On 20 Mar 2014, at 01:50, Charles Srstka <cocoa...@charlessoft.com> wrote:
> On Mar 19, 2014, at 7:29 PM, patrick machielse <patr...@hieper.nl> wrote: > >> We are working on a sandboxed application that keeps track of a large number >> of files through security scoped URLs. To access the files we carfully >> balance our calls to startAccessingSecurityScopedResource / >> stopAccessingSecurityScopedResource: >> >> [url startAccessingSecurityScopedResource] >> /* do some work */ >> [url stopAccessingSecurityScopedResource] >> >> >> All was fine until we needed to start accessing the files from multiple >> threads simultaneously. According to the documentation: >> >> "When you call the stopAccessingSecurityScopedResource method, you >> immediately lose access to the resource in question (even if you have >> previously called startAccessingSecurityScopedResource more than once)." >> >> Thus, as soon as 1 thread executes its >> 'stopAccessingSecurityScopedResource', all access in other threaded code >> blocks is lost. >> >> It seems that we must design our own bookkeeping around security scoped >> urls, make sure we don't manage resource access directly in our frameworks, >> and hope no 3rd party frameworks call stopAccessingSecurityScopedResource >> behind our backs. We find this API design disappointing (to say the least), >> it's as if we need to call retain / release *and also* manage the retain >> count ourselves... >> >> >> Sandboxing is a good idea in theory, but the implementation has been kicking >> sand (.) in our faces for a while now. >> >> Did we miss some hidden feature? Did anyone design a re-usable solution for >> accessing security scoped resources from multiple threads? >> >> We'd be grateful for any ideas! >> >> patrick > > Have you tried using CFURLStartAccessingSecurityScopedResource instead of > -startAccessingSecurityScopedResource? This is what the documentation has to > say about it: > > "Calls to the CFURLStartAccessingSecurityScopedResource function (or its > Cocoa equivalent) are nestable on a per-process basis. This means that if > your app calls the start method on a URL twice, to fully relinquish access to > the referenced resource you must call the corresponding stop method twice." > > Of course, it also claims that the Cocoa method does this, so who knows. The Cocoa method behaves the same. And the implementation as I understand it is path-based (rather being tied to a specific NSURL instance). It’s basically reference counting for file system access permissions. _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
