From 2f046187ca3b49aded86833b0c8bbe25abe5da53 Mon Sep 17 00:00:00 2001
From: David Willis <dwillis@nildram.co.uk>
Date: Sun, 10 Feb 2013 01:20:11 +0000
Subject: [PATCH] OP-825 Fix null reference and race condition when shutting
 down service

---
 .../androidgcs/telemetry/OPTelemetryService.java |  8 +++++++-
 .../androidgcs/telemetry/TelemetryTask.java      | 16 ++++++++++------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/androidgcs/src/org/openpilot/androidgcs/telemetry/OPTelemetryService.java b/androidgcs/src/org/openpilot/androidgcs/telemetry/OPTelemetryService.java
index 965a0aac4..7a2003588 100644
--- a/androidgcs/src/org/openpilot/androidgcs/telemetry/OPTelemetryService.java
+++ b/androidgcs/src/org/openpilot/androidgcs/telemetry/OPTelemetryService.java
@@ -241,7 +241,13 @@ public class OPTelemetryService extends Service {
 			telemTask = null;
 
 			try {
-				activeTelem.join();
+				// Race condition - if we shut the service down before the telemetry task
+				// thread has started, this will hang so we need to check thread is runnable.
+				if(activeTelem.getState() == Thread.State.RUNNABLE){
+					activeTelem.join();
+				}else{
+					Log.d(TAG, "onDestroy() shut down telemetry task before it has started");
+				}
 			} catch (InterruptedException e) {
 				e.printStackTrace();
 			}
diff --git a/androidgcs/src/org/openpilot/androidgcs/telemetry/TelemetryTask.java b/androidgcs/src/org/openpilot/androidgcs/telemetry/TelemetryTask.java
index ad23b2e00..dd1650487 100644
--- a/androidgcs/src/org/openpilot/androidgcs/telemetry/TelemetryTask.java
+++ b/androidgcs/src/org/openpilot/androidgcs/telemetry/TelemetryTask.java
@@ -142,12 +142,16 @@ public abstract class TelemetryTask implements Runnable {
 		}
 
 		// Stop the master telemetry thread
-		handler.post(new Runnable() {
-			@Override
-			public void run() {
-				Looper.myLooper().quit();
-			}
-		});
+		// Check handler is not null: if we attempt to disconnect before
+		// the connect process has completed, handler may be null.
+		if(handler != null){
+			handler.post(new Runnable() {
+				@Override
+				public void run() {
+					Looper.myLooper().quit();
+				}
+			});
+		}
 
 		if (inputProcessThread != null) {
 			inputProcessThread.interrupt();