From 207d300ca5ac4196a5fb19257af7d41fed40dff6 Mon Sep 17 00:00:00 2001
From: Pawel Pieczul <pieczul@gmail.com>
Date: Sun, 3 Jan 2021 08:00:50 +0100
Subject: [PATCH] [loxone] Fix for #8693 - removed deadlock (#9624)

Signed-off-by: Pawel Pieczul <pieczul@gmail.com>
---
 .../loxone/internal/LxServerHandler.java      | 30 +++++--------------
 1 file changed, 7 insertions(+), 23 deletions(-)

diff --git a/bundles/org.openhab.binding.loxone/src/main/java/org/openhab/binding/loxone/internal/LxServerHandler.java b/bundles/org.openhab.binding.loxone/src/main/java/org/openhab/binding/loxone/internal/LxServerHandler.java
index 560292e69a4..aa6b9d58ded 100644
--- a/bundles/org.openhab.binding.loxone/src/main/java/org/openhab/binding/loxone/internal/LxServerHandler.java
+++ b/bundles/org.openhab.binding.loxone/src/main/java/org/openhab/binding/loxone/internal/LxServerHandler.java
@@ -24,11 +24,11 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
-import java.util.concurrent.locks.Condition;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 
@@ -94,14 +94,12 @@ public class LxServerHandler extends BaseThingHandler implements LxServerHandler
     private int debugId = 0;
     private Thread monitorThread;
     private final Lock threadLock = new ReentrantLock();
-    private final Lock queueUpdatedLock = new ReentrantLock();
-    private final Condition queueUpdated = queueUpdatedLock.newCondition();
     private AtomicBoolean sessionActive = new AtomicBoolean(false);
 
     // Data structures
     private final Map<LxUuid, LxControl> controls = new HashMap<>();
     private final Map<ChannelUID, LxControl> channels = new HashMap<>();
-    private final ConcurrentLinkedQueue<LxStateUpdate> stateUpdateQueue = new ConcurrentLinkedQueue<>();
+    private final BlockingQueue<LxStateUpdate> stateUpdateQueue = new LinkedBlockingQueue<>();
 
     private LxDynamicStateDescriptionProvider dynamicStateDescriptionProvider;
     private final Logger logger = LoggerFactory.getLogger(LxServerHandler.class);
@@ -467,12 +465,6 @@ public class LxServerHandler extends BaseThingHandler implements LxServerHandler
      */
     void queueStateUpdate(LxUuid uuid, Object value) {
         stateUpdateQueue.add(new LxStateUpdate(uuid, value));
-        queueUpdatedLock.lock();
-        try {
-            queueUpdated.signalAll();
-        } finally {
-            queueUpdatedLock.unlock();
-        }
     }
 
     /**
@@ -672,21 +664,13 @@ public class LxServerHandler extends BaseThingHandler implements LxServerHandler
         private void processStateUpdates() throws InterruptedException {
             while (sessionActive.get()) {
                 logger.debug("[{}] Sleeping for {} seconds.", debugId, bindingConfig.keepAlivePeriod - elapsed);
-                queueUpdatedLock.lock();
-                try {
-                    if (!queueUpdated.await(bindingConfig.keepAlivePeriod - elapsed, TimeUnit.SECONDS)) {
-                        sendKeepAlive();
-                        continue;
-                    }
-                } finally {
-                    queueUpdatedLock.unlock();
-                }
+                LxStateUpdate update = stateUpdateQueue.poll(bindingConfig.keepAlivePeriod - elapsed, TimeUnit.SECONDS);
                 elapsed = Duration.between(lastKeepAlive, Instant.now()).getSeconds();
-                if (elapsed >= bindingConfig.keepAlivePeriod) {
+                if (update == null || elapsed >= bindingConfig.keepAlivePeriod) {
                     sendKeepAlive();
+                    elapsed = 0;
                 }
-                LxStateUpdate update;
-                while ((update = stateUpdateQueue.poll()) != null && sessionActive.get()) {
+                if (update != null) {
                     updateStateValue(update);
                 }
             }