The GMainContext struct is an opaque data type representing a set of sources to be handled in a main loop.


this(GMainContext* gMainContext, bool ownedRef)

Sets our main struct and passes it to the parent class.


Creates a new glib.MainContext structure.


A destructor is present on this object, but not explicitly documented in the source.



bool acquire()

Tries to become the owner of the specified context. If some other thread is the owner of the context, returns FALSE immediately. Ownership is properly recursive: the owner can require ownership again and will release ownership when MainContext.release is called as many times as MainContext.acquire.

void addPoll(GPollFD* fd, int priority)

Adds a file descriptor to the set of file descriptors polled for this context. This will very seldom be used directly. Instead a typical event source will use Source.addUnixFd instead.

bool check(int maxPriority, GPollFD[] fds)

Passes the results of polling back to the main loop.

void dispatch()

Dispatches all pending sources.

Source findSourceByFuncsUserData(GSourceFuncs* funcs, void* userData)

Finds a source with the given source functions and user data. If multiple sources exist with the same source function and user data, the first one found will be returned.

Source findSourceById(uint sourceId)

Finds a glib.Source given a pair of context and ID.

Source findSourceByUserData(void* userData)

Finds a source with the given user data for the callback. If multiple sources exist with the same user data, the first one found will be returned.

GMainContext* getMainContextStruct(bool transferOwnership)

Get the main Gtk struct

GPollFunc getPollFunc()

Gets the poll function set by MainContext.setPollFunc.

void* getStruct()

the main Gtk struct as a void*

void invoke(GSourceFunc function_, void* data)

Invokes a function in such a way that context is owned during the invocation of function.

void invokeFull(int priority, GSourceFunc function_, void* data, GDestroyNotify notify)

Invokes a function in such a way that context is owned during the invocation of function.

bool isOwner()

Determines whether this thread holds the (recursive) ownership of this glib.MainContext This is useful to know before waiting on another thread that may be blocking to get ownership of context.

bool iteration(bool mayBlock)

Runs a single iteration for the given main loop. This involves checking to see if any event sources are ready to be processed, then if no events sources are ready and may_block is TRUE, waiting for a source to become ready, then dispatching the highest priority events sources that are ready. Otherwise, if may_block is FALSE sources are not waited to become ready, only those highest priority events sources will be dispatched (if any), that are ready at this given moment without further waiting.

bool pending()

Checks if any sources have pending events for the given context.

void popThreadDefault()

Pops context off the thread-default context stack (verifying that it was on the top of the stack).

bool prepare(int priority)

Prepares to poll sources within a main loop. The resulting information for polling is determined by calling g_main_context_query ().

void pushThreadDefault()

Acquires context and sets it as the thread-default context for the current thread. This will cause certain asynchronous operations (such as most giogio-based I/O) which are started in this thread to run under context and deliver their results to its main loop, rather than running under the global default context in the main thread. Note that calling this function changes the context returned by MainContext.getThreadDefault, not the one returned by MainContext.default, so it does not affect the context used by functions like Idle.add.

int query(int maxPriority, int timeout, GPollFD[] fds)

Determines information necessary to poll this main loop.

MainContext ref_()

Increases the reference count on a glib.MainContext object by one.

void release()

Releases ownership of a context previously acquired by this thread with MainContext.acquire. If the context was acquired multiple times, the ownership will be released only when MainContext.release is called as many times as it was acquired.

void removePoll(GPollFD* fd)

Removes file descriptor from the set of file descriptors to be polled for a particular context.

void setPollFunc(GPollFunc func)

Sets the function to use to handle polling of file descriptors. It will be used instead of the poll() system call (or GLib's replacement function, which is used where poll() isn't available).

void unref()

Decreases the reference count on a glib.MainContext object by one. If the result is zero, free the context and free all associated memory.

bool wait(Cond cond, Mutex mutex)

Tries to become the owner of the specified context, as with MainContext.acquire. But if another thread is the owner, atomically drop mutex and wait on cond until that owner releases ownership or until cond is signaled, then try again (once) to become the owner.

void wakeup()

If context is currently blocking in MainContext.iteration waiting for a source to become ready, cause it to stop blocking and return. Otherwise, cause the next invocation of MainContext.iteration to return without blocking.

Static functions

MainContext default_()

Returns the global default main context. This is the main context used for main loop functions when a main loop is not explicitly specified, and corresponds to the "main" main loop. See also MainContext.getThreadDefault.

MainContext getThreadDefault()

Gets the thread-default glib.MainContext for this thread. Asynchronous operations that want to be able to be run in contexts other than the default one should call this method or MainContext.refThreadDefault to get a glib.MainContext to add their glib.Sources to. (Note that even in single-threaded programs applications may sometimes want to temporarily push a non-default context, so it is not safe to assume that this will always return NULL if you are running in the default thread.)

MainContext refThreadDefault()

Gets the thread-default glib.MainContext for this thread, as with MainContext.getThreadDefault, but also adds a reference to it with MainContext.ref. In addition, unlike MainContext.getThreadDefault, if the thread-default context is the global default context, this will return that glib.MainContext (with a ref added to it) rather than returning NULL.


GMainContext* gMainContext;

the main Gtk struct