Ah - just double-checked. It'll crash just fine without adding the
usleep() to OpenThreads; I had my builds mixed up.
AC
On 9/20/07, Adam Coates <[EMAIL PROTECTED]> wrote:
> Hi, Robert,
>
> The following is sufficient (basically what you said):
>
> #include <OpenThreads/Thread>
>
> class MyThread : public OpenThreads::Thread {
> public:
> void run(void) { }
> };
>
> int main(int argc, char* argv[]) {
> {
> MyThread thread;
> thread.startThread();
> }
> while(1) ;
> return 0;
> }
>
> You need the while(1) ; to prevent the process from dying and cleaning
> up the thread before it wrecks. This alone wouldn't reproduce the bug
> because the interleaving doesn't happen (it's a very short window in
> which it can happen). To force the bug, I added ::usleep(1000000) at
> the beginning of ThreadPrivateActions::StartThread().
>
> AC
>
> On 9/20/07, Robert Osfield <[EMAIL PROTECTED]> wrote:
> > Hi Adam,
> >
> > On 9/20/07, Adam Coates <[EMAIL PROTECTED]> wrote:
> > > So, I just realized that the OSG folks are not synonymous with the
> > > OpenThreads folks. ^_^ Sorry for dropping this on the wrong list
> > > then.
> >
> > Well OpenThreads list is a flat line, almost all (99.9%) OpenThreads
> > activity and development is done by members of the OpenSceneGraph
> > community. So this is probably the best place to raise issues like
> > this. Responsibility for maintaining OpenThreads has also fallen on
> > my shoulders as it effectively became an orphaned project when the
> > original project lead got sucked into non coding management.
> >
> > >In that light, it may not even be considered a bug in OT,
> > > since, theoretically, it might be unfair to call the Thread destructor
> > > while the thread is running (even though I'm pretty sure they intended
> > > isRunning() to work as we'd expect).
> >
> > Well this type of usage is kinda abusing the Thread class, but I'd
> > still say this way a bug.
> >
> > > It should be possible to add a workaround in the following way:
> > >
> > > 1. Before starting the thread, set a flag to indicate that the thread
> > > is "starting up".
> > > 2. Have the thread's run() routine unset this flag.
> > >
> > > Before deleting the Thread, make sure that both the "starting up" flag
> > > and the isRunning flag are false. One of these will have to be true
> > > if the thread has not reached the run() method yet, or has not
> > > completely exited from run() -- thus avoiding the problem.
> >
> > I'll have ponder in this issue, I'm more inclined to use a mutex in
> > some way that just a straight flag.
> >
> > > My question: does somebody want me to implement this workaround and
> > > submit it to you? Alternatively, I can just point out the break to
> > > the OpenThreads people and we can wait for a patch...
> >
> > It's best to just roll your sleeves up and get stuck in. First up we
> > need a test that can reliably reproduce the error. Would the
> > following code block do the trick?
> >
> > {
> > OpenThreads::Thread thread;
> > thread.startThread();
> > }
> >
> > Robert.
> > _______________________________________________
> > osg-users mailing list
> > [email protected]
> > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
> >
>
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