Mbed: Add timer and internal event queue to AppTask.cpp

Fixes: project-chip#100
Fixes: project-chip#103

examples/lock-app/mbed/main/AppTask.cpp

@@ -17,13 +17,26 @@
  */
 
 #include "AppTask.h"
+
 #include <support/logging/CHIPLogging.h>
 
+#include "mbed.h"
+
+static mbed::Ticker sFunctionTimer;
+
+// TODO: change EventQueue default event size
+static EventQueue sAppEventQueue;
+
 AppTask AppTask::sAppTask;
 
 int AppTask::Init()
 {
-    // TODO: Add led, buttons, hardware initialization.
+    mFunctionTimerActive = false;
+
+    // Timer initialization
+    // TODO: timer period to FACTORY_RESET_CANCEL_WINDOW_TIMEOUT
+    StartTimer(50);
+
     return 0;
 }
 
@@ -37,6 +50,75 @@ int AppTask::StartApp()
         return ret;
     }
 
-    // TODO: Add event msg queue handling
+    while (true)
+    {
+        sAppEventQueue.dispatch(100);
+    }
+
     return 0;
-}
+}
+
+void AppTask::CancelTimer()
+{
+    if (mFunctionTimerActive)
+    {
+        sFunctionTimer.detach();
+        mFunctionTimerActive = false;
+    }
+}
+
+void AppTask::StartTimer(uint32_t aTimeoutInMs)
+{
+    auto chronoTimeoutMs = std::chrono::duration<uint32_t, std::milli>(aTimeoutInMs);
+
+    if (mFunctionTimerActive)
+    {
+        ChipLogError(NotSpecified, "App timer already started!");
+        CancelTimer();
+    }
+
+    sFunctionTimer.attach(&AppTask::TimerEventHandler, chronoTimeoutMs);
+    mFunctionTimerActive = true;
+}
+
+void AppTask::PostEvent(AppEvent * aEvent)
+{
+    auto handle = sAppEventQueue.call([event = *aEvent, this] { DispatchEvent(&event); });
+    if (!handle)
+    {
+        ChipLogError(NotSpecified, "Failed to post event to app task event queue: Not enough memory");
+    }
+}
+
+void AppTask::DispatchEvent(const AppEvent * aEvent)
+{
+    if (aEvent->Handler)
+    {
+        aEvent->Handler(const_cast<AppEvent *>(aEvent));
+    }
+    else
+    {
+        ChipLogError(NotSpecified, "Event received with no handler. Dropping event.");
+    }
+}
+
+// static
+void AppTask::TimerEventHandler()
+{
+    AppEvent event;
+    event.Type               = AppEvent::kEventType_Timer;
+    event.TimerEvent.Context = nullptr;
+    event.Handler            = FunctionTimerEventHandler;
+    sAppTask.PostEvent(&event);
+}
+
+// static
+void AppTask::FunctionTimerEventHandler(AppEvent * aEvent)
+{
+    // Below code is only for debug purpose!
+    static DigitalOut led(LED1);
+    if (aEvent->Type != AppEvent::kEventType_Timer)
+        return;
+
+    led = !led;
+}

examples/lock-app/mbed/main/include/AppEvent.h

@@ -0,0 +1,58 @@
+/*
+ *
+ *    Copyright (c) 2021 Project CHIP Authors
+ *    Copyright (c) 2018 Nest Labs, Inc.
+ *    All rights reserved.
+ *
+ *    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 <cstdint>
+
+struct AppEvent;
+typedef void (*EventHandler)(AppEvent *);
+
+struct AppEvent
+{
+    enum AppEventTypes
+    {
+        kEventType_Button = 0,
+        kEventType_Timer,
+        kEventType_Lock,
+        kEventType_Install,
+    };
+
+    uint16_t Type;
+
+    union
+    {
+        struct
+        {
+            uint8_t ButtonIdx;
+            uint8_t Action;
+        } ButtonEvent;
+        struct
+        {
+            void * Context;
+        } TimerEvent;
+        struct
+        {
+            uint8_t Action;
+            int32_t Actor;
+        } LockEvent;
+    };
+
+    EventHandler Handler;
+};

examples/lock-app/mbed/main/include/AppTask.h

@@ -17,16 +17,33 @@
  *    limitations under the License.
  */
 
+#pragma once
+
+#include "AppEvent.h"
+
 class AppTask
 {
 public:
     int StartApp();
 
+    void PostEvent(AppEvent * aEvent);
+
 private:
     friend AppTask & GetAppTask(void);
 
     int Init();
 
+    void CancelTimer(void);
+
+    void DispatchEvent(const AppEvent * event);
+
+    static void FunctionTimerEventHandler(AppEvent * aEvent);
+
+    static void TimerEventHandler();
+
+    void StartTimer(uint32_t aTimeoutInMs);
+
+    bool mFunctionTimerActive;
     static AppTask sAppTask;
 };