Task

A gstreamer.Task represents and manages a cancellable "task".

Asynchronous operations

The most common usage of gstreamer.Task is as a GAsyncResult, to manage data during an asynchronous operation. You call Task.new in the "start" method, followed by Task.setTaskData and the like if you need to keep some additional data associated with the task, and then pass the task object around through your asynchronous operation. Eventually, you will call a method such as Task.returnPointer or Task.returnError, which will save the value you give it and then invoke the task's callback function in the [thread-default main context][g-main-context-push-thread-default] where it was created (waiting until the next iteration of the main loop first, if necessary). The caller will pass the gstreamer.Task back to the operation's finish function (as a GAsyncResult), and you can use Task.propagatePointer or the like to extract the return value.

Here is an example for using GTask as a GAsyncResult:

1 
2 typedef struct {
3 CakeFrostingType frosting;
4 char *message;
5 } DecorationData;
6 
7 static void
8 decoration_data_free (DecorationData *decoration)
9 {
10 g_free (decoration->message);
11 g_slice_free (DecorationData, decoration);
12 }
13 
14 static void
15 baked_cb (Cake     *cake,
16 gpointer  user_data)
17 {
18 GTask *task = user_data;
19 DecorationData *decoration = g_task_get_task_data (task);
20 GError *error = NULL;
21 
22 if (cake == NULL)
23 {
24 g_task_return_new_error (task, BAKER_ERROR, BAKER_ERROR_NO_FLOUR,
25 "Go to the supermarket");
26 g_object_unref (task);
27 return;
28 }
29 
30 if (!cake_decorate (cake, decoration->frosting, decoration->message, &error))
31 {
32 g_object_unref (cake);
33 // [gstreamer.Task.Task.returnError|Task.returnError] takes ownership of error
34 g_task_return_error (task, error);
35 g_object_unref (task);
36 return;
37 }
38 
39 g_task_return_pointer (task, cake, g_object_unref);
40 g_object_unref (task);
41 }
42 
43 void
44 baker_bake_cake_async (Baker               *self,
45 guint                radius,
46 CakeFlavor           flavor,
47 CakeFrostingType     frosting,
48 const char          *message,
49 GCancellable        *cancellable,
50 GAsyncReadyCallback  callback,
51 gpointer             user_data)
52 {
53 GTask *task;
54 DecorationData *decoration;
55 Cake  *cake;
56 
57 task = g_task_new (self, cancellable, callback, user_data);
58 if (radius < 3)
59 {
60 g_task_return_new_error (task, BAKER_ERROR, BAKER_ERROR_TOO_SMALL,
61 "`ucm` radius cakes are silly",
62 radius);
63 g_object_unref (task);
64 return;
65 }
66 
67 cake = _baker_get_cached_cake (self, radius, flavor, frosting, message);
68 if (cake != NULL)
69 {
70 // `_baker_get_cached_cake()` returns a reffed cake
71 g_task_return_pointer (task, cake, g_object_unref);
72 g_object_unref (task);
73 return;
74 }
75 
76 decoration = g_slice_new (DecorationData);
77 decoration->frosting = frosting;
78 decoration->message = g_strdup (message);
79 g_task_set_task_data (task, decoration, (GDestroyNotify) decoration_data_free);
80 
81 _baker_begin_cake (self, radius, flavor, cancellable, baked_cb, task);
82 }
83 
84 Cake *
85 baker_bake_cake_finish (Baker         *self,
86 GAsyncResult  *result,
87 GError       **error)
88 {
89 g_return_val_if_fail (g_task_is_valid (result, self), NULL);
90 
91 return g_task_propagate_pointer (G_TASK (result), error);
92 }

Chained asynchronous operations

gstreamer.Task also tries to simplify asynchronous operations that internally chain together several smaller asynchronous operations. Task.getCancellable, Task.getContext, and Task.getPriority allow you to get back the task's gio.Cancellable, glib.MainContext, and [I/O priority][io-priority] when starting a new subtask, so you don't have to keep track of them yourself. Task.attachSource simplifies the case of waiting for a source to fire (automatically using the correct glib.MainContext and priority).

Here is an example for chained asynchronous operations:

1 
2 typedef struct {
3 Cake *cake;
4 CakeFrostingType frosting;
5 char *message;
6 } BakingData;
7 
8 static void
9 decoration_data_free (BakingData *bd)
10 {
11 if (bd->cake)
12 g_object_unref (bd->cake);
13 g_free (bd->message);
14 g_slice_free (BakingData, bd);
15 }
16 
17 static void
18 decorated_cb (Cake         *cake,
19 GAsyncResult *result,
20 gpointer      user_data)
21 {
22 GTask *task = user_data;
23 GError *error = NULL;
24 
25 if (!cake_decorate_finish (cake, result, &error))
26 {
27 g_object_unref (cake);
28 g_task_return_error (task, error);
29 g_object_unref (task);
30 return;
31 }
32 
33 // `baking_data_free()` will drop its ref on the cake, so we have to
34 // take another here to give to the caller.
35 g_task_return_pointer (task, g_object_ref (cake), g_object_unref);
36 g_object_unref (task);
37 }
38 
39 static gboolean
40 decorator_ready (gpointer user_data)
41 {
42 GTask *task = user_data;
43 BakingData *bd = g_task_get_task_data (task);
44 
45 cake_decorate_async (bd->cake, bd->frosting, bd->message,
46 g_task_get_cancellable (task),
47 decorated_cb, task);
48 
49 return G_SOURCE_REMOVE;
50 }
51 
52 static void
53 baked_cb (Cake     *cake,
54 gpointer  user_data)
55 {
56 GTask *task = user_data;
57 BakingData *bd = g_task_get_task_data (task);
58 GError *error = NULL;
59 
60 if (cake == NULL)
61 {
62 g_task_return_new_error (task, BAKER_ERROR, BAKER_ERROR_NO_FLOUR,
63 "Go to the supermarket");
64 g_object_unref (task);
65 return;
66 }
67 
68 bd->cake = cake;
69 
70 // Bail out now if the user has already cancelled
71 if (g_task_return_error_if_cancelled (task))
72 {
73 g_object_unref (task);
74 return;
75 }
76 
77 if (cake_decorator_available (cake))
78 decorator_ready (task);
79 else
80 {
81 GSource *source;
82 
83 source = cake_decorator_wait_source_new (cake);
84 // Attach `source` to `task`'s GMainContext and have it call
85 // `decorator_ready()` when it is ready.
86 g_task_attach_source (task, source, decorator_ready);
87 g_source_unref (source);
88 }
89 }
90 
91 void
92 baker_bake_cake_async (Baker               *self,
93 guint                radius,
94 CakeFlavor           flavor,
95 CakeFrostingType     frosting,
96 const char          *message,
97 gint                 priority,
98 GCancellable        *cancellable,
99 GAsyncReadyCallback  callback,
100 gpointer             user_data)
101 {
102 GTask *task;
103 BakingData *bd;
104 
105 task = g_task_new (self, cancellable, callback, user_data);
106 g_task_set_priority (task, priority);
107 
108 bd = g_slice_new0 (BakingData);
109 bd->frosting = frosting;
110 bd->message = g_strdup (message);
111 g_task_set_task_data (task, bd, (GDestroyNotify) baking_data_free);
112 
113 _baker_begin_cake (self, radius, flavor, cancellable, baked_cb, task);
114 }
115 
116 Cake *
117 baker_bake_cake_finish (Baker         *self,
118 GAsyncResult  *result,
119 GError       **error)
120 {
121 g_return_val_if_fail (g_task_is_valid (result, self), NULL);
122 
123 return g_task_propagate_pointer (G_TASK (result), error);
124 }

Asynchronous operations from synchronous ones

You can use Task.runInThread to turn a synchronous operation into an asynchronous one, by running it in a thread. When it completes, the result will be dispatched to the [thread-default main context][g-main-context-push-thread-default] where the gstreamer.Task was created.

Running a task in a thread:

1 
2 typedef struct {
3 guint radius;
4 CakeFlavor flavor;
5 CakeFrostingType frosting;
6 char *message;
7 } CakeData;
8 
9 static void
10 cake_data_free (CakeData *cake_data)
11 {
12 g_free (cake_data->message);
13 g_slice_free (CakeData, cake_data);
14 }
15 
16 static void
17 bake_cake_thread (GTask         *task,
18 gpointer       source_object,
19 gpointer       task_data,
20 GCancellable  *cancellable)
21 {
22 Baker *self = source_object;
23 CakeData *cake_data = task_data;
24 Cake *cake;
25 GError *error = NULL;
26 
27 cake = bake_cake (baker, cake_data->radius, cake_data->flavor,
28 cake_data->frosting, cake_data->message,
29 cancellable, &error);
30 if (cake)
31 g_task_return_pointer (task, cake, g_object_unref);
32 else
33 g_task_return_error (task, error);
34 }
35 
36 void
37 baker_bake_cake_async (Baker               *self,
38 guint                radius,
39 CakeFlavor           flavor,
40 CakeFrostingType     frosting,
41 const char          *message,
42 GCancellable        *cancellable,
43 GAsyncReadyCallback  callback,
44 gpointer             user_data)
45 {
46 CakeData *cake_data;
47 GTask *task;
48 
49 cake_data = g_slice_new (CakeData);
50 cake_data->radius = radius;
51 cake_data->flavor = flavor;
52 cake_data->frosting = frosting;
53 cake_data->message = g_strdup (message);
54 task = g_task_new (self, cancellable, callback, user_data);
55 g_task_set_task_data (task, cake_data, (GDestroyNotify) cake_data_free);
56 g_task_run_in_thread (task, bake_cake_thread);
57 g_object_unref (task);
58 }
59 
60 Cake *
61 baker_bake_cake_finish (Baker         *self,
62 GAsyncResult  *result,
63 GError       **error)
64 {
65 g_return_val_if_fail (g_task_is_valid (result, self), NULL);
66 
67 return g_task_propagate_pointer (G_TASK (result), error);
68 }

Adding cancellability to uncancellable tasks

Finally, Task.runInThread and Task.runInThreadSync can be used to turn an uncancellable operation into a cancellable one. If you call Task.setReturnOnCancel, passing TRUE, then if the task's gio.Cancellable is cancelled, it will return control back to the caller immediately, while allowing the task thread to continue running in the background (and simply discarding its result when it finally does finish). Provided that the task thread is careful about how it uses locks and other externally-visible resources, this allows you to make "GLib-friendly" asynchronous and cancellable synchronous variants of blocking APIs.

Cancelling a task:

1 
2 static void
3 bake_cake_thread (GTask         *task,
4 gpointer       source_object,
5 gpointer       task_data,
6 GCancellable  *cancellable)
7 {
8 Baker *self = source_object;
9 CakeData *cake_data = task_data;
10 Cake *cake;
11 GError *error = NULL;
12 
13 cake = bake_cake (baker, cake_data->radius, cake_data->flavor,
14 cake_data->frosting, cake_data->message,
15 &error);
16 if (error)
17 {
18 g_task_return_error (task, error);
19 return;
20 }
21 
22 // If the task has already been cancelled, then we don't want to add
23 // the cake to the cake cache. Likewise, we don't  want to have the
24 // task get cancelled in the middle of updating the cache.
25 // [gstreamer.Task.Task.setReturnOnCancel|Task.setReturnOnCancel] will return `TRUE` here if it managed
26 // to disable return-on-cancel, or `FALSE` if the task was cancelled
27 // before it could.
28 if (g_task_set_return_on_cancel (task, FALSE))
29 {
30 // If the caller cancels at this point, their
31 // GAsyncReadyCallback won't be invoked until we return,
32 // so we don't have to worry that this code will run at
33 // the same time as that code does. But if there were
34 // other functions that might look at the cake cache,
35 // then we'd probably need a GMutex here as well.
36 baker_add_cake_to_cache (baker, cake);
37 g_task_return_pointer (task, cake, g_object_unref);
38 }
39 }
40 
41 void
42 baker_bake_cake_async (Baker               *self,
43 guint                radius,
44 CakeFlavor           flavor,
45 CakeFrostingType     frosting,
46 const char          *message,
47 GCancellable        *cancellable,
48 GAsyncReadyCallback  callback,
49 gpointer             user_data)
50 {
51 CakeData *cake_data;
52 GTask *task;
53 
54 cake_data = g_slice_new (CakeData);
55 
56 ...
57 
58 task = g_task_new (self, cancellable, callback, user_data);
59 g_task_set_task_data (task, cake_data, (GDestroyNotify) cake_data_free);
60 g_task_set_return_on_cancel (task, TRUE);
61 g_task_run_in_thread (task, bake_cake_thread);
62 }
63 
64 Cake *
65 baker_bake_cake_sync (Baker               *self,
66 guint                radius,
67 CakeFlavor           flavor,
68 CakeFrostingType     frosting,
69 const char          *message,
70 GCancellable        *cancellable,
71 GError             **error)
72 {
73 CakeData *cake_data;
74 GTask *task;
75 Cake *cake;
76 
77 cake_data = g_slice_new (CakeData);
78 
79 ...
80 
81 task = g_task_new (self, cancellable, NULL, NULL);
82 g_task_set_task_data (task, cake_data, (GDestroyNotify) cake_data_free);
83 g_task_set_return_on_cancel (task, TRUE);
84 g_task_run_in_thread_sync (task, bake_cake_thread);
85 
86 cake = g_task_propagate_pointer (task, error);
87 g_object_unref (task);
88 return cake;
89 }

Porting from GSimpleAsyncResult

gstreamer.Task's API attempts to be simpler than gio.SimpleAsyncResult's in several ways: - You can save task-specific data with Task.setTaskData, and retrieve it later with Task.getTaskData. This replaces the abuse of SimpleAsyncResult.setOpResGpointer for the same purpose with gio.SimpleAsyncResult - In addition to the task data, gstreamer.Task also keeps track of the priority[io-priority], gio.Cancellable, and glib.MainContext associated with the task, so tasks that consist of a chain of simpler asynchronous operations will have easy access to those values when starting each sub-task. - Task.returnErrorIfCancelled provides simplified handling for cancellation. In addition, cancellation overrides any other gstreamer.Task return value by default, like gio.SimpleAsyncResult does when SimpleAsyncResult.setCheckCancellable is called. (You can use Task.setCheckCancellable to turn off that behavior.) On the other hand, Task.runInThread guarantees that it will always run your task_func, even if the task's gio.Cancellable is already cancelled before the task gets a chance to run; you can start your task_func with a Task.returnErrorIfCancelled check if you need the old behavior. - The "return" methods (eg, Task.returnPointer) automatically cause the task to be "completed" as well, and there is no need to worry about the "complete" vs "complete in idle" distinction. (gstreamer.Task automatically figures out whether the task's callback can be invoked directly, or if it needs to be sent to another glib.MainContext, or delayed until the next iteration of the current glib.MainContext) - The "finish" functions for gstreamer.Task based operations are generally much simpler than gio.SimpleAsyncResult ones, normally consisting of only a single call to Task.propagatePointer or the like. Since Task.propagatePointer "steals" the return value from the gstreamer.Task, it is not necessary to juggle pointers around to prevent it from being freed twice. - With gio.SimpleAsyncResult, it was common to call SimpleAsyncResult.propagateError from the `_finish()` wrapper function, and have virtual method implementations only deal with successful returns. This behavior is deprecated, because it makes it difficult for a subclass to chain to a parent class's async methods. Instead, the wrapper function should just be a simple wrapper, and the virtual method should call an appropriate g_task_propagate_ function. Note that wrapper methods can now use g_async_result_legacy_propagate_error() to do old-style gio.SimpleAsyncResult error-returning behavior, and g_async_result_is_tagged() to check if a result is tagged as having come from the `_async()` wrapper function (for "short-circuit" results, such as when passing 0 to InputStream.readAsync).

class Task : ObjectG , AsyncResultIF {

protected

GTask* gTask;

GTask* getTaskStruct(bool transferOwnership);

void* getStruct();

this(GTask* gTask, bool ownedRef);

static GType getType();

this(ObjectG sourceObject, Cancellable cancellable, GAsyncReadyCallback callback, void* callbackData);

static bool isValid(AsyncResultIF result, ObjectG sourceObject);

static void reportError(ObjectG sourceObject, GAsyncReadyCallback callback, void* callbackData, void* sourceTag, ErrorG error);

void attachSource(Source source, GSourceFunc callback);

Cancellable getCancellable();

bool getCheckCancellable();

bool getCompleted();

MainContext getContext();

string getName();

int getPriority();

bool getReturnOnCancel();

ObjectG getSourceObject();

void* getSourceTag();

void* getTaskData();

bool hadError();

bool propagateBoolean();

ptrdiff_t propagateInt();

void* propagatePointer();

bool propagateValue(Value value);

void returnBoolean(bool result);

void returnError(ErrorG error);

bool returnErrorIfCancelled();

void returnInt(ptrdiff_t result);

void returnPointer(void* result, GDestroyNotify resultDestroy);

void returnValue(Value result);

void runInThread(GTaskThreadFunc taskFunc);

void runInThreadSync(GTaskThreadFunc taskFunc);

void setCheckCancellable(bool checkCancellable);

void setName(string name);

void setPriority(int priority);

bool setReturnOnCancel(bool returnOnCancel);

void setSourceTag(void* sourceTag);

void setTaskData(void* taskData, GDestroyNotify taskDataDestroy);

}

Constructors

this this(GTask* gTask, bool ownedRef): Sets our main struct and passes it to the parent class.
this this(ObjectG sourceObject, Cancellable cancellable, GAsyncReadyCallback callback, void* callbackData): Creates a gstreamer.Task acting on source_object, which will eventually be used to invoke callback in the current [thread-default main context][g-main-context-push-thread-default].

Members

Functions

attachSource void attachSource(Source source, GSourceFunc callback): A utility function for dealing with async operations where you need to wait for a glib.Source to trigger. Attaches source to task's glib.MainContext with task's priority[io-priority], and sets source's callback to callback, with task as the callback's user_data.
getCancellable Cancellable getCancellable(): Gets task's gio.Cancellable
getCheckCancellable bool getCheckCancellable(): Gets task's check-cancellable flag. See Task.setCheckCancellable for more details.
getCompleted bool getCompleted(): Gets the value of completed. This changes from FALSE to TRUE after the task’s callback is invoked, and will return FALSE if called from inside the callback.
getContext MainContext getContext(): Gets the glib.MainContext that task will return its result in (that is, the context that was the [thread-default main context][g-main-context-push-thread-default] at the point when task was created).
getName string getName(): Gets task’s name. See Task.setName.
getPriority int getPriority(): Gets task's priority
getReturnOnCancel bool getReturnOnCancel(): Gets task's return-on-cancel flag. See Task.setReturnOnCancel for more details.
getSourceObject ObjectG getSourceObject(): Gets the source object from task. Like g_async_result_get_source_object(), but does not ref the object.
getSourceTag void* getSourceTag(): Gets task's source tag. See Task.setSourceTag.
getStruct void* getStruct(): the main Gtk struct as a void*
getTaskData void* getTaskData(): Gets task's task_data.
getTaskStruct GTask* getTaskStruct(bool transferOwnership): Get the main Gtk struct
hadError bool hadError(): Tests if task resulted in an error.
propagateBoolean bool propagateBoolean(): Gets the result of task as a gboolean
propagateInt ptrdiff_t propagateInt(): Gets the result of task as an integer (gssize).
propagatePointer void* propagatePointer(): Gets the result of task as a pointer, and transfers ownership of that value to the caller.
propagateValue bool propagateValue(Value value): Gets the result of task as a gobject.Value, and transfers ownership of that value to the caller. As with Task.returnValue, this is a generic low-level method; Task.propagatePointer and the like will usually be more useful for C code.
returnBoolean void returnBoolean(bool result): Sets task's result to result and completes the task (see Task.returnPointer for more discussion of exactly what this means).
returnError void returnError(ErrorG error): Sets task's result to error (which task assumes ownership of) and completes the task (see Task.returnPointer for more discussion of exactly what this means).
returnErrorIfCancelled bool returnErrorIfCancelled(): Checks if task's gio.Cancellable has been cancelled, and if so, sets task's error accordingly and completes the task (see Task.returnPointer for more discussion of exactly what this means).
returnInt void returnInt(ptrdiff_t result): Sets task's result to result and completes the task (see Task.returnPointer for more discussion of exactly what this means).
returnPointer void returnPointer(void* result, GDestroyNotify resultDestroy): Sets task's result to result and completes the task. If result is not NULL, then result_destroy will be used to free result if the caller does not take ownership of it with Task.propagatePointer.
returnValue void returnValue(Value result): Sets task's result to result (by copying it) and completes the task.
runInThread void runInThread(GTaskThreadFunc taskFunc): Runs task_func in another thread. When task_func returns, task's GAsyncReadyCallback will be invoked in task's glib.MainContext
runInThreadSync void runInThreadSync(GTaskThreadFunc taskFunc): Runs task_func in another thread, and waits for it to return or be cancelled. You can use Task.propagatePointer, etc, afterward to get the result of task_func.
setCheckCancellable void setCheckCancellable(bool checkCancellable): Sets or clears task's check-cancellable flag. If this is TRUE (the default), then Task.propagatePointer, etc, and Task.hadError will check the task's gio.Cancellable first, and if it has been cancelled, then they will consider the task to have returned an "Operation was cancelled" error (G_IO_ERROR_CANCELLED), regardless of any other error or return value the task may have had.
setName void setName(string name): Sets task’s name, used in debugging and profiling. The name defaults to NULL.
setPriority void setPriority(int priority): Sets task's priority. If you do not call this, it will default to G_PRIORITY_DEFAULT.
setReturnOnCancel bool setReturnOnCancel(bool returnOnCancel): Sets or clears task's return-on-cancel flag. This is only meaningful for tasks run via Task.runInThread or Task.runInThreadSync.
setSourceTag void setSourceTag(void* sourceTag): Sets task's source tag. You can use this to tag a task return value with a particular pointer (usually a pointer to the function doing the tagging) and then later check it using Task.getSourceTag (or g_async_result_is_tagged()) in the task's "finish" function, to figure out if the response came from a particular place.
setTaskData void setTaskData(void* taskData, GDestroyNotify taskDataDestroy): Sets task's task data (freeing the existing task data, if any).

Static functions

getType GType getType()
isValid bool isValid(AsyncResultIF result, ObjectG sourceObject): Checks that result is a gstreamer.Task, and that source_object is its source object (or that source_object is NULL and result has no source object). This can be used in g_return_if_fail() checks.
reportError void reportError(ObjectG sourceObject, GAsyncReadyCallback callback, void* callbackData, void* sourceTag, ErrorG error): Creates a gstreamer.Task and then immediately calls Task.returnError on it. Use this in the wrapper function of an asynchronous method when you want to avoid even calling the virtual method. You can then use g_async_result_is_tagged() in the finish method wrapper to check if the result there is tagged as having been created by the wrapper method, and deal with it appropriately if so.

Variables

gTask GTask* gTask;: the main Gtk struct

Inherited Members

From ObjectG

gObject GObject* gObject;: the main Gtk struct
getObjectGStruct GObject* getObjectGStruct(bool transferOwnership): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
opCast T opCast()
getDObject RT getDObject(U obj, bool ownedRef): Gets a D Object from the objects table of associations.
setProperty void setProperty(string propertyName, T value)
addOnNotify gulong addOnNotify(void delegate(ParamSpec, ObjectG) dlg, string property, ConnectFlags connectFlags): The notify signal is emitted on an object when one of its properties has been changed. Note that getting this signal doesn't guarantee that the value of the property has actually changed, it may also be emitted when the setter for the property is called to reinstate the previous value.
getType GType getType()
compatControl size_t compatControl(size_t what, void* data)
interfaceFindProperty ParamSpec interfaceFindProperty(TypeInterface gIface, string propertyName): Find the gobject.ParamSpec with the given name for an interface. Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().
interfaceInstallProperty void interfaceInstallProperty(TypeInterface gIface, ParamSpec pspec): Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created gobject.ParamSpec, but normally ObjectClass.overrideProperty will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property.
interfaceListProperties ParamSpec[] interfaceListProperties(TypeInterface gIface): Lists the properties of an interface.Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().
addToggleRef void addToggleRef(GToggleNotify notify, void* data): Increases the reference count of the object by one and sets a callback to be called when all other references to the object are dropped, or when this is already the last reference to the object and another reference is established.
addWeakPointer void addWeakPointer(void* weakPointerLocation): Adds a weak reference from weak_pointer to object to indicate that the pointer located at weak_pointer_location is only valid during the lifetime of object. When the object is finalized, weak_pointer will be set to NULL.
bindProperty Binding bindProperty(string sourceProperty, ObjectG target, string targetProperty, GBindingFlags flags): Creates a binding between source_property on source and target_property on target. Whenever the source_property is changed the target_property is updated using the same value. For instance:
bindPropertyFull Binding bindPropertyFull(string sourceProperty, ObjectG target, string targetProperty, GBindingFlags flags, GBindingTransformFunc transformTo, GBindingTransformFunc transformFrom, void* userData, GDestroyNotify notify): Complete version of g_object_bind_property().
bindPropertyWithClosures Binding bindPropertyWithClosures(string sourceProperty, ObjectG target, string targetProperty, GBindingFlags flags, Closure transformTo, Closure transformFrom): Creates a binding between source_property on source and target_property on target, allowing you to set the transformation functions to be used by the binding.
dupData void* dupData(string key, GDuplicateFunc dupFunc, void* userData): This is a variant of g_object_get_data() which returns a 'duplicate' of the value. dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object.
dupQdata void* dupQdata(GQuark quark, GDuplicateFunc dupFunc, void* userData): This is a variant of g_object_get_qdata() which returns a 'duplicate' of the value. dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object.
forceFloating void forceFloating(): This function is intended for GObject implementations to re-enforce a floating[floating-ref] object reference. Doing this is seldom required: all GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling g_object_ref_sink().
freezeNotify void freezeNotify(): Increases the freeze count on object. If the freeze count is non-zero, the emission of "notify" signals on object is stopped. The signals are queued until the freeze count is decreased to zero. Duplicate notifications are squashed so that at most one notify signal is emitted for each property modified while the object is frozen.
getData void* getData(string key): Gets a named field from the objects table of associations (see g_object_set_data()).
getProperty void getProperty(string propertyName, Value value): Gets a property of an object.
getQdata void* getQdata(GQuark quark): This function gets back user data pointers stored via g_object_set_qdata().
getValist void getValist(string firstPropertyName, void* varArgs): Gets properties of an object.
getv void getv(string[] names, Value[] values): Gets n_properties properties for an object. Obtained properties will be set to values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.
isFloating bool isFloating(): Checks whether object has a floating[floating-ref] reference.
notify void notify(string propertyName): Emits a "notify" signal for the property property_name on object.
notifyByPspec void notifyByPspec(ParamSpec pspec): Emits a "notify" signal for the property specified by pspec on object.
ref_ ObjectG ref_(): Increases the reference count of object.
refSink ObjectG refSink(): Increase the reference count of object, and possibly remove the floating[floating-ref] reference, if object has a floating reference.
removeToggleRef void removeToggleRef(GToggleNotify notify, void* data): Removes a reference added with g_object_add_toggle_ref(). The reference count of the object is decreased by one.
removeWeakPointer void removeWeakPointer(void* weakPointerLocation): Removes a weak reference from object that was previously added using g_object_add_weak_pointer(). The weak_pointer_location has to match the one used with g_object_add_weak_pointer().
replaceData bool replaceData(string key, void* oldval, void* newval, GDestroyNotify destroy, GDestroyNotify oldDestroy): Compares the user data for the key key on object with oldval, and if they are the same, replaces oldval with newval.
replaceQdata bool replaceQdata(GQuark quark, void* oldval, void* newval, GDestroyNotify destroy, GDestroyNotify oldDestroy): Compares the user data for the key quark on object with oldval, and if they are the same, replaces oldval with newval.
runDispose void runDispose(): Releases all references to other objects. This can be used to break reference cycles.
setData void setData(string key, void* data): Each object carries around a table of associations from strings to pointers. This function lets you set an association.
setDataFull void setDataFull(string key, void* data, GDestroyNotify destroy): Like g_object_set_data() except it adds notification for when the association is destroyed, either by setting it to a different value or when the object is destroyed.
setProperty void setProperty(string propertyName, Value value): Sets a property on an object.
setQdata void setQdata(GQuark quark, void* data): This sets an opaque, named pointer on an object. The name is specified through a GQuark (retrived e.g. via g_quark_from_static_string()), and the pointer can be gotten back from the object with g_object_get_qdata() until the object is finalized. Setting a previously set user data pointer, overrides (frees) the old pointer set, using NULL as pointer essentially removes the data stored.
setQdataFull void setQdataFull(GQuark quark, void* data, GDestroyNotify destroy): This function works like g_object_set_qdata(), but in addition, a void (*destroy) (gpointer) function may be specified which is called with data as argument when the object is finalized, or the data is being overwritten by a call to g_object_set_qdata() with the same quark.
setValist void setValist(string firstPropertyName, void* varArgs): Sets properties on an object.
setv void setv(string[] names, Value[] values): Sets n_properties properties for an object. Properties to be set will be taken from values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.
stealData void* stealData(string key): Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
stealQdata void* stealQdata(GQuark quark): This function gets back user data pointers stored via g_object_set_qdata() and removes the data from object without invoking its destroy() function (if any was set). Usually, calling this function is only required to update user data pointers with a destroy notifier, for example:
thawNotify void thawNotify(): Reverts the effect of a previous call to g_object_freeze_notify(). The freeze count is decreased on object and when it reaches zero, queued "notify" signals are emitted.
unref void unref(): Decreases the reference count of object. When its reference count drops to 0, the object is finalized (i.e. its memory is freed).
watchClosure void watchClosure(Closure closure): This function essentially limits the life time of the closure to the life time of the object. That is, when the object is finalized, the closure is invalidated by calling Closure.invalidate on it, in order to prevent invocations of the closure with a finalized (nonexisting) object. Also, g_object_ref() and g_object_unref() are added as marshal guards to the closure, to ensure that an extra reference count is held on object during invocation of the closure. Usually, this function will be called on closures that use this object as closure data.
weakRef void weakRef(GWeakNotify notify, void* data): Adds a weak reference callback to an object. Weak references are used for notification when an object is finalized. They are called "weak references" because they allow you to safely hold a pointer to an object without calling g_object_ref() (g_object_ref() adds a strong reference, that is, forces the object to stay alive).
weakUnref void weakUnref(GWeakNotify notify, void* data): Removes a weak reference callback to an object.
clearObject void clearObject(ObjectG objectPtr): Clears a reference to a GObject

From AsyncResultIF

getAsyncResultStruct GAsyncResult* getAsyncResultStruct(bool transferOwnership): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
getType GType getType()
getSourceObject ObjectG getSourceObject(): Gets the source object from a GAsyncResult
getUserData void* getUserData(): Gets the user data from a GAsyncResult
isTagged bool isTagged(void* sourceTag): Checks if res has the given source_tag (generally a function pointer indicating the function res was created by).
legacyPropagateError bool legacyPropagateError(): If res is a gio.SimpleAsyncResult, this is equivalent to SimpleAsyncResult.propagateError. Otherwise it returns FALSE.

gio Task classes

Task