1 /*
2  * Copyright (C) 2020 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 #define LOG_NDEBUG 0
18 #define LOG_TAG "AActivityManager"
19 #include <utils/Log.h>
20 
21 #include <android/activity_manager.h>
22 #include <binder/ActivityManager.h>
23 
24 namespace android {
25 namespace activitymanager {
26 
27 // Global instance of ActivityManager, service is obtained only on first use.
28 static ActivityManager gAm;
29 // String tag used with ActivityManager.
getTag()30 static const String16& getTag() {
31     static String16 tag("libandroid");
32     return tag;
33 }
34 
35 struct UidObserver : public BnUidObserver, public virtual IBinder::DeathRecipient {
UidObserverandroid::activitymanager::UidObserver36     explicit UidObserver(const AActivityManager_onUidImportance& cb,
37                          int32_t cutpoint, void* cookie)
38           : mCallback(cb), mImportanceCutpoint(cutpoint), mCookie(cookie), mRegistered(false) {}
39     bool registerSelf();
40     void unregisterSelf();
41 
42     // IUidObserver
43     void onUidGone(uid_t uid, bool disabled) override;
44     void onUidActive(uid_t uid) override;
45     void onUidIdle(uid_t uid, bool disabled) override;
46     void onUidStateChanged(uid_t uid, int32_t procState, int64_t procStateSeq,
47                            int32_t capability) override;
48     void onUidProcAdjChanged(uid_t uid, int32_t adj) override;
49 
50     // IBinder::DeathRecipient implementation
51     void binderDied(const wp<IBinder>& who) override;
52 
53     static int32_t procStateToImportance(int32_t procState);
54     static int32_t importanceToProcState(int32_t importance);
55 
56     AActivityManager_onUidImportance mCallback;
57     int32_t mImportanceCutpoint;
58     void* mCookie;
59     std::mutex mRegisteredLock;
60     bool mRegistered GUARDED_BY(mRegisteredLock);
61 };
62 
63 //static
procStateToImportance(int32_t procState)64 int32_t UidObserver::procStateToImportance(int32_t procState) {
65     // TODO: remove this after adding Importance to onUidStateChanged callback.
66     if (procState == ActivityManager::PROCESS_STATE_NONEXISTENT) {
67         return AACTIVITYMANAGER_IMPORTANCE_GONE;
68     } else if (procState >= ActivityManager::PROCESS_STATE_HOME) {
69         return AACTIVITYMANAGER_IMPORTANCE_CACHED;
70     } else if (procState == ActivityManager::PROCESS_STATE_HEAVY_WEIGHT) {
71         return AACTIVITYMANAGER_IMPORTANCE_CANT_SAVE_STATE;
72     } else if (procState >= ActivityManager::PROCESS_STATE_TOP_SLEEPING) {
73         return AACTIVITYMANAGER_IMPORTANCE_TOP_SLEEPING;
74     } else if (procState >= ActivityManager::PROCESS_STATE_SERVICE) {
75         return AACTIVITYMANAGER_IMPORTANCE_SERVICE;
76     } else if (procState >= ActivityManager::PROCESS_STATE_TRANSIENT_BACKGROUND) {
77         return AACTIVITYMANAGER_IMPORTANCE_PERCEPTIBLE;
78     } else if (procState >= ActivityManager::PROCESS_STATE_IMPORTANT_FOREGROUND) {
79         return AACTIVITYMANAGER_IMPORTANCE_VISIBLE;
80     } else if (procState >= ActivityManager::PROCESS_STATE_FOREGROUND_SERVICE) {
81         return AACTIVITYMANAGER_IMPORTANCE_FOREGROUND_SERVICE;
82     } else {
83         return AACTIVITYMANAGER_IMPORTANCE_FOREGROUND;
84     }
85 }
86 
87 //static
importanceToProcState(int32_t importance)88 int32_t UidObserver::importanceToProcState(int32_t importance) {
89     // TODO: remove this after adding Importance to onUidStateChanged callback.
90     if (importance == AACTIVITYMANAGER_IMPORTANCE_GONE) {
91         return ActivityManager::PROCESS_STATE_NONEXISTENT;
92     } else if (importance >= AACTIVITYMANAGER_IMPORTANCE_CACHED) {
93         return ActivityManager::PROCESS_STATE_HOME;
94     } else if (importance >= AACTIVITYMANAGER_IMPORTANCE_CANT_SAVE_STATE) {
95         return ActivityManager::PROCESS_STATE_HEAVY_WEIGHT;
96     } else if (importance >= AACTIVITYMANAGER_IMPORTANCE_TOP_SLEEPING) {
97         return ActivityManager::PROCESS_STATE_TOP_SLEEPING;
98     } else if (importance >= AACTIVITYMANAGER_IMPORTANCE_SERVICE) {
99         return ActivityManager::PROCESS_STATE_SERVICE;
100     } else if (importance >= AACTIVITYMANAGER_IMPORTANCE_PERCEPTIBLE) {
101         return ActivityManager::PROCESS_STATE_TRANSIENT_BACKGROUND;
102     } else if (importance >= AACTIVITYMANAGER_IMPORTANCE_VISIBLE) {
103         return ActivityManager::PROCESS_STATE_IMPORTANT_FOREGROUND;
104     } else if (importance >= AACTIVITYMANAGER_IMPORTANCE_FOREGROUND_SERVICE) {
105         return ActivityManager::PROCESS_STATE_FOREGROUND_SERVICE;
106     } else {
107         return ActivityManager::PROCESS_STATE_TOP;
108     }
109 }
110 
111 
onUidGone(uid_t uid,bool disabled __unused)112 void UidObserver::onUidGone(uid_t uid, bool disabled __unused) {
113     std::scoped_lock lock{mRegisteredLock};
114 
115     if (mRegistered && mCallback) {
116         mCallback(uid, AACTIVITYMANAGER_IMPORTANCE_GONE, mCookie);
117     }
118 }
119 
onUidActive(uid_t uid __unused)120 void UidObserver::onUidActive(uid_t uid __unused) {}
121 
onUidIdle(uid_t uid __unused,bool disabled __unused)122 void UidObserver::onUidIdle(uid_t uid __unused, bool disabled __unused) {}
123 
onUidProcAdjChanged(uid_t uid __unused,int32_t adj __unused)124 void UidObserver::onUidProcAdjChanged(uid_t uid __unused, int32_t adj __unused) {}
125 
onUidStateChanged(uid_t uid,int32_t procState,int64_t procStateSeq __unused,int32_t capability __unused)126 void UidObserver::onUidStateChanged(uid_t uid, int32_t procState,
127                                     int64_t procStateSeq __unused,
128                                     int32_t capability __unused) {
129     std::scoped_lock lock{mRegisteredLock};
130 
131     if (mRegistered && mCallback) {
132         mCallback(uid, procStateToImportance(procState), mCookie);
133     }
134 }
135 
binderDied(const wp<IBinder> &)136 void UidObserver::binderDied(const wp<IBinder>& /*who*/) {
137     // ActivityManager is dead, try to re-register.
138     {
139         std::scoped_lock lock{mRegisteredLock};
140         // If client already unregistered, don't try to re-register.
141         if (!mRegistered) {
142             return;
143         }
144         // Clear mRegistered to re-register.
145         mRegistered = false;
146     }
147     registerSelf();
148 }
149 
registerSelf()150 bool UidObserver::registerSelf() {
151     std::scoped_lock lock{mRegisteredLock};
152     if (mRegistered) {
153         return true;
154     }
155 
156     status_t res = gAm.linkToDeath(this);
157     if (res != OK) {
158         ALOGE("UidObserver: Failed to linkToDeath with ActivityManager (err %d)", res);
159         return false;
160     }
161 
162     // TODO: it seems only way to get all changes is to set cutoff to PROCESS_STATE_UNKNOWN.
163     // But there is no equivalent of PROCESS_STATE_UNKNOWN in the UidImportance.
164     // If mImportanceCutpoint is < 0, use PROCESS_STATE_UNKNOWN instead.
165     res = gAm.registerUidObserver(
166             this,
167             ActivityManager::UID_OBSERVER_GONE | ActivityManager::UID_OBSERVER_PROCSTATE,
168             (mImportanceCutpoint < 0) ? ActivityManager::PROCESS_STATE_UNKNOWN
169                                       : importanceToProcState(mImportanceCutpoint),
170             getTag());
171     if (res != OK) {
172         ALOGE("UidObserver: Failed to register with ActivityManager (err %d)", res);
173         gAm.unlinkToDeath(this);
174         return false;
175     }
176 
177     mRegistered = true;
178     ALOGV("UidObserver: Registered with ActivityManager");
179     return true;
180 }
181 
unregisterSelf()182 void UidObserver::unregisterSelf() {
183     std::scoped_lock lock{mRegisteredLock};
184 
185     if (mRegistered) {
186         gAm.unregisterUidObserver(this);
187         gAm.unlinkToDeath(this);
188         mRegistered = false;
189     }
190 
191     ALOGV("UidObserver: Unregistered with ActivityManager");
192 }
193 
194 } // activitymanager
195 } // android
196 
197 using namespace android;
198 using namespace activitymanager;
199 
200 struct AActivityManager_UidImportanceListener : public UidObserver {
201 };
202 
AActivityManager_addUidImportanceListener(AActivityManager_onUidImportance onUidImportance,int32_t importanceCutpoint,void * cookie)203 AActivityManager_UidImportanceListener* AActivityManager_addUidImportanceListener(
204         AActivityManager_onUidImportance onUidImportance, int32_t importanceCutpoint, void* cookie) {
205     sp<UidObserver> observer(new UidObserver(onUidImportance, importanceCutpoint, cookie));
206     if (observer == nullptr || !observer->registerSelf()) {
207         return nullptr;
208     }
209     observer->incStrong((void *)AActivityManager_addUidImportanceListener);
210     return static_cast<AActivityManager_UidImportanceListener*>(observer.get());
211 }
212 
AActivityManager_removeUidImportanceListener(AActivityManager_UidImportanceListener * listener)213 void AActivityManager_removeUidImportanceListener(
214         AActivityManager_UidImportanceListener* listener) {
215     if (listener != nullptr) {
216         UidObserver* observer = static_cast<UidObserver*>(listener);
217         observer->unregisterSelf();
218         observer->decStrong((void *)AActivityManager_addUidImportanceListener);
219     }
220 }
221 
AActivityManager_isUidActive(uid_t uid)222 bool AActivityManager_isUidActive(uid_t uid) {
223     return gAm.isUidActive(uid, getTag());
224 }
225 
AActivityManager_getUidImportance(uid_t uid)226 int32_t AActivityManager_getUidImportance(uid_t uid) {
227     return UidObserver::procStateToImportance(gAm.getUidProcessState(uid, getTag()));
228 }
229 
230