#ifdef G_OS_UNIX
#include "glib-unix.h"
+#include <pthread.h>
#ifdef HAVE_EVENTFD
#include <sys/eventfd.h>
#endif
#include "gwakeup.h"
+#include "glib-private.h"
+
/**
* SECTION:main
* @title: The Main Event Loop
* <graphic fileref="mainloop-states.gif" format="GIF"></graphic>
* </figure>
* </refsect2>
+ *
+ * On Unix, the GLib mainloop is incompatible with fork(). Any program
+ * using the mainloop must either exec() or exit() from the child
+ * without returning to the mainloop.
*/
/* Types */
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 _GMainContext
{
-#ifdef G_THREADS_ENABLED
/* The following lock is used for both the list of sources
* and the list of poll records
*/
- GStaticMutex mutex;
+ GMutex mutex;
GCond *cond;
GThread *owner;
guint owner_count;
GSList *waiters;
-#endif
gint ref_count;
GPollFD *cached_poll_array;
guint cached_poll_array_size;
-#ifdef G_THREADS_ENABLED
GWakeup *wakeup;
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
#ifdef G_OS_WIN32
GPollFD poll;
#else /* G_OS_WIN32 */
- gint count;
gboolean child_exited;
#endif /* G_OS_WIN32 */
};
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 LOCK_CONTEXT(context) g_mutex_lock (&context->mutex)
+#define UNLOCK_CONTEXT(context) g_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 && \
GPollFD *fd);
static void g_main_context_remove_poll_unlocked (GMainContext *context,
GPollFD *fd);
-static void g_main_context_wakeup_unlocked (GMainContext *context);
-
-static void _g_main_wake_up_all_contexts (void);
static gboolean g_timeout_prepare (GSource *source,
gint *timeout);
static gboolean g_child_watch_dispatch (GSource *source,
GSourceFunc callback,
gpointer user_data);
+static void g_child_watch_finalize (GSource *source);
#ifdef G_OS_UNIX
-static gpointer unix_signal_helper_thread (gpointer data) G_GNUC_NORETURN;
static void g_unix_signal_handler (int signum);
static gboolean g_unix_signal_watch_prepare (GSource *source,
gint *timeout);
GSourceFunc callback,
gpointer user_data);
+static GMainContext *glib_worker_context;
+static gboolean g_main_context_fork_detected;
+
G_LOCK_DEFINE_STATIC (main_loop);
static GMainContext *default_main_context;
-static GSList *main_contexts_without_pipe = NULL;
#ifndef G_OS_WIN32
-/* The UNIX signal pipe contains a single byte specifying which
- * signal was received.
- */
-#define _UNIX_SIGNAL_PIPE_SIGCHLD_CHAR 'C'
-#define _UNIX_SIGNAL_PIPE_SIGHUP_CHAR 'H'
-#define _UNIX_SIGNAL_PIPE_SIGINT_CHAR 'I'
-#define _UNIX_SIGNAL_PIPE_SIGTERM_CHAR 'T'
-/* Guards all the data below */
+
+/* UNIX signals work by marking one of these variables then waking the
+ * worker context to check on them and dispatch accordingly.
+ */
+static volatile gchar unix_signal_pending[NSIG];
+static volatile gboolean any_unix_signal_pending;
+
+/* Guards all the data below */
G_LOCK_DEFINE_STATIC (unix_signal_lock);
-enum {
- UNIX_SIGNAL_UNINITIALIZED = 0,
- UNIX_SIGNAL_INITIALIZED_SINGLE,
- UNIX_SIGNAL_INITIALIZED_THREADED
-};
-static gint unix_signal_init_state = UNIX_SIGNAL_UNINITIALIZED;
-typedef struct {
- /* These are only used in the UNIX_SIGNAL_INITIALIZED_SINGLE case */
- gboolean sighup_delivered : 1;
- gboolean sigint_delivered : 1;
- gboolean sigterm_delivered : 1;
-} UnixSignalState;
-static sigset_t unix_signal_mask;
-static UnixSignalState unix_signal_state;
-static gint unix_signal_wake_up_pipe[2];
-GSList *unix_signal_watches;
-
-/* Not guarded ( FIXME should it be? ) */
-static gint child_watch_count = 1;
+static GSList *unix_signal_watches;
+static GSList *unix_child_watches;
static GSourceFuncs g_unix_signal_funcs =
{
g_child_watch_prepare,
g_child_watch_check,
g_child_watch_dispatch,
- NULL
+ g_child_watch_finalize
};
GSourceFuncs g_idle_funcs =
source = next;
}
-#ifdef G_THREADS_ENABLED
- g_static_mutex_free (&context->mutex);
-#endif
+ g_mutex_clear (&context->mutex);
g_ptr_array_free (context->pending_dispatches, TRUE);
g_free (context->cached_poll_array);
poll_rec_list_free (context, context->poll_records);
-
-#ifdef G_THREADS_ENABLED
- if (g_thread_supported())
- g_wakeup_free (context->wakeup);
- else
- main_contexts_without_pipe = g_slist_remove (main_contexts_without_pipe,
- context);
+ g_wakeup_free (context->wakeup);
if (context->cond != NULL)
g_cond_free (context->cond);
-#endif
g_free (context);
}
-#ifdef G_THREADS_ENABLED
+#ifdef G_OS_UNIX
static void
-g_main_context_init_pipe (GMainContext *context)
+g_main_context_forked (void)
{
- context->wakeup = g_wakeup_new ();
- g_wakeup_get_pollfd (context->wakeup, &context->wake_up_rec);
- g_main_context_add_poll_unlocked (context, 0, &context->wake_up_rec);
+ g_main_context_fork_detected = TRUE;
}
-
-void
-_g_main_thread_init (void)
-{
- GSList *curr;
-
- 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 */
+#endif
/**
* g_main_context_new:
GMainContext *
g_main_context_new (void)
{
- GMainContext *context = g_new0 (GMainContext, 1);
+ static gsize initialised;
+ GMainContext *context;
+ g_thread_init_glib ();
+
+ if (g_once_init_enter (&initialised))
+ {
#ifdef G_MAIN_POLL_DEBUG
- {
- static gboolean beenhere = FALSE;
+ if (getenv ("G_MAIN_POLL_DEBUG") != NULL)
+ _g_main_poll_debug = TRUE;
+#endif
- if (!beenhere)
- {
- if (getenv ("G_MAIN_POLL_DEBUG") != NULL)
- _g_main_poll_debug = TRUE;
- beenhere = TRUE;
- }
- }
+#ifdef G_OS_UNIX
+ pthread_atfork (NULL, NULL, g_main_context_forked);
#endif
-#ifdef G_THREADS_ENABLED
- g_static_mutex_init (&context->mutex);
+ g_once_init_leave (&initialised, TRUE);
+ }
+
+ context = g_new0 (GMainContext, 1);
+
+ g_mutex_init (&context->mutex);
context->owner = NULL;
context->waiters = NULL;
-#endif
context->ref_count = 1;
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
+ context->wakeup = g_wakeup_new ();
+ g_wakeup_get_pollfd (context->wakeup, &context->wake_up_rec);
+ g_main_context_add_poll_unlocked (context, 0, &context->wake_up_rec);
G_LOCK (main_context_list);
main_context_list = g_slist_append (main_context_list, context);
* specified, and corresponds to the "main" main loop. See also
* g_main_context_get_thread_default().
*
- * Return value: the global default main context.
+ * Return value: (transfer none): the global default main context.
**/
GMainContext *
g_main_context_default (void)
* 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.
+ * Returns: (transfer none): the thread-default #GMainContext, or
+ * %NULL if the thread-default context is the global default context.
*
* Since: 2.22
**/
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
+ /* If another thread has acquired the context, wake it up since it
+ * might be in poll() right now.
+ */
+ if (context->owner && context->owner != G_THREAD_SELF)
+ g_wakeup_signal (context->wakeup);
UNLOCK_CONTEXT (context);
* 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.
+ * Return value: (transfer none): 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)
*
* Finds a #GSource given a pair of context and ID.
*
- * Return value: the #GSource if found, otherwise, %NULL
+ * Return value: (transfer none): the #GSource if found, otherwise, %NULL
**/
GSource *
g_main_context_find_source_by_id (GMainContext *context,
* 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
+ * Return value: (transfer none): the source, if one was found, otherwise %NULL
**/
GSource *
g_main_context_find_source_by_funcs_user_data (GMainContext *context,
* 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
+ * Return value: (transfer none): the source, if one was found, otherwise %NULL
**/
GSource *
g_main_context_find_source_by_user_data (GMainContext *context,
*
* Returns the currently firing source for this thread.
*
- * Return value: The currently firing source or %NULL.
+ * Return value: (transfer none): The currently firing source or %NULL.
*
* Since: 2.12
*/
gboolean
g_main_context_acquire (GMainContext *context)
{
-#ifdef G_THREADS_ENABLED
gboolean result = FALSE;
GThread *self = G_THREAD_SELF;
UNLOCK_CONTEXT (context);
return result;
-#else /* !G_THREADS_ENABLED */
- return TRUE;
-#endif /* G_THREADS_ENABLED */
}
/**
void
g_main_context_release (GMainContext *context)
{
-#ifdef G_THREADS_ENABLED
if (context == NULL)
context = g_main_context_default ();
if (context->waiters)
{
GMainWaiter *waiter = context->waiters->data;
- gboolean loop_internal_waiter =
- (waiter->mutex == g_static_mutex_get_mutex (&context->mutex));
+ gboolean loop_internal_waiter = (waiter->mutex == &context->mutex);
context->waiters = g_slist_delete_link (context->waiters,
context->waiters);
if (!loop_internal_waiter)
}
UNLOCK_CONTEXT (context);
-#endif /* G_THREADS_ENABLED */
}
/**
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));
+ loop_internal_waiter = (mutex == &context->mutex);
if (!loop_internal_waiter)
LOCK_CONTEXT (context);
UNLOCK_CONTEXT (context);
return result;
-#else /* !G_THREADS_ENABLED */
- return TRUE;
-#endif /* G_THREADS_ENABLED */
}
/**
LOCK_CONTEXT (context);
context->time_is_fresh = FALSE;
- context->real_time_is_fresh = FALSE;
if (context->in_check_or_prepare)
{
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)
* 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.
+ * @timeout_: (out): location to store timeout to be used in polling
+ * @fds: (out caller-allocates) (array length=n_fds): location to
+ * store #GPollFD records that need to be polled.
* @n_fds: length of @fds.
*
* Determines information necessary to poll this main loop.
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;
- }
+ context->time_is_fresh = FALSE;
}
UNLOCK_CONTEXT (context);
* 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()
+ * @fds: (array length=n_fds): array of #GPollFD's that was passed to
+ * the last call to g_main_context_query()
* @n_fds: return value of g_main_context_query()
*
* Passes the results of polling back to the main loop.
UNLOCK_CONTEXT (context);
return FALSE;
}
-
-#ifdef G_THREADS_ENABLED
- if (!context->poll_waiting)
- g_wakeup_acknowledge (context->wakeup);
- else
- context->poll_waiting = FALSE;
+ if (context->wake_up_rec.events)
+ g_wakeup_acknowledge (context->wakeup);
/* If the set of poll file descriptors changed, bail out
* and let the main loop rerun
UNLOCK_CONTEXT (context);
return FALSE;
}
-#endif /* G_THREADS_ENABLED */
pollrec = context->poll_records;
i = 0;
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;
got_ownership = g_main_context_wait (context,
context->cond,
- g_static_mutex_get_mutex (&context->mutex));
+ &context->mutex);
if (!got_ownership)
return FALSE;
}
else
LOCK_CONTEXT (context);
-#endif /* G_THREADS_ENABLED */
if (!context->cached_poll_array)
{
if (!block)
timeout = 0;
+ g_assert (!g_main_context_fork_detected);
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);
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);
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));
+ &loop->context->mutex);
if (!loop->is_running)
{
}
else
LOCK_CONTEXT (loop->context);
-#endif /* G_THREADS_ENABLED */
if (loop->context->in_check_or_prepare)
{
UNLOCK_CONTEXT (loop->context);
-#ifdef G_THREADS_ENABLED
g_main_context_release (loop->context);
-#endif /* G_THREADS_ENABLED */
g_main_loop_unref (loop);
}
LOCK_CONTEXT (loop->context);
loop->is_running = FALSE;
- g_main_context_wakeup_unlocked (loop->context);
+ g_wakeup_signal (loop->context->wakeup);
-#ifdef G_THREADS_ENABLED
if (loop->context->cond)
g_cond_broadcast (loop->context->cond);
-#endif /* G_THREADS_ENABLED */
UNLOCK_CONTEXT (loop->context);
}
*
* Returns the #GMainContext of @loop.
*
- * Return value: the #GMainContext of @loop
+ * Return value: (transfer none): the #GMainContext of @loop
**/
GMainContext *
g_main_loop_get_context (GMainLoop *loop)
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_wakeup_signal (context->wakeup);
}
/**
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_wakeup_signal (context->wakeup);
}
/**
* 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.
+ *
+ * This function ignores @source and is otherwise the same as
+ * g_get_current_time().
*
* Deprecated: 2.28: use g_source_get_time() instead
**/
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_get_current_time (timeval);
}
/**
return result;
}
-static void
-_g_main_wake_up_all_contexts (void)
-{
- GSList *list;
-
- /* 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 = list->data;
-
- LOCK_CONTEXT (context);
- g_main_context_wakeup_unlocked (context);
- UNLOCK_CONTEXT (context);
- }
- G_UNLOCK (main_context_list);
-}
-
-
-/* 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;
- g_wakeup_signal (context->wakeup);
- }
-#endif
-}
-
/**
* g_main_context_wakeup:
* @context: a #GMainContext
{
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_wakeup_signal (context->wakeup);
}
/**
* @context: a #GMainContext
*
* Determines whether this thread holds the (recursive)
- * ownership of this #GMaincontext. This is useful to
+ * ownership of this #GMainContext. This is useful to
* know before waiting on another thread that may be
* blocking to get ownership of @context.
*
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;
}
return FALSE;
}
-
static gboolean
g_child_watch_check (GSource *source)
{
return child_exited;
}
+static void
+g_child_watch_finalize (GSource *source)
+{
+}
+
#else /* G_OS_WIN32 */
-static gboolean
-check_for_child_exited (GSource *source)
+static void
+wake_source (GSource *source)
{
- GChildWatchSource *child_watch_source;
- gint count;
+ GMainContext *context;
- /* protect against another SIGCHLD in the middle of this call */
- count = child_watch_count;
+ /* This should be thread-safe:
+ *
+ * - if the source is currently being added to a context, that
+ * context will be woken up anyway
+ *
+ * - if the source is currently being destroyed, we simply need not
+ * to crash:
+ *
+ * - the memory for the source will remain valid until after the
+ * source finalize function was called (which would remove the
+ * source from the global list which we are currently holding the
+ * lock for)
+ *
+ * - the GMainContext will either be NULL or point to a live
+ * GMainContext
+ *
+ * - the GMainContext will remain valid since we hold the
+ * main_context_list lock
+ *
+ * Since we are holding a lot of locks here, don't try to enter any
+ * more GMainContext functions for fear of dealock -- just hit the
+ * GWakeup and run. Even if that's safe now, it could easily become
+ * unsafe with some very minor changes in the future, and signal
+ * handling is not the most well-tested codepath.
+ */
+ G_LOCK(main_context_list);
+ context = source->context;
+ if (context)
+ g_wakeup_signal (context->wakeup);
+ G_UNLOCK(main_context_list);
+}
- child_watch_source = (GChildWatchSource *) source;
+static void
+dispatch_unix_signals (void)
+{
+ GSList *node;
+
+ /* clear this first incase another one arrives while we're processing */
+ any_unix_signal_pending = FALSE;
- if (child_watch_source->child_exited)
- return TRUE;
+ G_LOCK(unix_signal_lock);
- if (child_watch_source->count < count)
+ /* handle GChildWatchSource instances */
+ if (unix_signal_pending[SIGCHLD])
{
- gint child_status;
+ unix_signal_pending[SIGCHLD] = FALSE;
+
+ /* The only way we can do this is to scan all of the children.
+ *
+ * The docs promise that we will not reap children that we are not
+ * explicitly watching, so that ties our hands from calling
+ * waitpid(-1). We also can't use siginfo's si_pid field since if
+ * multiple SIGCHLD arrive at the same time, one of them can be
+ * dropped (since a given UNIX signal can only be pending once).
+ */
+ for (node = unix_child_watches; node; node = node->next)
+ {
+ GChildWatchSource *source = node->data;
- if (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;
+ if (!source->child_exited)
+ {
+ if (waitpid (source->pid, &source->child_status, WNOHANG) > 0)
+ {
+ source->child_exited = TRUE;
+
+ wake_source ((GSource *) source);
+ }
+ }
+ }
}
- return child_watch_source->child_exited;
+ /* handle GUnixSignalWatchSource instances */
+ for (node = unix_signal_watches; node; node = node->next)
+ {
+ GUnixSignalWatchSource *source = node->data;
+
+ if (!source->pending)
+ {
+ if (unix_signal_pending[source->signum])
+ {
+ unix_signal_pending[source->signum] = FALSE;
+ source->pending = TRUE;
+
+ wake_source ((GSource *) source);
+ }
+ }
+ }
+
+ G_UNLOCK(unix_signal_lock);
}
static gboolean
g_child_watch_prepare (GSource *source,
gint *timeout)
{
- *timeout = -1;
+ GChildWatchSource *child_watch_source;
- return check_for_child_exited (source);
-}
+ child_watch_source = (GChildWatchSource *) source;
-static gboolean
-g_child_watch_check (GSource *source)
-{
- return check_for_child_exited (source);
+ return child_watch_source->child_exited;
}
static gboolean
-check_for_signal_delivery (GSource *source)
+g_child_watch_check (GSource *source)
{
- GUnixSignalWatchSource *unix_signal_source = (GUnixSignalWatchSource*) source;
- gboolean delivered;
+ GChildWatchSource *child_watch_source;
- G_LOCK (unix_signal_lock);
- if (unix_signal_init_state == UNIX_SIGNAL_INITIALIZED_SINGLE)
- {
- switch (unix_signal_source->signum)
- {
- case SIGHUP:
- delivered = unix_signal_state.sighup_delivered;
- break;
- case SIGINT:
- delivered = unix_signal_state.sigint_delivered;
- break;
- case SIGTERM:
- delivered = unix_signal_state.sigterm_delivered;
- break;
- default:
- g_assert_not_reached ();
- delivered = FALSE;
- break;
- }
- }
- else
- {
- g_assert (unix_signal_init_state == UNIX_SIGNAL_INITIALIZED_THREADED);
- delivered = unix_signal_source->pending;
- }
- G_UNLOCK (unix_signal_lock);
+ child_watch_source = (GChildWatchSource *) source;
- return delivered;
+ return child_watch_source->child_exited;
}
static gboolean
g_unix_signal_watch_prepare (GSource *source,
gint *timeout)
{
- *timeout = -1;
+ GUnixSignalWatchSource *unix_signal_source;
+
+ unix_signal_source = (GUnixSignalWatchSource *) source;
- return check_for_signal_delivery (source);
+ return unix_signal_source->pending;
}
-static gboolean
+static gboolean
g_unix_signal_watch_check (GSource *source)
{
- return check_for_signal_delivery (source);
+ GUnixSignalWatchSource *unix_signal_source;
+
+ unix_signal_source = (GUnixSignalWatchSource *) source;
+
+ return unix_signal_source->pending;
}
static gboolean
}
(callback) (user_data);
-
- G_LOCK (unix_signal_lock);
- if (unix_signal_init_state == UNIX_SIGNAL_INITIALIZED_SINGLE)
- {
- switch (unix_signal_source->signum)
- {
- case SIGHUP:
- unix_signal_state.sighup_delivered = FALSE;
- break;
- case SIGINT:
- unix_signal_state.sigint_delivered = FALSE;
- break;
- case SIGTERM:
- unix_signal_state.sigterm_delivered = FALSE;
- break;
- }
- }
- else
- {
- g_assert (unix_signal_init_state == UNIX_SIGNAL_INITIALIZED_THREADED);
- unix_signal_source->pending = FALSE;
- }
- G_UNLOCK (unix_signal_lock);
+
+ unix_signal_source->pending = FALSE;
return TRUE;
}
static void
ensure_unix_signal_handler_installed_unlocked (int signum)
{
+ static sigset_t installed_signal_mask;
+ static gboolean initialized;
struct sigaction action;
- GError *error = NULL;
-
- if (unix_signal_init_state == UNIX_SIGNAL_UNINITIALIZED)
- {
- sigemptyset (&unix_signal_mask);
- }
- if (unix_signal_init_state == UNIX_SIGNAL_UNINITIALIZED
- || unix_signal_init_state == UNIX_SIGNAL_INITIALIZED_SINGLE)
+ if (!initialized)
{
- if (!g_thread_supported ())
- {
- /* There is nothing to do for initializing in the non-threaded
- * case.
- */
- if (unix_signal_init_state == UNIX_SIGNAL_UNINITIALIZED)
- unix_signal_init_state = UNIX_SIGNAL_INITIALIZED_SINGLE;
- }
- else
- {
- if (!g_unix_open_pipe (unix_signal_wake_up_pipe, FD_CLOEXEC, &error))
- g_error ("Cannot create UNIX signal wake up pipe: %s\n", error->message);
- g_unix_set_fd_nonblocking (unix_signal_wake_up_pipe[1], TRUE, NULL);
-
- /* We create a helper thread that polls on the wakeup pipe indefinitely */
- if (g_thread_create (unix_signal_helper_thread, NULL, FALSE, &error) == NULL)
- g_error ("Cannot create a thread to monitor UNIX signals: %s\n", error->message);
-
- unix_signal_init_state = UNIX_SIGNAL_INITIALIZED_THREADED;
- }
+ sigemptyset (&installed_signal_mask);
+ g_get_worker_context ();
+ initialized = TRUE;
}
- if (sigismember (&unix_signal_mask, signum))
+ if (sigismember (&installed_signal_mask, signum))
return;
- sigaddset (&unix_signal_mask, signum);
+ sigaddset (&installed_signal_mask, signum);
action.sa_handler = g_unix_signal_handler;
sigemptyset (&action.sa_mask);
G_LOCK (unix_signal_lock);
ensure_unix_signal_handler_installed_unlocked (signum);
unix_signal_watches = g_slist_prepend (unix_signal_watches, unix_signal_source);
+ if (unix_signal_pending[signum])
+ unix_signal_source->pending = TRUE;
+ unix_signal_pending[signum] = FALSE;
G_UNLOCK (unix_signal_lock);
return source;
}
-static void
+static void
g_unix_signal_watch_finalize (GSource *source)
{
G_LOCK (unix_signal_lock);
G_UNLOCK (unix_signal_lock);
}
+static void
+g_child_watch_finalize (GSource *source)
+{
+ G_LOCK (unix_signal_lock);
+ unix_child_watches = g_slist_remove (unix_child_watches, source);
+ G_UNLOCK (unix_signal_lock);
+}
+
#endif /* G_OS_WIN32 */
static gboolean
static void
g_unix_signal_handler (int signum)
{
- if (signum == SIGCHLD)
- child_watch_count ++;
+ unix_signal_pending[signum] = TRUE;
+ any_unix_signal_pending = TRUE;
- if (unix_signal_init_state == UNIX_SIGNAL_INITIALIZED_THREADED)
- {
- char buf[1];
- switch (signum)
- {
- case SIGCHLD:
- buf[0] = _UNIX_SIGNAL_PIPE_SIGCHLD_CHAR;
- break;
- case SIGHUP:
- buf[0] = _UNIX_SIGNAL_PIPE_SIGHUP_CHAR;
- break;
- case SIGINT:
- buf[0] = _UNIX_SIGNAL_PIPE_SIGINT_CHAR;
- break;
- case SIGTERM:
- buf[0] = _UNIX_SIGNAL_PIPE_SIGTERM_CHAR;
- break;
- default:
- /* Shouldn't happen */
- return;
- }
- write (unix_signal_wake_up_pipe[1], buf, 1);
- }
- else
- {
- /* We count on the signal interrupting the poll in the same thread. */
- switch (signum)
- {
- case SIGCHLD:
- /* Nothing to do - the handler will call waitpid() */
- break;
- case SIGHUP:
- unix_signal_state.sighup_delivered = TRUE;
- break;
- case SIGINT:
- unix_signal_state.sigint_delivered = TRUE;
- break;
- case SIGTERM:
- unix_signal_state.sigterm_delivered = TRUE;
- break;
- default:
- g_assert_not_reached ();
- break;
- }
- }
-}
-
-static void
-deliver_unix_signal (int signum)
-{
- GSList *iter;
- g_assert (signum == SIGHUP || signum == SIGINT || signum == SIGTERM);
-
- G_LOCK (unix_signal_lock);
- for (iter = unix_signal_watches; iter; iter = iter->next)
- {
- GUnixSignalWatchSource *source = iter->data;
-
- if (source->signum != signum)
- continue;
-
- source->pending = TRUE;
- }
- G_UNLOCK (unix_signal_lock);
-}
-
-/*
- * This thread is created whenever anything in GLib needs
- * to deal with UNIX signals; at present, just SIGCHLD
- * from g_child_watch_source_new().
- *
- * Note: We could eventually make this thread a more public interface
- * and allow e.g. GDBus to use it instead of its own worker thread.
- */
-static gpointer
-unix_signal_helper_thread (gpointer data)
-{
- while (1)
- {
- gchar b[128];
- ssize_t i, bytes_read;
- gboolean sigterm_received = FALSE;
- gboolean sigint_received = FALSE;
- gboolean sighup_received = FALSE;
-
- bytes_read = read (unix_signal_wake_up_pipe[0], b, sizeof (b));
- if (bytes_read < 0)
- {
- g_warning ("Failed to read from child watch wake up pipe: %s",
- strerror (errno));
- /* Not much we can do here sanely; just wait a second and hope
- * it was transient.
- */
- g_usleep (G_USEC_PER_SEC);
- continue;
- }
- for (i = 0; i < bytes_read; i++)
- {
- switch (b[i])
- {
- case _UNIX_SIGNAL_PIPE_SIGCHLD_CHAR:
- /* The child watch source will call waitpid() in its
- * prepare() and check() methods; however, we don't
- * know which pid exited, so we need to wake up
- * all contexts. Note: actually we could get the pid
- * from the "siginfo_t" via the handler, but to pass
- * that info down the pipe would require a more structured
- * data stream (as opposed to a single byte).
- */
- break;
- case _UNIX_SIGNAL_PIPE_SIGTERM_CHAR:
- sigterm_received = TRUE;
- break;
- case _UNIX_SIGNAL_PIPE_SIGHUP_CHAR:
- sighup_received = TRUE;
- break;
- case _UNIX_SIGNAL_PIPE_SIGINT_CHAR:
- sigint_received = TRUE;
- break;
- default:
- g_warning ("Invalid char '%c' read from child watch pipe", b[i]);
- break;
- }
- }
- if (sigterm_received)
- deliver_unix_signal (SIGTERM);
- if (sigint_received)
- deliver_unix_signal (SIGINT);
- if (sighup_received)
- deliver_unix_signal (SIGHUP);
- _g_main_wake_up_all_contexts ();
- }
-}
-
-static void
-g_child_watch_source_init (void)
-{
- G_LOCK (unix_signal_lock);
- ensure_unix_signal_handler_installed_unlocked (SIGCHLD);
- G_UNLOCK (unix_signal_lock);
+ g_wakeup_signal (glib_worker_context->wakeup);
}
#endif /* !G_OS_WIN32 */
GSource *source = g_source_new (&g_child_watch_funcs, sizeof (GChildWatchSource));
GChildWatchSource *child_watch_source = (GChildWatchSource *)source;
+ child_watch_source->pid = pid;
+
#ifdef G_OS_WIN32
child_watch_source->poll.fd = (gintptr) pid;
child_watch_source->poll.events = G_IO_IN;
g_source_add_poll (source, &child_watch_source->poll);
#else /* G_OS_WIN32 */
- g_child_watch_source_init ();
+ G_LOCK (unix_signal_lock);
+ ensure_unix_signal_handler_installed_unlocked (SIGCHLD);
+ unix_child_watches = g_slist_prepend (unix_child_watches, child_watch_source);
+ if (waitpid (pid, &child_watch_source->child_status, WNOHANG) > 0)
+ child_watch_source->child_exited = TRUE;
+ G_UNLOCK (unix_signal_lock);
#endif /* G_OS_WIN32 */
- child_watch_source->pid = pid;
-
return source;
}
/**
* g_main_context_invoke:
- * @context: a #GMainContext, or %NULL
+ * @context: (allow-none): a #GMainContext, or %NULL
* @function: function to call
* @data: data to pass to @function
*
/**
* g_main_context_invoke_full:
- * @context: a #GMainContext, or %NULL
+ * @context: (allow-none): a #GMainContext, or %NULL
* @priority: the priority at which to run @function
* @function: function to call
* @data: data to pass to @function
}
}
}
+
+static gpointer
+glib_worker_main (gpointer data)
+{
+ while (TRUE)
+ {
+ g_main_context_iteration (glib_worker_context, TRUE);
+
+#ifdef G_OS_UNIX
+ if (any_unix_signal_pending)
+ dispatch_unix_signals ();
+#endif
+ }
+
+ return NULL; /* worst GCC warning message ever... */
+}
+
+GMainContext *
+g_get_worker_context (void)
+{
+ static gsize initialised;
+
+ g_thread_init_glib ();
+
+ if (g_once_init_enter (&initialised))
+ {
+ GError *error = NULL;
+
+ glib_worker_context = g_main_context_new ();
+ if (g_thread_new ("gmain", glib_worker_main, NULL, FALSE, &error) == NULL)
+ g_error ("Creating GLib worker thread failed: %s\n", error->message);
+
+ g_once_init_leave (&initialised, TRUE);
+ }
+
+ return glib_worker_context;
+}
projects / platform / upstream / glib.git / blobdiff