aio_suspend (original) (raw)

The Open Group Base Specifications Issue 6
IEEE Std 1003.1, 2004 Edition
Copyright © 2001-2004 The IEEE and The Open Group, All Rights reserved.

A newer edition of this document exists here

NAME

aio_suspend - wait for an asynchronous I/O request (REALTIME)

SYNOPSIS

`[AIO] [Option Start] #include <aio.h>

int aio_suspend(const struct aiocb * const

list[], int nent,
const struct timespec *timeout); [Option End]`

DESCRIPTION

The aio_suspend() function shall suspend 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 shall return without suspending the calling thread. 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. Each aiocbstructure pointed to has been used in initiating an asynchronous I/O request via aio_read(), aio_write(), or lio_listio(). 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 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() shall return with an error. [MON] [Option Start] If the Monotonic Clock option is supported, the clock that shall be used to measure this time interval shall be the CLOCK_MONOTONIC clock.[Option End]

RETURN VALUE

If the aio_suspend() function returns after one or more asynchronous I/O operations have completed, the function shall return zero. Otherwise, the function shall return a value of -1 and set 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() and aio_return(), respectively.

ERRORS

The aio_suspend() function shall fail if:

[EAGAIN]

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

[EINTR]

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

The following sections are informative.

EXAMPLES

None.

APPLICATION USAGE

The aio_suspend() function is part of the Asynchronous Input and Output option and need not be available on all implementations.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

aio_read(), aio_write(), lio_listio(), the Base Definitions volume of IEEE Std 1003.1-2001, <aio.h>

CHANGE HISTORY

First released in Issue 5. Included for alignment with the POSIX Realtime Extension.

Issue 6

The [ENOSYS] error condition has been removed as stubs need not be provided if an implementation does not support the Asynchronous Input and Output option.

The APPLICATION USAGE section is added.

The DESCRIPTION is updated for alignment with IEEE Std 1003.1j-2000 by specifying that the CLOCK_MONOTONIC clock, if supported, is used.

End of informative text.

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