Zabbix

/*

** Copyright (C) 2001-2025 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** 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 Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

#include "zbxnix.h"

​

#include "zbxcommon.h"

​

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

 *                                                                            *

 * Purpose: creates dynamic shared memory segment                             *

 *                                                                            *

 * Parameters: shm       - [OUT] the dynamic shared memory data               *

 *             shm_size  - [IN] the initial size (can be 0)                   *

 *             mutex     - [IN] the name of mutex used to synchronize memory  *

 *                              access                                        *

 *             copy_func - [IN] the function used to copy shared memory       *

 *                              contents during reallocation                  *

 *             errmsg    - [OUT] the error message                            *

 *                                                                            *

 * Return value: SUCCEED - the dynamic shared memory segment was created      *

 *                         successfully.                                      *

 *               FAIL    - otherwise. The errmsg contains error message and   *

 *                         must be freed by the caller.                       *

 *                                                                            *

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

int zbx_dshm_create(zbx_dshm_t *shm, size_t shm_size, zbx_mutex_name_t mutex,

        zbx_shm_copy_func_t copy_func, char **errmsg)

{

    int ret = FAIL;

​

    zabbix_log(LOG_LEVEL_DEBUG, "In %s() size:" ZBX_FS_SIZE_T, __func__, (zbx_fs_size_t)shm_size);

​

    if (SUCCEED != zbx_mutex_create(&shm->lock, mutex, errmsg))

        goto out;

​

    if (0 < shm_size)

    {

        if (-1 == (shm->shmid = zbx_shm_create(shm_size)))

        {

            *errmsg = zbx_strdup(*errmsg, "cannot allocate shared memory");

            goto out;

        }

    }

    else

        shm->shmid = ZBX_NONEXISTENT_SHMID;

​

    shm->size = shm_size;

    shm->copy_func = copy_func;

​

    ret = SUCCEED;

out:

    zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%s shmid:%d", __func__, zbx_result_string(ret), shm->shmid);