LUCENE-9160: add params/docs to override jvm params in gradle build, default C2 off in tests.

Adds some build parameters to tune how tests run. There is an example
shown by "gradle helpLocalSettings"

Default C2 off in tests as it is wasteful locally and causes slowdown of
tests runs. You can override this by setting tests.jvmargs for gradle,
or args for ant.

Some crazy lucene stress tests may need to be toned down after the
change, as they may have been doing too many iterations by default...
but this is not a new problem.

gradle/testing/defaults-tests.gradle

@@ -1,4 +1,5 @@
 import org.apache.tools.ant.taskdefs.condition.Os
+import org.apache.tools.ant.types.Commandline
 import org.gradle.api.tasks.testing.logging.*
 import org.apache.lucene.gradle.ErrorReportingTestListener
 
@@ -9,8 +10,8 @@ allprojects {
     def verboseMode = Boolean.parseBoolean(propertyOrDefault("tests.verbose", "false"))
 
     project.ext {
-      testsWorkDir = file("${buildDir}/tmp/tests-cwd")
+      testsCwd = file("${buildDir}/tmp/tests-cwd")
-      testsTmpDir = file("${buildDir}/tmp/tests-tmp")
+      testsTmpDir = file(propertyOrDefault("tests.workDir", "${buildDir}/tmp/tests-tmp"))
       commonDir = project(":lucene").projectDir
       commonSolrDir = project(":solr").projectDir
     }
@@ -43,11 +44,13 @@ allprojects {
         maxParallelForks = propertyOrDefault("tests.jvms", (int) Math.max(1, Math.min(Runtime.runtime.availableProcessors() / 2.0, 4.0)))
       }
 
-      workingDir testsWorkDir
+      workingDir testsCwd
       useJUnit()
 
-      minHeapSize = "256m"
+      minHeapSize = propertyOrDefault("tests.minheapsize", "256m")
-      maxHeapSize = "512m"
+      maxHeapSize = propertyOrDefault("tests.heapsize", "512m")
+
+      jvmArgs Commandline.translateCommandline(propertyOrDefault("tests.jvmargs", "-XX:TieredStopAtLevel=1"))
 
       systemProperty 'java.util.logging.config.file', file("${commonDir}/tools/junit4/logging.properties")
       systemProperty 'java.awt.headless', 'true'
@@ -72,7 +75,7 @@ allprojects {
       systemProperty("java.io.tmpdir", testsTmpDir)
       systemProperty("tempDir", testsTmpDir)
       doFirst {
-        testsWorkDir.mkdirs()
+        testsCwd.mkdirs()
         testsTmpDir.mkdirs()
       }
 
@@ -101,7 +104,7 @@ allprojects {
 
       doFirst {
         // Print some diagnostics about locations used.
-        logger.info("Test folders for {}: cwd={}, tmp={}", project.path, testsWorkDir, testsTmpDir)
+        logger.info("Test folders for {}: cwd={}, tmp={}", project.path, testsCwd, testsTmpDir)
       }
     }
   }

help/localSettings.txt

@@ -33,6 +33,17 @@ it too high may not help.
 You can always override these settings locally using command line as well:
 gradlew -Ptests.jvms=N --max-workers=X
 
+Test JVMS
+---------
+
+Test JVMs have their own set of arguments which can be customized. These are configured
+separately from the gradle workers, for example:
+
+tests.jvms=3
+tests.heapsize=512m
+tests.minheapsize=512m
+tests.jvmargs=-XX:+UseParallelGC -XX:TieredStopAtLevel=1
+
 Gradle Daemon
 -------------
 

lucene/common-build.xml

@@ -106,7 +106,7 @@
   </path>
 
   <!-- default arguments to pass to JVM executing tests -->
-  <property name="args" value=""/>
+  <property name="args" value="-XX:TieredStopAtLevel=1"/>
 
   <property name="tests.seed" value="" />