Unblocks the main thread during asynchronous saving.
- macOS 10.7+
save is writing on a non-main thread because
can has returned
YES, but it is still blocking the main thread, this method unblocks the main thread. Otherwise, it does nothing. For example, the default implementation of
file invokes this when it has created the
NSFile object to return. Assuming that the
NSFile is not mutated by subsequent user actions, it is effectively a "snapshot" of the document’s contents, and once it is created it is safe to resume handling user events on the main thread, even though some of those user events might change the document’s contents before the
NSFile object has been safely written. You can invoke this method to make asynchronous saving actually asynchronous if you’ve overridden
write in such a way that the invocation of this method done by the
write default implementation won’t happen during writing.