I have an application based on the "Cocoa Application" template in Xcode (x86_64, currently testing on OSX 10.6.5) that listens for client messages using an NSConnection. Both client and server have been designed for garbage collection, and are compiled GC-only. The client is a simple command-line program that uses
[NSConnection rootProxyForConnectionWithRegisteredName:serverName host:nil]; to send it's messages to the server. The messages direct the server to load large-ish data files (200MB) and perform processing on them. Periodically the client may direct the server to unload all of the large datasets from memory, which the server does by calling the 'removeAllObjects' method of a mutable array that holds the list of all loaded datasets. Under real conditions, we would expect to load around five of these datasets at a time, perform processing, unload, and then load another five. I have overridden the 'finalize' method of the dataset class to print a log message before calling [super finalize], and when I perform a single processing 'run' in which the client sends a message to the server directing it to load a 200MB dataset and then perform a series of processing operations which result in five datasets being open, I have noticed that - while the finalize methods are indeed called - they are called around five to ten seconds after the last processing directive is sent from the client. For five datasets the above behaviour is not a problem, but in more realistic tests where we generate five datasets, flush, then generate five more, before repeating the cycle perhaps 10 times, the finalize methods never appear to be called (or at least no log messages appear). The memory usage becomes huge, and eventually the program crashes. In these runs, a shell script repeatedly invokes the client program to send messages to the server program. The server (which has a UI) might spend all it's time in an 'inactive' state with no user input. The commands are currently run on the main thread of the server. However the memory accumulation and crash happen whether or not I click on the server window to bring it to the foreground. I'm pretty sure I'm not leaking the memory with an unintended reference, as the datasets *are* collected (albeit not very quickly) after I run a set of five operations and the server returns to be waiting for user input. I'm wondering if it could be because collection will not happen until the end of a run loop, and by bombarding the server with messages then collection is never triggered because it never senses the end of the run loop. I gather that there may be special considerations with runloops and NSConnection. Note that I *am* calling collectExhaustively right after the various stages in the server when data should be flushed, but this does not seem to help. I do the call at the end of the method in which client messages are processed - is it possible this should be run using performSelector after the current run loop? I'm at the point where I am reconsidering whether GC is really appropriate for this application, but also think I may well be doing something silly that can easily be fixed. Would be grateful for any suggestions! Rick _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
