Unable to call php user define function from Zend Extension

[azcpavel]

I am trying to create a PHP extension for PHP 7.2, I have already managed to create for 5.6 in PHP 7.2 I have made the required changes in the code based on the new Zend API, but now I am stuck in this point, I want to call a php user define function from the extension.

I have tried with the call_user_function_ex function to call my user define function.

zval *function_name, *retval_ptr, *param_file, **params[1]; 

TSRMLS_FETCH();

ZVAL_STRINGL(function_name, functionRequire,
        strlen(functionRequire));

ZVAL_STRINGL(param_file, ranKey,
        strlen(ranKey));    

params[0] = &param_file;        
php_printf("%s %s 1st",functionRequire,ranKey);
//RETURN_NULL();
if (call_user_function_ex(CG(function_table), NULL, function_name,
        &retval_ptr, 1, params, 0, NULL TSRMLS_CC) != SUCCESS) {
    php_printf("%s\n",contactInfo );        
    zend_error(E_ERROR, "Function call failed ");
    RETURN_NULL();
}
php_printf("%s %s 2nd",functionRequire,ranKey);
RETURN_NULL();
FREE_ZVAL(function_nameCh);

FREE_ZVAL(function_name);
FREE_ZVAL(param_file);

I have tried with printing the value after each statement after that I realize that it getting crashed when it tried to call “call_user_function_ex” function. Am I doing anything wrong but the same code is working fine in PHP 5.6

Please Help.