multi threading safety

[trendspike]

I am using websocket. It is simple and powerful. The websocket server application has two threads which broadcast to clients. Are they thread safe? If no, how can I make sure the two threads can broadcast?

Currently I use lock. when one thread is broadcasting, I turn on the lock. Is the solution ok?

I am not a professional Java program. I appreciate your kind help.

[lakeoffaith]

you can turn list to ConcurrentLinkedQueue, then just call poll() to get item.
then server.broadcast(Collections.singletonList(item))

[PhilipRoman]

Broadcasting from multiple threads is fine