Function

dispatch_io_create_with_path

Creates a dispatch I/O channel with the associated path name.

Declaration

dispatch_io_t dispatch_io_create_with_path(dispatch_io_type_t type, const char *path, int oflag, mode_t mode, dispatch_queue_t queue, void (^cleanup_handler)(int error));

Parameters

type

The type of channel to create. For a list of possible options, see dispatch_io_type_t.

path

The file system path to open and use for the channel I/O. This path is opened using the open system call.

oflag

The flags to pass to the open function when opening the path.

mode

The mode to pass to the open function when creating a file at the specified path. If you are not creating a file, specify 0.

queue

The dispatch queue to associate with the channel. This queue is used to execute the channel’s clean up handler. The channel retains this queue.

cleanup_handler

The block to enqueue when the system relinquishes control of the channel’s file descriptor. This channel takes a single parameter that indicates the reason why control was relinquished. If the error parameter contains a non zero value, control was relinquished because there was an error creating the channel; otherwise, this value should be 0.

Return Value

The dispatch I/O channel or NULL if an error occurred. The returned object is retained before it is returned; it is your responsibility to close the channel and then release this object when you are done using it.

Discussion

This function associates the specified path with the channel but does not open a file descriptor for that path until you perform the first I/O operation. While it is open, the channel owns the file descriptor. The channel closes the file descriptor and calls its cleanup handler when one of the following occurs:

  • You close the channel by calling the dispatch_io_close function.

  • An unrecoverable error occurs on the file descriptor.

  • All references to the channel are released.

See Also

Creating a Dispatch I/O Object

dispatch_io_create

Creates a dispatch I/O channel and associates it with the specified file descriptor.

dispatch_io_create_with_io

Creates a new dispatch I/O channel from an existing channel.

dispatch_io_t

A dispatch I/O channel.

dispatch_fd_t

A file descriptor used for I/O operations.

dispatch_io_type_t

The type of a dispatch I/O channel.