[vlc-commits] fingerprinter: use vlc_cond_t instead of sleep

[Alexandre Janniaux]

vlc | branch: master | Alexandre Janniaux <ajanni at videolabs.io> | Mon Mar 23 19:03:42 2020 +0100| [c6ae7c0d256b3f02355b77caff9e9f18d3232ea5] | committer: Alexandre Janniaux

fingerprinter: use vlc_cond_t instead of sleep

Instead of checking new requests every seconds, wait for actual new
requests to be enqueued before trying to do any processing. This avoid
the harmful sleep warning on vlc_tick_sleep as well as providing better
latency for new fingerprinting requests on a cold fingerprinter.

The vlc_tick_sleep() was a vlc_cond_timedwait before and became a msleep
since 832d5a6d7435397f178c3455e70995ea5752fad0, so there was no clear
reason why it is there.

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=c6ae7c0d256b3f02355b77caff9e9f18d3232ea5
---

 modules/misc/fingerprinter.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/modules/misc/fingerprinter.c b/modules/misc/fingerprinter.c
index 99a05346f0..fa568d6cd7 100644
--- a/modules/misc/fingerprinter.c
+++ b/modules/misc/fingerprinter.c
@@ -51,6 +51,8 @@ struct fingerprinter_sys_t
         vlc_mutex_t         lock;
     } incoming, results;
 
+    vlc_cond_t              incoming_cond;
+
     struct
     {
         vlc_array_t         queue;
@@ -85,14 +87,13 @@ static int EnqueueRequest( fingerprinter_thread_t *f, fingerprint_request_t *r )
     fingerprinter_sys_t *p_sys = f->p_sys;
     vlc_mutex_lock( &p_sys->incoming.lock );
     int i_ret = vlc_array_append( &p_sys->incoming.queue, r );
+    vlc_cond_signal( &p_sys->incoming_cond );
     vlc_mutex_unlock( &p_sys->incoming.lock );
     return i_ret;
 }
 
 static void QueueIncomingRequests( fingerprinter_sys_t *p_sys )
 {
-    vlc_mutex_lock( &p_sys->incoming.lock );
-
     for( size_t i = vlc_array_count( &p_sys->incoming.queue ); i > 0 ; i-- )
     {
         fingerprint_request_t *r = vlc_array_item_at_index( &p_sys->incoming.queue, i - 1 );
@@ -100,7 +101,6 @@ static void QueueIncomingRequests( fingerprinter_sys_t *p_sys )
             fingerprint_request_Delete( r );
     }
     vlc_array_clear( &p_sys->incoming.queue );
-    vlc_mutex_unlock(&p_sys->incoming.lock);
 }
 
 static fingerprint_request_t * GetResult( fingerprinter_thread_t *f )
@@ -250,6 +250,7 @@ static int Open(vlc_object_t *p_this)
 
     vlc_array_init( &p_sys->incoming.queue );
     vlc_mutex_init( &p_sys->incoming.lock );
+    vlc_cond_init( &p_sys->incoming_cond );
 
     vlc_array_init( &p_sys->processing.queue );
     vlc_cond_init( &p_sys->processing.cond );
@@ -344,11 +345,16 @@ static void *Run( void *opaque )
     /* main loop */
     for (;;)
     {
-        vlc_tick_sleep( VLC_TICK_FROM_SEC(1) );
+        vlc_mutex_lock( &p_sys->incoming.lock );
+        mutex_cleanup_push( &p_sys->incoming.lock );
+
+        while( vlc_array_count( &p_sys->incoming.queue ) == 0 )
+            vlc_cond_wait( &p_sys->incoming_cond, &p_sys->incoming.lock );
 
         QueueIncomingRequests( p_sys );
 
-        vlc_testcancel();
+        vlc_cleanup_pop();
+        vlc_mutex_unlock( &p_sys->incoming.lock );
 
         bool results_available = false;
         while( vlc_array_count( &p_sys->processing.queue ) )