RFR: JDK-8154326: bash >(...) construct causes race conditions

[Tim Bell]

Erik:

> After switching to the new hotspot build, we have seen some sporadic 
> build errors related to the generation of dtrace JvmOffsets.h file on 
> Solaris. The errors look like a compile target that depends on the 
> header file fails because the header file is either empty or 
> incomplete. I have managed to reproduce this by running this 
> particular part of the build in a loop within 5 minutes.
>
> The header file generation uses the rather new ExecuteWithLog macro, 
> which uses the also rather new ">(tee logfile)" construct to save 
> output to a log file while still echoing both stderr and stdout 
> separately to the console. It seems however, that when using this 
> construct, bash spawns background processes which may not be done when 
> the main process is done.
>
> I have noted a similar effect when switching to this construct for the 
> main makefile build.log. The last line of make output would be echoed 
> to the console after my prompt returned.
>
> To solve this, I added "&& wait" in each location where the >(...) 
> trick is used. I have then rerun the loop over night and could no 
> longer reproduce the problem. I believe this to be the proper solution.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8154326
> Webrev: http://cr.openjdk.java.net/~erikj/8154326/webrev.01/

Looks good.

/Tim