comm_layer: yield process before getting message queue length
comm_layer: yield process before getting message queue length

-> let other processes try to enqueue more messages to bundle before setting the desired bundle size
caijieming-baidu/scalaris,jvf/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,jvf/scalaris,jvf/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris,jvf/scalaris,caijieming-baidu/scalaris,jvf/scalaris,jvf/scalaris,caijieming-baidu/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,jvf/scalaris,scalaris-team/scalaris,scalaris-team/scalaris