aio_cancel(3aio)                                    aio_cancel(3aio)


       NAME
             aio_cancel - asynchronous cancel

       SYNOPSIS
             cc [options] -D_REENTRANT file -lthread
             #include <aio.h>
             struct aiocb *aio_cancel(int fildes, struct aiocb *aiocbp);

       DESCRIPTION
             aio_cancel allows you to cancel one or more outstanding
             asynchronous I/O requests.  fildes and key are used to
             identify the asynchronous I/O requests that should be
             canceled.

             The aio_cancel function attempts to cancel one or more
             asynchronous I/O requests currently outstanding against file
             descriptor fildes.  The aiocbp argument points to the
             asynchronous I/O control block for a particular request to be
             canceled.  If aiocbp is NULL, all outstanding cancelable
             asynchronous I/O requests agains fildes are canceled.

             Normal notification occurs for asynchronous I/O operations
             that are successfully canceled.  If there are requests which
             cannot be canceled, then the normal asynchronous completion
             process shall take place for those requests when they are
             completed.

             For requested operations that are successfully canceled, the
             associated error status is set to ECANCELED and the return
             status is -1.  For requested operations that are not
             successfully canceled, the aiocbp is not modified by
             aio_cancel.

             If aiocbp is not NULL, and fildes does not have the same value
             as the file descriptor with which the asynchronous operation
             was initiated, unspecified results occur.

       Return Values
             The aio_cancel function returns the value AIO_CANCELED to the
             calling process if the requested operation(s) were canceled.
             The value AIO_NOTCANCELED is returned if at least one of the
             requested operation(s) cannot be canceled because it is in
             progress.  In this case, the state of the other operations, if
             any, referenced in the call to aio_cancel is not indicated by
             the return value of aio_cancel.  The application may determine
             the state of affairs for these operations by using aio_error.


                           Copyright 1994 Novell, Inc.               Page 1

      aio_cancel(3aio)                                    aio_cancel(3aio)


            The value AIO_ALLDONE is returned if all of the operations
            have already completed.  Otherwise, the function returns -1,
            and sets errno to indicate the error.

         Errors
            Under the following conditions, aio_cancel fails and sets
            errno to:

            EBADF            fildes is not a valid file descriptor.

            EINVAL           no asynchronous I/O has ever been requested
                             for fildes

            ENOSYS           aio_cancel called on SVR4.2

      REFERENCES
            aiocb(5), aio_read(3aio), aio_suspend(3aio), aio_write(3aio)































                          Copyright 1994 Novell, Inc.               Page 2