Task.setReturnOnCancel

Sets or clears @task's return-on-cancel flag. This is only meaningful for tasks run via g_task_run_in_thread() or g_task_run_in_thread_sync().

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 g_task_return_error_if_cancelled() 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 g_task_set_return_on_cancel() 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, g_task_set_return_on_cancel() 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 g_task_set_return_on_cancel() 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 g_task_run_in_thread()/g_task_run_in_thread_sync(), then the #GTaskThreadFunc will still be run (for consistency), but the task will also be completed right away.

class Task
bool
setReturnOnCancel

Parameters

returnOnCancel bool

whether the task returns automatically when it is cancelled.

Return Value

Type: bool

%TRUE if @task's return-on-cancel flag was changed to match @return_on_cancel. %FALSE if @task has already been cancelled.

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Since

2.36