aio_suspend(3)

NAME
aio_suspend - wait for asynchronous I/O operation or timeout

LIBRARY
Real-time library (librt, -lrt)

SYNOPSIS

#include <aio.h>

int aio_suspend(const struct aiocb *const aiocb_list[], int nitems,
                const struct timespec *restrict timeout);

DESCRIPTION
The aio_suspend() function suspends the calling thread until one of the following occurs:

•   One or more of the asynchronous I/O requests in the list aiocb_list has completed.

•   A signal is delivered.

•   timeout is not NULL and the specified time interval has passed. (For details of the timespec structure, see nanosleep(2).)

The nitems argument specifies the number of items in aiocb_list. Each item in the list pointed to by aiocb_list must be either NULL (and then is ignored), or a pointer to a control block on which I/O was initiated using aio_read(3), aio_write(3), or lio_listio(3). (See aio(7) for a description of the aiocb structure.)

If CLOCK_MONOTONIC is supported, this clock is used to measure the timeout interval (see clock_gettime(2)).

RETURN VALUE
If this function returns after completion of one of the I/O requests specified in aiocb_list, 0 is returned. Otherwise, -1 is returned, and errno is set to indicate the error.

ERRORS

EAGAIN
    The call timed out before any of the indicated operations had completed.

EINTR
    The call was ended by signal (possibly the completion signal of one of the operations we were waiting for); see signal(7).

ENOSYS
    aio_suspend() is not implemented.

ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value
 | Thread safety | MT-Safe

STANDARDS
POSIX.1-2008.

HISTORY
glibc 2.1. POSIX.1-2001.

POSIX doesn't specify the parameters to be restrict; that is specific to glibc.

NOTES
One can achieve polling by using a non-NULL timeout that specifies a zero time interval.

If one or more of the asynchronous I/O operations specified in aiocb_list has already completed at the time of the call to aio_suspend(), then the call returns immediately.

To determine which I/O operations have completed after a successful return from aio_suspend(), use aio_error(3) to scan the list of aiocb structures pointed to by aiocb_list.

BUGS
The glibc implementation of aio_suspend() is not async-signal-safe, in violation of the requirements of POSIX.1.

SEE ALSO
aio_cancel(3), aio_error(3), aio_fsync(3), aio_read(3), aio_return(3), aio_write(3), lio_listio(3), aio(7), time(7)