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   │
       ├───────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │aio_suspend()                                                  │ 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)