Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Cancel all asynchronous operations associated with the socket.
void cancel();
This function causes all outstanding asynchronous connect, send and receive
operations to finish immediately, and the handlers for cancelled operations
will be passed the boost::asio::error::operation_aborted
error.
Thrown on failure.
Calls to cancel()
will always fail with boost::asio::error::operation_not_supported
when run on Windows XP, Windows Server 2003, and earlier versions of
Windows, unless BOOST_ASIO_ENABLE_CANCELIO is defined. However, the CancelIo
function has two issues that should be considered before enabling its
use:
For portable cancellation, consider using one of the following alternatives:
close()
function to simultaneously cancel the outstanding operations and
close the socket.
When running on Windows Vista, Windows Server 2008, and later, the CancelIoEx function is always used. This function does not have the problems described above.