没错，while doing sth的意思是“当做某事的时候”，它是whle sb is / was doing sth的省略形式，这种省略原则上要求主句与从句的主语一致。如：

He fell asleep while (he was) doing his homework. 他做着做着功课就睡着了。

While (we were) doing so, we decided to sell our boat. 在这样做时，我们决定把船卖掉。

She watched a few of the games while (she was) waiting to go on court.  她在等待上场时观看了几场比赛。

Most pregnant women remain off cigarettes while (they are) carrying the child. 大多数孕妇都在孕期戒了烟。