/* GLIB - Library of useful routines for C programming * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald * * gmain.c: Main loop abstraction, timeouts, and idle functions * Copyright 1998 Owen Taylor * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, see . */ /* * Modified by the GLib Team and others 1997-2000. See the AUTHORS * file for a list of people on the GLib Team. See the ChangeLog * files for a list of changes. These files are distributed with * GLib at ftp://ftp.gtk.org/pub/gtk/. */ /* * MT safe */ #include "config.h" #include "glibconfig.h" #include "glib_trace.h" /* Uncomment the next line (and the corresponding line in gpoll.c) to * enable debugging printouts if the environment variable * G_MAIN_POLL_DEBUG is set to some value. */ /* #define G_MAIN_POLL_DEBUG */ #ifdef _WIN32 /* Always enable debugging printout on Windows, as it is more often * needed there... */ #define G_MAIN_POLL_DEBUG #endif #ifdef G_OS_UNIX #include "glib-unix.h" #include #ifdef HAVE_EVENTFD #include #endif #endif #include #include #include #include #ifdef HAVE_SYS_TIME_H #include #endif /* HAVE_SYS_TIME_H */ #ifdef G_OS_UNIX #include #endif /* G_OS_UNIX */ #include #include #ifdef G_OS_WIN32 #define STRICT #include #endif /* G_OS_WIN32 */ #ifdef HAVE_MACH_MACH_TIME_H #include #endif #include "glib_trace.h" #include "gmain.h" #include "garray.h" #include "giochannel.h" #include "ghash.h" #include "ghook.h" #include "gqueue.h" #include "gstrfuncs.h" #include "gtestutils.h" #ifdef G_OS_WIN32 #include "gwin32.h" #endif #ifdef G_MAIN_POLL_DEBUG #include "gtimer.h" #endif #include "gwakeup.h" #include "gmain-internal.h" #include "glib-init.h" #include "glib-private.h" /** * SECTION:main * @title: The Main Event Loop * @short_description: manages all available sources of events * * The main event loop manages all the available sources of events for * GLib and GTK+ applications. These events can come from any number of * different types of sources such as file descriptors (plain files, * pipes or sockets) and timeouts. New types of event sources can also * be added using g_source_attach(). * * To allow multiple independent sets of sources to be handled in * different threads, each source is associated with a #GMainContext. * A GMainContext can only be running in a single thread, but * sources can be added to it and removed from it from other threads. * * Each event source is assigned a priority. The default priority, * #G_PRIORITY_DEFAULT, is 0. Values less than 0 denote higher priorities. * Values greater than 0 denote lower priorities. Events from high priority * sources are always processed before events from lower priority sources. * * Idle functions can also be added, and assigned a priority. These will * be run whenever no events with a higher priority are ready to be processed. * * The #GMainLoop data type represents a main event loop. A GMainLoop is * created with g_main_loop_new(). After adding the initial event sources, * g_main_loop_run() is called. This continuously checks for new events from * each of the event sources and dispatches them. Finally, the processing of * an event from one of the sources leads to a call to g_main_loop_quit() to * exit the main loop, and g_main_loop_run() returns. * * It is possible to create new instances of #GMainLoop recursively. * This is often used in GTK+ applications when showing modal dialog * boxes. Note that event sources are associated with a particular * #GMainContext, and will be checked and dispatched for all main * loops associated with that GMainContext. * * GTK+ contains wrappers of some of these functions, e.g. gtk_main(), * gtk_main_quit() and gtk_events_pending(). * * ## Creating new source types * * One of the unusual features of the #GMainLoop functionality * is that new types of event source can be created and used in * addition to the builtin type of event source. A new event source * type is used for handling GDK events. A new source type is created * by "deriving" from the #GSource structure. The derived type of * source is represented by a structure that has the #GSource structure * as a first element, and other elements specific to the new source * type. To create an instance of the new source type, call * g_source_new() passing in the size of the derived structure and * a table of functions. These #GSourceFuncs determine the behavior of * the new source type. * * New source types basically interact with the main context * in two ways. Their prepare function in #GSourceFuncs can set a timeout * to determine the maximum amount of time that the main loop will sleep * before checking the source again. In addition, or as well, the source * can add file descriptors to the set that the main context checks using * g_source_add_poll(). * * ## Customizing the main loop iteration * * Single iterations of a #GMainContext can be run with * g_main_context_iteration(). In some cases, more detailed control * of exactly how the details of the main loop work is desired, for * instance, when integrating the #GMainLoop with an external main loop. * In such cases, you can call the component functions of * g_main_context_iteration() directly. These functions are * g_main_context_prepare(), g_main_context_query(), * g_main_context_check() and g_main_context_dispatch(). * * ## State of a Main Context # {#mainloop-states} * * The operation of these functions can best be seen in terms * of a state diagram, as shown in this image. * * ![](mainloop-states.gif) * * On UNIX, the GLib mainloop is incompatible with fork(). Any program * using the mainloop must either exec() or exit() from the child * without returning to the mainloop. * * ## Memory management of sources # {#mainloop-memory-management} * * There are two options for memory management of the user data passed to a * #GSource to be passed to its callback on invocation. This data is provided * in calls to g_timeout_add(), g_timeout_add_full(), g_idle_add(), etc. and * more generally, using g_source_set_callback(). This data is typically an * object which ‘owns’ the timeout or idle callback, such as a widget or a * network protocol implementation. In many cases, it is an error for the * callback to be invoked after this owning object has been destroyed, as that * results in use of freed memory. * * The first, and preferred, option is to store the source ID returned by * functions such as g_timeout_add() or g_source_attach(), and explicitly * remove that source from the main context using g_source_remove() when the * owning object is finalized. This ensures that the callback can only be * invoked while the object is still alive. * * The second option is to hold a strong reference to the object in the * callback, and to release it in the callback’s #GDestroyNotify. This ensures * that the object is kept alive until after the source is finalized, which is * guaranteed to be after it is invoked for the final time. The #GDestroyNotify * is another callback passed to the ‘full’ variants of #GSource functions (for * example, g_timeout_add_full()). It is called when the source is finalized, * and is designed for releasing references like this. * * One important caveat of this second approach is that it will keep the object * alive indefinitely if the main loop is stopped before the #GSource is * invoked, which may be undesirable. */ /* Types */ typedef struct _GTimeoutSource GTimeoutSource; typedef struct _GChildWatchSource GChildWatchSource; typedef struct _GUnixSignalWatchSource GUnixSignalWatchSource; typedef struct _GPollRec GPollRec; typedef struct _GSourceCallback GSourceCallback; typedef enum { G_SOURCE_READY = 1 << G_HOOK_FLAG_USER_SHIFT, G_SOURCE_CAN_RECURSE = 1 << (G_HOOK_FLAG_USER_SHIFT + 1), G_SOURCE_BLOCKED = 1 << (G_HOOK_FLAG_USER_SHIFT + 2) } GSourceFlags; typedef struct _GSourceList GSourceList; struct _GSourceList { GSource *head, *tail; gint priority; }; typedef struct _GMainWaiter GMainWaiter; struct _GMainWaiter { GCond *cond; GMutex *mutex; }; typedef struct _GMainDispatch GMainDispatch; struct _GMainDispatch { gint depth; GSource *source; }; #ifdef G_MAIN_POLL_DEBUG gboolean _g_main_poll_debug = FALSE; #endif struct _GMainContext { /* The following lock is used for both the list of sources * and the list of poll records */ GMutex mutex; GCond cond; GThread *owner; guint owner_count; GSList *waiters; volatile gint ref_count; GHashTable *sources; /* guint -> GSource */ GPtrArray *pending_dispatches; gint timeout; /* Timeout for current iteration */ guint next_id; GList *source_lists; gint in_check_or_prepare; GPollRec *poll_records; guint n_poll_records; GPollFD *cached_poll_array; guint cached_poll_array_size; GWakeup *wakeup; GPollFD wake_up_rec; /* Flag indicating whether the set of fd's changed during a poll */ gboolean poll_changed; GPollFunc poll_func; gint64 time; gboolean time_is_fresh; }; struct _GSourceCallback { volatile gint ref_count; GSourceFunc func; gpointer data; GDestroyNotify notify; }; struct _GMainLoop { GMainContext *context; gboolean is_running; volatile gint ref_count; }; struct _GTimeoutSource { GSource source; guint interval; gboolean seconds; }; struct _GChildWatchSource { GSource source; GPid pid; gint child_status; #ifdef G_OS_WIN32 GPollFD poll; #else /* G_OS_WIN32 */ gboolean child_exited; #endif /* G_OS_WIN32 */ }; struct _GUnixSignalWatchSource { GSource source; int signum; gboolean pending; }; struct _GPollRec { GPollFD *fd; GPollRec *prev; GPollRec *next; gint priority; }; struct _GSourcePrivate { GSList *child_sources; GSource *parent_source; gint64 ready_time; /* This is currently only used on UNIX, but we always declare it (and * let it remain empty on Windows) to avoid #ifdef all over the place. */ GSList *fds; }; typedef struct _GSourceIter { GMainContext *context; gboolean may_modify; GList *current_list; GSource *source; } GSourceIter; #define LOCK_CONTEXT(context) g_mutex_lock (&context->mutex) #define UNLOCK_CONTEXT(context) g_mutex_unlock (&context->mutex) #define G_THREAD_SELF g_thread_self () #define SOURCE_DESTROYED(source) (((source)->flags & G_HOOK_FLAG_ACTIVE) == 0) #define SOURCE_BLOCKED(source) (((source)->flags & G_SOURCE_BLOCKED) != 0) #define SOURCE_UNREF(source, context) \ G_STMT_START { \ if ((source)->ref_count > 1) \ (source)->ref_count--; \ else \ g_source_unref_internal ((source), (context), TRUE); \ } G_STMT_END /* Forward declarations */ static void g_source_unref_internal (GSource *source, GMainContext *context, gboolean have_lock); static void g_source_destroy_internal (GSource *source, GMainContext *context, gboolean have_lock); static void g_source_set_priority_unlocked (GSource *source, GMainContext *context, gint priority); static void g_child_source_remove_internal (GSource *child_source, GMainContext *context); static void g_main_context_poll (GMainContext *context, gint timeout, gint priority, GPollFD *fds, gint n_fds); static void g_main_context_add_poll_unlocked (GMainContext *context, gint priority, GPollFD *fd); static void g_main_context_remove_poll_unlocked (GMainContext *context, GPollFD *fd); static void g_source_iter_init (GSourceIter *iter, GMainContext *context, gboolean may_modify); static gboolean g_source_iter_next (GSourceIter *iter, GSource **source); static void g_source_iter_clear (GSourceIter *iter); static gboolean g_timeout_dispatch (GSource *source, GSourceFunc callback, gpointer user_data); static gboolean g_child_watch_prepare (GSource *source, gint *timeout); static gboolean g_child_watch_check (GSource *source); static gboolean g_child_watch_dispatch (GSource *source, GSourceFunc callback, gpointer user_data); static void g_child_watch_finalize (GSource *source); #ifdef G_OS_UNIX static void g_unix_signal_handler (int signum); static gboolean g_unix_signal_watch_prepare (GSource *source, gint *timeout); static gboolean g_unix_signal_watch_check (GSource *source); static gboolean g_unix_signal_watch_dispatch (GSource *source, GSourceFunc callback, gpointer user_data); static void g_unix_signal_watch_finalize (GSource *source); #endif static gboolean g_idle_prepare (GSource *source, gint *timeout); static gboolean g_idle_check (GSource *source); static gboolean g_idle_dispatch (GSource *source, GSourceFunc callback, gpointer user_data); static void block_source (GSource *source); static GMainContext *glib_worker_context; G_LOCK_DEFINE_STATIC (main_loop); static GMainContext *default_main_context; #ifndef G_OS_WIN32 /* UNIX signals work by marking one of these variables then waking the * worker context to check on them and dispatch accordingly. */ #ifdef HAVE_SIG_ATOMIC_T static volatile sig_atomic_t unix_signal_pending[NSIG]; static volatile sig_atomic_t any_unix_signal_pending; #else static volatile int unix_signal_pending[NSIG]; static volatile int any_unix_signal_pending; #endif static volatile guint unix_signal_refcount[NSIG]; /* Guards all the data below */ G_LOCK_DEFINE_STATIC (unix_signal_lock); static GSList *unix_signal_watches; static GSList *unix_child_watches; GSourceFuncs g_unix_signal_funcs = { g_unix_signal_watch_prepare, g_unix_signal_watch_check, g_unix_signal_watch_dispatch, g_unix_signal_watch_finalize }; #endif /* !G_OS_WIN32 */ G_LOCK_DEFINE_STATIC (main_context_list); static GSList *main_context_list = NULL; GSourceFuncs g_timeout_funcs = { NULL, /* prepare */ NULL, /* check */ g_timeout_dispatch, NULL }; GSourceFuncs g_child_watch_funcs = { g_child_watch_prepare, g_child_watch_check, g_child_watch_dispatch, g_child_watch_finalize }; GSourceFuncs g_idle_funcs = { g_idle_prepare, g_idle_check, g_idle_dispatch, NULL }; /** * g_main_context_ref: * @context: a #GMainContext * * Increases the reference count on a #GMainContext object by one. * * Returns: the @context that was passed in (since 2.6) **/ GMainContext * g_main_context_ref (GMainContext *context) { g_return_val_if_fail (context != NULL, NULL); g_return_val_if_fail (g_atomic_int_get (&context->ref_count) > 0, NULL); g_atomic_int_inc (&context->ref_count); return context; } static inline void poll_rec_list_free (GMainContext *context, GPollRec *list) { g_slice_free_chain (GPollRec, list, next); } /** * g_main_context_unref: * @context: a #GMainContext * * Decreases the reference count on a #GMainContext object by one. If * the result is zero, free the context and free all associated memory. **/ void g_main_context_unref (GMainContext *context) { GSourceIter iter; GSource *source; GList *sl_iter; GSourceList *list; guint i; g_return_if_fail (context != NULL); g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0); if (!g_atomic_int_dec_and_test (&context->ref_count)) return; G_LOCK (main_context_list); main_context_list = g_slist_remove (main_context_list, context); G_UNLOCK (main_context_list); /* Free pending dispatches */ for (i = 0; i < context->pending_dispatches->len; i++) g_source_unref_internal (context->pending_dispatches->pdata[i], context, FALSE); /* g_source_iter_next() assumes the context is locked. */ LOCK_CONTEXT (context); g_source_iter_init (&iter, context, TRUE); while (g_source_iter_next (&iter, &source)) { source->context = NULL; g_source_destroy_internal (source, context, TRUE); } UNLOCK_CONTEXT (context); for (sl_iter = context->source_lists; sl_iter; sl_iter = sl_iter->next) { list = sl_iter->data; g_slice_free (GSourceList, list); } g_list_free (context->source_lists); g_hash_table_destroy (context->sources); g_mutex_clear (&context->mutex); g_ptr_array_free (context->pending_dispatches, TRUE); g_free (context->cached_poll_array); poll_rec_list_free (context, context->poll_records); g_wakeup_free (context->wakeup); g_cond_clear (&context->cond); g_free (context); } /* Helper function used by mainloop/overflow test. */ GMainContext * g_main_context_new_with_next_id (guint next_id) { GMainContext *ret = g_main_context_new (); ret->next_id = next_id; return ret; } /** * g_main_context_new: * * Creates a new #GMainContext structure. * * Returns: the new #GMainContext **/ GMainContext * g_main_context_new (void) { static gsize initialised; GMainContext *context; if (g_once_init_enter (&initialised)) { #ifdef G_MAIN_POLL_DEBUG if (getenv ("G_MAIN_POLL_DEBUG") != NULL) _g_main_poll_debug = TRUE; #endif g_once_init_leave (&initialised, TRUE); } context = g_new0 (GMainContext, 1); TRACE (GLIB_MAIN_CONTEXT_NEW (context)); g_mutex_init (&context->mutex); g_cond_init (&context->cond); context->sources = g_hash_table_new (NULL, NULL); context->owner = NULL; context->waiters = NULL; context->ref_count = 1; context->next_id = 1; context->source_lists = NULL; context->poll_func = g_poll; context->cached_poll_array = NULL; context->cached_poll_array_size = 0; context->pending_dispatches = g_ptr_array_new (); context->time_is_fresh = FALSE; context->wakeup = g_wakeup_new (); g_wakeup_get_pollfd (context->wakeup, &context->wake_up_rec); g_main_context_add_poll_unlocked (context, 0, &context->wake_up_rec); G_LOCK (main_context_list); main_context_list = g_slist_append (main_context_list, context); #ifdef G_MAIN_POLL_DEBUG if (_g_main_poll_debug) g_print ("created context=%p\n", context); #endif G_UNLOCK (main_context_list); return context; } /** * g_main_context_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 * g_main_context_get_thread_default(). * * Returns: (transfer none): the global default main context. **/ GMainContext * g_main_context_default (void) { /* Slow, but safe */ G_LOCK (main_loop); if (!default_main_context) { default_main_context = g_main_context_new (); TRACE (GLIB_MAIN_CONTEXT_DEFAULT (default_main_context)); #ifdef G_MAIN_POLL_DEBUG if (_g_main_poll_debug) g_print ("default context=%p\n", default_main_context); #endif } G_UNLOCK (main_loop); return default_main_context; } static void free_context (gpointer data) { GMainContext *context = data; TRACE (GLIB_MAIN_CONTEXT_FREE (context)); g_main_context_release (context); if (context) g_main_context_unref (context); } static void free_context_stack (gpointer data) { g_queue_free_full((GQueue *) data, (GDestroyNotify) free_context); } static GPrivate thread_context_stack = G_PRIVATE_INIT (free_context_stack); /** * g_main_context_push_thread_default: * @context: (nullable): a #GMainContext, or %NULL for the global default context * * Acquires @context and sets it as the thread-default context for the * current thread. This will cause certain asynchronous operations * (such as most [gio][gio]-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 g_main_context_get_thread_default(), * not the one returned by g_main_context_default(), so it does not affect * the context used by functions like g_idle_add(). * * Normally you would call this function shortly after creating a new * thread, passing it a #GMainContext which will be run by a * #GMainLoop in that thread, to set a new default context for all * async operations in that thread. In this case you may not need to * ever call g_main_context_pop_thread_default(), assuming you want the * new #GMainContext to be the default for the whole lifecycle of the * thread. * * If you don't have control over how the new thread was created (e.g. * in the new thread isn't newly created, or if the thread life * cycle is managed by a #GThreadPool), it is always suggested to wrap * the logic that needs to use the new #GMainContext inside a * g_main_context_push_thread_default() / g_main_context_pop_thread_default() * pair, otherwise threads that are re-used will end up never explicitly * releasing the #GMainContext reference they hold. * * In some cases you may want to schedule a single operation in a * non-default context, or temporarily use a non-default context in * the main thread. In that case, you can wrap the call to the * asynchronous operation inside a * g_main_context_push_thread_default() / * g_main_context_pop_thread_default() pair, but it is up to you to * ensure that no other asynchronous operations accidentally get * started while the non-default context is active. * * Beware that libraries that predate this function may not correctly * handle being used from a thread with a thread-default context. Eg, * see g_file_supports_thread_contexts(). * * Since: 2.22 **/ void g_main_context_push_thread_default (GMainContext *context) { GQueue *stack; gboolean acquired_context; acquired_context = g_main_context_acquire (context); g_return_if_fail (acquired_context); if (context == g_main_context_default ()) context = NULL; else if (context) g_main_context_ref (context); stack = g_private_get (&thread_context_stack); if (!stack) { stack = g_queue_new (); g_private_set (&thread_context_stack, stack); } g_queue_push_head (stack, context); TRACE (GLIB_MAIN_CONTEXT_PUSH_THREAD_DEFAULT (context)); } /** * g_main_context_pop_thread_default: * @context: (nullable): a #GMainContext object, or %NULL * * Pops @context off the thread-default context stack (verifying that * it was on the top of the stack). * * Since: 2.22 **/ void g_main_context_pop_thread_default (GMainContext *context) { GQueue *stack; if (context == g_main_context_default ()) context = NULL; stack = g_private_get (&thread_context_stack); g_return_if_fail (stack != NULL); g_return_if_fail (g_queue_peek_head (stack) == context); TRACE (GLIB_MAIN_CONTEXT_POP_THREAD_DEFAULT (context)); g_queue_pop_head (stack); g_main_context_release (context); if (context) g_main_context_unref (context); } /** * g_main_context_get_thread_default: * * Gets the thread-default #GMainContext 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 * g_main_context_ref_thread_default() to get a #GMainContext to add * their #GSources 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.) * * If you need to hold a reference on the context, use * g_main_context_ref_thread_default() instead. * * Returns: (transfer none): the thread-default #GMainContext, or * %NULL if the thread-default context is the global default context. * * Since: 2.22 **/ GMainContext * g_main_context_get_thread_default (void) { GQueue *stack; stack = g_private_get (&thread_context_stack); if (stack) return g_queue_peek_head (stack); else return NULL; } /** * g_main_context_ref_thread_default: * * Gets the thread-default #GMainContext for this thread, as with * g_main_context_get_thread_default(), but also adds a reference to * it with g_main_context_ref(). In addition, unlike * g_main_context_get_thread_default(), if the thread-default context * is the global default context, this will return that #GMainContext * (with a ref added to it) rather than returning %NULL. * * Returns: (transfer full): the thread-default #GMainContext. Unref * with g_main_context_unref() when you are done with it. * * Since: 2.32 */ GMainContext * g_main_context_ref_thread_default (void) { GMainContext *context; context = g_main_context_get_thread_default (); if (!context) context = g_main_context_default (); return g_main_context_ref (context); } /* Hooks for adding to the main loop */ /** * g_source_new: * @source_funcs: structure containing functions that implement * the sources behavior. * @struct_size: size of the #GSource structure to create. * * Creates a new #GSource structure. The size is specified to * allow creating structures derived from #GSource that contain * additional data. The size passed in must be at least * `sizeof (GSource)`. * * The source will not initially be associated with any #GMainContext * and must be added to one with g_source_attach() before it will be * executed. * * Returns: the newly-created #GSource. **/ GSource * g_source_new (GSourceFuncs *source_funcs, guint struct_size) { GSource *source; g_return_val_if_fail (source_funcs != NULL, NULL); g_return_val_if_fail (struct_size >= sizeof (GSource), NULL); source = (GSource*) g_malloc0 (struct_size); source->priv = g_slice_new0 (GSourcePrivate); source->source_funcs = source_funcs; source->ref_count = 1; source->priority = G_PRIORITY_DEFAULT; source->flags = G_HOOK_FLAG_ACTIVE; source->priv->ready_time = -1; /* NULL/0 initialization for all other fields */ TRACE (GLIB_SOURCE_NEW (source, source_funcs->prepare, source_funcs->check, source_funcs->dispatch, source_funcs->finalize, struct_size)); return source; } /* Holds context's lock */ static void g_source_iter_init (GSourceIter *iter, GMainContext *context, gboolean may_modify) { iter->context = context; iter->current_list = NULL; iter->source = NULL; iter->may_modify = may_modify; } /* Holds context's lock */ static gboolean g_source_iter_next (GSourceIter *iter, GSource **source) { GSource *next_source; if (iter->source) next_source = iter->source->next; else next_source = NULL; if (!next_source) { if (iter->current_list) iter->current_list = iter->current_list->next; else iter->current_list = iter->context->source_lists; if (iter->current_list) { GSourceList *source_list = iter->current_list->data; next_source = source_list->head; } } /* Note: unreffing iter->source could potentially cause its * GSourceList to be removed from source_lists (if iter->source is * the only source in its list, and it is destroyed), so we have to * keep it reffed until after we advance iter->current_list, above. */ if (iter->source && iter->may_modify) SOURCE_UNREF (iter->source, iter->context); iter->source = next_source; if (iter->source && iter->may_modify) iter->source->ref_count++; *source = iter->source; return *source != NULL; } /* Holds context's lock. Only necessary to call if you broke out of * the g_source_iter_next() loop early. */ static void g_source_iter_clear (GSourceIter *iter) { if (iter->source && iter->may_modify) { SOURCE_UNREF (iter->source, iter->context); iter->source = NULL; } } /* Holds context's lock */ static GSourceList * find_source_list_for_priority (GMainContext *context, gint priority, gboolean create) { GList *iter, *last; GSourceList *source_list; last = NULL; for (iter = context->source_lists; iter != NULL; last = iter, iter = iter->next) { source_list = iter->data; if (source_list->priority == priority) return source_list; if (source_list->priority > priority) { if (!create) return NULL; source_list = g_slice_new0 (GSourceList); source_list->priority = priority; context->source_lists = g_list_insert_before (context->source_lists, iter, source_list); return source_list; } } if (!create) return NULL; source_list = g_slice_new0 (GSourceList); source_list->priority = priority; if (!last) context->source_lists = g_list_append (NULL, source_list); else { /* This just appends source_list to the end of * context->source_lists without having to walk the list again. */ last = g_list_append (last, source_list); } return source_list; } /* Holds context's lock */ static void source_add_to_context (GSource *source, GMainContext *context) { GSourceList *source_list; GSource *prev, *next; source_list = find_source_list_for_priority (context, source->priority, TRUE); if (source->priv->parent_source) { g_assert (source_list->head != NULL); /* Put the source immediately before its parent */ prev = source->priv->parent_source->prev; next = source->priv->parent_source; } else { prev = source_list->tail; next = NULL; } source->next = next; if (next) next->prev = source; else source_list->tail = source; source->prev = prev; if (prev) prev->next = source; else source_list->head = source; } /* Holds context's lock */ static void source_remove_from_context (GSource *source, GMainContext *context) { GSourceList *source_list; source_list = find_source_list_for_priority (context, source->priority, FALSE); g_return_if_fail (source_list != NULL); if (source->prev) source->prev->next = source->next; else source_list->head = source->next; if (source->next) source->next->prev = source->prev; else source_list->tail = source->prev; source->prev = NULL; source->next = NULL; if (source_list->head == NULL) { context->source_lists = g_list_remove (context->source_lists, source_list); g_slice_free (GSourceList, source_list); } } static guint g_source_attach_unlocked (GSource *source, GMainContext *context, gboolean do_wakeup) { GSList *tmp_list; guint id; /* The counter may have wrapped, so we must ensure that we do not * reuse the source id of an existing source. */ do id = context->next_id++; while (id == 0 || g_hash_table_contains (context->sources, GUINT_TO_POINTER (id))); source->context = context; source->source_id = id; source->ref_count++; g_hash_table_insert (context->sources, GUINT_TO_POINTER (id), source); source_add_to_context (source, context); if (!SOURCE_BLOCKED (source)) { tmp_list = source->poll_fds; while (tmp_list) { g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data); tmp_list = tmp_list->next; } for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next) g_main_context_add_poll_unlocked (context, source->priority, tmp_list->data); } tmp_list = source->priv->child_sources; while (tmp_list) { g_source_attach_unlocked (tmp_list->data, context, FALSE); tmp_list = tmp_list->next; } /* If another thread has acquired the context, wake it up since it * might be in poll() right now. */ if (do_wakeup && context->owner && context->owner != G_THREAD_SELF) g_wakeup_signal (context->wakeup); return source->source_id; } /** * g_source_attach: * @source: a #GSource * @context: (nullable): a #GMainContext (if %NULL, the default context will be used) * * Adds a #GSource to a @context so that it will be executed within * that context. Remove it by calling g_source_destroy(). * * Returns: the ID (greater than 0) for the source within the * #GMainContext. **/ guint g_source_attach (GSource *source, GMainContext *context) { guint result = 0; g_return_val_if_fail (source->context == NULL, 0); g_return_val_if_fail (!SOURCE_DESTROYED (source), 0); if (!context) context = g_main_context_default (); LOCK_CONTEXT (context); result = g_source_attach_unlocked (source, context, TRUE); TRACE (GLIB_MAIN_SOURCE_ATTACH (g_source_get_name (source), source, context, result)); UNLOCK_CONTEXT (context); return result; } static void g_source_destroy_internal (GSource *source, GMainContext *context, gboolean have_lock) { TRACE (GLIB_MAIN_SOURCE_DESTROY (g_source_get_name (source), source, context)); if (!have_lock) LOCK_CONTEXT (context); if (!SOURCE_DESTROYED (source)) { GSList *tmp_list; gpointer old_cb_data; GSourceCallbackFuncs *old_cb_funcs; source->flags &= ~G_HOOK_FLAG_ACTIVE; old_cb_data = source->callback_data; old_cb_funcs = source->callback_funcs; source->callback_data = NULL; source->callback_funcs = NULL; if (old_cb_funcs) { UNLOCK_CONTEXT (context); old_cb_funcs->unref (old_cb_data); LOCK_CONTEXT (context); } if (!SOURCE_BLOCKED (source)) { tmp_list = source->poll_fds; while (tmp_list) { g_main_context_remove_poll_unlocked (context, tmp_list->data); tmp_list = tmp_list->next; } for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next) g_main_context_remove_poll_unlocked (context, tmp_list->data); } while (source->priv->child_sources) g_child_source_remove_internal (source->priv->child_sources->data, context); if (source->priv->parent_source) g_child_source_remove_internal (source, context); g_source_unref_internal (source, context, TRUE); } if (!have_lock) UNLOCK_CONTEXT (context); } /** * g_source_destroy: * @source: a #GSource * * Removes a source from its #GMainContext, if any, and mark 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. **/ void g_source_destroy (GSource *source) { GMainContext *context; g_return_if_fail (source != NULL); context = source->context; if (context) g_source_destroy_internal (source, context, FALSE); else source->flags &= ~G_HOOK_FLAG_ACTIVE; } /** * g_source_get_id: * @source: a #GSource * * 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 g_main_context_find_source_by_id(). * * Returns: the ID (greater than 0) for the source **/ guint g_source_get_id (GSource *source) { guint result; g_return_val_if_fail (source != NULL, 0); g_return_val_if_fail (source->context != NULL, 0); LOCK_CONTEXT (source->context); result = source->source_id; UNLOCK_CONTEXT (source->context); return result; } /** * g_source_get_context: * @source: a #GSource * * Gets the #GMainContext with which the source is associated. * * You can call this on a source that has been destroyed, provided * that the #GMainContext it was attached to still exists (in which * case it will return that #GMainContext). In particular, you can * always call this function on the source returned from * g_main_current_source(). But calling this function on a source * whose #GMainContext has been destroyed is an error. * * Returns: (transfer none) (nullable): the #GMainContext with which the * source is associated, or %NULL if the context has not * yet been added to a source. **/ GMainContext * g_source_get_context (GSource *source) { g_return_val_if_fail (source->context != NULL || !SOURCE_DESTROYED (source), NULL); return source->context; } /** * g_source_add_poll: * @source:a #GSource * @fd: a #GPollFD structure holding information about a file * descriptor to watch. * * Adds a file descriptor to the set of file descriptors polled for * this source. This is usually combined with g_source_new() to add an * event source. The event source's check function will typically test * the @revents field in the #GPollFD struct and return %TRUE if events need * to be processed. * * This API is only intended to be used by implementations of #GSource. * Do not call this API on a #GSource 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. **/ void g_source_add_poll (GSource *source, GPollFD *fd) { GMainContext *context; g_return_if_fail (source != NULL); g_return_if_fail (fd != NULL); g_return_if_fail (!SOURCE_DESTROYED (source)); context = source->context; if (context) LOCK_CONTEXT (context); source->poll_fds = g_slist_prepend (source->poll_fds, fd); if (context) { if (!SOURCE_BLOCKED (source)) g_main_context_add_poll_unlocked (context, source->priority, fd); UNLOCK_CONTEXT (context); } } /** * g_source_remove_poll: * @source:a #GSource * @fd: a #GPollFD structure previously passed to g_source_add_poll(). * * 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 #GSource. * Do not call this API on a #GSource that you did not create. **/ void g_source_remove_poll (GSource *source, GPollFD *fd) { GMainContext *context; g_return_if_fail (source != NULL); g_return_if_fail (fd != NULL); g_return_if_fail (!SOURCE_DESTROYED (source)); context = source->context; if (context) LOCK_CONTEXT (context); source->poll_fds = g_slist_remove (source->poll_fds, fd); if (context) { if (!SOURCE_BLOCKED (source)) g_main_context_remove_poll_unlocked (context, fd); UNLOCK_CONTEXT (context); } } /** * g_source_add_child_source: * @source:a #GSource * @child_source: a second #GSource that @source should "poll" * * Adds @child_source to @source as a "polled" source; when @source is * added to a #GMainContext, @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. (@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). * * @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 #GSource. * Do not call this API on a #GSource that you did not create. * * Since: 2.28 **/ void g_source_add_child_source (GSource *source, GSource *child_source) { GMainContext *context; g_return_if_fail (source != NULL); g_return_if_fail (child_source != NULL); g_return_if_fail (!SOURCE_DESTROYED (source)); g_return_if_fail (!SOURCE_DESTROYED (child_source)); g_return_if_fail (child_source->context == NULL); g_return_if_fail (child_source->priv->parent_source == NULL); context = source->context; if (context) LOCK_CONTEXT (context); TRACE (GLIB_SOURCE_ADD_CHILD_SOURCE (source, child_source)); source->priv->child_sources = g_slist_prepend (source->priv->child_sources, g_source_ref (child_source)); child_source->priv->parent_source = source; g_source_set_priority_unlocked (child_source, NULL, source->priority); if (SOURCE_BLOCKED (source)) block_source (child_source); if (context) { g_source_attach_unlocked (child_source, context, TRUE); UNLOCK_CONTEXT (context); } } static void g_child_source_remove_internal (GSource *child_source, GMainContext *context) { GSource *parent_source = child_source->priv->parent_source; parent_source->priv->child_sources = g_slist_remove (parent_source->priv->child_sources, child_source); child_source->priv->parent_source = NULL; g_source_destroy_internal (child_source, context, TRUE); g_source_unref_internal (child_source, context, TRUE); } /** * g_source_remove_child_source: * @source:a #GSource * @child_source: a #GSource previously passed to * g_source_add_child_source(). * * Detaches @child_source from @source and destroys it. * * This API is only intended to be used by implementations of #GSource. * Do not call this API on a #GSource that you did not create. * * Since: 2.28 **/ void g_source_remove_child_source (GSource *source, GSource *child_source) { GMainContext *context; g_return_if_fail (source != NULL); g_return_if_fail (child_source != NULL); g_return_if_fail (child_source->priv->parent_source == source); g_return_if_fail (!SOURCE_DESTROYED (source)); g_return_if_fail (!SOURCE_DESTROYED (child_source)); context = source->context; if (context) LOCK_CONTEXT (context); g_child_source_remove_internal (child_source, context); if (context) UNLOCK_CONTEXT (context); } static void g_source_callback_ref (gpointer cb_data) { GSourceCallback *callback = cb_data; g_atomic_int_inc (&callback->ref_count); } static void g_source_callback_unref (gpointer cb_data) { GSourceCallback *callback = cb_data; if (g_atomic_int_dec_and_test (&callback->ref_count)) { if (callback->notify) callback->notify (callback->data); g_free (callback); } } static void g_source_callback_get (gpointer cb_data, GSource *source, GSourceFunc *func, gpointer *data) { GSourceCallback *callback = cb_data; *func = callback->func; *data = callback->data; } static GSourceCallbackFuncs g_source_callback_funcs = { g_source_callback_ref, g_source_callback_unref, g_source_callback_get, }; /** * g_source_set_callback_indirect: * @source: the source * @callback_data: pointer to callback data "object" * @callback_funcs: functions for reference counting @callback_data * and getting the callback and data * * Sets the callback function storing the data as a refcounted callback * "object". This is used internally. Note that calling * g_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. **/ void g_source_set_callback_indirect (GSource *source, gpointer callback_data, GSourceCallbackFuncs *callback_funcs) { GMainContext *context; gpointer old_cb_data; GSourceCallbackFuncs *old_cb_funcs; g_return_if_fail (source != NULL); g_return_if_fail (callback_funcs != NULL || callback_data == NULL); context = source->context; if (context) LOCK_CONTEXT (context); if (callback_funcs != &g_source_callback_funcs) TRACE (GLIB_SOURCE_SET_CALLBACK_INDIRECT (source, callback_data, callback_funcs->ref, callback_funcs->unref, callback_funcs->get)); old_cb_data = source->callback_data; old_cb_funcs = source->callback_funcs; source->callback_data = callback_data; source->callback_funcs = callback_funcs; if (context) UNLOCK_CONTEXT (context); if (old_cb_funcs) old_cb_funcs->unref (old_cb_data); } /** * g_source_set_callback: * @source: the source * @func: a callback function * @data: the data to pass to callback function * @notify: (nullable): a function to call when @data is no longer in use, or %NULL. * * 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. * * See [memory management of sources][mainloop-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. **/ void g_source_set_callback (GSource *source, GSourceFunc func, gpointer data, GDestroyNotify notify) { GSourceCallback *new_callback; g_return_if_fail (source != NULL); TRACE (GLIB_SOURCE_SET_CALLBACK (source, func, data, notify)); new_callback = g_new (GSourceCallback, 1); new_callback->ref_count = 1; new_callback->func = func; new_callback->data = data; new_callback->notify = notify; g_source_set_callback_indirect (source, new_callback, &g_source_callback_funcs); } /** * g_source_set_funcs: * @source: a #GSource * @funcs: the new #GSourceFuncs * * Sets the source functions (can be used to override * default implementations) of an unattached source. * * Since: 2.12 */ void g_source_set_funcs (GSource *source, GSourceFuncs *funcs) { g_return_if_fail (source != NULL); g_return_if_fail (source->context == NULL); g_return_if_fail (source->ref_count > 0); g_return_if_fail (funcs != NULL); source->source_funcs = funcs; } static void g_source_set_priority_unlocked (GSource *source, GMainContext *context, gint priority) { GSList *tmp_list; g_return_if_fail (source->priv->parent_source == NULL || source->priv->parent_source->priority == priority); TRACE (GLIB_SOURCE_SET_PRIORITY (source, context, priority)); if (context) { /* Remove the source from the context's source and then * add it back after so it is sorted in the correct place */ source_remove_from_context (source, source->context); } source->priority = priority; if (context) { source_add_to_context (source, source->context); if (!SOURCE_BLOCKED (source)) { tmp_list = source->poll_fds; while (tmp_list) { g_main_context_remove_poll_unlocked (context, tmp_list->data); g_main_context_add_poll_unlocked (context, priority, tmp_list->data); tmp_list = tmp_list->next; } for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next) { g_main_context_remove_poll_unlocked (context, tmp_list->data); g_main_context_add_poll_unlocked (context, priority, tmp_list->data); } } } if (source->priv->child_sources) { tmp_list = source->priv->child_sources; while (tmp_list) { g_source_set_priority_unlocked (tmp_list->data, context, priority); tmp_list = tmp_list->next; } } } /** * g_source_set_priority: * @source: a #GSource * @priority: the new 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. **/ void g_source_set_priority (GSource *source, gint priority) { GMainContext *context; g_return_if_fail (source != NULL); g_return_if_fail (source->priv->parent_source == NULL); context = source->context; if (context) LOCK_CONTEXT (context); g_source_set_priority_unlocked (source, context, priority); if (context) UNLOCK_CONTEXT (context); } /** * g_source_get_priority: * @source: a #GSource * * Gets the priority of a source. * * Returns: the priority of the source **/ gint g_source_get_priority (GSource *source) { g_return_val_if_fail (source != NULL, 0); return source->priority; } /** * g_source_set_ready_time: * @source: a #GSource * @ready_time: the monotonic time at which the source will be ready, * 0 for "immediately", -1 for "never" * * Sets a #GSource 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 #GSource which has already been * destroyed with g_source_destroy(). * * This API is only intended to be used by implementations of #GSource. * Do not call this API on a #GSource that you did not create. * * Since: 2.36 **/ void g_source_set_ready_time (GSource *source, gint64 ready_time) { GMainContext *context; g_return_if_fail (source != NULL); /* We deliberately don't check for ref_count > 0 here, because that * breaks cancellable_source_cancelled() in GCancellable: it has no * way to find out that the last-unref has happened until the * finalize() function is called, but that's too late, because the * ref_count already has already reached 0 before that time. * However, priv is only poisoned (set to NULL) after finalize(), * so we can use this as a simple guard against use-after-free. * See https://bugzilla.gnome.org/show_bug.cgi?id=791754 */ g_return_if_fail (source->priv != NULL); context = source->context; if (context) LOCK_CONTEXT (context); if (source->priv->ready_time == ready_time) { if (context) UNLOCK_CONTEXT (context); return; } source->priv->ready_time = ready_time; TRACE (GLIB_SOURCE_SET_READY_TIME (source, ready_time)); if (context) { /* Quite likely that we need to change the timeout on the poll */ if (!SOURCE_BLOCKED (source)) g_wakeup_signal (context->wakeup); UNLOCK_CONTEXT (context); } } /** * g_source_get_ready_time: * @source: a #GSource * * Gets the "ready time" of @source, as set by * g_source_set_ready_time(). * * Any time before the current monotonic time (including 0) is an * indication that the source will fire immediately. * * Returns: the monotonic ready time, -1 for "never" **/ gint64 g_source_get_ready_time (GSource *source) { g_return_val_if_fail (source != NULL, -1); return source->priv->ready_time; } /** * g_source_set_can_recurse: * @source: a #GSource * @can_recurse: whether recursion is allowed for this source * * 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. **/ void g_source_set_can_recurse (GSource *source, gboolean can_recurse) { GMainContext *context; g_return_if_fail (source != NULL); context = source->context; if (context) LOCK_CONTEXT (context); if (can_recurse) source->flags |= G_SOURCE_CAN_RECURSE; else source->flags &= ~G_SOURCE_CAN_RECURSE; if (context) UNLOCK_CONTEXT (context); } /** * g_source_get_can_recurse: * @source: a #GSource * * Checks whether a source is allowed to be called recursively. * see g_source_set_can_recurse(). * * Returns: whether recursion is allowed. **/ gboolean g_source_get_can_recurse (GSource *source) { g_return_val_if_fail (source != NULL, FALSE); return (source->flags & G_SOURCE_CAN_RECURSE) != 0; } /** * g_source_set_name: * @source: a #GSource * @name: debug name for the source * * 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" or whatever it is. * * 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 #GSourceFuncs * 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 g_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. * * Since: 2.26 **/ void g_source_set_name (GSource *source, const char *name) { GMainContext *context; g_return_if_fail (source != NULL); context = source->context; if (context) LOCK_CONTEXT (context); TRACE (GLIB_SOURCE_SET_NAME (source, name)); /* setting back to NULL is allowed, just because it's * weird if get_name can return NULL but you can't * set that. */ g_free (source->name); source->name = g_strdup (name); if (context) UNLOCK_CONTEXT (context); } /** * g_source_get_name: * @source: a #GSource * * Gets a name for the source, used in debugging and profiling. The * name may be #NULL if it has never been set with g_source_set_name(). * * Returns: the name of the source * * Since: 2.26 **/ const char * g_source_get_name (GSource *source) { g_return_val_if_fail (source != NULL, NULL); return source->name; } /** * g_source_set_name_by_id: * @tag: a #GSource ID * @name: debug name for the source * * Sets the name of a source using its ID. * * This is a convenience utility to set source names from the return * value of g_idle_add(), g_timeout_add(), etc. * * It is a programmer error to attempt to set the name of a non-existent * source. * * More specifically: source IDs can be reissued after a source has been * destroyed and therefore it is never valid to use this function with a * source ID which may have already been removed. An example is when * scheduling an idle to run in another thread with g_idle_add(): the * idle may already have run and been removed by the time this function * is called on its (now invalid) source ID. This source ID may have * been reissued, leading to the operation being performed against the * wrong source. * * Since: 2.26 **/ void g_source_set_name_by_id (guint tag, const char *name) { GSource *source; g_return_if_fail (tag > 0); source = g_main_context_find_source_by_id (NULL, tag); if (source == NULL) return; g_source_set_name (source, name); } /** * g_source_ref: * @source: a #GSource * * Increases the reference count on a source by one. * * Returns: @source **/ GSource * g_source_ref (GSource *source) { GMainContext *context; g_return_val_if_fail (source != NULL, NULL); context = source->context; if (context) LOCK_CONTEXT (context); source->ref_count++; if (context) UNLOCK_CONTEXT (context); return source; } /* g_source_unref() but possible to call within context lock */ static void g_source_unref_internal (GSource *source, GMainContext *context, gboolean have_lock) { gpointer old_cb_data = NULL; GSourceCallbackFuncs *old_cb_funcs = NULL; g_return_if_fail (source != NULL); if (!have_lock && context) LOCK_CONTEXT (context); source->ref_count--; if (source->ref_count == 0) { TRACE (GLIB_SOURCE_BEFORE_FREE (source, context, source->source_funcs->finalize)); old_cb_data = source->callback_data; old_cb_funcs = source->callback_funcs; source->callback_data = NULL; source->callback_funcs = NULL; if (context) { if (!SOURCE_DESTROYED (source)) g_warning (G_STRLOC ": ref_count == 0, but source was still attached to a context!"); source_remove_from_context (source, context); g_hash_table_remove (context->sources, GUINT_TO_POINTER (source->source_id)); } if (source->source_funcs->finalize) { /* Temporarily increase the ref count again so that GSource methods * can be called from finalize(). */ source->ref_count++; if (context) UNLOCK_CONTEXT (context); source->source_funcs->finalize (source); if (context) LOCK_CONTEXT (context); source->ref_count--; } if (old_cb_funcs) { /* Temporarily increase the ref count again so that GSource methods * can be called from callback_funcs.unref(). */ source->ref_count++; if (context) UNLOCK_CONTEXT (context); old_cb_funcs->unref (old_cb_data); if (context) LOCK_CONTEXT (context); source->ref_count--; } g_free (source->name); source->name = NULL; g_slist_free (source->poll_fds); source->poll_fds = NULL; g_slist_free_full (source->priv->fds, g_free); while (source->priv->child_sources) { GSource *child_source = source->priv->child_sources->data; source->priv->child_sources = g_slist_remove (source->priv->child_sources, child_source); child_source->priv->parent_source = NULL; g_source_unref_internal (child_source, context, have_lock); } g_slice_free (GSourcePrivate, source->priv); source->priv = NULL; g_free (source); } if (!have_lock && context) UNLOCK_CONTEXT (context); } /** * g_source_unref: * @source: a #GSource * * Decreases the reference count of a source by one. If the * resulting reference count is zero the source and associated * memory will be destroyed. **/ void g_source_unref (GSource *source) { g_return_if_fail (source != NULL); g_source_unref_internal (source, source->context, FALSE); } /** * g_main_context_find_source_by_id: * @context: (nullable): a #GMainContext (if %NULL, the default context will be used) * @source_id: the source ID, as returned by g_source_get_id(). * * Finds a #GSource given a pair of context and ID. * * It is a programmer error to attempt to lookup a non-existent source. * * More specifically: source IDs can be reissued after a source has been * destroyed and therefore it is never valid to use this function with a * source ID which may have already been removed. An example is when * scheduling an idle to run in another thread with g_idle_add(): the * idle may already have run and been removed by the time this function * is called on its (now invalid) source ID. This source ID may have * been reissued, leading to the operation being performed against the * wrong source. * * Returns: (transfer none): the #GSource **/ GSource * g_main_context_find_source_by_id (GMainContext *context, guint source_id) { GSource *source; g_return_val_if_fail (source_id > 0, NULL); if (context == NULL) context = g_main_context_default (); LOCK_CONTEXT (context); source = g_hash_table_lookup (context->sources, GUINT_TO_POINTER (source_id)); UNLOCK_CONTEXT (context); if (source && SOURCE_DESTROYED (source)) source = NULL; return source; } /** * g_main_context_find_source_by_funcs_user_data: * @context: (nullable): a #GMainContext (if %NULL, the default context will be used). * @funcs: the @source_funcs passed to g_source_new(). * @user_data: the user data from the callback. * * 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. * * Returns: (transfer none): the source, if one was found, otherwise %NULL **/ GSource * g_main_context_find_source_by_funcs_user_data (GMainContext *context, GSourceFuncs *funcs, gpointer user_data) { GSourceIter iter; GSource *source; g_return_val_if_fail (funcs != NULL, NULL); if (context == NULL) context = g_main_context_default (); LOCK_CONTEXT (context); g_source_iter_init (&iter, context, FALSE); while (g_source_iter_next (&iter, &source)) { if (!SOURCE_DESTROYED (source) && source->source_funcs == funcs && source->callback_funcs) { GSourceFunc callback; gpointer callback_data; source->callback_funcs->get (source->callback_data, source, &callback, &callback_data); if (callback_data == user_data) break; } } g_source_iter_clear (&iter); UNLOCK_CONTEXT (context); return source; } /** * g_main_context_find_source_by_user_data: * @context: a #GMainContext * @user_data: the user_data for the callback. * * 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. * * Returns: (transfer none): the source, if one was found, otherwise %NULL **/ GSource * g_main_context_find_source_by_user_data (GMainContext *context, gpointer user_data) { GSourceIter iter; GSource *source; if (context == NULL) context = g_main_context_default (); LOCK_CONTEXT (context); g_source_iter_init (&iter, context, FALSE); while (g_source_iter_next (&iter, &source)) { if (!SOURCE_DESTROYED (source) && source->callback_funcs) { GSourceFunc callback; gpointer callback_data = NULL; source->callback_funcs->get (source->callback_data, source, &callback, &callback_data); if (callback_data == user_data) break; } } g_source_iter_clear (&iter); UNLOCK_CONTEXT (context); return source; } /** * g_source_remove: * @tag: the ID of the source to remove. * * Removes the source with the given ID from the default main context. You must * use g_source_destroy() for sources added to a non-default main context. * * The ID of a #GSource is given by g_source_get_id(), or will be * returned by the functions g_source_attach(), g_idle_add(), * g_idle_add_full(), g_timeout_add(), g_timeout_add_full(), * g_child_watch_add(), g_child_watch_add_full(), g_io_add_watch(), and * g_io_add_watch_full(). * * It is a programmer error to attempt to remove a non-existent source. * * More specifically: source IDs can be reissued after a source has been * destroyed and therefore it is never valid to use this function with a * source ID which may have already been removed. An example is when * scheduling an idle to run in another thread with g_idle_add(): the * idle may already have run and been removed by the time this function * is called on its (now invalid) source ID. This source ID may have * been reissued, leading to the operation being performed against the * wrong source. * * Returns: For historical reasons, this function always returns %TRUE **/ gboolean g_source_remove (guint tag) { GSource *source; g_return_val_if_fail (tag > 0, FALSE); source = g_main_context_find_source_by_id (NULL, tag); if (source) g_source_destroy (source); else g_critical ("Source ID %u was not found when attempting to remove it", tag); return source != NULL; } /** * g_source_remove_by_user_data: * @user_data: the user_data for the callback. * * Removes a source from the default main loop context given the user * data for the callback. If multiple sources exist with the same user * data, only one will be destroyed. * * Returns: %TRUE if a source was found and removed. **/ gboolean g_source_remove_by_user_data (gpointer user_data) { GSource *source; source = g_main_context_find_source_by_user_data (NULL, user_data); if (source) { g_source_destroy (source); return TRUE; } else return FALSE; } /** * g_source_remove_by_funcs_user_data: * @funcs: The @source_funcs passed to g_source_new() * @user_data: the user data for the callback * * Removes a source from the default main loop context given the * source functions and user data. If multiple sources exist with the * same source functions and user data, only one will be destroyed. * * Returns: %TRUE if a source was found and removed. **/ gboolean g_source_remove_by_funcs_user_data (GSourceFuncs *funcs, gpointer user_data) { GSource *source; g_return_val_if_fail (funcs != NULL, FALSE); source = g_main_context_find_source_by_funcs_user_data (NULL, funcs, user_data); if (source) { g_source_destroy (source); return TRUE; } else return FALSE; } /** * g_clear_handle_id: (skip) * @tag_ptr: (not nullable): a pointer to the handler ID * @clear_func: (not nullable): the function to call to clear the handler * * Clears a numeric handler, such as a #GSource ID. * * @tag_ptr must be a valid pointer to the variable holding the handler. * * If the ID is zero then this function does nothing. * Otherwise, clear_func() is called with the ID as a parameter, and the tag is * set to zero. * * A macro is also included that allows this function to be used without * pointer casts. * * Since: 2.56 */ #undef g_clear_handle_id void g_clear_handle_id (guint *tag_ptr, GClearHandleFunc clear_func) { guint _handle_id; _handle_id = *tag_ptr; if (_handle_id > 0) { *tag_ptr = 0; if (clear_func != NULL) clear_func (_handle_id); } } #ifdef G_OS_UNIX /** * g_source_add_unix_fd: * @source: a #GSource * @fd: the fd to monitor * @events: an event mask * * 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 g_source_remove_unix_fd() or * g_source_modify_unix_fd(). * * It is not necessary to remove the fd before destroying the source; it * will be cleaned up automatically. * * This API is only intended to be used by implementations of #GSource. * Do not call this API on a #GSource that you did not create. * * As the name suggests, this function is not available on Windows. * * Returns: (not nullable): an opaque tag * * Since: 2.36 **/ gpointer g_source_add_unix_fd (GSource *source, gint fd, GIOCondition events) { GMainContext *context; GPollFD *poll_fd; g_return_val_if_fail (source != NULL, NULL); g_return_val_if_fail (!SOURCE_DESTROYED (source), NULL); poll_fd = g_new (GPollFD, 1); poll_fd->fd = fd; poll_fd->events = events; poll_fd->revents = 0; context = source->context; if (context) LOCK_CONTEXT (context); source->priv->fds = g_slist_prepend (source->priv->fds, poll_fd); if (context) { if (!SOURCE_BLOCKED (source)) g_main_context_add_poll_unlocked (context, source->priority, poll_fd); UNLOCK_CONTEXT (context); } return poll_fd; } /** * g_source_modify_unix_fd: * @source: a #GSource * @tag: (not nullable): the tag from g_source_add_unix_fd() * @new_events: the new event mask to watch * * Updates the event mask to watch for the fd identified by @tag. * * @tag is the tag returned from g_source_add_unix_fd(). * * If you want to remove a fd, don't set its event mask to zero. * Instead, call g_source_remove_unix_fd(). * * This API is only intended to be used by implementations of #GSource. * Do not call this API on a #GSource that you did not create. * * As the name suggests, this function is not available on Windows. * * Since: 2.36 **/ void g_source_modify_unix_fd (GSource *source, gpointer tag, GIOCondition new_events) { GMainContext *context; GPollFD *poll_fd; g_return_if_fail (source != NULL); g_return_if_fail (g_slist_find (source->priv->fds, tag)); context = source->context; poll_fd = tag; poll_fd->events = new_events; if (context) g_main_context_wakeup (context); } /** * g_source_remove_unix_fd: * @source: a #GSource * @tag: (not nullable): the tag from g_source_add_unix_fd() * * Reverses the effect of a previous call to g_source_add_unix_fd(). * * You only need to call this if you want to remove an fd 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 #GSource. * Do not call this API on a #GSource that you did not create. * * As the name suggests, this function is not available on Windows. * * Since: 2.36 **/ void g_source_remove_unix_fd (GSource *source, gpointer tag) { GMainContext *context; GPollFD *poll_fd; g_return_if_fail (source != NULL); g_return_if_fail (g_slist_find (source->priv->fds, tag)); context = source->context; poll_fd = tag; if (context) LOCK_CONTEXT (context); source->priv->fds = g_slist_remove (source->priv->fds, poll_fd); if (context) { if (!SOURCE_BLOCKED (source)) g_main_context_remove_poll_unlocked (context, poll_fd); UNLOCK_CONTEXT (context); } g_free (poll_fd); } /** * g_source_query_unix_fd: * @source: a #GSource * @tag: (not nullable): the tag from g_source_add_unix_fd() * * Queries the events reported for the fd 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 #GSource. * Do not call this API on a #GSource that you did not create. * * As the name suggests, this function is not available on Windows. * * Returns: the conditions reported on the fd * * Since: 2.36 **/ GIOCondition g_source_query_unix_fd (GSource *source, gpointer tag) { GPollFD *poll_fd; g_return_val_if_fail (source != NULL, 0); g_return_val_if_fail (g_slist_find (source->priv->fds, tag), 0); poll_fd = tag; return poll_fd->revents; } #endif /* G_OS_UNIX */ /** * g_get_current_time: * @result: #GTimeVal structure in which to store current time. * * Equivalent to the UNIX gettimeofday() function, but portable. * * You may find g_get_real_time() to be more convenient. **/ void g_get_current_time (GTimeVal *result) { #ifndef G_OS_WIN32 struct timeval r; g_return_if_fail (result != NULL); /*this is required on alpha, there the timeval structs are int's not longs and a cast only would fail horribly*/ gettimeofday (&r, NULL); result->tv_sec = r.tv_sec; result->tv_usec = r.tv_usec; #else FILETIME ft; guint64 time64; g_return_if_fail (result != NULL); GetSystemTimeAsFileTime (&ft); memmove (&time64, &ft, sizeof (FILETIME)); /* Convert from 100s of nanoseconds since 1601-01-01 * to Unix epoch. Yes, this is Y2038 unsafe. */ time64 -= G_GINT64_CONSTANT (116444736000000000); time64 /= 10; result->tv_sec = time64 / 1000000; result->tv_usec = time64 % 1000000; #endif } /** * g_get_real_time: * * Queries the system wall-clock time. * * This call is functionally equivalent to g_get_current_time() except * that the return value is often more convenient than dealing with a * #GTimeVal. * * You should only use this call if you are actually interested in the real * wall-clock time. g_get_monotonic_time() is probably more useful for * measuring intervals. * * Returns: the number of microseconds since January 1, 1970 UTC. * * Since: 2.28 **/ gint64 g_get_real_time (void) { GTimeVal tv; g_get_current_time (&tv); return (((gint64) tv.tv_sec) * 1000000) + tv.tv_usec; } /** * g_get_monotonic_time: * * Queries the system monotonic time. * * The monotonic clock will always increase and doesn't suffer * discontinuities when the user (or NTP) changes the system time. It * may or may not continue to tick during times where the machine is * suspended. * * We try to use the clock that corresponds as closely as possible to * the passage of time as measured by system calls such as poll() but it * may not always be possible to do this. * * Returns: the monotonic time, in microseconds * * Since: 2.28 **/ #if defined (G_OS_WIN32) /* NOTE: * time_usec = ticks_since_boot * usec_per_sec / ticks_per_sec * * Doing (ticks_since_boot * usec_per_sec) before the division can overflow 64 bits * (ticks_since_boot / ticks_per_sec) and then multiply would not be accurate enough. * So for now we calculate (usec_per_sec / ticks_per_sec) and use floating point */ static gdouble g_monotonic_usec_per_tick = 0; void g_clock_win32_init (void) { LARGE_INTEGER freq; if (!QueryPerformanceFrequency (&freq) || freq.QuadPart == 0) { /* The documentation says that this should never happen */ g_assert_not_reached (); return; } g_monotonic_usec_per_tick = (gdouble)G_USEC_PER_SEC / freq.QuadPart; } gint64 g_get_monotonic_time (void) { if (G_LIKELY (g_monotonic_usec_per_tick != 0)) { LARGE_INTEGER ticks; if (QueryPerformanceCounter (&ticks)) return (gint64)(ticks.QuadPart * g_monotonic_usec_per_tick); g_warning ("QueryPerformanceCounter Failed (%lu)", GetLastError ()); g_monotonic_usec_per_tick = 0; } return 0; } #elif defined(HAVE_MACH_MACH_TIME_H) /* Mac OS */ gint64 g_get_monotonic_time (void) { static mach_timebase_info_data_t timebase_info; if (timebase_info.denom == 0) { /* This is a fraction that we must use to scale * mach_absolute_time() by in order to reach nanoseconds. * * We've only ever observed this to be 1/1, but maybe it could be * 1000/1 if mach time is microseconds already, or 1/1000 if * picoseconds. Try to deal nicely with that. */ mach_timebase_info (&timebase_info); /* We actually want microseconds... */ if (timebase_info.numer % 1000 == 0) timebase_info.numer /= 1000; else timebase_info.denom *= 1000; /* We want to make the numer 1 to avoid having to multiply... */ if (timebase_info.denom % timebase_info.numer == 0) { timebase_info.denom /= timebase_info.numer; timebase_info.numer = 1; } else { /* We could just multiply by timebase_info.numer below, but why * bother for a case that may never actually exist... * * Plus -- performing the multiplication would risk integer * overflow. If we ever actually end up in this situation, we * should more carefully evaluate the correct course of action. */ mach_timebase_info (&timebase_info); /* Get a fresh copy for a better message */ g_error ("Got weird mach timebase info of %d/%d. Please file a bug against GLib.", timebase_info.numer, timebase_info.denom); } } return mach_absolute_time () / timebase_info.denom; } #else gint64 g_get_monotonic_time (void) { struct timespec ts; gint result; result = clock_gettime (CLOCK_MONOTONIC, &ts); if G_UNLIKELY (result != 0) g_error ("GLib requires working CLOCK_MONOTONIC"); return (((gint64) ts.tv_sec) * 1000000) + (ts.tv_nsec / 1000); } #endif static void g_main_dispatch_free (gpointer dispatch) { g_slice_free (GMainDispatch, dispatch); } /* Running the main loop */ static GMainDispatch * get_dispatch (void) { static GPrivate depth_private = G_PRIVATE_INIT (g_main_dispatch_free); GMainDispatch *dispatch; dispatch = g_private_get (&depth_private); if (!dispatch) { dispatch = g_slice_new0 (GMainDispatch); g_private_set (&depth_private, dispatch); } return dispatch; } /** * g_main_depth: * * Returns the depth of the stack of calls to * g_main_context_dispatch() on any #GMainContext in the current thread. * That is, when called from the toplevel, it gives 0. When * called from within a callback from g_main_context_iteration() * (or g_main_loop_run(), etc.) it returns 1. When called from within * a callback to a recursive call to g_main_context_iteration(), * it returns 2. And so forth. * * This function is useful in a situation like the following: * Imagine an extremely simple "garbage collected" system. * * |[ * static GList *free_list; * * gpointer * allocate_memory (gsize size) * { * gpointer result = g_malloc (size); * free_list = g_list_prepend (free_list, result); * return result; * } * * void * free_allocated_memory (void) * { * GList *l; * for (l = free_list; l; l = l->next); * g_free (l->data); * g_list_free (free_list); * free_list = NULL; * } * * [...] * * while (TRUE); * { * g_main_context_iteration (NULL, TRUE); * free_allocated_memory(); * } * ]| * * This works from an application, however, if you want to do the same * thing from a library, it gets more difficult, since you no longer * control the main loop. You might think you can simply use an idle * function to make the call to free_allocated_memory(), but that * doesn't work, since the idle function could be called from a * recursive callback. This can be fixed by using g_main_depth() * * |[ * gpointer * allocate_memory (gsize size) * { * FreeListBlock *block = g_new (FreeListBlock, 1); * block->mem = g_malloc (size); * block->depth = g_main_depth (); * free_list = g_list_prepend (free_list, block); * return block->mem; * } * * void * free_allocated_memory (void) * { * GList *l; * * int depth = g_main_depth (); * for (l = free_list; l; ); * { * GList *next = l->next; * FreeListBlock *block = l->data; * if (block->depth > depth) * { * g_free (block->mem); * g_free (block); * free_list = g_list_delete_link (free_list, l); * } * * l = next; * } * } * ]| * * There is a temptation to use g_main_depth() to solve * problems with reentrancy. For instance, while waiting for data * to be received from the network in response to a menu item, * the menu item might be selected again. It might seem that * one could make the menu item's callback return immediately * and do nothing if g_main_depth() returns a value greater than 1. * However, this should be avoided since the user then sees selecting * the menu item do nothing. Furthermore, you'll find yourself adding * these checks all over your code, since there are doubtless many, * many things that the user could do. Instead, you can use the * following techniques: * * 1. Use gtk_widget_set_sensitive() or modal dialogs to prevent * the user from interacting with elements while the main * loop is recursing. * * 2. Avoid main loop recursion in situations where you can't handle * arbitrary callbacks. Instead, structure your code so that you * simply return to the main loop and then get called again when * there is more work to do. * * Returns: The main loop recursion level in the current thread */ int g_main_depth (void) { GMainDispatch *dispatch = get_dispatch (); return dispatch->depth; } /** * g_main_current_source: * * Returns the currently firing source for this thread. * * Returns: (transfer none): The currently firing source or %NULL. * * Since: 2.12 */ GSource * g_main_current_source (void) { GMainDispatch *dispatch = get_dispatch (); return dispatch->source; } /** * g_source_is_destroyed: * @source: a #GSource * * 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. * * |[ * static gboolean * idle_callback (gpointer data) * { * SomeWidget *self = data; * * GDK_THREADS_ENTER (); * // do stuff with self * self->idle_id = 0; * GDK_THREADS_LEAVE (); * * return G_SOURCE_REMOVE; * } * * static void * some_widget_do_stuff_later (SomeWidget *self) * { * self->idle_id = g_idle_add (idle_callback, self); * } * * static void * some_widget_finalize (GObject *object) * { * SomeWidget *self = SOME_WIDGET (object); * * if (self->idle_id) * g_source_remove (self->idle_id); * * 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. * * |[ * static gboolean * idle_callback (gpointer data) * { * SomeWidget *self = data; * * GDK_THREADS_ENTER (); * if (!g_source_is_destroyed (g_main_current_source ())) * { * // do stuff with self * } * GDK_THREADS_LEAVE (); * * return FALSE; * } * ]| * * Calls to this function from a thread other than the one acquired by the * #GMainContext the #GSource 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. * * Returns: %TRUE if the source has been destroyed * * Since: 2.12 */ gboolean g_source_is_destroyed (GSource *source) { return SOURCE_DESTROYED (source); } /* Temporarily remove all this source's file descriptors from the * poll(), so that if data comes available for one of the file descriptors * we don't continually spin in the poll() */ /* HOLDS: source->context's lock */ static void block_source (GSource *source) { GSList *tmp_list; g_return_if_fail (!SOURCE_BLOCKED (source)); source->flags |= G_SOURCE_BLOCKED; if (source->context) { tmp_list = source->poll_fds; while (tmp_list) { g_main_context_remove_poll_unlocked (source->context, tmp_list->data); tmp_list = tmp_list->next; } for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next) g_main_context_remove_poll_unlocked (source->context, tmp_list->data); } if (source->priv && source->priv->child_sources) { tmp_list = source->priv->child_sources; while (tmp_list) { block_source (tmp_list->data); tmp_list = tmp_list->next; } } } /* HOLDS: source->context's lock */ static void unblock_source (GSource *source) { GSList *tmp_list; g_return_if_fail (SOURCE_BLOCKED (source)); /* Source already unblocked */ g_return_if_fail (!SOURCE_DESTROYED (source)); source->flags &= ~G_SOURCE_BLOCKED; tmp_list = source->poll_fds; while (tmp_list) { g_main_context_add_poll_unlocked (source->context, source->priority, tmp_list->data); tmp_list = tmp_list->next; } for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next) g_main_context_add_poll_unlocked (source->context, source->priority, tmp_list->data); if (source->priv && source->priv->child_sources) { tmp_list = source->priv->child_sources; while (tmp_list) { unblock_source (tmp_list->data); tmp_list = tmp_list->next; } } } /* HOLDS: context's lock */ static void g_main_dispatch (GMainContext *context) { GMainDispatch *current = get_dispatch (); guint i; for (i = 0; i < context->pending_dispatches->len; i++) { GSource *source = context->pending_dispatches->pdata[i]; context->pending_dispatches->pdata[i] = NULL; g_assert (source); source->flags &= ~G_SOURCE_READY; if (!SOURCE_DESTROYED (source)) { gboolean was_in_call; gpointer user_data = NULL; GSourceFunc callback = NULL; GSourceCallbackFuncs *cb_funcs; gpointer cb_data; gboolean need_destroy; gboolean (*dispatch) (GSource *, GSourceFunc, gpointer); GSource *prev_source; dispatch = source->source_funcs->dispatch; cb_funcs = source->callback_funcs; cb_data = source->callback_data; if (cb_funcs) cb_funcs->ref (cb_data); if ((source->flags & G_SOURCE_CAN_RECURSE) == 0) block_source (source); was_in_call = source->flags & G_HOOK_FLAG_IN_CALL; source->flags |= G_HOOK_FLAG_IN_CALL; if (cb_funcs) cb_funcs->get (cb_data, source, &callback, &user_data); UNLOCK_CONTEXT (context); /* These operations are safe because 'current' is thread-local * and not modified from anywhere but this function. */ prev_source = current->source; current->source = source; current->depth++; TRACE (GLIB_MAIN_BEFORE_DISPATCH (g_source_get_name (source), source, dispatch, callback, user_data)); need_destroy = !(* dispatch) (source, callback, user_data); TRACE (GLIB_MAIN_AFTER_DISPATCH (g_source_get_name (source), source, dispatch, need_destroy)); current->source = prev_source; current->depth--; if (cb_funcs) cb_funcs->unref (cb_data); LOCK_CONTEXT (context); if (!was_in_call) source->flags &= ~G_HOOK_FLAG_IN_CALL; if (SOURCE_BLOCKED (source) && !SOURCE_DESTROYED (source)) unblock_source (source); /* Note: this depends on the fact that we can't switch * sources from one main context to another */ if (need_destroy && !SOURCE_DESTROYED (source)) { g_assert (source->context == context); g_source_destroy_internal (source, context, TRUE); } } SOURCE_UNREF (source, context); } g_ptr_array_set_size (context->pending_dispatches, 0); } /** * g_main_context_acquire: * @context: a #GMainContext * * 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 g_main_context_release() * is called as many times as g_main_context_acquire(). * * You must be the owner of a context before you * can call g_main_context_prepare(), g_main_context_query(), * g_main_context_check(), g_main_context_dispatch(). * * Returns: %TRUE if the operation succeeded, and * this thread is now the owner of @context. **/ gboolean g_main_context_acquire (GMainContext *context) { gboolean result = FALSE; GThread *self = G_THREAD_SELF; if (context == NULL) context = g_main_context_default (); LOCK_CONTEXT (context); if (!context->owner) { context->owner = self; g_assert (context->owner_count == 0); TRACE (GLIB_MAIN_CONTEXT_ACQUIRE (context, TRUE /* success */)); } if (context->owner == self) { context->owner_count++; result = TRUE; } else { TRACE (GLIB_MAIN_CONTEXT_ACQUIRE (context, FALSE /* failure */)); } UNLOCK_CONTEXT (context); return result; } /** * g_main_context_release: * @context: a #GMainContext * * Releases ownership of a context previously acquired by this thread * with g_main_context_acquire(). If the context was acquired multiple * times, the ownership will be released only when g_main_context_release() * is called as many times as it was acquired. **/ void g_main_context_release (GMainContext *context) { if (context == NULL) context = g_main_context_default (); LOCK_CONTEXT (context); context->owner_count--; if (context->owner_count == 0) { TRACE (GLIB_MAIN_CONTEXT_RELEASE (context)); context->owner = NULL; if (context->waiters) { GMainWaiter *waiter = context->waiters->data; gboolean loop_internal_waiter = (waiter->mutex == &context->mutex); context->waiters = g_slist_delete_link (context->waiters, context->waiters); if (!loop_internal_waiter) g_mutex_lock (waiter->mutex); g_cond_signal (waiter->cond); if (!loop_internal_waiter) g_mutex_unlock (waiter->mutex); } } UNLOCK_CONTEXT (context); } /** * g_main_context_wait: * @context: a #GMainContext * @cond: a condition variable * @mutex: a mutex, currently held * * Tries to become the owner of the specified context, * as with g_main_context_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. * * Returns: %TRUE if the operation succeeded, and * this thread is now the owner of @context. **/ gboolean g_main_context_wait (GMainContext *context, GCond *cond, GMutex *mutex) { gboolean result = FALSE; GThread *self = G_THREAD_SELF; gboolean loop_internal_waiter; if (context == NULL) context = g_main_context_default (); if G_UNLIKELY (cond != &context->cond || mutex != &context->mutex) { static gboolean warned; if (!warned) { g_critical ("WARNING!! g_main_context_wait() will be removed in a future release. " "If you see this message, please file a bug immediately."); warned = TRUE; } } loop_internal_waiter = (mutex == &context->mutex); if (!loop_internal_waiter) LOCK_CONTEXT (context); if (context->owner && context->owner != self) { GMainWaiter waiter; waiter.cond = cond; waiter.mutex = mutex; context->waiters = g_slist_append (context->waiters, &waiter); if (!loop_internal_waiter) UNLOCK_CONTEXT (context); g_cond_wait (cond, mutex); if (!loop_internal_waiter) LOCK_CONTEXT (context); context->waiters = g_slist_remove (context->waiters, &waiter); } if (!context->owner) { context->owner = self; g_assert (context->owner_count == 0); } if (context->owner == self) { context->owner_count++; result = TRUE; } if (!loop_internal_waiter) UNLOCK_CONTEXT (context); return result; } /** * g_main_context_prepare: * @context: a #GMainContext * @priority: location to store priority of highest priority * source already ready. * * Prepares to poll sources within a main loop. The resulting information * for polling is determined by calling g_main_context_query (). * * You must have successfully acquired the context with * g_main_context_acquire() before you may call this function. * * Returns: %TRUE if some source is ready to be dispatched * prior to polling. **/ gboolean g_main_context_prepare (GMainContext *context, gint *priority) { guint i; gint n_ready = 0; gint current_priority = G_MAXINT; GSource *source; GSourceIter iter; if (context == NULL) context = g_main_context_default (); LOCK_CONTEXT (context); context->time_is_fresh = FALSE; if (context->in_check_or_prepare) { g_warning ("g_main_context_prepare() called recursively from within a source's check() or " "prepare() member."); UNLOCK_CONTEXT (context); return FALSE; } TRACE (GLIB_MAIN_CONTEXT_BEFORE_PREPARE (context)); #if 0 /* If recursing, finish up current dispatch, before starting over */ if (context->pending_dispatches) { if (dispatch) g_main_dispatch (context, ¤t_time); UNLOCK_CONTEXT (context); return TRUE; } #endif /* If recursing, clear list of pending dispatches */ for (i = 0; i < context->pending_dispatches->len; i++) { if (context->pending_dispatches->pdata[i]) SOURCE_UNREF ((GSource *)context->pending_dispatches->pdata[i], context); } g_ptr_array_set_size (context->pending_dispatches, 0); /* Prepare all sources */ context->timeout = -1; g_source_iter_init (&iter, context, TRUE); while (g_source_iter_next (&iter, &source)) { gint source_timeout = -1; if (SOURCE_DESTROYED (source) || SOURCE_BLOCKED (source)) continue; if ((n_ready > 0) && (source->priority > current_priority)) break; if (!(source->flags & G_SOURCE_READY)) { gboolean result; gboolean (* prepare) (GSource *source, gint *timeout); prepare = source->source_funcs->prepare; if (prepare) { context->in_check_or_prepare++; UNLOCK_CONTEXT (context); result = (* prepare) (source, &source_timeout); TRACE (GLIB_MAIN_AFTER_PREPARE (source, prepare, source_timeout)); LOCK_CONTEXT (context); context->in_check_or_prepare--; } else { source_timeout = -1; result = FALSE; } if (result == FALSE && source->priv->ready_time != -1) { if (!context->time_is_fresh) { context->time = g_get_monotonic_time (); context->time_is_fresh = TRUE; } if (source->priv->ready_time <= context->time) { source_timeout = 0; result = TRUE; } else { gint timeout; /* rounding down will lead to spinning, so always round up */ timeout = (source->priv->ready_time - context->time + 999) / 1000; if (source_timeout < 0 || timeout < source_timeout) source_timeout = timeout; } } if (result) { GSource *ready_source = source; while (ready_source) { ready_source->flags |= G_SOURCE_READY; ready_source = ready_source->priv->parent_source; } } } if (source->flags & G_SOURCE_READY) { n_ready++; current_priority = source->priority; context->timeout = 0; } if (source_timeout >= 0) { if (context->timeout < 0) context->timeout = source_timeout; else context->timeout = MIN (context->timeout, source_timeout); } } g_source_iter_clear (&iter); TRACE (GLIB_MAIN_CONTEXT_AFTER_PREPARE (context, current_priority, n_ready)); UNLOCK_CONTEXT (context); if (priority) *priority = current_priority; return (n_ready > 0); } /** * g_main_context_query: * @context: a #GMainContext * @max_priority: maximum priority source to check * @timeout_: (out): location to store timeout to be used in polling * @fds: (out caller-allocates) (array length=n_fds): location to * store #GPollFD records that need to be polled. * @n_fds: (in): length of @fds. * * Determines information necessary to poll this main loop. * * You must have successfully acquired the context with * g_main_context_acquire() before you may call this function. * * Returns: the number of records actually stored in @fds, * or, if more than @n_fds records need to be stored, the number * of records that need to be stored. **/ gint g_main_context_query (GMainContext *context, gint max_priority, gint *timeout, GPollFD *fds, gint n_fds) { gint n_poll; GPollRec *pollrec, *lastpollrec; gushort events; LOCK_CONTEXT (context); TRACE (GLIB_MAIN_CONTEXT_BEFORE_QUERY (context, max_priority)); n_poll = 0; lastpollrec = NULL; for (pollrec = context->poll_records; pollrec; pollrec = pollrec->next) { if (pollrec->priority > max_priority) continue; /* In direct contradiction to the Unix98 spec, IRIX runs into * difficulty if you pass in POLLERR, POLLHUP or POLLNVAL * flags in the events field of the pollfd while it should * just ignoring them. So we mask them out here. */ events = pollrec->fd->events & ~(G_IO_ERR|G_IO_HUP|G_IO_NVAL); if (lastpollrec && pollrec->fd->fd == lastpollrec->fd->fd) { if (n_poll - 1 < n_fds) fds[n_poll - 1].events |= events; } else { if (n_poll < n_fds) { fds[n_poll].fd = pollrec->fd->fd; fds[n_poll].events = events; fds[n_poll].revents = 0; } n_poll++; } lastpollrec = pollrec; } context->poll_changed = FALSE; if (timeout) { *timeout = context->timeout; if (*timeout != 0) context->time_is_fresh = FALSE; } TRACE (GLIB_MAIN_CONTEXT_AFTER_QUERY (context, context->timeout, fds, n_poll)); UNLOCK_CONTEXT (context); return n_poll; } /** * g_main_context_check: * @context: a #GMainContext * @max_priority: the maximum numerical priority of sources to check * @fds: (array length=n_fds): array of #GPollFD's that was passed to * the last call to g_main_context_query() * @n_fds: return value of g_main_context_query() * * Passes the results of polling back to the main loop. * * You must have successfully acquired the context with * g_main_context_acquire() before you may call this function. * * Returns: %TRUE if some sources are ready to be dispatched. **/ gboolean g_main_context_check (GMainContext *context, gint max_priority, GPollFD *fds, gint n_fds) { GSource *source; GSourceIter iter; GPollRec *pollrec; gint n_ready = 0; gint i; LOCK_CONTEXT (context); if (context->in_check_or_prepare) { g_warning ("g_main_context_check() called recursively from within a source's check() or " "prepare() member."); UNLOCK_CONTEXT (context); return FALSE; } TRACE (GLIB_MAIN_CONTEXT_BEFORE_CHECK (context, max_priority, fds, n_fds)); for (i = 0; i < n_fds; i++) { if (fds[i].fd == context->wake_up_rec.fd) { if (fds[i].revents) { TRACE (GLIB_MAIN_CONTEXT_WAKEUP_ACKNOWLEDGE (context)); g_wakeup_acknowledge (context->wakeup); } break; } } /* If the set of poll file descriptors changed, bail out * and let the main loop rerun */ if (context->poll_changed) { TRACE (GLIB_MAIN_CONTEXT_AFTER_CHECK (context, 0)); UNLOCK_CONTEXT (context); return FALSE; } pollrec = context->poll_records; i = 0; while (pollrec && i < n_fds) { while (pollrec && pollrec->fd->fd == fds[i].fd) { if (pollrec->priority <= max_priority) { pollrec->fd->revents = fds[i].revents & (pollrec->fd->events | G_IO_ERR | G_IO_HUP | G_IO_NVAL); } pollrec = pollrec->next; } i++; } g_source_iter_init (&iter, context, TRUE); while (g_source_iter_next (&iter, &source)) { if (SOURCE_DESTROYED (source) || SOURCE_BLOCKED (source)) continue; if ((n_ready > 0) && (source->priority > max_priority)) break; if (!(source->flags & G_SOURCE_READY)) { gboolean result; gboolean (* check) (GSource *source); check = source->source_funcs->check; if (check) { /* If the check function is set, call it. */ context->in_check_or_prepare++; UNLOCK_CONTEXT (context); result = (* check) (source); TRACE (GLIB_MAIN_AFTER_CHECK (source, check, result)); LOCK_CONTEXT (context); context->in_check_or_prepare--; } else result = FALSE; if (result == FALSE) { GSList *tmp_list; /* If not already explicitly flagged ready by ->check() * (or if we have no check) then we can still be ready if * any of our fds poll as ready. */ for (tmp_list = source->priv->fds; tmp_list; tmp_list = tmp_list->next) { GPollFD *pollfd = tmp_list->data; if (pollfd->revents) { result = TRUE; break; } } } if (result == FALSE && source->priv->ready_time != -1) { if (!context->time_is_fresh) { context->time = g_get_monotonic_time (); context->time_is_fresh = TRUE; } if (source->priv->ready_time <= context->time) result = TRUE; } if (result) { GSource *ready_source = source; while (ready_source) { ready_source->flags |= G_SOURCE_READY; ready_source = ready_source->priv->parent_source; } } } if (source->flags & G_SOURCE_READY) { source->ref_count++; g_ptr_array_add (context->pending_dispatches, source); n_ready++; /* never dispatch sources with less priority than the first * one we choose to dispatch */ max_priority = source->priority; } } g_source_iter_clear (&iter); TRACE (GLIB_MAIN_CONTEXT_AFTER_CHECK (context, n_ready)); UNLOCK_CONTEXT (context); return n_ready > 0; } /** * g_main_context_dispatch: * @context: a #GMainContext * * Dispatches all pending sources. * * You must have successfully acquired the context with * g_main_context_acquire() before you may call this function. **/ void g_main_context_dispatch (GMainContext *context) { LOCK_CONTEXT (context); TRACE (GLIB_MAIN_CONTEXT_BEFORE_DISPATCH (context)); if (context->pending_dispatches->len > 0) { g_main_dispatch (context); } TRACE (GLIB_MAIN_CONTEXT_AFTER_DISPATCH (context)); UNLOCK_CONTEXT (context); } /* HOLDS context lock */ static gboolean g_main_context_iterate (GMainContext *context, gboolean block, gboolean dispatch, GThread *self) { gint max_priority; gint timeout; gboolean some_ready; gint nfds, allocated_nfds; GPollFD *fds = NULL; UNLOCK_CONTEXT (context); if (!g_main_context_acquire (context)) { gboolean got_ownership; LOCK_CONTEXT (context); if (!block) return FALSE; got_ownership = g_main_context_wait (context, &context->cond, &context->mutex); if (!got_ownership) return FALSE; } else LOCK_CONTEXT (context); if (!context->cached_poll_array) { context->cached_poll_array_size = context->n_poll_records; context->cached_poll_array = g_new (GPollFD, context->n_poll_records); } allocated_nfds = context->cached_poll_array_size; fds = context->cached_poll_array; UNLOCK_CONTEXT (context); g_main_context_prepare (context, &max_priority); while ((nfds = g_main_context_query (context, max_priority, &timeout, fds, allocated_nfds)) > allocated_nfds) { LOCK_CONTEXT (context); g_free (fds); context->cached_poll_array_size = allocated_nfds = nfds; context->cached_poll_array = fds = g_new (GPollFD, nfds); UNLOCK_CONTEXT (context); } if (!block) timeout = 0; g_main_context_poll (context, timeout, max_priority, fds, nfds); some_ready = g_main_context_check (context, max_priority, fds, nfds); if (dispatch) g_main_context_dispatch (context); g_main_context_release (context); LOCK_CONTEXT (context); return some_ready; } /** * g_main_context_pending: * @context: (nullable): a #GMainContext (if %NULL, the default context will be used) * * Checks if any sources have pending events for the given context. * * Returns: %TRUE if events are pending. **/ gboolean g_main_context_pending (GMainContext *context) { gboolean retval; if (!context) context = g_main_context_default(); LOCK_CONTEXT (context); retval = g_main_context_iterate (context, FALSE, FALSE, G_THREAD_SELF); UNLOCK_CONTEXT (context); return retval; } /** * g_main_context_iteration: * @context: (nullable): a #GMainContext (if %NULL, the default context will be used) * @may_block: whether the call may block. * * 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. * * Note that even when @may_block is %TRUE, it is still possible for * g_main_context_iteration() to return %FALSE, since the wait may * be interrupted for other reasons than an event source becoming ready. * * Returns: %TRUE if events were dispatched. **/ gboolean g_main_context_iteration (GMainContext *context, gboolean may_block) { gboolean retval; if (!context) context = g_main_context_default(); LOCK_CONTEXT (context); retval = g_main_context_iterate (context, may_block, TRUE, G_THREAD_SELF); UNLOCK_CONTEXT (context); return retval; } /** * g_main_loop_new: * @context: (nullable): a #GMainContext (if %NULL, the default context will be used). * @is_running: set to %TRUE to indicate that the loop is running. This * is not very important since calling g_main_loop_run() will set this to * %TRUE anyway. * * Creates a new #GMainLoop structure. * * Returns: a new #GMainLoop. **/ GMainLoop * g_main_loop_new (GMainContext *context, gboolean is_running) { GMainLoop *loop; if (!context) context = g_main_context_default(); g_main_context_ref (context); loop = g_new0 (GMainLoop, 1); loop->context = context; loop->is_running = is_running != FALSE; loop->ref_count = 1; TRACE (GLIB_MAIN_LOOP_NEW (loop, context)); return loop; } /** * g_main_loop_ref: * @loop: a #GMainLoop * * Increases the reference count on a #GMainLoop object by one. * * Returns: @loop **/ GMainLoop * g_main_loop_ref (GMainLoop *loop) { g_return_val_if_fail (loop != NULL, NULL); g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, NULL); g_atomic_int_inc (&loop->ref_count); return loop; } /** * g_main_loop_unref: * @loop: a #GMainLoop * * Decreases the reference count on a #GMainLoop object by one. If * the result is zero, free the loop and free all associated memory. **/ void g_main_loop_unref (GMainLoop *loop) { g_return_if_fail (loop != NULL); g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0); if (!g_atomic_int_dec_and_test (&loop->ref_count)) return; g_main_context_unref (loop->context); g_free (loop); } /** * g_main_loop_run: * @loop: a #GMainLoop * * Runs a main loop until g_main_loop_quit() is called on the loop. * If this is called for the thread of the loop's #GMainContext, * it will process events from the loop, otherwise it will * simply wait. **/ void g_main_loop_run (GMainLoop *loop) { GThread *self = G_THREAD_SELF; g_return_if_fail (loop != NULL); g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0); if (!g_main_context_acquire (loop->context)) { gboolean got_ownership = FALSE; /* Another thread owns this context */ LOCK_CONTEXT (loop->context); g_atomic_int_inc (&loop->ref_count); if (!loop->is_running) loop->is_running = TRUE; while (loop->is_running && !got_ownership) got_ownership = g_main_context_wait (loop->context, &loop->context->cond, &loop->context->mutex); if (!loop->is_running) { UNLOCK_CONTEXT (loop->context); if (got_ownership) g_main_context_release (loop->context); g_main_loop_unref (loop); return; } g_assert (got_ownership); } else LOCK_CONTEXT (loop->context); if (loop->context->in_check_or_prepare) { g_warning ("g_main_loop_run(): called recursively from within a source's " "check() or prepare() member, iteration not possible."); return; } g_atomic_int_inc (&loop->ref_count); loop->is_running = TRUE; while (loop->is_running) g_main_context_iterate (loop->context, TRUE, TRUE, self); UNLOCK_CONTEXT (loop->context); g_main_context_release (loop->context); g_main_loop_unref (loop); } /** * g_main_loop_quit: * @loop: a #GMainLoop * * Stops a #GMainLoop from running. Any calls to g_main_loop_run() * for the loop will return. * * Note that sources that have already been dispatched when * g_main_loop_quit() is called will still be executed. **/ void g_main_loop_quit (GMainLoop *loop) { g_return_if_fail (loop != NULL); g_return_if_fail (g_atomic_int_get (&loop->ref_count) > 0); LOCK_CONTEXT (loop->context); loop->is_running = FALSE; g_wakeup_signal (loop->context->wakeup); g_cond_broadcast (&loop->context->cond); UNLOCK_CONTEXT (loop->context); TRACE (GLIB_MAIN_LOOP_QUIT (loop)); } /** * g_main_loop_is_running: * @loop: a #GMainLoop. * * Checks to see if the main loop is currently being run via g_main_loop_run(). * * Returns: %TRUE if the mainloop is currently being run. **/ gboolean g_main_loop_is_running (GMainLoop *loop) { g_return_val_if_fail (loop != NULL, FALSE); g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, FALSE); return loop->is_running; } /** * g_main_loop_get_context: * @loop: a #GMainLoop. * * Returns the #GMainContext of @loop. * * Returns: (transfer none): the #GMainContext of @loop **/ GMainContext * g_main_loop_get_context (GMainLoop *loop) { g_return_val_if_fail (loop != NULL, NULL); g_return_val_if_fail (g_atomic_int_get (&loop->ref_count) > 0, NULL); return loop->context; } /* HOLDS: context's lock */ static void g_main_context_poll (GMainContext *context, gint timeout, gint priority, GPollFD *fds, gint n_fds) { #ifdef G_MAIN_POLL_DEBUG GTimer *poll_timer; GPollRec *pollrec; gint i; #endif GPollFunc poll_func; if (n_fds || timeout != 0) { int ret, errsv; #ifdef G_MAIN_POLL_DEBUG poll_timer = NULL; if (_g_main_poll_debug) { g_print ("polling context=%p n=%d timeout=%d\n", context, n_fds, timeout); poll_timer = g_timer_new (); } #endif LOCK_CONTEXT (context); poll_func = context->poll_func; UNLOCK_CONTEXT (context); ret = (*poll_func) (fds, n_fds, timeout); errsv = errno; if (ret < 0 && errsv != EINTR) { #ifndef G_OS_WIN32 g_warning ("poll(2) failed due to: %s.", g_strerror (errsv)); #else /* If g_poll () returns -1, it has already called g_warning() */ #endif } #ifdef G_MAIN_POLL_DEBUG if (_g_main_poll_debug) { LOCK_CONTEXT (context); g_print ("g_main_poll(%d) timeout: %d - elapsed %12.10f seconds", n_fds, timeout, g_timer_elapsed (poll_timer, NULL)); g_timer_destroy (poll_timer); pollrec = context->poll_records; while (pollrec != NULL) { i = 0; while (i < n_fds) { if (fds[i].fd == pollrec->fd->fd && pollrec->fd->events && fds[i].revents) { g_print (" [" G_POLLFD_FORMAT " :", fds[i].fd); if (fds[i].revents & G_IO_IN) g_print ("i"); if (fds[i].revents & G_IO_OUT) g_print ("o"); if (fds[i].revents & G_IO_PRI) g_print ("p"); if (fds[i].revents & G_IO_ERR) g_print ("e"); if (fds[i].revents & G_IO_HUP) g_print ("h"); if (fds[i].revents & G_IO_NVAL) g_print ("n"); g_print ("]"); } i++; } pollrec = pollrec->next; } g_print ("\n"); UNLOCK_CONTEXT (context); } #endif } /* if (n_fds || timeout != 0) */ } /** * g_main_context_add_poll: * @context: (nullable): a #GMainContext (or %NULL for the default context) * @fd: a #GPollFD structure holding information about a file * descriptor to watch. * @priority: the priority for this file descriptor which should be * the same as the priority used for g_source_attach() to ensure that the * file descriptor is polled whenever the results may be needed. * * 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 g_source_add_unix_fd() instead. **/ void g_main_context_add_poll (GMainContext *context, GPollFD *fd, gint priority) { if (!context) context = g_main_context_default (); g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0); g_return_if_fail (fd); LOCK_CONTEXT (context); g_main_context_add_poll_unlocked (context, priority, fd); UNLOCK_CONTEXT (context); } /* HOLDS: main_loop_lock */ static void g_main_context_add_poll_unlocked (GMainContext *context, gint priority, GPollFD *fd) { GPollRec *prevrec, *nextrec; GPollRec *newrec = g_slice_new (GPollRec); /* This file descriptor may be checked before we ever poll */ fd->revents = 0; newrec->fd = fd; newrec->priority = priority; prevrec = NULL; nextrec = context->poll_records; while (nextrec) { if (nextrec->fd->fd > fd->fd) break; prevrec = nextrec; nextrec = nextrec->next; } if (prevrec) prevrec->next = newrec; else context->poll_records = newrec; newrec->prev = prevrec; newrec->next = nextrec; if (nextrec) nextrec->prev = newrec; context->n_poll_records++; context->poll_changed = TRUE; /* Now wake up the main loop if it is waiting in the poll() */ g_wakeup_signal (context->wakeup); } /** * g_main_context_remove_poll: * @context:a #GMainContext * @fd: a #GPollFD descriptor previously added with g_main_context_add_poll() * * Removes file descriptor from the set of file descriptors to be * polled for a particular context. **/ void g_main_context_remove_poll (GMainContext *context, GPollFD *fd) { if (!context) context = g_main_context_default (); g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0); g_return_if_fail (fd); LOCK_CONTEXT (context); g_main_context_remove_poll_unlocked (context, fd); UNLOCK_CONTEXT (context); } static void g_main_context_remove_poll_unlocked (GMainContext *context, GPollFD *fd) { GPollRec *pollrec, *prevrec, *nextrec; prevrec = NULL; pollrec = context->poll_records; while (pollrec) { nextrec = pollrec->next; if (pollrec->fd == fd) { if (prevrec != NULL) prevrec->next = nextrec; else context->poll_records = nextrec; if (nextrec != NULL) nextrec->prev = prevrec; g_slice_free (GPollRec, pollrec); context->n_poll_records--; break; } prevrec = pollrec; pollrec = nextrec; } context->poll_changed = TRUE; /* Now wake up the main loop if it is waiting in the poll() */ g_wakeup_signal (context->wakeup); } /** * g_source_get_current_time: * @source: a #GSource * @timeval: #GTimeVal structure in which to store current time. * * This function ignores @source and is otherwise the same as * g_get_current_time(). * * Deprecated: 2.28: use g_source_get_time() instead **/ void g_source_get_current_time (GSource *source, GTimeVal *timeval) { g_get_current_time (timeval); } /** * g_source_get_time: * @source: a #GSource * * Gets the time to be used when checking this source. The advantage of * calling this function over calling g_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 g_get_monotonic_time(). * * Returns: the monotonic time in microseconds * * Since: 2.28 **/ gint64 g_source_get_time (GSource *source) { GMainContext *context; gint64 result; g_return_val_if_fail (source->context != NULL, 0); context = source->context; LOCK_CONTEXT (context); if (!context->time_is_fresh) { context->time = g_get_monotonic_time (); context->time_is_fresh = TRUE; } result = context->time; UNLOCK_CONTEXT (context); return result; } /** * g_main_context_set_poll_func: * @context: a #GMainContext * @func: the function to call to poll all file descriptors * * 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). * * This function could possibly be used to integrate the GLib event * loop with an external event loop. **/ void g_main_context_set_poll_func (GMainContext *context, GPollFunc func) { if (!context) context = g_main_context_default (); g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0); LOCK_CONTEXT (context); if (func) context->poll_func = func; else context->poll_func = g_poll; UNLOCK_CONTEXT (context); } /** * g_main_context_get_poll_func: * @context: a #GMainContext * * Gets the poll function set by g_main_context_set_poll_func(). * * Returns: the poll function **/ GPollFunc g_main_context_get_poll_func (GMainContext *context) { GPollFunc result; if (!context) context = g_main_context_default (); g_return_val_if_fail (g_atomic_int_get (&context->ref_count) > 0, NULL); LOCK_CONTEXT (context); result = context->poll_func; UNLOCK_CONTEXT (context); return result; } /** * g_main_context_wakeup: * @context: a #GMainContext * * If @context is currently blocking in g_main_context_iteration() * waiting for a source to become ready, cause it to stop blocking * and return. Otherwise, cause the next invocation of * g_main_context_iteration() to return without blocking. * * This API is useful for low-level control over #GMainContext; for * example, integrating it with main loop implementations such as * #GMainLoop. * * Another related use for this function is when implementing a main * loop with a termination condition, computed from multiple threads: * * |[ * #define NUM_TASKS 10 * static volatile gint tasks_remaining = NUM_TASKS; * ... * * while (g_atomic_int_get (&tasks_remaining) != 0) * g_main_context_iteration (NULL, TRUE); * ]| * * Then in a thread: * |[ * perform_work(); * * if (g_atomic_int_dec_and_test (&tasks_remaining)) * g_main_context_wakeup (NULL); * ]| **/ void g_main_context_wakeup (GMainContext *context) { if (!context) context = g_main_context_default (); g_return_if_fail (g_atomic_int_get (&context->ref_count) > 0); TRACE (GLIB_MAIN_CONTEXT_WAKEUP (context)); g_wakeup_signal (context->wakeup); } /** * g_main_context_is_owner: * @context: a #GMainContext * * Determines whether this thread holds the (recursive) * ownership of this #GMainContext. This is useful to * know before waiting on another thread that may be * blocking to get ownership of @context. * * Returns: %TRUE if current thread is owner of @context. * * Since: 2.10 **/ gboolean g_main_context_is_owner (GMainContext *context) { gboolean is_owner; if (!context) context = g_main_context_default (); LOCK_CONTEXT (context); is_owner = context->owner == G_THREAD_SELF; UNLOCK_CONTEXT (context); return is_owner; } /* Timeouts */ static void g_timeout_set_expiration (GTimeoutSource *timeout_source, gint64 current_time) { gint64 expiration; expiration = current_time + (guint64) timeout_source->interval * 1000; if (timeout_source->seconds) { gint64 remainder; static gint timer_perturb = -1; if (timer_perturb == -1) { /* * we want a per machine/session unique 'random' value; try the dbus * address first, that has a UUID in it. If there is no dbus, use the * hostname for hashing. */ const char *session_bus_address = g_getenv ("DBUS_SESSION_BUS_ADDRESS"); if (!session_bus_address) session_bus_address = g_getenv ("HOSTNAME"); if (session_bus_address) timer_perturb = ABS ((gint) g_str_hash (session_bus_address)) % 1000000; else timer_perturb = 0; } /* We want the microseconds part of the timeout to land on the * 'timer_perturb' mark, but we need to make sure we don't try to * set the timeout in the past. We do this by ensuring that we * always only *increase* the expiration time by adding a full * second in the case that the microsecond portion decreases. */ expiration -= timer_perturb; remainder = expiration % 1000000; if (remainder >= 1000000/4) expiration += 1000000; expiration -= remainder; expiration += timer_perturb; } g_source_set_ready_time ((GSource *) timeout_source, expiration); } static gboolean g_timeout_dispatch (GSource *source, GSourceFunc callback, gpointer user_data) { GTimeoutSource *timeout_source = (GTimeoutSource *)source; gboolean again; if (!callback) { g_warning ("Timeout source dispatched without callback\n" "You must call g_source_set_callback()."); return FALSE; } again = callback (user_data); TRACE (GLIB_TIMEOUT_DISPATCH (source, source->context, callback, user_data, again)); if (again) g_timeout_set_expiration (timeout_source, g_source_get_time (source)); return again; } /** * g_timeout_source_new: * @interval: the timeout interval in milliseconds. * * Creates a new timeout source. * * The source will not initially be associated with any #GMainContext * and must be added to one with g_source_attach() before it will be * executed. * * The interval given is in terms of monotonic time, not wall clock * time. See g_get_monotonic_time(). * * Returns: the newly-created timeout source **/ GSource * g_timeout_source_new (guint interval) { GSource *source = g_source_new (&g_timeout_funcs, sizeof (GTimeoutSource)); GTimeoutSource *timeout_source = (GTimeoutSource *)source; timeout_source->interval = interval; g_timeout_set_expiration (timeout_source, g_get_monotonic_time ()); return source; } /** * g_timeout_source_new_seconds: * @interval: the timeout interval in seconds * * Creates a new timeout source. * * The source will not initially be associated with any #GMainContext * and must be added to one with g_source_attach() before it will be * executed. * * The scheduling granularity/accuracy of this timeout source will be * in seconds. * * The interval given in terms of monotonic time, not wall clock time. * See g_get_monotonic_time(). * * Returns: the newly-created timeout source * * Since: 2.14 **/ GSource * g_timeout_source_new_seconds (guint interval) { GSource *source = g_source_new (&g_timeout_funcs, sizeof (GTimeoutSource)); GTimeoutSource *timeout_source = (GTimeoutSource *)source; timeout_source->interval = 1000 * interval; timeout_source->seconds = TRUE; g_timeout_set_expiration (timeout_source, g_get_monotonic_time ()); return source; } /** * g_timeout_add_full: (rename-to g_timeout_add) * @priority: the priority of the timeout source. Typically this will be in * the range between #G_PRIORITY_DEFAULT and #G_PRIORITY_HIGH. * @interval: the time between calls to the function, in milliseconds * (1/1000ths of a second) * @function: function to call * @data: data to pass to @function * @notify: (nullable): function to call when the timeout is removed, or %NULL * * Sets a function to be called at regular intervals, with the given * priority. The function is called repeatedly until it returns * %FALSE, at which point the timeout is automatically destroyed and * the function will not be called again. The @notify function is * called when the timeout is destroyed. The first call to the * function will be at the end of the first @interval. * * Note that timeout functions may be delayed, due to the processing of other * event sources. Thus they should not be relied on for precise timing. * After each call to the timeout function, the time of the next * timeout is recalculated based on the current time and the given interval * (it does not try to 'catch up' time lost in delays). * * See [memory management of sources][mainloop-memory-management] for details * on how to handle the return value and memory management of @data. * * This internally creates a main loop source using g_timeout_source_new() * and attaches it to the global #GMainContext using g_source_attach(), so * the callback will be invoked in whichever thread is running that main * context. You can do these steps manually if you need greater control or to * use a custom main context. * * The interval given in terms of monotonic time, not wall clock time. * See g_get_monotonic_time(). * * Returns: the ID (greater than 0) of the event source. **/ guint g_timeout_add_full (gint priority, guint interval, GSourceFunc function, gpointer data, GDestroyNotify notify) { GSource *source; guint id; g_return_val_if_fail (function != NULL, 0); source = g_timeout_source_new (interval); if (priority != G_PRIORITY_DEFAULT) g_source_set_priority (source, priority); g_source_set_callback (source, function, data, notify); id = g_source_attach (source, NULL); TRACE (GLIB_TIMEOUT_ADD (source, g_main_context_default (), id, priority, interval, function, data)); g_source_unref (source); return id; } /** * g_timeout_add: * @interval: the time between calls to the function, in milliseconds * (1/1000ths of a second) * @function: function to call * @data: data to pass to @function * * Sets a function to be called at regular intervals, with the default * priority, #G_PRIORITY_DEFAULT. The function is called repeatedly * until it returns %FALSE, at which point the timeout is automatically * destroyed and the function will not be called again. The first call * to the function will be at the end of the first @interval. * * Note that timeout functions may be delayed, due to the processing of other * event sources. Thus they should not be relied on for precise timing. * After each call to the timeout function, the time of the next * timeout is recalculated based on the current time and the given interval * (it does not try to 'catch up' time lost in delays). * * See [memory management of sources][mainloop-memory-management] for details * on how to handle the return value and memory management of @data. * * If you want to have a timer in the "seconds" range and do not care * about the exact time of the first call of the timer, use the * g_timeout_add_seconds() function; this function allows for more * optimizations and more efficient system power usage. * * This internally creates a main loop source using g_timeout_source_new() * and attaches it to the global #GMainContext using g_source_attach(), so * the callback will be invoked in whichever thread is running that main * context. You can do these steps manually if you need greater control or to * use a custom main context. * * The interval given is in terms of monotonic time, not wall clock * time. See g_get_monotonic_time(). * * Returns: the ID (greater than 0) of the event source. **/ guint g_timeout_add (guint32 interval, GSourceFunc function, gpointer data) { return g_timeout_add_full (G_PRIORITY_DEFAULT, interval, function, data, NULL); } /** * g_timeout_add_seconds_full: (rename-to g_timeout_add_seconds) * @priority: the priority of the timeout source. Typically this will be in * the range between #G_PRIORITY_DEFAULT and #G_PRIORITY_HIGH. * @interval: the time between calls to the function, in seconds * @function: function to call * @data: data to pass to @function * @notify: (nullable): function to call when the timeout is removed, or %NULL * * Sets a function to be called at regular intervals, with @priority. * The function is called repeatedly until it returns %FALSE, at which * point the timeout is automatically destroyed and the function will * not be called again. * * Unlike g_timeout_add(), this function operates at whole second granularity. * The initial starting point of the timer is determined by the implementation * and the implementation is expected to group multiple timers together so that * they fire all at the same time. * To allow this grouping, the @interval to the first timer is rounded * and can deviate up to one second from the specified interval. * Subsequent timer iterations will generally run at the specified interval. * * Note that timeout functions may be delayed, due to the processing of other * event sources. Thus they should not be relied on for precise timing. * After each call to the timeout function, the time of the next * timeout is recalculated based on the current time and the given @interval * * See [memory management of sources][mainloop-memory-management] for details * on how to handle the return value and memory management of @data. * * If you want timing more precise than whole seconds, use g_timeout_add() * instead. * * The grouping of timers to fire at the same time results in a more power * and CPU efficient behavior so if your timer is in multiples of seconds * and you don't require the first timer exactly one second from now, the * use of g_timeout_add_seconds() is preferred over g_timeout_add(). * * This internally creates a main loop source using * g_timeout_source_new_seconds() and attaches it to the main loop context * using g_source_attach(). You can do these steps manually if you need * greater control. * * The interval given is in terms of monotonic time, not wall clock * time. See g_get_monotonic_time(). * * Returns: the ID (greater than 0) of the event source. * * Since: 2.14 **/ guint g_timeout_add_seconds_full (gint priority, guint32 interval, GSourceFunc function, gpointer data, GDestroyNotify notify) { GSource *source; guint id; g_return_val_if_fail (function != NULL, 0); source = g_timeout_source_new_seconds (interval); if (priority != G_PRIORITY_DEFAULT) g_source_set_priority (source, priority); g_source_set_callback (source, function, data, notify); id = g_source_attach (source, NULL); g_source_unref (source); return id; } /** * g_timeout_add_seconds: * @interval: the time between calls to the function, in seconds * @function: function to call * @data: data to pass to @function * * Sets a function to be called at regular intervals with the default * priority, #G_PRIORITY_DEFAULT. The function is called repeatedly until * it returns %FALSE, at which point the timeout is automatically destroyed * and the function will not be called again. * * This internally creates a main loop source using * g_timeout_source_new_seconds() and attaches it to the main loop context * using g_source_attach(). You can do these steps manually if you need * greater control. Also see g_timeout_add_seconds_full(). * * Note that the first call of the timer may not be precise for timeouts * of one second. If you need finer precision and have such a timeout, * you may want to use g_timeout_add() instead. * * See [memory management of sources][mainloop-memory-management] for details * on how to handle the return value and memory management of @data. * * The interval given is in terms of monotonic time, not wall clock * time. See g_get_monotonic_time(). * * Returns: the ID (greater than 0) of the event source. * * Since: 2.14 **/ guint g_timeout_add_seconds (guint interval, GSourceFunc function, gpointer data) { g_return_val_if_fail (function != NULL, 0); return g_timeout_add_seconds_full (G_PRIORITY_DEFAULT, interval, function, data, NULL); } /* Child watch functions */ #ifdef G_OS_WIN32 static gboolean g_child_watch_prepare (GSource *source, gint *timeout) { *timeout = -1; return FALSE; } static gboolean g_child_watch_check (GSource *source) { GChildWatchSource *child_watch_source; gboolean child_exited; child_watch_source = (GChildWatchSource *) source; child_exited = child_watch_source->poll.revents & G_IO_IN; if (child_exited) { DWORD child_status; /* * Note: We do _not_ check for the special value of STILL_ACTIVE * since we know that the process has exited and doing so runs into * problems if the child process "happens to return STILL_ACTIVE(259)" * as Microsoft's Platform SDK puts it. */ if (!GetExitCodeProcess (child_watch_source->pid, &child_status)) { gchar *emsg = g_win32_error_message (GetLastError ()); g_warning (G_STRLOC ": GetExitCodeProcess() failed: %s", emsg); g_free (emsg); child_watch_source->child_status = -1; } else child_watch_source->child_status = child_status; } return child_exited; } static void g_child_watch_finalize (GSource *source) { } #else /* G_OS_WIN32 */ static void wake_source (GSource *source) { GMainContext *context; /* This should be thread-safe: * * - if the source is currently being added to a context, that * context will be woken up anyway * * - if the source is currently being destroyed, we simply need not * to crash: * * - the memory for the source will remain valid until after the * source finalize function was called (which would remove the * source from the global list which we are currently holding the * lock for) * * - the GMainContext will either be NULL or point to a live * GMainContext * * - the GMainContext will remain valid since we hold the * main_context_list lock * * Since we are holding a lot of locks here, don't try to enter any * more GMainContext functions for fear of dealock -- just hit the * GWakeup and run. Even if that's safe now, it could easily become * unsafe with some very minor changes in the future, and signal * handling is not the most well-tested codepath. */ G_LOCK(main_context_list); context = source->context; if (context) g_wakeup_signal (context->wakeup); G_UNLOCK(main_context_list); } static void dispatch_unix_signals_unlocked (void) { gboolean pending[NSIG]; GSList *node; gint i; /* clear this first in case another one arrives while we're processing */ any_unix_signal_pending = FALSE; /* We atomically test/clear the bit from the global array in case * other signals arrive while we are dispatching. * * We then can safely use our own array below without worrying about * races. */ for (i = 0; i < NSIG; i++) { /* Be very careful with (the volatile) unix_signal_pending. * * We must ensure that it's not possible that we clear it without * handling the signal. We therefore must ensure that our pending * array has a field set (ie: we will do something about the * signal) before we clear the item in unix_signal_pending. * * Note specifically: we must check _our_ array. */ pending[i] = unix_signal_pending[i]; if (pending[i]) unix_signal_pending[i] = FALSE; } /* handle GChildWatchSource instances */ if (pending[SIGCHLD]) { /* The only way we can do this is to scan all of the children. * * The docs promise that we will not reap children that we are not * explicitly watching, so that ties our hands from calling * waitpid(-1). We also can't use siginfo's si_pid field since if * multiple SIGCHLD arrive at the same time, one of them can be * dropped (since a given UNIX signal can only be pending once). */ for (node = unix_child_watches; node; node = node->next) { GChildWatchSource *source = node->data; if (!source->child_exited) { pid_t pid; do { g_assert (source->pid > 0); pid = waitpid (source->pid, &source->child_status, WNOHANG); if (pid > 0) { source->child_exited = TRUE; wake_source ((GSource *) source); } else if (pid == -1 && errno == ECHILD) { g_warning ("GChildWatchSource: Exit status of a child process was requested but ECHILD was received by waitpid(). See the documentation of g_child_watch_source_new() for possible causes."); source->child_exited = TRUE; source->child_status = 0; wake_source ((GSource *) source); } } while (pid == -1 && errno == EINTR); } } } /* handle GUnixSignalWatchSource instances */ for (node = unix_signal_watches; node; node = node->next) { GUnixSignalWatchSource *source = node->data; if (!source->pending) { if (pending[source->signum]) { source->pending = TRUE; wake_source ((GSource *) source); } } } } static void dispatch_unix_signals (void) { G_LOCK(unix_signal_lock); dispatch_unix_signals_unlocked (); G_UNLOCK(unix_signal_lock); } static gboolean g_child_watch_prepare (GSource *source, gint *timeout) { GChildWatchSource *child_watch_source; child_watch_source = (GChildWatchSource *) source; return child_watch_source->child_exited; } static gboolean g_child_watch_check (GSource *source) { GChildWatchSource *child_watch_source; child_watch_source = (GChildWatchSource *) source; return child_watch_source->child_exited; } static gboolean g_unix_signal_watch_prepare (GSource *source, gint *timeout) { GUnixSignalWatchSource *unix_signal_source; unix_signal_source = (GUnixSignalWatchSource *) source; return unix_signal_source->pending; } static gboolean g_unix_signal_watch_check (GSource *source) { GUnixSignalWatchSource *unix_signal_source; unix_signal_source = (GUnixSignalWatchSource *) source; return unix_signal_source->pending; } static gboolean g_unix_signal_watch_dispatch (GSource *source, GSourceFunc callback, gpointer user_data) { GUnixSignalWatchSource *unix_signal_source; gboolean again; unix_signal_source = (GUnixSignalWatchSource *) source; if (!callback) { g_warning ("Unix signal source dispatched without callback\n" "You must call g_source_set_callback()."); return FALSE; } again = (callback) (user_data); unix_signal_source->pending = FALSE; return again; } static void ref_unix_signal_handler_unlocked (int signum) { /* Ensure we have the worker context */ g_get_worker_context (); unix_signal_refcount[signum]++; if (unix_signal_refcount[signum] == 1) { struct sigaction action; action.sa_handler = g_unix_signal_handler; sigemptyset (&action.sa_mask); #ifdef SA_RESTART action.sa_flags = SA_RESTART | SA_NOCLDSTOP; #else action.sa_flags = SA_NOCLDSTOP; #endif sigaction (signum, &action, NULL); } } static void unref_unix_signal_handler_unlocked (int signum) { unix_signal_refcount[signum]--; if (unix_signal_refcount[signum] == 0) { struct sigaction action; memset (&action, 0, sizeof (action)); action.sa_handler = SIG_DFL; sigemptyset (&action.sa_mask); sigaction (signum, &action, NULL); } } GSource * _g_main_create_unix_signal_watch (int signum) { GSource *source; GUnixSignalWatchSource *unix_signal_source; source = g_source_new (&g_unix_signal_funcs, sizeof (GUnixSignalWatchSource)); unix_signal_source = (GUnixSignalWatchSource *) source; unix_signal_source->signum = signum; unix_signal_source->pending = FALSE; G_LOCK (unix_signal_lock); ref_unix_signal_handler_unlocked (signum); unix_signal_watches = g_slist_prepend (unix_signal_watches, unix_signal_source); dispatch_unix_signals_unlocked (); G_UNLOCK (unix_signal_lock); return source; } static void g_unix_signal_watch_finalize (GSource *source) { GUnixSignalWatchSource *unix_signal_source; unix_signal_source = (GUnixSignalWatchSource *) source; G_LOCK (unix_signal_lock); unref_unix_signal_handler_unlocked (unix_signal_source->signum); unix_signal_watches = g_slist_remove (unix_signal_watches, source); G_UNLOCK (unix_signal_lock); } static void g_child_watch_finalize (GSource *source) { G_LOCK (unix_signal_lock); unix_child_watches = g_slist_remove (unix_child_watches, source); unref_unix_signal_handler_unlocked (SIGCHLD); G_UNLOCK (unix_signal_lock); } #endif /* G_OS_WIN32 */ static gboolean g_child_watch_dispatch (GSource *source, GSourceFunc callback, gpointer user_data) { GChildWatchSource *child_watch_source; GChildWatchFunc child_watch_callback = (GChildWatchFunc) callback; child_watch_source = (GChildWatchSource *) source; if (!callback) { g_warning ("Child watch source dispatched without callback\n" "You must call g_source_set_callback()."); return FALSE; } (child_watch_callback) (child_watch_source->pid, child_watch_source->child_status, user_data); /* We never keep a child watch source around as the child is gone */ return FALSE; } #ifndef G_OS_WIN32 static void g_unix_signal_handler (int signum) { gint saved_errno = errno; unix_signal_pending[signum] = TRUE; any_unix_signal_pending = TRUE; g_wakeup_signal (glib_worker_context->wakeup); errno = saved_errno; } #endif /* !G_OS_WIN32 */ /** * g_child_watch_source_new: * @pid: process to watch. On POSIX the positive pid of a child process. On * Windows a handle for a process (which doesn't have to be a child). * * Creates a new child_watch source. * * The source will not initially be associated with any #GMainContext * and must be added to one with g_source_attach() before it will be * executed. * * Note that child watch sources can only be used in conjunction with * `g_spawn...` when the %G_SPAWN_DO_NOT_REAP_CHILD flag is used. * * Note that on platforms where #GPid must be explicitly closed * (see g_spawn_close_pid()) @pid must not be closed while the * source is still active. Typically, you will want to call * g_spawn_close_pid() in the callback function for the source. * * On POSIX platforms, the following restrictions apply to this API * due to limitations in POSIX process interfaces: * * * @pid must be a child of this process * * @pid must be positive * * the application must not call `waitpid` with a non-positive * first argument, for instance in another thread * * the application must not wait for @pid to exit by any other * mechanism, including `waitpid(pid, ...)` or a second child-watch * source for the same @pid * * the application must not ignore SIGCHILD * * If any of those conditions are not met, this and related APIs will * not work correctly. This can often be diagnosed via a GLib warning * stating that `ECHILD` was received by `waitpid`. * * Calling `waitpid` for specific processes other than @pid remains a * valid thing to do. * * Returns: the newly-created child watch source * * Since: 2.4 **/ GSource * g_child_watch_source_new (GPid pid) { GSource *source; GChildWatchSource *child_watch_source; #ifndef G_OS_WIN32 g_return_val_if_fail (pid > 0, NULL); #endif source = g_source_new (&g_child_watch_funcs, sizeof (GChildWatchSource)); child_watch_source = (GChildWatchSource *)source; child_watch_source->pid = pid; #ifdef G_OS_WIN32 child_watch_source->poll.fd = (gintptr) pid; child_watch_source->poll.events = G_IO_IN; g_source_add_poll (source, &child_watch_source->poll); #else /* G_OS_WIN32 */ G_LOCK (unix_signal_lock); ref_unix_signal_handler_unlocked (SIGCHLD); unix_child_watches = g_slist_prepend (unix_child_watches, child_watch_source); if (waitpid (pid, &child_watch_source->child_status, WNOHANG) > 0) child_watch_source->child_exited = TRUE; G_UNLOCK (unix_signal_lock); #endif /* G_OS_WIN32 */ return source; } /** * g_child_watch_add_full: (rename-to g_child_watch_add) * @priority: the priority of the idle source. Typically this will be in the * range between #G_PRIORITY_DEFAULT_IDLE and #G_PRIORITY_HIGH_IDLE. * @pid: process to watch. On POSIX the positive pid of a child process. On * Windows a handle for a process (which doesn't have to be a child). * @function: function to call * @data: data to pass to @function * @notify: (nullable): function to call when the idle is removed, or %NULL * * Sets a function to be called when the child indicated by @pid * exits, at the priority @priority. * * If you obtain @pid from g_spawn_async() or g_spawn_async_with_pipes() * you will need to pass #G_SPAWN_DO_NOT_REAP_CHILD as flag to * the spawn function for the child watching to work. * * In many programs, you will want to call g_spawn_check_exit_status() * in the callback to determine whether or not the child exited * successfully. * * Also, note that on platforms where #GPid must be explicitly closed * (see g_spawn_close_pid()) @pid must not be closed while the source * is still active. Typically, you should invoke g_spawn_close_pid() * in the callback function for the source. * * GLib supports only a single callback per process id. * On POSIX platforms, the same restrictions mentioned for * g_child_watch_source_new() apply to this function. * * This internally creates a main loop source using * g_child_watch_source_new() and attaches it to the main loop context * using g_source_attach(). You can do these steps manually if you * need greater control. * * Returns: the ID (greater than 0) of the event source. * * Since: 2.4 **/ guint g_child_watch_add_full (gint priority, GPid pid, GChildWatchFunc function, gpointer data, GDestroyNotify notify) { GSource *source; guint id; g_return_val_if_fail (function != NULL, 0); #ifndef G_OS_WIN32 g_return_val_if_fail (pid > 0, 0); #endif source = g_child_watch_source_new (pid); if (priority != G_PRIORITY_DEFAULT) g_source_set_priority (source, priority); g_source_set_callback (source, (GSourceFunc) function, data, notify); id = g_source_attach (source, NULL); g_source_unref (source); return id; } /** * g_child_watch_add: * @pid: process id to watch. On POSIX the positive pid of a child * process. On Windows a handle for a process (which doesn't have to be * a child). * @function: function to call * @data: data to pass to @function * * Sets a function to be called when the child indicated by @pid * exits, at a default priority, #G_PRIORITY_DEFAULT. * * If you obtain @pid from g_spawn_async() or g_spawn_async_with_pipes() * you will need to pass #G_SPAWN_DO_NOT_REAP_CHILD as flag to * the spawn function for the child watching to work. * * Note that on platforms where #GPid must be explicitly closed * (see g_spawn_close_pid()) @pid must not be closed while the * source is still active. Typically, you will want to call * g_spawn_close_pid() in the callback function for the source. * * GLib supports only a single callback per process id. * On POSIX platforms, the same restrictions mentioned for * g_child_watch_source_new() apply to this function. * * This internally creates a main loop source using * g_child_watch_source_new() and attaches it to the main loop context * using g_source_attach(). You can do these steps manually if you * need greater control. * * Returns: the ID (greater than 0) of the event source. * * Since: 2.4 **/ guint g_child_watch_add (GPid pid, GChildWatchFunc function, gpointer data) { return g_child_watch_add_full (G_PRIORITY_DEFAULT, pid, function, data, NULL); } /* Idle functions */ static gboolean g_idle_prepare (GSource *source, gint *timeout) { *timeout = 0; return TRUE; } static gboolean g_idle_check (GSource *source) { return TRUE; } static gboolean g_idle_dispatch (GSource *source, GSourceFunc callback, gpointer user_data) { gboolean again; if (!callback) { g_warning ("Idle source dispatched without callback\n" "You must call g_source_set_callback()."); return FALSE; } again = callback (user_data); TRACE (GLIB_IDLE_DISPATCH (source, source->context, callback, user_data, again)); return again; } /** * g_idle_source_new: * * Creates a new idle source. * * The source will not initially be associated with any #GMainContext * and must be added to one with g_source_attach() before it will be * executed. Note that the default priority for idle sources is * %G_PRIORITY_DEFAULT_IDLE, as compared to other sources which * have a default priority of %G_PRIORITY_DEFAULT. * * Returns: the newly-created idle source **/ GSource * g_idle_source_new (void) { GSource *source; source = g_source_new (&g_idle_funcs, sizeof (GSource)); g_source_set_priority (source, G_PRIORITY_DEFAULT_IDLE); return source; } /** * g_idle_add_full: (rename-to g_idle_add) * @priority: the priority of the idle source. Typically this will be in the * range between #G_PRIORITY_DEFAULT_IDLE and #G_PRIORITY_HIGH_IDLE. * @function: function to call * @data: data to pass to @function * @notify: (nullable): function to call when the idle is removed, or %NULL * * Adds a function to be called whenever there are no higher priority * events pending. If the function returns %FALSE it is automatically * removed from the list of event sources and will not be called again. * * See [memory management of sources][mainloop-memory-management] for details * on how to handle the return value and memory management of @data. * * This internally creates a main loop source using g_idle_source_new() * and attaches it to the global #GMainContext using g_source_attach(), so * the callback will be invoked in whichever thread is running that main * context. You can do these steps manually if you need greater control or to * use a custom main context. * * Returns: the ID (greater than 0) of the event source. **/ guint g_idle_add_full (gint priority, GSourceFunc function, gpointer data, GDestroyNotify notify) { GSource *source; guint id; g_return_val_if_fail (function != NULL, 0); source = g_idle_source_new (); if (priority != G_PRIORITY_DEFAULT_IDLE) g_source_set_priority (source, priority); g_source_set_callback (source, function, data, notify); id = g_source_attach (source, NULL); TRACE (GLIB_IDLE_ADD (source, g_main_context_default (), id, priority, function, data)); g_source_unref (source); return id; } /** * g_idle_add: * @function: function to call * @data: data to pass to @function. * * Adds a function to be called whenever there are no higher priority * events pending to the default main loop. The function is given the * default idle priority, #G_PRIORITY_DEFAULT_IDLE. If the function * returns %FALSE it is automatically removed from the list of event * sources and will not be called again. * * See [memory management of sources][mainloop-memory-management] for details * on how to handle the return value and memory management of @data. * * This internally creates a main loop source using g_idle_source_new() * and attaches it to the global #GMainContext using g_source_attach(), so * the callback will be invoked in whichever thread is running that main * context. You can do these steps manually if you need greater control or to * use a custom main context. * * Returns: the ID (greater than 0) of the event source. **/ guint g_idle_add (GSourceFunc function, gpointer data) { return g_idle_add_full (G_PRIORITY_DEFAULT_IDLE, function, data, NULL); } /** * g_idle_remove_by_data: * @data: the data for the idle source's callback. * * Removes the idle function with the given data. * * Returns: %TRUE if an idle source was found and removed. **/ gboolean g_idle_remove_by_data (gpointer data) { return g_source_remove_by_funcs_user_data (&g_idle_funcs, data); } /** * g_main_context_invoke: * @context: (nullable): a #GMainContext, or %NULL * @function: function to call * @data: data to pass to @function * * Invokes a function in such a way that @context is owned during the * invocation of @function. * * If @context is %NULL then the global default main context — as * returned by g_main_context_default() — is used. * * If @context is owned by the current thread, @function is called * directly. Otherwise, if @context is the thread-default main context * of the current thread and g_main_context_acquire() succeeds, then * @function is called and g_main_context_release() is called * afterwards. * * In any other case, an idle source is created to call @function and * that source is attached to @context (presumably to be run in another * thread). The idle source is attached with #G_PRIORITY_DEFAULT * priority. If you want a different priority, use * g_main_context_invoke_full(). * * Note that, as with normal idle functions, @function should probably * return %FALSE. If it returns %TRUE, it will be continuously run in a * loop (and may prevent this call from returning). * * Since: 2.28 **/ void g_main_context_invoke (GMainContext *context, GSourceFunc function, gpointer data) { g_main_context_invoke_full (context, G_PRIORITY_DEFAULT, function, data, NULL); } /** * g_main_context_invoke_full: * @context: (nullable): a #GMainContext, or %NULL * @priority: the priority at which to run @function * @function: function to call * @data: data to pass to @function * @notify: (nullable): a function to call when @data is no longer in use, or %NULL. * * Invokes a function in such a way that @context is owned during the * invocation of @function. * * This function is the same as g_main_context_invoke() except that it * lets you specify the priority in case @function ends up being * scheduled as an idle and also lets you give a #GDestroyNotify for @data. * * @notify should not assume that it is called from any particular * thread or with any particular context acquired. * * Since: 2.28 **/ void g_main_context_invoke_full (GMainContext *context, gint priority, GSourceFunc function, gpointer data, GDestroyNotify notify) { g_return_if_fail (function != NULL); if (!context) context = g_main_context_default (); if (g_main_context_is_owner (context)) { while (function (data)); if (notify != NULL) notify (data); } else { GMainContext *thread_default; thread_default = g_main_context_get_thread_default (); if (!thread_default) thread_default = g_main_context_default (); if (thread_default == context && g_main_context_acquire (context)) { while (function (data)); g_main_context_release (context); if (notify != NULL) notify (data); } else { GSource *source; source = g_idle_source_new (); g_source_set_priority (source, priority); g_source_set_callback (source, function, data, notify); g_source_attach (source, context); g_source_unref (source); } } } static gpointer glib_worker_main (gpointer data) { while (TRUE) { g_main_context_iteration (glib_worker_context, TRUE); #ifdef G_OS_UNIX if (any_unix_signal_pending) dispatch_unix_signals (); #endif } return NULL; /* worst GCC warning message ever... */ } GMainContext * g_get_worker_context (void) { static gsize initialised; if (g_once_init_enter (&initialised)) { /* mask all signals in the worker thread */ #ifdef G_OS_UNIX sigset_t prev_mask; sigset_t all; sigfillset (&all); pthread_sigmask (SIG_SETMASK, &all, &prev_mask); #endif glib_worker_context = g_main_context_new (); g_thread_new ("gmain", glib_worker_main, NULL); #ifdef G_OS_UNIX pthread_sigmask (SIG_SETMASK, &prev_mask, NULL); #endif g_once_init_leave (&initialised, TRUE); } return glib_worker_context; }