Zabbix

/*

** Zabbix

** Copyright (C) 2001-2023 Zabbix SIA

**

** This program is free software; you can redistribute it and/or modify

** it under the terms of the GNU General Public License as published by

** the Free Software Foundation; either version 2 of the License, or

** (at your option) any later version.

**

** This program is distributed in the hope that it will be useful,

** but WITHOUT ANY WARRANTY; without even the implied warranty of

** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

** GNU General Public License for more details.

**

** You should have received a copy of the GNU General Public License

** along with this program; if not, write to the Free Software

** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

**/

​

#include "zbxthreads.h"

​

#include "log.h"

​

#if defined(_WINDOWS) || defined(__MINGW32__)

#include "zbxwin32.h"

​

static ZBX_THREAD_ENTRY(zbx_win_thread_entry, args)

{

    __try

    {

        zbx_thread_args_t   *thread_args = (zbx_thread_args_t *)args;

​

        return thread_args->entry(thread_args);

    }

    __except(zbx_win_seh_handler(GetExceptionInformation()))

    {

        zbx_thread_exit(EXIT_SUCCESS);

    }

}

​

void CALLBACK   ZBXEndThread(ULONG_PTR dwParam)

{

    _endthreadex(SUCCEED);

}

#else

/******************************************************************************

 *                                                                            *

 * Purpose: Flush stdout and stderr before forking                            *

 *                                                                            *

 * Return value: same as system fork() function                               *

 *                                                                            *

 ******************************************************************************/

int zbx_fork(void)

{

    fflush(stdout);

    fflush(stderr);

    return fork();

}

​

/******************************************************************************

 *                                                                            *

 * Purpose: fork from master process and set SIGCHLD handler                  *

 *                                                                            *

 * Return value: same as system fork() function                               *

 *                                                                            *

 * Comments: use this function only for forks from the main process           *

 *                                                                            *

 ******************************************************************************/

void    zbx_child_fork(pid_t *pid)

{

    sigset_t    mask, orig_mask;

​

    /* block signals during fork to avoid deadlock (we've seen one in __unregister_atfork()) */

    sigemptyset(&mask);

    sigaddset(&mask, SIGTERM);

    sigaddset(&mask, SIGUSR2);

    sigaddset(&mask, SIGHUP);

    sigaddset(&mask, SIGINT);

    sigaddset(&mask, SIGQUIT);

    sigaddset(&mask, SIGCHLD);

​

    zbx_sigmask(SIG_BLOCK, &mask, &orig_mask);

​

    /* set process id instead of returning, this is to avoid race condition when signal arrives before return */

    *pid = zbx_fork();

​

    zbx_sigmask(SIG_SETMASK, &orig_mask, NULL);

​

    /* ignore SIGCHLD to avoid problems with exiting scripts in zbx_execute() and other cases */

    if (0 == *pid)

        signal(SIGCHLD, SIG_DFL);