Hi all. I'm using NSTask and NSPipe to launch lots of little processes, and I'm running out of file descriptors. In my googling and archive searching, I found some info that led me to several approaches:
1. I ran ObjectAlloc and Leaks under Instruments and confirmed that I am not leaking pipes or file handles. Nor is it an autorelease pool issue; the run loop is running freely as I start and stop tasks, so the pipes and file handles get dealloced properly. All pipes and file handles made by my task code were listed by ObjectAlloc as "transitory". 2. I used "lsof -p <pid> | grep -v " txt " | wc -l" to monitor the file descriptors used by my app, and observed that it went steadily upwards as tasks got started and stopped; the file descriptors were not being freed, even though the pipes were being freed correctly. 3. I added [[pipe fileHandleForWriting] closeFile] and [[pipe fileHandleForReading] closeFile] calls to close the files associated with the pipes when my tasks completed. This change fixed the problem; I no longer run out of file descriptors. So I have a workaround for the problem, but I want to understand *why* it works. Shouldn't NSPipe close its associated files when it deallocs? Why should it be necessary to call -closeFile? This behavior seems to be specifically contradicted by the documentation on NSPipe, which says (in -fileHandleForReading) "The descriptor represented by this object is deleted, and the object itself is automatically deallocated when the receiver is deallocated." Well, when my NSPipes are deallocated, the file handles are indeed automatically deallocated (a funny way to put it), but the descriptor is *not* deleted. Is this a bug? More likely I'm misunderstanding something; can anybody clarify this for me? Thanks! Ben Haller McGill University _______________________________________________ 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
