[vlc-devel] [PATCH] dshow: Use MTA and stop leaking thread context out of the module

[Rémi Denis-Courmont]

Le torstaina 1. kesäkuuta 2017, 18.43.19 EEST Hugo Beauzée-Luyssen a écrit :
> Fix #16935
> ---
>  modules/access/dshow/dshow.cpp | 44
> +++++++++++++++++++++++++++++++----------- 1 file changed, 33
> insertions(+), 11 deletions(-)
> 
> diff --git a/modules/access/dshow/dshow.cpp b/modules/access/dshow/dshow.cpp
> index d42ec0871e..817584f86d 100644
> --- a/modules/access/dshow/dshow.cpp
> +++ b/modules/access/dshow/dshow.cpp
> @@ -35,6 +35,7 @@
>  #include <list>
>  #include <string>
>  #include <assert.h>
> +#include <stdexcept>
> 
>  #define VLC_MODULE_LICENSE VLC_LICENSE_GPL_2_PLUS
>  #include <vlc_common.h>
> @@ -299,6 +300,19 @@ vlc_module_begin ()
> 
>  vlc_module_end ()
> 
> +struct ComContext
> +{
> +    ComContext( int mode )
> +    {
> +        if( !SUCCEEDED( CoInitializeEx( NULL, mode ) ) )

Nit but why not if(FAILED()) ?

> +            throw std::runtime_error( "CoInitializeEx failed" );
> +    }
> +    ~ComContext()
> +    {
> +        CoUninitialize();
> +    }
> +
> +};
> 
>  /**************************************************************************
> *** * DirectShow elementary stream descriptor
> @@ -392,10 +406,6 @@ static int CommonOpen( vlc_object_t *p_this,
> access_sys_t *p_sys, bool b_use_audio = true;
>      bool b_use_video = true;
> 
> -    /* Initialize OLE/COM */
> -    if( FAILED(CoInitializeEx( NULL, COINIT_APARTMENTTHREADED )) )
> -        vlc_assert_unreachable();
> -
>      var_Create( p_this,  CFG_PREFIX "config", VLC_VAR_BOOL |
> VLC_VAR_DOINHERIT ); var_Create( p_this,  CFG_PREFIX "tuner", VLC_VAR_BOOL
> | VLC_VAR_DOINHERIT ); psz_val = var_CreateGetString( p_this, CFG_PREFIX
> "vdev" );
> @@ -665,6 +675,8 @@ static int DemuxOpen( vlc_object_t *p_this )
>          return VLC_ENOMEM;
>      p_demux->p_sys = (demux_sys_t *)p_sys;
> 
> +    ComContext ctx( COINIT_MULTITHREADED );
> +
>      if( CommonOpen( p_this, p_sys, true ) != VLC_SUCCESS )
>      {
>          CommonClose( p_this, p_sys );
> @@ -770,6 +782,8 @@ static int AccessOpen( vlc_object_t *p_this )
>      if( !p_sys )
>          return VLC_ENOMEM;
> 
> +    ComContext ctx( COINIT_MULTITHREADED );
> +
>      if( CommonOpen( p_this, p_sys, false ) != VLC_SUCCESS )
>      {
>          CommonClose( p_this, p_sys );
> @@ -804,9 +818,6 @@ static void CommonClose( vlc_object_t *p_this,
> access_sys_t *p_sys )
> 
>      DeleteDirectShowGraph( p_this, p_sys );
> 
> -    /* Uninitialize OLE/COM */
> -    CoUninitialize();
> -
>      vlc_delete_all( p_sys->pp_streams );
> 
>      vlc_mutex_destroy( &p_sys->lock );
> @@ -823,6 +834,8 @@ static void AccessClose( vlc_object_t *p_this )
>      access_t     *p_access = (access_t *)p_this;
>      access_sys_t *p_sys    = (access_sys_t *)p_access->p_sys;
> 
> +    ComContext ctx( COINIT_MULTITHREADED );
> +
>      /* Stop capturing stuff */
>      p_sys->p_control->Stop();
> 
> @@ -837,6 +850,8 @@ static void DemuxClose( vlc_object_t *p_this )
>      demux_t      *p_demux = (demux_t *)p_this;
>      access_sys_t *p_sys   = (access_sys_t *)p_demux->p_sys;
> 
> +    ComContext ctx( COINIT_MULTITHREADED );
> +
>      /* Stop capturing stuff */
>      p_sys->p_control->Stop();
> 
> @@ -1738,6 +1753,8 @@ static size_t EnumDeviceCaps( vlc_object_t *p_this,
> IBaseFilter *p_filter,
> ***************************************************************************
> **/ static block_t *ReadCompressed( access_t *p_access, bool *eof )
>  {
> +    ComContext ctx( COINIT_MULTITHREADED );
> +
>      access_sys_t   *p_sys = (access_sys_t *)p_access->p_sys;
>      /* There must be only 1 elementary stream to produce a valid stream
>       * of MPEG or DV data */
> @@ -1783,6 +1800,8 @@ out:
>  
> ***************************************************************************
> */ static int Demux( demux_t *p_demux )
>  {
> +    ComContext ctx( COINIT_MULTITHREADED );
> +
>      access_sys_t *p_sys = (access_sys_t *)p_demux->p_sys;
>      int i_found_samples;
> 
> @@ -2017,11 +2036,12 @@ static int FindDevices( vlc_object_t *p_this, const
> char *psz_name, {
>      /* Find list of devices */
>      std::list<std::string> list_devices;
> -    if( SUCCEEDED(CoInitializeEx( NULL, COINIT_MULTITHREADED ))
> -     || SUCCEEDED(CoInitializeEx( NULL, COINIT_APARTMENTTHREADED )) )
> +    try
>      {
>          bool b_audio = !strcmp( psz_name, CFG_PREFIX "adev" );
> 
> +        ComContext ctx( COINIT_MULTITHREADED );
> +
>          FindCaptureDevice( p_this, NULL, &list_devices, b_audio );
> 
>          if( b_audio )
> @@ -2031,8 +2051,10 @@ static int FindDevices( vlc_object_t *p_this, const
> char *psz_name, if( !list_vdevs.empty() )
>                  AppendAudioEnabledVDevs( p_this, list_devices, list_vdevs
> ); }
> -
> -        CoUninitialize();
> +    }
> +    catch (const std::runtime_error& ex)
> +    {
> +        msg_Err( p_this, "Failed fetch devices: %s", ex.what() );
>      }
> 
>      unsigned count = 2 + list_devices.size(), i = 2;


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