view src/event/quic/ngx_event_quic_ack.h @ 9138:a90f79792b5d

QUIC: optimized ACK delay. Previously ACK was not generated if max_ack_delay was not yet expired and the number of unacknowledged ack-eliciting packets was less than two, as allowed by RFC 9000 13.2.1-13.2.2. However this only makes sense to avoid sending ACK-only packets, as explained by the RFC: On the other hand, reducing the frequency of packets that carry only acknowledgments reduces packet transmission and processing cost at both endpoints. Now ACK is delayed only if output frame queue is empty. Otherwise ACK is sent immediately, which significantly improves QUIC performance with certain tests.
author Roman Arutyunyan <arut@nginx.com>
date Thu, 27 Jul 2023 16:37:17 +0400
parents 4117aa7fa38e
children
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/*
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_EVENT_QUIC_ACK_H_INCLUDED_
#define _NGX_EVENT_QUIC_ACK_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


ngx_int_t ngx_quic_handle_ack_frame(ngx_connection_t *c,
    ngx_quic_header_t *pkt, ngx_quic_frame_t *f);

void ngx_quic_congestion_ack(ngx_connection_t *c,
    ngx_quic_frame_t *frame);
void ngx_quic_resend_frames(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx);
void ngx_quic_set_lost_timer(ngx_connection_t *c);
void ngx_quic_pto_handler(ngx_event_t *ev);
ngx_msec_t ngx_quic_pto(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx);

ngx_int_t ngx_quic_ack_packet(ngx_connection_t *c,
    ngx_quic_header_t *pkt);
ngx_int_t ngx_quic_generate_ack(ngx_connection_t *c,
    ngx_quic_send_ctx_t *ctx);

#endif /* _NGX_EVENT_QUIC_ACK_H_INCLUDED_ */