Christopher Tate | 8662cab5 | 2012-02-23 14:59:36 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 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 | |
| 17 | package android.os; |
| 18 | |
Artur Satayev | afdb23a | 2019-12-10 17:47:53 +0000 | [diff] [blame] | 19 | import android.compat.annotation.UnsupportedAppUsage; |
Christopher Tate | 8662cab5 | 2012-02-23 14:59:36 -0800 | [diff] [blame] | 20 | import android.content.Context; |
| 21 | import android.util.Log; |
| 22 | |
| 23 | /** |
| 24 | * Advisory wakelock-like mechanism by which processes that should not be interrupted for |
| 25 | * OTA/update purposes can so advise the OS. This is particularly relevant for headless |
| 26 | * or kiosk-like operation. |
| 27 | * |
| 28 | * @hide |
| 29 | */ |
| 30 | public class UpdateLock { |
| 31 | private static final boolean DEBUG = false; |
| 32 | private static final String TAG = "UpdateLock"; |
| 33 | |
| 34 | private static IUpdateLock sService; |
| 35 | private static void checkService() { |
| 36 | if (sService == null) { |
| 37 | sService = IUpdateLock.Stub.asInterface( |
| 38 | ServiceManager.getService(Context.UPDATE_LOCK_SERVICE)); |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | IBinder mToken; |
| 43 | int mCount = 0; |
| 44 | boolean mRefCounted = true; |
| 45 | boolean mHeld = false; |
| 46 | final String mTag; |
| 47 | |
| 48 | /** |
| 49 | * Broadcast Intent action sent when the global update lock state changes, |
| 50 | * i.e. when the first locker acquires an update lock, or when the last |
| 51 | * locker releases theirs. The broadcast is sticky but is sent only to |
| 52 | * registered receivers. |
| 53 | */ |
Andrei Onea | 24ec321 | 2019-03-15 17:35:05 +0000 | [diff] [blame] | 54 | @UnsupportedAppUsage |
Christopher Tate | 8662cab5 | 2012-02-23 14:59:36 -0800 | [diff] [blame] | 55 | public static final String UPDATE_LOCK_CHANGED = "android.os.UpdateLock.UPDATE_LOCK_CHANGED"; |
| 56 | |
| 57 | /** |
| 58 | * Boolean Intent extra on the UPDATE_LOCK_CHANGED sticky broadcast, indicating |
| 59 | * whether now is an appropriate time to interrupt device activity with an |
| 60 | * update operation. True means that updates are okay right now; false indicates |
| 61 | * that perhaps later would be a better time. |
| 62 | */ |
Andrei Onea | 24ec321 | 2019-03-15 17:35:05 +0000 | [diff] [blame] | 63 | @UnsupportedAppUsage |
Christopher Tate | 8662cab5 | 2012-02-23 14:59:36 -0800 | [diff] [blame] | 64 | public static final String NOW_IS_CONVENIENT = "nowisconvenient"; |
| 65 | |
| 66 | /** |
| 67 | * Long Intent extra on the UPDATE_LOCK_CHANGED sticky broadcast, marking the |
| 68 | * wall-clock time [in UTC] at which the broadcast was sent. Note that this is |
| 69 | * in the System.currentTimeMillis() time base, which may be non-monotonic especially |
| 70 | * around reboots. |
| 71 | */ |
Andrei Onea | 24ec321 | 2019-03-15 17:35:05 +0000 | [diff] [blame] | 72 | @UnsupportedAppUsage |
Christopher Tate | 8662cab5 | 2012-02-23 14:59:36 -0800 | [diff] [blame] | 73 | public static final String TIMESTAMP = "timestamp"; |
| 74 | |
| 75 | /** |
| 76 | * Construct an UpdateLock instance. |
| 77 | * @param tag An arbitrary string used to identify this lock instance in dump output. |
| 78 | */ |
| 79 | public UpdateLock(String tag) { |
| 80 | mTag = tag; |
| 81 | mToken = new Binder(); |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Change the refcount behavior of this update lock. |
| 86 | */ |
| 87 | public void setReferenceCounted(boolean isRefCounted) { |
| 88 | if (DEBUG) { |
| 89 | Log.v(TAG, "setting refcounted=" + isRefCounted + " : " + this); |
| 90 | } |
| 91 | mRefCounted = isRefCounted; |
| 92 | } |
| 93 | |
| 94 | /** |
| 95 | * Is this lock currently held? |
| 96 | */ |
Andrei Onea | 24ec321 | 2019-03-15 17:35:05 +0000 | [diff] [blame] | 97 | @UnsupportedAppUsage |
Christopher Tate | 8662cab5 | 2012-02-23 14:59:36 -0800 | [diff] [blame] | 98 | public boolean isHeld() { |
| 99 | synchronized (mToken) { |
| 100 | return mHeld; |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | /** |
| 105 | * Acquire an update lock. |
| 106 | */ |
Andrei Onea | 24ec321 | 2019-03-15 17:35:05 +0000 | [diff] [blame] | 107 | @UnsupportedAppUsage |
Christopher Tate | 8662cab5 | 2012-02-23 14:59:36 -0800 | [diff] [blame] | 108 | public void acquire() { |
| 109 | if (DEBUG) { |
| 110 | Log.v(TAG, "acquire() : " + this, new RuntimeException("here")); |
| 111 | } |
| 112 | checkService(); |
| 113 | synchronized (mToken) { |
| 114 | acquireLocked(); |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | private void acquireLocked() { |
| 119 | if (!mRefCounted || mCount++ == 0) { |
| 120 | if (sService != null) { |
| 121 | try { |
| 122 | sService.acquireUpdateLock(mToken, mTag); |
| 123 | } catch (RemoteException e) { |
| 124 | Log.e(TAG, "Unable to contact service to acquire"); |
| 125 | } |
| 126 | } |
| 127 | mHeld = true; |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | * Release this update lock. |
| 133 | */ |
Andrei Onea | 24ec321 | 2019-03-15 17:35:05 +0000 | [diff] [blame] | 134 | @UnsupportedAppUsage |
Christopher Tate | 8662cab5 | 2012-02-23 14:59:36 -0800 | [diff] [blame] | 135 | public void release() { |
| 136 | if (DEBUG) Log.v(TAG, "release() : " + this, new RuntimeException("here")); |
| 137 | checkService(); |
| 138 | synchronized (mToken) { |
| 139 | releaseLocked(); |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | private void releaseLocked() { |
| 144 | if (!mRefCounted || --mCount == 0) { |
| 145 | if (sService != null) { |
| 146 | try { |
| 147 | sService.releaseUpdateLock(mToken); |
| 148 | } catch (RemoteException e) { |
| 149 | Log.e(TAG, "Unable to contact service to release"); |
| 150 | } |
| 151 | } |
| 152 | mHeld = false; |
| 153 | } |
| 154 | if (mCount < 0) { |
| 155 | throw new RuntimeException("UpdateLock under-locked"); |
| 156 | } |
| 157 | } |
| 158 | |
| 159 | @Override |
| 160 | protected void finalize() throws Throwable { |
| 161 | synchronized (mToken) { |
| 162 | // if mHeld is true, sService must be non-null |
| 163 | if (mHeld) { |
| 164 | Log.wtf(TAG, "UpdateLock finalized while still held"); |
| 165 | try { |
| 166 | sService.releaseUpdateLock(mToken); |
| 167 | } catch (RemoteException e) { |
| 168 | Log.e(TAG, "Unable to contact service to release"); |
| 169 | } |
| 170 | } |
| 171 | } |
| 172 | } |
| 173 | } |