RFR: 8246622: Remove CollectedHeap::print_gc_threads_on()

[stefan.johansson at oracle.com]

Nice cleanup Per,

On 2020-06-04 20:42, Per Liden wrote:
> Instead of having all GCs implement 
> CollectedHeap::print_gc_threads_on(), we can just let the single caller 
> (Threads::print_on) provide a closure and use 
> CollectedHeap::gc_threads_do(). That will better match what 
> Threads::print_on_error() is already doing, and remove repetitive code 
> in the GCs.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8246622
> Webrev: http://cr.openjdk.java.net/~pliden/8246622/webrev.0
> 
Looks good,
Stefan

> /Per