On Sat, 10 Jul 2010, Paul Romero wrote:

> The problem occurred due to the following stupid assumption about socket and
> file descriptors. The assumption is that they can be programmed to generate
> an event when there is a transition from output being blocked to not being
> blocked. This is not true for any Linux/Unix drivers I know of

That's not the job of any "driver". SIGIO/SIGPOLL is a matter for the TCP/IP
stack itself. But if you're going for wide portability as you say you do, then
libcurl already provides much greater portability for asynch transfers than
you'll achieve with anything using SIGIO.

If you're going for something properly event-based, you're much better off
using a portable event-library such as libev or libevent that can use any of a
set of backends depending on what the target operating system provides. Any
libcurl works perfectly fine with event-based approaches as well. If you're
going beyond a few hundred connections that's the only sane approach.

-- 
  / daniel.haxx.se
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