view src/os/win32/ngx_time.c @ 8045:aa28c802409f

Resolver: make TCP write timer event cancelable. Similar to 70e65bf8dfd7, the change is made to ensure that the ability to cancel resolver tasks is fully controlled by the caller. As mentioned in the referenced commit, it is safe to make this timer cancelable because resolve tasks can have their own timeouts that are not cancelable. The scenario where this may become a problem is a periodic background resolve task (not tied to a specific request or a client connection), which receives a response with short TTL, large enough to warrant fallback to a TCP query. With each event loop wakeup, we either have a previously set write timer instance or schedule a new one. The non-cancelable write timer can delay or block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable flag is set by the API user, and there are no other tasks or connections. We use the resolver API in this way to maintain the list of upstream server addresses specified with the 'resolve' parameter, and there could be third-party modules implementing similar logic.
author Aleksei Bavshin <a.bavshin@f5.com>
date Wed, 01 Jun 2022 20:17:23 -0700
parents f95de1361039
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


void
ngx_gettimeofday(struct timeval *tp)
{
    uint64_t  intervals;
    FILETIME  ft;

    GetSystemTimeAsFileTime(&ft);

    /*
     * A file time is a 64-bit value that represents the number
     * of 100-nanosecond intervals that have elapsed since
     * January 1, 1601 12:00 A.M. UTC.
     *
     * Between January 1, 1970 (Epoch) and January 1, 1601 there were
     * 134774 days,
     * 11644473600 seconds or
     * 11644473600,000,000,0 100-nanosecond intervals.
     *
     * See also MSKB Q167296.
     */

    intervals = ((uint64_t) ft.dwHighDateTime << 32) | ft.dwLowDateTime;
    intervals -= 116444736000000000;

    tp->tv_sec = (long) (intervals / 10000000);
    tp->tv_usec = (long) ((intervals % 10000000) / 10);
}


void
ngx_libc_localtime(time_t s, struct tm *tm)
{
    struct tm  *t;

    t = localtime(&s);
    *tm = *t;
}


void
ngx_libc_gmtime(time_t s, struct tm *tm)
{
    struct tm  *t;

    t = gmtime(&s);
    *tm = *t;
}


ngx_int_t
ngx_gettimezone(void)
{
    u_long                 n;
    TIME_ZONE_INFORMATION  tz;

    n = GetTimeZoneInformation(&tz);

    switch (n) {

    case TIME_ZONE_ID_UNKNOWN:
        return -tz.Bias;

    case TIME_ZONE_ID_STANDARD:
        return -(tz.Bias + tz.StandardBias);

    case TIME_ZONE_ID_DAYLIGHT:
        return -(tz.Bias + tz.DaylightBias);

    default: /* TIME_ZONE_ID_INVALID */
        return 0;
    }
}