Boost C++ Libraries of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Click here to view the latest version of this page.
basic_deadline_timer::cancel (2 of 2 overloads)

Cancel any asynchronous operations that are waiting on the timer.

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

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

Cancelling the timer does not change the expiry time.



Set to indicate what error occurred, if any.

Return Value

The number of asynchronous operations that were cancelled.


If the timer has already expired when 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.