Re: Asynchronous cancel

[Ross Johnson <rpj@ise.canberra.edu.au>]

On Tue, 10 Aug 1999, Rajiv K Shukla wrote:

> Hello All,
> 
> Sorry if the question has been asked before. We're trying to see if we
> could use the pthreads-win32 package to port our code to NT. It's been
> fine so far but we have hit a snag. It seems that
> pthread_setcanceltype doesn't really do anything. It sets an integer
> variable cancelType (which is part of the pthread_t structure) but the
> flag is used no where. Looks like the only way to cancel a thread is
> to call pthread_cancel and within the cancelled thread call
> pthread_testcancel. But we'd like to be able to cancel a thread
> asynchronously, e.g one of our thread sleeps for a configurable amount
> of time and it could be set pretty high, 1 hour, or 10 hours, or
> whatever. If within the thread I need to call pthread_testcancel in
> order to be cancelled then it's a problem. We'd have to wait that much
> time before we're even able to call pthread_testcancel. 
> 
> I'd appreciate any suggestion that you may have.
> 

At present there is no way in general to asynchronously cancel a
thread. The best device on offer in the package is the
pthreadCancelableWait() and pthreadCancelableTimedWait() functions
(both non-POSIX and non-portable). See the code and comments in
misc.c. They respond to pthread_cancel().

Cheers.
Ross

+----------------------+---+
| Ross Johnson         |   | E-Mail: rpj@ise.canberra.edu.au
| Info Sciences and Eng|___|
| University of Canberra   | FAX:    +61 6 2015227
| PO Box 1                 |
| Belconnen  ACT    2616   | WWW:    http://willow.canberra.edu.au/~rpj/
| AUSTRALIA                |
+--------------------------+