view src/os/unix/ngx_posix_init.c @ 9270:3d455e37abf8 default tip

Core: PID file writing synchronization. Now, ngx_daemon() does not call exit() in the parent process immediately, but instead waits for the child process to signal it actually started (and wrote the PID file if configured to). This ensures that the PID file already exists when the parent process exits. To make sure that signal handlers won't cause unexpected logging in the parent process if the child process dies (for example, due to errors when writing the PID file), ngx_init_signals() is moved to the child process. This resolves "PID file ... not readable (yet?) after start" and "Failed to parse PID from file..." errors as observed with systemd. Note that the errors observed are considered to be a bug in systemd, which isn't able to work properly with traditional Unix daemons. Still, the workaround is implemented to make sure there will be no OS vendor patches trying to address this.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 13 May 2024 06:13:22 +0300
parents 057adb2a9d23
children
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


ngx_int_t   ngx_ncpu;
ngx_int_t   ngx_max_sockets;
ngx_uint_t  ngx_inherited_nonblocking;
ngx_uint_t  ngx_tcp_nodelay_and_tcp_nopush;


struct rlimit  rlmt;


ngx_os_io_t ngx_os_io = {
    ngx_unix_recv,
    ngx_readv_chain,
    ngx_udp_unix_recv,
    ngx_unix_send,
    ngx_udp_unix_send,
    ngx_udp_unix_sendmsg_chain,
    ngx_writev_chain,
    0
};


ngx_int_t
ngx_os_init(ngx_log_t *log)
{
    ngx_time_t  *tp;
    ngx_uint_t   n;
#if (NGX_HAVE_LEVEL1_DCACHE_LINESIZE)
    long         size;
#endif

#if (NGX_HAVE_OS_SPECIFIC_INIT)
    if (ngx_os_specific_init(log) != NGX_OK) {
        return NGX_ERROR;
    }
#endif

    if (ngx_init_setproctitle(log) != NGX_OK) {
        return NGX_ERROR;
    }

    ngx_pagesize = getpagesize();
    ngx_cacheline_size = NGX_CPU_CACHE_LINE;

    for (n = ngx_pagesize; n >>= 1; ngx_pagesize_shift++) { /* void */ }

#if (NGX_HAVE_SC_NPROCESSORS_ONLN)
    if (ngx_ncpu == 0) {
        ngx_ncpu = sysconf(_SC_NPROCESSORS_ONLN);
    }
#endif

    if (ngx_ncpu < 1) {
        ngx_ncpu = 1;
    }

#if (NGX_HAVE_LEVEL1_DCACHE_LINESIZE)
    size = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
    if (size > 0) {
        ngx_cacheline_size = size;
    }
#endif

    ngx_cpuinfo();

    if (getrlimit(RLIMIT_NOFILE, &rlmt) == -1) {
        ngx_log_error(NGX_LOG_ALERT, log, errno,
                      "getrlimit(RLIMIT_NOFILE) failed");
        return NGX_ERROR;
    }

    ngx_max_sockets = (ngx_int_t) rlmt.rlim_cur;

#if (NGX_HAVE_INHERITED_NONBLOCK || NGX_HAVE_ACCEPT4)
    ngx_inherited_nonblocking = 1;
#else
    ngx_inherited_nonblocking = 0;
#endif

    tp = ngx_timeofday();
    srandom(((unsigned) ngx_pid << 16) ^ tp->sec ^ tp->msec);

    return NGX_OK;
}


void
ngx_os_status(ngx_log_t *log)
{
    ngx_log_error(NGX_LOG_NOTICE, log, 0, NGINX_VER_BUILD);

#ifdef NGX_COMPILER
    ngx_log_error(NGX_LOG_NOTICE, log, 0, "built by " NGX_COMPILER);
#endif

#if (NGX_HAVE_OS_SPECIFIC_INIT)
    ngx_os_specific_status(log);
#endif

    ngx_log_error(NGX_LOG_NOTICE, log, 0,
                  "getrlimit(RLIMIT_NOFILE): %r:%r",
                  rlmt.rlim_cur, rlmt.rlim_max);
}


#if 0

ngx_int_t
ngx_posix_post_conf_init(ngx_log_t *log)
{
    ngx_fd_t  pp[2];

    if (pipe(pp) == -1) {
        ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "pipe() failed");
        return NGX_ERROR;
    }

    if (dup2(pp[1], STDERR_FILENO) == -1) {
        ngx_log_error(NGX_LOG_EMERG, log, errno, "dup2(STDERR) failed");
        return NGX_ERROR;
    }

    if (pp[1] > STDERR_FILENO) {
        if (close(pp[1]) == -1) {
            ngx_log_error(NGX_LOG_EMERG, log, errno, "close() failed");
            return NGX_ERROR;
        }
    }

    return NGX_OK;
}

#endif