Rewrite C++ Notifier to use HAL multi-notifier support.

This removes redundant queue code from the C++ library.

The old queue code is still needed by simulation, and as the delta between
the simulation and athena headers has grown significantly, this splits the
header into two separate files.

Change-Id: Ia76b38337a25eb9d4890b3eb9bd76b1cbda7f285

wpilibc/shared/include/Notifier.h

@@ -1,57 +0,0 @@
-/*----------------------------------------------------------------------------*/
-/* Copyright (c) FIRST 2008. All Rights Reserved.
- */
-/* Open Source Software - may be modified and shared by FRC teams. The code   */
-/* must be accompanied by the FIRST BSD license file in $(WIND_BASE)/WPILib.  */
-/*----------------------------------------------------------------------------*/
-#pragma once
-
-#include "ErrorBase.h"
-#include "HAL/cpp/priority_mutex.h"
-#include <thread>
-#include <atomic>
-
-typedef void (*TimerEventHandler)(void *param);
-
-class Notifier : public ErrorBase {
- public:
-  Notifier(TimerEventHandler handler, void *param = nullptr);
-  virtual ~Notifier();
-
-  Notifier(const Notifier&) = delete;
-  Notifier& operator=(const Notifier&) = delete;
-
-  void StartSingle(double delay);
-  void StartPeriodic(double period);
-  void Stop();
-
- private:
-  static Notifier *timerQueueHead;
-  static priority_recursive_mutex queueMutex;
-  static priority_mutex halMutex;
-  static void *m_notifier;
-  static std::atomic<int> refcount;
-
-  static void ProcessQueue(
-      uint32_t mask, void *params);  // process the timer queue on a timer event
-  static void
-  UpdateAlarm();  // update the FPGA alarm since the queue has changed
-  void InsertInQueue(
-      bool reschedule);         // insert this Notifier in the timer queue
-  void DeleteFromQueue();       // delete this Notifier from the timer queue
-  TimerEventHandler m_handler;  // address of the handler
-  void *m_param;                // a parameter to pass to the handler
-  double m_period = 0;              // the relative time (either periodic or single)
-  double m_expirationTime = 0;  // absolute expiration time for the current event
-  Notifier *m_nextEvent = nullptr;    // next Nofifier event
-  bool m_periodic = false;          // true if this is a periodic event
-  bool m_queued = false;            // indicates if this entry is queued
-  priority_mutex m_handlerMutex;  // held by interrupt manager task while
-                                    // handler call is in progress
-
-#ifdef FRC_SIMULATOR
-  static std::thread m_task;
-  static std::atomic<bool> m_stopped;
-#endif
-  static void Run();
-};