io: add ability to associate an error with a task

Currently when a task fails, the error is never explicitly
associated with the task object, it is just passed along
through the completion callback. This adds the ability to
explicitly associate an error with the task.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/include/io/task.h b/include/io/task.h
index ece1372..47daba9 100644
--- a/include/io/task.h
+++ b/include/io/task.h
@@ -240,6 +240,38 @@ void qio_task_abort(QIOTask *task,
 
 
 /**
+ * qio_task_set_error:
+ * @task: the task struct
+ * @err: pointer to the error, or NULL
+ *
+ * Associate an error with the task, which can later
+ * be retrieved with the qio_task_propagate_error()
+ * method. This method takes ownership of @err, so
+ * it is not valid to access it after this call
+ * completes. If @err is NULL this is a no-op. If
+ * this is call multiple times, only the first
+ * provided @err will be recorded, later ones will
+ * be discarded and freed.
+ */
+void qio_task_set_error(QIOTask *task,
+                        Error *err);
+
+
+/**
+ * qio_task_propagate_error:
+ * @task: the task struct
+ * @errp: pointer to a NULL-initialized error object
+ *
+ * Propagate the error associated with @task
+ * into @errp.
+ *
+ * Returns: true if an error was propagated, false otherwise
+ */
+bool qio_task_propagate_error(QIOTask *task,
+                              Error **errp);
+
+
+/**
  * qio_task_set_result_pointer:
  * @task: the task struct
  * @result: pointer to the result data