[ICD] Subscription report emission when becoming active (#28266)

* Added mechanism to emit report when switching to active mode if
necessary

* Restyled by clang-format

* Reworked the logic to force a report emission when min elapsed and inject the scheduler in the ICD manager from Server::Init()

* Update src/app/reporting/ReportScheduler.h

Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>

* Created StateObserver as an interface class to fix dependencies issues in app/BUILD.gn

* Restyled by whitespace

* Update src/app/icd/ICDManager.cpp

Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>

* Moved the report on active mode ifdef to ReportSchedulerImpl and removed misleading comment

* Restyled by clang-format

* Put the now timestamp in the #if check to avoid unused variable error

---------

Co-authored-by: Restyled.io <commits@restyled.io>
Co-authored-by: Boris Zbarsky <bzbarsky@apple.com>

src/app/BUILD.gn

@@ -213,7 +213,7 @@ static_library("app") {
   public_deps = [
     ":app_config",
     "${chip_root}/src/access",
-    "${chip_root}/src/app/icd:cluster-srcs",
+    "${chip_root}/src/app/icd:observer-srcs",
     "${chip_root}/src/lib/address_resolve",
     "${chip_root}/src/lib/support",
     "${chip_root}/src/messaging",

src/app/ReadHandler.h

@@ -418,8 +418,8 @@ class ReadHandler : public Messaging::ExchangeDelegate
     friend class chip::app::reporting::Engine;
     friend class chip::app::InteractionModelEngine;
 
-    // The report scheduler needs to be able to access StateFlag private functions IsReportable(), IsGeneratingReports() and
-    // IsDirty() to know when to schedule a run so it is declared as a friend class.
+    // The report scheduler needs to be able to access StateFlag private functions IsReportable(), IsGeneratingReports(),
+    // ForceDirtyState() and IsDirty() to know when to schedule a run so it is declared as a friend class.
     friend class chip::app::reporting::ReportScheduler;
 
     enum class HandlerState : uint8_t

src/app/icd/BUILD.gn

@@ -17,6 +17,10 @@ import("icd.gni")
 
 # ICD Server sources and configurations
 
+source_set("observer-srcs") {
+  sources = [ "ICDStateObserver.h" ]
+}
+
 # ICD Manager source-set is broken out of the main source-set to enable unit tests
 # All sources and configurations used by the ICDManager need to go in this source-set
 source_set("manager-srcs") {
@@ -25,7 +29,10 @@ source_set("manager-srcs") {
     "ICDManager.h",
   ]
 
-  deps = [ ":cluster-srcs" ]
+  deps = [
+    ":cluster-srcs",
+    ":observer-srcs",
+  ]
   public_deps = [ "${chip_root}/src/credentials:credentials" ]
 }
 

src/app/icd/ICDManager.cpp

@@ -33,19 +33,27 @@
 #define ICD_ENFORCE_SIT_SLOW_POLL_LIMIT 0
 #endif
 
+#ifndef ICD_REPORT_ON_ENTER_ACTIVE_MODE
+// Enabling this makes the device emit subscription reports when transitioning from idle to active mode.
+#define ICD_REPORT_ON_ENTER_ACTIVE_MODE 0
+#endif
+
 namespace chip {
 namespace app {
 
 using namespace chip::app;
 using namespace chip::app::Clusters;
 using namespace chip::app::Clusters::IcdManagement;
 
-void ICDManager::Init(PersistentStorageDelegate * storage, FabricTable * fabricTable)
+void ICDManager::Init(PersistentStorageDelegate * storage, FabricTable * fabricTable, ICDStateObserver * stateObserver)
 {
     VerifyOrDie(storage != nullptr);
     VerifyOrDie(fabricTable != nullptr);
-    mStorage     = storage;
-    mFabricTable = fabricTable;
+    VerifyOrDie(stateObserver != nullptr);
+
+    mStorage       = storage;
+    mFabricTable   = fabricTable;
+    mStateObserver = stateObserver;
 
     uint32_t activeModeInterval = IcdManagementServer::GetInstance().GetActiveModeInterval();
     VerifyOrDie(kFastPollingInterval.count() < activeModeInterval);
@@ -152,6 +160,8 @@ void ICDManager::UpdateOperationState(OperationalState state)
             {
                 ChipLogError(AppServer, "Failed to set Polling Interval: err %" CHIP_ERROR_FORMAT, err.Format());
             }
+
+            mStateObserver->OnEnterActiveMode();
         }
         else
         {

src/app/icd/ICDManager.h

@@ -16,6 +16,7 @@
  */
 #pragma once
 
+#include <app/icd/ICDStateObserver.h>
 #include <credentials/FabricTable.h>
 #include <lib/support/BitFlags.h>
 #include <platform/CHIPDeviceConfig.h>
@@ -51,7 +52,7 @@ class ICDManager
     };
 
     ICDManager() {}
-    void Init(PersistentStorageDelegate * storage, FabricTable * fabricTable);
+    void Init(PersistentStorageDelegate * storage, FabricTable * fabricTable, ICDStateObserver * stateObserver);
     void Shutdown();
     void UpdateIcdMode();
     void UpdateOperationState(OperationalState state);
@@ -86,6 +87,7 @@ class ICDManager
     ICDMode mICDMode                     = ICDMode::SIT;
     PersistentStorageDelegate * mStorage = nullptr;
     FabricTable * mFabricTable           = nullptr;
+    ICDStateObserver * mStateObserver    = nullptr;
 };
 
 } // namespace app

src/app/icd/ICDStateObserver.h

@@ -0,0 +1,30 @@
+/*
+ *
+ *    Copyright (c) 2023 Project CHIP Authors
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+#pragma once
+
+namespace chip {
+namespace app {
+
+class ICDStateObserver
+{
+public:
+    virtual ~ICDStateObserver() {}
+    virtual void OnEnterActiveMode() = 0;
+};
+
+} // namespace app
+} // namespace chip

src/app/reporting/ReportScheduler.h

@@ -19,6 +19,7 @@
 #pragma once
 
 #include <app/ReadHandler.h>
+#include <app/icd/ICDStateObserver.h>
 #include <lib/core/CHIPError.h>
 #include <system/SystemClock.h>
 
@@ -38,7 +39,7 @@ class TimerContext
     virtual void TimerFired() = 0;
 };
 
-class ReportScheduler : public ReadHandler::Observer
+class ReportScheduler : public ReadHandler::Observer, public ICDStateObserver
 {
 public:
     /// @brief This class acts as an interface between the report scheduler and the system timer to reduce dependencies on the
@@ -172,6 +173,8 @@ class ReportScheduler : public ReadHandler::Observer
     bool IsReportableNow(ReadHandler * aReadHandler) { return FindReadHandlerNode(aReadHandler)->IsReportableNow(); }
     /// @brief Check if a ReadHandler is reportable without considering the timing
     bool IsReadHandlerReportable(ReadHandler * aReadHandler) const { return aReadHandler->IsReportable(); }
+    /// @brief Sets the ForceDirty flag of a ReadHandler
+    void HandlerForceDirtyState(ReadHandler * aReadHandler) { aReadHandler->ForceDirtyState(); }
 
     /// @brief Get the number of ReadHandlers registered in the scheduler's node pool
     size_t GetNumReadHandlers() const { return mNodesPool.Allocated(); }

src/app/reporting/ReportSchedulerImpl.cpp

@@ -37,6 +37,23 @@ ReportSchedulerImpl::ReportSchedulerImpl(TimerDelegate * aTimerDelegate) : Repor
     VerifyOrDie(nullptr != mTimerDelegate);
 }
 
+/// @brief Method that triggers a report emission on each ReadHandler that is not blocked on its min interval.
+///        Each read handler that is not blocked is immediately marked dirty so that it will report as soon as possible.
+void ReportSchedulerImpl::OnEnterActiveMode()
+{
+#if ICD_REPORT_ON_ENTER_ACTIVE_MODE
+    Timestamp now = mTimerDelegate->GetCurrentMonotonicTimestamp();
+    mNodesPool.ForEachActiveObject([now, this](ReadHandlerNode * node) {
+        if (now >= node->GetMinTimestamp())
+        {
+            this->HandlerForceDirtyState(node->GetReadHandler());
+        }
+
+        return Loop::Continue;
+    });
+#endif
+}
+
 /// @brief When a ReadHandler is added, register it, which will schedule an engine run
 void ReportSchedulerImpl::OnReadHandlerCreated(ReadHandler * aReadHandler)
 {

src/app/reporting/ReportSchedulerImpl.h

@@ -32,6 +32,9 @@ class ReportSchedulerImpl : public ReportScheduler
     ReportSchedulerImpl(TimerDelegate * aTimerDelegate);
     ~ReportSchedulerImpl() override { UnregisterAllHandlers(); }
 
+    // ICDStateObserver
+    void OnEnterActiveMode() override;
+
     // ReadHandlerObserver
     void OnReadHandlerCreated(ReadHandler * aReadHandler) final;
     void OnBecameReportable(ReadHandler * aReadHandler) final;

src/app/server/Server.cpp

@@ -250,7 +250,7 @@ CHIP_ERROR Server::Init(const ServerInitParams & initParams)
 #endif // CHIP_CONFIG_ENABLE_SERVER_IM_EVENT
 
 #if CHIP_CONFIG_ENABLE_ICD_SERVER
-    mICDManager.Init(mDeviceStorage, &GetFabricTable());
+    mICDManager.Init(mDeviceStorage, &GetFabricTable(), &mReportScheduler);
     mICDEventManager.Init(&mICDManager);
 #endif // CHIP_CONFIG_ENABLE_ICD_SERVER