Function pwrite

src/jrd/os/posix/unix.cpp:1128–1158

}

static SLONG pwrite(int fd, SCHAR* buf, SLONG nbytes, SLONG offset)
/**************************************
 *
 *	p w r i t e
 *
 **************************************
 *
 * Functional description
 *
 *   This function uses Asynchronous I/O calls to implement
 *   positioned write from a given offset
 **************************************/
{
	struct aiocb io;
	io.aio_fildes = fd;
	io.aio_offset = offset;
	io.aio_buf = buf;
	io.aio_nbytes = nbytes;
	io.aio_reqprio = 0;
	io.aio_sigevent.sigev_notify = SIGEV_NONE;
	int err = aio_write(&io);	// atomically reads at offset
	if (err != 0)
		return (err);			// errno is set

	struct aiocb *list[1];
	list[0] = &io;
	err = aio_suspend(list, 1, NULL);	// wait for I/O to complete
	if (err != 0)
		return (err);			// errno is set
	return (aio_return(&io));	// return I/O status
}

#endif // !(HAVE_PREAD && HAVE_PWRITE)