Mercurial > hg > nginx
view src/event/ngx_event_timer.h @ 7584:9d2ad2fb4423
SSL: available bytes handling (ticket #1431).
Added code to track number of bytes available in the socket.
This makes it possible to avoid looping for a long time while
working with fast enough peer when data are added to the socket buffer
faster than we are able to read and process data.
When kernel does not provide number of bytes available, it is
retrieved using ioctl(FIONREAD) as long as a buffer is filled by
SSL_read().
It is assumed that number of bytes returned by SSL_read() is close
to the number of bytes read from the socket, as we do not use
SSL compression. But even if it is not true for some reason, this
is not important, as we post an additional reading event anyway.
Note that data can be buffered at SSL layer, and it is not possible
to simply stop reading at some point and wait till the event will
be reported by the kernel again. This can be only done when there
are no data in SSL buffers, and there is no good way to find out if
it's the case.
Instead of trying to figure out if SSL buffers are empty, this patch
introduces events posted for the next event loop iteration - such
events will be processed only on the next event loop iteration,
after going into the kernel and retrieving additional events. This
seems to be simple and reliable approach.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 17 Oct 2019 16:02:24 +0300 |
parents | 3069dd358ba2 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_EVENT_TIMER_H_INCLUDED_ #define _NGX_EVENT_TIMER_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #define NGX_TIMER_INFINITE (ngx_msec_t) -1 #define NGX_TIMER_LAZY_DELAY 300 ngx_int_t ngx_event_timer_init(ngx_log_t *log); ngx_msec_t ngx_event_find_timer(void); void ngx_event_expire_timers(void); ngx_int_t ngx_event_no_timers_left(void); extern ngx_rbtree_t ngx_event_timer_rbtree; static ngx_inline void ngx_event_del_timer(ngx_event_t *ev) { ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "event timer del: %d: %M", ngx_event_ident(ev->data), ev->timer.key); ngx_rbtree_delete(&ngx_event_timer_rbtree, &ev->timer); #if (NGX_DEBUG) ev->timer.left = NULL; ev->timer.right = NULL; ev->timer.parent = NULL; #endif ev->timer_set = 0; } static ngx_inline void ngx_event_add_timer(ngx_event_t *ev, ngx_msec_t timer) { ngx_msec_t key; ngx_msec_int_t diff; key = ngx_current_msec + timer; if (ev->timer_set) { /* * Use a previous timer value if difference between it and a new * value is less than NGX_TIMER_LAZY_DELAY milliseconds: this allows * to minimize the rbtree operations for fast connections. */ diff = (ngx_msec_int_t) (key - ev->timer.key); if (ngx_abs(diff) < NGX_TIMER_LAZY_DELAY) { ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0, "event timer: %d, old: %M, new: %M", ngx_event_ident(ev->data), ev->timer.key, key); return; } ngx_del_timer(ev); } ev->timer.key = key; ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0, "event timer add: %d: %M:%M", ngx_event_ident(ev->data), timer, ev->timer.key); ngx_rbtree_insert(&ngx_event_timer_rbtree, &ev->timer); ev->timer_set = 1; } #endif /* _NGX_EVENT_TIMER_H_INCLUDED_ */