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Commit 43c92538 authored by Rémi Denis-Courmont's avatar Rémi Denis-Courmont
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live555: use timer for time-out prevention 

This removes the data races on i_timeout, b_handle_keep_alive and
b_timeout_call.
parent f9ecbd07
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Showing with 50 additions and 99 deletions
modules/access/live555.cpp
View file @ 43c92538
......@@ -173,13 +173,6 @@ typedef struct
} live_track_t;
struct timeout_thread_t
{
demux_t *p_demux;
vlc_thread_t handle;
bool b_handle_keep_alive;
};
class RTSPClientVlc;
struct demux_sys_t
......@@ -209,9 +202,7 @@ struct demux_sys_t
double f_npt_start;
/* timeout thread information */
int i_timeout; /* session timeout value in seconds */
bool b_timeout_call;/* mark to send an RTSP call to prevent server timeout */
timeout_thread_t *p_timeout; /* the actual thread that makes sure we don't timeout */
vlc_timer_t timer;
vlc_mutex_t timeout_mutex; /* Serialise calls to live555 in timeout thread w.r.t. Demux()/Control() */
/* */
......@@ -265,7 +256,7 @@ static void StreamClose ( void * );
static void TaskInterruptData( void * );
static void TaskInterruptRTSP( void * );
static void* TimeoutPrevention( void * );
static void TimeoutPrevention( void * );
static unsigned char* parseH264ConfigStr( char const* configStr,
unsigned int& configSize );
......@@ -303,6 +294,12 @@ static int Open ( vlc_object_t *p_this )
p_demux->p_sys = p_sys = (demux_sys_t*)calloc( 1, sizeof( demux_sys_t ) );
if( !p_sys ) return VLC_ENOMEM;
if( vlc_timer_create(&p_sys->timer, TimeoutPrevention, p_demux) )
{
free( p_sys );
return VLC_ENOMEM;
}
msg_Dbg( p_demux, "version " LIVEMEDIA_LIBRARY_VERSION_STRING );
TAB_INIT( p_sys->i_track, p_sys->track );
......@@ -420,12 +417,7 @@ static void Close( vlc_object_t *p_this )
demux_t *p_demux = (demux_t*)p_this;
demux_sys_t *p_sys = p_demux->p_sys;
if( p_sys->p_timeout )
{
vlc_cancel( p_sys->p_timeout->handle );
vlc_join( p_sys->p_timeout->handle, NULL );
free( p_sys->p_timeout );
}
vlc_timer_destroy(p_sys->timer);
if( p_sys->rtsp && p_sys->ms ) p_sys->rtsp->sendTeardownCommand( *p_sys->ms, NULL );
if( p_sys->ms ) Medium::close( p_sys->ms );
......@@ -1232,33 +1224,13 @@ static int Play( demux_t *p_demux )
}
/* Retrieve the timeout value and set up a timeout prevention thread */
p_sys->i_timeout = p_sys->rtsp->sessionTimeoutParameter();
if( p_sys->i_timeout <= 0 )
p_sys->i_timeout = 60; /* default value from RFC2326 */
int timeout = p_sys->rtsp->sessionTimeoutParameter();
if( timeout <= 2 )
timeout = 60; /* default value from RFC2326 */
msg_Dbg( p_demux, "We have a timeout of %d seconds", timeout );
/* start timeout-thread. GET_PARAMETER will be used if supported by
* the server. OPTIONS will be used as a fallback */
if( !p_sys->p_timeout )
{
msg_Dbg( p_demux, "We have a timeout of %d seconds", p_sys->i_timeout );
p_sys->p_timeout = (timeout_thread_t *)malloc( sizeof(timeout_thread_t) );
if( p_sys->p_timeout )
{
memset( p_sys->p_timeout, 0, sizeof(timeout_thread_t) );
p_sys->p_timeout->p_demux = p_demux;
if( vlc_clone( &p_sys->p_timeout->handle, TimeoutPrevention,
p_sys->p_timeout, VLC_THREAD_PRIORITY_LOW ) )
{
msg_Err( p_demux, "cannot spawn liveMedia timeout thread" );
free( p_sys->p_timeout );
p_sys->p_timeout = NULL;
}
else
msg_Dbg( p_demux, "spawned timeout thread" );
}
else
msg_Err( p_demux, "cannot spawn liveMedia timeout thread" );
}
mtime_t interval = (timeout - 2) * CLOCK_FREQ;
vlc_timer_schedule( p_sys->timer, false, interval, interval);
}
p_sys->i_pcr = VLC_TS_INVALID;
......@@ -1287,20 +1259,6 @@ static int Demux( demux_t *p_demux )
during pause */
vlc_mutex_locker locker(&p_sys->timeout_mutex);
/* Check if we need to send the server a Keep-A-Live signal */
if( p_sys->b_timeout_call && p_sys->rtsp && p_sys->ms )
{
char *psz_bye = NULL;
/* Use GET_PARAMETERS if supported. wmserver dialect supports
* it, but does not report this properly. */
if( p_sys->b_get_param || var_GetBool( p_demux, "rtsp-wmserver" ) )
p_sys->rtsp->sendGetParameterCommand( *p_sys->ms, NULL, psz_bye );
else
p_sys->rtsp->sendOptionsCommand(NULL, NULL);
p_sys->b_timeout_call = false;
}
for( i = 0; i < p_sys->i_track; i++ )
{
live_track_t *tk = p_sys->track[i];
......@@ -1649,19 +1607,6 @@ static int Control( demux_t *p_demux, int i_query, va_list args )
p_sys->f_seek_request = -1;
p_sys->b_paused = b_pause;
/* When we Pause, we'll need the TimeoutPrevention thread to
* handle sending the "Keep Alive" message to the server.
* Unfortunately Live555 isn't thread safe and so can't
* do this normally while the main Demux thread is handling
* a live stream. We end up with the Timeout thread blocking
* waiting for a response from the server. So when we PAUSE
* we set a flag that the TimeoutPrevention function will check
* and if it's set, it will trigger the GET_PARAMETER message */
if( p_sys->b_paused && p_sys->p_timeout != NULL )
p_sys->p_timeout->b_handle_keep_alive = true;
else if( !p_sys->b_paused && p_sys->p_timeout != NULL )
p_sys->p_timeout->b_handle_keep_alive = false;
if( !p_sys->b_paused )
{
for( int i = 0; i < p_sys->i_track; i++ )
......@@ -1685,6 +1630,7 @@ static int Control( demux_t *p_demux, int i_query, va_list args )
p_sys->f_npt_length = p_sys->ms->playEndTime();
msg_Dbg( p_demux, "pause start: %f stop:%f", p_sys->f_npt_start, p_sys->f_npt_length );
return VLC_SUCCESS;
}
case DEMUX_GET_TITLE_INFO:
......@@ -1716,6 +1662,7 @@ static int RollOverTcp( demux_t *p_demux )
var_SetBool( p_demux, "rtsp-tcp", true );
/* We close the old RTSP session */
vlc_timer_schedule(p_sys->timer, false, 0, 0);
p_sys->rtsp->sendTeardownCommand( *p_sys->ms, NULL );
Medium::close( p_sys->ms );
RTSPClient::close( p_sys->rtsp );
......@@ -2118,41 +2065,45 @@ static void TaskInterruptData( void *p_private )
/*****************************************************************************
*
*****************************************************************************/
VLC_NORETURN
static void* TimeoutPrevention( void *p_data )
static void TimeoutPrevention( void *p_data )
{
timeout_thread_t *p_timeout = (timeout_thread_t *)p_data;
demux_t *p_demux = p_timeout->p_demux;
demux_t *p_demux = (demux_t *) p_data;
demux_sys_t *p_sys = p_demux->p_sys;
char *bye = NULL;
for( ;; )
{
/* Voodoo (= no) thread safety here! *Ahem* */
if( p_timeout->b_handle_keep_alive )
{
/* Protect Live555 from us calling their functions simultaneously
with Demux() or Control() */
vlc_mutex_locker locker(&p_sys->timeout_mutex);
char *psz_bye = NULL;
int canc = vlc_savecancel ();
p_sys->rtsp->sendGetParameterCommand( *p_sys->ms, default_live555_callback, psz_bye );
if( !wait_Live555_response( p_demux ) )
{
msg_Err( p_demux, "GET_PARAMETER keepalive failed: %s",
p_sys->env->getResultMsg() );
/* Just continue, worst case is we get timed out later */
}
/* Protect Live555 from us calling their functions simultaneously
with Demux() or Control() */
vlc_mutex_locker locker(&p_sys->timeout_mutex);
vlc_restorecancel (canc);
}
p_sys->b_timeout_call = !p_timeout->b_handle_keep_alive;
/* If the timer fires while the demuxer owns the lock, and the demuxer
* then torns the session down, the pointers will become NULL. By the time
* this timer callback obtains the callback, either a new session was
* created and the timer is rescheduled, or the pointers are still NULL
* and the timer is descheduled. In the second case, bail out (then wait
* for the timer to be rescheduled or destroyed). In the first case, this
* might send an early refresh - that´s harmless but suboptimal (FIXME). */
if( p_sys->rtsp == NULL || p_sys->ms == NULL )
return;
bool use_get_param = p_sys->b_get_param;
/* Use GET_PARAMETERS if supported. wmserver dialect supports
* it, but does not report this properly. */
if( var_GetBool( p_demux, "rtsp-wmserver" ) )
use_get_param = true;
if( use_get_param )
p_sys->rtsp->sendGetParameterCommand( *p_sys->ms,
default_live555_callback, bye );
else
p_sys->rtsp->sendOptionsCommand( default_live555_callback, NULL );
msleep (((int64_t)p_sys->i_timeout - 2) * CLOCK_FREQ);
if( !wait_Live555_response( p_demux ) )
{
msg_Err( p_demux, "keep-alive failed: %s",
p_sys->env->getResultMsg() );
/* Just continue, worst case is we get timed out later */
}
vlc_assert_unreachable(); /* dead code */
}
/*****************************************************************************
......
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