/*
* Copyright (c) 2008-2024 Jonathan Schleifer <js@nil.im>
*
* All rights reserved.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License version 3.0 only,
* as published by the Free Software Foundation.
*
* 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 Lesser General Public License
* version 3.0 for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* version 3.0 along with this program. If not, see
* <https://www.gnu.org/licenses/>.
*/
#include "objfw-defs.h"
#import "macros.h"
#if defined(OF_HAVE_PTHREADS)
# include <pthread.h>
typedef pthread_once_t OFOnceControl;
# define OFOnceControlInitValue PTHREAD_ONCE_INIT
#elif defined(OF_HAVE_ATOMIC_OPS)
typedef volatile int OFOnceControl;
# define OFOnceControlInitValue 0
#elif defined(OF_AMIGAOS) || !defined(OF_HAVE_THREADS)
typedef int OFOnceControl;
# define OFOnceControlInitValue 0
#endif
OF_ASSUME_NONNULL_BEGIN
/** @file */
typedef void (*OFOnceFunction)(void);
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Executes the specified function exactly once in the application's
* lifetime, even in a multi-threaded environment.
*
* @param control An OFOnceControl. This should be a static variable
* preinitialized to `OFOnceControlInitValue`.
* @param function The function to execute once
*/
extern void OFOnce(OFOnceControl *control, OFOnceFunction function);
#ifdef __cplusplus
}
#endif
OF_ASSUME_NONNULL_END