[Link Event Damping] Add tracker to track the selectable timers used …

…by link event damper.

HLD: sonic-net/SONiC#1071

syncd/Makefile.am

@@ -43,6 +43,7 @@ libSyncd_a_SOURCES = \
 				SaiObj.cpp \
 				SaiSwitch.cpp \
 				SaiSwitchInterface.cpp \
+				SelectablesTracker.cpp \
 				ServiceMethodTable.cpp \
 				SingleReiniter.cpp \
 				SwitchNotifications.cpp \

syncd/SelectableEventHandler.h

@@ -0,0 +1,42 @@
+// Copyright 2021 Google LLC
+//
+// 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
+
+#include "swss/logger.h"
+#include "swss/sal.h"
+
+namespace syncd
+{
+
+    // This class implements handler for Selectable events.
+    class SelectableEventHandler {
+        public:
+
+            virtual ~SelectableEventHandler()
+            {
+              SWSS_LOG_ENTER();
+            }
+
+            virtual void handleSelectableEvent() = 0;
+
+        protected:
+
+            SelectableEventHandler()
+            {
+              SWSS_LOG_ENTER();
+            }
+    };
+
+}  // namespace syncd

syncd/SelectablesTracker.cpp

@@ -0,0 +1,114 @@
+// Copyright 2021 Google LLC
+//
+// 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.
+
+#include "SelectablesTracker.h"
+
+using namespace syncd;
+
+bool SelectablesTracker::addSelectableToTracker(
+        swss::Selectable *selectable,
+        SelectableEventHandler *eventHandler)
+{
+    SWSS_LOG_ENTER();
+
+    if (selectable == nullptr)
+    {
+        SWSS_LOG_ERROR("Invalid Selectable:Selectable is NULL.");
+
+        return false;
+    }
+
+    int fd = selectable->getFd();
+    if (eventHandler == nullptr)
+    {
+        SWSS_LOG_ERROR("Event handler for Selectable with fd: %d is NULL.", fd);
+
+        return false;
+    }
+
+    if (m_selectableFdToEventHandlerMap.count(fd) != 0)
+    {
+        SWSS_LOG_ERROR("Selectable with fd %d is already in use.", fd);
+
+        return false;
+    }
+
+    SWSS_LOG_INFO("Adding the Selectable with fd: %d.", fd);
+    m_selectableFdToEventHandlerMap[fd] = eventHandler;
+
+    return true;
+}
+
+bool SelectablesTracker::removeSelectableFromTracker(
+        swss::Selectable *selectable)
+{
+    SWSS_LOG_ENTER();
+
+    if (selectable == nullptr)
+    {
+        SWSS_LOG_ERROR("Invalid Selectable:Selectable is NULL.");
+        return false;
+    }
+
+    int fd = selectable->getFd();
+
+    SWSS_LOG_INFO("Removing the Selectable with fd: %d.", fd);
+    if (m_selectableFdToEventHandlerMap.erase(fd) == 0)
+    {
+        SWSS_LOG_ERROR("Selectable with fd %d is not present in the map!", fd);
+
+        return false;
+    }
+
+    return true;
+}
+
+bool SelectablesTracker::selectableIsTracked(
+        swss::Selectable *selectable)
+{
+    SWSS_LOG_ENTER();
+
+    if ((selectable == nullptr) ||
+        (m_selectableFdToEventHandlerMap.count(selectable->getFd()) == 0))
+    {
+        return false;
+    }
+
+    return true;
+}
+
+SelectableEventHandler *SelectablesTracker::getEventHandlerForSelectable(
+        swss::Selectable *selectable)
+{
+    SWSS_LOG_ENTER();
+
+    if (selectable == nullptr)
+    {
+        SWSS_LOG_ERROR("Invalid Selectable:Selectable is NULL.");
+
+        return nullptr;
+    }
+
+    int fd = selectable->getFd();
+    auto it = m_selectableFdToEventHandlerMap.find(fd);
+
+    if (it == m_selectableFdToEventHandlerMap.end())
+    {
+        SWSS_LOG_ERROR("Selectable with fd %d is not present in the map!", fd);
+
+        return nullptr;
+    }
+
+    return it->second;
+}

syncd/SelectablesTracker.h

@@ -0,0 +1,72 @@
+// Copyright 2021 Google LLC
+//
+// 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
+
+#include <unordered_map>
+
+#include "SelectableEventHandler.h"
+#include "swss/logger.h"
+#include "swss/sal.h"
+#include "swss/selectable.h"
+#include "swss/selectabletimer.h"
+
+namespace syncd
+{
+    // This class keeps track of Selectable being used by an entity and their
+    // corresponding EventHandler objects.
+    class SelectablesTracker
+    {
+        public:
+
+            SelectablesTracker()
+            {
+                SWSS_LOG_ENTER();
+            }
+            virtual ~SelectablesTracker()
+            {
+                SWSS_LOG_ENTER();
+            }
+
+            // Not copyable or movable.
+            SelectablesTracker(const SelectablesTracker &) = delete;
+            SelectablesTracker(SelectablesTracker &&) = delete;
+            SelectablesTracker &operator=(const SelectablesTracker &) = delete;
+            SelectablesTracker &operator=(SelectablesTracker &&) = delete;
+
+            // Adds the mapping of Selectable and it's corresponding EventHandler object.
+            virtual bool addSelectableToTracker(
+                    _In_ swss::Selectable *selectable,
+                    _In_ SelectableEventHandler *eventHandler);
+
+            // Removes a Selectable from the map.
+            virtual bool removeSelectableFromTracker(
+                    _In_ swss::Selectable *selectable);
+
+            // Checks if Selectable is present in the tracker map.
+            virtual bool selectableIsTracked(
+                    _In_ swss::Selectable *selectable);
+
+            // Gets the EventHandler for a Selectable.
+            virtual SelectableEventHandler *getEventHandlerForSelectable(
+                    _In_ swss::Selectable *selectable);
+
+        private:
+
+            using SelectableFdToEventHandlerMap = std::unordered_map<int, SelectableEventHandler *>;
+
+            SelectableFdToEventHandlerMap m_selectableFdToEventHandlerMap;
+    };
+
+}  // namespace syncd

tests/aspell.en.pws

@@ -148,6 +148,7 @@ config
 const
 CONST
 consts
+copyable
 counterName
 countOnly
 cout

unittest/syncd/Makefile.am

@@ -17,6 +17,7 @@ tests_SOURCES = main.cpp \
 				TestNotificationHandler.cpp \
 				TestMdioIpcServer.cpp \
 				TestPortStateChangeHandler.cpp \
+				TestSelectablesTracker.cpp \
 				TestVendorSai.cpp
 
 tests_CXXFLAGS = $(DBGFLAGS) $(AM_CXXFLAGS) $(CXXFLAGS_COMMON)

unittest/syncd/MockSelectablesTracker.h

@@ -0,0 +1,37 @@
+// Copyright 2021 Google LLC
+//
+// 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
+
+#include "SelectablesTracker.h"
+#include "gmock/gmock.h"
+
+namespace syncd
+{
+
+     class MockSelectablesTracker : public SelectablesTracker
+     {
+          public:
+
+               MockSelectablesTracker() : SelectablesTracker() {}
+
+               ~MockSelectablesTracker() override {}
+
+               MOCK_METHOD2(addSelectableToTracker, bool(swss::Selectable *selectable,
+                              SelectableEventHandler *eventHandler) override);
+
+               MOCK_METHOD1(removeSelectableFromTracker,
+                              bool(swss::Selectable *selectable) override);
+     };
+}  // namespace syncd