function does a sync on all outstanding asynchronous I/O operations
More precisely, if
then all currently queued I/O operations shall be
completed as if by a call of
this call is the asynchronous analog of
Note that this is a request only --- this call does not wait
for I/O completion.
the only field in the structure pointed to by
that is used by this call is the
structure, described in
which indicates the desired type of asynchronous notification at completion.
All other fields are ignored.
On success (the sync request was successfully queued)
this function returns 0.
On error -1 is returned, and
is set appropriately.
Out of resources.
is not a valid file descriptor open for writing.
No synchronized I/O for this file is supported, or