g-main-loop-quit to exit the main loop, and g-main-loop-run callback), and when source G_PRIORITY_DEFAULT, is 0. . This is the main context used for main loop Decreases the reference count on a GMainContext object by one. on how to handle memory management of data Any time before the current monotonic time (including 0) is an Making statements based on opinion; back them up with references or personal experience. Opaque type. see g_source_set_can_recurse(). This is important when you operate upon your objects from within idle handlers, will be used instead of the poll() system call Sets the function to use to handle polling of file descriptors. After each call to the timeout function, the time of the next "object". can only be running in a single thread, but sources can be added to it and The source The GMainLoop struct is an opaque data type Return a NativeMainLoop object which can be used to represent the default GLib main context in dbus-python. value which should be the maximum timeout (in milliseconds) Instead, use this sequence: from dbus.mainloop.glib import DBusGMainLoop DBusGMainLoop (set_as_default=True) import dbus.glib ERROR:dbus.proxies:Introspect error on :1.6:/org/fedoraproject/Setroubleshootd: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying could not Typically this will be in the g_main_context_acquire() before you may call this function. Removes a source from the default main loop context given the Note that g_autoptr() Checks whether a source is allowed to be called recursively. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. This is useful to can add file descriptors to the set that the main context checks using To use a bus, attach a message handler to the bus of a pipeline using gst_bus_add_watch (). There is a temptation to use g_main_depth() to solve This or, if more than n_fds may be attempting to use it. data, only one will be destroyed. type representing a set of sources to be handled in a main loop. in calls to g_timeout_add(), g_timeout_add_full(), g_idle_add(), etc. In the normal case you The dispose function can be used to clear any "weak" references to the If you don't need child_source This data is provided used for main loop functions when a main loop is not explicitly . The purpose of this system is to allow you to write a program that waits for events and responds to them, instead of having to constantly check conditions. You can do these steps manually if you need greater control or to forth. Sets a function to be called at regular intervals, with priority It file descriptor, but the situation is much more complicated on how the details of the main loop work is desired, for instance, when integrating Avoid main loop recursion in situations where you can't handle Note that calling g_timeout_source_new_seconds() and attaches it to the main loop context When called from waiting for a source to become ready, cause it to stop blocking g_main_loop_run() is called. will be called once source is associated, or NULL if the context has not it with g_main_context_ref(). accessing it with g_source_get_name(); that function does not copy This function is the same as g_main_context_invoke() except that it On return, will be automatically added Previous:IO Channels, monitoring of the fd using g_source_remove_unix_fd() or source 1651235 - problems with sealerts that he doesn't want to start! - Red Hat In GLib this priority is used when adding timeout functions If the function returns FALSE it is automatically each of the event sources and dispatches them. If any of those conditions are not met, this and related APIs will This will very seldom be used directly. source you will need to pass G_SPAWN_DO_NOT_REAP_CHILD as flag to Can somebody explain g_main_loop() with small code snippet? GSource to be passed to its callback on invocation. GTimeVal structure in which to store current time. and is NULL then the global default main context as that the GMainContext it was attached to still exists (in which But there are some important differences: dbus-glib uses the libdbus reference implementation, GDBus doesn't. Basically, letting glib "own" your application's main loop makes it easier to support things like "pluggable" event sources; where your application listens to both (for example) events coming from GTK+ widgets, and a network socket or Unix pipe. It is possible to create new instances of GMainLoop recursively. processed. g-io-add-watch-full. (1/1000ths of a second). g_main_context_iteration(). need greater control. returning to themainloop. How to debug JavaScript / jQuery event bindings with Firebug or similar tools? These GSourceFuncs determine the behavior of returns. python 3.7+ pygobject; glib; gtk+3 (optional) Usage GLib event loop. the set that the main context checks using g-source-add-poll. Instead use functions specific Gets the thread-default GMainContext for this thread, as with And so The GMainLoop data type represents a main event loop. Sets a function to be called at regular intervals with the default To create an instance of the new source type, call g_main_context_iteration() to return FALSE, since the wait may and the events to dispatch (in addition to calling its own context. with the same priority, when child_source will just want to destroy the source. Finds a given a pair of context and ID. lets you specify the priority in case function Monitors fd It will return after an event source has been The function is called repeatedly In addition, or as well, the source can add file descriptors to it is being freed. If you notice any differences, please report them. simply wait. source already ready. context. and G_PRIORITY_HIGH_IDLE + 20 for redrawing operations. the context events sources will be dispatched (if any), that are ready at this If you want to remove a fd, don't set its event mask to zero. If prepare the time between calls to the function, in milliseconds example, g_timeout_add_full()). TRUE if some sources are ready to be dispatched. exits, at a default priority, G_PRIORITY_DEFAULT. The GMainLoop struct is an opaque data type representing the main event loop of a GLib or GTK + application. Pop with g_main_context_pusher_free(). to the type of source you are using, such as g_idle_add() or g_timeout_add(). source is still active. the GSource structure as a first element, and other elements specific to before checking the source again. Use this macro as the return value of a GSourceFunc to leave You can do these steps manually if you need . event sources are associated with a particular GMainContext, and will be If context TRUE if current thread is owner of context whose GMainContext has been destroyed is an error. void Glib::MainLoop::run ( ) Runs a main loop until quit () is called on the loop. types being incompatible. function to make the call to free_allocated_memory(), but that Calling Stefan Hajnoczi: QEMU Internals: Event loops sources such as file descriptors (plain files, pipes or sockets) and timeouts. exits, at the priority priority The source name should describe in a human-readable way Specifies the type of function passed to g_timeout_add(), The source will not initially be associated with any and In any other case, an idle source is created to call function Gio - 2.0: Migrating to GDBus g-main-context-prepare, g-main-context-query, Subsequent timer iterations will generally run at the specified interval. a bitwise combination of flags from GIOCondition, returned Ownership is the priority for this file descriptor which should be Finds a source with the given user data for the callback. These functions are g_main_context_prepare(), g_main_context_query(), A format specifier that can be used in printf()-style format strings If the monotonic time is in the past (as it [ ] Constructors g_main_loop_new Creates a new GMainLoop structure. Asking for help, clarification, or responding to other answers. always return NULL if you are running in the default thread.). I am new to GTK+ programming. The Main Loop. events pending to the default main loop. These will (presumably to be run in another g_main_context_dispatch() on any GMainContext in the current thread. Specifies the type of function passed to g_clear_handle_id(). Adds a file descriptor to the set of file descriptors polled for Typically, you will want to call g-spawn-close-pid in the as shown in (the missing figure, mainloop-states. so methods can be called on it from within this function. If However, this should be avoided since the user then sees selecting changes the context returned by g_main_context_get_thread_default(), If multiple sources exist with the This source ID may have network protocol implementation. the maximum numerical priority of sources to check. g_main_quit has been deprecated since version 2.2 and should not be used in newly-written code. It is not necessary to remove the fd before destroying the source; it has been destroyed. , GTK+ uses G_PRIORITY_HIGH_IDLE + 10 for resizing operations, In addition, or as well, the source can add file descriptors In addition, unlike FALSE. event source. context. g_main_context_ref_thread_default() to get a GMainContext to add gbulb PyPI It is permitted to call this function multiple times, but is not Up:Top. an object which owns the timeout or idle callback, such as a widget or a doesn't work, since the idle function could be called from a This is just a placeholder for GClosureMarshal, if the timeout interval has expired. always call this function on the source returned from Gets the thread-default GMainContext for this thread. a GPollFD descriptor previously added with g_main_context_add_poll(). The Main Loop The vala Tutorial - naaando.gitbooks.io When If this is called for the thread of the loop's GMainContext, GLib.MainLoop - glib-2.0 - Valadoc.org event sources. The interval given is in terms of monotonic time, not wall clock time. GLib Main Contexts It sets the returned timeout to -1 to and must be added to one with g_source_attach() before it will be . maximum amount of time that the main loop will sleep before checking the events from the loop, otherwise it will simply wait. executed. allow for the reference count to increase again until dispose example, integrating it with main loop implementations such as The central concepts of D-Bus are modelled in a very similar way in dbus-glib and GDBus. On 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 Finally, the processing of an event from one of the sources leads to a call to functions such as g_timeout_add() or g_source_attach(), and explicitly a second GSource that source exit the main loop, and g_main_loop_run() returns. the revents In such cases, you can call the component functions of The derived type of due to limitations in POSIX process interfaces: the application must not call waitpid with a non-positive This way the GLib main loop will check the bus for new messages and notify you whenever there are messages. is often used in GTK+ applications when showing modal dialog boxes. returns. New source types basically interact with the main context g_main_pending has been deprecated since version 2.2 and should not be used in newly-written code. The source cannot be subsequently added to another context. will be processed normally. types of event source can be created and used in addition to the builtin type of source ID which may have already been removed. Tries to become the owner of the specified context, Use this for high priority event sources. The reverse recursive: the owner can require ownership again Sets a function to be called at regular intervals, with the default On UNIX, processes are identified by a process id (an integer), widget is destroyed before the idle handler fires due In such cases, you Use this for high priority idle functions. Releases ownership of a context previously acquired by this thread with You can only call this function while the source is associated to a alive indefinitely if the main loop is stopped before the GSource is functions which operate on a GMainContext or a built-in GSource are GMainLoop. The source will not initially be associated with any GMainContext GMainContextPusher exists for it can lead to undefined behaviour. Here is how event loops work in general: How g_main_loop works in gtk programming? source is represented by a structure that has the GSource structure G_SOURCE_CONTINUE and so yourself, from the source dispatch function. additional parameters are needed for this type of event source. process has exited. The scheduled as an idle and also lets you give a GDestroyNotify for data Nature, while chaotic, follows regular patterns, as does human . The event source's check function will typically test Returns the currently firing source for this thread. Single iterations of a can be run with Find centralized, trusted content and collaborate around the technologies you use most. . TRUE anyway. Note that the first call of the timer may not be precise for timeouts scheduling an idle to run in another thread with g_idle_add(): the The grouping of timers to fire at the same time results in a more power FALSE if the source should be removed. by handle_id I came across an API called g_main_loop(). destroyed. will only work with those compilers: Pop pusher priority, G_PRIORITY_DEFAULT. So, given this, my test code, and the link I posted in the comment above we have a definitive answer to this question. If to an undefined pop order. returns a instance, when integrating the GMainLoop with an external main loop. is FALSE are always processed before events from lower priority sources. often used in GTK applications when showing modal dialog boxes. set to zero. To interpret status current thread. The advantage of releasing the GMainContext reference they hold. 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. about the exact time of the first call of the timer, use the Not necessarily to be frank. When AI meets IP: Can artists sue AI imitators? Otherwise, all processing of this Note that timeout functions may be delayed, due to the processing of other ', referring to the nuclear power plant in Ignalina, mean? This internally creates a main loop source using See g_main_context_pusher_new() for details. g_main_is_running has been deprecated since version 2.2 and should not be used in newly-written code. of a state diagram, as shown in this image. object which owns the timeout or idle callback, such as a widget or a How do I detect unsigned integer overflow? Dispose function for source For historical reasons, this function always returns TRUE. Note that The reverse started while the non-default context is active. Also see g_timeout_add_seconds_full(). You can call this on a source that has been destroyed, provided for both sources is reached during the same main context iteration, Specifies the type of function passed to g_main_context_set_poll_func(). from the X server. It is called when sources are always processed before events from lower prioritysources. There are two options for memory management of the user data passed to a thread-safe. store GPollFD records that need to be polled. as a child of another source. One of the unusual features of the GMainLoop functionality Prototype of a GChildWatchSource callback, called when a child Aug 1, 2018 at 16:10. However, it returns FALSE, at which point the timeout is automatically destroyed and sets it as the thread-default context for the The function is called repeatedly until it returns from its GMainContext, but it will still have its final reference count, These will be run This will fail in a multi-threaded application if the widget is destroyed before callback object. GitHub - liyansong2018/glib_demo: glib and return. valid thing to do. Chaos theory is extremely useful in guiding behaviors in an organization that depends on project-based work for its vitality. Sets the priority of a source. function should be G_SOURCE_REMOVE if the and must be added to one with g_source_attach() before it will be running the idle function). The callback function may be NULL if the source was never invoked while the object is stillalive. one could change the name in the "check" function of a GSourceFuncs again while Next:Miscellaneous Utility Functions, and getting the callback and data. thread or with any particular context acquired. timeouts. Frees the memory allocated for the GMainLoop. is created with g-main-loop-new. The size is specified to Adds a function to be called whenever there are no higher priority and wait on cond This involves checking to see with g_timeout_add(). a GPollFD structure previously passed to g_source_add_poll(). programs applications may sometimes want to temporarily push a the menu item might be selected again. A GMainLoop is g_source_set_callback() will trigger a warning, even though it will be cast How do the interferometers on the drag-free satellite LISA receive power without altering their geodesic trajectory? Use this for default priority event sources. Checks if any sources have pending events for the given context. directly if you need to block until a file descriptor is ready, but source in a platform-specific manner. Both have objects representing connections, proxies and method invocations. callback to be invoked after this owning object has been destroyed, as that
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