public IOCondition condition_check (IOCondition condition)

Checks on the readiness of this to perform operations.

The operations specified in condition are checked for and masked against the currently-satisfied conditions on this. The result is returned.

g_io_in will be set in the return value if data is available to read with receive_messages, or if the connection is closed remotely (EOS); and if the datagram_based has not been closed locally using some implementation-specific method (such as close or shutdown with shutdown_read set, if it’s a Socket).

If the connection is shut down or closed (by calling close or shutdown with shutdown_read set, if it’s a Socket, for example), all calls to this function will return g_io_error_closed.

g_io_out will be set if it is expected that at least one byte can be sent using send_messages without blocking. It will not be set if the datagram_based has been closed locally.

g_io_hup will be set if the connection has been closed locally.

g_io_err will be set if there was an asynchronous error in transmitting data previously enqueued using send_messages.

Note that on Windows, it is possible for an operation to return g_io_error_would_block even immediately after condition_check has claimed that the DatagramBased is ready for writing. Rather than calling condition_check and then writing to the DatagramBased if it succeeds, it is generally better to simply try writing right away, and try again later if the initial attempt returns g_io_error_would_block.

It is meaningless to specify g_io_err or g_io_hup in condition ; these conditions will always be set in the output if they are true. Apart from these flags, the output is guaranteed to be masked by condition.

This call never blocks.



a DatagramBased


a IOCondition mask to check


the IOCondition mask of the current state