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1 : /*
2 : *
3 : * Copyright (c) 2023 Project CHIP Authors
4 : * All rights reserved.
5 : *
6 : * Licensed under the Apache License, Version 2.0 (the "License");
7 : * you may not use this file except in compliance with the License.
8 : * You may obtain a copy of the License at
9 : *
10 : * http://www.apache.org/licenses/LICENSE-2.0
11 : *
12 : * Unless required by applicable law or agreed to in writing, software
13 : * distributed under the License is distributed on an "AS IS" BASIS,
14 : * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 : * See the License for the specific language governing permissions and
16 : * limitations under the License.
17 : */
18 :
19 : #pragma once
20 :
21 : #include <app/ReadHandler.h>
22 : #include <app/icd/server/ICDStateObserver.h>
23 : #include <lib/core/CHIPError.h>
24 : #include <system/SystemClock.h>
25 :
26 : namespace chip {
27 : namespace app {
28 : namespace reporting {
29 :
30 : // Forward declaration of TestReportScheduler to allow it to be friend with ReportScheduler
31 : class TestReportScheduler;
32 :
33 : class TimerContext
34 : {
35 : public:
36 0 : virtual ~TimerContext() {}
37 : virtual void TimerFired() = 0;
38 : };
39 :
40 : /**
41 : * @class ReportScheduler
42 : *
43 : * @brief This class is responsible for scheduling Engine runs based on the reporting intervals of the ReadHandlers.
44 : *
45 : *
46 : * This class holds a pool of ReadHandlerNodes that are used to keep track of the minimum and maximum timestamps for a report to be
47 : * emitted based on the reporting intervals of the ReadHandlers associated with the node.
48 : *
49 : * The ReportScheduler also holds a TimerDelegate pointer that is used to start and cancel timers for the ReadHandlers depending
50 : * on the reporting logic of the Scheduler.
51 : *
52 : * It inherits the ReadHandler::Observer class to be notified of reportability changes in the ReadHandlers.
53 : * It inherits the ICDStateObserver class to allow the implementation to generate reports based on the changes in ICD devices state,
54 : * such as going from idle to active mode and vice-versa.
55 : *
56 : * @note The logic for how and when to schedule reports is implemented in the subclasses of ReportScheduler, such as
57 : * ReportSchedulerImpl and SyncronizedReportSchedulerImpl.
58 : */
59 : class ReportScheduler : public ReadHandler::Observer, public ICDStateObserver
60 : {
61 : public:
62 : using Timestamp = System::Clock::Timestamp;
63 :
64 : /// @brief This class acts as an interface between the report scheduler and the system timer to reduce dependencies on the
65 : /// system layer.
66 : class TimerDelegate
67 : {
68 : public:
69 0 : virtual ~TimerDelegate() {}
70 : /// @brief Start a timer for a given context. The report scheduler must always cancel an existing timer for a context (using
71 : /// CancelTimer) before starting a new one for that context.
72 : /// @param context context to pass to the timer callback.
73 : /// @param aTimeout time in milliseconds before the timer expires
74 : virtual CHIP_ERROR StartTimer(TimerContext * context, System::Clock::Timeout aTimeout) = 0;
75 : /// @brief Cancel a timer for a given context
76 : /// @param context used to identify the timer to cancel
77 : virtual void CancelTimer(TimerContext * context) = 0;
78 : virtual bool IsTimerActive(TimerContext * context) = 0;
79 : virtual Timestamp GetCurrentMonotonicTimestamp() = 0;
80 : };
81 :
82 : /**
83 : * @class ReadHandlerNode
84 : *
85 : * @brief This class is responsible for determining when a ReadHandler is reportable depending on the monotonic timestamp of
86 : * the system and the intervals of the ReadHandler. It inherits the TimerContext class to allow it to be used as a context for
87 : * a TimerDelegate so that the TimerDelegate can call the TimerFired method when the timer expires.
88 : *
89 : * Three conditions that can prevent the ReadHandler from being reportable:
90 : * 1: The ReadHandler is not in the CanStartReporting state:
91 : * This condition can be resolved by setting the CanStartReporting flag on the ReadHandler
92 : *
93 : * 2: The minimal interval since the last report has not elapsed
94 : * This condition can be resolved after enough time has passed since the last report or by setting the EngineRunScheduled
95 : * flag
96 : *
97 : * 3: The maximal interval since the last report has not elapsed and the ReadHandler is not dirty:
98 : * This condition can be resolved after enough time has passed since the last report to reach the max interval, by the
99 : * ReadHandler becoming dirty or by setting the CanBeSynced flag and having another ReadHandler needing to report.
100 : *
101 : * Once the 3 conditions are met, the ReadHandler is considered reportable.
102 : *
103 : * Flags:
104 : *
105 : * CanBeSynced: Mechanism to allow the ReadHandler to emit a report if another readHandler is ReportableNow.
106 : * This flag is currently only used by the SynchronizedReportScheduler to allow firing reports of ReadHandlers at the same
107 : * time.
108 : *
109 : * EngineRunScheduled: Mechanism to ensure that the reporting engine will see the ReadHandler as reportable if a timer fires.
110 : * This flag is used to confirm that the next report timer has fired for a ReadHandler, thus allowing reporting when timers
111 : * fire earlier than the minimal timestamp due to mechanisms such as NTP clock adjustments.
112 : *
113 : */
114 : class ReadHandlerNode : public TimerContext
115 : {
116 : public:
117 : enum class ReadHandlerNodeFlags : uint8_t
118 : {
119 : // Flag to indicate if the engine run is already scheduled so the scheduler can ignore
120 : // it when calculating the next run time
121 : EngineRunScheduled = (1 << 0),
122 : // Flag to allow the read handler to be synced with other handlers that have an earlier max timestamp
123 : CanBeSynced = (1 << 1),
124 : };
125 :
126 302 : ReadHandlerNode(ReadHandler * aReadHandler, ReportScheduler * aScheduler, const Timestamp & now) : mScheduler(aScheduler)
127 : {
128 302 : VerifyOrDie(aReadHandler != nullptr);
129 302 : VerifyOrDie(aScheduler != nullptr);
130 :
131 302 : mReadHandler = aReadHandler;
132 302 : SetIntervalTimeStamps(aReadHandler, now);
133 302 : }
134 27636 : ReadHandler * GetReadHandler() const { return mReadHandler; }
135 :
136 : /// @brief Check if the Node is reportable now, meaning its readhandler was made reportable by attribute dirtying and
137 : /// handler state, and minimal time interval since the last report has elapsed, or the maximal time interval since the last
138 : /// report has elapsed.
139 : /// @note If a handler has been flagged as scheduled for an engine run, it will be reported regardless of the timestamps.
140 : /// This is done to guarantee that the reporting engine will see the handler as reportable if a timer fires, even if it
141 : /// fires early.
142 : /// @param now current time to use for the check, the user must ensure to provide a valid time for this to be reliable
143 636 : bool IsReportableNow(const Timestamp & now) const
144 : {
145 1818 : return (mReadHandler->CanStartReporting() &&
146 1672 : ((now >= mMinTimestamp && (mReadHandler->IsDirty() || now >= mMaxTimestamp || CanBeSynced())) ||
147 1127 : IsEngineRunScheduled()));
148 : }
149 :
150 65 : bool CanStartReporting() const { return mReadHandler->CanStartReporting(); }
151 80 : bool IsChunkedReport() const { return mReadHandler->IsChunkedReport(); }
152 491 : bool IsEngineRunScheduled() const { return mFlags.Has(ReadHandlerNodeFlags::EngineRunScheduled); }
153 307 : void SetEngineRunScheduled(bool aEngineRunScheduled)
154 : {
155 307 : mFlags.Set(ReadHandlerNodeFlags::EngineRunScheduled, aEngineRunScheduled);
156 307 : }
157 490 : bool CanBeSynced() const { return mFlags.Has(ReadHandlerNodeFlags::CanBeSynced); }
158 178 : void SetCanBeSynced(bool aCanBeSynced) { mFlags.Set(ReadHandlerNodeFlags::CanBeSynced, aCanBeSynced); }
159 :
160 : /// @brief Set the interval timestamps for the node based on the read handler reporting intervals
161 : /// @param aReadHandler read handler to get the intervals from
162 : /// @param now current time to calculate the mMin and mMax timestamps, the user must ensure to provide a valid time for this
163 : /// to be reliable
164 323 : void SetIntervalTimeStamps(ReadHandler * aReadHandler, const Timestamp & now)
165 : {
166 : uint16_t minInterval, maxInterval;
167 323 : aReadHandler->GetReportingIntervals(minInterval, maxInterval);
168 323 : mMinTimestamp = now + System::Clock::Seconds16(minInterval);
169 323 : mMaxTimestamp = now + System::Clock::Seconds16(maxInterval);
170 323 : }
171 :
172 129 : void TimerFired() override
173 : {
174 129 : SetEngineRunScheduled(true);
175 129 : mScheduler->ReportTimerCallback();
176 129 : }
177 :
178 472 : System::Clock::Timestamp GetMinTimestamp() const { return mMinTimestamp; }
179 768 : System::Clock::Timestamp GetMaxTimestamp() const { return mMaxTimestamp; }
180 :
181 : private:
182 : ReadHandler * mReadHandler;
183 : ReportScheduler * mScheduler;
184 : Timestamp mMinTimestamp;
185 : Timestamp mMaxTimestamp;
186 :
187 : BitFlags<ReadHandlerNodeFlags> mFlags;
188 : };
189 :
190 54 : ReportScheduler(TimerDelegate * aTimerDelegate) : mTimerDelegate(aTimerDelegate) {}
191 :
192 0 : virtual ~ReportScheduler() = default;
193 :
194 : virtual void ReportTimerCallback() = 0;
195 :
196 : /// @brief Check whether a ReadHandler is reportable right now, taking into account its minimum and maximum intervals.
197 : /// @param aReadHandler read handler to check
198 286 : bool IsReportableNow(ReadHandler * aReadHandler)
199 : {
200 : // Update the now timestamp to ensure external calls to IsReportableNow are always comparing to the current time
201 286 : Timestamp now = mTimerDelegate->GetCurrentMonotonicTimestamp();
202 286 : ReadHandlerNode * node = FindReadHandlerNode(aReadHandler);
203 286 : return (nullptr != node) ? node->IsReportableNow(now) : false;
204 : }
205 :
206 : /// @brief Check if a ReadHandler is reportable without considering the timing
207 413 : bool IsReadHandlerReportable(ReadHandler * aReadHandler) const
208 : {
209 413 : return (nullptr != aReadHandler) ? aReadHandler->ShouldStartReporting() : false;
210 : }
211 : /// @brief Sets the ForceDirty flag of a ReadHandler
212 : void HandlerForceDirtyState(ReadHandler * aReadHandler) { aReadHandler->ForceDirtyState(); }
213 :
214 : /// @brief Get the number of ReadHandlers registered in the scheduler's node pool
215 : size_t GetNumReadHandlers() const { return mNodesPool.Allocated(); }
216 :
217 : #if CONFIG_BUILD_FOR_HOST_UNIT_TEST
218 : Timestamp GetMinTimestampForHandler(const ReadHandler * aReadHandler)
219 : {
220 : ReadHandlerNode * node = FindReadHandlerNode(aReadHandler);
221 : return node->GetMinTimestamp();
222 : }
223 : Timestamp GetMaxTimestampForHandler(const ReadHandler * aReadHandler)
224 : {
225 : ReadHandlerNode * node = FindReadHandlerNode(aReadHandler);
226 : return node->GetMaxTimestamp();
227 : }
228 : ReadHandlerNode * GetReadHandlerNode(const ReadHandler * aReadHandler) { return FindReadHandlerNode(aReadHandler); }
229 : #endif // CONFIG_BUILD_FOR_HOST_UNIT_TEST
230 :
231 : protected:
232 : friend class chip::app::reporting::TestReportScheduler;
233 :
234 : /// @brief Find the ReadHandlerNode for a given ReadHandler pointer
235 : /// @param [in] aReadHandler ReadHandler pointer to look for in the ReadHandler nodes list
236 : /// @return Node Address if the node was found, nullptr otherwise
237 3494 : ReadHandlerNode * FindReadHandlerNode(const ReadHandler * aReadHandler)
238 : {
239 3494 : ReadHandlerNode * foundNode = nullptr;
240 3494 : mNodesPool.ForEachActiveObject([&foundNode, aReadHandler](ReadHandlerNode * node) {
241 26990 : if (node->GetReadHandler() == aReadHandler)
242 : {
243 1458 : foundNode = node;
244 1458 : return Loop::Break;
245 : }
246 :
247 25532 : return Loop::Continue;
248 : });
249 3494 : return foundNode;
250 : }
251 :
252 : ObjectPool<ReadHandlerNode, CHIP_IM_MAX_NUM_READS + CHIP_IM_MAX_NUM_SUBSCRIPTIONS> mNodesPool;
253 : TimerDelegate * mTimerDelegate;
254 : };
255 : }; // namespace reporting
256 : }; // namespace app
257 : }; // namespace chip
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