From 15ea6f002ffbe1f3463639d3fe8c0bc07526a6d8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= <ondrej@isc.org>
Date: Fri, 1 Apr 2022 10:40:37 +0200
Subject: [PATCH] Add isc_task_setquantum() and use it for post-init zone
 loading

Add isc_task_setquantum() function that modifies quantum for the future
isc_task_run() invocations.

NOTE: The current isc_task_run() caches the task->quantum into a local
variable and therefore the current event loop is not affected by any
quantum change.
---
 lib/isc/include/isc/task.h |  9 +++++++++
 lib/isc/task.c             | 16 ++++++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/lib/isc/include/isc/task.h b/lib/isc/include/isc/task.h
index 9bff6f8b60..923d39e18f 100644
--- a/lib/isc/include/isc/task.h
+++ b/lib/isc/include/isc/task.h
@@ -398,6 +398,15 @@ isc_task_gettag(isc_task_t *task);
  *\li	'task' is a valid task.
  */
 
+void
+isc_task_setquantum(isc_task_t *task, unsigned int quantum);
+/*%<
+ * Set future 'task' quantum to 'quantum'.  The current 'task' quantum will be
+ * kept for the current isc_task_run() loop, and will be changed for the next
+ * run.  Therefore, the function is save to use from the event callback as it
+ * will not affect the current event loop processing.
+ */
+
 isc_result_t
 isc_task_beginexclusive(isc_task_t *task);
 /*%<
diff --git a/lib/isc/task.c b/lib/isc/task.c
index cc76a6541f..f2c60b9b8a 100644
--- a/lib/isc/task.c
+++ b/lib/isc/task.c
@@ -660,6 +660,16 @@ isc_task_getnetmgr(isc_task_t *task) {
 	return (task->manager->netmgr);
 }
 
+void
+isc_task_setquantum(isc_task_t *task, unsigned int quantum) {
+	REQUIRE(VALID_TASK(task));
+
+	LOCK(&task->lock);
+	task->quantum = (quantum > 0) ? quantum
+				      : task->manager->default_quantum;
+	UNLOCK(&task->lock);
+}
+
 /***
  *** Task Manager.
  ***/
@@ -670,11 +680,13 @@ task_run(isc_task_t *task) {
 	bool finished = false;
 	isc_event_t *event = NULL;
 	isc_result_t result = ISC_R_SUCCESS;
+	uint32_t quantum;
 
 	REQUIRE(VALID_TASK(task));
 
 	LOCK(&task->lock);
-	/* FIXME */
+	quantum = task->quantum;
+
 	if (task->state != task_state_ready) {
 		goto done;
 	}
@@ -747,7 +759,7 @@ task_run(isc_task_t *task) {
 				task->state = task_state_idle;
 			}
 			break;
-		} else if (dispatch_count >= task->quantum) {
+		} else if (dispatch_count >= quantum) {
 			/*
 			 * Our quantum has expired, but there is more work to be
 			 * done.  We'll requeue it to the ready queue later.