videotoolbox_async: remove unused lock

ios/IJKMediaPlayer/IJKMediaPlayer/ijkmedia/ijkplayer/ios/pipeline/IJKVideoToolBoxAsync.m

@@ -104,9 +104,6 @@ struct Ijk_VideoToolBox_Opaque {
     SDL_SpeedSampler            sampler;
 };
 
-static volatile int _Atomic vtb_active = 0;
-static SDL_mutex *vtb_cond_mutex = NULL;
-static SDL_cond *vtb_cond = NULL;
 
 static void vtbformat_destroy(VTBFormatDesc *fmt_desc);
 static int  vtbformat_init(VTBFormatDesc *fmt_desc, AVCodecParameters *codecpar);
@@ -946,11 +943,6 @@ void videotoolbox_async_free(Ijk_VideoToolBox_Opaque* context)
     vtbformat_destroy(&context->fmt_desc);
 
     avcodec_parameters_free(&context->codecpar);
-    assert(vtb_cond && vtb_cond_mutex);
-    SDL_LockMutex(vtb_cond_mutex);
-    atomic_store(&vtb_active, 0);
-    SDL_CondSignal(vtb_cond);
-    SDL_UnlockMutex(vtb_cond_mutex);
 }
 
 int videotoolbox_async_decode_frame(Ijk_VideoToolBox_Opaque* context)
@@ -1137,26 +1129,8 @@ fail:
 
 Ijk_VideoToolBox_Opaque* videotoolbox_async_create(FFPlayer* ffp, AVCodecContext* avctx)
 {
-    static dispatch_once_t onceToken;
-    dispatch_once(&onceToken, ^{
-        vtb_active = 0;
-        atomic_store(&vtb_active, 0);
-        vtb_cond = SDL_CreateCond();
-        vtb_cond_mutex = SDL_CreateMutex();
-    });
-
     int ret = 0;
 
-    SDL_LockMutex(vtb_cond_mutex);
-    if (atomic_load(&vtb_active)) {
-        SDL_CondWaitTimeout(vtb_cond, vtb_cond_mutex, 1000 * 10);
-        ret = atomic_load(&vtb_active);
-    }
-    if (!ret) {
-        atomic_store(&vtb_active, 1);
-    }
-    SDL_UnlockMutex(vtb_cond_mutex);
-
     if (ret) {
         ALOGW("%s - videotoolbox can not exists twice at the same time", __FUNCTION__);
         return NULL;