On Tuesday, 7 July 2015 at 16:41:41 UTC, Frank Pagliughi wrote:
Instead of pulling values out, have you considered pushing
them? E.g. by supplying a delegate that gets called when the
asynchronous action completed.
I've always been on the fence about push vs pull when writing
libraries of this type. The callback/delegate method is
probably more powerful and may reduce latency and context
switching, but since the callback happens in the context of the
library thread, it exposes the client application to the
messiness and problems of managing threads, race conditions,
locking and all that. And it can expose the library to
performance issues by handing over it's thread to user code
which may not return for a long, long time. Plus most of the
time I've found that client apps just set a flag and signal a
condition variable anyway.
The delegate could send a message to user code in another
thread/fiber. In any case it removes a blocking get_result() and
possibly the need for get_result_timeout().
