1 /*
2  * Copyright (C) 2018 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 com.android.server.wm;
18 
19 import android.annotation.IntDef;
20 import android.annotation.NonNull;
21 import android.annotation.Nullable;
22 import android.content.Intent;
23 
24 import java.lang.annotation.Retention;
25 import java.lang.annotation.RetentionPolicy;
26 
27 /**
28  * Observe activity manager launch sequences.
29  *
30  * The activity manager can have at most 1 concurrent launch sequences. Calls to this interface
31  * are ordered by a happens-before relation for each defined state transition (see below).
32  *
33  * When a new launch sequence is made, that sequence is in the {@code INTENT_STARTED} state which
34  * is communicated by the {@link #onIntentStarted} callback. This is a transient state.
35  *
36  * The intent can fail to launch the activity, in which case the sequence's state transitions to
37  * {@code INTENT_FAILED} via {@link #onIntentFailed}. This is a terminal state.
38  *
39  * If an activity is successfully started, the launch sequence's state will transition into
40  * {@code STARTED} via {@link #onActivityLaunched}. This is a transient state.
41  *
42  * It must then transition to either {@code CANCELLED} with {@link #onActivityLaunchCancelled}
43  * or into {@code FINISHED} with {@link #onActivityLaunchFinished}. These are terminal states.
44  *
45  * Note that the {@code ActivityRecordProto} provided as a parameter to some state transitions isn't
46  * necessarily the same within a single launch sequence: it is only the top-most activity at the
47  * time (if any). Trampoline activities coalesce several activity starts into a single launch
48  * sequence.
49  *
50  * Upon reaching a terminal state, it is considered that there are no active launch sequences
51  * until a subsequent transition into {@code INTENT_STARTED} initiates a new launch sequence.
52  *
53  * <pre>
54  *        ┌⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯┐     ┌⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯┐     ╔══════════════════════════╗
55  *    ╴╴▶ ⋮ INTENT_STARTED ⋮ ──▶ ⋮     ACTIVITY_LAUNCHED     ⋮ ──▶ ║ ACTIVITY_LAUNCH_FINISHED ║
56  *        └⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯┘     └⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯⋯┘     ╚══════════════════════════╝
57  *          :                      :
58  *          :                      :
59  *          ▼                      ▼
60  *        ╔════════════════╗     ╔═══════════════════════════╗
61  *        ║ INTENT_FAILED  ║     ║ ACTIVITY_LAUNCH_CANCELLED ║
62  *        ╚════════════════╝     ╚═══════════════════════════╝
63  * </pre>
64  */
65 public interface ActivityMetricsLaunchObserver {
66     /**
67      * The 'temperature' at which a launch sequence had started.
68      *
69      * The lower the temperature the more work has to be done during start-up.
70      * A 'cold' temperature means that a new process has been started and likely
71      * nothing is cached.
72      *
73      * A hot temperature means the existing activity is brought to the foreground.
74      * It may need to regenerate some objects as a result of {@code onTrimMemory}.
75      *
76      * A warm temperature is in the middle; an existing process is used, but the activity
77      * has to be created from scratch with {@code #onCreate}.
78      *
79      * @see https://developer.android.com/topic/performance/vitals/launch-time
80      */
81     @Retention(RetentionPolicy.SOURCE)
82     @IntDef({
83             TEMPERATURE_COLD,
84             TEMPERATURE_WARM,
85             TEMPERATURE_HOT
86     })
87     @interface Temperature {}
88 
89     /** Cold launch sequence: a new process has started. */
90     public static final int TEMPERATURE_COLD = 1;
91     /** Warm launch sequence: process reused, but activity has to be created. */
92     public static final int TEMPERATURE_WARM = 2;
93     /** Hot launch sequence: process reused, activity brought-to-top. */
94     public static final int TEMPERATURE_HOT = 3;
95 
96     /**
97      * Typedef marker that a {@code byte[]} actually contains an
98      * <a href="proto/android/server/activitymanagerservice.proto">ActivityRecordProto</a>
99      * in the protobuf format.
100      */
101     @Retention(RetentionPolicy.SOURCE)
102     @interface ActivityRecordProto {}
103 
104     /**
105      * Notifies the observer that a new launch sequence has begun as a result of a new intent.
106      *
107      * Once a launch sequence begins, the resolved activity will either subsequently start with
108      * {@link #onActivityLaunched} or abort early (for example due to a resolution error or due to
109      * a security error) with {@link #onIntentFailed}.
110      *
111      * Multiple calls to this method cannot occur without first terminating the current
112      * launch sequence.
113      */
onIntentStarted(@onNull Intent intent)114     public void onIntentStarted(@NonNull Intent intent);
115 
116     /**
117      * Notifies the observer that the current launch sequence has failed to launch an activity.
118      *
119      * This function call terminates the current launch sequence. The next method call, if any,
120      * must be {@link #onIntentStarted}.
121      *
122      * Examples of this happening:
123      *  - Failure to resolve to an activity
124      *  - Calling package did not have the security permissions to call the requested activity
125      *  - Resolved activity was already running and only needed to be brought to the top
126      *
127      * Multiple calls to this method cannot occur without first terminating the current
128      * launch sequence.
129      */
onIntentFailed()130     public void onIntentFailed();
131 
132     /**
133      * Notifies the observer that the current launch sequence had begun starting an activity.
134      *
135      * This is an intermediate state: once an activity begins starting, the entire launch sequence
136      * will later terminate by either finishing or cancelling.
137      *
138      * The initial activity is the first activity to be started as part of a launch sequence:
139      * it is represented by {@param activity} However, it isn't
140      * necessarily the activity which will be considered as displayed when the activity
141      * finishes launching (e.g. {@code activity} in {@link #onActivityLaunchFinished}).
142      *
143      * Multiple calls to this method cannot occur without first terminating the current
144      * launch sequence.
145      */
onActivityLaunched(@onNull @ctivityRecordProto byte[] activity, @Temperature int temperature)146     public void onActivityLaunched(@NonNull @ActivityRecordProto byte[] activity,
147                                    @Temperature int temperature);
148 
149     /**
150      * Notifies the observer that the current launch sequence has been aborted.
151      *
152      * This function call terminates the current launch sequence. The next method call, if any,
153      * must be {@link #onIntentStarted}.
154      *
155      * This can happen for many reasons, for example the user switches away to another app
156      * prior to the launch sequence completing, or the application being killed.
157      *
158      * Multiple calls to this method cannot occur without first terminating the current
159      * launch sequence.
160      *
161      * @param abortingActivity the last activity that had the top-most window during abort
162      *                         (this can be {@code null} in rare situations its unknown).
163      *
164      * @apiNote The aborting activity isn't necessarily the same as the starting activity;
165      *          in the case of a trampoline, multiple activities could've been started
166      *          and only the latest activity is reported here.
167      */
onActivityLaunchCancelled(@ullable @ctivityRecordProto byte[] abortingActivity)168     public void onActivityLaunchCancelled(@Nullable @ActivityRecordProto byte[] abortingActivity);
169 
170     /**
171      * Notifies the observer that the current launch sequence has been successfully finished.
172      *
173      * This function call terminates the current launch sequence. The next method call, if any,
174      * must be {@link #onIntentStarted}.
175      *
176      * A launch sequence is considered to be successfully finished when a frame is fully
177      * drawn for the first time: the top-most activity at the time is what's reported here.
178      *
179      * @param finalActivity the top-most activity whose windows were first to fully draw
180      *
181      * Multiple calls to this method cannot occur without first terminating the current
182      * launch sequence.
183      *
184      * @apiNote The finishing activity isn't necessarily the same as the starting activity;
185      *          in the case of a trampoline, multiple activities could've been started
186      *          and only the latest activity that was top-most during first-frame drawn
187      *          is reported here.
188      */
onActivityLaunchFinished(@onNull @ctivityRecordProto byte[] finalActivity)189     public void onActivityLaunchFinished(@NonNull @ActivityRecordProto byte[] finalActivity);
190 }
191