[vlc-devel] [PATCH 1/3] upnp: add and use a callback listener interface

Hugo Beauzée-Luyssen hugo at beauzee.fr
Wed Jun 27 12:47:57 CEST 2018


Hi,

On Mon, Jun 25, 2018, at 6:49 AM, Shaleen Jain wrote:
> Introduce a Listener interface to
> UpnpInstanceWrapper that can be used
> by modules to get UpnpEvent callbacks
> from libupnp, decoupling UpnpInstanceWrapper
> from any specific module or their members.
> ---
>  modules/services_discovery/upnp.cpp | 127 +++++++++++-----------------
>  modules/services_discovery/upnp.hpp |  44 +++++++---
>  2 files changed, 79 insertions(+), 92 deletions(-)
> 
> diff --git a/modules/services_discovery/upnp.cpp b/modules/
> services_discovery/upnp.cpp
> index 7455ceb299..fc81a847a2 100644
> --- a/modules/services_discovery/upnp.cpp
> +++ b/modules/services_discovery/upnp.cpp
> @@ -1,13 +1,14 @@
>  /
> *****************************************************************************
>   * upnp.cpp :  UPnP discovery module (libupnp)
>   
> *****************************************************************************
> - * Copyright (C) 2004-2016 VLC authors and VideoLAN
> + * Copyright (C) 2004-2018 VLC authors and VideoLAN
>   * $Id$
>   *
>   * Authors: Rémi Denis-Courmont <rem # videolan.org> (original plugin)
>   *          Christian Henz <henz # c-lab.de>
>   *          Mirsal Ennaime <mirsal dot ennaime at gmail dot com>
>   *          Hugo Beauzée-Luyssen <hugo at beauzee.fr>
> + *          Shaleen Jain <shaleen at jain.sh>
>   *
>   * This program is free software; you can redistribute it and/or modify 
> it
>   * under the terms of the GNU Lesser General Public License as 
> published by
> @@ -84,6 +85,7 @@ static const char *const 
> ppsz_readible_satip_channel_lists[] = {
>  struct services_discovery_sys_t
>  {
>      UpnpInstanceWrapper* p_upnp;
> +    std::shared_ptr<SD::MediaServerList> p_server_list;
>      vlc_thread_t         thread;
>  };
>  
> @@ -93,8 +95,8 @@ struct access_sys_t
>  };
>  
>  UpnpInstanceWrapper* UpnpInstanceWrapper::s_instance;
> +UpnpInstanceWrapper::Listeners UpnpInstanceWrapper::s_listeners;
>  vlc_mutex_t UpnpInstanceWrapper::s_lock = VLC_STATIC_MUTEX;
> -SD::MediaServerList *UpnpInstanceWrapper::p_server_list = NULL;
>  
>  /*
>   * VLC callback prototypes
> @@ -227,7 +229,7 @@ SearchThread( void *p_data )
>  
>      /* Search for media servers */
>      int i_res = UpnpSearchAsync( p_sys->p_upnp->handle(), 5,
> -            MEDIA_SERVER_DEVICE_TYPE, p_sys->p_upnp );
> +            MEDIA_SERVER_DEVICE_TYPE, MEDIA_SERVER_DEVICE_TYPE );
>      if( i_res != UPNP_E_SUCCESS )
>      {
>          msg_Err( p_sd, "Error sending search request: %s", 
> UpnpGetErrorMessage( i_res ) );
> @@ -236,7 +238,7 @@ SearchThread( void *p_data )
>  
>      /* Search for Sat Ip servers*/
>      i_res = UpnpSearchAsync( p_sys->p_upnp->handle(), 5,
> -            SATIP_SERVER_DEVICE_TYPE, p_sys->p_upnp );
> +            SATIP_SERVER_DEVICE_TYPE, MEDIA_SERVER_DEVICE_TYPE );
>      if( i_res != UPNP_E_SUCCESS )
>          msg_Err( p_sd, "Error sending search request: %s", 
> UpnpGetErrorMessage( i_res ) );
>      return NULL;
> @@ -256,20 +258,29 @@ static int Open( vlc_object_t *p_this )
>  
>      p_sd->description = _("Universal Plug'n'Play");
>  
> -    p_sys->p_upnp = UpnpInstanceWrapper::get( p_this, p_sd );
> +    p_sys->p_upnp = UpnpInstanceWrapper::get( p_this );
>      if ( !p_sys->p_upnp )
>      {
>          free(p_sys);
>          return VLC_EGENERIC;
>      }
>  
> +    p_sys->p_server_list = 
> std::make_shared<SD::MediaServerList>( p_sd );
> +    if ( unlikely( p_sys->p_server_list == NULL ) )

make_shared will throw a std::bad_alloc in case of allocation failure, but it won't return NULL/nullptr

> +    {
> +        msg_Err( p_sd, "Failed to create a MediaServerList");
> +        return VLC_EGENERIC;
> +    }
> +    p_sys->p_upnp->addListener( p_sys->p_server_list );
> +
>      /* XXX: Contrary to what the libupnp doc states, UpnpSearchAsync is
>       * blocking (select() and send() are called). Therefore, Call
>       * UpnpSearchAsync from an other thread. */
>      if ( vlc_clone( &p_sys->thread, SearchThread, p_this,
>                      VLC_THREAD_PRIORITY_LOW ) )
>      {
> -        p_sys->p_upnp->release( true );
> +        p_sys->p_upnp->removeListener( p_sys->p_server_list );
> +        p_sys->p_upnp->release();
>          free(p_sys);
>          return VLC_EGENERIC;
>      }
> @@ -286,7 +297,8 @@ static void Close( vlc_object_t *p_this )
>      services_discovery_sys_t *p_sys = 
> reinterpret_cast<services_discovery_sys_t *>( p_sd->p_sys );
>  
>      vlc_join( p_sys->thread, NULL );
> -    p_sys->p_upnp->release( true );
> +    p_sys->p_upnp->removeListener( p_sys->p_server_list );
> +    p_sys->p_upnp->release();
>      free( p_sys );
>  }
>  
> @@ -702,8 +714,11 @@ void MediaServerList::removeServer( const 
> std::string& udn )
>  /*
>   * Handles servers listing UPnP events
>   */
> -int MediaServerList::Callback( Upnp_EventType event_type, UpnpEventPtr 
> p_event )
> +int MediaServerList::onEvent( Upnp_EventType event_type, UpnpEventPtr 
> p_event, void* p_user_data )
>  {
> +    if (p_user_data != MEDIA_SERVER_DEVICE_TYPE)
> +        return 0;
> +
>      switch( event_type )
>      {
>      case UPNP_DISCOVERY_ADVERTISEMENT_ALIVE:
> @@ -716,23 +731,14 @@ int MediaServerList::Callback( Upnp_EventType 
> event_type, UpnpEventPtr p_event )
>          int i_res;
>          i_res = 
> UpnpDownloadXmlDoc( UpnpDiscovery_get_Location_cstr( p_discovery ), 
> &p_description_doc );
>  
> -        MediaServerList *self = 
> UpnpInstanceWrapper::lockMediaServerList();
> -        if ( !self )
> -        {
> -            UpnpInstanceWrapper::unlockMediaServerList();
> -            return UPNP_E_CANCELED;
> -        }
> -
>          if ( i_res != UPNP_E_SUCCESS )
>          {
> -            msg_Warn( self->m_sd, "Could not download device 
> description! "
> +            msg_Warn( m_sd, "Could not download device description! "
>                              "Fetching data from %s failed: %s",
>                              
> UpnpDiscovery_get_Location_cstr( p_discovery ), 
> UpnpGetErrorMessage( i_res ) );
> -            UpnpInstanceWrapper::unlockMediaServerList();
>              return i_res;
>          }
> -        self->parseNewServer( p_description_doc, 
> UpnpDiscovery_get_Location_cstr( p_discovery ) );
> -        UpnpInstanceWrapper::unlockMediaServerList();
> +        parseNewServer( p_description_doc, 
> UpnpDiscovery_get_Location_cstr( p_discovery ) );
>          ixmlDocument_free( p_description_doc );
>      }
>      break;
> @@ -740,29 +746,19 @@ int MediaServerList::Callback( Upnp_EventType 
> event_type, UpnpEventPtr p_event )
>      case UPNP_DISCOVERY_ADVERTISEMENT_BYEBYE:
>      {
>          const UpnpDiscovery* p_discovery = ( const 
> UpnpDiscovery* )p_event;
> -
> -        MediaServerList *self = 
> UpnpInstanceWrapper::lockMediaServerList();
> -        if ( self )
> -            self-
> >removeServer( UpnpDiscovery_get_DeviceID_cstr( p_discovery ) );
> -        UpnpInstanceWrapper::unlockMediaServerList();
> +        removeServer( UpnpDiscovery_get_DeviceID_cstr( p_discovery ) );
>      }
>      break;
>  
>      case UPNP_EVENT_SUBSCRIBE_COMPLETE:
>      {
> -        MediaServerList *self = UpnpInstanceWrapper::lockMediaServerList();
> -        if ( self )
> -            msg_Warn( self->m_sd, "subscription complete" );
> -        UpnpInstanceWrapper::unlockMediaServerList();
> +        msg_Warn( m_sd, "subscription complete" );
>      }
>          break;
>  
>      case UPNP_DISCOVERY_SEARCH_TIMEOUT:
>      {
> -        MediaServerList *self = UpnpInstanceWrapper::lockMediaServerList();
> -        if ( self )
> -            msg_Warn( self->m_sd, "search timeout" );
> -        UpnpInstanceWrapper::unlockMediaServerList();
> +        msg_Warn( m_sd, "search timeout" );
>      }
>          break;
>  
> @@ -774,10 +770,7 @@ int MediaServerList::Callback( Upnp_EventType 
> event_type, UpnpEventPtr p_event )
>  
>      default:
>      {
> -        MediaServerList *self = 
> UpnpInstanceWrapper::lockMediaServerList();
> -        if ( self )
> -            msg_Err( self->m_sd, "Unhandled event, please report 
> ( type=%d )", event_type );
> -        UpnpInstanceWrapper::unlockMediaServerList();
> +        msg_Err( m_sd, "Unhandled event, please report ( type=%d )", 
> event_type );
>      }
>          break;
>      }
> @@ -1293,7 +1286,7 @@ static int Open( vlc_object_t *p_this )
>          return VLC_ENOMEM;
>  
>      p_access->p_sys = p_sys;
> -    p_sys->p_upnp = UpnpInstanceWrapper::get( p_this, NULL );
> +    p_sys->p_upnp = UpnpInstanceWrapper::get( p_this );
>      if ( !p_sys->p_upnp )
>      {
>          delete p_sys;
> @@ -1311,7 +1304,7 @@ static void Close( vlc_object_t* p_this )
>      stream_t* p_access = (stream_t*)p_this;
>      access_sys_t *sys = (access_sys_t *)p_access->p_sys;
>  
> -    sys->p_upnp->release( false );
> +    sys->p_upnp->release();
>      delete sys;
>  }
>  
> @@ -1537,26 +1530,14 @@ static char *getIpv4ForMulticast()
>  
>  #endif /* _WIN32 */
>  
> -UpnpInstanceWrapper *UpnpInstanceWrapper::get(vlc_object_t *p_obj, 
> services_discovery_t *p_sd)
> +UpnpInstanceWrapper *UpnpInstanceWrapper::get(vlc_object_t *p_obj)
>  {
> -    SD::MediaServerList *p_server_list = NULL;
> -    if (p_sd)
> -    {
> -        p_server_list = new(std::nothrow) SD::MediaServerList( p_sd );
> -        if ( unlikely( p_server_list == NULL ) )
> -        {
> -            msg_Err( p_sd, "Failed to create a MediaServerList");
> -            return NULL;
> -        }
> -    }
> -
>      vlc_mutex_locker lock( &s_lock );
>      if ( s_instance == NULL )
>      {
>          UpnpInstanceWrapper* instance = new(std::nothrow) 
> UpnpInstanceWrapper;
>          if ( unlikely( !instance ) )
>          {
> -            delete p_server_list;
>              return NULL;
>          }
>  
> @@ -1577,7 +1558,6 @@ UpnpInstanceWrapper 
> *UpnpInstanceWrapper::get(vlc_object_t *p_obj, services_disc
>          {
>              msg_Err( p_obj, "Initialization failed: %s", 
> UpnpGetErrorMessage( i_res ) );
>              delete instance;
> -            delete p_server_list;
>              return NULL;
>          }
>  
> @@ -1589,7 +1569,6 @@ UpnpInstanceWrapper 
> *UpnpInstanceWrapper::get(vlc_object_t *p_obj, services_disc
>          {
>              msg_Err( p_obj, "Client registration failed: %s", 
> UpnpGetErrorMessage( i_res ) );
>              delete instance;
> -            delete p_server_list;
>              return NULL;
>          }
>  
> @@ -1601,30 +1580,18 @@ UpnpInstanceWrapper 
> *UpnpInstanceWrapper::get(vlc_object_t *p_obj, services_disc
>              msg_Err( p_obj, "Failed to set maximum content length: %s",
>                      UpnpGetErrorMessage( i_res ));
>              delete instance;
> -            delete p_server_list;
>              return NULL;
>          }
>          s_instance = instance;
>      }
>      s_instance->m_refcount++;
> -    // This assumes a single UPNP SD instance
> -    if (p_server_list != NULL)
> -    {
> -        assert(!UpnpInstanceWrapper::p_server_list);
> -        UpnpInstanceWrapper::p_server_list = p_server_list;
> -    }
>      return s_instance;
>  }
>  
> -void UpnpInstanceWrapper::release(bool isSd)
> +void UpnpInstanceWrapper::release()
>  {
>      UpnpInstanceWrapper *p_delete = NULL;
>      vlc_mutex_lock( &s_lock );
> -    if ( isSd )
> -    {
> -        delete UpnpInstanceWrapper::p_server_list;
> -        UpnpInstanceWrapper::p_server_list = NULL;
> -    }
>      if (--s_instance->m_refcount == 0)
>      {
>          p_delete = s_instance;
> @@ -1641,26 +1608,30 @@ UpnpClient_Handle UpnpInstanceWrapper::handle() const
>  
>  int UpnpInstanceWrapper::Callback(Upnp_EventType event_type, 
> UpnpEventPtr p_event, void *p_user_data)
>  {
> -    VLC_UNUSED(p_user_data);
> -    vlc_mutex_lock( &s_lock );
> -    if ( !UpnpInstanceWrapper::p_server_list )
> +    for (Listeners::iterator iter = s_listeners.begin(); iter != 
> s_listeners.end(); ++iter)
>      {
> -        vlc_mutex_unlock( &s_lock );
> -        /* no MediaServerList available (anymore), do nothing */
> -        return 0;
> +        (*iter)->onEvent(event_type, p_event, p_user_data);
>      }
> -    vlc_mutex_unlock( &s_lock );
> -    SD::MediaServerList::Callback( event_type, p_event );
> +
>      return 0;
>  }
>  
> -SD::MediaServerList *UpnpInstanceWrapper::lockMediaServerList()
> +void UpnpInstanceWrapper::addListener(ListenerPtr listener)
>  {
> -    vlc_mutex_lock( &s_lock ); /* do not allow deleting the 
> p_server_list while using it */
> -    return UpnpInstanceWrapper::p_server_list;
> +    vlc_mutex_lock( &s_lock );
> +    if ( std::find( s_listeners.begin(), s_listeners.end(), listener) !
> = s_listeners.end() )
> +        return;
> +    s_listeners.push_back( std::move(listener) );
> +    vlc_mutex_unlock( &s_lock );
>  }
>  
> -void UpnpInstanceWrapper::unlockMediaServerList()
> +void UpnpInstanceWrapper::removeListener(ListenerPtr listener)
>  {
> +    vlc_mutex_lock( &s_lock );
> +    Listeners::iterator iter = std::find( s_listeners.begin(), 
> s_listeners.end(), listener );
> +    if ( iter == s_listeners.end() )
> +        return;
> +
> +    s_listeners.erase( iter );
>      vlc_mutex_unlock( &s_lock );
>  }
> diff --git a/modules/services_discovery/upnp.hpp b/modules/
> services_discovery/upnp.hpp
> index 14286276db..8c13265fc8 100644
> --- a/modules/services_discovery/upnp.hpp
> +++ b/modules/services_discovery/upnp.hpp
> @@ -1,13 +1,14 @@
>  /
> *****************************************************************************
>   * upnp.hpp :  UPnP discovery module (libupnp) header
>   
> *****************************************************************************
> - * Copyright (C) 2004-2016 VLC authors and VideoLAN
> + * Copyright (C) 2004-2018 VLC authors and VideoLAN
>   * $Id$
>   *
>   * Authors: Rémi Denis-Courmont <rem # videolan.org> (original plugin)
>   *          Christian Henz <henz # c-lab.de>
>   *          Mirsal Ennaime <mirsal dot ennaime at gmail dot com>
>   *          Hugo Beauzée-Luyssen <hugo at beauzee.fr>
> + *          Shaleen Jain <shaleen at jain.sh>
>   *
>   * This program is free software; you can redistribute it and/or modify 
> it
>   * under the terms of the GNU Lesser General Public License as 
> published by
> @@ -30,6 +31,7 @@
>  
>  #include <vector>
>  #include <string>
> +#include <memory>
>  
>  #ifdef _WIN32
>  #include <windows.h>
> @@ -64,26 +66,38 @@ namespace SD
>   */
>  class UpnpInstanceWrapper
>  {
> +public:
> +    class Listener
> +    {
> +        public:
> +        virtual ~Listener() {}
> +        virtual int onEvent( Upnp_EventType event_type,
> +                             UpnpEventPtr p_event,
> +                             void* p_user_data ) = 0;
> +    };
> +
> +private:
> +    static UpnpInstanceWrapper* s_instance;
> +    static vlc_mutex_t s_lock;
> +    UpnpClient_Handle m_handle;
> +    int m_refcount;
> +    typedef std::shared_ptr<Listener> ListenerPtr;
> +    typedef std::vector<ListenerPtr> Listeners;
> +    static Listeners s_listeners;
> +
>  public:
>      // This increases the refcount before returning the instance
> -    static UpnpInstanceWrapper* get(vlc_object_t* p_obj, 
> services_discovery_t *p_sd);
> -    void release(bool isSd);
> +    static UpnpInstanceWrapper* get( vlc_object_t* p_obj );
> +    void release();
>      UpnpClient_Handle handle() const;
> -    static SD::MediaServerList *lockMediaServerList();
> -    static void unlockMediaServerList();
> +    void addListener(ListenerPtr listener);
> +    void removeListener(ListenerPtr listener);
>  
>  private:
>      static int Callback( Upnp_EventType event_type, UpnpEventPtr 
> p_event, void* p_user_data );
>  
>      UpnpInstanceWrapper();
>      ~UpnpInstanceWrapper();
> -
> -private:
> -    static UpnpInstanceWrapper* s_instance;
> -    static vlc_mutex_t s_lock;
> -    UpnpClient_Handle m_handle;
> -    static SD::MediaServerList* p_server_list;
> -    int m_refcount;
>  };
>  
>  namespace SD
> @@ -104,7 +118,7 @@ struct MediaServerDesc
>  };
>  
>  
> -class MediaServerList
> +class MediaServerList : public UpnpInstanceWrapper::Listener
>  {
>  public:
>  
> @@ -114,7 +128,9 @@ public:
>      bool addServer(MediaServerDesc *desc );
>      void removeServer(const std::string &udn );
>      MediaServerDesc* getServer( const std::string& udn );
> -    static int Callback( Upnp_EventType event_type, UpnpEventPtr p_event );
> +    int onEvent( Upnp_EventType event_type,
> +                 UpnpEventPtr p_event,
> +                 void* p_user_data ) override;
>  
>  private:
>      void parseNewServer( IXML_Document* doc, const std::string& location );
> -- 
> 2.18.0
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> vlc-devel mailing list
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Aside from that, LGTM

-- 
  Hugo Beauzée-Luyssen
  hugo at beauzee.fr


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