AcctIdx: hold ranges in memory uses multiple threads

[jeffwashington]

Problem

see comment in code

Summary of Changes

Fixes #

[codecov]

Codecov Report

Merging #22031 (008b55d) into master (d896ff7) will increase coverage by 0.0%.
The diff coverage is 100.0%.

❗ Current head 008b55d differs from pull request most recent head 463efc5. Consider uploading reports for the commit 463efc5 to get more accurate results

@@           Coverage Diff           @@
##           master   #22031   +/-   ##
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  Coverage    81.3%    81.3%           
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  Files         517      517           
  Lines      145586   145540   -46     
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+ Hits       118445   118469   +24     
+ Misses      27141    27071   -70     

[brooksprumo]

I think the idea makes sense. I know there's the AccountsDb thread_pool field; would that be applicable to use here, instead of specifying max_threads? (I forget, is this called from a background thread too?)

[jeffwashington]

I think the idea makes sense. I know there's the AccountsDb thread_pool field; would that be applicable to use here, instead of specifying max_threads? (I forget, is this called from a background thread too?)

I was thinking I'd avoid that plumbing, but it didn't turn out to be that bad. So, done.

[brooksprumo]

lgtm

Pull request has been modified.