view src/os/unix/ngx_time.c @ 7784:8cc5b0365ee5

Improved maximum errno detection. Previously, systems without sys_nerr (or _sys_nerr) were handled with an assumption that errors start at 0 and continuous. This is, however, not something POSIX requires, and not true on some platforms. Notably, on Linux, where sys_nerr is no longer available for newly linked binaries starting with glibc 2.32, there are gaps in error list, which used to stop us from properly detecting maximum errno. Further, on GNU/Hurd errors start at 0x40000001. With this change, maximum errno detection is moved to the runtime code, now able to ignore gaps, and also detects the first error if needed. This fixes observed "Unknown error" messages as seen on Linux with glibc 2.32 and on GNU/Hurd.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 01 Mar 2021 20:00:43 +0300
parents d620f497c50f
children
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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
}