We have A1 <- A2 <- A3 <- ... <- (A1 is upstream of A2, which is upstream of A3, ...)
We'd lilke to achieve the following and didn't find it possible:

1. A1 is to be started by a scheduled (SVN) polling.
2. If there is source change, start the build. When it finished, trigger downstream (A2) to build (no need to do the polling). (This is already happening).
3. If there is no source change, trigger downstream (A2) to do polling. Go back to Step 2 until end of the stream. (This is the one needs to be implemented).

I have tried the users@hudson.dev.java.net and found no solution so far.

Could someone please kind enough write a plugin for it? If there is a way currently to achieve it, it would be appreciated very much if this info can be shared with me.

Thanks a lot.