Orace开源的异步IO编程库，特点是接口非常简单

 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 */