RFR: 8042810: (s) hgforest: some shells run read in sub-shell and can't use fifo

[Mike Duigou]

On May 9 2014, at 01:54 , pointo1d <pointo1d at gmail.com> wrote:

> Hi Mike ,
> 
> On 09/05/14 08:25, Mike Duigou wrote:
>> On May 8 2014, at 22:35 , Chris Hegarty <chris.hegarty at oracle.com> wrote:
>> 
>>> Looks fine to me Mike.
>>> 
>>> Trivially while you are there (not related to your changes), or i can do it separately, --sequentially now runs with up to two parallel commands.
>> Ah sorry, I know why that is. It is due to shell having less-than but no less-than-or-equal-to operator. I can fix this easily and will do so before pushing. It's simply a matter of reducing at_a_time to 0. This will look odd but solve the problem.
> 
> You didn't mean 'test -le' for the less-than-or-equal-to operator, did you ?

I must have been looking at a strange manual (possibly for not quite the right shell) that didn't include -le in the expression capability.

I've since checked and now use -le which makes some expressions more natural!

Mike

> 
>>> -Chris
>>> 
>>>> On 9 May 2014, at 03:19, Mike Duigou <mike.duigou at oracle.com> wrote:
>>>> 
>>>> Hello all;
>>>> 
>>>> This issue is a follow-on bug fix to JDK-8041151 (Improve hgforest.sh concurrency). That changeset introduced use of fifos for monitoring sub-shell completion and included an alternative implementation for configurations which did not properly support fifos. This changeset detects another unsupported configuration, older shells which run the "read" command using a sub-shell.
>>>> 
>>>> I've tested the change on Solaris 10u11, Solaris 11u1, Ubuntu Linux 13.10 x64, MacOS 10.9. Of these only the Bash 3.2 shell on Solaris 10u11 does not support FIFOs. I have not tested this specific change on Cygwin as FIFOs were already disabled on Cygwin.
>>>> 
>>>> https://bugs.openjdk.java.net/browse/JDK-8042810
>>>> http://cr.openjdk.java.net/~mduigou/JDK-8042810/0/webrev/
>>>> 
>>>> Mike
> 
> Best rgds ,
> 
> -- 
> Dave Pointon FIAP MBCS
> 
> Now I saw, tho' too late, the folly of beginning a work before we count the cost and before we we judge rightly of our strength to go thro' with it - Robinson Crusoe
>