отменить запрос асинхронного ввода-вывода (cancel an asynchronous I/O request)
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
aio_cancel — cancel an asynchronous I/O request
Синопсис (Synopsis)
#include <aio.h>
int aio_cancel(int fildes, struct aiocb *aiocbp);
Описание (Description)
The aio_cancel() function shall attempt 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, then all outstanding cancelable
asynchronous I/O requests against fildes shall be canceled.
Normal asynchronous notification shall occur for asynchronous I/O
operations that are successfully canceled. If there are requests
that 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 shall be set to [ECANCELED] and the
return status shall be -1. For requested operations that are not
successfully canceled, the aiocbp shall not be modified by
aio_cancel().
If aiocbp is not NULL, then if fildes does not have the same
value as the file descriptor with which the asynchronous
operation was initiated, unspecified results occur.
Which operations are cancelable is implementation-defined.
Возвращаемое значение (Return value)
The aio_cancel() function shall return the value AIO_CANCELED if
the requested operation(s) were canceled. The value
AIO_NOTCANCELED shall be 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().
The value AIO_ALLDONE is returned if all of the operations have
already completed. Otherwise, the function shall return -1 and
set errno to indicate the error.
Ошибки (Error)
The aio_cancel() function shall fail if:
EBADF The fildes argument is not a valid file descriptor.
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
aio_read(3p), aio_write(3p)
The Base Definitions volume of POSIX.1‐2017, aio.h(0p)
