macOS

asynchronous execution

here are 3 methods of executing code asynchronously

using NSThread (and threading in general) is the usual way, recommended for longer-running threads

the other 2 methods are typically recommended for use "locally", that is limited to the lifetime of the object that spawns the async code

NSThread

TODO

performSelectorInBackground:withObject:

the performSelectorInBackground method of NSObject spawns a new thread to execute your provided method (via selector)

this also means that you have to take care of your releases or create a release pool, just as with NSThread

typical usage:

- (void)mainMethod
{
    // ...
    [self performSelectorInBackground:@selector(asyncMethod:) withObject:someParam];
    // code here is executed (almost) immediately after the above call,
    // as the asyncMethod's code is now being executed in separate thread
    // ...
}
NSArray* foo = [[[NSArray alloc] initWithObjects:@"a", @"b", nil] autorelease];
[bar performSelectorInBackground:@selector(baz:) withObject:foo];

- (void)asyncMethod:(id)param
{
    NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
    // your code that will be executed asynchronously
    [pool release];
}

dispatch_async()

TODO

updating and cleaning up MacPorts

$ sudo port selfupdate
$ sudo port upgrade outdated
$ sudo port uninstall inactive
$ (just once) sudo port install port_cutleaves
$ sudo port_cutleaves