diff options
Diffstat (limited to 'src/main/java/org/traccar/database/CommandsManager.java')
| -rw-r--r-- | src/main/java/org/traccar/database/CommandsManager.java | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/src/main/java/org/traccar/database/CommandsManager.java b/src/main/java/org/traccar/database/CommandsManager.java index dc9512d9e..de6eeeba8 100644 --- a/src/main/java/org/traccar/database/CommandsManager.java +++ b/src/main/java/org/traccar/database/CommandsManager.java @@ -1,5 +1,5 @@ /* - * Copyright 2017 Anton Tananaev (anton@traccar.org) + * Copyright 2017 - 2020 Anton Tananaev (anton@traccar.org) * Copyright 2017 Andrey Kunitsyn (andrey@traccar.org) * * Licensed under the Apache License, Version 2.0 (the "License"); @@ -142,14 +142,33 @@ public class CommandsManager extends ExtendedObjectManager<Command> { } private Queue<Command> getDeviceQueue(long deviceId) { - if (!deviceQueues.containsKey(deviceId)) { - deviceQueues.put(deviceId, new ConcurrentLinkedQueue<Command>()); + Queue<Command> deviceQueue; + try { + readLock(); + deviceQueue = deviceQueues.get(deviceId); + } finally { + readUnlock(); + } + if (deviceQueue != null) { + return deviceQueue; + } else { + try { + writeLock(); + return deviceQueues.computeIfAbsent(deviceId, key -> new ConcurrentLinkedQueue<>()); + } finally { + writeUnlock(); + } } - return deviceQueues.get(deviceId); } public void sendQueuedCommands(ActiveDevice activeDevice) { - Queue<Command> deviceQueue = deviceQueues.get(activeDevice.getDeviceId()); + Queue<Command> deviceQueue; + try { + readLock(); + deviceQueue = deviceQueues.get(activeDevice.getDeviceId()); + } finally { + readUnlock(); + } if (deviceQueue != null) { Command command = deviceQueue.poll(); while (command != null) { |