Asynchronicity in D

[Sean Kelly]

On Apr 1, 2011, at 12:59 PM, Jonas Drewsen wrote:

> On 01/04/11 17.21, Sean Kelly wrote:
>> 
>> On Apr 1, 2011, at 7:49 AM, Jonas Drewsen wrote:
>>> 
>>> There doesn't have to be a thread for each socket. Actually many servers have very few threads with many sockets each. 32000 sockets is not unimaginable for certain server loads e.g. websockets or game servers. But I know it is not that common.
>> 
>> Hopefully not at all common.  With that level of concurrency the process will spend more time context switching than executing code.
> 
> For services where clients spend most time inactive this works. An example could be a server for messenger like clients. Most of the time the clients are just connected waiting for messages. As long as nothing is transmitted no context switching is done.

Fair enough.  Though I'd still say it's a terrible use of resources, given available asynchronous socket APIs.  And as an aside, I think 32K sockets per process is not at all surprising.  I've seen apps that use orders of magnitude more than that, though breaking the 64K barrier does get a bit weird.