Task.setReturnOnCancel

Sets or clears task's return-on-cancel flag. This is only meaningful for tasks run via [gio.task.Task.runInThread] or [gio.task.Task.runInThreadSync].

If return_on_cancel is true, then cancelling task's #GCancellable will immediately cause it to return, as though the task's #GTaskThreadFunc had called [gio.task.Task.returnErrorIfCancelled] and then returned.

This allows you to create a cancellable wrapper around an uninterruptible function. The #GTaskThreadFunc just needs to be careful that it does not modify any externally-visible state after it has been cancelled. To do that, the thread should call [gio.task.Task.setReturnOnCancel] again to (atomically) set return-on-cancel false before making externally-visible changes; if the task gets cancelled before the return-on-cancel flag could be changed, [gio.task.Task.setReturnOnCancel] will indicate this by returning false.

You can disable and re-enable this flag multiple times if you wish. If the task's #GCancellable is cancelled while return-on-cancel is false, then calling [gio.task.Task.setReturnOnCancel] to set it true again will cause the task to be cancelled at that point.

If the task's #GCancellable is already cancelled before you call [gio.task.Task.runInThread]/[gio.task.Task.runInThreadSync], then the #GTaskThreadFunc will still be run (for consistency), but the task will also be completed right away.