aio_suspend

- wait for asynchronous I/O request

Synopsis

#include <aio.h>

int aio_suspend(const struct aiocb * const list[], int nent,
     const struct timespec *timeout);

Description

The aio_suspend() function suspends the calling thread until at least one of the asynchronous I/O operations referenced by the list argument has completed, until a signal interrupts the function, or, if timeout is not NULL, until the time interval specified by timeout has passed. If any of the aiocb structures in the list correspond to completed asynchronous I/O operations (that is, the error status for the operation is not equal to EINPROGRESS) at the time of the call, the function returns without suspending the calling thread. If there are no outstanding asynchronous I/O operations, aio_suspend() returns immediately with EAGAIN. The list argument is an array of pointers to asynchronous I/O control blocks. The nent argument indicates the number of elements in the array and is limited to _AIO_LISTIO_MAX = 4096. Each aiocb structure pointed to will have been used in initiating an asynchronous I/O request via aio_read(3C), aio_write(3C), or lio_listio(3C). This array may contain null pointers, which are ignored. If this array contains pointers that refer to aiocb structures that have not been used in submitting asynchronous I/O, the effect is undefined. If there are no outstanding asynchronous I/O operations, aio_suspend() returns immediately with EAGAIN.

If the time interval indicated in the timespec structure pointed to by timeout passes before any of the I/O operations referenced by list are completed, then aio_suspend() returns with an error. If this array contains pointers that refer to aiocb structures that have not been used in submitting asynchronous I/O, the effect is undefined.

Return Values

If aio_suspend() returns after one or more asynchronous I/O operations have completed, it returns 0. Otherwise, it returns -1, and sets errno to indicate the error.

The application may determine which asynchronous I/O completed by scanning the associated error and return status using aio_error(3C) and aio_return(3C), respectively.

Errors

The aio_suspend() function will fail if:

EAGAIN

No asynchronous I/O indicated in the list referenced by list completed in the time interval indicated by timeout.

There are no asynchronous I/O operations.

EINTR

A signal interrupted the aio_suspend() function. Since each asynchronous I/O operation might provoke a signal when it completes, this error return can be caused by the completion of one or more of the very I/O operations being awaited.

EINVAL

The nent argument is less than or equal to 0 or greater than _AIO_LISTIO_MAX, or the timespec structure pointed to by timeout is not properly set because tv_sec is less than 0 or tv_nsec is either less than 0 or greater than 10⁹.

ENOMEM

There is currently not enough available memory; the application can try again later.

ENOSYS

The aio_suspend() function is not supported by the system.

Usage

The aio_suspend() function has a transitional interface for 64-bit file offsets. See lf64(5).

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

aio.h(3HEAD), aio_fsync(3C), aio_read(3C), aio_return(3C), aio_write(3C), lio_listio(3C), signal.h(3HEAD), attributes(5), lf64(5), standards(5)