Re: [boost] asio review -- number of allowed timers

From: Christopher Kohlhoff (chris_at_[hidden])
Date: 2005-12-31 02:16:21

Hi Jeff,

--- Jeff Garland <jeff_at_[hidden]> wrote:
<snip>
> So the questions are:
> 
> 1) Is the intent to support an 'unlimited' number of timers
> portably?

Yes.

> 2) If yes, does the implementation do this for all platforms?

Yes.

First a minor clarification to put things in asio terminology:
the question is not just about whether you can have an unlimited
number of deadline_timer objects, but also whether you can have
an unlimited number of pending asynchronous waits.

The implementation of a deadline_timer object is just an expiry
time (stored as a boost::posix_time::ptime).

Each pending asynchronous wait on a timer is represented by an
entry in a heap, sorted by expiry. Only the earliest expiry is
fed into the demultiplexer as a timeout, so in that sense there
is only one OS timer being used.

Cheers,
Chris