Measure by grade report runs with threads

app/models/report/measure_by_grade.rb

@@ -16,7 +16,15 @@ module Report
       CSV.generate(headers: true) do |csv|
         csv << headers
         academic_years.each do |academic_year|
-          measures.each do |measure|
+          puts "Processing: #{academic_year.range}"
+          pool_size = 8
+          jobs = Queue.new
+          measures.each { |measure| jobs << measure }
+
+          workers = pool_size.times.map do
+            Thread.new do
+              while measure = jobs.pop(true)
+                puts "Processing: #{measure.name}"
                 scores = schools.map do |school|
                   measure.score(school:, academic_year:).average
                 end.remove_blanks
@@ -67,6 +75,10 @@ module Report
 
                 csv << tmp1.concat(tmp2)
               end
+            rescue ThreadError
+            end
+          end
+          workers.each(&:join)
         end
       end
     end