官网：
https://oss.oracle.com/projects/libaio-oracle/，正如标题所说，非常简单了，不用多解释，请直接看头文件，其中aio_poll类似于poll，重要的结构是aiocb64，类似于epoll_event。
- #ifndef _SKGAIO_H
- #define _SKGAIO_H
-
- #define IOCB_CMD_READ 0
- #define IOCB_CMD_WRITE 1
- #define IOCB_CMD_NOP 2
- #define IOCB_CMD_CANCEL 3
- #define IOCB_CMD_FSYNC 4
- #define IOCB_CMD_FDSYNC 5
- #define IOCB_CMD_RUNNING 6
- #define IOCB_CMD_DONE 7
-
- /* Maximum number of events to retrieve at once */
- #define MAX_EVENTS 512
- #define MAX_AIO_REAP MAX_EVENTS
-
- #include stdlib.h>
- #include asm/unistd.h>
- #include linux/types.h>
- #include signal.h>
- /*
- * we always use a 64bit off_t when communicating
- * with userland. its up to libraries to do the
- * proper padding and aio_error abstraction
- *
- * FIXME: this must change from glibc's definition
- * as we do *not* use the sigevent structure which
- * is big and bloated.
- */
- struct aiocb64 {
- int aio_fildes; /* File desriptor. */
- short aio_lio_opcode; /* Operation to be performed. */
- short aio_reqprio; /* Request priority offset. */
- void *aio_buf; /* Location of buffer. */
- size_t aio_nbytes; /* Length of transfer. */
- loff_t aio_offset; /* File offset. */
- /* these are internal to the kernel/libc. */
- long __aio_key; // kernel sets this to -1 if completed
- // otherwise >= 0 (the request#)
- void * __aio_data; // pointer to be returned in event's data
- int __error_code;
- };
-
-
-
- #ifdef DEBUG
- #define dbg_printf(fmt,arg...)\
- printf(fmt, ##arg)
- #else
- #define dbg_printf(fmt,arg...)\
- do { } while(0);
- #endif
-
-
- #define aiocb aiocb64
- #define aio_read aio_read64
- #define aio_write aio_write64
- #define aio_poll aio_poll64
- #define aio_error aio_error64
- #define aio_return aio_return64
- #define aio_cancel aio_cancel64
- #define aio_suspend aio_suspend64
- #define lio_listio lio_listio64
- #define aio_reap aio_reap64
-
-
- /* Initialize async i/o with the given maximum number of requests */
- int aio_init(int max_requests);
-
- /* Enqueue read request for given number of bytes and the given priority. */
- int aio_read64(struct aiocb64 *aiocbp);
-
- /* Enqueue write request for given number of bytes and the given priority. */
- int aio_write64(struct aiocb64 *aiocbp);
-
- /* Enqueue a poll request for a given fd. */
- int aio_poll64(struct aiocb64 *aiocbp);
-
- /*
- * Returns the status of the aiocb.
- * If the operation is incomplete, the return value is undefined
- * -1 is -errno for the call.
- * >= -1 is the return code of the completed operation
- */
- ssize_t aio_return64(struct aiocb64 *aiocbp);
-
- /*
- * Returns the error status of the aiocb.
- * 0 is -errno for the call.
- * 0 is successfully complete
- * EINPROGRESS is not complete at all.
- * > 0 is errno for unsuccessful completion.
- */
- int aio_error64(struct aiocb64 *aiocbp);
-
- /*
- * Try to cancel asynchronous I/O requests outstanding against file
- * descriptor FILDES.
- */
- int aio_cancel64 ( int fildes, struct aiocb64 *aiocbp);
-
- /*
- * Suspend calling thread until at least one of the asynchronous I/O
- * operations referenced by LIST has completed.
- */
- int aio_suspend64(const struct aiocb64 * const list[],int nent,
- const struct timespec *timeout);
-
- /*
- * Suspend calling thread until waitfor asynchronouse I/O operations
- * outstanding have completed.
- */
- int aio_reap64(struct timespec *timeout, int waitfor,
- struct aiocb *out_list[], int listsize,
- int *completed_count);
-
-
- int lio_listio64(int mode, struct aiocb64 * const list[], int nent,
- struct sigevent *__restrict __sig);
-
- /* Operation codes for `aio_lio_opcode'. */
- enum
- {
- LIO_READ,
- #define LIO_READ LIO_READ
- LIO_WRITE,
- #define LIO_WRITE LIO_WRITE
- LIO_NOP,
- #define LIO_NOP LIO_NOP
- LIO_POLL,
- #define LIO_POLL LIO_POLL
- };
-
- /* Return values of cancelation function. */
- enum
- {
- AIO_CANCELED,
- #define AIO_CANCELED AIO_CANCELED
- AIO_NOTCANCELED,
- #define AIO_NOTCANCELED AIO_NOTCANCELED
- AIO_ALLDONE
- #define AIO_ALLDONE AIO_ALLDONE
- };
-
-
- /* Synchronization options for `lio_listio' function. */
- enum
- {
- LIO_WAIT,
- #define LIO_WAIT LIO_WAIT
- LIO_NOWAIT
- #define LIO_NOWAIT LIO_NOWAIT
- };
-
- #endif /* _SKGAIO_H */
