From c2f24ac739f5bca266e2468970c1f4ea06cb48a1 Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Mon, 8 Aug 2022 13:41:27 +0200
Subject: [PATCH] Speed up the build (#169)

The build is sped up in two ways:
1. By tweaking the JVM flags passed to the main process.
2. By tweaking the JVM flags passed to the forked Surefire processes.
---
 .mvn/jvm.config |  3 +++
 pom.xml         | 18 +++++++++++-------
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/.mvn/jvm.config b/.mvn/jvm.config
index 504456f9..58e147c3 100644
--- a/.mvn/jvm.config
+++ b/.mvn/jvm.config
@@ -1,3 +1,6 @@
+-XX:ReservedCodeCacheSize=512m
+-XX:SoftRefLRUPolicyMSPerMB=10
+-XX:+UseParallelGC
 --add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED
 --add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED
 --add-exports=jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED
diff --git a/pom.xml b/pom.xml
index f6dcce2c..da13965a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -75,11 +75,14 @@
         arguments. In particular, JaCoCo relies on this for the configuration
         of its Java agent. -->
         <argLine>
-            <!-- Error Prone makes extensive use of unsupported
+            <!-- The JVM arguments specified in `.mvn/jvm.config` also apply to
+            test JVMs, as those are also non-interactive processess running
+            Error Prone, and thus similarly make extensive use of unsupported
             `javac`-internal APIs, in some cases even reflectively inspecting
-            them. These APIs are accessed at compile time and when running
-            tests. The former case is covered by flags in `.mvn/jvm.config`;
-            the latter is covered here. -->
+            them. -->
+            -XX:ReservedCodeCacheSize=512m
+            -XX:SoftRefLRUPolicyMSPerMB=10
+            -XX:+UseParallelGC
             --add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED
             --add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED
             --add-exports=jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED
@@ -93,9 +96,10 @@
             <!-- The test JVMs are short-running. By disabling certain
             expensive JIT optimizations we actually speed up most tests. -->
             -XX:TieredStopAtLevel=1
-            <!-- We cap memory usage. This is primarily relevant for build agents,
-            but locally this should also be more than enough. -->
-            -Xmx512m
+            <!-- We cap memory usage. This may be relevant for build agents,
+            but also prevents excessive memory usage by heavily parallelized
+            local builds. -->
+            -Xmx1024m
             <!-- This argument cannot be set through Surefire's
             'systemPropertyVariables' configuration setting. Setting the file
             encoding is necessary because forked unit test invocations