Set heap and permgen sizes to maximum values

Glyn Normington · Glyn Normington · commit 1df0ada2c950 · 2013-11-19T10:11:09.000Z
Set -Xms to the same value as -Xms and -XX:PermSize to the same value
as -XX:MaxPermSize. This ensures that the committed memory for the
heap and the permanent generation does not increase during the
lifetime of the application. This should reduce the possibility of
warden killing the JVM process once the application is running.

[#59731874]
diff --git a/lib/java_buildpack/jre/memory/openjdk_memory_heuristic_factory.rb b/lib/java_buildpack/jre/memory/openjdk_memory_heuristic_factory.rb
@@ -43,10 +43,10 @@ def self.permgen_or_metaspace(version)
     VALID_TYPES = %w(heap stack native).freeze
 
     JAVA_OPTS = {
-        'heap' => '-Xmx',
-        'metaspace' => '-XX:MaxMetaspaceSize=',
-        'permgen' => '-XX:MaxPermSize=',
-        'stack' => '-Xss',
+        'heap' => ->(v) { "-Xmx#{v} -Xms#{v}" },
+        'metaspace' => ->(v) { "-XX:MaxMetaspaceSize=#{v}" },
+        'permgen' => ->(v) { "-XX:MaxPermSize=#{v} -XX:PermSize=#{v}" },
+        'stack' => ->(v) { "-Xss#{v}" }
     }.freeze
 
   end
diff --git a/lib/java_buildpack/jre/memory/weight_balancing_memory_heuristic.rb b/lib/java_buildpack/jre/memory/weight_balancing_memory_heuristic.rb
@@ -220,7 +220,7 @@ def check_close_to_default(type, bucket, total_weighting)
     end
 
     def set_switches(buckets)
-      buckets.map { |type, bucket| "#{@java_opts[type]}#{bucket.size}" if bucket.size && bucket.size > 0 && @java_opts.key?(type) }.compact
+      buckets.map { |type, bucket| @java_opts[type][bucket.size] if bucket.size && bucket.size > 0 && @java_opts.key?(type) }.compact
     end
 
   end
diff --git a/spec/java_buildpack/jre/memory/openjdk_memory_heuristic_factory_spec.rb b/spec/java_buildpack/jre/memory/openjdk_memory_heuristic_factory_spec.rb
@@ -26,15 +26,41 @@ module JavaBuildpack::Jre
     HEURISTICS = { 'c' => 'd' }
     PRE_8 = JavaBuildpack::Util::TokenizedVersion.new('1.7.0')
     POST_8 = JavaBuildpack::Util::TokenizedVersion.new('1.8.0')
-    EXPECTED_JAVA_MEMORY_OPTIONS = { 'heap' => '-Xmx', 'metaspace' => '-XX:MaxMetaspaceSize=', 'permgen' => '-XX:MaxPermSize=', 'stack' => '-Xss' }
+    EXPECTED_JAVA_MEMORY_OPTIONS = {
+        'heap' => ->(v) { "-Xmx#{v} -Xms#{v}" },
+        'metaspace' => ->(v) { "-XX:MaxMetaspaceSize=#{v}" },
+        'permgen' => ->(v) { "-XX:MaxPermSize=#{v} -XX:PermSize=#{v}" },
+        'stack' => ->(v) { "-Xss#{v}" }
+    }
+
+    class HashOfLambdasMatching
+      def initialize(hash)
+        @hash = hash
+      end
+
+      def ==(other)
+        @hash['heap']['1m'] == other['heap']['1m'] &&
+        @hash['metaspace']['2m'] == other['metaspace']['2m'] &&
+        @hash['permgen']['3m'] == other['permgen']['3m'] &&
+        @hash['stack']['4m'] == other['stack']['4m']
+      end
+
+      def inspect
+        "a hash containing lambdas #{@hash.inspect}"
+      end
+    end
+
+    def hash_of_lambdas_matching(hash)
+      HashOfLambdasMatching.new(hash)
+    end
 
     it 'should pass the appropriate constructor parameters for versions prior to 1.8' do
-      WeightBalancingMemoryHeuristic.stub(:new).with(SIZES, HEURISTICS, %w(heap stack native permgen), EXPECTED_JAVA_MEMORY_OPTIONS)
+      WeightBalancingMemoryHeuristic.stub(:new).with(SIZES, HEURISTICS, %w(heap stack native permgen), hash_of_lambdas_matching(EXPECTED_JAVA_MEMORY_OPTIONS))
       OpenJDKMemoryHeuristicFactory.create_memory_heuristic(SIZES, HEURISTICS, PRE_8)
     end
 
     it 'should pass the appropriate constructor parameters for versions 1.8 and higher' do
-      WeightBalancingMemoryHeuristic.stub(:new).with(SIZES, HEURISTICS, %w(heap stack native metaspace), EXPECTED_JAVA_MEMORY_OPTIONS)
+      WeightBalancingMemoryHeuristic.stub(:new).with(SIZES, HEURISTICS, %w(heap stack native metaspace), hash_of_lambdas_matching(EXPECTED_JAVA_MEMORY_OPTIONS))
       OpenJDKMemoryHeuristicFactory.create_memory_heuristic(SIZES, HEURISTICS, POST_8)
     end
   end
diff --git a/spec/java_buildpack/jre/memory/weight_balancing_memory_heuristic_spec.rb b/spec/java_buildpack/jre/memory/weight_balancing_memory_heuristic_spec.rb
@@ -35,9 +35,9 @@ module JavaBuildpack::Jre
     }
 
     PRE8_JAVA_OPTS = {
-        'heap' => '-Xmx',
-        'permgen' => '-XX:MaxPermSize=',
-        'stack' => '-Xss',
+        'heap' => ->(v) { "-Xmx#{v}" },
+        'permgen' => ->(v) { "-XX:MaxPermSize=#{v}" },
+        'stack' => ->(v) { "-Xss#{v}" }
     }.freeze
 
     PRE8_VALID_TYPES = %w(heap permgen stack native)
