int flock()

in src/main/c/Posix/PosixHelperFunctions.c [1071:1099]

• 27 lines of code
• 8 McCabe index (conditional complexity)

int flock(int fd, int op)
{
	int rc = 0;

#if defined(F_SETLK) && defined(F_SETLKW)
	struct flock fl = { 0 };
	switch (op & (LOCK_EX | LOCK_SH | LOCK_UN))
	{
		case LOCK_EX:
			fl.l_type = F_WRLCK;
			break;
		case LOCK_SH:
			fl.l_type = F_RDLCK;
			break;
		case LOCK_UN:
			fl.l_type = F_UNLCK;
			break;
		default:
			errno = EINVAL;
			return -1;
	}
	fl.l_whence = SEEK_SET;
	rc = fcntl(fd, op & LOCK_NB ? F_SETLK : F_SETLKW, &fl);
	if (rc && (errno == EAGAIN))
		errno = EWOULDBLOCK;
#endif

	return rc;
}