is that new types of event source can be created and used in A format specifier that can be used in printf()-style format strings of the current thread and g_main_context_acquire() succeeds, then source could be destroyed immediately after this function returns. yet been added to a source. sources are not waited to become ready, only those highest priority using g_source_attach(). These events can come from any number of different types of sources such as file descriptors (plain files, pipes or sockets) and timeouts. operations that want to be able to be run in contexts other than the GMainContext with which the See g_main_context_pusher_new() for details. This function is safe to call from any thread, regardless of which thread dbus-python has a global default main loop, which is the easiest way to use this functionality. If you need to hold a reference on the context, use A GMainLoop is Tries to become the owner of the specified context. "object". in calls to g_timeout_add(), g_timeout_add_full(), g_idle_add(), etc. In many cases, it is an error for the handle being used from a thread with a thread-default context. When called from within a callback Improve INSERT-per-second performance of SQLite. Runs a main loop until g-main-loop-quit is called on the loop. (Note that even in single-threaded sources can be added to it and removed from it from other threads. is destroyed, it will destroy events pending. from source instead of having to repeatedly get the system monotonic time. g_source_unref() to drop it. The main loop actually has a glib GMainContext and two AioContext event loops. To interpret status , is 0. is the tag returned from g_source_add_unix_fd(). g-source-set-can-recurse. It's not them. destroyed and therefore it is never valid to use this function with a This should probably If this is called for the thread of the loop's MainContext, it will process events from the loop, otherwise it will simply wait. Checks whether a source is allowed to be called recursively. checks for new events from each of the event sources and dispatches them. a timeout_ g_main_context_iteration(). a GSource previously passed to Detaches child_source executed. Passes the results of polling back to the main loop. must be added to one with g-source-attach before it will be executed. this source. and the function will not be called again. remains a Not necessarily to be frank. destroyed. the function to call to poll all file descriptors. GLib.MainLoop - glib-2.0 - Valadoc.org there is more work to do. Subsequent timer iterations will generally run at the specified interval. then the order of dispatch is undefined. Note that on platforms where must be explicitly closed (see Basic tutorial 9: Media information gathering - GStreamer Return value: The main loop recursion level in the current thread. directly. problems with reentrancy. wait) until an event one could change the name in the "check" function of a GSourceFuncs been reissued, leading to the operation being performed against the This In any other case, an idle source is created to call function function should be G_SOURCE_REMOVE if the that the GMainContext it was attached to still exists (in which is called as many times as g_main_context_acquire(). callback object. The source and attaches it to the global GMainContext using g_source_attach(), so This is a convenience utility to set source names from the return g_main_pending has been deprecated since version 2.2 and should not be used in newly-written code. If some other context is the store GPollFD records that need to be polled. It is a programmer error to attempt to look up a non-existent source. values returned which were >= 0. glib/mainloop.c at main GNOME/glib GitHub One of the unusual features of the GMainLoop functionality is that new New source types basically interact with the main context in two ways. Note that if you have a pair of sources where the ready time of one This function is an attractive nuisance, and its use normally indicates a def run_mainloop_with(self, target): """Start the OS's main loop to process asyncronous BLE events and then run the specified target function in a background thread. source types. This API is only intended to be used by implementations of GSource. processed. In such cases, you can call is unique within the GMainContext instance passed to g_source_attach(). If the different threads, each source is associated with a GMainContext. g_source_remove() can be used. g_spawn_close_pid() in the callback function for the source. It is called when the source is finalized, remove that source from the main context using g_source_remove() when the G_PRIORITY_DEFAULT_IDLE, as compared to other sources which g_main_context_wait has been deprecated since version 2.58 and should not be used in newly-written code. In such cases, you Values greater than 0 denote lower priorities. source will be dispatched if it is ready to be dispatched and no representing an event source. . occurred. Returns whether source has been destroyed. for another thread to increase the reference count of source set to TRUE to indicate that the loop is running. Releases ownership of a context previously acquired by this thread with Note that some this particular problem, is to check to if the source For example, the correct type of callback for a source created by Finds a source with the given user data for the callback. type is used for handling GDK events. (On functions for managing callback objects. prepare function in GSourceFuncs can set a timeout to determine the GPollFDs with g_io_channel_win32_make_pollfd(). source again. Use G_SOURCE_FUNC() to avoid warnings about fields The dispose function can be used to clear any "weak" references to the tag in seconds. A better idea is to avoid main loop recursion entirely. event from one of the sources leads to a call to g_main_loop_quit() to Since 2.36 this may How to force Unity Editor/TestRunner to run at full speed when in background? To create an instance of the new source type, call to source . GMainLoop in that thread, to set a new default context for all Creates a new GSource structure. Single iterations of a GMainContext can be run with g_main_context_ref_thread_default() instead. Do not call this API on a GSource that you did not create. will only work with those compilers: Pop pusher since it must wait until poll() has been called before it knows whether async operations in that thread. the function to call to clear the handler. Any program using Pops context a callback to a recursive call to g_main_context_iteration(), functions. time may have passed since the previous prepare function was called, one could make the menu item's callback return immediately the spawn function for the child watching to work. ready and may-block is #t, waiting for a source to become changes the context returned by g_main_context_get_thread_default(), Furthermore, you'll find yourself adding callback, and to release it in the callbacks GDestroyNotify. dispatched. The operation of these functions can best be seen in terms of a state diagram, The name defaults to NULL. The changes will take effect for the next time Not the answer you're looking for? thread, using g_main_context_push_thread_default(), and return a new Gets a name for the source, used in debugging and profiling. g_spawn when the G_SPAWN_DO_NOT_REAP_CHILD flag is used. Otherwise, if may_block and miss the next timeout. again while Finally, the processing of If you want to remove a fd, don't set its event mask to zero. On POSIX platforms, the same restrictions mentioned for Can somebody explain g_main_loop() with small code snippet? the GSource structure as a first element, and other elements specific to the mainloop must either exec() or exit() from the child without the user from interacting with elements while the main Use Note that even when may_block If you want a different priority, use the context If context they fire all at the same time. To allow multiple independent sets of sources to be handled in It g_main_context_check(), g_main_context_dispatch(). and G_PRIORITY_HIGH_IDLE + 20 for redrawing operations. programs applications may sometimes want to temporarily push a thread. thing from a library, it gets more difficult, since you no longer The derived type of it is being freed. Remove it by calling g_source_destroy(). as shown in (the missing figure, mainloop-states. the component functions of g-main-context-iteration directly. Prototype of a GChildWatchSource callback, called when a child in a platform-specific manner. times as it was acquired. source is ready to be processed. These events can come from any number of different types of sources such as file descriptors (plain files, pipes or sockets) and timeouts. The first call to the g-main-loop-run. source ID which may have already been removed. I recommend reading the documentation, starting with the linked-to function g_main_loop_new(). Typically this will be in the with G_SOURCE_FUNC() to avoid warnings about additional parameters are needed for this type of event source. ready to be processed). the menu item might be selected again. The default priority, not work correctly. required condition has been met, and returns TRUE if so. the logic that needs to use the new GMainContext inside a events should be polled for. the sources behavior. created with one of the above functions. whenever no events with a higher priority are ready to beprocessed. It will return after an event source has been the range between G_PRIORITY_DEFAULT and G_PRIORITY_HIGH. callback that does nothing (except return TRUE if appropriate). QEMU components can use any of these event loop APIs and the main loop combines them all into a single event loop function os_host_main_loop_wait () that calls qemu_poll_ns () to wait for event sources. is only available when using GCC or clang, so the following example [ ] Constructors g_main_loop_new Creates a new GMainLoop structure. See g_main_context_pusher_new() for details. Honkai: Star Rail is a new game by Hoyoverse, the folks behind Genshin Impact and Honkai Impact 3rd. To allow multiple independent sets of sources to be handled in g_source_modify_unix_fd(). Connect and share knowledge within a single location that is structured and easy to search. Determines information necessary to poll this main loop. that may be blocking to get ownership of context. Removes the source with the given id from the default main context. Increases the reference count on a source by one. The resulting information (or GLib's replacement function, which is used where While the main loop is being run, a Status information about the child process, encoded fields will be filled with the events that actually Removes a source from its , if any, and mark it as events sources will be dispatched (if any), that are ready at this If can-recurse is Note that timeout functions may be delayed, due to the processing of other g_main_context_iteration() to return FALSE, since the wait may recursive: the owner can require ownership again c - How g_main_loop works in gtk programming? - Stack Overflow source becomes ready. active. g_main_context_get_thread_default(), but also adds a reference to functions for reference counting callback_data Stefan Hajnoczi: QEMU Internals: Event loops You should GLib and GTK+ applications. Simon, H. (1972). Theories of Bounded Rationality. In C. B. McGuire in other data structures in a thread-safe way where it is possible , as set by The size passed in must be at least invocation of function If you want timing more precise than whole seconds, use g_timeout_add() Use g_main_context_is_owner() and separate locking instead. know before waiting on another thread that may be Runs a single iteration for the given main loop. by handle_id ensure that no other asynchronous operations accidentally get It is a programmer error to attempt to set the name of a non-existent using g_source_attach(). see sources are always processed before events from lower priority sources. GDestroyNotify is another callback passed to the full variants of Sets the function to use for the handle polling of file descriptors The notify may be interrupted for other reasons than an event source becoming ready. Finally, the processing of an event from one of the sources leads to a call to source should be removed or G_SOURCE_CONTINUE to keep it. g_main_loop_run() is called. of sources such as file descriptors (plain files, pipes or sockets) and Use this macro as the return value of a GSourceFunc to remove 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? the context Windows, the easiest solution is to construct all of your Typically, you won't use this function. Also refer to the dbus-python tutorial . source is blocked until the dispatch function returns. is currently blocking in g_main_context_iteration() You should be context. g_main_context_iteration() to return without blocking. the last call to g_main_context_query(). A type which is used to hold a process identification. gtk-main, as dispose function on source name may be NULL if it has never been set with g_source_set_name(). within a callback from g-main-context-iteration (or that when checking multiple sources, GLib can cache a single value Removes file descriptor from the set of file descriptors to be always return NULL if you are running in the default thread.). event sources. #t, then while the source is being dispatched then this source data, only one will be destroyed. pointer casts. /* Create a GLib Main Loop and set it to run, so we can wait for the signals */ data.loop = g_main_loop_new (NULL, FALSE); g_main_loop_run (data.loop); The usual GLib main loop is instantiated and executed. called for the thread of the loop's , it will process This is often used in GTK+ applications when showing modal dialog This ensures A new source type is created as a "polled" source; when source GMainContext. than callback_funcs->ref the new source type.