Making library thread-safety

[ventaquil]

I want to ask why library is not thread-safe by default?
For example in Server.emit method docblock we can read Note: this method is not thread safe..
It's going to be more useful when library does such things under the hood.

The simplest solution is to create Lock immediately after client connects to the server - and removes lock after client disconnects. Emit method uses that lock if it's emmiting data to specified client.
There should be something like lock-aggregator to handle broadcast and room emits too (such aggregator waits for all child-locks).

I can prepare PR but maybe there is a reason why you don't implement this feature. I am open for discussion.

[miguelgrinberg]

The reason is that most people do not need this. Adding a lock is expensive, there is no reason to punish the majority of users, this is easy enough to be implemented by the application when it is needed.

[ventaquil]

If it's intentional decision I think that I am out of questions now.