StackOverflow2013

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plurals

PO
primarykey
Id
11875357
data
AcceptedAnswerId
0
AnswerCount
0
ClosedDate
CommentCount
4
CommunityOwnedDate
CreationDate
2012-08-09T00:59:02.797
FavoriteCount
0
LastActivityDate
2012-08-09T00:59:02.797
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LastEditorUserId
0
OwnerUserId
97337
ParentId
11875288
PostTypeId
2
Score
1
ViewCount
0
LastEditorDisplayName
text
Body
This is exactly what <code>NSOperation</code> is designed for. Dispatch queues are much lower-level handlers, and you'd have to construct many of the pieces you need for this. You can of course do that (<code>NSOperationQueue</code> is built on top of GCD), but you'd be reinventing <code>NSOperation</code>. You can handle <code>NSOperation</code> two ways for the most part. If it's simple, you can just create an <code>NSBlockOperation</code>. If it's a bit more complex, you can subclass <code>NSOperation</code> and override the <code>main</code> method to do what you want. There are several ways to cancel all the other operations. You could have a separate operation queue per group. Then you can easily call <code>cancelAllOperations</code> to shut down everything. Or you could have a separate controller that knows the list of related operations and it could call <code>cancel</code> on them. Remember that "cancel" just means "don't schedule if it hasn't stared, and set <code>isCancelled</code> if it has." It doesn't abort a running operation. If you want to abort a running operation, the operation needs to periodically check <code>isCancelled</code>. You typically should limit the number of concurrent operations the queue will run. Use <code>setMaximimumConcurrentOperationCount:</code>. There are two ways to determine that all the operations are finished. You can make an extra operation (usually a <code>BlockOperation</code>) and use <code>addDependency:</code> to make it depend on all the other operations. That's a nice asynchronous solution. If you can handle a synchronous solution, then you can use <code>waitUntilAllOperationsAreFinished</code>. I typically prefer the former.
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Title
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1. This table or related slice is empty.
PostParentId
1. PODispatch queues, concurrency and completion handling
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PostTypePostTypeId
1. PTAnswer
UserLastEditorUserId
1. This table or related slice is empty.
UserOwnerUserId
1. USRob Napier
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PostsAcceptedAnswerId
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PostsParentIdCreationDate
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VotesPostIdCreationDate
1. VO
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CommentsPostId
1. COHow this class could look to fulfill these requirements?
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 USvoromax
2. CO+1 for `addDependency:`. I was really missing it.
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