From: Lukáš Ondráček <lukas.ondracek@nic.cz>
Date: Mon, 14 Oct 2024 16:36:15 +0000 (+0200)
Subject: daemon/defer: cleanup heads of queues after idle
X-Git-Tag: v6.0.9~1^2~17
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=refs%2Fenvironments%2Fdocs-develop-rrl-8r8r8r%2Fdeployments%2F5334;p=thirdparty%2Fknot-resolver.git

daemon/defer: cleanup heads of queues after idle
---

diff --git a/daemon/defer.c b/daemon/defer.c
index 2d78786ad..b0375ceec 100644
--- a/daemon/defer.c
+++ b/daemon/defer.c
@@ -210,6 +210,21 @@ static inline void push_query(struct protolayer_iter_ctx *ctx, int priority, boo
 	}
 }
 
+/// Pop and return query from the specified queue, deactivate idle if not needed.
+static inline struct protolayer_iter_ctx *pop_query_queue(int priority)
+{
+	kr_assert(queue_len(queues[priority]) > 0);
+	struct protolayer_iter_ctx *ctx = queue_head(queues[priority]);
+	queue_pop(queues[priority]);
+	if (--waiting_requests <= 0) {
+		kr_assert(waiting_requests == 0);
+		uv_idle_stop(&idle_handle);
+		VERBOSE_LOG("  deactivating idle\n");
+	}
+	return ctx;
+}
+
+
 /// Pop and return the query with the highest priority, UDP or non-UDP based on current phase,
 /// deactivate idle if not needed.
 static inline struct protolayer_iter_ctx *pop_query(void)
@@ -238,17 +253,28 @@ static inline struct protolayer_iter_ctx *pop_query(void)
 		i = PRIORITY_UDP;
 	}
 
-	struct protolayer_iter_ctx *ctx = queue_head(queues[i]);
-	queue_pop(queues[i]);
-	if (--waiting_requests <= 0) {
-		kr_assert(waiting_requests == 0);
-		uv_idle_stop(&idle_handle);
-		VERBOSE_LOG("  deactivating idle\n");
-	}
-	return ctx;
+	return pop_query_queue(i);
 }
 
 
+// Break the given query; for streams break also all follow-up queries and force-close the stream.
+static inline void break_query(struct protolayer_iter_ctx *ctx, int err)
+{
+	if (ctx->session->stream) {
+		struct pl_defer_sess_data *sdata = protolayer_sess_data_get_current(ctx);
+		if (!ctx->session->closing) {
+			session2_force_close(ctx->session); // session is not freed here as iter contexts exist
+		}
+		queue_pop(sdata->queue);
+		while (queue_len(sdata->queue) > 0) {
+			protolayer_break(ctx, kr_error(err)); // session is not freed here as other contexts exist
+			ctx = queue_head(sdata->queue);
+			queue_pop(sdata->queue);
+		}
+	}
+	protolayer_break(ctx, kr_error(err));
+}
+
 /// Process a single deferred query (or defer again) if there is any.
 /// Time accounting should have been just started, the stamp is used, accounted address is set.
 static inline void process_single_deferred(void) {
@@ -269,30 +295,13 @@ static inline void process_single_deferred(void) {
 
 	if (ctx->session->closing) {
 		VERBOSE_LOG("    BREAK (session is closing)\n");
-		if (ctx->session->stream) {
-			queue_pop(sdata->queue);
-			while (queue_len(sdata->queue) > 0) {
-				protolayer_break(ctx, kr_error(ECANCELED)); // session is not freed here as other contexts exist
-				ctx = queue_head(sdata->queue);
-				queue_pop(sdata->queue);
-			}
-		}
-		protolayer_break(ctx, kr_error(ECANCELED));
+		break_query(ctx, ECANCELED);
 		return;
 	}
 
 	if (age_ns >= REQ_TIMEOUT) {
 		VERBOSE_LOG("    BREAK (timeout)\n");
-		if (ctx->session->stream) {
-			while (queue_len(sdata->queue) > 0) {
-				ctx = queue_head(sdata->queue);
-				queue_pop(sdata->queue);
-				protolayer_break(ctx, kr_error(ETIME)); // session is not freed here as it is not closing yet
-			}
-			session2_force_close(ctx->session);
-		} else {
-			protolayer_break(ctx, kr_error(ETIME));
-		}
+		break_query(ctx, ETIME);
 		return;
 	}
 
@@ -316,6 +325,25 @@ static inline void process_single_deferred(void) {
 	protolayer_continue(ctx);
 }
 
+/// Break expired requests at the beginning of queues, uses current stamp.
+static inline void cleanup_queues(void) {
+	for (int i = 0; i < QUEUES_CNT; i++) {
+		int cnt = 0;
+		while (queue_len(queues[i]) > 0) {
+			struct protolayer_iter_ctx *ctx = queue_head(queues[i]);
+			struct pl_defer_iter_data *idata = protolayer_iter_data_get_current(ctx);
+			uint64_t age_ns = defer_sample_state.stamp - idata->req_stamp;
+			if (age_ns < REQ_TIMEOUT) break;
+			pop_query_queue(i);
+			break_query(ctx, ETIME);
+			cnt++;
+		}
+		if (cnt > 0) {
+			VERBOSE_LOG("  BREAK %d queries from %d\n", cnt, i);
+		}
+	}
+}
+
 /// Unwrap: defer or process the query synchronously.
 /// Time accounting should have been started, the stamp is used, accounted address is set.
 static enum protolayer_iter_cb_result pl_defer_unwrap(
@@ -372,6 +400,7 @@ static void defer_queues_idle(uv_idle_t *handle) {
 		process_single_deferred();
 		defer_sample_restart();
 	}
+	cleanup_queues();
 	defer_sample_stop();  // TODO skip calling and use just restart elsewhere?
 	udp_queue_send_all();