1 /*
2  * Copyright (C) 2017 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 #pragma once
18 
19 #include <android/os/IStatsCompanionService.h>
20 #include <android/os/IStatsPullerCallback.h>
21 #include <binder/IServiceManager.h>
22 #include <utils/RefBase.h>
23 #include <utils/threads.h>
24 #include <list>
25 #include <vector>
26 #include "PullDataReceiver.h"
27 #include "StatsPuller.h"
28 #include "guardrail/StatsdStats.h"
29 #include "logd/LogEvent.h"
30 
31 namespace android {
32 namespace os {
33 namespace statsd {
34 
35 typedef struct {
36     // The field numbers of the fields that need to be summed when merging
37     // isolated uid with host uid.
38     std::vector<int> additiveFields;
39     // Minimum time before this puller does actual pull again.
40     // Pullers can cause significant impact to system health and battery.
41     // So that we don't pull too frequently.
42     // If a pull request comes before cooldown, a cached version from previous pull
43     // will be returned.
44     int64_t coolDownNs = 1 * NS_PER_SEC;
45     // The actual puller
46     sp<StatsPuller> puller;
47     // Max time allowed to pull this atom.
48     // We cannot reliably kill a pull thread. So we don't terminate the puller.
49     // The data is discarded if the pull takes longer than this and mHasGoodData
50     // marked as false.
51     int64_t pullTimeoutNs = StatsdStats::kPullMaxDelayNs;
52 } PullAtomInfo;
53 
54 class StatsPullerManager : public virtual RefBase {
55 public:
56     StatsPullerManager();
57 
~StatsPullerManager()58     virtual ~StatsPullerManager() {
59     }
60 
61     // Registers a receiver for tagId. It will be pulled on the nextPullTimeNs
62     // and then every intervalNs thereafter.
63     virtual void RegisterReceiver(int tagId, wp<PullDataReceiver> receiver, int64_t nextPullTimeNs,
64                                   int64_t intervalNs);
65 
66     // Stop listening on a tagId.
67     virtual void UnRegisterReceiver(int tagId, wp<PullDataReceiver> receiver);
68 
69     // Verify if we know how to pull for this matcher
70     bool PullerForMatcherExists(int tagId) const;
71 
72     void OnAlarmFired(int64_t elapsedTimeNs);
73 
74     // Pulls the most recent data.
75     // The data may be served from cache if consecutive pulls come within
76     // mCoolDownNs.
77     // Returns true if the pull was successful.
78     // Returns false when
79     //   1) the pull fails
80     //   2) pull takes longer than mPullTimeoutNs (intrinsic to puller)
81     // If the metric wants to make any change to the data, like timestamps, they
82     // should make a copy as this data may be shared with multiple metrics.
83     virtual bool Pull(int tagId, vector<std::shared_ptr<LogEvent>>* data);
84 
85     // Clear pull data cache immediately.
86     int ForceClearPullerCache();
87 
88     // Clear pull data cache if it is beyond respective cool down time.
89     int ClearPullerCacheIfNecessary(int64_t timestampNs);
90 
91     void SetStatsCompanionService(sp<IStatsCompanionService> statsCompanionService);
92 
93     void RegisterPullerCallback(int32_t atomTag,
94                                 const sp<IStatsPullerCallback>& callback);
95 
96     void UnregisterPullerCallback(int32_t atomTag);
97 
98     static std::map<int, PullAtomInfo> kAllPullAtomInfo;
99 
100 private:
101     sp<IStatsCompanionService> mStatsCompanionService = nullptr;
102 
103     typedef struct {
104         int64_t nextPullTimeNs;
105         int64_t intervalNs;
106         wp<PullDataReceiver> receiver;
107     } ReceiverInfo;
108 
109     // mapping from simple matcher tagId to receivers
110     std::map<int, std::list<ReceiverInfo>> mReceivers;
111 
112     // locks for data receiver and StatsCompanionService changes
113     Mutex mLock;
114 
115     void updateAlarmLocked();
116 
117     int64_t mNextPullTimeNs;
118 
119     FRIEND_TEST(GaugeMetricE2eTest, TestRandomSamplePulledEvents);
120     FRIEND_TEST(GaugeMetricE2eTest, TestRandomSamplePulledEvent_LateAlarm);
121     FRIEND_TEST(GaugeMetricE2eTest, TestRandomSamplePulledEventsWithActivation);
122     FRIEND_TEST(GaugeMetricE2eTest, TestRandomSamplePulledEventsNoCondition);
123     FRIEND_TEST(ValueMetricE2eTest, TestPulledEvents);
124     FRIEND_TEST(ValueMetricE2eTest, TestPulledEvents_LateAlarm);
125     FRIEND_TEST(ValueMetricE2eTest, TestPulledEvents_WithActivation);
126 };
127 
128 }  // namespace statsd
129 }  // namespace os
130 }  // namespace android
131