From 5ca00dddbeffd825f41efa17259574e2d75f4d08 Mon Sep 17 00:00:00 2001
From: Tyler Veness <calcmogul@gmail.com>
Date: Sat, 27 Jan 2018 01:01:15 -0800
Subject: [PATCH] Added TimedRobot::GetPeriod() (#915)

Fixes #914.
---
 wpilibc/src/main/native/cpp/TimedRobot.cpp               | 7 ++++++-
 wpilibc/src/main/native/include/TimedRobot.h             | 4 +++-
 .../src/main/java/edu/wpi/first/wpilibj/TimedRobot.java  | 9 ++++++++-
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/wpilibc/src/main/native/cpp/TimedRobot.cpp b/wpilibc/src/main/native/cpp/TimedRobot.cpp
index 9ef480e112..eef3f5c993 100644
--- a/wpilibc/src/main/native/cpp/TimedRobot.cpp
+++ b/wpilibc/src/main/native/cpp/TimedRobot.cpp
@@ -43,10 +43,15 @@ void TimedRobot::SetPeriod(double period) {
   m_period = period;
 
   if (m_startLoop) {
-    m_loop->StartPeriodic(m_period);
+    m_loop->StartPeriodic(period);
   }
 }
 
+/**
+ * Get time period between calls to Periodic() functions.
+ */
+double TimedRobot::GetPeriod() const { return m_period; }
+
 TimedRobot::TimedRobot() {
   m_loop = std::make_unique<Notifier>(&TimedRobot::LoopFunc, this);
 
diff --git a/wpilibc/src/main/native/include/TimedRobot.h b/wpilibc/src/main/native/include/TimedRobot.h
index ca348dbad5..ba2f812a5d 100644
--- a/wpilibc/src/main/native/include/TimedRobot.h
+++ b/wpilibc/src/main/native/include/TimedRobot.h
@@ -7,6 +7,7 @@
 
 #pragma once
 
+#include <atomic>
 #include <memory>
 
 #include "IterativeRobotBase.h"
@@ -30,13 +31,14 @@ class TimedRobot : public IterativeRobotBase {
   void StartCompetition() override;
 
   void SetPeriod(double seconds);
+  double GetPeriod() const;
 
  protected:
   TimedRobot();
   virtual ~TimedRobot();
 
  private:
-  double m_period = kDefaultPeriod;
+  std::atomic<double> m_period{kDefaultPeriod};
 
   // Prevents loop from starting if user calls SetPeriod() in RobotInit()
   bool m_startLoop = false;
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/TimedRobot.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/TimedRobot.java
index d533313dc1..06aa6165f6 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/TimedRobot.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/TimedRobot.java
@@ -21,7 +21,7 @@ import edu.wpi.first.wpilibj.hal.HAL;
 public class TimedRobot extends IterativeRobotBase {
   public static final double DEFAULT_PERIOD = 0.02;
 
-  private double m_period = DEFAULT_PERIOD;
+  private volatile double m_period = DEFAULT_PERIOD;
 
   // Prevents loop from starting if user calls setPeriod() in robotInit()
   private boolean m_startLoop = false;
@@ -68,4 +68,11 @@ public class TimedRobot extends IterativeRobotBase {
       m_loop.startPeriodic(m_period);
     }
   }
+
+  /**
+   * Get time period between calls to Periodic() functions.
+   */
+  public double getPeriod() {
+    return m_period;
+  }
 }