view src/os/unix/ngx_time.c @ 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 d620f497c50f
children
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


/*
 * FreeBSD does not test /etc/localtime change, however, we can workaround it
 * by calling tzset() with TZ and then without TZ to update timezone.
 * The trick should work since FreeBSD 2.1.0.
 *
 * Linux does not test /etc/localtime change in localtime(),
 * but may stat("/etc/localtime") several times in every strftime(),
 * therefore we use it to update timezone.
 *
 * Solaris does not test /etc/TIMEZONE change too and no workaround available.
 */

void
ngx_timezone_update(void)
{
#if (NGX_FREEBSD)

    if (getenv("TZ")) {
        return;
    }

    putenv("TZ=UTC");

    tzset();

    unsetenv("TZ");

    tzset();

#elif (NGX_LINUX)
    time_t      s;
    struct tm  *t;
    char        buf[4];

    s = time(0);

    t = localtime(&s);

    strftime(buf, 4, "%H", t);

#endif
}


void
ngx_localtime(time_t s, ngx_tm_t *tm)
{
#if (NGX_HAVE_LOCALTIME_R)
    (void) localtime_r(&s, tm);

#else
    ngx_tm_t  *t;

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

#endif

    tm->ngx_tm_mon++;
    tm->ngx_tm_year += 1900;
}


void
ngx_libc_localtime(time_t s, struct tm *tm)
{
#if (NGX_HAVE_LOCALTIME_R)
    (void) localtime_r(&s, tm);

#else
    struct tm  *t;

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

#endif
}


void
ngx_libc_gmtime(time_t s, struct tm *tm)
{
#if (NGX_HAVE_LOCALTIME_R)
    (void) gmtime_r(&s, tm);

#else
    struct tm  *t;

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

#endif
}