Mercurial > hg > nginx
view src/event/ngx_event_pipe.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 | adc2414856b1 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_EVENT_PIPE_H_INCLUDED_ #define _NGX_EVENT_PIPE_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> typedef struct ngx_event_pipe_s ngx_event_pipe_t; typedef ngx_int_t (*ngx_event_pipe_input_filter_pt)(ngx_event_pipe_t *p, ngx_buf_t *buf); typedef ngx_int_t (*ngx_event_pipe_output_filter_pt)(void *data, ngx_chain_t *chain); struct ngx_event_pipe_s { ngx_connection_t *upstream; ngx_connection_t *downstream; ngx_chain_t *free_raw_bufs; ngx_chain_t *in; ngx_chain_t **last_in; ngx_chain_t *writing; ngx_chain_t *out; ngx_chain_t *free; ngx_chain_t *busy; /* * the input filter i.e. that moves HTTP/1.1 chunks * from the raw bufs to an incoming chain */ ngx_event_pipe_input_filter_pt input_filter; void *input_ctx; ngx_event_pipe_output_filter_pt output_filter; void *output_ctx; #if (NGX_THREADS || NGX_COMPAT) ngx_int_t (*thread_handler)(ngx_thread_task_t *task, ngx_file_t *file); void *thread_ctx; ngx_thread_task_t *thread_task; #endif unsigned read:1; unsigned cacheable:1; unsigned single_buf:1; unsigned free_bufs:1; unsigned upstream_done:1; unsigned upstream_error:1; unsigned upstream_eof:1; unsigned upstream_blocked:1; unsigned downstream_done:1; unsigned downstream_error:1; unsigned cyclic_temp_file:1; unsigned aio:1; ngx_int_t allocated; ngx_bufs_t bufs; ngx_buf_tag_t tag; ssize_t busy_size; off_t read_length; off_t length; off_t max_temp_file_size; ssize_t temp_file_write_size; ngx_msec_t read_timeout; ngx_msec_t send_timeout; ssize_t send_lowat; ngx_pool_t *pool; ngx_log_t *log; ngx_chain_t *preread_bufs; size_t preread_size; ngx_buf_t *buf_to_file; size_t limit_rate; time_t start_sec; ngx_temp_file_t *temp_file; /* STUB */ int num; }; ngx_int_t ngx_event_pipe(ngx_event_pipe_t *p, ngx_int_t do_write); ngx_int_t ngx_event_pipe_copy_input_filter(ngx_event_pipe_t *p, ngx_buf_t *buf); ngx_int_t ngx_event_pipe_add_free_buf(ngx_event_pipe_t *p, ngx_buf_t *b); #endif /* _NGX_EVENT_PIPE_H_INCLUDED_ */