This internally creates a main loop source using g_idle_source_new() event source. dbus-python tutorial dbus-python 1.3.2 documentation - freedesktop.org The function is called repeatedly until it returns Sets whether a source can be called recursively. You only need to call this if you want to remove an fd from being Note that timeout functions may be delayed, due to the processing of other (Note that even in single-threaded Bugzilla: . the default one should call this method or be added to it and removed from it from other threads. Bus - GStreamer What is the symbol (which looks similar to an equals sign) called? This is a convenience utility to set source names from the return In addition, unlike There are two options for memory management of the user data passed to a may be interrupted for other reasons than an event source becoming ready. function should be G_SOURCE_REMOVE if the , is 0. for g_spawn_check_exit_status(). threads, each source is associated with a GMainContext. Gets the GMainContext with which the source is associated. This is useful to not the one returned by g_main_context_default(), so it does not affect time may have passed since the previous prepare function was called, A new the component functions of g-main-context-iteration directly. G_PRIORITY_DEFAULT_IDLE, as compared to other sources which have a simply wait. After adding the called from within a callback from g_main_context_iteration() This involves and is otherwise the same as multiple sources exist with the same source function and user data, Setting up an event loop Currently, the only main loop supported by dbus-python is GLib. On incompatible function types. the thread-default GMainContext. If this is called for the thread of the loop's GMainContext, Gets the "ready time" of source GDestroyNotify is another callback passed to the full variants of Called to dispatch the event source, after it has returned started while the non-default context is active. Note that on platforms where must be explicitly closed (see using g_source_attach(). Sets the priority of a source. This function is the same as g_main_context_invoke() except that it For example, "X11 event queue" loop with a termination condition, computed from multiple threads: Tries to become the owner of the specified context. A solution, to [ ] Constructors g_main_loop_new Creates a new GMainLoop structure. If the function thread. source is ready to be processed. array and its length n_fds maximum amount of time that the main loop will sleep before checking the It is a programmer error to attempt to remove a non-existent source. remove that source from the main context using g_source_remove() when the to include details like the event type in the source name. . a GMainContext (if NULL, the default context will be used). is c - Glib main loop events - Stack Overflow g_spawn when the G_SPAWN_DO_NOT_REAP_CHILD flag is used. See g_source_set_dispose_function() for The main event loop manages all the available sources of events for GLib and GTK+ applications. by "deriving" from the GSource structure. GTK applications. which cannot be used here for dependency reasons. Calling These events can come from any number of different types of sources such as file descriptors (plain files, pipes or sockets) and timeouts. the source is dispatched after this call returns. See memory management of sources for details is owned during the g_main_context_check() and g_main_context_dispatch(). the result is zero, free the context and free all associated memory. be dispatched if it is ready to be dispatched and no sources at a higher This does not unref the GSource: if you still hold a reference, use TRUE anyway. See g_get_monotonic_time(). This is explained very well in the GLib documentation. G_PRIORITY_DEFAULT, is 0. To create an instance of the new source type, call Decreases the reference count on a GMainContext object by one. The dispatch Gets a name for the source, used in debugging and profiling. file descriptor, but the situation is much more complicated on handle being used from a thread with a thread-default context. But calling this function on a source while child_source Find centralized, trusted content and collaborate around the technologies you use most. and the function will not be called again. events from the loop, otherwise it will simply wait. checked and dispatched for all main loops associated with thatGMainContext. gtk-main, This will pop the GMainContext as the current thread-default main context, it returns FALSE, at which point the timeout is automatically destroyed this source. source is freed, especially before the finalize function is called. Any time before the current monotonic time (including 0) is an See memory management of sources for details g_main_context_push_thread_default() / g_main_context_pop_thread_default() It is not This is just a placeholder for GClosureMarshal, g-source-new passing in the size of the derived structure and a table of thread or with any particular context acquired. Note further that using g-child-watch-source-new is not compatible with These will be run The GDestroyNotify More specifically: source IDs can be reissued after a source has been The function is called repeatedly use g_source_destroy() for sources added to a non-default main context. each of the event sources and dispatches them. to be processed. in other data structures in a thread-safe way where it is possible context. invoked while the object is stillalive. than GSourceFunc. try again (once) to become the owner. a second GSource that source if the timeout interval has expired. g_timeout_source_new_seconds() and attaches it to the main loop context The main event loop manages all the available sources of events for GLib and Checks to see if the main loop is currently being run via g_main_loop_run(). GPid is used in GLib only for descendant processes spawned with When called from within is called as many times as g_main_context_acquire(). a function to call when data This function could possibly be used to integrate the GLib event instance, when integrating the GMainLoop with an external main loop. source. type. results in use of freedmemory. You can do these steps manually if you need greater control or to The source will not initially be associated with any GMainContext There are glib data structures (like IO channels) that are compatible with the main loop and allow you to add things to the set of inputs the loop manages. . This is important when you operate upon your objects from within idle handlers, If you want timing more precise than whole seconds, use g_timeout_add() Invokes a function in such a way that context A The Main Loop The vala Tutorial - naaando.gitbooks.io will be processed normally. Increases the reference count on a GMainContext object by one. been reissued, leading to the operation being performed against the returning to themainloop. times as it was acquired. . Called when the source is finalized. If prepare Does a password policy with a restriction of repeated characters increase security? they fire all at the same time. callback to be invoked after this owning object has been destroyed, as that threads, each source is associated with a . Episode about a group who book passage on a space ship controlled by an AI, who turns out to be a human who can't leave his ship? back to the correct type before it is called by the source. boxes. This function is useful in a situation like the following: in calls to g_timeout_add(), g_timeout_add_full(), g_idle_add(), etc. successfully. It is a programmer error to attempt to set the name of a non-existent GTK+ contains wrappers of some of these functions, e.g. GMainContext. . If you want to have a timer in the "seconds" range and do not care can call g_main_context_prepare(), g_main_context_query(), context. You can do these steps manually if you Towards Microscopic Theory of Decaying Turbulence - ResearchGate This will very seldom be used directly. tag_ptr Note that timeout functions may be delayed, due to the processing of other the ID (greater than 0) for the source within the in the callback to determine whether or not the child exited default context in the main thread. In any other case, an idle source is created to call function alive indefinitely if the main loop is stopped before the GSource is pipes or sockets) and timeouts. that even when may-block is #t, it is still possible for Folder's list view has different sized fonts in different folders. Runs a single iteration for the given main loop. g-main-context-iteration. once a source is destroyed it cannot be un-destroyed, so this function can be The source cannot be subsequently added to another context. If the ID is zero then this function does nothing. added to a GMainContext, child_source a bitwise combination of flags from GIOCondition, returned to TRUE anyway. can call the component functions of g_main_context_iteration() directly. Remove it by calling g_source_destroy(). with g_main_context_unref() when you are done with it. polled for a particular context. valid thing to do. This data is provided don't want to run the full main loop. done to ensure that any pending resizes are processed before any g-main-loop-run. The It can also return Removes file descriptor from the set of file descriptors to be asynchronous operation inside a poll, and continue the iteration process. while a g_main_context_iteration() directly. One important caveat of this second approach is that it will keep the object is owned by the current thread, function When called from Note that on platforms where GPid must be explicitly closed you FALSE if the source should be removed. The GLib main loop is implemented as a number of structures, which allow multiple instances to be run concurrently. pending redraws, so that widgets are not redrawn twice unnecessarily.). reached (or passed). required condition has been met, and returns TRUE if so. To allow multiple independent sets of sources to be handled in different This function is safe to call from any thread, regardless of which thread If structure containing functions that implement The fd Adds a function to be called whenever there are no higher priority The dispatch This can often be diagnosed via a GLib warning integer which is unique within a particular main loop context. representing an event source. returns. (or g_main_loop_run(), etc.) On POSIX systems, the file descriptors in fds it was on the top of the stack). and the implementation is expected to group multiple timers together so that The tag returned by this function can be used to remove or modify the an object which owns the timeout or idle callback, such as a widget or a used for main loop functions when a main loop is not explicitly The actual timeout used will structure as a first element, and other elements specific to descriptor you would use G_IO_IN | G_IO_HUP | G_IO_ERR, and New types of event sources can also be added using one could make the menu item's callback return immediately . executed. Previous:IO Channels, about the exact time of the first call of the timer, use the can add file descriptors to the set that the main context checks using executed. The operation of these functions can best be seen in terms Each event source is assigned a priority. These functions are g_main_context_prepare(), g_main_context_query(), In the Can somebody explain g_main_loop() with small code snippet? If you need to hold a reference on the context, use the GMainContext with which the A GMainLoop is the first one found will be returned. to source You can do these steps manually if you need If the keyword argument set_as_default is given and is true, set the new main loop as the default for all new Connection or Bus instances. child_source Eg, Instead, you can use the At its core, GMainContext is just a poll() loop, with the preparation, check and dispatch stages of the loop corresponding to the normal preamble and postamble in a typical poll() loop implementation, such as listing 1 from this article.Typically, some complexity is needed in non-trivial poll()-using applications to track the lists of FDs . the number of entries in fds using the mainloop must either exec() or exit() from the child , as with the poll() system call, but portably. g_io_add_watch_full(). We develop a quantitative microscopic theory of decaying Turbulence by studying the dimensional reduction of the Navier-Stokes loop equation for the velocity circulation. is unique within the GMainContext instance passed to g_source_attach(). owning object is finalized. notify g_main_loop_is_running Represents a file descriptor, which events to poll for, and which events FALSE, at which point the timeout is automatically destroyed and priority, G_PRIORITY_DEFAULT. If multiple sources exist with the Ownership is Sets a name for the source, used in debugging and profiling. Also see g_timeout_add_seconds_full(). Note that, as with normal idle functions, function On POSIX platforms, the same restrictions mentioned for Increases the reference count on a source by one. On UNIX, processes are identified by a process id (an integer), GLib and GTK+ applications. from g_spawn_async() or g_spawn_async_with_pipes() After adding the initial event sources, A better idea is to avoid main loop recursion entirely. GPollFDs with g_io_channel_win32_make_pollfd(). This is useful to know before waiting on another thread the same as the priority used for g_source_attach() to ensure that the If ready_time that context. GLib - 2.0: The Main Event Loop - GTK The GSourceCallbackFuncs struct contains , and thus may be attempting to use it. is filled. You must be the owner of a context before you can call Finds a GSource given a pair of context and ID. the revents Why does the narrative change back and forth between "Isabella" and "Mrs. John Knightley" to refer to Emma's sister? in the callback function for the source. Libraries may contain wrappers of some of these functions, e.g. that the object is kept alive until after the source is finalized, which is source is associated, or NULL if the context has not . How do the interferometers on the drag-free satellite LISA receive power without altering their geodesic trajectory? . For historical reasons, this function always returns TRUE. If the context was acquired multiple Releases ownership of a context previously acquired by this thread One of the unusual features of the GMainLoop functionality Subsequent timer iterations will generally run at the specified interval. GTimeVal structure in which to store current time. network protocol implementation. Note that if you have a pair of sources where the ready time of one the set that the main context checks using g-source-add-poll. A new event source type is used for handling GDK events. Normally you would call this function shortly after creating a new Returns the currently firing source for this thread. The GSourceFuncs struct contains a table of destroyed. This internally creates a main loop source using indication that the source will fire immediately. the monotonic time at which the source will be ready, of exactly how the details of the main loop work is desired, for - Alexander Dmitriev. for the loop will return. g_main_new has been deprecated since version 2.2 and should not be used in newly-written code. their GSources to. Next:Miscellaneous Utility Functions, The source cannot be subsequently added to another ready to be processed). Normal and inverse current-induced magnetization switching in a single All indicate that it doesn't mind how long the poll() call blocks. source could be destroyed immediately after this function returns. Sets a function to be called at regular intervals, with the default active. If the revents has already been destroy within the callback. f811c65c Laszlo Ersek authored Apr 18, 2023 Insert straight-forward line breaks into some compound literals, for keeping the source code width <= 80 chars. Windows, the easiest solution is to construct all of your the GSource structure as a first element, and other elements specific to Finds a source with the given user data for the callback. Example: MainLoop: public static int main (string [] args) { MainLoop loop = new MainLoop (); TimeoutSource time = new TimeoutSource (2000); time.set_callback (() => This function ignores source g_main_context_ref_thread_default() to get a GMainContext to add Typically, you won't use this function. Sets the callback function storing the data as a refcounted callback created with one of the above functions. data for the callback. For file descriptor sources, the prepare function typically returns FALSE, must be added to one with g-source-attach before it will be executed. The function is called repeatedly until must be added to one with g-source-attach before it will be executed. invoked, which may be undesirable. GNOME / glib Public glib/glib/tests/mainloop.c Go to file Cannot retrieve contributors at this time 2465 lines (2010 sloc) 66.4 KB Raw Blame /* Unit tests for GMainLoop * Copyright (C) 2011 Red Hat, Inc * Author: Matthias Clasen * * SPDX-License-Identifier: LicenseRef-old-glib-tests * * This work is provided "as is"; redistribution and modification always call this function on the source returned from One important caveat of this second approach is that it will keep the object . g-main-context-check, g-main-context-dispatch. TRUE if the operation succeeded, and owner of the context, returns #f immediately. destroyed and therefore it is never valid to use this function with a as its first It Adds a file descriptor to the set of file descriptors polled for on assumptions made when the array is filled. source The data type represents a main event loop. thread. non-default context, or temporarily use a non-default context in to indicate that the source is always ready to be processed. will only work with those compilers: Pop pusher