/* 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 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, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ /* * 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 */ #ifndef _WIN32 /* for pipe2; need to define it first to avoid * other headers pulling in unistd.h */ /* The meaning of_GNU_SOURCE that is intended here is present only on * Linux; avoid the possibility that some misguided header in MinGW * looks at it. Ideally we should define _GNU_SOURCE only on platforms * where we know what it means and that is what we want here * (i.e. Linux with glibc). After all, there might be some other POSIX * platform even where _GNU_SOURCE is used for some unrelated change * in semantics that isn't wanted. Sigh. */ #define _GNU_SOURCE #endif #include "config.h" #include "glibconfig.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 #include #include #include #include #ifdef HAVE_SYS_TIME_H #include #endif /* HAVE_SYS_TIME_H */ #ifdef HAVE_UNISTD_H #include #endif /* HAVE_UNISTD_H */ #include #ifdef G_OS_WIN32 #define STRICT #include #endif /* G_OS_WIN32 */ #ifdef G_OS_BEOS #include #include #endif /* G_OS_BEOS */ #ifdef G_OS_UNIX #include #include #endif #include "gmain.h" #include "garray.h" #include "giochannel.h" #include "ghash.h" #include "ghook.h" #include "gqueue.h" #include "gstrfuncs.h" #include "gtestutils.h" #include "gthreadprivate.h" #ifdef G_OS_WIN32 #include "gwin32.h" #endif #ifdef G_MAIN_POLL_DEBUG #include "gtimer.h" #endif /** * 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(). * The operation of these functions can best be seen in terms * of a state diagram, as shown in . *
States of a Main Context * *
* */ /* Types */ typedef struct _GTimeoutSource GTimeoutSource; typedef struct _GChildWatchSource GChildWatchSource; 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) } GSourceFlags; #ifdef G_THREADS_ENABLED typedef struct _GMainWaiter GMainWaiter; struct _GMainWaiter { GCond *cond; GMutex *mutex; }; #endif typedef struct _GMainDispatch GMainDispatch; struct _GMainDispatch { gint depth; GSList *dispatching_sources; /* stack of current sources */ }; #ifdef G_MAIN_POLL_DEBUG gboolean _g_main_poll_debug = FALSE; #endif struct _GMainContext { #ifdef G_THREADS_ENABLED /* The following lock is used for both the list of sources * and the list of poll records */ GStaticMutex mutex; GCond *cond; GThread *owner; guint owner_count; GSList *waiters; #endif gint ref_count; GPtrArray *pending_dispatches; gint timeout; /* Timeout for current iteration */ guint next_id; GSource *source_list; gint in_check_or_prepare; GPollRec *poll_records, *poll_records_tail; guint n_poll_records; GPollFD *cached_poll_array; guint cached_poll_array_size; #ifdef G_THREADS_ENABLED #ifndef G_OS_WIN32 /* this pipe is used to wake up the main loop when a source is added. */ gint wake_up_pipe[2]; #else /* G_OS_WIN32 */ HANDLE wake_up_semaphore; #endif /* G_OS_WIN32 */ GPollFD wake_up_rec; gboolean poll_waiting; /* Flag indicating whether the set of fd's changed during a poll */ gboolean poll_changed; #endif /* G_THREADS_ENABLED */ GPollFunc poll_func; gint64 time; gboolean time_is_fresh; gint64 real_time; gboolean real_time_is_fresh; }; struct _GSourceCallback { guint ref_count; GSourceFunc func; gpointer data; GDestroyNotify notify; }; struct _GMainLoop { GMainContext *context; gboolean is_running; gint ref_count; }; struct _GTimeoutSource { GSource source; gint64 expiration; guint interval; gboolean seconds; }; struct _GChildWatchSource { GSource source; GPid pid; gint child_status; #ifdef G_OS_WIN32 GPollFD poll; #else /* G_OS_WIN32 */ gint count; gboolean child_exited; #endif /* G_OS_WIN32 */ }; struct _GPollRec { GPollFD *fd; GPollRec *prev; GPollRec *next; gint priority; }; struct _GSourcePrivate { GSList *child_sources; GSource *parent_source; }; #ifdef G_THREADS_ENABLED #define LOCK_CONTEXT(context) g_static_mutex_lock (&context->mutex) #define UNLOCK_CONTEXT(context) g_static_mutex_unlock (&context->mutex) #define G_THREAD_SELF g_thread_self () #else #define LOCK_CONTEXT(context) (void)0 #define UNLOCK_CONTEXT(context) (void)0 #define G_THREAD_SELF NULL #endif #define SOURCE_DESTROYED(source) (((source)->flags & G_HOOK_FLAG_ACTIVE) == 0) #define SOURCE_BLOCKED(source) (((source)->flags & G_HOOK_FLAG_IN_CALL) != 0 && \ ((source)->flags & G_SOURCE_CAN_RECURSE) == 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_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_main_context_wakeup_unlocked (GMainContext *context); static gboolean g_timeout_prepare (GSource *source, gint *timeout); static gboolean g_timeout_check (GSource *source); 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 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); G_LOCK_DEFINE_STATIC (main_loop); static GMainContext *default_main_context; static GSList *main_contexts_without_pipe = NULL; #ifndef G_OS_WIN32 /* Child status monitoring code */ enum { CHILD_WATCH_UNINITIALIZED, CHILD_WATCH_INITIALIZED_SINGLE, CHILD_WATCH_INITIALIZED_THREADED }; static gint child_watch_init_state = CHILD_WATCH_UNINITIALIZED; static gint child_watch_count = 1; static gint child_watch_wake_up_pipe[2] = {0, 0}; #endif /* !G_OS_WIN32 */ G_LOCK_DEFINE_STATIC (main_context_list); static GSList *main_context_list = NULL; GSourceFuncs g_timeout_funcs = { g_timeout_prepare, g_timeout_check, g_timeout_dispatch, NULL }; GSourceFuncs g_child_watch_funcs = { g_child_watch_prepare, g_child_watch_check, g_child_watch_dispatch, NULL }; 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) { GSource *source; 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); source = context->source_list; while (source) { GSource *next = source->next; g_source_destroy_internal (source, context, FALSE); source = next; } #ifdef G_THREADS_ENABLED g_static_mutex_free (&context->mutex); #endif g_ptr_array_free (context->pending_dispatches, TRUE); g_free (context->cached_poll_array); poll_rec_list_free (context, context->poll_records); #ifdef G_THREADS_ENABLED if (g_thread_supported()) { #ifndef G_OS_WIN32 close (context->wake_up_pipe[0]); close (context->wake_up_pipe[1]); #else CloseHandle (context->wake_up_semaphore); #endif } else main_contexts_without_pipe = g_slist_remove (main_contexts_without_pipe, context); if (context->cond != NULL) g_cond_free (context->cond); #endif g_free (context); } #ifdef G_THREADS_ENABLED static void g_main_context_init_pipe (GMainContext *context) { # ifndef G_OS_WIN32 if (context->wake_up_pipe[0] != -1) return; #ifdef HAVE_PIPE2 /* if this fails, we fall through and try pipe */ pipe2 (context->wake_up_pipe, O_CLOEXEC); #endif if (context->wake_up_pipe[0] == -1) { if (pipe (context->wake_up_pipe) < 0) g_error ("Cannot create pipe main loop wake-up: %s\n", g_strerror (errno)); fcntl (context->wake_up_pipe[0], F_SETFD, FD_CLOEXEC); fcntl (context->wake_up_pipe[1], F_SETFD, FD_CLOEXEC); } context->wake_up_rec.fd = context->wake_up_pipe[0]; context->wake_up_rec.events = G_IO_IN; # else if (context->wake_up_semaphore != NULL) return; context->wake_up_semaphore = CreateSemaphore (NULL, 0, 100, NULL); if (context->wake_up_semaphore == NULL) g_error ("Cannot create wake-up semaphore: %s", g_win32_error_message (GetLastError ())); context->wake_up_rec.fd = (gintptr) context->wake_up_semaphore; context->wake_up_rec.events = G_IO_IN; if (_g_main_poll_debug) g_print ("wake-up semaphore: %p\n", context->wake_up_semaphore); # endif g_main_context_add_poll_unlocked (context, 0, &context->wake_up_rec); } void _g_main_thread_init (void) { GSList *curr = main_contexts_without_pipe; while (curr) { g_main_context_init_pipe ((GMainContext *)curr->data); curr = curr->next; } g_slist_free (main_contexts_without_pipe); main_contexts_without_pipe = NULL; } #endif /* G_THREADS_ENABLED */ /** * g_main_context_new: * * Creates a new #GMainContext structure. * * Return value: the new #GMainContext **/ GMainContext * g_main_context_new (void) { GMainContext *context = g_new0 (GMainContext, 1); #ifdef G_MAIN_POLL_DEBUG { static gboolean beenhere = FALSE; if (!beenhere) { if (getenv ("G_MAIN_POLL_DEBUG") != NULL) _g_main_poll_debug = TRUE; beenhere = TRUE; } } #endif #ifdef G_THREADS_ENABLED g_static_mutex_init (&context->mutex); context->owner = NULL; context->waiters = NULL; # ifndef G_OS_WIN32 context->wake_up_pipe[0] = -1; context->wake_up_pipe[1] = -1; # else context->wake_up_semaphore = NULL; # endif #endif context->ref_count = 1; context->next_id = 1; context->source_list = 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->real_time_is_fresh = FALSE; #ifdef G_THREADS_ENABLED if (g_thread_supported ()) g_main_context_init_pipe (context); else main_contexts_without_pipe = g_slist_prepend (main_contexts_without_pipe, context); #endif 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(). * * Return value: 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 (); #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 GStaticPrivate thread_context_stack = G_STATIC_PRIVATE_INIT; static void free_context_stack (gpointer data) { GQueue *stack = data; GMainContext *context; while (!g_queue_is_empty (stack)) { context = g_queue_pop_head (stack); g_main_context_release (context); if (context) g_main_context_unref (context); } g_queue_free (stack); } /** * g_main_context_push_thread_default: * @context: 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-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 don't need to * ever call g_main_context_pop_thread_default().) In some cases * however, 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_static_private_get (&thread_context_stack); if (!stack) { stack = g_queue_new (); g_static_private_set (&thread_context_stack, stack, free_context_stack); } g_queue_push_head (stack, context); } /** * g_main_context_pop_thread_default: * @context: 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_static_private_get (&thread_context_stack); g_return_if_fail (stack != NULL); g_return_if_fail (g_queue_peek_head (stack) == 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 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 threads are not initialized.) * * Returns: 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_static_private_get (&thread_context_stack); if (stack) return g_queue_peek_head (stack); else return NULL; } /* 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. * * Return value: 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); #ifdef GSTREAMER_LITE if (source == NULL) return NULL; #endif // GSTREAMER_LITE source->source_funcs = source_funcs; source->ref_count = 1; source->priority = G_PRIORITY_DEFAULT; source->flags = G_HOOK_FLAG_ACTIVE; /* NULL/0 initialization for all other fields */ return source; } /* Holds context's lock */ static void g_source_list_add (GSource *source, GMainContext *context) { GSource *tmp_source, *last_source; if (source->priv && source->priv->parent_source) { /* Put the source immediately before its parent */ tmp_source = source->priv->parent_source; last_source = source->priv->parent_source->prev; } else { last_source = NULL; tmp_source = context->source_list; while (tmp_source && tmp_source->priority <= source->priority) { last_source = tmp_source; tmp_source = tmp_source->next; } } source->next = tmp_source; if (tmp_source) tmp_source->prev = source; source->prev = last_source; if (last_source) last_source->next = source; else context->source_list = source; } /* Holds context's lock */ static void g_source_list_remove (GSource *source, GMainContext *context) { if (source->prev) source->prev->next = source->next; else context->source_list = source->next; if (source->next) source->next->prev = source->prev; source->prev = NULL; source->next = NULL; } static guint g_source_attach_unlocked (GSource *source, GMainContext *context) { guint result = 0; GSList *tmp_list; source->context = context; result = source->source_id = context->next_id++; source->ref_count++; g_source_list_add (source, context); 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; } if (source->priv) { tmp_list = source->priv->child_sources; while (tmp_list) { g_source_attach_unlocked (tmp_list->data, context); tmp_list = tmp_list->next; } } return result; } /** * g_source_attach: * @source: a #GSource * @context: 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(). * * Return value: the ID (greater than 0) for the source within the * #GMainContext. **/ guint g_source_attach (GSource *source, GMainContext *context) { guint result = 0; #ifdef GSTREAMER_LITE if (source == NULL) { return 0; } #endif // GSTREAMER_LITE 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); #ifdef G_THREADS_ENABLED /* Now wake up the main loop if it is waiting in the poll() */ g_main_context_wakeup_unlocked (context); #endif UNLOCK_CONTEXT (context); return result; } static void g_source_destroy_internal (GSource *source, GMainContext *context, gboolean have_lock) { 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; } } if (source->priv && source->priv->child_sources) { /* This is safe because even if a child_source finalizer or * closure notify tried to modify source->priv->child_sources * from outside the lock, it would fail since * SOURCE_DESTROYED(source) is now TRUE. */ tmp_list = source->priv->child_sources; while (tmp_list) { g_source_destroy_internal (tmp_list->data, context, TRUE); g_source_unref_internal (tmp_list->data, context, TRUE); tmp_list = tmp_list->next; } g_slist_free (source->priv->child_sources); source->priv->child_sources = NULL; } 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. **/ 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(). * * Return value: 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. * Calling this function on a destroyed source is an error. * * Return value: 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_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. **/ 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)); #ifdef GSTREAMER_LITE if (source == NULL) return; #endif // GSTREAMER_LITE 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. **/ 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)); #ifdef GSTREAMER_LITE if (source == NULL) return; #endif // GSTREAMER_LITE 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. * * 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 == NULL || child_source->priv->parent_source == NULL); context = source->context; if (context) LOCK_CONTEXT (context); if (!source->priv) source->priv = g_slice_new0 (GSourcePrivate); if (!child_source->priv) child_source->priv = g_slice_new0 (GSourcePrivate); 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, context, source->priority); if (context) { UNLOCK_CONTEXT (context); g_source_attach (child_source, context); } } /** * 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. * * 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 != NULL && 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); source->priv->child_sources = g_slist_remove (source->priv->child_sources, child_source); g_source_destroy_internal (child_source, context, TRUE); g_source_unref_internal (child_source, context, TRUE); if (context) UNLOCK_CONTEXT (context); } /** * 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); 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); } static void g_source_callback_ref (gpointer cb_data) { GSourceCallback *callback = cb_data; callback->ref_count++; } static void g_source_callback_unref (gpointer cb_data) { GSourceCallback *callback = cb_data; callback->ref_count--; if (callback->ref_count == 0) { 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: * @source: the source * @func: a callback function * @data: the data to pass to callback function * @notify: 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. * * 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); #ifdef GSTREAMER_LITE if (source == NULL) return; #endif // GSTREAMER_LITE 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; source->priority = priority; if (context) { /* Remove the source from the context's source and then * add it back so it is sorted in the correct place */ g_source_list_remove (source, source->context); g_source_list_add (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; } } } if (source->priv && 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. **/ void g_source_set_priority (GSource *source, gint priority) { GMainContext *context; #ifdef GSTREAMER_LITE if (source == NULL || source->priv == NULL || source->priv->parent_source == NULL) return; #endif // GSTREAMER_LITE g_return_if_fail (source != NULL); context = source->context; if (context) LOCK_CONTEXT (context); g_source_set_priority_unlocked (source, context, priority); if (context) UNLOCK_CONTEXT (source->context); } /** * g_source_get_priority: * @source: a #GSource * * Gets the priority of a source. * * Return value: 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_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(). * * Return value: 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. * * Since: 2.26 **/ void g_source_set_name (GSource *source, const char *name) { g_return_if_fail (source != NULL); /* 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); } /** * 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(). * * Return value: the name of the source * Since: 2.26 **/ G_CONST_RETURN 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. * * 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. * * Return value: @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) { 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!"); g_source_list_remove (source, context); } if (source->source_funcs->finalize) { if (context) UNLOCK_CONTEXT (context); source->source_funcs->finalize (source); if (context) LOCK_CONTEXT (context); } g_free (source->name); source->name = NULL; g_slist_free (source->poll_fds); source->poll_fds = NULL; g_free (source); } if (!have_lock && context) UNLOCK_CONTEXT (context); if (old_cb_funcs) { if (have_lock) UNLOCK_CONTEXT (context); old_cb_funcs->unref (old_cb_data); if (have_lock) LOCK_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); #ifdef GSTREAMER_LITE if (source == NULL) return; #endif // GSTREAMER_LITE g_source_unref_internal (source, source->context, FALSE); } /** * g_main_context_find_source_by_id: * @context: 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. * * Return value: the #GSource if found, otherwise, %NULL **/ 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 = context->source_list; while (source) { if (!SOURCE_DESTROYED (source) && source->source_id == source_id) break; source = source->next; } UNLOCK_CONTEXT (context); return source; } /** * g_main_context_find_source_by_funcs_user_data: * @context: 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. * * Return value: 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) { GSource *source; g_return_val_if_fail (funcs != NULL, NULL); if (context == NULL) context = g_main_context_default (); LOCK_CONTEXT (context); source = context->source_list; while (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; } source = source->next; } 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. * * Return value: the source, if one was found, otherwise %NULL **/ GSource * g_main_context_find_source_by_user_data (GMainContext *context, gpointer user_data) { GSource *source; if (context == NULL) context = g_main_context_default (); LOCK_CONTEXT (context); source = context->source_list; while (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; } source = source->next; } 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. * 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(). * * See also g_source_destroy(). You must use g_source_destroy() for sources * added to a non-default main context. * * Return value: %TRUE if the source was found and removed. **/ 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); 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. * * Return value: %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. * * Return value: %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_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, if available. * * On POSIX systems with clock_gettime() and %CLOCK_MONOTONIC this call * is a very shallow wrapper for that. Otherwise, we make a best effort * that probably involves returning the wall clock time (with at least * microsecond accuracy, subject to the limitations of the OS kernel). * * Note that, on Windows, "limitations of the OS kernel" is a rather * substantial statement. Depending on the configuration of the system, * the wall clock time is updated as infrequently as 64 times a second * (which is approximately every 16ms). * * Returns: the monotonic time, in microseconds * * Since: 2.28 **/ gint64 g_get_monotonic_time (void) { #ifdef HAVE_CLOCK_GETTIME /* librt clock_gettime() is our first choice */ { static int clockid = CLOCK_REALTIME; struct timespec ts; #ifdef HAVE_MONOTONIC_CLOCK /* We have to check if we actually have monotonic clock support. * * There is no thread safety issue here since there is no harm if we * check twice. */ { static gboolean checked; if G_UNLIKELY (!checked) { if (sysconf (_SC_MONOTONIC_CLOCK) >= 0) clockid = CLOCK_MONOTONIC; checked = TRUE; } } #endif clock_gettime (clockid, &ts); /* In theory monotonic time can have any epoch. * * glib presently assumes the following: * * 1) The epoch comes some time after the birth of Jesus of Nazareth, but * not more than 10000 years later. * * 2) The current time also falls sometime within this range. * * These two reasonable assumptions leave us with a maximum deviation from * the epoch of 10000 years, or 315569520000000000 seconds. * * If we restrict ourselves to this range then the number of microseconds * will always fit well inside the constraints of a int64 (by a factor of * about 29). * * If you actually hit the following assertion, probably you should file a * bug against your operating system for being excessively silly. **/ g_assert (G_GINT64_CONSTANT (-315569520000000000) < ts.tv_sec && ts.tv_sec < G_GINT64_CONSTANT (315569520000000000)); return (((gint64) ts.tv_sec) * 1000000) + (ts.tv_nsec / 1000); } #else /* It may look like we are discarding accuracy on Windows (since its * current time is expressed in 100s of nanoseconds) but according to * many sources, the time is only updated 64 times per second, so * microsecond accuracy is more than enough. */ { GTimeVal tv; g_get_current_time (&tv); return (((gint64) tv.tv_sec) * 1000000) + tv.tv_usec; } #endif } static void g_main_dispatch_free (gpointer dispatch) { g_slice_free (GMainDispatch, dispatch); } /* Running the main loop */ static GMainDispatch * get_dispatch (void) { static GStaticPrivate depth_private = G_STATIC_PRIVATE_INIT; GMainDispatch *dispatch = g_static_private_get (&depth_private); if (!dispatch) { dispatch = g_slice_new0 (GMainDispatch); g_static_private_set (&depth_private, dispatch, g_main_dispatch_free); } 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: * * * * * Use gtk_widget_set_sensitive() or modal dialogs to prevent * the user from interacting with elements while the main * loop is recursing. * * * * * 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. * * * * * Return value: 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. * * Return value: The currently firing source or %NULL. * * Since: 2.12 */ GSource * g_main_current_source (void) { GMainDispatch *dispatch = get_dispatch (); return dispatch->dispatching_sources ? dispatch->dispatching_sources->data : NULL; } /** * 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 FALSE; * } * * 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; * } * ]| * * Return value: %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)); tmp_list = source->poll_fds; while (tmp_list) { g_main_context_remove_poll_unlocked (source->context, 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)); 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; } } /* 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); GSList current_source_link; 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); current->depth++; /* The on-stack allocation of the GSList is unconventional, but * we know that the lifetime of the link is bounded to this * function as the link is kept in a thread specific list and * not manipulated outside of this function and its descendants. * Avoiding the overhead of a g_slist_alloc() is useful as many * applications do little more than dispatch events. * * This is a performance hack - do not revert to g_slist_prepend()! */ current_source_link.data = source; current_source_link.next = current->dispatching_sources; current->dispatching_sources = ¤t_source_link; need_destroy = ! dispatch (source, callback, user_data); g_assert (current->dispatching_sources == ¤t_source_link); current->dispatching_sources = current_source_link.next; 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->flags & G_SOURCE_CAN_RECURSE) == 0 && !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); } /* Holds context's lock */ static inline GSource * next_valid_source (GMainContext *context, GSource *source) { GSource *new_source = source ? source->next : context->source_list; while (new_source) { if (!SOURCE_DESTROYED (new_source)) { new_source->ref_count++; break; } new_source = new_source->next; } if (source) SOURCE_UNREF (source, context); return new_source; } /** * 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(). * * Return value: %TRUE if the operation succeeded, and * this thread is now the owner of @context. **/ gboolean g_main_context_acquire (GMainContext *context) { #ifdef G_THREADS_ENABLED 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); } if (context->owner == self) { context->owner_count++; result = TRUE; } UNLOCK_CONTEXT (context); return result; #else /* !G_THREADS_ENABLED */ return TRUE; #endif /* G_THREADS_ENABLED */ } /** * 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) { #ifdef G_THREADS_ENABLED if (context == NULL) context = g_main_context_default (); LOCK_CONTEXT (context); context->owner_count--; if (context->owner_count == 0) { context->owner = NULL; if (context->waiters) { GMainWaiter *waiter = context->waiters->data; gboolean loop_internal_waiter = (waiter->mutex == g_static_mutex_get_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); #endif /* G_THREADS_ENABLED */ } /** * 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. * * Return value: %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) { #ifdef G_THREADS_ENABLED gboolean result = FALSE; GThread *self = G_THREAD_SELF; gboolean loop_internal_waiter; if (context == NULL) context = g_main_context_default (); loop_internal_waiter = (mutex == g_static_mutex_get_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; #else /* !G_THREADS_ENABLED */ return TRUE; #endif /* G_THREADS_ENABLED */ } /** * 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 (). * * Return value: %TRUE if some source is ready to be dispatched * prior to polling. **/ gboolean g_main_context_prepare (GMainContext *context, gint *priority) { gint i; gint n_ready = 0; gint current_priority = G_MAXINT; GSource *source; if (context == NULL) context = g_main_context_default (); LOCK_CONTEXT (context); context->time_is_fresh = FALSE; context->real_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; } #ifdef G_THREADS_ENABLED if (context->poll_waiting) { g_warning("g_main_context_prepare(): main loop already active in another thread"); UNLOCK_CONTEXT (context); return FALSE; } context->poll_waiting = TRUE; #endif /* G_THREADS_ENABLED */ #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; source = next_valid_source (context, NULL); while (source) { gint source_timeout = -1; if ((n_ready > 0) && (source->priority > current_priority)) { SOURCE_UNREF (source, context); break; } if (SOURCE_BLOCKED (source)) goto next; if (!(source->flags & G_SOURCE_READY)) { gboolean result; gboolean (*prepare) (GSource *source, gint *timeout); prepare = source->source_funcs->prepare; context->in_check_or_prepare++; UNLOCK_CONTEXT (context); result = (*prepare) (source, &source_timeout); LOCK_CONTEXT (context); context->in_check_or_prepare--; if (result) { GSource *ready_source = source; while (ready_source) { ready_source->flags |= G_SOURCE_READY; ready_source = ready_source->priv ? ready_source->priv->parent_source : NULL; } } } 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); } next: source = next_valid_source (context, source); } 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_: location to store timeout to be used in polling * @fds: location to store #GPollFD records that need to be polled. * @n_fds: length of @fds. * * Determines information necessary to poll this main loop. * * Return value: 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; LOCK_CONTEXT (context); pollrec = context->poll_records; n_poll = 0; while (pollrec && max_priority >= pollrec->priority) { /* We need to include entries with fd->events == 0 in the array because * otherwise if the application changes fd->events behind our back and * makes it non-zero, we'll be out of sync when we check the fds[] array. * (Changing fd->events after adding an FD wasn't an anticipated use of * this API, but it occurs in practice.) */ if (n_poll < n_fds) { fds[n_poll].fd = pollrec->fd->fd; /* 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. */ fds[n_poll].events = pollrec->fd->events & ~(G_IO_ERR|G_IO_HUP|G_IO_NVAL); fds[n_poll].revents = 0; } pollrec = pollrec->next; n_poll++; } #ifdef G_THREADS_ENABLED context->poll_changed = FALSE; #endif if (timeout) { *timeout = context->timeout; if (*timeout != 0) { context->time_is_fresh = FALSE; context->real_time_is_fresh = FALSE; } } 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 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. * * Return value: %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; 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; } #ifdef G_THREADS_ENABLED if (!context->poll_waiting) { #ifndef G_OS_WIN32 gchar a; read (context->wake_up_pipe[0], &a, 1); #endif } else context->poll_waiting = FALSE; /* If the set of poll file descriptors changed, bail out * and let the main loop rerun */ if (context->poll_changed) { UNLOCK_CONTEXT (context); return FALSE; } #endif /* G_THREADS_ENABLED */ pollrec = context->poll_records; i = 0; while (i < n_fds) { if (pollrec->fd->events) pollrec->fd->revents = fds[i].revents; pollrec = pollrec->next; i++; } source = next_valid_source (context, NULL); while (source) { if ((n_ready > 0) && (source->priority > max_priority)) { SOURCE_UNREF (source, context); break; } if (SOURCE_BLOCKED (source)) goto next; if (!(source->flags & G_SOURCE_READY)) { gboolean result; gboolean (*check) (GSource *source); check = source->source_funcs->check; context->in_check_or_prepare++; UNLOCK_CONTEXT (context); result = (*check) (source); LOCK_CONTEXT (context); context->in_check_or_prepare--; if (result) { GSource *ready_source = source; while (ready_source) { ready_source->flags |= G_SOURCE_READY; ready_source = ready_source->priv ? ready_source->priv->parent_source : NULL; } } } 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; } next: source = next_valid_source (context, source); } UNLOCK_CONTEXT (context); return n_ready > 0; } /** * g_main_context_dispatch: * @context: a #GMainContext * * Dispatches all pending sources. **/ void g_main_context_dispatch (GMainContext *context) { LOCK_CONTEXT (context); if (context->pending_dispatches->len > 0) { g_main_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); #ifdef G_THREADS_ENABLED if (!g_main_context_acquire (context)) { gboolean got_ownership; LOCK_CONTEXT (context); g_return_val_if_fail (g_thread_supported (), FALSE); if (!block) return FALSE; if (!context->cond) context->cond = g_cond_new (); got_ownership = g_main_context_wait (context, context->cond, g_static_mutex_get_mutex (&context->mutex)); if (!got_ownership) return FALSE; } else LOCK_CONTEXT (context); #endif /* G_THREADS_ENABLED */ 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); #ifdef G_THREADS_ENABLED g_main_context_release (context); #endif /* G_THREADS_ENABLED */ LOCK_CONTEXT (context); return some_ready; } /** * g_main_context_pending: * @context: a #GMainContext (if %NULL, the default context will be used) * * Checks if any sources have pending events for the given context. * * Return value: %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: 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 the wait may * be interrupted for other reasons than an event source becoming ready. * * Return value: %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: 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. * * Return value: 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; return loop; } /** * g_main_loop_ref: * @loop: a #GMainLoop * * Increases the reference count on a #GMainLoop object by one. * * Return value: @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); #ifdef G_THREADS_ENABLED if (!g_main_context_acquire (loop->context)) { gboolean got_ownership = FALSE; /* Another thread owns this context */ if (!g_thread_supported ()) { g_warning ("g_main_loop_run() was called from second thread but " "g_thread_init() was never called."); return; } LOCK_CONTEXT (loop->context); g_atomic_int_inc (&loop->ref_count); if (!loop->is_running) loop->is_running = TRUE; if (!loop->context->cond) loop->context->cond = g_cond_new (); while (loop->is_running && !got_ownership) got_ownership = g_main_context_wait (loop->context, loop->context->cond, g_static_mutex_get_mutex (&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); #endif /* G_THREADS_ENABLED */ 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); #ifdef G_THREADS_ENABLED g_main_context_release (loop->context); #endif /* G_THREADS_ENABLED */ 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_main_context_wakeup_unlocked (loop->context); #ifdef G_THREADS_ENABLED if (loop->context->cond) g_cond_broadcast (loop->context->cond); #endif /* G_THREADS_ENABLED */ UNLOCK_CONTEXT (loop->context); } /** * g_main_loop_is_running: * @loop: a #GMainLoop. * * Checks to see if the main loop is currently being run via g_main_loop_run(). * * Return value: %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. * * Return value: 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) { #ifdef G_MAIN_POLL_DEBUG 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); if ((*poll_func) (fds, n_fds, timeout) < 0 && errno != EINTR) { #ifndef G_OS_WIN32 g_warning ("poll(2) failed due to: %s.", g_strerror (errno)); #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: 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 seldomly be used directly. Instead * a typical event source will use g_source_add_poll() 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); #ifdef GSTREAMER_LITE if (newrec == NULL) { return; } #endif // GSTREAMER_LITE /* This file descriptor may be checked before we ever poll */ fd->revents = 0; newrec->fd = fd; newrec->priority = priority; prevrec = context->poll_records_tail; nextrec = NULL; while (prevrec && priority < prevrec->priority) { nextrec = prevrec; prevrec = prevrec->prev; } if (prevrec) prevrec->next = newrec; else context->poll_records = newrec; newrec->prev = prevrec; newrec->next = nextrec; if (nextrec) nextrec->prev = newrec; else context->poll_records_tail = newrec; context->n_poll_records++; #ifdef G_THREADS_ENABLED context->poll_changed = TRUE; /* Now wake up the main loop if it is waiting in the poll() */ g_main_context_wakeup_unlocked (context); #endif } /** * 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; else context->poll_records_tail = prevrec; g_slice_free (GPollRec, pollrec); context->n_poll_records--; break; } prevrec = pollrec; pollrec = nextrec; } #ifdef G_THREADS_ENABLED context->poll_changed = TRUE; /* Now wake up the main loop if it is waiting in the poll() */ g_main_context_wakeup_unlocked (context); #endif } /** * g_source_get_current_time: * @source: a #GSource * @timeval: #GTimeVal structure in which to store current time. * * Gets the "current time" to be used when checking * this source. The advantage of calling this function over * calling g_get_current_time() directly is that when * checking multiple sources, GLib can cache a single value * instead of having to repeatedly get the system time. * * Deprecated: 2.28: use g_source_get_time() instead **/ void g_source_get_current_time (GSource *source, GTimeVal *timeval) { GMainContext *context; g_return_if_fail (source->context != NULL); context = source->context; LOCK_CONTEXT (context); if (!context->real_time_is_fresh) { context->real_time = g_get_real_time (); context->real_time_is_fresh = TRUE; } timeval->tv_sec = context->real_time / 1000000; timeval->tv_usec = context->real_time % 1000000; UNLOCK_CONTEXT (context); } /** * 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(). * * Return value: 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; } /* HOLDS: context's lock */ /* Wake the main loop up from a poll() */ static void g_main_context_wakeup_unlocked (GMainContext *context) { #ifdef G_THREADS_ENABLED if (g_thread_supported() && context->poll_waiting) { context->poll_waiting = FALSE; #ifndef G_OS_WIN32 write (context->wake_up_pipe[1], "A", 1); #else ReleaseSemaphore (context->wake_up_semaphore, 1, NULL); #endif } #endif } /** * g_main_context_wakeup: * @context: a #GMainContext * * If @context is currently waiting in a poll(), interrupt * the poll(), and continue the iteration process. **/ 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); LOCK_CONTEXT (context); g_main_context_wakeup_unlocked (context); UNLOCK_CONTEXT (context); } /** * 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 (); #ifdef G_THREADS_ENABLED LOCK_CONTEXT (context); is_owner = context->owner == G_THREAD_SELF; UNLOCK_CONTEXT (context); #else is_owner = TRUE; #endif return is_owner; } /* Timeouts */ static void g_timeout_set_expiration (GTimeoutSource *timeout_source, gint64 current_time) { timeout_source->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. */ timeout_source->expiration -= timer_perturb; remainder = timeout_source->expiration % 1000000; if (remainder >= 1000000/4) timeout_source->expiration += 1000000; timeout_source->expiration -= remainder; timeout_source->expiration += timer_perturb; } } static gboolean g_timeout_prepare (GSource *source, gint *timeout) { GTimeoutSource *timeout_source = (GTimeoutSource *) source; gint64 now = g_source_get_time (source); if (now < timeout_source->expiration) { /* Round up to ensure that we don't try again too early */ *timeout = (timeout_source->expiration - now + 999) / 1000; return FALSE; } *timeout = 0; return TRUE; } static gboolean g_timeout_check (GSource *source) { GTimeoutSource *timeout_source = (GTimeoutSource *) source; gint64 now = g_source_get_time (source); return timeout_source->expiration <= now; } 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); 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. * * Return value: the newly-created timeout source **/ GSource * g_timeout_source_new (guint interval) { GSource *source = g_source_new (&g_timeout_funcs, sizeof (GTimeoutSource)); #ifdef GSTREAMER_LITE if (source == NULL) return NULL; #endif // GSTREAMER_LITE GTimeoutSource *timeout_source = (GTimeoutSource *)source; timeout_source->interval = interval; g_timeout_set_expiration (timeout_source, g_get_monotonic_time ()); return source; } #ifndef GSTREAMER_LITE /** * 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. * * Return value: 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; } #endif // GSTREAMER_LITE /** * g_timeout_add_full: * @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: 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). * * This internally creates a main loop source using g_timeout_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. * * Return value: 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); #ifdef GSTREAMER_LITE if (source == NULL) return 0; #endif // GSTREAMER_LITE 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: * @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). * * 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 main loop context using g_source_attach(). You can * do these steps manually if you need greater control. * * Return value: 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); } #ifndef GSTREAMER_LITE /** * g_timeout_add_seconds_full: * @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: 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 * * 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. * * Return value: 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_timout_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. * * Return value: 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); } #endif // GSTREAMER_LITE /* 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; } #else /* G_OS_WIN32 */ static gboolean check_for_child_exited (GSource *source) { GChildWatchSource *child_watch_source; gint count; /* protect against another SIGCHLD in the middle of this call */ count = child_watch_count; child_watch_source = (GChildWatchSource *) source; if (child_watch_source->child_exited) return TRUE; if (child_watch_source->count < count) { gint child_status; if (waitpid (child_watch_source->pid, &child_status, WNOHANG) > 0) { child_watch_source->child_status = child_status; child_watch_source->child_exited = TRUE; } child_watch_source->count = count; } return child_watch_source->child_exited; } static gboolean g_child_watch_prepare (GSource *source, gint *timeout) { *timeout = -1; return check_for_child_exited (source); } static gboolean g_child_watch_check (GSource *source) { return check_for_child_exited (source); } #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_child_watch_signal_handler (int signum) { child_watch_count ++; if (child_watch_init_state == CHILD_WATCH_INITIALIZED_THREADED) { write (child_watch_wake_up_pipe[1], "B", 1); } else { /* We count on the signal interrupting the poll in the same thread. */ } } static void g_child_watch_source_init_single (void) { struct sigaction action; g_assert (! g_thread_supported()); g_assert (child_watch_init_state == CHILD_WATCH_UNINITIALIZED); child_watch_init_state = CHILD_WATCH_INITIALIZED_SINGLE; action.sa_handler = g_child_watch_signal_handler; sigemptyset (&action.sa_mask); action.sa_flags = SA_NOCLDSTOP; sigaction (SIGCHLD, &action, NULL); } G_GNUC_NORETURN static gpointer child_watch_helper_thread (gpointer data) { while (1) { gchar b[20]; GSList *list; read (child_watch_wake_up_pipe[0], b, 20); /* We were woken up. Wake up all other contexts in all other threads */ G_LOCK (main_context_list); for (list = main_context_list; list; list = list->next) { GMainContext *context; context = list->data; if (g_atomic_int_get (&context->ref_count) > 0) /* Due to racing conditions we can find ref_count == 0, in * that case, however, the context is still not destroyed * and no poll can be active, otherwise the ref_count * wouldn't be 0 */ g_main_context_wakeup (context); } G_UNLOCK (main_context_list); } } static void g_child_watch_source_init_multi_threaded (void) { GError *error = NULL; struct sigaction action; g_assert (g_thread_supported()); if (pipe (child_watch_wake_up_pipe) < 0) g_error ("Cannot create wake up pipe: %s\n", g_strerror (errno)); fcntl (child_watch_wake_up_pipe[1], F_SETFL, O_NONBLOCK | fcntl (child_watch_wake_up_pipe[1], F_GETFL)); /* We create a helper thread that polls on the wakeup pipe indefinitely */ /* FIXME: Think this through for races */ if (g_thread_create (child_watch_helper_thread, NULL, FALSE, &error) == NULL) g_error ("Cannot create a thread to monitor child exit status: %s\n", error->message); child_watch_init_state = CHILD_WATCH_INITIALIZED_THREADED; action.sa_handler = g_child_watch_signal_handler; sigemptyset (&action.sa_mask); action.sa_flags = SA_RESTART | SA_NOCLDSTOP; sigaction (SIGCHLD, &action, NULL); } static void g_child_watch_source_init_promote_single_to_threaded (void) { g_child_watch_source_init_multi_threaded (); } static void g_child_watch_source_init (void) { if (g_thread_supported()) { if (child_watch_init_state == CHILD_WATCH_UNINITIALIZED) g_child_watch_source_init_multi_threaded (); else if (child_watch_init_state == CHILD_WATCH_INITIALIZED_SINGLE) g_child_watch_source_init_promote_single_to_threaded (); } else { if (child_watch_init_state == CHILD_WATCH_UNINITIALIZED) g_child_watch_source_init_single (); } } #endif /* !G_OS_WIN32 */ /** * g_child_watch_source_new: * @pid: process to watch. On POSIX the 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. * * Note further that using g_child_watch_source_new() is not * compatible with calling waitpid(-1) in * the application. Calling waitpid() for individual pids will * still work fine. * * Return value: the newly-created child watch source * * Since: 2.4 **/ GSource * g_child_watch_source_new (GPid pid) { GSource *source = g_source_new (&g_child_watch_funcs, sizeof (GChildWatchSource)); GChildWatchSource *child_watch_source = (GChildWatchSource *)source; #ifdef GSTREAMER_LITE if (source == NULL) return NULL; #endif // GSTREAMER_LITE #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_child_watch_source_init (); #endif /* G_OS_WIN32 */ child_watch_source->pid = pid; return source; } /** * g_child_watch_add_full: * @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 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: 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. * * 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. * * 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. * * Return value: 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); 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 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. * * 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. * * Return value: 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) { if (!callback) { g_warning ("Idle source dispatched without callback\n" "You must call g_source_set_callback()."); return FALSE; } return callback (user_data); } /** * 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. * * Return value: 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: * @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: 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. * * This internally creates a main loop source using g_idle_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. * * Return value: 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); 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. * * This internally creates a main loop source using g_idle_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. * * Return value: 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. * * Return value: %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: 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: a #GMainContext, or %NULL * @priority: the priority at which to run @function * @function: function to call * @data: data to pass to @function * @notify: 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 incase @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); } } }