Subj : Re: Threading and Timeouts
To   : comp.programming.threads
From : Joe Seigh
Date : Mon Jul 18 2005 07:17 pm

MC wrote:
> Hi all,
> 
> Please let me know if there's a more appropriate group for my
> question--perhaps a Windows group.  I suspect it's more of a general
> threading Q though...
> 
> First off, I'm in the WinAPI environment and I'm finding that
> asynchronous API calls for connecting to an FTP server are very
> tedious.  I'd prefer not to deal with all the states and handles if
> possible--hence the idea of using synchronous API calls in a separate
> thread.  Here's the question: if the main thread creates a worker
> thread and the worker makes a synchronous call--say to connect to the
> FTP server--what's the best way to implement a timeout on that call?
> What I've thought of so far is:
> 
> main thread starts a timer
> main thread starts worker thread
> if timer ticks before worker is complete then terminate worker thread
> 
> However, according to MSDN, terminating a thread should only be used
> as a last resort because it doesn't do proper cleanup.  But then how
> else can a timeout be implemented, given that the worker thread is
> busy in a synchronous API call?  Am I doing this all wrong??
> 

Use non-blocking i/o with select() or poll().  Or just indicate i/o
has timed out without "canceling" it, just let the i/o complete normally.
Socket connections can't be shutdown instantaneously anyway.


-- 
Joe Seigh

When you get lemons, you make lemonade.
When you get hardware, you make software.

.