BinderInternal.java revision 6090995951c6e2e4dcf38102f01793f8a94166e1 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.internal.os;
18
19import android.os.IBinder;
20import android.os.SystemClock;
21import android.util.EventLog;
22import java.lang.ref.WeakReference;
23
24/**
25 * Private and debugging Binder APIs.
26 *
27 * @see IBinder
28 */
29public class BinderInternal {
30    static WeakReference<GcWatcher> mGcWatcher
31            = new WeakReference<GcWatcher>(new GcWatcher());
32    static long mLastGcTime;
33
34    static final class GcWatcher {
35        @Override
36        protected void finalize() throws Throwable {
37            handleGc();
38            mLastGcTime = SystemClock.uptimeMillis();
39            mGcWatcher = new WeakReference<GcWatcher>(new GcWatcher());
40        }
41    }
42
43    /**
44     * Add the calling thread to the IPC thread pool.  This function does
45     * not return until the current process is exiting.
46     */
47    public static final native void joinThreadPool();
48
49    /**
50     * Return the system time (as reported by {@link SystemClock#uptimeMillis
51     * SystemClock.uptimeMillis()}) that the last garbage collection occurred
52     * in this process.  This is not for general application use, and the
53     * meaning of "when a garbage collection occurred" will change as the
54     * garbage collector evolves.
55     *
56     * @return Returns the time as per {@link SystemClock#uptimeMillis
57     * SystemClock.uptimeMillis()} of the last garbage collection.
58     */
59    public static long getLastGcTime() {
60        return mLastGcTime;
61    }
62
63    /**
64     * Return the global "context object" of the system.  This is usually
65     * an implementation of IServiceManager, which you can use to find
66     * other services.
67     */
68    public static final native IBinder getContextObject();
69
70    /**
71     * Special for system process to not allow incoming calls to run at
72     * background scheduling priority.
73     * @hide
74     */
75    public static final native void disableBackgroundScheduling(boolean disable);
76
77    static native final void handleGc();
78
79    public static void forceGc(String reason) {
80        EventLog.writeEvent(2741, reason);
81        Runtime.getRuntime().gc();
82    }
83
84    static void forceBinderGc() {
85        forceGc("Binder");
86    }
87}
88