[9] RFR(XXS): 8036091: compiler/membars/DekkerTest.java fails with -XX:CICompilerCount=1

[Aleksey Shipilev]

On 03/03/2014 04:25 PM, Albert wrote:
> I agree with you that the current approach (report an error) exposes
> an unnecessary implementation detail of HS. However, the fact that
> tiered compilation is enabled by default and that tiered compilation 
> is provided by two different compilers is implementation-specific to 
> Hotspot. If someone looks at the code in globals.hpp and reads
> "Number of compiler threads to run" he/she expects to have 1
> compiler thread when starting Hotspot with -XX:CICompilerCount=1.

I understand this as the purity argument, and I do think we need to make
CICC as non-ambiguous and non-surprising as possible. My point is that
both solutions (keeping the implicit CICC for Tiered, or report VM
error) are bad in users' eyes. For example, it will require me to treat
Tiered separately in most of my benchmarking/analysis scripts -- that is
why I feel strongly about this whole thing.

Thanks,
-Aleksey.