From 951c81f5b7381b329a7b4395d56d217a0be32531 Mon Sep 17 00:00:00 2001
From: Thad House <thadhouse1@gmail.com>
Date: Thu, 24 Dec 2015 21:10:47 -0800
Subject: [PATCH] Adds WaitResult to Java waitForInterrupt

WaitResult gets returned from C++ and the JNI, so should probably be returned
in Java as well.

Adds WaitResult tests to Java AbstractInterruptTest

Change-Id: Ic3cb2919652696c458c39006b2f716301c0736f4
---
 .../wpilibj/InterruptableSensorBase.java      | 33 +++++++++--
 .../first/wpilibj/AbstractInterruptTest.java  | 56 +++++++++++++++++++
 2 files changed, 85 insertions(+), 4 deletions(-)

diff --git a/wpilibj/src/athena/java/edu/wpi/first/wpilibj/InterruptableSensorBase.java b/wpilibj/src/athena/java/edu/wpi/first/wpilibj/InterruptableSensorBase.java
index 744e59f1f0..d7a5012df2 100644
--- a/wpilibj/src/athena/java/edu/wpi/first/wpilibj/InterruptableSensorBase.java
+++ b/wpilibj/src/athena/java/edu/wpi/first/wpilibj/InterruptableSensorBase.java
@@ -15,6 +15,27 @@ import edu.wpi.first.wpilibj.util.CheckedAllocationException;
  * Base for sensors to be used with interrupts
  */
 public abstract class InterruptableSensorBase extends SensorBase {
+
+  public static enum WaitResult {
+    kTimeout(0x0), kRisingEdge(0x1), kFallingEdge(0x100), kBoth(0x101);
+
+    public final int value;
+
+    public static WaitResult valueOf(int value) {
+      for (WaitResult mode : values()) {
+        if (mode.value == value) {
+          return mode;
+        }
+      }
+      return null;
+    }
+
+
+    private WaitResult(int value) {
+      this.value = value;
+    }
+  }
+
   /**
    * The interrupt resource
    */
@@ -141,21 +162,25 @@ public abstract class InterruptableSensorBase extends SensorBase {
    * @param timeout Timeout in seconds
    * @param ignorePrevious If true, ignore interrupts that happened before
    *        waitForInterrupt was called.
+   * @return Result of the wait.
    */
-  public void waitForInterrupt(double timeout, boolean ignorePrevious) {
+  public WaitResult waitForInterrupt(double timeout, boolean ignorePrevious) {
     if (m_interrupt == 0) {
       throw new IllegalStateException("The interrupt is not allocated.");
     }
-    InterruptJNI.waitForInterrupt(m_interrupt, timeout, ignorePrevious);
+    int result = InterruptJNI.waitForInterrupt(m_interrupt, timeout, ignorePrevious);
+
+    return WaitResult.valueOf(result);
   }
 
   /**
    * In synchronous mode, wait for the defined interrupt to occur.
    *
    * @param timeout Timeout in seconds
+   * @return Result of the wait.
    */
-  public void waitForInterrupt(double timeout) {
-    waitForInterrupt(timeout, true);
+  public WaitResult waitForInterrupt(double timeout) {
+    return waitForInterrupt(timeout, true);
   }
 
   /**
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AbstractInterruptTest.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AbstractInterruptTest.java
index 2ca2931767..4115d705ed 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AbstractInterruptTest.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AbstractInterruptTest.java
@@ -218,6 +218,62 @@ public abstract class AbstractInterruptTest extends AbstractComsSetup {
         synchronousDelay, interruptRunTime, .1);
   }
 
+  @Test(timeout = (long) (synchronousTimeout * 1e3))
+  public void testSynchronousInterruptsWaitResultTimeout() {
+    // Given
+    getInterruptable().requestInterrupts();
+
+    //Don't fire interrupt. Expect it to timeout.
+    InterruptableSensorBase.WaitResult result = getInterruptable().waitForInterrupt(synchronousTimeout / 2);
+
+    assertEquals("The interrupt did not time out correctly.", result, InterruptableSensorBase.WaitResult.kTimeout);
+  }
+
+  @Test(timeout = (long) (synchronousTimeout * 1e3))
+  public void testSynchronousInterruptsWaitResultRisingEdge() {
+    // Given
+    getInterruptable().requestInterrupts();
+
+    final double synchronousDelay = synchronousTimeout / 2.;
+    Runnable r = new Runnable() {
+      @Override
+      public void run() {
+        Timer.delay(synchronousDelay);
+        setInterruptLow();
+        setInterruptHigh();
+      }
+    };
+
+    new Thread(r).start();
+    // Delay for twice as long as the timeout so the test should fail first
+    InterruptableSensorBase.WaitResult result = getInterruptable().waitForInterrupt(synchronousTimeout * 2);
+
+    assertEquals("The interrupt did not fire on the rising edge.", result, InterruptableSensorBase.WaitResult.kRisingEdge);
+  }
+
+  @Test(timeout = (long) (synchronousTimeout * 1e3))
+  public void testSynchronousInterruptsWaitResultFallingEdge() {
+    // Given
+    getInterruptable().requestInterrupts();
+    getInterruptable().setUpSourceEdge(false, true);
+
+    final double synchronousDelay = synchronousTimeout / 2.;
+    Runnable r = new Runnable() {
+      @Override
+      public void run() {
+        Timer.delay(synchronousDelay);
+        setInterruptHigh();
+        setInterruptLow();
+      }
+    };
+
+    new Thread(r).start();
+    // Delay for twice as long as the timeout so the test should fail first
+    InterruptableSensorBase.WaitResult result = getInterruptable().waitForInterrupt(synchronousTimeout * 2);
+
+    assertEquals("The interrupt did not fire on the falling edge.", result, InterruptableSensorBase.WaitResult.kFallingEdge);
+  }
+
 
   @Test(timeout = 4000)
   public void testDisableStopsInterruptFiring() {