Not receiving events from spawned Cocoa thread.

[Jim Trankelson]

Hi,

I'm trying to integrate the spacenavigator into my cocoa app, and really need the event handling to be done in another thread. In my app initialization, I set up the thread like this:

[NSThread detachNewThreadSelector:@selector(setupSN:) toTarget:[self retain] withObject:self];

- (void)setupSN:(id)arg
{
[arg spaceNavigatorBootstrap];
}

- (void) spaceNavigatorBootstrap
{
OSErr oserr;

// Make sure the framework is installed
if(InstallConnexionHandlers != NULL) {

// Install message handler and register our client
oserr = InstallConnexionHandlers(SNHandler, 0L, 0L);

fConnexionClientID = RegisterConnexionClient(kConnexionClientWildcard, 0L, kConnexionClientModeTakeOver, kConnexionMaskAll);
}
...
}

All of the handling is copied from the Cocoa SDK example. The problem is that I'm not actually receiving any events when I set things up like this. My callback function isn't getting called. I've read something about using the NSRunLoop somehow, but I'm slightly confused about how to go about setting that up. Can anyone give me a pointer?

Thanks!

-jt

[ettore]

Hi Jim,

is your thread exiting immediately after the spaceNavigatorBootstrap method has completed? That's what it seems like. Please verify it using ThreadViewer.app.

The thread spawned (detached) using detachNewThreadSelector: will exit if you don't set up a loop after the call to the spaceNavigatorBootstrap method.

Have a look at Apple's website for how to setup a run loop, there are good resources (explained better than what I could do here):
http://developer.apple.com/documentatio ... index.html

and also the reference class documentation for NSRunLoop:
http://developer.apple.com/documentatio ... rence.html

[Jim Trankelson]

Yes!

Thanks. This helped me immensely.

What I needed to do is create a port and continue to run the thread's run loop.

// Install message handler and register our client
oserr = InstallConnexionHandlers(SNHandler, 0L, 0L);

fConnexionClientID = RegisterConnexionClient(...)

[[NSRunLoop currentRunLoop] addPort:self.portObj forMode:NSDefaultRunLoopMode];

NSDate *endDate = [NSDate distantFuture];

// Start the run loop.
for(;;) {
[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:endDate];
}


And then the callback will be invoked. Thanks!

-jt