**
         * Raw data about the crash (typically a stack trace).
         */
        public byte[] crashData;

        public ProcessErrorStateInfo() {
        }

        public int describeContents() {
            return 0;
        }

        public void writeToParcel(Parcel dest, int flags) {
            dest.writeInt(condition);
            dest.writeString(processName);
            dest.writeInt(pid);
            dest.writeInt(uid);
            dest.writeString(tag);
            dest.writeString(shortMsg);
            dest.writeString(longMsg);
            dest.writeInt(crashData == null ? -1 : crashData.length);
            dest.writeByteArray(crashData);
        }

        public void readFromParcel(Parcel source) {
            condition = source.readInt();
            processName = source.readString();
            pid = source.readInt();
            uid = source.readInt();
            tag = source.readString();
            shortMsg = source.readString();
            longMsg = source.readString();
            int cdLen = source.readInt();
            if (cdLen == -1) {
                crashData = null;
            } else {
                crashData = new byte[cdLen];
                source.readByteArray(crashData);
            }
        }

        public static final Creator<ProcessErrorStateInfo> CREATOR =
                new Creator<ProcessErrorStateInfo>() {
            public ProcessErrorStateInfo createFromParcel(Parcel source) {
                return new ProcessErrorStateInfo(source);
            }
            public ProcessErrorStateInfo[] newArray(int size) {
                return new ProcessErrorStateInfo[size];
            }
        };

        private ProcessErrorStateInfo(Parcel source) {
            readFromParcel(source);
        }
    }

    /**
     * Returns a list of any processes that are currently in an error condition.  The result
     * will be null if all processes are running properly at this time.
     *
     * @return Returns a list of ProcessErrorStateInfo records, or null if there are no
     * current error conditions (it will not return an empty list).  This list ordering is not
     * specified.
     */
    public List<ProcessErrorStateInfo> getProcessesInErrorState() {
        try {
            return ActivityManagerNative.getDefault().getProcessesInErrorState();
        } catch (RemoteException e) {
            return null;
        }
    }
}