fix race condition
fix race condition

Original commit message from CVS:
fix race condition

mparis/gstreamer,mrchapp/gstreamer,centricular/gstreamer,jpakkane/gstreamer,collects/gstreamer,cablelabs/gstreamer,drothlis/gstreamer,collects/gstreamer,mparis/gstreamer,cablelabs/gstreamer,ahmedammar/platform_external_gst_gstreamer,surround-io/gstreamer,StreamUtils/gstreamer,mrchapp/gstreamer,jpxiong/gstreamer,ahmedammar/platform_external_gst_gstreamer,mparis/gstreamer,ylatuya/gstreamer,surround-io/gstreamer,jpxiong/gstreamer,mrchapp/gstreamer,magcius/gstreamer,krichter722/gstreamer,Lachann/gstreamer,cfoch/gstreamer,jpakkane/gstreamer,drothlis/gstreamer,ensonic/gstreamer,Distrotech/gstreamer,lubosz/gstreamer,shelsonjava/gstreamer,magcius/gstreamer,krichter722/gstreamer,Distrotech/gstreamer,justinjoy/gstreamer,jpakkane/gstreamer,surround-io/gstreamer,surround-io/gstreamer,mrchapp/gstreamer,jpxiong/gstreamer,jpxiong/gstreamer,mrchapp/gstreamer,cfoch/gstreamer,justinjoy/gstreamer,krieger-od/gstreamer,ylatuya/gstreamer,ylatuya/gstreamer,lovebug356/gstreamer,ensonic/gstreamer,ahmedammar/platform_external_gst_gstreamer,ylatuya/gstreamer,krichter722/gstreamer,collects/gstreamer,cablelabs/gstreamer,lubosz/gstreamer,krichter722/gstreamer,ensonic/gstreamer,mparis/gstreamer,krichter722/gstreamer,cfoch/gstreamer,centricular/gstreamer,Lachann/gstreamer,justinjoy/gstreamer,krieger-od/gstreamer,lubosz/gstreamer,cfoch/gstreamer,ahmedammar/platform_external_gst_gstreamer,surround-io/gstreamer,justinjoy/gstreamer,centricular/gstreamer,cablelabs/gstreamer,Distrotech/gstreamer,centricular/gstreamer,collects/gstreamer,ensonic/gstreamer,Lachann/gstreamer,krieger-od/gstreamer,krieger-od/gstreamer,jpxiong/gstreamer,Lachann/gstreamer,Lachann/gstreamer,StreamUtils/gstreamer,centricular/gstreamer,magcius/gstreamer,Distrotech/gstreamer,mparis/gstreamer,krieger-od/gstreamer,jpakkane/gstreamer,ylatuya/gstreamer,StreamUtils/gstreamer,drothlis/gstreamer,collects/gstreamer,drothlis/gstreamer,lovebug356/gstreamer,lovebug356/gstreamer,lubosz/gstreamer,justinjoy/gstreamer,shelsonjava/gstreamer,ensonic/gstreamer,jpakkane/gstreamer,magcius/gstreamer,shelsonjava/gstreamer,StreamUtils/gstreamer,shelsonjava/gstreamer,lovebug356/gstreamer,Distrotech/gstreamer,cablelabs/gstreamer,StreamUtils/gstreamer,cfoch/gstreamer,magcius/gstreamer,lubosz/gstreamer,drothlis/gstreamer,ahmedammar/platform_external_gst_gstreamer,lovebug356/gstreamer,shelsonjava/gstreamer