[IM] Fix EnsureResourceForSubscription (project-chip#18533)

* [IM] Fix EnsureResourceForSubscription * Address comments * Fix * Remove TestReadHandlerResourceExhaustion_MultipleSubscriptions since it is covered by resource minimas of subscription tests * Add comments * address comments * Fix merge
mspang · May 25, 2022 · ebc8c17 · ebc8c17
1 parent 5167991
commit ebc8c17
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Showing 3 changed files with 225 additions and 136 deletions.
diff --git a/src/app/InteractionModelEngine.cpp b/src/app/InteractionModelEngine.cpp
@@ -372,25 +372,13 @@ CHIP_ERROR InteractionModelEngine::OnReadInitialRequest(Messaging::ExchangeConte
         }
     }
 
-    size_t handlerPoolCapacity = mReadHandlers.Capacity();
-
 #if CONFIG_IM_BUILD_FOR_UNIT_TEST
+    size_t handlerPoolCapacity = mReadHandlers.Capacity();
     if (mReadHandlerCapacityOverride != -1)
     {
         handlerPoolCapacity = (size_t) mReadHandlerCapacityOverride;
     }
-#endif
-
-    // Reserve the last ReadHandler for ReadInteraction
-    if (aInteractionType == ReadHandler::InteractionType::Subscribe && ((handlerPoolCapacity - GetNumActiveReadHandlers()) == 1) &&
-        !HasActiveRead())
-    {
-        ChipLogDetail(InteractionModel, "Reserve the last ReadHandler for IM read Interaction");
-        aStatus = Protocols::InteractionModel::Status::ResourceExhausted;
-        return CHIP_NO_ERROR;
-    }
 
-#if CONFIG_IM_BUILD_FOR_UNIT_TEST
     if ((handlerPoolCapacity - GetNumActiveReadHandlers()) == 0)
     {
         aStatus = Protocols::InteractionModel::Status::ResourceExhausted;
@@ -668,9 +656,27 @@ bool InteractionModelEngine::EnsureResourceForSubscription(FabricIndex aFabricIn
     const size_t readHandlerCap =
         allowUnlimited ? SIZE_MAX : static_cast<size_t>(readHandlerPoolCapacity - kReservedHandlersForReads);
 
-    size_t usedAttributePaths = mAttributePathPool.Allocated();
-    size_t usedEventPaths     = mEventPathPool.Allocated();
-    size_t usedReadHandlers   = mReadHandlers.Allocated();
+    size_t usedAttributePaths = 0;
+    size_t usedEventPaths     = 0;
+    size_t usedReadHandlers   = 0;
+
+    auto countResourceUsage = [&]() {
+        usedAttributePaths = 0;
+        usedEventPaths     = 0;
+        usedReadHandlers   = 0;
+        mReadHandlers.ForEachActiveObject([&](auto * handler) {
+            if (!handler->IsType(ReadHandler::InteractionType::Subscribe))
+            {
+                return Loop::Continue;
+            }
+            usedAttributePaths += handler->GetAttributePathCount();
+            usedEventPaths += handler->GetEventPathCount();
+            usedReadHandlers++;
+            return Loop::Continue;
+        });
+    };
+
+    countResourceUsage();
 
     if (usedAttributePaths + aRequestedAttributePathCount <= attributePathCap &&
         usedEventPaths + aRequestedEventPathCount <= eventPathCap && usedReadHandlers < readHandlerCap)
@@ -688,10 +694,8 @@ bool InteractionModelEngine::EnsureResourceForSubscription(FabricIndex aFabricIn
     }
 
     const auto evictAndUpdateResourceUsage = [&](FabricIndex fabricIndex, bool forceEvict) {
-        bool ret           = TrimFabric(fabricIndex, forceEvict);
-        usedAttributePaths = mAttributePathPool.Allocated();
-        usedEventPaths     = mEventPathPool.Allocated();
-        usedReadHandlers   = mReadHandlers.Allocated();
+        bool ret = TrimFabric(fabricIndex, forceEvict);
+        countResourceUsage();
         return ret;
     };
 
@@ -1181,5 +1185,18 @@ uint16_t InteractionModelEngine::GetMinSubscriptionsPerFabric() const
     return static_cast<uint16_t>(perFabricSubscriptionCapacity);
 }
 
+size_t InteractionModelEngine::GetNumDirtySubscriptions() const
+{
+    size_t numDirtySubscriptions = 0;
+    mReadHandlers.ForEachActiveObject([&](const auto readHandler) {
+        if (readHandler->IsType(ReadHandler::InteractionType::Subscribe) && readHandler->IsDirty())
+        {
+            numDirtySubscriptions++;
+        }
+        return Loop::Continue;
+    });
+    return numDirtySubscriptions;
+}
+
 } // namespace app
 } // namespace chip
diff --git a/src/app/InteractionModelEngine.h b/src/app/InteractionModelEngine.h
@@ -231,6 +231,11 @@ class InteractionModelEngine : public Messaging::UnsolicitedMessageHandler,
      */
     size_t GetNumActiveReadClients();
 
+    /**
+     * Returns the number of dirty subscriptions. Including the subscriptions that are generating reports.
+     */
+    size_t GetNumDirtySubscriptions() const;
+
     /**
      * Returns whether the write operation to the given path is conflict with another write operations. (i.e. another write
      * transaction is in the middle of processing the chunked value of the given path.)