Hopefully thread-safer replacement for intf_UserFatal

include/vlc_dialog.h

+/*****************************************************************************
+ * vlc_dialog.h: user interaction dialogs
+ *****************************************************************************
+ * Copyright (C) 2009 Rémi Denis-Courmont
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifndef VLC_DIALOG_H_
+#define VLC_DIALOG_H_
+
+/**
+ * \file vlc_dialog.h
+ * User interaction dialog APIs
+ */
+
+/**
+ * A fatal error dialog.
+ * No response expected from the user.
+ */
+typedef struct dialog_fatal_t
+{
+    const char *title;
+    const char *message;
+} dialog_fatal_t;
+
+VLC_EXPORT( void, dialog_Fatal, (vlc_object_t *, const char *, const char *, ...) ) LIBVLC_FORMAT(3, 4);
+#define dialog_Fatal(o, t, ...) \
+        dialog_Fatal(VLC_OBJECT(o), t, __VA_ARGS__)
+
+VLC_EXPORT( int, dialog_Register, (vlc_object_t *) );
+VLC_EXPORT( int, dialog_Unregister, (vlc_object_t *) );
+#define dialog_Register(o) dialog_Register(VLC_OBJECT(o))
+#define dialog_Unregister(o) dialog_Unregister(VLC_OBJECT(o))
+
+#endif

src/Makefile.am

@@ -50,6 +50,7 @@ pluginsinclude_HEADERS = \
 	../include/vlc_config.h \
 	../include/vlc_config_cat.h \
 	../include/vlc_configuration.h \
+	../include/vlc_dialog.h \
 	../include/vlc_demux.h \
 	../include/vlc_epg.h \
 	../include/vlc_es.h \
@@ -264,6 +265,7 @@ SOURCES_libvlc_common = \
 	libvlc-module.c \
 	missing.c \
 	version.c \
+	interface/dialog.c \
 	interface/interface.h \
 	interface/interface.c \
 	interface/intf_eject.c \

src/interface/dialog.c

+/*****************************************************************************
+ * dialog.c: User dialog functions
+ *****************************************************************************
+ * Copyright © 2009 Rémi Denis-Courmont
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+/**
+ * \file dialog.c
+ * User dialogs core
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdarg.h>
+
+#include <vlc_common.h>
+#include <vlc_dialog.h>
+#include <assert.h>
+#include "libvlc.h"
+
+static vlc_mutex_t provider_lock = VLC_STATIC_MUTEX;
+
+#undef dialog_Register
+/**
+ * Registers an object as the dialog provider.
+ * It is assumed that the appropriate variable callbacks are already
+ * registered.
+ */
+int dialog_Register (vlc_object_t *obj)
+{
+    libvlc_priv_t *priv = libvlc_priv (obj->p_libvlc);
+    int ret = VLC_EGENERIC;
+
+    vlc_mutex_lock (&provider_lock);
+    if (priv->p_dialog_provider == NULL)
+    {   /* Since the object is responsible for unregistering itself before
+         * it terminates, at reference is not needed. */
+        priv->p_dialog_provider = obj;
+        ret = VLC_SUCCESS;
+    }
+    vlc_mutex_unlock (&provider_lock);
+    return ret;
+}
+
+#undef dialog_Unregister
+/**
+ * Unregisters the dialog provider.
+ * Note that unless you have unregistered the callbacks already, the provider
+ * might still be in use by other threads. Also, you need to cancel all
+ * pending dialogs yourself.
+ */
+int dialog_Unregister (vlc_object_t *obj)
+{
+    libvlc_priv_t *priv = libvlc_priv (obj->p_libvlc);
+    int ret = VLC_EGENERIC;
+
+    vlc_mutex_lock (&provider_lock);
+    if (priv->p_dialog_provider == obj)
+    {
+        priv->p_dialog_provider = NULL;
+        ret = VLC_SUCCESS;
+    }
+    vlc_mutex_unlock (&provider_lock);
+    return ret;
+}
+
+static vlc_object_t *dialog_GetProvider (vlc_object_t *obj)
+{
+    libvlc_priv_t *priv = libvlc_priv (obj->p_libvlc);
+    vlc_object_t *provider;
+
+    vlc_mutex_lock (&provider_lock);
+    if ((provider = priv->p_dialog_provider) != NULL)
+        vlc_object_hold (provider);
+    vlc_mutex_unlock (&provider_lock);
+    return provider;
+}
+
+static
+void dialog_FatalVa (vlc_object_t *obj, const char *title,
+                     const char *fmt, va_list ap)
+{
+    char *text;
+
+    vlc_object_t *provider = dialog_GetProvider (obj);
+    if (provider == NULL)
+    {
+        msg_Err (obj, "%s", title);
+        msg_GenericVa (obj, VLC_MSG_ERR, MODULE_STRING, fmt, ap);
+        return;
+    }
+
+    if (vasprintf (&text, fmt, ap) == -1)
+        return;
+
+    dialog_fatal_t dialog = { title, text, };
+    var_SetAddress (provider, "dialog-fatal", &dialog);
+    free (text);
+}
+
+#undef dialog_Fatal
+/**
+ * Notify the user of some fatal error.
+ * This is a fire and forget function.
+ */
+void dialog_Fatal (vlc_object_t *obj, const char *title, const char *fmt, ...)
+{
+    va_list ap;
+
+    va_start (ap, fmt);
+    dialog_FatalVa (obj, title, fmt, ap);
+    va_end (ap);
+}

src/libvlc.c

@@ -259,6 +259,7 @@ libvlc_int_t * libvlc_InternalCreate( void )
     priv = libvlc_priv (p_libvlc);
     priv->p_playlist = NULL;
     priv->p_interaction = NULL;
+    priv->p_dialog_provider = NULL;
     priv->p_vlm = NULL;
     p_libvlc->psz_object_name = strdup( "libvlc" );
 

src/libvlc.h

@@ -220,8 +220,9 @@ typedef struct libvlc_priv_t
     module_t          *p_memcpy_module;  ///< Fast memcpy plugin used
     playlist_t        *p_playlist; //< the playlist singleton
     vlm_t             *p_vlm;  ///< the VLM singleton (or NULL)
-    interaction_t     *p_interaction;    ///< interface interaction object
-    intf_thread_t     *p_interaction_intf; ///< XXX interface for interaction
+    interaction_t     *p_interaction;    ///< old interaction object
+    intf_thread_t     *p_interaction_intf; ///< old interface for interaction
+    vlc_object_t      *p_dialog_provider; ///< dialog provider
     httpd_t           *p_httpd; ///< HTTP daemon (src/network/httpd.c)
 #ifdef ENABLE_SOUT
     sap_handler_t     *p_sap; ///< SAP SDP advertiser

src/libvlccore.sym

@@ -102,6 +102,9 @@ decode_URI_duplicate
 demux_PacketizerDestroy
 demux_PacketizerNew
 demux_vaControlHelper
+dialog_Fatal
+dialog_Register
+dialog_Unregister
 encode_URI_component
 EndMD5
 EnsureUTF8