Mercurial > hg > nginx
view src/core/ngx_queue.c @ 9225:1c9264603adc
Syslog: introduced ngx_syslog_send() error logging moderation.
Errors when logging to syslog are now logged at most once per second.
This ensures that persistent errors won't flood other logs, and spontaneous
errors, such as ENOBUFS as observed on BSD systems when syslogd cannot cope
with load, or EAGAIN as seen in similar situation on Linux, won't further
overload logging subsystem, leading to more errors.
Further, errors now can only trigger reconnects at most once per second.
This ensures that persistent errors, which cannot be fixed with reconnects,
don't trigger too much unneeded work.
Additionally, in case of connection errors, such as when syslogd is not
running, connection attempts are only made once per second.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Fri, 01 Mar 2024 05:42:12 +0300 |
parents | 3038bd4d7816 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> static void ngx_queue_merge(ngx_queue_t *queue, ngx_queue_t *tail, ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *)); /* * find the middle queue element if the queue has odd number of elements * or the first element of the queue's second part otherwise */ ngx_queue_t * ngx_queue_middle(ngx_queue_t *queue) { ngx_queue_t *middle, *next; middle = ngx_queue_head(queue); if (middle == ngx_queue_last(queue)) { return middle; } next = ngx_queue_head(queue); for ( ;; ) { middle = ngx_queue_next(middle); next = ngx_queue_next(next); if (next == ngx_queue_last(queue)) { return middle; } next = ngx_queue_next(next); if (next == ngx_queue_last(queue)) { return middle; } } } /* the stable merge sort */ void ngx_queue_sort(ngx_queue_t *queue, ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *)) { ngx_queue_t *q, tail; q = ngx_queue_head(queue); if (q == ngx_queue_last(queue)) { return; } q = ngx_queue_middle(queue); ngx_queue_split(queue, q, &tail); ngx_queue_sort(queue, cmp); ngx_queue_sort(&tail, cmp); ngx_queue_merge(queue, &tail, cmp); } static void ngx_queue_merge(ngx_queue_t *queue, ngx_queue_t *tail, ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *)) { ngx_queue_t *q1, *q2; q1 = ngx_queue_head(queue); q2 = ngx_queue_head(tail); for ( ;; ) { if (q1 == ngx_queue_sentinel(queue)) { ngx_queue_add(queue, tail); break; } if (q2 == ngx_queue_sentinel(tail)) { break; } if (cmp(q1, q2) <= 0) { q1 = ngx_queue_next(q1); continue; } ngx_queue_remove(q2); ngx_queue_insert_before(q1, q2); q2 = ngx_queue_head(tail); } }