class: GSource

[13:7] extends: object

The GSource struct is an opaque data type representing an event source.

Members

handleObj
lib
retainedCallbacks
signalHandlerNames
signalSetterHandlers

Methods

GSource (source_funcs = null, struct_size = null)

Creates a new [struct@GLib.Source] structure. The size is specified to allow creating structures derived from [struct@GLib.Source] that contain additional data. The size passed in must be at least sizeof (GSource). The source will not initially be associated with any [struct@GLib.MainContext] and must be added to one with [method@GLib.Source.attach] before it will be executed.
- @p source_funcs is structure containing functions that implement the source‘s behavior.
- @p struct_size is size of the [struct@GLib.Source] structure to create, in bytes.
toNativeHandle (Source)

Normalizes a constructor argument into a raw pointer carrier. Accepts a raw NativeHandle, a raw NativeBuffer returned from fn.call(...), another generated wrapper exposing handle(), or null. Returns null when the argument carries no pointer.
- @p Source is the raw handle, raw buffer, wrapper, or null.
- @r A raw pointer carrier or null when no pointer is present.
getLib ()

Returns the opened native library for this generated wrapper.
- @r The opened native library.
handle ()

Returns the wrapped NativeHandle.
- @r The wrapped NativeHandle.
isNull ()

Returns true when the wrapped handle is null.
- @r A bool.
describe ()

Returns a small string for debugging generated wrappers.
- @r A string.
add_child_source (object child_source)

Adds @child_source to @source as a ‘polled’ source. When @source is added to a [struct@GLib.MainContext], @child_source will be automatically added with the same priority. When @child_source is triggered, it will cause
- @source to dispatch (in addition to calling its own callback), and when
- @source is destroyed, it will destroy @child_source as well. The @source will also still be dispatched if its own prepare/check functions indicate that it is ready. If you don’t need @child_source to do anything on its own when it triggers, you can call g_source_set_dummy_callback() on it to set a callback that does nothing (except return true if appropriate). The @source will hold a reference on @child_source while @child_source is attached to it. This API is only intended to be used by implementations of [struct@GLib.Source]. Do not call this API on a [struct@GLib.Source] that you did not create.
- @p child_source is a second source that @source should ‘poll’.
- @r None.
add_poll (fd)

Adds a file descriptor to the set of file descriptors polled for this source. This is usually combined with [ctor@GLib.Source.new] to add an event source. The event source’s check function will typically test the
- @revents field in the [struct@GLib.PollFD] struct and return true if events need to be processed. This API is only intended to be used by implementations of [struct@GLib.Source]. Do not call this API on a [struct@GLib.Source] that you did not create. Using this API forces the linear scanning of event sources on each main loop iteration. Newly-written event sources should try to use g_source_add_unix_fd() instead of this API.
- @p fd is a [struct@GLib.PollFD] structure holding information about a file descriptor to watch.
- @r None.
add_unix_fd (int fd, string events)

Monitors @fd for the IO events in @events. The tag returned by this function can be used to remove or modify the monitoring of the @fd using [method@GLib.Source.remove_unix_fd] or [method@GLib.Source.modify_unix_fd]. It is not necessary to remove the file descriptor before destroying the source; it will be cleaned up automatically. This API is only intended to be used by implementations of [struct@GLib.Source]. Do not call this API on a [struct@GLib.Source] that you did not create. As the name suggests, this function is not available on Windows.
- @p fd is the file descriptor to monitor.
- @p events is an event mask.
- @r an opaque tag.
attach (object context)

Adds a [struct@GLib.Source] to a @context so that it will be executed within that context. Remove it by calling [method@GLib.Source.destroy]. This function is safe to call from any thread, regardless of which thread the @context is running in.
- @p context is a main context (if NULL, the global-default main context will be used).
- @r the ID (greater than 0) for the source within the [struct@GLib.MainContext].
destroy ()

Removes a source from its [struct@GLib.MainContext], if any, and marks it as destroyed. The source cannot be subsequently added to another context. It is safe to call this on sources which have already been removed from their context. This does not unref the [struct@GLib.Source]: if you still hold a reference, use [method@GLib.Source.unref] to drop it. This function is safe to call from any thread, regardless of which thread the [struct@GLib.MainContext] is running in. If the source is currently attached to a [struct@GLib.MainContext], destroying it will effectively unset the callback similar to calling [method@GLib.Source.set_callback]. This can mean, that the data’s [callback@GLib.DestroyNotify] gets called right away.
- @r None.
dup_context ()

Gets a reference to the [struct@GLib.MainContext] with which the source is associated. You can call this on a source that has been destroyed. You can always call this function on the source returned from [func@GLib.main_current_source].
- @r the [struct@GLib.MainContext] with which the source is associated, or NULL if the context has not yet been added to a source.
get_can_recurse ()

Checks whether a source is allowed to be called recursively. See [method@GLib.Source.set_can_recurse].
- @r whether recursion is allowed.
get_context ()

Gets the [struct@GLib.MainContext] with which the source is associated. You can call this on a source that has been destroyed, provided that the [struct@GLib.MainContext] it was attached to still exists (in which case it will return that [struct@GLib.MainContext]). In particular, you can always call this function on the source returned from [func@GLib.main_current_source]. But calling this function on a source whose [struct@GLib.MainContext] has been destroyed is an error. If the associated [struct@GLib.MainContext] could be destroy concurrently from a different thread, then this function is not safe to call and [method@GLib.Source.dup_context] should be used instead.
- @r the main context with which the source is associated, or NULL if the context has not yet been added to a source.
get_current_time (object timeval)

This function ignores @source and is otherwise the same as [func@GLib.get_current_time].
- @p timeval is [struct@GLib.TimeVal] structure in which to store current time.
- @r None.
get_id ()

Returns the numeric ID for a particular source. The ID of a source is a positive integer which is unique within a particular main loop context. The reverse mapping from ID to source is done by [method@GLib.MainContext.find_source_by_id]. You can only call this function while the source is associated to a [struct@GLib.MainContext] instance; calling this function before [method@GLib.Source.attach] or after [method@GLib.Source.destroy] yields undefined behavior. The ID returned is unique within the [struct@GLib.MainContext] instance passed to [method@GLib.Source.attach].
- @r the ID (greater than 0) for the source.
get_name ()

Gets a name for the source, used in debugging and profiling. The name may be NULL if it has never been set with [method@GLib.Source.set_name].
- @r the name of the source.
get_priority ()

Gets the priority of a source.
- @r the priority of the source.
get_ready_time ()

Gets the ‘ready time’ of @source, as set by [method@GLib.Source.set_ready_time]. Any time before or equal to the current monotonic time (including zero) is an indication that the source will fire immediately.
- @r the monotonic ready time, -1 for ‘never’.
get_time ()

Gets the time to be used when checking this source. The advantage of calling this function over calling [func@GLib.get_monotonic_time] directly is that when checking multiple sources, GLib can cache a single value instead of having to repeatedly get the system monotonic time. The time here is the system monotonic time, if available, or some other reasonable alternative otherwise. See [func@GLib.get_monotonic_time].
- @r the monotonic time in microseconds.
is_destroyed ()

Returns whether @source has been destroyed. This is important when you operate upon your objects from within idle handlers, but may have freed the object before the dispatch of your idle handler. c static gboolean idle_callback (gpointer data) { SomeWidget *self = data; g_mutex_lock (&self->idle_id_mutex); // do stuff with self self->idle_id = 0; g_mutex_unlock (&self->idle_id_mutex); return G_SOURCE_REMOVE; } static void some_widget_do_stuff_later (SomeWidget *self) { g_mutex_lock (&self->idle_id_mutex); self->idle_id = g_idle_add (idle_callback, self); g_mutex_unlock (&self->idle_id_mutex); } static void some_widget_init (SomeWidget *self) { g_mutex_init (&self->idle_id_mutex); // ... } static void some_widget_finalize (GObject *object) { SomeWidget *self = SOME_WIDGET (object); if (self->idle_id) g_source_remove (self->idle_id); g_mutex_clear (&self->idle_id_mutex); G_OBJECT_CLASS (parent_class)->finalize (object); } This will fail in a multi-threaded application if the widget is destroyed before the idle handler fires due to the use after free in the callback. A solution, to this particular problem, is to check to if the source has already been destroy within the callback. c static gboolean idle_callback (gpointer data) { SomeWidget *self = data; g_mutex_lock (&self->idle_id_mutex); if (!g_source_is_destroyed (g_main_current_source ())) { // do stuff with self } g_mutex_unlock (&self->idle_id_mutex); return FALSE; } Calls to this function from a thread other than the one acquired by the [struct@GLib.MainContext] the [struct@GLib.Source] is attached to are typically redundant, as the source could be destroyed immediately after this function returns. However, once a source is destroyed it cannot be un-destroyed, so this function can be used for opportunistic checks from any thread.
- @r true if the source has been destroyed, false otherwise.
modify_unix_fd (tag, string new_events)

Updates the event mask to watch for the file descriptor identified by
- @tag. The @tag is the tag returned from [method@GLib.Source.add_unix_fd]. If you want to remove a file descriptor, don’t set its event mask to zero. Instead, call [method@GLib.Source.remove_unix_fd]. This API is only intended to be used by implementations of [struct@GLib.Source]. Do not call this API on a [struct@GLib.Source] that you did not create. As the name suggests, this function is not available on Windows.
- @p tag is the tag from [method@GLib.Source.add_unix_fd].
- @p new_events is the new event mask to watch.
- @r None.
query_unix_fd (tag)

Queries the events reported for the file descriptor corresponding to @tag on @source during the last poll. The return value of this function is only defined when the function is called from the check or dispatch functions for @source. This API is only intended to be used by implementations of [struct@GLib.Source]. Do not call this API on a [struct@GLib.Source] that you did not create. As the name suggests, this function is not available on Windows.
- @p tag is the tag from [method@GLib.Source.add_unix_fd].
- @r the conditions reported on the file descriptor.
ref ()

Increases the reference count on a source by one.
- @r @source.
remove_child_source (object child_source)

Detaches @child_source from @source and destroys it. This API is only intended to be used by implementations of [struct@GLib.Source]. Do not call this API on a [struct@GLib.Source] that you did not create.
- @p child_source is a source previously passed to [method@GLib.Source.add_child_source].
- @r None.
remove_poll (fd)

Removes a file descriptor from the set of file descriptors polled for this source. This API is only intended to be used by implementations of [struct@GLib.Source]. Do not call this API on a [struct@GLib.Source] that you did not create.
- @p fd is a [struct@GLib.PollFD] structure previously passed to [method@GLib.Source.add_poll].
- @r None.
remove_unix_fd (tag)

Reverses the effect of a previous call to [method@GLib.Source.add_unix_fd]. You only need to call this if you want to remove a file descriptor from being watched while keeping the same source around. In the normal case you will just want to destroy the source. This API is only intended to be used by implementations of [struct@GLib.Source]. Do not call this API on a [struct@GLib.Source] that you did not create. As the name suggests, this function is not available on Windows.
- @p tag is the tag from [method@GLib.Source.add_unix_fd].
- @r None.
set_callback (object notify)

Sets the callback function for a source. The callback for a source is called from the source’s dispatch function. The exact type of @func depends on the type of source; ie. you should not count on @func being called with @data as its first parameter. Cast @func with [func@GLib.SOURCE_FUNC] to avoid warnings about incompatible function types. See main loop memory management for details on how to handle memory management of @data. Typically, you won’t use this function. Instead use functions specific to the type of source you are using, such as [func@GLib.idle_add] or [func@GLib.timeout_add]. It is safe to call this function multiple times on a source which has already been attached to a context. The changes will take effect for the next time the source is dispatched after this call returns. Note that [method@GLib.Source.destroy] for a currently attached source has the effect of also unsetting the callback.
- @p func is a callback function.
- @p data is the data to pass to callback function.
- @p notify is a function to call when @data is no longer in use.
- @r None.
set_callback_indirect (callback_data, object callback_funcs)

Sets the callback function storing the data as a reference counted callback ‘object’. This is used internally. Note that calling [method@GLib.Source.set_callback_indirect] assumes an initial reference count on @callback_data, and thus callback_funcs->unref will eventually be called once more than callback_funcs->ref. It is safe to call this function multiple times on a source which has already been attached to a context. The changes will take effect for the next time the source is dispatched after this call returns.
- @p callback_data is pointer to callback data ‘object’.
- @p callback_funcs is functions for reference counting @callback_data and getting the callback and data.
- @r None.
set_can_recurse (bool can_recurse)

Sets whether a source can be called recursively. If @can_recurse is true, then while the source is being dispatched then this source will be processed normally. Otherwise, all processing of this source is blocked until the dispatch function returns.
- @p can_recurse is whether recursion is allowed for this source.
- @r None.
set_dispose_function (object dispose)

Set @dispose as dispose function on @source. The @dispose function will be called once the reference count of @source reaches zero but before any of the state of the source is freed, especially before the finalize function (set as part of the [type@GLib.SourceFuncs]) is called. This means that at this point @source is still a valid [struct@GLib.Source] and it is allow for the reference count to increase again until @dispose returns. The dispose function can be used to clear any ‘weak’ references to the @source in other data structures in a thread-safe way where it is possible for another thread to increase the reference count of @source again while it is being freed. The finalize function can not be used for this purpose as at that point @source is already partially freed and not valid any more. This should only ever be called from [struct@GLib.Source] implementations.
- @p dispose is dispose function to set on the source.
- @r None.
set_funcs (object funcs)

Sets the source functions of an unattached source. These can be used to override the default implementations for the type of @source.
- @p funcs is the new source functions.
- @r None.
set_name (string name)

Sets a name for the source, used in debugging and profiling. The name defaults to NULL. The source name should describe in a human-readable way what the source does. For example, ‘X11 event queue’ or ‘GTK repaint idle handler’. It is permitted to call this function multiple times, but is not recommended due to the potential performance impact. For example, one could change the name in the check function of a [struct@GLib.SourceFuncs] to include details like the event type in the source name. Use caution if changing the name while another thread may be accessing it with [method@GLib.Source.get_name]; that function does not copy the value, and changing the value will free it while the other thread may be attempting to use it. Also see [method@GLib.Source.set_static_name].
- @p name is debug name for the source.
- @r None.
set_priority (int priority)

Sets the priority of a source. While the main loop is being run, a source will be dispatched if it is ready to be dispatched and no sources at a higher (numerically smaller) priority are ready to be dispatched. A child source always has the same priority as its parent. It is not permitted to change the priority of a source once it has been added as a child of another source.
- @p priority is the new priority.
- @r None.
set_ready_time (int ready_time)

Sets a source to be dispatched when the given monotonic time is reached (or passed). If the monotonic time is in the past (as it always will be if @ready_time is 0) then the source will be dispatched immediately. If
- @ready_time is -1 then the source is never woken up on the basis of the passage of time. Dispatching the source does not reset the ready time. You should do so yourself, from the source dispatch function. Note that if you have a pair of sources where the ready time of one suggests that it will be delivered first but the priority for the other suggests that it would be delivered first, and the ready time for both sources is reached during the same main context iteration, then the order of dispatch is undefined. It is a no-op to call this function on a [struct@GLib.Source] which has already been destroyed with [method@GLib.Source.destroy]. This API is only intended to be used by implementations of [struct@GLib.Source]. Do not call this API on a [struct@GLib.Source] that you did not create.
- @p ready_time is the monotonic time at which the source will be ready; 0 for ‘immediately’, -1 for ‘never’.
- @r None.
set_static_name (string name)

A variant of [method@GLib.Source.set_name] that does not duplicate the
- @name, and can only be used with string literals.
- @p name is debug name for the source.
- @r None.
unref ()

Decreases the reference count of a source by one. If the resulting reference count is zero the source and associated memory will be destroyed.
- @r None.