The <aio.h> header shall define the aiocb structure which shall include at least the following members:
int aio_fildes File descriptor. off_t aio_offset File offset. volatile void *aio_buf Location of buffer. size_t aio_nbytes Length of transfer. int aio_reqprio Request priority offset. struct sigevent aio_sigevent Signal number and value. int aio_lio_opcode Operation to be performed.
This header shall also include the following constants:
- A return value indicating that none of the requested operations could be canceled since they are already complete.
- A return value indicating that all requested operations have been canceled.
A return value indicating that some of the requested operations could not be canceled since they are in progress.
- A lio_listio() element operation option indicating that no transfer is requested.
- A lio_listio() synchronization operation indicating that the calling thread is to continue execution while the lio_listio() operation is being performed, and no notification is given when the operation is complete.
- A lio_listio() element operation option requesting a read.
- A lio_listio() synchronization operation indicating that the calling thread is to suspend until the lio_listio() operation is complete.
A lio_listio() element operation option requesting a write.
The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.
int aio_cancel(int, struct aiocb *); int aio_error(const struct aiocb *); int aio_fsync(int, struct aiocb *); int aio_read(struct aiocb *); ssize_t aio_return(struct aiocb *); int aio_suspend(const struct aiocb *const, int, const struct timespec *); int aio_write(struct aiocb *); int lio_listio(int, struct aiocb *restrict const[restrict], int, struct sigevent *restrict);
Inclusion of the <aio.h> header may make visible symbols defined in the headers <fcntl.h>, <signal.h>, <sys/types.h>, and <time.h>.
The following sections are informative.
COPYRIGHTPortions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .