Cancel all operations associated with the signal set.

boost::system::error_code cancel(
    boost::system::error_code & ec);

This function forces the completion of any pending asynchronous wait operations against the signal set. The handler for each cancelled operation will be invoked with the boost::asio::error::operation_aborted error code.

Cancellation does not alter the set of registered signals.

Parameters

Remarks

If a registered signal occurred before cancel() is called, then the handlers for asynchronous wait operations will:

These handlers can no longer be cancelled, and therefore are passed an error code that indicates the successful completion of the wait operation.