Type Alias


A handler block used to process operations on a dispatch I/O channel.


typedef void (^dispatch_io_handler_t)(bool done, dispatch_data_t data, int error);


The parameters of a dispatch I/O handler are as follows:

  • done - A flag indicating whether the operation is complete.

  • data - The data object to be handled. This object is retained by the system for the duration of the handler’s execution and is released when the handler block returns.

  • error - The error number (if any) reported for the operation. An error number of 0 typically indicates the operation was successful.

See Also

Reading from the File


Schedules an asynchronous read operation using the specified file descriptor.


Schedules an asynchronous read operation on the specified channel.