flock_win32_other_option.c

// flock_win32.h

#	ifndef LOCK_SH
#		define LOCK_SH 1
#		define LOCK_EX 2
#		define LOCK_NB 4
#		define LOCK_UN 8
#	endif

int __cdecl flock(int fd, int operation);

// flock_win32.c
#	include <synchapi.h>
#	include <fileapi.h>
#	include <io.h>
#	include <sys/locking.h>
#	include <errno.h>

static HANDLE __g_flock_win32_mtx;

#	define __flock_win32_lock()    __g_flock_win32_mtx = CreateMutex(NULL, TRUE, NULL)
#	define __flock_win32_unlock()  ReleaseMutex(__g_flock_win32_mtx); CloseHandle(__g_flock_win32_mtx)
#	define __flock_win32_fsize(fd) (long)GetFileSize(_get_osfhandle(fd))

int flock(int fd, int operation)
{
	int ret = -1, op, lk;

	__flock_win32_lock();
	op      = operation;
	lk      = 0;

	if (op & LOCK_NB) {
		op &= ~LOCK_NB;
	}

	switch (op)
	{
		case LOCK_EX:
			lk = _LK_LOCK;
		break;
		case LOCK_SH:
			lk = _LK_RLCK;
		break;
		case LOCK_UN:
			lk = _LK_UNLCK;
		break;
		default:
			__flock_win32_unlock();
			return ret;
	}
	ret     = _locking(fd, lk, __flock_win32_fsize(fd));
	__flock_win32_unlock();

	return ret;
}