Mercurial > hg > nginx
view src/os/unix/ngx_thread.h @ 7583:efd71d49bde0
Events: available bytes calculation via ioctl(FIONREAD).
This makes it possible to avoid looping for a long time while working
with a fast enough peer when data are added to the socket buffer faster
than we are able to read and process them (ticket #1431). This is
basically what we already do on FreeBSD with kqueue, where information
about the number of bytes in the socket buffer is returned by
the kevent() call.
With other event methods rev->available is now set to -1 when the socket
is ready for reading. Later in ngx_recv() and ngx_recv_chain(), if
full buffer is received, real number of bytes in the socket buffer is
retrieved using ioctl(FIONREAD). Reading more than this number of bytes
ensures that even with edge-triggered event methods the event will be
triggered again, so it is safe to stop processing of the socket and
switch to other connections.
Using ioctl(FIONREAD) only after reading a full buffer is an optimization.
With this approach we only call ioctl(FIONREAD) when there are at least
two recv()/readv() calls.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 17 Oct 2019 16:02:19 +0300 |
parents | d230c797b168 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_THREAD_H_INCLUDED_ #define _NGX_THREAD_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #if (NGX_THREADS) #include <pthread.h> typedef pthread_mutex_t ngx_thread_mutex_t; ngx_int_t ngx_thread_mutex_create(ngx_thread_mutex_t *mtx, ngx_log_t *log); ngx_int_t ngx_thread_mutex_destroy(ngx_thread_mutex_t *mtx, ngx_log_t *log); ngx_int_t ngx_thread_mutex_lock(ngx_thread_mutex_t *mtx, ngx_log_t *log); ngx_int_t ngx_thread_mutex_unlock(ngx_thread_mutex_t *mtx, ngx_log_t *log); typedef pthread_cond_t ngx_thread_cond_t; ngx_int_t ngx_thread_cond_create(ngx_thread_cond_t *cond, ngx_log_t *log); ngx_int_t ngx_thread_cond_destroy(ngx_thread_cond_t *cond, ngx_log_t *log); ngx_int_t ngx_thread_cond_signal(ngx_thread_cond_t *cond, ngx_log_t *log); ngx_int_t ngx_thread_cond_wait(ngx_thread_cond_t *cond, ngx_thread_mutex_t *mtx, ngx_log_t *log); #if (NGX_LINUX) typedef pid_t ngx_tid_t; #define NGX_TID_T_FMT "%P" #elif (NGX_FREEBSD) typedef uint32_t ngx_tid_t; #define NGX_TID_T_FMT "%uD" #elif (NGX_DARWIN) typedef uint64_t ngx_tid_t; #define NGX_TID_T_FMT "%uL" #else typedef uint64_t ngx_tid_t; #define NGX_TID_T_FMT "%uL" #endif ngx_tid_t ngx_thread_tid(void); #define ngx_log_tid ngx_thread_tid() #else #define ngx_log_tid 0 #define NGX_TID_T_FMT "%d" #endif #endif /* _NGX_THREAD_H_INCLUDED_ */