Get the main Gtk struct
Gets the source object from a GAsyncResult.
the main Gtk struct as a void*
Gets the user data from a GAsyncResult.
Checks if res has the given source_tag (generally a function pointer indicating the function res was created by). Since 2.34
If res is a GSimpleAsyncResult, this is equivalent to g_simple_async_result_propagate_error(). Otherwise it returns FALSE. This can be used for legacy error handling in async _finish() wrapper functions that traditionally handled GSimpleAsyncResult error returns themselves rather than calling into the virtual method. This should not be used in new code; GAsyncResult errors that are set by virtual methods should also be extracted by virtual methods, to enable subclasses to chain up correctly. Since 2.34
Provides a base class for implementing asynchronous function results.
Asynchronous operations are broken up into two separate operations which are chained together by a GAsyncReadyCallback. To begin an asynchronous operation, provide a GAsyncReadyCallback to the asynchronous function. This callback will be triggered when the operation has completed, and will be passed a GAsyncResult instance filled with the details of the operation's success or failure, the object the asynchronous function was started for and any error codes returned. The asynchronous callback function is then expected to call the corresponding "_finish()" function, passing the object the function was called for, the GAsyncResult instance, and (optionally) an error to grab any error conditions that may have occurred.
The "_finish()" function for an operation takes the generic result (of type GAsyncResult) and returns the specific result that the operation in question yields (e.g. a GFileEnumerator for a "enumerate children" operation). If the result or error status of the operation is not needed, there is no need to call the "_finish()" function; GIO will take care of cleaning up the result and error information after the GAsyncReadyCallback returns. You can pass NULL for the GAsyncReadyCallback if you don't need to take any action at all after the operation completes. Applications may also take a reference to the GAsyncResult and call "_finish()" later; however, the "_finish()" function may be called at most once.
Example of a typical asynchronous operation flow:
The callback for an asynchronous operation is called only once, and is always called, even in the case of a cancelled operation. On cancellation the result is a G_IO_ERROR_CANCELLED error.
Many I/O-related asynchronous operations have a priority parameter, which is used in certain cases to determine the order in which operations are executed. They are not used to determine system-wide I/O scheduling. Priorities are integers, with lower numbers indicating higher priority. It is recommended to choose priorities between G_PRIORITY_LOW and G_PRIORITY_HIGH, with G_PRIORITY_DEFAULT as a default.