pthreadpool: add pthreadpool_tevent_job_cancel()

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

1 files changed, 40 insertions, 0 deletions

diff --git a/lib/pthreadpool/pthreadpool_tevent.c b/lib/pthreadpool/pthreadpool_tevent.c
index 7c8015d2f59..bfd178c09a6 100644
--- a/lib/pthreadpool/pthreadpool_tevent.c
+++ b/lib/pthreadpool/pthreadpool_tevent.c
@@ -267,6 +267,7 @@ static void pthreadpool_tevent_job_fn(void *private_data);
 static void pthreadpool_tevent_job_done(struct tevent_context *ctx,
 					struct tevent_immediate *im,
 					void *private_data);
+static bool pthreadpool_tevent_job_cancel(struct tevent_req *req);
 
 static int pthreadpool_tevent_job_destructor(struct pthreadpool_tevent_job *job)
 {
@@ -441,6 +442,7 @@ struct tevent_req *pthreadpool_tevent_job_send(
 		return tevent_req_post(req, ev);
 	}
 
+	tevent_req_set_cancel_fn(req, pthreadpool_tevent_job_cancel);
 	return req;
 }
 
@@ -522,6 +524,44 @@ static void pthreadpool_tevent_job_done(struct tevent_context *ctx,
 	tevent_req_done(state->req);
 }
 
+static bool pthreadpool_tevent_job_cancel(struct tevent_req *req)
+{
+	struct pthreadpool_tevent_job_state *state =
+		tevent_req_data(req,
+		struct pthreadpool_tevent_job_state);
+	struct pthreadpool_tevent_job *job = state->job;
+	size_t num;
+
+	if (job == NULL) {
+		return false;
+	}
+
+	num = pthreadpool_cancel_job(job->pool->pool, 0,
+				     pthreadpool_tevent_job_fn,
+				     job);
+	if (num == 0) {
+		/*
+		 * It was too late to cancel the request.
+		 */
+		return false;
+	}
+
+	/*
+	 * It was not too late to cancel the request.
+	 *
+	 * We can remove job->im, as it will never be used.
+	 */
+	TALLOC_FREE(job->im);
+
+	/*
+	 * pthreadpool_tevent_job_cleanup()
+	 * will destroy the job.
+	 */
+	tevent_req_defer_callback(req, state->ev);
+	tevent_req_error(req, ECANCELED);
+	return true;
+}
+
 int pthreadpool_tevent_job_recv(struct tevent_req *req)
 {
 	return tevent_req_simple_recv_unix(req);