"Darryl Green" <Darryl.Green@unitab.com.au> writes:
-----Original Message----- From: Jeremy Maitin-Shepard [mailto:jbms@attbi.com] Sent: Thursday, 29 January 2004 7:03 PM To: boost@lists.boost.org Subject: Re: [boost] Re: Re: Boost.Thread : IO multiplexing
"Hurd, Matthew" <hurdm@sig.com> writes:
On Behalf Of Sean Kelly
What remains an issue in my mind is how far to take this. Socket and file classes for each platform at least... what else?
Waitable timers would be the other "main" one I'd guess.
Unfortunately, I do not believe that it is possible to wait on both a timer and a file descriptor on POSIX platforms, so this is the same situation as mutexes (see below).
It is easy enough to do this - for example see ACE's Reactor Notify for details. If you care about other threads you need the notify interface to force a wake-up when a new timeout needs to be calculated, otherwise just calculating the timeout parameter from the head of the timer queue before blocking is enough.
Okay, I suppose this can be done.
[snip]
I don't see why the library shouldn't be generic enough to allow a unification on a platform that supports it.
I suppose it is possible, but is there any platform other than Windows that supports it? Also, it seems that the interface to support waiting on a mutex would be too loo-level to then allow use of either asynchronous I/O or synchronous I/O, depending on the platform.
[snip]
On the opposite side of the coin, Linux 2.6 has extended aio in the kernel that should make aio a pretty reasonable option for that platform and at least tries to address most of the negatives mentioned re using aio on Posix platforms.
I may be mistaken, but it seems that the new asynchronous I/O completion system at least currently cannot be used with sockets. -- Jeremy Maitin-Shepard