[wpilib] Add option to flush NetworkTables every iterative loop

This functionality is disabled by default, but can be enabled by the user
program by calling setNetworkTablesFlushEnabled.

wpilibc/src/main/native/cpp/IterativeRobotBase.cpp

@@ -8,6 +8,7 @@
 #include "frc/IterativeRobotBase.h"
 
 #include <hal/DriverStation.h>
+#include <networktables/NetworkTableInstance.h>
 #include <wpi/Format.h>
 #include <wpi/SmallString.h>
 #include <wpi/raw_ostream.h>
@@ -98,6 +99,10 @@ void IterativeRobotBase::TestPeriodic() {
   }
 }
 
+void IterativeRobotBase::SetNetworkTablesFlushEnabled(bool enabled) {
+  m_ntFlushEnabled = enabled;
+}
+
 void IterativeRobotBase::LoopFunc() {
   m_watchdog.Reset();
 
@@ -179,6 +184,9 @@ void IterativeRobotBase::LoopFunc() {
 
   m_watchdog.Disable();
 
+  // Flush NetworkTables
+  if (m_ntFlushEnabled) nt::NetworkTableInstance::GetDefault().Flush();
+
   // Warn on loop time overruns
   if (m_watchdog.IsExpired()) {
     m_watchdog.PrintEpochs();

wpilibc/src/main/native/include/frc/IterativeRobotBase.h

@@ -155,6 +155,14 @@ class IterativeRobotBase : public RobotBase {
    */
   virtual void TestPeriodic();
 
+  /**
+   * Enables or disables flushing NetworkTables every loop iteration.
+   * By default, this is disabled.
+   *
+   * @param enabled True to enable, false to disable
+   */
+  void SetNetworkTablesFlushEnabled(bool enabled);
+
   /**
    * Constructor for IterativeRobotBase.
    *
@@ -188,6 +196,7 @@ class IterativeRobotBase : public RobotBase {
 
   Mode m_lastMode = Mode::kNone;
   Watchdog m_watchdog;
+  bool m_ntFlushEnabled = false;
 
   void PrintLoopOverrunMessage();
 };

wpilibj/src/main/java/edu/wpi/first/wpilibj/IterativeRobotBase.java

@@ -8,6 +8,7 @@
 package edu.wpi.first.wpilibj;
 
 import edu.wpi.first.hal.HAL;
+import edu.wpi.first.networktables.NetworkTableInstance;
 import edu.wpi.first.wpilibj.livewindow.LiveWindow;
 import edu.wpi.first.wpilibj.shuffleboard.Shuffleboard;
 import edu.wpi.first.wpilibj.smartdashboard.SmartDashboard;
@@ -55,6 +56,7 @@ public abstract class IterativeRobotBase extends RobotBase {
 
   private Mode m_lastMode = Mode.kNone;
   private final Watchdog m_watchdog;
+  private boolean m_ntFlushEnabled;
 
   /**
    * Constructor for IterativeRobotBase.
@@ -218,6 +220,16 @@ public abstract class IterativeRobotBase extends RobotBase {
     }
   }
 
+  /**
+   * Enables or disables flushing NetworkTables every loop iteration.
+   * By default, this is disabled.
+   *
+   * @param enabled True to enable, false to disable
+   */
+  public void setNetworkTablesFlushEnabled(boolean enabled) {
+    m_ntFlushEnabled = enabled;
+  }
+
   @SuppressWarnings("PMD.CyclomaticComplexity")
   protected void loopFunc() {
     m_watchdog.reset();
@@ -300,6 +312,11 @@ public abstract class IterativeRobotBase extends RobotBase {
 
     m_watchdog.disable();
 
+    // Flush NetworkTables
+    if (m_ntFlushEnabled) {
+      NetworkTableInstance.getDefault().flush();
+    }
+
     // Warn on loop time overruns
     if (m_watchdog.isExpired()) {
       m_watchdog.printEpochs();